Modelling infrared temperature measurements: implications for laser irradiation and cryogen cooling studies

Area of Science:

• Biomedical Engineering
• Optical Diagnostics
• Thermal Analysis

Background:

• Thermographic techniques are increasingly used for monitoring laser-tissue interactions.
• Infrared detector technology advancements have improved thermal camera capabilities.
• Accurate surface temperature measurement is critical for understanding laser-tissue thermal responses.

Purpose of the Study:

• To quantitatively demonstrate the discrepancy between measured and actual surface temperatures during laser irradiation.
• To investigate the limitations of thermal cameras in laser-tissue applications.
• To provide insights into the accuracy of radiometric temperature measurements.

Main Methods:

• Utilized a 1D finite difference model to simulate thermal behavior.
• Adapted three established laser ablation models and one cryogen spray cooling simulation.
• Calculated predictions of radiometric temperature measurements based on simulations.

Main Results:

• Steep superficial temperature gradients with a surface peak led to underestimation of actual surface temperature.
• Steep superficial temperature gradients with a subsurface peak resulted in overestimation.
• Small temperature gradients yielded relatively accurate temperature estimates.

Conclusions:

• Thermal camera measurements can deviate significantly from actual tissue surface temperatures.
• The accuracy of thermal imaging is dependent on the characteristics of the temperature gradient.
• Understanding these limitations is crucial for reliable thermal monitoring in laser-tissue procedures.