膀胱动力泵尿道阀的设计及可靠性研究
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摘要
神经源性膀胱是指由于人体控制排尿的中枢神经受到损害而引起的膀胱排尿功能障碍。该病可引发膀胱结石、泌尿系统感染、肾功能衰竭等并发症,给病人带来极大的痛苦,对其治疗或辅助病人排尿是医学界公认的难题。目前,对神经源性膀胱治疗尚无有效办法。针对此问题,本课题提出了一种体外电磁驱动的膀胱动力泵。通过体外电磁铁产生的电磁场对体内磁动子产生电磁驱动力,调节尿道口和输尿管口开闭,压迫膀胱排尿。模拟实验证明该泵工作原理可行,但开启尿道口所需的电磁驱动力较大,导致电磁铁结构较大。为了优化膀胱动力泵的结构,有必要对其尿液配流机构做出改进。
为此,本文设计了一种新型的膀胱动力泵尿道阀。运用电磁学理论和流体力学理论,建立了尿道阀的数学模型,利用该模型仿真分析了电流和气隙等不同因素对尿道阀特性的影响。通过仿真和实验对比,验证了所建立模型的有效性。在模拟实验台上,研究了尿道阀对膀胱动力泵排尿动力特性的影响规律。结果表明：增大电磁铁电流、减小电磁铁与尿道阀之间的气隙,有利于提高最大尿流率、缩短尿流时间。
尿道阀是膀胱动力泵实现尿液配流的重要部件,一旦发生失效,将导致泵失去辅助排尿作用。因此,研究提高尿道阀的可靠性具有重要的意义。为了提高尿道阀的工作可靠性,根据尿道阀的结构原理及故障树,建立了尿道阀可靠性仿真模型。基于蒙特卡罗方法基本思想,提出了尿道阀可靠性仿真算法,并仿真计算了尿道阀的可靠度、失效概率、底事件重要度和模式重要度等指标。仿真与实验结果表明：尿道阀寿命达到50000次的可靠度为0.73；弹性带脱落和老化是尿道阀的薄弱环节。
研究结果可为膀胱动力泵特性分析和结构优化设计提供依据,为设计新型的辅助排尿装置提供指导,对合理设计适用于人体的生物医学装置有参考作用。
Neurogenic bladder is a term applied to a malfunctioning urinary bladder, which is caused by the injured central nervous that controls urination. Some complications can be caused by the disease, such as bladder stone, urinary system infection, renal failure and so on. It can bring great pain to patients, and the treatment of the disease or assisting micturition has been generally acknowledged as difficult problem by medical researches. There is no effective way to the neurogenic bladder at present. In order to solve the problem, a bladder power pump driven by an external electromagnet was proposed. An external electromagnet produces electromagnetic force which acts on a magnetic mover, and the tension of magnetic mover makes the orifices of ureters and urethra close and open. As a result, the urine of urinary bladder is continuously discharged by the press of magnetic mover. The feasibility of the working principle of the pump was proved by simulated experiment. But, a great electromagnetic force for opening the orifice of urethra and a big electromagnet were required. To optimize the structure of the pump, the distribution mechanism of the pump should be improved.
Therefore, a new urethra valve of the bladder power pump was designed in this paper. The mathematical model of the urethra valve was built based on the theories of electromagnetics and hydromechanics. The model was used to analyze the characteristics of the urethra valve effected by different electromagnet current, air gap and so on. The validity of the model was confirmed through the comparison between simulation and experiment. The effects of the urethra valve on the micturition performance of the pump were studied on simulated experiment system. The results show that increasing electromagnet current and decreasing air gap between the electromagnet and the urethra valve are beneficial to increasing maximal urine flow rate and decreasing urine flow time.
The urethra valve is a major part of the pump for realizing flow distribution of urine. Once the urethra valve is in fault, the pump will lose the function of assisting micturition. So, it is important to study the reliability of the urethra valve. In order to improve the reliability of the urethra valve, a simulation model of the reliability of the urethra valve was built based on the structure principle and fault tree of the urethra valve. According to the principle of the Monte Carlo method, a simulation algorithm of the reliability of the urethra valve was proposed. Some reliability indexes of the urethra valve were calculated, such as reliability, failure probability, importance of bottom events, mode importance and so on. The simulation and experiment results showed that the reliability of the urethra valve is0.73when the life is50000times; both shedding and aging of elastic band are the weaknesses of the urethra valve.
