Figure 2.

Information on wearables and sensors. (A) Number of publications published per year and per type of sensor used. Publications using multiple types of sensors count multiple times, once for each type of sensor. Others: electrocardiogram, GPS, surface electromyography, portable metabolic system (VO2), skin impedance, force sensor, barometer, and thermometer. (B) Number of publications published per year and per type of accelerometer used. Publications using multiple types of accelerometers count multiple times, once for each type of accelerometer. (C) Distribution of the sensors per physical position and context in which it was worn (real-world setting, controlled laboratory setting, and mixed setting); others: head, pocket, bag, chest, and crutches.