Although everyone knows of the dangers of brain injuries, it’s often difficult to tell if such an injury has taken place. There are certainly cases in which athletes receive concussions, yet say that they feel fine when asked. That’s why Reebok and flexible electronics developer MC10 have created the CheckLight skull cap. It lets athletes and coaches know when a potentially brain-damaging impact has been delivered to its wearer’s head.

The cap can be worn beneath any type of traditional sports helmet, or on its own. It contains a tri-axial accelerometer and a gyroscope, to measure linear and rotational acceleration, respectively. A built-in microprocessor analyzes their output whenever an impact occurs.

If the impact meets or exceeds certain predetermined thresholds, either a yellow or red LED will start blinking – the color of the light indicates the severity of the impact. Because the lights hang off the bottom of the cap where they're in plain sight, coaches or other athletes will be able to see if an individual should be sidelined for testing and possibly hospitalization.

The microprocessor also logs the number of impacts it receives over time. Assuming that the same person always wears it, this can be used to keep track of their cumulative impacts.

According to MC10, the CheckLight is particularly accurate due the fact that the accelerometers are located directly against the wearer’s head. Other systems, in which sensors are mounted on the helmet, reportedly provide more of an indication as to what’s happened to the helmet than to what’s happened to the person wearing it.

The CheckLight should be available from Reebok later this month. Its price has yet to be announced, but prospective buyers can sign up for notifications via the first of the links below.

Sources: Reebok, MC10 via The New York Times