新型人工肛门括约肌系统的初步实验研究

目的观察自行研制的可用于治疗肛门失禁的新型植入式人工肛门括约肌系统（AASS）控制肠腔内容物的效果。方法 AASS由体内执行、体外控制和经皮能量传输3个模块构成,体内外通过无线模式通信。选择屠宰市场购买新鲜宰杀的猪结肠40 cm共4段,将其垂直固定放置,上端开放注入糊状内容物,下端套入AASS并关闭,向肠内缓慢注入糊状物,观察不渗漏所需注入AASS的液体量及囊内压力值;实验动物为贵州小型猪1只,体质量26.2 kg。肠道准备后麻醉开腹,距肛门8 cm处横断直肠套入AASS吻合,经皮能量接收线圈植入皮下,损坏动物肛门括约肌。术后1周开始AASS工作实验,1个月后麻醉开腹,观察AASS植入状态及工作状况。结果离体实验和活体实验均提示,在较少的注水量（9.0～10.5 mL）的情况下,AASS可产生对肠壁作用均匀的压力分布（3.34～7.26 kPa）,满意控制肠内容物渗漏。离体状态下4只AASS夹闭肠管所产生压力与空夹时有很好的相似性,植入活体猪体内1个月取出时系统功能完好,仍可满意夹闭肠管控制流质肠内容物,连续夹闭0.5 h无明显缺血改变。结论 AASS可以很好地模拟正常人体肛门括约肌功能,有望成为治疗肛门失禁和直肠癌术后原位肛门控便的一种新方法。     

基于新型微泵的人造肛门括约肌系统

人造肛门括约肌系统可以模拟人体正常肛门括约肌的工作,解决肛门失禁问题,缓解直肠切除病人的生活和心理压力.研究了人造肛门括约肌系统中的核心装置,提出了一种基于螺母丝杆结构的新型微泵,根据微泵的功率要求设计了无线能量传输模块,并进行了样机实验.测试结果表明该泵可以满足人造肛门括约肌系统的基本功能,该系统可以有效地控制肛门失禁问题.     

植入式人工肛门括约肌系统的实现及动物实验***

背景：研制新型的符合人体生理需求的人工肛门括约肌系统具有十分重要的意义。 目的：设计一种新型植入式人工肛门括约肌系统。 方法：利用无线通讯模块和压力传感器重建排便控制机制,并由经皮能量传输模块供电,采用机电系统模拟人体自然器官的功能,最终实现人体肛门括约肌的控制效果。 结果与结论：设计并实现了一种新型的植入式人工肛门括约肌系统,在重建排便机制和模型的基础上,一定程度上恢复肛门失禁患者的生物反馈控制能力,并带有经皮能量传输模块,为体内系统长期无缆式供电提供可能。该系统实现了植入式动物实验,完成了系统植入可行性和基本功能验证。 关键词：人工肛门括约肌;生物反馈控制;经皮能量传输;植入式动物实验;数字化医学  doi:10.3969/j.issn.1673-8225.2012.13.013     

新型原位植入式人工肛门括约肌样机及离体肠道实验研究

设计一款基于生物信号反馈机制的智能化可遥控式人工肛门括约肌系统。所设计的蠕动式微型医用泵在3.3 V 驱动电压下,最大流量为8.5 mL/min,最大封闭压可达170 kPa。新型括约肌假体在较小注水量（9～10.5 mL）的情况下,可实现对肠壁作用压的均匀分布（3.34～7.26 kPa）,符合人体肠道生理结构和安全压力阈值的要求,避免由于局部高压导致的缺血性坏死。人工括约肌系统采用体内充电电池、体外无线经皮能量充电的供电方式,实现系统的完全植入式移植。离体实验结果表明,该系统可以有效地抑制肠道内容物渗漏,成功建立排便感知信号,从而为严重肛门失禁、结肠造口等肛门功能严重缺失的患者提供一种人性化的治疗方案。     

