Abstract
In this study, we develop an effective noncontact technique for detecting rolling over in bed. We propose a new method for detecting rolling motion by measuring the current generated due to a change in the capacitance between a given electrode and the human body. The technique involves the detection of electrostatic induction current of the order of approximately sub-picoamperes flowing through the electrode that is placed at a distance of 1 m from a subject. A theoretical model is proposed for the electrostatic induction current generated due to a change in the electric potential of the human body. This model can be used to effectively explain the behavior of the electrostatic induction current flowing through the measurement electrode. We apply the noncontact technique to detect the timing of rolling over in bed. Thus, we could quantitatively estimate the timing of rolling over in bed under noncontact and nonattached conditions. Our technique enables easy in-situ detection of the timing of rolling over in bed.