The CapnoProbe system is a handheld device with an optical carbon dioxide (CO2) probe that is slipped under the tongue like a thermometer. The CapnoProbe non-invasively measures the carbon dioxide tissue of the mouth's mucous membrane. This measurement can assist physicians in diagnosing systemic hypoperfusion, which is an early indicator of impending or actual circulation collapse. The CapnoProbe system is designed to be used by qualified medical personnel to diagnose and monitor hospital patients during surgery, in the ICU, or in the emergency setting.