Abstract
For biological or cellular experiments using electromagnetic fields, it is essential that the parameters defining the field be carefully specified if the results are to be meaningful and are to be compared with the same experiment conducted in a different laboratory. The interaction of living systems with electric and magnetic fields can come only through forces exerted on the charges on the system. If the charges are stationary, the only origin of the force is the electric field. This electric field may be established by charge distributions, as in “capacitive plate” experiments, or by time-varying magnetic fields.
A geometry commonly used to produce time-varying magnetic fields consists of a pair of coaxial coils, each of equal radius and separated by a distance often equal to the radius. The electric field induced by a varying current in such a pair of coils varies both in space and in time. The electric field strength is zero on the axis of symmetry, and increases to a maximum near the radius of the coils. The strength is proportional to the time rate of change of the current in the coil, which depends not only on the amplitude and shape of the voltage pulse applied to the coil but also on the resistance and inductance of the coil.
The purpose of this article is to describe how these important physical parameters may be determined for both geometries.
Similar content being viewed by others
References
Basset, C. and L. Andrew. Pulsing electromagnetic fields: a new method to modify cell behavior in calcified and non-calcified tissues.Calcif. Tissue Int. 34:1–8, 1982.
Becker, R.O. Electrical osteogenesis — pro and con.Calcif. Tissue Res. 26:93–97, 1978.
Luther, P.W. and H.B. Peng. Changes in cell shape and actin distribution induced by constant electric fields.Nature 303:61–64, 1983.
Cooper, M.S. and R.E. Keller, Perpendicular orientation and directional migration of amphibian neural crest cells in dc electric fields.Proc. Natl. Acad. Sci. 81:160–164, 1984.
Erickson, C.A. and R. Nuccitelli. Embryonic fibroblast motility and orientation can be influenced by physiological electric fields.J. Cell. Biol. 98:296–307, 1984.
Scott, W.T.,The Physics of Electricity and Magnetism. New York: John Wiley and Sons, 1959, p. 228.
Korenstein, R., D. Somjen, H.K. Fischler and I. Binderman. Capacitative pulsed electric stimulation of bone cells.Biochim. Biophys. Acta 803:302–307, 1984.
Rodan, G.A., L.A. Bourret and Louis A. Norton. DNA systems in cartilage cells is stimulated by oscillating electric fields.Science 199:690, 1978.
Dierickx, M., M. Hisenkamp, L. Rybowski and F. Burny. Electromagnetic and electric field configurations produced by two coils.Acta Orthop. Scand. 53 (suppl 196):19, 1982.
Nuccitelli, R. Transcellular ion currents: signals and effectors of cell polarity.Mol. Cell Biol. 2:451–481, 1983.
System 204, Electro-Biology Inc; 277 Fairfield Road, Fairfield, NJ 07006.
Jackson, J.D.Classical Electrodynamics. New York: John Wiley and Sons, 1975.
Smythe, W.R.Static and Dynamic Electricity.3rd ed. New York: McGraw-Hill, 1968, p. 291.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Parkinson, W.C. Electromagnetic fields in biological studies. Ann Biomed Eng 13, 491–514 (1985). https://doi.org/10.1007/BF02584254
Issue Date:
DOI: https://doi.org/10.1007/BF02584254