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MSMS 2.2 User`s Guide - Medical Device Development

1. P 44 3 5 5 Parse ADL Ier 44 3 5 6 Write Motion File gcc cca a 44 3 5 7 Display Rendering Stats siete Aia RA 44 3 5 8 Toggle Rendering Stats Display Hz or MS ccccsccccssssscecsssseceeseaececessaeeeesesaeeecsesaeeeeseaaes 44 3 6 HOM a reete ne ke e euet en e aeter eim a Pere dh 45 3 6 1 MSMS User Guild irt ande 45 3 6 2 lA O 45 3 6 3 Request AA ON 45 3 6 4 MSMS RA A 45 3 6 5 MSMS DISCUSSION Group cssc aan atana cda 45 3 6 6 About MSMS LA A AAA A AAA au eae EH 45 Component Property Panels sisses aniei iiaea na E iaai araea iari aeaa isin e ED eoet 46 4 1 DOR ARTS TRUST CEPR ARDET IM 46 4 1 1 erc ad aa 46 4 1 2 lr ERE 46 4 1 3 Material de et E DE e he Da n a a oui tutes 47 4 1 4 IRAETA LR 49 4 1 5 image Editing WiINdOW vei i e Er aa oi 52 4 2 Joint sone cente itti doti et i test metadata sepu tett te reete iade de ye eee ge dues 56 4 2 1 G netal e Re RU RR eg ceded RE M I a eu 56 4 2 2 SEBMENUS fo se dec cree ese ERE 57 4 2 3 AKE S mS 58 4 2 4 MOOM ti tutti is 59 4 2 5 Passive Joint Momtuernit iE Sa a ee a ee 60 4 2 6 WIM ABC sao E E stiveetactueedes 60 4 3 Qu ce 61 4 3 1 erc 61 4 3 2 Muscle Path e ERA RN OK IR RE M IN RI RI 62 4 3 3 MorphoHnletry siete dt A x ed etae ia 64 4 3 4 Fibers TVpes erae eee etes de etti ed eon eie on de
2. ST 7 Scale Segment i Segment Proximal Joint Distal Joints clavicle SternoClavicular radius RadioUlnar right hand RadioCarpal Trunk Ground Trunk ulna HumeroUlnar Scale Fact 1 5 To scale a segment e Select a segment If the selected segment has one or more distal joints they will appear in the Distal Joints window If the segment has no distal joint it cannot be scaled with this tool e Select a distal joint to specify the axis from the proximal joint to the selected distal joint along which the segment must be scaled 35 e Enter a scale factor for the segment and click OK to scale the segment 3 3 17 Model Info This menu option allows you to obtain component ID numbers and the joint sequence numbers When developing a simulation program in Simulink or other environments to send Feature commands to MSMS the user needs to know the component IDs and the joint sequence numbers These numbers are available in the model XML files and can be obtained by opening them in a text editor and searching for the IDs and the sequence numbers But this process is time consuming and inconvenient The Model Info menu options allow you to display the component IDs in the Model Explorer or write model IDs or the joint sequence numbers into a text file in an easy to read tabular format 36 3 4 Simulation Menu Includes tools for setting up and cre
3. 62 Notes When the selected path object is a moving point or a wrapping object an Edit button will appear at the end of the row This edit button allows you to open the properties window of the path object and edit all of its parameters The coordinates of the moving points follow a linear trajectory as a function of a degree of freedom in the model To define the linear equations you must enter the values of the coordinates at the lower and higher end of the selected degree of freedom The coordinates of the moving points are therefore calculated automatically and cannot be entered by the user Function Of Value At Value At DofMin DofMax The first and last points in the path can only be Fixed points There can be only one wrapping object between two muscle points Muscles can be attached to the segments or the ground A muscle with all attachments on the ground can be used to model physiological experiments with isolated muscles In addition Virtual Muscle users can use this option to create a Simulink model that represents an isolated muscle 63 4 3 3 Morphometry The optimal fiber length optimal tendon length and the max musculotendon lengths can be set here For more information see Appendix D Opt Fasc Length Optimal fascicle length Use the current muscle length as a guide to select reasonable values here Opt Tendon Length Optimal tendon length Use the current muscle length as a guide to select reasonable
4. Pause animation e CTRL Shift V Stop animation e CTRL Shift J Display Rendering Stats e CTRL Shift K Toggle Rendering Stats Display Hz or ms 13 SHIFT LeftClick on Background Drag Move model in screen ALT LeftClick on Background Drag Rotate model in screen SHIFT UpArrow CTRL U u Move model up SHIFT DnArrow CTRL D d Move model down SHIFT LtArrow CTRL L I Move model left SHIFT RtArrow CTRL R r Move model right Alt Up Dn Arrow Rotate model about screen s vertical axis Alt Lt Rt Arrow Rotate model about screen s horizontal axis t CTRL t Rotate model about screen s normal axis i SHIFT i mouse wheel Zoom in o SHIFT o mouse wheel Zoom out 14 3 Menus 3 1 File Menu File View Model Simulation Animat T1 New model tw Open Ctrl O Reopen d E Save Ctrl S Save As Ctrl Alt S Close Ctrl C Preferences Import Model Exit 3 1 1 New Model This command creates an empty model i e a model with no components Once you have created a new model you can add components such as segments and muscles to complete it 3 1 2 Open This command loads an existing MSMS model from the disk drive A MSMS model is stored in a directory whose name is the name of the MSMS model The model directory has a number of required and optional sub directories and files that are described in Appendix E To open a MSMS model
5. kg m 2 0 0 0 1 Position Loop Proportional Gain k4p 1 0 Position Loop Derivative Gain k4d 0 1 oK cancel J Air Heb 77 4 7 5 Electrical Props Select electrical specifications of the motor 4 7 6 Mechanical Props Select the mechanical properties of the motor Power Electronic Block Max Voltage Output 12 0 Brushed DC Electrical Dynamics Torque Constant Kt Back EMF Constant Kb Winding Inductance L Winding Resistance R 0 0255 0 0255 4 1E 4 1 2 ox cancel Heb 4 7 7 Image Select to show hide the motor Rotor Inertia Jm b 25E 6 kg m 2 Motor Viscous Friction Bm 8 3E 6 N m s Transmission Stiffness K 1000 0 N m rad Gear Ratio n 0 01 In Out Torsional Damping BTrans 1 0 N m 5 78 4 8 Position Sensor 4 8 1 General Name A unique name for the sensor Group The group to which the sensor belongs Name Wrist Position Group HUMAN ok _Cancel Apply Heip 4 8 2 Attachment Name Select the parent segment for the sensor Position Select the position of the sensor in parent segment s reference frame Orientation Select the orientation of the sensor in parent s segment s reference frame not used for the position sensor Orientation Rx gt Ry gt R Rx 0 0 deg
6. 20 1 uint8 to turn message board on off 1 on 0 off 2 single values for x y position of the board on the screen 3 uint8 for RGB values of the text color 1 uint8 for the background transparency 0 100 3 uint8 for font type style and size 1 single for uniform scaling of the message board Message Board Write 21 1 int16 for the length of the text string to be written 1 string of characters of type unit8 whose length must be equal to that specified in the first parameter Sound File Playback 22 1 int32 for sound file 1 unit8 for sound volume Note You must name the sound files by a number only e g 1 wav and 2 wav etc and store them in a folder named Sound under model directory The first value specifies the number in the sound file e g 1 2 etc that must be played by MSMS Notes Unit8 8 bit unsigned integer int16 16 bit signed integer int32 32 bit signed integer single single precision float 32 bit IEEE 754 encoding 94 6 2 2 Example UDP Packets for Feature Commands Example 1 In the following Simulink model the transparency Feature 12 of a segment whose ID is S90 S90 z 32 83 90 is set to 5096 The Number of Features is set to 1 because only one feature in the model is modified Change Endianess Change Endianess Change Endianess Transparency PACK f W Function Block Parag Endianess1 X Wi Function
7. Frotai Foe Fpe mass Total muscle force Series elastic element Total contractile element force Initial energy consumption rate Recovery energy rate Energy Velocity HER CE rate related to cross bridge cycling E related to excitation 8 2 Recruitment type Three different recruitment strategies can be selected Natural Units Lumped Units and Intramuscular FES Each one divides the activation input into the recruitment and frequency outputs for each motor unit For Natural Units and Lumped Units recruitment the activation input is assumed to be the relative strength of the net synaptic drive or EMG envelope The Natural Units recruitment strategy recruits all motor units according to Henneman s size principle 1968 Lumped Units is a computationally efficient version of Natural Units that approximates whole muscle behavior using one motor unit element per fiber type The frequency of each unit begins at fmin when that unit is first recruited and reaches a maximum of fmax when input activation equals 1 In the Intramuscular FES algorithm fiber types are not recruited in any particular order instead the recruited portion of a given fiber type is equal to the normalized activation input and fires at a frequency equal to that of the stimulus 106 8 2 1 Natural Units The idea central to almost all recruitment functions for multiple motor units driven by a common i
8. Ry 0 0 deg r A Z0 m Rz 0 0 deg L ok J cancel J en j Help 4 8 3 Image Select to show hide the sensor 79 4 9 Camera A default camera is always present in MSMS which cannot be edited or removed from the model But you can add and configure as many new cameras as you want Only one camera can be active at a time You can use View gt gt Cameras menu to switch the desired camera 4 9 1 General Select a unique name for the camera 4 9 2 Position amp Orientation Select the position and orientation of the camera Orientation Rx gt Ry gt Rz x 80 deg y77 deg z90 deg 80 4 9 3 Frustum Projection Type Sets the projection type to either Perspective or Orthographic Screen Scale Sets the screen scale Near Clip Plane Sets the near Front clipping plane s distance Objects closer to the camera than this distance will not be visible Far Clip Plane Sets the far Back clipping plane s distance Objects farther from the camera than this distance will not be visible Field of View Sets the horizontal field of view Properties for General Pos amp Orient Frustum Projection Type Perspective X Screen Scale Near Clip Plane Back clipping plane Far Clip Plane Field of View g Esarcippins plane 0 30 60 90 120 OK Cancel 81 4 10 Light There are two default lights in any MSMS model that cannot be
9. 3 6 5 MSMS Discussion Group This command displays information about MSMS discussion group MSMS L 3 6 6 About MSMS This command displays information about MSMS and its developers 45 4 Component Property Panels 4 1 Segment The properties window for a segment includes 5 tabs Each tab enables the user to view and edit a number of related properties of the segment 4 1 1 General Name A unique name for the segment such as humerus Group All the components in a model are divided into three groups human prosthesis and world You can set a component s group using this drop down list 4 1 2 Inertia Mass Mass of the segment 46 Center of Mass Offset Location of the center of mass in the segment s reference frame When the segment is selected for viewing editing its center of mass is displayed by a small circle in the model window Inertia Matrix The mass moment of inertia of the segment has the form I I I Xx Xy XZ I rn T rm u E E Material Image Center of Mass Xx 0 0 m Y 0 1637 m Z 0 0 m 4 1 3 Material Static Friction Coefficient Coefficient of static friction Dynamic Friction Coefficient Coefficient of dynamic friction 47 Coefficient of Restitution Coefficient of restitution is between O and 1 and determines the elasticity of the segment A value of 0 means that the segment is completely elastic bouncy while a value of 1 means that the segment i
10. Cameras ights Elastic Elements A prosthetic limb imported from SolidWorks 3 1 8 2 Import OpenSim Model This command imports an OpenSim model into MSMS The Open dialog shows only OpenSim model files To successfully import models from OpenSim follow the following guidelines e Open and save the OpenSim model with the OpenSim version 2 2 0 or higher To save you must use Save As and select a name that is different from the original model name Otherwise OpenSim will not upgrade the model to the newer format e The 3D shapes of the segments vtp files required by the model must all be in a folder named Geometry in the same folder as the OpenSim model e When there are no equivalent components in MSMS the imported components are mapped to the closest MSMS component as described below If necessary you can edit these after importing e Ellipsoid wrapping object is converted to spherical wrapping object e Torus wrapping object is converted to Ring wrapping object e Muscle via points are converted to muscle fixed points 21 e When the functions for the coordinates of the moving point are nonlinear they are converted to linear functions e Tendon slack length is converted to optimal tendon length del Simulation Animation Help m AIxicpdgcp pco o BARA S esmmO amp S t FU Model Explorer BothLegs_msms Segments ground pelvis femur tibia femur Itibia ankle
11. D the three available attenuation options are 1 No attenuation where the light will not attenuate with distance 2 Linear attenuation where the light attenuates linearly with distance as expressed by the equation Intensity 1 1 D and 3 Quadratic attenuation where the light attenuates as the square of distance as expressed by the equation Intensity 1 1 D D 2 Concentration Specifies the extent to which light is concentrated in the center of a cross section of the radiated cone of light A highly concentrated light has most of its light rays near the cross section center the number of rays decreases with distance from the center Spread Angle Specifies the angle between the specified direction of light and a ray along the outer most edge of the resulting cone of light produced by the light source Values range from 0 0 to 90 in degrees Prope ties for General Pos amp Dir Color Attenuation None Concentration Y 32 Spread Angle ok Cancel Apply Help 85 5 Appendix A Motion File Formats MSMS is capable of animating data stored in three different file formats MSMS Motion File Format msm SIMM Motion File Format mot and data stored in Matlab mat files 5 1 MSMS Motion File Format msm MSMS motion file contains the data on the movement trajectories of the joints in a MSMS model MSMS can read the data in the motion
12. For example if the duration of animation in the motion file is 10 seconds setting the Animation Duration to 50 100 and 400 will cause it play in 5 10 and 40 seconds respectively From Live Source The animation data will be received from a live source in real time such as dynamic simulation running in Simulink Using the drop down list select the type of simulation data that will be sent by the live source The choices are e Feature Commands e Ordered Joint Angles 42 Feature Commands allows you to control model properties beyond its motion such as object sizes and color etc Ordered Joint Angles only sends the joint motion data to animate the model Source Of Animation Data 9 From File Input File C MotionFile msm Replay Duration of Real Time 100 500 750 1000 Real Time From Live Source Data Type Feature Commands OK Cancel The Edit window for Feature Commands allows you to select the UDP port number through which the live source and MSMS will send and receive animation data respectively In addition you can select Show On Screen Text to setup MSMS to display text in 3D model window The latter creates a billboard for text display in 3D window and prepares MSMS to receive the position of the billboard and the text from a simulation program The simulation program e g Simulink must use MSMS s feature commands to send these data to MSMS To learn more on how to display
13. HU FE v Damping Factor N m rad s or 0 1 Low Limit High Limit Y Active Y Active Value deg or m 0 Value deg or m 150 Restraining Function Linear zi Restraining Function Linear K N m rad or N m 10 0 K N m rad or N m 10 0 ox Cancel Apply Help 4 2 6 Image Not used for the joints 60 4 3 Muscle The muscle properties panel allows you to edit all muscle parameters The muscle model in MSMS is based on Virtual Muscle software that was distributed as standalone Matlab program in the past Virtual Muscle is now fully integrated in MSMS To learn more about muscle model and its features see Appendix D 4 3 1 General Name A unique name for the muscle component Group The group the muscle belongs to Name Elbow Flexor Group HUMAN 61 4 3 2 Muscle Path Here you define the path of the muscle from its origin to its insertion To add a new object to the path select a row above which you want to enter a new row and click Add Row After the new object is created you can change its type its parent segment and its position Rows Each row defines a single path object fixed point moving point or wrapping object Add Row Adds a new row path object above the selected row Remove Row Removed the selected row path object from the path Edit Edits the properties of the path object in the same row 1 4 4 4 Lt itl
14. Input File in Model lipataigrasp demo msm Browse Animation Speed of Real Time y 100 250 500 750 1000 From Live Source Data Type Feature Commands E C Use Live Data for Camera Positioning 9 The play icon in the MSMS toolbar must now turn to green Click on it to animate the ADL sequence 7 5 Rules and Guidelines for Creation of ADL sequence in PowerPoint e Repetition of the same movement To repeat a movement more than once duplicate the corresponding slide as many times a s necessary e Execution time To change the duration of the animation specified in a slide enter the Animations tab in PowerPoint and enter the duration time into the field labeled Automatically after The number here will determine the length of time it will take to complete the animation in the slide The time entered is of the form 00 00 00 indicating minutes seconds hundredths of seconds e Delays Pauses between movements To insert a delay or pause between two animations insert a blank slide between their corresponding slides Then insert an image into the blank slide whose name is pause e g pause jpg The default delay pause time is 1 second If you want to change the duration of the pause enter it into the Automatically after field of the Animations tab 100 8 Appendix D Muscle Model Virtual Muscle The models presented here were designed to meet the needs of physiologists and biomec
15. 77 2115 24 Scott S H and Loeb G E 1995 Mechanical properties of the aponeurosis and tendon of the cat soleus muscle during whole muscle isometric contractions J Morphol 224 73 86 Singh K Richmond FJR and Loeb GE Recruitment properties of intramuscular and nerve trunk stimulating electrodes IEEE Trans Rehabil Eng 8 276 285 2000 Song D Raphael G Lan N and Loeb GE 2008 Computationally efficient models of neuromuscular recruitment and mechancis J Neural Eng 5 175 184 Tsianos G A Rustin C and Loeb G E Mammalian muscle model for predicting force and energetics during physiological behaviors IEEE Trans TNSRE in press Zajac F E 1989 Muscle and tendon Properties models scaling and application to biomechanics and motor control Crit Rev Biomed Engng 17 359 411 116 9 Appendix E MSMS Files and Directory Structure A model and its corresponding simulation data in MSMS are stored in a model directory that has a number of required and optional subdirectories and files In addition MSMS uses a common image directory to store 3D mesh files and images and a Workspace xml file to store user installation specific data These are stored separate from the model directories see below 9 1 Model Directory Required A valid MSMS model must at a minimum contain the following folders and files My Model Model Humans human xml description of the human part of the mode My Model Model Prostheses proshthesis xml desc
16. All other light colors are combinations of these three For example yellow is a combination of equal amounts of red and green A simple way to designate a color is by its RGB values For example bright yellow can be designated as 1 0 1 0 0 and dark yellow as 0 5 0 5 0 Likewise white as 1 0 1 0 1 0 and black as 0 0 0 0 0 0 In MSMS s RGB color picker the range is 0 255 Hence white is represented as 255 255 255 The color of an object is actually the color of the light that reflects from it For example a leaf is green because the light that is reflected from it is green This is because the color green only reflects the green component of the light that it gets from the sun while absorbing the red and blue components In fact this is true for any color The blue ocean reflects only the blue component of the white light of the sun while absorbing the red and green components The situation is more complicated when the source light is not white i e it doesn t have all three RGB colors For example a green object in the presence of a purely red light appears black This is because the source light does not have any green component in it to be reflected from the object There are three types of light Ambient Diffuse and Specular Specular light is reflected perfectly such as from a mirror Diffuse reflection is imperfect such as from a wall Ambient is yet another type Note that each of these light types has a c
