Living things maintain small electric fields to (1) enhance certain
chemical reactions, (2) promote communication of states with in a cell,
(3) communicate between cells (of which the nervous system is a specialized
example), and perhaps other uses.  These electric fields change with location
and time in a large organism.  Special photographic techniques such as applying
external fields in Kirillian photography interact with these fields or the resistances
caused by these fields to make interesting pictures. Perhaps such pictures will
be diagonistic of disease problems in organisms when better understood. Perhaps not.

Studying the overall electric activity of biological systems is several hundred
years old, but not a popular activity.  Perhaps, except in the case of a few
tissues like nerves and the electric senses of fishes, it is hard to reduce the
investigation into small pieces that can be clearly analyzed.  There are some
hints that manipulating electric fields is a useful therapy such as speeding
the healing of broken bones, but not understood why.