There was no death or device malfunction associated with the defibrillation event.Device evaluation summary: monitor sn (b)(4) has not yet been recovered from the field.Belt sn (b)(4) was returned and evaluated at the distributor, in accordance with procedures recommended by zoll manufacturing corporation.The evaluation included review of downloaded software flag files on the day of the event and incoming functional testing.The review of the software flags consisted of an analysis of the downloaded data to identify any fault flags or unusual patterns of software flags.The software flag files did not suggest a device malfunction that would contribute to the inappropriate treatment.During the incoming functional testing, a 1hz simulated normal sinus rhythm signal was applied to the ecg electrodes, followed by a 5hz simulated treatable arrhythmia signal.During the transition to the 5hz signal, verification of the tactile vibration alarm and testing of the pulse delivery circuitry was completed successfully.The pulse delivery circuitry test verified proper delivery of a full energy 150j biphasic pulses.The functional testing confirmed proper ecg acquisition and pulse delivery functionality.There is no indication of a product malfunction contributing to the event the investigation into the event concludes that there was no device malfunction.A cause and effect analysis was conducted using all of the available information which includes the incident report, device evaluation, software flag files, and ecg strips.The primary cause of the inappropriate shock event was lack of response button use prior to shock delivery.The primary cause of the inappropriate shock event was lack of response button use prior to shock delivery.The ecg analysis, conducted by trained ecg technicians, identified the primary cause of the false detection as multiple counting of a low amplitude cardiac signal.Inappropriate defibrillations are an anticipated risk associated with the use of the lifevest.Patients are instructed through alarms, voice messages, ifu, and training to press the response buttons to prevent an inappropriate defibrillation.The current commercial inappropriate defibrillation rate is consistent with the observed rate during the pivotal clinical trial (b)(4).A summary of the safety and effectiveness data (ssed), including the inappropriate defibrillation safety objective supporting fda's approval of the lifevest, can be found at http://www.Accessdata.Fda.Gov/cdrh_docs/pdf/p010030b.Pdf.The lifevest detection algorithm complies with iec 60601-2-4 performance requirements for sensitivity and specificity.
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