Pneumatic Knee Exoskeleton Rotary Motion Generator
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing knee exoskeleton devices are bulky, cumbersome, and lack muscle stimulation capabilities, making them ineffective for daily use outside clinical settings and inadequate for helping stroke survivors relearn walking while preventing hyperextension of the knee during walking.
Innovation Solution
A pneumatically driven knee exoskeleton device with a rotary motion generator that includes a rotary shaft switchable between one-way and two-way rotation modes, featuring a moveable lever and elastomeric structures for torque generation, and an electrical stimulation system to stimulate muscles, facilitating adaptive movement and muscle contraction during gait.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If traditional knee exoskeleton devices use powerful electric motors and rigid metal frameworks, then they can provide sufficient mechanical support and stability, but they become bulky, heavy, and cumbersome for daily use
Solution Approach 1:
The patent replaces electric motors with a pneumatic muscle actuator that uses compressed air to generate mechanical force. The pneumatic muscle expands when pressurized, driving the rotary shaft to rotate and provide knee extension torque. This eliminates heavy electric motors while maintaining sufficient mechanical support through pneumatic pressure control.
Solution Approach 2:
The patent changes the operating parameters by using variable pneumatic pressure to control the force output of the actuator. By adjusting the air pressure supplied to the pneumatic muscle, the system can dynamically regulate the mechanical support provided during different gait phases, achieving the required strength without fixed heavy motor assemblies.
2Stability of the object's composition
If knee exoskeleton devices are designed with rigid structures for stability, then they can provide reliable mechanical support, but they lack adaptability to human movement and muscle stimulation capabilities
Solution Approach 1:
The patent introduces a rotary shaft mechanism that can rotate dynamically during gait cycles, allowing the exoskeleton to adapt to the natural movement patterns of the knee joint. The rotary shaft connects the pneumatic actuator to the lower arm, enabling controlled rotation that matches human knee motion while maintaining structural stability through the rigid rotary joint connection.
Solution Approach 2:
The patent incorporates sensors to detect knee joint position, movement velocity, and gait phase information. This feedback is processed by a control system that adjusts the pneumatic pressure in real-time, enabling the device to adapt to actual human movement patterns rather than following fixed rigid trajectories. The feedback loop allows the system to respond to variations in gait speed, terrain, and individual user needs.
3Extent of automation
If existing exoskeleton devices operate autonomously without muscle stimulation, then they can provide basic mechanical assistance, but they fail to maximize patient effort and active human-robot interaction
Solution Approach 1:
The patent merges the pneumatic actuation system with an electrical stimulation system that targets specific muscles (quadriceps and hamstrings). The electrical stimulation component delivers pulses to activate muscle groups during gait phases when mechanical assistance is needed, combining automated pneumatic support with biologically-based muscle activation to maximize patient effort and active human-robot interaction.
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 device provides a lightweight, compact, and safe means for patients to relearn walking by preventing hyperextension and enhancing muscle strength, making it suitable for daily use and improving gait rehabilitation outcomes.
Implementation Method 1
a first pneumatic muscle circumferentially arranged within the outer casing and engaged with the moveable lever to generate an output torque
Implementation Method 2
An electrical stimulation system is provided with a plurality of electrodes arranged to contact a plurality of regions of the thigh and the shank
Data Source
AI summary
A rotary motion generator for helping a patient to relearn walking is disclosed. The knee exoskeleton device includes a rotary shaft, a moveable lever, and a first elastomeric structure. The rotary shaft is switchable between a one-way rotation mode and a two-way rotation mode in a sagittal plane, and locking the joint position by the one-way rotation mode. The moveable lever protrudes from an outer periphery of the rotary shaft perpendicularly for rotating the rotary shaft. The first elastomeric structure is pneumatically controlled for engaging the moveable lever for generating an output torque and producing the relative rotatory movement of a lower arm with respect to an upper arm. The rotary shaft further comprises a pawl, a second elastomeric structure for projecting or retracting the pawl, and a rotation locking mechanism that switches the rotary shaft between the one-way rotation mode and the two-way rotation mode.