METHOD AND SYSTEM FOR NON-INVASIVE OPTICAL BLOOD GLUCOSE DETECTION UTILIZING SPECTRAL DATA ANALYSIS

• US 20130245405A1
• Filed: 09/11/2012
• Published: 09/19/2013
• Est. Priority Date: 05/22/2008
• Status: Active Grant

• Current Assignee: St. Louis Medical Devices, Inc.
• Original Assignee: St. Louis Medical Devices, Inc.
• Inventors: Xu, Zhi
• Granted Patent: US 9,629,576 B2
• Time in Patent Office: Days
• US Class Current: 600/316
• CPC Class Codes: A61B 2562/0238 Optical sensor arrangements for performing transmission measurements on body tissue
• CPC Class Codes: A61B 2576/00 Medical imaging apparatus involving image processing or analysis A61B1/00009, A61B6/52 and A61B8/52 take precedence; image processing per se G06T; details of algorithms for analysing medical images G06T7/0012
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/1455 using optical sensors, e.g. spectral photometrical oximeters
• CPC Class Codes: A61B 5/6826 Finger
• CPC Class Codes: A61B 5/6838 Clamps or clips
• CPC Class Codes: A61B 5/7225 Details of analog processing, e.g. isolation amplifier, gain or sensitivity adjustment, filtering, baseline or drift compensation A61B5/30, A61B5/316 take precedence; transformers for specific applications H01F38/00; amplifiers H03F
• CPC Class Codes: G16Z 99/00 Subject matter not provided for in other main groups of this subclass

Abstract

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 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, a processor configured to receive the output signal from the at least one light detector based on the received output signal, calculate the attenuance attributable to blood in a sample present in the target area with a ratio factor, eliminate effect of uncertainty caused by temperature dependent detector response of the at least one light detector, and then determine a blood glucose level with a sample present in target area based on the calculated attenuance with the processor.

Claims

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

utilizing at least one light source configured to strike a target area of a sample;

utilizing at least one light detector 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;

receiving the output signal from the at least one light detector with a processor and based on the received output signal;

calculating the attenuance attributable to blood in a sample present in the target area with a ratio factor with the processor;

eliminating effect of uncertainty caused by temperature dependent detector response of the at least one light detector with the processor; and

determining a blood glucose level associated with a sample present in the target area with the processor based on the calculated attenuance with the processor.

2. The method for detecting glucose in a biological sample according to claim 1, wherein the eliminating effect of uncertainty caused by temperature dependent detector response of the at least one light detector with the processor further includes calculating the standard deviation of the logarithm of the time dependent current with the processor.

3. The method for detecting glucose in a biological sample according to claim 1, wherein the at least one light detector includes a preamplifier having a feedback resistor.

4. The method for detecting glucose in a biological sample according to claim 3, further includes calculating at least one of a normalization factor Q_i(C,T) based on the preamplifier output voltage V_i(t) as a function of time and standard deviation σ

according to the equation;

5. The method for detecting glucose in a biological sample according to claim 3, further comprising utilizing an analog-to-digital convertor having a digitized voltage output.

6. The method for detecting glucose in a biological sample according to claim 5, further includes calculating at least one of a normalization factor Q_i(C,T) based on the analog-to-digital convertor voltage output Δ

(ADC)_i, where σ

is standard deviation according to the equation;

7. A system for detecting glucose in a biological sample, comprising:

at least one light source configured to strike a target area of a sample;

at least one light detector 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;

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 with a ratio factor, 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 present in the target area.

8. The system for detecting glucose in a biological sample according to claim 7, wherein the processor is configured to eliminate the effect of uncertainty caused by temperature dependent detector response of the at least one light detector by calculating the standard deviation of the logarithm of the time dependent current.

9. The system for detecting glucose in a biological sample according to claim 7, wherein the at least one light detector includes a preamplifier having a feedback resistor.

10. The system for detecting glucose in a biological sample according to claim 9, wherein the processor is configured to calculate at least one of a normalization factor Q_i(C,T) based on the preamplifier output voltage V_i(t) as a function of time and standard deviation σ

according to the equation;

11. The system for detecting glucose in a biological sample according to claim 7, further comprising an analog-to-digital convertor having a digitized voltage output.

12. The system for detecting glucose in a biological sample according to claim 11, wherein the processor is configured to calculate at least one of a normalization factor Q_i(C,T) based on the analog-to-digital convertor voltage output Δ

(ADC)_i, where σ

is standard deviation according to the equation;