Single Source-Detector Separation Approach to Calculate Tissue Oxygen Saturation Using Continuous Wave Near-Infrared Spectroscopy

Currently, common optical techniques to measure tissue oxygen saturation (StO 2 ) include time domain (TD), frequency (FD), and continuous wave (CW) near-infrared spectroscopy (NIRS). While TD- FD-NIRS can provide absolute hemoglobin concentration, these systems are often complex expensive. CW-NIRS, such as diffuse reflectance spatially resolved (SRS), simpler more affordable, but they still require at least two source-detector separations. Here, we propose a single separation (SSDS) approach StO using reflected intensities from three wavelengths. The accuracy of the SSDS-based measurement was verified an simulation in-vivo experiment. Simulated dependent generated Virtual Tissue Simulator on 1-layer model, which has ranging 0% 100%. SSDS calculation yielded equivalent actual value (average error = 0.3% ± 0.5%). We then performed measurements seven healthy volunteers in prefrontal cortex during simulated hypercapnia test CW-NIRS device. This device consists light source photodetectors, 30 mm 40 away source. cerebral calculated both SRS approach, uses separations, employs either or separation. SRS-based similar method difference 5.0% 1.1%). proposed will help advance development miniaturized technologies monitor continuously.