Joint Prosthesis Clutch and Gravity Compensator

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current joint prostheses, particularly prosthetic elbows, are unreliable, unintuitive, noisy, and costly, with high power consumption, making them uncomfortable and difficult to control, and they do not provide an experience similar to a natural limb.

Innovation Solution

A joint prosthesis with a clutch mechanism that allows for intuitive control, low noise, and low power consumption, featuring a mechanical architecture with a free swing mechanism and a gravity compensator, along with a servomotor and transmission system that enables responsive and natural movement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Extent of automation

If a motor with special transmission is used to drive joint prosthesis rotation, then the prosthesis can achieve active movement, but reliability decreases and power consumption increases

Engineering Contradiction:

Improveactive movement capabilityVSAvoidprosthesis reliability

Core Design Contradiction:

Extent of automationVSReliability

Solution Approach 1:

The patent extracts the motor from the prosthesis design entirely, eliminating the need for complex transmission systems. Instead, the prosthesis uses passive mechanical elements (pulley, cable, spring) to achieve movement, thereby improving reliability by removing the single point of failure that the motor represents.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The spring mechanism is positioned and tensioned to create a balanced system where gravitational forces and spring forces work together to maintain natural movement arcs. This equipotential design allows the prosthesis to move smoothly through its range of motion without requiring active power input, reducing power consumption to near zero.

Inventive Principle:

Principle #12Equipotentiality

2Extent of automation

If a motor with special transmission is used to drive joint prosthesis rotation, then the prosthesis can achieve active movement, but power consumption increases

Engineering Contradiction:

Improveactive movement capabilityVSAvoidpower consumption

Core Design Contradiction:

Extent of automationVSUse of energy by moving object

Solution Approach 1:

Inventive Principle:

Principle #12Equipotentiality

Solution Approach 2:

The prosthesis uses the user's own body movements and gravity to power the mechanism. The cable-pulley system converts natural arm motion into prosthesis movement, while the spring stores and releases energy to maintain motion, creating a self-sustaining system that requires minimal external power.

Inventive Principle:

Principle #25Self-service

3Extent of automation

If a motor with special transmission is used to drive joint prosthesis rotation, then the prosthesis can achieve active movement, but transmission noise increases

Engineering Contradiction:

Improveactive movement capabilityVSAvoidtransmission noise

Core Design Contradiction:

Extent of automationVSObject-generated harmful factors

Solution Approach 1:

The patent extracts the motor from the prosthesis design entirely, eliminating the need for complex transmission systems. Instead, the prosthesis uses passive mechanical elements (pulley, cable, spring) to achieve movement, thereby reducing transmission noise by removing the primary noise source.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the motor-driven transmission system with a passive cable-pulley-spring mechanism. This substitution eliminates the noisy components of traditional motor transmissions (gears, belts, motors) while maintaining the ability to achieve active movement through user-powered mechanical advantage.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

4Extent of automation

If complex transmission systems are used in joint prostheses, then active movement is achieved, but device complexity increases

Engineering Contradiction:

Improveactive movement capabilityVSAvoidtransmission complexity

Core Design Contradiction:

Extent of automationVSDevice complexity

Solution Approach 1:

The patent extracts the motor from the prosthesis design entirely, eliminating the need for complex transmission systems. Instead, the prosthesis uses passive mechanical elements (pulley, cable, spring) to achieve movement, thereby simplifying the device architecture while maintaining active movement capability.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The cable-pulley-spring mechanism serves multiple functions simultaneously: it transmits force, stores energy, controls motion arcs, and provides mechanical advantage. This multi-functionality reduces the need for separate components that would increase complexity in traditional motor-driven designs.

Inventive Principle:

Principle #6Universality (Multi-functionality)

5Extent of automation

If traditional prosthetic joints are designed with motor and transmission, then active movement is possible, but cost increases

Engineering Contradiction:

Improveactive movement capabilityVSAvoidmanufacturing cost

Core Design Contradiction:

Extent of automationVSEase of manufacture

Solution Approach 1:

The patent employs simple, inexpensive mechanical components (standard pulleys, cables, springs) that can be manufactured at low cost and replaced easily if needed. These components are far cheaper than motors and transmission systems, making the prosthesis more affordable while maintaining active movement capability.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 prosthesis provides a reliable, comfortable, and affordable solution with intuitive control, low noise, and extended battery life, allowing for natural and responsive movement similar to a real joint, capable of lifting heavy objects with reduced power and cost.

Implementation Method 1

a spring configured to apply a compensation force

Methodology Applied

Scientific EffectSpring force: Spring

Implementation Method 2

counteracting a force due to gravity on the first prosthesis

Methodology Applied

Scientific EffectGravitational force: Gravitation

Implementation Method 3

a pulley configured to vary the compensation force applied by the spring as a function of an angle between the attachments

Methodology Applied

Scientific EffectMechanical advantage through pulley: Pulley

Data Source

PatentUS20240350283A1Joint prosthesis

Publication Date: 2024.10.24 FOND INST ITAL DI TECH

AI summary

It is provided a joint prosthesis (1) configured to reciprocally rotate a first prosthesis (1a) and a second prosthesis (1b) and comprising: a first attachment (2) to the first prosthesis (1a); a second attachment (3) to the second prosthesis (1b): a hinge (4) defining an axis of rotation (4a) between the attachments (2, 3); a mover (5) configured to apply to the hinge (4) a driving torque defining a reciprocal rotation between the attachments (2, 3); and a compensator (6) configured to apply to the hinge (4) a variable locking torque depending on the angular opening between the attachments (2, 3) and defining the minimum torque to be applied to the hinge (4) to have said reciprocal rotation.