Surgical Knife Blade Orientation for Safe Removal

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Solution Overview

Problem

Existing surgical clamping and cutting instruments, such as staplers, lack maneuverability and often pose a hazard when failing to fully actuate, particularly due to restricted movement in minimally invasive procedures.

Innovation Solution

The design incorporates a proximal to distal knife movement mechanism that orients the knife to prevent unintentional cutting during instrument removal, with the knife and drive mechanism positioned distally to allow high motion wrist articulation and reduced instrument length, enabling enhanced maneuverability and safety.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the knife is positioned in conventional surgical staplers, then the instrument can perform cutting function, but the instrument lacks maneuverability and poses hazard during removal

Engineering Contradiction:
ImprovemaneuverabilityVSAvoidunintentional cutting hazard
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent inverts the conventional knife orientation by implementing proximal-to-distal movement instead of distal-to-proximal. The knife blade is positioned such that the sharp edge faces proximally rather than distally, so that during instrument removal the sharp edge moves away from tissue rather than toward it, eliminating the cutting hazard while maintaining maneuverability

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

Solution Approach 2:

The patent implements dynamic positioning of the knife blade through a drive mechanism that allows the knife to move between a retracted position (where the sharp edge is protected) and an extended position (where cutting occurs). This dynamic control enables the knife to be sharp and effective during surgery while safe during removal

Inventive Principle:
Principle #15Dynamics

2Length of moving object

If the knife and drive mechanism are positioned distally, then the instrument length is reduced, but the wrist articulation range of motion is restricted

Engineering Contradiction:
Improveinstrument lengthVSAvoidwrist articulation range of motion
Core Design Contradiction:
Length of moving objectVSAdaptability or versatility

Solution Approach 1:

The patent nests the drive mechanism and knife assembly within the distal portion of the instrument shaft, allowing compact integration. The lead screw mechanism and knife holder are arranged concentrically and sequentially to minimize the overall instrument length while maintaining full wrist articulation capability through proper positioning of the articulation joint

Inventive Principle:
Principle #7Nested doll (Nesting)

Data Source

PatentEP4154829B1Surgical instrument with integral knife blade
Publication Date: 2024.07.03 INTUITIVE SURGICAL OPERATIONS INC
  • EP4154829B1 patent drawingFigure 1
  • EP4154829B1 patent drawingFigure 2~3
  • EP4154829B1 patent drawingFigure 4~5A

AI summary

A cartridge of a surgical instrument includes a housing, a lead screw mounted for rotation in the housing, a drive member operatively coupled with the lead screw, and a knife member. The knife member is driven distally by the drive member and is configured to cut when moved distally. During an initial distal movement of the drive member, the knife member is coupled with the housing to restrain the knife member from moving distally. Subsequent to the initial distal movement of the drive member, the drive member drives the knife member toward the distal end.