Adjustable Trocar Cannula Axial Extension

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Solution Overview

Problem

Existing surgical access devices lack flexibility in depth adjustment, requiring surgeons to exchange cannulas during procedures when operating on anatomical sites at varying distances, which is time-consuming and increases procedural risks.

Innovation Solution

An adjustable trocar assembly featuring a cannula with an elongated tubular member and a plurality of circular ridges interconnected by flexible material, allowing for axial movement and maintaining axial uniformity through a collar and rim, enabling partial extension or retraction without compromising the inner diameter for surgical instrument passage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a rigid cannula is used for surgical access, then structural stability is maintained, but flexibility in depth adjustment is lost

Engineering Contradiction:
Improveflexibility in depth adjustmentVSAvoidstructural stability
Core Design Contradiction:
Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The cannula is divided into multiple circular ridges (first, second, third, and fourth circular ridges) that can independently move relative to each other along the longitudinal axis. This segmentation allows the distal end to extend or retract independently while maintaining the overall structural integrity of the cannula shaft.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The cannula transitions from a static rigid structure to a dynamic adjustable structure where the circular ridges can move along the longitudinal axis. The flexible material between ridges enables controlled deformation, allowing the cannula to adapt its effective length during surgery while maintaining stability when positioned.

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If the cannula length is extended to reach deeper anatomical sites, then access to target sites is improved, but the risk of complications increases

Engineering Contradiction:
Improveaccess to varying depth sitesVSAvoidprocedural safety
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The cannula allows dynamic adjustment of its effective length by moving the circular ridges along the longitudinal axis. The surgeon can extend the distal end to reach deeper anatomical sites when needed and retract it to reduce depth when approaching critical structures, thereby adapting the instrument length to match the specific surgical requirement and minimizing complications.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The effective length parameter of the cannula can be changed during the procedure by adjusting the position of circular ridges relative to each other. This parameter change allows the same cannula to serve multiple depth requirements without exchanging instruments, enabling precise control over the insertion depth to avoid complications.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If multiple cannulas are exchanged during a procedure to adjust depth, then depth flexibility is achieved, but procedure time increases

Engineering Contradiction:
Improvedepth adjustment capabilityVSAvoidprocedure time
Core Design Contradiction:
Adaptability or versatilityVSLoss of time

Solution Approach 1:

Instead of exchanging multiple rigid cannulas, the surgeon can dynamically adjust the effective length of a single cannula by moving the circular ridges along the longitudinal axis. This eliminates the time-consuming process of removing and reinserting different cannula sizes while achieving the same depth adjustment objective.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

A single adjustable cannula performs the function of multiple fixed-length cannulas. By adjusting the position of circular ridges, the same cannula can effectively reach different depths (e.g., 5cm, 10cm, 15cm) depending on the surgical requirement, eliminating the need to carry and switch between multiple specialized cannulas.

Inventive Principle:
Principle #6Universality (Multi-functionality)

4Measurement precision

If the inner diameter of the cannula is reduced to improve precision, then instrument passage is constrained, but adaptability for different instruments is reduced

Engineering Contradiction:
Improveprecision of instrument placementVSAvoidcompatibility with various surgical instruments
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The flexible material between circular ridges is segmented into multiple layers or zones that can independently deform. This segmentation allows the material to conform to different instrument diameters while maintaining the overall inner diameter opening, enabling precise instrument placement without compromising compatibility with various surgical tools.

Inventive Principle:
Principle #1Segmentation

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 adjustable trocar assembly provides variable length without the need for cannula exchange, reducing procedural complications and allowing precise access to target sites within the body, while maintaining axial uniformity for standard obturator use.

Implementation Method 1

Each circular ridge of the plurality of circular ridges is operably coupled to one or more adjacent circular ridges of the plurality of circular ridges by a flexible material interconnecting adjacent circular ridges

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3919010B1Surgical access device including adjustable cannula portion
Publication Date: 2024.12.11 COVIDIEN LP
  • EP3919010B1 patent drawingFigure 1
  • EP3919010B1 patent drawingFigure 2A~2C
  • EP3919010B1 patent drawingFigure 3A~3D

AI summary

An adjustable trocar assembly includes a housing configured to facilitate insertion of one or more surgical tools into a patient's body, and an elongated tubular member extending distally from the housing and defining a longitudinal axis. The elongated tubular member includes a channel configured to facilitate passage of surgical instruments through the elongated tubular member, an adjustable portion configured to facilitate axial movement of the elongated tubular member, a collar of fixed diameter; and a rim of fixed diameter equal to the diameter of the collar.