Dual-Stiffness Pigtail Cannula Assembly for Stable Pump Positioning

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Blood pump assemblies face challenges in maintaining stable positioning within the heart, leading to issues such as suction and arrhythmia due to improper placement, which can consume valuable time and impact patient health.

Innovation Solution

A cannula assembly with a dual stiffness pigtail extension, featuring a stiff proximal section and a soft distal section, is used to stabilize the blood pump assembly, ensuring proper positioning by preventing suction and reducing tissue trauma.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single-stiffness pigtail extension is used, then the cannula assembly can be simplified in structure, but the positioning precision and tissue trauma reduction are compromised

Engineering Contradiction:

Improvepigtail extension structureVSAvoidpositioning precision

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

The pigtail extension is divided into multiple sections with different stiffness characteristics. The proximal section has higher stiffness to resist buckling and maintain spacing, while the distal section has lower stiffness to conform to tissue and reduce trauma. This segmentation allows each section to perform its specific function optimally.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different sections of the pigtail extension are assigned different local qualities (stiffness values) to meet different functional requirements. The proximal section is made stiffer for structural support and positioning, while the distal section is made softer for tissue compatibility. This local differentiation resolves the contradiction between structural integrity and tissue trauma reduction.

Inventive Principle:

Principle #3Local quality

2Strength

If the pigtail extension is made uniformly stiff, then the cannula assembly maintains structural integrity, but tissue trauma increases

Engineering Contradiction:

Improvestructural integrityVSAvoidtissue trauma

Core Design Contradiction:

StrengthVSObject-affected harmful factors

Solution Approach 1:

The pigtail extension is segmented into stiff proximal sections and soft distal sections. The stiff proximal sections maintain structural integrity and resist buckling under pump thrust forces, while the soft distal sections minimize tissue trauma by conforming to the ventricular wall and distributing forces over a larger area.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different local stiffness qualities are assigned to different parts of the pigtail extension. The proximal sections have high stiffness for structural support, while the distal sections have low stiffness for tissue compatibility. This local quality differentiation simultaneously achieves structural integrity and reduces tissue trauma.

Inventive Principle:

Principle #3Local quality

3Length of moving object

If the blood pump assembly is positioned closer to the ventricle apex, then the cannula length is reduced, but suction and arrhythmia problems occur

Engineering Contradiction:

Improvecannula lengthVSAvoidsuction and arrhythmia prevention

Core Design Contradiction:

Length of moving objectVSReliability

Solution Approach 1:

The pigtail extension acts as an intermediary mechanical spacer between the blood pump assembly and the ventricle apex. It provides the necessary spacing to prevent the cannula tip from being too close to the apex, thereby avoiding suction and arrhythmia problems while allowing the cannula to be shorter than it would be without the pigtail extension.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The pigtail extension automatically provides the required spacing function through its own structural properties. The stiff proximal sections maintain the spacing distance without requiring active control or adjustment mechanisms, allowing the system to self-regulate the positioning to prevent harmful effects.

Inventive Principle:

Principle #25Self-service

4Object-affected harmful factors

If the pigtail extension is made uniformly soft, then tissue trauma is reduced, but the cannula assembly cannot resist buckling under compression

Engineering Contradiction:

Improvetissue traumaVSAvoidbuckling resistance

Core Design Contradiction:

Object-affected harmful factorsVSStrength

Solution Approach 1:

The pigtail extension is segmented into stiff proximal sections and soft distal sections. The stiff proximal sections provide buckling resistance under compression from the blood pump thrust forces, while the soft distal sections reduce tissue trauma by conforming to the ventricular wall. This segmentation simultaneously achieves both buckling resistance and tissue trauma reduction.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different local stiffness qualities are assigned to different parts of the pigtail extension. The proximal sections have high stiffness for buckling resistance, while the distal sections have low stiffness for tissue compatibility. This local quality differentiation resolves the contradiction between mechanical strength and tissue trauma reduction.

Inventive Principle:

Principle #3Local quality

Data Source

PatentEP4046678B1Cannula assembly

Publication Date: 2025.10.01 ABIOMED INC

Figure 1
Figure 2~3
Figure 4

AI summary

Cannula assemblies and methods of manufacturing cannula assemblies are provided. The cannula assembly includes a cannula and a pigtail extension coupled to the cannula. The pigtail extension includes a proximal section having a first stiffness and a distal section having a second stiffness, the first stiffness greater than the second stiffness. The proximal section of the pigtail extension is positioned between the cannula and at least a portion of the distal section.