Electrochemical sensor for continuous transcutaneous PCO2 measurement.
A sensor suitable for continuous transcutaneous PCO2 measurements is described. The sensor consists of an antimony-antimony oxide electrode in combination with a silver-silver chloride reference electrode, bathed in an electrolyte and covered by a Teflon membrane. A servo-controlled heater unit was used to maintain the sensor's temperature and to produce local hyperemia. The resulting oxidation-reduction potential under constant temperature is a linear function of the logarithm PCO2. Response time (95%) to step changes in PCO2 from 27 to 70 mmHg was 2.7 +/- 0.3 min. Following a 12-h "aging" time, the electrode exhibited a minimal drift of 5.2 +/- 2.2 mV for 16 h, representing an average PCO2 drift of 0.5 mmHg/h. This sensor was applied on three rabbits and on five human volunteers, and found satisfactory under normal physiological conditions.
D000818:Animals; D000965:Antimony; D002245:Carbon Dioxide / Q000032:analysis*; D004566:Electrodes; D006801:Humans; D008722:Methods; D011817:Rabbits; D012867:Skin
D002245:Carbon Dioxide; D000965:Antimony