Modular Lower Limb Exoskeleton With Remote Actuation for Natural Gait
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Solution Overview
Problem
Current lower limb exoskeletons are primarily designed for severe impairments and lack effectiveness for patients with moderate neurological disorders, such as Parkinson's disease, multiple sclerosis, and stroke, as they do not adequately address the need for mobility assistance and rehabilitation, and often require non-impaired upper limbs for use.
Innovation Solution
A modular, backdrivable, and highly dynamic lower limb exoskeleton with remotely placed actuation units and a cable transmission system, allowing for bidirectional interaction and adjustable assistance levels, which can be adapted to different users' needs through modular actuation units and visco-elastic mechanisms, enabling natural walking and balance control without external support.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If current lower limb exoskeletons are designed for severe impairments with fixed assistance levels, then they provide sufficient support for paraplegic patients, but they lack effectiveness and adaptability for patients with moderate neurological disorders
Solution Approach 1:
The exoskeleton implements dynamically adjustable assistance levels through controllable actuators that can modulate support force in real-time. The system transitions from fixed assistance to variable assistance, allowing adaptation to different impairment severities and rehabilitation stages through dynamic control parameters
Solution Approach 2:
The system changes key operational parameters including assistance level, stiffness, and damping characteristics to match user needs. By adjusting these parameters, the exoskeleton can effectively serve users ranging from severe to moderate impairments without requiring fundamentally different device designs
2Adaptability or versatility
If exoskeletons require non-impaired upper limbs for operation, then they can provide adequate control and support, but they cannot be used by users with upper limb impairments or those needing hands-free operation
Solution Approach 1:
The exoskeleton incorporates passive elastic elements and gravity compensation mechanisms that automatically provide support without requiring active user control. The system self-regulates to provide appropriate assistance based on user posture and movement intent, reducing the need for complex manual operation
Solution Approach 2:
The system replaces manual mechanical control with sensor-based detection and automated actuation. Sensors detect user intent and movement state, triggering automated actuator responses that eliminate the need for hand-operated controls while maintaining ease of use
3Power
If actuation units are placed close to joints, then they provide direct and efficient actuation, but they increase inertia and mass on distal segments reducing dynamics
Solution Approach 1:
The patent introduces cable transmission as an intermediary mechanism between the actuation units and the joints. This allows actuators to be positioned remotely (reducing distal mass) while still providing effective joint actuation through the cable-mediated force transmission, thus resolving the conflict between actuation efficiency and system dynamics
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The exoskeleton provides enhanced mobility and rehabilitation benefits, allowing users to manage their movements independently, with improved balance control and reduced risk of injury, while being adaptable to various impairments and conditions, offering a compact and user-friendly design.
Implementation Method 1
The exoskeleton structure comprises a set of different removable, adaptable and backdrivable actuation units dedicated to each joints of the structure and remotely located on the structure to decrease inertia and mass on the distal segments of the structure
Implementation Method 2
each joint can be modularily let free, or constrained by a visco-elastic mechanism or actuated by a corresponding actuation unit
Data Source
AI summary
In one embodiment, the exoskeleton structure is fastened to the body of the user by a brace and at the foot level. The exoskeleton includes at least one set of three joints corresponding to the hip abduction/adduction, the hip flexion/extension and the knee flexion/extension, wherein the architecture of the exoskeleton is compatible with a set of different removable, adaptable and backdrivable actuation units dedicated to each joints and remotely located around the trunk of the user to decrease inertia and mass on the distal segments, wherein each joint can be modularily let free, constrained by a visco-elastic mechanism or actuated by one corresponding actuation unit.