5. symbols used on emg16 and in the user manual
Contents
1. TAB 1 Connection modalities for the detection probes on EMG16 As shown it is possible to acquire signals simultaneously from two or four different probes this can be useful in case of investigation on different muscles at the same time pag 6 EMG 16 User Manual v3 1 Using the front panel keyboard or the acquisition software EMGACQ II it is possible to choose the number of probes and assign a gain value to each when the signals are detected from different muscles e g biceps brachii or upper trapezius it can be necessary to set a different gain level for each probe in order to have best quality recorded signals and exploit the full range of the A D converter EMG16 technical specifications are shown in TAB 2 below EMG channels Maximum input range 20 mVpp Gain 100 Bandwidth 10 500 Hz 4 order Bessel band pass filter Total noise RTI lt 0 7 uVrws differential lt 1 0 uVrms monopolar Selectable gain 100 200 500 1000 2000 5000 10000 20000 50000 Input impedance gt 90 MQ on the entire bandwidth CMRR gt 96 dB 103 dB typical Crosstalk between channels lt 75 dB monopolar and differential Insulation voltage 4000 Voc Auxiliary channel Mode torque force Load cells supply voltage 5 Vpc Gain 300 both channel A and B Bandwidth 0 65 Hz Output voltage Vu 300 S4 5V F1 FS Sa 5V F2 FS2 Output voltage ra2. as power supply range and fuse type This label must never be removed pag 14 EMG 16 User Manual v3 1 RS232 connector This connector is reserved for assistance operations It must not be used A NOTE connecting other devices to EMG16 through this connector can cause damages to the device ACQUISITION BUS connector This is a SCSI II type connector used to connect with the supplied cable the data acquisition card in PCI National Instruments PCI6045E or PCMCIA format National Instruments DAQ6045E supplied with the EMG16 amplifier AN NOTE the use of acquisition boards different from that supplied with the electromyograph can cause malfunctions and damages to the acquisition board and to the amplifier For further information about the use of other possible acquisition systems contact the Technical Support Service of OT Bioelettronica BLANKING INPUT connector This BNC type connector is used to connect the EMG16 amplifier to a compatible neuromuscular stimulator to allow EMG signal acquisition during electrically elicited contractions This input works with digital TTL compatible signals 0 5V coming from the stimulator that drives the internal blanking circuitry When the BLANKING signal is active 5V the amplifier stages are inhibited to prevent saturation and transients caused by the stimulation pulse A NOTE for further information about the joint use of the electromyograph with neuromuscular stimulators a
3. the lack of this connection prevents the correct acquisition of the EMG signal If a monopolar mode signal acquisition is planned Mode Monopolar connect another strap to the DRL IN plug using the enclosed cable The strap has to be wet with water to assure a good electric contact with the patient and has to be connected on a point without any electromyographic activity next to the patient ground strap e g the ankle or the wrist FIG 12 A NOTE the lack of this connection prevents the correct acquisition of the EMG signal in monopolar acquisition mode Mode Monopolar In case of high level interference during a monopolar mode signal acquisition Mode Monopolar caused by the presence of electrical equipment isokinetic machines or other electrical devices working in proximity of the amplifier it is necessary to connect another ground strap to the DRL OUT plug with the enclosed cable wetting it with water to assure a good electric contact with the patient and fixing it on a point without electromyographic activity e g the ankle or the wrist next to the straps connected to PATIENT REF and DRL IN plugs After these operations it is possible to continue with the next subsection MEASUREMENT EXECUTION pag 22 EMG 16 User Manual v3 1 Electromyograph yograp PATIENT REF Patient wrist Patien reference Enclosed strap cables Probe adapter FIG 11 Patient connection diagram for single differential
4. ACQUISITIONS Example screen Problem Saturated signals on all the channels Possible cause Reference strap is not connected Solution Connect the reference strap to PATIENT REF plug FIG 11 One channel not corresponding to the innervation zone indicated by the red arrow in the figure is weak or zero Two consecutive electrodes are short circuited SILVER BAR ELECTRODE ARRAY dry the skin and the array ADHESIVE ARRAY remove the adhesive array change the foam clean and dry the skin and reapply the array Signals on some channels are floating and unsteady Bad electrode skin contact under those electrodes SILVER BAR ELECTRODE ARRAY slightly wet the skin and the array press the array on the skin along its full length ADHESIVE ARRAY add some gel 10 ul recommended into the corresponding electrode holes Press slightly The signal is noisy and there are periodic or burst interferences superimposed to the signal Neon lamps with incorrect power factor interference 100 Hz burst interference Turn off sequentially the lights and identify the lamp s that cause the interference In a second time correct the power factor of those lights Computer monitor interference in particular LCD displays operating in proximity of the amplifier Move the electromyograph away from the display Notebook or desktop PC power supply interference Move the no
5. DRL OUT straps to the respective plugs FIG 12 and FIG 13 if the power line interference is not too high only the use of the DRL IN strap could be enough FIG 12 Monopolar EMG signal is clearly visible but it is superimposed with a suspicious power line interference High level power line interference and DRL OUT not connected Connect the DRL OUT strap to the relative plug FIG 13 After that if the signal loose many of those synchronous components keep on the DRL OUT strap TAB 7 Troubleshooting of the problems that can occur using the electromyograph in monopolar mode acquisition all the screens lasts 200 ms and the amplifier gain is set to have the best signal quality All the example signals are acquired with a 16 electrode array 10 mm interelectrode distance on biceps brachii muscle These problems may occasionally appear also in the differential mode configuration and are solved in the same way pag 38 EMG 16 User Manual v3 1 SIGNAL ACQUISITION DURING ELECTRICALLY ELICITED CONTRACTIONS DIFFERENTIAL MODE Problem Stimulus artifacts are visible before the M waves Example screen Possible cause Blanking time is too short Solution If it is possible increase the blanking time on the neuromuscular stimulator Stimulus artifact is partially or totally superimposed with the M wave that is no more recognizable There are no stimulus artifacts but the M w
6. also using instruments equipped with two sensors A DC offset compensation circuitry EMGACQ II software controlled can be used to compensate a residual force torque due for example to the weight of the limb For further information about this option refer to EMGACQ II user guide Of course it is possible to acquire the signal coming from just one transducer sending to the second input a zero signal In case of two sensors the voltage signal acquired on channel 16 can be evaluated as follows Vu 300 Si 5V F FS S2 5V F2 FS2 where S and S are the sensors sensitivity expressed as Vrs Vsuppry full range generated voltage for each volt of the load cell supply voltage F and F are the generated forces or toques and FS and FS are the full range forces or torques for each sensor Each cell is supplied with a voltage of 5Voc This is not true when using a circular array as well as in the case of EMG rectal and urethral probes In that case the channel 16 represents the single differential signal detected between electrode 16 and 1 pag 17 EMG 16 User Manual v3 1 In case of one sensor the voltage signal acquired on channel 16 can be evaluated as Vu 300 S 5V F FS where S is the sensitivity of the sensor F is the measured force or torque and FS is the full range force or torque value The output voltage Vu is directly acquired from the acquisition board with a maximum output voltage ra
7. be stored with all the enclosed accessories on a safe desk far from all the situations listed in the section Warnings EMG 16 has to be stored in the following ambient conditions Temperature from 20 C to 40 C Maximum relative humidity 75 Atmospheric pressure from 0 7 atm to 1 1 atm Cleaning use only a dry cloth to clean the device AN WARNING it is recommended to clean the probes with a disinfectant solution alcohol or other before using them on a different subject It is recommended to plan a device check every 24 months with the manufacturer The EMG16 can not be repaired by manufacturer external staff Every repair executed by unauthorized staff will be understood as a device violation releasing the manufacturer from the warranty and from the risks that can occur to the operator Disposal For nature preservation the device and the accessories have to be disposed in compliance with the relative standards in special equipped areas or with special waste pag 40 EMG 16 User Manual v3 1 11 TECHNICAL CHARACTERISTICS Risk class Insulation class Classification Case Power supply Consumption Limitations Working conditions Protections Input channels Amplifier Visualization Commands Dimensions Weight Maintenance and storage CE 0476 IIa in compliance with the standard 93 42 CEE BF type applied part in compliance with the European standard EN 60601 1 c
