Non-Invasive Glucose Estimation Based on Near Infrared Laser Diode Spectroscopy

Diabetes mellitus (DM) is a serious disease that affects not only the patient’s internal organs, circulation system and eyesight, but also their entire body. There are reportedly more than 120 million diabetic patients in the world at the moment and this figure is expected to double within the next ten years. India is the country with the highest rateof diabetes patient, with a current figure of 50.8 million. Modern laser diode spectroscopy is becoming important in medicine. The aim of this paper is to design a finger plethysmograph to measure (estimate) blood resistivity which relate to the amount of glucose level in the blood. The device construction consist of: laser Diode around 650 nm wavelength, Laser Driver, Voltage regulator (2), stepdown transformer (9v), Bridged rectifier circuit, photodetector (2), amplifier, ADC, microcontroller (Arduino Uno) and LCD to display the signal intensity. The device has been constructed in such a way to insert right index finger of the subject in-between the laser diode source and the photodetector. The signal intensity (V) were measured and different known glucose concentration as well as the in vivo calibration and the regression equations was obtained to help estimate the best fitting model (linear curve) and estimated values were correlated in validating the device with the biochemistry method. About 30 subjects aged 10 to 50 years were participated in FBS (fasting blood sugar) clinical study so far. The result of this new approach really shows a promising method for noninvasive measurement of blood glucose level to aid diabetic patients more painless, comfortable and bloodless life style.