Mechanical CPR device with variable resuscitation protocol
Contents
1. 9 2012 Office Action from U S Appl No 11 961 687 mailed Mar 25 2010 9 pp Office Action Response for U S Appl No 11 961 687 filed Jun 25 2010 19 pp U S Appl No 11 961 687 Final office action dated Sep 8 2010 10 pages U S Appl No 11 961 687 Non final office action dated Apr 25 2011 6 pages U S Appl No 11 961 687 Final office action dated Apr 13 2012 7 pages U S Appl No 11 961 687 Notice of Allowance dated Sep 28 2012 5 pages cited by examiner U S Patent Aug 5 2014 Sheet 1 of 4 US 8 795 208 B2 16 TIME oT COMPRESSION RELAXATION PHASE PHASE 14 15 CYCLE 13 m FIG 1 21 MODE U S Patent Aug 5 2014 Sheet 2 of 4 US 8 795 208 B2 35 30 gt 34 33 TIME T START a T1 T2 FIG 3 45 46 30 42 25 2 44 43 1 T START ne FIG 4 51 51 52 51 g 52 52 I I I T START U S Patent Aug 5 2014 Sheet 3 of 4 US 8 795 208 B2 67 65 gt 63 61 T START REST 1 T REST 2 T REST 3 62 64 66 FIG 6 S a 2 A 22 N z 74 FIG 7 US 8 795 208 B2 Sheet 4 of 4 Aug 5 2014 U S Patent ISAWHX4 SNIVUVddV 98 1 3110 41 02 o8 8 US 8 795 208 B2 1 MECHANICAL CPR DEVICE WITH VARIABLE2. matically change over time the delivery of mechanical CPR to a patient The device may also include a timer linked to the controller and may also include an input device linked to the controller whereby a user may select a CPR delivery protocol The controller may be configured to automatically provide mechanical CPR at a first frequency and subsequently at a second frequency Additionally the controller may be config ured to temporarily alternate between delivery of mechanical CPR and halting delivery of mechanical CPR Also addition ally the controller may be configured to accelerate or decel erate the frequency of mechanical CPR Still further the controller may be configured to alter the ratio of compression phase to decompression phase in a CPR cycle And yet still further the controller may be configured to vary the pressure applied by the means for compressing Other independent features characteristics and advan tages of the mechanical CPR device with a variable resusci tation protocol will become apparent from the following detailed description taken in conjunction with the accompa nying drawings which illustrate by way of example the principles of the invention BRIEF DESCRIPTION OF THE DRAWINGS FIG 1 is a graphical illustration of a typical compression decompression cycle in a mechanical CPR device FIG 2 is a graphical illustration of a form of CPR control according to a first exemplary embodiment in which CPR
3. Al 2007 0004992 Al OTHER PUBLICATIONS 5 2010 Caldarone et al 1 2013 Walker 7 2003 Bassuk et al 7 2003 Bassuk et al 11 2004 Steen 7 2005 Sherman et al 4 2006 Paradis 1 2007 Van Brunt et al Kern et al Efficacy of Chest Compression Only BLS CPR in the Presence of an Occluded Airway 1998 Elsevier Science Ireland Ltd Resuscitation 39 1998 Accpted Nov 11 1998 pp 179 188 Zhi Qing Zhao Joel S Corvera Michael E Halkos Faraz Kerendi Ning Ping Wang Robert A Guyton and Jakob Vinten Johansen Inhibition of myocardial injury by ischemic postconditioning during reperfusion comparison with ischemic preconditioning Am J Physiol Heart Cire Physiol 285 2003 p 579 588 The American Physiological Society Michael Galagudza Dmitry Kurapeev Sarkis Minasian Guro Valen and Jarle Vaage Ischemic postconditioning brief ischemia during reperfusion converts persistent ventricular fibrillation into regular rhythm European Journal of Cardio thoracic Surgery 25 2004 p 1006 1010 Elsevier B V Michael E Halkos Faraz Kerendi Joel S Corvera Ning Ping Wang Hajime Kin Christopher S Payne He Ying Sun Robert A Guyton Jakob Vinten Johansen and Zhi Qing Zhao The Society of Thoracic Surgeons 2004 p 961 969 Elsevier Inc Gerd Heusch Postconditioning Old Wine in a New Bottle Journal of the American College of Cardiology 2004 vol 44 No 5 p 1111 1112 Elsevier Inc Hajime Kin Zhi Qing Zhao
4. a next period of time T2 the CPR frequency is increased again to frequency3 35 Jumps or changes in fre quency can continue for any number that is desired In a preferred embodiment a maximum frequency is reached and then held without further higher jumps FIG 3 illustrates an embodiment ofa series of step changes in frequency that gradually ramp up until a final frequency is reached While a positive change in frequency has been illus trated a step change may also be negative moving to a lower frequency In the example illustrated in FIG 3 time periods for each successive frequency may be of increasing duration as preferred where T2 gt T1 However the time intervals may be of the same or different durations including the case in which a successive time period T2 is shorter than a previous time period where T2 lt T1 In the embodiment illustrated in FIG 3 the change in duty cycle frequency is a series of steps however in other embodi ments the change in frequency may also follow a more con tinuous acceleration without jumps or discontinuities Refer ring now to FIG 4 there is shown a graph that illustrates other embodiments of changes in CPR frequency As in FIG 3 the graph in FIG 4 illustrates CPR that begins at a start time preferably the time at which mechanical CPR is first applied to a patient There follows an acceleration period Three pos sible acceleration forms are illustrated a front loaded accelera
5. delivery is alternated between periods of delivery and periods of non delivery FIG 3 is a graphical illustration of a form of CPR control according to a second exemplary embodiment in which the frequency of CPR chest compression delivery is changed in step increments FIG 4 is a graphical illustration of a form of CPR control according to a third exemplary embodiment in which the frequency of CPR chest compression delivery is accelerated until reaching a desired frequency plateau FIG 5 is a graphical illustration of a form of CPR control according to a fourth exemplary embodiment in which the frequency of CPR chest compression delivery is accelerated toa first plateau frequency and is then accelerated to a second plateau frequency and is then accelerated to a third plateau frequency FIG 6 is a graphical illustration of a form of CPR control according to a fifth exemplary embodiment in which the frequency of CPR chest compression delivery is accelerated to a first plateau frequency is then halted is then accelerated to a second plateau frequency is then halted and is then accelerated to a third plateau frequency halted and finally accelerated to a fourth plateau frequency FIG 7 is a graphical illustration of a form of CPR control according to a sixth exemplary embodiment in which the force in the compression phase of CPR delivery is increasing with time and FIG 8 is a simplified functional block diagram of a mechanical CPR
