Heterogeneity of Skin Oxygen Density Distribution: Relation to Location of Acupuncture Points

(A) Schematic representation of the positioning of an oxygen (O₂) microsensor for the measurement of O₂ levels over hand skin. (B) The positions of analyzed points on the hand skin: LI 4 (▴) and the corresponding non-acupuncture point (▵), PC 8 (●) and the corresponding non-acupuncture point (○). PBS = phosphate-buffered saline.

Representative measured partial oxygen pressures as a function of time when the sensor was positioned over (A) LI 4 and the corresponding non-acupuncture point (AP) and (B) PC8 and the corresponding non-APs. Gray-colored regions represent the measurements made over non-APs.

Normalized oxygen levels measured at (A) LI 4 and (B) PC 8 points for five subjects. Dashed lines represent normalized oxygen levels measured at the corresponding non-acupuncture points.