the review of development of non planar body surface by means of ultrasonic waves

摘要

863,874. Ultrasonic inspection devices. KELVIN & HUGHES Ltd. April 24, 1959 [April 28, 1958], No. 13439/58. Class 40(7) [Also in Group V1] Relates to the ultrasonic examination of the interior of a body by a transmit/receive transducer means moved in a plane over the body's surface and scanning angularly about an axis. According to the invention an indicator is deflected over a straight line from an origin positionally controlled by the axis movement, the straight line direction is caused to follow the angular scan and the indicator is modulated or rendered operative and inoperative in dependence on received echo signals. In the embodiment the human body is explored and the indicator is an intensity-modulated cathode-ray tube (C.R.T.) beam. Probe 27 containing piezoelectric transmitting and receiving crystals is mounted for limited rocking about axis 28 the rocking being followed electrically by sine/cosine potentiometer 31. Probe support 23 is guided by rollers 24 for vertical movement and carriage 25 is horizontally movable on rails 26, these movements being followed electrically by potentiometers 40, 37. The transmitted pulse is delayed with respect to the initiation of the vertical and horizontal deflection sawtooth waveforms and a second delay circuit renders the C.R.T. operative before a pulse is transmitted, the Fig. (Prov., not shown). The second delay circuit may be adjustable and calibrated for ranging. The display produced shows the surface of, e.g. a cyst 44SP1/SP, the successive arcs 43SP1/SPa ... d over which the probe face rocks and the transmitted pulses aSP1/SP ... dSP1/SP; non-planar interior surfaces are thus well defined. The display may be photographed to enable the whole presentation to be viewed at one time or the screen phosphor stores a latent image until made visible by infra-red irradiation. Rails 26 are movable in a perpendicular direction for portrayal of parallel cross-sections. The indicator may be a pen recorder and the probe may be fixed but with an oscillating beam.