The Effect of Ash Cleaning Cycles on Thermal Characteristics of Moxibustion Therapy

Objective: In clinical treatment, ash cleaning is an effective way to enhance the thermal efficiency of moxibustion. Understanding the thermal characteristics of moxibustion therapy with ash cleaning is necessary to improve its clinical efficiency. Method: Temperature distributions of burning moxa sticks were measured with an infrared camera. The moxa burning duration was set at 20min with different ash cleaning cycles (3min, 4min, 5min and no ash cleaning). A moxa stick burning model with ash cleaning was built to analyze the detailed burning discipline and compared with experimental results. In addition, temperature distributions of in-vitro tissue during moxibustion with different ash cleaning cycles were obtained using thermocouples and infrared camera. Results: Ash cleaning has effectively extended the high-temperature areas of moxa sticks and accelerated the burning velocity. Shorter ash cleaning cycle led to higher average temperature of moxa sticks. The simulated results agreed well with experimental data, which indicates that the moxa stick burning model with ash cleaning is reliable to reveal the burning discipline of moxa sticks. For in-vitro tissue, ash cleaning induced obvious temperature rise at tissue surface and slight rise in deep tissue. Compared with 3 min and 5 min, the ash cleaning cycle of 4 min is the recommended value.