Sensor-actuator component for a Floating Mass Transducer-based fully implantable hearing aid.

Area of Science:

• Biomedical Engineering
• Otorhinolaryngology
• Medical Devices

Background:

• Current middle ear implants often have external components.
• The Vibrant Soundbridge is a leading middle ear implant system.
• Floating Mass Transducer (FMT) technology offers potential for implantable devices.

Purpose of the Study:

• To develop and evaluate a novel, fully implantable middle ear implant system using the Floating Mass Transducer (FMT).
• To replace the external microphone of current systems with an implantable piezoelectric sensor.
• To assess the functional gain and surgical advantages of the new FMT-based system.

Main Methods:

• Developed a system with an implantable piezoelectric sensor and an FMT coupled to the cochlear round window.
• Characterized intracochlear sound pressure gain using laser Doppler vibrometry in six temporal bones.
• Employed an adaptive control algorithm to manage closed-loop feedback oscillations.

Main Results:

• Achieved a mean functional gain of up to 40 dB, comparable to the Soundbridge.
• Demonstrated the system's ability to overcome limitations of closed-loop feedback oscillations.
• Laser Doppler vibrometry confirmed effective sound pressure transmission to the cochlea.

Conclusions:

• The novel FMT system represents a viable, fully implantable middle ear implant.
• The system offers advantages including simpler surgery, reversibility, and potentially natural hearing.
• This technology advances implantable hearing devices for sensorineural hearing loss.