【作者】 高鹏；

【导师】 颜国正；

【作者基本信息】 上海交通大学 ， 精密仪器及机械， 2012， 博士

【摘要】 本文以国家自然科学基金、国家高技术研究发展计划（863计划）、载人航天领域预先研究和上海市科委资助项目为依托，对结肠微型机器人进行详细研究和实验验证，力图探索出结肠主动微创诊疗的新途径。结肠主动微创诊疗对结肠微型机器人提出“动”、“能”、“诊”、“控”四项基本功能，它们分别对应于运动技术、供能技术、诊疗技术和通讯控制技术的研究。结肠微型机器人运动技术研究，以人体结肠的生理特性为出发点，详细分析了结肠的基本形态及生物力学特性，并通过综合分析确定了仿尺蠖运动方式和微型电机驱动方式。仿尺蠖运动机构主要包括两端径向钳位机构和中部轴向伸缩机构。径向钳位机构利用连杆机构伸缩腿实现60mm的钳位直径，轴向伸缩机构采用双向直线驱动机构实现45mm的轴向行程。通过力学特性分析，径向机构的理论最大输出为1.7N，轴向机构的理论最大输出为4.5N，它们都可以在无驱动下实现状态保持。结肠具有复杂的表面形态和粘弹的组织特性，使得结肠微型机器人的钳位接触效率较低，因此为了提高肠道接触效率和安全性，以肠道摩擦力模型为基础，通过实验验证和分析，设计并制造了适合肠道表面的接触装置。运动学、动力学、临界步距和运动效率的综合分析，进一步明确了结肠微型机器人的运动性能，为结肠微型机器人运动技术的发展提供了重要参考。结肠微型机器人的供能技术研究，以电磁感应原理为基础，通过无线方式来实现持续高功率能量供给。在无线供能系统中，Helmholtz发射线圈激励出均匀交变磁场从而提高了位置稳定性，三维接收线圈改进了姿态稳定性，并通过为发射线圈匹配补偿电容和可调电感解决频率稳定性。无线供能效率由发射系统、线圈耦合和接收系统共同影响，其深入研究为结肠微型机器人无线供能系统研制提供宝贵参考。本文研制出适合结肠微型机器人的无线供能系统，当系统输入功率为14.7W时，可以为结肠微型机器人提供最小378mW、最大705mW的能量。结肠微型机器人的诊疗技术研究，从临床诊疗需求出发对无线图像诊断和热疗进行详细研究。无线图像诊断借鉴胶囊内窥镜研究成果，并结合结肠诊疗需要，设计出双图像采集系统，可以实现30fps的连续图像采集，图像尺寸为320×240像素。热疗研究以肿瘤加热技术发展为出发点，并结合肠道生物组织导热特性，设计出了结肠腔内局部热疗线圈，并通过热疗线圈表面温度的详细实验，选择出了最优的线圈结构。热疗线圈装配了温度检测电路以实现41~45℃的结肠肿瘤热疗温域的精确控制。结肠微型机器人的通讯控制技术研究，以无线通讯为基础实现了医生对体内结肠微型机器人的实时监控。利用两块Si4420收发芯片并结合特定的通讯程序，在体内同体外间实现了半双工无线通讯。此外，为了提高结肠微型机器人对多任务和外设的管理能力，利用两片微控制器实现双硬核系统的同时，并为每个微控制器装配了具有四层优先级的软核程序构架。结肠微型机器人硬件电路和软件程序的设计，使其具有完备的协同运作和同步控制能力。结肠微型机器人关键技术研究同微机电系统加工的有机结合，研制出了结肠微型机器人样机，其直径17mm，收缩后轴向长度128mm，轴向行程44mm，最大径向钳位外径60mm。考虑到同结肠的生物相容性，结肠微型机器人样机壳体采用医用聚丙烯棒，利用数控机床加工而成，前后腔体间利用食品医用硅胶波纹管连接密封。为了降低样机重量，样机机架采用轻质航空铝材，并利用高精度线切割加工而成，最终样机净重53.5g。以结肠微型机器人样机作为实验对象，本文通过实验研究对结肠微型机器人关键技术给予充分评测。机器人样机的仿尺蠖运动机构具有简洁有效的运动步态，径向钳位机构的实际最大输出为1.5N，轴向伸缩机构的实际最大输出为4.2N，接近其理论输出值；此外，运动机构的运动过程符合结肠内主动运动需求。接触装置不仅使机器人样机的摩擦系数提高65%，而且使其在结肠中具有较为安全的主动接触特性。无线图像系统能够为医生提供连续而清晰的图像，便于结肠病灶点的诊出。机器人样机可在不同倾斜角度的刚性管道和柔性管道中有效运动，当随着运动环境的稳定性降低和倾斜角度的提高，机器人样机的运动速度也随之降低，但运动过程仍然连续平稳；机器人样机在离体肠道中具有复杂的运动特性，主要受到肠道形态和粘弹组织特性影响。在无线供能系统中，接收线圈会产生电热效应可能会提高结肠的局部温度，发射线圈激励谐振磁场也会影响人体的特定比吸收率和电流密度，而通过温度测定和人体数字模型分析，证明了无线供能系统对人体是相对安全的。最后，本文对机器人样机开展了活体实验，进一步验证了结肠微型机器人关键技术的应用价值，为实际临床应用提供了宝贵参考。更多还原

