Simulation Study On Bladder Power Pump And Urethral Valve Based On Virtual Prototype Technology

Neurogenic bladder is a disease of bladder dysfunction which is caused by the damage of the central nervous system, and there is no effective treatment for the disease. Urethral intubation drainage, bladder fistula bypass, abdominal thrusts and other measures which were usually taken to help bladder voiding in clinical are easy to cause urinary tract infections or other complications. In order to solve the problem of neurogenic bladder patients with difficult urination, a kind of urination assist system (also called bladder pump power) and a urethral valve driven by ultrasonic-vaporized steam were proposed in the early stage of the project. The auxiliary urination device assist bladder urinating is based on the principle of ultrasonic thermal effect and thermal conversion. In order to apply it in animal experiment and further clinical research, it is necessary to deeply study its performance by theoretical analysis and simulation experiment research. The main works of this paper are as follows:Firstly, the virtual prototype model of bladder power pump was established based on virtual prototype technology and fluid mechanics theory, the numerical simulation of the flow field distribution of bladder power pump was completed by using Fluent software, the validity of the model was verified by simulation experiments. The urine flow rate curve of different initial micturition driving pressure was obtained by changing the simulation parameters of the model. The results show that:the flow rate and the dynamic characteristics of the bladder power pump can be increased and improved by increasing the initial micturition pressure.Secondly, the simulation model of the drive capsule of urethral valve was built by using the virtual prototyping technology, and the establishment of the dynamic flow field of the driving pressure in the drive capsule was simulated by using Fluent software, the validity of the model was verified by simulation experiments. The influence of the driving performance on ultrasonic parameters and the structure parameters of the urethral valve are analyzed by using the simulation model. The results show that:the driving performance of the urethra valve can be improved by increasing the sound intensity, the radiation area, the frequency of ultrasound and reducing the volume of drive chamber.Thirdly, the two-dimensional dynamic numerical simulation for the movement of the valve spool during the opening process of urethral valve was completed by using the dynamic mesh and UDF technology of Fluent software. The change rule for the displacement and the force of valve spool during the movement process of valve spool was obtained.Lastly, based on the above analysis and research results of the urethra valve, a new type of urethral valve was proposed, the opening and closing performance of the urethral valve was studied by experiments. The results show that the opening and closing performance of the urethral valve is good.The research results can not only be regarded as a reference for the characteristics analysis and the structure optimization design of the bladder power pump and the urethra valve, and a guidance for the research of a new type of auxiliary urination program, but also be referenced for the analysis and design of other implantable system.