Heterogeneity of skin oxygen density distribution: relation to location of acupuncture points

To investigate possible functions of acupuncture, oxygen (O(2)) levels were measured at two different acupuncture points (APs) [Hegu and Laogong] and at the corresponding non-APs (3-5 cm away from the APs) in real time using a high sensitive electrochemical O(2) microsensor. The sensor had a small planar sensing platinum disk (diameter = 25 microm) and therefore was able to monitor the O(2) levels at the localized APs. Significantly higher O(2) levels (p < 0.05) were observed at both APs (n = 5, without exceptions) in comparison with the non-APs. Sufficient sensor sensitivity to distinguish the O(2) level differences between APs and non-APs was achieved. This research provides useful information on possible functions of APs and meridians.