When a surgeon performs an operation to remove gallstones, one of the most important things is to get them all out. If he leaves any behind, it may mean another operation.
Dr. Charles K. Kirby* of the University of Pennsylvania School of Medicine recently had an idea for making sure. He put Researcher Edward G. Thurston of Pennsylvania State College to work on a gadget. Result of their collaboration is a surgeon-alarm for gallstones: a tiny quartz crystal enclosed in silver at the end of a slender, hollow silver probe, and attached to an amplifier. The quartz acts like a phonograph pickup;...