Orthopedic Damping Device with Direction-Controlled Venting
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Solution Overview
Problem
Orthopedic damping devices with compressible media in prosthetic or orthotic joints can cause a 'catapult effect' at high movement speeds due to restoring forces, leading to undesirable joint behavior.
Innovation Solution
An orthopedic damping device with a movably mounted piston and chamber, featuring a position-independent and direction-controlled venting system through an outlet channel and closure element, which prevents restoring forces by allowing decompression only when the medium is no longer compressed, thereby enhancing adaptability and reducing the 'catapult effect'.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the compressible medium is used to provide damping and cushioning effect, then the joint behavior is improved during compression, but a restoring force is generated during decompression that causes a catapult effect at high movement speeds
Solution Approach 1:
The closure element is positioned in advance to block the outlet channel before decompression occurs. When the piston reverses direction, the closure element proactively seals the outlet channel, preventing the decompression of the compressible medium and thereby eliminating the restoring force that would cause the catapult effect.
Solution Approach 2:
The harmful restoring force is extracted from the system by selectively blocking the decompression path. The closure element removes the ability of the compressible medium to expand and push the piston back, thereby taking out the harmful catapult effect while preserving the useful damping effect during compression.
2Object-generated harmful factors
If the outlet channel is kept open to allow decompression, then the catapult effect is reduced, but the damping and cushioning effect during compression is compromised
Solution Approach 1:
The closure element dynamically changes the state of the outlet channel from closed to open based on the piston's movement direction. During compression, the outlet channel remains closed to maintain damping; during decompression, it opens to prevent the catapult effect. This dynamic adaptation resolves the contradiction by optimizing performance for each phase of operation.
Solution Approach 2:
The system changes the flow resistance parameter of the outlet channel from blocked to open state. By controlling whether the outlet channel is open or closed, the system adjusts the decompression behavior to eliminate the catapult effect while maintaining compression damping through the compressible medium.
3Adaptability or versatility
If a closure element is introduced to control venting, then position-independent and direction-controlled venting is achieved, but the device complexity increases
Solution Approach 1:
The closure element is designed to operate automatically based on the piston's movement without requiring external control systems. The mechanical connection between the piston and closure element allows the latter to self-actuate, opening or closing the outlet channel in response to compression or decompression phases, thereby achieving adaptive control without adding complex control mechanisms.
Solution Approach 2:
The closure element is integrated with the existing piston and outlet channel structure. By combining the venting control function with the existing compression mechanism, the patent achieves direction-controlled venting without adding entirely separate control systems, thereby minimizing the increase in device complexity.
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 solution effectively utilizes the damping and cushioning effects of the compressible medium while preventing unwanted restoring movements, improving the adaptability and performance of orthopedic damping devices, particularly in prosthetic and orthotic knee joints.
Implementation Method 1
the medium is compressed in a compression chamber by reducing the chamber volume by means of a piston
Implementation Method 2
the compressed medium, for example air, is decompressed and exerts a restoring force
Implementation Method 3
The closure element can be mounted frictionally and slidingly on the contact region, such that the switchover of the closure element from the closed state to the open state can be performed by a frictional force
Data Source
AI summary
An orthopedic damping device with a movably mounted piston and at least one chamber which has a wall and in which a compressible medium is compressed by moving the piston in a first direction and decompressed by moving the piston in an opposite second direction. The chamber is connected to a discharge channel. A closure element is paired with the discharge channel. The closure element is movably mounted on a support. The support is coupled to the piston or is designed as a piston. The closure element is coupled to a contact region which can be moved relative to the support.