Mid-Infrared Glucose Sensor Using Quantum Cascade Laser
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current noninvasive in vivo glucose detection methods, particularly those using near-infrared light, face challenges due to complex multivariate analysis requirements and weak signals, making them inconvenient and less accurate for diabetics.
Innovation Solution
A noninvasive mid-infrared glucose sensor utilizing a quantum cascade laser as a mid-infrared light source, coupled with optical fibers and an integrating sphere collector, allows for robust signal capture from the skin, avoiding overlapping spectral features with other biological absorbers and enabling direct measurement of glucose levels in interstitial fluid.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If near-infrared light is used for noninvasive glucose detection, then light penetration into skin is improved, but spectral overlap with other biological absorbers increases requiring complex multivariate analysis
Solution Approach 1:
The patent changes the wavelength parameter from near-infrared to mid-infrared region, where glucose has stronger fundamental absorption bands and less spectral overlap with other biological molecules, eliminating the need for complex multivariate analysis while maintaining noninvasive measurement capability
Solution Approach 2:
Instead of using near-infrared light and attempting to separate glucose signal from other absorbers through complex analysis, the patent inverts the approach by using mid-infrared light where glucose absorption is dominant and more easily distinguishable, simplifying the measurement system
2Device complexity
If near-infrared light is used for noninvasive glucose detection, then measurement is simplified, but signal strength from glucose is weak
Solution Approach 1:
The patent transitions to mid-infrared wavelength region where glucose exhibits strong fundamental vibrational absorption bands, significantly enhancing signal strength compared to the weak overtone and combination bands in the near-infrared region, while maintaining straightforward measurement protocols
3Illumination intensity
If mid-infrared light is used for glucose detection, then glucose absorption signal is strengthened, but water absorption also increases reducing light penetration
Solution Approach 1:
The patent selects specific mid-infrared wavelength regions where glucose has strong absorption features and water absorption is relatively lower, optimizing the signal-to-noise ratio for glucose detection while accounting for the increased overall water absorption in the mid-infrared compared to near-infrared
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 approach provides accurate and convenient glucose monitoring by minimizing the need for complex calibration and enhancing signal strength, achieving clinically relevant glucose concentration measurements with high accuracy and reliability.
Implementation Method 1
The sensor includes a mid-infrared light source configured to deliver a light beam to the skin of the test subject. The mid-infrared light source may be a quantum cascade laser.
Implementation Method 2
The sensor may include optical fibers configured to deliver the light beam to the skin of the test subject. The optical fibers may be hollow core optical fibers.
Implementation Method 3
The collector element may be an integrating sphere. The collector element may be a bundle of two or more optical fibers.
Implementation Method 4
a detector element configured to measure the collected backscattered light from the skin
Data Source
AI summary
A noninvasive mid-infrared in vivo glucose sensor for use in connection with the skin of a test subject is disclosed. The sensor includes a mid-infrared light source configured to deliver a light beam to the skin of the test subject, a collector element configured to collect backscattered light from the skin and direct it to the detector, and a detector element configured to measure the collected backscattered light from the skin. The mid-infrared light source may be a quantum cascade laser. The sensor may include optical fibers configured to deliver the light beam to the skin of the test subject. The collector element may be an integrating sphere or a bundle of two or more optical fibers. The sensor may also include a probe containing or connecting to optical fibers coupled to the mid-infrared light source and configured to be placed on the skin to take glucose level readings.