Bendable Ureteral Access Sheath with Segmented Kink-Resistant Design
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Solution Overview
Problem
Traditional ureteral access sheaths are straight and kink-resistant, leading to potential damage and inadequate drainage during ureteroscopy, especially in patients with curved ureters, resulting in complications like ureteral perforation and high intrapelvic pressure.
Innovation Solution
A bendable ureteral access sheath with a flexible and foldable corrugated tube structure, reinforced with steel wires and rings, allowing for directional change and reduced risk of ureteral damage, combined with a hydrophilic coating for smooth insertion and improved drainage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a traditional straight and kink-resistant ureteral access sheath is used, then the sheath maintains structural integrity and resists kinking, but it causes damage to the ureteral wall when passing through curvatures and leads to inadequate drainage in patients with curved ureters
Solution Approach 1:
The sheath tube is divided into multiple functional sections: a first straight tube section with reinforcing steel wires for kink resistance, a bendable tube section with flexible corrugated structure for navigating curvatures, and a second straight tube section with reinforcing steel wires. This segmentation allows different parts of the sheath to perform different functions, resolving the contradiction between maintaining structural integrity and adapting to curved anatomy.
Solution Approach 2:
Different sections of the sheath tube are given different local properties: the straight sections have high rigidity due to steel wire reinforcement to prevent kinking, while the bendable section has high flexibility due to its corrugated structure to conform to ureteral curvatures. This local differentiation of mechanical properties allows the sheath to simultaneously resist kinking in straight portions and adapt to curves without damaging the ureter.
2Stability of the object's composition
If a straight ureteral access sheath is used to maintain structural stability, then the sheath remains stable during insertion, but it cannot adequately navigate physiological or pathological curvatures of the ureter
Solution Approach 1:
The sheath is segmented into straight stable sections and a bendable adaptive section, allowing the overall structure to maintain stability while the bendable section provides directional adaptability when needed to navigate ureteral curvatures.
Solution Approach 2:
The sheath transitions from a static straight structure to a dynamic structure where the bendable tube section can change its shape and direction in response to the anatomical path of the ureter, while the reinforced sections maintain their structural stability.
3Adaptability or versatility
If a bendable tube section is introduced to navigate curvatures, then the sheath can adapt to ureteral anatomy, but the overall structural integrity and kink resistance may be compromised
Solution Approach 1:
By segmenting the sheath into reinforced straight sections and a flexible bendable section, the design ensures that the bendable portion handles the adaptive function while the reinforced sections maintain overall structural integrity and prevent kinking in the straight portions.
Solution Approach 2:
The sheath combines different materials and structures: rigid plastic with steel wire reinforcement for structural sections, and flexible corrugated material for the bendable section. This composite construction allows the sheath to simultaneously achieve structural integrity and bending capability.
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 bendable design enables safe and efficient navigation through curved ureters, reducing the risk of ureteral damage and improving drainage, thereby preventing complications such as urosepsis and enhancing surgical visibility and efficiency.
Implementation Method 1
both its inner and outer walls coated with hydrophilic coatings
Data Source
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AI summary
Provided herein is a bendable ureteral access sheath, comprising a sheath tube, an inner tube, and a sheath tube hub. The sheath tube is sleeved on the outside of the inner tube. The sheath tube hub is connected with the tail end of the sheath tube. The sheath tube comprises a first straight tube section, a bendable tube section, and a second straight tube section, which are connected to each other sequentially. The first and second straight tube sections are each reinforced with reinforcing steel wires in their tube walls and are kink-resistant, and the bendable tube section is of a flexible structure.