Multi-spectral X-ray Detector with Structured Spectral Filter

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional multi-spectral X-ray detectors can only discriminate between two parts of the X-ray spectrum, which may not be ideal for all applications, and pre-filter solutions reduce X-ray intensity and require significant absorbing material, compromising spatial and spectral resolution.

Innovation Solution

A multi-layer detector with a structured spectral filter positioned between two X-ray conversion layers, which divides each superpixel into pixels undergoing different spectral filtration, allowing for the discrimination of more than two parts of the X-ray spectrum without a pre-filter, thereby enhancing spectral separation and reducing X-ray dose.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a pre-filter is used to separate X-ray spectra, then spectral separation is improved, but X-ray intensity is reduced and spatial resolution deteriorates

Engineering Contradiction:
Improvespectral separationVSAvoidX-ray intensity
Core Design Contradiction:
Measurement precisionVSIllumination intensity

Solution Approach 1:

The detector is divided into multiple detector layers, each detecting different energy components of X-rays. The first detector layer detects low-energy X-rays while the second detector layer detects high-energy X-rays, enabling spectral separation without requiring a pre-filter that would reduce overall X-ray intensity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from a single-layer detection approach to a multi-layer detection architecture. By adding the dimension of depth (multiple layers), the system can simultaneously detect different energy spectra without using a pre-filter, thus maintaining X-ray intensity while achieving spectral separation.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Adaptability or versatility

If a pre-filter is used to alter X-ray spectrum, then spectral control is improved, but significant absorbing material is required compromising device complexity

Engineering Contradiction:
Improvespectral controlVSAvoidabsorbing material
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

Instead of placing a pre-filter before the detector to control the spectrum, the patent inverts the approach by using detector layers with different absorption characteristics to achieve spectral discrimination. The detection layers themselves perform the spectral separation function that would otherwise require a pre-filter.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The patent changes the absorption parameters of different detector layers to achieve spectral control. Each layer is designed with specific absorption characteristics that allow it to detect particular energy ranges, eliminating the need for external absorbing materials.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If two detector layers are used to detect different energy X-rays, then spectral discrimination is improved, but the ability to detect more than two spectrum parts is limited

Engineering Contradiction:
Improvespectral discriminationVSAvoidspectrum parts detection
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The second detector layer is segmented into multiple regions with different absorption characteristics. This segmentation allows the single layer to function as multiple virtual detectors, each sensitive to different energy ranges, thereby enabling detection of more than two spectrum parts without adding more physical layers.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The second detector layer serves multiple functions by having regions with different absorption properties. A single physical layer performs the work of multiple specialized detectors, enabling versatile spectral detection across multiple energy ranges while maintaining a compact structure.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 provides finer control over the X-ray spectrum, enabling more accurate material characterization and reducing the overall X-ray dose required, improving dose efficiency and spectral resolution compared to traditional pre-filter solutions.

Implementation Method 1

A top X-ray conversion layer closest to the X-ray source typically absorbs low energy components of the X-rays

Methodology Applied
Scientific EffectPhotoelectric absorption: Photoelectric Effect

Implementation Method 2

A bottom X-ray conversion layer positioned further from the X-ray source typically absorbs higher energy components of the X-ray spectrum

Methodology Applied
Scientific EffectCompton scattering: Compton Scattering

Implementation Method 3

A bottom X-ray conversion layer positioned further from the X-ray source typically absorbs higher energy components of the X-ray spectrum

Methodology Applied
Scientific EffectPhotoelectric absorption: Photoelectric Effect

Implementation Method 4

a structured filter enables a subset of pixels to receive a different X-ray spectrum

Methodology Applied
Scientific EffectSelective absorption: Absorption (EM radiation)

Data Source

PatentEP3746814B1Multi-spectral x-ray detector
Publication Date: 2024.07.24 KONINKLIJKE PHILIPS NV
  • EP3746814B1 patent drawingFigure 1
  • EP3746814B1 patent drawingFigure 2a~2d
  • EP3746814B1 patent drawingFigure 3

AI summary

Typically, a dual layer multi-spectral X-ray detector is capable of providing two points of spectral data about an imaged sample, because the front X-ray detector also acts to filter part of an incident X-ray spectrum before detection by a rear X-ray detector. A pre- filter can be placed in front of the front X-ray detector to enhance the spectral separation. However, the provision of a pre-filter implies that the intensity of the X-ray radiation must be increased to achieve the same signal to noise ratio. The present application concerns a multi-spectral X-ray detector with a front X-ray detector, a rear X-ray detector, and a structured spectral filter placed in-between them. The structured spectral filter has first and second regions configured to sample superpixels of the front X-ray detector, enabling three separate items of spectral information to be obtained per superpixel.