英文题名：
Research and Design of Wireless High-voltage Deep Brain Stimulator
中文关键词：
高压脑深部电刺激器;;闭环能量控制;;电压衰减器;;无线能量数据传输
中文摘要：
脑深部电刺激器(Deep Brain Stimulation,DBS)对癫痫、帕金森氏症、阿尔茨海默病等神经系统疾病具有一定的治疗效果已经得到临床证实。采用无线能量和数据传输的DBS可以克服传统的原电池供电的DBS使用周期短和占用空间大等缺点。有研究指出,高密度的电刺激对神经系统疾病具有更好的治疗效果。若要实现高密度的电刺激,就需要较多的刺激通道,植入到人体的刺激电极的直径比较小,其阻抗就会比较大,采用较高的刺激电压才能获到达到治疗效果的刺激电流。因此设计一款无线能量和数据传输的高压脑深部电刺激器具有重要的研究意义。本文通过对植入式电刺激器的发展进行调研和分析,设计了一款无线能量和数据传输的高压脑深部电刺激器。所设计的无线高压脑深部电刺激器采用感应耦合的能量传输方式和ASK的数据调制方式实现了能量和数据的稳定传输。具有高电源抑制比无片外电容的LDO为系统提供了±1.5V的直流低压,电流源型的无线高压传输结构为系统提供了±10V的直流高压,后端数据遥测电路实现了系统能量的闭环控制。数据和时钟恢复电路实现了控制信号和时钟的恢复,并通过电平转换电路实现了控制信号低压到高压的转换。电容串联形成的电压衰减器,将储存电容上的电压从高压范围衰减至低压范围,实现了±10V直流高压对储存电容的可控充电。放电电容选择电路和放电电极选择电路实现了储存电容放电对数的和放电通道的选择。电荷平衡电路实现了注入正负电荷数量的平衡。电路是在TSMC 0.18μm high voltage CMOS工艺下进行设计,使用Cadence-Spectre软件进行仿真。仿真结果表明,所设计的无线高压脑深部电刺激器芯片能向神经组织提供刺激幅值可调、刺激脉宽可调、正负电压刺激先后顺序和间隔可调的指数衰减型电刺激,正电压刺激可达10V,负电压刺激可达-10V,实现了高压刺激功能,满足高密度电刺激的需求。
英文摘要：
Deep Brain Stimulation(DBS)has been clinically proven to be effective in the treatment of neurological diseases such as Parkinson's disease.DBS with wireless energy and data transmission can overcome the shortcomings of traditional primary battery-powered DBS,such as short service cycle and large space occupation.And studies have shown that high-density electrical stimulation has a better therapeutic effect on nervous system diseases.In order to achieve high-density electrical stimulation,more stimulus channels are needed.The diameter of the stimulus electrode implanted into human body is relatively small,and its impedance will be relatively large.In order to obtain a stimulation current that achieves a therapeutic effect,a higher stimulation voltage is required.Therefore,it is of great significance to design a high-voltage DBS with wireless energy and data transmission.Based on the investigation and analysis of the development of implantable stimulator,a high-voltage DBS with wireless energy and data transmission is proposed in this thesis.The proposed wireless high-voltage DBS uses inductively coupled energy transmission and ASK data modulation to achieve stable transmission of energy and data.The external capacitor-less LDO with high power supply rejection ratio and current source based wireless high-voltage transmission structures provide ±1.5V DC low voltage and ± 10 V DC high voltage,respectively.The closed-loop control of energy is realized by the back-forward telemetry circuit.Data and clock recovery circuit realizes the recovery of control signal,and the conversion of control signal from low voltage to high voltage is realized by the level shift.In order to realize the controllable charging of storage capacitor by±10V DC high voltage,the voltage attenuator formed by series capacitors attenuates the voltage of storage capacitor from high voltage range to low voltage range.Moreover,the discharge capacitor selection circuit and the discharge electrode selection circuit realize the selection of the storage capacitor discharge logarithm and the discharge channel,respectively.The charge balancing circuit achieves the balance of the amount of positive and negative charges injected.The circuit is designed under TSMC 0.18μm high voltage CMOS technology and simulated by Cadence-Spectre.From the simulation results,it can be seen that the proposed wireless high-voltage DBS can provide exponential attenuation stimulation with adjustable amplitude,adjustable pulse width,adjustable sequence and interval of positive and negative voltage stimulation to nerve tissue.And the positive voltagestimulation can reach 10 V,the negative voltage stimulation can reach-10 V.The proposed wireless high-voltage DBS realizes the function of high-voltage stimulation and meets the needs of high-density stimulation.
