1920

American engineer William Bovie invents electrosurgical generator (the Bovie) in which level of energy in tissues could be much better regulated by increasing frequency of alternating current and supplying it in pulses (i.e., as modulated alternating current), enabling the effect of the heat applied to tissue at tip of scalpel to vary from coagulation to cutting. The Bovie was introduced into surgery by Harvey Cushing in 1926 (Van de Laar, ch 28).