Surgical Knife Position Display via Displacement Sensor Feedback

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing surgical stapling and cutting instruments lack accurate indication of the knife position, leading to potential unsafe conditions where the instrument may be unclamped prematurely, resulting in the displacement member being halted out of position and potentially firing with a spent cartridge.

Innovation Solution

A surgical instrument equipped with a sensor to detect the position of the displacement member and a control circuit that determines the knife's retraction status, ensuring the knife is fully retracted only when the displacement member is fully retracted, thereby safely indicating the knife's position to the operator.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the knife position is inferred based on the displacement member position and mechanical tolerances, then the device complexity is reduced, but the measurement precision of knife position deteriorates

Engineering Contradiction:
Improvedevice complexityVSAvoidknife position measurement precision
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent replaces mechanical tolerance-based inference with an optical sensing system. A sensor detects the position of the displacement member and converts it into visual feedback displayed to the operator. This substitution of mechanical estimation with optical detection resolves the contradiction by providing precise measurement without requiring complex mechanical coupling between the displacement member and knife position indication mechanisms.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Ease of operation

If the knife position is displayed based on displacement member position during articulation dead zone, then the ease of operation is improved, but the reliability of safety indication deteriorates

Engineering Contradiction:
Improveease of operationVSAvoidsafety indication reliability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent implements a feedback system where the sensor continuously monitors displacement member position and provides visual feedback to the operator. During the articulation dead zone, the system maintains accurate position indication by continuously tracking the displacement member, allowing the operator to make informed decisions about when the knife is fully retracted and it is safe to unclamp the instrument. This continuous feedback resolves the contradiction by providing reliable safety information without complicating the operation.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3501416B1Systems of displaying a knife position during transection for a surgical instrument
Publication Date: 2025.01.29 ETHICON INC
  • EP3501416B1 patent drawingFigure 1
  • EP3501416B1 patent drawingFigure 2
  • EP3501416B1 patent drawingFigure 3

AI summary

Various systems and methods of controlling the display of a knife position of a surgical cutting instrument according to the position of a displacement member. The surgical instrument includes a displacement member movable between a first position and a second position to drive a cutting member between an unfired position and a fire position, a sensor configured to detect a position of the displacement member and provide a signal indicative thereof and a display. The surgical instrument determines whether the knife is retracting and then only begins decrementing the displayed knife position once the displacement member has retracted from the distal or second position of its firing stroke by a particular distance.