Abstract: Variably compliant natural tissue valve leaflets and vascular bioprosthetics incorporating variably compliant leaflets are provided along with methods for their manufacture. The variably compliant leaflets are fixed with the leaflet base section under greater pressure than the leaflet tip section rendering them relatively stiff along the leaflet base section and more flexible at the leaflet tip section. The radially variable flexing characteristics of the valve leaflets promote even distribution of mechanical stress on the valve assembly during the cardiac cycle leading to improved hemodynamic performance while retarding the calcification of the leaflet tissue.

Abstract: An extracorporeal blood oxygenation system comprising an integrated blood pump/heat exchanger/membrane oxygenator assembly which is mountable upon, and engageable with, a separate motor/drive assembly. The blood pump of the system incorporates a novel axial/centrifugal impeller assembly. An optional blood reservoir may be incorporated into the system to receive and contain venous return and/or surgical site blood. Also, an optional arterial filter may be incorporated into the system for filtering the oxygenated blood before the blood is returned to the patient. The pump/heat exchanger/membrane oxygenator component is preferably constructed such that heat exchange fluid which is being infused into the heat exchanger will pass through and/or in contact with a portion of the membrane oxygenator so as to further maintain the temperature of blood as it passes through the membrane oxygenator.

Abstract: A suture ring for a rotatable artificial heart valve apparatus has a ring member covered by a fabric material. A portion of the fabric material covers a portion of the inner surface of the ring member. At least one protuberance is formed on the inner surface of the ring member so as to mitigate the frictional resistance to rotation which results from compression of the fabric between the suture ring and the heart valve. Thus, desirable rotation of the heart valve relative to the suture ring is assured over a range of thicknesses of the fabric material.

Abstract: A system for monitoring and controlling a temperature of a heating element in a thermodilution catheter to maintain it within safe physiological limits includes a calibration circuit, a device for controlling the supply of power to the system, a relay between the calibration circuit and the heating element for switching power therebetween, a transistorized voltage detecting circuit for determining whether power has been supplied to the calibration circuit, and a device responsive to transistorized voltage detecting circuit to remove power from the system. Also, a method for monitoring and controlling a temperature of a thermodilution catheter-mounted heating element including providing a calibration circuit, switching a supply of power to either the calibration circuit or the heating element, monitoring the supply of power to the calibration circuit, and removing power from either the calibration circuit or the heating element in response to the monitored power at the calibration circuit.