Automatic control of assist flow in totally implantable left ventricular assist device using variable pump rate

In this study, the automatic control algorithm in implantable left ventricular assist device to regulate cardiac output to the extent of preventing atrial-collapse and the high left atrial pressure (LAP) is proposed. Intersac pressure (ISP) waveform which reflects the status of left atrial pressure is used in automatic control. By analyzing the relationship between LAP and the negative peak of ISP, the equation for making the reference of PI-controller was set. By using the reference equation the proposed automatic controller which regulates the assist flow was designed. Through mock circulatory experiments and animal experiment, the automatic control algorithm was evaluated.