Robotic Surgical Manipulator Null-Space Path Tracking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current robotic surgical systems face challenges in providing consistent and predictable movement of manipulator arms during minimally invasive surgeries, often resulting in excessive movement outside the patient, which can lead to collisions and increased complexity, despite advancements in kinematic configurations and redundant degrees of freedom.
Innovation Solution
The implementation of a robotic surgical system with highly configurable manipulators that utilize holonomic or position-based constraints within joint-space or Cartesian-coordinate space, combined with virtual potential fields to guide joint movements within a null-space, allowing for precise control and reduced unnecessary motion, while incorporating additional redundant joints for reconfiguration and collision avoidance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If redundant degrees of freedom are added to robotic manipulators, then surgical dexterity and range of motion are improved, but manipulator movement consistency and predictability deteriorate
Solution Approach 1:
The system dynamically adjusts the operational constraints of redundant joints based on real-time surgical needs. The controller modifies constraint parameters during surgery, allowing the manipulator to transition between different operational modes while maintaining movement consistency through adaptive constraint management rather than fixed mechanical limitations
Solution Approach 2:
The patent changes the control parameters of redundant joints by imposing software-based operational constraints that limit joint movement to predefined safe ranges. These parameter changes ensure that while redundant degrees of freedom provide surgical dexterity, the actual joint movements remain consistent and predictable within constrained operational envelopes
2Reliability
If redundant joints are used for reconfiguration, then collision avoidance is improved, but system complexity increases
Solution Approach 1:
The patent replaces complex mechanical constraint mechanisms with software-based virtual constraints implemented through control algorithms. The controller uses computational models to define operational envelopes and constraint surfaces, substituting physical mechanical limiters with intelligent software control that achieves collision avoidance without adding mechanical complexity
Solution Approach 2:
The controller acts as an intermediary between the surgeon's commands and the manipulator joints, introducing virtual constraint surfaces as mediators. These computational intermediaries process joint position data and enforce operational constraints, enabling collision avoidance while maintaining system simplicity by keeping the physical manipulator structure unchanged
3Stability of the object's composition
If holonomic constraints are imposed on joint movements, then movement predictability is improved, but range of motion is reduced
Solution Approach 1:
The patent resolves the contradiction by moving constraints from joint-space to task-space or operational-space. Instead of constraining individual joint movements (one dimension), the system defines constraint surfaces in the six-dimensional operational space of the end effector, allowing greater range of motion in task-execution while maintaining predictability through constrained operational envelopes
Data Source
AI summary
Devices, systems, and methods for providing a desired movement of one or more joints of a manipulator arm having a plurality of joints with redundant degrees of freedom while effecting commanded movement of a distal end effector of the manipulator. Methods include defining a constraint, such as a network of paths, within a joint space defined by the one or more joints and determining a movement of the plurality of joints within a null-space to track the constraints with the one or more joints. Methods may further include calculating a reconfiguration movement of the joints and modifying the constraints to coincide with a reconfigured position of the one or more joints. Various configurations for devices and systems utilizing such methods are provided herein.