MINNEAPOLIS, April 23 -- Optical Sensors Inc. has received clearance from the US Food and Drug Administration to market a miniaturized version of its CapnoProbe Instrument (the Model 2000). The device provides a measurement of sublingual CO2 levels. Tissue CO2 as measured with the CapnoProbe Sensor correlates with other more invasive and costly indicators of a patient's changing condition. Clinical studies indicate that rapidly deployable, early perfusion indicators may allow quicker, more effective intervention by medical personnel in life critical situations.