Numerical Simulation of Temperature Distribution during Mild Moxibustion.

Mild moxibustion is a treatment approach belonging to moxa-hanging moxibustion. The burning end of the moxa stick is kept at a fixed distance from the moxibustion skin, aiming to make the patient feel warm without burning pain. The appropriate temperature distribution is critical for the mild moxibustion treatment. The purpose of this paper is to improve the efficacy of mild moxibustion on human tissues. By combining the radiative and conductive models with surface-to-surface heat transfer, biological heat transfer simulations are realized based on biological tissues in particular media. A finite element model of mild moxibustion was established to obtain the characteristics of skin tissue temperature distribution under various conditions. The model considers multiple factors, such as the moxa-burning temperature, the stick-to-skin distance, the moxa stick sizes, and the ambient temperature. The results show that the temperature distribution under various conditions is centered at the moxibustion point and the temperature decreases in the surrounding direction. The higher the moxa-burning temperature, the higher the skin surface temperature and the worse the stability in heating. The stick-to-skin distance is inversely proportional to the skin surface temperature. The moxa stick diameter is proportional to the skin surface temperature. The longer the moxibustion time, the higher the skin surface temperature. And the temperature change gradually flattened in the late stage of mild moxibustion. Finally, a set of moxibustion conditions with optimal temperature distribution was obtained by comparing the data of all groups.