Research On Anti-offset Optimization Of Wireless Power Transmission System For Implantable Device

Aiming at the problem that the relative positional offset of the coil group during the wireless power transmission of implanted medical devices causes the transmission efficiency and power to drop,this paper carried out research on anti-offset optimization of energy transmission system.First,by analyzing the magnetic coupling resonant S-S type circuit,the root cause of the decrease in system power and efficiency level when the coil assembly is offset is obtained.For this reason,a design scheme of anti-offset wireless power transmission system optimized by class E inverter is proposed,and the external transmission circuit part is optimized.The plan puts forward the system circuit design ideas and detailed design methods of component parameters,and then through the method of circuit simulation,when the relative position of the coil group is offset,the power and efficiency of the optimized circuit and the S-S circuit are compared and analyzed.Finally,a system experiment platform was built to verify the feasibility of the design.Experimental results show that the transmission efficiency range of the circuit after anti-offset optimization is between 73.4% and 83%,and the output power range is between 1.11W-1.28 W.Compared with the S-S circuit before optimization,the anti-offset ability is obvious improvement.Implantable medical devices need to be implanted inside the human body to work,so the implant security issues should be fully considered.This paper establishes a three-dimensional equivalent simulation model of an implantable medical device with multiple layers of skin,fat,and muscle tissue.Using the analysis method of "electric-magnetic-thermal" multiphysics coupling and field-circuit coupling,referring to the "ICNIRP,2020" guideline and the "ISO standard" human tissue safety limit values,the magnetic field,electric field,specific absorption rate SAR,temperature,four safety assessment indicators for simulation analysis.The simulation considers the relative positional offset of the coil group,and focuses on the analysis of the simulation results in human tissues.The simulation results show that all safety evaluation indicators are lower than the specified safety limit values.The research in this paper provides a certain reference value for the wireless power supply of implantable medical devices.The paper has 52 pictures,5 tables,and 73 references.