[Introduction of cold light to endoscopy].

It is the aim of the paper to describe how, 40 years ago, optic glass fibers were developed, and what has been K. Storz's contribution to the new technology. In 1951 the term "Cold Light" was used the first time for illumination of a French type film- and photoendoscope. In 1957 the gastroenterologist B. Hirschowitz at Ann Arbor, U.S.A. succeeded making glass fibers of high light-guiding properties. In 1961 the Cystoscope Makers Inc (ACMI) at New York using these fibers brought the first flexible gastroscope on the market, still equipped with a conventional electric lamp. But in 1960, the year before, the physicist's of ACMI, J. H. Hett and L. Curtiss built the first cold light endoscope using glass fibers for both light and images conduction. In the following years ACMI equipped all of his endoscopes with this new type of illumination. Not before 1963 did K. Storz and the other German manufacturers produce their first cold light cystoscopes. Not possessing the know-how of glass fiber manufacturing, they had to get their fibers from abroad. K. Storz transmitted the term "cold light", which before had been the label of his French-type endoscopes, to the new glass fiber illumination. He constructed an excellent light source for fiber illumination without having light cables of his own fabrication. That is why his name is intimately connected with cold light illumination. But, nevertheless, the invention of the new glass fiber illumination must be credited to B. Hirschowitz and the physicists of ACMI in the U.S.A.