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.