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

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.

Vibrotactile Feedback for Improving Standing Balance

“…These changes can be interpreted as a reduction of the postural sway, i.e., smaller and more frequent postural corrections (Dozza et al, 2005). This effect is consistent with the previous studies, e.g., in Xu et al (2017) where supplemental vibrotactile feedback was able to modify the postural sway in healthy young participants. The main novelty of these results were that:…”

“…In particular, vibrotactile feedback is widely used because it can provide additional information without interfering with basic functions like hearing or seeing (Haggerty et al, 2012). Usually, the vibrotactile devices use arrays of several vibration motors to convey postural sway information mainly on the torso (Van Erp, 2005;Verhoeff et al, 2009;Lee et al, 2012;Sienko et al, 2012;Xu et al, 2017). However, the feedback provided by the most common vibrotactile devices is difficult to interpret and integrate in the neural control (Culbertson et al, 2018).…”

“…In this framework, we designed and built a portable, lowweight and low-cost device to provide vibrotactile feedback to improve standing balance. Differently from the majority of current devices, based on arrays of vibration motors and often providing complex patterns of stimuli (Van Erp, 2005;Verhoeff et al, 2009;Lee et al, 2012;Xu et al, 2017), we used only two vibration motors placed on the opposite sides of the torso (abdomen and back) at the L5 level, namely in the CoM area. The idea was to activate them as function of the actual sway evaluated from the accelerometric signal.…”

Cueing Paradigms to Improve Gait and Posture in Parkinson’s Disease: A Narrative Review

“…Visual cues were spaced at distances based on the subject's average step/stride length measured at baseline trials. A few studies have investigated the use of somatosensory cues [53][54][55] using vibrating wrist-worn devices and a combination of audio/visual and or/somatosensory cues for rehabilitation [40,56,57].…”

Trainer in a pocket - proof-of-concept of mobile, real-time, foot kinematics feedback for gait pattern normalization in individuals after stroke, incomplete spinal cord injury and elderly patients

“…Wearable sensors are commonly used for offline sensing / tracking [ 27 , 28 ]. Some studies applied these sensors for balance training [ 29 – 31 ] or gait symmetry training [ 32 ]. Only a few mobile systems provide real-time feedback for use in a therapeutic setting [ 33 ].…”