Temperature evolution in tissues embedded with large blood vessels during photo-thermal heating

Area of Science:

• Biomedical Engineering
• Medical Physics
• Thermal Medicine

Background:

• Laser-assisted photothermal therapy requires precise temperature control for effective cell ablation.
• Large blood vessels near irradiated tissues can significantly alter temperature distribution.
• Understanding vascular cooling effects is crucial for optimizing thermal therapies.

Purpose of the Study:

• To predict the cooling effects of large blood vessels on tissue temperature during laser irradiation.
• To analyze heat transfer between blood vessels and surrounding tissues under laser exposure.
• To validate simulation models with experimental data from tissue mimics.

Main Methods:

• Finite element-based simulation of three-dimensional conjugate heat transfer equations.
• Incorporation of a volumetric heat source term based on the Beer-Lambert law for laser heating.
• Experimental validation using tissue mimics with and without simulated blood vessels.

Main Results:

• Simulations revealed that blood flow in large vessels significantly impacts transient temperature distribution.
• Surface temperature maps showed differences between vascularized tissues and bare tissue.
• Heating efficiency is influenced by vascular network characteristics, vessel size, flow rate, and laser parameters.

Conclusions:

• Blood flow through large vessels near photothermally heated tissue can lead to inefficient target heating.
• Accurate modeling of vascular effects is essential for successful laser-assisted thermal therapies.
• Further research can optimize laser parameters and treatment strategies considering vascular networks.