Avox Systems manufactures instruments to measure blood oxygen. The company is developing its patented light-scattering technology into a series of clinical instruments to serve various markets including cardiology, intensive care, and emergency medicine. The company's technology enables spectrophotometric measurements directly in unaltered whole blood without hemolysis or other sample preparation. AVOXimeters do not need the pumps, plumbing and hemolyzers employed by conventional co-oximeters. Therefore, they are faster and less expensive, and they require almost no maintenance. The AVOXimeter 1000, released in 1993, is already the oximeter of choice in cardiac catheterization labs in leading US hospitals. In 1996, the company introduced the AVOXimeter 4000, the world's first whole-blood co-oximete.