CD Laboratory for Active Implantable Systems

The focus of the work is on new strategies for stimulating auditory nerves using optimised implants in the inner ear (cochlear implants). Particular attention is paid to a new approach to transmitting acoustic fine structure information.

This approach is based on the use of simultaneous electrical stimulation pulses. In this way, information about the phases of acoustic waves can be used for cochlear implants, as it is precisely these phases that convey the acoustic fine structure information. However, they often cannot be transmitted electronically using existing methods, as these methods are often based on a strategy known as Continuous Interleaved Sampling (CIS). This involves using successive signal pulses for direct electrical stimulation of the auditory nerve. If acoustic fine structure information, such as phase information, is to be utilised in this way, pulse intervals must be so short that both the technical separation of the individual signals and their physiological summation rule out practical application.

The use of simultaneous stimulation pulses, as used here, is different. This allows the acoustic fine structure information to be transmitted effectively during electrical stimulation. A purely mathematical approach will solve the main problem - distorting interactions between the individual electrical channels of the cochlear implant.

In addition to the development and evaluation of this new approach, practical algorithms and methods for signal processing and the design of microchips are being developed. In this way, technically feasible and economically viable optimisations for cochlear implants can be achieved. The goal is a fully implantable cochlear prosthesis without external components. The expected improvements for patients are better sound quality in general, better understanding of speech in ambient noise and better understanding of music. For patients with a bilateral prosthesis, an improvement in directional hearing can also be expected.

Such a system would be the first fully implanted artificial sensory organ and thus undoubtedly a technological milestone in the field of medical technology.