title: Ultrashort microwave signals: a didactic discussion.
abstract: As a consequence of the variation with frequency of the attenuation and phase velocity of electromagnetic waves in tissue, the shape (variation of the electric field with time) of short electromagnetic pulses incident on tissue changes with depth of penetration. We show that a conjecture that such well-known and long understood changes in pulse shape may generate harmful biological effects is not credible. We also consider the suggestion that such pulses may be useful in medical imaging and the mapping of the electrical properties of complex tissues and show that such use is impracticably difficult for fundamental reasons.
mesh_terms: D055590:Electromagnetic Phenomena; D008872:Microwaves / Q000009:adverse effects*; D008954:Models, Biological; D014867:Water
chemical_list: D014867:Water