Capsule Cutter with Retractable Blade for Synovial Tissue Resection

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Solution Overview

Problem

Existing arthroscopic procedures for removing damaged tissue from synovial joints face challenges such as inadvertent damage to healthy tissue by exposed blades, risk of blade breakage, and the need for invasive procedures to retrieve broken blade portions.

Innovation Solution

A capsule cutter system that positions a blade within an inner lumen of a cannula with a cutting port, allowing the blade to be moved between deployed and retracted positions to minimize tissue damage and prevent blade breakage. The cannula's partially closed end reduces the risk of lost blade fragments and shields surrounding tissue.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the blade is fully exposed and maneuvered within the synovial cavity to cut damaged tissue, then the blade can effectively resect damaged tissue, but the exposed blade can inadvertently damage healthy tissue

Engineering Contradiction:

Improvetissue resection effectivenessVSAvoidinadvertent damage to healthy tissue

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The blade is nested within the cannula, which provides a protective sheath. The blade can be extended through the cannula's opening when needed for cutting, but remains protected when retracted, preventing inadvertent damage to healthy tissue while maintaining cutting effectiveness.

Inventive Principle:

Principle #7Nested doll (Nesting)

Solution Approach 2:

The blade is designed to be movable between extended and retracted positions within the cannula. This dynamic configuration allows the blade to be exposed only when actively cutting damaged tissue, and retracted when not in use, thereby controlling the harmful effects while maintaining productivity.

Inventive Principle:

Principle #15Dynamics

2Ease of operation

If the blade is made very thin to be passed through the cannula, then the blade can be inserted through the cannula, but the thin blade can often break off during the resecting of damaged tissue

Engineering Contradiction:

Improveblade insertion through cannulaVSAvoidblade breakage risk

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The thin blade is nested within the protective cannula during insertion and transport, allowing it to pass through the cannula without damage. The cannula acts as a protective sheath that prevents blade breakage during insertion while still allowing the blade to be thin enough for minimally invasive access.

Inventive Principle:

Principle #7Nested doll (Nesting)

Solution Approach 2:

The cannula provides protective cushioning to the thin blade during insertion and when not in use. This pre-protection prevents blade breakage before the blade is actually needed for cutting, allowing the use of thin blades without compromising reliability.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

3Adaptability or versatility

If the blade is fully exposed during manipulation, then the blade can be maneuvered freely to cut tissue, but the manipulation of the blade and cannula can cause unnecessary damage to the tissue wall

Engineering Contradiction:

Improveblade maneuverabilityVSAvoidunnecessary damage to tissue wall

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The blade remains nested within the cannula during insertion and positioning, protecting the tissue wall from unnecessary damage. The blade can be extended through the cannula's opening only when actual cutting is required, maintaining maneuverability while reducing harmful effects.

Inventive Principle:

Principle #7Nested doll (Nesting)

Solution Approach 2:

The cannula serves as an intermediary between the blade and the tissue wall. It allows the blade to be maneuvered freely when extended for cutting, but protects the tissue wall when the blade is retracted, thereby mediating between adaptability and harm reduction.

Inventive Principle:

Principle #24Intermediary (Mediator)

4Ease of repair

If a conventional invasive procedure is performed to retrieve a broken blade portion, then the broken blade can be retrieved, but a larger opening is formed in the articular capsule causing considerable risk and unnecessary damage

Engineering Contradiction:

Improveblade retrieval capabilityVSAvoiddamage from larger opening

Core Design Contradiction:

Ease of repairVSObject-affected harmful factors

Solution Approach 1:

The blade is extracted from the cannula only when needed for cutting damaged tissue. When the blade breaks, the proximal portion remains accessible through the existing small incision and cannula opening, allowing retrieval without requiring a larger invasive opening, thus avoiding additional damage to the articular capsule.

Inventive Principle:

Principle #2Taking out (Extraction)

Data Source

PatentEP3235455B1Capsule cutter

Publication Date: 2025.05.14 BIOMET SPORTS MEDICINE LLC

Figure 1
Figure 2A~2B
Figure 2C~2D

AI summary

A system for cutting tissue within a synovial cavity, which includes a cannula and a blade assembly. The cannula can define an internal lumen and a cutting port for accessing the internal lumen. The blade assembly can include a blade and a blade shaft extending from the blade. The blade can be inserted into the internal lumen of the cannula through an access port of the cannula such that the blade is proximal the cutting port. The blade shaft can be operated to move the blade within the internal lumen relative to the cutting port between a retracted position and a deployed position. The blade can be received within the internal lumen in the retracted position and positioned, at least partially, within the cutting port in the deployed position.