Movable EPID Support Arm for Radiotherapy
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current radiotherapy equipment has a limitation where the electronic portal imaging device (EPID) is always directly opposite to the treatment head, even when verification is not needed, leading to unnecessary exposure and a shorter service life of the EPID.
Innovation Solution
A support arm system for the EPID, comprising a guide assembly connected to the gantry, a movable support bracket, and a drive assembly with a motor and actuator, allowing the EPID to be positioned opposite or away from the treatment head as needed, using a drive gear and rack mechanism or screw rod, with position detection and locking mechanisms to ensure precise alignment and prevent exposure during non-operating states.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the EPID is always positioned directly opposite to the treatment head, then the alignment for verification is maintained, but the service life of the EPID is reduced due to unnecessary exposure during non-operating states
Solution Approach 1:
The EPID support bracket is designed to be movable rather than fixed, allowing it to dynamically adjust its position. The drive assembly enables the EPID to move between a first position (opposite the treatment head for verification) and a second position (away from the treatment head during non-operating states), transforming a static configuration into a dynamic one that adapts to operational requirements.
Solution Approach 2:
The system performs preliminary positioning by automatically moving the EPID to the appropriate position before operation begins. The drive assembly pre-positions the EPID in the first position before verification operations and moves it to the second position after operations complete, preventing unnecessary exposure before it occurs.
2Duration of action of stationary object
If the EPID is moved away from the treatment head during non-operating states, then the service life is prolonged, but the device complexity increases due to additional drive and positioning mechanisms
Solution Approach 1:
The support arm structure serves multiple functions: it provides mechanical support for the EPID, enables positional adjustment through the drive assembly, and incorporates positioning detection through the detection assembly. This multi-functionality consolidates what could be separate systems into a unified structure, managing complexity through functional integration.
Solution Approach 2:
The drive assembly acts as an intermediary mechanism between the control system and the EPID, translating control signals into precise positional movements. The detection assembly serves as an intermediary that provides feedback about the EPID's position, enabling automated control without requiring complex direct mechanical linkages.
3Duration of action of stationary object
If a drive assembly with motor and actuator is added to enable EPID movement, then the service life is extended, but the device complexity and manufacturing difficulty increase
Solution Approach 1:
The detection assembly enables the system to self-monitor its position, and the drive assembly automatically responds to position requirements without requiring external intervention. The system serves itself by using the detection assembly's feedback to control the drive assembly's movements, reducing the need for complex external control mechanisms.
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 effectively prolongs the service life of the EPID by ensuring it is only exposed to the radiation beam when necessary, reducing wear and tear and maintaining accurate alignment for verification during treatments.
Implementation Method 1
the actuator includes a drive gear; the guide assembly includes a rack in mesh with the drive gear; and the drive motor is connected to the drive gear, and the drive motor is configured to drive the drive gear to move along an extending direction of the rack
Implementation Method 2
the brake is configured to lock the motor output shaft after the support bracket is moved, such that the support bracket is fixed on the guide assembly
Implementation Method 3
the position encoder is connected to the detection gear, and the position encoder is configured to detect current position information of the support bracket relative to the rack based on rotation information of the detection gear
Data Source
AI summary
Provided is a support arm, including a guide assembly configured to be connected to a gantry of a radiotherapy equipment; a support bracket movably connected to the guide assembly and configured to support a detector; and a drive assembly connected to the support bracket and configured to drive the support bracket to move on the guide assembly.