Zoll medical canada evaluated the device and the device performed to specification.The device passed the final test and was recertified and returned to the customer.Review of the clinical data file from the reported event concluded the device worked as designed and within the limitations of the technology.There were five analyses performed during the event, for two of which a shock was advised.The analysis algorithm incorporated in zoll defibrillators works by taking a nine second ecg sample and dividing the sample into three, 3 second segments.The algorithm then makes calculations based on ten waveform characteristics for each segment.A minimum of two of the three segments need to be identified as "shockable" in order to have a result of shock advised.The second analysis event consisted of three segments, each individually analyzed to determine the shockability of the presenting waveform.The first two segments had matching results in this analysis.Both segments 1 & 2 were determined to be shockable, low-level non-correlating waveforms by the algorithm.The third segment was determined to be asystole and therefore non-shockable.It should also be noted that there were large fluctuations in the cpr waveform during the analysis.This could be representative of motion or cpr interference which could have impacted morphology of the waveform and the results of the analysis.The fifth analysis event consisted of three segments, each individually analyzed to determine the shockability of the presenting waveform.In this analysis the algorithm determined the rhythm to be ventricular fibrillation (vf) in all three segments.This was mainly due to low normalized amplitude, high qrs variability, low amplitude and a high number of recorded peaks in each of the segments.It should be noted that in this analysis both the cpr waveform and cpr bar recorded compressions throughout the analysis event.It is critical that cpr not be performed during an analysis as it can greatly impact the morphology of the waveform and therefore the results of the analysis.No trend is associated with reports of this type.
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