CPR CHEST COMPRESSION SYSTEM WITH TONOMETRIC INPUT AND FEEDBACK

• US 20150265497A1
• Filed: 03/16/2015
• Published: 09/24/2015
• Est. Priority Date: 03/18/2014
• Status: Active Grant

• Current Assignee: Zoll Medical Corporation (Asahi Kasei Corporation)
• Original Assignee: Zoll Medical Corporation (Asahi Kasei Corporation)
• Inventors: Freeman, Gary A., Kaufman, Christopher L.
• Granted Patent: US 10,596,064 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A61H 2011/005 with belt or strap expanding and contracting around an encircled body part
• CPC Class Codes: A61H 2201/1215 Rotary drive
• CPC Class Codes: A61H 2201/5007 computer controlled
• CPC Class Codes: A61H 2201/5046 Touch screens
• CPC Class Codes: A61H 2201/5071 Pressure sensors
• CPC Class Codes: A61H 2230/045 used as a control parameter for the apparatus
• CPC Class Codes: A61H 31/005 with feedback for the user
• CPC Class Codes: A61H 31/006 Power driven

Abstract

A CPR chest compression system which uses tonometric data as feedback for control of chest compression device.

Claims

1. A system for providing CPR compressions on a cardiac arrest victim, said system comprising:

a chest compression device operable to repetitively compress the chest of the cardiac arrest victim;

a tonometric sensor operable to detect CPR-induced pulse waves and produce a pulse wave signal corresponding to the pulse wave;

a control system operable to control the compression device to provide a plurality of test chest compression sets in a plurality of compression regimens characterized by one or more compression parameters;

wherein

the control system is programmed to receive the pulse wave signal and determine a pulse pressure waveform from the pulse wave signal for each of the plurality of compression regimens, and further programmed to determine a parameter of the pulse pressure waveform for each of the plurality of compression regimens;

said control system further programmed to determine which pulse pressure waveform provides the most effective CPR-compression-induced blood flow based on the values of the parameter; and

the control system is further programmed to operate the compression device to provide chest compressions according to the compression regimen corresponding to the pulse pressure waveform which provides the most effective CPR-compression-induced blood flow based on the values of the parameter, for an extended period of time.

2. The system of claim 1, wherein the tonometric sensors are adapted to detect the CPR-induced pulse waves at a peripheral artery of the cardiac arrest victim and produce a peripheral pulse wave signal corresponding to the pulse waves, and the control system is further programmed to determine the pulse pressure waveform from the peripheral pulse wave signal.

3. The system of claim 2, wherein the pulse pressure waveform determined from peripheral pulse wave signal is an estimated aortic pulse pressure waveform obtained by applying a transfer function to the peripheral pulse wave signal.

4. The system of claim 1, wherein parameter upon which the control system determines which pulse pressure waveform provides the most effective CPR-compression-induced blood flow, and thus which compression regimen provides the most effective CPR-compression-induced blood flow, is a pressure time integral of the pulse pressure waveform.

5. The system of claim 4, wherein the pressure time integral is a CPR systole pressure time integral associated with a compression period of the CPR compression device.

6. The system of claim 4, wherein the pressure time integral is a CPR diastole pressure time integral associated with a release period of the CPR compression device.

7. The system of claim 4, wherein the pressure time integral is a CPR total pressure time integral associated with an entire compression cycle of the CPR compression device.

8. The system of claim 1, wherein the parameter upon which the control system determines which pulse pressure waveform provides the most effective CPR-compression-induced blood flow, and thus which compression regimen provides the most effective CPR-compression-induced blood flow, is a peak pressure of the pulse pressure waveform.

9. The system of claim 1, wherein the parameter upon which the control system determines which pulse pressure waveform provides the most effective CPR-compression-induced blood flow, and thus which compression regimen provides the most effective CPR-compression-induced blood flow, is an inflection point or notch in the pulse pressure waveform.

10. The system of claim 1, wherein a first chest compression regimen is characterized by a first compression depth, and a second chest compression regimen is characterized by a second compression depth different from the first compression depth.

11. The system of claim 1, wherein a first chest compression regimen is characterized by a first release velocity, and a second chest compression regimen is characterized by a second release velocity different from the first release velocity.

14. The system of claim 1, 12 of 13 wherein the tonometric sensor comprises an array of pressure sensing elements disposed on a flexible substrate, where said flexible substrate is adapted for secure placement over a peripheral artery of the cardiac arrest victim, and the control system is operable to receive signals from pressure sensing elements and analyze those signals to determine a pulse pressure waveform of the peripheral artery.

