Abstract: The coagulation of blood is measured by introducing the blood into an annular gap in a beaker formed between the inner surface of the beaker and a cylindrical member depending into the beaker. The beaker is mounted on the upper end of a rod-like support. A coil arrangement about the lower part of the rod-like support impresses a circular orbiting motion on the support and beaker. Another core associated with the rod-like support measures changes in amplitude of the support produced by the development of fibrin in the blood sample in the annular gap.

Abstract: A prosthetic heart valve has a tubular valve housing, a suture ring, and a membrane-like gate supported within the housing. The flexible membrane is generally elliptical in shape and is fastened in the housing along half its periphery. Flexure of the membrane moves it between an open position which permits blood flow through the housing and a closed position which blocks the flow path of the housing.

Abstract: The coagulation of blood is measured by introducing the blood into an annular gap in a beaker formed between the inner surface of the beaker and a cylindrical member depending into the beaker. The beaker is mounted on the upper end of a rod-like support. A coil arrangement about the lower part of the rod-like support impresses a circular orbiting motion on the support and beaker. Another core associated with the rod-like support measures changes in amplitude of the support produced by the development of fibrin in the blood sample in the annular gap.