Self-Centering Vena Cava Filter with Curved Support

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Solution Overview

Problem

Conventional inferior vena cava filters have poor self-centering performance, leading to tilting and difficulty in retrieval, which increases operation time and risk of failure during removal.

Innovation Solution

A self-centering inferior vena cava filter design featuring a filter portion with staggered layers, a support portion that extends radially and curls inwardly to maintain point contact with the vessel wall, and a retrieval portion connected to prevent attachment to the vessel wall, enhancing self-centering and facilitating retrieval.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If a conventional cone-shaped inferior vena cava filter is used, then the filter structure is simple, but the self-centering performance is poor and the filter tilts after implantation

Engineering Contradiction:
Improveself-centering performanceVSAvoidfilter structure
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The filter structure is divided into multiple functional segments: a filter portion with filter members, a support portion with support members that curl inwardly, and a retrieval portion. This segmentation allows each component to perform its specific function - the support members provide self-centering while the filter members capture thrombi, resolving the contradiction between stability and structural simplicity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The support members are designed with a curved configuration that extends radially outward and then curls inwardly toward the central axis. This curvature enables the support members to contact the vessel wall and generate a restoring force that centers the filter, improving self-centering performance without requiring a complex active control system.

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Ease of operation

If the filter tilts after implantation, then the filter structure remains simple, but the retrieval hook attaches to the vessel wall making retrieval difficult

Engineering Contradiction:
Improveretrieval easeVSAvoidretrieval success
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The retrieval portion is pre-configured with a retrieval hook that maintains a specific spatial relationship with the support members. By designing the support members to curl inwardly and contact the vessel wall, the system preliminarily positions the retrieval hook away from the vessel wall, preventing attachment before retrieval is attempted and ensuring reliable retrieval operation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The support members act as an intermediary between the filter portion and the retrieval portion. They transmit the self-centering force to maintain filter orientation and simultaneously serve as a structural link that positions the retrieval hook in a safe location, mediating between the opposing requirements of simple structure and reliable retrieval.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If the retrieval hook is closely attached to the vessel wall due to filter tilting, then the implantation structure is simple, but the operation time increases and patient suffering increases

Engineering Contradiction:
Improveretrieval efficiencyVSAvoidretrieval operation
Core Design Contradiction:
ProductivityVSEase of operation

Solution Approach 1:

The support members are designed to automatically self-center the filter by contacting the vessel wall and generating a restoring force. This self-service mechanism eliminates the need for complex active centering systems or manual adjustment during implantation, maintaining simple structure while ensuring proper orientation for efficient retrieval.

Inventive Principle:
Principle #25Self-service

4Reliability

If the filter tilts, then the overall structure remains simple, but the retrieval operation may fail

Engineering Contradiction:
Improveretrieval success rateVSAvoidfilter structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The support members are positioned asymmetrically relative to the filter portion, with specific support members located at different angular positions around the central axis. This asymmetric arrangement ensures that at least some support members will contact the vessel wall to provide self-centering force, reliably preventing tilt and ensuring retrieval success without requiring symmetric complexity throughout the entire structure.

Inventive Principle:
Principle #4Asymmetry

Data Source

PatentEP3456290B1Vena cava filter with self-centrality
Publication Date: 2022.11.23 HANGZHOU WEIQIANG MEDICAL TECH CO LTD
  • EP3456290B1 patent drawingFigure 1~2
  • EP3456290B1 patent drawingFigure 3~4
  • EP3456290B1 patent drawingFigure 5~6

AI summary

The self-centering inferior vena cava filter is provided, which includes a filter portion, a support portion, and a retrieval portion. The filter portion is configured to filter thrombi and includes at least two layers of filter members extending along a central axis of the self-centering inferior vena cava filter, the at least two layers of filter members are adjacent to each other and staggered around the central axis. The support portion is configured to prevent the self-centering inferior vena cava filter from tilting, and extends outwardly radially from a center point of the self-centering inferior vena cava filter in a direction close to the filter portion and then curls inwardly radially in a direction away from the filter portion, and is supported on a blood vessel wall by point contact. The retrieval portion is connected with at least one of the filter portion and the support portion. The present disclosure provides the self-centering inferior vena cava filter with good self-centering performance to prevent a retrieval hook of the retrieval portion from being attached to the blood vessel wall.