22. The system of claim 1 wherein the compression parameters comprise one or more of compression depth, compression rate, compression rise time, compression hold time, and release velocity

12. A system for providing CPR compressions on a cardiac arrest victim, said system comprising:

a chest compression device operable to repetitively compress the chest of the cardiac arrest victim;

a tonometric sensor operable to detect CPR-induced pulse waves at a peripheral artery of the cardiac arrest victim and produce a pulse wave signal corresponding to the pulse wave;

a control system operable to control the compression device to provide a plurality of chest compression, accept user input regarding the administration of a therapeutic agent to the cardiac arrest victim and provide prompts to the user;

said control system programmed to receive the pulse wave signals and determine a pulse velocity from the pulse wave signal caused by the chest compressions;

said control system further programmed to accept user input indicating the administration of a therapeutic agent to the cardiac arrest victim during the course of CPR compressions;

said control system further programmed to compare pulse velocity before and after the administration of the therapeutic agent, and generate prompts to deliver prompts to the user regarding the effect of the therapeutic agent on the pulse velocity.

13. A system for providing CPR compressions on a cardiac arrest victim, said system comprising:

a chest compression device operable to repetitively compress the chest of the cardiac arrest victim;

a tonometric sensor operable to detect CPR-induced pulse waves and produce a pulse wave signal corresponding to the pulse wave;

a control system operable to control the compression device;

said control system programmed to receive the pulse wave signal and determine a pulse pressure waveform from the pulse wave signal;

said control system further programmed to operate the compression device to adjust operation of the chest compression device based on pulse pressure waveform.

15. A method of performing CPR on a cardiac arrest victim, said method comprising the steps of:

repetitively performing chest compressions on the cardiac arrest victim with a CPR chest compression device;

obtaining compression-induced pulse pressure waveforms from the cardiac arrest victim, where said pulse pressure waveforms are caused by chest compressions performed by the chest compression device;

adjusting a parameter of the chest compressions based on a characteristic of the pulse pressure waveforms.

16. The method of claim 15, wherein the parameter of the chest compression is one or more of compression rate (cpm), compression depth, compression rise time, compression hold time, and release velocity.

17. A method for providing CPR compressions on a cardiac arrest victim, said method comprising the steps of:

repetitively performing chest compressions on the cardiac arrest victim with a chest compression device;

obtaining compression-induced pulse pressure waveforms at peripheral locations of the cardiac arrest victim while performing chest compressions;

determining a characteristic of the compression-induced pulse pressure waveforms;

while performing the chest compressions, performing a first subset of compressions according to a first compression regimen, and performing a second set of compressions according to a second compression regimen;

determining a characteristic of the compression-induced pulse pressure waveforms associated with the first subset of compressions;

determining a characteristic of the compression-induced pulse pressure waveforms associated with the second subset of compressions;

comparing the characteristic of the compression-induced pulse pressure waveforms associated with the first subset of compressions and characteristic of the compression-induced pulse pressure waveforms associated with the second subset of compressions, and determining on the basis of the comparison which chest compression regimen is likely to provide better CPR-induced blood flow;

thereafter performing compressions according to the chest compression regimen determined to be likely to provide better CPR-induced blood flow to resuscitate the cardiac arrest victim.

18. The method of claim 17, wherein the pulse pressure waveform is an estimated aortic pulse pressure waveform derived a measured peripheral pulse pressure waveform.

19. The method of claim 17, wherein the characteristic used for the comparing step is CPR-SPTI, CPR-DPTI, CPR-TPTI, or size or timing of a pseudo-reflective notch, or the highest peak pressure of the pulse pressure waveform.

20. The method of claim 17, further comprising the steps of:

periodically, during a course of chest compressions, repeating the step of determining a characteristic of compression induced pulse pressure waveforms for different pair of subsets of compressions performed under differing compression regimens, comparing the characteristics of each new subset of compressions, and determining which of the differing compression regimens is likely to provide the better CPR-induced blood flow; and

thereafter performing compressions according to the chest compression regimen determined to be likely to provide better CPR-induced blood flow to resuscitate the cardiac arrest victim.

21. The method of claim 17, wherein the first chest compression regimen is characterized by a first combination of compression rate (cpm), compression depth, compression rise time, compression hold time, and release velocity and the second chest compression regimen is characterized by a second combination of compression rate (cpm), compression depth, compression rise time, compression hold time, and release velocity.