Analysis of infrared radiation emitted by moxibustion devices made of different materials using Fourier transform infrared spectroscopy

Abstract

Moxibustion has a long history of use as a traditional Chinese medicine therapy. Infrared radiation is an important and effective factor in moxibustion. Instead of the time-consuming and laborious process of holding moxa sticks in the hand, moxibustion devices are commonly used as moxibustion methods and tools in modern times. With the publication of the international standard of moxibustion devices (ISO18666:2021, Traditional Chinese Medicine - General requirements of moxibustion devices) published, moxibustion devices of various materials are now sold in the pharmacies and online stores. However, the influence of moxibustion devices on the therapeutic effect of moxibustion has not been studied. Therefore, this research was aimed to evaluate the infrared radiation of moxibustion devices, in order to select the moxibustion device that delivered infrared radiation closest to that of moxa stick combustion. The combination of combustion stability and infrared radiation intensity showed that cardboard tubes and silicone were better materials for moxibustion devices. In the mid-far infrared wave band, the moxibustion devices made from cardboard tubes and silica gels can better maintain the thermal effect generated by moxibustion and enable it to be more easily absorbed by the human body. The infrared radiation intensity of the cardboard moxibustion devices increased rapidly and steadily and could be maintained for the longest time. In conclusion, cardboard tubes are the better material for moxibustion devices with respect to infrared radiation.

Keywords: Combustion stability; Fourier transform infrared spectroscopy; Infrared radiation intensity; Integrative medicine; Moxibustion; Principal component analysis; Traditional Chinese medicine.

Fig. 1

Experimental platform layout diagram.

Fig. 2

Appearance of four types of moxibustion devices A) Cardboard moxibustion devices, B) Silicone moxibustion devices, C) Ceramic moxibustion devices D) Wooden moxibustion devices.

Fig. 3

The FTIR spectra of the moxibustion device with paper, semi permeable membrane (SPM), cowhide and human skin.

Fig. 4

The FTIR spectra of the four types of moxibustion device with and without cowhide.

Fig. 5

Combustion stability of moxibustion devices.

Fig. 6

Infrared radiation intensity of the moxa sticks burned in moxibustion devices for different combustion times.

Fig. 7

Repetitive analysis of infrared radiation intensity of moxibustion devices at different combustion times. *vs wooden moxibustion device, #vs ceramic moxibustion device, &vs control moxa sticks without device, MD means moxibustion device.

Fig. 8

The infrared radiation intensity of FTIR at different wavebands A)1.28–25 μm, B) 1.28–2.5 μm, C) 2.5–25 μm, d)7.5–10 μm, MD means moxibustion device.

Fig. 9

PCA score plot of infrared radiation intensity of moxibustion devices at different time points A) four moxibustion devices, B) moxibustion devices made from cardboard tubes vs silica gels.

Fig. 10

PCA score plot of infrared radiation intensity of moxibustion devices at different wavebands. A) cardboard moxibustion devices vs ceramics; B) cardboard moxibustion devices vs wood; C) cardboard moxibustion devices vs silica gels.