GB1475398A - Ultrasonic pulse echo apparatus and the investigation of moving objects - Google Patents

Abstract

1475398 Ultrasonic pulse-echo apparatus SIEMENS AG 29 May 1974 [30 May 1973] 23878/74 Heading G1G Ultrasonic pulse echo apparatus for investigating the movement of, e.g. the human larynx comprises two ultrasonic transducers which can be moved in relation to one another, electrical switching means connected to a first of the transducers to cause it to operate alternately as a transmitter or receiver a first indicating device operable to indicate echo pulses received by the first transducer, the second transducer being operable to receive ultrasonic energy transmitted by the first transducer and a second indicating device operable to indicate the intensity of the energy received by the second transducer. The movement of vocal chords 2 are displayed after an initial setting up procedure, whereby the most favourable orientation of transmitted signals is determined by transmitting ultrasonic signals, produced by generator 9 through switch 8 in position a, from transducer 3. When the oscillating vocal chords 2 are instantaneously closed these signals are passed through the neck to be received by transducer 4 which is connected by switch 12 in position c to receiver 13. Receiver 13 drives the vertical sweep on oscilloscope tube 24 to display the transmitted signals as a sawtooth waveform. The displayed signal is maximized by adjustment of the transducers, by displacement of the bow arms 5 and 6 on the U-shaped support, and this position is locked by clamp screw 7. The apparatus is then switched over to measure the vocal chord movement. Transducer 3 operates in a transmit/receive mode using switch 8 as a TR switch. Similarly, switch 12, being switched between positions d and e operates transducer 4 in a transmit/receive mode, the received signal being delayed at 14, so that the oscilloscope 18 displays the echo pulse signals from receiver 11 so that echoes from transducers 3 and 4, i.e. from the right side and the left side of the vocal chords respectively are displayed on different traces on CRT screen 18, switches 8 and 12 being automatically commutated between positions a and b and d and e in this mode, a manual selector being provided to select the setting up procedure.