Biophysical injury mechanisms in electrical shock trauma

Electrical shock trauma tends to produce a very complex pattern of injury, mainly because of the multiple modes of frequency-dependent tissue-field in teractions. Historically, Joule heating was thought to be the only cause of electrical injuries to tissue by commercial-frequency electrical shocks. I n the last 15 years, biomedical engineering research has improved the under standing of the underlying biophysical injury mechanisms. Besides thermal b ums secondary to Joule heating, permeabilization of cell membranes and dire ct electroconformational denaturation of macromolecules such as proteins ha ve also been identified as tissue-damage mechanisms. This review summarizes the physics of tissue injury caused by contact with commercial-frequency p ower lines, as well as exposure to lightning and radio frequency (RF), micr owave, and ionizing radiation. In addition, we describe the anatomic patter ns of the resultant tissue injury from these modes of electromagnetic expos ures.