With $10 million at stake, scientists compete to build a ‘Star Trek'-style medical tricorder

Fifty years ago, the "Star Trek" series envisioned a handheld medical device that could diagnose every condition with just a swipe over the patient's body. The tricorder was just one of the show's futuristic gadgets - but it's one that real-world scientists seized upon. And some have spent years working to bring it to existence, under…