Arc management apparatus and method for a high voltage generator

Abstract

The application designs an ARC management device and method of a high-voltage generator for a ball tube, belongs to the field of core components of high-end diagnostic medical equipment X-ray computed tomography systems, and first provides an ARC management device, specifically comprising: a high-voltage low-delay acquisition unit, a voltage signal differential transmission unit, a large-ARC signal identification unit, a small-ARC signal identification unit and an FPGA processing unit; the ARC of the ball tube is managed based on the above device; the high-voltage generator collects the number of large and small ARCs of the ball tube through the FPGA to perform mechanism management, avoids irreversible damage to the ball tube, prolongs the service life of the ball tube, avoids frequent shutdown interruption of the CT system, improves the use efficiency of the equipment, reduces the equipment maintenance cost, and reduces the number of repeated radiation of patients.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of core components of high-end diagnostic medical equipment X-ray computed tomography system, and particularly relates to an ARC management device and method of a high-voltage generator for a ball tube. BACKGROUND

[0002] The three major components in a CT system are a ball tube, a high-voltage generator and a detector, the high-voltage generator manages the ball tube to emit X-rays, the detector is responsible for receiving the X-rays and converting them into electrical signals, and an image is reconstructed by a post-processing system.

[0003] The ball tube is one of consumable components frequently replaced in a CT machine, and its structure is similar to that of a common rotary anode X-ray tube, being an electric vacuum device. Since its sales price is expensive, whether it is used well or not will directly affect the smooth progress of medical work of the CT machine, and will bring great influence on the economic benefit and social benefit of the hospital. Some common faults occur in the ball tube during use, among which the high-voltage ARC in the tube sleeve is the most serious. This fault will be transmitted to the CT system through the high-voltage generator, the system will terminate the scanning work, and it needs to be restarted or maintained to recover, which has a relatively large influence on the patient and the hospital CT equipment resource call. Since the ball tube is a vacuum device, there are hundreds of thousands of volts of high voltage in the limited volume, and it is impossible to avoid the occurrence of ARC phenomenon during use. How to handle it becomes a key technology. The ARC signal of the ball tube is a fast step signal, and needs to be collected without distortion. In addition, the degree of ARC is different, and the influence of kilovoltage fluctuation on the image needs to be distinguished to distinguish the degree of ARC, and different responses are made.

[0004] The ARC management mechanism of the current market high-voltage generator for the ball tube has the following disadvantages:

[0005] 1. The high-voltage generator does not process the ARC signal of the ball tube, directly transmits the fault information to the system, and causes frequent shutdown of the system and cannot normally scan;

[0006] 2. The high-voltage generator has filtering processing for the ARC signal of the ball tube, but does not distinguish the size of the ARC, does not understand the influence of the size of the ARC on the image, and also causes frequent shutdown of the system;

[0007] 3. The high-voltage generator adopts a resistance voltage division method to judge the kilovoltage mutation to identify the ball tube ARC, and can only roughly detect whether there is a load short circuit to cause kilovoltage drop, and cannot accurately judge the slope of the ARC signal;

[0008] 4. The ball tube ARC signal acquisition circuit in the high-voltage generator has a delay of more than 100us, and cannot accurately reflect the number of ball tube ARCs, causing the vacuum degree of the ball tube to decrease and reducing the service life of the ball tube. SUMMARY

[0009] In view of the deficiencies of the prior art, the application provides an ARC management device and method for a ball tube of a high-voltage generator; the device is applied to a medical CT device, and through low-delay and distortion-free acquisition of a kilovolt signal of the high-voltage generator, the real transmission of an ARC signal of the ball tube is ensured, then based on the influence of the ARC on an image and the service life of the ball tube, two sets of processing circuits are used to distinguish the strength of the ARC, finally, the number of times of large and small ARCs is acquired by using an FPGA processor, the ARC management mechanism is realized, the exposure function is immediately stopped when the large ARC occurs, and the fault information is uploaded to the system at the same time, the exposure function is stopped after the small ARC is detected for 5 times within 10 ms, and the high voltage is normally outputted when the small ARC is detected for less than 5 times. Through the low-delay and distortion-free signal acquisition and the distinction of the size of the ARC, the application ensures the use specification of the ball tube and does not cause permanent damage, reduces the number of system shutdowns on the basis of not affecting imaging, increases the use efficiency of the device, and avoids the repeated X-ray radiation of the patient.

[0010] An ARC management device for a ball tube of a high-voltage generator, specifically comprising: a high-voltage low-delay acquisition unit, a voltage signal differential transmission unit, a large-ARC signal identification unit, a small-ARC signal identification unit and an FPGA processing unit;

[0011] The high-voltage low-delay acquisition unit and the voltage signal differential transmission unit are in a TANK box body, the large-ARC signal identification unit, the small-ARC signal identification unit and the FPGA processing unit are in a power supply control box body, and the two are connected through a cable.

