Endocutter Cutline Detection Using Firing-Force Feedback

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Solution Overview

Problem

Existing endoscopic surgical instruments face challenges in maximizing the cutline length of staple cartridges without the need for tool characterization, which can be inconvenient and inaccurate due to variations in compliance and tissue properties.

Innovation Solution

An algorithm is implemented that detects the end of the cutline using proximal cutting edge and firing force information, allowing the motor to decelerate and project future firing forces to accurately stop at the end of the cutline without sensors or switches in the end effector.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If tool characterization is performed to determine cutline length, then cutting precision may be improved, but the process becomes inconvenient and inaccurate due to variations in compliance and tissue properties

Engineering Contradiction:

Improvecutline length precisionVSAvoidconvenience of tool characterization

Core Design Contradiction:

Manufacturing precisionVSEase of operation

Solution Approach 1:

The system performs self-characterization by using the motor's own firing force data and position information to determine cutline length and detect end of cutline, eliminating the need for separate tool characterization procedures or external calibration

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The control circuit continuously monitors firing force and position during the cutting stroke, using real-time feedback to project future firing forces and detect end of cutline conditions without requiring pre-characterization

Inventive Principle:

Principle #23Feedback

2Measurement precision

If sensors or switches are added to the end effector to detect end of cutline, then measurement precision may be improved, but device complexity increases

Engineering Contradiction:

Improveend of cutline detection accuracyVSAvoidcomplexity of end effector components

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The motor and drive train act as intermediaries that transmit both mechanical motion and electrical signals back to the control circuit, enabling detection without adding sensors to the end effector itself

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The system replaces mechanical sensors or switches at the end effector with an electrical feedback mechanism using the motor's existing position and force data to detect end of cutline conditions

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Productivity

If maximum cutline length is achieved, then productivity is improved, but risk of over-travel and instrument damage increases

Engineering Contradiction:

Improvecutline lengthVSAvoidrisk of instrument damage

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The control circuit projects future firing forces in advance to predict when end of cutline will be reached, allowing the motor to decelerate before impact occurs, preventing over-travel and potential damage

Inventive Principle:

Principle #9Preliminary anti-action

Solution Approach 2:

The system uses the motor's deceleration capability as a cushioning mechanism to gently stop at the end of cutline position, avoiding hard impacts that could damage the instrument or cartridge

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Data Source

PatentUS20250288292A1Indirect end of cutline detection on an endocutter which eliminates need for tool characterization for completion thereof

Publication Date: 2025.09.18 CILAG GMBH INTERNATIONAL

AI summary

A surgical stapler instrument drive system which indirectly maximizes the allowed/allotted cutline length of a staple cartridge, and associated staple deployment, with a reduced excess cutting force at the end thereof.