17. Block UU TEES Ex xpcreverseendian mask link pase ks o ings F Byte Reversal Change Endianess susci byte packing of input data into a single output Parameters Number of input ports Parameters 1 Input port data types cell array uint8 uint8 int16 int16 uint8 Machine word length Byte M Suar T Apply ok Cane He Aw Number of Features 1270 0 1 We Sink Block Parameters xpcudpbytesend mask link Parameters IP address to send to 255 255 255 255 for broadcast Remote IP port to send to 11114 Use the following local IP port 1 for automatic port assignment 1 Allow variable length packets Sample time 0 01 oe Go Cri Apply Note ChangeEndianess Pack and UDPSendBinary blocks are available in Matlab s xPC Target toolbox and can be used for real time or non real time simulations For real time simulations in a real time xPC Target PC you must use these blocks But if you don t have this toolbox and like to run only non real time simulations see the note for Example 2 below 95 Example 2 In the following Simulink model the transparency of segment S90 is set to 5096 and the color of the segment S88 is set to green R20 G 255 B 0 In this example Number of features is set to 2 because two features one segment s color and one segment s transparency are modified 32 Char1 Le Char2 Number o
18. Feature parameter describes what property of the component must be modified and is specified by a Feature Number provided as a 16 bit signed integer int16 The number and the types of the data values depend on the type of feature as shown in the following table Feature Type Feature Values Number Motion of 1 DOF Joint 1 1 single value for 1 DOF in meters and radians Specifies the absolute translation or rotation w r t the joint s zero position Motion of 2 DOF Joint 2 2 single values for 2 DOF in meters and radians Motion of 3 DOF Joint 3 3 single values for 3 DOF in meters and radians Motion of 4 DOF Joint 4 4 single values for 4 DOF in meters and radians Motion of 5 DOF Joint 5 5 single values for 5 DOF in meters and radians Motion of 6 DOF Joint 6 6 single values for 6 DOF in meters and radians Motion of Joint as Homogeneous 7 12 single values 3 for position and 9 for 3x3 rotation matrix Px Py Pz R1C1 RiC2 Transformation RiCs R2C1 R2C2 R2C3 R3C1 R3C2 R3C3 Motion of Joint as 3D Position 8 3 single values for xyz position of the joint Vector Motion of Joint as Rotation Matrix 9 9 single values for 3x3 rotation matrix of the joint orientation Segment Scaling 10 3 single values for scaling currently selected images of a component in X Y and Z axes w r t the original size when the model loaded Segment Muscle Color 11 3 uint8 values for RGB values of the seg
19. Leff Y S af 0 56 nfo Activation Delay Leff t TL 0 088 Rise and Fall Times feff t fint L fint t fenv L Tfi 48 4 Tf2 32 0 Sag S t feff asi Yield Y t cf 4 3 6 Image Here you can change the color of the muscle or select to show hide it The ability to change the color of muscles individually allows you to highlight a specific muscle or a group of muscles 68 4 4 Ligament 4 4 1 General Name A unique name for the ligament component Group The group the ligament belongs to Name NewLigament Group HUMAN ox J cancel J Ap Heb 69 4 4 2 Ligament Path Here you define the path of the ligament from its origin to its insertion The ligament path is similar to the muscle path and can be edited by following the instructions in Muscle Path section above ox cancel apply Help 70 4 4 3 Morphometry Here you define the morphometric properties of the ligament Use the current length as a guide to select a reasonable resting length Resting Length The length beyond which the ligament produces force Force at 5 Stretch The ligament force when it is stretched by 596 beyond the Resting Length CT KT LRT Coefficients of the ligament force length curve Typically you won t need to change these coefficients Properties for New Ligament General Ligament Path Morphometry Image Resting Length 9 48761 cm C
20. Tea e urea ev ce e THER TUR 26 3 3 8 Hide All Components o E A ad 26 3 3 9 nendum 26 3 3 10 gt Add Component ete ear eet ie eee ve ue edi a e vein 26 3 341 AddSegmient oe reete E T ea ego avete aveo ua Qus OY ve e Eve ud Re 27 3 3 12 Add Muscle tro tette tta e t paid det od 28 3 3 13 No Ligament nt eps RRRERD RE ee RU ene aa 31 3 3 14 Plot Anatomical Data for MusCleS oococccononccnnncnnoncccnonnnonnnnnnnncnoncnonnnnnnnn nn nan n cn nnn nana nannnccnnnss 33 3 3 15 Plot Anatomical Data for Ligaments ccoconccccccnnnnononononnnnnnnnnnnnnnnononnnnnnnnnnnnnnnnnnnnnnnnanannannnnnos 34 3 3 16 Scale Segment iet tes ott ev etie oett teli tts e o eR ERE ed 35 3 347 Model lO iine e RR eee IE TERR eee Be PA DERE eene 36 3 4 Simulation Ment ette tee a P aree se ER reae iras 37 3 4 1 Simulation Setup cis ine eei is tice Evo eve te ui vae uv des E VE Re ndn 37 S4ET E General HE Reto eati c totum 37 CUMPLA ee 38 SATS ON 38 3 4 1 4 Dynamic Englrie cedet t ee ee ee ete e bo Ere ee ee ue nea TON Re ER ER gu eA ES 39 34 15 Output Data ssa ahead dal aie tetti eto aide eds ie ee REA 39 3 4 2 Convert to Simulink 2 t E ere re E REESE EP E Re PM AREE 40 3 5 Animation MENU i eerte rete ttp a Peeters 42 3 5 1 Ie c he 42 3 5 2 rng E 44 3 5 3 Ere EET 44 3 5 4 SEO m
21. and save it in your desired directory e g C mydir Note that MSMS will not create myevents txt It has to be created first by the user in the specified directory Then add the following two lines to msms properties if not already present kpaulEnabled kpaulPipeFilename C mydir myevent txt Load your model to MSMS and animate it by feature command animation After the animation you can see the sequence of animation events handled by MSMS in myevents txt 125 13 Appendix H Revision Log 2 08 06 0 5 0 Beta e The model is now subdivided and categorized in to human prosthesis and world model each defined in separate XML file e World Objects are treated as segments connected to the world via 6 DOF joints e A primitive skinning tool covers the discontinuity in joints of the human limb by a patch e The model can now be closed to load a new model e Segments now have collision properties e Multiple images of mesh or primitive type can now be assigned to each segment Each image can be independently edited 0 5 1 Beta 12 20 06 e Bug for world object animation fixed e Bug to setting animation property of world objects is now fixed 0 5 3 Beta 01 22 07 e MSMS keeps the same IDs between saves 0 5 4 Beta 01 24 07 e MSMS buffer for receiving UDP packets has been extended to 5000 bytes 0 5 6 Beta 02 06 07 e Two new components have been added to the MSMS 0 5 6 version One corresponds to the light and the other to the ca
22. are functional 0 7 Beta 08 17 07 e Description of new features since 0 6 1 0 7 3 Beta 11 6 07 e Description of new features Rules for importable SIMM and SolidWorks models 0 7 5 Beta 07 01 08 Description of how to use the streaming data C S function Section 11 Description of how to modify the Simulink model to animation using Ordered Joint Angles Section 11 0 7 8 Beta 03 06 08 Fix to the export feature so that the seqNum parameter is always generated MSMS is now compatible with JRE 6 Modification of the Export to Simulink window Export button is replaced with OK Apply and Cancel buttons Default lights state on off can be set in the view xml file Camera light state on off can be set in the view xml file Save options are changed and include 3 options Save Save As and Save Simulation Addition of the ESC hotkey to exit from fullscreen Addition of toolbars for changing the view Addition of toolbars for accessing user manual New icons used to view the entire model or go into fullscreen Addition of a toolbar to setup start pause and stop animation New model explorer listing the model components in 4 different ways including alphabetical Addition of a list showing the attached components to the selected item Improvement of the Animation GUI Improvement of the Show axes menu item functionality MSMS detects if parameters that affect simulation have been changed and ask the user if he wants to overwrite simul
23. be inserted 0 x and PCSA distribution should be readjusted Frequency of FES recruited units is set by a second input to each motor unit which is the stimulus frequency applied by the user the algorithm converts the frequency from pps input to internal dimensionless units of f0 5 The stimulation frequency chosen for fixed frequency FES is usually a compromise between a frequency high enough to avoid tremor from unfused twitches and low enough to minimize fatigue Both constitute a moving target in clinical patients undergoing FES training because trophic factors tend to shift muscle fiber properties towards slower twitch properties and greater fatigue resistance Malmivuo 111 et al 1995 It is recommended to use 20Hz as excitation frequency for realistic clinical FES applications but VM now provides an explicit input for frequency as well as intensity of stimulation and it should represent total muscle force correctly if the appropriate physiological parameters are set for the unit types f0 5 frequency that produces half of maximal tetanic isometric tension at LO for each unit type It is useful to remember that a fixed firing rate tends to be much higher on the force frequency relationship of slow twitch muscle than fast twitch muscle so the relative force contributions will not be simply related to their relative PCSA 8 3 Energetics The formulation for energetics is based primarily on enthalpy data from tetanically stimulated m
24. click on File gt Open to bring up the model browser window Here you must choose the model directory where your model resides by double clicking on it or selecting it and clicking on Open to open it In the model browser the directories that contain a valid MSMS model with proper subfolders and model files are displayed with an MSMS icon indicating that they are valid MSMS models and can be opened by MSMS 15 Note When MSMS opens a model it searches model s local image folder for segment images first If it couldn t find all of the images required by the model it will then search the common image library set in File gt gt Preferences gt gt General If the common image library folder is wrong e g C V instead of C users models images MSMS will search C and all of its subfolders for the images Depending on the size of the image folder the search could take a very long time When this happens pay attention to the progress window that is displayed while opening a model In progress window MSMS displays the image folders it is currently searching for the images If you notice that the wrong folders are being searched change the image library path in File gt gt Preferences gt gt General 3 1 3 Reopen This command provides a list of five recently opened models and allows the user to quickly open one of them 3 1 4 Save This command saves the changes to the model 3 1 5 Save As This command saves changes to the
25. e Inside the Y Axis box select the muscle attribute you want to plot and the muscles for which you want to plot these attributes for e Inside the X Axis box select the joint degree of freedom against which you want to plot the muscle attributes Also select the increments for the joint angle e Click Add Curves to plot the data This will add the new curves to the plot area add the corresponding legends and add the names of the new curves to the Curve List window Please note that e Atany time you can right click on the plot area and select Import from file to import experimentally measured data or data previously exported from the plotter The imported file must be a text file with the following format The header row includes the name of the degree of freedom against which all muscle attributes are to be plotted followed by the names of the muscle attributes There must be only one degree of freedom name which signify the X axis 33 but there is no limit on the number of the muscle attributes which signify the Y axis variables The data rows contain the data corresponding to the variables in the header Joint DOF Attribute 1 Attribute 2 0 0 50 200 0 1 0 52 210 0 2 0 55 215 e Atany time you can right click on the plot area and select Export to file to save the curves to a text file The exported files follow the format of the imported files If the data in the current plot contains more than one X axi
26. edited or removed But they can be turned on off from the View menu In addition you can add and configure as many new lights as you want For more information on MSMS lights see Appendix F 4 10 1 General Name A unique name for the light source Light Type The type of the light source Ambient Directional Point or Spot Light State Turns the light source on or off General Pos amp Dir Color misc Name Roof Light Light State On Ambient Light Models the light called background light reflected from other visual objects For example a room with no lights may not be pitch dark because light from some external source has entered the room and bounced and reflected along room boundaries and other objects to reach the viewer s eye Typically only one Ambient light source is specified for any 3D environment 82 Directional Light Models a distant light source like the sun where all light rays emanate from the same direction in parallel and with equal intensity When illuminated by Directional light only parts of objects exposed to the rays will be illuminated Point Light Models an Omni directional light source such as a light bulb which emits light uniformly in all directions from a given position within the 3D environment An Attenuation control is available such that the farther away an object is from a Point light source the less bright it will be Spot Light Models real life
27. for New Muscle clavicle ground radius right_hand Trunk ulna Insertion Segment clavicle ground humerus radius right_hand Trunk ulna Note Add Component tool collects only the most basic information to quickly add new components to the model It therefore does not allow you to edit all parameters of the component while it is added to the model For Segments and joints Muscles and Ligaments there are interactive wizards that give you more control over the parameters of the added component see below In addition all parameters of the new components can be edited later from their properties panel 3 3 11 Add Segment This command will bring up the segment creation wizard The wizard allows you to quickly build a segment joint pair and interactively configure its properties 27 File View Model Simulation Animation Help slg A E CD G2 6D OD GD CD Model Explorer New Model Segments Segment Creation V Parent Segm ground Actuators Sensors Wrapping Obj Cameras Attachment Joint Name NewJoint Type Pin Revolute 1000 500 500 1000 1000 500 500 1000 1000 500 500 1000 New Segment Na NewSegment CappedCylinder i Height 0 25 Image Properties Radius 0 025 In the wizard you must specify the parent segment where the new segment will attach to the name and the typ
28. for the Spot type which offers an indirect intensity control via its Concentration parameter 120 11 Appendix G Collision and Contact MSMS uses collision detection libraries of Open Dynamic Engine ODE http www ode org to detect collision between segments It then uses the collision information and the material properties of the segments to calculate the collision forces and apply them to the colliding segments MSMS provides maximum flexibility to setup and simulate collisions Because it allows you to include exclude specific segment images in collision you can have a segment that has two types of images complex 3D shapes for visual representation and simpler primitive shapes for collisions Simpler 3D shapes can significantly speed up simulations because it is computationally faster to detect their collisions To simulate collisions in MSMS models you have to do the following e Ifyou want to include a segment in collisions go to its properties panel gt gt Images and select the collision check box of the images that will be used for collision detection Currently the collision algorithm supports primitive shapes So do not select 3D meshes for collision e Forthe segments included in collision go to their properties panel gt gt Material and enter the material properties of the segments e Create Simulink model of the MSMS model from File Save Simulation The Simulink model will have a collision block with properti
29. mesh to a segment add a new image and select Mesh from the 3D Shape drop down menu Then import the 3D mesh by clicking on the Add button that will allow you to browse for the 3D mesh files For complex shapes made of multiple 3D meshes you can either add more images to the segment each containing one 3D mesh or you may add multiple 3D meshes to one image In the later case any editing to the image will apply to all of the 3D meshes attached to it The 3D meshes may be in one of the many 3D file formats but the one that is completely supported by the MSMS is OBJ file format So before importing to MSMS you must first convert your 3D meshes to OBJ file format if needed Before adding 3D meshes to your segment you must have created or obtained these 3D meshes You can obtain your 3D shapes by purchasing them from the 3D model vendors by finding and downloading them free of charge from the Internet or by creating them yourself in a 3D modeling software such as MAYA 3ds Max Blender etc These software tools allow you to create new 3D shapes customize them by editing their shape and texture and perform file format conversion when necessary 49 General Inertia Material Image Select Collisi Image W Bone OK Cancel Apply Select This checkbox toggles on and off the visibility of the image in the 3D pane Collision This checkbox toggles on and off to indicate whether th
30. model under a different name or the same name at another location on disk If the model contains images that are not stored in the MSMS Image Library folder these images are copied to the new model location Furthermore if the Save Main Library Images option is checked even the images located in the Image Library are copied to the new model location When MSMS loads a model it searches for the required images in the local model folder and the main image library specified in the File gt gt Preferences This allows you to keep large image files in the main library and reuse them in many models But if you like to share your model with others or open them in a different computer you have two choices You can share your image folder along with the model or make sure that all required images are saved in the model s local folder by selecting Save Main Library Images 3 1 6 Close This command closes the model in MSMS workspace 3 1 7 Preferences Preferences setup allows you to specify the location of your image library the background color and the 2D and 3D displays Preferences Setup includes four tabs 16 General Display Framing User General Segment Image Data Path C MSMSImageLibrary aromo I OK Cancel Apply 3 1 7 1 General In the General tab you can change or set the path for the common image folder When loading a model MSMS first searches the model s local image f
31. number uniquely identifies a component in MSMS For example the ID AB32000 refers to the component AB whose number is 32000 For example the ID can identify a segment a joint an actuator a camera etc Component type is a two 8 bit ASCII values specified as Char1 char2 If one character is used it is specified as blank Char1 e g S LS MSMS components and their identifiers are shown in the following table 91 Component number is a 16 bit signed integer int16 and can be obtained from the MSMS model s XML file You can open the XML file in a text editor and find the XML description of the component by searching for its name The component number is specified in the middle of the lt componentNumber gt lt componentNumber gt tag For those components that are not explicitly specified in the XML file e g Head Tracking Sound Playback Trajectory Path Message Board Setup and Message Board Write use O for the component number MSMS Component Two character Identifier ASCII Values Segment Se 32 83 Joint us 32 74 Muscle M 32 77 Light Source LS 76 83 Position Sensor PS 80 83 External Actuator EA 69 65 Head Tracking HT 72 84 Sound File Playback SO 83 79 Trajectory Path TR 84 82 Message Board Setup BS 66 83 Message Board Write BW 66 87 92 Features and Values The