[0012] The high-voltage low-delay acquisition unit uses an RC matching circuit to perform low-delay sampling on the actual high voltage at both ends of the ball tube; the voltage signal differential transmission unit uses a high-precision differential acquisition chip to transmit the high-voltage acquisition signal back to the control part without distortion; the large-ARC signal identification unit uses a comparator to judge the slope of the high-voltage drop signal, and the threshold of the comparator is controlled by a program, and 15 kV / us is taken as the lower limit; the small-ARC signal identification unit uses a comparator to judge the slope of the high-voltage drop signal, and the threshold of the comparator is controlled by a program, and 10 kV / ms is taken as the upper limit; the FPGA processing unit acquires the number of times of large and small ARC signals, stops the exposure timing when the large ARC occurs once, uploads the fault information, and stops the exposure timing when the small ARC occurs for 5 times within 10 ms, and keeps the high voltage normally outputted when the small ARC occurs for less than 5 times.

[0013] An ARC management method for a ball tube of a high-voltage generator, which is realized by using the above-mentioned ARC management device for the ball tube of the high-voltage generator, and comprises the following steps:

[0014] Step 1: after the high-voltage generator receives a CT exposure instruction, the filament, kilovolt and milliamper parameters are set according to different product specifications, so that the ball tube can be exposed;

[0015] Step 2: High-voltage generator real-time monitoring of the ball tube filament, kilovoltage, and milliampere parameters during the exposure process;

[0016] Step 3: When the ball tube appears ARC, the kilovoltage signal appears a step drop, and the high-voltage low-delay acquisition unit acquires in real time;

[0017] Step 4: After acquiring the kilovoltage drop signal, the voltage differential transmission unit is used for lossless transmission;

[0018] Step 5: The size ARC signal recognition module compares the slope of the kilovoltage drop signal, and the result is output to the FPGA;

[0019] Step 6: The FPGA distinguishes between large and small ARC, and the exposure timing is immediately stopped for large ARC, and the exposure timing is stopped within 10 ms for small ARC if the acquisition is continuously acquired for 5 times, then the error priority is raised to the first place, and the high-voltage generator enable output is turned off; if it is less than 5 times, it is judged that the ball tube ARC has no influence on the system imaging, the ARC data is recorded, and no shutdown processing is performed to keep the high voltage normal output.

[0020] The present application has the beneficial technical effects:

[0021] To solve the problems of the high-voltage generator in the CT system, such as not processing the ball tube ARC information directly uploading, judging whether there is ball tube ARC by simple resistance voltage division, high-voltage acquisition circuit delay time exceeding 100us ignoring ball tube ARC information, affecting the service life of the ball tube, and frequently shutting down the CT system during use, a high-voltage generator ball tube ARC management mechanism is proposed:

[0022] 1. The high-voltage generator matches the impedance through the high-voltage low-delay acquisition circuit, and completely restores the real signal of the ball tube ARC;

[0023] 2. The high-voltage generator transmits the signal losslessly through the voltage differential transmission module, and improves the signal transmission anti-interference performance;

[0024] 3. The high-voltage generator judges the kilovoltage drop by slope comparison, and dynamically distinguishes the size of the ball tube ARC;

[0025] 4. The high-voltage generator manages the number of ball tube ARC through the FPGA acquisition, avoids irreversible damage to the ball tube, and prolongs the service life of the ball tube;

[0026] 5. The high-voltage generator manages the number of ball tube ARC through the FPGA acquisition, avoids frequent shutdown of the CT system, improves the use efficiency of the equipment, reduces the equipment maintenance cost, and reduces the number of repeated radiation of patients. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1A high-voltage generator ARC management device structure diagram for a ball tube of the present application;

[0028] Figure 2 A high-voltage low-delay acquisition unit schematic diagram of an embodiment of the present application;

[0029] Figure 3 A voltage signal differential transmission schematic diagram of an embodiment of the present application;

[0030] Figure 4 A large ARC signal identification schematic diagram of an embodiment of the present application;

[0031] Figure 5 A small ARC signal identification schematic diagram of an embodiment of the present application;

[0032] Figure 6 A FPGA processing unit schematic diagram of an embodiment of the present application;

[0033] Figure 7 A high-voltage generator ARC management method logic diagram for a ball tube of the present application. DETAILED DESCRIPTION

[0034] An implementation of the present application will be described in detail below with reference to the accompanying drawings.