6. harness or compression arm In operation pump 84 provides a force such as pressure through valve 83 and into compression applying element 86 thereby deforming the compression applying element 86 and compressing the chest If a device such as a belt is used it will be understood that force constricts the belt When desired valve 83 also releases the pressure thus allowing compression applicator 86 to deflate relax and thereby release compressive force on the chest cavity Additionally FIG 8 shows a mechanical CPR means 87 The mechanical CPR means 87 represents the combination of power 85 pump 84 valve 83 and apparatus 86 Mechanical CPR means 87 is also linked to controller 81 US 8 795 208 B2 9 Controller 81 is configured such that CPR delivery follows a desired pattern A configured pattern may be any of the CPR controls and protocols discussed herein and variations of the same In a preferred embodiment the controller 81 includes software and or hardware that allows for selection and deliv ery of a particular CPR delivery protocol Also preferably the controller allows a user to select from more than one CPR delivery forms by an appropriate input 82 It is also preferred that a timer not shown be included in controller 81 or otherwise linked to controller 81 A timer can provide time information needed to follow a desired CPR protocol In operation the preferred delivery of mechanical CPR may be selected depending f
7. mechanical CPR device Once the device is positioned on a patient and activated it begins to provide CPR at the preset frequency Various mechanical CPR devices are described in U S Pat Nos 5 743 864 5 722 613 5 716 318 4 570 615 4 060 079 and U S patent application Ser Nos 2003 0135139 A1 and 2003 0135085 These U S patents and patent applications are incorporated herein by reference Referring now to FIG 2 there is shown a graphical repre sentation of controlled CPR delivery according to an illustra tive embodiment of the invention The graph is a plot of CPR mode 21 against time 22 In this embodiment CPR delivery is stuttered between on and off modes 23 24 The on mode 23 here means a mode in which CPR is being applied to the patient and off mode 24 means a mode in which there is no application of CPR Preferably the switching between on and off modes 23 24 occurs for a period of time after which the device remains permanently in the on mode Thus as shown the protocol begins with CPR being applied for a first interval of time 25 represented as TON1 There follows an interval TOFF1 26 in which CPR is not applied Next CPR is again applied for a period 2 27 At this point in some embodi ments the CPR device remains on without further interrup tion to the application of CPR However in other embodi ments CPR may again switch between an off and on state Thus in some embodiments after TON2 there follo
8. patient during a CPR delivery period and means for automatically controlling the delivery of chest compressions to provide a gradual increase in net blood flow to the patient to lessen the potential for reperfusion injury to the patient relative to immediately restoring net blood flow to the patient at a beginning portion of the CPR delivery period and a greater net blood flow than with the beginning portion over a remaining portion of the CPR delivery period and wherein the remaining portion extends from the end of the beginning portion until the end of the CPR delivery period
9. the compression phase may then gradu ally be increased or decreased from one compression de compression cycle to the next As before changes can occur through various functions including step changes accelera tions and decelerations each of which may be linear or non linear In operation a mechanical CPR device according to an embodiment of the invention includes a controller The con troller is linked to other device components so as to be able to control compression means and relaxation means that are part of the CPR device The controller can thus regulate the deliv ery of CPR including control of parameters such as cycle frequency on off delivery of CPR compression and decom pression phase and compression force The controller may also be linked to an input device which allows a user to select a form of CPR delivery parameter to be varied and the manner or rate at which it is to be varied Referring now to FIG 8 there is shown a simplified func tional block diagram of a mechanical CPR device according to an embodiment of the present invention CPR device 80 includes controller 81 with a linked input device 82 Control ler 81 is further linked to valve 83 and pump 84 A power supply 85 provides power to pump 84 A compression apply ing element 86 is also linked to the device 80 as through valve 83 Compression applying element 86 may comprise any of the chest shaping devices mentioned before such as a vest cuirass strap
10. the second period of time 8 The method according to claim 5 wherein the length of the fourth period of time is less than the length of the second period of time 9 The method according to claim 4 wherein the step of delivering chest compressions fora first period of time further comprises delivering chest compressions at a first frequency and wherein the step of resuming delivery of chest compres sions further comprises delivering chest compressions at a second frequency 10 The method according to claim 9 wherein the first frequency and the second frequency are different 11 The method according to claim 10 wherein the first frequency is less than the second frequency 12 The method according to claim 10 wherein the first frequency is greater than the second frequency 13 The method according to claim 4 wherein the second period of time is greater than 10 seconds 14 A method of administering cardiopulmonary resusci tation CPR to a patient through a CPR device according to a CPR protocol programmed in a controller of the CPR device the CPR protocol comprising delivering chest compressions to the patient with the CPR device during a first time segment within a CPR admin istration period refraining from delivery of chest compressions and from delivery of ventilations to the patient during a second time segment with the CPR administration period the second segment immediately following the first seg ment and delive
