经皮供能的反馈式人工肛门括约肌系统关键技术及实验研究

发布时间：2018-04-16 08:20

  本文选题：人工肛门括约肌 + 肛门失禁　； 参考：《上海交通大学》2015年博士论文

【摘要】：肛门失禁(Fecal Incontinence,FI)是指肛门括约肌失去对粪便及气体排出的控制能力,是临床上常见病症,此病症虽不致命但却给患者带来生活不便和身心痛苦。现有的人工肛门括约肌无法感知肠道粪便量,不能自主控制排便时间,需要通过反复挤压的方式控制假体,且手术方式复杂。随着科技的发展和患者对生活质量要求的不断提高,针对越来越普遍的肛门失禁病症,结合经皮供能和射频通信控制技术,研究集肠道控便和便意检测为一体的植入式智能人工括约肌系统已经成为医工研究的一个重要方向。本文以国家自然科学基金(NO.31170968)和上海交通大学医工交叉基金资助项目(NO.YG2009ZD103)为依托,深入研究了基于经皮供能的反馈式人工肛门括约肌系统的关键技术,采用理论、工程和实验相结合的方法,完成了射频通信控制系统、经皮供能系统和仿生括约肌假体三大模块的研究设计工作,并结合完整的离体和动物实验,验证了系统的可行性和功能,具体工作分为以下几个方面:1.根据本文的研究目标和技术方案,通过硬件模块设计和软件程序设计实现智能控制系统的基本功能。其中,硬件模块主要涉及无线通讯控制模块、生物反馈模块、充电模块和微控制器模块;软件程序设计包括基于射频数据收发的双向通讯程序的编写,以及体内系统控制软件的低功耗设计。在此基础上,对体内系统进行集成和生物相容性封装,并测试了主要指标。硬件模块的设计和软件程序的编写,旨在模拟人体正常的神经感知和控便排便机理,使系统具有完备的协同运作和自主控制能力。2.通过对经皮供能系统的电路建模分析发现链路耦合效率ηl对系统整体性能的提高起到至关重要的作用,而耦合线圈的性能又决定了ηl的高低。围绕线圈结构的参数化设计,对平面螺线管磁片式litz线圈进行电磁场建模,运用自由空间微分场定律和边界条件推导出关于线圈匝数nt、线径Фc、外径ro、内径ri、磁片厚度t和磁片相对磁导率μr的集总参数(l、m、rs)解析模型,从而为优化链路耦合效率提供了重要理论依据。基于matlab编程的图形化设计方法和有限元分析,以高耦合效率为目标,对初次级线圈的nt、Фc、ro、ri、t、μr和层数nl做了参数化设计。优化后的线圈组合在5~25mm的传输距离内,链路耦合效率84.91%~98.78%,与原有按照经验设计的实心铜线线圈相比,平均效率提高36.1%。设计过程中,结合多组示例线圈,运用fea仿真和实验测量结果验证解析模型预测参数的准确性,以及ηl优化方法的有效性。3.为了保证能量供给的稳定性,建立了与线圈耦合系数、次级负载和工作频率相关的经皮供能系统传输方程,研究自适应功率调节的方法,针对不同工况,分别设计了反馈式闭环频控调节和闭环相控调节。频控调节主要针对变耦合系数工况,通过对频率控制方程的推导,得到频率与耦合系数变化的关系,从而通过调节发射频率补偿耦合系数变化对接收电压的影响,离体实验证明当耦合系数在0.1~0.42范围内变化时,频控系统的体内接收功率可以稳定在700mw,系统最大传输效率为67.5%。相控调节主要针对耦合系数和负载同时变化的工况,通过对相控方程的推导,得到mosfets驱动电压的相位差与初级等效输入电压的关系,从而通过调节相位差补偿工况变化对接收电压的影响,离体实验表明当耦合系数和负载分别在0.09~0.29和50~120Ω范围内变化时,相控系统的体内接收电压可以稳定在7v,传输功率根据负载情况在410~950mw范围内实现自适应调节,系统最大传输效率为74.2%。4.在实际应用中,考虑到人体腹部皮下组织将暴露于能量线圈的电磁场中,运用理论剂量学的方法,在maxwell有限元软件中对耦合线圈及其移植环境进行多层组织结构的建模仿真,分析组织内部电流密度和sar值的分布情况。仿真参数(模型结构、组织电特性和发射电流)均设置为实际应用值,仿真结果表明本文设计的经皮供能系统对皮下组织的电磁辐射影响在安全范围内。5.设计了三款人工肛门括约肌假体(传统液压式假体、弹性伸缩式假体和仿耻骨直肠肌式假体)。其中,液压式假体在较小注水量(9ml-10.5ml)的情况下可实现对肠壁作用压的均匀分布(4.05kpa~7.16kpa),控制微泵在3.3v驱动电压下,最大流量为8.5ml/min,最大封闭压可达70kpa。弹性伸缩式假体和仿耻骨直肠肌式假体均属于机械仿生式假体,前者利用弹簧的自然伸张和可控等距收缩的特性,实现对肠壁的闭合和释放;后者的设计灵感源自对耻骨直肠肌的解剖结构及其功能的理解和抽象,模拟u形肌将肛管直肠连接部向前牵引形成直肠角,通过放松和收缩控制角度的大小,从而实现控便排便的功能。机械仿生式假体的工作原理符合括约肌功能要求,相比于水泵式括约肌系统,体内移植模块更加精简。系统的离体实验结果表明上述三款假体均可以有效安全地抑制肠道内容物渗漏,并验证了便意检测的可行性。6.针对第一代水泵式人工肛门括约肌系统WP-AASSΙ,开展了小香猪动物实验,首次验证了WP-AASSΙ控便排便的功能和便意检测的可行性,积累了有关手术方式、移植部位、术后管理和系统测试等方面的经验,同时也发现了系统存在的不足。在此基础上,针对优化后的系统WP-AASSΙΙ,开展了比格犬动物实验,进一步探索了水泵式系统的控便效果和便意检测,并进行了影像学分析,肛肠测压分析,血清化学分析和组织病理学分析。两次动物实验均验证了系统的功能和应用价值,为假体的设计和系统的优化,以及进一步临床实验提供了宝贵的经验和数据。本文对人工肛门括约肌系统的假体机构、便意检测、经皮供能、通信控制和动物实验进行了深入研究,为智能型人工括约肌系统的设计和实用化提供了理论基础和设计经验。在论文最后,对本文的工作做了总结,结合动物实验的数据和经验,提出了今后的研究方向。
[Abstract]:Anal incontinence (Fecal Incontinence FI) refers to the anal sphincter lose the ability to control discharge of feces and gas, is a common clinical disease, the disease is not fatal but bring inconvenience to life and physical and mental pain to the patient. The existing artificial anal sphincter cannot sense the intestinal weight, control defecation time not, need to control prosthesis through repeated extrusion, and the operation is complex. With the development of science and technology and the quality of life of patients with increasing requirements for increasingly common anal incontinence symptoms, combined with transcutaneous energy and radio frequency communication control technology, control and research in intestinal defecation testing as one of the intelligent implantable artificial sphincter system has has become an important direction of biomedical engineering research. Based on the National Natural Science Foundation (NO.31170968) and the Shanghai Jiao Tong University biomedical engineering project (NO.YG2009ZD 103) based on the in-depth research of the key technology, transcutaneous energy feedback artificial anal sphincter system based on the theory and method of engineering and combining experiment, completed the RF communication control system, transcutaneous energy transmission and bionic sphincter