"........ (Donald was)... using a very much the worse-for-wear "black-crackle"- painted Kelvin & Hughes Mk IIb 'Supersonic Flaw Detector'. This ancient instrument had not even been made by Kelvin & Hughes, but was built to their designs by some other company under a Ministry of Supply manufacturing contract. It had been designed, as were most early British machines of that type, for separate transmitting and receiving (quartz) transducer operation. This machine had been modified at the Royal Marsden Hospital before Donald got his hands on it. No doubt it was done with the best of intentions, but the "conversion" to single-transducer operation was achieved by simply connecting the output of the thousand-volt transmitter pulser more-or-less directly into the amplifier input. This caused the amplifier, never designed for such insult, to go into complete paralysis for several hundred microseconds, before staggering back into some degree of normal function.
The Kelvin and Hughes® Mk IV metal flaw detector
This "paralysis" problem was the reason for the comical arrangement which greeted me when I first saw 'the apparatus', of an open-ended glass cylinder, large carafe of water, and a large jar of "Vaseline".
Ever the practical improviser, and realising that he had somehow to allow the amplifier to de-saturate after being clobbered by the transmitter pulse, Donald greased one end of the glass cylinder with Vaseline, stuck it on the patient's abdomen, filled it up to the brim with water, and placed the ultrasound probe in the end, directed through the water into the patient. The amplifier then had time to de-saturate while the sound pulse was travelling down the water column, and Donald was able to see echoes coming back from inside the abdomen when the sound pulse reached it...... ".
" ......... The MKIV was also a double-transducer machine, but when used with a decent double-transducer 'probe' the results were strikingly better than anything Donald had ever seen before ....... . The other thing I was able to do at that time was to dig up an old, but still functional 'Cossor' oscilloscope camera with which to record the traces on the screen on 35mm film. This seems to have been a much more significant addition to the system, at least so far as Donald was concerned, than I realised at the time, though on my part it was just another bit of scrounging, at which I was to become rather adept. From the A-scope experiments it appeared that there actually was a lot of echo "data" being returned from inside the patient. Whether this was all really going to lead to useful "information" was of course not known, but even with the A-scope we were already able to recognise fluid-filled cysts, and to discriminate reasonably confidently between these and solid masses, and between either and the 'normal' bowel echoes.........." ---- Tom Brown .
....... The same machine together with the prototype "fetal cephalometer" (or "ultrasonic caliper" as I re-named it later) made by Tom Duggan of the Regional Medical Physics Dept. in Glasgow under John Lenihan. -- Tom Brown.
Pictures courtesy of Mr Tom Brown.
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