Validation of Hemoglobin and Water Molar Absorption Spectra in Near-Infrared Diffuse Optical Tomography

Near Infrared diffuse optical tomography was used to measure the molar absorption spectra for deoxyhemoglobin, oxyhemoglobin and water through phantom experiments. The measured spectra compensate for any systemic errors and errors arising from model-based estimation of concentrations of these chromophores, and show reasonable agreement with existing literature values. The spectra were validated by phantom experiments to obtain the oxygen dissociation curve. Variation of the partial pressure of oxygen in solution yielded results consistent with theory with mean error of 7.6% in estimation of oxygen saturation, and accurate within 5% in estimation of hemoglobin.