Clinical summary: at switch-on, all electrodes were reported as operational.
However within 4 months an electrode was detected as an open circuit.
Over the next three months the number of electrodes detected as open circuits increased, until 10 electrodes were found to be non-functional.
An integrity test conducted by coclear staff on the 28th may 2002 confirmed 10 electrodes non-functional.
The patient was re-implanted with a nucleus 24k.
Result of analysis: bends and kinks consistent with explantation were observed along the electrode lead and array.
Kinks, cuts and exposed wires consistent with explantation were observed along the ball electrode lead.
The electrode lead was severed near the beginning of the electrode array, and was returned with the device.
Broken electrode wires were observed along the electrode lad at the middle of the electrode lead (where the helix ends and the straight part of the lead starts).
Coninuity between electrodes was checked on the sererved electrode array.
Continuity was observed on all electrodes.
Continuity of the electrode lead was checked at the location of the broken electrode wires.
Continuity was confirmed along the electrode lead stimulator body and the location of the broken electrode wires.
X-rays of the device showed no anomalies aside from those described above.
The device passed all electrical testing conducted to confirm operation of the stimulator.
Conclusion: the device has multiple broken wires at the midpoint of the electrode lead.
Open circuits were detected at the location of the break.
It cannot be ruled out that additional electrode damage occurred during explantation.
The device passed all tests conducted to verify the proper operation of the stimulator.
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