Objective To analyze the real-time effects of electroacupuncture(EA) stimulation by means of multiport network theory and measurement of the electric signals transfer coefficient

so as to explore a way for determining the running course of acupuncture meridian and for characterizing its physiological activities in the living body.Methods The body was modeled as a complex inhomogeneous 3-dimensions multi-port network

and the meridians were assumed to be "the most smoothly channels for signal transmission".Experiments were performed in 12 beheaded toads whose forelimbs and hindlimbs were divided into proportional coordinates.A concentric electrode with a conical tip was inserted into the toad leg for electrical stimulation of the local muscle

and another electrode alike was inserted into different spots of the limbs to detect the spreading signals in a 3-dimensional scanning mode.Following detecting the response electric voltage values of various spots and calculating their transfer coefficients

the spots which acquired a maximum signal value were considered to be the "acupoints".The imaginary connective lines passing the "acupoints" were regarded as the running courses of acupuncture meridians.Results A total of twelve 3-dimensional curves were detected based on the connected lines of electric signal transfer function extremum spots 2 mm beneath the skin of the ipsilateral fore-and hind-limbs of 12 spinal toads.Conclusion The present study initially validates the feasibility of electric signal transfer coefficient measurement for displaying the running course of acupuncture meridian in the toad fore-and hind-limbs.