Medical Technology Oxygen manufacture and flasher valves later led to the development of advanced medical technology. Continuous development in the clinical equipment sector led to the formation of AGA Medical in 1973. In 1980 AGA transferred these operations to Siemens Elema. Medical gases and their applications remain a significant part of AGA's activities. Oxygen apparatus for aviators and medical breathing assistance have been used in Sweden since 1925. In 1930 some Swedish hospitals started using nitrous oxide as an anesthetic. (The gas itself was no new invention, the first nitrous oxide anesthetics were given as early as 1845.) The use of the gas to relieve pain had been successful abroad but nitrous oxide imports were expensive. This led Professor Key at Stockholm's Maria Hospital to suggest that AGA start manufacturing both the gas and the equipment. The foundation was thus laid for a new business area for AGA. The production and sale of nitrous oxide fitted naturally into the AGA program which then mainly comprised extensive manufacture of acetylene and gas equipment.