超声汽化蒸汽驱动的膀胱动力泵元件结构设计与研究

发布时间：2018-10-22 17:18

【摘要】：因神经源性膀胱所引起的排尿功能障碍,不仅会给患者生活和工作带来极大的不便,也易引发患者泌尿系统感染、结石、肾积水等病症,影响患者的生活质量和寿命。该病通常难以用药物或手术治愈,必须采取人工辅助排尿措施。针对因神经源性膀胱引发的排尿功能障碍的问题,课题前期提出了一种超声汽化蒸汽驱动的膀胱动力泵,其中机架和尿道阀是泵的重要组成元件。为了合理设计膀胱动力泵的结构,本文设计了膀胱动力泵机架和尿道阀,并对其结构进行了有限元仿真分析,建立了尿道阀的数学模型,仿真和实验验证了数学模型的有效性,开展了尿道阀特性实验研究和膀胱动力泵辅助排尿模拟实验研究,提出了膀胱动力泵的可靠性仿真算法,研究了膀胱动力泵的可靠性。具体工作内容如下：根据人体生理结构特点和膀胱动力泵组成原理,设计了膀胱动力泵机架和尿道阀的结构,选择了与人体生理组织相容结构的主要材料。利用Solidworks软件和ANSYS Workbench软件建立了机架和尿道阀的三维实体模型和有限元模型,对机架进行了静力学分析、模态分析和优化设计,仿真和实验研究了驱动力对尿道阀开口量的影响,仿真分析了尿道阀的结构以及不同材料和受力方式对尿道阀开口量的影响。基于超声学、热力学和流体力学理论,建立了尿道阀的驱动力和尿流率数学模型。设计并搭建了模拟实验平台,实验验证了驱动力数学模型和尿流率数学模型的有效性。利用Matlab和模拟实验平台仿真和实验分析了不同超声控制参数对尿道阀驱动特性的影响,实验验证了尿道阀的启闭特性良好,制作了膀胱动力泵的物理模型,开展了膀胱动力泵的辅助排尿模拟实验研究。根据膀胱动力泵的结构特点和工作原理,利用故障树分析法建立并分析了膀胱动力泵的故障树。基于故障树分析结合蒙特卡罗法,提出了膀胱动力泵的可靠性仿真算法,仿真计算了膀胱动力泵的可靠性指标,通过理论计算验证了可靠性仿真算法的有效性。研究结果表明：所设计的膀胱动力泵机架和尿道阀具有符合人体生理结构的特点,选用钛合金和硅橡胶材料作为机架和尿道阀的材料是可行的；尿道阀的数学模型和膀胱动力泵的可靠性仿真算法简单有效；增大超声控制参数可以提高尿道阀的驱动特性,尿道阀的启闭特性良好,膀胱动力泵的辅助排尿性能良好；膀胱动力泵平均寿命达到80000次的可靠度为0.88。研究结果可为进一步设计优化膀胱动力泵元件结构和提高系统的可靠性提供依据,也可为其它人体可植入式元件的设计提供重要参考。
[Abstract]:Urinary dysfunction caused by neurogenic bladder will not only bring great inconvenience to patients' life and work, but also easily lead to urinary tract infection, stone, hydronephrosis and other diseases, which will affect the quality of life and life span of patients. The disease is usually difficult to cure with drugs or surgery, and must be assisted with micturition. In order to solve the problem of urinary dysfunction caused by neurogenic bladder, a bladder dynamic pump driven by ultrasonic vaporization steam was proposed, in which the rack and the urethral valve were important components of the pump. In order to design the structure of bladder power pump reasonably, this paper designs the frame of bladder power pump and urethral valve, and carries on the finite element simulation analysis to its structure, establishes the mathematical model of the urethral valve, and verifies the validity of the mathematical model by simulation and experiment. The experiments of urethral valve characteristics and bladder dynamic pump assisted urination simulation were carried out. The reliability simulation algorithm of bladder dynamic pump was put forward and the reliability of bladder dynamic pump was studied. The main contents are as follows: according to the characteristics of human physiological structure and the principle of bladder dynamic pump, the structure of bladder power pump frame and urethral valve is designed, and the main materials compatible with human physiological tissue are selected. The three-dimensional solid model and finite element model of frame and urethral valve were established by using Solidworks software and ANSYS Workbench software. The static analysis, modal analysis and optimization design of the frame were carried out. The influence of driving force on the opening of urethral valve was studied by simulation and experiment. The structure of urethral valve and the influence of different material and force on the opening of urethral valve were analyzed. Based on the theories of ultrasound, thermodynamics and fluid mechanics, a mathematical model of the driving force and flow rate of urethral valve was established. A simulation experiment platform was designed and built to verify the validity of the driving force mathematical model and the urine flow rate mathematical model. The effects of different ultrasonic control parameters on the driving characteristics of the urethral valve were analyzed by Matlab and simulation platform. The good opening and closing characteristics of the urethral valve were verified, and the physical model of the bladder power pump was made. An experimental study on assisted urination simulation of bladder dynamic pump was carried out. According to the structure characteristics and working principle of bladder dynamic pump, the fault tree of bladder dynamic pump was established and analyzed by fault tree analysis. Based on fault tree analysis and Monte Carlo method, the reliability simulation algorithm of bladder dynamic pump is proposed. The reliability index of bladder dynamic pump is simulated and calculated. The validity of reliability simulation algorithm is verified by theoretical calculation. The results show that the designed bladder power pump rack and urethral valve have the characteristics of human physiological structure, and it is feasible to select titanium alloy and silicone rubber as the materials of the frame and urethral valve. The mathematical model of urethral valve and the reliability simulation algorithm of bladder power pump are simple and effective, the driving characteristics of urethral valve can be improved by increasing ultrasonic control parameters, the opening and closing characteristics of urethral valve are good, and the auxiliary urination performance of bladder power pump is good. The average life span of bladder power pump was 0.88 when it reached 80000 times. The results can provide a basis for further design and optimization of bladder power pump components and improve the reliability of the system, and also provide important reference for the design of other implantable components in human body.
【学位授予单位】：广东工业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TH789

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