The conclusion can provide the basis for performance analysis and structural optimization design of the bladder power pump, and provide the guidance for the design of new device for assisting the bladder micturating, as well as the guidance for the design of biomedicine device.
为此,本文设计了一种新型的膀胱动力泵尿道阀。运用电磁学理论和流体力学理论,建立了尿道阀的数学模型,利用该模型仿真分析了电流和气隙等不同因素对尿道阀特性的影响。通过仿真和实验对比,验证了所建立模型的有效性。在模拟实验台上,研究了尿道阀对膀胱动力泵排尿动力特性的影响规律。结果表明：增大电磁铁电流、减小电磁铁与尿道阀之间的气隙,有利于提高最大尿流率、缩短尿流时间。
尿道阀是膀胱动力泵实现尿液配流的重要部件,一旦发生失效,将导致泵失去辅助排尿作用。因此,研究提高尿道阀的可靠性具有重要的意义。为了提高尿道阀的工作可靠性,根据尿道阀的结构原理及故障树,建立了尿道阀可靠性仿真模型。基于蒙特卡罗方法基本思想,提出了尿道阀可靠性仿真算法,并仿真计算了尿道阀的可靠度、失效概率、底事件重要度和模式重要度等指标。仿真与实验结果表明：尿道阀寿命达到50000次的可靠度为0.73；弹性带脱落和老化是尿道阀的薄弱环节。
研究结果可为膀胱动力泵特性分析和结构优化设计提供依据,为设计新型的辅助排尿装置提供指导,对合理设计适用于人体的生物医学装置有参考作用。
Neurogenic bladder is a term applied to a malfunctioning urinary bladder, which is caused by the injured central nervous that controls urination. Some complications can be caused by the disease, such as bladder stone, urinary system infection, renal failure and so on. It can bring great pain to patients, and the treatment of the disease or assisting micturition has been generally acknowledged as difficult problem by medical researches. There is no effective way to the neurogenic bladder at present. In order to solve the problem, a bladder power pump driven by an external electromagnet was proposed. An external electromagnet produces electromagnetic force which acts on a magnetic mover, and the tension of magnetic mover makes the orifices of ureters and urethra close and open. As a result, the urine of urinary bladder is continuously discharged by the press of magnetic mover. The feasibility of the working principle of the pump was proved by simulated experiment. But, a great electromagnetic force for opening the orifice of urethra and a big electromagnet were required. To optimize the structure of the pump, the distribution mechanism of the pump should be improved.
Therefore, a new urethra valve of the bladder power pump was designed in this paper. The mathematical model of the urethra valve was built based on the theories of electromagnetics and hydromechanics. The model was used to analyze the characteristics of the urethra valve effected by different electromagnet current, air gap and so on. The validity of the model was confirmed through the comparison between simulation and experiment. The effects of the urethra valve on the micturition performance of the pump were studied on simulated experiment system. The results show that increasing electromagnet current and decreasing air gap between the electromagnet and the urethra valve are beneficial to increasing maximal urine flow rate and decreasing urine flow time.
The urethra valve is a major part of the pump for realizing flow distribution of urine. Once the urethra valve is in fault, the pump will lose the function of assisting micturition. So, it is important to study the reliability of the urethra valve. In order to improve the reliability of the urethra valve, a simulation model of the reliability of the urethra valve was built based on the structure principle and fault tree of the urethra valve. According to the principle of the Monte Carlo method, a simulation algorithm of the reliability of the urethra valve was proposed. Some reliability indexes of the urethra valve were calculated, such as reliability, failure probability, importance of bottom events, mode importance and so on. The simulation and experiment results showed that the reliability of the urethra valve is0.73when the life is50000times; both shedding and aging of elastic band are the weaknesses of the urethra valve.