仿耻骨直肠肌式人工肛门括约肌系统

目的国内外一直在探寻肛肠的奥秘以及救助肛门失禁病患的办法,开展了许多人工肛门括约肌系统的研究。本文设计了一种仿耻骨直肠肌式的新型人工肛门括约肌系统,以解决现有人工肛门括约肌系统存在的血供不足、无"便意"感知以及没有安全且稳定的能量供给等问题。方法系统主要功能为通过自制压力传感模块提取肠道周围压力信息,传递至微型处理器,最终控制括约肌执行结构实现排便操作。其关键技术包括括约肌执行机构内侧嵌入超薄自制生物压力传感器实时感知肠道压力变化,根据此压力参数,系统智能识别便意并实现排便预警。系统采用仿人体机制的运作方式并且结合血供压力的采集模块,能有效避免出现局部高压导致肠道缺血性坏死。系统采用无线能量传输方式提供能量实现安全供能。结果采用淀粉糊状物以及水来验证括约肌执行结构对糊状以及液态粪便的夹持效果,结果表明夹持状况良好。通过体外肠道动物实验得到了模拟肠道周围的压力信号与"便意"产生的关系,验证了系统能够在排便阈值达到以后实现报警,进而提醒患者进行排便操作。实验表明,通过使用无线供能的方式以及低功耗处理,可使系统每次充电后工作6.2天。结论通过实验验证表明系统可有效控制排泄物,并成功建立排便感知信号,实现智能控便。     

反馈式人工肛门括约肌的经皮能量传输系统

针对反馈式人工肛门括约肌的供能问题,研究经皮能量传输系统原理,并研制出经皮能量传输系统,使得反馈式人工肛门括约肌能够模拟实现人体排便功能。通过实验分析接收端负载以及两线圈位置偏移对传输效率的影响,验证了系统的传输性能。实验结果表明,研制的经皮能量传输系统在发射和接收线圈轴向距离为15mm条件下,能稳定传输超过400mW功率,传输效率可达10％,保证人工肛门括约肌的正常工作。     

仿生人工肛门括约肌系统生物相容性及便意感知实验研究

目的 针对人工肛门括约肌(artificial anal sphincter,AAS)长期植入活体后出现的生物相容性不佳、缺乏便意感知能力和血供安全性问题,提出一种仿生人工肛门括约肌系统(bionic artificial anal sphincter,BAAS)并进行实验评估.方法 首先建立仿生人工肛门括约肌系统,系统采用封闭连杆式"三环"机构作为括约肌假体,外覆一体化医用硅橡胶薄膜以增强生物相容性,环臂嵌入10路压力传感模块,并采用经皮无线能量传输和无线通信实现体内外系统能量供给与信息交互.然后进行体外实验,以评估括约肌假体的控便能力与血供安全性,并创新地利用压力向量相似度作为便意判断的新标准建立便意智能感知模型.最后进行动物实验,对BAAS系统整体植入效果、生物相容性、控便及便意感知能力等进行观察和评估.结果 体外实验表明,括约肌假体对肠道内容物的蓄控效果满足便意阈值需求,且最大夹持压力在肠道血供安全性范围内,满足控便和血供安全性要求.动物实验表明括约肌假体具有良好的密封性和生物相容性,验证了便意智能感知模型的可靠性,体内便意预警准确率最高可达80％.结论 BAAS系统可以模拟肛门括约肌的功能,作为治疗重度肛门失禁的方法.     

生物反馈式括约肌控制装置

针对肛门失禁患者的排便控制问题,在前人工作的基础上改进生物反馈式肛门括约肌装置.根据正常人排便控制原理及内括约肌松弛反射过程,系统分为体内模块和体外模块:体内模块利用压力传感器对肠道压力进行测量,并将信号通过nRF401传到体外模块,实现生物反馈;体外模块通过nRF401控制体内模块完成排泄的整个生理过程,装置采用MSP430F1232单片机进行控制.     

