Implantable Stimulator Failures: Causes, Outcomes, and Solutions

Current designs of implantable stimulators for neuroprostheses exploit trade-offs in power consumption, functionality, volume, selectivity and ease of use. However, no stimulator design should compromise reliability or safety. In this paper, we consider the common failures in implantable stimulators, their causes, outcomes and solutions. A new coding scheme, Manchester non-return-to-zero code, is proposed to format the cable signal in order to avoid prolonged DC current between cable exposures. Thus, in the event of cable failure, the bidirectional charge-balanced current between cable exposures maintains the nearby tissue in safe condition.