A Pilot Study on Perception of Direction Cues Delivered Using A Portable Electro-Tactile Biofeedback Device

Impaired postural control can affect gait performance and result in severe disability due to falling. Training with a biofeedback device can help in reducing this problem. Here, we propose an inexpensive electro-tactile biofeedback system that utilizes transcutaneous electrical nerve stimulation (TENS) to deliver direction cues to the user that may be used as augmented feedback for postural control. In the proposed device, omni-directional tactile feedback is achieved by modulating the intensity of electrical stimuli delivered by 4 TENS channels according to Stevens' power law for human perception. In this study, three healthy young participants performed the task of identifying the direction of cues delivered by the developed device under both normal and muscle fatigue conditions. For comparison, the participants also identified the direction of cues delivered via a vibromotor array under the same conditions. The results of this pilot study indicate that the directional information provided by the developed device may be highly perceivable in both normal and muscle fatigue conditions. Therefore, the proposed system may be used to provide directional balance biofeedback in either condition. In future work, the feasibility of using the proposed device for balance biofeedback will be confirmed through further experimentation.