[0035] A high-voltage generator ARC management device for a ball tube, as shown in the accompanying drawings, specifically comprises: a high-voltage low-delay acquisition unit, a voltage signal differential transmission unit, a large ARC signal identification unit, a small ARC signal identification unit, and a FPGA processing unit. Figure 1

[0036] Among them, the high-voltage low-delay acquisition unit and the voltage signal differential transmission unit are in the TANK box, and the large ARC signal identification unit, the small ARC signal identification unit, and the FPGA processing unit are in the power supply control box, and the two are connected through a cable.

[0037] The high-voltage low-delay acquisition unit uses an RC matching circuit to perform low-delay sampling on the actual high voltage at both ends of the ball tube; the voltage signal differential transmission unit uses a high-precision differential acquisition chip to transmit the high-voltage acquisition signal back to the control part without distortion; the large ARC signal identification unit uses a comparator to judge the high-voltage drop signal slope, and the comparator threshold is controlled by the program, taking 15kV / us as the lower limit; the small ARC signal identification unit uses a comparator to judge the high-voltage drop signal slope, and the comparator threshold is controlled by the program, taking 10kV / ms as the upper limit; the FPGA processing unit collects the number of times that large ARC and small ARC signals appear, and stops the exposure timing when large ARC appears once, uploads fault information, and stops the exposure timing when small ARC appears 5 times within 10ms, and less than 5 times to maintain normal high-voltage output.

[0038] As​Figure 2 The high-voltage low-delay acquisition unit of the application is shown in the schematic diagram, the circuit uses high-precision resistors Rh and Rl for voltage sampling, since the high voltage reaches tens of thousands of volts, therefore, the capacitor and the resistor are connected in parallel to perform voltage equalization processing, avoiding damage to the resistor due to uneven voltage distribution, the capacitor Ch is connected in parallel to the resistor Rh, and the capacitor Cl is connected in parallel to the resistor Rl, the design element parameters meet Rh*Ch=Rl*Cl, which conforms to the impedance matching principle, so that the high-voltage dynamic signal is fed back with low delay and no distortion.

[0039] As shown in the schematic diagram of the voltage signal differential transmission of the application, the differential transmission chip selects ADI company's AD8131, which can be used as a differential driver for high-speed signal transmission through low-cost twisted pair or coaxial cable, for transmission of analog, digital video signals or other high-speed data signals, manufactured by ADI company's new generation XFCB bipolar process, with a -3dB bandwidth of 400MHz, providing differential signals with very low harmonic distortion. Compared with operational amplifiers, AD8131 has made great progress in driving long line signals or driving differential input ADC. It has a unique internal feedback feature that provides output gain and phase matching balanced to -68dB at 10MHz, which can reduce electromagnetic interference (EMI) and suppress harmonics. Figure 3 As shown in the schematic diagram of the large ARC signal identification of the application, the circuit is composed of a level operational amplifier and a level comparator, the motion amplifier realizes proportional change of the kilovolt feedback signal, and the comparator realizes slope judgment of the kilovolt drop signal. The kilovolt feedback signal KV_FB is converted in proportion through R1-R4 and U1, the output signal of U1 is connected to pin 3 of U3 after charging C1 through D1, and this signal serves as a slope comparison threshold; KV_FB is connected to pins 2 and 3 of U2 for comparison, and when the slope is higher than the threshold, U2 outputs a high-level signal to complete the large ARC slope identification function.

[0040] Figure 4 As shown in the schematic diagram of the small ARC signal identification of the application, the circuit is composed of a level operational amplifier and a level comparator, the motion amplifier realizes proportional change of the kilovolt feedback signal, and the comparator realizes slope judgment of the kilovolt drop signal. The kilovolt feedback signal KV_FB is converted in proportion through R7-R10 and U3, the output signal of U3 is connected to pin 3 of U4 after charging C2 through D2, and this signal serves as a slope comparison threshold; KV_FB is connected to pins 2 and 3 of U4 for comparison, and when the slope is higher than the threshold, U4 outputs a high-level signal to complete the small ARC slope identification function.

[0041] As shown in the schematic diagram of the large ARC signal identification of the application, the circuit is composed of a level operational amplifier and a level comparator, the motion amplifier realizes proportional change of the kilovolt feedback signal, and the comparator realizes slope judgment of the kilovolt drop signal. The kilovolt feedback signal KV_FB is converted in proportion through R1-R4 and U1, the output signal of U1 is connected to pin 3 of U3 after charging C1 through D1, and this signal serves as a slope comparison threshold; KV_FB is connected to pins 2 and 3 of U2 for comparison, and when the slope is higher than the threshold, U2 outputs a high-level signal to complete the large ARC slope identification function. Figure 5 As shown in the schematic diagram of the small ARC signal identification of the application, the circuit is composed of a level operational amplifier and a level comparator, the motion amplifier realizes proportional change of the kilovolt feedback signal, and the comparator realizes slope judgment of the kilovolt drop signal. The kilovolt feedback signal KV_FB is converted in proportion through R7-R10 and U3, the output signal of U3 is connected to pin 3 of U4 after charging C2 through D2, and this signal serves as a slope comparison threshold; KV_FB is connected to pins 2 and 3 of U4 for comparison, and when the slope is higher than the threshold, U4 outputs a high-level signal to complete the small ARC slope identification function.