11. He Ying Sun Ning Ping Wang Joel S Corvera Michael E Halkos Faraz Kerendi Robert A Guyton and Jakob Vinten Johansen Postconditioning attenuates myocardial ischemia reperfusion injury by inhibiting events in the early minutes of reperfusion Cardiovascular Research 62 2004 p 75 85 Elsevier B V Andrew Tsang Derek J Housenloy Mihaela M Mocanu and Derek Yellon Postconditioning A Form of Modified Reperfusion Protects the Myocardium by Activating the Phosphatidylinositol 3 Kinase Akt Pathway Circulation Research 2004 p 230 232 American Heart Association Inc Xi Ming Yang J Bradley Proctor Thomas Kreig James Downey and Michael V Cohen Multiple Brief Coronary Occlusions During Early Reperfusion Protect Rabbit Hearts by Targeting Cell Signaling Pathways Journal of the American College of Cardiology 2004 vol 44 No 5 1103 1110 Elsevier Inc Roberto J Diaz and Gregory J Wilson Modifying the first minute of reperfusion potential for myocardial salvage Cardiovascular Research 62 2004 p 4 6 Elsevier B V International Search Report and Written Opinion PCT US2005 39633 Intl filing date Nov 2 2005 Office Action dated Apr 1 2009 for U S Appl No 11 961 687 8 pgs Responsive Amendment dated Jul 1 2009 for U S Appl No 11 96 1 687 14 pgs Office Action Response for U S Appl No 11 961 687 filed Jun 25 2010 19 pp Berg RA et al Part 5 adult basic life support 2010 Am
12. RESUSCITATION PROTOCOL FIELD OF THE INVENTION The present invention generally relates to methods and apparatus for performing mechanical cardiopulmonary resuscitation or CPR More particularly the present invention relates to the control of the delivery of CPR Still more par ticularly the present invention relates to protocols configured or programmed within the controller of a mechanical CPR device BACKGROUND OF THE INVENTION CPR as manually applied by human rescuers is generally a combination of techniques including artificial respiration through rescue breathing for example and artificial circu lation by chest compression One purpose of CPR is to provide oxygenated blood through the body and to the brain in those patients where a prolonged loss of circulation places the patient at risk For example after a period of time without restored circulation typically within four to six minutes cells in the human brain can begin to be damaged by lack of oxygen CPR techniques attempt to provide some circulation and in many cases respiration until further medical treat ment can be delivered CPR is frequently though not exclu sively performed on patients who have suffered some type of sudden cardiac arrest such as ventricular fibrillation where the patient s natural heart rhythm is interrupted It has been found that the desired effects of CPR when delivered manually can suffer from inadequate performance In order to h
13. US008795208B2 az United States Patent 10 Patent No US 8 795 208 B2 Walker 45 Date of Patent Aug 5 2014 54 MECHANICAL CPR DEVICE WITH 5 716 318 A 2 1998 Manning VARIABLE RESUSCITATION PROTOCOL 5 722 613 A 3 1998 Michael 5 743 864 A 4 1998 Baldwin 5 997 488 A 12 1999 Gelfand et al 75 Inventor Rob Walker Bothell WA US 6390996 5 2002 Halperin et al 6 398 745 6 2002 Sherman etal 601 41 73 Assignee Physio Control Inc Redmond WA 6 676 613 B2 1 2004 Cantrell et al US 7 311 680 B2 12 2007 Lenhart et al ere i Continued Notice Subject to any disclaimer the term of this patent is extended or adjusted under 35 FOREIGN PATENT DOCUMENTS U S C 154 b by 272 days GB 2446124 A 8 2008 21 Appl No 10 981 365 OTHER PUBLICATIONS 22 Filed Nov 3 2004 Hallstrom et al Cardiopulmonary Resuscitation by Chest Com 65 Prior Publication Data pression Alone or with Mouth To Mouth Ventilation May 25 2000 The New England Journal of Medicine vol 342 No 21 pp 1546 US 2006 0094991 Al May 4 2006 1553 51 Int Cl Continued A61H 31 00 2006 01 52 108 Primary Examiner Quang D Thanh USPC Sasa gaa qa nrun NVRR 601 41 601 108 74 Attorney Agent or Firm Baker amp Hostetler LLP 58 Field of Classification Search CPC A61H 31 00 A61H 31 004 A61H 31 006 57 ABSTRACT A61H 2031 00 A61H 2031 001 A61H Methods to control the delivery of CPR to a pat
14. ardiac arrest a cardiovascular postresuscitation syndrome often ensues characterized by various forms of cardiac dysfunction In many cases this postresuscitation dysfunction can lead to heart failure and death Furthermore the study of reperfusion after ischemia has revealed that a particular kind of injury can develop in the first moments of reperfusion This injury known as ischemia reperfusion injury occurs for reasons not fully understood It however is known to result in a variety of symptoms that can contribute to postresuscitation cardiac dysfunction More importantly 20 25 30 35 40 45 50 55 60 65 2 ischemia reperfusion injury is known to be affected by the quality of reperfusion experienced after a period of inter rupted blood flow A cardiac arrest patient who has had no blood flow for several minutes and who then receives CPR for some period of time may be expected to experience ischemia reperfusion injury Without wishing to be bound by any theory the following explanation is offered to illustrate the current understanding of ischemia reperfusion injury Generally ischemia reperfu sion injury initiates at the cellular level and chemically relates most strongly to the transition between conditions of anoxia hypoxia insufficient oxygen and ischemia insufficient blood flow and conditions of proper oxygenation and blood flow Pathophysiologically reperfusion is associated with a v
15. ardiop ulmonary resuscitation CPR to a patient through a mechani cal CPR device according to a CPR protocol programmed in a controller of the mechanical CPR device the CPR protocol comprising delivering chest compressions to the patient with the mechanical CPR device for a first period of time during a CPR administration period after expiration of the first period of time halting delivery of chest compressions fora second period of time during the CPR administration period and after expiration of the second period of time resuming the delivery of chest compressions to the patient with the mechanical CPR device uninterrupted for the remainder of the CPR administration period wherein the remain der of the CPR delivery period is longer than the first period of time during the CPR administration period 5 The method according to claim 4 further comprising after expiration of the second period of time and before the step of resuming the delivery of chest compressions uninterrupted delivering chest compressions with the mechanical CPR device for a third period of time during the CPR administration period and after expiration of the third period of time halting delivery of chest compressions for a fourth period of time 6 The method according to claim 5 wherein the fourth period of time is the same length as the second period of time 7 The method according to claim 5 wherein the fourth period of time is greater in length than