8. may be found by EMG16 users with some suggestions to solve them In case of problems that could have different causes these are listed in a decreasing order of importance If the problem is referred to the acquisition of the EMG signal an example signal screen of a duration of 200 ms is reported TAB 4 shows some example of signals properly acquired in the three modes differential monopolar and during electrically elicited contractions For problems not described in this section contact the Technical Support Service of OT Bioelettronica PROPERLY ACQUIRED EXAMPLE SIGNALS During electrically Differential mode Monopolar mode ne elicited contractions 16 10mm array on biceps brachii muscle 16 10mm array on biceps brachii muscle 16 10mm array on biceps brachii muscle G 10 000 low level contraction G 2 000 low level contraction G 1 000 mid low level stimulation intensity 200 ms screen 200 ms screen 200 ms screen TAB 4 Examples of signals properly acquired in the three modes differential monopolar and during electrically elicited contractions All the screens last 200 ms and the amplifier gain is set to have the best signal quality All these signals are acquired with a 16 electrode array 10 mm interelectrode distance on biceps brachii muscle pag 34 EMG 16 User Manual v3 1 Problem The electromyograph does not turn on The electromyograph turns on but the characters are not shown properly on t
9. mode signal acquisitions Mode Differential DRL IN EI h ectromyograp PATIENT REF Patient wrist Reference Enclosed straps cables Probe adapter FIG 12 Patient connection diagram for monopolar mode signal acquisitions Mode Monopolar This configuration may be used also for differential detection DRL IN DRL OUT EI h ectromyograp PATIENT REF Patient Reference straps Enclosed cables Probe adapter FIG 13 Patient connection diagram for monopolar mode signal acquisitions Mode Monopolar in presence of high level interference electric equipment isokinetic machines etc pag 23 EMG 16 User Manual v3 1 MEASUREMENT EXECUTION If all the instructions listed above has been followed correctly it is now possible to perform an EMG signal acquisition In this section it will be assumed that the patient reference strap the electrodes array adapter and the optional DRL straps are correctly connected The following paragraphs show how to position an electrode array and how to configure the electromyograph to acquire good quality signals Differential mode acquisition The single differential mode acquisition is the most used because it is less sensitive to external electromagnetic interference In addition in this acquisition mode the so called end of fiber effect of the motor unit action potential UAP is reduced Each EMG signal traces represents in sin
10. set of output voltages that are an amplified conditioned and filtered version of the input voltages EMG16 allows the acquisition of signals generated by muscles during voluntary or electrically elicited contractions recorded by surface electrode arrays system in different configurations one 16 electrodes array two 8 electrodes arrays four 4 electrodes arrays This device assures the complete safety for the patient and considerably reduces interference signals in particular 50 60 Hz line interference Moreover it allows the connection of optional devices such as force torque meters or articular goniometers to perform joint biomechanical and electromyographic measures For optimal signal acquisition we suggest the use of the software package EMGACQ or EMGACQ II developed at LISIN Bioengineering Center Polytechnic of Turin Italy 2 EMG 16 KIT CONTENT n 1 EMG 16 surface EMG amplifier n 1 cable adapter with a 16 electrodes array for EMG signal detection n 1 conductive gel package n 1 EMG 16 user manual 3 END USER EMG 16 electromyograph is a medical device developed and designed for therapists and trainers for outpatient treatment use EMG16 surface EMG amplifier allows the non invasive detection of the electromyographic signal EMG generated during voluntary or electrically elicited muscular contractions recorded using surface electrode arrays placed over the skin aligned in the direction of muscle fibers Contra
11. 086 Rivarolo C se TO ITALY Tel 39 0124 29897 Fax 39 0124 26312 URL www ottinosnc it e mail mail ottinosnc it pag 44
12. 42 CEE on medical instrumentation Class BF for circuitry applied to patient Read carefully the instruction notes before use Dangerous voltage level device supplied with line voltage Multifunction keys to select the parameter to be modified Multifunction keys to modify the selected parameter value Multifunction key to enter the selected parameter value Signals input Signals output SLI NE O Power on I switch on power line voltage supply Power off O switch off power line voltage supply 6 TECHNICAL SPECIFICATIONS EMG16 surface EMG amplifier is an optically and galvanically insulated device to guarantee a high level of safety to patient and user in all the operating conditions separating the part of the circuitry connected to patient from the circuitry that could be connected to external non medical devices The EMG16 electromyograph can be used to detect surface EMG signals in monopolar or in single differential mode suitable in presence of high level interference during voluntary or electrically elicited contractions An embedded common mode voltage reduction circuit can be used to reduce interference in monopolar mode acquisition See section 8 Surface EMG signals can be detected using different array configurations as reported below in TAB 1 Array electrode number Number of probes that can be used simultaneously 16 electrodes 1 probe 8 electrodes 2 probes 4 electrodes 4 probes
13. Bioelettronica LISIN Bioengineering Center Polytechnic of Turin Department of Electronics EMG 16 16 channels surface electromyographic signal amplifier User Manual A Read this manual carefully before using the EMG16 amplifier C 0476 This product is manufactured in compliance with the European standard 93 42 CEE about medical instrumentation EMG 16 User Manual v3 1 INDEX 1 GENERAL DESCRIPTION i nln i i nn nn nn ni i i i i inne pag 2 EMG 16 KIT CONTENT pag 3 END USERS cla aa i pag CONTRAINDIGATIONS givciseseeccvecevevedestetudtiea cave a a aaa pag SIDE EFFECTS isssstevenevcnscavedeuatevdsceavauatensseudysuacavastuadeidsdeaudetsssgtendyaeasauaseuatindets pag 4 WARNINGS ia pag 5 SYMBOLS USED ON EMG 16 AND IN THE USER MANUAL pag 6 TECHNICAL SPECIFICATIONS EEEE E Ena pag 7 PRELIMINARY INSTRUCTIONS Ennn nnna pag FRONT PANEL AUX IN CONNGCCOM eerren pag ARRAY IN connector pag PATIENT REF plug sicuri ai ati pag DREIN PIUG sscccceteatecesdessccoeten eain aa aa ii pag DRL OUT PIUG birarik noian niian aaa Aauy ened enuatdad denuvilieg ene dens pag Liquid crystal display and keyboard ii pag REAR PANEL Power supply CONNECKOL ii pag Power supply Switch i pag FUSES DOX sicilia pag Fallin pag ID labels iaaa a a aE h pag RS232 CONNECLOr 10 pag ACQUISIT
14. IG 19 In case of high level interference try to use the DRL OUT strap FIG 13 or refer to section 9 TROUBLESHOOTING m After verifying the signal quality start the acquisition as described above Muscle biceps brachii Array 16 ch 10mm Gain 2000 Mode monopolar Screen time base 200 ms FIG 19 Example of a good quality EMG monopolar signal pag 31 EMG 16 User Manual v3 1 Positioning of the recording array adhesive electrode array m Follow the same instructions listed above for the positioning of the adhesive arrays Acquisition during electrically elicited contractions m Follow the same instructions listed above for the differential mode m After verifying the good signal quality in differential mode connect the stimulation electrodes to the patient and turn on the neuromuscular stimulator If necessary search for the optimal position motor point before array placement using a pen electrode to stimulate the muscle searching for the point where the mechanical response is the maximum with the minimum of stimulation current intensity For further details read carefully the neuromuscular stimulator user manual JN NOTE typically but not always the motor point is situated near to the innervation zone which is localized as described above in the section about array placement m Configure the acquisition software tool in electrically elicited contraction mode For further details refer to the software user guide
