Validation of a Hyperspectral NIRS Method for Measuring Tissue Oxygen Saturation

Abstract

Brain injury during preterm infancy can cause serious intellectual and behavioral disabilities, as such, measurements of cerebral health are needed to aid in the diagnosis and treatment of these injuries. Near infrared spectroscopy (NIRS) is considered ideal for this purpose because it is non-invasive and provides a continuous measure of tissue oxygen saturation (StO2), a key marker of cerebral health. Current commercial NIRS systems have considerable variability between devices and between infants restricting them to monitoring trends. Time-resolved (TR) NIRS is considered the gold standard in biomedical optics for quantifying tissue optical properties, but the technology is more complex and has struggled with integration into clinical settings. As an inexpensive alternative, the present study investigated using a hyperspectral NIRS (H-NIRS) method to quantify StO2. Experiments were conducted using newborn piglets and StO2 measured at different oxygenation levels by H-NIRS and by TR-NIRS for validation. Measurements were acquired at step-wise reduction in StO2 caused by reducing the fraction of inspired oxygen. Across eight animals, there was no significant effect between StO2 measurements from the two techniques (F5,35 = 1.591, p \u3e 0.05). The strong agreement (R2 = 0.95) in the StO2 measurements suggests that H-NIRS is a strong candidate for clinical use considering it is both quantitative and technically simple