16. ariety of deleterious events including substantial and rapid increases in oxidant stress intracellular calcium accumula tion and immune system activation These events can spawn a variety of injury cascades with consequences such as car diac contractile protein dysfunction systemic inflammatory response hyperactivation and tissue death via necrosis and apoptosis Unfortunately following cardiac arrest ischemia reperfusion injury and the resulting postresuscitation syn drome is serious enough to cause recovery complication and death in many instances Hence there exists a need for an improved mechanical CPR device and methods for using the same It would be desired to develop CPR methods and particularly CPR meth ods for use with a mechanical CPR device that lessen the severity of ischemia reperfusion injury and that offer an improved level of response and patient treatment The present invention addresses one or more of these needs BRIEF SUMMARY OF THE INVENTION In one embodiment and by way of example only the present invention provides a method for controlling the deliv ery of cardiopulmonary resuscitation through a mechanical CPR device comprising the steps of delivering CPR at a first frequency and subsequently delivering CPR at a second fre quency wherein the second frequency is different from the first frequency The second frequency may be greater than or less than the first frequency Additionally the method m
17. art The frequency of the CPR accelerates to a first frequency plateau 61 at F1 where it is held constant for a desired period of time CPR is then halted for a period of time Trest1 62 CPR then begins again At this point CPR begins at a frequency F2 that is below F1 61 and the CPR accelerates to a second frequency plateau 63 at frequency level F3 Again the CPR frequency is held constant for a desired period of time After that time CPR again halts for a time Trest2 64 This pattern is next shown as repeating After Trest2 64 CPR begins anew at a frequency lower than second frequency plateau 63 accelerates plateaus 65 and stops for a Trest3 66 This cycle can then be repeated as many times as desired Eventually a maximum frequency FMAX 67 is reached As shown in FIG 6 the frequency is held constant at the maxi mum frequency 67 FMAX and no further rest periods are taken In the embodiment illustrated in FIG 6 rest periods Trest1 Trest2 etc successively grow shorter Other relation ships between rest period durations are possible in other embodiments And the time during which CPR is delivered between rest periods which includes the acceleration phase and plateau phase grows longer in successive cycles though 20 35 40 45 8 other relationships are possible in other embodiments In this manner CPR chest compression frequency can be increased over time As mentioned above CPR delivery may also be contro
18. at a first frequency and wherein the step of resuming delivery of chest compres sions further comprises delivering chest compressions at a second frequency 30 The method according to claim 29 wherein the first frequency and the second frequency are different 31 The method according to claim 29 wherein the first frequency is less than the second frequency 32 The method of claim 24 further comprising after expi ration of the second period of time resuming the delivery of chest compressions with the CPR device uninterrupted for the remainder the CPR administration period wherein the remainder of the CPR delivery period is longer than the sum total of the first and second periods of time 33 The method of claim 20 further comprising after expi ration of the fourth time segment resuming the delivery of chest compressions with the CPR device uninterrupted for the remainder the CPR administration period wherein the remainder of the CPR delivery period is longer than the sum total of the first second third and fourth time segments 34 The method of claim 33 wherein the third time seg ment is longer than the first time segment 35 The method of claim 34 wherein the second time segment is longer than the fourth time segment 36 A method of controlling the administration of cardiop ulmonary resuscitation CPR to a patient according toa CPR protocol programmed in a controller of the mechanical CPR device the CPR protocol comp
19. ave the greatest chance at success CPR must typically be performed with some degree of force for an extended period of time Often the time and exertion required for good performance of CPR is such that the human responder begins to fatigue Consequently the quality of CPR performance by human responders may trail off as more time elapses Mechanical CPR devices have been developed which provide chest compression using various mechanical means such as for example reciprocating thrusters or belts or vests which tighten or constrict around the chest area In these automated CPR devices motive power is supplied by a source other than human effort such as for example electrical power or a compressed gas source Mechanical CPR devices have the singular advantage of not fatiguing as do human respond ers Additionally mechanical CPR devices may be advanta geous when no person trained or qualified in manual CPR is able to respond to the patient Thus the advent of mechanical CPR devices now allows for the consistent application of CPR chest compressions for extended periods of time When a patient experiences cardiac arrest the heart ceases to pump blood throughout the body The cessation of blood flow is known as ischemia When CPR chest compressions are commenced some blood flow is restored The restoration of blood flow after a period of ischemia is known as reperfu sion The study of CPR has revealed that after initial resusci tation from c
20. ay include halting the delivery of CPR for a period of time between the delivery of CPR at a first frequency and the delivery of CPR at a second frequency Still further the method may include accelerating or decelerating the rate of delivery of CPR from the first frequency to the second fre quency In a further embodiment still by way of example there is provided a method of controlling the administration of CPR to a patient through a mechanical CPR device comprising temporarily alternating between a period of delivery of CPR and a period of non delivery of CPR The alternating between a period of delivery of CPR and a period of non delivery of CPR may begin once mechanical CPR is first delivered to a patient Additionally alternating between a period of delivery of CPR and a period ofnon delivery of CPR may occur during the first minute after mechanical CPR is first delivered to a patient In still a further embodiment and still by way of example there is provided a device for the delivery of mechanical CPR that is also configured to regulate the delivery of CPR to a patient comprising a means for compressing a patient s chest a means for actively decompressing or permitting pas sive decompression of a patient s chest and a controller linked to the means for compressing and the means for actively decompressing or permitting passive decompres US 8 795 208 B2 3 sion and wherein the controller is also configured to auto