32. set to Virtual Eye is at viewable distance from point of interest the eye position will need to be specified with respect to the screen and not with respect to the head The title text Eye Position with respect to Head will change to Eye Position with respect to Image Plate to reflect this 3 1 8 Import Model 3 18 1 Import SolidWorks Model This command imports a SolidWorks model into MSMS MSMS allows importing CAD designs from SolidWorks This process is as follows Engineers can build accurate models of prosthetic limbs in SolidWorks and automatically convert it to a Physical Modeling XML file This conversion is done in the SolidWorks environment using the CAD to SimMechanics translator a free add on utility available from Mathworks website The Physical Modeling XML file can be read into SimMechanics to dynamically simulate the prosthetic limb The same file can also be read into MSMS to represent the prosthetic limb in MSMS No MATLAB component is required at any time to perform the import to MSMS The Physical Modeling XML includes bodies to represent the assembly s parts and maps the constraints between the parts into joints The Part the Constraints or mates the Fundamental Root and the Subassembly Solidworks components correspond respectively to the Body the Joints the Ground Root Weld Root Body and the Subsystem in SimMechanics After importing the prosthetic limb model 18 into
33. ta 83 4 10 3 NN 84 ALO Mi dia 85 5 Appendix A Motion File FormatS cccoconococncnnnnnnonononnnnnancnnnnnnnnnnnnnnncnnnnnononnnnnnnnnnnnno no nnnnncnnanannnnnnnnns 86 5 1 MSMS Motion File Format MSM ccccccessccecssscececsessececsssaececsesaeeeeseaaececsesaeeeceesaeeeeseaaeeeeseaaes 86 5 1 1 RSS O 86 5 1 2 Format ofthe data r OWS imstande 87 5 1 3 An Example msm Motion File cccccconocoononcnnnnnnnnnnonnnnnnncnnnnnononnnnnnnonnnnnononnnnnnnnnnnnnnnos 88 5 2 SIMM Motion File Format Motsa aseaine aas EINAN AI ANEA ATEAN E R 89 6 Appendix B Protocol for Live Animation Feature Commands sess 90 6 1 Ordered Joint Angles ir e Eds 90 6 2 Feature COMMAS eC em 90 6 2 1 Packet Protocol for Feature Commands sees 91 6 2 2 Example UDP Packets for Feature Commands coccccccnonononononononnnanononnnnnoncnnonannnnnnnnnnnnnnnnonos 95 7 Appendix C Animation of ADL in PowerPoint ccccononococnconcnnnonononnnnnnnononanononnnnnnnnnannnononnnnnnnnannnnannnnnss 97 7 1 Using MSMS and PowerPoint to Animate ADL movements sess 97 7 2 MSMS Models oct ttr etia eia et tena teda tta 97 7 3 Library of the motion files on se onn A a 97 7 4 ADL Animation Sequences ccccccccccnonononononononononononononononononnnn nono nnnnnnnn nn nono nnnnnnnnnnnnnnnn nono nnnnnnnnonononnns 98 7 5 Rules and Guidelines for Creation of ADL sequence in PowerPOiNt ccccconononocnc
34. values here Max MT Length Maximum musculotendon length is used to calculate the passive muscle force Typically this should be equal to the length of the muscle at the joint extremes Use the current muscle length as a guide to select reasonable values here Mass Mass of the muscle fascicle and the optimal fascicle length is used to calculate the muscle s physiological cross section and its maximum isometric force See Appendix D for more details V Opt Fascicle Length Curr Fasc Length 24 1311 cm Opt Tendon Length Curr Tendon Length 10 0 cm Max MT Length Curr MT Length 34 1311 cm Mass PCSA 8 57632 cm Max Force 272 727 N Note The optimal lengths must be selected with care Unreasonable values here could result in dynamic simulations that could be unstable 64 4 3 4 Fibers Types This panel allows you to select additional features and configure the fiber composition of the muscle For more information see Appendix D General Muscle Path Morphometry Fiber Types Features Energetics Recruitment Type Natural Units Apportion Method Different Sizes Geometric Algorithm Fractional Increase In PCSA 0 0010 Maximum Recruitment Activation 0 8 Fiber Composition ORTA MONKEY F PCSA MONKEY MU ok cancel Apply Help Energetics If sel
35. B d Hide Remove SS Show Only ts B int Show All Segments SternoClavicular Ground_Trunk Translate Model Shift LeftClick Drag Shift Arrow Ctrl U D L R Rotate Model All The MSMS graphic user interface consists of the following sections e Menu Bar located at the top of the MSMS window and gives access to most MSMS features e Toolbar is located just below the Menu Bar and gives access to the most frequently used features such as opening and saving models or choosing the background color e Model Explorer lists all of the components in the opened model The list can be viewed in four different ways by clicking on one of the four buttons on the Model Explorer Once a component is selected in the top Pane its attached components are displayed in the bottom Pane Double clicking on a component s name will bring up its properties dialog box Right clicking on a component will bring up a menu with options to edit remove show or hide the component There are also options to show only or show all components of the same type If the component does not have a visual representation in the model window e g joints the right click menu options will be limited to edit and remove e 3D Model Window is where the MSMS models are visualized edited and animated Here double clicking on a component s name will bring up its properties dialog box Right clicking on a compo
36. E 17 23 17 3 Eratfillg uie AE 18 BTA SOP PLI 18 3 1 8 MA PONE Model EE 18 3 1 8 1 Import SolidWorks Modlel esses nennen enne nennt nn nsns eene an 18 3 1 8 2 Import OpenSim Model ccccsessscccececeesessaececececesseseeaeeececscessesaaeeeeecssesseeeaeeeeeeeseesags 21 3 1 9 EXI X 22 3 2 MIeW MOLHBU ii epe e Ee RD e EDU OE D RE ED e eee ce RE ee Eu Eu electa 23 3 2 1 FIODLE zoe A O E ca cerdas 23 3 2 2 Ba CK EE 23 3 2 3 PIA AE ettet ere Sask ra clot Satins Ceuta ac e bu esa E oet a ca Sait Sed to nea eua d te en savin Colne 23 3 2 4 OO 23 3 2 5 M 24 3 2 6 Bottom Und ttiam te idt titi idet 24 3 2 7 CUM ned tct t e Set t Io t n E det Ede t ev S tette uns 24 3 2 8 Camera light On ie e pee n ee knee eee ens cio 24 3 2 9 Default Lights O I aE A i eet est t gues A RE A A Ee env ean 24 3 2 10 View All xvii 24 3 2 11 F ll Sereen sd ed etait t tee anata des RENE RECS 24 3 3 Model Men ie EU RI DU RI ere e HR EUER E Re e edd 25 3 3 1 Show AIL AXeS ecce efte AAA denter e RR Te espe ts sae ee eee id 25 3 3 2 Show Ground AROS eed et eie ettet ia 25 3 3 3 Show Joint Gontto s ote et b t ec a pete e 25 3 3 4 IINE IEEE 25 3 3 5 Hide Li MENS 22 erret A T ere eA FUR e Eve Rt detur Ka 26 3 3 6 Hide Segrnents ce EHE HEN UA 26 3 3 7 Hide Wrapping OD Cts a eid ete mre exeo n de eder
37. MSMS it can be populated with components such as actuators and sensors it can be attached to a human model in MSMS and it can be simulated within an appropriate task environment In its import process MSMS also uses STL files exported from SolidWorks to properly visualize the prosthetic limb segments Therefore MSMS integrates a complete set of information directly available from the SolidWorks CAD design software the assembly and its visualization The process should be completely automatic and the user should not have to modify the linkage manually in the XML file This aspect of the translation guarantees the data has not been corrupted Because conversion from CAD to SimMechanics involves interpretations of what each element in the CAD model is and how it has to be represented in SimMechanics Mathworks provides guidance and instructions on configuration and export of your CAD model so that it can be successfully imported into SimMechanics You can find these guidelines in MathWorks web site at http www mathworks com access helpdesk help toolbox physmod mech Further current MSMS tools for importing CAD models do not handle all system topologies which imposes additional constraints on importable CAD models For example e The MSMS converter does not yet handle closed loop mechanical systems and subassemblies If the SolidWorks model includes a closed loop system or a subassembly it cannot get converted to MSMS Subassemblies can be avo
38. MSMS User s Manual Medical Device Development Facility Biomedical Engineering Department University of Southern California By Rahman Davoodi Version 2 2 Table of Contents 1 General infor Mati Mini ia 10 1 1 Ntro ducati 10 1 2 Minimum System Requirements ococococccncnnononononnnnnncnnononononononncnnonnnnnonnnnnnnn nono nono nnnnnncnnnrnnnnonnnnnns 10 1 3 Installation Proc d r cte ER 10 1 4 Key Feat fr6es eei het ts ee erede ENE RETE E dus Paetus Asked actus ede de OE tee 10 2 Starting MSM ES PC o Mm 11 2 1 Using Windows Shortcuts ene ee te re e p rte E are ttv ep tee ates 11 2 2 Using Command Line Interface ccccccccccccessssssscecececssseseaesecececesseaaeseeeescsssesesaeseeeessessessaaeess 11 2 3 MSMS Graphic User Interface rt te env et EE e reed nux ER RR E Eu Ys 12 2 4 Keyboard SHOrtcuts cccccsssssccececessesessesecececessesnaesecesecesseseaaeseceeecessesauseeeeeesesusesaaaeseceessessussaaeess 13 3 rn E E AA E A E A E 15 3 1 File MENU isinna aE ee ea Ea a E Ae Aa E A E aE EE 15 3 1 1 New Model ici dale 15 3 1 2 OPEN DET 15 3 1 3 aleae ERE 16 3 1 4 sr 16 3 1 5 MIT 16 3 1 6 COS tio aan 16 3 1 7 Juice 16 3 L7 1 G n ral oe oet nere tnn osea lesa put an e RE RR ieu aM MERE 17 3172 Displayiisisotst addat etie ate ate duet aded eU II UNIO ID
39. Mosby Co p 1717 32 Hoffer J A Sugano N Loeb G E Marks W B O Donovan M J and Pratt C A Cat hindlimb motoneurons during locomotion Il Normal activity patterns J Neurophysiol 57 530 553 1987 Loeb G E and Levine W S 1990 Linking musculoskeletal mechanics to sensorimotor neurophysiology In Winters J M and Woo S L Y editors Multiple Muscle Systems Biomechanics and movement organization New York Springer Verlag p 165 81 115 Malmivuo J and Plonsey R 1995 Bioelectromagnetism Principles and Applications of Bioelectric and Biomagnetic Fields Oxford U K OxfordUniv Press Mendez J and Keyes A 1960 Density and composition of mammalian muscle Metabolism 9 184 8 Milner Brown H S Stein R B and Yemm R 1973 The orderly recruitment of human motor units during voluntary isometric contractions J Physiol 230 359 70 Mileusnic M P Brown I E Lan N and Loeb G E 2006 Mathematical models of proprioceptors Control and transduction in the muscle spindle J Neurophysiol 96 1772 1788 Mileusnic M P and Loeb G E 2009 Force estimation from ensembles of Golgi tendon organs J Neural Eng 6 1 15 Monster A W and Chan H 1977 Isometric force production by motor units of extensor digitorum communis in man J Neurophysiol 40 1432 43 Roszek B Baan G C and Huijing P A 1994 Decreasing stimulation frequency dependent length force characteristics of rat muscle J Appl Physiol
40. SIMM motion file format is described in SIMM s documentation and contains frames of data for all degrees of freedom of the model in rows A sample SIMM motion file is Shown below name motion data datacolumns 2 datarows 50 range 0 0 5 0 endheader Shoulder FE Elbow FE 0 0 0 0 0 1 0 15 0 5 0 5 e datacolumns is the number of DOF in the model that are being animated e Datarows is the number of data frames e Range is the time span of animation Sampling time can be calculated by dividing the range by the number of datarows e Shoulder FE are the names of the DOF e The numbers that follow are values of the DOF 89 6 Appendix B Protocol for Live Animation Feature Commands Using the Animation Setup you can setup MSMS to receive and animate motion data from live sources such as a motion capture system or a simulation program After setting up and starting the animation MSMS will be on standby to receive animation data and use it to animate the model The animation data must be sent using UDP protocol and through a port number similar to that in the Animation Setup The UDP packet must contain the animation data in a format that matches the selected animation type in the Animation Setup The automatically exported model to Simulink will have the necessary blocks to create the appropriate UDP packet In this case you don t have to worry about the format of the UDP packet But if you are using your own program to send the
41. Simulink C S functions included in MSMS installation to perform similar functions as their counterparts in xPC Target toolbox but they won t run in real time xPC Target PC The main advantage of these MSMS blocks is that they relieve the non real time users from having to purchase Matlab s xPC Target toolbox 96 7 Appendix C Animation of ADL in PowerPoint 7 1 Using MSMS and PowerPoint to Animate ADL movements This document describes the process of building a library of ADL animation files for MSMS and using Microsoft s PowerPoint to organize them into more complex ADL animation sequences To perform ADL animations one must create a MSMS model to visualize the movement build a library of MSMS motion files representing simple movements and use PowerPoint to combine the simple movements into more complex ADL animation sequences The first two steps must be performed by expert users who are familiar with MSMS and its motion file format The final stage however can be performed by non experts as long as they are familiar with the user interface of the PowerPoint application 7 2 MSMS model Depending on the application models of varying complexity can be built in MSMS For example a model of the human hand is adequate for an application that requires animation of the grasp movement But for animation of reaching movement the human arm must also be modeled The library of motion files and the ADL sequences are model dependent because they w
42. a recorded EMG envelope in order to use it as an activation input There is one piece of evidence suggesting that the EMG envelope is in fact linearly related to the input signal to the motoneuron pool itself as currently structured in the model When such a recorded EMG envelope was scaled linearly and applied as an intracellularly injected depolarizing current to individual motoneurons those motoneurons reproduced the frequency modulation recorded from single motor axons recorded at the same time as the EMG envelope Hoffer et al 1987 The appropriate theoretical relationship probably lies somewhere between linear and square root of EMG envelope Practically the effects of electrode design and placement and underlying muscle architecture are likely to be much larger For example skin surface electrodes are highly biased toward large superficial motor units that are recruited only at high activation levels severely underestimating low levels of recruitment Such records would be better modeled by taking the square root of the recorded envelope 8 2 4 Lumped Units Lumped Units Recruitment is designed to match the average behavior of Natural Units Recruitment strategy see Song et al 2008 and Tsianos et al submitted 110 Firing Frequency f fs Uy U 0 001 Up 2 U tU FI U 1 pesa r Activation U 0 1 Instead of modeling each unit explicitly the Natural Continuous algorithm lumps the multiple units
43. according to the corresponding fiber types thus requiring only one unit per fiber type Each unit or fiber type becomes active at a threshold Us that depends on the distribution of fractional PCSA Fpcsa between slow and fast twitch fiber types and their recruitment order This significantly improves the computational efficiency of the algorithm by reducing the number of states to be solved from 2 3 of motor units to 3 3 of fiber types 8 2 5 Intramuscular FES The Intramuscular FES recruitment is based upon the assumption that motor axon branchlets within a muscle belly are not recruited in any preferential fiber type order this assumption is based on the Data of Singh et al 2000 The algorithm recruits a fraction of the muscle s PCSA equal to the activation input In order to decrease the amount of computation for real time applications there is only one motor unit per fiber type representing the entire population of motor units Consider for example a muscle composed of 30 slow fibers and 7096 fast fibers then the numbers 0 3 x and 0 7 y should be added under S and F columns respectively The value of x and y after the specify the number of motor unit for that fiber type No matter what that number is besides zero we have modeled only one motor unit for each fiber type In case that the user has defined a fiber type but would like to shut down that fiber type without having to redefine a new fiber type database the following should
44. aces File name grasp1 xml Save as type powerPoint XML Presentation xml PowerPoint Add In ppam PowerPoint 97 2003 Add In ppa PowerPoint XML Presentation xml Single File Web Page mht mhtml 5 Run MSMS and open the MSMS model For this you need to brows to the model s 7 8 parent folder Once you select the parent folder the valid MSMS models under that folder appear in the Simulation Configurations list If it doesn t you are in the wrong folder and need to go back and select the model s parent folder Double click on the model name to open Once the model is loaded Click on Animation gt ADL File Parsing menu item In the popup window brows to the model s ADL folder and select the XML file created in step 5 above and Click OK This creates a MSMS motion file for the whole ADL sequence and stores it in the model s data folder Model nameMdata The created motion file for the ADL sequence has the same name as the PowerPoint presentation file but its extension is msm ADL PPT File Selection moere OOOO To animate the ADL sequence created in step 6 click on Animation gt Setup In the Animation setup window select From File radio button Then brows to the model s data folder select the motion file for the ADL sequence and click OK to close the Animation Setup window 99 Animation Setup Source Of Animation Data From File
45. aget ar eed edt a ten teu 65 4 3 5 Fibers Properties o tree tr t etat ve t dta vi 66 4 3 6 urri kc ERN EE 68 4 4 E ee vein eR a E aS 69 4 4 1 General EE 69 4 4 2 Ligament Path ERHEBEN BEI IE 70 4 4 3 MOrphOMety ii Dt A eae add esta aA Sead et 71 4 4 4 luECBETE EP 71 45 Wrapping Object vec cette trm eap bates epa pii eate e dios i 72 4 5 1 A ON 72 4 5 2 A A a 72 4 5 3 POS Se Orls ub Ee Ue ee e t ce aa ea 73 4 5 4 Path Comiponents e petet std ats gues A E Aera Eaei faaan 73 4 5 5 nrc 74 4 6 Mrd Em 75 4 6 1 G neral A ER RU er HI REP E e e eqs 75 4 6 2 Attachments erue eee etr ee eee i gente et n e Eq aad aute tens 75 4 6 3 uror 75 4 7 hue ER 76 4 7 1 erulcee ETE 76 4 7 2 ATICO MENS coe 76 4 7 3 Mass Pr pS IA ia 77 4 7 4 Control Props 4s m tecti e oa tei edid de tes eed tts Ot ete d ad tn one GM TREATS DEUS 77 4 7 5 Electrical Props o EE E REG ER RI WIR RENTES 78 4 7 6 Mechanical Props iit trn nete oin x ed rete RA d e aget e tb P diee der de vate du 78 4 7 7 NIM ABC sae uM 78 4 8 ROSITION SA beetle tou i ed ee 79 4 8 1 Ge n talu x sace ete ette tie AA tute ta one ditta fts 79 4 8 2 Attachments ue RR RR RET id 79 4 8 3 WIM ABCs mec 79 4 9 Camera i iid dit nibh P 80 4 9 1 G neral on EE 80 4 9 2 Position Orientation ae ENAA a ue ED a a 80 4 9 3 EU a tdt N ario AE 81 AIO Mii dass 82 AOL CO lui A AAA A AAA AA 82 4 10 2 Position amp Direction aii
46. akaa ea aaas 118 9 3 Workspate xml aee teta etre eee 118 10 Appendix Fi MSMS Lights retten id oa Rn een Va YN a UE EN ER cias 119 11 Appendix G Collision and Contact o oooooocccccnonononaonnnnnnnnonnnonnnnnnncnnnnnnnonnonnnnnnnnnnnonnnnnnnnnnnnnenonnnnnnanon 121 12 Appendix H Special Features ccccccssssccccecessesssneseeececessesssaeeeeececssseseeaeeeseessessesasaeeeesesseeseaaeaeeeesens 124 12 1 Blanking the model SCreen cccccnnnonoononcnnnnnnononannnnnonnnononenonnnnnnnnnonnnonnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnennannns 124 12 2 Writing animation events to file cccocnnnnocoonnnncninnnonannnnnnnnnononononnnnnnononnnnn nn nnnnncnnnnnnnnonanons 124 13 Appendix HzRevision LOB dette de netta a Oi ead dae ec n edat ado edel e equae aen ini dea dadas 126 1 General Information 1 1 Introduction MSMS is a software application for modeling and simulation of neural prostheses systems It can be used to model and simulate human and prosthetic limbs and the task environment they operate in The simulations can be executed in a standalone computer to develop and test neural control systems or in a virtual reality environment where the human or animal subject can interact with and therefore affect the behavior of the simulated limb If you are new to MSMS start with the tutorials where you will learn about the basic tools and features in MSMS You can find the tutorials in your MSMS installation folder In cha
47. allocated to that motor unit increases linearly from fmin to fmax However when the second motor unit reaches threshold there is a jump in motor unit activation as the PCSA for the second motor unit becomes recruited and also frequency modulates from its own fmin to fmax Thus the mean frequency driving the total muscle PCSA increases at a higher rate at this point With more than two compartments sudden transients in mean frequency are reduced in magnitude but the non linearity in frequency response remains The figure above on the left depicts the mean frequency driving the total PCSA for the entire muscle when two yellow five magenta and ten cyan motor units are modeled To linearize the response of the muscle one method is to take the square root of activation input before applying it to the muscle The figure above on the right depicts the effects of using a square root adjustment on the activation 109 1 3 2 input With fewer than 10 compartments a lower exponent might be desired such as u However u fits relatively well for 5 or more compartments The relationship between recorded EMG and effective muscle activation is complex and probably depends on the recording method If all regions and fiber types in the muscle are sampled without bias then it should be possible to estimate this relationship from first principles A single action potential in a single motor unit should produce a unitary potential whose amplit
