Retrieval Snare with Shape Memory Loop Elements
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Solution Overview
Problem
Current retrieval devices face challenges in efficiently engaging and removing medical devices, such as vena cava filters and kidney stones, due to geometric complexities and visualization difficulties within body lumens, particularly in procedures like stenting and thrombectomy.
Innovation Solution
A novel retrieval snare device with a shaft and deployable loop elements, made from shape memory wires and radiopaque materials, is designed to capture and retrieve objects by deploying in various configurations to conform to lumen geometry, facilitating easier engagement and removal through minimally invasive procedures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a traditional snare device is used to engage retrieval features, then the retrieval process can be completed, but the procedure is difficult and time-consuming due to geometric complexities and visualization difficulties
Solution Approach 1:
The snare device employs dynamically deployable loop elements that can transition from a compressed delivery state to an expanded engagement state. The loop elements are configured to deploy in various configurations (e.g., figure-eight, circular, or asymmetric patterns) to adapt to different retrieval feature geometries, enabling easier and faster engagement compared to static traditional snares.
Solution Approach 2:
The device utilizes shape memory wires (e.g., nitinol) that change their physical parameters (shape, stiffness, expandability) in response to temperature or mechanical triggers. This allows the loop elements to transform from a compact delivery configuration to an expanded engagement configuration, improving ease of operation while reducing retrieval time.
2Adaptability or versatility
If the snare device uses complex loop element configurations to adapt to different geometries, then engagement capability is improved, but device complexity increases
Solution Approach 1:
The snare device divides the engagement structure into multiple independent loop elements (e.g., first loop element and second loop element) that can deploy and function semi-independently. This segmentation allows each loop element to adapt to different geometries while the overall device structure remains modular and manageable, balancing versatility with complexity.
Solution Approach 2:
The loop elements are designed with universal engagement capability, where the same basic loop structure can achieve effective engagement across various retrieval feature geometries (e.g., hooks, rings, or irregular shapes) by deploying in different configurations. This multi-functionality reduces the need for multiple specialized device variants, thereby controlling overall device complexity.
3Difficulty of detecting and measuring
If radiopaque materials are incorporated into the snare device, then visualization is improved, but the device structure becomes more complex
Solution Approach 1:
The snare device incorporates radiopaque materials (e.g., barium sulfate, tungsten, or platinum) composite-integrated into the loop element structures, particularly at strategic locations such as loop crossings or distal tips. This provides enhanced fluoroscopic visualization without requiring completely radiopaque construction of the entire device, thereby improving detection while limiting the increase in material complexity.
4Adaptability or versatility
If the loop elements are designed to deploy in multiple configurations, then adaptability to different lumens is improved, but manufacturing precision requirements increase
Solution Approach 1:
The loop elements are pre-configured during manufacturing with predetermined memory shapes (e.g., figure-eight, circular, or asymmetric patterns) that automatically deploy into the desired configurations upon delivery to the target site. This preliminary action eliminates the need for complex real-time manipulation during the procedure, reducing manufacturing precision requirements while maintaining adaptability to different lumen geometries.
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 device enhances the ability to capture and remove foreign objects from body lumens by providing controlled deployment and visualization, improving the efficiency and accuracy of retrieval processes, especially in complex anatomical locations.
Implementation Method 1
made from shape memory wires
Implementation Method 2
made from shape memory wires and radiopaque materials
Data Source
AI summary
The present invention relates generally to devices and methods for retrieving or manipulating objects within a lumen. More specifically, embodiments of the invention relate to devices and methods for retrieving or manipulating medical devices from a body lumen. One embodiment of the present invention provides a novel and improved retrieval snare and method of fabricating and using the same. The snare includes a snare wire, having a distal end and a proximal end, for use in the human anatomy, such as but not limited to blood vessels, pulmonary airways, reproductive anatomy, gastrointestinal anatomy, and organs such as the kidneys or lungs. The device enables a user to capture a foreign object located within the human anatomy, grasp said object in a controlled manner, and retrieve and remove said object from the human anatomy.