Author: Wu Benjie 1//Wang Xiubi 2//Wang Zijun 3//Liu Jianben 4
Dept Biophysics, Beijing Medical University, Beijing 100083, China  //Institute of Somatic Science, Beijing 100094, China  //Nanjing University, Nanjing 210008, China  //Institute of Geophysics, State Bureau of Seismology, Beijing 100081, China 
Conference/Journal: 2nd World Conf Acad Exch Med Qigong
Date published: 1993
Other: Pages: 75 , Word Count: 345
In the previous article we finished a dynamic study of qigong (QG) magnetic signals (MS) by a flux-gate magnetometer in a magnetically shielded room. Under the QG state, MS was <2 Hz in frequency and several nT in amplitude (T=Tesla, the unit of magnetic flux density, In T= lO-9T). In order to deeply understand the MS dynamic properties, human weak MS was investigated by a superconducting biomagnetometer. In comparison with the flux-gate magnetometer. the superconducting biomagnetometer is wider in frequency response (DC to lO KHz only DC to lO Hz in the flux-gate magnetometer) and higher in sensitivity. Through a frequency-power spectrum analysis by a computer, the MS changes under QG state can be analyzed quantitatively.
20 persons (38 tests) were selected as subjects, and divided into two groups. (1) The control group consisting of 3 persons did not practice qigong, 46.3 years old in average; (2) The qigong group (practicing for 1-20 years) consisted of 17 persons (31 tests), 48.3 years old in average.
The subjects took off all magnetic things; then came into a magnetically shielded room, and the acupoint to be measured aiming at the probe. The distance between the probe and Laogong (P8) is about 6 cm, and that between the probe and head acupoints is about 4. 5 cm. The MS dynamic changes were recorded continuously before. during and after QG state (3
MS was measured by a superconducting biomagnetometer, Model M-601. and recorded by a tape recorder, Model MR-30C (2. 4 cm/sec in tape velocity). The frequency-power spectra were analyzed by a signal processor, Model 7T17-S. In this paper the power changes were all of relative values.
The experimental results indicate that under the QG state three kinds of MS (<l Hz, 3 Hz and 2 KHz) are measured from different acupoints Laogong (P8), Baihui Du 20), Yintang (Extra); there are three kinds of MS changes in intensity: increasing, decreasing, and no change; and there is a good repetition of the change patterns and signal frequency of MS. Two novel phenomena were found, i. e., decrease of power and the change of frequency spectrum in MS during the QG.