Even the world’s steadiest surgeons can’t avoid minuscule, involuntary hand motions. Researchers at Carnegie Mellon’s Robotics Institute have developed active surgical instruments that can sense and compensate for these tremors. Tiny motion sensors on the tip of each instrument track its location, relaying the information to a computer. Software analyzes this data to distinguish intentional hand movements from the higher-frequency tremors. The computer sends a signal to piezoelectric actuators within the instrument’s handle that cancel out unwanted motion.The researchers have shown they can cut the size of surgeons’ tremors in half, says project leader Cameron Riviere. These auto-steadying instruments should be cheaper and simpler to master than alternatives such as an electronically manipulated robotic arm. Within a year, the University of Southern California’s Retina Institute will test the devices in real surgery; several companies have expressed interest in commercializing the technology.