Hand-Operated Pulling Mechanism for Vascular Implant Precision

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Solution Overview

Problem

Vascular implant delivery devices face challenges in accurately deploying implants due to the risk of unintended movement when pulling a tensile member, which can result in inaccurate placement of the implant during vascular procedures.

Innovation Solution

A hand-operated mechanism for vascular implant delivery devices that includes a lever and cam system, allowing for controlled and precise pulling of the tensile member to move the release mechanism toward the proximal end of the elongated shaft, reducing the likelihood of axial movement and improving placement accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the tensile member is pulled manually without a control mechanism, then the operation is simple, but the placement precision deteriorates due to unintended movement of the medical device

Engineering Contradiction:

Improvesimplicity of pulling operationVSAvoidplacement precision of implant

Core Design Contradiction:

Ease of operationVSManufacturing precision

Solution Approach 1:

The patent introduces an intermediary control mechanism (the pulling mechanism with cam and lever) between the operator's hand and the tensile member. This intermediary device translates simple hand motion into controlled, precise linear displacement of the tensile member, eliminating direct manual pulling while maintaining operational simplicity.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the direct mechanical pulling action with a mechanical substitution system consisting of a cam, lever, and linkage mechanism. This substitution converts uncontrolled manual pulling into controlled, incremental displacement through mechanical advantage and geometric constraints.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Manufacturing precision

If a complex pulling mechanism is used to improve placement precision, then the placement precision improves, but the device complexity increases

Engineering Contradiction:

Improveplacement precision of implantVSAvoidcomplexity of pulling mechanism

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent segments the pulling function into distinct modular components: a cam element for converting rotational to linear motion, a lever for providing mechanical advantage, and a linkage system for transmitting force. This segmentation allows each component to perform a specific function while maintaining overall system manageability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent employs dynamic elements including a rotatable cam that converts rotational input into controlled linear displacement, and a lever that provides variable mechanical advantage throughout the range of motion. These dynamic components enable precise control without requiring complex static mechanisms.

Inventive Principle:

Principle #15Dynamics

3Device complexity

If the tensile member is pulled in a straight line, then the mechanism is simple, but the control precision deteriorates due to lack of constrained motion

Engineering Contradiction:

Improvesimplicity of pulling mechanismVSAvoidcontrol precision of tensile member displacement

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent employs curved geometric elements, specifically a cam profile with a curved surface, to convert rotational motion into precise linear displacement. The curved geometry provides inherent motion constraints and ensures controlled, repeatable displacement increments with each rotation cycle.

Inventive Principle:

Principle #14Spheroidality (Curvature)

Solution Approach 2:

The patent adds a rotational dimension to the pulling mechanism by using a rotatable cam and lever system. This dimensional transformation converts simple linear pulling into a controlled rotational-to-linear motion conversion, providing precise displacement control through angular positioning.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

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

The mechanism enables precise control over the tensile member's movement, minimizing the risk of inaccurate implant placement and enhancing the reliability of vascular implant deployment.

Implementation Method 1

a cam for a length of the tensile member between the first point and the second point, wherein the cam is coupled to the elongated shaft

Methodology Applied

Scientific EffectCam mechanism: Cam

Implementation Method 2

a lever rotatably coupled to the elongated shaft

Methodology Applied

Scientific EffectMechanical advantage: Mechanical Advantage

Data Source

PatentUS11020255B2Apparatus for and method of pulling a tensile member from a medical device

Publication Date: 2021.06.01 CORDIS US CORP

AI summary

Mechanisms for pulling a tensile member a predetermined distance from a medical device having an intracorporeal end and an extracorporeal end are disclosed. Such mechanisms may be safely operated using a robot, two hands, or in some embodiments, only one hand. Such mechanisms may include one or more cams, drums, or pulley-like members and a lever, and may be physically coupled to an extracorporeal portion of the medical device.