There was no death or device malfunction associated with the inappropriate defibrillation event.Device evaluation of monitor sn (b)(4) has been completed. the reported problem (patient treatment) was confirmed. 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.Device evaluation of electrode belt sn (b)(4) has been completed. the reported problem ("add gel" messages) was confirmed. gel did not fully deploy from the therapy electrodes.The therapy electrode is designed to exceed the surface area requirements of ansi/aami df80:2003. additionally, the garment's silver-impregnated mesh that holds each therapy electrode provides a conductive interface from the shocking surface of the therapy electrode to the patient's skin.The cause for the failure was isolated to broken gel fire wires in the dn pca.The root cause for the failure could not be positively identified.Biocompatibility testing to iso 10993 was successfully completed on skin-contacting surfaces of the lifevest device as well as the blue¿ defibrillation gel. device manufacture date: monitor: 06/29/2017, electrode belt: 06/19/2018.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 (attached), and ecg strips.The primary cause of the inappropriate shock was lack of response button use prior to the treatment shock (patient error).The ecg analysis, conducted by trained ecg technicians, identified the primary cause of the false detection was motion artifact.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.
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