Linear IV Flow Controller With Wedge Actuation for Precise Infusion

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Solution Overview

Problem

Existing IV fluid administration systems using roller clamps struggle to provide precise control over flow rates, making it difficult to maintain desired infusion rates during gravity-driven medical fluid delivery.

Innovation Solution

A linearly actuated flow controller with interlocked wedge structures and a rotational control mechanism that translates rotational motion into linear motion to compress the IV tubing, allowing for precise control of fluid flow through the use of a pair of ramped wedge structures and a scotch yoke mechanism.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a roller clamp is used to control flow rate in IV tubing, then the device structure is simple, but the flow rate control precision is insufficient

Engineering Contradiction:
Improveflow rate control precisionVSAvoiddevice structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces the traditional roller clamp mechanical system with a microfluidic-based flow control system that uses a occlusion member positioned within a recess to compress the tubing. This substitution allows for more precise flow rate control through controlled compression while maintaining relative structural simplicity through the use of a linear actuator and microfluidic channel geometry.

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

Solution Approach 2:

The patent changes the control parameter from rotational motion (roller clamp) to linear compression distance. The occlusion member's linear displacement along the microfluidic channel allows for precise adjustment of compression force and contact point, enabling fine control over flow rate by varying the compression parameter rather than relying on roller pressure alone.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If a roller clamp is used for flow control, then the device is easy to manufacture, but the flow rate adjustment precision is difficult to achieve

Engineering Contradiction:
Improveflow rate adjustment precisionVSAvoiddevice manufacturing complexity
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent segments the flow control function into distinct components: the occlusion member for compression, the recess structure for positioning, the linear actuator for precise displacement control, and the microfluidic channel for fluid guidance. This segmentation allows each component to be optimized for its specific function while maintaining manufacturability through modular assembly.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a linear actuator as an intermediary device between the user input and the occlusion member. This intermediary provides precise control of the occlusion member's position and compression force, enabling fine flow rate adjustment without requiring complex manual manipulation of the clamp mechanism itself.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of operation

If gravity infusion is used to deliver medical fluid, then the system is simple, but the flow rate control is difficult to provide

Engineering Contradiction:
Improveflow rate control easeVSAvoidinfusion system complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent employs a linear actuator that can be manually operated to provide self-contained flow rate control within the device. The actuator translates user input directly into precise linear motion of the occlusion member, allowing the device to self-regulate flow rate without requiring external control systems or complex mechanical linkages.

Inventive Principle:
Principle #25Self-service

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 solution provides finer control and improved maintenance of flow rates compared to roller clamps, enabling constant adjustable control of fluid flow from full open to complete occlusion, with tactile feedback and secure locking in the closed position.

Implementation Method 1

a pair of ramped wedge structures and a scotch yoke mechanism

Methodology Applied
Scientific EffectWedge mechanism: Wedge

Implementation Method 2

first ramped wedge structure, a second ramped wedge structure configured to slide over the first ramped wedge structure to compress a portion of the IV tubing

Methodology Applied
Scientific EffectMechanical advantage: Mechanical Advantage

Implementation Method 3

a yoke having a linear slot, a wheel having a pin that is radially separated from a center of the wheel and is slidably disposed in the linear slot, and a transfer structure coupled to the yoke and the first ramped wedge structure

Methodology Applied
Scientific EffectScotch yoke mechanism:

Data Source

PatentEP3768367B1Linearly actuated flow controller for intravenous (IV) fluid administration
Publication Date: 2024.05.08 CAREFUSION 303 INC
  • EP3768367B1 patent drawingFigure 1
  • EP3768367B1 patent drawingFigure 2~3
  • EP3768367B1 patent drawingFigure 4~5

AI summary

Flow controllers for intravenous (IV) tubing are provided. A flow controller may include first and second structural members defining a cavity therebetween for a portion of the tubing, wherein the first structural member is linearly slidable along a length of the tubing to compress at least part of the portion of the tubing to control flow of a medical fluid through the tubing. A flow controller may include a first ramped wedge structure, a second ramped wedge structure configured to slide over the first ramped wedge structure to compress a portion of the IV tubing disposed between the first ramped wedge structure and the second ramped wedge structure, a yoke having a linear slot, a wheel having a pin that is radially separated form a center of the wheel and is slidably disposed in the linear slot, and a transfer structure coupled to the yoke and the first ramped wedge structure. IV sets that include a flow controller are also provided.