21. device according to an embodiment of the present invention DETAILED DESCRIPTION The following detailed description of the invention is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention Fur thermore there is no intention to be bound by any expressed or implied theory presented in the preceding background of 0 25 35 40 45 50 60 65 4 the invention or the following detailed description of the invention Reference will now be made in detail to exemplary embodiments of the invention examples of which are illus trated in the accompanying drawings Wherever possible the same reference numbers will be used throughout the draw ings to refer to the same or like parts It has now been conceived that the application of CPR through a mechanical CPR device can be controlled in a manner so as to lessen the potential for post treatment ischemia reperfusion injury In general an embodiment of the invention includes accelerating or increasing the delivery rate or frequency of CPR when first responding to a patient in a manner that results in blood flow being gradually rather than suddenly restored Another embodiment of the inven tion includes temporarily alternating on and off the delivery of CPR when first responding to a patient in a manner that similarly results in net blood flow being gradually rather than suddenly restored The gradual or the in
22. erican Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Circulation Nov 2 2010 122 18 Suppl 3 S685 705 Cave DM et al Part 7 CPR techniques and devices 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Circulation Nov 2 2010 122 18 Suppl 3 S720 8 Chapman F W et al A Feedback Controller for Ventilatory Therapy Annals of Biomedical Engineering 1985 13 359 372 Maquet Servo Ventilator 900 C D E Service Manual Maquet Criti cal Care AB May 2009 55 pages Neumar RW et al Part 8 adult advanced cardiovascular life support 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Circulation Nov 2 2010 122 18 Suppl 3 S729 67 Ovize M et al Working Group of Cellular Biology of Heart of European Society of Cardiology Postconditioning and protection from reperfusion injury where do we stand Position paper from the Working Group of Cellular Biology of the Heart of the European Society of Cardiology Cardiovasc Res Aug 1 2010 87 3 406 23 Part 4 Adult Basic Life Support Circulation 2005 112 18 to 34 Part 6 CPR Techniques and Devices Circulation 2005 112 47 to IV 50 Segal N et al Ischemic postconditioning at the initiation of cardiopulmonary resuscitation facilitates functional cardiac and cerebral rec
23. fore changes in frequency need not be exclusively to increase the frequency Frequency may be decreased or even halted Now it will also be appreciated that on off mode control may also be combined with any of the forms of control shown in FIGS 3 4 and 5 Thus for example at any point in the operation illustrated in FIG 3 4 or 5 there could be inserted an off interval And after a period of being in off mode delivery of chest compressions may be commenced again Further when stutter control mixed on off control is uti lized along with a control that varies the cycle frequency the frequency at a second start point need not coincide with the frequency when the off mode began It may be preferred for example to begin delivery of chest compressions at a lower cycle frequency than was being done just prior to off mode While the term off or off mode or other similar terms has been used herein it will be appreciated that this does not necessarily mean that the device powers off or turns off Rather it means that delivery of CPR is halted or suspended CPR delivery is off Preferably the CPR device would at all times remain in a powered up energized condition Referring now to FIG 6 there is shown an embodiment of a more complex control of the CPR frequency that combines accelerations stepped plateau frequencies and off periods with no CPR delivery In this embodiment CPR is applied at atime Tst
24. ient through a 2031 003 A61H 2201 1619 mechanical CPR device are described The method generally 2201 5007 A61H 2203 0456 A61H 2205 08 allows for a gradual increase in the frequency of CPR cycles USPC 601 41 42 43 44 107 108 128 898 The gradual increase be regulated by protocols pro See application file for complete search history grammed within the CPR device such as intermittently start ing and stopping the delivery of CPR accelerating the deliv 56 References Cited ery of CPR stepping up the CPR frequency increasing the force of CPR and adjusting the ratio of compression and U S PATENT DOCUMENTS decompression ina cycle Combinations of each of these 4 060 079 A 11 1977 Reinhold Jr forms may also be used to control the delivery of CPR This 4 397 306 A 8 1983 Weisfeldt et al 601 41 manner of gradually accelerating artificial blood flow during 4 424 806 A 1 1984 Newman et al the first minutes of mechanical CPR delivery can serve to Toren einer Tape al lessen the potential for ischemia reperfusion injury in the 5 020 516 A 6 1991 Biondi et al patient who receives mechanical CPR treatment 5 261 394 A 11 1993 Mulligan et al 5 490 820 A 2 1996 Schock et al 45 Claims 4 Drawing Sheets US 8 795 208 B2 Page 2 56 References Cited U S PATENT DOCUMENTS 7 717 855 B2 8 343 081 B2 2003 0135085 Al 2003 0135139 Al 2004 0230140 Al 2005 0165335 Al 2006 0089574
25. ient with the CPR device during a first time segment within a CPR admin istration period refraining from delivery of chest compressions to the patient and from delivery of ventilations to the patient during a second time segment within the CPR adminis tration period the second time segment immediately following the first time segment delivering chest compressions to the patient with the CPR device during a third time segment within the CPR administration period the third time segment immedi ately following the second time segment and refraining from delivery of chest compressions to the patient and from delivery of ventilations to the patient during a fourth time segment within the CPR adminis tration period the fourth time segment following the third time segment 21 The method of claim 20 wherein the step of delivering chest compressions during the third time segment further comprises alternating between a time segment of delivery of chest compression and a time segment of refraining from delivery of chest compression and from delivery of ven tilations 22 The method of claim 21 further comprising repeating the alternating step 23 The method of claim 20 wherein the initial second and third time segments occur within the first minute after com mencement of chest compression delivery 24 A method of controlling the administration of cardiop ulmonary resuscitation CPR to a patient through mechani cal CPR device duri
