The pt is doing well with her reimplanted device.
This is the final report.
On 10/28/1996, pt experience overstimulation during intial programming sessions after unplugging his processor during mapping.
10/29/1996, equipment problem report was completed for processor # 343095 and processor was replaced (replacement processor #340094) after that pt refused to wear his processor even though t and c levels were reset to very low levels (t=1; c=10 current levels).
Pt was then managed by cochlear implant centre in basel at parents request, until 6/1997 when family relocated to england.
Since then pt has been seen at hosp and currently under the facility, with reported progressive loss of electrode function.
He became non user approx 20 months post implant.
Integrity test: pt's external equipment was checked and found to be working.
Integrity test was performed with cochlear's own test processor.
Automated integrity test for ci22 protocol was used.
Continuity and rf parameter tests were satisfactory.
Intermittent results were obtained during electrode tests.
No pulse recorded during amplitude growth test.
Pulse width test / rate and range and complex stimuli test were within expected limits.
Visual inspection: electrode array was observed to be severed between helix and stiffening rings.
Silastic at tip of helix was observed to be damaged, exposing 1 electorde wire.
On severed part of array, 4 electrode rings and 6 stiffening rings were noted to be damaged.
Cuts and other damage in silastic of stimulator body was observed.
X-rays of unit showed breaks in electrode wires at tip of helix.
Electrical tests: unit passed reflected receiver coil impedance test.
Unit passed remote test.
Two point probe test could not be performed since electrode array was severed.
After exposing electrode feedthroughs, two point probe test was performed at feedthroughs.
Full output was obtained for all electrodes.
Unit passed test of amplitude growth (at electrode feedthroughs).
Conclusion: implant failed due to damage to electrode array at tip of helix.
Results of analysis visual inspection found elecrode array severed between helix and stiffening rings.
Silastic at tip of helix was damaged, exposing one electrode wire.
On severed part of array, four electrode rings and six stiffening rings were noted to be damaged.
Cuts and other damage in silastic of stimulator body was observed.
X-rays of unit showed breaks in electrode wires at tip of helix.
Full electrical output test could not be performed since electorde array was severed.
However, after exposing electrode feedthroughs, electrical output test was performed at feedthroughs.
Full output was obtained for all electrodes.
Unit passed all other electrical tests.
Conclusion: implant failed due to damage to electrode array at tip of helix.
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