Electromagnetic object detector for a medical diagnostic apparatus

Abstract

An apparatus for medical diagnosis and/or therapy, includes an electromagnetic obstacle sensor. Due to variations of the ambient temperature and humidity and/or due to the hanging of, for example a cloth around the sensors (16,18), drift of the zero point of the control may occur, so that the approaching of an obstacle by a movable part (6) of the apparatus could be incorrectly interpreted by the apparatus. In order to compensate for such drift there is provided a control unit (25) for automatically controlling the output signal V.sub.o of the receiver (27) back to the zero value in the absence of an object in the vicinity of the movable part (6). This control preferably takes place at a comparatively high speed when a cloth or moisture is moved into the vicinity of the sensors, and at a comparatively low speed upon removal of the cloth or the moisture. As a result, the nature of the movement of the drive is maintained for some time after the displacement of the movable part, thus contributing to the ease of operation of the apparatus.

Dependencies are inferred from the claim text.