Optical Cannula Dislocation Detection for Dialysis Safety

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Solution Overview

Problem

Current systems for detecting venous needle dislocation (VND) during dialysis are not 100% reliable, often resulting in delayed detection, false alarms, and increased risk of blood loss, due to reliance on pressure monitoring and additional costly sensors, which are complex and prone to human error.

Innovation Solution

A safety device for extracorporeal blood treatment machines that detects changes in the relative position of patient access cannulas, triggering a mechanical or electronic shut-off mechanism to immediately stop blood flow, eliminating the need for pressure monitoring and reducing complexity and costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If pressure monitoring is used to detect venous needle dislocation, then detection capability is provided, but reliability is reduced due to delayed detection and false alarms

Engineering Contradiction:
Improvedetection reliabilityVSAvoiddetection delay
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent replaces the mechanical pressure monitoring system with an optical detection system. Optical sensors detect changes in light transmission or reflection properties of the catheter or surrounding tissue, providing direct and immediate detection of needle dislocation without the delays and false alarms associated with pressure monitoring.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent uses optical properties (light transmission, reflection) as a substitute measurement for physical position. By monitoring changes in optical characteristics rather than pressure, the system creates an alternative detection mechanism that is more reliable and responsive to actual needle dislocation events.

Inventive Principle:
Principle #26Copying

2Measurement precision

If additional sensors are added to improve detection accuracy, then measurement precision is improved, but device complexity increases

Engineering Contradiction:
Improvedetection accuracyVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical pressure sensors and multiple detection components with a simpler optical detection system. The optical sensors can be integrated into existing catheter structures or positioned externally, reducing the overall complexity while maintaining or improving detection accuracy.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The optical detection system serves multiple functions: detecting needle dislocation, monitoring catheter position, and potentially detecting other complications. This multi-functionality reduces the need for separate specialized sensors, thereby simplifying the overall system while improving measurement precision.

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

3Reliability

If pressure monitoring systems are used, then detection capability is provided, but costs increase due to additional sensors and system complexity

Engineering Contradiction:
ImproveVND detection reliabilityVSAvoidsystem cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent employs disposable optical sensors or optical indicators integrated into single-use catheters. These inexpensive disposable components eliminate the need for expensive reusable pressure monitoring systems, reducing overall costs while maintaining reliable detection capability throughout the treatment period.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent replaces expensive mechanical pressure sensors and complex monitoring systems with simpler, cheaper optical detection methods. Optical sensors and light-based detection mechanisms are generally less costly than precision pressure measurement systems, reducing manufacturing and operational costs.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentEP3539589B1Safety device with needle dislocation detection and shut-off mechanism for an emergency stop of extracorporeal blood transport system
Publication Date: 2023.04.26 B BRAUN AVITUM
  • EP3539589B1 patent drawingFigure 1
  • EP3539589B1 patent drawingFigure 2~3
  • EP3539589B1 patent drawingFigure 4

AI summary

The present invention relates to a shut-off device of an extracorporeal blood treatment machine, preferably a dialysis machine, for triggering an emergency shut-off of an extracorporeal blood supply system of the extracorporeal blood treatment machine in the event of a needle dislocation.The shut-off device has a shut-off mechanism (8) adapted to reduce or shut off blood flow through a line (7, 9) of the extracorporeal blood treatment machine, and an actuating/triggering device (11) adapted to actuate/trigger the shut-off mechanism (8) when a venous patient access/connection (10), preferably an access cannula, and an arterial patient access/connection (6), preferably an access cannula, of the extracorporeal blood supply system, which have or are set to a predetermined initial relative position to each other, move or are moved out of this predetermined initial relative position.