Objective: To study the influence caused by strong magnetic pulse stimulation on human pain threshold.

Methods: 2 cone-shaped coils of l0cm in diameter were put on the surface of the subject's body. The 2 bases of the coils formed a certain angle. When this equipment was electrified, a strong magnetic field was generated. The interval between 2 pulses was fixed at 5s. The stimulation output was fixed at l .25T. 2 experiments were done: (1) The influence of strong magnetic pulse stimulation on pain threshold of healthy people and patients with broken fibrous ring of lumber intervertebral disk; subjects took supine position for 15mins and then accepted test of pain threshold on 3 parts at 25°C. Three parts tested: Left forearm; Area on the left side of the second vertebra; Posterior area of the left leg. Three tests with each interval of 5mins were done. Then the pain- inducing method of K+ infiltration was employed. The area of the electrode was 0.5 X 0.5cm.The data were demonstrated in terms of the value of gradually intensified direct current. The current was cut when the subject felt a pain. Then the final value was recorded. The instrument of magnetic coils BT5672 made in Japan was put on the subject's Yaoyangguan (GV3). The electricity value was fixed at 800A. Stimulation was given once every 5 seconds, 20 times in total. The pain threshold was tested at such moments following the stimulation: immediately, 5min, l0min, 20min, 30min, 40min, 50min, 60min; (2) Comparison between acupuncture and strong magnetic pulse stimulation in terms of the influence on pain threshold of patients with broken fibrous ring of lumber intervertebral disk; The subjects were divided into magnetic pulse stimulation group and acupuncture group. The 2 groups were experimented under the sarne conditions. In acupuncture group, Shenshu (BL23), Ciliao (BL32). Weizhong (BL40), Chengshan (BL57), Zusanli (ST36) were selected. Even reinforcing & reducing manipulation was performed. The needles were twirled once every 5min and withdrawn 30min later. The observation was done for 60min in total.

Results: (1) Strong magnetic pulse stimulation caused a stable and long-time rise of pain threshold in healthy people. The sharpest rise occurred on the upper limb, with the highest value being l.05 times of that before stimulation, at 60 min. In patients, the most remarkable rise of pain threshold occurred in lumbar region, giving the highest value 2.6 times of that before stimulation, at 30min; (2) Acupuncture caused a mild rise of pain threshold. By comparison, strong magnetic pulse stimulation generated a sharp rise. At 30min, the value of pain threshold caused by magnetic pulse stimulation was remarkably higher than that caused by acupuncture.

Conclusion: Strong magnetic pulse stimulation can raise pain threshold. Its effect is better than that of acupuncture.

　　Gao Ling, Zhou Yulin, Liu Hongen & Feng Ziqian.
　　Changchun College of TCM, Jilin 130021, China.