Kate Rosenbluth

Can a simple wristband replace invasive brain surgery? That’s the audacious idea behind Cala Health, a medical-device company that makes wearable bioelectronics for the 7 million Americans who suffer from essential tremors. Founder Kate Rosenbluth, a 38-year-old neuroscientist and engineer, designed an FDA-cleared watchlike device that stimulates the nerves in its wearer’s wrist, easing hand tremors—and offering an alternative to the surgeries that can be particularly risky for older people suffering from neurological disorders. Rosenbluth, now Cala’s chief scientific officer, started her company in 2014 at Stanford University before spinning it out, and has since raised $80 million in venture funding.