“…Wearable sensors : Wearable device-based approaches use triaxial gyroscopes [ 12 , 13 ], accelerometers [ 8 , 9 , 10 , 11 , 15 , 34 , 35 ] or both types of sensors [ 36 ] to monitor the person and detect posture changes and inactivity. In these solutions, data acquired by the sensors are used to compute different features, such as angles [ 9 , 12 ], differences and derivatives of the sum X , Y and directions [ 8 , 9 ], maximum acceleration and fluctuation frequency [ 12 ], decreasing of heat rates [ 10 ], variation of different parts of the body [ 11 ], the acceleration of the body parts [ 13 ], mutual information and removing highly correlated features using Pearson correlation coefficient and Boruta algorithm [ 35 ], etc.In addition, they distinguish fall and non-fall events by using thresholds [ 8 , 9 , 10 ], machine learning [ 11 , 12 , 13 , 14 , 35 ] and deep learning algorithms [ 15 , 34 ].…”