Manipulator Arm Null-Space Positioning for Robotic Surgery
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Solution Overview
Problem
Current robotic surgical systems face challenges in providing consistent and predictable movement of manipulator arms during setup and positioning, especially when performing minimally invasive surgeries, due to excessive movement outside the patient and increased complexity, which can lead to collisions and require significant training to configure correctly.
Innovation Solution
The implementation of highly configurable robotic manipulators with redundant degrees of freedom, allowing joints to float within a null-perpendicular space for improved movement and positioning, enabling manual backdriving of the end effector while driving other joints within a null-space for tasks like collision avoidance and desired pose alignment, simplifying setup and enhancing motion range without increasing mechanical complexity or cost.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If manipulator arms are used for minimally invasive surgery, then surgical precision is improved, but excessive movement outside the patient occurs leading to collisions and setup complexity
Solution Approach 1:
The system performs preliminary positioning of the manipulator arm using null-space movement to place the end effector at the desired location before surgical operation begins. This preliminary action allows the arm to be positioned accurately without requiring complex manual configuration, thereby reducing setup complexity and preventing excessive movement during actual surgery.
Solution Approach 2:
The patent introduces an intermediary control mechanism that separates the positioning function from the surgical manipulation function. By using null-space movement as an intermediary mode, the system allows independent positioning of the manipulator arm without affecting the surgical workspace, thereby preventing collisions and excessive movement while maintaining surgical precision.
2Ease of operation
If manipulator arms are configured for precise positioning, then surgical dexterity is improved, but setup complexity and training requirements increase
Solution Approach 1:
The manipulator arm performs self-positioning through null-space movement, automatically configuring itself to the desired position without requiring complex manual setup by operators. This self-service capability simplifies the setup process and reduces training requirements while maintaining surgical dexterity, as the system autonomously handles the complex positioning tasks.
3Adaptability or versatility
If redundant degrees of freedom are added to manipulator arms, then range of motion is improved, but system complexity increases
Solution Approach 1:
The system dynamically utilizes redundant degrees of freedom through null-space movement, allowing the manipulator arm to adapt its configuration based on the surgical task requirements. This dynamic approach enables the system to achieve enhanced range of motion and versatility without permanently increasing mechanical complexity, as the redundant degrees of freedom are activated only when needed for specific positioning tasks.
Data Source
AI summary
Devices, systems, and methods for positioning an end effector or remote center of a manipulator arm by floating a first set of joints within a null-perpendicular joint velocity sub-space and providing a desired state or movement of a proximal portion of a manipulator arm concurrent with end effector positioning by driving a second set of joints within a null-space orthogonal to the null-perpendicular space. Methods include floating a first set of joints within a null-perpendicular space to allow manual positioning of one or both of a remote center or end effector position within a work space and driving a second set of joints according to an auxiliary movement calculated within a null-space according to a desired state or movement of the manipulator arm during the floating of the joints. Various configurations for devices and systems utilizing such methods are provided herein.