Balance Assistance Without Mechanical Support Using a Virtual Cane with Haptic Feedback.

Abstract

Light Touch (LT) has been known to improve standing balance without mechanical support by providing sensory information about the movement of the body. Inspired by this, this work developed a Virtual Cane (VC) which gives no physical support but provides other sensory information that a physical cane would. The VC is developed with a distance sensor and vibration actuators to provide cane tip-to-ground distance information to the user. The extent to which this haptic feedback improves standing balance was assessed in a human experiment. 10 healthy young participants underwent a standing balance experiment with tandem stance and eyes closed, using VC with No Feedback (NF) as the baseline, VC with feedback, and with physical cane (PC). Center-of-Pressure (CoP) metrics as well as Sway-density metrics were analyzed to study the effect of these conditions on standing balance. It was found that the CoP metrics in VC were significantly improved compared to baseline (NF) and approaching the benefit of a full physical cane (PC). Sway-density metrics showed no difference between the conditions. This shows that simple, binary feedback from VC on the position of the body and cane was sufficient to positively affect standing balance without significantly altering the biomechanical strategy of standing balance. This is also a demonstration of an assistive device with a complete absence of mechanical support that can provide substantial benefit to balance.