Ultrasound refers to sound waves (acoustic waves) having a frequency higher than what may be perceived by the human ear. This technology has found applications across various fields and, for many, the most common interaction with ultrasound is through prenatal or obstetric scans, which use these sound waves to create visual images, allowing for routine checks on the growth and health of a developing foetus.
The medical ultrasound scanner must surely rank as one of the most significant medical breakthroughs of the 20th century and its impact has been felt worldwide. However, it is fair to say that the origin of this technology is probably less well known. As Glasgow celebrates its 850th anniversary, I've taken a closer look at how the city played a pivotal role in the development of the first obstetric ultrasound scanner.
Ships and Blips
The story begins in post-war Glasgow with a machine known as the ultrasonic flaw detector. As the name suggests, the machine used ultrasound to detect flaws, such as cracks or other discontinuities in welds and was an essential tool in Glasgow's shipbuilding industry.
Professor Ian Donald, who at the time was the Regius Professor of Midwifery of Obstetrics and Gynaecology at the University of Glasgow, had developed an interest in sonar and radar technology while serving as a Medical Officer in the Royal Air Force during World War II.
Professor Ian Donald
According to reports, while working at the Western Infirmary in Glasgow, a patient of Donald's introduced him to her husband, a director at Babcock and Wilcox, an industrial fabrication company based in nearby Renfrew and a user of industrial ultrasound for examining boilers for ships.
Donald was invited to a demonstration of the ultrasonic flaw detector - a machine produced by Kelvin & Hughes – a Glasgow-based manufacturer. As detailed in an excellent account by Nicholson and Fleming, it was reported that Donald noticed that the technicians were in the habit of testing the ultrasound equipment by bouncing the beam off the bones in their thumbs.
Intrigued by the potential of ultrasound to distinguish between different types of tissue, Donald conducted a series of experiments during subsequent visits, including testing different pathological specimens and, as reports suggest, using "an enormous lump of steak" as a control material. Donald later recalled:
All I wanted to know, quite simply, was whether these various masses differed in their ultrasonic echo characteristics. The results were beyond my wildest dreams and, even with the primitive apparatus of those days, clearly showed that a cyst produced echoes only at depth from the near and far walls, whereas a solid tumour progressively attenuated echoes at increasing depths of penetration.
As a result of those experiments, Donald was able to distinguish between a cyst and a myoma using the so-called A-mode (or amplitude mode) signatures produced by the ultrasonic flaw detector.
n ultrasound A-mode scan – the large non-reflective space between two echoes marks the presence of an ovarian cyst.7
Those A-mode signatures appeared as small blips and were very different to the ultrasound images we are familiar with. They were also not straightforward to interpret, especially in a clinical environment. Enter Tom Brown (an engineer at Kelvin Hughes) and physician John MacVicar. Together, they developed the industrial flaw detector into the world's first ultrasound contact scanner. Unlike the ultrasound flaw detector, their contact scanner was capable of producing 2-D ultrasound images (in so-called B-mode or Brightness mode), bringing the output images closer in appearance to the images we see today.
This groundbreaking work of Donald, MacVicar and Brown was first made public in 1958, with the patent application (British patent No 863, 874 2) in the name of Kelvin and Hughes) and the publication of the team's first paper (Donald, I., MacVicar, J. & Brown, T.G., (1958), 'Investigation of abdominal masses' 3). A prototype of that first-ever contact ultrasound scanner is on display at the Hunterian in Glasgow.
Front page of GB patent specification 863, 874 2
Image taken from The Lancet article in 1958 3 – an image of the uterus at 14 weeks gestation, reportedly the first published obstetrical sonogram.
Despite that rather obscure title, the paper was directed mainly to ultrasound studies in clinical obstetrics and gynaecology and contained the first ultrasound images of the foetus and also gynaecological masses.
Following the release of that paper, and further collaboration with Glasgow-based designer Dugald Cameron (a fascinating story reported in 4), the design evolved, through a number of iterations, into the world's first production model of an obstetric ultrasound machine, the Diasonograph.
Image of Dianosograph - By Dugald Cameron - source BBC
A Patent Dispute
While Kelvin and Hughes (part of Smiths Industries) secured a patent for the contact scanner, reports suggest that a patent dispute over earlier patents played a significant role in the firm's eventual departure from the medical scanning sector.
While the exact details are not clear, it appears that the dispute was between Smiths Industries and US-based Automation Industries Inc. regarding the so-called "Firestone patents". According to reports 5, those earlier patents (including patent US 2280226A 6) granted them the commercial rights to medical contact scanning. Although these earlier patents appear to have been originally drafted with industrial flaw detection in mind - without reference to obstetric or medical applications - reports suggest they were broad enough to cover future developments like medical contact scanning.
Looking back, Tom Brown himself offered an interesting perspective on this dispute, explaining that "the 'Firestone Patents' were primarily concerned with high-speed testing of railway tracks, using the Sperry wheel probe. This was an ultrasonic probe arrangement with transducers fixed inside two hollow, water-filled rubber tyres, which ran along the rails and could detect cracks even at high speeds. The crucial aspect was that there was something - specifically, the water and the tyre wall - between the transducer and the object being tested". Brown elaborated: "This was patented, and the crux of the patent battle was that any arrangement with anything between the transducer and the test piece was said to come within the patent claims." 7
According to accounts, Kelvin and Hughes left the medical scanning sector. However, Nuclear Enterprises appear to have taken over where Kelvin and Hughes left off, and continued to develop and manufacture ultrasound scanners, producing scanners that were distributed and widely used in hospitals across Scotland. An example of one of these scanners, the NE4102, is now on display at the National Museum of Scotland in Edinburgh 8).
Looking to the Future
The earlier production model - the Diasonograph - was reportedly often referred to as the Dinosaurograph due to its large, bulky size, which in itself served as a reminder of the machine's industrial roots in Glasgow. While that machine may seem somewhat archaic compared to today's sleek and modern devices, it is undeniable that its creation was groundbreaking and laid the foundation for decades of advancements in ultrasound technology - leading to further advancements such as real-time imaging and 3D imaging.
Over the years, our team of patent and trade mark attorneys at Marks & Clerk have seen Glasgow, and Scotland as a whole, continue to play a pivotal role in innovation in ultrasound and medical technology. Novosound, based in Glasgow, are the perfect example of Scotland at the forefront of ultrasound technology, developing cutting-edge products across a range of applications, from industrial testing to wearable sensors. Thanks to Scotland's thriving tech ecosystem and its world-leading Universities, we look forward to seeing this progress continue in years to come.
Footnotes
1. Nicholson and Fleming “Imaging and Imagining the Fetus: The Development of Obstetric Ultrasound”
2. https://patents.google.com/patent/GB863874A/en?oq=GB863874
3. INVESTIGATION OF ABDOMINAL MASSES BY PULSED ULTRASOUND, Donald, Ian et al., The Lancet, Volume 271, Issue 7032, 1188 - 1195
4. Alastair S Macdonald “From first concepts to Diasonograph: The role of product design in the first medical obstetric ultrasound machines in 1960s Glasgow”
5. Obstetric ultrasound History Web, Dr Joseph Woo, https://www.ob-ultrasound.net/
6. https://patents.google.com/patent/US2280226A/en?oq=2280226
7. Tansey, E. and Christie, D. (Eds). (2000) Looking at the unborn: historical aspects of obstetric ultrasound. Wellcome Witnesses to Twentieth Century Medicine: Vol.5. Wellcome Trust: London, UK
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