Abstract: An optical alignment system using at least one CCD array for positioning an instrument in a chosen relationship to an object is disclosed. Means for "electronically" aligning the optical components and providing a macro view of the object on a CRT without additional illumination are also disclosed. Alignment may be achieved manually, if the operator observes the position of symbols on a CRT that move in response to movement of the instrument by the operator using a joystick, or automatically using information provided by the array.

Abstract: An interference filter for the removal of power line interference from amplifying systems, such as electrocardiographs, which includes a band-rejection filter tuned to reject the power line frequency interference, a differential amplifier to which the signal being amplified and the output of the notch filter are applied to produce an output consisting of only the interference signal. The interference signal is fed to and stored in a memory which is constantly updated and the output of the memory is then summed with the original signal. Since the phase of the output of the memory is reversed from the interference in the original signal, only the original signal will result. An electronic switch is connected between the output of the differential amplifier and the memory and is operated by a velocity detector connected with the output of the band-rejection filter.

Abstract: Electrocardiographic apparatus including a novel and improved recording paper feed and lead switching arrangement which include a platen having a platen roller, both movable from an open position for installing a supply of recording paper to a position wherein the platen roller with recording paper fed about the surface thereof is moved to an operating position with the platen roller in recording engagement with a recording pen. A paper drive roller is positioned in adjoining relationship to the platen roller and engages the platen roller with the paper thereon when in the operating position. The recording paper is provided with spaced cue marks and transverse perforations between successive cue marks and the apparatus includes a cue detector and associated electric circuitry for detecting said cues so that heart muscle signals from successive groups of patient leads will be recorded on successive segments of the paper defined by the perforations.