Defibrillator-embedded rapid recovery electrocardiogram amplifier.
One of the most important performances of the defibrillator-embedded amplifier-monitor-recorder tract, connected to defibrillator electrodes, is its rapid recovery after the application of the shock pulse. Practically near-immediate restoration of the signal trace is mandatory for studies of post-shock effects on the myocardium. Automatic analysis of the electrocardiogram signal in public-access defibrillation, aiming for about 100% correct recognition of shockable and non-shockable rhythms, now requires fast amplifier settling, as the decision time should not exceed 10-20 s. Two circuits of post-shock amplifier transient suppressors were developed with non-linear feedback, resulting in second-order high-pass filtering, with gradual return to normally accepted first-order response. Simulation and testing in real conditions resulted in recovery periods in the range of 1-2 s for an amplifier tract of 1-30 Hz bandwidth, depending on the pulse waveform and electrode type.
Neycheva
T
T
Center for Biomedical Engineering, Bulgarian Academy of Science, Sofia, Bulgaria.
Krasteva
V
V
D000669:Amplifiers, Electronic; D004554:Electric Countershock / Q000295:instrumentation* / Q000379:methods; D004562:Electrocardiography / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005246:Feedback; D011786:Quality Control; D012815:Signal Processing, Computer-Assisted