Sports engineers are Griffith University in Australia are working with researchers at the Helmut Schmidt University in Germany on a device that will gather and send measurements on movements such as stroke count wirelessly in real time to a heads-up goggle display and poolside coach.
Underwater wireless communication is a particularly challenging area since electromagnetic signals such as radio frequencies cannot propagate effectively through water, while the acoustic sources currently used are limited by the speed of sound and experience path losses.
The researchers are therefore turning to wireless optical communication with modified LEDs, which can propagate through water effectively over short distances with quite a high bandwidth compared to acoustic sources. A device including accelerometer and gyroscope sensors mounted on a chip performs data processing on site (that is, the swimmer?), which is then transmitted via a near-infrared emitter using red light to work as well as possible in pool water.
So far, the group has successfully tested the transmission of data in a sectioned-off experimental pool-based setup. They will now look to develop the heads-up goggle display, with challenges to overcome like bubbles interfering with the signal.
Read more here on the Engineer.