Sir Martin Wood, engineer who with Oxford Instruments developed superconducting magnets and the first MRI body scanner – obituary

Sir Martin Wood, who has died aged 94, was an inventor and engineer whose company, Oxford Instruments, developed under his aegis the world’s first commercial superconducting magnets and the first commercial MRI scanner.

Beginning as a research officer with Clarendon Laboratory in Oxford, where his work involved developing magnet technology, Wood set up Oxford Instruments (OI) with his wife Audrey in 1959. It started life in a workshop at the bottom of the Woods’ garden and was soon taking orders for complete magnets intended for use inside nuclear reactors, as well as for “pancake-type” magnets made up of stacked cylindrical coils of wire. A current in the wire produced a magnetic field at the centre of the coil.

By 1961 operations were beginning to outgrow the shed and the company moved to a former stables and slaughterhouse (complete with old-fashioned butchers’ bikes) in a North Oxford back street.

At the same time demand was picking up in America, following recent breakthroughs in superconductivity – the property of zero electrical resistance, which could be created in certain substances provided that they were kept extremely cold. At the time these superconductors produced unreliable results, and the liquid helium needed to cool them was expensive.

However, Wood soon saw that if these problems could be overcome then the potential market could be huge. He bought a pound of niobium zirconium alloy wire and set about building the largest superconducting magnet he could. The magnet was the first of its kind to be produced outside America, and the interest from the scientific community was huge. Wood gave a demonstration of the magnet in action at a Royal Society soirée; he caught the attention of the Queen Mother, who was in attendance, and who compared the magnetic pull on an iron chain to the experience of taking her corgis for a walk.

Though the excitement surrounding superconductors was not to last, and many of the small companies that made laboratory-scale magnets struggled to stay afloat, OI stood out as one of the few such companies that could boast a number of employees with experience in high magnetic fields. Between 1962 and 1970 the company grew from having no full-time staff to employing about 100, with an annual turnover of £350,000. Wood left Oxford University in 1969 to devote his full attention to the company, and in 1974 OI acquired Newport Instruments, which specialised in technology based on Nuclear Magnetic Resonance.

For some time scientists had mooted the idea of using NMR as a safer alternative to traditional X-rays for scanning the human body, and in 1980 OI supplied Hammersmith Hospital in London with the first commercial scanner to make use of whole-body superconducting magnets; a prototype MRI system based on the same principle as NMR. Another prototype went to the Imaging Laboratory of the University of California.

Despite some teething problems – staff operating the scanners had to keep their credit cards at a safe distance, or else face having the magnetic strips wiped – sales soon climbed quickly. By 1982 Oxford Instruments controlled some 90 per cent of the market in superconducting magnets. By the time the company was floated on the Stock Exchange in 1983 it had grown into a global concern with 1,100 staff. Wood was knighted in 1986, and the following year he was elected a Fellow of the Royal Society.

The youngest of five children of Arthur Wood, a civil servant, and his wife Katharine, Martin Francis Wood was born in Great Milton, Oxfordshire, on April 19 1927. Throughout his childhood his mother encouraged the children on adventurous exploits such as camping, while Arthur would take himself off to France on separate holidays. However, Arthur took an active role in their education, and there was an expectation that all their offspring would attend university. Martin opted to study engineering at Cambridge, but before he could begin the course he was called up.

His National Service was spent working as a Bevin Boy at a South Wales coalfield, as an alternative to what he called the “boring” Army. Though the work was dark and sweaty, Wood found the underground environment an exciting challenge, and he enjoyed pondering the ways in which mining could be made more efficient.

He was involved in a modest “work-to-rule” protest to highlight the injustices within the industry, a move which resulted in his being assigned to the lowest and wettest coalface in the mine. It was an experience that impressed upon him the importance of working as a team in order to bring about real change, and of the need for bosses to encourage workers in their efforts – or else see a decline in creativity.

There followed six years studying engineering at Cambridge and Imperial College on a Coal Board scholarship; he spent several months doing jobs around America, ranging from foundry worker to eagle scarer on a turkey farm.

For a time Wood worked as a management trainee in the coal industry, but his hope that he could change practices for the better soon soured, and he moved south to take up a position in what he called the “powerful but ageing” engineering faculty of Oxford University, where he designed equipment for research scientists.

Sensing a commercial opportunity, he applied to the university’s Visitatorial Board for permission to start a company and to devote part of his time to its running. The bulk of the equipment came second-hand and the first employees were Oxford alumni. From the 1970s, all new employees joining the company became shareholders – an idea Wood had championed since his mining days – as a way of improving competitiveness and team morale. “I wanted them to feel part of it, and they wanted it to succeed,” he recalled.

The company began to diversify in a big way, expanding its remit to include the development of ambulatory monitoring systems – for recording a person’s heart rate or brain activity over a 24-hour period – and foetal monitoring.

As the volume of business grew, Oxford Magnet Technology – a wholly owned subsidiary of Oxford Instruments – formed a 15-year joint venture with Siemens, with a dedicated factory based in Eynsham, Oxfordshire. By 2003 Siemens had come to own OMT outright, and the next year it was rechristened Siemens Magnet Technology.

Though Wood continued to take an interest in the company’s activities, his formal involvement with OI had come to an end when he stepped down as chairman in 1983. In retirement he became governor of a comprehensive school and served on the council of his local Wildlife Trust.

His love of nature was expressed in a passion for woodland conservation, to which end he and Audrey Wood set up a number of charities. These included the Oxford Trust, Earth Trust and Wild Oxfordshire. The Sylva Foundation operated nationwide, supporting people whose careers rely on the use of wood and providing educational resources on conservation to schools and young people.

Having once described himself as a social person “by necessity rather than inclination”, Wood enjoyed cultivating a public image as a somewhat idiosyncratic CEO. Profiles in financial newspapers tended to linger upon his preference for wearing sandals and what one called his “Senior Common Room air”.

He married, in 1955, Audrey (née Stanfield); she was appointed OBE in 2006 and survives him with a son and two stepchildren; his daughter Patsy died in 2007.

Sir Martin Wood, born April 19 1927, died November 23 2021