【Abstract】 Under the supports of the National Natural Science Foundation ofChina, the National High Technology Research and Development Programof China (863Program), the Advanced Study of Manned Space Project andthe Program of Shanghai Science and Technology Commision, the keytechnologies and experiments of a colonic microrobot were researched withthe purpose of exploring a new way for colonic diagnosis and therapy withminimal invasion or non invasion. The colonic minimal invasive diagnosiand therapy make four basic functions to the colonic microrbot. The basicfunctions are locomotion, power, treat and manipulation respectivelycorresponding to locomotion technology research, wireless power supplytechnology research, diagnosis&therapy technology research andcommunication&control technology research.The research on locomotion technology of the colonic microrobotstarted from the characteristics of the colonic tract, and detailedly analysedthe basic form and biomechanical characteristics of the colonic environment. Based on comprehensive analyses, the inchworm like locomotion and themotor actuator were proposed for the active locomotion of the colonicmicrorobot. The inchworm like locomotion mechanism was composed ofradial clamping mechanisms at the two ends and axial telescopic mechanismin the middle section. The clamping mechanism was used to realize themaximum clamping diameter of60mm and the maximum clamping force of1.7N. Moreover, the telescopic mechanism was used to realize themaximum axial stroke of45mm and the maximum axial force of4.5N.These mechanisms could keep the locomotion state without extra powercomsumption. The colonic tract, with complicated surface morphology andviscelastic characteristiss, would reduce the locomotion contact efficiency.In order to effectively control the contact friction on the colonic surface, acontact device was designed and fabricated, based on the intestinal fricitionmodel, experiments and analyses. In addition, the colonic microrobot wasimplemented with kinematic analysis, dynamic analysis, critical stepanalysis and locomotion efficiency analysis in order to clearly acquise itslocomotion performance, which could improve the development of thelocomotion technology of the colonic microrobot.The research on wireless power supply technology of the colonicmicrorobot, based on the electromagnetic induction principle, foused on thewireless way to realize the continuous high power supply. Helmholtz coil was used to stimulate a uniform resonant magnetic field to improve positionstability;3D receiving coils improved the attitude stability; the frequencystability was improved by matching compensation capacitor and adjustableinductance for the Helmholtz coil. The efficiency researche of the wirelessspower supply relate to some influences caused by transmission system, coilscoupling and receiving system. A wireless power supply system wasdesigned and fabricated，which, with14.7W input, could provide theminimum378mW and the maximum705mW for the colonic microrobot.The diagnosis&therapy technology research of the colonic microrobotincludes wireless image diagnosis and hyperthermia. Considering therequirements of colonoscopy, the wireless image diagnosis based onwireless capsule endoscope proposed a double imge acquisition system,which can realize the continuous image acquisition at30fps for320×240pixels. The research on hyperthermia, based on the development of tumorhyperthermia, proposed a colonic heating coil, and exploited an optimalheating coil by testing the surface temperature of the experimental coils. Inorder to realize the precise temperature control, the heating coil wasequeiped with a temperature detection circuit. Therefore, the surfacetemperature of the heating coil could be maintained in the tumorhyperthermia region of41~45℃with a precise temperature control. The research on communication&control technology of the colonicmicrorobot, based on wireless communication, helped the doctor to monitorthe colonic microrobot in time. A half duplex communication between thein vivo and the in vitro was established under the use of two Si4420transceiver chips and combined with the specific communication program.In order to improve multitasking and multiperipheral management, a doublehard core was build up with two micro controllers. There was a four prioritysoft core in each hard core. The design of hardware and software make thecolonic robot have the abilities of collaboration operating andsynchronization control.The combination of the key technologies and MEMS developed aprototype of the colonic microrobot. The prototype has the diameter of17mm, the contracted axial length of128mm, the maximum axial stroke of44mm and the maximum clamping diameter of60mm. Consideringbiocompatibility of the colonic tract, the prototype’s shell was made ofmedical polypropylene material and fabricated with CNC. A bellows madeof food medicine silicone ruber was used as the sealing connection betweenthe two cavities of the prototype. In order to reduce the weight, the frame ofthe prototype was made of light aviation aluminum and fabricated with highaccuracy wire cutting machine. The total weight of the prototype was only53.5g. Some experiments were carried out to evaluate the key technologies ofthe colonic microrobot. The prototype of the colonic microrobot had theconcise and efficient locomotion gait. The actual output force of theclamping mechanism was1.5N, and the one of the telescopic mechanismwas4.2N. They were closed to their theory values, and the locomotionprocess was according to the locomotion requirements in the colonic tract.The customized contact device not only increased the friction coefficient65%, but also made the active contact with the colonic tract safer. Thewireless image system could provide the continuous and clear images for thevisual diagnosis. The prototype could move in the rigid or flexible tubeswith different oblique angles. With the decrease of the tube rigid and theincrease of the oblique angle, the locomotion speed of the prototype wasreduced, but its locomotion processes was still stable and continuous. Theprototype had the complicated locomotion characteristics in the in vitrocolonic tract, which was caused by colonic morphology and viscoelastictissue. In the wireless power supply system, the receiving coils couldproduce the heat to improve the environment temperature; in addition, theresonant magnetic field actuated by the transmission coil could affectspecific absorption rate and the current density of the human body. However,the temperate tests and the analyses of human digital model confirmed thatthat the wireless power supply system was relatively safe for the human body. It was worth nothing that some experiments were first carried out inthe living environment. Obviously, the key technologies have the goodactual application value in clinic, and will provid some valuable referencesfor the development of the colonic microrobot.更多还原