The Development Of No-Invasive Measurement System For X-Ray Exposure Parameters In Radiography

ObjectiveAn accurate diagnosis of X-ray machine implementation of tube voltage (kV), tube current (mA) and exposure time (t) and other important parameters of the test, the equipment running at its best. Ensure diagnostic image quality and reduce patient irradiation dose, and eventually the case without dismantling the machine status parameters measured and displayed on the host computer and print.MethodsThis topic can be divided into acquisition and interference optical detection part of the hardware unit and the data calculated from the correlation algorithm, the data compilation of self-calibration and communications software section.Hardware parts: the main double by the PIN photodiode, DDC112 dual inputΔ-ΣA / D converter, STC12C2051 micro-controller, MAX232A communication conversion unit and the second form of power supply voltage.PIN detectors used in optical detectors. The form of dual probes of the subject, the main purpose is to increase the detection area of measuring dispersion, reducing errors and increasing the reliability of measurement results.DDC112 is based on TI has introduced a number of current integration of the direct current preamplifier integrated analog to digital conversion chip. It integrates two points within the amplifier and a 20-bit ADC. Computer through the analog input channels (AI) and digital input channels (DI) real-time data collection, and then calculated according to certain rules, the final control signals, and through the analog output channels (AO) and the switch output channel (DO ) direct control of the production process. After receiving the signal detector, the DDC122 into a serial pulse sequence and to quantify the digital signals. Access to the digital signal transmitted by the channel interface circuit external computer, after treatment in the form of waveforms displayed on the computer screen. Software: X ray detector received, the photoelectron firing a weak light detector current output, uA level current analog signal into DDC122, DDC112 20BIT signal integration into the serial digital signal output to the micro-controller STC12C2051. By calculation, look-up table, software such as anti-jamming measures kV exposure parameters for real-time data, through the RS232C communication port communication protocols, according to a specific host computer, the host computer display, save, summarize, print.ResultsAfter testing, the system stable state, running in good condition, can be achieved by way of non-intervention in the kV X-ray photography and other major parameters of the system testing, and be able to communicate in the host computer through the display.Conclusion:Using this test system can immediately be under a single exposure tube voltage, tube current and exposure time and other information, the system is relatively simple circuit structure, debugging. Photocurrent by DDC112 directly converted into digital signals, to avoid nonlinear amplification and conditioning circuit and poor consistency of many problems, system hardware, low cost, small size, suitable for X-ray photography applied to the inspection system equipment, maintenance and Identification of other fields.