Noninvasive Temperature Determination via Discrete Wavelength Absorption
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current noninvasive methods for temperature determination in water-containing media, such as body tissue or blood, are complex and require complete spectrum recording, limiting their applicability for continuous monitoring and precision.
Innovation Solution
A method involving irradiation with two discrete light wavelengths on either side of the absorption maximum, where the temperature is determined from the ratio of absorption values, allowing for precise temperature measurement without needing to fully record the absorption line or determine its position, using calibration data to evaluate the slope between these values.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If complete spectrum recording is performed to determine temperature, then measurement precision is improved, but device complexity and measurement time increase
Solution Approach 1:
The patent divides the continuous spectrum into discrete wavelength segments by selecting specific wavelengths on either side of the absorption maximum. Instead of recording the entire absorption line, the method measures only at these discrete points, significantly simplifying the spectrometer requirements while maintaining temperature measurement capability through ratio-based analysis
Solution Approach 2:
The patent extracts only the essential information needed for temperature determination by measuring absorption at specific wavelengths flanking the absorption maximum. This extraction approach eliminates the need for complete spectrum recording, reducing device complexity while preserving the temperature-dependent absorption ratio signal
2Measurement precision
If complete absorption line measurement is performed, then temperature determination accuracy is improved, but loss of time increases
Solution Approach 1:
The patent applies partial action by measuring only at the essential wavelengths needed for temperature determination rather than recording the complete absorption line. By selecting specific wavelengths on either side of the absorption maximum and using their ratio, the method achieves sufficient accuracy for continuous monitoring applications without the time penalty of full spectral recording
3Measurement precision
If high spectrometer resolution is used to detect line shifting, then measurement precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent changes the measurement parameter from absolute wavelength position to absorption ratio at fixed wavelengths. By measuring the ratio of absorptions at two discrete wavelengths and monitoring how this ratio changes with temperature, the method achieves temperature sensitivity without requiring high-resolution spectrometers capable of detecting small line shifts
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
Enables simple, noninvasive, and precise temperature determination in water-containing media, suitable for continuous monitoring within the body, with a precision of ±0.01° C, and can be combined with blood component concentration measurements.
Implementation Method 1
the medium to be analyzed is irradiated by infrared and/or visible light near an absorption line whose position depends on the temperature of the medium, and where the absorption of the light is measured near the absorption line
Data Source
AI summary
Disclosed is a method for the non-invasive optic determination of the temperature of a medium, preferably a water-containing medium, wherein the medium to be analyzed is illuminated by infrared and/or visible light in the region of an absorption line, the position of which depends on the temperature of the medium, and wherein absorption of the light in the region of the absorption line is measured and the temperature is determined from said measurement by comparison with calibration data. Said method is characterized in that the medium is illuminated with at least two discrete light wavelengths (λ1, λ2), which are in the region of the absorption line (B) on different sides of the absorption maximum, that at least one measured value (ΔA/Δλ) dependent on temperature is determined from the relationship of these two determined absorption values to one another, and that the temperature is determined from said measured value by comparison with the previously recorded calibration data.