Patient Support Table Braking for Controlled Power-Off Lowering
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing patient support devices in radiation therapy systems face challenges in ensuring precise and controlled movement, particularly during power interruptions, due to the reliance on hydraulic systems which are expensive, less reliable, and less accurate in motion control.
Innovation Solution
The implementation of an electromechanical roller screw configuration with a motor control system that includes a brake control module, passive dynamic load module, rectification module, and controlled dynamic load module to provide controlled braking and speed regulation, ensuring accurate and reliable motion even in powered-off situations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If hydraulic systems are used for patient support device movement, then the device can support patient weight and provide motion, but the system becomes expensive, less reliable, and less accurate in motion control
Solution Approach 1:
The patent replaces hydraulic systems with an electromechanical system comprising a motor, roller screw mechanism, and brake control module. This substitution eliminates hydraulic fluids, pumps, and associated sealing systems, resulting in a more reliable and maintainable system while achieving superior motion control accuracy through electronic feedback and controlled braking.
Solution Approach 2:
The brake control module automatically engages when power is interrupted, providing fail-safe operation without requiring external intervention. The system uses the motor's own electrical circuitry and the brake control module's automatic detection of power loss to engage braking, making the system self-protecting and more reliable.
2Manufacturing precision
If hydraulic systems are used for patient support device movement, then the device can support patient weight and provide motion, but motion control accuracy deteriorates
Solution Approach 1:
The brake control module continuously monitors motor power status and automatically engages the brake when power interruption is detected. This feedback mechanism ensures precise control of the table assembly's position and prevents uncontrolled movement, achieving high motion control accuracy while enhancing system reliability through automatic safety responses.
Solution Approach 2:
The system dynamically adjusts between motor-driven motion and brake-engaged holding based on power availability. The brake control module enables the system to transition smoothly between active control mode and passive holding mode, maintaining precision and reliability across different operational states.
3Reliability
If simple motor control is used without braking mechanisms, then the system is simpler, but the device cannot maintain controlled movement during power interruptions
Solution Approach 1:
The brake control module is pre-configured to automatically engage the brake when power interruption occurs. This preliminary setup ensures that the braking function is immediately available when needed, providing controlled movement during power interruptions without requiring complex real-time decision-making or additional sensors.
Solution Approach 2:
The brake control module acts as a protective mechanism that engages beforehand when power loss is detected, preventing uncontrolled movement or crashes. This prior cushioning approach protects the system and patient by anticipating potential failures and activating safety measures before damage can occur.
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 precise and controlled movement of the patient support device, maintaining consistent speed and preventing crashes during power interruptions, thus enhancing the reliability and accuracy of radiation therapy delivery.
Implementation Method 1
a rectification module electrically coupled to the motor and operable to convert AC voltage to DC voltage when the AC voltage reaches a predetermined value
Implementation Method 2
a passive dynamic load module electrically coupled to the motor to increase speed of the motor
Data Source
AI summary
A patient support device of a radiation therapy treatment system includes an electromechanical motor and control system for raising and lowering the support device in the Z direction. The control system utilizes regenerative braking concepts, converting the motor into a generator as the support device is lowered such that no matter the load, the support device will be lowered at a constant speed. The control system also allows for lowering of the support device in the powered off situation (i.e., when there is no power to the support device).