26. lled through variation of the compressive force applied to the patient through the CPR device Referring now to FIG 7 there is shown a plot of force versus time that illustrates an increase in peak force applied by the mechanical CPR device over time The curve 73 illustrates a growing magnitude of successive oscillations this represents that more force pres sure is being applied to successive mechanical CPR cycles Force pressure 71 grows until it reaches a desired maximum 74 From that point forward it would be preferred to maintain the peak force pressure at the desired maximum FIG 7 represents the magnitude of peak force growing ina relatively linear fashion in successive cycles However it will be appreciated that other rates of changes in peak force are possible For example peak force may increase or decrease over time in a step wise manner Likewise force may be increased or decreased non linearly such as for example by exponential growth or decay Also CPR may be controlled through variations in the compression decompression cycle The relative length of the compression phase may change with respect to its corre sponding decompression phase This change in the cycle can also occur so that the overall cycle time remains constant or changes Thus in one embodiment early in mechanical CPR treatment it may be desired to have a relatively shorter com pression phase compared to later compression phases The relative duration of
27. ng a CPR administration period accord ing to a CPR protocol programmed in a controller of the mechanical CPR device the CPR protocol comprising delivering chest compressions to the patient for a first period of time during the CPR administration period after expiration of the first period of time halting delivery of chest compressions to the patient for a second period of time during the CPR administration period the sec ond period of time being substantially equal in length to the first period of time 25 The method according to claim 24 further comprising after expiration of the second period of time delivering chest compressions for a third period of time during the CPR administration period and 20 25 30 35 40 45 60 12 after expiration of the third period of time halting delivery of chest compressions for a fourth period of time during the CPR administration period 26 The method according to claim 25 wherein the fourth period of time is the same length as the second period of time 27 The method according to claim 25 wherein the fourth period of time is greater in length than the second period of time 28 The method according to claim 25 wherein the length of the fourth period of time is less than the length of the second period of time 29 The method according to claim 25 wherein the step of delivering chest compressions for a first period of time further comprises delivering chest compressions
28. nt through a mechani cal CPR device during a CPR delivery period according to a CPR protocol programmed in a controller of the mechanical CPR device the CPR protocol comprising alternating between a period of delivery of chest compres sions to the patient with the mechanical CPR device and a period of non delivery of chest compressions to the patient for an initial portion of the CPR delivery period and after the step of alternating between the period of delivery of chest compressions and the period of non delivery of chest compressions delivering an uninterrupted series of chest compressions to the patient with the mechanical CPR device for the remainder of the CPR delivery period wherein the remainder of the CPR delivery period is longer than the period of delivery of chest compressions during the initial portion of the CPR deliv ery period 2 The method according to claim 1 wherein alternating between the period of delivery of chest compressions and the period of non delivery of chest compressions begins once mechanical CPR is first delivered to the patient 3 The method according to claim 1 wherein alternating between the period of delivery of chest compressions and the period of non delivery of chest compressions occurs only during the first minute after mechanical CPR is first delivered to the patient 0 5 25 30 35 40 45 55 60 65 10 4 method of controlling the administration of c
29. omprising a chest compression mechanism for delivering chest com pressions to a patient during a CPR delivery period and a controller that operates the chest compression mecha nism according to a CPR protocol programmed within the CPR device wherein the CPR protocol includes a beginning portion during the first minutes of the CPR delivery period wherein the beginning portion pro vides a gradual increase in net blood flow to the patient to lessen the potential for reperfusion injury to the patient relative to immediately restoring net blood flow to the patient at the beginning portion of the CPR delivery period and a remaining portion following the beginning portion wherein the remaining portion provides a greater net blood flow than with the beginning portion wherein the net blood is constant over the remaining portion wherein the remaining portion extends from the end of the beginning portion until the end of the CPR delivery period 43 The CPR device of claim 42 wherein the CPR protocol comprises a gradual acceleration in a delivery rate of chest compressions during the beginning portion 20 14 44 The CPR device of claim 42 wherein the beginning portion of the CPR protocol consists of alternating between periods of delivery of chest compressions and periods of non delivery of chest compressions during 45 A mechanical cardiopulmonary resuscitation CPR device comprising means for delivering chest compressions to a
