Numerical simulations of volume conduction can be used to analyze the process of energy transfer and explore the effects of some physical factors on energy transfer efficiency. We analyzed the 3D quasi-static electric field by the finite element method, and developed A 3D coupled field-circuit model of volume conduction basing on the coupling between the circuit and the electric field. The model includes a circuit simulation of the volume conduction to provide direct theoretical guidance for energy transfer optimization design. A field-circuit coupling model with circular cylinder electrodes was established on the platform of the software FEM3.5. Based on this, the effects of electrode cross section area, electrode distance and circuit parameters on the performance of volume conduction system were obtained, which provided a basis for optimized design of energy transfer efficiency.
Algorithms ; Electric Conductivity ; Electrodes ; Electromagnetic Fields ; Equipment Design ; Finite Element Analysis ; Models, Theoretical ; Prostheses and Implants ; Skin Physiological Phenomena

In order to study the effect of excessive iodine on immune function of lymphocytes and the role of selenium supplementation with excessive iodine intake, the changes of T lymphocyte number, ratio of subsets, activity of natural killer (NK) cells and lymphocytes proliferation response were investigated. 150 female BALB/C mice were randomly divided into 5 groups in terms of their body weight (n=30 in each group), and 10 of each group were taken as one batch for test. Mice in the 5 groups were orally administrated with iodine 0 (group Ⅰ ), 1500 (group Ⅱ), 3000 (group Ⅲ),6000 μg/L (group Ⅳ), iodine 6000 μg/L plus selenium 0.3 mg/L (group Ⅴ) respectively for 30 days.Lymphocyte proliferation response, CD4+/CD8+, Th1/Th2 and the activity of NK cells were measured. CD4+/CD8+ was significantly lower, while lymphocyte proliferation response stronger, and Th1/Th2 and the activity of NK cells significantly higher in group Ⅳ than in group Ⅰ (P＜0.01).There was no significant difference in all indexes between group Ⅴ and group Ⅰ (P＞0.05). It was suggested that excessive iodine as exogenous chemical materials can induce disorders of T lymphocyte immune function in mice. 0.3 mg/L selenium supplementation can protect mice against toxicity induced by 6000 μg/L iodine.