Portable DR Detector Self-Calibration via Dark Difference Imaging

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Solution Overview

Problem

Portable digital radiography (DR) detectors require frequent calibration to maintain image quality, but existing methods are not reliable and disrupt clinical workflows, especially in emergency situations, due to their computational intensity and need for operator intervention.

Innovation Solution

A method and system for monitoring the calibration state of portable DR detectors using dark imaging characteristics and embedded microprocessors to identify defective pixels through dark difference images, allowing for field calibration updates without operator intervention, thereby reducing the need for frequent recalibration and minimizing disruption to clinical operations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If frequent calibration is performed to maintain image quality, then image quality is improved, but workflow disruption and time loss increase

Engineering Contradiction:
Improveimage qualityVSAvoidcalibration time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The detector performs self-calibration by automatically identifying defective pixels through dark difference imaging and updating its own calibration parameters without requiring external intervention. The embedded microprocessor executes calibration algorithms using dark images captured during idle periods, enabling the system to maintain image quality autonomously.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system performs calibration actions in advance by continuously monitoring dark difference images during idle periods between patient exams. Defective pixels are identified and calibrated before they affect clinical imaging, preventing quality degradation rather than correcting it after occurrence.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If manual calibration procedures are used, then calibration accuracy is improved, but operator intervention and productivity loss increase

Engineering Contradiction:
Improvecalibration accuracyVSAvoidclinical productivity
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The embedded microprocessor executes calibration algorithms autonomously, processing dark difference images and updating calibration parameters without operator intervention. The system self-manages the entire calibration workflow including defect detection, parameter calculation, and calibration map generation, eliminating the need for radiology staff time.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system continuously monitors detector performance through dark difference imaging and uses this feedback to automatically identify and correct defective pixels. The calibration process is driven by real-time performance data, allowing the system to adapt and maintain accuracy without manual inspection or intervention.

Inventive Principle:
Principle #23Feedback

3Ease of operation

If computational intensity of calibration is reduced, then workflow disruption is minimized, but calibration reliability decreases

Engineering Contradiction:
Improveworkflow disruptionVSAvoidcalibration reliability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The system performs partial calibration using only dark difference images rather than complete multi-step calibration procedures. By focusing computational resources on analyzing dark image differences to identify defective pixels, the system achieves sufficient calibration reliability without requiring the full computational intensity of traditional calibration methods.

Inventive Principle:
Principle #16Partial or excessive action

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 enables continuous monitoring and calibration of portable DR detectors, improving image quality and reducing workflow disruptions by identifying defective pixels autonomously, thus maintaining image quality without requiring frequent recalibration or operator intervention.

Implementation Method 1

a scintillator, consisting of a material, such as gadolinium oxysulfide, Gd2O2S:Tb (GOS) or cesium iodide (CsI), that absorbs x-rays incident thereon and converts the x-ray energy to visible light photons

Methodology Applied
Scientific EffectScintillation: Scintillation

Implementation Method 2

The light sensitive material converts the incident light into electrical charge which is stored in the internal capacitance of each pixel

Methodology Applied
Scientific EffectPhotoelectric Effect: Photoelectric Effect

Data Source

PatentUS9195899B2Self correcting portable digital radiography detector, methods and systems for same
Publication Date: 2015.11.24 CARESTREAM HEALTH INC
  • US9195899B2 patent drawing
  • US9195899B2 patent drawing
  • US9195899B2 patent drawing

AI summary

Embodiments of radiographic imaging systems and/or methods can monitor the state of calibration of a digital x-ray detector, the detector including a solid state sensor with a plurality of pixels, an optional scintillating screen and at least one embedded microprocessor. In one embodiment, a method can use a computer or the embedded microprocessor or both, for setting a calibration operating mode of the portable detector; taking a plurality of dark images in the calibration mode; determining a dark difference image between pixel readings between two of the plurality of dark images; identifying pixels in the dark difference image that differ by over a threshold amount from at least some surrounding pixels in the dark difference image as defective pixels.