Oxyhemoglobin Measurements Using 1064 nm Light

While standard optical oximetry systems make use of two/more wavelengths across the isosbestic point of oxy/deoxy-hemoglobin and between 650 and 900 nm, this work explores the possibility to use only light at 1064 nm wavelength to detect the absolute oxyhemoglobin concentration in tissues using time-domain diffuse optics. Furthermore, the possibility to exploit a 1064 nm wavelength coupled with wavelengths of classical approaches is also discussed. Our findings demonstrate a reasonable overlap of the new approaches as compared to the standard one, with confined discrepancies potentially linked to a not established agreement in the scientific community on the exact value of extinction coefficients of tissue constituents beyond 1000 nm, as well as to an increased penetration depth in the tissue at 1064 nm due to a lower scattering coefficient as compared to the visible range. These findings open the way to further studies in the field, also given the increasing advancements in lasers and detectors at 1064 nm.