Development of a Gait Rehabilitation Robot Using an Exoskeleton and Functional Electrical Stimulation: Validation in a Pseudo-paraplegic Model

Abstract

Objective: We have developed a robot for gait rehabilitation of paraplegics for use in combination with functional electrical stimulation (FES). The purpose of this study was to verify whether the robot-derived torque can be reduced by using FES in a healthy-person pseudo-paraplegic model. Methods: Nine healthy participants (22–36 years old) participated in this study. The robot exoskeleton was designed based on the hip–knee–ankle–foot orthosis for paraplegia. Participants walked on a treadmill using a rehabilitation lift to support their weight. The bilateral quadriceps femoris and hamstrings were stimulated using FES. The participants walked both with and without FES, and two walking speeds, 0.8 and 1.2 km/h, were used. Participants walked for 1 min in each of the four conditions: (a) 0.8 km/h without FES, (b) 0.8 km/h with FES, (c) 1.2 km/h without FES, and (d) 1.2 km/h with FES. The required robot torques in these conditions were compared for each hip and knee joint. The maximum torque was compared using one-way analysis of variance to determine whether there was a difference in the amount of assist torque for each gait cycle. Results: Walking with the exoskeleton robot in combination with FES significantly reduced the torque in hip and knee joints, except for the right hip during extension. Conclusions: In the healthy-participant pseudo-paraplegic model, walking with FES showed a reduction in the robot-derived torque at both the hip and knee joints. Our rehabilitation robot combined with FES has the potential to assist paraplegics with various degrees of muscle weakness and thereby provide effective rehabilitation.

Measurement, Evaluation, and Control of Active Intelligent Gait Training Systems—Analysis of the Current State of the Art

“…Functional Electrical Stimulation (FES) is a method of applying low-frequency pulsed current or amplifying it through signal-current conversion and then sending it into the human body to produce immediate effects, artificially causing movement in humans who are paralyzed by damage to the central nervous system. Recently, a large number of research studies proposed robotic systems for gait rehabilitation based on FES method [103][104][105]. Studies have proven that, combined with FES, the assistive torque required of the gait training systems can be reduced and the muscle strength and joint range of motion of the human body can be improved.…”

Immediate Effect Evaluation of a Robotic Ankle–Foot Orthosis with Customized Algorithm for a Foot Drop Patient: A Quantitative and Qualitative Case Report

“…The powered AFO generates ankle movements to force the user to walk normally in several scenarios, such as flat walking [ 25 ], sit-to-standing motions [ 26 ], and ascending and descending stairs [ 27 ]. The Functional Electrical Stimulation (FES) AFO provokes muscle activation by sending electrical signals into the limb accordingly [ 28 ]. Here, the AFO prescription should suit the patient’s needs.…”

Robot Ankle Foot Orthosis with Auto Flexion Mode for Foot Drop Training on Post-Stroke Patient in Indonesia

“…Robot AFO reported in [10] shows a pneumatically powered soft actuator assisting the walking and standing. Other works as presented by [11], shows the effectiveness of functional electrical stimulation (FES) to improve a motor-driven robot AFO. There are still many kinds of robot AFO that has been developed 350 in the last decade.…”

“…The air tank should also be considered as the wearable part if this kind of AFO want to be used to assist daily activity. On the other hand, a FES controlled AFO has the simplest hardware configuration at it comprises of cable and electrode only without hard actuator [11]. But the electrode attachment might require expert intervention rather than self-attaching by the patient themselves.…”