AN AUTOMATIC EXTERNAL CARDIOVERTER/DEFIBRILLATOR WITH CARDIAC RATE DETECTOR

摘要

An external defibrillator (10) includes a detector (74, 76, 78) used to detect a life threatening condition of a patient, a controller (70) operating the defibrillator automatically and a therapy delivery circuit (84) that delivers appropriate therapy. The defibrillator is attached to a patient and is adapted to monitor the patient and when a life threatening condition is detected, to apply therapy automatically. An averaging scheme is used to determine a current cardiac rate by taking a first average of the intervals between a preset number of successive cardiac events, establishing a differential between this average and the intervals, and dropping the interval corresponding to the largest differential. In this manner, the effects of over- and under-sensing are eliminated or at least reduced.