48. alue can then be compared with literature values for optimal sarcomere lengths For example if average sarcomere length from your muscle was 2 0 um and optimal sarcomere length for skeletal muscle in the same species is 2 4 um then you would have to multiply your in situ fascicle length by 1 2 to obtain Lo 113 Tendon length Lo This is the sum of any external tendon plus all in series aponeurosis as this has been shown to have similar mechanical properties to external tendon Scott and Loeb 1995 This value scales the length of the tendon for the purposes of series elastic force production This parameter differs from Zajac s 1989 model which uses tendon slack length The Lo length is a measure of tendon length when the tendon is stretched by the maximal tetanic force of the fascicles Brown et al 1996 As mentioned above this value is also used in the calculation of the fascicle Lmax The external tendon component of Ly can be measured directly from the tendon using a ruler in situ Unfortunately it is impossible to measure Lo from a typical dissection without a system to stimulate the fascicles and measure the length of the tendon when the fascicles are producing an isometric force of Fo In the absence of direct L measures it can be approximated by using 105 of tendon slack length The aponeurosis component of Lo is the mean amount of aponeurosis that is in series with each fascicle This can be approximated by halvi
49. am When executed the simulation model will generate motion data that are sent to MSMS via UDP for on line animation To view the simulated motion in MSMS while the simulation is running in Simulink you need to setup and run the animation from the Animation menu When the simulation ends or stopped by the user the resulting motion data for the duration of simulation are also saved in a MSMS compatible msm motion file This motion file can be loaded to MSMS to animate the model off line Notes e Torun the Simulink models you have to add MSMS s Matlab folder e g C MSMS MSMS 1 0 bin Matlab to the Matlab path using File gt gt Set Path In some operating systems if you want Matlab to remember the set path for future sessions you have to run Matlab as administrator to set the path right click on Matlab shortcut and choose Run as administrator This setup has to be done once after a new MSMS installation e Usually after creating a Simulink model you will add other Simulink blocks to the model to provide inputs to the model or display the results If you make such changes by adding your user blocks Save Simulation will give you the option to keep or overwrite your changes This option can be very useful if you make frequent changes to your MSMS model and create new Simulink blocks but you don t want to add the user blocks every time you do it If you choose to keep your changes MSMS will overwrite the blocks that it usually generate
50. animation data to MSMS you must build your UDP packets according to the following formats 6 1 Ordered Joint Angles In this protocol the positions of all joint DOF in the model must be sent in a single UDP packet to MSMS The format of the data is single precision float and the order of the data in the UDP packet must match the order expected by MSMS You can find the data order expected by MSMS in two ways Export the model to Simulink and then examine the Simulink block that assembles the DOF data into a single UDP packet You will clearly see the place of each DOF in the UDP packet Examine the simulationsetup xml file in the model folder An xml tag in this file segNum is used to define joint order the order in which joint data is passed to MSMS via UDP By examining all occurrences of this tag you can get the order of data for all DOF in the model 6 2 Feature Commands One drawback of using Ordered Joint Angles protocol is that all data must be transmitted at the same time to avoid violating the order constraints A significant improvement on that approach is to assign an ID to each joint object thus allowing unique specification of any joint to be commanded This improved approach is called Feature Commands and allows you to send the data in arbitrarily small amounts In addition it allows you to modify parameters of other objects such as segments e g color and size and also add additional elements to your VR scene such as trajec
51. ation data MSMS now searches for images in the model folder and in the subdirectories of the C MSMS Model LibraryNmages 128 folder e The user can now change joint types via the Axes tab If the number of dofs is changed this gets reflected in other panels and in the saved model e Fix to the motion tab in the joint properties panel The sliders for translational dofs are now working e Allow the user to set the range for translational dofs e Fix to the Cancel button in the Export to Simulink Panel e Fix to the 3D arrow visualization cone drawn at the tip of the rotation axis The cone orientation did not match the direction of the axis e The passive joint moment panel was not working properly It wasn t possible to enter values for multiple dofs Now the panel is fully functional and works for both rotational and translation dofs e Update to the user manual 0 7 8 Beta 04 18 08 e Muscle Tendon Length 0 8 2 Beta e Rendering time displayed in MSMS e Optimizing MSMS rendering 0 8 4 Beta 03 03 09 e Trajectory display e Sound e Fix to selection of objects with multiple images e Text display 0 8 7 Beta 04 21 09 e Fix to ADL animations for EMG Animation synchronization e Modifications to motion file to explicitly represent pause slides Fix to allow selection unselection of objects by mouse clicks New icons in the toolbar for camera controls Modifications to allow installation of MSMS in Linux 0 8 8 B
52. ation of a Simulink model to simulate the physics based movement of the MSMS model File View Model Animation Help um E Y Simulation Setup Ctrl Alt C Convert To Simulink Ctrl Alt E gt Model Explorer Human_Right_Arm 3 4 1 Simulation Setup The Simulation Setup allows you to setup the simulation configuration before exporting it to Simulink 3 4 1 1 General Here you can set the gravity vector for physics based simulation The default gravity vector 0 9 81 0 should not be changed unless the simulated movements occur on the Space station or the moon Simulation Setup General Setup Solver Dynamic Engine Output Data Gravity Vector X p o m s 2 Y 9 81 m s 2 Z 0 0 m s 2 37 3 4 1 2 Setup In the setup tab you can see the tree structure view of the model and enter the initial conditions for each degree of freedom in the model The initial positions are initially set to the default joint angles set in the Joint properties panel but can be modified here to simulate the model from any starting posture General Setup Solver Dynamic Engine Output Data Top level Components ground Trunk clavicle humerus s radius right_hand Initial Condition for HumeroUlnar Name Position Unit Velocity ok apply J Cancel Help 3 4 1 3 Solver Here you can select the simulation time the type of numerical integration Fixed s
53. ctively constant across different fiber types see Brown et al 1998 so it is set as a single value The second purpose of muscle mass is to provide stability in the simulation for the interaction between the visco elastic contractile element and the elastic tendon element see Loeb and Levine 1990 In our model half of this value is incorporated to provide inertial damping i e the muscle mass is assumed to centered halfway along the length of the fascicles The stability of the model proved relatively insensitive to the amount of muscle mass used a change in the stabilizing mass by an order of magnitude only changed rise and fall times of force production by a few milliseconds The only stipulation for collecting this value is that the wet weight be used not the weight of desiccated muscle If you already have a muscle volume multiply by the density of muscle 1 06 g cm to obtain a mass Fascicle length Lo Fascicle length not muscle belly length is important for three purposes As previously discussed it is important for determining PCSA and hence Fo Second it scales the velocity and length dependence of the contractile element of the muscle and thus changes the sensitivity of the contractile element to changes in total musculotendon path length Thus a shorter fascicle will show greater changes in force output with the same total length change Finally it is used in conjunction with optimal tendon length Lo and maximal mu
54. determined by best fit procedures using data from experiments that explored these processes under a wide range of physiological conditions This strategy improves the likelihood that the model will extrapolate accurately to deal with ranges and combinations of input conditions that may occur during normal use of muscles but may not have been tested explicitly in the source experiments It also makes it simpler to identify the terms and coefficients that must be changed to describe muscles with different morphologies or different fiber type properties such as from different species Our goal is to capture accurately the complex mechanical properties of real muscles and tendons so that the user can understand the consequences of those properties for the control of musculoskeletal systems 101 8 1 Structure of the Model Sensorimotor control Muscle Muscle morphometry mechanics Skeletal dynamics Our muscle modeling system is intended for use in a hierarchical framework The mechanical dynamics of the skeletal segments comprise the lowest level and are acted on by a realistic representation of physiological muscle properties at the middle level At the top level the muscles are controlled by any arbitrary set of activation commands ranging from pre recorded EMG data to dynamic feedback driven reflex models to high level simulations of cortical commands Our software provides the middle level of the hierarchy It enables users who may
55. diagram below summarizes the functions that comprise the force and energetics models within Virtual Muscle The contractile force and energy consumption of muscle can be separated into contributions from a number of physiological processes some of which affect both formulations The force produced by the contractile element strains the series elastic element representing the tendon aponeurosis through an intermediate mass to generate a pulling force on the attached segments The contractile force has passive and active contributions The passive portion is a result of the visco elastic properties of stretching muscle and the elastic properties of the thick filament upon compression at short muscle lengths The active portion can be divided into three major physiological processes Activation force Af Force length FL and Force Velociy FV The FV relationship is mainly related to the overall strain of cross bridges which depends on the angle of attachment of the myosin heads onto the actin sites The FL relationship captures the effect of myofilament overlap on force and is related to the number of cross bridges formed The Af relationship reflects the portion of overlapping myofilaments that bind and is dependent on firing rate muscle length and fiber specific properties e g sag and yield The weighting function W only applies to the Lumped Units recruitment model see 16 2 2 and is used to scale the activation force relationship of the lum
56. e image will be considered for collision or not In other software you will have to apply collisions to the whole model or a group of segments But MSMS allows you to include exclude individual images of segments in collision This provides maximum flexibility and could be very useful in optimizing the speed of simulations For example you can use a complex 3D mesh to represent the realistic features of the fingertip in MSMS and add a simpler second image to the fingertip segment such as a sphere whose collision detection is much faster than 3D meshes to handle its collision with other objects You can hide this second image so that it doesn t obstruct the realistic appearance of the segment For more info on MSMS collision detection and handling see Appendix G Add This command adds an image to the segment Edit If clicked after selecting an image it opens the image edit window to edit the selected image s properties see below Remove Deletes the selected image 50 51 4 1 5 Image Editing Window General An image name can be chosen here The name does not need to be unique For the shape of a 3D image there are five primitive choices and a general mesh choice The primitives are Cylinder Sphere Box Hemisphere and Capped Cylinder Edit Image Data for Bone o gt L x General Material Pos amp Orient Scaling General Image Name Bone 3D Shape Mesh r humerus asc 52 Mater
57. e of early recruited types the distribution will always represent the physiological phenomenon whereby fast 108 fatigable units which have a higher Recruitment Rank have a smaller range of sizes than slow twitch units Burke et al 1973 The user can also choose one of two other automatic apportioning schemes each of which can be applied to either a single muscle or multiple muscles The geometric one will ask the user for the fractional increase between one motor unit and the next and will then distribute the PCSAs appropriately for each fiber type The equal one simply makes all motor units of each fiber type equal in size to the other motor units of that fiber type 8 2 3 Multiple motor unit recruitment behavior As a consequence of the interaction between having both an increased recruitment of motor units and an increase in the firing frequency of each motor unit with increasing activation the relationship between activation and the frequency envelope driving the motor units becomes non linear As an example of why this occurs consider first the simplest case having a muscle modeled as a single motor unit When activation reaches U the motor unit is activated at a frequency of fmin and the frequency envelope for the whole muscle rises linearly until fmax is reached Next consider a case with two compartments When threshold for the first motor unit is reached the frequency envelop for the portion of the muscle s PCSA
58. e of the joint between the parent segment and the new segment the joint offset from the parent segment and the shape of the new segment If a segment in the model is already highlighted selected Add segment will use it as the parent for the new segment Don t worry if the shape of the new segment does not have the desired position orientation or the material properties You can edit these later in the new segment s property panel 3 3 12 Add Muscle This command will bring up the muscle creation wizard The wizard allows you to quickly add a muscle and interactively configure its path and properties 28 ation Animation Help sa9 ona i E OADADA RARA Aena t Sia Model Expl 4 jodel Explorer N Y Human 3D Arm Segments Joints Actuators BIC_In BIC_sh BRA BRD PQ PT SUP TRLIn TRI It TRLm Sensors Wrapping Objects Cameras Lights Elastic Elements Binz Name New Muscle Opt Fascicle Length 17 9093 cm Curr Fasc Length 17 909 Opt Tendon Length 8 95465 cm Curr Tendon Length 8 9546 Max MT Length 32 2365 cm Curr MT Length 26 864C Mass 100 0 g PCSA 5 2676C 4 Max Force 167 506 N OK Cancel Apply Help Attachment Pt Coords in meters 0 01 0 226 0 016 After selecting this command the cursor will turn into a red cursor To interactively create the muscle you have to e Click to select origin then drag as
59. e properties window will be update to reflect the new path Once the desired path is drawn enter the remaining parameters Use the current ligament lengths as a guide to come up with reasonable values for the resting length Click OK to complete the ligament creation wizard and create the new ligament 32 3 3 14 Plot Anatomical Data for Muscles This command will open the anatomical data plotter for muscles 0 025 0 020 0 015 0 010 0 005 0 000 0 005 0 010 0 015 0 040 moment arm hu fe 0 045 0 050 0 055 0 060 BIC In Moment Arm HU FE vs hu fe ient Arm HU FE vs hu 1 _Arm _ HU_FE vs hu_fe it Arm HU FE vs hu fe TRI ln Moment Arm HU FE TRI It Moment Arm HU FE vs hu fe Muscle Att Moment Arm HU FE Muscles BIC InjBIC sh BRA BRD PQ FT SUP TRI In TRI It TRI m X Axis Joints HU FE Increment deg m 0 1 Add Curves 10 20 3c 40 50 60 70 80 90 100 110 120 130 140 150 humeroulnar _ hu_fe Curve Config Curve list Y Axis BIC_In_Moment_Arm _ HU_FE vs hu_fe BRD_Moment_Arm _ HU_FE vs hu_fe PQ_Moment_Arm _ HU_FE vs hu_fe PT_Moment_Arm _ HU_FE vs hu_fe SUP_Moment_Arm _ HU_FE vs hu_fe ITRI In Moment Arm HU FE vs hu fe TRI t Moment Arm HU FE vs hu fe Clear Here you can plot muscles anatomical data in the model and compare them with the experimentally measured data To plot new curves
60. ected metabolic energy consumption over the range of conditions that muscle behavior will be simulated The energetics option only applies to models of muscle that are composed of some combination of generic slow and generic fast twitch fiber types This option creates four additional outputs in the automatically created Simulink model of the muscle there are two outputs for each fiber type that correspond to energy related to muscle excitation and energy related to cross bridge cycling respectively Proprioceptors If selected spindle and GTO responses will be simulated This will create two additional inputs in the automatically created Simulink model of the muscle that correspond to gamma 65 static and gamma dynamic fusimotor stimulation It also creates three additional outputs for spindle la spindle Il and GTO Ib responses Recruitment Type Select one of the three recruitment options Natural Units Natural Lumped and FES Natural Units recruitment algorithm models the behavior of muscle down to the motor unit level This makes it especially suitable for modeling isolated muscle Natural Lumped recruitment algorithm captures the behavior of whole muscle with arbitrary composition of slow and fast twich fibers and is computationally efficient thus it is recommended for modeling large scale musculoskeletal systems Intramuscular FES models motor unit recruitment and resulting force of electrically stimulated muscle Apportion Meth
61. efault when you add a segment to your model using Add Component wizard it does not have any shapes attached to it Therefore you can see the newly added segment in the Model Explorer but not in the 3D model window You can design the appearance of your segment by adding image to your segment To add an image double click on the new component name and edit its image properties in the image tab If you add a segment using the Add Segment wizard you can add images to the segment in a single step MSMS allow you to add two types of shapes to your segments primitives and 3D meshes Primitives Can be used in segments that have relatively simple appearance The supported primitives include cylinder sphere box hemisphere and capped cylinder Because MSMS allows you to add any number of shapes to each segment you can combine multiple primitives to build more complex shapes if necessary Once a primitive shape is added to a segment all of its properties such as material properties its position and orientation with respect to the segment and its scaling parameters can be edited independent of any other shape attached to that segment This provides the maximum flexibility and enables the users to build segments with the desired appearance even with the use of simple primitives 3D Meshes Can model any 3D shape and can be used to model the appearance of segments with complex shapes such as human body segments bones and prosthetic limbs To add a 3D
62. eled with a virtual spring damper model at the contact point When a contact between two objects is detected we assume that they first enter static contact mode At this mode we connect the two objects at the contact points using a virtual spring and damper pair As the contact points in two objects move away from each other we calculate the force developed in the virtual spring damper pair as the static friction force as follows 122 FS ksl v5 a Iv Where FS static friction force ks friction force spring constant I relative tangential displacements between the two contact points k54 friction force damping constant T v relative tangential velocity between the two contact points In static contact mode the static friction force F calculated above is compared to the maximum static friction force FM When the static friction force exceeds the maximum static friction force the two objects enter the dynamic contact mode Maximum static friction is calculated using static friction formula as follows MS _ N FMS p F Where FMS maximum static friction Ls static friction coefficient 123 12 Appendix H Special Features This appendix describes the features that have been developed to specifically address the needs of a specific MSMS user or application These features therefore are application specific and are not generally useful But we are describing them here because there may be users wi
