Vibrotactile feedback to control the amount of weight shift during walking — A first step towards better control of an exoskeleton for spinal cord injury subjects

Abstract

People with Spinal Cord Injury do not only lack the ability to control their muscles, but also miss the sensory information from below the level of their lesion. Therefore, it may become difficult for them to perceive the state of the body during walking, which is however often used to control wearable exoskeletons. In the present study the possibilities of providing vibrotactile feedback about the Center of Mass (CoM) during walking were investigated. The results showed that healthy subjects could successfully interpret the provided vibrotactile cues and change their walking pattern accordingly. Vibrotactile stimulation was either provided in a concurrent (over the complete CoM movement) or terminal (only when the desired CoM displacement was reached) way. The latter led to a better accuracy and can be easily implemented in a wearable exoskeleton where a certain amount of CoM displacement is needed to initiate stepping.

Integrating Tactile Feedback Technologies Into Home-Based Telerehabilitation: Opportunities and Challenges in Light of COVID-19 Pandemic

“…Results from a meta-analysis indicated that vibrotactile feedback was effective in reducing task completion times, but neither forces nor errors were significantly reduced (Nitsch and Färber, 2012 ). In addition, vibration feedback encoding center of mass or center of pressure motion was used to improve standing balance (Lee et al, 2012 ; Ma and Lee, 2017 ; Ballardini et al, 2020 ) and walking patterns (Janssen et al, 2009 ; Muijzer-Witteveen et al, 2017 ; Xu et al, 2017 ). Vibrotactile feedback based on stochastic resonance was applied for improving visuomotor temporal integration in hand control (Nobusako et al, 2019 ) and balance control (Magalhães and Kohn, 2011 ).…”

First Steps Towards Facilitating the Learning of Using Wearable Lower-limb Exoskeletons withImmersive Virtual Reality

“…However, only a few studies have investigated the effectiveness of using augmented feedback for learning to control wearable exoskeletons for overground walking, mainly focusing on vibrotactile and electrostimulation feedback [29][30][31][32][33][34]. Examples of applications include the improvement of the gait cycle pattern [34] and body awareness [32] to empower users to correct undesired movements while improving the efficacy of the therapeutic intervention [28]. Yet, long setup times and an intact somatosensory system are usually required to enable the use of this type of feedback.…”

“…In the field of robotic gait rehabilitation, recent research has started evaluating the integration of feedback systems to enhance motor learning and motor performance [27,28]. However, only a few studies have investigated the effectiveness of using augmented feedback for learning to control wearable exoskeletons for overground walking, mainly focusing on vibrotactile and electrostimulation feedback [29][30][31][32][33][34]. Examples of applications include the improvement of the gait cycle pattern [34] and body awareness [32] to empower users to correct undesired movements while improving the efficacy of the therapeutic intervention [28].…”

Vibrotactile Feedback for Improving Standing Balance

“…Several studies suggest indeed that, in presence of sensory deficits, providing a supplemental sensory information to the central nervous system might improve postural stability, decreasing the postural sway and even the risk of falling (Wall et al, 2001;Dozza et al, 2005;Danilov et al, 2007;Sienko et al, 2012). This supplemental information could play a crucial role for subjects using exoskeletons (Muijzer-Witteveen et al, 2017) or lower limb prosthetics (Lee et al, 2007), where the loss of somatosensation associated with the lesion or the amputation is an obstacle for achieving stable and efficient standing balance and walking patterns.…”