Optical Blood Glucose Sensor Using Light Collection System
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Solution Overview
Problem
Current non-invasive blood glucose monitoring devices face challenges in accurately measuring glucose levels due to interference from skin, fat, muscle, bone, and interstitial fluid, resulting in high baseline noise and low signal-to-noise ratios, which limits the detection of the small cyclic pattern of light absorption by blood.
Innovation Solution
The use of a light collection system with a light illumination funnel and an aspheric lens to increase light power and improve signal-to-noise ratios, including a processor to calculate the change in light absorption caused by blood using multiple light beams of different wavelengths and interference filters to focus and concentrate light onto a detector array.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If non-invasive optical spectroscopy is used to measure blood glucose, then the pain and inconvenience of blood sampling is eliminated, but the measurement accuracy deteriorates due to interference from skin, fat, muscle, bone, and interstitial fluid
Solution Approach 1:
The optical spectrum is segmented into multiple wavelength regions, with specific emphasis on the 900-1100 nm range where blood absorbs light differently than other tissues. By analyzing specific spectral segments rather than the entire spectrum, the device can isolate blood-related absorption patterns from interference by skin, fat, muscle, and bone.
Solution Approach 2:
The patent applies local quality by using wavelength-specific detection where different wavelengths are optimized for different penetration depths and tissue types. The 900-1100 nm range provides optimal local quality for blood glucose detection because this spectral region exhibits characteristic absorption by hemoglobin and glucose while minimizing absorption by other tissues.
2Ease of operation
If the detection area includes all body tissues (skin, fat, muscle, bone, blood), then non-invasive measurement is achieved, but the signal-to-noise ratio deteriorates due to overwhelming background absorption from non-blood tissues
Solution Approach 1:
The patent extracts the useful blood-related signal from the total optical absorption by using wavelength regions where blood has characteristic absorption patterns. By focusing on 900-1100 nm where hemoglobin and glucose exhibit distinctive absorption, the device extracts blood-specific information while taking out (excluding) the overwhelming background absorption from skin, fat, muscle, and bone that occurs at other wavelengths.
Solution Approach 2:
The patent changes the detection parameter from broad-spectrum absorption to wavelength-specific absorption in the 900-1100 nm range. This parameter change allows the system to detect subtle variations in blood glucose concentration by measuring absorption at wavelengths where blood components have characteristic spectral signatures, thereby improving signal-to-noise ratio despite measuring through all body tissues.
3Measurement precision
If multiple wavelengths are used to improve glucose detection accuracy, then measurement precision improves, but device complexity increases
Solution Approach 1:
The patent applies universality by using a single broad-band light source (900-1100 nm) that can detect multiple parameters simultaneously. This wavelength range allows the device to measure glucose concentration, detect blood presence, and compensate for variations in tissue composition all with one light source and detector system, rather than requiring separate systems for each measurement.
Solution Approach 2:
The patent uses partial action by focusing on a specific wavelength subset (900-1100 nm) rather than analyzing the entire optical spectrum. This partial spectral analysis provides sufficient information for accurate glucose detection while avoiding the excessive complexity that would result from full-spectrum analysis across all wavelengths.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration significantly increases the light power received by detectors, enhancing the signal-to-noise ratio and allowing for more accurate determination of glucose levels without increasing device size or battery power consumption.
Implementation Method 1
an aspheric lens to increase light power and improve signal-to-noise ratios, including a processor to calculate the change in light absorption caused by blood using multiple light beams of different wavelengths and interference filters to focus and concentrate light onto a detector array
Implementation Method 2
interference filters to focus and concentrate light onto a detector array
Implementation Method 3
A fundamental property of a sample, whether it is a gas, liquid or solid, is its tendency or lack of tendency to absorb or scatter light at certain wavelengths
Data Source
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AI summary
Embodiments of the invention relate to an apparatus including a light source to generate a plurality of light beams with each of the plurality of light beams having a different wavelength range. The apparatus also includes a light funnel to direct the plurality of light beams to the target area, an aperture to direct the plurality of light beams emitting from the target area to a lens, the lens configured to collect the light beams emitting from the target area. Further, the apparatus includes a detector including a plurality of light-sensing devices each configured to detect a light beam and configured to generate an output signal indicative of an intensity of light detected and a processor for determining the blood characteristic as a function of each generated output signal.