There was no death or device malfunction associated with the defibrillation event.Device evaluation summary: device evaluation of monitor sn (b)(4) has been completed at the distributor.During the incoming functional testing, a 1hz simulated normal sinus rhythm signal was applied to the monitor, followed by a 5hz simulated treatable arrhythmia signal which verified proper performance of the detection algorithm.During the transition to the 5hz signal, the device was confirmed to properly enter into a treatment sequence which includes a verification of the audio messaging and siren alarms, as well as a test of the pulse delivery circuitry.The pulse delivery circuitry test verified proper charging of the high voltage capacitors and proper delivery of five full energy 150j biphasic pulses.The functional testing confirmed proper response button functionality, ecg acquisition, detection algorithm performance, and pulse delivery functionality.There is no indication of a product malfunction.Electrode belt sn (b)(4) has been returned to the distributor but has not been evaluated yet.Device evaluation includes review of downloaded software flag files on the days surrounding the event.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 patient treatment.Manufacture date: monitor - (b)(4) - 07/15/2013, belt - (b)(4) - 06/09/2014.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 was lack of response button use by the patient during the false detection.The ecg analysis, conducted by trained ecg technicians, identified the primary cause of the false detection was multiple counting and motion artifact.The multiple counting satisfied the rate detector of the detection algorithm.The source of the artifact could not be positively identified through cause and effect analysis.The following could not be ruled out as contributing factors: body motion, poor ecg contact with skin.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) (0.69% per patient-month with 90% confidence).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.Inappropriate treatment events are assessed during the monthly data analysis of complaints per (b)(4).
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