Electrochemical in vivo oxygen sensing on cochlear implants

Abstract Cochlear Implants (CIs) are the most frequently implanted neuroprotheses. Despite the clinical success of the CI, the processes actually occurring at the electrodes postimplantation remain unknown, and the majority of research is limited to end point analyses. Electrochemical methods offer the possibility of using implant platinum electrodes as sensor electrodes for in vivo measurements without the need for implant modifications. We demonstrated this possibility by sensing different oxygen concentrations in a CI-supplied rat model. Exploiting CIs as electrochemical in vivo sensors promises viable insight into reactions of the biological microenvironment to the implant, such as inflammation and encapsulation. Furthermore, electrochemical methods offer the possibility of monitoring in situ electrode conditions.