Most of what you know about concussions is wrong, including the belief that there is no helmet design that can truly protect the brain, says former college football player and Stanford bioengineer David Camarillo. His lab is determined to build a better, smarter helmet, based on their new discoveries about what actually causes concussions. And he plans to accomplish this before his 2-year-old daughter starts riding her bike on the road. In his talk at TedxStanford, he explains how.