Hearing through light

Traditional cochlear implants are based on the concept of electrically stimulating nerve fibres. However, the geometric conditions inside the cochlea limit the options to focus the electric field. This may lead to a reduction of the quality of hearing.

An alternative is laser based stimulation: hearing through light. The laser, which is placed inside the cochlea, generates a very short pulse of infrared light. The pulse is absorbed by the liquid inside the cochlea. The liquid heats up and, consequently, expands rapidly and thus creates a sound wave. The opto-acoustic stimulation is similar to natural hearing, which relies on a sound wave being generated by the stapes pushing against the oval window at the base of the cochlea.

CSEM from Switzerland provided a complete miniaturized laser package to investigate this application. Laser and electronics are sealed with biocompatible materials to protect the system and the body. The transparent housing material – Sapphire – does not elicit any undesired effects in the host and is well suited as a long term implant.

The miniaturization offers tremendous advantages: it will allow new medical treatments due to the fact that smaller implants may be placed in parts of the body which are inaccessible to current size implants. Furthermore, surgical procedures will be less invasive and thus less stressful for patients. Recovery will be much quicker.

Contact: Mark Fretz, CSEM Centre Suisse d'Electronique et de Microtechnique SA
info@csem.ch