Adjustable-Length Stabilizer Arm With Flexible-to-Rigid Locking

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Solution Overview

Problem

Existing stabilizer arms for surgical procedures have limited adjustability in length, restricting their ability to conform to various contoured paths and maintain desired shapes due to fixed overall length, which hampers their effectiveness in crowded surgical sites.

Innovation Solution

A stabilizer arm with a plurality of successive articulating and length-adjustable links, a tension cable, and a control mechanism that allows selective separation of length-adjustable links to adjust tension and rigidity, enabling adjustable length and improved configuration flexibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the stabilizer arm has a fixed overall length, then the structure is simple and easy to manufacture, but the adaptability to conform to various contoured paths is limited

Engineering Contradiction:
Improveability to conform to contoured pathsVSAvoidstructure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The stabilizer arm is divided into multiple telescopic segments that can extend and retract relative to each other. Each segment contains articulating links with ball and socket joints, allowing independent adjustment. This segmentation enables the arm to conform to various contoured paths while maintaining a manageable structure through modular design.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The stabilizer arm incorporates a tensioning mechanism with a cable and pulley system that dynamically adjusts the tension applied to the articulating links. This dynamic tensioning allows the arm to transition between flexible configuration states and rigid locked states, providing adaptability to different surgical site geometries while maintaining structural integrity.

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If the stabilizer arm has fixed length, then the device is simpler to operate, but the degrees of freedom to obtain desired configuration are limited

Engineering Contradiction:
Improvedegrees of freedom for configurationVSAvoidoperation simplicity
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The tensioning mechanism includes a cable running through pulleys that can be adjusted to change the tension applied to the articulating links. This dynamic adjustment capability provides additional degrees of freedom for configuring the arm to desired positions while maintaining operational simplicity through a single primary control mechanism.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The stabilizer arm allows changing the effective length parameter through telescopic segments that can extend or retract. This parameter change capability increases the degrees of freedom for obtaining desired configurations without significantly complicating operation, as the length adjustment is integrated into the existing articulation mechanism.

Inventive Principle:
Principle #35Parameter changes

3Stability of the object's composition

If the stabilizer arm is made rigid to maintain positioning, then the stability is improved, but the flexibility to conform to desired shape is reduced

Engineering Contradiction:
Improvepositioning stabilityVSAvoidflexibility to conform to shape
Core Design Contradiction:
Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The stabilizer arm employs a tensioning mechanism that can dynamically transition the arm between flexible and rigid states. When the cable tension is adjusted to a specific level, the articulating links are locked into place, providing stable positioning. When tension is reduced, the links can move freely, allowing the arm to conform to desired shapes. This dynamic state change resolves the contradiction between rigidity and flexibility.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The physical state of the stabilizer arm is changed by adjusting the tension parameter in the cable. By varying this parameter, the arm transitions between a flexible state suitable for conforming to complex geometries and a rigid state suitable for maintaining stable positioning during surgical procedures.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3687435B1Articulating stabilizer arm with adjustable length
Publication Date: 2022.07.06 TERUMO CARDIOVASCULAR SYSTEMS CORP
  • EP3687435B1 patent drawingFigure 1
  • EP3687435B1 patent drawingFigure 2
  • EP3687435B1 patent drawingFigure 3

AI summary

A reusable flexible arm stabilizes tissues during surgical procedures. The stabilizer arm switches between a flexible state for conforming to a desired curvature and a rigid state for maintain a desired positioning. A suspension length provided by the stabilizer arm is also adjustable. The arm has an articulating portion with successive articulating links each having a central passage. A length adjustable portion has successive length-adjustable links each having a central passage. A tension cable extends through the central passages between a proximal one of the length-adjustable links and a distal one of the articulating links. A base member captures the length-adjustable links at a position corresponding to a desired extension length of the arm. A control mechanism is movable between a retracted position and an extended position to selectably separate the captured length-adjustable links, thereby adjusting a tension in the tension cable and a rigidity of the stabilizer arm.