“…One study used both types of sensors—an ambient sensor and an accelerometer [ 25 ]. The sensing modality was infrared (38%) [ 11 , 13 , 15 , 17 , 23 , 25 ], acceleration force (38%) [ 16 , 18 , 20 , 21 , 22 , 25 ], RGB color (25%) [ 13 , 15 , 17 , 23 ], EMG (13%) [ 12 , 14 ], light and temperature (13%) [ 19 , 25 ], and radio signal (6%) [ 24 ], considering some studies used more than one sensing modality. The most common site of proximate sensor placement was the arm (38%) [ 12 , 14 , 16 , 21 , 22 , 25 ], followed by the trunk and leg (6%) [ 18 ].…”