The conclusion can provide the basis for performance analysis and structural optimization design of the bladder power pump, and provide the guidance for the design of new device for assisting the bladder micturating, as well as the guidance for the design of biomedicine device.
引文
[1]陈忠,崔喆,双卫兵.神经源性膀胱[M].北京：人民卫生出版社,2009.
[2]Lapides J, Diokno AC, Silber, et al. Spinal cord injury in children:Long-term urodynamic and urological outcomes[J]. J Urol,2004,172 (3):1092-1094.
[3]Mulcahy JJ, James HE, Mcroberts JW. Oxybutynin chloride combined with intermittent clean catheterization in the treatment of myelomeningocele patients[J]. J Urol,1977,118 (1):95-96.
[4]Remmler D, Olson L, Duke D, et al. Presurgical finite element analysis from routine computed tomography studies for craniofacial distraction:An engineering prediction model for gradual correction of asymmetric skull deformities [J]. Plast Reconstr Surg, 1998,102(5):1395-1404.
[5]Wiart L, Joseph PA, Petit H, et al. The effects of capsaicin on the neurogenic hyperreflexic detrusor. A double blind placebo controlled study in patients with spinal cord disease. Preliminary results [J]. Spinal Cord,1998,36 (2):95-99.
[6]Xiao CG, Du MX, Dai C, et al. An artificial somatic-central nervous system-autonomic reflex pathway for controllable micturition after spinal cord injury:preliminary results in 15 patients [J]. J Urol,2003,170(4 Pt 1):1237-1241.
[7]李笑,关婷.一种体外电磁驱动的膀胱动力泵[P].中国专利ZL200710031081.1，2010-09-19.
[8]李笑,关婷.体外电磁驱动的膀胱动力泵及模拟实验系统设计[J].机床与液压,2009,37(11)：70-73.
[9]李笑,黄维佳,关婷.体外电磁驱动的膀胱动力泵的建模与仿真分析[J].系统仿真学报,2010,22(12)：2963-2966,2989.
[10]赵克中.磁力驱动技术与设备[M].北京：化学工业出版社,2004.
[11]苏彦宏,张泽慧.磁传动技术的发展和应用[J].甘肃科技,2004,20(8)：82-86.
[12]赵克中,徐成海.磁力驱动阀门的结构原理与试验研究[J].化工机械,2004,31(1)：9-13.
[13]贾彦璋,孙冰,杜鹏,等.磁力驱动防盗锁闭阀的研究[J].机械研究与应用,2007,20(5)：120-121.
[14]赵红,李国荣,朱晓东,等.动力性主动脉瓣的远距离磁驱动研究[J].解剖学报,2002,33(6)：627-630.
[15]侯明文.永磁悬挂除铁器所需工作磁力分析[J].机械工程与自动化,2004,(6)：78-79.
[16]Ona M, Wakabayashi N. Influence of alveolar support on stress in periodontal structures [J]. J Dent Res,2006,85(12):1087-1091.
[17]Millner A, Menn D, Ochs B, et al. Development of an efficient electrohydraulic total artificial heart [J]. ASAIO Trans,1990,36 (3):245-249.
[18]Weiss W J, et al. Resent improvements in a completely implanted total artificial heart. ASAIO Journal.1996.42:M342.
[19]Erik Koppert, et al.A total artificial heart of neonates allowing bridging to transplantation. ASAIO. Journal.1990.36:M226.
[20]龚中良,谭建平.外场驱动血泵磁力耦合传动受力分析[J].机械科学与技术,2006,25(6)：725-726.
[21]Bulter KC, Morse JC, Wampler RK. The Hemopump-a New Cardiac Protbesis Device. IEEE Trans Biomed Eng 1990:37:193b.
[22]Parnis SM, Conger JL, Fuqua JM, et al. Progress in the Development of Transcuraneously Powered Axial Flow Blood Pump Ventricular Assist System [J]. ASAIO,1997,13,567-580.
[23]周继良,郑洪涛,谭智勇.CFD在水泵设计中的应用[J].汽轮机技术,2004,46(1)：23-24.
