Surgical Handle Latch Track for Stable Tissue Sealing and Division

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Solution Overview

Problem

Existing energy-based surgical instruments struggle to achieve effective hemostasis and sealing of large blood vessels and tissues, requiring additional sealing processes after coagulation, and lack efficient mechanisms for tissue division.

Innovation Solution

A surgical instrument with a housing, end effector assembly, movable handle, drive assembly, and latch assembly, featuring a latch track and ramped surface to lock the handle in actuated positions, and a trigger assembly for deploying a deployable component like a knife for tissue division.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If coagulation is used for hemostasis, then it is sufficient for non-vascular tissue and small blood vessels, but it is insufficient for large blood vessels above two millimeters in diameter

Engineering Contradiction:
Improvehemostasis effectivenessVSAvoidapplicability to different vessel sizes
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent transitions from coagulation (heating tissue to coagulate) to sealing (heating collagen to denature and reform into a fused mass) by changing the thermal parameters and treatment intensity. This allows the same instrument to effectively handle both small vessels through coagulation and large vessels through sealing, resolving the limitation of coagulation insufficiency for large vessels.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If a latch mechanism is added to lock the movable handle, then the handle can be locked in actuated position, but the device complexity increases

Engineering Contradiction:
Improvehandle position stabilityVSAvoidlatch assembly structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The latch assembly is configured to automatically engage and lock the movable handle in the actuated position through the interaction between the latch post and latch track with ramped surface. The system uses the natural movement of the handle through over-center positioning to automatically trigger the latch engagement without requiring additional actuators or complex control mechanisms, thereby maintaining simplicity while achieving reliable locking.

Inventive Principle:
Principle #25Self-service

3Ease of operation

If the latch post is permitted to enter the ramped surface via the ramped end, then controlled engagement is achieved, but reverse travel is inhibited

Engineering Contradiction:
Improvelatch engagement controlVSAvoidbidirectional movement capability
Core Design Contradiction:
Ease of operationVSAdaptability or versatility

Solution Approach 1:

The latch track features an asymmetric design with a ramped surface that has a ramped end and a cliff end. The ramped end allows controlled engagement of the latch post during forward movement, while the cliff end prevents reverse travel. This asymmetric geometry enables the system to distinguish between forward actuation (allowed) and reverse movement (inhibited), achieving controlled engagement while maintaining unidirectional locking capability.

Inventive Principle:
Principle #4Asymmetry

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enables secure grasping, sealing, and efficient division of tissues, including large blood vessels, with controlled jaw force and tactile/audible feedback, enhancing surgical precision and efficiency.

Implementation Method 1

The return path includes a ramped surface configured to inhibit reverse travel of the latch post into the return path

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

a latch arm including a latch post extending therefrom... The latch post is configured to move through the entry path, the latching path, and into the saddle upon movement of the movable handle

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP4262602B1Energy-based surgical instrument for grasping, treating, and/or dividing tissue
Publication Date: 2025.12.10 COVIDIEN LP
  • EP4262602B1 patent drawingFigure 1
  • EP4262602B1 patent drawingFigure 2
  • EP4262602B1 patent drawingFigure 3

AI summary

A surgical instrument includes a movable handle (1310) movable relative a housing to manipulate an end effector assembly, and a latch assembly. The latch assembly includes a latch arm (1030) including a latch post (1034), and a latch track defining an entry path (1062), a latching path (1064), a saddle (1066), an un-latching path (1068), and a return path (1070). The latch post moves through the entry path, the latching path, and into the saddle upon movement of the movable handle from an un-actuated position to an over-actuated position and back to an actuated position to lock the movable handle. The latch post moves from the saddle through the un-latching path and the return path upon movement of the movable handle from actuated position to the over-actuated position and back to the un- actuated position. The return path includes a ramped surface (1080) configured to inhibit reverse travel of the latch post into the return path.