CT Scanner Focus Correction via Electron Beam Deflection
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Solution Overview
Problem
Conventional CT devices rely on mechanical components for focus correction, which are slow, costly, and limited in real-time adjustment, making it difficult to accurately control the direction and angle of X-ray rays due to mechanical errors caused by factors like anode target rotation and thermal expansion.
Innovation Solution
A method and apparatus that calculate and correct the focus shift of a CT device using scanning data, including gantry rotation, anode target rotation, and heat storage, by establishing shift models and superposing focus shifts to adjust the electron beam's deflection through information processing, eliminating the need for mechanical modifications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If mechanical components are used for focus correction, then the focus position can be adjusted, but the adjustment speed is slow and real-time correction is difficult
Solution Approach 1:
The patent replaces the mechanical focus correction system with an electronic control system. Instead of physically moving the anode target or gantry to correct focus shifts, the system calculates the focus shift based on scanning data and compensates by adjusting the electron beam deflection angles through electronic control of the tube's focusing electrodes, achieving fast real-time correction without mechanical movement
Solution Approach 2:
The patent changes the control parameter from mechanical position adjustment to electronic deflection angle adjustment. By calculating the focus shift and converting it to corresponding electron beam deflection corrections, the system achieves focus position control through parameter transformation rather than physical movement, enabling rapid real-time correction
2Manufacturing precision
If mechanical components are used for focus correction, then the focus position can be adjusted, but hardware modification cost is high
Solution Approach 1:
The patent eliminates the need for complex mechanical correction components by substituting them with an electronic calculation and control system. The focus correction is achieved through software-based focus shift calculation and electronic deflection adjustment, avoiding expensive hardware modifications to the mechanical structure
Solution Approach 2:
The patent creates a virtual model of the focus shift through calculation based on scanning data, rather than physically replicating or modifying mechanical components. The focus correction is achieved by computing the shift and applying compensatory deflection, eliminating the need for physical hardware copies or modifications
3Manufacturing precision
If mechanical components are used for focus correction, then the focus position can be adjusted, but the system complexity increases
Solution Approach 1:
The patent simplifies the overall system by replacing complex mechanical correction mechanisms with a straightforward electronic control approach. The focus correction function is integrated into the existing electronic control system through calculation and deflection adjustment, reducing mechanical complexity while maintaining precision
4Manufacturing precision
If mechanical components are used for focus correction, then the focus position can be adjusted, but mechanical errors affect the accuracy
Solution Approach 1:
The patent eliminates mechanical errors by replacing the mechanical correction system with an electronic control system. Since the correction is achieved through electronic deflection adjustment rather than mechanical movement, sources of mechanical error such as friction, backlash, and mechanical play are completely avoided, improving reliability and control accuracy
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 allows for faster and more accurate focus correction without mechanical restrictions, meeting real-time performance requirements and avoiding hardware modification costs, ensuring precise control of the X-ray focus position.
Implementation Method 1
an electron beam, generated from a cathode of the tube under an effect of a high voltage filament, shoots at an anode target to be refracted as rays in a fan geometry
Implementation Method 2
cold shrinkage and thermal expansion of the anode target may affect the focus position
Implementation Method 3
as the anode target and the gantry rotate, the anode target shifts to the position represented by the dashed line due to an effect of gravity
Data Source
AI summary
A method and apparatus for correcting a focus of a CT device are provided. The method includes: calculating a total focus shift according to scanning data; and correcting, when the CT device is running, a deflection of an electron beam emitted from a ray source of the CT device, based on the total focus shift. The device includes: a shift calculation module, configured to calculate a total focus shift according to scanning data; and a shift correction module, configured to correct, when the CT device is running, a deflection of an electron beam emitted from a ray source of the CT device, based on the total focus shift.