Peripheral vascular resistances during total left heart bypass with an oscillated blood flow

For development aimed at a totally implantable type ventricular assist devi ce (VAD), the vibrating flow pump (VFP) has been developed at Tohoku Univer sity. A transcutaneous energy transmission system (TETS) using amorphous fi bers was developed to power the totally implantable VAD system. The VFP wor ks at a high frequency compared to that of a natural heart of a biological system. It is a frequency of 10-50 Hz. In this research, animal experiments with left heart bypass were carried out with healthy adult goats. For comp arison between nonpulsatile now and oscillated flow, a rotary pump (RP) and the VFP were used in the experiments. For the achievement of total left he art bypass, left ventricular approaches were carried out, and blood was pum ped from the left ventricle to the descending aorta. Adequate support of th e left heart was provided by both pumps. In terms of the results, the vascu lar resistances tended to decrease during the use of both pumps during 100% bypass driving. When we compared these pumps at the same flow rate, the re sistances during RP driving were significantly smaller than those during VF P driving. These results may suggest that the influences of the VFP upon th e peripheral vessels may be relatively small compared to those of the RP. T his may be an important result when a stable hemodynamic condition is requi red during artificial circulation. The VFP was considered as a candidate fo r a totally implantable VAD as a result.