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Updated: Feb 1, 2026

The Frequency Domain Thermoreflectance Technique for Thermal Property Measurements
Published on: December 5, 2025
Machine learning approach for rapid and accurate estimation of optical properties using spatial frequency domain
Swapnesh Panigrahi1, Sylvain Gioux1
1University of Strasbourg, ICube Laboratory, Strasbourg, France.
We developed a fast machine learning method to estimate tissue optical properties from reflectance measurements. This approach enables real-time, quantitative mapping of vital signs using absorption and scattering coefficients.
Area of Science:
- Biomedical Optics
- Medical Imaging
- Machine Learning Applications
Background:
- Quantitative optical properties of tissues are crucial for non-invasive physiological monitoring.
- Current methods for estimating optical properties can be slow and limited in scope.
- Real-time, wide-field mapping of tissue optical properties could significantly advance diagnostic capabilities.
Purpose of the Study:
- To present a novel machine learning-based approach for rapid estimation of tissue optical properties.
- To enable real-time, quantitative mapping of absorption and reduced scattering coefficients.
- To validate the accuracy and speed of the proposed method.
Main Methods:
- Utilized a random forest regression algorithm trained on Monte Carlo photon transport simulation data.
- Estimated optical properties in the spatial frequency domain using diffuse reflectance at two spatial frequencies.
- Applied the trained algorithm to 1-megapixel images for property estimation.
Main Results:
- Achieved high-speed estimation of absorption and reduced scattering coefficients.
- Acquired optical properties over a 1-megapixel image in just 450 milliseconds.
- Demonstrated low estimation errors: 0.556% for absorption and 0.126% for reduced scattering.
Conclusions:
- The machine learning approach enables fast and accurate estimation of tissue optical properties.
- This method facilitates real-time, wide-field quantitative mapping of vital tissue optical parameters.
- The technique holds promise for advancing non-invasive physiological monitoring and medical diagnostics.
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