Experimental and Numerical Study on the Temperature Elevation in Tissue during Moxibustion Therapy.

Moxibustion is a thermal therapy in traditional Chinese medicine that relies on the heat from burning moxa to be transferred beneath the skin surface. Although moxibustion has long been in widespread practice, the mechanism of heat transfer modality and temperature distribution during this treatment is not yet well understood. The current paper presents the first examination by magnetic resonance imaging (MRI) of the three-dimensional temperature elevation during moxibustion treatment. A mathematical model for the prediction of temperature elevation during moxibustion therapy has been constructed and compared with the experimental data. Good agreement between the measured temperature and the results of numerical calculations has been found. Tissue up to 3 cm deep can be heated during the treatment. It was revealed that both heat conduction and radiation heat transfer play important roles during the treatment. The results presented in the current paper can be used for understanding the mechanisms of Chinese medicine and developing useful guidelines for Chinese medicine doctors.

Heat transfer involved in a warm (moxa-heated) needle treatment.

A numerical study was performed to reveal the temperature distributions in tissues around the GB38 acupoint during the warm (moxa-heated) needle treatment (WNT). The proposed WNT model involves a needle, needle handle and the calf section around the GB38 acupoint. For validating the numerical results, measurement using the calibrated infrared (IR) camera was also conducted. Our aim was to calculate the skin surface temperature and the temperatures under warm needle at different depths beneath the skin. From the temperature profile along the centerline of the acupuncture needle, the temperature is seen to decrease rapidly from the burning moxa section (200 degrees C) to the skin surface (36 degrees C). The temperature near the needle (36 degrees C) is only 1 degrees C higher than those predicted at other places (approximately 35 degrees C). This phenomenon explains why this treatment practice is called the warm needle rather than the hot needle treatment.