Stapler Cartridge with Integral Retracting Knife for Safe Replacement

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Solution Overview

Problem

Existing minimally invasive surgical stapling devices face issues with dull knives due to their integration with replaceable cartridges, leading to complex mechanisms and high costs, while integral knife designs in surgical instruments pose failure risks and are costly.

Innovation Solution

A stapling cartridge with an integral knife member that retracts into the cartridge body after use, ensuring a sharp knife for each operation, simplifying the actuation mechanism, and reducing the overall length and cost of the surgical instrument.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the knife is integral to the surgical instrument and reused with multiple cartridges, then device complexity is reduced, but the knife becomes duller with each use, compromising cutting performance

Engineering Contradiction:

Improveknife mechanism complexityVSAvoidcutting performance

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The knife is segmented from the surgical instrument and integrated into the disposable cartridge instead. This allows the knife to be replaced with each new cartridge, ensuring fresh cutting performance while keeping the main instrument simple and reusable.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The knife is made part of a disposable cartridge that is discarded after a single use. This inexpensive, single-use approach ensures the knife remains sharp and reliable without requiring complex mechanisms for maintenance or replacement.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

2Reliability

If the knife is integral to the disposable cartridge, then a fresh knife is ensured for each operation, but the knife driving mechanism becomes complex and requires the knife to be returned to its starting position

Engineering Contradiction:

Improveknife sharpnessVSAvoidknife driving mechanism complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

Instead of returning the knife to its starting position after use, the design inverts the approach by leaving the knife in its final position within the disposable cartridge. The entire cartridge is then discarded, eliminating the need for complex return mechanisms while ensuring the knife is fresh for each operation.

Inventive Principle:

Principle #13The other way round (Inversion)

3Device complexity

If the knife remains exposed at the distal end after use, then the actuation mechanism is simpler, but the risk of accidental touching and safety hazards increases

Engineering Contradiction:

Improveactuation mechanism simplicityVSAvoidaccidental knife contact

Core Design Contradiction:

Device complexityVSObject-affected harmful factors

Solution Approach 1:

The knife is nested within the cartridge body after use, with the cartridge structure serving as a protective enclosure. This nesting approach provides safety by containing the sharp knife within the disposable cartridge, preventing accidental contact while maintaining actuation mechanism simplicity.

Inventive Principle:

Principle #7Nested doll (Nesting)

Data Source

PatentUS12364478B2Stapler cartridge with an integral knife

Publication Date: 2025.07.22 INTUITIVE SURGICAL OPERATIONS INC

AI summary

Stapler cartridges and surgical apparatus that include a stapler cartridge can include a knife that retracts into the stapler cartridge after cutting stapled tissue to prevent an operator being cut by the knife during replacement of the used stapler cartridge with a new stapler cartridge. A stapler cartridge includes a staple pushing shuttle, a knife member slidably coupled with the staple pushing shuttle, and a cartridge body. The staple pushing shuttle is slidably coupled to the cartridge body. The cartridge body includes a guide track engaged by the knife member and configured so that a cutting blade of the knife member protrudes from the cartridge body during a first portion of a distal movement of the staple pushing shuttle and the cutting blade is retracted into the cartridge body during a second portion of the distal movement of the staple pushing shuttle.