An iPad app tests athletes for concussions (a Cleveland Clinic video). The players perform a series of balance, memory, vision, and reaction time experiments to obtain a baseline reading. If they receive a blow to the head during a game or practice, these tests can be redone to determine when it is safe for the athlete to return to action.

References:

Concussion Center - Cleveland Clinic.
Cleveland Clinic Treats Concussions With iPad App. Fox News.

Source:
http://feeds.feedburner.com/CasesBlog