Improvements in or relating to methods of and apparatus for detecting electric potentials on surfaces

摘要

778,107. Physioligical tests. FARLAND. D. H. April 29, 1955 [May 5, 1954], No. 12556/55. Class 81(2) [Also in Group XXXVI] A device for use in detecting potentials on the skin due to muscular activity comprises at least two electrodes adapted to be placed on the skin surface, one electrode being so arranged as to screen unwanted potentials from the area in which it is desired to detect the desired potentials. This device is used in conjunction with amplifying means and with means adapted to indicate or record the detected potentials. In one form, the device comprises an inner disc electrode 1 surrounded by an annular ring electrode 2 but insulated therefrom at 4, this electrode 2 providing the screening effect when the two electrodes, which are mounted in a body 7 movable by handle 8, are placed in contact with the skin or other surface. A lead 10 from electrode 1 is connected to an amplifier (notshown) in circuit with, e.g. a C.R.O. or a loudspeaker. In a second embodiment, the electrode 2 surrounds two inner electrodes of semi-circular form and slightly separated, a voltage being applied to one of the inner electrodes.