X-ray Tube Filament Current Correction for Degradation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
X-ray tubes in radiographic equipment experience filament degradation over time, leading to variable tube current values and measurement errors, which can result in excessive x-ray production and increased filament temperature, potentially causing equipment failure and safety risks during patient examinations.
Innovation Solution
The equipment includes storing means for filament current settings, tube current difference measuring means, and filament current setting value correcting means to adjust the filament current based on calculated differences over a specific period, reducing variability and measurement errors, and warning systems for impending filament failure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If feedback control is performed using measured tube current values, then tube current can be maintained at a constant value, but the slow response speed of filament temperature makes it impossible to perform accurate feedback control over short periods
Solution Approach 1:
The patent applies preliminary action by measuring tube current values over a specific period before performing feedback control, and by calculating average values in advance. This allows the system to account for the slow thermal response of the filament by using historical data, thereby achieving accurate control without waiting for immediate stabilization.
Solution Approach 2:
The patent implements feedback control by comparing measured tube current values with target values and adjusting the filament current accordingly. The system calculates average tube current values over a specific period and uses this feedback to correct filament current settings, maintaining stable tube current despite the slow thermal response.
2Ease of operation
If filament current is held constant, then operation is simple, but tube current varies over time due to filament degradation
Solution Approach 1:
The patent uses feedback control to monitor tube current values and adjust filament current dynamically. By measuring the actual tube current and comparing it with the target value, the system automatically corrects filament current settings to compensate for degradation, maintaining consistent tube current without manual intervention.
Solution Approach 2:
The patent changes the filament current parameter dynamically based on measured tube current values. Instead of holding filament current constant, the system adjusts this parameter over time to compensate for filament degradation, ensuring consistent tube current output while maintaining simple automated operation.
3Device complexity
If measured tube current values are used directly for correction, then control is simple, but variability and measurement errors are reflected in correction values
Solution Approach 1:
The patent applies preliminary action by calculating average tube current values over a specific period before using them for feedback control. This preprocessing step filters out random variability and measurement errors, providing more reliable data for correction calculations while maintaining relatively simple control logic.
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 allows for accurate correction of tube current variability due to filament degradation, anticipating and preventing equipment failures, thus ensuring safe and stable x-ray production by gradually adjusting the filament current and providing timely warnings for maintenance.
Implementation Method 1
X-ray tubes that are used in this type of radiographic equipment have structures that produce x-rays through collisions with an anode of thermal electrons that are from a cathode that is provided with a filament
Implementation Method 2
produce x-rays through collisions with an anode of thermal electrons
Data Source
AI summary
A filament current that is to be supplied to a filament of an x-ray tube under imaging conditions, from the imaging conditions of the tube current and the tube voltage that is to be supplied to the x-ray tube at the time of radiographic imaging, are stored as a filament current setting value in a storing portion, and the difference between an anticipated value for the tube current when x-ray emission is performed at a given filament current and a measured value for the tube current when x-ray emission is actually performed at that filament current is measured over time as a tube current value difference, and when the mean value for the tube current value difference over a specific time interval exceeds a setting value that has been set in advance, the filament current setting value that is stored in the storing portion is corrected.