Dynamic Characteristics Of Large-gap Magnetic-driven Blood Pump

In order to conquer engineering and medical problems of bolod pump brought by traditional driven approach effectively, a large gap magnetic drive method was taken as the way of energy supply. The driving mode of the blood pump driven by large gap magnetic force is stepping, thus its speed is determined by the pulse frequency of the current. To obtain optimal speed adjustable control parameters, then realize a smooth and fast start-up and speed regulation process, the dynamic characteristics and operation rules of the pump were studied.The virtual prototype of the blood pump rotor was obtained using Pro/E and ADAMS. Simulations of the acceleration process were done using ADAMS, and the speed curves and acceleration curves of the blood pump were obtained.According to the transition process theory of hydraulic machine installations, a more accurate mathematical model of the blood pump's load torque was established to conquer the low reliability and accuracy of the empirical load torque model. Then a dynamic model of the blood pump during start-up period was deduced. The dynamic model was solved using MATLAB, and relation between various important parameters such as speed, flow with regard to time was obtained.Compared dynamic characteristics research based on ADAMS with the one based on MATLAB, the former can be done without figuring out characteristic curve of the pump and related geometric parameters, so its workload is small, and its results reveal rough dynamics of the blood pump.While the latter has a much heavier workload, but its results are more comprehensive and accurate in response to the start-up period of the blood pump. Then the optimal driver was designed according to the discretization of the acceleration curve, and used for blood pump experimental research.The research results confirmed that compared to the driver based on linear acceleration curve, the driver based on these study results can significantly shorten the acceleration time, and achieve the optimal control of pulse frequency during start-up process.