Bruce Del Mar (b. 1913) graduated from the University of California, Berkeley, in 1937 with a Bachelor of Science in Mechanical Engineering. During his college summer breaks, Del Mar had worked at Douglas Aircraft Company, and after his graduation he returned to to Douglas full-time. At Douglas he worked with other scientists on airplane cabin pressurization, which would allow passengers to comfortably fly above 10,000 feet without oxygen masks. Del Mar, along with Douglas engineer Wolfgang Klemperer, held the patent for the first pressurization system of a commercial aircraft. In 1952, Del Mar used the money he received from royalties on his patents and inventions to found Del Mar Engineering Laboratories in Santa Monica, California. His company, later renamed Del Mar Avionics, built targeting systems for military aircraft. During later years, the company produced HydraSet, a hydraulic lifting device used to hoist space shuttles onto 747s for transport to Cape Kennedy and to move fuel rods in nuclear power plants. Besides his work in the aviation field, Del Mar also had great success in the medical field and in 1963 he was the first to patent and produce the Holter monitor, an electrocardiogram system that allowed physicians to track their patients' hearts continuously.