Multi-lumen Catheter Extrusion Without Mandrels
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Solution Overview
Problem
The manufacturing of steerable catheters and sheaths is inefficient and costly due to the need for mandrels to prevent collapse of minor lumens during the manufacturing process, and the discrete extrusion method requires labor-intensive and time-consuming steps for producing short lengths of multi-lumen devices.
Innovation Solution
The method involves extruding at least one layer of material over a first lumen tube and a second lumen tube to form an elongate body, where the second lumen tube maintains patency without a solid core, using materials with a higher durometer than the first lumen tube, such as polyimide or fluorinated ethylene propylene, allowing for continuous extrusion and elimination of mandrels, and depositing a mesh layer followed by a second extrusion pass to create a multi-lumen medical device.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a thin layer of PTFE is used for minor lumens to achieve low friction, then the coefficient of friction is reduced, but the lumen collapses during manufacturing
Solution Approach 1:
The patent uses a composite structure where an inner PTFE layer provides low friction properties while an outer thermoplastic layer provides structural support and prevents collapse during manufacturing. This composite approach allows the minor lumen to maintain both low friction and structural integrity simultaneously.
2Reliability
If a rigid mandrel is inserted into each minor lumen to prevent collapse, then lumen patency is maintained, but manufacturing cost and complexity increase
Solution Approach 1:
The patent eliminates the need for mandrels by using a thermoplastic outer layer that provides sufficient structural support to maintain lumen patency during manufacturing. This removes the mandrel component and simplifies the manufacturing process while still preventing lumen collapse.
Solution Approach 2:
The patent changes the material parameters by using a thermoplastic material with appropriate durometer and melting characteristics. This allows the outer layer to provide structural support during manufacturing and then be removed or melted away, eliminating the need for mandrels while maintaining lumen patency.
3Adaptability or versatility
If discrete extrusion method is used to produce short lengths of catheter, then manufacturing flexibility is maintained, but productivity and efficiency decrease
Solution Approach 1:
The patent enables continuous extrusion of multi-lumen structures by using thermoplastic outer layers that can be extruded continuously and then removed or melted away. This continuous process eliminates the need for discrete step-by-step manufacturing, significantly improving productivity while maintaining the ability to produce various lengths and configurations.
4Manufacturing precision
If multiple discrete extrusion steps are used to create multi-lumen devices, then manufacturing precision is maintained, but production time and labor increase
Solution Approach 1:
The patent combines multiple extrusion operations into a single continuous extrusion process. The thermoplastic outer layer is extruded continuously over the PTFE inner layer, creating the complete multi-lumen structure in one step. This merging of operations maintains dimensional accuracy while dramatically reducing production time and eliminating multiple heating and cooling cycles.
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 approach reduces production costs and labor by eliminating the need for mandrels and enables continuous extrusion of longer lengths of multi-lumen devices, maintaining lumen patency and allowing for various lumen cross-sections, thus improving efficiency and cost-effectiveness in manufacturing steerable catheters and sheaths.
Implementation Method 1
The second lumen tube may be composed of a material having a durometer that is greater than the material from which the first lumen tube is composed
Implementation Method 2
extruding at least one layer of material over a first lumen tube and a second lumen tube to form an elongate body
Implementation Method 3
depositing a mesh layer followed by a second extrusion pass
Data Source
AI summary
A method of producing a multi-lumen elongate body for a medical device. Unlike known methods requiring a solid core of material inserted into each lumen to maintain patency of the lumens during manufacture, the present method obviates the need for a solid core within one or more minor lumens, which saves cost and production complexity. One or more material overlay and mesh overlay steps may be used to produce the multi-lumen elongate body, but only the main lumen may include a solid core therein during all manufacturing steps. The one or more minor lumens may each be defined by a lumen tube having a sufficient stiffness to withstand external pressure during all manufacturing steps without the need for a solid core within.