15. ION BUS coONNEctor ii pag BLANKING INPUT CONnNECUOF ii pag TRIGGER INPUT connector i pag 8 USE OF THE ELECTROMYOGRAPH i i i i i i iin pag ELECROMIOGRAPH SETUP i i i i i inne pag ACCESSORIES CONNECTION i pag Force TOrque SEnNSoOrs iii pag Articular goniometer sna ieinn iaaeaie anaia saran pag General purpose analog iNPUt sssssssssssssrssesssrsrnrrtinnnnnnnnrnnnnnnnnnnnnnnnnnnn nnn pag Neuromuscular stimulator iii pag PATIENT CONNECTION i i i i i i nen pag MEASUREMENT EXECUTION i i inne pag Differential mode acquisition ii pag Monopolar mode acquisition ii pag Acquisition during electrically elicited contractions ia pag 9 TROUBLESHOOTING 0 GG oGogagaga saga pag 10 EMG16 MAINTENANCE AND STORAGE i i i i i i ieee pag 11 TECHNICAL CHARACTERISTICS i i i i i i i i i iii i inne pag 12 WARRANTY GG iii pag WARRANTY CONDITIONS iii pag pag 2 pi i O nD KB WWW U WQ EMG 16 User Manual v3 1 1 GENERAL DESCRIPTION EMG16 is a 16 channels surface elecromyogram EMG amplifier which accepts input voltages detected by surface EMG electrodes and provides a
16. PC screen If necessary change the gain settings to ensure good signal quality JN NOTE if one or more channels appear more weak or absent with respect to the neighbors it is possible that some gel leaked between consecutive electrodes Remove the array clean and dry the skin and the array change the adhesive foam and replace the adhesive array as described above m Follow the instructions above for all the arrays used m Acquire the EMG signal during muscular contraction using the acquisition software EMGACQ II For further details refer to EMGACQ II user guide A NOTE after the use of the adhesive array remove carefully the foam avoiding to damage the array wash with running water the semi reusable part to remove gel to ensure future use Do not abrade the electrode surface If the array has been cleaned after every use it can be applied for up to 10 times without affecting the signal quality Direction of t a Gel injection propagation lug Electrode hole Tendon Gel hole f position SS o o IZ position o Leg Adhesive ag foam 5 Gel dispenser _ Semi reusable o 30 pl array all Tendon Lone position Connector EMG conductive gel Muscle e _ Array adapter x A B Muscle FIG 18 Adhesive array positioning diagram after positioning the adhesive foam on the semi reusable array the array is applied on the skin A in the optimal position found before using a silver bar electrode a
17. Test the tape compatibility before use Verify that the electromyograph is turned off connect the array s to the adapter and plug it into the ARRAY IN connector Turn on the electromyograph select the differential mode Mode Differential and the input configuration corresponding to the selected probe type e g Probes 1x16 set a gain for each probe of 2000 or 5000 e g G1 2k Turn on the PC and start the acquisition software tool in display mode it allows to see in real time the row EMG signal detected by the array on the PC screen Select a time base of about 50 100 ms screen Fill the array holes with EMG conductive gel with a dispenser It is recommended to use 30 ul of gel for each hole Dispenser type Eppendorf Multipette plus Eppendorf AG 22331 Hamburg Germany www eppendorf com is highly recommended Inject the gel keeping the outlet nozzle at an angle with the skin Alternatively keep it perpendicular to the skin but do not press it on the skin The gel must fill completely each cavity of the foam After the insertion of the gel the recorded signal traces must be flat pag 29 EMG 16 User Manual v3 1 m If necessary remove the gel excess using a paper napkin taking care to not cause gel connections between consecutive holes Wipe the excess gel in the transverse and not in the longitudinal direction m Ask the patient to perform a contraction to test the quality of the signals displayed on the
18. US Fuses box Power supply RS232 ACQUISITION BUS connector connector connector FIG 3 EMG16 rear panel view Power supply connector TRIGGER INPUT connector TRIGGER INPUT This plug must be connected to power line socket only with the supplied cable Be aware that the socket and the power supply cable are equipped with the ground conductor A DANGER the use of extension cords multiple sockets or adapters can deteriorate the device performances Connection to sockets lacking in the ground conductor earth conductor or with a bad quality of this connection can deteriorate the device performances and cause a potential risk for both patient and user Power switch Power supply switch allows switching on off operations Switch to position I to turn on the EMG 16 amplifier switch to position O to turn off the device To improve safety the switch interrupts both the power line wires When the EMG16 amplifier is not in use it has to be turned off by this switch pag 13 EMG 16 User Manual v3 1 Fuses box On the same panel of power supply switch and power line connector there is an extractable fuses box containing one fuse for each power line wire In normal conditions fuses have to be integer breakdown of one or both the fuses occurs only in case of a device break down therefore the device could be no longer in compliance with the safety standards even after the fuses replacement with other of
19. a ground strap must be connected to this plug with the supplied cable The strap must be wet with water to assure a good electric contact with the patient and must be fixed on a point without electromyographic activity e g the ankle or the wrist next to the strap used for patient grounding AN NOTE lack of this connection prevents the correct acquisition of the EMG signal in monopolar mode Mode Monopolar pag 10 EMG 16 User Manual v3 1 DRL OUT plug This output must be used primarily during acquisition in monopolar mode Mode Monopolar in presence of high level interference due for example to electric equipment isokinetic machines or other electrical devices working in EMG16 proximity A ground strap has to be connected to this plug with the supplied cable The strap must be wet with water to assure a good electric contact with the patient and has to be fixed on a point without electromyographic activity e g the ankle or the wrist next to the straps connected to PATIENT REF and DRL IN plugs AN NOTE in case of high level interference the lack of this connection prevents the correct acquisition of the EMG signal Liquid crystal display and keyboard The liquid crystal display turns on when the EMG16 amplifier is switched on After an introducing screen the EMG16 settings are presented on a screen as indicated in FIG 2 Probes 4x4CH 500 100 G4 20k Mode Differential CH16 Force Torque FIG 2 E
20. articular goniometer FIG 7 Pinout of the 7 poles AUX IN connector in case of the connection of an articular goniometer A connection diagram of an articular goniometer B General purpose analog input Channel 16 of the electromyograph can be used to acquire a signal from a generic analog input with a maximum input range of 5V 5V The signal is not amplified but low pass filtered 65 Hz 4 order Bessel filter The maximum output range is 5V 5V To acquire a signal from a generic analog input follow the instructions listed below m Connect the generic analog input signal to the AUX IN input taking care the EMG16 is turned off for further information refer to FIG 8 or contact the Technical Support Service of OT Bioelettronica to evaluate the best connection solution m Turn on the EMG16 electromyograph and select the mode CH16 Angle GND C INPUT w o A AUX IN connector pinout B Connection of a generic soldering side analog input FIG 8 Pinout of the 7 poles AUX IN connector in case of the connection of a generic analog input A connection diagram of a generic analog input B pag 19 EMG 16 User Manual v3 1 Neuromuscular stimulator The EMG16 surface EMG amplifier can be used to detect EMG signals during electrically elicited contractions It is equipped with an internal circuitry controlled by the BLANKING INPUT signal that provides stimulus artifact cancellation by turning off the amplifi
21. aves appear windowed especially on the channels more proximal to the stimulation electrode One channel not corresponding to the innervation zone is weak or zero Neuromuscular stimulator output is not designed to work with an electromyograph Blanking time is too long Two consecutive electrodes are short circuited Is not possible to perform the measure contact the Technical Support Service of OT Bioelettronica to select a compatible stimulator If it is possible decrease the blanking time on the neuromuscular stimulator SILVER BAR ELECTRODE ARRAY dry the skin and the array ADHESIVE ARRAY remove the adhesive array change the foam clean the skin and reapply the array TAB 8 Troubleshooting of the problems that can occur using the electromyograph during electrically elicited contraction signal acquisition all the screens lasts 200 ms and the amplifier gain is set to have the best signal quality All the example signals are acquired with a 16 electrode array 10 mm interelectrode distance on biceps brachii muscle pag 39 EMG 16 User Manual v3 1 10 EMG16 MAINTENANCE AND STORAGE EMG 16 has to be used in the following ambient conditions Temperature from 0 C to 40 C Maximum relative humidity 75 Atmospheric pressure from 0 7 atm to 1 1 atm It is recommended to turn off EMG 16 at the end of each measurement session and to remove all the cables and connections EMG 16 might
