Papers Published

1. Altman, K.W. and Plonsey, R., Analysis of excitable cell activation: relative effects of external electrical stimuli, Med. Biol. Eng. Comput. (UK), vol. 28 no. 6 (1990), pp. 574 - 80 .
   (last updated on 2007/04/16)

   Abstract:
   In the functional electrical stimulation of nerve an expression defined as the `activating function' has been introduced to evaluate the propensity for a particular fibre to excite. This approach to determine resulting activation is only an approximation as it neglects the presence of the fibres on the applied field, in contrast to activity determined from a rigorous solution to the core conductor/excitable membrane equations. An alternative approach to determining relative excitability based on the induced transmembrane potential is presented, thereby allowing for current redistribution via the space constant of the target fibre. The authors critically examine the approximations made with activating functions, and conclude that as currently formulated the activating function has limitations in predicting relative excitability under a number of important conditions. In contrast, it is the induced (passive) transmembrane potential that provides a quantitatively reliable estimate of the tendency for fibres to excite

   Keywords:
   bioelectric phenomena;cellular biophysics;muscle;neurophysiology;