植入式三线圈自适应无线能量传输系统的设计与研究

发布时间：2018-03-10 07:03

本文选题：无线能量传输　切入点：三线圈耦合　出处：《华南理工大学》2014年硕士论文　论文类型：学位论文

【摘要】：随着科技的发展，植入式生物医疗电子设备的应用日益普及，在生物研究和医学诊断等方面发挥着越来越重要的作用。对于实际的植入式电子设备，电源的长期、稳定及安全供给是至关重要的问题。无线能量传输是当今比较热门的研究领域，它能够透过皮肤将能量源源不断地供应给体内的植入式电子设备，因此被越来越多的植入式医疗电子系统采用。当前无线能量传输的基础是近场互感耦合理论，但传统的互感耦合结构存在传输效率随距离增大迅速下降的缺点，所接收恢复的电源能量随距离变化存在明显波动，容易导致生物体体组织损伤，，且实现上大量的分立元件也增加了植入体内的难度。本文以线圈耦合结构、体内集成电路设计及能量反馈控制等角度为切入点，设计了一套具备无线供能自适应调节机制的植入式三线圈能量传输系统。该系统由体外发射、三线圈耦合结构、体内能量收集与电源恢复电路组成，体外发射电路包括驱动电路、功率放大器、LSK解调模块、MCU及数字可控电源，体内能量收集与电源恢复电路主要包括低压差线性稳压源、PWM以及LSK调制电路。对于耦合结构，本文在互感耦合理论的基础上，分析影响其传输效率的关键因素，结合强磁耦合利用高Q值共振器提高远距离传输效率的思路，提出了一种三线圈耦合结构，并对其进行理论推导、仿真及实验验证。结果表明，三线圈耦合结构在中远距离时对传输效率有增强作用；克服了互感耦合结构仅能在特定负载实现最优效率的局限，实现了大负载范围的高效能量传输。同时本文以低功耗、小面积及低复杂度为原则，采用Global Foundry0.18um CMOS工艺对体内能量收集与电源恢复电路进行了版图设计与验证。流片测试结果表明，电源管理模块实现了输出电压1.850V，输出电流102.4mA，静态电流68.43uA，负载调整率为2%，线性调整率为0.9%，电源抑制比在直流时小于-80dB，1MHz时小于-35dB。最后本文提出了一种结合PWM和LSK的反馈控制技术，实验表明，该反馈可有效控制能量的传输，在距离变化时保证接收能量的稳定，提高能量传输的安全性，且能显著提高近距离传输的效率，在距离小于2mm时可提升5.7倍。
[Abstract]:With the development of science and technology, the application of implantable biomedical electronic devices is becoming more and more popular, which plays an increasingly important role in biological research and medical diagnosis. Stability and safe supply are critical issues. Wireless energy transmission is a hot area of research today, and it can continuously supply energy through the skin to implanted electronic devices in the body. Therefore, more and more implantable medical electronic systems are adopted. At present, the basis of wireless energy transmission is the near-field mutual inductance coupling theory, but the traditional mutual inductance coupling structure has the shortcoming that the transmission efficiency decreases rapidly with the increase of distance. The energy of the received and restored power source fluctuates obviously with the change of distance, which can easily lead to the damage of organism tissue, and a large number of discrete elements also increase the difficulty of implanting in vivo. In this paper, an implantable three-coil energy transmission system with adaptive regulation mechanism of wireless power supply is designed from the aspects of coil coupling structure, in vivo integrated circuit design and energy feedback control, etc. The system is launched in vitro. Three coils coupling structure, in vivo energy collection and power supply recovery circuit, external transmission circuit includes driving circuit, power amplifier LSK demodulation module MCU and digital controllable power supply. In vivo energy collection and power recovery circuits mainly include low voltage difference linear voltage regulator PWM and LSK modulation circuit. On the basis of the theory of mutual inductance coupling, this paper analyzes the key factors that affect the transmission efficiency of coupling structure, and proposes a three-coil coupling structure based on the idea of using high Q value resonator in strong magnetic coupling to improve the transmission efficiency of long distance. The theoretical derivation, simulation and experimental results show that the three-coil coupling structure can enhance the transmission efficiency at medium and long distance, and overcome the limitation that the mutual inductance coupling structure can only achieve the optimal efficiency under a specific load. High efficiency energy transmission is realized in large load range. At the same time, based on the principle of low power consumption, small area and low complexity, the layout design and verification of energy collection and power recovery circuit in vivo are carried out by using Global Foundry0.18um CMOS technology. The power management module realizes the output voltage of 1.850V, the output current of 102.4 Ma, the static current of 68.43 uA, the load adjustment rate of 2, the linear adjustment rate of 0.9 and the power rejection ratio of less than -80 dB ~ (-1 MHz) when DC is less than -35 dB. Finally, a feedback control technique combining PWM and LSK is proposed. The experimental results show that the feedback can effectively control the transmission of energy, ensure the stability of the received energy and improve the security of energy transmission when the distance varies. The efficiency of short distance transmission can be improved by 5.7 times when the distance is less than 2 mm.
【学位授予单位】：华南理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM724

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