Imaging Detector Anti-aliasing Filter Readout Electronics

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Solution Overview

Problem

Current CT scanner detector arrays face issues with substrate noise and crosstalk between analog and digital readout electronics, which affect detector linearity, gain, and noise performance, limiting low-dose imaging capabilities.

Innovation Solution

The implementation of individual readout channel wells for each detector pixel, combined with anti-aliasing filters located in the photosensor array or readout electronics, provides electrical isolation and effective noise reduction, improving linearity and noise performance without increasing the overall footprint of the electronics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If analog and digital readout electronics are placed in the same substrate, then device complexity is reduced, but substrate noise and crosstalk increase affecting detector linearity and noise performance

Engineering Contradiction:
Improvereadout electronics structureVSAvoidsubstrate noise and crosstalk
Core Design Contradiction:
Device complexityVSObject-affected harmful factors

Solution Approach 1:

The patent divides the readout electronics into separate analog and digital segments, with analog readout electronics positioned in a first region and digital readout electronics in a second region of the substrate. This spatial segmentation reduces crosstalk and noise coupling while maintaining a unified substrate structure, thereby resolving the contradiction between device simplicity and noise reduction.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent extracts the analog readout electronics from the digital substrate region and positions them in a dedicated first region, separating them from digital components. This extraction eliminates the harmful electromagnetic interference and crosstalk that would otherwise affect detector linearity and noise performance, while keeping the overall device structure integrated.

Inventive Principle:
Principle #2Taking out (Extraction)

2Object-affected harmful factors

If anti-aliasing filter is added to reduce quantum noise and electronics noise, then noise performance improves, but overall footprint of electronics increases

Engineering Contradiction:
Improvequantum noise and electronics noiseVSAvoidelectronics footprint
Core Design Contradiction:
Object-affected harmful factorsVSArea of stationary object

Solution Approach 1:

The patent combines the anti-aliasing filter functionality with the existing readout electronics structure by integrating the filter into the signal path between the detector pixels and the analog-to-digital converter. This merging approach provides effective noise filtering without requiring separate dedicated filter components, thereby minimizing the increase in overall electronics footprint while improving noise performance.

Inventive Principle:
Principle #5Merging (Combining)

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 configuration enhances detector linearity and noise performance, making the system suitable for low-dose imaging by effectively isolating analog and digital components and reducing quantum and electronics noise.

Implementation Method 1

Anti-aliasing filtering has been used in connection with the detector to reduce quantum noise and electronics noise by limiting the bandwidth of the signal before processing by the ASIC

Methodology Applied
Scientific EffectAnti-aliasing filtering: Filter (electronic)

Implementation Method 2

a first well 202 electrically isolates the analog readout electronics 108 and 114 from the substrate 120 and the digital readout electronics 110, 116 and 118

Methodology Applied
Scientific EffectElectrical isolation: Electrical Impedance Tomography

Implementation Method 3

a second well 204 electrically isolates the digital readout electronics 110, 116 and 118 from the substrate 120 and the analog channels 108 and 114

Methodology Applied
Scientific EffectElectrical isolation: Electrical Impedance Tomography

Implementation Method 4

A detector array subtends an angular arc opposite the examination region from the x-ray tube, detects radiation that traverses the examination region, and generates a signal indicative thereof

Methodology Applied
Scientific EffectPhotoelectric effect: Photoelectric Effect

Implementation Method 5

Each detector tile includes a scintillator layer optically coupled to a two-dimensional (2D) back-illuminated photodiode array

Methodology Applied
Scientific EffectScintillation: Scintillation

Data Source

PatentEP2845229B1Imaging detector with Anti-aliasing filter in the readout electronics and/or photosensor
Publication Date: 2021.07.07 KONINKLIJKE PHILIPS NV
  • EP2845229B1 patent drawingFigure 1~3
  • EP2845229B1 patent drawingFigure 4
  • EP2845229B1 patent drawingFigure 5~6

AI summary

An imaging apparatus (400) includes a detector array (412) with at least one detector tile (418). The detector tile includes a photosensor array (422) with a two dimensional array of individual photosensitive detector pixels (424) located within a non- photosensitive area (426). The imaging apparatus also includes readout electronics (432) coupled to the photosensor array and including individual readout channel wells (602, 604) corresponding to the individual detector pixels. The imaging apparatus also includes an anti-aliasing filter (800) for a detector pixel that is located in at least one of a region of the photosensor array corresponding to the detector pixel or a region of the readout electronics corresponding to the detector pixel.