Keeping cool on the pitch

Biological engineering students at the University of Arkansas have developed a wireless biosensor for sportspeople that could eventually prevent death due to heat stroke.

The prototype sensor has been designed to accurately record and monitor an American football player’s body temperature while the player is active without compromising safety or affecting comfort and performance. It wirelessly gathers and monitors body temperature and communicates information on many players in real time. It includes a thermocouple temperature sensor, a transmitter, two amplifiers and a base-station receiver connected to a laptop with user-interface software.

A sensor in a football helmet adheres to a dense pad, which touches the surface of the player’s forehead and records the body’s temperature from the temporal artery. The sensor sends an analogue signal to the transmitter, which converts the signal into digital data. The amplifiers increase voltage from the sensor to enable it to provide linear, higher-resolution data, which allows the researchers to measure temperature within a fraction of a degree.

The connected components communicate with a base-station receiver, which transfers data into a laptop computer. The system has a transmission distance of approximately 300m, long enough to work in the largest football stadiums.

American football players are especially vulnerable to heat exhaustion and heat stroke because their protective gear prevents the body from efficiently releasing heat in order to cool down.