Implantable medical device having means for discriminating between true R- waves and ventricular fibrillation

摘要

An improved "VF immune" cardiac event detector for an implantable medical device consists of high-frequency and a low-frequency delta converters coupled to an intracardiac signal. The high-frequency delta converter is tuned to be responsive to R-waves and VF waveforms. However, the low-frequency delta converter is tuned to be responsive only to VF waveforms. By monitoring the difference between the outputs of the high- frequency and the low-frequency delta converters, the system can effectively discriminate between "true" R-waves and VF waveforms.