[24]成立,薛坚,刘超,等.CFD技术在泵装置水力优化设计中的应用[J].南水北调与水利科技,2007,5(3)：33-34,37.
[25]王芳群,曾培,茹伟民,等.应用CFD研究叶轮设计对人工心脏泵内流场的影响[J]中国生物医学工程学报,2005,24(5)：578-582.
[26]姜华,席光.心脏泵的研究进展[J].医疗卫生装备,2006,27(8)：33-35,51.
[27]王鹰鹏,宋新伟,应纯同.后置导轮对人工轴流心脏泵的影响分析[J].中国生物 医学工程学报,2007,26(5)：758-762.
[28]黄维佳.体外电磁驱动的膀胱动力泵及其模拟实验系统设计[D].广州：广东工业大学,2009.
[29]梁超寰.膀胱动力泵的优化设计及模拟实验研究[D].广州：广东工业大学,2010.
[30]王秀英.膀胱动力泵虚拟样机设计及其特性研究[D].广州：广东工业大学,2010.
[31]周东才.膀胱动力泵排尿动力特性分析及模拟试验研究[D].广州：广东工业大学,2011.
[32]Freudenthal A M. Safety of structures [J]. Trans action, ASCE,1947,112:125-180.
[33]Stulen F B. Preventing fatigue failures [J]. Machine Design,1961,33:159-165.
[34]Freudenthal A M, Garrelts M, Shinozuka M. The analysis of structural safety [J]. Journal Structural Division, ASCE 92,1966:267-325.
[35]Haugen E B. Probabilistic Approaches to Design[M]. New York:John Weily and Sons,1968.
[36]Kececioglu D. Reliability analysis of mechanical components and systems [J]. Nuclear Engineering and Design,1972,19:259-290.
[37]Kececioglu D. Probability design methods for reliability and their data and research requirements [J]. Failure Prevention and Reliability, ASME,1977:285-309.
[38]A.Naess, B.J.Leira, O.Batsevych. System reliability analysis by enhanced Monte Carlo simulation [J]. Structural Safety,2009,31 (5):349-355.
[39]王正,谢里阳,李兵.随机载荷作用下的零件动态可靠性模型[J].机械工程学报,2007,43(12)：20-25.
[40]王少萍.工程可靠性[M].北京：北京航空航天大学出版社,2000.
[41]Chen J B, Li J. The extreme value distribution and dynamic reliability analysis of nonlinear structures with uncertain parameters [J]. Structural Safety,2007,29 (2):77-93.
[42]杨玉良,张红东.高分子科学中的Monte Carlo方法[M].上海：复旦大学出版社,1993.
[43]杨耀臣.蒙特卡罗方法与人口仿真学[M].合肥：中国科学技术大学出版社,1999.
[44]董聪.现代系统结构可靠性理论及应用[M].北京：科学出版社,2001.
[45]周金宇.系统非整数阶可靠性分析[M].沈阳：东北大学出版社,2005.
[46]杨为民,盛一兴.系统可靠性数字仿真[M].北京：北京航空航天大学出版社,1990.
[47]Wang Z, Xie L Y, Li B. Time-dependent reliability models of systems with common cause failure [J]. International Journal of Performability Engineering,2007,3 (4):419-432.
[48]王正,谢里阳,李兵.考虑载荷作用次数的失效相关系统可靠性模型[J].东北大学学报(自然科学版),2007,28(5)：704-707.
[49]谢里阳,周金宇,李翠玲,等.系统共因失效分析及其概率预测的离散化建模方法[J].机械工程学报,2006,42(1)：62-68.
[50]王正,谢里阳,张君一.载荷多次作用下的共因失效系统可靠性模型[J].航空学报,2007,28：116-120.
[51]李景魁.基于蒙特卡罗法数控机床液压系统可靠性分析[J].液压与气动,2011(11)：115-117.
[52]蒋金良,王遂,任震.基于蒙特卡罗法的高压直流输电系统可靠性评估[J].华南理工大学学报：自然科学版,2008,36(2)：128-132.
[53]钱文学,尹晓伟,谢里阳,等.轮盘疲劳可靠性分析的Monte-Carlo数字仿真[J].系统仿真学报,2007,19(2)：254-256,266.
