Master Grip Ratcheting for Teleoperated Surgical Alignment

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Solution Overview

Problem

Current minimally-invasive surgical systems require powered master tool manipulators for aligning master and slave surgical instrument tips, which can cause delays and necessitate costly, powered components, hindering intuitive control and increasing system complexity.

Innovation Solution

A ratcheting system within the teleoperation servo control system continuously improves alignment between the master grip and slave surgical instrument tip in a common coordinate frame, allowing for intuitive alignment without autonomous motion and enabling the use of unpowered master grips, thus reducing costs and enhancing operational efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If powered master tool manipulators are used for aligning master and slave surgical instrument tips, then alignment precision is improved, but device complexity and cost increase

Engineering Contradiction:
Improvealignment precisionVSAvoidsystem complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical powered alignment system with a computational ratcheting algorithm. Instead of using motors and mechanical actuators in the master manipulator to actively maintain alignment, the system uses a control algorithm that processes sensor data about master-slave orientation differences and generates corrective commands. This substitution of mechanical components with computational logic reduces device complexity while maintaining alignment precision.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The ratcheting alignment system is self-correcting and continuously adjusts alignment based on real-time feedback without requiring external powered intervention. The control algorithm automatically detects misalignment through sensors and generates corrective commands, allowing the system to self-regulate alignment without additional mechanical alignment mechanisms or powered master manipulator components.

Inventive Principle:
Principle #25Self-service

2Manufacturing precision

If powered master tool manipulators are used for aligning master and slave surgical instrument tips, then alignment precision is improved, but cost increases

Engineering Contradiction:
Improvealignment precisionVSAvoidsystem cost
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

By replacing expensive mechanical powered alignment mechanisms with a software-based ratcheting control algorithm, the patent significantly reduces system cost. The algorithm runs on existing control system hardware, eliminating the need for additional motors, sensors, and mechanical components that would be required for powered master manipulator alignment.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent uses computationally inexpensive algorithms rather than expensive hardware components. The ratcheting control logic can be implemented as software that processes standard sensor data, avoiding the need for costly specialized hardware and reducing overall system manufacturing cost while maintaining alignment precision.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Manufacturing precision

If powered master tool manipulators are used for alignment, then alignment precision is improved, but operation speed decreases due to delays

Engineering Contradiction:
Improvealignment precisionVSAvoidoperation speed
Core Design Contradiction:
Manufacturing precisionVSSpeed

Solution Approach 1:

The ratcheting alignment system operates continuously and seamlessly during teleoperation, constantly processing sensor feedback and generating corrective commands without interruption. This continuous computational process eliminates the delays associated with mechanical powered systems that require activation, response time, and mechanical adjustment, enabling real-time alignment maintenance at full operation speed.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

By replacing mechanical powered alignment mechanisms with computational processing, the patent eliminates mechanical response delays, inertia, and activation times. The control algorithm processes alignment corrections instantly based on sensor feedback, enabling alignment maintenance to keep pace with the surgeon's manipulations without operational delays.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

4Manufacturing precision

If powered master tool manipulators are used for alignment, then alignment precision is improved, but the system requires autonomous motion capability increasing complexity

Engineering Contradiction:
Improvealignment precisionVSAvoidautonomous motion capability
Core Design Contradiction:
Manufacturing precisionVSExtent of automation

Solution Approach 1:

The ratcheting alignment system uses continuous feedback from sensors that monitor master and slave orientation. The control algorithm processes this feedback and generates corrective commands that maintain alignment without requiring autonomous motion initiation. The system reacts to and corrects misalignment based on feedback rather than autonomously initiating alignment actions, reducing the extent of automation required.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The alignment system serves itself by automatically detecting and correcting misalignment through computational processing of sensor data. This self-correcting mechanism does not require autonomous motion capabilities in the master manipulator, as the alignment maintenance is achieved through control logic that processes feedback and generates appropriate slave manipulator commands.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP3459687B1Ratcheting for master alignment of a teleoperated minimally-invasive surgical instrument
Publication Date: 2023.05.10 INTUITIVE SURGICAL OPERATIONS INC
  • EP3459687B1 patent drawingFigure 1
  • EP3459687B1 patent drawingFigure 2A~2C
  • EP3459687B1 patent drawingFigure 3A~3B

AI summary

A minimally-invasive surgical system includes a slave surgical instrument having a slave surgical instrument tip and a master grip. The slave surgical instrument tip has an alignment in a common frame of reference and the master grip, which is coupled to the slave surgical instrument, has an alignment in the common frame of reference. An alignment error, in the common frame of reference, is a difference in alignment between the alignment of the slave surgical instrument tip and the alignment of the master grip. A ratcheting system (i) coupled to the master grip to receive the alignment of the master grip and (ii) coupled to the slave surgical instrument, to control motion of the slave by continuously reducing the alignment error, as the master grip moves, without autonomous motion of the slave surgical instrument tip and without autonomous motion of the master grip.