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CURATOR

PhD student, National University of Singapore / Advanced Robotic Centre Singapore

PINBOARD SUMMARY

Development of a novel over-ground walking device for gait rehabilitation in older stroke survivors

With growing numbers of stroke survivors, walking assistive robots have recently received much attention. In our research, we propose an effective robotic walker system to support the biological gait pattern of neurologically challenged individuals for the practical daily use. This system consists on an omni-directional mobile platform as well as an active body weight support (BWS) unit to facilitate active pelvic motions, which simplifies the mechanical structure by eliminating additional actuators. The user interacts with the system through a six DOF force/torque sensor and an admittance controller which enables a natural and intuitive interface. In this way, the system can provide stability, balance, and gait training. It can also provide perturbation, resistance, and error augmentation training methods to enhance training efficacy. A set of wearable sensors (IMU and EMG) are used to provide quantitative measures of gait recovery and to monitor muscle condition and activation pattern. Current research involves integrating functional electrical stimulation module into the system to provide simulations for patients with severe drop foot to enhance gait recovery.

Preliminary tests in both healthy and stroke survivors have shown that the device perform adequately and present no hazard to the user [1-2]. Ongoing research will clinically validate rehabilitation protocols for this system based on principles of motor learning and neuroplasticity in 100 older chronic stroke patients. For this, a prospective single blind randomized control trial will be performed to compare conventional gait training vs. gait rehabilitation with the new walker. Our hypothesis is that a) the most effective gait training can only be achieved in the most natural setting which elicit proper sensory input and feedback closest to actual walking: the over-ground, and b) applying the motor learning principles such as error augmentation and motion adaptation will enhance the functional outcome.

[1] Y. Jing, F. A. Reyes and H. Yu. A Novel Robotic Walker for Over-Ground Gait Rehabilitation; Converging Clinical and Engineering Research on Neurorehabilitation II Biosystems & Biorobotics, pp. 1223-227, 2016. [2] F. Anaya Reyes, R. M. Kyung, H. Yu and V. Pasqui;Détermination d’un indice du risque imminent de chute pour la compensation active des instabilités posturales avec un robot d’assistance à la marche; Neurophysiologie Clinique/Clinical

3 ITEMS PINNED

Restriction of pelvic lateral and rotational motions alters lower limb kinematics and muscle activation pattern during over-ground walking.

Abstract: Restriction of pelvic lateral and rotational motions caused by robotic gait assistive devices can hinder satisfactory functional outcomes as it alters normal gait patterns. However, the effect of pelvic motion restriction caused by assistive devices on human locomotion is still unclear; thus, we empirically evaluated the influences of pelvic lateral and rotational motions on gait during over-ground walking by inhibiting the respective pelvic motions. The pelvic motions were restricted through a newly developed over-ground walking device. Variations in gait descriptive parameters as well as joint kinematics and muscle activation patterns were measured to indicate gait difference caused by pelvic restrictions. The results showed that pelvic lateral and rotational restriction significantly reduced the stride and step length as well as gait velocity and increased ratio of stance phase. It was also observed that the restriction caused a significant reduction in the range of motion of the ankle, knee, and hip joints. In addition, significantly higher muscle activations and prolonged patterns were observed in the tibialis anterior, gastrocnemius, and biceps femoris muscles, as compared to the normal patterns when the pelvis was restricted. We concluded that the pelvic restriction significantly altered normal gait dynamics, thus inhibiting the efficacy of gait rehabilitation.

Pub.: 03 Feb '16, Pinned: 30 Aug '17