Geared Grip Actuation for Manual and Robotic Medical Instruments

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Solution Overview

Problem

Minimally-invasive medical procedures require precise control of complex grip manipulations, and existing medical instruments face challenges in providing compact actuation mechanisms that allow for multiple degrees of freedom while preventing damage from excessive manual force.

Innovation Solution

A grip actuation mechanism using a face gear and pinion to drive a push-pull element, coupled with a slip clutch to limit manual torque, allowing both robotic and manual control of grip motion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a compact actuation mechanism is used to provide precise grip control, then the instrument can accommodate multiple degrees of freedom, but the mechanism becomes vulnerable to damage from excessive manual force

Engineering Contradiction:

Improvegrip control precisionVSAvoidprotection from excessive force

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The patent incorporates a slip clutch mechanism into the actuation system that proactively prevents damage by allowing controlled slippage when excessive torque is applied. This protective feature is built into the mechanism beforehand, cushioning against potential damage from manual over-rotation or robotic actuation errors before they can harm the精密 grip mechanism.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

2Measurement precision

If a high gear ratio is used in the actuation mechanism, then precise grip control is achieved, but the mechanism becomes more complex and harder to manufacture

Engineering Contradiction:

Improvegrip control precisionVSAvoidactuation mechanism complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The face gear and pinion assembly serves multiple functions simultaneously: it provides the high gear ratio needed for precise grip control, accommodates both manual and robotic actuation modes, and integrates the protective slip clutch mechanism. This multi-functionality reduces overall system complexity despite the high gear ratio requirement.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The face gear acts as an intermediary element between the pinion and the grip mechanism, translating rotational motion into precise linear displacement of the grip. This intermediary gear allows for a high effective gear ratio while maintaining a relatively simple mechanical structure that is easier to manufacture than alternative high-ratio mechanisms.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Adaptability or versatility

If the actuation mechanism allows manual rotation, then manual operation is possible, but excessive force can damage the instrument

Engineering Contradiction:

Improvemanual operation capabilityVSAvoiddamage from excessive force

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The slip clutch mechanism converts the potentially harmful effect of excessive manual force into a beneficial protective feature. When users apply too much torque during manual operation, the clutch allows controlled slippage that prevents damage to the精密 grip mechanism, while still allowing normal manual operation. This transforms the risk of manual over-rotation into a safety feature.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

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 and durable grip actuation with a high gear ratio, accommodating misalignment and allowing manual operation without damaging the instrument, suitable for both robotic and manual use.

Implementation Method 1

a gear structure including a face gear and a pinion for precision driving of back-and-forth movement

Methodology Applied

Scientific EffectMechanical Advantage: Mechanical Advantage

Implementation Method 2

The face gear meshes with the pinion

Methodology Applied

Scientific EffectGear: Gear

Implementation Method 3

A manipulator coupled for manual rotation of the actuation mechanism may include a slip clutch to prevent manual application of excessive force to the actuation mechanism

Methodology Applied

Scientific EffectFriction: Friction

Data Source

PatentUS12433701B2Geared grip actuation for medical instruments

Publication Date: 2025.10.07 INTUITIVE SURGICAL OPERATIONS INC

AI summary

An actuation mechanism for a medical instrument includes a pinion and a face gear that move a push-pull element. The pinion has a mounting that permits rotation of the pinion by an external control system such as a robot. The face gear meshes with the pinion. The push-pull element may have a proximal end coupled to the face gear and a distal end coupled to a tool at a distal end of an instrument shaft. A manipulator coupled for manual rotation of the actuation mechanism may include a slip clutch to prevent manual application of excessive force to the actuation mechanism.