Patent ID: 9579049
Date: 2017-02-28
CPC Classifications: A61B,G16Z

Claim:
1. A system for detecting glucose in a biological sample, comprising: at least one light source configured to generate one or more light beams having a wavelength in a range between 800 nm and 1600 nm to strike a target area of a biological sample; at least one photocurrent signal generating light detector positioned to receive light from the at least one light source and to generate an output photocurrent signal, having a time dependent current, which is indicative of the power of light detected; wherein the time dependent output current is a function of a baseline current, a noise current and a time dependent cyclic current corresponding to a heartbeat; and a light absorbance change determining algorithm implemented processor programmed to calculate a change in a light absorption caused by blood in the biological sample and configured to receive the output photocurrent signal from the at least one photocurrent signal generating light detector and based on the received output photocurrent signal, calculate the attenuance attributable to blood in the biological sample present in the target area with a signal-to-noise ratio of at least 20-to-1, and based on the calculated attenuance, determine a blood glucose level associated with the biological sample present in the target area; and wherein the calculated attenuance is based on an equation for improving a signal-to-noise ratio having at least in part on a standard deviation of a logarithm of the time dependent output current generated by the power of light from the same target area of the biological sample, wherein the equation comprises where A(t) is the change in light absorption due to blood in the biological sample as a function of time, ΔA is the peak-to-valley height of A(t) plot during the time interval of one heartbeat, I D (t) is the time dependent detector current, log I D (t) is the logarithm of the time dependent detector current, k is the proportionality constant, σ[A(t)] is the standard deviation of A(t), and σ[log I D (t)] represents the standard deviation of log I D (t).