Safety Scalpel Resilient Lock Prevents Blade Exposure

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Solution Overview

Problem

Conventional surgical scalpels pose risks of injury and contamination due to the difficulty and danger of mounting and dismounting blades, and the potential for self-retracting blades to remain extended during removal, leading to exposure hazards.

Innovation Solution

A safety scalpel design featuring a blade cartridge with a resilient lock member that engages the blade holder to lock the cartridge to the handle when the blade is in a cutting position, combined with a cartridge release mechanism allowing perpendicular force application for safe detachment, preventing inadvertent activation and ensuring the blade is retracted before removal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the blade is extended to a cutting position for surgical use, then the cutting functionality is improved, but the risk of injury and contamination from exposed blade increases

Engineering Contradiction:
Improvecutting functionalityVSAvoidinjury and contamination risk
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The blade assembly is segmented into a replaceable blade cartridge that can be detached from the handle. The blade is contained within a cartridge housing that provides physical containment, separating the sharp cutting element from the user's hand during both extended and retracted states

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The blade is nested within the blade cartridge housing, which itself is nested within or attached to the handle assembly. The blade holder retracts the blade into the cartridge housing, creating a nested configuration that contains the sharp edge within multiple protective layers

Inventive Principle:
Principle #7Nested doll (Nesting)

2Ease of repair

If the blade cartridge is made easily detachable for replacement, then the ease of maintenance is improved, but the risk of inadvertent detachment and injury increases

Engineering Contradiction:
Improveblade replacement easeVSAvoidinadvertent detachment risk
Core Design Contradiction:
Ease of repairVSReliability

Solution Approach 1:

The locking mechanism transitions between locked and unlocked states dynamically. The resilient lock member automatically engages when the blade cartridge is inserted and can be deliberately disengaged only when the blade is retracted, providing adaptive security that responds to the operational state of the device

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The resilient lock member provides automatic locking upon insertion of the blade cartridge, eliminating the need for manual locking actions. The system self-regulates to prevent removal when the blade is extended, requiring user awareness and proper sequencing of operations

Inventive Principle:
Principle #25Self-service

3Object-affected harmful factors

If a self-retracting blade mechanism is implemented, then the safety during removal is improved, but the complexity of the mechanism increases

Engineering Contradiction:
Improveexposure hazard during removalVSAvoidretracting mechanism complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The blade itself is designed as a disposable element that is replaced rather than repeatedly retracted and extended. This eliminates the need for complex long-term retraction mechanisms for the blade, as each blade is used once and then discarded with its cartridge

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The blade holder provides dynamic positioning of the blade between extended and retracted states through simple spring-based resilience, allowing automatic retraction without complex mechanical systems

Inventive Principle:
Principle #15Dynamics

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 design enhances user safety by preventing accidental blade exposure during handling and ensures the blade is securely locked in the stowed position, reducing the risk of injury and contamination, while allowing easy and safe release of the cartridge.

Implementation Method 1

a resilient lock member disposed within the housing, wherein the resilient lock member is in an unbiased condition when the blade holder is in the pre-cutting state, and wherein the resilient lock member is configured to engage the blade holder to lock the blade cartridge to the handle when the blade is in the cutting position

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3496633B1Safety scalpel with replaceable blade cartridge
Publication Date: 2024.04.24 MEDIPURPOSE PTE
  • EP3496633B1 patent drawingFigure 1A~1C
  • EP3496633B1 patent drawingFigure 2A~2C
  • EP3496633B1 patent drawingFigure 3~4

AI summary

In an embodiment, there is a safety scalpel having a handle, and a replaceable blade cartridge assembly that is releasably attached to the handle. The handle comprises a first end and a second end. The blade cartridge assembly comprises a housing that can be slideably mounted onto the second end of the handle, a blade holder that can be disposed within the housing, and a blade that can be attached to the blade holder. The blade holder is configured to allow the blade to extend between a stowed position in a pre-cutting state of the blade holder and a cutting position upon activation of the blade holder. The safety scalpel also has a resilient lock member dispose d within the cartridge that prevents the cartridge assembly from being detached from the handle, by being configured to engage the blade holder to lock the blade cartridge to the handle when the blade is in the cutting position.