Imaging Catheter Flow-Path Structure to Prevent Drive Shaft Buckling
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Solution Overview
Problem
Image diagnosis catheters face issues with drive shaft buckling during operation and require complex priming processes due to the concentration of load at buckled portions and the need for filling lumens with priming solutions.
Innovation Solution
The catheter design includes an inner tube spacer that holds the inner-tube support tube, defining separate inner and outer flow paths, with partition flow paths to prevent buckling and facilitate easy priming by synchronizing the flow of priming solution through these paths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the drive shaft is buckled inside the inner tube during operation, then the catheter can be pushed into the outer tube, but load concentrates on the buckled portion causing damage
Solution Approach 1:
The patent introduces an inner-tube support tube as an intermediary component between the drive shaft and the inner tube. This support tube prevents direct contact and buckling of the drive shaft inside the inner tube during pushing operations, while still allowing the inner tube to be pushed into the outer tube. The support tube acts as a mediator that protects the drive shaft from damage.
2Reliability
If the lumen is filled with priming solution before use, then the catheter is ready for operation, but the priming process is complex and time-consuming
Solution Approach 1:
The patent divides the lumen into separate flow paths using an inner-tube spacer that creates distinct inner and outer flow paths. This segmentation allows priming solution to flow through different paths simultaneously or independently, simplifying the priming process and reducing the time required to fill the entire lumen compared to a single continuous path.
Solution Approach 2:
The patent incorporates flow path definitions and spacer structures during manufacturing, so that the flow paths are pre-established and ready for priming. The inner-tube spacer is pre-positioned to create the flow path separation, eliminating the need for complex manual configuration during the priming process.
3Ease of operation
If separate flow paths are defined by the inner tube spacer, then priming is simplified, but the device structure becomes more complex
Solution Approach 1:
The inner-tube spacer serves multiple functions: it defines the flow paths for priming, provides structural support to prevent buckling, and maintains the relative positions of the inner tube and drive shaft. By making this single component multi-functional, the patent avoids adding separate elements for each function, thereby limiting the increase in overall device complexity.
Data Source
AI summary
An image diagnosis catheter, which includes an outer tube, an inner tube, an inner-tube support tube, and a drive shaft in this order, and further includes: an inner tube spacer that holds the inner-tube support tube so as to define an inner-tube support tube outer flow path; a connector hub movable to a distal end side and a proximal end side relative to the outer tube together with the inner tube, the inner-tube support tube, the drive shaft, and the inner tube spacer; and an inner flow path and an outer flow path through which a priming solution flows. An inner-tube-spacer proximal-side flow path is formed on the proximal end side relative to the inner tube spacer. At least the inner tube spacer defines an inner-tube-spacer partition flow path.