Dual-Trigger Ultrasonic Surgical Handle for Clamping Force Feedback

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Solution Overview

Problem

Conventional ultrasonic surgical instruments lack the ability for surgeons to accurately sense and adjust the clamping force applied by the jaws, leading to potential tissue damage from excessive force or inadequate cutting due to insufficient force.

Innovation Solution

An ultrasonic surgical instrument with a dual-trigger actuation mechanism that provides mechanical advantage and feedback, allowing surgeons to feel and adjust the clamping force through independent movement of first and second triggers, with a biasing member limiting movement until a predetermined force is exceeded.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a single trigger is used to actuate the clamping assembly, then the device complexity is reduced, but the surgeon cannot sense the clamping force strength and cannot adjust force based on tissue conditions

Engineering Contradiction:
Improveclamping force sensing and adjustmentVSAvoidactuation mechanism
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The actuation mechanism is segmented into two independent triggers: a first trigger for actuating the clamping assembly and a second trigger for sensing and feedback. This segmentation allows the surgeon to independently control clamping force application and sensing, resolving the contradiction between operational capability and device simplicity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A mechanical feedback linkage serves as an intermediary between the clamping assembly and the second trigger. This linkage transmits clamping force information to the surgeon's hand through the second trigger, enabling force sensing without requiring electronic sensors or complex feedback systems.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If the clamping assembly is actuated to close by pulling the trigger, then the clamping function is achieved, but the maximum clamping force is constant and cannot be adjusted for various tissue conditions

Engineering Contradiction:
Improveclamping force adjustmentVSAvoidclamping control
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The actuation mechanism transitions from a static, fixed-force system to a dynamic, adjustable-force system. The second trigger provides real-time feedback about clamping force, allowing the surgeon to dynamically adjust the applied force based on tissue conditions, thereby achieving adaptability while maintaining ease of operation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

A mechanical feedback loop is established where the second trigger communicates clamping force information back to the surgeon's hand. This feedback enables the surgeon to sense the actual clamping force and adjust their input accordingly, achieving variable force control for different tissue types.

Inventive Principle:
Principle #23Feedback

3Productivity

If force is applied too much to the tissue, then the cutting effect is improved, but the tissue may get damaged

Engineering Contradiction:
Improvecutting efficiencyVSAvoidtissue damage
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The mechanical feedback linkage provides real-time information about clamping force to the surgeon through the second trigger. This feedback mechanism allows the surgeon to sense when sufficient force is applied for effective cutting and stop before applying excessive force that could damage the tissue, thus resolving the contradiction between cutting efficiency and tissue safety.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The feedback system provides preliminary warning to the surgeon before excessive force is applied. By sensing the clamping force through the second trigger, the surgeon can anticipate and prevent tissue damage before it occurs, rather than reacting after damage has already happened.

Inventive Principle:
Principle #9Preliminary anti-action

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 precise control of clamping force, preventing tissue damage and expanding the instrument's application range by allowing surgeons to adjust force based on tissue conditions.

Implementation Method 1

a biasing member configured for biasing the second trigger until force against the driving member exceeding a predetermined limit

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

the ultrasonic transducer is adapted to convert electrical energy at a resonant frequency that is typically provided by the ultrasonic generator, into mechanical power, for example, into vibration motion

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 3

The mechanical vibratory energy is further amplified and transmitted by the ultrasonic surgical instrument and eventually to be transmitted to the tissue, so as to cutting, coagulation and/or dissection of tissue through intracellular water vaporization, protein hydrogen bonds break

Methodology Applied
Scientific EffectUltrasonic vibration: Ultrasonic Vibration

Implementation Method 4

cutting, coagulation and/or dissection of tissue through intracellular water vaporization

Methodology Applied
Scientific EffectCavitation: Cavitation

Data Source

PatentEP3881789B1Actuation mechanism and ultrasonic surgical instrument
Publication Date: 2026.01.28 REACH SURGICAL INC
  • EP3881789B1 patent drawingFigure 1~2
  • EP3881789B1 patent drawingFigure 3~4
  • EP3881789B1 patent drawingFigure 5~6

AI summary

Disclosed are an actuation mechanism and an ultrasound surgical instrument, wherein the ultrasonic surgical instrument includes: an elongated body (2), a clamping assembly (3) and an actuation mechanism configured to actuate the clamping assembly (3), wherein the actuation mechanism includes: a handle portion (1); a first trigger (4) and a second trigger (5) pivotally engaged with the handle portion (1), respectively; a driving member (9) configured to actuate the clamping assembly (3), wherein the clamping assembly (3) is arranged on a distal portion of the elongated body (2); wherein the first trigger (4) is engaged with the driving member (9) through a first link (8), and the second trigger (5) is engaged with the driving member (9) through the first link (8) and a second link (7), and wherein the first trigger (4) is movable independently with respect to the second trigger (5) during a portion of movement of the first trigger (4).