Development of a new left ventricular assist device: the dynamic aortic valve.

We have been developing a new left ventricular assist device, an axial flow pump implanted at the aortic valve position. Since the device is intended for long-term use, its motor unit and pump are physically separated. The device consists of a "rotor-impeller" and a support cage. The rotor joins the impeller at one end and provides torque needed to spin the impeller. The support cage consists of a cantilever, a cantilever shaft, a top ring, and an end ring. The support cage is designed to fit within the ascending aorta and sutured to the aortic annulus during implantation. The magnetic rotor will rotate in the presence of alternating magnetic fields generated by an electric motor. The assembly also serves as a valve by maintaining the appropriate pressure drop across the aortic orifice. A prototype device was fabricated and tested in vitro. It produced a flow rate up to 5 L/min with a rotation rate of 12,600 rpm at a pressure difference of 100 mm Hg. The results proved the feasibility of the new device.