Biomedical instrumentation & technology / Association for the Advancement of Medical Instrumentation
-
Biomed Instrum Technol · Jul 1990
Comparative StudyComputer-aided characterization and optimization of the Thumper compression waveform in closed-chest CPR.
Optimization of blood flow and blood pressure is critical for a positive outcome of cardiopulmonary resuscitation (CPR). The use of models can facilitate the analysis of different methods of performing CPR. Programming with SPICE software, the authors modified a hardware model electrically equivalent to the human cardiovascular system into a software model to analyze and predict the hemodynamic output parameters of different compression waveform inputs used in thoracic pump CPR. ⋯ The model also predicted increased mean systolic pressure when the duty cycle increased from 20% to 80% while diastolic pressure decreased slightly. Although mean systolic pressure increased with increased duty cycle, the model predicted a decrease in coronary flow at the higher duty cycles of all compression waveforms. Increases of 75% to 100% in systolic pressure and blood flow were produced when increases in chest compression force and the rapidity of the rise time, termed "spike-impulse" CPR, were simulated.