Partially Degradable Vena Cava Filter for Secondary Surgery Avoidance
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Solution Overview
Problem
Current Vena Cava Filters (VCFs) either require secondary surgery for retrieval or remain in the body as a long-term foreign object, leading to complications such as vena cava blockage and perforation, and existing partially degradable filters cannot be retrieved once implanted.
Innovation Solution
A filter device with a filtering part, a degradable constraining part, and a stent part that can be retrieved within a preset time window and partially degraded beyond that, converting into a tubular stent to reduce long-term complications and avoid secondary surgery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a permanent VCF is implanted to prevent PE, then the filter can effectively intercept detached thrombus, but it causes long-term complications such as vena cava obstruction
Solution Approach 1:
The filter utilizes material degradation parameter changes over time. The degradable filament material gradually degrades in the body, transforming the filter from a permanent obstruction into a temporary support structure, thereby eliminating long-term vena cava obstruction while maintaining initial thrombus interception capability
Solution Approach 2:
The filter employs composite material construction combining degradable filament material with a metal stent framework. This composite structure allows the filter to provide immediate mechanical support for thrombus interception while the degradable portion eliminates long-term foreign body presence, resolving the contradiction between reliability and harmful effects
2Object-affected harmful factors
If a retrievable VCF is implanted to avoid long-term complications, then the filter can be removed after PE risk is removed, but secondary surgery is required and retrieval success is not guaranteed
Solution Approach 1:
The degradable filament portion of the filter performs self-service by automatically degrading and detaching from the filtering part over time. This eliminates the need for secondary surgical retrieval operations, as the filter spontaneously releases itself after serving its protective function, thereby improving ease of operation while maintaining reduced long-term complications
3Ease of operation
If a partially degradable filter is used to eliminate retrieval surgery, then the filter converts to a stent, but the filter remains as a metal foreign body causing potential risks
Solution Approach 1:
The design extracts the degradable filament portion from the permanent metal stent structure. The degradable filament serves its filtering function temporarily and then detaches and degrades, leaving only the essential metal stent framework that provides structural support without the harmful filtering mesh, thereby reducing metal foreign body risk while maintaining ease of operation
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 retrieval of the filter device within a preset time frame or its conversion into a tubular stent, reducing the incidence of vena cava blockage and perforation, and eliminating the need for secondary surgery, thus alleviating patient suffering.
Implementation Method 1
the degradable filament is degraded in the blood vessel
Data Source
AI summary
The present invention provides a filter device, including a filtering part, a constraining part, a stent part, and a connecting part. The filtering part has a first end and a second end opposite to each other. The constraining part is degradable and at least configured to constrain the first end of the filtering part. The stent part has a first end and a second end opposite to each other. The first end of the stent part is connected to the second end of the filtering part, and disposed coaxial with the filtering part. The connecting part is disposed on one or more of the first end of the filtering part and the second end of the stent part, and is configured to connect to an external mechanism, and the constraining part is further configured to constrain the second end of the stent part when the connecting part is disposed at the second end of the stent part. The present invention can be taken out from the human body and can also be partially degraded in the human body so that the occurrence rate of long-term complications is reduced, and secondary surgery can thus be avoided.