Multi-Diameter Cannula Depth Limiter for Stable Trocar Insertion

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Solution Overview

Problem

Existing surgical access devices lack effective mechanisms to limit the depth of insertion into the abdominal cavity and stabilize the trocar relative to the abdominal wall, potentially leading to unintended over-insertion or under-insertion, which can cause damage to anatomical structures and instability during surgical procedures.

Innovation Solution

The introduction of depth limiters that can be coupled with cannula tubes to restrict axial movement and stabilize the trocar, featuring movable and fixed configurations to ensure precise insertion depth and stability, compatible with various cannula diameters.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional trocars are used without depth limiters, then the device complexity is reduced, but the reliability and precision of insertion depth are compromised

Engineering Contradiction:

Improveinsertion depth controlVSAvoiddevice structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The depth limiter is designed as a component that fits within or attaches to the existing cannula assembly structure. The depth limiter includes a body portion that receives the cannula tube and a depth limiting portion that extends from the body portion, creating a nested configuration where the depth limiter integrates with the cannula assembly without requiring a completely separate device.

Inventive Principle:

Principle #7Nested doll (Nesting)

Solution Approach 2:

The depth limiter acts as an intermediary component between the cannula assembly and the abdominal wall. It includes a depth limiting portion that contacts the abdominal wall to prevent over-insertion, while the body portion maintains coupling with the cannula tube to stabilize the trocar during the procedure.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Stability of the object's composition

If the trocar is allowed to move freely during insertion, then the ease of operation is improved, but the stability and precision of the trocar position deteriorate

Engineering Contradiction:

Improvetrocar stabilityVSAvoidinsertion flexibility

Core Design Contradiction:

Stability of the object's compositionVSEase of operation

Solution Approach 1:

The depth limiter is designed to provide dynamic stabilization during the surgical procedure. The body portion maintains coupling with the cannula tube to prevent rotation or lateral movement, while the depth limiting portion can be actuated to engage with the abdominal wall at the desired depth, providing stability only when needed and maintaining ease of operation during insertion.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The depth limiter is pre-configured with a depth limiting portion that is positioned to engage with the abdominal wall at a predetermined depth. This preliminary positioning allows the trocar to be inserted smoothly without resistance until the desired depth is reached, at which point the depth limiting portion engages to stabilize the trocar, preventing over-insertion without compromising the ease of initial insertion.

Inventive Principle:

Principle #10Preliminary action

3Adaptability or versatility

If a single-size depth limiter is used, then the device complexity is reduced, but the adaptability to different cannula diameters deteriorates

Engineering Contradiction:

Improvecannula compatibilityVSAvoiddepth limiter variants

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The depth limiter is designed with a body portion that can receive cannula tubes of various diameters. The body portion includes a receiving space that accommodates different cannula tube sizes, and the depth limiting portion can be actuated independently of the cannula diameter. This universal design allows a single depth limiter model to be used with multiple cannula sizes (e.g., 5mm, 8mm, 10mm, 12mm), providing adaptability without requiring multiple specialized depth limiters.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS20250345092A1Multi-diameter cannula depth limiter

Publication Date: 2025.11.13 CILAG GMBH INTERNATIONAL

AI summary

A depth limiter that is configured to couple with first and second trocar cannulas having different diameters. The depth limiter includes first and second body portions. First and second body portions each include first and second gripping surfaces. The first and second body portions are pivotably coupled together and are movable between an open configuration and a closed configuration. In the open configuration, the first and second body portions are configured to allow for axial movement of the depth limiter relative to the first and second trocar cannulas. The first gripping surfaces of the first and second body portions are configured to restrict axial movement of the depth limiter relative to the first trocar cannula in the closed configuration. The second gripping surfaces of the first and second body portions are configured to restrict axial movement of the depth limiter relative to the second trocar cannula in the closed configuration.