CONTROLLER DESIGN OF LEFT VENTRICLE ASSIST DEVICE

摘要

A left ventricle assist device (LVAD) is a device composed mainly of a pump and a controller. It is used not only to save lives of patients who suffer from left ventricle failure, but also to help them live like healthy people. Due to the continuing increasing number of left ventricle heart failure cases and limited number of heart donations for heart transplant, the need for LVADs become more and more demanding. The inlet of LVAD is connected to left ventricle and the outlet is connected to the aorta, which makes the LVAD work parallel with the left ventricle. The flow rate provided by the pump can compensate for low cardiac output due to failure of the left ventricle and restore the total peripheral blood flow rate to normal values, which is the sum of cardiac output and pump output. If the LVAD only works in one condition, one specific speed can always be found by testing or other methods in advance. But normal daily life involves much more than one condition, an automatic controller is necessary to fulfill all tasks. Actually, the biggest challenge of LVAD will be adaptability to different situations. LVAD should be able to provide needed flow rate in different conditions, which is varying in different conditions. Different conditions include dynamic and emotion condition, like sleeping, sitting, walking, happy, angry, surprised.