The acousto-optic tunable filter (AOTF) spectrometer has been used to measure various gases of clinical interest using infrared spectroscopy. The AOTF is a birefringent crystal capable of high speed, random wavelength access. Various crystals can cover the range from 250 nm to 5 microns. Infrared transmitting fibers have been used for remote diagnostics of carbon dioxide and anesthesia gas. We will report on system specifications such as sensitivity, noise, and drift.