Proceedings in the study of transcutaneous CO2 emission in acupuncture and meridians

Abstract

AIM: To observe the features of acupuncture and meridians by measuring transcutaneous CO₂ emission (TCE).

METHODS: A high sensitive CO₂ analyzer was used to measure the TCE. TCE on 31 levels of meridian points and control points along stomach meridian on leg, large intestine meridian on arm (30) and pericardium meridian on whole course (22) were measured. During needling Jianshi (P5), the changes of TCE on distal side, proximal side and outside of the pericardium meridian were measured in 20 healthy people. TCE on 24 source points of twelve meridians in 30 healthy people and some related source points in patients were measured. TCE on source points, connecting points and sea points in 20 healthy cases were measured. Acupoints and reference points (no opening time) were measured on the opening time and non opening time according to day prescription in midnight-noon Ebb-flow law in 15 healthy people. The relation between TCE and skin temperature and TCE change after muscular exercise were also studied.

RESULTS: The mean TCE on the meridians was significantly higher (P < 0.05, same below) than control points. About 40% levers showed significantly higher TCE on meridian points than on control points among which two third were acupoints, mostly were Jing point and He point where Qi were rich. TCE increased significantly in both the meridian and control points during the needling, while moderately increased on the meridian line, particularly the proximal direction. The correlative coefficient (CC) between the points along pericardium meridian was 0.65 between acupoints which was significantly higher than 0.56 between non acupoints. For the 24 source points, CC between the points on same meridian, exterior meridian and internal meridian, same named hand and foot meridian and normal meridian were 0.81, 0.65, 0.51 and 0.38 respectively with significant difference. The mean CC between connecting points was 0.67, significantly higher than 0.61 between source points and 0.56 between sea points. The imbalance degree (ID) between left and right meridian points, Yin and Yang meridian points and same named hand and foot meridian points were 13.6%, 17.6% and 19.6% respectively, while ID was 30.2% in patients, significantly higher than in healthy people. For midnight-noon law, TCE relative to the reference points on the opening time was 1.25 which was significantly higher than 1.08 before the opening time. The certain correlation (r = 0.19, P < 0.01）between TCE and skin temperature and the increase after muscular exercise illustrate that TCE can indicate the energy metabolism level on meridians.

CONCLUSION: TCE is an ideal index to show the feature of acupuncture and meridians and may widely be used in the study and practice of traditional Chinese medicine.

Key Words: Acupuncture; Meridians; Transcutaneous CO₂ emission; Traditional Chinese medicine