Numerical analysis of intracochlear mechanical auditory stimulation using piezoelectric bending actuators

Area of Science:

• Biomedical Engineering
• Auditory Neuroscience
• Acoustics

Background:

• Cochlear implants partially restore hearing for profound hearing loss.
• Combining cochlear implants with hearing aids benefits patients with residual hearing.
• Current external hearing aids may be supplemented or replaced by internal stimulation methods.

Purpose of the Study:

• To investigate the use of miniaturized piezoelectric actuators for internal cochlear stimulation.
• To derive guidelines for actuator layout to maximize mechanical stimuli within the cochlea.
• To analyze the impact of actuator positioning on the basilar membrane oscillation and auditory perception.

Main Methods:

• Finite element analysis (FEA) was employed to model cochlear mechanics.
• Simulations focused on optimizing actuator design and placement for effective electromechanical stimulation (EMS).
• Basilar membrane responses were analyzed under various actuator configurations.

Main Results:

• Guidelines for actuator layout were established to maximize acoustic stimuli.
• Actuator position significantly influences the basilar membrane's oscillation profile and patient outcomes.
• Internal stimulation, considering cochlear tonotopy, may improve frequency selectivity.

Conclusions:

• Miniaturized piezoelectric actuators offer a promising internal stimulation alternative to external hearing aids.
• Optimized actuator design and placement are crucial for effective cochlear stimulation.
• Internal EMS has the potential to enhance frequency selectivity in cochlear implant users.