Articulating Cannula with Compression Spring for 0-90° Motion

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Solution Overview

Problem

Existing cannulas have stiff and non-articulating distal ends, which are incompatible with articulating endoscope tips and surgical instruments, limiting their use in robotic-assisted surgeries.

Innovation Solution

An articulating cannula with a distal end that can move between two positions, featuring a hollow tubular shaft segmented into two parts secured by flexible material, including a compression spring to facilitate articulation and maintain a constant cross-section.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If the distal end of the cannula is made stiff for structural stability, then the cannula maintains its shape and prevents collapse, but it becomes incompatible with articulating endoscope tips and surgical instruments

Engineering Contradiction:

Improvestructural stabilityVSAvoidcompatibility with articulating instruments

Core Design Contradiction:

Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The cannula is divided into multiple segments along its length, with different articulation capabilities assigned to different segments. The proximal segments maintain stiffness for structural stability, while the distal segments are made flexible to accommodate articulating instruments, resolving the contradiction between overall stability and local adaptability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different portions of the cannula are assigned different mechanical properties: the proximal end maintains rigidity for structural support, while the distal end incorporates flexible materials and articulation joints to enable compatibility with articulating endoscope tips and surgical instruments.

Inventive Principle:

Principle #3Local quality

2Adaptability or versatility

If the distal end of the cannula is made flexible to accommodate articulating instruments, then compatibility with endoscope tips is improved, but the distal end may collapse during articulation

Engineering Contradiction:

Improvecompatibility with articulating instrumentsVSAvoidresistance to collapse

Core Design Contradiction:

Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The cannula incorporates composite material structures combining flexible polymers with reinforcing elements such as metallic meshes or rigid inserts. This composite construction allows the distal end to flex and articulate while the reinforcing elements prevent collapse, simultaneously achieving adaptability and structural integrity.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The cannula incorporates dynamic articulation joints that allow controlled movement between segments. These joints enable the distal end to adapt its shape for instrument compatibility while maintaining structural stability through controlled mechanical movement rather than rigid flexibility.

Inventive Principle:

Principle #15Dynamics

3Stability of the object's composition

If a compression spring is added to maintain constant cross-section during articulation, then structural integrity is improved, but device complexity increases

Engineering Contradiction:

Improveconstant cross-section maintenanceVSAvoidnumber of components

Core Design Contradiction:

Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The compression spring is integrated into the articulation mechanism itself, using the natural compression and expansion of the spring during articulation movements to automatically maintain constant cross-section. The spring serves dual purposes: enabling articulation and maintaining structural integrity, thereby reducing overall device complexity.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The compression spring functionality is merged with the articulation joint structure, combining the flexibility mechanism and the cross-section maintenance mechanism into a single integrated component rather than separate elements, thus minimizing device complexity while achieving both functions.

Inventive Principle:

Principle #5Merging (Combining)

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 articulating cannula allows for a 0-90° range of motion all around, ensuring compatibility with articulating surgical instruments and endoscopes, while preventing collapse of the distal end during articulation.

Implementation Method 1

The spring is configured to maintain a constant cross section of the second shaft with or without articulation

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentUS20250098947A1An articulating cannula

Publication Date: 2025.03.27 SSI IP HOLDINGS INC

AI summary

The application provides an articulating cannula (300) comprising a proximal end (302) and a distal end (304) connected with a hollow tubular shaft (306). The distal end (304) is configured to articulate between a first position (310) and a second position (312). The shaft (306) is segmented into a first shaft (414) and a second shaft (316) which are secured by a flexible material. The proximal end (302) comprises of a housing (308) having diameter substantially greater than the diameter of the shaft (306) and configured to allow insertion of an articulating surgical instrument (318). The second shaft (316) comprises of an outer layer (320) and an inner layer (322) of the flexible material with a compression spring (324) in between, the second shaft (316) is configured to facilitate the articulation of the distal end (304) and to prevent collapse of second shaft (316) at the distal end (304). The spring (324) is configured to maintain a constant cross section of the second shaft (316) with or without articulation.