Adaptive Ankle Exoskeleton Torque Control for Gait Phase Synchronization
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Solution Overview
Problem
Conventional physical rehabilitation methods using exo-skeletal robots impose prescribed dynamics of healthy joints on impaired joints, leading to out-of-sync movements and potential destabilization of patients due to mismatched speed and range of motion.
Innovation Solution
A system with a variable torque motor and processor that provides deficit-adjusted, adaptive assistance by determining adaptive timing and magnitude of robot-applied torque based on sensor data, matching the impaired joint's movement phases and parameters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional exo-skeletal robots impose prescribed dynamics of healthy joints on impaired joints, then the robot can provide standardized rehabilitation assistance, but the mismatch in speed and range of motion causes out-of-sync movements and potential patient destabilization
Solution Approach 1:
The system dynamically adjusts the robot's torque magnitude and timing parameters in real-time based on the patient's actual movement phase and deficit parameters, transforming the rigid prescribed dynamics into adaptive dynamics that synchronize with the impaired joint's actual movement capabilities
Solution Approach 2:
The system changes key parameters including torque magnitude, timing relative to movement phase, and frequency of assistance based on the patient's measured deficit parameters, allowing the robot to adapt from standardized healthy joint dynamics to customized impaired joint dynamics
2Productivity
If the robot operates at normal speed and range of motion, then the robot maintains standardized performance, but the impaired joint moves at reduced speed and range of motion causing mismatch and inhibition of movement
Solution Approach 1:
The system uses sensors to detect the patient's actual movement speed, range of motion, and movement phase, then feeds this information back to adjust the torque timing and magnitude, creating a closed-loop control system that synchronizes robot assistance with the patient's actual movement capabilities
Solution Approach 2:
The system determines deficit parameters and plans adaptive torque application in advance based on predicted movement phases, preparing the robot to provide assistance at the optimal timing before the patient's movement phase transitions
Data Source
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AI summary
A method is described for providing deficit-adjusted adaptive assistance during movement phases of an impaired ankle. The method includes determining, on the processor, a value for a deficit parameter for each movement phase of a compound ankle function based on a difference between a parameter trace for a normal subject and the parameter trace for an impaired subject. The method further includes determining, on the processor, an adaptive magnitude for the robot-applied torque based on the value for the deficit parameter. The method further includes applying, to the robot joint, the adaptive magnitude for the robot-applied torque in only a first plane for the current movement phase, based on an adaptive timing. An apparatus is also described for providing deficit-adjusted adaptive assistance during movement phases of the impaired ankle.