High-Sensitivity Pulsation Estimation for Heartbeat-Synchronized Control in Magnetically-Levitated Ventricular Assist Devices

As the number of heart failure patients continues to increase, the use of ventricular assist devices(VAD) has been prolonged. However, there is a problem with high readmission rates. Therefore, the VAD performs heartbeat synchronization control to assist blood flow in accordance with the pulsations of the diseased heart. To implement this control, it is necessary to accurately estimate the pulsations of the diseased heart, but there is a challenge due to the low signal-to-noise ratio (S/N ratio) of those pulsations, making it difficult to estimate weak pulsations effectively. To address this problem, I shaped the impedance characteristics using the loop shaping method based on $\mathbf{H}_{\infty}$ control theory. As a result, I was able to enhance the S/N ratio of the fluid forces estimated for pulsation compared to conventional control systems.