Investigating novel pulse shapes through computational modeling of the neural-electrode interface and psychophysics experiments

Sarantos Mantzagriotis

A major limitation in Cochlear Implantation (CI) is the spread of current excitation induced by each electrode, resulting in a reduced efficiency between the electrical pulse and auditory nerve responses. This current spreading mis-activates neuronal populations of the auditory nerve resulting in poor frequency resolution, dynamic range, and distortion of the original acoustical signal. It is hypothesized that currently used rectangular pulses, are far from optimal for maximizing information transmission within the neural-electrode interface.

In addition, a CI’s outcome is highly dependent on a patient’s anatomical characteristics such as cochlear morphology and auditory nerve fiber distribution. Current pre-surgical planning software for CI can reconstruct a patient-specific cochlear morphology based on high-resolution scans in order to identify the most optimal electrode location and depth, that minimizes current spread. However, these frameworks are still underdeveloped to identify most-optimal parameters of a CI stimulation strategy and pulse shapes.

The project aims at improving pitch discrimination and musical perception in CI by optimizing in-silico, pulse shapes and stimulation strategy parameters. Initially, it will investigate this by creating a computational framework that couples phenomenological neuronal models, based on animal experimentation, with 3D cochlear electrical conduction models. The framework will then be extended to investigate collective neuronal behavior based on  population models, combining feedback from psycho-acoustical experimentation.

Supervisor: Jeremy Marozeau (DTU Health Tech). Co-Supervisor: Bastian Epp (DTU Health Tech).

This PhD project is funded by the William Demant Foundation

To be completed in 2023

DTU Orbit

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Sarantos Mantzagriotis
PhD student
DTU Health Tech