22. bles are covered by a 6 months warranty all the parts subjected to wear and tear electrodes are excluded from the warranty Warranty is released in case of device violation or in case of intervention from unauthorized staff Warranty conditions are reported hereinafter SEND THE BLU CARD AND KEEP THE GREEN CARD NOTE purchaser s care to validate the warranty send the blue card to manufacturer after it has been compiled in all its fields and after it has been stamped by the authorized reseller In case of intervention under warranty conditions the device has to be packed in order to avoid any damage during transport and has to be sent to the manufacturer with all the accessories taking care of compiling the green assistance card in all of its fields The purchaser have to send the device with the green card signed by the authorized reseller with a receipt or the bill of sale that certify the origin of the device Warranty conditions 1 To validate the warranty the purchaser must send the blue card to manufacturer compiled in all its fields and stamped by the authorized reseller after the purchasing 2 In case of intervention under warranty conditions the purchaser must compile the green assistance card sending it to the manufacturer with the device The purchaser must enclose a copy of the bill of sale or the buying receipt 3 The warranty lasts 24 months on the electronic parts Warranty is provided by the authorized r
23. c signals should be observed If this is not the case refer to the section 9 TROUBLESHOOTING Ask the patient to contract his muscle to about the half of his maximum voluntary contraction level and look at the signal quality on the PC screen With respect to the position of the array to the innervation zone s and to the level of the contraction it should be possible to observe a signal like that in FIG 15 in which are present several action potentials MUAA that are propagating along the muscle fibers pag 25 EMG 16 User Manual v3 1 Muscle biceps brachii Array 16 ch 10mm Gain 2000 Mode differential Screen time base 200 ms FIG 15 Example of a good quality EMG signal detected in differential mode m If the signal appears too low or too high in amplitude change proportionally the gain to obtain a good quality signal displayed m If the signal is too noisy try to wet again the array and the muscle if necessary slightly abrade the skin using abrasive paste m When a good quality signal has been obtained move the array along the muscle fiber direction until you can observe the innervation zone JZ near the middle of the array it has to be possible to detect clearly the action potentials inversion Identify the position of the JZ as indicated in FIG 16 and mark it on the skin with a biocompatible marker Note that different MUAPS may have different IZ m Rotate the array around the IZ untill it is possible to obser
24. d EMG 16 User Manual v3 1 e The presence of electrical equipment or devices relay remote control switch neon lights with incorrect power factor paging systems etc near the EMG16 electromyograph could be a source of electromagnetic interference for the amplifier The presence of electromagnetic fields is not dangerous for the subject but can modify the detected signals and affect the electromyographic estimations e The use of the EMG16 electromyograph by unqualified staff is not dangerous for patients but it is not suggested because a correct interpretation of measurement results can be done only by qualified and adequately trained people having the necessary basic clinical and physiological knowledge e Incorrect estimates could be the consequence of the use of the device by unauthorized staff or by the presence of high sources of disturbances e g high level electromagnetic fields that are easily recognizable by adequately trained people e EMG16 electromyograph is not a portable equipment It could be moved but it has to be guaranteed that the device is adequately packaged even in case of short distances and that it is not exposed during transport to vibrations This could be dangerous and could cause risk for the patient because the safety standards could be violated pag 5 EMG 16 User Manual v3 1 5 SYMBOLS USED ON EMG16 AND IN THE USER MANUAL Product manufactured in compliance with the European standard 93
25. d place it on the skin in the position previously marked m Verify that the electromyograph is turned off connect the array s to the adapter and plug it into the ARRAY IN connector m Turn on the electromyograph select the differential mode Mode Differential and the input configuration corresponding to the selected probe type e g Probes 1x16 set a gain for each probe of 2000 or 5000 e g G1 2k m Turn on the PC and start the acquisition software tool in display mode it allows to see in real time the raw EMG signal detected by the array on the PC screen Select a time base of about 50 100 ms screen pag 27 EMG 16 User Manual v3 1 m Slightly massage the skin over the muscle using abrasive past than wet with water the array and the skin Clean the skin with a wet cloth and remove the abrasive paste m Align the array along muscle fiber direction as marked before FIG 17 m If muscle fiber conduction velocity estimation is desired it is recommended to have the maximum number of channels in the same propagation direction to reduce estimation variance with respect to the markers set before put the array with the maximum electrode number between IZ and the one tendon instead of symmetrically on IZ m Fix the array with a strap a biocompatible adhesive tape or in case of a very short term acquisition ask the patient to keep the array in the selected position exerting a light and uniform pressure on it using his h
26. e stimulator with the TRIGGER INPUT of the electromyograph EMG16 FIG 9 m Alternatively the blanking signal of the stimulator can be used also as trigger signal connecting the cables with a T BNC joint as shown in FIG 10 m Turn on the PC m Turn on the electromyograph m Turn on the neuromuscular stimulator m If it is necessary and allowed by the stimulator it is possible to adjust the duration of the blanking signal provided by the stimulator to prolong or shorten the time of intervention of the circuitry that provides stimulus artifact cancellation to obtain good quality EMG signals avoiding excessive signal windowing and loss of information For further details refer to the subsection MEASUREMENT EXECUTION pag 20 EMG 16 User Manual v3 1 EES OT Electromyograph BLANKING TRIGGER Neuromuscular stimulator BNC BNC cables FIG 9 Connection of the electromyograph to a neuromuscular stimulator equipped with the blanking and trigger outputs flat cable and power supply connections are omitted for simplicity Electromyograph BLANKING TRIGGER Neuromuscular INPUT INPUT stimulator BNC BNC cables T BNC joint FIG 10 Connection of the electromyograph to a neuromuscular stimulator equipped only with the trigger output flat cable and power supply connections are omitted for simplicity A NOTE always turn off the neuromuscular stimulator before turning off the electromyograph than turn off the computer ot
27. er fingers m Ask the patient to perform a contraction to test the quality of the signals displayed on the PC screen If necessary change the gain settings to ensure good signal quality m Follow the instructions above for all the arrays used m Acquire the EMG signal during muscular contraction using the acquisition software EMGACQ II For further details refer to EMGACQ II user guide Direction of th propagation Merl FIG 17 Silver bar electrode array placement diagram the array has to be placed along the muscle fiber direction marked as described previously If muscle fiber conduction velocity estimation IZ position is desired it is recommended to have the maximum number of channels in the same propagation direction to reduce estimation variance With respect to the markers set before put the array with the maximum electrode number between IZ and one tendon on Tendon the area in which there is the best propagation the subcutaneous ee layer is thinner and or we are far from other muscle tendons Silver bar Muscle i Note when the array is aligned with the muscle fiber directions the MUAPs are very similar in shape on each channel The only difference between consecutive channels is the different time delay between the MUAPS because the signal is propagating along the muscle fibre This method is used for a visual assessment of good signal quality pag 28 EMG 16 User Manual v3 1 Positioning of the record
