Adaptive Feedback Capacitor for X-ray Detection
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Solution Overview
Problem
Conventional X-ray detecting devices with constant feedback capacitors are inadequate for high-speed operation and fail to optimize X-ray irradiation based on subject transmissivity, leading to suboptimal detective quantum efficiency.
Innovation Solution
An X-ray detecting device with a feedback capacitor system that adjusts capacitance based on subject transmissivity, using a differential amplifier, feedback capacitors, and switches to control the integrator's capacitance during pre-exposure and main exposure intervals, allowing for adaptive optimization of X-ray irradiation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a feedback capacitor with constant electrical capacity is used, then the device can operate with simple circuit design, but the detective quantum efficiency cannot be optimized for different subject transmissivities
Solution Approach 1:
The feedback capacitor's electrical capacity is made dynamically adjustable through a capacitor selection circuit that connects different capacitor values to the integrator based on pre-measured subject transmissivity. This allows the system to adapt to different subjects (e.g., chest vs. extremity imaging) and optimize detective quantum efficiency for each case.
Solution Approach 2:
The system performs a pre-exposure measurement to determine subject transmissivity before the main exposure. Based on this preliminary measurement, the capacitor selection circuit pre-configures the appropriate feedback capacitor value, ensuring optimal detection performance is ready before the actual imaging begins.
2Productivity
If a feedback capacitor with constant electrical capacity is used, then the circuit design remains simple, but the device cannot achieve high-speed operation with optimized detection
Solution Approach 1:
The pre-exposure measurement and capacitor selection are performed before the main exposure, allowing the system to be pre-configured for optimal detection. This preliminary setup enables high-speed operation during the actual imaging without requiring real-time capacitor switching during the critical detection phase.
Solution Approach 2:
The feedback capacitor is divided into multiple discrete capacitor elements with different electrical capacities. The capacitor selection circuit selectively connects the appropriate capacitor element to the integrator based on subject transmissivity, enabling optimized detection for different imaging scenarios.
3Reliability
If automatic exposure control is implemented to optimize detective quantum efficiency, then detection performance improves, but the device complexity and control mechanisms increase
Solution Approach 1:
Instead of implementing a complex system-wide automatic exposure control mechanism, the invention optimizes detective quantum efficiency by locally adjusting only the feedback capacitor value in the integrator based on subject transmissivity. This targeted approach improves detection performance without requiring complex control systems throughout the entire device.
Solution Approach 2:
The system changes the electrical capacity parameter of the feedback capacitor based on measured subject transmissivity. By adjusting this single critical parameter, the system optimizes detective quantum efficiency without implementing comprehensive automatic exposure control mechanisms.
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 enhances detective quantum efficiency by optimizing capacitance according to subject transmissivity, eliminating the need for automatic exposure control and reducing errors related to subject position, thereby improving image detection speed and quality.
Implementation Method 1
Each photodetecting pixel detects the X-rays generated by the X-ray generating device and outputs electrical signals
Implementation Method 2
an integrator, connected to the corresponding data line, for generating an output voltage by integrating the transmitted data signal
Data Source
AI summary
An X-ray detecting device includes: an X-ray receiving panel including a plurality of scan lines, a plurality of data lines, and a plurality of photodetecting pixels connected to the scan lines and the data lines; a scan driver, connected to the scan lines, for applying a scan signal for controlling outputs of data signals of the photodetecting pixels; and a data detector, connected to the data lines, for receiving the data signals output by the photodetecting pixels, reading the data signals, and controlling capacitance according to transmissivity of a subject. Detective quantum efficiency of the X-ray detecting device can be improved by adaptively controlling capacitance of an integrator according to measured transmissivity of a subject.