63. ents 3 3 7 Hide Wrapping Objects Shows hides all wrapping objects 3 3 8 Hide AII Components Shows hides all model components 3 3 9 Add Model Using this command one can add an entire human prosthesis or world assembly to the current model To add you must browse to the XML file of the desired assembly human xml prosthesis xml or world xml and add it to your model For example you can remove a prosthesis in the model and add a different one to replace it This allows you to combine a human model with various prosthesis and world models to quickly build different task models 3 3 10 Add Component Brings up the add component wizard that allows you to add any model component supported by MSMS Joints are automatically created when you create a segment Once a component is inserted it will show up in the model explorer as the currently selected component The newly created component may belong to one of the Human Prosthesis or World Category If you attach the new component to an existing component it will inherit its parent s category by default If you are adding a component to a new blank model it will assume Human Category by default If this is not desirable open the component s GUI after its creation and change its category 26 New Component Segment 2 Actuator Kinematic Driver Motor i Position Sensor Wrapping Object Camera Light Elastic Elements Ligament Comp Name MyNewMuscle Parents
64. es and connections to handle collisions The collision algorithm uses the following state diagram to handle the transitions among different contact states No Contact Contact with Static Friction and Contact with Dynamic Friction No Contact NO CONTACT Contact No Contact NOTA STATIC FRICTION No Contact A Static friction gt Maximum static friction AND B There is contact AND Relative velocity is not zero Relative velocity is less than threshold not imp ented yet DYNAMIC FRICTION NOT B Not implemented yet 121 When the two bodies collide they enter static friction mode first The two objects stay in static friction mode until the friction force exceeds the maximum static friction force and the relative velocities are nonzero the objects enter the dynamic friction mode When there is a contact the normal and tangential contact forces are calculated and applied to the colliding segments as follows Normal contact force is modeled using a spring damper pair as follows FN kN5p n k p4n Where F normal contact force kNS normal force spring constant kNd normal force damping constant Pa penetration depth n normal vector Dynamic friction force is calculated using dynamic friction formula P pallP 3 3 Where F dynamic friction force Hg dynamic friction coefficient T Vp relative tangential velocity at the contact point Static friction force is mod
65. eta 05 19 09 Fixes to segment scaling via feature commands so that they are not accumulative A new feature to allow switching between the model and blank window by clicking on the spacebar key 0 9 0 Beta 07 14 09 e New Model Info menu item e Fixed the cylindrical wrapping algorithm so that muscle and its wrapping object can be attached to different segments e Added a feature to display the component IDs and joint 129 0 9 1 Beta 0 9 2 Beta 0 9 3 Beta 0 9 4 Beta 10 28 09 6 25 10 11 16 10 2 2 11 sequence numbers Fixed a bug to prevent MSMS from assigning component IDs that were too large Fixed visibility feature command Corrected the link to the user manual in help menu Fixed issues with head tracking feature command Fixed head tracking feature command that was throwing exceptions Fixed another issue with live head tracking where large numbers of new cameras were being created causing MSMS to run out of component IDs Upgraded to Java 6 update 20 Upgraded to Java3D 1 5 2 Fixed issues with Windows 7 installation Significant upgrades to muscle path modeling including ring wrapping object fixed via points and moving via points Significant upgrades to muscle properties panel for editing muscle path and fiber types database Upgrades to interactive graphical editing of wrapping objects and muscles Complete integration of Virtual Muscle in MSMS with the ability to model single muscles or muscles attached to
66. etric units and the STL format does not include any information about the units even though the unit may be specified in the comments in the STL file Check Do not translate STL output data to positive space For manufacturing vertices coordinates will be converted to positive space However in MSMS it is important to keep the coordinates as they are to preserve the concordance between the images and the Physical Modeling XML file SolidWorks Model of Prosthesis Y Actuator amp Sensor Data Human Model Data STL Files Physical Modeling World Model Data XML File M ii b atla MEMS SimMechanics Simulink Model of Simulink Model of Prosthesis Human World Prosthesis Importing a SolidWorks model to MSMS SolidWorks outputs a Physical Modeling XML file describing the mechanical linkage and STL files representing the appearance of each segment Both sets of outputs are used by MSMS to create an accurate model of the prosthetic limb in MSMS The final Simulink model can be built via Matlab SimMechanics or MSMS But the use of MSMS allows the users to attach the imported prosthetic limb to a human add additional prosthetic components such as actuators and simulate it in an appropriate task environment 20 File View Model Simulation Animation Help suo s 1E e Fado FU Model Explorer MPL H Joints Actuators Sensors Wrapping Objects
67. f Features MSMS_Pack B MSMS_reverseEndianess MSMS_UDP_Send P MSMS reverseEndianess a Feature MSMS_reverseEndianess Transparency 32 chart g o char2 o o MSMS_reverseEndianess MSMS_reverseEndianess Feature Low ume MSMS_reverseEndianess R uins MSMS reverseEndianess G 9 unis MSMS reverseEndianess B Wi Function Block P Wi Function Block Parameters udpPackPlantl Wi Function Block Parameters MSMS UDP so 7 S Function S Function S Function gt User definable block Blocks can be written in C MATLAB Level 1 and Fortran and must conform to S function standards The variables t x u and flag are automatically passed to the S function by Simulink You can specify additional parameters in the S function parameters field If the S function block requires additional source files for building generated code specify the filenames in the S function modules field Enter the filenames only do not use extensions or full pathnames e g enter src srcl not src c srci c Parameters S function name MSMS reverseEndianess Edit S function parameters S function modules Lok Cancel Help A User definable block Blocks can be written in C MATLAB Level 1 and Fortran and must conform to S function standards The variables t x u and flag are automatically passed to the S function by Simulink You can specify additional pa
68. f the wrapping object Transparency Sets the transparency of the wrapping object or select to show hide Surface Color Transparency Factor 0 0 ox j cancel Appi Help 74 4 6 Kinematic Driver 4 6 1 General Name A unique name for the kinematic driver Group The group to which the kinematic driver belongs Elbow Driver ok J cancel J b Help 4 6 2 Attachments Joint Selects the joint to be actuated Joint Axis Selects the joint axis to be actuated 4 6 3 Image Select to show hide the kinematic driver 75 4 7 Motor 4 7 4 General Name A unique name for the kinematic driver Group The group to which the kinematic driver belongs 4 7 2 Attachments Segment Select the segment to which this motor is attached Host Segment Selects the position and orientation of the motor in the host segment s reference frame Joint Selects the joint to be actuated Joint Axis Selects the joint axis to be actuated Orientation Rx gt Ry gt Rz x 0 0 deg Name Shoulder Motor Yoo m y0 0 deg Group HUMAN v Z00 m z 0 0 deg Actuated Joint Joint GlenoHumeral Y Joint Axis Gh FE v ox J God J apply J heb ox J cancel J h J Heb 76 4 7 3 Mass Props Select mass and mass moment of inertia of the motor 4 7 4 Control Props Select the motor control mode and the corresponding control coefficients Mass Moment of Inertia
69. femoral tibial hip lankle Ifemoral tibial Ihip Isubtalar Itoe itp pelvis subtalar toe tp Actuators ADDBREV ADDLONG A leg model imported from OpenSim Note To import SIMM models first import them into OpenSim and save them as OpenSim models Then you can import the OpenSim models to MSMS 3 1 9 Exit This command closes the currently open model and exits MSMS 22 3 2 View Menu File Model Simulation Animation Front Shift F Back Shift B Right Shift R Left Shift L Top Shift T Bottom Under Shift U Cameras Camera Light On Default Lights On View All Shift A Full Screen Shift S 3 2 1 Front This command shows the Front view Keyboard shortcut Shift F The Front view is the Y Z plane projection of the model with Y axis pointing upwards and Z axis pointing to the left of the screen 3 2 2 Back This command shows the Back view Keyboard shortcut Shift B The Back view is the Y Z plane projection of the model with Y axis pointing upwards and Z axis pointing to the right of the screen 3 2 3 Right This command shows the Right view Keyboard shortcut Shift R The Right view is the Y X plane projection of the model with Y axis pointing upwards and X axis pointing to the right of the screen 3 2 4 Left This command shows the Left view Keyboard shortcut Shift L The Left view is the Y X plane projection of the model with Y axis pointing upwards and X axis po
70. file and use it to animate the model The MSMS motion file format has the extension msm and has to be built following the guidelines described below The motion file is in ASCII format and can be edited using any text editor or any program that can generate ASCII files The motion file is composed of arbitrary number of rows The first row is the header and contains the names of the degrees of freedom DOF in the model that must be animated The following rows contain frames of data for the DOFs listed in the first row 5 1 1 Format of the header row Below is an example of the header row TIME Joint1 Tx Joint1 Ty Joint1 Tz Joint1 Rx Joint1 Ry Joint1 Rz Joint2 FE Joint2 AbAd Joint2 Rot e The header row starts with the word TIME which identifies the time column and it is followed by the names of the DOF in the animated model e All DOF names must be separated by spaces e The header is limited to a single line e The DOFs are either rotational or translational e The first element in the header is always TIME e DOF names must be single strings with no space in between the characters Joint2 FE is a valid name whereas Joint2 FE is not The DoF names are determined by the model and the user must obtain them form the model when building the motion files e The header does not have to include all the DOF names The only restriction is that if one DOF of a joint is included in the header then all of the DOFs of the same join
71. firing frequencies to a single maximal firing frequency at maximal activation have been demonstrated experimentally De Luca et al 1996 There is some suggestion that the frequency modulation of earlier recruited units is hyperbolic rather than linear Monster and Chan 1977 This can be approximated by setting fmax artificially high for such fiber types and taking advantage of the sigmoidal shape of the force frequency relationship 8 2 2 Apportioning PCSA among motor units By default assigning PCSA and number of motor units to a previously unassigned fiber type will result in an automatic distribution of PCSA for the motor units of that muscle and fiber type using the default apportioning algorithm For the default apportioning scheme the proportion of PCSA automatically allocated to each motor unit is based on the recruitment rank of the fiber type and on the total number of units of that type as in the following equation Recruitment Rank n PCSA h PCSA n motorunit lc type n Recruit Rak T 1 Recruit Rak 2 Tuc Recruit Rak total motor units Effectively this distribution scheme assigns a larger proportion of PCSA to later recruited motor units of a given type Increasing the absolute value of the Recruitment Rank parameter for the fiber type reduces the differences in PCSA between consecutively recruited motor units Because the Recruitment Rank values of late recruited fiber types must always be greater than thos
72. ground color 3 Camera descriptions including position and orientation 4 Lighting information 117 9 2 Common Image Directory As described above the model directory has a local image subdirectory to store the 3D meshes and textures But the size of these files is usually large and they are often reused in many MSMS models resulting in larger model sizes which require larger storage In MSMS the user has the option to store the model images in their local image directory or in a common image directory The images stored in local image directory are used only by that specific model But the images in the common image library are accessible and can be used by any MSMS model on the same computer When MSMS opens a model it first searches the local image directory for the required 3D files If MSMS cannot find all of the required 3D files it will continue searching the common image directory You can specify the location of your common image directory in Files gt gt Preferences gt gt General 9 3 Workspace xml This file stores user installation specific data This data includes screen size screen viewing preferences and other items such as which directories were last visited This file is created by MSMS and is located in the user s home directory e g C Documents and Settings User Name or C Users User Name for Windows users 118 10 Appendix F MSMS Lights Light has only three pure colors Red Green and Blue
73. hanists interested in the use of muscles to produce natural behaviors The model system provides a framework for constructing accurate muscle models that can be incorporated easily into complete neuromusculoskeletal systems The muscle model includes the following components which can be scaled according to commonly available morphometric data e Motor nuclei that accept a single command input e g net synaptic drive or EMG envelope and apportion it into recruitment and frequency modulation of subgroups of motor units with type specific properties e Type specific contractile elements that produce force as a function of firing frequency past and present length and velocity e Passive elastic elements for passive muscle force e M Passive elastic elements for series compliance of tendons and aponeuroses We have found it useful where possible to divide the model into components that have an obvious one to one correspondence with anatomical entities and physiological processes that occur in motoneurons muscle and tendon The experiments on which this model is based were designed to identify the specific structures and processes within muscle that give rise to complex phenomena e g passive vs active force series compliance recruitment and frequency modulation frequency length interactions yield sag etc The functions that comprise the model were chosen to describe those structures and processes explicitly and their coefficients were
74. have only minimal interest in the details of muscle physiology to create realistic mathematical representations of muscles At the same time it is possible for those who wish to delve into and modify the mathematics of the muscle model to do so The hierarchical database structure described below was designed to facilitate such modifications 1 Fiber type specific details 2 Whole muscle details including 4 motor units tendon and overall morphometry 3 Joint level with multiple muscles acting simultaneously 102 8 1 1 Fiber type level It has been shown that the behavior of the contractile element of the muscle scales well from the sarcomere level up to the whole muscle fiber level and again up to the level of an entire recruitment group of motor units Zajac 1989 There are two critical assumptions behind lumping of individual sarcomeres into a single group e All the sarcomeres in such a group must operate homogeneously with similar activation length and velocity While some phenomena are believed to arise specifically because of intra fiber sarcomere heterogeneity and or damage e g persistent stretch induced force changes these changes are small or rare under physiological use conditions Brown and Loeb Ms III e The sarcomeres must all have the same contractile properties i e their force length velocity relationship parallel elasticity and so forth These characteristics have been shown to be homogenous withi
75. he users who like to inspect the motion file or edit it manually e Nocomments are allowed in the motion file e The MSMS motion file is compatible with and can be used by any MSMS model as long as the model has all the DOFs listed in the motion file header Notes e The motion file does not contain data on camera position and orientation The user can use the keyboard and mouse to position and orient the camera as desired 87 5 1 3 An Example msm Motion File TIME Joint Tx Joint Ty Joint Tz Jointi Rx Joint Ry Jointi Rz Joint2 FE Joint2 AbAd Joint2 Rot 0 328 0 03452 0 04704 0 06464 0 56901 0 21084 0 055849 0 08625 0 902 0 0 36 0 03452 0 04704 0 06464 0 56901 0 21084 0 055849 0 08625 0 902 0 0 391 0 03452 0 04704 0 06464 0 56901 0 21084 0 055849 0 08625 0 902 0 0 438 0 03452 0 04704 0 06464 0 56901 0 21084 0 055849 0 08625 0 902 0 0 485 0 03452 0 04704 0 06464 0 56901 0 21084 0 055849 0 08625 0 902 0 0 516 0 03452 0 04704 0 06464 0 56901 0 21084 0 055849 0 08625 0 902 0 0 563 0 03452 0 04704 0 06464 0 56901 0 21084 0 055849 0 08625 0 902 0 0 61 0 03452 0 04704 0 06464 0 56901 0 21084 0 055849 0 08625 0 902 0 0 641 0 03452 0 04704 0 06464 0 56901 0 21084 0 055849 0 08625 0 902 0 0 688 0 03452 0 04704 0 06464 0 56901 0 21084 0 055849 0 069 0 902 0 0 735 0 03452 0 04704 0 06464 0 56901 0 21084 0 055849 0 069 0 902 0 0 766 0 03452 0 04704 0 06464 0 56901 0 21084 0 055849 0 069 0 902 0 5 2 SIMM Motion File Format mot The
76. ial Here the object s appearance can be set by choosing Object color Ambient Diffuse Specular Shininess and Transparency You can select an object s color by clicking on Pick The color selected will be applied to all color types for the object i e ambient diffuse and specular Therefore it will be approximately the color of the object in all light types Advanced users can select the color for each individual color type by clicking on Advanced Color Options Pos amp Orient Scaling Object Color red 51 green 51 blue 51 Advanced Color Options Shininess Shininess 64 0 Transparency 0 5 53 Position amp Orientation Here the image can be translated along and rotated about any of the x y and z axes of its parent segment Translation Axes Translation along x axis Translation along y axis Translation along z axis Rotation Axes Rotation about x axis Rotation about y axis Rotation about z axis ox J apply Cancel 54 Scaling Here the image can be scaled along any of x y and z axes or uniformly along all axes Scalars by 96 g 100 0 200 400 600 800 1000 y 100 0 200 400 600 800 1000 E 100 0 200 400 600 800 1000 Scaling along x axis Scaling along y axis Scaling along z axis 55 4 2 Joint The properties window for a joint includes 6 tabs Each tab enables the u
77. ided in the model by bringing the parts and the constraints contained in the subassembly to the higher hierarchical level In other words a flat assembly is required all parts are mated together at the top level e The CAD assembly parts need to have masses and inertia tensors This may be automatically computed from density and geometry as long as all parts have material properties defined e Unnecessary constraints must be avoided because they are translated into many weld joints that complicate the simulation model but are not necessary e Only the complete assembly can be exported to XML and not a part of it Finally the user must export the segment images from the CAD model MSMS uses these images to visualize the imported CAD model The following rules will ensure that the images are exported properly e A Coarse resolution is sufficient for visualization purposes STL files have very high resolution because they are meant to be used for manufacturing stereolithography MSMS reads directly the STL format However this format describes only surface geometry of 3D objects and does not include any information about color or texture It can be useful to convert the STL files to the OBJ format and then include color and texture properties e Set the Output parameter to binary ASCII STL files can quickly become very large Therefore the binary STL is a better option 19 Set the Units to meters The MSMS environment uses m
