Time-dependent interfacial charging effects of electrical fields applied to biological systems

Abstract

An important aspect of the interaction of a biological system with an externally produced electric field is that of charge separation and interfacial charging. This aspect has been ignored in some recent experimental and theoretical work. In the case of small regions of lower electrical resistivity imbedded in a higher resistivity medium, charge separation across the lower resistivity regions will result in charging of the interfaces between the lower and higher resistivity regions. The field produced by this charge separation will significantly affect the shape and the magnitude of the net electric field pulse within the lower resistivity regions. In particular, the field experienced by bone cells will be quite different from the externally produced field. The shape as well as the magnitude of the net electric field experienced by the cells depends on the time rate of change of the rising and falling phases of the externally produced electric field pulse.