Incorporating an immersed boundary method to study thermal effects of vascular systems during tissue cryo-freezing.
In this paper, the three-dimensional thermal effects of a clinically-extracted vascular tissue undergoing cryo-freezing are numerically investigated. Based on the measured experimental temperature field, the numerical results of the Pennes bioheat model combined with the boundary condition-enforced immersed boundary method (IBM) agreed well with experimental data with a maximum temperature discrepancy of 2.9°C. For simulating the temperature profile of a tumor sited in a dominantly vascularized tissue, our model is able to capture with ease the thermal effects at specified junctions of the blood vessels. The vascular complexity and the ice-ball shape irregularity which cannot be easily quantified via clinical experiments are also analyzed and compared for both two-dimensional and three-dimensional settings with different vessel configurations and developments. For the three-dimensional numerical simulations, a n-furcated liver vessels model from a three-dimensional segmented volume using hole-making and subdivision methods is applied. A specific study revealed that the structure and complexity of the vascular network can markedly affect the tissue's freezing configuration with increasing ice-ball irregularity for greater blood vessel complexity.
Department of Mechanical Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117576, Singapore.
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MY
Ge
Department of Mechanical Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117576, Singapore.
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C
Shu
Department of Mechanical Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117576, Singapore.
W M
WM
Yang
Department of Mechanical Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117576, Singapore. Electronic address: mpeckje@nus.edu.sg.
K J
KJ
Chua
D000818:Animals; D001808:Blood Vessels / Q000502:physiology*; D003198:Computer Simulation; D015925:Cryopreservation; D003452:Cryosurgery / Q000009:adverse effects; D005615:Freezing / Q000009:adverse effects*; D006801:Humans; D008099:Liver / Q000098:blood supply; D009389:Neovascularization, Pathologic
Cryosurgery; Immersed boundary method; Three-dimensional model; Vascular system