目前针刺麻醉的临床实践和理论研究工作中

普遍采用针麻仪代替手法运针

作为维持穴位针感的刺激方法。临床实践中人们普遍地认为选用的电针刺激参数与针麻效果关系密切.因而合理地掌握刺激量是提高针麻效果的一个重要条件。这就要求我们对电针的刺激参数进行筛选

以求得针麻适宜的刺激条件.为此目的我们在北京大学高等数学教研组和生物系的指导下设计了如下一组动物实验来观察针麻仪(电针)主要的几种刺激参数对针麻效果的影响.From the neurophysiologic point of view

the stimulating effects of ele- ctric needle in acupuncture anesthesia is a kind of induced effect causing transmission of nerve impulse.In the instrument design

it is not necessary to provide stronger power output as for electric therapy or electric an- esthesia.Since 1966

we have successfully applied the intermittent oscillator as the main oscillating circuit in the operations under acupuncture anesth- esia.For more than 10 years

the fundamental circuit design was mostly used in various types of acupuncture anesthesia apparatus. Through the clinical and experimental observations

it was found that there were 4 characteristics in the pulse produced: 1.High pulse amplitude

usually reaching 1-200 V(peak-to-peak pulse amplitude). 2.Small pulse

width range within 0.2-0.5ms. 3.Accumulating volume of DC component is small

or even negligible

so that there are no burns and electrolysis produced. 4.High ouput impedance. In order to observe the relationship between the stimulating parameters of electric needle and the effects of acupuncture anesthesia

and to further improve the stimulating parameters of electric needle

we simulated the acute trauma of surgical abdominal exploration as the pain stimulation

and took the stuggle reactions in experimental celiotomy of animal models as the pain index

through the quantitative calculation of the pain struggle reactions of the rabbit during the course of operation under acupuncture anesthesia. We screened the parameters of the strength

wave width

duty ratio and frequency of electric needle.The results obtained were follows. 1.The main factor influencing the effects of acupuncture anesthesia in the strength

wave width

duty ratio and frequency is the strength of stimula- tion. 2.The best stimulating strength chosen in this experiment is identical with the standard of stimulations selected in the clinical operations under acupuncture anesthesia

e.g.the largest stimulation strength which could be tolerated by the patient. 3.The relationship between the variation of the frequency within 10-100 kHz and the effects of acupuncture anesthesia was not correlated markedly

Thus

the determining factors of frequency

e.g.

the combination of wave width and duty ratio should be further studied in the future.