Robotic Manipulator Null Space Control for Surgical Dexterity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current surgical robotic systems face challenges in minimizing unnecessary movement of manipulator arms during tasks, which can lead to increased mechanical complexity, cost, and reduced dexterity, while also requiring expanded configurations and motion ranges within the patient.
Innovation Solution
The implementation of highly configurable robotic manipulators with redundant degrees of freedom, utilizing a processor to calculate weighted joint velocities within a null-perpendicular space of the Jacobian matrix, allowing for anisotropic emphasis of joint motion to achieve desired end effector movements while minimizing unwanted arm movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If manipulator arms are designed with expanded configurations and motion ranges to perform tasks within the patient, then the ability to perform surgical tasks is improved, but unnecessary movement outside the body increases
Solution Approach 1:
The manipulator arm movement is segmented into task-relevant components (within patient) and task-irrelevant components (outside patient). The control system selectively manages each segment, allowing full motion ranges for surgical tasks while minimizing extraneous movement through independent control of manipulator segments.
Solution Approach 2:
The patent introduces a new control dimension by separating manipulator motion into two independent spaces: task execution space (within patient) and minimization space (outside patient). This dimensional separation allows the system to optimize for surgical task performance while simultaneously reducing unnecessary movement through differential control strategies.
2Ease of operation
If manipulator arms are designed with higher dexterity to perform intricate surgical tasks, then surgical precision is improved, but mechanical complexity and cost increase
Solution Approach 1:
The control system achieves multiple functions using the same manipulator hardware: it provides high dexterity for intricate surgical tasks while simultaneously minimizing unnecessary movement. This multi-functionality is accomplished through software-based control strategies that manage the manipulator's redundant degrees of freedom, eliminating the need for additional mechanical components.
Solution Approach 2:
The patent dynamically changes control parameters (motion weighting factors, task priorities, minimization coefficients) based on surgical context. These parameter adjustments allow the manipulator to switch between high-dexterity modes for complex tasks and motion-minimization modes for routine operations, optimizing performance without increasing mechanical complexity.
Data Source
AI summary
Devices, systems, and methods for providing commanded movement of an end effector of a manipulator while providing a desired movement of one or more joints of the manipulator. Methods include calculating weighted joint velocities using a weighting matrix within the joint space to anisotropically emphasize joint movement within a null-space to provide the desired movement of a first set of joints. Methods may include calculating joint velocities that achieve the desired end effector movement using a pseudo-inverse solution and adjusting the calculated joint velocities using a potential function gradient within the joint space corresponding to the desired movement of the first set of joints. Methods may include use of a weighted pseudo-inverse solution and also an augmented Jacobian solution. One or more auxiliary movements may also be provided using joint velocities calculated from the pseudo-inverse solution. Various configurations for systems utilizing such methods are provided herein.