Vascular Stent Deployment Ratchet Mechanism

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Solution Overview

Problem

Current vascular prosthesis deployment devices lack incremental deployment control and feedback mechanisms, making precise placement and deployment of self-expanding stents within the body challenging, and often require significant manual force and awkward handling positions.

Innovation Solution

A deployment device with a handle assembly and elongate delivery catheter that includes a ratchet slide mechanism providing incremental deployment control, visual, audible, and tactile feedback, and mechanical advantage, allowing for one-handed, ambidextrous operation with ergonomic design for enhanced user comfort and control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a traditional vascular prosthesis deployment device is used, then the device structure is simple, but the deployment control precision is poor and incremental deployment is not achievable

Engineering Contradiction:
Improvedeployment control precisionVSAvoiddevice structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The deployment device is segmented into multiple functional components: a delivery catheter assembly with outer sheath, intermediate sheath, and inner core member; a ratchet mechanism with multiple ratchet teeth; and a carrier assembly. This segmentation allows each component to perform a specific function, enabling incremental deployment control while maintaining manageable overall device complexity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The ratchet mechanism is pre-configured with multiple ratchet teeth that engage with corresponding pawls on the carrier assembly. This preliminary arrangement of mechanical elements enables incremental deployment to occur automatically as the outer sheath is retracted, providing precise control without requiring complex active control systems

Inventive Principle:
Principle #10Preliminary action

2Ease of operation

If a traditional deployment device is used, then the device is easy to manufacture, but user control during deployment is poor and feedback mechanisms are absent

Engineering Contradiction:
Improveuser control and feedbackVSAvoidmanufacturing complexity
Core Design Contradiction:
Ease of operationVSEase of manufacture

Solution Approach 1:

The ratchet mechanism provides inherent mechanical feedback to the operator during deployment. As the outer sheath is retracted incrementally, each ratchet engagement produces audible clicks and tactile sensations, giving the operator real-time feedback on the deployment progress and allowing precise control of the stent expansion process

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The device employs a nested structure where the inner core member is surrounded by the intermediate sheath, which is in turn surrounded by the outer sheath. This nested arrangement allows the components to be manufactured separately using standard techniques, then assembled together, balancing manufacturing ease with the ability to provide controlled deployment and user feedback

Inventive Principle:
Principle #7Nested doll (Nesting)

3Ease of operation

If significant manual force is applied to deploy the stent, then the deployment can be achieved, but the handling becomes awkward and user comfort is reduced

Engineering Contradiction:
Improveuser comfort and handlingVSAvoidmanual force requirement
Core Design Contradiction:
Ease of operationVSForce

Solution Approach 1:

The deployment device transitions from a static structure to a dynamic system as deployment progresses. The ratchet mechanism allows the device to adapt its mechanical properties during retraction, providing mechanical advantage that reduces the force required by the operator while maintaining secure engagement, thereby improving user comfort and handling

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The ratchet mechanism acts as an intermediary between the operator's manual retraction force and the stent deployment force. It translates small incremental retraction movements into controlled expansion forces, reducing the overall manual force requirement while maintaining effective stent deployment, thus improving user comfort

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Enables precise, incremental deployment of stents with enhanced user control, reduced manual force requirement, and improved ergonomics, facilitating safer and more efficient vascular prosthesis placement within the body.

Implementation Method 1

the ratchet slide includes a distal end configured to engage the carrier assembly such that relative movement between the ratchet slide and the carrier assembly results in incremental displacement of the outer sheath with respect to the inner core member

Methodology Applied
Scientific EffectRatchet mechanism: Ratchet

Implementation Method 2

a spring positioned between the actuator and the housing and configured to return the actuator to the unconstrained position

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 3

mechanical advantage, allowing for one-handed, ambidextrous operation with ergonomic design for enhanced user comfort and control

Methodology Applied
Scientific EffectMechanical advantage: Mechanical Advantage

Data Source

PatentEP3265025B1Vascular prosthesis deployment device
Publication Date: 2022.04.13 MERIT MEDICAL SYSTEMS INC
  • EP3265025B1 patent drawingFigure 1
  • EP3265025B1 patent drawingFigure 2
  • EP3265025B1 patent drawingFigure 3A~3B

AI summary

A vascular prosthesis deployment device and related methods are disclosed. In some embodiments the deployment device may provide audible, tactile, or visual feedback to a practitioner as to the degree of deployment of a prosthesis. The deployment device may also provide mechanical advantage when deploying a prosthesis. The deployment device may be configured to incrementally deploy a prosthesis.