The osmotic swelling characteristics of cardiac valve prostheses

Several types of mechanical cardiac prostheses have been constructed with D elrin occluders, a material that is subject to osmotic swelling. The leafle ts are designed to expand to specific tolerances when immersed in blood. Th e synthetic blood analogs commonly used in vitro contain hydrophilic compou nds that can alter the osmotic expansion of the Delrin occluders. A static leak test chamber was employed to illustrate the effects of various test fl uids on the sustained regurgitation phase of Delrin valves. [S0148-0731(00) 02104-X].