[0042] Figure 6 ​​As shown is a schematic diagram of the FPGA processing unit of the application, comprising a large ARC signal processing module, a small ARC signal processing module, a high-voltage generator error management module, and a high-voltage exposure module, characterized by a ball tube size ARC signal management mechanism:

[0043] An ARC management method of a high-voltage generator for a ball tube, which is implemented by using the ARC management device of the high-voltage generator for the ball tube, as shown in the accompanying Figure 7 As shown, comprising the following steps:

[0044] Step 1: After the high-voltage generator receives a CT exposure instruction, the filament, kilovoltage, and milliampere parameters are set according to different product specifications, and the ball tube exposure is enabled;

[0045] Step 2: The high-voltage generator monitors the filament, kilovoltage, and milliampere parameters of the ball tube in real time during the exposure process;

[0046] Step 3: When the ball tube appears ARC, the kilovoltage signal appears a step drop, and the high-voltage low-delay acquisition unit acquires in real time;

[0047] Step 4: After acquiring the kilovoltage drop signal, the voltage differential transmission unit is used for lossless transmission;

[0048] Step 5: The large and small ARC signal identification module compares the slope of the kilovoltage drop signal, and the result is output to the FPGA;

[0049] Step 6: The FPGA distinguishes between large and small ARC, and immediately stops the exposure timing when large ARC occurs. When small ARC occurs, the exposure timing is stopped if 5 consecutive acquisitions are made within 10 ms, and the error priority is raised to the first place, and the high-voltage generator enable output is turned off. If less than 5 times, it is judged that the ball tube ARC has no impact on system imaging, the ARC data is recorded, and no shutdown processing is performed to maintain normal high-voltage output.

Claims

1. An ARC management device for a ball tube of a high voltage generator, characterized by, Specifically comprising: The high-voltage low-delay acquisition unit, the voltage signal differential transmission unit, the large ARC signal identification unit, the small ARC signal identification unit and the FPGA processing unit are connected through cables. The high-voltage low-delay acquisition unit uses an RC matching circuit to perform low-delay sampling on the actual high voltage at both ends of the bulb; the voltage signal differential transmission unit uses a high-precision differential acquisition chip to transmit the high-voltage acquisition signal back to the control part without distortion; the large ARC signal identification unit uses a comparator to determine the slope of the high-voltage drop signal, and the comparator threshold is controlled by a program, taking 15kV / us as the lower limit; the small ARC signal identification unit uses a comparator to determine the slope of the high-voltage drop signal, and the comparator threshold is controlled by a program, taking 10kV / ms as the upper limit; the FPGA processing unit collects the number of times that the large ARC and small ARC signals appear, and stops the exposure timing when the large ARC appears once, uploads fault information, and stops the exposure timing when the small ARC appears 5 times within 10ms, and keeps the high voltage normal output if less than 5 times. The method comprises the following steps:

2. The method for managing ARC of a ball tube by a high-voltage generator, based on the device for managing ARC of a ball tube by a high-voltage generator according to claim 1, characterized in that, Step 1: After the high-voltage generator receives the CT exposure instruction, the filament, kilovoltage and milliampere parameters are set according to different product specifications, and the bulb exposure is enabled; Step 2: The high-voltage generator monitors the filament, kilovoltage and milliampere parameters of the bulb in real time during exposure; Step 3: When the bulb appears ARC, the kilovoltage signal appears a step drop, and the high-voltage low-delay acquisition unit collects in real time; Step 4: After collecting the kilovoltage drop signal, the voltage differential transmission unit transmits it without distortion; Step 5: The large and small ARC signal identification modules compare the slope of the kilovoltage drop signal, and the result is output to the FPGA; Step 6: The FPGA distinguishes between large and small ARC, and immediately stops the exposure timing when large ARC occurs, and stops the exposure timing when small ARC is continuously collected 5 times within 10ms, then raises the error priority to the first place, and turns off the high-voltage generator enable output; if less than 5 times, it is judged that the bulb ARC has no effect on system imaging at this time, the ARC data is recorded, and no shutdown processing is performed to keep the high voltage normal output. ​

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