Braided Catheter Marker Integration for Uniform Shaft Dimensions

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Solution Overview

Problem

Existing catheters with radiopaque markers and reinforcement bodies face issues of increased shaft thickness due to the placement of markers, which affects pushing performance and torque transmission, especially when long shafts are required for accessing lower limb arteries.

Innovation Solution

A catheter design with a reinforcement body and radiopaque marker configuration that maintains a uniform outer and inner diameter by embedding the marker within a small diameter portion of the shaft, using a braided wire structure and crimping to ensure the marker is firmly fixed, allowing for a longer effective length without increasing shaft thickness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the wire diameter of the braided wire is increased to improve pushing performance and torque transmission performance, then the pushing performance and torque transmission performance are improved, but the thickness of the shaft increases

Engineering Contradiction:
Improvepushing performance and torque transmission performanceVSAvoidthickness of the shaft
Core Design Contradiction:
StrengthVSShape

Solution Approach 1:

The radiopaque marker is embedded within the shaft structure, nested between the inner layer and outer layer, with the braided wire also positioned within these layers. This nesting arrangement allows the marker to be housed without increasing the overall outer diameter of the shaft, while the braided wire provides reinforcement without requiring additional external space.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The shaft structure is designed with localized variations in layer thickness. The inner layer has a smaller thickness in the region where the marker is disposed compared to adjacent regions, while the outer layer compensates to maintain uniform outer diameter. This local quality adjustment allows the marker to be accommodated without increasing overall shaft thickness.

Inventive Principle:
Principle #3Local quality

2Length of moving object

If a long shaft is used to reach lower limb arteries from radial artery, then the catheter can access distant vessels, but it becomes difficult to transmit pushing force and torque from proximal to distal portion

Engineering Contradiction:
Improvelength of the shaftVSAvoidtransmission of pushing force and torque
Core Design Contradiction:
Length of moving objectVSForce

Solution Approach 1:

The shaft is constructed as a composite structure with multiple layers including an inner layer, outer layer, and braided wire reinforcement. This composite design provides both the necessary length for reaching distant vessels and the mechanical strength to transmit pushing forces and torques along the entire length of the shaft.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The braided wire is nested within the shaft structure, positioned between the inner and outer layers. This nested reinforcement structure provides continuous mechanical support along the length of the shaft, enabling effective transmission of forces over long distances while maintaining a flexible, insertable configuration.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Measurement precision

If the marker is disposed on the shaft with reinforcement body, then the catheter position can be recognized, but the thickness of the shaft increases

Engineering Contradiction:
Improveposition recognition capabilityVSAvoidthickness of the shaft
Core Design Contradiction:
Measurement precisionVSShape

Solution Approach 1:

The radiopaque marker is embedded within the shaft structure, nested between the inner layer and outer layer. This nesting allows the marker to be housed without increasing the overall outer diameter of the shaft, as the marker occupies space within the existing layered structure rather than adding to it externally.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The shaft layers are designed with localized thickness variations to accommodate the marker. The inner layer has reduced thickness in the marker region, and the outer layer is configured to maintain uniform outer diameter, allowing the marker to be integrated without increasing overall shaft dimensions.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP4147739B1catheter
Publication Date: 2025.09.03 TERUMO KK
  • EP4147739B1 patent drawingFigure 1~2
  • EP4147739B1 patent drawingFigure 3(A)~4
  • EP4147739B1 patent drawingFigure 5~6

AI summary

Provided is a catheter capable of preventing an increase in a thickness of a shaft while disposing an radiopaque marker in a shaft provided with a reinforcement body. In a catheter (1) that includes a shaft (2) including a lumen (5) communicating from a distal end to a proximal end, the shaft (2) includes a reinforcement body (20) including a plurality of wires (21) that are disposed on at least a part between an inner surface (11) of the shaft (2) forming the lumen (5) and an outer surface (41) of the shaft (2) and that are braided in a tubular shape, and at least one or more radiopaque markers (30) that are disposed between the reinforcement body (20) and the outer surface (41), and an outer diameter difference, which is a difference between an outer diameter (D1) of the shaft (2) in a portion where the marker (30) is disposed and an outer diameter (D2) of the shaft (2) in a portion adjacent to the marker (30) in an axial direction X of the shaft (2), is smaller than twice a thickness (T) of the marker (30).