 In 1965, Brown was appointed to a post of chief engineer at Honeywell with a move to Hemel Hempstead.At Honeywell he worked on the design of open-heart surgery and coronary care machines, as well as prefabricated operating theatres.In 1967, Brown left Honeywell to work at Nuclear Enterprises in Edinburgh, the business that bought the medical ultrasound unit from Kelvin & Hughes in 1966.