Articulating Knife Actuator for 360° Shaft Rotation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional electrosurgical instruments lack the ability to rotate their shaft continuously while allowing the knife blade to be operated effectively, limiting the versatility and precision of vessel sealing and cutting procedures.

Innovation Solution

A knife driving assembly that allows the knife to advance and retract along the jaws' pathway regardless of the shaft's rotational position, utilizing a lever, bearing sleeve, and drive shaft mechanism to enable 360-degree rotation of the shaft without compromising the knife's operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the shaft is allowed to rotate continuously through 360 degrees, then the versatility and positioning flexibility of the instrument is improved, but the ability to operate the knife blade effectively is compromised

Engineering Contradiction:
Improveshaft rotation flexibilityVSAvoidknife blade operation
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The knife actuator is segmented into multiple functional components: a lever for user input, a bearing cup for rotational accommodation, a drive shaft for linear force transmission, and a knife for cutting. This segmentation allows each component to perform its specific function independently, enabling shaft rotation while maintaining knife operability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The bearing cup acts as an intermediary element between the rotating shaft and the linear knife actuation mechanism. It accommodates the rotational movement of the shaft while allowing the drive shaft to transmit linear forcing motion to the knife, effectively decoupling the rotational and linear motions.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If a conventional knife driving mechanism is used, then the structure is simpler, but the shaft cannot rotate continuously while maintaining knife operation

Engineering Contradiction:
Improvemechanism structureVSAvoidcontinuous rotation capability
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The mechanism transitions from a static, fixed-orientation knife drive to a dynamic system where the bearing cup accommodates continuous shaft rotation. The drive shaft can move linearly within the bearing cup regardless of the shaft's rotational position, enabling dynamic adaptation to any angular orientation while maintaining knife actuation capability.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP4225184B1Articulating knife actuator for electrosurgical instrument
Publication Date: 2026.03.25 CONMED CORP
  • EP4225184B1 patent drawingFigure 1
  • EP4225184B1 patent drawingFigure 2
  • EP4225184B1 patent drawingFigure 3

AI summary

A knife driving assembly that can advance and retract a knife along a knife blade pathway defined by the jaws of the surgical instrument regardless of continuous rotation of the shaft and jaws. The assembly includes a housing having a shaft extending along a longitudinal axis and supporting to a pair of jaws that define a knife pathway and a lever pivotally mounted to housing and extending into the housing. A knife actuator is coupled to the lever at a first end and to a bearing sleeve at a second end. A drive shaft is secured to the bearing sleeve and extends within the shaft to move a knife along the knife pathway in response to movement of the bearing sleeve. As a result, the main shaft, and the drive shaft, may be rotated through 360 degrees with movement of lever capable of moving the knife.