无SAR评估条件下心脏起搏器谐振式无线供能系统研究

Research on the resonant wireless energy supply system of pacemaker without SAR evaluation

目前,心脏起搏器谐振式无线充电系统存在比吸收率(SAR)安全问题。为最大限度避免SAR损伤,在频率10~100 kHz范围内,设计了一种基于LCC-C补偿的谐振式无线供能系统。同时考虑到频率、线圈偏移及补偿参数对系统传输性能的影响,建立了考虑等效串联电阻(ESR)的损耗电路模型。通过分析不同频率、LC参数和耦合系数条件下系统的输出功率和传输效率,综合确定了最佳频率及补偿参数。最后搭建实验系统检验系统供能效率、抗偏移能力、以及相应安全指标;结果表明,在两线圈圆心距横向偏移0~2/3条件下系统传输效率可达43.3%~73.2%,最大温升仅为0.8℃,且无需进行SAR评估,为提高人体植入式设备的安全性设计提供了一种有效的方法。

At present,there is a safety problem of specific absorption rate(SAR)in the resonant wireless charging system of pacemaker.To avoid the damage caused by SAR,a resonant wireless energy supply system based on LCC-C compensation is designed in the frequency range of 10~100 kHz.The influences of frequency,coil offset and compensation parameters on the transmission performance of the system are considered.A loss circuit model is formulated,which considers the equivalent series resistance.By analyzing the output power and transmission efficiency of the system under different frequencies,LC parameters and coupling coefficients,the optimal frequency and compensation parameters are comprehensively determined.Finally,an experimental system is set up to check the system′s energy supply efficiency,anti-offset capability,and corresponding safety indicators.Results show that the transmission efficiency of the system can reach 43.3%~73.2%and the maximum temperature rise is only 0.8℃under the condition of 0~2/3 lateral offset of the center distance of two coils.Meanwhile,SAR evaluation is not necessary.It provides an effective method for improving the safety design of human implantable equipment.