Prosthesis Lever Mechanism for Joint Axis Positioning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing prosthetic solutions for long stumps and disarticulation stumps often result in an unnatural limb length, causing visibility issues and discomfort, especially in public settings, and do not allow for optimal positioning of the joint axis close to the natural joint axis, leading to inadequate fit and mobility.
Innovation Solution
A prosthesis design featuring a pivot joint with a damper, spring, or actuator device mounted between the carrier part and the distal prosthesis component, utilizing a lever mechanism to adjust the joint axis position and leverage ratio, allowing for a more natural limb length and improved mobility, with the option to position the joint axis proximally to the stump end.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If the joint axis is positioned distally to accommodate long stumps, then the prosthetic limb length increases, but the unnatural limb length causes visibility issues and discomfort in public settings
Solution Approach 1:
The patent introduces a lever mechanism that transforms the linear positioning problem into a rotational dimension. By positioning the pivot axis proximally and using a lever with appropriate arm length ratios, the system achieves effective distal functionality while maintaining a compact proximal structure, thus reducing visible limb length without sacrificing functional reach
Solution Approach 2:
The lever acts as an intermediary between the proximal pivot axis and the distal functional requirements. The lever transfers and amplifies the rotational motion from the proximal axis to achieve the necessary distal movement range, allowing the joint axis to be positioned proximally while still accommodating long stump requirements
2Ease of operation
If the joint axis is positioned proximally to reduce visible limb length, then social acceptance improves, but the fit and mobility for long stumps deteriorates
Solution Approach 1:
The lever mechanism serves multiple functions simultaneously: it acts as a force amplifier, a motion transformer, and a length adjuster. By varying the lever arm lengths, the same proximal pivot configuration can accommodate different stump lengths and provide appropriate functional range, thus maintaining reliability across various user requirements
Solution Approach 2:
The system allows adjustment of the lever arm length ratio to change the mechanical advantage and functional range. This parameter adjustment enables the prosthetic to be tuned for different stump lengths and user requirements, maintaining optimal fit and mobility performance while keeping the joint axis positioned proximally
3Force
If a damping device is mounted directly on the joint axis, then force transmission is direct, but the arrangement is inadequate for optimal positioning close to the natural joint axis
Solution Approach 1:
The lever serves as an intermediary that decouples the damping device mounting location from the functional joint axis position. The damping device can be mounted on the lever at an optimized location while the lever's rotational motion about the proximal pivot axis maintains the natural joint axis positioning, thus achieving both direct force transmission and optimal positioning flexibility
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
Enables a more natural and comfortable limb length, allowing for easier use of bicycles and reduced conspicuousness, with the ability to position the joint axis optimally, minimizing the length of the prosthetic limb and enhancing the fit with the non-supported side, thus improving the overall user experience.
Implementation Method 1
A damping device for damping the flexion and/or extension of the distal prosthetic component relative to the carrier part or the receiving element
Implementation Method 2
a spring device or an actuator device, for example a motor, a linear drive, a magnetic drive, or the like, can be arranged between the distal prosthetic component and the carrier part to store forces, convert them, or supply mechanical energy to the joint
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention relates to a prosthesis with a support part (10) on which a pivot joint (70) is secured or formed. A distal prosthesis component (20) is secured to the support part (10) via the pivot joint (70), and the pivot joint (70) allows a flexion and extension of the distal prosthesis component (20) about a pivot axis (15) relative to the receiving element (60) or to the support part (10). A damping device (30), spring device, and/or actuator is arranged between the distal prosthesis component (20) and the support part (10), and the damping device (30), spring device, and/or actuator is mounted on the distal prosthesis component (20) by means of a first bearing point (310) and is mounted on a lever (50) or an arm (40) by means of a second bearing point (320). The lever (50) is mounted on the distal prosthesis component (20) in a pivotal manner about a pivot axis (51). A distal portion (42) of the arm (40) is mounted on the lever (50), and a proximal portion (41) is mounted on the support part (10).