人工肛门括约肌经皮能量传输系统研究

针对现有人工肛门括约肌系统无供能装置或供能装置更换可能引发感染等问题,本文提出了电磁谐振耦合的无线供能方法,对人工肛门括约肌系统进行非接触的经皮无线供能.本文在对能量传输电路、发送接收线圈参数研究基础上,提出通过选择SRC电路作为发射、接收端耦合电路以增大铁芯耦合面积,从而提高发射及接收线圈Q值,进而提高能量传输效率.实验结果表明,使用G25磁芯线圈进行电磁耦合,当两线圈轴向距离为10mm时,能量传输效率可高于60%,可保证人工肛门括约肌系统的正常工作.     

基于无线充电技术的胃肠电刺激系统

目的设计一种新型的植入式胃肠道刺激系统,不仅具有刺激功能,还具有肠电和压力检测功能,可用于检测胃肠道刺激的效果,同时增加无线能量供给,以实现刺激器的长期植入。方法系统由体内刺激模块、体外控制模块及无线能量传输模块组成。体外控制模块通过无线射频将控制信号传输到体内刺激模块,体内刺激模块的能量由体外能量发射装置通过电磁耦合进行供给。通过生物反馈控制检测不同刺激参数对胃肠道收缩活动的作用效果,实时调整刺激参数,输出需要的刺激脉冲。以模拟心电信号模拟肠电信号,进行了相关的体外实验。结果在体外实验中,系统可有效检测到2—20次／min的模拟心电信号,并实现实时刺激参数修改输出不同的刺激脉冲。该系统实现了电流检测功能,监测作用部分的胃肠电阻。经皮无线能量在两级线圈轴向距离为22mm时的接收充电稳定功率最大为0．93W,体内锂离子的充电电流为180～240mA。结论系统可检测到最大变化范围的模拟肠电信号。验证电流的作用效应为后续的恒流刺激模式提供参考。该系统的无线充电功能可满足植入式刺激器长期植入的能量需求。     

生物反馈式人工肛门感知系统的研制及效果

背景：人工肛门为治疗肛门失禁开辟了一条新的思路,然而现有的人工肛门没有感知和反馈功能。患者只能通过习惯而不是肠内容物的实际情况排便。因此人工肛门感知和反馈系统的研制是亟待解决的问题。 目的：研制能感知和反馈肠内容物量和压力变化的人工肛门感知系统。 方法：通过实验分别向20只新西兰兔近结肠远端10 cm肠管内注入不同体积的模拟气体、液体、半流体、固体肠内容物,并测量肠管和压力感应套囊的压力变化,分析4种状态肠内容物体积与肠管压力和压力感应套囊压力的关系。 结果与结论：实验结果表明,肠管内压力和套囊压力随肠内容物体积的增加而增大,套囊压力与肠内容物体积和肠管压力在一定范围内成正相关。通过实验证实,该生物反馈式人工肛门感知系统能有效的反映肠内容物的多少和肠内压的变化,是解决人工肛门感知和反馈的有效策略,为生物反馈式智能人工肛门的研制打下基础。     

Feedback control of TET system with variable coupling coefficients for a novel artificial anal sphincter

For treating severe faecal incontinence, the authors developed an intelligent artificial anal sphincter system (AASS) equipped with a feedback sensor that utilized a transcutaneous energy transfer system (TETS). To deliver the correct amount of power (i.e. to match the load demand under variable coupling conditions caused by changes in positioning between the coils due to fitting and changes in posture), a regulating method to stabilize output voltage with a closed loop variable-frequency controller was developed in this paper. The method via which the voltage gain characteristics of a voltage-fed series-tuned TETS were derived is also described. The theoretical analysis was verified by the results of the experiment. A numerical analysis method was used as a control rule with respect to the relationship between operating frequency and output voltage. To validate the feedback control rules, a prototype of the TET charging system was constructed, and its performance was validated with the coupling variation between 0.12–0.42. The results show that the output voltage of the secondary side can be maintained at a constant 7?V across the whole coupling coefficient range, with a switching frequency regulation range of 271.4–320.5?kHz, and the proposed controller has reached a maximal end-to-end power efficiency of 67.5% at 1?W.     

