Measurement of Tissue Oxygenation Level in Human Lip

Kashima (Optics Laser Technol 35: 485–489, 2003) reported a method based on the Beer–Lambert law for measuring blood volume and its oxygenation in a small volume of tissue (<1 cm3). In the present study, the applicability of a tissue blood oxygenation monitor based on Kashima’s report (Optics Laser Technol 35: 485–489, 2003) to human lip was examined. The amount of oxy-hemoglobin, the amount of deoxy-hemoglobin, total amount of hemoglobin (THb) and oxygen saturation levels (StO2) in human lower lips and in fingerpads of five healthy participants (age: 28–55) were measured using the tissue blood oxygenation monitor. Tissue oxygenation levels in lips ranged between 81% and 88%, while those in fingerpads ranged between 77% and 83%. Deep breath evoked a transient decrease of StO2 both in lip and fingerpad, and the change in StO2 was not synchronous either with BF or THb. The results indicated that the device used in this study reflected tissue oxygenation levels.