Harold Hopkins, the son of a baker, was born in Leicester and educated locally. He went on to Leicester University, where he took his BSc in physics and mathematics in 1939, working afterwards as an optical physicist for several companies and briefly for the Ministry of Aircraft Production during the Second World War. In 1947 he joined Imperial College, London, as a research fellow, later becoming a reader in optics. He moved to Reading in 1967 as professor of applied optics and was head of the department of physics between 1977 and 1980. He retired in 1984.
He was a remarkably inventive man, whose work included the design of the television camera zoom lens and the optics of the video disc, but his outstanding contribution to medicine was in fibre optics, flexible endoscopes and the rod-lens system. At a dinner party in 1950 he was approached by Hugh Gainsborough [Munk’s Roll, Vol.VII, p.197], consultant physician at St Georges Hospital, who complained about the poor illumination, image quality and rigidity of the traditional gastroscope. In 1951 Hopkins developed the idea of using a bundle of optical fibres for transporting an optical image and began experiments in 1952 with a grant from the Royal Society. By 1953 he and his research student, N S Kapany, had produced a coherent fibre bundle in which the fibres were of precisely the same order at the distal and proximal ends. The invention was announced in Nature in 1954 and, after a conference, in Optica Acta in 1955. Basil Hirschowitz was later to collaborate with C Wilbur Peters and Lawrence Curtiss to develop a permanent insulated glass coated optical fibre, making it possible in 1957 to build the first fibre-optic gastroscope. The first commercial gastroscope based on the prototype was produced by ACMI (American Cystoscope Makers Inc) in 1960, leading on to flexible fibre-endoscopes to inspect, biopsy and intervene throughout the GI tract.
Hopkins was then approached by the urologist, J G Gow, asking if he could develop a better cystoscope, and he invented the rod-lens system to allow better light transmission from the bladder cavity. For the urologist this provided a 50-fold improvement in the light level. A prototype cystoscope using rod-lenses and a camera was made at Imperial College in 1961. The UK and USA manufacturers were not interested, but after Hopkins lectured in Dusseldorf in 1963 Karl Storz combined this rod-lens with his cold light. The Storz cystoscope was produced in 1967 and similar rigid fibre endoscopes have been used in every part of the body.
Hopkins produced a number of ancillary devices for his endoscopes, in particular the dual-viewing or teaching attachment, which allowed the endoscopist to carry out examinations and operative procedures with an observer. The learner could observe whilst the instructor performed and later the instructor could monitor the learners performance. The teaching attachment was useful for photography and, with a colour TV camera attached, could display images on a large screen and allow video recordings.
In 1973 Hopkins was elected a fellow of the Royal Society and in 1984 the Society awarded him their Rumford medal. He was made an honorary fellow of the Royal College of Surgeons in 1979 and an honorary fellow of the Royal Society of Medicine in 1989. He received honorary doctorates from many universities and medals from several institutions. He was president of the International Commission for Optics between 1969 and 1972 and president of the mathematics and physics section of the British Association for the Advancement of Science. The British Society of Gastroenterology commemorated him with their Hopkins endoscopy prize.
Hopkins was modest, unflamboyant and unpretentious in his scientific authority and inventiveness. He believed strongly in the accuracy of instrumentation.
J H Baron