28. er stages avoiding transients and saturation caused by the stimulation pulse present on the input Another input signal TRIGGER IN allows the screen refreshing of the acquisition software EMGACQ II after each stimulation pulse maintaining the EMG signal traces synchronized with the stimulation pulses AN NOTE to guarantee good performances to the system it is necessary to use a medical neuromuscular stimulator built in compliance with the European standards EN 60601 1 and EN 60601 2 10 with special characteristics and able to provide the special synchronization signals to be interfaced with the electromyograph For further information about the joint use of the electromyograph with neuromuscular stimulators and to verify logic signal compatibility contact the Technical Support Service of OT Bioelettronica The use of neuromuscular stimulator incompatible can cause damages to both the stimulator and the electromyograph To use the electromyograph with a neuromuscular stimulator follow the instructions listed below m Verify the compatibility between the electromyograph and the neuromuscular stimulator contacting the Technical Support Service of OT Bioelettronica m Taking care that the electromyograph and the stimulator are turned off connect using a BNC BNC cable not supplied the blanking output of the stimulator with the BLANKING INPUT of the electromyograph EMG16 m Connect using a BNC BNC cable not supplied the trigger output of th
29. eseller or directly by the manufacturer 4 The warranty covers only device damages that cause malfunctioning The product must have the same serial number indicated on the certificate or the warranty is released 5 The warranty covers only the bill free repair or substitutions of defective components included the costs of labour pag 42 EMG 16 User Manual v3 1 6 Warranty is released in case of damages caused by negligence use not in compliance with the instructions supplied unauthorized repairs and accidental circumstances especially for the external part 7 Warranty is released if the damages are caused by the use of incorrect power supply voltages 8 Warranty is not applied on all the parts subjected to wear and tear 9 Warranty does not include transport and selling costs that are under purchaser s care 10 After 24 months the warranty is released All the substituted parts the costs of labour and the transport costs will be charged to the purchaser in accordance with the current rates 11 The law court of the city of Treviso Italy has exclusive jurisdiction for any controversy pag 43 EMG 16 User Manual v3 1 For further information LISIN Bioengineering Center Politecnico di Torino Via Cavalli 22 G 10138 Torino ITALY Tel 39 011 4330476 Fax 39 011 4330404 URL www lisin polito it e mail lisin polito it merletti polito it OT Bioelettronica Via M di Belfiore 25 10
30. ested electrode type In case of permeation of extraneous matters into the device contact immediately the reseller or the manufacturer In case of fall verify that there is no presence of fissures crack or any kind of damage on the box or contact the reseller or the manufacturer EMG16 is subject to environmental disturbances e g electrostatic or electromagnetic interference generated by electrical equipment or other sources that are not dangerous for the patient they can only affect the estimate of the physiological variables extracted from the EMG signal These parameters are not used to make a diagnosis so they are not dangerous for the patient at all Before performing a measure it is necessary to verify the quality of the ground connections because the use of medical devices with electrical outlet without ground represents an high risk for the user Verify that multiple outlets and extension cords if used do not interrupt the ground connection Power up the EMG16 and the data acquisition PC using only Power supply connectors connected with an insulation transformer The connection between EMG16 and other electrical devices e g a PC must comply with the European standard EN 60601 1 1 on medical devices pag 4 e Use the device only with a PC manufactured in compliance with the European standards EN 60950 safety standard for information technology devices EN 55022 EMC standard and EN 55024 immunity standar
31. gle differential mode the difference between the signals detected under two consecutive electrodes of the array For example channel 1 trace represents the difference between the signal detected by electrode 1 and 2 and so on FIG 14 AN electrodes array allows the acquisition of N monopolar signals and N 1 single differential signals Propagating End of fiber Propagating MUAP effect MUAP E1 Chi gt SD1 M1 M2 E2 Muscle Ch2 gt SD2 M2 M3 E3 Ch3 P Small end of W fiber effect Electrode EMG signal monopolar EMG signal single Tendon array recording differential recording gt SD3 M3 M4 or E4 FIG 14 Correspondence between the recording electrodes E1 E4 and the acquired signals registered in monopolar mode M1 M4 and single differential mode SD1 SD3 Note that a monopolar signal is corresponding to the recording electrode whereas the single differential signal is corresponding to the difference between the monopolar voltages of adjacent electrodes Moreover note that the end fiber effect is strongly reduced in single differential signals pag 24 EMG 16 User Manual v3 1 To acquire a signal in differential mode follow the instruction listed below Defining the optimal array position Take care that the patient reference strap is wet wounded on the wrist or the ankle and connected to PATIENT REF plug on the front panel of the electromyograph Choose the most suitable silver bar elect
32. gnals are acquired on channel 16 To acquire on channel 16 a signal from an articular goniometer generic analog input the mode CH16 Angle must be selected on the display In this mode the signal on AUX IN is sent to channel 16 without any amplification To acquire on channel 16 a signal from a couple of preamplified force torque sensor it has to be selected on the display the mode CH16 Force Torque In this mode the output signal of two external force torque transducers collected on the AUX IN input are summed and the resultant signal is amplified and sent to channel 16 of the amplifier after compensating the DC offset by software To acquire on channel 16 an EMG signal this make sense only in monopolar mode or in single differential mode with a circular array it has to be selected on the display the mode CH16 EMG For detailed information about how to change the EMG16 settings refer to the paragraph Liquid crystal display and keyboard subsection pag 8 EMG 16 User Manual v3 1 A NOTE for technical information about the use of the AUX IN connector with other external transducers contact the Technical Support Service of OT Bioelttronica pag 9 EMG 16 User Manual v3 1 ARRAY IN connector ARRAY IN is used to connect a 16 electrodes array adapter mode Probes 1x16CH a double adapter for two 8 electrodes arrays mode Probes 2x8CH or a quadruple adapter for four 4 electrodes arrays mode Pr
33. he display The keyboard does not work The electromyograph is installed but the acquired signal is always zero TAB 5 Troubleshooting of the general problem that can occur using the electromyograph Possible cause Power supply switch off or defective wall receptacle or no voltage at the receptacle Example screen Solution Check the voltage presence at the wall receptacle and move on I the power supply switch Power supply cable is not inserted properly in the amplifier or into the socket Check the power supply cable and the socket connection pag 35 Breakdown of the fuses Ambient temperature is too low The electromyograph is software controlled by EMGACQ II tool The acquisition board flat cable is not connected The acquisition board is not properly installed The acquisition software is not properly installed Contact the Technical Support Service of OT Bioelettronica Wait that the electromyograph warms up Disable the EMGACQ II software control refer to the software user guide Connect the flat cable between the electromyograph and the acquisition board FIG 5 Check the configuration settings or reinstall the acquisition board refer to the acquisition board user manual Check the configuration settings or reinstall the acquisition software refer to the software user guide EMG 16 User Manual v3 1 DIFFERENTIAL MODE SIGNAL
34. herwise the shut down operation can cause damages to the acquisition board to the electromyograph or to the neuromuscular stimulator pag 21 EMG 16 User Manual v3 1 PATIENT CONNECTION After the correct installation of the electromyograph and after verifying that it works properly it is possible to connect the sensors to the patient in order to perform an electromyographic test Follow the instructions listed below Select the most suitable adapter with respect to the assessment to perform 16 electrodes array probe double 8 electrodes array probe or quadruple 4 electrodes array probe and plug it into the ARRAY IN connector Connect the probe to the array or the arrays selected It is possible to connect to each adapter a silver bar electrode array suitable to find the best position to place the array on the muscle and to perform short time isometric measurements or an adhesive array suitable for long term signal acquisition and or during dynamic contractions Even If it has been planned to use an adhesive array a silver bar electrode array should be used before to detect the optimal position for the adhesive array as described hereinafter Connect a patient ground strap to PATIENT REF plug with the enclosed cable The strap has to be wet with water to assure a good electric contact with the patient and has to be applied on a point without any electromyographic activity e g the ankle or the wrist FIG 11 JAN NOTE
