An assistive lower limb exoskeleton for people with neurological gait disorders

Abstract

Lower limb exoskeletons have already proven the capability to give back mobility to people suffering from spinal cord injury (SCI). Other important populations such as people with multiple sclerosis or muscular dystrophy, frail elderly and stroke victims, suffer from severe gait impairments and could benefit from similar technology. The work presented in the current paper describes a novel design of a 6-actuated degrees of freedom (DOFs) assistive lower limb exoskeleton for people with moderate mobility impairments. The electrical actuators are all remotely located on the back of the user for a more compact design with high dynamics. Cable driven solutions are used to transmit the flexion/extension of the hip and knee joints, while a powerful ballscrew carries out the hip adduction/abduction. The design of this exoskeleton, named AUTONOMYO, follows the key specifications of being highly back-drivable and able to perform dynamic motions at low energy consumption. AUTONOMYO is capable to assist the user's balance by providing complementary torques at the hip and the knee. Results show that the projected level of assistance for sit-to-stand transition varies from 50% to 100% in function of the user's bodyweight and height while higher level of assistance are reached for walking and stairs climbing activities.

Are Functional Measures Sufficient to Capture Acceptance? A Qualitative Study on Lower Limb Exoskeleton Use for Older People

“…Indeed, a specific LLE is being developed for potential users with neuromuscular weaknesses by the research group REHAssist of the Swiss Federal Institute of Technology (EPFL). This device, called AUTONOMYO [12,13], is innovative given its light weight and character, which echoes the structure and dimensions of human lower limbs. Also, AUTONOMYO's originality relies on its potential to reproduce human movements to assist with walking.…”

“…1 Illustration of a powered lower limb exoskeleton actuated at the level of the hip and knee joints. It assists the abduction/abduction and flexion/extension of the hip joint, and the flexion/extension of the knee joint (LLE Autonomyo, [12,13]) residencies or at home, and who require special assistance to carry out everyday activities.…”

Preliminary Study on a Novel Protocol for Improving Familiarity with a Lower-Limb Robotic Exoskeleton in Able-Bodied, First-Time Users

“…Lower-limb exoskeletons have been developed for applications like spinal cord injury (SCI) and stroke rehabilitation. Developed by Ecole Polytechnique Fédérale de Lausanne, the AUTONOMYO is targeted for users with moderate neurological disorders such as Parkinson’s disease, multiple sclerosis, and stroke ( Ortlieb et al, 2017 ). Weighing at 22.5 kg, the exoskeleton has three passive degrees of freedom (DOFs) at the ankle and six active DOFs to enable hip flexion/extension, hip abduction/adduction, and knee flexion/extension.…”

Design and Implementation of a Robotic Hip Exoskeleton for Gait Rehabilitation

“…Wearable robotic exoskeletons are a mechanical structure whose joints and links have compatibility with the limbs of human beings [5]. In applications to assist lower extremities, many robotic lower-limb exoskeletons, such as BLEEX [6], AUTONOMYO [7], PH-EXOS [8], HUMA [9], and HAL [10], have been devised to implement rehabilitation or augment power. Generally, these robotic exoskeletons are classified as hip-knee-ankle motion, hip-knee motion, hip motion, or knee motion based on the various assistance functions [11].…”