Remote Current Control for Distal Motors in Medical Robotics
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Medical robotic systems face space and heating challenges when trying to co-locate current controllers with motors and sensors in small housings, particularly in distal locations where motors actuate degrees of freedom of slave manipulators and medical devices.
Innovation Solution
Implementing a remote current controller system where current controllers are housed in a different location than the motors, using a daisy chain or hybrid networked motor control system to manage pulse-width modulated current signals and sensor information, allowing for efficient control of motors while minimizing space and heat issues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If current controllers are co-located with motors and sensors in small housings, then control precision and response time are improved, but space availability and heat dissipation are worsened
Solution Approach 1:
The system segments the control architecture by separating current controllers from motors and sensors. Motors and sensors remain co-located in distal housings for precise control, while current controllers are distributed to separate locations (proximal housings or base) that provide adequate space and heat dissipation. This segmentation resolves the contradiction by allowing each component type to be optimally positioned independently.
Solution Approach 2:
A networked communication system acts as an intermediary between the distal motors/sensors and proximal current controllers. This intermediary enables precise control signals and sensor feedback to be transmitted across the physical separation, maintaining control precision while allowing spatial distribution for heat management and space availability.
2Measurement precision
If current controllers are co-located with motors and sensors in small housings, then control precision and response time are improved, but heat dissipation is worsened
Solution Approach 1:
The system segments the thermal management by separating heat-generating current controllers from motor assemblies. Current controllers are positioned in locations with better thermal characteristics (proximal housings or base), while motors remain at distal locations. This segmentation allows each component to operate in its optimal thermal environment while maintaining control precision through the networked communication system.
Solution Approach 2:
The networked communication system serves as a thermal intermediary, allowing control signals and feedback to be transmitted without physical thermal coupling. This enables precise control while preventing heat transfer between components, as the electrical/communication connection replaces direct thermal pathways.
3Volume of moving object
If current controllers are relocated to different housings, then space and heat issues are minimized, but system complexity increases
Solution Approach 1:
The system replaces direct mechanical/electrical coupling between current controllers and motors with a networked communication system. This substitution eliminates the need for complex wired connections and physical integration, reducing system complexity despite spatial distribution. The modular architecture with standardized communication protocols simplifies the overall system integration.
4Temperature
If current controllers are relocated to different housings, then heat dissipation is improved, but system complexity increases
Solution Approach 1:
The networked communication system replaces complex thermal management requirements with a simple electrical/communication architecture. By separating current controllers from motors, each component can be optimized for its thermal environment without requiring complex active cooling or thermal coupling mechanisms. The communication network provides a simple interface that manages the distributed architecture.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution enables effective control of robotic arm movements and medical device actuations while addressing space and heating constraints, ensuring reliable and precise operation of medical robotic systems.
Implementation Method 1
A remote current controller is provided in a proximal housing different from the distal housing. The remote current controller provides pulse-width modulated currents to a plurality of motors housed in the distal housing.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A medical robotic system includes a manipulator having links that form housings which are movable by motor actuated joints. Motors for actuating the joints and sensors for sensing states of the motors are housed in one or more distal housings formed from corresponding links or other structure(s) of the manipulator. A position controller is housed in a proximal housing and provides current commands for the motors to a remote current controller that is housed in an intermediate housing and generates drive signals for the motors by using the provided current commands and sensed states of the motors.