35. indications EMG16 has no particular contraindications related to its joint use with neuromuscular stimulators or personal computers provided that all the electrical devices connected with it and the electrical power distribution system are in compliance with the relative safety rules and standards in particular proper connection to ground is required Side effects pag 3 EMG 16 User Manual v3 1 No significant side effects are known All the materials used for the manufacturing of the parts of that could be in contact with patient are biocompatible possible allergic cutaneous reactions e g skin reddening are reduced to the minimum also because of the short duration of the electromyographic signal acquisition 4 WARNINGS The use is forbidden with electro surgery equipment with short waves or microwaves therapy devices The use is forbidden to mentally incompetent people The use is forbidden to people who suffer from sensitivity disorders The use is forbidden to temporarily disabled people if not assisted by qualified staff e g medical doctor or therapist The use is forbidden in presence of deterioration or damage of the equipment itself The use is forbidden near inflammable substances or in ambient at high oxygen concentration Consult a doctor before use in case of osteosynthesis metal devices on patient Use electrodes supplied by manufacturer only EMG16 is tested and guaranteed if used with the sugg
36. ing array adhesive electrode array AN NOTE indications below are referred to adhesive electrode arrays suitable for long term signal acquisitions and or during dynamic contractions Select the most suitable array with respect to the number of electrodes for each muscle and to the experimental issues see TAB 2 If necessary shave the area where the array will be placed Slightly abrade the skin using abrasive paste then clean the skin with a wet cloth and dry carefully the skin Peel off the tape from one side of the adhesive foam and apply the foam on the array taking care to cover neither the electrodes black rectangular shaped nor the holes for gel injection Peel off the other side of the adhesive foam and stick the array on the skin FIG 18 with respect to the position marked before as in the case of the silver bar electrode arrays Take care that the array has been correctly applied on the skin to avoid conductive gel leakage that can cause short circuits between consecutive electrodes AN NOTE in case of wrong positioning is not possible to peel off the array and replace it It is necessary to remove the array change the foam with a new one repeating the procedures explained above If large movements are planned fix to the skin the semi reusable part of the array next to the probe connector using biocompatible adhesive tape A NOTE some adhesive tape are too sticky and can damage the semi reusable part of the array
37. lass I about the protection from indirect contact IP20 about the of fluids and dust penetration device not protected painted metallic case voltage from 90Vac to 260Vac 10 frequency from 47 to 400Hz 50 W the device is not suitable for use in high oxygen concentration ambient and or flammable fluids and or gases do not use with electro surgery or short wave microwave therapy equipment device suitable for continuative work 2 x 2 5A fuses 16 independent 1 auxiliary channel for force torque detection Maximum input range 20 mVpp with gain 100 Bandwidth 10 500 Hz Total noise RTI lt 0 7 uVrws differential lt 1 0 uVrms monopolar 100 200 500 1000 2000 5000 10000 20000 50000 gt 90 MQ on the entire bandwidth gt 96 dB 103 dB typical lt 75 dB monopolar and differential 4000 Voc Selectable gain Input impedance CMRR Crosstalk between channels Insulation voltage graphic LCD 128x64 pixel display 5 keys keyboard protected by polycarbonate membrane 350 x 271 x 98 mm 3 Kg refer to the section 10 EMG16 MAINTENANCE AND STORAGE Manufactured in compliance with the European standard 93 42 CEE about medical instrumentation pag 41 EMG 16 User Manual v3 1 12 WARRANTY to validate these warranty conditions compile and send the blue card to the manufacturer EMG 16 is covered by a 24 months warranty starting from the electronic parts purchasing date Connection ca
38. lifier gain in groups of 8 electrodes each channels mode 2x8CH or in groups of 4 channels mode m 4x4cH 4 probes of 4 4x4CH electrodes each G1 G2 Probe gain in mode 1x16CH G1 is the gain of the 16 100 200 500 G3 G4 electrodes array in mode 2x8CH G1 e G2 are the gains of the 1k 2k 5k two 8 electrodes array and so on To allow flexibility the gains 10k 20k 50k G1 and G2 can be different in different modes NOTE 1k 1000 Mode Acquisition mode monopolar or single differential bipolar Monopolar Differential CH16 Select the source for EMG16 channel 16 In Force Torque EMG mode the signal is generated by the sum of the two signals coming from the couple of transducers connected on AUX IN input in Angle mode the signal comes directly from an articular goniometer or from a generic analog connected on AUX IN input in EMG mode the channel 16 is used to acquire EMG signal from the 16 electrode of the array in monopolar mode or as the difference between the 16 and the 1 electrode of the array in differential mode that makes sense only with the use of a circular array E Force Torque couple of force torque transducers Angle articular goniometer or generic analog input TAB 3 EMG16 amplifier settings pag 12 EMG 16 User Manual v3 1 REAR PANEL EMG16 rear panel is shown in FIG 3 Power switch Fan ID label BLANKING INPUT connector BLANKING INPUT ACQUISITION B
39. m Start to stimulate with a frequency of 2 4 Hz and change the stimulation intensity untill a muscular contraction synchronized with the stimulation pulses is visible m Look at the EMG signals detected M wave after each stimulus the acquisition software has to display an EMG trace similar to a single MUAP shape but higher in amplitude If necessary change the gain settings to allow a good quality signal assessment on the PC screen usually during electrically elicited contractions is used a gain from 100 to 1000 Muscle biceps brachii Array 16ch 10mm Gain 1000 Screen time base 200 ms FIG 20 Example of a good quality EMG signal acquired in differential mode during electrically elicited contractions pag 32 Mode differential electrically elicited 2 Hz OT m Some stimulators compatible with the use of an electromyograph are equipped with a EMG 16 User Manual v3 1 blanking command used to control a stimulus artifact cancellation circuitry implemented in the amplifier If it is possible adjust the blanking command settings on the stimulator to remove all the artifact without cutting the M wave blanking time too long to avoid loss of information m For further details refer to section 9 TROUBLESHOOTING m After verifying the signal quality start the acquisition as described above pag 33 EMG 16 User Manual v3 1 9 TROUBLESHOOTING This section describes the most common problems that
40. nd for logic signal compatibility contact the Technical Support Service of OT Bioelettronica TRIGGER INPUT connector This BNC type connector is used to connect the electromyograph with a compatible neuromuscular stimulator to allow EMG signal acquisition during electrically elicited contractions This input accepts a digital TTL compatible signal 0 5V coming from the stimulator that is sent to the acquisition board to allow the acquisition software to synchronize the PC screen refresh with the stimulation pulse through the rising edge of the TRIGGER signal and to acquire properly the EMG signal Minimal duration of the trigger pulse is 100 us A NOTE for further information about the joint use of the electromyograph with neuromuscular stimulators and for logic signal compatibility contact the Technical Support Service of OT Bioelettronica pag 15 EMG 16 User Manual v3 1 8 USE OF THE ELECTROMYOGRAPH ELECTROMYOGRAPH SETUP Before performing a data acquisition it is necessary to setup all the instrumentation this operation has to be done keeping the equipment turned off Take care to connect all the cables properly into the respective plugs and sockets To setup correctly the electromyograph follow these instructions FIG 5 Make sure that the computer that will be used with the electromyograph is turned off Make sure that the EMG16 power on switch is set in O position Connect the ACQUISITION BUS connec
