In 1977, Lilly ventured into medical instruments with the acquisition of IVAC Corporation, which manufactures vital signs and intravenous fluid infusion monitoring systems. Lilly also purchased Cardiac Pacemakers Incorporated, a manufacturer of heart pacemakers in 1977. In 1980, Lilly acquired Physio-Control Corporation. Other acquisitions included Advance Cardiovasular Systems Incorporated in 1984, Hybritech in 1986, and Devices for Vascular Intervention, Incorporated in 1989. Lilly acquired Pacific Biotech in 1990 and Origin Medsystems and Heart Rhythm Technologies, Incorporated in 1992. In the early 1990s, Lilly combined these medical equipment companies into a Medical Devices and Diagnostics Division that "contributed about 20 percent" of Lilly's annual revenues.