Prevention of electrical costimulation by triphasic pulses in cochlear implants

• Applicant: Privatdozent Dr. Andreas Bahmer
• Subject Area: Otolaryngology, Phoniatrics and Audiology ; Cognitive, Systems and Behavioural Neurobiology
• Term: from 2017 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 332109708

Cochlear implants are the most successful neuroprostheses which can restore the hearing abilibities of deaf patients to a great extent. But unpleasant side effects can arise when the auditory nerve is electrically stimulated: the electrical field outside of the cochlea may stimulate parts of the facial nerve. The stimulation results typically in a twitching around the eye and/or the mouth. Recently, it was found that the application of a certain type of pulse shape frequently results in the prevention of the costimulation (Schatzer 2014, Bahmer & Baumann 2016). This type of pulse (triphasic pulses) consists of three consecutive phases which in sum cancel inherently their charge. Previous measurements demonstrated that the neuronal response after triphasic stimulation is weaker than with biphasic stimulation. The detailed mechanism remains still unclear. To uncover the underlying mechanism is part of the project. Another possible stimulation mode is the application of precision triphasic pulses ("pt-pulses"). Up to now measurement and clinical experiences with pt-pulses are still missing. This will be another part of the project.

• DFG Programme: Research Grants