Surgical Robot Input Device Scaling for Roll Pitch Yaw Alignment

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Solution Overview

Problem

Robotic surgical systems face challenges with scaling factors that limit the range of motion of input device handles, leading to frequent reaching of the handle's end of motion and misalignment issues during procedures, particularly when rotating the end effector about roll, pitch, and yaw axes.

Innovation Solution

A robotic surgical system with an input device, display device, and processing unit that adjusts scaling factors to realign the input device with the end effector by increasing or decreasing the scale factor based on misalignment, allowing for a predetermined offset and incorporating 'trim' and 'flip' algorithms to maintain alignment and improve dexterity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a scaling factor is used to scale down the motions of the surgeon's hands to determine the desired position of the end effector, then the precision of end effector positioning is improved, but the range of motion of the input device handle is reduced

Engineering Contradiction:

Improveprecision of end effector positioningVSAvoidrange of motion of input device handle

Core Design Contradiction:

Measurement precisionVSLength of moving object

Solution Approach 1:

The patent applies dynamics by making the scaling factor variable rather than fixed. The system dynamically adjusts the scaling factor based on the current position and orientation of the end effector, allowing the input device to maintain alignment throughout the range of motion. This resolves the contradiction by enabling high precision positioning while preserving the full range of motion of the input handle through real-time adaptation of the scaling relationship.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of the scaling factor from a constant value to a variable that depends on the end effector's position and orientation. By adjusting the scaling factor dynamically based on system state parameters, the input device can maintain optimal alignment and precision across different operational positions, eliminating the need for the handle to reach its motion limits frequently.

Inventive Principle:

Principle #35Parameter changes

2Adaptability or versatility

If the surgeon rotates the end effector about roll, pitch, and yaw axes to properly position it, then the versatility of surgical manipulation is improved, but the alignment between the input device handle and end effector is lost

Engineering Contradiction:

Improveversatility of surgical manipulationVSAvoidalignment between input device handle and end effector

Core Design Contradiction:

Adaptability or versatilityVSEase of operation

Solution Approach 1:

The patent implements feedback by continuously monitoring the position and orientation of the end effector and using this information to adjust the scaling factor. This closed-loop control ensures that the input device handle remains aligned with the end effector even as the surgeon rotates it about roll, pitch, and yaw axes. The system detects misalignment and dynamically compensates, maintaining ease of operation while enabling full versatility of surgical manipulation.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system dynamically adapts the scaling relationship between the input device and end effector based on real-time orientation data. As the surgeon rotates the end effector, the scaling factor is continuously adjusted to maintain proper alignment, allowing versatile manipulation in multiple axes without losing the intuitive connection between handle position and tool orientation.

Inventive Principle:

Principle #15Dynamics

3Device complexity

If the input device handle has a fixed range of motion, then the simplicity of the input device design is improved, but the ability to maintain alignment during large scaling factors is reduced

Engineering Contradiction:

Improvesimplicity of input device designVSAvoidability to maintain alignment during large scaling factors

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent resolves this contradiction by changing the scaling factor from a fixed parameter to a dynamically adjustable one. The input device maintains its simple fixed range of motion design, while the system compensates for large scaling factors by adjusting the scaling parameter in real-time based on the end effector's position and orientation, thereby maintaining alignment reliability without increasing mechanical complexity.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentEP3678580B1Robotic surgical systems with roll, pitch, and yaw realignment including trim and flip algorithms

Publication Date: 2025.01.01 COVIDIEN LP

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AI summary

A robotic surgical system or simulator includes an input device, a display device, and a processing unit. The display device includes a representation of a surgical tool that is operably associated with the input device. The processing unit is in communication with the input device and is associated with the representation of a surgical tool to rotate the representation about a first axis of movement based on a scaled rotation of the input device about a first axis of rotation. In an aligned configuration, the input device is aligned with the representation about the first axis of rotation. When the input device is misaligned with the representation, the processing unit varies the scaled rotation of the input device to return the input device to the first aligned configuration until the input device is misaligned about the first axis of rotation a first predetermined offset from the aligned configuration.