Abstract: A ventricular assist device may include a cardiac compression assembly which comprises a gel-filled pad of generally concave configuration, mounted on a pressure plate with peripheral portions of the pad extending beyond the periphery of the plate, to preclude damage to the heart by the peripheral edges of the plate. The gel-filled pad may have undulating opposite sides formed by intersecting rows of raised dimples. The pad also includes portions for suturing the pad to a heart ventricle, and at least some of the dimples on the side of the pad facing the heart ventricle are provided with ventricle tissue growth-promoting islands. An electrode, in the form of a grid having intersecting strips which define dimple-receiving openings therebetween, also may be mounted on the venticle side of the pad. As many as eight circumferentially arranged cardiac compression assemblies, having lower ends pivotally mounted on a support member adapted to be located adjacent the apex of a heart ventricle, may be provided.

Abstract: The fail safe architecture for a computer system includes a read only memory (ROM) self-check module, a random access memory (RAM) self-check module and operation code instructions (op code) self-check module which are actuated periodically by a non-maskable interrupt (NMI) to a microprocessor. The microprocessor then suspends the current applications routine being executed. If the self-check module detects a failure, the microprocessor enters a fail safe trap routine which initially resynchronizes the operation of the microprocessor and then delays the generation of a critical timing pulse (fail safe trigger) with a series of "jump to yourself" steps. The fail safe trigger signal activates a device which sends a fail safe square wave to a narrow bandwidth, digital, band-pass filter.