Adjustable Inner Diameter Robotic End Effector

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Solution Overview

Problem

Current minimally-invasive surgical procedures face challenges in efficiently guiding surgical tools of varying sizes through cannulas with consistent insertion and retraction friction, and in providing precise control and adjustment for different instrument diameters during robotic-assisted surgeries.

Innovation Solution

A robotic-assisted surgical system with an adjustable-diameter end effector, featuring a hollow tube with moveable flutes and a rotating collar mechanism, allows for precise adjustment of the internal diameter to accommodate tools of different sizes, ensuring symmetrical insertion and retraction forces and maintaining a fixed trajectory.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a fixed-diameter cannula is used, then the structure is simple and easy to manufacture, but it cannot accommodate surgical tools of varying sizes

Engineering Contradiction:

Improveaccommodation of tools of varying sizesVSAvoidcannula structure complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The cannula incorporates moveable flutes that can dynamically adjust their position relative to the cannula body, transforming a static structure into a dynamic one. This allows the internal diameter to be changed by moving the flutes, enabling accommodation of tools with different diameters while maintaining a relatively simple overall cannula structure.

Inventive Principle:

Principle #15Dynamics

2Adaptability or versatility

If an adjustable-diameter end effector is implemented, then tools of different sizes can be accommodated, but the device complexity increases

Engineering Contradiction:

Improveadjustable internal diameterVSAvoidend effector mechanism complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The adjustable-diameter mechanism uses a nested structure where flutes are positioned within the cannula body and can move radially. The flutes are essentially nested within the cannula's internal volume, allowing them to expand outward or retract inward to adjust the effective internal diameter without adding significant external complexity to the end effector.

Inventive Principle:

Principle #7Nested doll (Nesting)

3Adaptability or versatility

If moveable flutes are used to adjust diameter, then adaptability improves, but ensuring symmetrical insertion and retraction forces becomes more difficult

Engineering Contradiction:

Improvediameter adjustment capabilityVSAvoidsymmetrical friction forces

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The flutes are designed with asymmetric engagement features relative to the tool shaft, where the insertion side has different geometric characteristics than the retraction side. This asymmetric design compensates for the movement of flutes during diameter adjustment, ensuring that friction forces remain symmetrical and balanced throughout the adjustment range, thereby maintaining reliable and predictable tool insertion and retraction.

Inventive Principle:

Principle #4Asymmetry

Data Source

PatentEP3600118B1Robotic end effector with adjustable inner diameter

Publication Date: 2025.01.15 MOBIUS IMAGING LLC

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AI summary

An end effector for a robotic-assisted surgical system having an adjustable inner diameter. In embodiments, the end effector includes a main body having an opening extending through the main body, one or more members located within the main body that extend into and retract from the opening to vary a diameter of the opening through which a tool may be inserted, and an adjustment mechanism on the end effector and coupled to the one or more members for varying the diameter of the opening.