Concentric Catheter With Slidable Inner Catheter for Blood Withdrawal

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Catheters used for prolonged vascular access face issues such as vein narrowing, collapse, kinking, blockage, and tip adherence, making blood withdrawal difficult and requiring additional needle sticks, which are painful and costly.

Innovation Solution

A concentric catheter system with a slidable inner catheter and toggle joint mechanism that allows for aspiration, blood draw, and infusion while reducing microbial ingress and dislodgement, featuring fenestrations and a flexible polymer toggle joint to manage fluid flow and catheter position.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of stationary object

If a catheter is left inserted in the patient for a prolonged period of time, then the catheter remains in place for future blood withdrawal or fluid infusion, but the catheter or vein becomes more susceptible to narrowing, collapse, kinking, blockage, and tip adherence

Engineering Contradiction:
Improvecatheter dwell timeVSAvoidcatheter functionality
Core Design Contradiction:
Duration of action of stationary objectVSReliability

Solution Approach 1:

The inner catheter is designed to be movable relative to the outer catheter, allowing it to be repositioned between a retracted position (where it blocks the distal opening) and an extended position (where it protrudes from the distal opening). This dynamic configuration enables the catheter to maintain functionality during prolonged dwell periods by allowing the inner catheter to be extended for blood withdrawal while being retracted to prevent blockage and maintain vein patency during the infusion phase.

Inventive Principle:
Principle #15Dynamics

2Ease of operation

If the inner catheter is extended beyond the outer catheter for blood withdrawal, then blood can be drawn through the inner catheter, but the catheter may become dislodged or compromised

Engineering Contradiction:
Improveblood withdrawal capabilityVSAvoidcatheter stability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The catheter system is divided into an outer catheter and an inner catheter that can move independently relative to each other. The inner catheter can be extended beyond the outer catheter for blood withdrawal while the outer catheter remains stationary in the vein, providing stable access. This segmentation allows the blood withdrawal function to be performed without compromising the overall catheter stability, as the outer catheter maintains its position while the inner catheter is temporarily extended for sampling.

Inventive Principle:
Principle #1Segmentation

3Quantity of substance

If additional needle stick is used for blood collection during catheter dwell period, then blood sample can be obtained, but patient experiences pain and higher material costs

Engineering Contradiction:
Improveblood sample acquisitionVSAvoidpatient pain and cost
Core Design Contradiction:
Quantity of substanceVSObject-affected harmful factors

Solution Approach 1:

The catheter system is designed with multi-functionality, allowing it to serve both as an infusion catheter and as a blood withdrawal device. The inner catheter can be extended to enable blood sampling through the same catheter used for infusion, eliminating the need for additional needle sticks. This universal design provides blood sample acquisition capability while avoiding the pain and costs associated with separate blood collection procedures.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP4171700B1Concentric catheter system
Publication Date: 2025.09.24 BECTON DICKINSON & CO
  • EP4171700B1 patent drawingFigure 1A~1B
  • EP4171700B1 patent drawingFigure 2A~2B
  • EP4171700B1 patent drawingFigure 3

AI summary

A catheter system (10) includes an outer catheter adapter (12), an outer catheter (18) having an outer catheter lumen (24) extending through the outer catheter, an inner catheter adapter (28), an inner catheter lumen (34) extending through the inner catheter adapter (28) and an inner catheter (36) extending distally from the inner catheter adapter (28) such that the inner catheter (36) is disposed within the outer catheter lumen (24), wherein the inner catheter (36) and the inner catheter adapter (28) are configured to move with respect to the outer catheter (18) and the outer catheter adapter (12) between a proximal position and a distal position.