Journal of medical engineering & technology
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This paper presents a robust finite element model (FEM) with multiple-layers of varying properties for investigation of burn effects on human skin during a burning process resulting from exposure of skin surface to a contact heat source and a hot moving fluid. Henriques' theory of skin burns is used in conjunction with two-dimensional Pennes bioheat transfer equation for determining the spatial and temporal extent of burn injury. The model developed is a two-dimensional axisymmetric model in cylindrical coordinates. ⋯ The mesh employed in this model consists of a high density of nodes and elements in which a thorough mesh convergence study was done. A comparison of the transient temperature field computed by this model against Diller's results using the FE technique with a comparatively coarse mesh of 125 elements and experimental data by Orgill et al. has been done in the present study. It concluded that improved accurate solutions have been performed using the robust model developed due to the achievement of a mesh-independent solution.
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Compression therapy is frequently used to prevent hypertrophy of post-burn scars. This pilot study was performed in 6 patients to assess non-invasive changes induced in the tensile strength of the skin before any clinical improvement can be perceived. Assessments were performed using a computerized suction device delivering three 5 s cycles of 500 mbar depression. ⋯ Comparisons were made between the intact skin, the ungrafted and grafted post-burn scars and the graft donor sites. Data show that garment compression therapy alters the tensile strength in the skin of all test sites. The most reliable variations consist of an increase in both the extensibility and elasticity of the tissues submitted to traction.
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Moving and rotating platforms are often used in experimental investigations of human balance and postural control. These devices are not well suited for testing elderly and neurologically impaired individuals, because of inherent risk of injury to the experimental subject due to a potential fall. ⋯ The accuracy and repeatability of the perturbations elicited in eight different directions was evaluated. The results, showing a high degree of correlation between the trajectories in both degrees of freedom of the apparatus, demonstrate that accurate and repeatable perturbations can be imposed on the subjects tested.