Vascular Puncture Sheath With Expandable Stent for Stable Redirection
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Solution Overview
Problem
Existing vascular puncture sheaths lack stability in blood vessels, often leading to detachment during surgery, necessitating secondary punctures and increasing surgical difficulty and patient harm, and are unable to adjust direction for accessing different blood vessel ends or parts, requiring additional punctures and complicating surgeries.
Innovation Solution
A vascular puncture sheath with an inner and outer sheath tube system, featuring a metal stent with memory metal wires and an adjustment mechanism, allowing controlled expansion and contraction to stabilize the sheath in the vessel and facilitate guidewire redirection, using a ratchet and pawl system for unidirectional rotation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional vascular puncture sheath is used, then the procedure is simple, but the sheath is unstable in the blood vessel and may detach during surgery
Solution Approach 1:
The puncture sheath is divided into an inner sheath tube and an outer sheath tube that can move relative to each other. The metal stent is segmented into multiple memory metal wires arranged in a grid pattern, allowing independent deformation and adaptation to the blood vessel geometry while maintaining overall structural integrity and stability.
Solution Approach 2:
The inner sheath tube is nested within the outer sheath tube, forming a telescopic structure. The metal stent is nested within the outer sheath tube and can expand outward when needed. This nested configuration allows the device to maintain a compact profile during insertion while providing expanded functionality for stabilization and redirection during the procedure.
2Adaptability or versatility
If the sheath tube is made stable in the blood vessel, then detachment is prevented, but the device cannot adjust direction to access different blood vessel ends
Solution Approach 1:
The outer sheath tube is designed to rotate relative to the inner sheath tube, enabling dynamic direction adjustment. The metal stent can expand and contract to provide stabilization during rotation. This dynamic design allows the sheath to maintain stability while adapting to different directional requirements for accessing various blood vessel ends or target locations.
3Ease of operation
If the guidewire is swung for redirection, then the target blood vessel can be accessed, but the guidewire contacts the sheath tube and drives it to shift
Solution Approach 1:
The metal stent expands to abut tightly against the blood vessel wall before guidewire redirection is performed. This creates a stabilizing support structure that cushions and prevents the sheath tube from shifting when the guidewire is swung for redirection, thereby maintaining sheath position stability while enabling ease of guidewire manipulation.
4Adaptability or versatility
If a second puncture is performed to reposition the sheath, then the target blood vessel can be accessed, but surgical difficulty and patient harm increase
Solution Approach 1:
The sheath system incorporates dynamic capabilities including rotation of the outer sheath tube relative to the inner sheath tube and expansion/contraction of the metal stent. This allows the sheath to be repositioned and redirected within the blood vessel without requiring removal and reinsertion, thereby providing access to target blood vessels while eliminating the harmful effects of repeated punctures.
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 sheath maintains stable fixation in the blood vessel, reducing detachment and enabling easier guidewire redirection, thereby improving surgical efficiency and reducing the need for secondary punctures.
Implementation Method 1
the metal stent includes a plurality of memory metal wires, lower ends of the memory metal wires are fixed on an outer wall of the outer sheath tube
Implementation Method 2
Through the engagement of the ratchet and the pawls, the outer sheath tube can only rotate unidirectionally relative to the inner sheath tube, thereby controlling the metal stent to expand step by step
Data Source
AI summary
A vascular puncture sheath facilitating fixation and redirection comprises: a puncture base; an inner sheath tube, connected to lower end of the puncture base; an outer sheath tube, movably sleeved on outside of the inner sheath tube; a metal stent, fixedly arranged at lower end of the outer sheath tube and used for fixing the outer sheath tube in the blood vessel; wherein, a chamber is provided between the inner sheath tube and the outer sheath tube; a tube wall of the outer sheath tube is provided with a plurality of through-holes communicating with the chamber, the metal stent includes a plurality of memory metal wires, lower ends of the memory metal wires are fixed on outer wall of the outer sheath tube, and upper ends of the memory metal wires pass through corresponding through-holes into the chamber and are connected to tube wall of the inner sheath tube.