| abstract |
The concentration (and thus the partial pressure) of certain gases, such as carbon dioxide and oxygen and the pH (hydrogen ion concentration) in arterial blood are determined without the need for contacting the blood by first stripping off the top dry skin layer forming a "window" of small size. A small chamber is sealed to the skin around the window and the absorption in the chamber of electro-magnetic radiation of particular wavelengths resulting from the constituent of interest is noted as a measurement from which the concentration of that constituent in arterial blood is calculated. Specific embodiments of such electro-optical measuring chambers are described for measuring concentration of various specific constituents in arterial blood. |