Intravascular Ultrasound Catheter Wiring for Small Diameter Stability

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Solution Overview

Problem

Existing ultrasound probes for intravascular examination face challenges in reducing catheter diameter due to lead wires, which are difficult to downsize without increasing connection defects or manufacturing difficulties.

Innovation Solution

The ultrasound examination device employs a conductive thin film to connect the first lead wire to the ultrasound probe, with a resin holder insulating and supporting the second lead wire, and a coaxial cable configuration to minimize the outer diameter and prevent short circuits.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the lead wires and connection portions are downsized to reduce the outer diameter of the catheter, then the catheter can be inserted into thinner blood vessels, but the risk of connection defects such as wire breakage or short circuit increases

Engineering Contradiction:
Improveouter diameter of catheterVSAvoidconnection stability
Core Design Contradiction:
Volume of moving objectVSReliability

Solution Approach 1:

The patent implements a nested structure where the first lead wire is inserted through the second lead wire, forming a coaxial cable configuration. The conductive thin film is nested within the resin holder which contains the second lead wire. This nested arrangement allows efficient space utilization, enabling the lead wires to be closely positioned without increasing the overall outer diameter, thus maintaining small catheter size while ensuring reliable electrical connections through proper structural support and insulation.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The resin holder acts as an intermediary component that provides structural support and electrical insulation for the lead wires. It prevents direct contact between the conductive thin film and the second lead wire, eliminating short circuit risks. The insulating support member serves as an intermediary to support the second lead wire and prevent its breakage. These intermediary elements enable reliable connections without requiring larger wire gauges.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Volume of moving object

If the lead wires are made excessively thin to reduce catheter diameter, then the outer diameter can be minimized, but manufacturing becomes difficult and connection defects increase

Engineering Contradiction:
Improveouter diameter of catheterVSAvoidmanufacturing difficulty
Core Design Contradiction:
Volume of moving objectVSEase of manufacture

Solution Approach 1:

The patent employs a conductive thin film as a flexible conducting element that can be easily manufactured and integrated. The thin film provides a reliable electrical connection between the first lead wire and the ultrasound probe without requiring thick or rigid wire structures. The resin holder serves as a flexible yet supportive encapsulation that protects the thin lead wires and thin film while maintaining the overall small diameter, making the assembly easier to manufacture with standard processes.

Inventive Principle:
Principle #30Flexible shells and thin films

3Volume of moving object

If the connection portions are made small to downsize the ultrasound probe, then the outer diameter can be reduced, but the risk of short circuit between conductive components increases

Engineering Contradiction:
Improveouter diameter of catheterVSAvoidshort circuit risk
Core Design Contradiction:
Volume of moving objectVSObject-affected harmful factors

Solution Approach 1:

The resin holder serves as an insulating intermediary that physically separates the conductive thin film from the second lead wire, preventing short circuits. The insulating support member acts as an intermediary to position and isolate the second lead wire from other conductive components. These intermediary insulating structures enable close positioning of lead wires and thin films without compromising electrical isolation, thus maintaining small dimensions while eliminating short circuit hazards.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent applies localized insulation properties by using a resin holder that specifically encapsulates the region where the second lead wire and conductive thin film are in close proximity. The insulating support member provides localized support and isolation at the critical connection point of the second lead wire. This localized application of insulating quality prevents short circuits at critical points without requiring insulating materials throughout the entire catheter structure, maintaining compact size while ensuring electrical safety.

Inventive Principle:
Principle #3Local quality

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

The device achieves a small outer diameter with electrical stability by integrating the lead wires through a conductive thin film and resin holder, reducing connection defects and short circuits while maintaining flexibility and ease of manufacturing.

Implementation Method 1

a piezoelectric element sheet (53)

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Data Source

PatentEP4684739A1Ultrasonic inspection device and intravascular ultrasonic inspection catheter
Publication Date: 2026.01.28 NIPRO CORP
  • EP4684739A1 patent drawingFigure 1
  • EP4684739A1 patent drawingFigure 2
  • EP4684739A1 patent drawingFigure 3

AI summary

[Problem] To provide an ultrasound examination device that has a small outer diameter and is electrically stable. [Solution] An ultrasound examination device 14 includes a shaft 21, a first lead wire 22A and a second lead wire 22B inserted into an internal space of the shaft 21 and extended out from a distal end of the shaft 21, a conductive thin film 23 extending from the distal end of the shaft 21 toward a distal side and electrically connected to the first lead wire 22A, an ultrasound probe 25 located on the distal side of the distal end of the shaft 21 and having a first electrode layer 52 electrically connected to the conductive thin film 23 and a second electrode layer 54 electrically connected to the second lead wire 22B, and a resin holder 26 configured to hold, at least, a portion belonging to the second lead wire 22B and extended out from the shaft 21, the conductive thin film 23, and the ultrasound probe 25.