To improve the urine distributing mechanism of bladder power pump, a novel urethra valve was proposed in this study. The urine-flow-rate performance equation of the valve was derived on the basis of hydromechanics and electromagnetic theories, and the effect of different parameters on the urine-flow-rate performance was analyzed. The reliability simulation model of the valve was established according to the working principle and fault tree of the valve, a reliability simulation algorithm was proposed based on the basic idea of Monte Carlo method, and some reliability indexes were gained. The results show that increasing electromagnet current and decreasing air gap can increase the maximal urine-flow-rate, the reliability of the valve reaches 0.73 when the average life of the valve is 50000 times, and the shedding and aging of elastic bands are the weak links of the valve. The conclusions can provide the basis for the structural optimization and reliability improvement of bladder power pump, as well as the guidance for the design of implantable biomedicine electromechanical device.
