Cannula With Lateral Fluid Outlets for DMEK Graft Deployment

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Solution Overview

Problem

Existing deployment cannulas for ophthalmological procedures, such as DMEK, face challenges in safely and accurately positioning and unrolling transplants or implants within the anterior chamber of the eye due to uncontrolled fluid flow, leading to potential damage or loss of the transplant during insertion through small incisions.

Innovation Solution

A cannula design featuring multiple lateral fluid outlets along its working area, which distribute fluid flow radially to prevent uncontrolled displacement of the transplant, allowing for controlled and safe deployment by ensuring even volume flow distribution and precise positioning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a single opening at the distal end of the cannula is used for fluid delivery, then the graft or implant can be unrolled, but the fluid flow causes uncontrolled displacement and potential damage to the graft

Engineering Contradiction:
Improveunrolling capabilityVSAvoidpositioning control
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The single distal opening is segmented into multiple lateral openings distributed along the working area of the cannula. This segmentation distributes the fluid flow into multiple smaller jets rather than one concentrated stream, preventing uncontrolled displacement of the graft while maintaining the unrolling function.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The fluid flow characteristics are made non-uniform by distributing openings at different locations along the working area. Each lateral opening creates a localized fluid jet that acts on specific portions of the graft, enabling controlled unrolling without causing overall displacement. The local fluid action is tailored to the local requirements of graft deployment.

Inventive Principle:
Principle #3Local quality

2Length of moving object

If the cannula working area is dimensioned to insert into the rolled-up graft through a small incision, then minimal incision size is achieved, but the graft cannot be positioned within the device from the outset

Engineering Contradiction:
Improveincision sizeVSAvoidpositioning capability
Core Design Contradiction:
Length of moving objectVSEase of operation

Solution Approach 1:

The graft is prepared in a rolled-up state before insertion, which is the preliminary action required to fit through the small incision. The lateral openings are designed to act on the graft after insertion, performing the positioning action that cannot be done before insertion due to the size constraint.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The lateral fluid openings serve as an intermediary mechanism that enables positioning of the graft within the cannula after insertion. The fluid flow acts as a mediator between the operator's intent to position the graft and the physical constraints of the small incision device, allowing indirect manipulation of the graft through fluid pressure.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If fluid flow is used to unroll the graft or implant, then deployment is achieved, but the graft is propelled uncontrollably away from the center of the anterior chamber

Engineering Contradiction:
Improvedeployment speedVSAvoidpositioning accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The single fluid jet is segmented into multiple smaller jets through the lateral openings distributed along the working area. This maintains the total fluid flow volume for rapid deployment while distributing the force across multiple contact points on the graft, preventing uncontrolled propulsion and maintaining positioning accuracy in the center of the anterior chamber.

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

Enables controlled and safe deployment of transplants or implants within the anterior chamber, reducing the risk of damage or loss and facilitating rapid visual rehabilitation by ensuring accurate positioning and unfolding.

Implementation Method 1

the wall of the working area has at least one, preferably two, lateral openings through which a fluid flow escapes in a substantially radial direction along the cannula

Methodology Applied
Scientific EffectFluid pressure distribution: Pressure Gradient

Data Source

PatentEP3525723B1Cannula for guiding and deploying a graft or implant
Publication Date: 2023.11.08 GEUDER AG
  • EP3525723B1 patent drawingFigure 1
  • EP3525723B1 patent drawingFigure 2

AI summary

A cannula (5) for guiding and deploying a graft (9) or implant, in particular for performing a DMEK operation, with a work region (15) which is located at and/or near the distal end of the cannula and which serves for insertion into an anterior chamber (2) of an eye and is dimensioned in such a way that it can be pushed at least in part into a rolled up graft or implant, wherein the wall of the work region at the distal end has an opening (16a) allowing a fluid, preferably a liquid, to flow in and/or out, is characterized in that the wall of the work region has at least one lateral opening (16b), preferably two lateral openings (16b).