Virtual light touch contact: A novel concept for mitigation of body sway

This paper proposes a novel concept called virtual light touch contact (VLTC), which helps to reduce human postural sway in standing and walking states. The VLTC system essentially creates a virtual partition around the user and enables estimation of the virtual force caused when the partition is touched. The resulting force data are fed back to the user's fingertips in the form of vibrotactile stimulation, allowing sensation of the virtual partition in any location. To verify the validity of the proposed method, a prototype system was developed using motion-capture technology and a tactile stimulator, and preliminary experiments involving a healthy subject were conducted. The results indicated that the system is capable of helping to reduce the postural sway of the user during tandem (heel-to-toe) standing.