Interconnected Loop Retrieval Snare for Vessel Extraction
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Solution Overview
Problem
Existing retrieval snares for removing foreign objects from body tracts lack structural rigidity and dilatation ability, leading to displacement and entanglement issues during operation, which hinders effective extraction.
Innovation Solution
A retrieval snare with a petal-shaped structure formed by interconnected filaments that extend from a proximal portion to a distal portion, providing structural rigidity and dilatation ability through twisting connections, and optionally made from non-metallic or metallic materials with thermo-mechanical shape memory characteristics, radiopacity, and a radiopaque coating or markers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of moving object
If multi loop snares with free loops are used to improve cross sectional vessel coverage, then the area of the snare is improved, but the loops become displaced and entangled due to lack of structural rigidity
Solution Approach 1:
The snare is divided into multiple interconnected loops arranged in a grid pattern, where each loop is a separate element but connected to adjacent loops at multiple points. This segmentation allows the snare to expand across the vessel cross-section while maintaining individual loop integrity through connections that prevent displacement and entanglement.
Solution Approach 2:
The snare incorporates shape memory alloy filaments that combine the flexibility needed for vessel navigation with the structural rigidity required to maintain loop geometry. The composite structure of interconnected loops with shape memory material provides both the area coverage and stability needed to resolve the contradiction.
2Adaptability or versatility
If free loops are used to increase snare opening capability, then the dilatation ability is improved, but the loops lack resistance to counter forces causing displacement
Solution Approach 1:
The loops are pre-configured in a compressed state within a catheter with predetermined geometric relationships established through multiple connection points. This preliminary arrangement ensures that when deployed, the loops maintain their relative positions and resist displacement while still allowing for opening capability.
Solution Approach 2:
The snare structure transitions from a compressed static state within the catheter to an expanded dynamic state during deployment. The interconnected loops with shape memory material provide dynamic adaptability for opening while maintaining structural strength to resist counter forces during the transition and operation.
3Stability of the object's composition
If loops are interconnected to provide structural rigidity, then the stability is improved, but the loops may become entangled during retraction
Solution Approach 1:
The interconnected loop structure is designed to nest within the catheter in a controlled manner during retraction. The grid pattern and connection points allow loops to fold and compress systematically, preventing entanglement while maintaining geometric stability when deployed. The nested configuration enables smooth retraction without compromising the structural integrity of the loop arrangement.
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 snare effectively maintains loop geometry and resists counter forces, ensuring reliable and efficient extraction of foreign objects by providing structural rigidity and dilatation ability, preventing displacement and entanglement.
Implementation Method 1
The connection of the sides of the loops along the proximal portion is achieved by twisting each pair of the filaments forming the corresponding sides by one or more turns
Implementation Method 2
the filaments are made of metallic material. The metallic material can have a thermo-mechanical shape memory characteristic
Implementation Method 3
The metallic material can have a thermo-mechanical shape memory characteristic. Moreover, the metallic material can have superelastic characteristic. Examples of the metallic material include, but are not limited to, NiTi based alloy and stainless steel. When desired, the metallic material includes a material which provides radiopacity
Data Source
AI summary
A retrieval snare for entrapping and retaining a foreign object located in a body and a method for manufacturing of the snare are provided. The snare comprises a structure having a proximal portion and a distal portion and includes a plurality of filaments. The filaments extend from an end of the proximal portion towards the distal portion and return to the end of the proximal portion to form a plurality of loops. The loops are not interconnected at the distal portion, but each side of each loop are connected to a side of an adjacent loop in the proximal portion at more than one point, thereby providing structural rigidity and dilatation ability to the snare.