Computationally Efficient Impact Estimation of Coil Misalignment for Magnet-Free Cochlear Implants.

Area of Science:

• Biomedical Engineering
• Medical Devices
• Signal Processing

Background:

• Cochlear implant (CI) systems utilize coupled coils for power and data transmission, incorporating a central magnet for alignment.
• The magnet in current CIs poses a significant risk during Magnetic Resonance Imaging (MRI) scans due to strong magnetic fields.
• Developing magnet-free CI systems is crucial to overcome MRI incompatibility and advance hearing implant technology.

Purpose of the Study:

• To investigate the feasibility of magnet-free cochlear implant (CI) systems.
• To analyze the impact of coil misalignment on inductive coupling for wireless power and data transfer in CI systems.
• To establish a reliable simulation method for evaluating magnet-free implant designs.

Main Methods:

• Coil misalignment (lateral, vertical, angular) effects on coupling coefficient were modeled using MATLAB, based on Neumann's equation derivations.
• Finite Element Analysis (FEA) was used for verification, comparing simulation results against FEA software.
• The MATLAB model's accuracy was validated, showing a median 8% relative error in coupling coefficient prediction.

Main Results:

• The MATLAB model accurately predicts coupling coefficients under various misalignments, with a median 8% relative error compared to FEA.
• Incorporating patient-specific factors like skin-flap thickness and mechanical dimensions reduced the mean error to below 5%.
• The study demonstrates that magnet-free CI designs are feasible, with reliable power and data transfer.

Conclusions:

• Magnet-free cochlear implants are a feasible alternative to current systems, mitigating MRI risks.
• The developed MATLAB model provides a valuable tool for designing and assessing magnet-free wireless power and data transmission systems.
• Further consideration of patient and technological constraints is key to optimizing magnet-free CI performance.