Doctors would normally fix a tremor like Roger Frisch’s by keeping him awake during surgery, inserting electrodes deep into his brain until the trembling appeared to stop. But for a concert violinist, even the slightest remaining tremor would mean the end of the career, so in 2009 doctors at the Mayo Clinic designed a special violin for Frisch to play through his surgery. An accelerometer at the tip of the bow measured Frisch’s trembling, allowing doctors to fine-tune the placement of their electrodes.

The surgery worked, and the Mayo Clinic has released a follow-up interview with Frisch and his doctors. By turning on a battery and sending a current into his brain, Frisch can now switch off his tremors whenever he needs to play.