41. nge 5V 5V Torque force offset removal 2V 2V software controlled Auxiliary channel Mode angle analog input Maximum input range 5V 5V Gain 1 Bandwidth 0 65 Hz 4 order Bessel band pass filter Maximum output range 5V 5V Example using a couple of sensors with a sensitivity S 1 mV Full Range Vsuppy each of them gives a full range output of 1 mV Vsuppy 5 5 mV 5 mV for negative range If each sensors are at full range the output voltage ill be Vu 300 5 mV 5mV 3V Output voltage range is 3V 3V In previous example offset removal has a range 2V 3V 100 67 F R it will be able to null an offset up to the 67 of the full output range TAB 2 EMG16 technical specification pag 7 EMG 16 User Manual v3 1 7 PRELIMINARY INSTRUCTIONS FRONT PANEL EMG16 front panel is shown in FIG 1 AUX IN connector ARRAY IN connector DRL IN plug DRL OUT plug Mi REJECTION ra rr IIO PATIENT REF plug Liquid crystal display Keyboard FIG 1 EMG16 amplifier front panel view AUX IN Connector AUX IN connector can be used to connect an articular goniometer a generic analog signal with a maximum input range of 5V 5V or a couple of non preamplified force torque sensors a pre amplifier stage is included into EMG16 Sampling frequency and resolution is the same used in the EMG channels set by acquisition software and acquisition board and si
42. nge of 5V 5V This output voltage depends from the force or torque applied to the sensor but also from the full scale range and from the sensitivity of the transducers used For example choosing a sensor having a sensitivity of 1 mVrs Vsuppy the maximum output voltage positive of the sensor will be Vu 300 1 mVrs Va 5V 1 1 5 V A NOTE when using two transducers if the sensitivity of the load cells is greater than 1 7 mVrs Vsuppiy it may be impossible to measure forces or torques proximal to the full scale values If both the transducers were at full scale the output voltage will be Vu 300 1 7 mVrs Vac 5V 1 1 7 mVrs Va 5V 1 5 1 V greater that the maximum output voltage range 5V In this conditions the electromyograph is not damaged but the acquired signal appears saturated and can not be measured correctly Using only one transducer the maximum sensitivity allowed to acquire correct values till the full scale is 3 4 mVrs Vsuppry Commercial available transducers have in general a sensitivity range between 1 typical and 3 mVrs Vsuppiy To acquire force torque signals follow the instructions listed below m Verify that the EMG16 is turned off Connect the sensor or the sensors to the AUX IN input for further information refer to FIG 6 or contact the Technical Support Service of OT Bioelettronica to evaluate the best connection solution m Turn on the EMG16 electromyograph and
43. not aligned with directions amplitude can be muscle fibers different depending on the thickness of the subcutaneous Good propagation only in layers one direction with respect to the innervation zone on the other side signals are Use an array with a shorter weak and do not propagate The array i aligned with interelectrode distance applied very much muscle fiber but there is a where there is the best signal thicker subcutaneous layer or propagation to have a greater a tendon even of another number of propagating muscle under those signals use only channels with electrodes good propagation properties for signal processing Signal amplitude is too low Amplifier gain is too low Increase the amplifier gain Signal amplitude i too high and MUAP appear clipped Amplifier gain is too high Decrease the amplifier gain TAB 6 Troubleshooting of the problems that can occur using the electromyograph in differential mode acquisition all the screens lasts 200 ms and the amplifier gain is set to have the best signal quality All the example signals are acquired with a 16 electrode array 10 mm interelectrode distance on biceps brachii muscle pag 37 EMG 16 User Manual v3 1 MONOPOLAR MODE SIGNAL ACQUISITIONS Problem Signals are zero or there is only a high power line interference 50 Hz Example screen Possible cause DRL IN and DRL OUT straps are not connected Solution Connect DRL IN and
44. obes 4x4CH The Probes mode has to be selected corresponding to the selected array adapter For detailed information about how to change the EMG16 settings refer to Liquid crystal display and keyboard subsection Each adapter can be connected to both a standard silver bar electrodes array suitable to find the best position to place the array on the muscle and to perform short time isometric measurements and an adhesive array suitable for long term signal acquisition and or during dynamic contractions JN NOTE for correct signal recordings is always necessary to connect the patient ground to the PATIENT REF plug using a strap fixed on a point where there is no electromyographic activity e g the ankle or the wrist In monopolar mode acquisitions Mode Monopolar is necessary to connect another ground strap to DRL IN plug and in case of high level interference a third one to DRL OUT plug For further information refer to DRL IN plug and DRL OUT plug subsections PATIENT REF plug This plug is always used to connect a point without electromyographic activity e g the ankle or the wrist of the patient to the EMG16 as patient ground using the supplied ground strap The strap has to be wet with water to assure a good electric contact with the patient JN NOTE lack of this connection prevents the correct acquisition of the EMG signal DRL IN plug This input should be used primarily during acquisition in monopolar mode Mode Monopolar
45. ograph pag 16 EMG 16 User Manual v3 1 A NOTE when the instrumentation is turned off always turn off firstly the electromyograph and than the PC Shutting down the PC before the electromyograph has been turned off can cause damages to the acquisition board and to the electromyograph m To connect accessories biomechanical measurement instruments force torque transducers neuromuscular stimulators refer to the subsections hereinafter ACCESSORIES CONNECTION It is possible to interface EMG16 with external devices as neuromuscular stimulators or biomechanical measurements instrumentation to detect for example the EMG signal during electrically elicited contractions or to measure the articular force torque during a voluntary contraction Subsections hereinafter show how to use the electromyograph in these conditions and how to connect EMG16 to external devices Force Torque sensors During EMG signal acquisition in single differential mode using a linear 16 electrodes array the channel 16 of the electromyograph has no sense as EMG channel so it is possible to use this channel to acquire a signal coming from a couple of force torque sensors transducer input impedance lt 100kQ The electromyograph contains two amplifiers that can be connected to a load cell or torsiometer each whose output signals are summed together to obtain the final force torque signal This way it is possible to measure the total force torque
46. rode array with respect to muscle length taking the one with the highest number of electrodes fitting the muscle length better if 8 or 16 This array won t be used for signal recordings Verify that the electromyograph is turned off connect the array to its own adapter supplied and plug it into the ARRAY IN connector on the front panel of the electromyograph Turn on the electromyograph select differential mode Mode Differential select the input configuration e g Probes 1x16 or 2x8 and the array than set for the array selected a gain of 2000 or 5000 e g G1 2k Turn on the PC and start the acquisition software tool in display mode it allows to see in real time the raw EMG signal detected by the array on the PC screen Select a time base of about 50 100 ms screen Slightly wet the skin over the muscle with water and massage with a wet cloth In case of very dry skin massage the skin with abrasive conductive paste and clean it with a wet cloth Place the array on the muscle belly taking care to align it with fiber directions keep it in place with a uniform pressure If it is possible ask the patient to hold the array on his her muscle because the contact with the operator can introduce interference on the acquired signals Ask the patient to relax the muscle waiting 10 20 seconds to allow the electrode skin contact to stabilize traces on the PC display might be flat and no interference signal e g spikes glitches periodi
47. rray A conductive gel for EMG application is injected into the provided holes with a dispenser B pag 30 EMG 16 User Manual v3 1 When EMG signal is acquired in monopolar mode each signal trace corresponds to an electrode of Monopolar mode acquisition the array The monopolar signal presents with respect to the single differential signal some typical EMG signal components the so called end of fiber effect generated by the potential extinction on tendons The steps to follow to record a signal in monopolar mode are similar to those for the single differential acquisition except for the following points Defining the optimal array position m The optimal array position has to be found as described above using the differential acquisition mode more suitable for the recognition of the anatomic characteristics because the non translating components are attenuated even the end of fiber effect and the IZ can be identified more easily Positioning of the recording array silver bar electrode array Follow the same instructions listed above for the differential mode m After verifying the good signal quality in differential mode configure the electromyograph to work in monopolar mode Mode Monopolar and if not already done connect the DRL IN reference strap FIG 12 m Ask the patient to contract the muscle to test the signal quality A monopolar mode signal correctly acquired appears as the signal shown in F
