Phase Stepping Strategy for Defect Compensation in DAX Imaging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Phase contrast and dark-field imaging technologies face issues with image artifacts due to local imperfections in imaging facilitator devices, which can occlude detector pixels and reduce contrast, leading to undesirable image artifacts in phase contrast and dark-field imagery.
Innovation Solution
An imaging system with a periodic structure and a phase stepping mechanism that facilitates a relative phase stepping motion between the imaging device and the X-ray source, covering a distance greater than the spatial period, to reduce or eliminate image artifacts. This system includes a suspension system with a frame and actuator to impart phase stepping motion, allowing for a curved scan path with a single actuator and using flexure bearings for suspension, and an image processing method to adjust phase stepping based on defective region sizes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional phase stepping is used with step width equal to the spatial period, then the imaging system is simple and fast, but image artifacts occur due to defects occluding detector pixels
Solution Approach 1:
The patent applies dynamics by making the phase stepping strategy adaptive rather than fixed. The system dynamically adjusts the step width and number of steps based on the detected defect characteristics (size, position, occlusion severity). This allows the imaging process to optimize between speed and quality in real-time, resolving the contradiction between fast conventional imaging and artifact-free imaging.
Solution Approach 2:
The patent changes the parameters of phase stepping (step width, number of steps, starting position) based on defect analysis. By modifying these parameters dynamically according to the specific defect situation, the system achieves both fast imaging (when defects are minimal) and high-quality artifact-free imaging (when defects are significant), thus resolving the time-quality trade-off.
2Reliability
If phase stepping covers distance greater than spatial period to avoid defect occlusion, then image artifacts are reduced, but device complexity increases
Solution Approach 1:
The patent resolves the contradiction by adding computational intelligence (a software/digital dimension) to the phase stepping mechanism. Instead of making the hardware more complex with multiple actuators or sophisticated mechanical systems, the patent uses image processing algorithms and defect detection software to analyze defect characteristics and dynamically adjust stepping parameters, thereby achieving complex adaptive behavior through software rather than hardware complexity.
Solution Approach 2:
The patent implements feedback by detecting defects in the imaging facilitator device, analyzing their characteristics, and using this information to adjust the phase stepping strategy. This closed-loop feedback system allows the mechanism to automatically adapt to defect conditions, reducing artifacts without requiring complex pre-configured hardware solutions.
3Measurement precision
If multiple actuators are used for phase stepping to achieve precise motion control, then positioning accuracy is improved, but device complexity and cost increase
Solution Approach 1:
The patent replaces complex mechanical positioning systems with computational methods. Instead of using multiple actuators with sophisticated mechanical linkages to achieve precise positioning, the patent uses software algorithms to analyze defect patterns and calculate optimal stepping parameters, thereby achieving precise effective positioning through intelligent control rather than mechanical complexity.
Solution Approach 2:
The patent makes a single actuator perform multiple functions: it not only provides the driving force for phase stepping but also its motion parameters are dynamically adjusted based on defect analysis. The same actuator system serves both as the mechanical driver and as part of the adaptive control system, reducing the need for separate precision positioning mechanisms.
Data Source
AI summary
An imaging system (IS) including device (G, IFD) for phase contrast and/or dark field imaging such as a grating (G). The device has a periodic structure with a spatial period p. The imaging system (IS) further includes a phase stepping mechanism (PSM) configured to facilitate a relative phase stepping motion between the device (G, IFD) and a focal spot (FS) of an X-ray source (XS) of the imaging system (IS). The relative phase stepping motion covers a distance greater than the said spatial period to reduce artifacts in dark-field or phase contrast imagery caused by defects in the grating.