A Mouthguard that Detects Head Injuries
From: Wireless Design & Development - 10/27/2014

Force Impact Technologies has developed a mouthguard for athletes that
provides a comprehensive approach to identify, document, and respond to
potential head injuries in sporting activities. The FITGuard measures linear
and angular acceleration, and then processes those inputs through a
proprietary algorithm to determine the severity of an impact. It can be
programmed with the user's age, gender, and weight, to customize the risk
thresholds for the wearer. If certain thresholds are breached, LEDs embedded
in the front of the mouthguard illuminate to indicate when a user should be
removed from play. The LEDs have a blue indication for a "medium" force
impact and a red indication for a "severe" force impact, and they provide an
instant, visual, indication to coaches and officials, that a player should be
removed from the field. The FITGuard also uses Bluetooth technology to
transmit impact data to a FIT smartphone application. After a severe impact,
the FIT application prompts individuals to perform an Acute Concussion
Evaluation (ACE) for the player that has been removed for play.

Source:
http://www.wirelessdesignmag.com/videos/2014/10/hotspot-episode-86-mouthguard-detects-head-injuries

Links:
Force Impact Technologies (with video 3:14)
https://www.fitguard.me/

Mouthguard That Monitors Impact of Concussions Coming to Market
http://www.forbes.com/sites/davidlariviere/2014/10/17/mouthguard-that-monitors-impact-of-concussions-coming-to-market/