78. ill be built using the data on the MSMS model For example the motion files will use the names of the joints degrees of freedom in the MSMS model to indicate what their movement is 7 3 Library of the motion files Once the MSMS model is built a library of compatible motion files must be created These files represent simple and primitive movements such as elbow flexion palmar grasp elbow extension etc and can be created following the MSMS motion file format These files can be created manually by entering the data in a text editor or constructed by a computer program that can write formatted data into a text file The motion data themselves could be handcrafted by an expert synthesized following well known bell shaped velocity curves for human movements or captured from subjects performing these movements using a motion capture system Each motion file is represented by two files the motion file and an image representative of the movement in the motion file The image file can be created using photography or by screen shots from MSMS screen The motion file and the image file must have the same name but different extensions e g pinchgrip msm and pinchgrasp jpg The set of motion files and their corresponding image files must be stored in the model directory structure under Model_name data ADL 97 7 4 ADL Animation Sequences The ADL animation sequences can be built using Microsoft s PowerPoint application whose interface i
79. inting to the left of the screen 23 3 2 5 Top This command shows the Top view Keyboard shortcut Shift T The Top view is the X Z plane projection of the model with X axis pointing upwards and Z axis pointing to the right of the screen 3 2 6 Bottom Under This command shows the Bottom view Keyboard shortcut Shift U The Bottom view is the X Z plane projection of the model with X axis pointing upwards and Z axis pointing to the left of the screen 3 2 7 Cameras All models have a default camera for viewing the model The user however can create any number of custom cameras for a model All such cameras will be listed here and can be chosen as the active camera by the user 3 2 8 Camera Light On This command toggles on and off the spotlight that is attached to the camera and always points in the same direction as the camera 3 2 9 Default Lights On This menu option toggles on and off the default lights which is a combination of one ambient light and two directional lights In addition to the camera and default lights the user can add new lights Lighting of the MSMS world can be accomplished by four basic types of light 1 ambient 2 directional 3 point and 4 spotlight 3 2 10 View All This menu option redirects the camera toward the model and moves it back until the whole model can be seen This is useful when the camera is pointing to the wrong direction and the model is invisible 3 2 11 Full Screen This
80. light sources such as flashlights or torches that have reflectors or lenses In addition to Attenuation Spotlight sources provide Direction Concentration and Spread Angle controls When specifying Direction the Spread Angle control defines a cone in the direction of the light such as a flash light that emits a cone of light in a particular direction The Concentration control affects the intensity of light across a cross section of the cone of light or how much of the light is concentrated in the center of the cross section versus attenuating outwards The higher the concentration the more light is focused in the center When concentration is zeroed then spread of light will be uniform throughout the cross section 4 10 2 Position amp Direction Sets the position and direction of the light source The light emits in the direction of a vector emanating from the position of light source to the point specified for the Direction General Pos Dir Color Misc Position Direction X b o Y 3 0 Z 0 0 OK Cancel Apply Help 83 4 10 3 Color Specifies the color of the light source Preview mn O MM Sample Text Sample Text E a LI Sample Text Sample Text ES 84 4 10 4 Misc Selects the remaining properties of the light source Attenuation Sets the attenuation of the light source to one of None Linear or Quadratic Defining the distance from the light source as
81. ludes la and ll afferent responses The GTO model generates a response that represents activity from an ensemble of group Ib afferents in response to whole muscle tension 8 5 Tips for obtaining morphometric measures The first step in using this package is to create a database of fiber properties For most purposes the included database of feline muscle fiber types will provide a good starting point By knowing a few key parameters it may be possible to estimate values for other species by scaling the coefficients provided for feline muscle If you wish to collect your own data and fit it to the equations provided this is beyond the scope of the present text see Brown et al 1999 and Brown and Loeb 2000 for a more detailed discussion Assuming you already have a satisfactory set of fiber type parameters that match the subject you are trying to model the next step is to provide information on the muscle you are attempting to model A brief description of the function of and methods to obtain the parameters follow Muscle mass In the muscle model this value serves two purposes The first is to provide the volume of the muscle in conjunction with the density of muscle which is fixed at 1 06 g cm Mendez and Keyes 112 1960 which is then used to calculate physiological cross sectional area PCSA PCSA relates to Fo or maximal tetanic force which in turn scales all of the force output of the muscle The specific tension of muscle is effe
82. ment Muscle color In the case of segment it applies to the currently visible images of a segment Segment Transparency 12 1 unit8 value for the transparency of the segment Applies to currently selected images of a segment and varies between 0 opaque and 100 clear Segment Visibility 13 1 unit8 value for visibility of the segment 1 Visible O InVisible Head Tracking 14 6 single values 3 for position and 3 for xyz orientation of the head Motion of Joint with Rot DOF as 15 4 single for the rotational DOF specified by quaternion Quaternion Motion of Joint with 1 Trans DOF 16 1 single for translational DOF and Rot DOF as quaternion 4 single for the rotational DOF specified by quaternion Motion of Joint with 2 Trans DOF 17 2 single for translational DOF and Rot DOF as quaternion 4 single for the rotational DOF specified by quaternion 93 Motion of Joint with 3 Trans DOF and Rot DOF as quaternion 18 3 single for translational DOF 4 single for the rotational DOF specified by quaternion Trajectory Path 19 1 single for diameter of the trajectory path 3 uint8 for RGB values of the trajectory color 1 uint8 for the transparency of the trajectory 0 100 1 int16 for the number of the trajectory points 1 vector of single values specifying the xyz coordinates of the trajectory points The length of this vector must be equal to 3 times the number of trajectory points Message Board Setup
83. menu option enlarges the 3D window to cover the entire screen The keyboard shortcut for this command is Shift S You can press Esc to get back to the normal screen mode 24 3 3 Model Menu Includes tools for building and editing of models MSMS Human Right Arm File View Simulation Animation Help s E Show All Axes del Show Ground Axes Model Ex Show Joint Controls Human f H Segm E Joints Hide Muscles cH Actua Hide Ligaments Sens E Wrapl Hide Segments Came Hide Wrapping Objects Eights Hide All Components t Add Model Ctrl Shift M Gt Add Component Ctrl Shift N FS Add Segment Ctrl Shift X M Add Muscle Ctrl Shift P L Add Ligament Ctrl Shift Q Plot Anatomical Data for Muscles Plot Anatomical Data for Ligaments Scale Segment Model Info 3 3 1 Show All Axes Shows hides the local reference frame of all components 3 3 2 Show Ground Axes Shows hides Ground reference frame 3 3 3 Show Joint Controls Shows hides joint controls for all joint degrees of freedom in the model To facilitate finding the desired degree of freedom in large models the names of the degrees of freedom are sorted in alphabetical order You can these sliders to control the motion of the individual joint degrees of freedom in the model 3 3 4 Hide Muscles Shows hides all muscles 25 3 3 5 Hide Ligaments Shows hides all ligaments 3 3 6 Hide Segments Shows hides all segm
84. mera e Lights were there in previous versions but have been recently updated e Two new menu items allow disabling the default lights and selecting which camera is active e The camera light which was ON by default is now set to OFF 126 0 5 7 Beta 0 6 0 Beta 0 6 1 Beta 0 6 1 Beta 02 16 07 05 23 07 05 30 07 06 07 07 A hotkey was added so that it becomes possible to switch between different views without getting out of full screen mode CTRL C Fix to animation of Fitts scenario Increase the update rate for animation New Directory structure workspace xml for storing user preferences view xml to store model visualization Fix to user defined cameras Fix to switching between different views CTRL SHIFT F now works for going into full screen sequencing of joint angles is made simpler simulationSetup xml replaces Simulation setup xml file New Open dialog Models can be closed Saving default camera pos and orientation when the model is saved Fix to MSMS so that it animates a model with only the world Model name is show next to the MSMS title bar Problem with lights when closing the model in MSMS Allowing MSMS to open models from any location Projection camera property was not read correctly Fix to the transparency slider and edit box Remove model specific data from view xml Export to simulink menu item is grayed out if no model is 127 loaded e Open and help menu button
85. mum musculotendon path length values can be entered ad hoc so that the calculated Lmax value equals any approximation that you wish to use This is the only function of the maximum musculotendon path length input value so it does not need to correspond to a physiological measure so long as the calculated Lmax is reasonable In fact if the range of motion used in your model is in the midrange of motion of the muscles involved passive force from the fascicles is minimal At Lmax it has been measured at typically less than 796 of Fo at Lo or shorter it is negligible Pennation angle This muscle model assumes that there is no pennation angle in the muscles This appears to be accurate when pennation angle is less than 10 15 e g Zajac 1989 In most such muscles the main effect of pennation is to provide a long aponeurosis for insertion of large numbers of relatively short muscle fibers whose forces combine in parallel This important feature is now well 114 captured by the ability to set Lo and Lo independently In more highly pinnate muscles the angle changes with the length of the muscle This necessitates a dynamic pennation angle to modify both the length and the velocity of the fascicles as well as to compute the portion of the force vector that acts on the line of pull of the muscle For small ranges of motion the force output of the muscle can be adjusted with the cosine of a fixed pennation angle but with the current muscle model la
86. n a single histochemical fiber type 8 1 2 Whole muscle level Muscles are organized into motor units each of which consists of a motoneuron and the several hundred muscle fibers that it controls All fibers in a unit are the same type Groups of similar motor unit types tend to be recruited together Different types of motor units tend to be recruited in a fixed order This fact provides an ideal way to simplify the model Each whole muscle is broken into motor units consisting of a single fiber type with each unit being defined by its fiber type its order of recruitment and its force producing capacity which is proportional to its total physiological cross sectional area It is assumed that the motor nucleus of the whole muscle receives a single time varying neural activation command signal which is then apportioned by the model to activate each unit in turn according to its defined recruitment order Within each motor unit the frequency of motoneuronal firing is modulated in a realistic manner Normally a muscle has about 100 or more motor units While it is possible to create such a detailed muscle model with our software this resolution will make the model run very slowly and is not usually necessary For most uses it will be sufficient to create a small number of model motor units perhaps 3 I 5 for each fiber type where each unit represents a group of real motor units with a total physiological cross sectional area PCSA of ar
87. nal Axes Name Axis Vector meters mium HumeroUlnar R i 0 0 58 4 2 4 Motion Translational Axes The slider and numerical field allow you to move the joint along its translational axes Rotational Axes The slider and numerical field allow you to move the joint along its rotational axes Motion Passive Joint Moments Image Translational Axes Y 4 0 2 4 0 8 0 8 2 4 4 0 1 HumeroUlnar X g p 000 m 4 0 2 4 0 8 0 8 2 4 4 0 2 HumeroUlnar Y Rotational Axes 1 HumeroUlnar R 60 90 120 150 4 2 5 Passive Joint Moment Here you can specify the parameters of the passive joint moments for each degree of freedom in the joint DOF Name Select a degree of freedom from the drop down list Damping Factor Set a damping factor for the selected degree of freedom Low Limit Check Active if you want the passive moments applied at the lower end of the joint s motion Select a torque function for calculation of the passive joint moment and enter its coefficients The selected function will be used to calculate a passive joint moment that will grow as a function of how much the joint angle exceeds the specified limit The value of the limit can be edited in the joint s Axes tab High Limit Set the parameters for the joint s high limit similar to the above Prope General Segments Axes Motion Passive Joint Moments Image DOF Name
88. nent will bring up a menu with options to edit remove show or hide the component There are also options to show only or show all components of the same type e Status Bar displays properties of muscles and wrapping objects when they are edited In other times it displays the commonly used shortcuts for model manipulation and navigation 12 2 4 Keyboard Shortcuts Keyboard Shortcuts allow you to quickly perform important functions in the menus and navigate the model in 3D window When you move your mouse over the buttons in the toolbar you will see a text that shows the equivalent keyboard shortcut for that button For the model window shortcuts to work you have to click on the 3D model window to bring it to focus Here is the list of keyboard shortcuts Keyboard Shortcuts e CTRL O Open e CTRL S Save e CTRL Alt S Save As e CTRL C Close e SHIFT F view front e SHIFT B view back e SHIFT R view right e SHIFT L view left e SHIFT T view top e SHIFT U view bottom e SHIFT A View all e SHIFT S Full screen e Esc Exit full screen e CTRL Shift M Add Model e CTRL Shift N Add component e CTRL Shift X Add segment e CTRL Shift P Add muscle e CTRL Shift Q Add ligament e CTRL Alt C Simulation setup e CTRL Alt E Convert to Simulink e CTRL Shift C Setup animation e CTRL Shift G Start Animation e CTRL Shift H
89. ng the sum of the total aponeurosis length at the origin plus the insertion scaled by 10596 if measured when the muscle was slack If you have a measurement of musculotendon path length at the skeletal posture where the muscle produces optimal force Lo then Lg Lo Lo Maximal musculotendon path length Lmax The sole purpose of this value for the muscle model is to calculate maximal fascicle length Maximal fascicle length Lmax is calculated as Li Lo which is then divided by fascicle Lo to provide a scaled value for Lmax It has been shown that a separate Lmax term is more appropriate than simply Lo for scaling passive forces produced by muscle Brown et al 1996 The value Lmax is measured by moving the appropriate joints to the extreme anatomical positions that produce a maximal in situ musculotendon path length Lmax The manner in which Lmax is calculated subtracting Lo and then dividing by Lo is based on two assumptions The first is that Lo will represent the length of the tendon when the muscle is fully stretched this is reasonable considering that Lo represents the tendon length when it is already stretched to a certain degree The second is that pennation angle is negligible this assumption will be discussed later If this value cannot be measured and is unavailable in literature reasonable values for Lmax have been shown to be between 1 1 and 1 42 Lo in five cat hindlimb muscles Brown et al 1996 Maxi
90. nput is the Henneman 1968 size principle which states that smaller motor units are recruited before larger motor units In our natural recruitment function this is applied to motor units of different histochemical fiber types reflecting the normal tendency of slow twitch motor units to be smaller than fast twitch motor units and thus recruited first Physiologically motor units of the same fiber type are also recruited according to their sizes In our model recruitment order within a fiber type is determined by their size see 16 2 1 1 A strict PCSA based recruitment order was not enforced at this level for two reasons 1 the user is able to simulate this behavior by apportioning smaller fractions of PCSA to the first motor units and larger PCSA to later motor units and 2 the simulated motor units are not necessarily intended to model individual motor units instead they represent groups of motor units to reduce computational time The auto distribution of PCSA feature actually replicates this behavior to an extent by apportioning less PCSA to the earlier recruited motor units This also serves a practical purpose in that it makes the onset of force production more gradual by making the first recruited motor units of a given fiber type smaller than the later recruited ones The ideas behind the implementation of the natural recruitment function are described by Brown 1998 with some minor variations All the motor units in a given p
91. nslate and rotate the model that were not working smoothly Made many minor improvements and bug fixes 132
92. nt Angles In Storage In File box specify the sampling time for data storage and the name of the output file In Live Animation box select the sampling time for sending the live motion data the method for sending the motion data via MSMS UDP Block or xPC UDP Block and the type of protocol for packaging the motion data Feature Commands or Joint Angles MSMS UDP Block works even if you don t have xPC Target toolbox But xPC UDP Block requires xPC Target toolbox If you plan on executing the simulation in real time xPC Target PC you must use xPC UDP Block If you don t have this toolbox or you don t want to run the simulations in a real time target you can use MSMS UDP Block The animation data can be packaged using two different protocols Feature Commands and Joint Angles The Joint Angles format can be used to send only the joint motions but Feature Commands is a more comprehensive format and can be used to send not only the joint motions but also commands to control the VR simulations such as sound playback drawing trajectories changing the color or size of objects etc For more see Appendix B 3 4 2 Convert to Simulink This command saves a Simulink simulation model mdl in the model s Matlab folder This simulation model represents the algorithms that can simulate the movement of the MSMS model in response to control excitations and external forces You can open and run the Simulink model in Matlab s Simulink progr
93. od Fractional Increase in PCSA Maximum Recruitment Activation see Appendix D Fiber Composition Select the fiber composition of the muscle Please note that the fractional PCSA F PCSA for all selected fiber types must add up to 1 The Edit button opens new windows where you can edit the specific coefficients of the mathematical models for individual fiber types 4 3 5 Fibers Properties This panel allows you to edit the properties of individual fiber types The default values have been carefully determined Cheng et al 2000 Appendix D so generally should not be changed But if you are familiar with these coefficients from Appendix D and the related literature you can change them here Optimal Sarcomere Length super slow soleus generic slow twitch generic fast twitch generic super fast super slow soleus This window Enter optimal sarcomere length and the high level properties of the individual fiber types Reset Resets the fiber properties to default 66 Edit Opens a window to edit generic coefficients of the fiber types Fiber Types Name Opens a window to edit the low level coefficients of the individual fibers Specific Tension 31 8 Viscosity part of FPE1 0 01 Coefficients for Force Lenath Curve FL L FL_omega Force Velocity Curve FV V L Vmax 4 06 cV0 avo 47 avi Effective Activation Af feff
94. older for the required images 3D meshes and textures But if it couldn t find all of the images in the local image folder it will search the common image folder and its subfolders When loading the model the progress window displays the folders searched for the images In this tab you can also change the background color of the 3D model window 3 1 7 2 Display MSMS supports both 2D and 3D displays In the Display Tab the following can be edited e The number of screens that the display contains This would be required in case of head mount displays or multi projection displays both of which have multiple screens and the user needs to configure each screen individually e The monoscopic view needs to be set in some cases for example a head mount display that gets its left and right feed from two different video channels In that case you cannot get stereo vision by just enabling stereo 3D Instead you need to set the monoscopic view of one screen to Left Eye and the other screen to Right Eye 17 2D Regular Monitors 3D Stereoscopic 3D Stereoscopic Head MountDisplays Monitors and Shutter Glasses 3 1 7 3 Framing The Framing Tab controls aspects specific to how the MSMS window affects the view as seen by the user Based upon the settings the view frustum gets modified 3 1 7 4 User The User tab is used to control settings that are user dependant e g the position of eyes When the physical to virtual eye correspondence is