[54]张也影.流体力学[M].北京：高等教育出版社,1998.
[2]Lapides J, Diokno AC, Silber, et al. Spinal cord injury in children:Long-term urodynamic and urological outcomes[J]. J Urol,2004,172 (3):1092-1094.
[3]Mulcahy JJ, James HE, Mcroberts JW. Oxybutynin chloride combined with intermittent clean catheterization in the treatment of myelomeningocele patients[J]. J Urol,1977,118 (1):95-96.
[4]Remmler D, Olson L, Duke D, et al. Presurgical finite element analysis from routine computed tomography studies for craniofacial distraction:An engineering prediction model for gradual correction of asymmetric skull deformities [J]. Plast Reconstr Surg, 1998,102(5):1395-1404.
[5]Wiart L, Joseph PA, Petit H, et al. The effects of capsaicin on the neurogenic hyperreflexic detrusor. A double blind placebo controlled study in patients with spinal cord disease. Preliminary results [J]. Spinal Cord,1998,36 (2):95-99.
[6]Xiao CG, Du MX, Dai C, et al. An artificial somatic-central nervous system-autonomic reflex pathway for controllable micturition after spinal cord injury:preliminary results in 15 patients [J]. J Urol,2003,170(4 Pt 1):1237-1241.
[7]李笑,关婷.一种体外电磁驱动的膀胱动力泵[P].中国专利ZL200710031081.1，2010-09-19.
[8]李笑,关婷.体外电磁驱动的膀胱动力泵及模拟实验系统设计[J].机床与液压,2009,37(11)：70-73.
[9]李笑,黄维佳,关婷.体外电磁驱动的膀胱动力泵的建模与仿真分析[J].系统仿真学报,2010,22(12)：2963-2966,2989.
[10]赵克中.磁力驱动技术与设备[M].北京：化学工业出版社,2004.
[11]苏彦宏,张泽慧.磁传动技术的发展和应用[J].甘肃科技,2004,20(8)：82-86.
[12]赵克中,徐成海.磁力驱动阀门的结构原理与试验研究[J].化工机械,2004,31(1)：9-13.
[13]贾彦璋,孙冰,杜鹏,等.磁力驱动防盗锁闭阀的研究[J].机械研究与应用,2007,20(5)：120-121.
[14]赵红,李国荣,朱晓东,等.动力性主动脉瓣的远距离磁驱动研究[J].解剖学报,2002,33(6)：627-630.
[15]侯明文.永磁悬挂除铁器所需工作磁力分析[J].机械工程与自动化,2004,(6)：78-79.
[16]Ona M, Wakabayashi N. Influence of alveolar support on stress in periodontal structures [J]. J Dent Res,2006,85(12):1087-1091.
[17]Millner A, Menn D, Ochs B, et al. Development of an efficient electrohydraulic total artificial heart [J]. ASAIO Trans,1990,36 (3):245-249.
[18]Weiss W J, et al. Resent improvements in a completely implanted total artificial heart. ASAIO Journal.1996.42:M342.
[19]Erik Koppert, et al.A total artificial heart of neonates allowing bridging to transplantation. ASAIO. Journal.1990.36:M226.
[20]龚中良,谭建平.外场驱动血泵磁力耦合传动受力分析[J].机械科学与技术,2006,25(6)：725-726.
[21]Bulter KC, Morse JC, Wampler RK. The Hemopump-a New Cardiac Protbesis Device. IEEE Trans Biomed Eng 1990:37:193b.
[22]Parnis SM, Conger JL, Fuqua JM, et al. Progress in the Development of Transcuraneously Powered Axial Flow Blood Pump Ventricular Assist System [J]. ASAIO,1997,13,567-580.
[23]周继良,郑洪涛,谭智勇.CFD在水泵设计中的应用[J].汽轮机技术,2004,46(1)：23-24.
[24]成立,薛坚,刘超,等.CFD技术在泵装置水力优化设计中的应用[J].南水北调与水利科技,2007,5(3)：33-34,37.