30. or example on how the patient had been treated prior to the arrival of the CPR device A patient who had been receiving manual CPR for an extended period of time may be treated differently than a patient who has not received any CPR In the former case a quick ramp up time or even no ramp up time may be desired and in the latter case a relatively more gentle extended ramp up tech nique may be desired In view of the foregoing it should be appreciated that methods and apparatus are available that allow a mechanical CPR device to follow a variable resuscitation protocol While a finite number of exemplary embodiments have been pre sented in the foregoing detailed description of the invention it should be appreciated that a vast number of variations exist It should also be appreciated that the exemplary embodiments are only examples and are not intended to limit the scope applicability or configuration of the invention in any way Rather the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing exemplary embodiments of the invention It should also be understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope of the inven tion as set forth in the appended claims What is claimed is 1 A method of controlling the administration of cardiop ulmonary resuscitation CPR to a patie
31. overy after prolonged untreated ventricular fibrillation Resuscitation Nov 2012 83 11 1397 1403 Travers AH et al Part 4 CPR overview 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Circulation Nov 2 2010 122 18 Suppl 3 S676 84 Wang JY et al Ischemic postconditioning protects against global cerebral ischemia reperfusion induced injury in rats Stroke Mar 2008 39 3 983 90 Yannopoulos D et al Controlled pauses at the initiation of sodium nitroprusside enhanced cardiopulmonary resuscitation facilitate neurological and cardiac recovery after 15 mins of untreated ventricular fibrillation Crit Care Med May 2012 40 5 1562 9 Yannopoulos D et al Ischemic post conditioning and vasodilator therapy during standard cardiopulmonary resuscitation to reduce cardiac and brain injury after prolonged untreated ventricular fibril lation Resuscitation Aug 2013 84 8 1143 9 Epub Jan 29 2013 Zhao Heng The Protective Effects of Ischemic Postconditioning against Stroke From Rapid to Delayed and Remote Postcondition ing The Open Drug Discovery Journal 2010 2 138 147 Zhou Y et al Postconditioning in cardiopulmonary resuscitation a better protocol for cardiopulmonary resuscitation Med Hypoth eses Sep 2009 73 3 321 3 2009 03 014 Epub Apr 24 2009 The Free Dictionary Definition of a mechanical device p 1 of 2 Apr
32. ring chest compressions to the patient with the CPR device during a third time segment within the CPR administration period the third segment immediately following the second segment wherein the third time period is longer than the first time period 15 The method of claim 14 wherein the step of delivering chest compressions during the third segment further com prises US 8 795 208 B2 11 alternating between a time segment of delivery of chest compression and a time segment of refraining from delivery of chest compression and from delivery of ven tilations 16 The method of claim 15 further comprising repeating the alternating step 17 The method of claim 14 wherein the first second and third segments occur within the first minute after commence ment of chest compression delivery 18 The method according to claim 14 wherein the step of delivering chest compressions during a first segment includes delivering chest compressions at a first frequency and wherein the step of delivering chest compressions during a third segment includes delivering chest compressions at a second frequency 19 The method according to claim 18 wherein the first frequency is less than the second frequency 20 A method of administering cardiopulmonary resusci tation CPR to a patient through a CPR device according to a CPR protocol programmed in a controller of the CPR device the CPR protocol comprising delivering chest compressions to the pat
33. rising for the first minutes of CPR performance during a CPR administration period iteratively switching between an on mode in which chest compressions are delivered to the patient and an off mode in which no chest compres sions are delivered to the patient and after the first minutes of CPR performance during the CPR administration period permanently remaining in the on mode during the administration of CPR to the patient 37 The method of claim 36 wherein each iteration of the on mode is progressively longer than the previous iteration of the on mode 38 The method of claim 37 wherein each iteration of the off mode is progressively shorter than the previous iteration of the off mode 39 The method of claim 36 wherein a frequency of the chest compressions for each iteration of the on mode is pro gressively greater than a frequency of the chest compressions for the previous iteration of the on mode 40 The method of claim 36 wherein the on mode includes delivering ventilations to the patient with a mechanical CPR device and wherein the off mode includes delivering venti lations to the patient with the mechanical CPR device 41 The method of claim 36 wherein the on mode includes delivering ventilations to the patient with a mechanical CPR device and wherein the off mode includes refraining from delivery of ventilations to the patient US 8 795 208 B2 13 42 A mechanical cardiopulmonary resuscitation CPR device c
34. t s chest cavity After com pression the mechanical CPR device then experiences a period of decompression During the period of decompres sion the patient s chest cavity is either allowed to decompress passively for a period of time or is actively decompressed through a direct coupling of the mechanical CPR device to the patient s chest In a mechanical device decompression may be achieved by relieving pressure and or force for a period of time Active decompression in a mechanical device may be achieved by directly coupling the mechanical device to the patient s chest during the decompression phase for example by use of a suction cup Other devices may alternate force between a constriction and an expansion of for example a belt harness or vest CPR including mechanical CPR is thus a cycle of repeat ing compressions Referring now to FIG 1 there is shown a graphical representation of an exemplary mechanical CPR cycle The curve 10 represents a plot of varying force or pressure 11 against time 12 The force pressure is any mea sure of force or pressure such as pressure applied to a chest cuirass or force applied on the chest A typical cycle 13 includes a compression phase 14 and a decompression phase 15 in the device During compression phase 13 force and or pressure is applied in the example illustrated force is steadily increased until a plateau pressure 16 is reached The force is US 8 795 208 B2 5 held at the pla
