Noninvasive monitoring of temporal variation in transcutaneous oxygen saturation for clinical assessment of skin microcirculatory activity

Abstract

This work demonstrated the use of Extended Modified Lambert Beer model (EMLB) for continuous monitoring of one’s transcutaneous oxygen saturation based on reflectance spectroscopic data collected from the developed noncontact optical system. This quantification technique relies on spectral signature of hemoglobin components in the wavelength range of 520 − 600nm to give the best guess of transcutaneous oxygen saturation value. We conducted spectroscopic measurement on right index finger of fourteen recruited Asian volunteers in resting condition and after an application of pressure to their upper right arm for demonstration work. The obtained results revealed time- and subjectaveraged transcutaneous oxygen saturation, StO2, of 91.2 ± 5.4% and 12.3 ± 8.9%, respectively, for volunteers at rest and blood flow occlusion experiments. The range and variation in the StO2 value observed in this work agreed reasonably well with that presented in most of the literature. This work concluded that the detected fluctuation in StO2 value is likely due to respiratory and vasomotion activity, and the proposed technique could potentially be used to clinically assess oxygen demand in local tissues and regional microcirculatory system.