Analysis of power dissipation and temperature rise of an inductive link for retinal implants

Retinal implants operating with inductive coils for wireless power and data transmission are being developed to help restore vision to the blind. In this work, we analyze temperature increase in the tissue surrounding a retinal implant due to resistive heating of the coils. Using principles of heat transfer and power dissipation data, we estimate temperature rise in the tissue. From our analysis, we found that heat generation and convection are the most important factors in determining temperature rise near the transmit coil. Near the receive coil, heat generation and location of the coil have the biggest impact on maximum temperature rise. Finally, if the implant chip is located near highly vascularised regions of the retina, temperature rise at the retina is negligible. This work is expected to benefit future development of wireless power and data telemetry for retinal implants.