Clinical Thermography of the Diabetic Foot Using a Low-Cost Thermal Camera: Processing and Instrumental Framework

Area of Science:

• Biomedical Engineering
• Medical Imaging
• Diabetic Foot Care

Background:

• Infrared thermography is a valuable non-contact tool for monitoring diabetic foot inflammation.
• Quantitative bedside use of low-cost thermal cameras is hindered by issues like radiometric drift, non-uniformity, and parallax.

Purpose of the Study:

• To develop an end-to-end framework for reproducible and physically consistent temperature estimation using affordable thermal cameras.
• To enable accurate detection of plantar temperature asymmetries in diabetic foot care.

Main Methods:

• A standardized mobile acquisition setup and protocol were combined with raw image radiometric data extraction.
• Radiometric inversion, atmospheric correction, vignette correction, and geometric calibration of visible-infrared sensors were performed.
• Hybrid heated markers ensured accurate visible-infrared registration for downstream analysis.

Main Results:

• The developed framework achieved quantitative thermograms with radiometric errors below 0.15 °C.
• Sub-pixel multimodal alignment was obtained, facilitating reliable overlay and analysis.
• The system supports the detection of clinically relevant plantar temperature asymmetries.

Conclusions:

• The presented framework enables calibrated, low-cost thermography for routine use in diabetic foot care.
• This approach overcomes technical challenges, paving the way for improved inflammatory process monitoring.