Implantable Left Ventricular Assist Device Driver Design

The heart disease has become the major threat to human life,the number of patients with heart failure are increasing. The left ventricular assist device (LVAD) as a primary means of treating heart disease, has been widespread attention to the medical profession at home and abroad. In recent several decades,with the development of science and technology the research of the LVAD has made new progress.A left ventricular assist pump which has simple structure is used in the subject, The control system has been designed. Blood pump drives circulation of blood inside to achieve the function of left ventricular through the rotation of permanent magnet.Firstly, the paper introduced the current situation and the development trend of the LVAD , briefly illustrated the research significance.Then it introduced the whole design scheme of control system on the basis of functional of the LVAD;Taking into account the special structure of the blood pump,the paper identified the actual stator coil module;then described the structure of the blood pump and working principle in detail at the same time.The key technology of control system is discussed in the paper. Researched and optimized the method of starting ,the rotor position detection and commutation algorithm as well as PID control principle in theory,and designed the appropriate control algorithm according to the theory.Finally,the paper designed hardware circuit and software program by the control requirements of the blood pump.Through debugging the blood pump to determine the optimal installation location of stator coils; For the problem of temperature rise of the blood pump, optimized the back EMF zero.crossing detection algorithm, commutation algorithm and the motor starting curve,this situation has improved temperature conditions; In order to achieve accurate speed control of blood pump, this paper used the double closed.loop control, also joined the anti.windup module, and ultimately achieved stable control of blood pump.Finally, the blood pump control experiment has been to correct and handle the problems arising in the control process of the blood pump.The experimental results show that the design of the control system is able to meet the requirement of the left ventricular assist device with fast starting, stability operation, load capability, as well as little heat.