The vns generator was explanted and replaced due to battery depletion, and the explanted product was received back to the manufacturer for product analysis.During visual analysis, a bubble was observed in the generator header that placed the device component outside of its listed product specification.The bubble was found between two feedthru wires and bridged two non-common conductors.A comprehensive automated electrical evaluation showed that the pulse generator performed according to functional specifications; however, an atypical output waveform was observed during testing.While performing system diagnostic tests, the pulse generator is connected to an oscilloscope to observe the output waveform.An atypical output waveform was observed in the product analysis lab, and it was concluded that moisture was causing leakage to increase in header.The phenomenon, however, had no adverse effect on either the diagnostic tests or the comprehensive automated electrical test results; all results were successful.The device history record was reviewed, and the generator successfully passed all assembly steps, including header securement and backfill.This is the process step during which the feed through cavities are completely backfilled with silicon.However, given the failure mode observed, it appears this process step was not completed adequately.Besides this event, there were no performance or any other type of adverse conditions found with the pulse generator.No other relevant information has been received to date.
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