An Intracochlear Pressure Sensor as a Microphone for a Fully Implantable Cochlear Implant

Area of Science:

• Biomedical Engineering
• Otolaryngology
• Materials Science

Background:

• Cochlear implants are crucial for hearing restoration.
• A fully implantable cochlear implant requires an internal microphone.
• Measuring intracochlear pressure is key to developing such a device.

Purpose of the Study:

• To validate an intracochlear piezoelectric sensor.
• To assess its function as a microphone for fully implantable cochlear implants.
• To detect intracochlear pressure.

Main Methods:

• A polyvinylidene fluoride (PVDF) piezoelectric pressure sensor was inserted into human cadaveric round windows.
• External sound pressure stimuli were applied to the external auditory canal (EAC).
• EAC pressure, stapes velocity, and sensor voltage were recorded.

Main Results:

• The PVDF sensor successfully detected intracochlear sound pressure.
• Sensor frequency response matched EAC pressure, with expected middle ear phase delay.
• Deeper insertion into the scala tympani improved and smoothed the response magnitude.

Conclusions:

• A novel method for measuring intracochlear pressure using a piezoelectric polymer sensor was demonstrated.
• The study shows feasibility for an otologic microphone.
• Future work aims to enhance sensitivity and bandwidth for integration into cochlear implants.