35. t indicates a first time with respect to the chart may also correspond to some time in the patient s treatment history after the first delivery of mechanical CPR This is also true for the other figures that include a time variable Thus the varied or controlled CPR shown in the figures may illustrate CPR control that occurs at any point during mechanical CPR delivery The protocol discussed in FIG 2 deals with a stuttered on off delivery of CPR However CPR delivery may also be varied with respect to other CPR variables beyond the on off mode As discussed the mechanical delivery of CPR gener ally comprises cycles of compression and decompression The rate or frequency of this cycle may be varied Addition ally the individual components of the cycle such as force of the compression stroke may be varied Finally the ratio of compression decompression components the duty cycle may also be varied Referring now to FIG 3 there is shown a graphical illus tration ofa varied CPR delivery according to another embodi ment of the invention FIG 3 represents a plot 30 of the frequency 31 of the CPR cycle compression and decompres sion phases of the device against time 32 In general terms FIG 3 illustrates a step up in the delivery of CPR where the frequency increases from a lower rate to a higher rate Thus CPR delivery begins with a frequency1 33 After a period of time T1 the CPR frequency is stepped up to frequency2 34 After
36. teau 16 As is known in the art plateau 16 typically represents a maximum pressure that takes into account considerations of both safety and resuscitation effec tiveness After a desired time force is released and this begins the decompression phase 15 A controlled release may occur providing a gradual decrease in force or as illustrated a full uncontrolled and quicker release takes place During the decompression phase 15 pressure decreases In the example shown pressure decays until no pressure exists The decompression phase 15 continues for a desired time and then a new compression phase 14 begins The frequency measured in cycles unit time of the compression decompres sion cycle is a measure of the rate or speed at which CPR is applied to the patient Mechanical CPR devices are typically designed with a preset frequency the present frequency may attempt to mimic the frequency of an ideal human performed CPR Thus a mechanical CPR device may come with a preset cycle frequency of approximately one hundred 100 cycles per minute Additionally some mechanical CPR devices are designed to include a regular periodic pause for ventilation in their protocols For example the device may provide for a pause after a set of compressions Other devices are designed to provide continuous compressions without pause for venti lation The CPR device with variable resuscitation protocol described herein is equally applicable to either type of
37. termittent restoration of blood flow allows the body s natural metabolism and chemical processing mechanisms to better neutralize the potentially harmful effects of reperfusion and a sudden increase in the supply of oxygen to the body s tissues The starting point for the gradual or the intermittent restoration of blood flow preferably coincides with the first delivery of CPR to the patient The method may include control techniques that affect variables in mechanical CPR delivery these con trol techniques include for example a gradual acceleration increase in the CPR delivery rate or also periods of CPR interspersed with periods of non delivery of CPR While the CPR control techniques described herein may be performed at any time they are preferably to be applied to a patient during the first minutes of CPR performance The CPR control methods described herein can be adapted to any mechanical CPR device that provides chest compres sion There are various designs of mechanical CPR devices Many designs rely on a vest cuirass strap or harness that surrounds a patient s chest cavity The vest cuirass harness can be constricted compressed inflated or otherwise manipulated so that the patient s chest cavity is compressed Other devices may rely on the direct application of force on the patient s chest as through a compressor arm Regardless of the mechanical means used the mechanical CPR device effects a compression of the patien
38. tion 42 a linear acceleration 43 and a back loaded acceleration 44 The term front loaded indicates that there is a rapid non linear increase in the cycle such as exponen tial growth followed by a gradual approach to a steady fre quency The term linear indicates that there is a steady rate of increase as represented by a linear function And the term back loaded indicates that the acceleration occurs later US 8 795 208 B2 7 during the time that acceleration occurs again as represented in example by an exponential or other non linear function Each period of acceleration ends at point 45 Following that there is shown a steady application of CPR at a constant frequency 46 It will be understood however that the admin istration of CPR may continue to be modified and shaped beyond what is illustrated A further embodiment that combines elements of the step increase and continuous increase is shown in FIG 5 In this figure the delivery of CPR is controlled whereby a series of plateaus 51 at successively increasing frequencies are reached Each successive plateau represents an increase in cycle frequency However there is added in FIG 5 intermit tent periods of acceleration 52 between each plateau The form of intermittent acceleration 52 is shown as non linear growth in the figure however other forms of frequency accel eration may be applied The time at each frequency plateau may vary And as stated be
39. ws TOFF2 28 Applying CPR again after TOFF2 there follows TON3 29 This alternating or switching between applying and halting CPR can continue for as many iterations as desired It will be appreciated that the lengths of time represented by 25 and TON2 27 may be the same or different In a preferred embodiment TON2 is greater than if TON3 is present TON3 is greater than TON2 In this manner there is aramp up in CPR delivered to the patient in that each period during which the patient receives CPR is increased in duration Tn similar manner duration of off periods can be the same or different Again in a preferred embodiment duration of off intervals become successively shorter 1 TOFF1 gt TOFF2 Again by shortening successive off periods the patient expe riences a gradual ramp up in the active delivery of CPR The 0 5 25 40 45 55 6 duration of CPR increases It will also be appreciated that the relative lengths of each TON period and each TOFF period may be the same or different For example the duration of the first TOFF period may be equal to the duration of the imme diately following TON period as illustrated in FIG 2 In FIG 2 the graph shows a switching between on and off modes beginning at a start time Tstart Tstart may preferably coincide with the first delivery of mechanical CPR to a patient but that need not be the case Thus for example Tstart while i
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