Fecal incontinence. Studies on physiology,pathophysiology and surgical treatment

The thesis consists of ten previously published studies and a review. The physiological and pathophysiological mechanisms in fecal incontinence has been studied by anal manometry, both by standard static anal manometry and by a new method, dynamic anal manometry, where anal sphincter pressure can be measured during simultaneous opening and closing of the anal canal. Patients with fecal incontinence showed abnormal sphincter pressures more frequently when dynamic anal manometry was used compared to standard anal manometry. The physiology and pathophysiology of the rectum was studied using rectal compliance measurements. Patients with normal anorectal function had a large variation in rectal compliance. Patients with fecal incontinence had as a group, lower rectal compliance than continent patients. This may lead to increased frequency of incontinence episodes in patients with fecal incontinence. The relationship between idiopathic fecal incontinence and pudendal nerve terminal latency was studied in 178 patients. The far majority of patients had normal latencies, and there was no correlation between latency and anal manometry. In contrast to previous suggestions, idiopathic fecal incontinence does not seem to be caused by pudendal nerve damage. Reconstruction of the external anal sphincter in patients with fecal incontinence due to obstetric sphincter lesion showed a poorer functional result among patients older than forty years compared to younger. This indicates that the general muscular weakening with age contribute to the incontinence in these patients. The treatment of more complicated forms of fecal incontinence consists of, apart from conservative treatment or colostomi, mainly in muscle transpositions or artificial anal sphincter. Transposition of the distal part of the gluteus maximus muscle to encircle the anal canal, did not lead to acceptable continence in any of the patients studied. Transposition of the gracilis muscle lead to acceptable continence in half the patients. Patients where the transposed muscle were stimulated by a neurostimulator had satisfactory continence in most cases. However, with this method several re-operations were necessary in some patients. In addition, some patients developed severe evacuation difficulties. Implantation of an artificial sphincter resulted in long-term improvement of continence in that half of patients in whom the artificial sphincter remained implanted. The other half of the patients had the artificial sphincter explanted due to various reasons, most frequently due to infection around the device. In selected patients with more complicated fecal incontinence, stimulated gracilis transposition or implantation of an artificial anal sphincter may be offered as an alternative to colostomy. Sacral nerve stimulation is a new method which seems to provide the best results among the more advanced procedures. Its minimally invasive character also contribute to the increasing use of this method in the last few years. Evaluation and treatment of fecal incontinence is presently in a state of rapid change with focus on more elaborate investigative methods and more diversified treatment.     

Development of an implantable artificial anal sphincter by the use of the shape memory alloy

In this study, we developed and assessed an artificial anal sphincter driven by an shape memory alloy actuator (AS-SMA). The performance characteristics of the device were analyzed with a measurement system. Assessment showed that the AS-SMA could generate a pressure of 55 mm Hg at an atmospheric temperature of 36 degrees C, and displacement of the SMA actuator was 7.5 mm when the temperature of the SMA plate was 55 degrees C. To evaluate opening and closing, we studied a piglet colostomy model, in which the AS-SMA was implanted around the colostomy in the extraperitoneal space. Flow control tests using living porcine intestine revealed that the AS-SMA could maintain fecal continence against an intestinal pressure of 75 mm Hg. The high pressure zone corresponding to the location of the device was demonstrated in a manometric examination. For 6 days after surgery, we activated the AS-SMA twice a day and observed the bowel movements. The animal experiment indicated that the AS-SMA is able to control the bowel movements of patients with fecal incontinence if several problems, such as burning of tissue around the device and compression injury of the intestine, are resolved.     

