Offset Drive Shaft Layout for Articulated Surgical End Effectors

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Solution Overview

Problem

Existing minimally invasive surgical devices face challenges with maneuverability and clamping force, particularly in robotic surgery, where known devices often have difficulty maneuvering opposing jaws and may not generate sufficient clamping force for certain surgical applications.

Innovation Solution

The use of an offset drive shaft mounted within an independently rotating member, which allows for high actuation power transfer to an end effector while maintaining space for routing control components, enabling enhanced maneuverability and clamping force through a combination of shaft and cable actuation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a conventional surgical device with opposing jaws is used, then the device structure is simple, but the maneuverability of the jaws is difficult

Engineering Contradiction:

ImprovemaneuverabilityVSAvoiddevice structure

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

The drive system is segmented into multiple independent drive shafts (first drive shaft and second drive shaft) that can be independently actuated. This allows the end effector to achieve complex maneuvers through coordinated rotation of multiple shafts, resolving the contradiction between maneuverability and structural simplicity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The first and second drive shafts are nested within the instrument shaft, with each drive shaft rotatably mounted inside the instrument shaft. This nested configuration enables multiple drive shafts to occupy the same spatial envelope, improving maneuverability without significantly increasing external device dimensions.

Inventive Principle:

Principle #7Nested doll (Nesting)

2Force

If high actuation power is transferred to the end effector, then clamping force is sufficient, but the device structure becomes complex

Engineering Contradiction:

Improveclamping forceVSAvoiddrive shaft structure

Core Design Contradiction:

ForceVSDevice complexity

Solution Approach 1:

The patent replaces traditional cable-driven mechanical systems with a direct shaft rotation mechanism. The drive shafts rotate within the instrument shaft to directly actuate the end effector, providing high clamping force through direct mechanical transmission while reducing the complexity associated with multiple cables and pulleys.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If multiple drive shafts are added for enhanced actuation, then clamping force and maneuverability improve, but the number of failure points increases

Engineering Contradiction:

Improvesystem reliabilityVSAvoidnumber of components

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

Multiple drive shafts are merged within a single instrument shaft assembly, with all drive shafts and the end effector contained within one integrated structure. This consolidation reduces the number of external components and connection points, thereby reducing failure points while maintaining the enhanced actuation capabilities provided by multiple drive shafts.

Inventive Principle:

Principle #5Merging (Combining)

Data Source

PatentUS12564461B2Motor interface for parallel drive shafts within an independently rotating member

Publication Date: 2026.03.03 INTUITIVE SURGICAL OPERATIONS INC

AI summary

Method of actuating an end effector of a surgical device employ a drive shaft to actuate the end effector. A method of actuating an end effector of a surgical device includes rotating a main shaft relative to the proximal chassis. An end effector base of the end effector is supported by a wrist mechanism coupled between the end effector base and the main shaft. The end effector base is reoriented relative to the main shaft by operating a wrist articulation mechanism. A drive shaft is supported for rotation within a lumen of the main shaft. A feature of the end effector is actuated by rotating an input shaft of the end effector by rotating the drive shaft relative to the main shaft.