This invention relates to a method and apparatus for in-vivo, real time
measurement of pH, pCO.sub.2, base excess, hemoglobin, and hemoglobin
oxygen saturation. Specifically, the invention relates to an apparatus
placed in-line with an existing invasive patient access line to provide
continuous, semi-continuous, or non-continuous monitoring of blood pH,
pCO.sub.2, base excess, hemoglobin, and hemoglobin oxygen saturation in a
manner which is relatively non-invasive. Further, the device and apparatus
allows monitoring of the listed parameters in a non-destructive manner
such that the blood sample under analysis can be returned to the patient.
