Expandable Percutaneous Catheter Reducing Invasiveness and Pressure Loss

Solution Overview

Problem

In percutaneous cardiopulmonary support methods, the trade-off between minimizing patient load and reducing pressure loss in the circulation circuit is challenging due to the need for a balance between tube diameter and flow rate, where smaller diameters increase pressure loss and larger diameters increase invasiveness.

Innovation Solution

A percutaneous catheter with an expandable design, featuring a non-coated portion made of braided wires and a coated portion, which expands axially when a dilator is inserted to reduce inner diameter and minimize invasiveness, and returns to a larger diameter when the dilator is withdrawn to reduce pressure loss.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If the inner diameter of the catheter tube is increased to reduce pressure loss and ensure required flow rate, then the pressure loss decreases and flow rate is ensured, but the outer diameter increases which increases invasiveness and load to the patient's body

Engineering Contradiction:

Improvepressure lossVSAvoidinvasiveness

Core Design Contradiction:

Loss of energyVSObject-affected harmful factors

Solution Approach 1:

The catheter tube employs a dynamic diameter design where the non-coated portion can expand axially when a dilator is inserted, reducing its inner diameter during insertion to minimize invasiveness, and then contracts back to its original larger diameter when the dilator is withdrawn to reduce pressure loss and ensure required flow rate for blood circulation

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The inner diameter parameter of the non-coated portion is changed dynamically: it is reduced during insertion by axial expansion caused by dilator insertion, and then restored to its original larger value after dilator withdrawal, thereby optimizing both invasiveness and flow characteristics at different operational stages

Inventive Principle:

Principle #35Parameter changes

2Object-affected harmful factors

If the inner diameter of the catheter tube is decreased to reduce invasiveness and load to the patient, then the invasiveness is reduced, but the pressure loss increases and the required flow rate cannot be obtained

Engineering Contradiction:

ImproveinvasivenessVSAvoidpressure loss

Core Design Contradiction:

Object-affected harmful factorsVSLoss of energy

Solution Approach 1:

The catheter tube employs a dynamic diameter design where the non-coated portion can expand axially when a dilator is inserted, reducing its inner diameter during insertion to minimize invasiveness, and then contracts back to its original larger diameter when the dilator is withdrawn to reduce pressure loss and ensure required flow rate for blood circulation

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The inner diameter parameter of the non-coated portion is changed dynamically: it is reduced during insertion by axial expansion caused by dilator insertion, and then restored to its original larger value after dilator withdrawal, thereby optimizing both invasiveness and flow characteristics at different operational stages

Inventive Principle:

Principle #35Parameter changes

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 design minimizes patient load during insertion and ensures a required flow rate by reducing pressure loss in the circulation circuit while maintaining a low-invasive technique.

Implementation Method 1

When the dilator is inserted through the percutaneous catheter, the non-coated portion expands in the axial direction and is reduced in inner diameter

Methodology Applied

Scientific EffectElastic deformation: Elasticity

Implementation Method 2

If the dilator is withdrawn from the percutaneous catheter after the percutaneous catheter indwells inside a living body, the catheter tube contracts in the axial direction and returns to the original state

Methodology Applied

Scientific EffectElastic recovery: Elasticity

Data Source

PatentUS11260159B2Percutaneous catheter and percutaneous catheter assembly

Publication Date: 2022.03.01 TERUMO KK

AI summary

A percutaneous catheter provides an adjustable diameter in order to reduce pressure loss, maintain a required flow, and avoid increasing a load to the patient. A catheter tube is formed of braided wires in an intersecting manner and extends in an axial direction. A distal tip is affixed to a distal side of the catheter tube and is configured to engaged a distal end of a dilator. The catheter tube includes a non-coated portion on a proximal side of the distal tip and a coated portion embedded in a resin material. An inner diameter of the non-coated portion is larger than an outer diameter of the dilator. When the dilator is fully inserted through the percutaneous catheter, the non-coated portion expands in the axial direction, reducing its in inner diameter so that an inner surface of the non-coated portion comes into tight contact with an outer surface of the dilator.