Robot Arm Environment Characterization for Collision Avoidance

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Solution Overview

Problem

Existing surgical robots face challenges in establishing spatial relationships between their arms and other objects in the operating environment, such as an operating table, due to their bulky design and limited range of motion, which restricts the range of surgical procedures and can lead to collisions.

Innovation Solution

A method and system where a surgical robot with a flexible arm and position sensors calculates the distance and orientation of its arm relative to other objects by contacting a datum on the arm with a datum on the object, using this information to reconfigure the arm and prevent collisions, and can also control the arm to maintain a desired configuration or orientation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If surgical robots are designed with multiple arms stemming from a single fixed base, then the spatial relationship between arms is inherently established, but the system becomes bulky and difficult to move into place in an operating theatre

Engineering Contradiction:

Improvespatial relationship between armsVSAvoidmobility in operating theatre

Core Design Contradiction:

Stability of the object's compositionVSEase of operation

Solution Approach 1:

The robot system is divided into separate mobile robotic units, each with its own base and arm, rather than a single fixed multi-armed system. This allows each unit to be independently moved into position and then locked, providing both mobility and stable spatial relationships during surgery.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system transitions from a static fixed-base configuration to a dynamic mobile configuration. The robotic units can be moved and repositioned as needed, and once positioned, their bases are locked to provide stability during the surgical procedure.

Inventive Principle:

Principle #15Dynamics

2Adaptability or versatility

If multiple jigs or floor markings are provided to establish spatial relationships, then the full range of surgical procedures can be supported, but the complexity and number of required components increases significantly

Engineering Contradiction:

Improverange of surgical proceduresVSAvoidnumber of jigs and markings

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The robotic units autonomously determine their own spatial relationships and orientations through onboard sensors and processors. Each robot independently calculates its position relative to other robots and the operating table, eliminating the need for external jigs or floor markings.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

Physical mechanical systems (jigs and floor markings) are replaced with electronic sensing and computational systems. The robots use sensors to detect datums on other objects and processors to calculate spatial relationships, substituting mechanical alignment aids with electronic measurement and computation.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If manual measurement and data input is used to establish spatial relationships, then accurate positioning can be achieved, but the process is time-consuming and prone to human error

Engineering Contradiction:

Improvespatial relationship accuracyVSAvoidtime to characterise environment

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

Manual measurement processes are replaced with automated electronic sensing. The robotic units use onboard sensors to automatically detect datums and processors to calculate spatial relationships, eliminating manual measurement and data entry while maintaining accuracy and reducing time.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The system implements automated feedback loops where sensors continuously detect the positions of datums, the processor calculates spatial relationships, and this information is used to control the robotic units. This automated feedback process eliminates manual intervention and reduces both time and human error.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS11597094B2Characterising robot environments

Publication Date: 2023.03.07 CMR SURGICAL LTD

AI summary

A method for characterising the environment of a robot, the robot having a flexible arm having a plurality of joints, a datum carried by the arm, a plurality of drivers arranged to drive the joints to move and a plurality of position sensors for sensing the position of each of the joints, the method comprising: contacting the datum carried by the arm with a first datum on a second robot in the environment of the first robot, wherein the second robot has a flexible arm having a plurality of joints, and a plurality of drivers arranged to drive those joints to move; calculating in dependence on the outputs of the position sensors a distance between a reference location defined in a frame of reference local to the robot and the first datum; and controlling the drivers to reconfigure the first arm in dependence on at least the calculated distance.