Electric and magnetic phenomena are associated with a special form of manifestation of matter - electric and magnetic fields and their interaction. These fields are generally so interdependent that it is customary to refer to the electromagnetic field.
Electromagnetic phenomena have three directions of medical and biological applications. The first of them is understanding the electrical processes taking place in the body, as well as studying electrical and magnetic properties of biological media, for instance, the physics underlying electrocardiography, magnetobiology, rheography, electric conductivity of biological tissues and fluids, etc. The second direction is related to understanding the mechanism of electromagnetic fields impact on the body. This impact can serve as therapeutic, industrial, or climatic factor. The third direction is instrumental. Electrodynamics is the theoretical basis of electronics and, in particular, medical electronics. In this respect, electrodynamics is more important for medicine because many non-electrical parameters of biological systems, such as temperature, are measured by conversion into an electric signal to facilitate measurement and recording.
Chapter 14 Electric field
An electric field is a kind of matter by means of which a force action is carried out on electric charges located in this field. The characteristics of the electric field generated by biological structures are a source of information about the state of the body.
§ 14.1. INTENSITY AND POTENTIAL AS CHARACTERISTICS OF ELECTRIC FIELD
The force characteristic of an electric field is its intensity equal to the ratio of the force acting at a given point of the field on a point charge, to the value of the charge: