Retrieval Device with Multi-Segment Expandable Loop
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing medical retrieval devices are limited by the size of their front loop, which restricts the capture and manipulation of larger objects, and often feature complex designs with many components, making them bulky, expensive, and prone to failure.
Innovation Solution
A retrieval device with a sheath and at least three support members, each with varying cross-sectional shapes along its length, allowing for a contracted state for easy insertion and an expanded state for capturing larger objects, along with movable members that extend through lumens of the support members to facilitate expansion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the front loop size of the end effector is increased to capture larger objects, then the capture capability is improved, but the device profile increases making insertion and withdrawal more difficult
Solution Approach 1:
The end effector is designed with a front loop that can dynamically change its size between a small profile state for insertion and a large expanded state for capturing objects. The loop is formed by movable members that can be actuated to expand or contract, allowing the same structure to adapt to different operational requirements without requiring multiple devices.
Solution Approach 2:
When in the contracted state, the movable members are positioned within or alongside the support members, allowing the end effector to occupy minimal space within the retrieval device. This nesting arrangement enables the large-capacity loop to be collapsed into a compact configuration that can pass through narrow body passages.
2Adaptability or versatility
If the end effector is designed with a large front loop for capturing larger objects, then the capture capability is improved, but the risk of loop entanglement increases
Solution Approach 1:
The front loop is divided into multiple independent segments formed by separate movable members (first movable member, second movable member, etc.). Each segment can be actuated independently through its own actuator, allowing controlled expansion and reducing the likelihood of entanglement between segments. This modular approach maintains capture capability while improving reliability.
3Ease of manufacture
If the retrieval device uses complex joining mechanisms to assemble small parts, then the manufacturing capability is improved, but the device profile increases and structural strength decreases
Solution Approach 1:
Multiple functions are merged into the support members themselves. The support members serve as both structural elements and as guides for the movable members, eliminating the need for separate joining mechanisms. The proximal ends of the support members are coupled to the sheath in a way that integrates the support structure with the drive mechanism, reducing overall device complexity while maintaining assembly capability.
Data Source
AI summary
A retrieval device may have a contracted state and an expanded state. The retrieval device may include a sheath and at least three support members. Each of the support members may have a first portion with a first cross-sectional shape and a second portion with a second cross-sectional shape different from the first cross-sectional shape. A proximal end fixed of each of the support members may be coupled to the sheath, and a distal end may be movable relative to the sheath. The retrieval device may further include at least three movable members movable relative to the support members. Each movable member may extend through a lumen of one support member of the at least three support members and through a lumen of a different support member of the at least three support members.