Quantitative deconvolution of human thermal infrared emittance

Area of Science:

• Biophysics
• Medical Imaging
• Thermal Physiology

Background:

• Conventional bioheat transfer models for human thermal infrared (TIR) emittance rely on assumptions of universal graybody emissivity and significant subsurface heat transmission.
• The validity of these assumptions in diverse anatomical locations and physiological states is not well-established.

Purpose of the Study:

• To critically evaluate the assumptions of universal graybody emissivity and significant subsurface heat transmission in human TIR emittance.
• To introduce a novel approach for quantitative deconvolution of human TIR emittance by integrating bioheat transfer models with tissue thermophysical properties.

Main Methods:

• Conducted a series of clinical and laboratory experiments analyzing TIR images of human facial and tibial regions.
• Employed objective analyses to assess spectral thermophysical property variations across different anatomical locations.
• Introduced a novel joint inversion approach for bioheat transfer models, utilizing the temperature-dependency of proton resonance frequency in soft tissues.

Main Results:

• Demonstrated significant variations in spectral thermophysical properties at different anatomical locations on the human body.
• Found limited validity for the conventional assumptions of universal graybody emissivity and significant subsurface heat transmission.
• Established a method to characterize the relationship between subsurface 3D tissue temperature profiles and TIR emittance.

Conclusions:

• The conventional assumptions in bioheat transfer models for human TIR emittance are not universally valid.
• Quantitative deconvolution of human TIR emittance is crucial for accurate clinical, psychophysiological, and critical applications.
• The novel joint inversion approach offers a promising method for improving the accuracy of bioheat transfer modeling and TIR analysis.