Japanese Acupuncture and Moxibustion (Online)
Core temperature of a burning moxa ball and temperature when dropped from a moxa needle
NAGAOKA Satomi1),SHINBARA Hisashi1),HINO Kokoro1),TANIGUCHI Hiroshi1),SUMIYA Eiji1)
1)Department of Basic Acupuncture and Moxibustion, Meiji University of Integrative Medicine
[Objective] The aim of this study was to prevent accidental burns caused by touching a heated needle shaft or by a burning moxa ball falling from a moxa needle. Therefore, we measured the central temperature (Tc) of a burning moxa ball and the temperature at the landing point (Td) of a falling moxa ball.
[Methods] Stainless steel acupuncture needles and unrefined moxa for moxa needles were used. The moxa balls weighed 0.15 g (diameter, 13 ± 1 mm), 0.30 g (diameter, 16 ± 1 mm), and 0.60 g (diameter, 24 ± 1 mm). To measure the Tc of a moxa ball, a K-type thermocouple temperature probe was inserted into the centre of the ball. The Td of a moxa ball was measured by placing the probe 2 mm directly below the moxa ball. At each point in time, the moxa ball was forced to drop after ignition. Each measurement was repeated 5 times. The data were expressed as mean ± standard deviation.
[Results] The maximum Tc of the 0.15, 0.30, and 0.60 g moxa balls was 569 ± 26°C at 72 ± 8 s after ignition, 606 ± 26°C at 109 ± 4 s, and 624 ± 48°C at 167 ± 14 s, respectively. Tc of each ball decreased to less than 45°C at 180 ± 8 s, 225 ± 4 s, and 345 ± 13 s after ignition, respectively. When a 0.15 g moxa ball was dropped 30 s after ignition, Td measured 1, 5, and 10 s after the drop was 60 ± 6°C, 97 ± 7°C, and 137 ± 31°C, respectively. Td was less than 45 degrees 120 seconds after ignition. When a 0.30 g moxa ball was dropped 120 s after ignition, Td measured 1, 5, and 10 s after the drop was 66 ± 7°C, 96 ± 6°C, and 129 ± 2°C, respectively. Td was less than 40 degrees 120 seconds after ignition. Td was less than 45 degrees 180 seconds after ignition. When a 0.60 g moxa ball was dropped 180 s after ignition, Td measured 1, 5, and 10 s after the drop was 69 ± 3°C, 96 ± 14°C, and 135 ± 20°C, respectively. Td was less than 45 degrees 270 seconds after ignition.
[Conclusion] For 0.15, 0.30, and 0.60 g moxa balls, if Tc, that is the temperature of the probe, is considered to be the temperature of the needle shaft, burns may be caused by touching the heated shaft up until about 180, 240, and 360 s after ignition, respectively. Furthermore, there is a risk of burns caused by dropping a burning 0.15, 0.30, or 0.60 g moxa ball before 120, 180, or 270 s after ignition, respectively.