X-ray Phase Contrast Imaging Displacement Measurement
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Solution Overview
Problem
Current methods for measuring the relative lateral distance of components in Talbot-Lau apparatuses for X-ray phase contrast imaging are prone to interference and require optical measurements, which are difficult to perform accurately.
Innovation Solution
The method involves fixing the X-ray image detector and phase/grating components together, aligning them with the object to expose free fields, and recording X-ray images during relative lateral displacement, calculating displacement distances and reference phases from pixel intensity values to determine the relative position of components without optical measurements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If optical interferometry is used to measure the relative lateral distance of components, then measurement capability is provided, but the measurement becomes difficult and prone to interference
Solution Approach 1:
The patent replaces optical interferometry with X-ray based measurement. The X-ray source, grating system, and detector are used to measure the relative lateral distance of components K1 and K2 through X-ray phase contrast imaging, eliminating the need for optical interferometers and avoiding optical interference problems.
Solution Approach 2:
The patent introduces an X-ray beam as an intermediary to measure the relative lateral distance. The X-ray beam passes through the grating system and detects the phase differences caused by the lateral displacement of components, providing a reliable measurement path that avoids direct optical interference.
2Measurement precision
If optical measurements are used to determine component positions, then measurement function is achieved, but accuracy is difficult to perform
Solution Approach 1:
The patent substitutes optical measurement systems with an X-ray based system. The X-ray emitter, grating assembly, and detector work together to measure component positions with higher reliability by using X-ray phase information rather than optical interference patterns that are prone to errors.
3Productivity
If gratings are mounted on a fixed rack with controlled lateral displacement, then phase stepping is achieved, but the system complexity increases
Solution Approach 1:
The patent makes the grating system dynamic by allowing controlled lateral displacement of the gratings relative to each other. This enables phase stepping for measuring different phase angles, transforming a static measurement system into a dynamic one that can capture multiple phase states.
Solution Approach 2:
The patent implements periodic lateral displacement of the gratings through controlled movement in fractions of the grating period. This periodic action creates varying phase shifts that allow extraction of multiple image variables (absorption, phase displacement, dark field) from the X-ray intensity distribution.
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 simplifies the measurement of relative lateral displacement between components, reducing errors and eliminating the need for optical interferometry, thereby enhancing the accuracy and reliability of X-ray phase contrast imaging.
Implementation Method 1
at least one X-ray emitter (3) for generating a quasi-coherent X-ray beam
Implementation Method 2
a diffraction or phase grating (G1) which is arranged between the object and the X-ray image detector (4)
Implementation Method 3
an analyzer grating (G2) associated with the phase grating (G1) for generating an intensity pattern or interference pattern
Data Source
AI summary
A method, for examining an object using an X-ray recording system, includes aligning the object in the X-ray beam and the X-ray recording system with one another such that regions in the X-ray beam are uncovered for measurement of a free field. During an X-ray image recording, the components are moved relative to one another with a lateral displacement. In a position of the relative lateral displacement of the components, a reference image containing free fields is recorded. The X-ray image recording is generated from partial images during the displacement and the position of the second component relative to the first component is determined for each partial recording such that the displacement distances of the displacements and the reference phases are calculated from a selected set of pixels and the measured intensity values thereof. Finally, the image information is determined from the partial images, the displacements and the reference phases.