OxiCarbo (R), a single sensor for the non-invasive measurement of arterialoxygen saturation and CO2 partial pressure at the ear lobe

The paper describes the characteristics and results obtained in adults with a new miniaturised sensor combining the measurement of arterial oxygen sat uration by optical means and arterial P-CO2 by electrochemical means (OxiCa rbo (R) sensor). The sensor is heated to 42 degreesC to create arterialisat ion of the cutaneous tissue and is applied to the ear lobe with a special l ow-pressure clip. The use of the sensor heating significantly improves the performance of the Sp(O2) measurement. The heating increases the arterial p ulsation signal and decreases the non-arterialised tissue signal. The fluct uations of the measurement are reduced. The quantitative results of the Sp( O2) measurements are not affected by the heating. The measurement at the ea r lobe improves also the P-CO2 measurement by decreasing the arterialisatio n time from approximately 7 min at the forearm to less than 3 min at the ea r lobe. At a temperature of 42 degreesC, the sensor may be left at the same central site for over 12 h without the risk of a skin burn. (C) 2001 Elsev ier Science B.V. All rights reserved.