95. olor So in MSMS each light type is represented by an RGB value There are four light sources in MSMS Ambient Directional Point and Spot Ambient light has no position or direction It is present everywhere similar to the light on a cloudy day Directional light is emitted in one direction but has no position similar to the light on a sunny day Point light has position and is emitted in all directions similar to a light bulb in a room Spot light has both a position and a direction similar to a flashlight The source of the light in MSMS is very important because it indicates what type of light is emitted In MSMS an ambient source emits ambient light a directional source emits diffuse and specular lights and a point source emits diffuse and specular lights Example Let s assume that the color of an object in MSMS is set to 1 Ambient blue 0 0 1 0 2 Specular black 0 O 0 3 Diffuse black O O 0 Now if we have a white 1 0 1 0 1 0 ambient source then this source emits ambient white light The object then reflects only the blue component of the emitted ambient light and appears blue Now what 119 if the source light is changed to directional which only emits diffuse and specular lights Well the object only reflects ambient light which is now non existent So the object will appear black Also note that overall light intensity is not controllable directly but is modified by the three color values except
96. ononnnananannnnnos 100 Appendix D Muscle Model Virtual Muscle esses enne enhn nennen inns 101 8 11 Structureof the Model ER p eR sued ana e SANE Rude 102 8 1 1 A A E E ree ea a patere rau d eene n des parl 103 8 1 2 Whole muscle level ERU te o 103 8 1 3 Interactions with Neural and Skeletal ElementS oonncccnnnccononaconocnconconanonononcnnnncnnnncncnnnos 104 8 1 4 Summary of Virtual Muscle s formulations ccoconocoooonnonononanonnnnnnnnnnananononnnnncononananonanoss 105 8 2 Recruitment type eue pn ttt dh e n he qu Wlincatactiunnch st RE RT Eee que Decatur ead 106 8 2 1 Natural Units 107 8 2 2 Apportioning PCSA among motor units ococcccccccnonononononononononononnnononononnnonononononnnnnnnnnnnns 108 8 2 3 Multiple motor unit recruitment behavior coconoococccncnonononononnnnnnnonanonononnnnnnnnonanannnancnnnanons 109 8 2 4 LUM PO Units 5 ise ertt oak e tr red ere e E ER D nde ri en eth eet 110 8 2 5 Intramusculat FES ads 111 8 3 A A deseaed late aSeounees 112 8 4 Propriocepti n comodato vel E a E a Aa E a e a aaie eaaa 112 8 5 Tips for obtaining morphometric measures esses nnne enne nn nnns 112 8 6 References oA EAR RE REFER eel UY eee ele 115 Appendix E MSMS Files and Directory Structure ccccccccccecssssssssecececscsssesneaeeeeeesseesessaeeeeeesseeseea 117 9 1 Model Directory iR Du 117 9 2 Common Image Directory aineisiin nsien anaa eraen aei p ia idea ea Ka
97. ool are driven by a common activation signal U Motor units are recruited sequentially based on the recruitment rank of each fiber type and their relative size As U increases more motor units are recruited until U is reached this is the point at which all motor units have been recruited increases in activation beyond this point result only in frequency modulation of motor units Motor unit recruitment threshold is determined based on a combination of the cumulative fractional PCSA of all motor units recruited prior to the given motor unit with range of recruitment between 0 and U as depicted in the figure below As an example the first two compartments are slow twitch and are thus recruited first and the U for the muscle is 0 8 Note that while it appears that both slow and fast twitch motor units have the same firing frequency range recall that fmin and fmax are in units of fos and that fo 5 has different values depending on fiber type 107 Firing Frequency f Lo s Un Uy Ug Un Un U 6 U 1 Activation U 0 1 For each motor unit the frequency modulates from a predetermined fmin when the unit is first recruited up to fax which occurs at a full activation for the muscle This linear change in firing frequency change relative to change in EMG has been demonstrated experimentally e g Milner Brown et al 1973 The common initial firing frequency for motor units of a given fiber type and the convergence of their
98. ound 1096 of the muscle first recruited units should be smaller than later recruited ones as in real muscle This will generally produce an acceptably smooth force modulation because of two features built into the model 1 The model motor units always produce a smooth output force even at sub tetanic frequencies simulating the force that would have been produced by a large number of asynchronously active motor units all firing at the same sub tetanic frequency 103 The normal range of frequency modulation results in about a 4 1 range of force modulation so the force step contributed by a newly recruited motor unit is relatively low until it gradually increases its firing frequency as activation of the muscle increases further If a muscle is compartmentalized in its mechanical actions and or different neural activation is desired for each compartment each such compartment should be treated as a separate muscle within the model For simplicity throughout this document the term muscle will be used to denote a single neuromuscular entity with a unidimensional command signal and a homogeneous mechanical action Modified Hill type model ga actie Semel seis mass active contractile series elastic element A given muscle consists of three interacting elements the contractile element a series elastic element and a muscle mass The contractile element and series elastic element both act on the muscle mass which has inertial proper
99. ped unit in order to match the total Af of a realistic ensemble of motor units The effective frequency input fer to the Af relationship is determined by calculating the stimulation frequency feny first which is directly proportional to the neural drive U if U is greater than the firing threshold A second order low pass filter whose exact form depends on fascicle length and activation is then applied to feny to obtain fer Because Af and FL together provide a measure of the number of cross bridges they also affect the energy related to cross bridge cycling E They are used to scale the tetanic EV relationship obtained experimentally at optimal sarcomere length The energy related to excitation E is simply a function of stimulation frequency which is added to E to obtain the total energy consumed during the initial phase of contraction Ejnitia This energy represents the amount of ATP and PCr molecules consumed and therefore determines the energy needed to resynthesize them E ecovery The sum of Ei and Erecovery iS the total energy consumed 105 Neural Drive U Stimulation o frequency g x Sag Yield aa REN Weighting ost L Af feny wit u function Rise and fall time do elastic Thick filament gt ee Force Velocity element compression ij res Fresa Fo Fpe1 Af Fpez Total parallel elastic force Af L fer S Y Activation force relationship Active contractile force
100. pter 3 you will learn about all of the menus and their typical usage In chapter 4 the graphic user interface for editing the properties of the MSMS model components are described Finally the Appendices provide more detailed information on important MSMS features and capabilities To see what is new in this version of MSMS see the revision log in Appendix H 1 2 Minimum System Requirements e Operating system Windows XP Windows 7 32 bit Windows 7 64 bit e 512MB of RAM or higher e Processor speed of 1 2GHz or higher recommended e Graphic card with 512 MB or higher For stereoscopic display 3D stereo graphic cards are available from NVIDIA and ATI 1 3 Installation Procedure MSMS is distributed through a single compressed zip file To install MSMS unzip the compressed file to get the executable installer Then run the installer and follow the instructions 1 4 Key Features e Interactive tools for building and validation of human and prosthetic limbs and models of the objects in the task environment e Tools for importing existing models from OpenSim SIMM and SolidWorks e Tools for physics based simulations in Simulink e Tools for simulations in real time virtual reality environments with the subject in the loop e Tools for animation of models off line or in real time e Tools for building animations of activities of daily life in PowerPoint 10 2 Starting MSMS 2 1 Using Windows Shortcuts Click on the MSMS shortcut in Windows sta
101. rameters in the S function parameters field If the S function block requires additional source files for building generated code specify the filenames in the S function modules field Enter the filenames only do not use extensions or full pathnames e g enter src src1 not src c srci c Parameters S function name MSMS Pack S function parameters uint8 uint8 int16 int16 uint8 S function modules additional source files for building generated code specify the E User definable block Blocks can be written in C MATLAB Level 1 and Fortran and must conform to S function standards The variables t x u and flag are automatically passed to the S function by Simulink You can specify additional parameters in the S function parameters field If the S function block requires filenames in the S function modules field Enter the filenames only do not use extensions or full pathnames e g enter src srci not src c srci c Parameters S function name MSMS UDP Send Edit S function parameters 127 0 0 1 11114 1 0 01 S function modules m Help Apply ok cancel Note If you plan to run the Simulink model in a regular non real time PC you don t have to purchase Matlab s xPC Target toolbox that has the ChangeEndianess Pack and UDPSendBinary blocks You can instead use MSMS versions of these blocks as shown in the figure These blocks use
102. re to use an already highlighted segment as parent when creating a new segment using the segment creation wizard Added a feature to the Simulink model to automatically create a MSMS compatible motion file after completing a simulation Fixed the problem with MSMS objects that were leaving black shadows behind when they were made invisible or hidden Added a feature to allow the user to keep their changes to MSMS created Simulink blocks when they create new Simulink blocks in MSMS Made many minor improvements and bug fixes Simplified the steps to select and open a MSMS model Added on screen hints on how to manipulate and navigate MSMS model Improved joint axes display Segments centers of mass are now displayed when they are selected Made many minor improvements and bug fixes Added a plotter to plot the anatomical data of Ligaments Added a feature command to animate muscles color as a function of their activation levels Added right click menu items to edit remove show and hide a component in model window The user can also display only or display all components of the same type Fixed an issue with anatomical data plotter that was producing noisy data when the joint controls panel or joint properties panel were open 131 Fixed an issue with muscle path code that was wrongly complaining that there should be muscle points on either side of a wrapping object even though there were Fixed issues with the use of mouse to tra
103. red line and release at the insertion point to create a muscle with straight line path between the origin and insertion points A panel showing the current and default morphometric properties of the muscle will open e f necessary click on the muscle path and drag to a point on a segment and release to create new via point Repeat as needed While adding new via points the contents of the muscle properties window will be update to reflect the new path e f necessary click on a wrapping object and then click on a muscle segment This associates the wrapping object with that segment of the muscle Repeat as needed While adding wrapping objects to the path the contents of the muscle properties window will be update to reflect the new path 29 Once the desired path is drawn enter the remaining morphometric parameters and click Apply Use the current muscle lengths as a guide to come up with reasonable values for optimal muscle and tendon lengths and the mass Click OK to close the Morphometry window This will bring up the Fiber Types window In the Fiber Types window select whether you want the muscle model to output energy consumption or model proprioceptive sensors muscle spindles and Golgi tendon organs select the recruitment type and the muscle fascicle s fiber composition Click OK to complete the muscle creation wizard and create the new muscle 30 3 3 13 Add Ligament This command will bring up the ligament creation wi
104. rge ranges of motion may not be correctly modeled using this simple approximation This condition is beyond the scope of the current discussion 8 6 References Brown I E 1998 Measured and Modeled Properties of Mammalian Skeletal Muscle Ph D Thesis Queen s University Brown I E Cheng E J and Loeb G E 1999 Measured and Modeled Properties of Mammalian Skeletal Muscle Il The effects of stimulus frequency on force length and force velocity relationships J Musc Res Cell Motil 20 627 643 Brown I E Liinamaa T L and Loeb G E 1996 Relationships between range of motion Lo and passive force in five strap like muscles of the feline hindlimb J Morphol 230 69 77 Brown I E and Loeb G E 2000 Measured and Modeled Properties of Mammalian Skeletal Muscle IV Dynamics of Activation and Deactivation J Musc Res Cell Motil 21 33 47 Burke R E Levine D N Tsairis P and Zajac F E 1973 Physiological types and histochemical profiles in motor units of the cat gastrocnemius J Physiol 234 723 48 Close R I 1972 The relations between sarcomere length and characteristics of isometric twitch contractions of frog sartorious muscle J Physiol 220 745 62 De Luca C J Foley P J and Erim Z 1996 Motor Unit Control Properties in Constant Force Isometric Contractions J Neurophysiol 76 1503 16 Henneman E 1968 Organization of the spinal cord In Mountcastle B ed Medical Physiology 12 ed St Louis C V
105. ription of the prosthesis part of the mode My Model Model Worlds world xml description of the world part of the mode Optional A model may contain a local image folder My ModellModell Images stores local images 3D meshes and textures of the model If the model uses only MSMS s primitive shapes or obtains its images from a common image directory see below then this folder will not be present When loading a model MSMS first searches this directory and subdirectories for images and if it cannot find the required images it will search the common image directory and subdirectories Each image is given its own subdirectory that contains all the files necessary to produce the image e g an image subdirectory might include an obj file an mtl file and several jpg texture files Optional A model may contain simulation folders My Model Setup contains the simulation parameters My ModellMatlab contains the Simulink model created by MSMS When the Simulink model is run it will produce simulation data that are also saved in this directory Optional A model may contain a view file My Model Model View xml The view file contains data that only pertains to the viewing of the model This data does not define any aspect of the model itself If a model does not contain the view file MSMS will create it when the model is saved Examples of the contents of the view file are 1 Flag indicating if the ground axes are displayed 2 Back
106. rt menu 2 2 Using Command Line Interface To run MSMS from command line use the following syntax runmsms Model Folder A Live Data Stereo 3D Fullscreen Installation Folder Where Model Folder Directory name where the MSMS model resides directory name must be in quotes A Tells MSMS to start in Feature Command animation mode Live Data Controls head tracking mode use arguments ON or OFF Stereo 3D Controls stereo mode use arguments ON or OFF Fullscreen Controls full screen mode use arguments ON or OFF Installation Folder MSMS installation folder Example runmsms c models mymodel a on off off C MSMS MSMS 1 0 NOTE The command line is designed primarily to quickly put MSMS in animation mode so that it can receive and animate the motion data from the UDP port In this mode some editing functions may not function properly Therefore if you plan on editing your model start MSMS from Windows start menu 11 2 3 MSMS Graphic User Interface File View Model Simulation Animation Help sa9 o E PARADA RINA Mennad n e sm Model Explorer 4 Human Right Arm Segments C3 ground E Trunk Er clavicle humerus B ulna E radius right hand Joints GlenoHumeral Ground Trunk HumeroUlnar RadioCarpal RadioUlnar SternoClavicular Actuators Sensors gt gt 5 Wrapping Objects amp a Edit Cameras E bolts p Show Elastic Elements
107. s familiar to most clinicians The assumption here is that a MSMS model has been built and a library of compatible motion files have been created and stored in the models ADL folder The steps below describe how to create an ADL sequence in PowerPoint and animate it in MSMS This will be followed by a more detailed set of rules for the use of PowerPoint to create ADL sequences 1 Open the PowerPoint and create a new presentation 2 Insert a new slide and in the new slide insert an image corresponding to the movement you like to animate first in the ADL sequence For this you will need to brows to your MSMS model s ADL folder and select one of the images Insert Picture Look in 5 adi My Recent Documents Desktop am Documents erac igrasp movement segl jigrasp movement seq grasp movement jpg pause JPG M AS a My Network Places File name v Files of type all Pictures emf wimf jng jpeg jfif jpe png bmp dib rle bmz gif gfa emz Tools Cancel 3 Repeat step 2 as many times as necessary to insert new movements into the ADL sequence 4 Once the ADL sequence is complete use Save As menu item to save the PowerPoint presentation into the model s ADL folder in XML format as shown in the image below see the highlighted selection 98 Save in c a My Recent Documents Desktop av Documents g Computer 9 My Network p
108. s and will keep the 40 user blocks intact If you choose not to keep your changes MSMS will delete the user blocks from the Simulink model 41 3 5 Animation Menu Includes the tools for animation of the MSMS models using motion data stored in files or motion data sent to MSMS via a live source in real time File View Model Simulation Help SE e bm seu Ctrl Shift C by Model Explorer b Start Ctrl Shift G Human_Right_Arm Pause Ctrl Shift H Segments B Stop Ctrl Shift V Joints Actuators Parse ADL File Sensors 2 3 4 Wrapping Objects Write Motion File Cameras P Lights Display Rendering Stats Ctrl Shift J Elastic Elements Toggle Rendering Stats Display Hz or ms Ctrl Shift K 3 5 1 Setup Here you can setup the animation by selecting the source of animation data and its parameters This setup enables MSMS to load motion data from a file or prepares it to receive the motion data from a live stream After this setup the Start Pause ands Stop buttons will be activated From File The animation data will be read from a motion file in one of two formats SIMM OpenSim motion file mot and MSMS motion file msm For more information on supported motion file formats see Appendix A You can also select the speed of animation Replay Duration The duration of replay as the percentage of the real animation time To play it in real time set the Animation Duration to 100
109. s completely inelastic sticky Currently this parameter is not used by MSMS s collision algorithm Softness Softness is a value between 0 and 1 and determines how deformable the segment is Currently this parameter is not used by MSMS s collision algorithm Normal Force Spring Constant Spring constant used to calculate the elastic component of the normal collision force Normal Force Damping Constant Damping constant used to calculate the damping component of the normal collision force Friction Force Spring Constant Spring constant used to calculate the elastic component of the static friction force in contact Friction Force Damping Constant Damping constant used to calculate the damping component of the static friction force in contact Static Friction Coefficient 0 0 Dynamic Friction Coefficient 0 0 Coefficient of Restitution Not Used 0 0 Coefficient of Softness Not Used 0 0 Normal Force Spring Constant N m 0 0 Normal Force Damping Constant N s m 0 0 Friction Force Spring Constant N m 0 0 Friction Force Damping Constant N s m 0 0 ox ces J w j Heb To learn more about collisions in MSMS see Appendix G 48 4 1 4 Image To provide the maximum flexibility in designing the appearance of the segments MSMS allows the users to add any number of shapes to represent a segment These shapes can be individually added removed edited and positioned on a segment By d