prosthesis three modules of the design and research work, combined with in vitro and animal experiments, the feasibility and function of the system is verified, the specific work is divided into the following aspects: 1. according to the research objectives and technical scheme of this paper, through the realization of the basic functions of the intelligent control system hardware design and software program design. The hardware module mainly relates to the wireless communication control module, biological feedback module, charging the module and the microcontroller module; software design including the preparation of radio data transceiver based on two-way communication program, and the software control system in low power consumption based design. On the basis of in vivo, system compatibility package integration and biology, and test the key indicators. And software program of hardware module, designed to simulate the neural control of human perception and normal defecation mechanism, so the system has to work and self control ability of.2. on the circuit model of transcutaneous energy supply system analysis shows that the improved link efficiency l coupling on the performance of the whole system plays an important role in the comprehensive performance, coupling coil determines the level of ETA L. Around the parametric design of the coil structure, electromagnetic field model of planar magnetic solenoid type Litz coil, the use of free space differential law and the boundary conditions are derived about the number of turns of the coil wire diameter NT, diameter C, diameter RO, diameter RI, thickness T and magnetic disk relative permeability lumped parameter r (L, m, RS) analytical model, so as to optimize the coupling efficiency chain road Provides an important theoretical basis. Based on the analysis of the graphic design matlab programming method and finite element method, with high coupling efficiency as the goal, the primary and secondary coils NT, C, RO, RI, t, R and NL layers do parametric design. The optimized coil combination in transmission distance in 5~25mm link, the coupling efficiency of 84.91%~98.78%, and according to the original design of the solid copper wire coil experience compared to the average efficiency of 36.1%. in the design process, combined with multiple sample measuring coil, FEA simulation and experimental results verify the accuracy of prediction parameters using the analytical model, the effectiveness of the.3. and l optimization methods in order to ensure the stability of energy supply, establish the coil and the coupling coefficient, secondary load and working frequency related to the transcutaneous energy transmission equation, method of adaptive power adjustment research, according to different working conditions were designed for closed loop feedback control loop and frequency adjustment Phase control. Frequency control regulation for variable coupling coefficient conditions, through the derivation of frequency control equations of the relationship between changes of frequency and coupling coefficient, thereby regulating the variation of transmission frequency compensation of coupling coefficient on the effect of receiving voltage, in vitro experiments show that when the coupling coefficient changes in the range of 0.1~0.42, frequency control system in the received power can be stabilized in 700MW system, the maximum transmission efficiency is 67.5%. phase control mainly for coupling coefficient and load change condition, through the derivation of the phase control equation of the relationship between phase difference and driving voltage of MOSFETs primary equivalent input voltage, thereby regulating the phase difference compensation condition change effect on the receiving voltage. In vitro experiments showed that, when the coupling coefficient