Development of the functionally total artificial heart using an artery pump.

Based on the assumption that only the pump function of the diseased heart should be assisted or replaced by device while resecting the native heart is unnecessary, the concept of a "functionally total artificial heart (FTAH)" was explored. An artery pump (AP) was designed for the FTAH. The fabricated pattern of the AP, having an outer diameter of 28 mm and a length of 42 mm, was implanted in the position of ascending aorta or pulmonary trunk, joining in series to the chambers of the left ventricle or the right ventricle. The total weight of the AP pattern is 74 g, and it displaces 29 mL of volume and can achieve 5 L/min against 100 mm Hg pressure with a speed lower than 10,000 rpm. In mock circulation, two APs were connected in series with each other, and their flow rates could automatically balance each other. Simulative cardiac output and atria pressures can be maintained within a suitable range by properly adjusting the rotational speeds of each pump. Because the response of the APs to the pressure alterations at their inlets and outlets are similar to that of native heart, no intricate regulating mechanism would be necessary. This preliminary study shows that the concept of the FTAH is feasible if two APs are simultaneously implanted to replace native heart function.