Stationary X-Ray Source With Rotating Anode
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current stationary X-ray source systems for digital breast tomosynthesis are not reliable due to the instability of field-emission cathodes, which have been a challenge since their introduction in the 1920s, limiting their use in clinical settings.
Innovation Solution
A stationary multisource X-ray imaging system incorporating a rotating anode and an array of thermionic cathodes, which allows for high-speed, reliable X-ray flux operation by sequentially firing individual cathodes at up to 200 Hz rates, enabling 3D image reconstruction without mechanical motion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If field-emission cathodes are used in stationary X-ray sources, then the system can operate without mechanical motion, but the reliability is insufficient for clinical use
Solution Approach 1:
The patent divides the single X-ray source into multiple stationary sources arranged in an array. Each source uses a thermionic cathode with a focus cup grid that can be independently controlled. This segmentation allows the system to achieve tomographic imaging through electronic switching of multiple sources rather than mechanical motion, while using reliable thermionic cathodes instead of unstable field-emission cathodes.
Solution Approach 2:
The patent introduces dynamic control of the focus cup grids to selectively activate individual cathodes in the array. By dynamically switching which cathodes are active and adjusting their timing, the system creates the effect of a moving source without actual mechanical motion, resolving the contradiction between stationary operation and reliable cathode technology.
2Productivity
If a rotating anode is used to increase X-ray flux, then the system can operate at high speeds, but mechanical vibration increases
Solution Approach 1:
The patent extracts the rotation function from the anode itself and separates it from the X-ray generation function. The anode rotates to distribute heat and enable high flux operation, while the actual X-ray emission occurs at multiple stationary focal spots created by the array of cathodes. This separation allows the anode to rotate without directly causing vibration in the X-ray beam path.
Solution Approach 2:
The patent replaces the mechanical scanning system (single source moving physically) with an electronic control system that switches between multiple stationary sources. The rotating anode provides the necessary thermal management and high flux capability, while the electronic switching of cathodes and focus cup grids creates the tomographic imaging effect without mechanical vibration in the imaging path.
3Loss of time
If multiple stationary cathodes are fired sequentially, then scan time is reduced, but heat distribution control becomes more complex
Solution Approach 1:
The patent implements feedback control through the focus cup grids, which are electrically connected to the cathodes. The system can detect and control the thermal state of the anode and adjust the firing sequence and timing of individual cathodes accordingly. This feedback mechanism allows optimized heat distribution across the rotating anode while maintaining reduced scan times through sequential firing of multiple cathodes.
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 approach results in significantly shorter scan times, improved image quality, reduced mechanical vibration, and lower system costs, with scan times up to 10 times shorter than conventional systems, effectively addressing the reliability and efficiency issues of existing technologies.
Implementation Method 1
The stationary multi-X-ray source array may include a plurality of cathodes such as gridded thermionic cathodes
Implementation Method 2
Focal spots may be provided on the surface of the plurality of discs such that electrons emitted by the plurality of cathodes hit the focal spots of the anode to generate X-rays
Implementation Method 3
A coolant (such as water) circulates in the inner flow chamber to carry heat away from the anode
Data Source
AI summary
Embodiments provide a stationary X-ray source for a multisource X-ray imaging system for tomographic imaging. The stationary X-ray source includes an array of thermionic cathodes and, in most embodiments a rotating anode. The anode rotates about a rotation axis, however the anode is stationary in the horizontal or vertical dimensions (e.g. about axes perpendicular to the rotation axis). The elimination of mechanical motion improves the image quality by elimination of mechanical vibration and source motion; simplifies system design that reduces system size and cost; increases angular coverage with no increase in scan time; and results in short scan times to, in medical some medical imaging applications, reduce patient-motion-induced blurring.