Therapeutic Knee Device with Load Cell Feedback
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Solution Overview
Problem
Current rehabilitation methods for total knee replacement (TKR) patients are inadequate in preventing scar tissue formation and improving range of motion due to limitations in pain management, pressure variability, and inability to address periarticular fluid accumulation, leading to suboptimal mobility and increased risk of further injury.
Innovation Solution
A therapeutic exercise device with a load cell and actuation arm that applies controlled pressure and resistance to the knee joint, allowing for customizable therapy parameters and gradual increase in range of motion, while minimizing pain and facilitating fluid drainage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If early range of motion therapy is applied to prevent scar tissue formation, then mobility recovery is improved, but patient pain increases significantly
Solution Approach 1:
The CPM machine dynamically adjusts the range of motion and motion amplitude based on patient tolerance, allowing therapy to progress from small to larger movements as pain decreases and mobility improves, resolving the contradiction between early therapy benefits and pain management
Solution Approach 2:
The system changes therapy parameters including motion amplitude, speed, and duration to optimize the balance between therapeutic effectiveness and patient comfort, enabling early intervention while controlling pain through progressive parameter adjustment
2Productivity
If manual pressure is increased to improve range of motion, then therapy effectiveness is improved, but risk of joint damage increases
Solution Approach 1:
The CPM machine provides controlled, gradual pressure application with built-in safety limits and monitoring, cushioning the joint against excessive force while maintaining therapeutic effectiveness through progressive loading that prevents damage risk
Solution Approach 2:
The system incorporates feedback mechanisms to monitor patient response and adjust pressure accordingly, preventing excessive force application while maintaining optimal therapy intensity for range of motion improvement
3Ease of operation
If CPM machine operates within fixed range of motion limits, then patient comfort is maintained, but fluid drainage and scar tissue prevention are insufficient
Solution Approach 1:
The CPM machine transitions from static range limits to dynamic adjustment where the range of motion expands progressively as therapy progresses, enabling effective fluid drainage and scar tissue prevention while maintaining patient comfort through adaptive motion control
4Productivity
If aggressive range of motion therapy is applied, then mobility recovery is accelerated, but inflammatory cycle is repeated and injury risk increases
Solution Approach 1:
The CPM machine applies periodic motion with controlled cycles that allow for fluid drainage intervals and progressive loading, preventing continuous excessive stress that would trigger inflammation while maintaining accelerated recovery through consistent therapeutic stimulation
Data Source
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AI summary
The present teachings provide for an exercise device for exercising a joint and a limb. The device includes a controller, an actuation member, a load cell, and a motor. The actuation member is controlled by the controller and is configured to extend and flex the limb. The load cell is mounted to the actuation member and configured to measure force between the limb and the actuation member. The motor is configured to control movement of the actuation member in response to inputs from the controller.