As a person who has received a concussion, I'm going bananas. Its a brand new idea that is being real-life tested on my old high school's (St. Xavier High School) hockey and football team. It's a collar placed on ones neck that increases the blood pressure in the skull, which acts like bubblerap around the brain. Here's an article on it. Read it. It's insane.
The product I believe is still in R&D still though. I'm buying one the second they sell them.