Stylet Notch Alignment for Dynamic Flexibility Control

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Solution Overview

Problem

Current medical devices lack the ability to dynamically adjust flexibility and rigidity, making them inadequate for navigating complex anatomical paths and procedures such as ERCP, where they often require both high flexibility and pushability, which existing technologies fail to provide simultaneously.

Innovation Solution

The Dynaflex technology allows for customizable notch designs and orientations in stylets and cannulas, enabling real-time adjustment of flexibility and rigidity by rotating the stylet within the cannula, thereby aligning notched and non-notched segments to achieve specific flexibility profiles at critical points along the device.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional flexible materials are used to allow device to traverse contorted passages, then flexibility is improved, but pushability and tip rigidity deteriorate

Engineering Contradiction:
ImproveflexibilityVSAvoidtip rigidity and pushability
Core Design Contradiction:
Adaptability or versatilityVSStrength

Solution Approach 1:

The device is divided into multiple sections with different flexibility characteristics. The stylet contains notched segments that can be independently positioned relative to the cannula, allowing each section to have customized flexibility properties while maintaining overall structural integrity and force transmission capability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The device transitions from static flexibility to dynamic flexibility through rotational adjustment. The stylet can be rotated within the cannula to change the alignment between notched and non-notched segments, enabling real-time modification of flexibility characteristics to match procedural requirements.

Inventive Principle:
Principle #15Dynamics

2Strength

If stainless steel is used to provide rigidity and pushability, then tip rigidity and pushability are improved, but flexibility deteriorates

Engineering Contradiction:
Improvetip rigidity and pushabilityVSAvoidflexibility
Core Design Contradiction:
StrengthVSAdaptability or versatility

Solution Approach 1:

Different sections of the device have different material properties and structural characteristics. The stylet incorporates both notched (more flexible) and non-notched (more rigid) segments in specific configurations, allowing rigid sections to provide pushability while flexible sections enable navigation of contorted passages.

Inventive Principle:
Principle #3Local quality

3Adaptability or versatility

If relief notches are added to increase flexibility, then flexibility is improved, but the ability to provide custom or adjustable flexibility deteriorates

Engineering Contradiction:
ImproveflexibilityVSAvoidadjustability
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The device incorporates multiple notched segments that can be rotated to different positions, transforming static flexibility into dynamic flexibility. This allows the operator to adjust the flexibility characteristics by rotating the stylet to align notched segments with or perpendicular to the cannula's notches, providing custom flexibility profiles without complex mechanisms.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP2359890B1Stylet for bilumenal flexible medical device
Publication Date: 2019.05.15 PETERSEN EINAR GJALDBAEK
  • EP2359890B1 patent drawingFigure 1~2
  • EP2359890B1 patent drawingFigure 3~4B
  • EP2359890B1 patent drawingFigure 5A~6

AI summary

Utilizing the technology and methods disclosed, the characteristics of flexibility and rigidity for intralumenal devices, including coaxial two piece devices such as stylet and needle sets, can be adapted by a physician or device manufacturer according to the type of procedure, the patient size and unique anatomical challenges of a given procedure. Rigidity and flexibility are actively controlled by the operator at predefined portions of a device through rotating the stylet within the cannula to bring about alignments of customized notches to impart target flexibility or rigidity profiles at specific spots on the device. The device operator is able to alter the relationship and orientation of specific notched and non-notched segments of either or both the stylet and cannula that are strategically located at said critical points along the length of the device.