Month: April 2020

Londoner Sir Peter Mansfield (1933-2017) was among several developers of the Magnetic Resonance Imaging (MRI) technique and one of two physicists who were awarded the 2003 Nobel Prize in Physiology or Medicine for bringing it to fruition. In 1973 his assistant’s finger was the first body part to be scanned and in 1977 Mansfield himself had the first whole-body MRI scan.

He began working on an imaging system in 1972 and, unlike his co-awardee Paul Lauterbur who was looking at a slow ‘projection-reconstruction’ method, Mansfield’s innovation was ‘slice selection’ in which linear magnetic field gradients are measured. Still researching in his later years, he was always concerned with reducing the time required to take a scan, which can be up to 90 minutes depending on what is under investigation. Since the patient must lie still throughout, children and people with claustrophia sometimes have to be given a general anaesthetic, unfortunately.

MRI is selected over another technique such as ultrasound when more detail is needed or the issue is over a large area or it is behind bone, e.g. in the brain. MRI is more expensive; a scanner is large and has its own room where no metal is allowed, as there are super-magnets in the machine.

(Image of mobile MRI scanner unit parked outside hospital: Robin Webster at geograph.org.uk / CC BY-SA 2.0)

The ten Colossus machines built at Bletchley Park during WW2 were the first electronic programming computers, albeit for one specific purpose ~ the decoding of secret German communications. It is thought that their success in 1944, particularly around the time of D-Day, shortened the war by two years. Eight of the machines were dismantled immediately after the war and two continued to be used by British Intelligence until the 1960s. The one on display at the National Museum of Computing is a working replica.

Bill Tutte (1917-2002) was a man inspired when he broke the code being generated by Dr. G. Grimsen’s Lorenz cipher in Germany and deduced the design of the machine producing it. Max Newman (1897-1984) commissioned Tommy H. Flowers (1905-98) to assemble a corresponding machine by which to reverse the process and read the messages.

Flowers chose to use 2,500 valves and keep the machine running 24/7 to protect them from breaking. This was unheard of but it worked. Colossus was able to read 5,000 characters per second, generating so much heat that the WREN operators often stripped to their underwear! Tutte, Newman, Flowers and their team are unsung heroes, as the post-WW2 Cold War meant that their work remained classified for decades.

(Image: Wikimedia Commons / Public domain)