Method and system for non-invasive optical blood glucose detection utilizing spectral data analysis
Systems and methods are disclosed for non-invasively measuring blood glucose levels in a biological sample based on spectral data. This includes at least one light source configured to strike a target area of a sample, at least one light detector, which includes a preamplifier having a feedback resistor, positioned to receive light from the at least one light source and to generate an output signal, having a time dependent current, which is indicative of the power of light detected, and a processor configured to receive the output signal from the at least one light detector and based on the received output signal, calculate the attenuance attributable to blood in a sample present in the target area and eliminate effect of uncertainty caused by temperature dependent detector response of the at least one light detector, and based on the calculated attenuance, determine a blood glucose level associated with a sample.
1 . A system for detecting glucose in a biological sample, comprising:
at least one light beam generating structure;
at least one photocurrent signal generating light detector;
a light absorbance change determining algorithm implemented processor programmed to calculate a change in a light absorption caused by blood in a 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 to determine a blood glucose level associated with the biological sample present in the target area, wherein the light absorbance change determining algorithm implemented processor is programmed to eliminate effect of uncertainty caused by temperature dependent detector response of the at least one photocurrent signal generating light detector; and
an analog-to-digital convertor providing a digitized voltage output, wherein the light absorbance change determining algorithm implemented processor is configured to calculate the normalization factor based on an analog-to-digital converter voltage output of an ith analog-to-digital converter, where a standard deviation is determined according to an equation, wherein the equation factors in a temperature of the biological sample and a concentration of blood glucose in the biological sample.
2 . The system of claim 1 , wherein the light beam emitter generates one or more light beams have a wavelength in a range between 800 nm and 1600 nm.
3 . The system of claim 1 , further comprising a preamplifier having a feedback resistor, positioned to receive light from the light beam emitter, and generating an output photocurrent signal, having a time dependent current, which is indicative of power of light detected.
4 . A system for detecting glucose in a biological sample, comprising:
at least one light beam emitter;
at least one light detector, wherein the at least one light detector generates photocurrent signal; 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 light detector and based on the received output photocurrent signal to determine a blood glucose level associated with the biological sample present in a target area, wherein the light absorbance change determining algorithm implemented processor is configured to calculate a ratio factor Y ij (C,T) based on an output voltage V i (t) of the i th preamplifier and an output voltage V j (t) of the j th preamplifier as a function of time, where σ is standard deviation according to the equation:
Y
ij
(
C
,
T
)
σ
[
log
V
i
(
t
)
]
σ
[
log
V
j
(
t
)
]
;
wherein T is a temperature of the biological sample and C is a concentration of blood glucose in the biological sample.
5 . The system of claim 4 , wherein the light absorbance change determining algorithm implemented processor is programmed to calculate the attenuance attributable to blood in the biological sample based on the received output photocurrent signal.
6 . The system of claim 4 , wherein the light absorbance change determining algorithm implemented processor is programmed to eliminate effect of uncertainty caused by temperature dependent detector response of the at least one light detector by calculating the standard deviation of a logarithm of the time dependent voltage signal.
7 . The system of claim 4 , further comprising an analog-to-digital convertor having a digitized voltage output.
8 . The system of claim 4 , wherein the at least one light beam emitter is configured to strike the target area of the biological sample and generates one or more light beams having a wavelength in a range between 800 nm and 1600 nm.
9 . The system of claim 4 , wherein the at least one light detector includes a preamplifier having a feedback resistor, positioned to receive light from the at least one light beam emitter and to generate an output photocurrent signal, having a time dependent current, which is indicative of power of light detected.
10 . The system of claim 9 , wherein the preamplifier has a feedback resistor, which is configured to convert the time dependent current into a time dependent voltage signal.