Wirerope-driven exoskeleton to assist lower-limb rehabilitation of hemiplegic patients by using motion capture

Abstract

Purpose The purpose of this paper is to design a lower limb exoskeleton to enhance hemiplegic patient’s muscle strength and help the affected side return to normal gait after a long period of training. Design/methodology/approach A wire rope-driven exoskeleton that combines rigid bracket and flexible driven method was presented to assist the patients with rehabilitative walking training. By using three noncontact cameras, the patient’s gait was captured and the target trajectory of the affected side was analyzed. Meanwhile, a controlling strategy of the affected side, which mimics the gait of the healthy side, was developed to help hemiplegic patients with varying degrees of hemiplegic gait obtain personalized walking rehabilitation training. Findings The results show that the hemiplegic gait of hip excessive abduction and strephenopodia was prevented. After wearing the exoskeleton, the movement trajectories of both sides of the lower limb were approximately identical. Based on the controlling strategy, the exoskeleton can correct the impaired gait and provide assistance for patients during walking. The exoskeleton has great benefits in walking rehabilitation training for hemiplegic patients. Originality/value This work improves the efficiency of the patient’s individualized training in the room. The presented exoskeleton provides great benefits in walking rehabilitation training for hemiplegic patients.

Review of control strategies for lower-limb exoskeletons to assist gait

“…In a different approach, the trajectory is generated online before each step based on the spring-loaded inverted pendulum (SLIP) model, taking the dimensions of possible obstacles into account [201]. For exoskeletons targeted at hemiplegic people, the movement of the nonparetic side at each step has also been recorded and used as the reference trajectory for the paretic leg [202,203]. In a similar approach, kernel-based nonlinear filters have been used to learn the movements of the nonparetic leg as a function of gait phase online, and the learned functions are then used to generate the reference trajectory for the paretic leg [204].…”

Systematic Design of a Parallel Robotic System for Lower Limb Rehabilitation

“…Since RAISE is designed for the rehabilitation of the bedridden stroke patients, the emphasis on the ankle mechanism is not required when the load is considered (since the sole of the foot will not touch the floor). Other example of exoskeleton rehabilitation device is found in [24] where the authors used wire based actuators. However the device does not provide the rehabilitation for the ankle joint.…”

“…The sensors used during the experiments are provided by Biometrics having all the certifications required by biomedical applications [12]. For the experimental bench the following Although there are far more precise technical solutions for tracking the anatomic joints motions, see for example the OptiTrack package [28] (which can track markers with precision better than 1 mm), or other camera based methods such as in [24], the authors opted to use the goniometers since in the rehabilitation process does not require a very high accuracy of the robotic device (as opposed to robots designed for percutaneous procedures such as biopsy and brachytherapy). As long as the goniometers are well calibrated their use for the rehabilitation is preferred (at least according to the kineto-therapists and medical personnel) since it is far easier to mount the sensors on the limb (than to mount the trackers and calibrate the camera tracking device which may be needed if the robot is moved in other place).…”

Mechanical Efficiency Investigation of an ankle-assisted robot for human walking with a backpack-load

“…Research and technology on human dynamics modeling have been well established (Mcruer et al,1980), and the inverse kinematic equation can be used to derive the shutdown torque from the kinematic information and plantar pressure of the human body as it walks. Then the power of our joint torque can be obtained by integrating the torque with the angular velocity of the joint motion (Xie et al,2019). The effect of the weight of the device on the output of human mechanical work during a gait cycle is shown in equation: where P, θ, T, and W represent the ankle moment, angle, mechanical power and mechanical work, respectively, f vicon is the frame number of motion capture, and k is the number of points sampled within a gait cycle.…”

“…Since the weight of our equipment is not very large in relation to the weight of the load, the calculation from the fitted results has a large error. Because the power from the device is input into the ankle, for output power, we also study the effect of device weight on the mechanical work of the human body from the perspective of ankle-joint power.Research and technology on human dynamics modeling have been well established(Mcruer et al,1980), and the inverse kinematic equation can be used to derive the shutdown torque from the kinematic information and plantar pressure of the human body as it walks.Then the power of our joint torque can be obtained by integrating the torque with the angular velocity of the joint motion(Xie et al,2019). The effect of the weight of the device on the output of human mechanical work during a gait cycle is shown in equation：…”