Abstract: An inflatable prosthetic cardiovascular valve which is constructed so as to be initially deployable in a deflated "collapsed" configuration wherein the valve may be passed through the lumen of a cardiovascular catheter and subsequently inflated to an "operative" configuration so as to perform its intended valving function at its intended site of implantation within the cardiovascular system. The inflated valve may be held in place by mechanical means (e.g., hooks, projections), by chemical adhesive or through biological assimilation by the heart tissue.

Abstract: An x-ray diagnostics installation for subtraction angiography has an image memory connected to an output of an x-ray image intensifier video chain which has a number of addresses for storing individual x-ray video signals obtained during a dynamic body cycle of a patient under observation. A differencing unit receives stored signals from the image memory as well as current video signals and substracts those signals to form a superimposed image. Entry and readout of signals to and from the image memory is under the command of a control unit which is connected to the patient through, for example, an EKG circuit for identifying selected occurrences in the body cycle under observation. Entry and readout of data from the image memory is thereby controlled in synchronization with the selected occurrences in the cycle.