Patent US 4,922,909

Video monitoring apparatus for use in an application in which changes in relative spatial relationship of features of a biological tissue are to be observed. A video camera electronically produces a first image of the tissue and also electronically produces a subsequent image of the tissue after a period of time. A video display unit displays a representation of an image of the tissue derived from the camera. Circuitry connected to the camera and to the display unit electronically stores a representation of the first image of the tissue, and transmits the representation of the first image of the tissue to the display unit with a representation of the subsequent image of the tissue so that the first and subsequent images of the tissue appear superimposed. In this way, any differences in the relative spatial relationship of features in the images of the tissue are readily observed. A surgical reapposition monitor and methods are also disclosed.