Surgical Knife Blade Geometry for Thick Tissue Cutting

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Solution Overview

Problem

Current surgical instruments face challenges in effectively cutting through thick tissue due to limitations in knife blade geometry and design, which can lead to inefficiencies in endoscopic and laparoscopic procedures.

Innovation Solution

The surgical instrument features a unique end effector with a drive beam and knife assembly that includes blades with angled or curved configurations, such as a 'V' shape or 'C' shape, and serrated edges, allowing for improved tissue cutting by varying the blade geometry and contact area.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a traditional knife blade is used in surgical instruments, then the structure is simple and easy to manufacture, but the ability to cut through thick tissue is insufficient

Engineering Contradiction:
Improvetissue cutting abilityVSAvoidblade structure complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The knife blade is divided into multiple segments or sections with different geometric configurations. Each segment can have varying angles, curvatures, or edge types (serrated, smooth, etc.) to address different tissue thicknesses and densities encountered during the cutting path, thereby improving overall cutting effectiveness without requiring a completely new blade design

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The blade geometry transitions from traditional two-dimensional flat surfaces to three-dimensional configurations including curved surfaces, angled facets, and multi-level edges. This dimensional enhancement allows the blade to engage thick tissue more effectively by creating progressive cutting angles and reducing initial contact area, thus improving cutting ability while maintaining structural feasibility

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Productivity

If the blade geometry is varied to improve tissue slicing ability, then the cutting efficiency is improved, but the manufacturing precision requirements increase

Engineering Contradiction:
Improvetissue transection efficiencyVSAvoidblade geometry precision
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

Different regions of the blade are given different geometric properties - such as varying angles, curvatures, and edge types - to optimize cutting performance at specific locations. This allows high cutting efficiency where needed while using simpler geometries in other areas, thereby reducing overall manufacturing precision requirements while maintaining high productivity

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The blade design incorporates variable geometric parameters along its length, such as changing angles, radii of curvature, and edge configurations. By strategically varying these parameters, the blade achieves superior cutting performance on thick tissue while the variations are designed to be manufacturable within standard tolerances, balancing productivity improvement with manufacturing feasibility

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3245958B1Cutting member for a surgical instrument
Publication Date: 2022.11.02 COVIDIEN LP
  • EP3245958B1 patent drawingFigure 1
  • EP3245958B1 patent drawingFigure 2
  • EP3245958B1 patent drawingFigure 3

AI summary

A surgical instrument includes an anvil assembly, a cartridge assembly, and a knife assembly having first and second blades, a curved blade or a circular blade, any of which may be serrated or uniform.