110. s variable the data will be exported into multiple files each containing only one X variable e Youcanselect one or more curves form the Curve list and click Remove to delete them from the plot e Clicking on Clear deletes all the curves in the plot e You should select the increment for the X Axis with care Large increment reduces the data points that must be calculated and is faster But the curves will not be smooth More importantly the moment arm and moment curves that require numerical differentiation of the muscle length will be noisy A very small increment on the other hand may take a long time to plot because many more data points must be calculated So use the default value for the increment unless it produces noise curves or takes too long to plot 3 3 15 Plot Anatomical Data for Ligaments This command will open the anatomical data plotter for ligaments The operation of the ligament plotter is similar to the muscle plotter see section 3 3 14 above 34 3 3 16 Scale Segment This command allows you to scale a segment that has joints on both proximal and distal ends The scaling is done along the axis connecting the proximal and distal joints of the segment Model Explorer Human Right Arm Segments Joints GlenoHumeral Ground_Trunk HumeroUlnar RadioCarpal RadioUlnar SternoClavicular Actuators Sensors Wrapping Objects PTWrap SUPWrap Cameras Lights Elastic Elements
111. sculotendon path length Lmax to determine fascicle Lmax This term scales the passive force produced by the contractile element which will be discussed later It is important that the actual fascicles for the muscle you are studying are measured and not simply the muscle belly length or the whole musculotendon path length Commonly muscle belly length is reported in literature but this is usually an inaccurate representation of fascicle length for muscles with even a minimal pennation angle An additional factor is that the fascicles must be at Lo the length that provides maximal tetanic force It is inaccurate to assume that Lo will occur when muscle is at the midpoint of its range of motion for example cat hindlimb muscles typically function at lengths slightly below Lo Similarly it is inaccurate to assume that Ly is the length at which peak twitch force is evoked as that length is typically 10 3096 longer than Lo Close 1972 Roszek et al 1994 Brown and Loeb 1998 Short of using actual tetanic stimulation and force recordings from the subject muscles we use the following technique to obtain Lo Fix the muscle in situ and measure its fascicle length Next excise bundles of a few muscle fibers mount them with glycerol and coverslip them and examine them under a light microscope at approximately 400x magnification Using a calibrated measuring graticule it is possible to obtain measures of sarcomere lengths in the fixed muscle This v
112. ser to view and edit a number of related properties of the joint 4 2 1 General Name A unique name for the joint such as Elbow Group All the components in a model are divided into three groups human prosthesis and world You can set a component s group using this drop down list Name HumeroUlnar Group HUMAN 56 4 2 2 Segments Proximal Segment Name Selects the proximal segment for this joint Joint Center Offset Sets the joint center offset in proximal segment s local reference frame Distal Segment Name Sets the distal segment for this joint Axes Motion Passive Joint Moments Image Proximal Segment Joint Center Offset X 0 0 m Name humerus v Y 028 m Z 0 0 m Distal Segment Name ulna ok cancel Any Web 57 4 2 3 Axes Joint Type Sets the type of the joint Translational Axes Sets the name and axes of the translational degrees of freedom of the joint Click the numbered button next to the name field to set the minimum maximum and default values Rotational Axes Sets the name and axes of the rotation degrees of freedom of the joint Click the numbered button next to the name field to set the minimum maximum and default values Motion Passive Joint Moments Image Joint Type Planar Translational Axes Name Axis Vector meters nium 1 HumeroUlnar X mun 2 HumeroUlnar Y Rotatio
113. t MUST be included as well Let s consider a hip joint that has three dofs hip add hip flex and hip rot If for example hip flex is included in the header then for the motion file to be valid both hip add and hip rot must also be included in the header e Each DOF in the header identifies a data column which describes the motion data for that DOF 86 e The DOF names in the header do not have to be listed in any specific order For example the header rows below are both valid TIME Joint1 Tx Joint1 Ty Joint1 Tz Joint1 Rx Joint1_Ry Joint1 Rz Joint2 FE Joint2 AbAd Joint2 Rot TIME Joint1 Ty Joint1 Tz Joint1 Tx Joint1 Rx Joint1_Rz Joint1 Ry Joint2 AbAd Joint2 Rot Joint2 FE 5 1 2 Format of the data rows e The number of the data rows that follow the header are not limited e The number of the entries in each data row must match the number of the labels in the header and must follow the same order e Data entries in a row are separated by spaces e All numerical values will be stored as double precision floating point e Each row of data must be on the same line each line ends with an end of line EOL character s which is dependent on the operating system e The unit for the time data in the first column is second e The units of data for rotational and translational DOF are in degrees and meters respectively The reason for using degrees instead of the SI unit for angular position radians is that it is more intuitive for t
114. tep or Variable step the type of the numerical integration algorithm and the numerical integration step sizes and tolerances These will be passed to the automatically created Simulink model You can also change these parameters later in the Simulink model These solver parameters are important for the physics based simulation and must be chosen with care For more information on choosing the right solver options for your specific model consult the Simulink documentation 38 Solver Dynamic Engine Output Data Simulation Time Start Time 0 0 sec Stop Time 10 0 sec Solver Options Integration Type Variable Step Solver ode45 Dormand Prince Min Step Size 1 0E 16 sec Absolute Tolerance 1 0E 6 Max Step Size 0 0010 sec Relative Tolerance 1 0E 6 Initial Step Size 1 0E 16 sec 3 4 1 4 Dynamic Engine Here the dynamic engine can be chosen Currently Matlab s SimMechanics is the only supported dynamic engine 3 4 1 5 Output Data Here you can select how the simulation data will be stored in a file or send via UDP to MSMS for animation General Setup Solver Dynamic Engine Output Data Storage In File Sampling Time 0 01 sec Output Data Filename MotionData mat Live Animation Sampling Time 0 01 sec Data Streaming Method Q MSMS UDP Block xPC UDP Block Requires xPC Target Toolbox Data Type Q Feature Commands gt Ordered Joi
115. text in 3D window see Appendix B The Edit window for Ordered Joint Angles allows you to select the UDP port number through which the live source and MSMS will send and receive animation data respectively In addition you can select Use Live Data for Camera Positioning if the live source will send data to control the position and orientation of the camera 43 3 5 2 Start This command starts animation It will be active after the animation is Setup 3 5 3 Pause This command pauses animation It will be active after the animation is Setup 3 5 4 Stop This command stops animation It will be active after the animation is Setup 3 5 5 Parse ADL File This command allows you to convert an animation sequence built in Microsoft PowerPoint to the msm motion file format that can be animated in MSMS For more details on how to build complex animation sequences in PowerPoint see Appendix C 3 5 6 Write Motion File This command allows MSMS to create a msm motion file with single frame of data corresponding to the current posture of the model in MSMS There are two potential uses for these motion files First because these files have the correct motion file format they can be used as starting point to manually create new motion files Second motion files created in the start and end postures of a movement can be used to create primitive motion files that interpolate the frames in between these two postures For more details see Appendi
116. th similar applications and issues who might find them useful 12 1 Blanking the model screen One of the MSMS users who employ MSMS to display virtual objects to the monkeys in cortical control experiments needed the ability to make the MSMS model disappear by clicking on the spacebar in the keyboard This feature is implemented in MSMS and can be enabled by the interested users by adding the following line to msms properties file kpaulEnabled msms properties file is located in MSMS root directory and can be edited by any text editor such as Notepad The presence of this line will direct MSMS to enable the blanking feature To use this feature open a model and repeatedly press on the spacebar to switch between the model and the blank windows For this to work the focus must be on the model area which is done by clicking once in the model area 12 2 Writing animation events to file The same MSMS user who employed MSMS to display virtual objects to the monkeys in cortical control experiments also needed the ability to record the sequence of the following MSMS animation events in a text file 1 Animation packet received 2 Rendering started 3 Rendering completed 4 Ready to receive packet This feature is implemented and if it is enabled it will write the occurrence of the above events represented by their respective numbers into a text file 124 To enable this feasture Create an empty text file e g myevents txt
117. the skeletal system Addition of Proprioception and Energetics to muscle models New tools for live animation in PCs with no xPC Target toolbox Many bug fixes and improvements Added new tools to show hide all segments muscles and wrapping objects Fixed the backward compatibility with older model files Fixed issues with the change of joint types Fixed issues with updating muscle path when a wrapping object is created or deleted from the model Fixed the MSMS bug that was leaving the open dialogs open even after the model is closed Fixed the bug that was preventing MSMS from creating Simulink models when the ordered joint angles was selected Organized the DOF names in the joint slider panel in alphabetical order 130 8 8 11 2 20 12 5 11 2012 9 20 2012 Added segment muscle ligament creation wizards Added import tool for OpenSim Added anatomical data plotter tool Added show hide tools for segments muscles wrapping objects Improved the GUI Reorganized the tutorials and added video instructions for the tutorials Made many minor improvements and bug fixes Added collision detection and handling that runs in both 32 and 64 bit version of Matlab Upgraded the Simulink conversion utility to export models with collision enabled segments Added a feature to allow changing of individual muscle or ligament Added a feature to display the progress and the folders searched for images when opening a model Added a featu
118. ties to prevent instabilities from arising within the muscle The contractile element in effect consists of as many smaller contractile elements as are defined by the number of motor units each of which has a passive parallel elastic element an individually defined firing frequency and force length velocity relationships as determined by the fiber type properties The parallel elastic element includes a small viscosity for the purposes of stability These active sub compartments sum together to produce the total contractile element force 8 1 3 Interactions with Neural and Skeletal Elements The interaction between the muscle model and dynamics model is two way The muscle blocks produce output force which is used by the dynamics model to produce changes in kinematics These kinematic changes are then passed back to the muscle model as changes in muscle length which in turn result in 104 changes in muscle force Concurrent with this data exchange must be a source of neural activation for the muscles This presumably will arise either from a data file of pre recorded or pre generated activations possibly from EMG data or from a control model built in SIMULINK or MATLAB that will generate the activation for each muscle As discussed in 16 2 1 2 it may be necessary or appropriate to create a nonlinear scaling function between the source data and the activation applied to the model 8 1 4 Summary of Virtual Muscle s formulations The schematic
119. tories sounds etc 90 6 2 1 Packet Protocol for Feature Commands The animation data is sent to MSMS via UDP communication which is a packet oriented protocol UDP sends packets and does not keep track of them The latest packet received by MSMS is considered to include the most recent data Each packet includes the following basic structure LID F V ID F V ID F V Where ID Identifier Identifies an object in MSMS model F Feature Indicates which feature of the object is to be modified V Value Specifies the value s of the specified feature This elementary set of data is general enough to deal with motion data but also allows changing physical properties of objects such as color and size Data is sent using big endian protocol where the most significant byte of multi byte words is transmitted first Note that a single packet can contain feature value pairs for different objects and as many pairs as will fit within the packet size constraints The Value is specific to the feature it characterizes The number of entries and their types are variable The required values for each attribute are described below Identifier The Identifier ID is composed of two characters followed by a signed 16 bit integer number as defined below The characters identify the type of component and the integer is unique value attributed to that component The combination of both the component type and
120. ude corresponds approximately to the total physiological cross sectional area of its muscle fibers This assumes that the recorded action potential reflects the total action current which is the sum of the synchronous action currents in each muscle fiber The action current generated by a spike in a simple cylindrical conductor such as an unmyelinated axon tends to depend on diameter i e surface area rather than cross sectional area but the action currents of muscle fibers may scale more closely to their cross sectional area because of active conduction down the transverse tubules Fortunately the range of muscle fiber diameters is relatively small with more of the range in motor unit size related to innervation ratio number of muscle fibers per motor unit Unfortunately the recorded EMG is not a simple linear summation of these unitary action potentials because of occlusion the tendency of biphasic action potentials to cancel each other when their opposite polarity phases happen to overlap The higher the aggregate rate of action potentials the more likely they are to be partially occluded before they can contribute to the recorded AC waveform whose area under the curve is taken to represent activation This would suggest that the recorded EMG should be squared to more accurately reflect the underlying total muscle activation Thus this effect might be expected to counteract the above noted suggestion that you should use the square root of
121. urrent Length 9 48761 cm Force at 5 Stretch 100 0 N CT 27 8 KT 0 0047 LRT 0 964 44 4 Image Here you can change the color of the ligament or select to show hide it The ability to change the color of ligaments individually allows you to highlight a specific ligament ora group of ligaments 71 4 5 Wrapping Object 4 5 1 General Name A Unique name for the Wrapping Object Group The group to which wrapping Object belongs It can be Human Prosthesis or World X Name BICWrap Group HUMAN 4 5 2 Type Shape Select the shape of the Wrapping Object Cylinder Sphere or Ring Radius Set the radius of the Wrapping Object Height Set the height of the Wrapping Object for cylinder type only Shape Cylinder Md Radius 0 019 m Height 0 01 m ok J cene App Heb 72 4 5 3 Pos amp Ori Segment Select the parent segment to of the wrapping object Position set the position of the Wrapping Object in its parent s reference frame Orientation Set the orientation of the Wrapping Object in its parent s reference frame Segment humerus Position Orientation Rx gt Ry gt R X00 m 0 0 deg Y 0 27 m Ry 90 deg Z 0 04 m Rz 0 0 deg ok J cancel apply Heb 4 5 4 Path Components This window shows the list of muscles that are currently using this wrapping object in their path 73 4 5 5 Image Surface Color Sets the color o
122. uscle at optimal fascicle length from which it is extrapolated to untested conditions based on well characterized physiological processes that compose the muscle force model see Tsianos et al in press for details Within the SIMULINK muscle block energy consumption is computed separately for each motor unit according to its firing frequency and kinematic behavior Energy consumption is partitioned for each motor unit into physiological processes corresponding to cation pumping related to excitation E and cross bridge cycling related to force production Ex The muscle block in SIMULINK consists of separate outputs for E and E for slow and fast twitch fiber types according to the selected recruitment scheme It also consists of an output representing the total energy consumption rate Ej assuming that energy related to metabolism is consumed in phase with the contraction The actual dynamics of metabolic processes are captured by the output labeled Erec w ay 8 4 Proprioception If the proprioception feature is selected for a particular muscle then the muscle block in SIMULINK will include formulations that estimate the behavior of muscle spindles Mileusnic et al 2006 and Golgi tendon organs GTO Mileusnic amp Loeb 2009 The muscle spindle model generates a response depending on fascicle kinematics and fusimotor excitation with separate gamma static and gamma dynamic control of length and velocity sensitivity respectively The model inc
123. x C 3 5 7 Display Rendering Stats When a model is animated in MSMS this command will display the rendering statistics in status bar By default the rendering rates in Hz will be displayed You can use this feature to see how fast MSMS and your visualization PC can render a specific model This evaluation can help you take actions such as simplifying the model or acquiring faster video cards if necessary to animate your model in real time 3 5 8 Toggle Rendering Stats Display Hz or ms This command toggles the display of the rendering statistics between rendering rates in Hz and rendering periods in ms For this command to work the Display Rendering Stats command must be selected first 44 3 6 Help Menu Ms File View Model Simulation Animation Help ld D S M m A EZ 9 MSMS User Guide Model Explorer Report Bug JE Human_Right_Arm Request Feature c Segments Joints Actuators MSMS Web Page Sensors MSMS Discussion Group Wrapping Objects About MSMS Cameras H Liahts 3 6 1 MSMS User Guide This command opens this document 3 6 2 Report Bug This command opens your default email application and allows you to report MSMS bugs and defects to the MSMS development team 3 6 3 Request Feature This command opens your default email application and allows you to request new MSMS features 3 6 4 MSMS Web Page This command opens the MSMS web page
124. zard The wizard allows you to quickly add a ligament and interactively configure its path and properties Simulation Animation Help na A E CO p D OD CO D RARA S en m IC es FSI fii FU Model Explorer Human 3D Arm H Segments Joints 4 Actuators Sensors Wrapping Objects Cameras Lights Elastic Elements amp Properties for Ligament Name New Ligament Resting Length 9 48761 cm Current Length 9 48761 Force at 596 Stretch 1 0 N CT 27 8 KT 0 0047 LRT 0 964 Cancel Apply Help After selecting this command the cursor will turn into a red cursor You can follow steps similar to those in Add Muscle above to interactively create new ligaments e Click to select origin then drag as red line and release at the insertion point to create a ligament with straight line path between the origin and insertion points A panel showing the current and default properties of the ligament will open e f necessary click on the ligament path and drag to a point on a segment and release to create new via point Repeat as needed While adding new via points the contents of the properties window will be update to reflect the new path 31 If necessary click on a wrapping object and then click on a ligament segment This associates the wrapping object with that segment of the ligament Repeat as needed While adding wrapping objects to the path the contents of th

MSMS 2.2 User`s Guide - Medical Device Development

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