Design of near-optimal waveforms for chest and abdominal compression and decompression in CPR using...

Area of Science:

• Cardiovascular Physiology
• Biomedical Engineering
• Resuscitation Science

Background:

• External chest and abdominal compression waveforms are critical for effective cardiopulmonary resuscitation (CPR).
• Optimizing these waveforms may enhance blood flow and patient outcomes during cardiac arrest.

Purpose of the Study:

• To identify optimal design principles for external chest and abdominal compression and decompression waveforms during CPR.
• To improve mean perfusion pressure during simulated cardiac arrest.

Main Methods:

• A 14-compartment mathematical model of the cardiopulmonary system was used to simulate CPR.
• Successive generations of randomly mutated compression waveforms were tested, with superior waveforms selected based on systemic or coronary perfusion pressure.
• 64,414 CPR episodes were simulated to characterize evolved waveforms.

Main Results:

• Optimized waveforms featuring reciprocal chest and abdominal compression/decompression significantly increased mean perfusion pressure (1.5-3 times standard CPR).
• Maximized systemic perfusion pressure favored a chest compression/abdominal decompression phase of ~70%, while maximized coronary perfusion pressure favored ~30%.
• A compromise waveform at 80 min⁻¹ with a 50% duty cycle achieved near-maximal systemic and coronary perfusion pressure.

Conclusions:

• Optimized thoraco-abdominal compression-decompression waveforms integrate features of active decompression and interposed abdominal compression.
• These advanced waveforms can be implemented via manual or mechanical devices for non-invasive blood perfusion during cardiac arrest.
• The study provides design principles for developing more effective CPR devices and techniques.