Non-invasive hemoglobin monitoring device

This paper deals with a non- invasive hemoglobin-monitoring device that measures hemoglobin concentration of a person without utilizing a drop of blood. The method proposed in this paper uses the principle of photoplethysmography and Beer Lambert law to measure the hemoglobin levels in blood. Two PPG signals are obtained by shining lights corresponding to Red and IR wavelengths on the fingertip of a person and absorbance levels are computed. Path length travelled by the light is determined using the refractive index of hemoglobin and the physical distance between source and detector. Using the two measured values with the known extinction coefficients, a relationship is derived to determine the hemoglobin concentration removing the need for any calibration. Discrete Kalman filter is designed to remove artifacts from the signal. Arduino microcontroller board is used for signal acquisition and data is transferred via serial communication to PC for further analysis.