1 Introduction
The effect of electricity on the human body is related to the waveshape of the applied voltage, its points of application, and the subsequent current in the body [1]–[4]. While it is the current delivered that primarily determines the effect, usually only the applied voltage is known so that the current must be calculated by appropriate impedance of the human body. However the impedances of the human body depend on a number of factors. Two impedances are generally used to describe the pathway impedance of the human body: the internal impedance of the body and the impedance of the skin at a contact point [5]. These two combine vectorially to produce the total pathway impedance. Figure 1 presents the equivalent circuit appropriate for shock studies [6]. The shock can be applied to any combination of extremities or points on the torso, and as shown in the figure, the shock current through the body is a function of the source voltage and source impedance as well as body impedance. In some cases, it may be acceptable to model the body as a single lumped-element impedance. But the ranges of situations for which this model will provide valid results are quite narrow. Incorporating all of the known effects in a circuit model is extremely challenging. Much work on the subject has been done. Equivalent circuit shock scenario conditions