Catheter Lubricious Linings via Rolled Coated Sheet Assembly
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Solution Overview
Problem
Current methods for creating tubular devices with lubricious linings, such as catheters, face challenges in bonding inner cores like PTFE and PE, and applying hydrophilic coatings to inner surfaces due to difficulties in accessing and evenly coating small, complex geometries, leading to inefficient lubricity and increased manufacturing complexity and cost.
Innovation Solution
A method involving coating a thin sheet with desired properties, rolling it into a sleeve, and attaching a tubular structure around it using laminating, bonding, or heat sealing to create a tubular device with a coated inner surface, which can include a polyurethane liner and outer layers like PEBAX or nylon, ensuring the coating's properties are maintained.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If PTFE or PE inner cores are used to provide lubricious inner surface, then lubricity is improved, but bonding difficulty increases and manufacturing complexity increases
Solution Approach 1:
The catheter is divided into separate components: an outer catheter body and an inner core with lubricious coating. The inner core is manufactured separately with pre-applied lubricious coating, then inserted into the outer catheter body. This segmentation allows the lubricious coating to be applied under optimal conditions and eliminates the bonding difficulties associated with coating PTFE or PE directly onto the catheter lumen.
2Strength
If mechanical abrasion or etching is applied to inner surfaces to facilitate bonding, then bondability is improved, but manufacturing complexity increases and inner surface accessibility becomes difficult
Solution Approach 1:
The lubricious coating is applied to the inner core before final assembly, when the surface is easily accessible. This preliminary coating application eliminates the need for subsequent mechanical abrasion or etching steps that would be required to bond coatings to the inner lumen surface after catheter assembly.
3Ease of operation
If hydrophilic coating is applied to inner surfaces by dipping, then lubricity is improved, but even coating distribution becomes difficult and evaporation control becomes problematic
Solution Approach 1:
Instead of attempting to dip-coat the inner lumen surface of the finished catheter, the invention applies the hydrophilic coating to an outer surface of a separate inner core component. This outer surface is easily accessible and can be coated uniformly, then the coated inner core is inserted into the catheter body, effectively copying the desired lubricious surface property to the internal flow path.
4Strength
If UV light or heat is applied to cross-link coating, then adhesion strength is improved, but material degradation occurs and inner surface accessibility becomes difficult
Solution Approach 1:
The coating is applied and cross-linked on the outer surface of the inner core before assembly, when UV light or heat can be uniformly applied without causing degradation. This preliminary cross-linking establishes strong adhesion before the component is inserted into the catheter body, eliminating the need for subsequent cross-linking steps inside the finished device.
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 method simplifies the manufacturing of tubular devices with coated inner surfaces, enhancing lubricity and reducing production complexity and costs, while maintaining the desired properties of the coatings for improved performance in medical procedures.
Implementation Method 1
coating a thin sheet with desired properties
Implementation Method 2
rolling it into a sleeve
Implementation Method 3
attaching a tubular structure around it using laminating, bonding, or heat sealing
Data Source
Figure 1A~1B
Figure 2A~2D
Figure 3A~3E
AI summary
A method for making a tubular device includes coating a first surface of a thin sheet, rolling the sheet such that side edges of the sheet are disposed adjacent one another with the coating disposed inwardly, creating a longitudinal seam along the side edges to create a sleeve, and attaching a tubular structure around the sleeve. In another embodiment, the method includes coating a first surface of a thin sheet, wrapping the sheet partially around a mandrel with the coating disposed inwardly, positioning a slotted tube around the sheet and mandrel, attaching the tube to the thin, and trimming any excess material of the sheet. In another embodiment, the method includes coating an outer surface of a thin sleeve, inverting the sleeve, and attaching a tubular structure around the inverted sleeve, thereby providing a tubular device including a lubricious, hydrophilic, and/or otherwise coated inner surface.