Cochlear implant electrodes as electrochemical sensors in vivo

Cochlear implants (CIs) are widely used neural prostheses to restore hearing in hearing impaired patients. The implant's platinum electrodes are comparable to microelectrodes typically used in bio- and chemo-sensors. We show how advanced electrochemical protocols can be used to turn CI electrodes into electrochemical sensors, e.g. for oxygen. The overall goal is to measure the implant's microenvironment and characterize electrode degradation in order to improve implant function and life-time. For the first time, we characterized the performance of CI electrodes as chemical sensors and demonstrated the in vivo measurement of intracochlear oxygen levels with a CI in an animal model.