Introducer Sheath Wire Frame Density Gradient
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Solution Overview
Problem
Current introducer sheaths often experience vascular access bleeding and kinking issues due to thin walls, which can lead to blocked passageways and medical instrument misfitting, necessitating reinforcement to maintain shape and prevent deformation.
Innovation Solution
The introduction of a wire frame with a distal portion having wires more densely disposed than the proximal portion, utilizing braided or coiled metal frames with annealed and unannealed sections to enhance stiffness, kink resistance, and spring temper, along with a polymer jacket and liner for structural integrity and fluoroscopic visibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the wall thickness of the introducer sheath is reduced, then the sheath becomes more flexible and easier to insert, but the sheath experiences kinking and deformation that blocks passageways
Solution Approach 1:
The wire frame is constructed with varying wire density along its length - more densely disposed wires in the distal portion and less densely disposed wires in the proximal portion. This creates local variations in stiffness that allow the sheath to be flexible enough for insertion while maintaining structural integrity to prevent kinking in critical areas.
Solution Approach 2:
The introducer sheath combines multiple materials - a polymer material for the sheath wall and a wire frame reinforcement element. This composite structure provides both the flexibility needed for insertion and the strength required to prevent kinking, as the polymer provides elasticity while the wire frame provides structural support.
2Adaptability or versatility
If the wall thickness of the introducer sheath is reduced, then the sheath allows better instrument fitting and navigation, but the sheath deforms and loses its shape
Solution Approach 1:
The wire frame employs non-uniform wire distribution with different densities at different locations. The distal portion has higher wire density to maintain shape stability, while the proximal portion has lower wire density to allow adaptability for instrument passage, resolving the contradiction between shape maintenance and instrument compatibility.
Solution Approach 2:
The wire frame structure allows dynamic deformation - it can elastically deform to accommodate instruments passing through while the annealed and unannealed sections provide different degrees of flexibility and recovery, enabling the sheath to adapt to various instruments while maintaining its overall shape.
3Strength
If the wire frame density is increased throughout, then the sheath gains kink resistance, but the sheath becomes too rigid for elastic deformation
Solution Approach 1:
Rather than uniform wire density throughout, the invention uses localized variations in wire density. The distal portion has higher density for kink resistance, while the proximal portion has lower density for elastic deformation capability. This local differentiation resolves the contradiction between strength and adaptability.
Solution Approach 2:
The wire density parameter is changed along the length of the wire frame, creating a gradient from high density at the distal end to lower density at the proximal end. This parameter variation allows different sections to exhibit different mechanical properties - high kink resistance where needed and high elasticity where instrument flexibility is required.
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
This design reduces bleeding complications, maintains the sheath's shape to prevent kinking, and allows for temporary elastic deformation without permanent kinking, improving the introducer's performance and usability in vascular procedures.
Implementation Method 1
utilizing braided or coiled metal frames with annealed and unannealed sections to enhance stiffness, kink resistance, and spring temper
Data Source
AI summary
The present disclosure illustrates an introducer sheath with a braided or coiled wire frame. The wire frame of the introducer sheaths described herein include a distal portion having the wire disposed more densely than a proximal portion of the wire frame. The introducer sheaths also include a jacket encompassing the wire frame and a liner forming an inner wall.