Tapered Proximal Catheter Lumen for Smoother Guide Wire Insertion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing catheters face issues with wire insertion due to the proximal end of the tubular shaft being caught by the polymeric tubular sleeve or experiencing unevenness from heat during injection molding, leading to difficulty in inserting guide wires.
Innovation Solution
A catheter design with a reinforced portion and an unreinforced portion having a tapered inner diameter, where the unreinforced portion is fixed to a larger first lumen, satisfying specific diameter ratios, facilitating wire insertion by reducing the likelihood of catching and enhancing guide wire movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the polymeric tubular sleeve extends proximally beyond the proximal end of the tubular shaft to protect it from heat, then heat protection is improved, but wire insertion is hindered because the guide wire tip may be caught by the proximal end of the tubular shaft in the sleeve lumen
Solution Approach 1:
The tubular shaft is divided into a reinforced portion (distal) and an unreinforced portion (proximal). The unreinforced portion lacks the polymeric tubular sleeve, creating a sleeve-free zone that prevents wire catching while the reinforced portion maintains heat protection where needed.
Solution Approach 2:
The polymeric tubular sleeve is applied selectively only to the reinforced portion of the tubular shaft, not the entire shaft. This local application provides heat protection precisely where the shaft needs reinforcement while leaving the proximal unreinforced portion exposed to prevent wire insertion problems.
2Temperature
If the proximal end of the tubular shaft matches the proximal end of the polymeric tubular sleeve, then heat protection is reduced, but wire insertion becomes difficult due to unevenness or fusion from heat damage
Solution Approach 1:
The tubular shaft is segmented into reinforced and unreinforced portions, with the unreinforced portion extending beyond the sleeve end. This segmentation prevents the sleeve from contacting the proximal end, eliminating heat-induced fusion and surface unevenness at the critical wire insertion zone.
Solution Approach 2:
The unreinforced portion acts as an intermediary zone between the sleeved reinforced portion and the hub assembly. This intermediate section provides a smooth, heat-undamaged transition area that prevents direct contact between the sleeve and the proximal shaft end, avoiding fusion issues.
3Ease of operation
If the unreinforced portion has a tapered configuration with proximally increased inner diameter, then wire insertion is facilitated by reducing catching, but the structural reinforcement is reduced in the proximal region
Solution Approach 1:
The tapered configuration is applied locally only to the unreinforced proximal portion of the tubular shaft. This localized tapering provides wire insertion assistance where needed while maintaining full reinforcement in the distal portion that requires structural strength for navigation and treatment delivery.
Solution Approach 2:
The tubular shaft is segmented into a reinforced distal portion with constant diameter and an unreinforced proximal portion with tapered configuration. This segmentation allows each section to have optimized properties: strength where needed and wire insertion facilitation where needed.
Data Source
AI summary
The catheter of the present invention includes a tubular member having a reinforced portion and an unreinforced portion having a tapered portion; and a handle connected to a proximal end portion of the tubular member; wherein the handle has a first lumen and a second lumen positioned proximally beyond the first lumen, the unreinforced portion is fixed to the first lumen with a proximal end of the unreinforced portion positioned at the proximal end of the first lumen, and the catheter satisfies formulae (1) to (3):a<b (1)a<c (2)b≥c (3),where a is an inner diameter at a position apart by 1 mm distally from a proximal end of the reinforced portion, b is an inner diameter at the proximal end of the unreinforced portion, and c is an inner diameter at the distal end of the second lumen of the handle.