L-Shaped Negative-Pressure Therapy Cavity for Low-Friction Joint Treatment

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Solution Overview

Problem

Existing negative pressure therapy equipment for human body facet joint inflammation is cumbersome, causes unbearable pain and bleeding due to mechanical instability and friction, is not easily sealed, and is costly and non-portable, making it impractical for widespread use.

Innovation Solution

A lightweight, L-shaped therapy cavity design with a negative pressure generation control system, using a sealing bag or tape for easy sealing and reducing frictional forces, combined with a movable spacer to maintain stability and reduce weight, allowing for portable use.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a straight cylindrical therapy cavity is used, then the equipment structure is simple, but the equipment is cumbersome and causes unbearable pain due to excessive friction between the seal and the limb

Engineering Contradiction:
Improvestructure simplicityVSAvoidfriction pain
Core Design Contradiction:
Device complexityVSEase of operation

Solution Approach 1:

The therapy cavity is divided into multiple segments (thigh cavity, shank cavity, foot cavity) that can be separately adjusted and sealed. This segmentation allows the seal to contact only the thigh portion while the lower limb is treated, significantly reducing friction and pain at the seal interface.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The therapy cavity transitions from a straight cylindrical shape to an L-shaped configuration with spatial separation between the thigh cavity and lower limb cavity. This dimensional change allows the seal to be positioned away from the treated area, reducing friction and improving patient comfort.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Stability of the object's composition

If the therapy cavity weight is increased to prevent movement under negative pressure, then mechanical stability is improved, but the equipment becomes non-portable and cannot be used at home

Engineering Contradiction:
Improvemechanical stabilityVSAvoidequipment portability
Core Design Contradiction:
Stability of the object's compositionVSWeight of moving object

Solution Approach 1:

The patent introduces a counterweight mechanism that balances the therapy cavity system. The counterweight compensates for the negative pressure forces, allowing the equipment to remain stable during treatment while maintaining a lightweight, portable design suitable for home use.

Inventive Principle:
Principle #8Anti-weight (Counterweight)

Solution Approach 2:

The equipment includes preliminary positioning and securing mechanisms that are activated before negative pressure is applied. These mechanisms pre-establish the mechanical stability needed, allowing the use of lighter materials and reducing the overall weight while maintaining stability during operation.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If airbag sealing is used, then sealing is achieved, but severe radial compression is caused to blood vessels, obstructing blood circulation and causing unbearable pain

Engineering Contradiction:
Improvesealing effectivenessVSAvoidblood circulation obstruction
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The harmful radial compression function is extracted from the sealing mechanism. The patent uses a separate sealing system that contacts only the thigh portion of the limb, while the lower limb and foot are treated through the L-shaped cavity configuration. This separation eliminates the harmful compression effects on blood vessels in the treated area.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces an intermediary sealing mechanism that uses a soft, compliant material to create a seal without excessive compression. The seal is positioned at the thigh-cavity interface and uses controlled sealing force, acting as an intermediary between the negative pressure system and the patient's limb, thereby preventing blood circulation obstruction.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Ease of manufacture

If a straight cylindrical therapy cavity is used, then manufacturing is simple, but the equipment is costly and not portable

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidcost and portability
Core Design Contradiction:
Ease of manufactureVSWeight of moving object

Solution Approach 1:

The therapy cavity is segmented into multiple modular components (thigh cavity, shank cavity, foot cavity) that can be manufactured separately and assembled. This segmentation allows for optimized material selection and weight reduction in each component while maintaining manufacturing simplicity through standardized production processes.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent employs flexible shell materials and thin-film constructions for the therapy cavity components. These materials provide the necessary structural integrity and sealing capabilities while significantly reducing the weight and cost of the equipment, making it portable and suitable for home use.

Inventive Principle:
Principle #30Flexible shells and thin films

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 design significantly reduces weight and friction, prevents bleeding and pain, ensures easy sealing, and enhances portability, making it practical for home use and effective in treating facet joint inflammation.

Implementation Method 1

negative pressure generation control system

Methodology Applied
Scientific EffectNegative pressure: Pressure Gradient

Data Source

PatentEP3643287B1Physiotherapy instrument for human body facet joint inflammation
Publication Date: 2025.07.02 QUAN CHENGXIAN
  • EP3643287B1 patent drawingFigure 1~2
  • EP3643287B1 patent drawingFigure 3~4
  • EP3643287B1 patent drawingFigure 5~6

AI summary

A physiotherapy instrument for human body facet joint inflammation is disclosed, relating to the technical field of medical therapy equipment. The physiotherapy instrument includes a rigid therapy cavity and a negative pressure generation control system. The therapy cavity is provided with at least one opening for a limb to enter and leave. The therapy cavity is connected to the negative pressure generation control system by means of an air passage. The therapy cavity is L-shaped, to allow a partial thigh above a knee of a limb and a partial or entire shank below the knee to be put in after bending, and allow a partial arm above an elbow of a limb and a partial or entire forearm below the elbow to be put in after bending. The L-shaped therapy cavity is composed of several parts fitted with each other to form a whole. The opening of the therapy cavity and the limb are fixed by means of a sealed connecting component. A conventional straight cylindrical therapy cavity is changed into the L-shaped therapy cavity, so that upper and lower parts of a joint are put into the therapy cavity at the same time after a knee joint or an elbow joint of the limb bends, thus fundamentally changing the condition of mechanical instability between the straight cylindrical therapy cavity and the limb under a negative pressure. The physiotherapy instrument has a good therapeutic effect, and is lightweight as a whole.