Mark Cavendish, the sprinter in the HTC-Highroad, the cycling team of 2011 tour de France, is holding the Compex Wireless which uses Nordic Semiconductor's nRF24LE1, 2.4GHz SoC. The simulator, developed by Swiss Compex Médical, is used during training to target specific muscles. It can also be used between training sessions and competitive events to accelerate recovery cycles and to treat common intensive training ailments, such as lower back pain. It uses mechanical biofeedback (mi-SCAN) technology to automatically adjust the stimulation settings to the specific needs of each muscle. On each of the four wireless, 55mm diameter stimulators, is an SoC with an on-board microcontroller, running a wireless networking protocol. The stimulators are 18mm thick and weight 50g. These four communicate with another nRF24LE1 SoC which is located within a wireless controller. This has a 61mm colour LCD screen and a user interface, to set up and control the Compex Wireless. A typically demanding schedule of use would be two training programmes at high power and three recovery programmes. Each stimulator can operate for an entire day, between recharges from a built-in 450mAH Li-Ion polymer rechargeable battery. All stimulators have to be precisely synchronised and the wireless network demands very low latency so that should the system need to stop, it does so immediately and simultaneously rather than over a few seconds. The simulator also has to work reliably even in challenging RF environments shared with other users in close proximity (for example, during races) and also in proximity of other active 2.4GHz sources such as WiFi and Bluetooth wireless technology. Professional atheletes and sports and fitness can set training objectives and download relevant muscle stimulation programs and ready-to-use schedules from the Complex Wireless website (www.compexwireless.com).
