Surgical Slave Robot Collision Mitigation Using External Torque Feedback

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Solution Overview

Problem

Surgical robots may collide with objects or people during operations, leading to potential damage or injury, as the operator may not be aware of the collision due to their focus on the display screen.

Innovation Solution

A method and system for controlling a surgical slave robot to mitigate collisions by obtaining external torque and joint angle data, calculating a target joint angle to attenuate the external torque, and controlling the robot to change its position accordingly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the operator focuses on the display member to manipulate the device, then the manipulation precision is improved, but the operator cannot identify the position of the slave robot or recognize collision situations

Engineering Contradiction:

Improvemanipulation precisionVSAvoidspatial awareness

Core Design Contradiction:

Measurement precisionVSLoss of information

Solution Approach 1:

The system implements feedback by detecting external torque applied to the slave robot and notifying the operator of collision situations. This allows the operator to maintain focus on the display while receiving automatic feedback about the robot's spatial status and potential collisions, resolving the contradiction between manipulation precision and spatial awareness.

Inventive Principle:

Principle #23Feedback

2Productivity

If the slave robot continues to move during collision, then the surgical operation can proceed, but damage to the slave robot or patient may occur

Engineering Contradiction:

Improvesurgical operation efficiencyVSAvoidcollision damage

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The system applies preliminary anti-action by detecting external torque that indicates a collision is occurring and automatically controlling the slave robot to stop moving or retreat. This prevents further damage while allowing the operator to address the situation, balancing operational continuity with safety.

Inventive Principle:

Principle #9Preliminary anti-action

Solution Approach 2:

The system converts the harmful external torque of collision into useful information by detecting it as a signal to stop or retreat. The collision force itself becomes the trigger for the protective response, transforming a harmful event into a beneficial safety mechanism.

Inventive Principle:

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

3Reliability

If the slave robot is equipped with collision detection and automatic retreat control, then safety is improved, but the device complexity increases

Engineering Contradiction:

Improvecollision safetyVSAvoidcontrol system complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The system replaces complex mechanical collision avoidance mechanisms with a simpler sensor-based approach. By using external torque sensors and software-based control logic to detect and respond to collisions, the system achieves high reliability with reduced mechanical complexity compared to traditional mechanical limit switches or physical barriers.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentUS12324643B2Method and system for mitigating collision of surgical robot

Publication Date: 2025.06.10 MEERE CO INC

AI summary

This application relates to a method of mitigating a collision of a slave robot for surgery. In one aspect, the method includes obtaining an external torque generated when the slave robot collides with another object or a person and obtaining a joint angle of the slave robot. The method may also include calculating a target joint angle for changing a position of the slave robot based on the obtained external torque and the obtained joint angle, such that the external torque is attenuated. The method may further include controlling the slave robot to change the position thereof from the obtained joint angle to the calculated target joint angle.