Mark Wefers Bettink

Verification of calibration in man and comparison with vascular occlusion tests in healthy volunteers with COMET 4 67 in figure. 5c. Fifteen minutes after cyanide application the mitoVO 2 was measured in the skin to assess recovery of mitochondrial respiration (figure 5d). A B 1 2 1 2 3 4 C Figure 1: A) The incubator, sealed to prevent nitrogen gas leakage and provide a controlled air temperature of 37 0 C. B) Probe position of 1. O2C LFX-43 probe , 2. INVOS, 3. SenTec OxiVenT, and 4. COMET Skin Sensor on the lower arm. C) The ALA application side after cyanide application. A temporary hyperemia phase was seen as a red square on the arm. 2.3 Comparison during vascular occlusion testing To compare the behavior of mitoVO 2 of COMET to other oxygen metabolism-related measurements, a variety of clinical bedsidemonitoring devices with a temporal resolution of seconds were used. The following devices were included; 1) Oxygen To See with the LFX-43 probe (O2C version 2424, Lea Medizintechnik GmbH, Germany), which combines direct (infra)red light spectroscopy with laser doppler. It measures local capillary venous saturation (SO 2 ), and local microvascular blood flow is provided in flow units (FU). 2) Near- infrared spectroscopy (INVOS), which measures the tissue saturation and 3) a SenTec Digital Monitoring System with an OxiVenT™ Sensor (SenTec AG, Therwil, Switzerland) which transcutaneously measures blood gases and provides tcPCO 2 values. The location of the different probes on the arm can be seen in Figure 1b. We measured during and after an arterial occlusion test of the arm. Arterial occlusion was achieved by insufflation of a cuff to at least 50 mmHg above the systolic blood pressure. The absence of skin blood flow was confirmed with laser-doppler blood flow measurement with the O2C. During 2 minutes the COMET monitor measured mitoPO 2