[25]王芳群,曾培,茹伟民,等.应用CFD研究叶轮设计对人工心脏泵内流场的影响[J]中国生物医学工程学报,2005,24(5)：578-582.
[26]姜华,席光.心脏泵的研究进展[J].医疗卫生装备,2006,27(8)：33-35,51.
[27]王鹰鹏,宋新伟,应纯同.后置导轮对人工轴流心脏泵的影响分析[J].中国生物 医学工程学报,2007,26(5)：758-762.
[28]黄维佳.体外电磁驱动的膀胱动力泵及其模拟实验系统设计[D].广州：广东工业大学,2009.
[29]梁超寰.膀胱动力泵的优化设计及模拟实验研究[D].广州：广东工业大学,2010.
[30]王秀英.膀胱动力泵虚拟样机设计及其特性研究[D].广州：广东工业大学,2010.
[31]周东才.膀胱动力泵排尿动力特性分析及模拟试验研究[D].广州：广东工业大学,2011.
[32]Freudenthal A M. Safety of structures [J]. Trans action, ASCE,1947,112:125-180.
[33]Stulen F B. Preventing fatigue failures [J]. Machine Design,1961,33:159-165.
[34]Freudenthal A M, Garrelts M, Shinozuka M. The analysis of structural safety [J]. Journal Structural Division, ASCE 92,1966:267-325.
[35]Haugen E B. Probabilistic Approaches to Design[M]. New York:John Weily and Sons,1968.
[36]Kececioglu D. Reliability analysis of mechanical components and systems [J]. Nuclear Engineering and Design,1972,19:259-290.
[37]Kececioglu D. Probability design methods for reliability and their data and research requirements [J]. Failure Prevention and Reliability, ASME,1977:285-309.
[38]A.Naess, B.J.Leira, O.Batsevych. System reliability analysis by enhanced Monte Carlo simulation [J]. Structural Safety,2009,31 (5):349-355.
[39]王正,谢里阳,李兵.随机载荷作用下的零件动态可靠性模型[J].机械工程学报,2007,43(12)：20-25.
[40]王少萍.工程可靠性[M].北京：北京航空航天大学出版社,2000.
[41]Chen J B, Li J. The extreme value distribution and dynamic reliability analysis of nonlinear structures with uncertain parameters [J]. Structural Safety,2007,29 (2):77-93.
[42]杨玉良,张红东.高分子科学中的Monte Carlo方法[M].上海：复旦大学出版社,1993.
[43]杨耀臣.蒙特卡罗方法与人口仿真学[M].合肥：中国科学技术大学出版社,1999.
[44]董聪.现代系统结构可靠性理论及应用[M].北京：科学出版社,2001.
[45]周金宇.系统非整数阶可靠性分析[M].沈阳：东北大学出版社,2005.
[46]杨为民,盛一兴.系统可靠性数字仿真[M].北京：北京航空航天大学出版社,1990.
[47]Wang Z, Xie L Y, Li B. Time-dependent reliability models of systems with common cause failure [J]. International Journal of Performability Engineering,2007,3 (4):419-432.
[48]王正,谢里阳,李兵.考虑载荷作用次数的失效相关系统可靠性模型[J].东北大学学报(自然科学版),2007,28(5)：704-707.
[49]谢里阳,周金宇,李翠玲,等.系统共因失效分析及其概率预测的离散化建模方法[J].机械工程学报,2006,42(1)：62-68.
[50]王正,谢里阳,张君一.载荷多次作用下的共因失效系统可靠性模型[J].航空学报,2007,28：116-120.
[51]李景魁.基于蒙特卡罗法数控机床液压系统可靠性分析[J].液压与气动,2011(11)：115-117.
[52]蒋金良,王遂,任震.基于蒙特卡罗法的高压直流输电系统可靠性评估[J].华南理工大学学报：自然科学版,2008,36(2)：128-132.
[53]钱文学,尹晓伟,谢里阳,等.轮盘疲劳可靠性分析的Monte-Carlo数字仿真[J].系统仿真学报,2007,19(2)：254-256,266.
[54]张也影.流体力学[M].北京：高等教育出版社,1998.