Undergraduate Research at FIU (URFIU) Conference

Validation of Near Infrared Optical Scanner to Assess Saturated Oxygen Changes in Response to Breath Hold

FIU Wellness & Recreation Center

A near-infrared optical scanner (NIROS) was developed in-house, to determine relative oxygenated (DHbO) and deoxygenated (DHbR) hemoglobin levels in the wound and the surrounding tissue. The goal of this study is to measure perfusion changes in terms of saturated oxygen in subsurface tissues as a response to a breath-holding paradigm using NIROS, and validated against a hospital grade pulse oximeter and photo-spectrometer. Comparison of perfusion changes between the devices can assist in correlating these measurements and thus calibrate and validate our recently developed NIROS device. Furthermore, assessing oxygenated perfusion change can potentially help demarcate regions of poor oxygen flow, thus aiding clinicians assess the potential to heal in chronic or acute wounds. NIROS is a hand-held, non-contact optical device composed of an NIR-sensitive CMOS camera and a multi-wavelength LED source system utilizing wavelengths in the 660nm-805nm, that measures diffuse reflectance signals of 2D tissue regions. NIROS was used to collect diffused reflected images from 729nm and 799nm light, which was later processed with modified Beer-Lambert’s Law to produce dynamic HbO and HbR maps. Trendlines produced from these maps were bandpass filtered between 0.01-0.1 Hz to remove system noise. The total study time lasted 5 minutes with a breath hold paradigm implemented at the two-minute mark. The same study design was used for all imaging modalities. The measurements of oxygen saturation in blood before/after breath holding were collected using a Pulse Oximeter (Nellcor- PM10N), a spectrometer and NIROS. NIROS was able to measure perfusion changes in terms of saturated oxygen in subsurface tissues as a response to a breath-holding paradigm. Extensive in-vivo studies on controls are carried out to quantitatively validate NIROS against a hospital grade pulse oximeter and photo-spectrometer.