The Role of Heat in the Production of Ultrasonic Focal Lesions

Abstract

A method was evolved to calculate the temperature cycles at the focus center of an intermittent beam of high‐frequency mechanical waves. The computed temperatures were checked in brain tissue, using microthermocouples, for doses just sufficient to damage tissue at the focus center. Similar temperature cycles were produced in brain tissue, in the absence of mechanical wave energy, by applying pulses of electric current to embedded resistance wires in order to find out how far the tissue alteration could be ascribed to heating.