Control strategy for biventricular assistance with mixed-flow pumps

A left ventricular assist device (LVAD) is an effective method to rescue se vere heart failure. Although some require a biventricular assist, the contr ol method for the biventricular assist device (BVAD) with a rotary pump is rarely shown. The objective of this study was to investigate the strategy f or controlling BVAD with rotary pumps by in vivo studies. Using 5 piglets, we set a BVAD through a left thoracotomy and made global ischemia for 30 mi n by clamping the base of the ascending aorta. After unclamping, the analys is of pumping performance acted for 6 h reperfusion. We set the target flow of the LVAD and set the right ventricular assist device (RVAD) speed limit as less than when the atrial collapse occurs. To detect the ventricular co llapse without any specific sensor, we calculated the index of current ampl itude from motor current waveform and simultaneous mean current value. In a ll cases, over 6 h of observation was performed, and the RVAD was weaned al most automatically.