Orthopedic Joint Hinge With Offset Interface Surfaces
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Solution Overview
Problem
Current orthopedic hinge assemblies fail to effectively limit unwanted joint motion during medical treatments, which can lead to injury and hinder therapeutic joint motion.
Innovation Solution
An orthopedic hinge assembly with offset interface surfaces and a coupling mechanism that allows rotation in one direction while blocking it in the opposite direction, using a coupling shaft and retention members to constrain joint motion, and adjustable interface assemblies for patient interaction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a hinge assembly allows rotation in one direction, then therapeutic joint motion is facilitated, but unwanted joint motion in the opposite direction cannot be blocked
Solution Approach 1:
The interface surfaces are designed with asymmetric geometry where the first interface surface and second interface surface are offset from the axis of rotation. This asymmetric configuration creates a mechanical advantage that allows the hinge to rotate freely in one direction (therapeutic motion) while automatically blocking rotation in the opposite direction (unwanted motion), resolving the contradiction between ease of operation and reliability
Solution Approach 2:
The offset interface surfaces act as intermediary elements between the first and second elongated members. These surfaces mediate the rotational interaction by engaging to block unwanted motion while allowing therapeutic motion to pass through, effectively controlling joint movement without requiring complex active control mechanisms
2Stability of the object's composition
If interface surfaces are offset from the axis of rotation to block rotation, then joint stability is improved, but the complexity of the hinge mechanism increases
Solution Approach 1:
The asymmetric offset configuration of the interface surfaces provides joint stability through a simple geometric relationship rather than complex mechanical components. The offset distance and angular orientation create the blocking effect naturally, avoiding the need for additional actuators, sensors, or control systems that would increase device complexity
Solution Approach 2:
The hinge mechanism is designed to be self-regulating, where the offset interface surfaces automatically engage to block unwanted rotation and disengage to allow therapeutic rotation without external control. This self-service capability maintains joint stability while minimizing the complexity of control mechanisms
Data Source
AI summary
An orthopedic joint hinge assembly includes a first elongated member, a first coupler attached to the first elongated member and including a first interface surface, a second elongated member, and a second coupler attached to the second elongated member and including a second interface surface. Each of the first and second couplers is constrained to rotate about an axis of rotation. The first and second interface surfaces are offset from the axis of rotation and engage each other to block a relative rotation between the first and second members in a first direction and separate from each other to permit a relative rotation in an opposite direction.