Mark Wefers Bettink

Verification of calibration in man and comparison with vascular occlusion tests in healthy volunteers with COMET 4 75 A 0 50 100 150 0 50 100 150 200 time (sec) MitoPO 2 (mmHg) O2C flow (FU) O2C sat (%) OxiVent TcPCO2 (mmHg) OxiVent heating power (mW) NIRS sat (%) arterial occlusion arterial flow B 20 40 60 -2 -1 0 1 2 3 time (sec) z-score MitoPO 2 O2C flow O2C sat NIRS sat OxiVent TcPCO 2 OxiVent heating power Figure 7: A)Typical example of arterial occlusion of the forearm. At t=10 seconds the blood pressure cuff was inflated to 50 mmHg above the blood pressure measured earlier. At t=120 seconds the blood pressure cuff was released and arterial flow returned. B) Average data of 9 subjects. Data shown in z-score transformation, z=(data point – mean)/standard deviation to compare the overall decline part of the data. 4. Discussion This study demonstrates that the calibration of COMET device, originally determined in animal experiments, is adequate for cutaneous mitoPO 2 measurements in man. Furthermore, dynamic oxygenation measurements aimed at gaining insight in tissue oxygen consumption depend on the specific measuring technique and method to cease oxygen supply to the measurement spot. The COMET measurement system measures relatively high mitoPO 2 values compared to the general idea that mitoPO 2 should be very low in order to drive oxygen diffusion [6, 18, 19]. This study shows that such high mitoPO 2 values are not the result of an