不同型别的功能性便秘患儿肛门直肠测压对照研究

目的探讨功能性便秘（FC）患儿与健康儿童肛门直肠动力学差异,为其临床分型诊断及治疗提供依据。方法采用功能性胃肠病罗马Ⅲ诊断标准,收集2008年1月至2009年1月在第四军医大学唐都医院儿科门诊及住院的FC患儿为FC组。选取同期无消化系统症状,平日排便正常的健康儿童为正常对照组。采用不透光X线硫酸钡条测定结肠传输指数（TI）,依据TI将FC组分为出口梗阻型（OOC）亚组、慢传输型（STC）亚组和混合型（MIX）亚组。通过肛门直肠测压法分析FC各亚组与正常对照组肛门直肠动力学差异。结果研究期间FC组纳入25例,其中STC亚组10例,OOC亚组15例,未发现MIX患儿;正常对照组纳入10名。FC组与正常对照组肛门括约肌静息压差异无统计学意义（P〉0.05）。STC亚组肛门括约肌最大收缩压与正常对照组差异无统计学意义（P〉0.05）,OOC亚组肛门括约肌最大收缩压显著高于正常对照组及STC亚组（P〈0.05）。FC组直肠最低敏感量及最大耐受量均显著高于正常对照组（P均〈0.05）。STC亚组与OOC亚组直肠最低敏感量及最大耐受量差异均无统计学意义（P均〉0.05）。结论FC患儿存在明显的肛门直肠动力和感觉异常;OOC和STC患儿的肛门直肠动力学存在差异。肛门直肠测压检查对协助诊断FC有一定价值。     

先天性巨结肠Ⅰ期经肛门术后肛肠功能评估

目的探讨先天性巨结肠I期经肛门术后患儿的排便功能、结肠和肛门括约肌功能。方法对I期经肛门术后5～9年的89例先天性巨结肠患儿进行排便功能问卷调查,同时对来院随访的58例患儿进行肛门直肠测压和钡灌肠检查,评价其术后肛肠功能。结果 89例先天性巨结肠术后患儿中,72例排便功能良好,排便次数1～2次/d,仅6例3～4次/d,7例稀便时污便,1例经常污便;3例便秘。89例患儿均有便意无便失禁。直肠肛门测压结果：2例患儿术后直肠肛管反射弱阳性;污便组肛管静息压较无症状组及对照组显著降低[（29.4±3.2）mmHg vs（40.2±5.1）mmHg vs（36.9±2.6）mmHg,P〈0.05,P〈0.05）],而直肠静息压显著增高[（65.9±7.2）mmHg vs（25.7±4.1）mmHg vs（11.0±1.3）mmHg,P〈0.05,P〈0.05）];污便组肛管收缩压明显低于无症状组及对照组[（183.5±15.6）mmHg vs（210.2±18.3）mmHg vs（200.6±13.8）mmHg,P〈0.01];而持续缩榨时间三组间差异无统计学意义。便秘组与其他三组间比较差异无统计学意义,且有1例出现括约肌反常运动。钡灌肠结果：先天性巨结肠术后所有患儿的结肠形态恢复良好,结肠框基本正常,未见到明显的痉挛段、移行段和扩张段,乙状结肠迂曲减少或消失,与术中切除肠管长度相符。先天性巨结肠术后所有病例的直肠肛管角比对照组明显增大（121.6°±14.2°vs 82.0°±11.4°,P〈0.01）,污便组又较便秘组及无症状组明显增大（138.4°±16.8°vs 106.3°±13.8°vs 110.6°±15.2°,P〈0.05）。结论先天性巨结肠I期经肛门术后患儿多数排便功能良好,结肠形态及肛门括约肌功能恢复良好,少数患儿污便可能与拖出结肠储便功能代偿不全、乙状结肠迂曲减少或消失、肛门括约肌损伤等有关。     

小儿不全性肛门失禁的手术治疗

目的：探讨小儿不全性肛门失禁的手术修复方法及效果。方法：6例不完全性肛门失禁儿童患，年龄4岁－11岁，均采用肛门外括约肌残存断端缝合重建外括约肌功能，5例行邻近皮瓣转移、1例V－Y推进重建肛周皮肤及会阴体形态。结果：所有患儿术后肛门外形及效果满意，能自主控制大便。随访4－24个月，无任何并发症发生。结论：肛门外括约肌移位残端修补并邻近皮瓣转移，手术简单、合乎生理，是不全性肛门失禁手术治疗方法的良好选择。