Method and system for non-invasive optical blood glucose detection utilizing spectral data analysis

A method for detecting glucose in a biological sample, comprising:

• receiving an output photocurrent signal from the at least one photocurrent signal generating light detector;
• programming a processor to calculate a change in a light absorption caused by blood in the biological sample based on the received output photocurrent signal;
• calculating an 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;
• determining a blood glucose level associated with the biological sample present in the target area based on the calculated attenuance with the processor, wherein the processor is configured to calculate a peak-to-valley height of the change in light absorption due to blood in the sample in relationship to time, which is a function of a standard deviation of a logarithm of the time dependent output current divided by a proportionality constant:
• Δ
• ⁢
• ⁢
• A
• =
• σ
• ⁡
• [
• A
• ⁡
• (
• t
• )
• ]
• k
• =
• σ
• ⁡
• [
• log
• ⁢
• ⁢
• I
• D
• ⁡
• (
• t
• )
• ]
• k
• ,
• where A(t) is the change in light absorption due to blood in the sample as a function of time, ΔA is the peak-to-valley height of A(t) plot during the time interval of one heartbeat, ID(t) is the time dependent detector current, log ID(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 ID(t)] represents the standard deviation of log ID(t);
• and
• programming the processor to reduce noise without increase data acquisition time by using the σ[A(t)].