Developing a Flexible Cochlear Implant Research Stimulation Interface for Animal: Stimulator and Dedicated Electrode Arrays

Introduction: Cochlear implants (CIs) are designed to produce hearing sensations in people suffering from severe to profound deafness. Besides their medical utility in directly stimulating the auditory nerve fibers, CIs are now considered by the research community as a formidable opportunity to better understand the hearing system. The possibilities are however technically limited by the CI systems already available. By design, most manufacturer’s stimulator chips are restricted so that the battery consumption is limited during a clinical use. The generation of multiple different electrical waveforms and stimulation modes can be therefore extremely limited.

Portable CI stimulator: The Animal Stimulation Platform (ASP) is a portable research interface that contains an unleashed version of the Oticon Medical stimulation chip. Contrary to its clinical version, the ASP chip is controlled both by a microcontroller and a field programmable gate array (FPGA) to ensure enough data power transfer. This enables the generation of a large possibility of pulse waveforms while keeping accessible clinical functionalities such as backward telemetries (Impedance and eCAPs). The user is then able to drive complex stimulations using a dedicated software from any computer, designed to automatically drive pre-programmed stimulation patterns, and is able to synchronize with an external storing system to record eCAPs and/or eABRs.

Dedicated electrodes: Standard clinical electrode arrays are compatible with the ASP. In addition of those Oticon Medical collaborates with researchers to realize dedicated electrode arrays for specifics animals - array lengths and electrode diameters being configurable – and for research in-vivo, chronic or acute experiments.