and load respectively in 0.09~0.29 and 50~120 range, the body receives the voltage can be stabilized in the 7 phase control system V, the transmission power according to the load in the range of 410~950mw to realize the adaptive regulation system, maximum transmission efficiency of 74.2%.4. in the practical application, taking into account the subcutaneous tissue of the abdomen of the human body electromagnetic coil will be exposed to energy, using the method of theoretical dosimetry, modeling and Simulation of multi organizational structure for coupling coil and its transplant environment in Maxwell finite element in the software, analyze the distribution of internal current density and SAR value. The simulation parameters (model structure, electrical properties and emission current organization are set) for actual application value, the simulation results show that the transcutaneous energy impact of electromagnetic radiation on the subcutaneous tissue of the system in a safe range of.5. designed three kinds of artificial anus sphincter prosthesis (traditional hydraulic prosthesis, elastic telescopic prosthesis and imitation puborectal muscle implants). The hydraulic components in small water injection (9ml-10.5 Ml) of intestinal wall pressure distribution can be the case (4.05kpa~7.16kpa), control of micro pump in 3.3V driving voltage, the maximum flow rate is 8.5ml/min, the maximum sealing pressure can reach 70kpa. elastic telescopic prosthesis and imitation puborectal muscle type prosthesis are belongs to the mechanical characteristics of the former using bionic prosthesis, natural stretch and spring controlled isometric contraction, the intestinal wall closure and release; the latter design inspiration from the anatomy structure of the puborectalis muscle and its function of understanding and abstract, simulation U shaped muscle will anorectal junction formed by rectum forward traction angle, relaxation and contraction of control angle, so as to realize the function of defecation control. The working principle of the mechanical bionic prosthesis with sphincter function, compared to the pump type sphincter system, in vivo module system more streamlined. In vitro experiment results show that the above three models The prosthesis was effective and safe to inhibit intestinal leakage of content, and verifies the feasibility of detecting.6. meaning for the first generation of pump type artificial anal sphincter system WP-AASS 1, launched a small pig animal experiment, for the first time to verify the feasibility of WP-AASS 1 control function and meaning of the detection of stool, accumulated about surgery, transplantation on site, postoperative management and system test experience, also found that the shortcomings of the system. On this basis, according to the optimized system of WP-AASS mode II, the canine animal experiment, to further explore the pump system control effect and meaning detection, and the imaging analysis. Anorectal manometry analysis, analysis of serum chemical analysis and pathology. Two animal experiments have proved the system's function and application value for the optimization design and the system of the prosthesis, and further clinical practice Experience has provided valuable experience and data. The mechanism of prosthesis of artificial anal sphincter system, meaning detection, transcutaneous energy, communication control and animal experiments conducted in-depth research, provide a theoretical basis and experience for the design of intelligent artificial sphincter system design and practical. At the end of this paper, the work is summarized, combined with the animal experiment data and experience, put forward the research direction in the future.

【学位授予单位】：上海交通大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TH789;R318.1
，

本文编号：1758073