Noninvasive measurement of blood hemoglobin concentration by time-resolved transmission spectroscopy

An optical spectroscopic method is investigated theoretically for noninvasive and continuous monitoring of blood hemoglobin levels. The method may provide accurate measurement of hemoglobin concentration by detection and analysis of dynamic dual wavelength time-resolved transmission under a condition of artificial blood flow kinetics in a human finger. This condition can assist light scattering and leads to a better signal-to-noise ratio necessary to accurate measurement of transmission. The modified parametric slopes were derived from the Laplace transformed data of the time-resolved transmittance. Continuous hemoglobin concentration was measured in the range from 6 to 16 g/dl and the results show that the sensitivity of hemoglobin sensing is enhanced when we use selected values of the Laplace transform parameter p = 5 × 1010 s−1 comparing with the continuous wave situation.