A pathway for information transmission to the ear

Area of Science:

• Biomedical Engineering
• Otolaryngology
• Medical Devices

Background:

• Implantable hearing aids and cochlear implants are established treatments for neurosensory deafness.
• Current signal transmission methods (transcutaneous radiofrequency and percutaneous coupling) have drawbacks: electromagnetic interference and infection risk, respectively.
• A need exists for a more robust and safer signal transmission method for auditory prosthetics.

Purpose of the Study:

• To develop and test an infrared (IR) system for transmitting audio signals through the tympanic membrane.
• To evaluate the feasibility of using the tympanic membrane as a translucent interface for auditory data transmission.

Main Methods:

• An IR transmitter/receiver system utilizing an infrared light emitting diode (LED) and a photovoltaic cell was designed.
• The system was tested in four dogs, with the LED placed in the auditory canal and the photovoltaic cell in the tympanic cavity.
• Sinusoidal signal modulation was applied to the LED, and signal detection was performed after transmission through the tympanic membrane.

Main Results:

• The IR signal was detected undistorted after passing through the tympanic membrane, with an average absorbance of 20%.
• The system demonstrated adequate high-frequency cut-off, suitable for cochlear implant and general audio prosthetic applications.
• The tympanic membrane proved to be an effective translucent interface with minimal power loss and good frequency response.

Conclusions:

• The tympanic membrane can serve as a sealed, translucent interface for transmitting audio-range data to the middle and inner ear.
• The proposed IR system offers immunity to electromagnetic interference and reduces infection risks compared to existing methods.
• This technology shows significant potential for improving signal transmission in advanced auditory prosthetic devices.