PTFE-Covered Stent End Structure for Bent Part Protection
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Solution Overview
Problem
Conventional stents with polytetrafluoroethylene (PTFE) coatings suffer from exposed sharp bent parts that cause friction and irritation in the lumen, failing to effectively address the technical problem of existing technologies is the inability to address the issue of existing technologies is the inability to address the issue of existing technologies is the inability to address the issue of existing technologies is the inability to effectively prevent exposure of sharp bent parts in stents, which cause friction and irritation in lumens with stenotic or occlusive lesions.
Innovation Solution
A covered stent with PTFE protection members covering the sharp bent parts, formed by bonding PTFE tapes on the stent's inner and outer surfaces and incorporating hollow cylindrical PTFE protection members at the ends to cover the bent parts, preventing exposure and friction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If PTFE film part is formed on the stent surface, then the stent provides a smooth coating, but the sharp bent parts remain exposed causing friction and irritation in the lumen
Solution Approach 1:
The stent is divided into multiple sections: the main cylindrical body with PTFE coating and separate bent parts at the ends. The bent parts are covered with additional PTFE material forming protection members, segmenting the coating application to address the sharp edges specifically without affecting the overall stent structure.
Solution Approach 2:
The PTFE coating is applied differently to different parts of the stent. The bent parts at the ends receive additional PTFE protection members specifically, while the main body has standard coating. This local differentiation ensures that sharp edges are covered while maintaining the overall stent functionality.
2Reliability
If the stent is inserted into a narrowed or blocked lesion area, then the stent expands the lumen, but the sharp bent parts repeatedly stick the lumen or cause friction
Solution Approach 1:
The harmful sharp bent parts are extracted from the stent structure by covering them with additional PTFE protection members. This removes the source of friction and irritation while preserving the stent's ability to expand the lumen through its main body.
Solution Approach 2:
The bent parts that originally caused harm are covered with PTFE material, converting them from sharp edges into smooth surfaces. The same PTFE material that provides coating is used to create protection members that eliminate the harmful friction while maintaining structural integrity.
3Ease of manufacture
If multiple bent parts are formed at the ends of the stent, then the stent can be manufactured, but the PTFE inner and outer artificial vessel layers cannot be properly coated
Solution Approach 1:
The bent parts are covered with PTFE protection members before the final assembly. This preliminary coating action ensures that all surfaces, including the difficult-to-reach bent parts, are properly coated before the stent is inserted into the body.
Solution Approach 2:
The PTFE protection members are nested onto the bent parts of the stent, creating a layered structure. The protection members fit over the bent parts and are bonded to the PTFE film part, creating a nested configuration that ensures complete coverage.
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 PTFE protection members prevent the sharp bent parts from sticking or causing friction, reducing irritation and inflammation, while allowing the stent to adapt to curved lumens and remain securely in place.
Implementation Method 1
a stent having a hollow cylindrical body formed by weaving crossed wires of super-elastic shape memory alloy
Implementation Method 2
bonding the inner and outer artificial blood vessel layers integrally with the stent as the inner and outer artificial blood vessel layers are thermally fused together by heating
Implementation Method 3
a polytetrafluoroethylene (PTFE) protection member provided at each end of the cylindrical stent, having a hollow cylindrical shape and having a groove formed at a thickness portion to cover each bent part
Data Source
AI summary
Disclosure relates to a covered stent preventing a bent part due to poor coating of a polytetrafluoroethylene (PTFE) film part from being exposed and sticking or causing friction to a lumen of the body at a lesion area. The covered stent includes a cylindrical stent made of shape memory alloy wires intersected together into a hollow cylindrical mesh shape to form multiple space parts, and having multiple bent parts formed on each end along circumference, a film part formed by bonding first and second PTFE tapes on inner and outer surfaces of the stent with heat and pressure, and a PTFE protection member provided at each stent end, having a hollow cylindrical shape and having a groove formed at a thickness portion to cover each bent part with an end of the cylindrical stent inserted therein, and bonded to an outer portion of the film part with heat and pressure.