Narrow Results

Computational simulation of the thermal transport phenomena in the human body has recently aroused a great deal of interest among researchers, because it can be applied in different areas such as medicine, rehabilitation, space suits, and others. In this study, we developed a coupling model to analyze the temperature distribution of the human middle finger. Firstly, a one-dimensional thermo-fluid model of blood circulation in the human upper limb is constructed. Secondly, a two-dimensional thermal model of the human finger, which consists of skin, tendon, bone, main arteries, and veins is developed. The two models are further coupled weakly through data transfer. The blood pressure, blood flow rate, and blood temperature at different vessel sites and the tissue temperature are thus obtained. The effect of viscosity on the finger skin temperature was also investigated. Simultaneously, the thermograms of the human hand were also obtained using thermograpy under the resting condition and after jogging, to observe the variation in the blood circulation. The temperature at different points was extracted from the thermograms. It is observed that there is a periodic variation in skin temperature near the blood vessels after jogging. It is expected that this coupling model will be applicable to hyperthermia, drug delivery, and sports training.

A mathematical and numerical study is presented for simulating temperature distribution in a two-dimensional tissue medium using Pennes bioheat transfer equation, when the tissue is subjected to ultrasonic waves. Following nondimensionalization of the governing partial differential equation, a novel variational iteration method (VIM) solution is developed. This excellent technique introduced by He [Variational iteration method — a kind of non-linear analytical technique: Some examples, Int J Non-Linear Mech.34:699–708, 1999] employs Lagrange multipliers which can be identified optimally via variational theory. The space and time distributions of temperature are studied and solutions visualized via Mathematica. The influence of thermal conductivity and relaxation time are also examined. Excellent stability and convergence characteristics of VIM are demonstrated. Validation is achieved with a Chebyschev spectral collocation method (CSCM). The present work demonstrates the excellent potential of this powerful semi-numerical method in nonlinear biological heat transfer and furthermore provides an alternative strategy to conventional finite element and finite difference computational simulations. The model finds applications in minimally-invasive spinal laser treatments, glaucoma therapy in ophthalmology and thermoradiotherapy for malignant tumors.