Rotary Vitrectomy Probe With Offset Blades

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Solution Overview

Problem

Conventional vitrectomy probes are aggressive and inefficient due to turbulence and pulsational operation, which is exacerbated by the elasticity of the vitreous body, leading to unpredictable and unsafe removal during ophthalmological procedures.

Innovation Solution

A rotary vitrectomy probe with an immovable external cutting tube and a coaxially mounted internal cutting tube featuring cutting blades offset along its circumference, providing a constant aeration surface area and reducing turbulence, allowing for gradual cutting and aspiration of the vitreous body.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional vitrectomy probe uses a pulsational cutting mechanism with an internal cutting element that opens and closes the port, then the vitreous body can be cut off piece by piece to avoid vitreomacular traction, but the operation generates heavy turbulence and aggressive flow that reduces efficiency and predictability

Engineering Contradiction:
ImprovesafetyVSAvoidefficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent applies periodic action through the rotary motion of the internal cutting element with multiple cutting blades. The blades are offset circumferentially and rotate to periodically contact the vitreous body at the port, creating a rhythmic cutting action that maintains safety while reducing turbulence compared to the rapid open-close mechanism of conventional probes.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent inverts the conventional mechanism by making the internal cutting element rotatable rather than reciprocating. Instead of the cutting element moving linearly to open and close the port rapidly, it rotates gradually with blades that sequentially engage the vitreous body, transforming the aggressive pulsational flow into a more controlled laminar flow.

Inventive Principle:
Principle #13The other way round (Inversion)

2Productivity

If the internal cutting element moves rapidly to cut off vitreous body portions, then cutting efficiency increases, but the elasticity of the vitreous body causes it to jump away unpredictably, reducing safety and control

Engineering Contradiction:
Improvecutting speedVSAvoidpredictability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies dynamics by implementing a rotatable internal cutting element with multiple blades that can continuously engage the vitreous body. Instead of rapid reciprocating motion that causes the vitreous to jump away, the rotational motion allows gradual engagement and continuous cutting, maintaining predictability while achieving efficient removal.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent segments the cutting function into multiple blades distributed circumferentially on the internal cutting element. This segmentation allows the cutting action to be distributed over time during rotation, with each blade contributing to the cutting process sequentially, thereby maintaining continuous engagement with the vitreous body and improving predictability.

Inventive Principle:
Principle #1Segmentation

3Device complexity

If a guillotine style probe uses pneumatic pressure to activate the cutting element, then the mechanism is simple and reliable, but the rapid activation and deactivation creates aggressive flow and turbulence

Engineering Contradiction:
Improvemechanism simplicityVSAvoidturbulence
Core Design Contradiction:
Device complexityVSObject-generated harmful factors

Solution Approach 1:

The patent replaces the rapid pneumatic activation mechanism with a rotational mechanical system. Instead of using pneumatic pressure to rapidly drive the cutting element open and closed, the system uses rotational motion to gradually bring the cutting blades into contact with the vitreous body, eliminating the aggressive flow and turbulence associated with rapid pneumatic actuation.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

4Productivity

If the port of the vitrectomy probe is kept open for aspiration, then the vitreous body can be removed continuously, but the constant negative pressure creates turbulent flow and aggressive operation

Engineering Contradiction:
Improvecontinuous removalVSAvoidaggressive flow
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent maintains continuity of useful action through the rotational motion of the internal cutting element. The cutting blades continuously engage and remove the vitreous body as the element rotates, while the port remains open for aspiration. This continuous rotational cutting action eliminates the pulsational flow pattern, creating a more stable and laminar flow regime.

Inventive Principle:
Principle #20Continuity of useful action

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 solution enhances safety and predictability by minimizing the impact of vitreous body elasticity, reduces turbulence, and achieves a more efficient, laminar flow during vitreous body removal, improving the precision and control of the procedure.

Implementation Method 1

an internal cutting tube mounted rotatably and coaxially in the external cutting tube, with cutting blades offset along its circumference

Methodology Applied
Scientific EffectRotational motion:

Implementation Method 2

which has a suction system and a moving element mounted in the cannula to cyclically cut off small portions of the vitreous body, sucked into the cannula

Methodology Applied
Scientific EffectSuction: Suction

Data Source

PatentEP4356881A1A rotary vitrectomy probe
Publication Date: 2024.04.24 KRASNICKI PAWEL
  • EP4356881A1 patent drawingFigure 1~8
  • EP4356881A1 patent drawingFigure 3~10
  • EP4356881A1 patent drawing

AI summary

The invention describes a rotary vitrectomy probe with several cutting blades.