Adjustable Slave Manipulator Control for Safe Surgical Positioning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Medical robotic systems with fixed slave manipulator strength and stiffness characteristics can pose safety hazards and operational challenges, as they may not adequately adjust to different surgical procedures or devices, leading to unsafe force applications and difficulty in manual positioning.
Innovation Solution
A method for dynamically adjusting the characteristics of slave manipulators based on the current mode of operation, type of medical device, and phase of the procedure, including adjusting stiffness and strength, and issuing warnings for excessive forces, to enhance safety and operational efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the slave manipulator has high strength and stiffness, then safety is improved during surgical procedures, but it becomes difficult for support staff to manually position during setup
Solution Approach 1:
The slave manipulator's strength and stiffness characteristics are made dynamically adjustable through a controller that modifies control parameters in real-time. During setup, the system reduces strength and stiffness to enable easy manual positioning by support staff. During surgical procedures, the system increases strength and stiffness to ensure safety and prevent excessive force application on patient anatomy.
Solution Approach 2:
The system changes the control parameters of the slave manipulator based on operational mode. The controller adjusts parameters such as maximum torque limits and stiffness coefficients dynamically - using lower parameter values during setup for ease of positioning and higher parameter values during surgery for enhanced safety and controlled force application.
2Device complexity
If the slave manipulator has fixed strength and stiffness characteristics, then the system is simple to control, but it may apply too much or too little force in different surgical scenarios
Solution Approach 1:
The slave manipulator transitions from fixed to dynamic characteristics through real-time parameter adjustment. The controller continuously monitors the operational phase and device type, then dynamically adjusts strength and stiffness parameters to match the specific surgical requirements, enabling appropriate force application across diverse scenarios while maintaining a relatively simple overall control architecture.
Solution Approach 2:
The system employs parameter changes to adapt the slave manipulator's force characteristics. By modifying control parameters such as torque limits, stiffness coefficients, and force thresholds based on the surgical procedure phase and device being manipulated, the system achieves versatile force application capabilities without requiring a completely complex control system redesign.
3Reliability
If the slave manipulator strength is increased to prevent safety hazards during heart stabilizer application, then safety is improved, but excessive force may be applied to patient anatomy
Solution Approach 1:
The controller dynamically adjusts the strength parameters of the slave manipulator based on the specific surgical context. When a heart stabilizer is detected, the system sets appropriate torque and force parameters that provide sufficient strength to prevent safety hazards during application while simultaneously limiting the maximum force to levels safe for patient anatomy. This contextual parameter adjustment resolves the contradiction between needing high strength for safety and avoiding excessive force application.
Solution Approach 2:
The system implements feedback mechanisms that monitor the slave manipulator's operational state and the forces being applied. The controller receives feedback about the current surgical phase, device type, and force levels, then adjusts strength parameters in real-time to maintain safety without causing harmful excessive force application to patient tissues.
Data Source
AI summary
A slave manipulator manipulates a medical device in response to operator manipulation of an input device through joint control systems. The stiffness and strength of the slave manipulator are adjustable according to criteria such as the mode of operation of the slave manipulator, the functional type of the medical device currently being held by the slave manipulator, and the current phase of a medical procedure being performed using the slave manipulator by changing corresponding parameters of the control system. For safety purposes, such changes are not made until it is determined that it can be done in a smooth manner without causing jerking of the medical device. Further, an excessive force warning may be provided to surgery staff when excessive forces are being commanded on the slave manipulator for more than a specified period of time.