First Focused Ultrasound Device

William Fry, a physicist veteran of naval sonar research, and his brother, Francis Fry, began civilian research at the Bioacoustic Research Laboratory (University of Illinois) and a research team developed a focused ultrasound device that mechanically aligned four focused ultrasound generators to produce a pinpoint lesion without damage to the surrounding tissue.

W. J. Fry, J. W. Barnard, F. J. Fry, R. F. Krumins, and J. F. Brennan: Science 122 (1955) 517.