Clinic notes were received from a visit on (b)(6) 2015 indicating a patient was in referral to have his vns replaced due to the device reaching near end-of service.Device diagnostics were within normal limits on (b)(6) 2015.A call was later received on (b)(6) 2015 from a friend of the patient at their request stating that the patient was experiencing pain in his neck and he believes the device is trying to boost energy as the battery is about dead.It was reported that the feeling began that day after the neurologist visit.The physician had provided a new seizure medication until he can get the vns replaced as she had observed seizure activity at the visit.The generator was explanted on (b)(6) 2015.It was reported on (b)(6) 2015 that the reason for replacement was "unable to interrogate due to battery depletion".An estimate of battery life calculation was performed with the available history which estimated 6.5 years remaining until near end of service.However, the full history was not available in the programming database, and does not taken into account any programming changes since the last date of programming available, (b)(6) 2012, or magnet usage.The explanted generator was received and analysis was completed 01/14/2016.The reported failure to program was duplicated and measurement of the battery voltage determined that the battery was depleted.The supply current wait measurement did not meet the specification requirement.Analysis on the test bench identified and confirmed the c4 capacitor component as the root cause for the increased current drain.After the c4 capacitor component was cut out of the circuit and bridged with a known good bench c4 capacitor component, the generator module performed according to the functional specifications.The c4 capacitor leakage current demonstrated an increased current consumption for the device and potentially contributing to a premature end of the battery life.The reason for the c4 capacitor's increase in leakage current could not be determined.Review of the device manufacturing records revealed no anomalies during the manufacture of the device.The supply current tests, and all other tests met all specifications at the time of manufacture.No additional relevant information has been received to-date.
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