Department of Physics, Surface Physics Laboratory (State Key Laboratory), and Synchrotron Radiation Research Center of Fudan University, Shanghai 200433, People's Republic of China. Shanghai Research Center of Acupuncture and Meridian, Pudong, Shanghai 201203, People's Republic of China.
We used synchrotron x-ray fluorescence analysis to probe the distribution of four chemical elements in and around acupuncture points, two located in the forearm and two in the lower leg. Three of the four acupuncture points showed significantly elevated concentrations of elements Ca, Fe, Cu and Zn in relation to levels in the surrounding tissue, with similar elevation ratios for Cu and Fe. The mapped distribution of these elements implies that each acupuncture point seems to be elliptical with the long axis along the meridian.