ABSTRACT.
Near-infrared spectroscopy is an affordable technology that can be used in monitoring muscle oxygenation in exercise and sport setting. In this study, we presented a portable, wireless, multichannel near-infrared spectroscopy device for real-time monitoring of muscle activity. Wireless communication was applied to data transmission in order to avoid cumbersome wires, and the whole system is highly integrated. We took special care to eliminate motion artifact when designing the near-infrared spectroscopy sensor for attachment to human skin. In addition, the system is designed with a high sampling rate so as to monitor rapid oxygenation changes during muscle activity. The wireless near-infrared spectroscopy sensor was designed using commercially available electronic components that were mounted onto a 4-layer rigid-flexible printed circuit board. We performed in vivo experiments including arterial occlusion and isometric voluntary forearm muscle contraction among wrestlers and demonstrated that the system can effectively monitor muscle oxygenation parameters, even in exercise.