Configurable, wearable sensing and vibrotactile feedback system for real-time postural balance and gait training: proof-of-concept

Junkai Xu,Yangjian Huang,Wendy Carender,Peter B Shull,Catherine Kinnaird,Ung Hee Lee,Tian Bao,Kathleen H Sienko

doi:10.1186/s12984-017-0313-3

Abstract

BackgroundPostural balance and gait training is important for treating persons with functional impairments, however current systems are generally not portable and are unable to train different types of movements.MethodsThis paper describes a proof-of-concept design of a configurable, wearable sensing and feedback system for real-time postural balance and gait training targeted for home-based treatments and other portable usage. Sensing and vibrotactile feedback are performed via eight distributed, wireless nodes or “Dots” (size: 22.5 × 20.5 × 15.0 mm, weight: 12.0 g) that can each be configured for sensing and/or feedback according to movement training requirements. In the first experiment, four healthy older adults were trained to reduce medial-lateral (M/L) trunk tilt while performing balance exercises. When trunk tilt deviated too far from vertical (estimated via a sensing Dot on the lower spine), vibrotactile feedback (via feedback Dots placed on the left and right sides of the lower torso) cued participants to move away from the vibration and back toward the vertical no feedback zone to correct their posture. A second experiment was conducted with the same wearable system to train six healthy older adults to alter their foot progression angle in real-time by internally or externally rotating their feet while walking. Foot progression angle was estimated via a sensing Dot adhered to the dorsal side of the foot, and vibrotactile feedback was provided via feedback Dots placed on the medial and lateral sides of the mid-shank cued participants to internally or externally rotate their foot away from vibration.ResultsIn the first experiment, the wearable system enabled participants to significantly reduce trunk tilt and increase the amount of time inside the no feedback zone. In the second experiment, all participants were able to adopt new gait patterns of internal and external foot rotation within two minutes of real-time training with the wearable system.ConclusionThese results suggest that the configurable, wearable sensing and feedback system is portable and effective for different types of real-time human movement training and thus may be suitable for home-based or clinic-based rehabilitation applications.

Highlights

Postural balance and gait training is important for treating persons with functional impairments, current systems are generally not portable and are unable to train different types of movements
Mean root mean square (RMS) trunk tilt was smaller with feedback than without feedback (F(1,3) = 72.007, p = 0.003) and the percentage of time inside the no feedback zone was larger with feedback than without feedback (F(1,3) = 31.395, p = 0.011) (Fig. 6)
Significant interactions between feedback and difficulty of exercise was not found for RMS tilt (p = 0.094) or the percentage of time inside the no feedback zone (p = 0.255)

Summary

Introduction

Postural balance and gait training is important for treating persons with functional impairments, current systems are generally not portable and are unable to train different types of movements. Postural balance and gait training are important for treating functional impairments. Current systems are in general designed for monitoring but not training movement as they do not have the capability of providing real-time feedback [7, 8]. Yigit et al [9] presented a wearable soft sensing suit to estimate hip, knee, and ankle sagittal plane joint angles to non-invasively monitor the motion of impaired individuals in unrestricted settings. Donath et al [10] presented a body-worn inertial sensor system to estimate stride length, stride time and cadence in real-time to allow clinicians and other health professionals to assess gait patterns related to functional limitations due to neurological or orthopedic conditions. Wearable sensing systems typically provide kinematic information for diagnosing and monitoring, though movement training still primarily relies on therapist/physician observation and judgment [13]

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Conclusion