Segmented Catheter for Biliary Stone Retrieval
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Solution Overview
Problem
Endoscopic devices face challenges in precisely navigating and maintaining position within the biliary and pancreatic tracts, particularly when removing objects like stones, due to the difficulty in advancing and retracting devices through the papilla of Vater and maintaining catheter position.
Innovation Solution
A catheter with a longitudinal slit, slot, or line of weakness is designed to facilitate the retraction of end effectors and maintain catheter position, allowing for easier removal of objects from the biliary or pancreatic tract by enabling the end effector to be retracted through the catheter while maintaining the catheter's position within the body lumen.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a catheter is used to access the biliary tract through the papilla of Vater, then biliary access is achieved, but the catheter position is difficult to maintain during end effector retraction
Solution Approach 1:
The catheter is divided into multiple segments or sections along its length, with each segment capable of independent movement or expansion. This segmentation allows the catheter to maintain its position at the papilla while permitting the end effector to be retracted through the catheter structure without displacing the entire catheter assembly.
Solution Approach 2:
The catheter incorporates dynamic elements such as expandable balloons, movable segments, or shape-memory materials that can change configuration during the procedure. These dynamic features allow the catheter to anchor securely at the papilla while providing a pathway for end effector retraction without losing positional stability.
2Stability of the object's composition
If the catheter structure is made rigid to maintain position, then position stability is improved, but the ability to retract end effectors becomes more difficult
Solution Approach 1:
Different sections of the catheter are designed with different mechanical properties. The proximal section may be more rigid to maintain overall positioning, while distal sections or specific segments are made flexible or collapsible to accommodate end effector retraction. This local variation in structural properties resolves the contradiction between overall stability and local flexibility.
Solution Approach 2:
The catheter is constructed using composite materials that combine rigid and flexible properties within a single structure. For example, a rigid outer framework may be combined with flexible inner layers or coating, allowing the catheter to maintain its shape and position while permitting the passage and retraction of end effectors through its structure.
3Ease of operation
If the catheter is designed to allow easy end effector passage, then ease of operation is improved, but catheter position may be lost during retraction
Solution Approach 1:
The catheter is pre-configured with expansion elements, anchoring features, or locking mechanisms that are activated before end effector retraction begins. This preliminary action secures the catheter position in advance, creating a stable framework that allows easy end effector passage without compromising positional retention during the retraction process.
Solution Approach 2:
The catheter design incorporates nested structures where inner components can move or retract through outer components. The end effector is nested within the catheter structure during insertion, and the catheter's nested design allows the effector to be retracted through it while the outer catheter layers maintain anchoring features that prevent position loss during this nested retraction process.
Data Source
AI summary
Endoscopes, endoscopic instruments, and methods for making and using the same. An illustrative endoscopic instrument includes a catheter that can extend through the working channel of an endoscope. The catheter may include an end effector passing region.