Masters of the martial art of Tae Kwon Do have gotten so lightning-quick that even a team of four judges placed around a competition ring can have a hard time keeping up. That is where a human-computer interface invented by Jin Y. Song, a veteran Silicon Valley–based electrical engineer and Tae Kwon Do black belt, comes in. The invention relies on three different types of sensors embedded in traditional Tae Kwon Do head and torso protectors, plus modern wireless technology and magnets to accurately track and score blows to the body and head delivered in the blink of an eye. “If someone pushes you really hard, this thing will not pick it up,” says Song, referring to the pressure sensor located near the torso. “There has to be a quick impact.”

Impacts to the head are picked up by the same acceleration detectors found in car air bags. Magnets embedded in foot protectors alert a third class of sensors that impact from a foot is imminent, which helps the sensors distinguish valid hits from incidental contact with other parts of the body. (A BlackBerry uses the same magnet to turn off when slid into a case.) Finally, wireless transmitters convey signals to a computer sitting on top of a nearby scorer’s table, where officials keep track of who is winning the match.

Song received final approval for his patent in February. The device has already been used successfully to score a handful of martial arts competitions, including the World University Taekwondo Championship in Spain and a major martial arts competition in Beijing. The International Olympics Committee is also currently considering using the device to score the 2012 Games. Song is now in the process of adapting the technology for use in other sports, among them football, which is beset by a high occurrence of concussions. He thinks the sensor could be valuable for monitoring blows to the head of football players.