48. select the mode CH16 Force Torque m If it is necessary use the EMGACQ II acquisition software tool to remove the residual DC offset For further informations refer to EMGACQ II user guide 5V 7 S1B B A 6 S2A 2 S1A 45V 5 S2B 3 5V 4 5V A AUX IN connector pinout B Connection of a couple of C Connection of a stand soldering side force torque sensors alone force torque sensor FIG 6 Pinout of the 7 poles AUX IN connector in case of the connection of force torque sensors A connection diagram of a couple of force torque sensors B and of a stand alone sensor C pag 18 EMG 16 User Manual v3 1 Channel 16 of the electromyograph can be used to acquire the signal generated by an articular Articular goniometer goniometer transducer input impedance lt 100k in this case the signal is not amplified but just low pass filtered 65 Hz 4 order Bessel filter The maximum output range is as in the previous mode between 5V and 5V To acquire a signal from an articular goniometer follow the instructions listed below m Connect the sensor or the sensors to the AUX IN input taking care the EMG 16 is turned off For further information refer to FIG 7 or contact the Technical Support Service of OT Bioelettronica to evaluate the best connection solution m Turn onthe EMG16 electromyograph and select the mode CH16 Angle 2 INPUT 3 5V 4 5V A AUX IN connector pinout B Connection of an soldering side
49. tebook or desktop PC power supply away connect the electromyograph to a different wall socket if using a notebook try to use battery power supply and disconnect the power supply from the wall socket Use power line filters on PC power supply connections Electric equipment interference e g isokinetic machines working in proximity of the amplifier Connect the electromyograph to a wall socket far from the electric device if it is possible using a different power line phase check for a correct ground connection of the disturbing device pag 36 Interference due to power active devices with a metallic case working in proximity of the amplifier Check for a correct ground connection of the disturbing device The metal case of any electrical device must be connected to ground Check for incorrect use of groundless extension cords and multiple outlets EMG 16 User Manual v3 1 DIFFERENTIAL MODE SIGNAL ACQUISITIONS Problem Example screen Possible cause Solution Good electrode skin Move the array along muscle contact but the signal is f fiber direction toward the weak and the signal does tendon zone use an array not propagate on one or Electrodes placed on Tendon with a smaller interelectrode more electrodes at the distance to have a greater extremity of the array number of propagating signals Rotate the array to observe a symmetric propagation in both The array is
50. the same type Fuse type is reported on the rear ID label AN DANGER in case of breakdown of one or both the fuses do not replace them but contact immediately the Technical Support Service of OT Bioelettronica The fuses breakdown could be caused by a malfunction that could represent a potential risk for the patient and the user and it is necessary to detect it before restarting to use the device Replacing the fuses with other fuse types can be very dangerous for the patient and the user Remove the power cable before opening the fuse box Fan A cooling fan is placed on the rear panel for the internal circuitry of the EMG16 amplifier Take care to leave at least 8cm space behind the EMG16 to ensure an appropriate air flow and do not obstruct the slots on the lower panel and the grid on the rear panel to let air flow to avoid overheating FIG 4 AN NOTE block of the air flow can cause overheating and device break down Verify that the fan is free to spin and that there is no presence of dust or other substances that could block it Hot air flow fan Cold air flow lower panel slots FIG 4 flow and minimum required space behind the device ID label The ID label placed on the rear panel reports the serial number of the EMG16 amplifier see section 12 WARRANTY to be sent to OT Bioelettronica some identification data required by law certification number and symbol C 0476 manufacturer address and some technical information
51. tor placed on the EMG16 rear panel to the acquisition board using the flat cable provided taking care to insert it properly If the acquisition board is a PCMCIA card suitable for notebooks connect the flat cable provided to the board taking care to insert it properly then insert the card into the first free PCMCIA slot of your notebook If the acquisition board is a PCI board suitable for desktop computers contact the Technical Support Service of OT Bioelettronica for installation troubleshooting when the PCI card has been correctly installed connect the flat cable to the acquisition board taking care to insert it properly Connect the EMG16 power supply connector placed on the rear panel to a 90 260 Vac 50 60 Hz power line supply voltage using the provided cable A DANGER the use of extension cords multiple sockets or adapters can deteriorate the device performances Connection to sockets lacking in the ground conductor earth conductor or with a bad quality of this connection can deteriorate the device performances and cause a potential risk for patient and user m Turn on the PC desktop computer or notebook m Install the acquisition software following the instructions reported on the provided user manual Computer with an installed Electromyograph acquisition board i Power line socket Power supply cable mii i ad wee Flat cable FIG 5 Standard setup of the electromy
52. ve a symmetric propagation the slope of the imaginary line that connects the propagating MUAP has to be the same above and below the IZ Mark the optimal direction found with a biocompatible marker If it is clear mark also the position of the tendons where the signals stop to propagate and is weak m In case of non isometric contractions repeat the instructions above for the maximum and the minimum articular angle predicted Some muscle or some individuals show a single IZ other muscles or individuals show multiple innervation zones pag 26 EMG 16 User Manual v3 1 Ei El gt SD1 SD1 E2 gt E2 gt SD2 SD2 E3 gt E3 gt SD3 SD3 IZ E4 gt E4 gt SD4 IZ SD4 E5 gt E5 gt SD5 SD5 E6 gt E6 gt SD6 SD6 SD7 SD7 ES gt t ES gt t A B FIG 16 Example of identification of the innervation zone IZ of a motor unit A If the trace SD4 is reversed with respect to SD3 IZ is in the middle between the two signals detection points under the electrode E4 B If the trace SD4 is flat IZ is in the middle between electrode E4 and E5 Positioning of the recording array silver bar electrode array A NOTE indications below are referred to silver bar electrode array use suitable during isometric contractions or for short term signal acquisitions m Select the most suitable array with respect to the number of electrodes for the muscle length and to the experimental issues see TAB 2 an
53. xample of a screen on the liquid crystal display The embedded keyboard allows the user to change the settings of EMG16 amplifier to do that follow these instructions m Move the arrow on the parameter to be modified using the keys O and m Press to confirm the selection of the parameter to be modified the arrow will be displayed in negative W to indicate that it is now possible to change the value of the selected parameter m Scroll the available options and select the desired value using the keys and gt the parameter will be changed directly to allow the user to monitor the effect m Press to accept the new parameter value JN NOTE display s ligh is turned on by any key pressure and it is turned off automatically 5 second after the last key pressure pag 11 EMG 16 User Manual v3 1 A NOTE EMGAQQ II acquisition software allows the remote control of the EMG16 amplifier when this option is active the keyboard is disabled and the display shows the string PC Link The selectable options for each programmable parameter of the EMG16 amplifier are listed below in TAB 3 Parameter Description Available options Probes EMG input probes configuration 16 electrodes array probe 1x16CH 1 probe of 16 double 8 electrodes array probe quadruple 4 electrodes array electrodes probe The only difference between these modes consists in 2x8CH 2 probes of 8 the possibility of changing the amp
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