CT high voltage generator

Abstract

The application relates to a CT high-voltage generator, which belongs to the technical field of medical devices. The CT high-voltage generator comprises a control unit, a power inverter unit and a high-voltage oil tank. The control unit comprises an ARM processor, an FPGA, a digital-analog conversion module, a high-speed analog switch module and a voltage control module. The ARM processor outputs a digital quantity of a first voltage. The digital-analog conversion module converts the digital quantity of the first voltage into an analog quantity of the first voltage. The FPGA outputs a control signal. The input end of the high-speed analog switch module is connected with the analog quantity of the first voltage, and the control end of the high-speed analog switch module acquires the control signal. The FPGA controls the high-speed analog switch module to generate a reference working voltage of an X-ray tube according to the analog quantity of the first voltage. The voltage control module is used for outputting a PWM signal and adjusting the duty cycle of the PWM signal according to a tube voltage and the reference working voltage. The power inverter unit generates corresponding output power according to the duty cycle of the PWM signal, and the high-voltage oil tank updates the tube voltage according to the output power.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, specifically to a CT high-voltage generator. Background Technology

[0002] The global CT equipment market accounts for 9.5% of the total medical imaging equipment market, with developed countries having reached maturity. With technological advancements, global CT equipment has achieved breakthroughs in functions such as cardiac scanning, lung screening, and pediatric disease examination. my country's CT equipment market is in a phase of rapid development, with sales volume and market size showing rapid growth. On the one hand, with increased investment in the healthcare industry, rising public health awareness, the gradual implementation of tiered medical services, and increased support for primary healthcare institutions, hospitals' demand for CT equipment will continue to increase, and CT equipment penetration will continue to strengthen.

[0003] Currently, CT equipment using single-source acquisition technology mainly achieves this by using two grid-controlled control units to alternately block the electron beam emitted from the cathode filaments towards the target, thereby achieving rapid switching of electron beam energy reaching the anode target surface. This method places high demands on the X-ray tube, requiring two pairs of grid-controlled electrodes, and the CT high-voltage generator needs to output two sets of continuous voltages with different peak values, respectively clamped to the two cathode filaments of the X-ray tube. This not only presents significant implementation challenges but also drastically increases the cost of the X-ray tube. Therefore, it restricts the application of CT high-voltage generators in low- to mid-range CT scanners. When the CT high-voltage generator needs to output two sets of continuous voltages with different peak values, the corresponding output voltage cannot switch between high and low kilovolts within microseconds. If a common step signal is used for drive control, overshoot is highly likely to occur, leading to arcing or even damage to the X-ray tube of the CT high-voltage generator. Summary of the Invention

[0004] The main technical problem solved by this invention is that when the CT high voltage generator outputs continuous voltages with different peak values, it is impossible to switch between them within a microsecond time.

[0005] According to the first aspect, one embodiment provides a CT high-voltage generator, including: a control unit, a power inverter unit, and a high-voltage oil tank;

[0006] The control unit includes an ARM processor, an FPGA, a digital-to-analog converter module, a high-speed analog switch module, and a voltage control module;

[0007] The ARM processor is used to output a digital value of the first voltage;

[0008] The input terminal of the digital-to-analog converter module is connected to the ARM processor and is used to convert the digital value of the first voltage into the analog value of the first voltage.

[0009] The FPGA is used to output control signals;

[0010] The input terminal of the high-speed analog switch module is connected to the analog quantity of the first voltage, and the control terminal of the high-speed analog switch module is connected to the control signal; the FPGA controls the high-speed analog switch module to generate the reference operating voltage of the X-ray tube according to the analog quantity of the first voltage.

[0011] The voltage control module is used to output a PWM signal and adjust the duty cycle of the PWM signal according to the tube voltage and the reference operating voltage.

[0012] The power inverter unit is used to obtain the duty cycle of the PWM signal and generate the corresponding output power according to the duty cycle of the PWM signal.

[0013] The high-pressure oil tank acquires the output power and updates the tube voltage based on the output power.

[0014] In one embodiment, the high-speed analog switch module includes NAND gates U2A, U2B, U2C, and U2D, and a non-inverting amplifier. The input terminals of NAND gates U2A, U2B, U2C, and U2D are connected to the analog quantity of the first voltage, and the control terminals of NAND gates U2A, U2B, U2C, and U2D are connected to the control signal. The FPGA uses the control signal to control the switching of NAND gates U2A, U2B, U2C, and U2D to output a set number of analog quantities of the first voltage. The non-inverting amplifier acquires the set number of analog quantities of the first voltage and generates the reference operating voltage of the X-ray tube based on the set number of analog quantities of the first voltage.

[0015] In one embodiment, the voltage control module includes a first amplifier module, a second amplifier module, a first comparator module, and a first control chip; the first control chip is an SG3525 control chip.

[0016] The non-inverting input terminal of the first amplifier module receives the tube voltage of the X-ray tube, and the inverting input terminal of the second amplifier module receives the reference operating voltage of the X-ray tube. The output terminals of the first amplifier module and the second amplifier module are connected to the input terminal of the first comparator module to compare the tube voltage with the reference operating voltage. The output terminal of the first comparator module is connected to the non-inverting input terminal of the first control chip to adjust the duty cycle of the PWM signal based on the comparison result of the tube voltage and the reference operating voltage.

[0017] In one embodiment, the control unit further includes a current warning module, which includes a second comparator module and a second control chip; the second control chip is a 74HC74 chip.

[0018] The inverting input of the second comparator module receives a current limit, and the non-inverting input of the second comparator module receives the tube current of the X-ray tube; when the tube current exceeds the current limit, the second control chip outputs an error signal.

[0019] In one embodiment, the control unit further includes a voltage warning module, which includes a third comparator module and a third control chip; the third control chip is a 74HC74 chip.

[0020] The non-inverting input of the third comparator module receives a limiting voltage, and the inverting input of the third comparator module receives the tube voltage of the X-ray tube; when the tube voltage is greater than the limiting voltage, the third control chip outputs an error signal.

[0021] In some embodiments, the control unit further includes a protection signal module, which includes an optocoupler-isolated input circuit and a transistor output circuit;

[0022] The input terminal of the optocoupler isolated input circuit acquires the error signal and converts the error signal into a low level output to the ARM processor;

[0023] The input terminal of the transistor output circuit is connected to the ARM processor. The ARM processor converts the low level of the error signal to a high level and sends it to the transistor output circuit to shut down the CT high voltage generator.

[0024] In one embodiment, the control unit further includes an analog voltage regulator module;

[0025] The analog voltage regulator module includes a first buck module and a second buck module. The first buck module is used to step down the voltage to determine a first operating voltage, and the first operating voltage is used to power the second buck module. The second buck module is used to step down the first operating voltage to determine a second operating voltage, and the second operating voltage is used to power the ARM processor.

[0026] In one embodiment, the control unit further includes a communication module, which includes a third control chip, namely a MAX3232.

[0027] The communication module is powered by the first operating voltage, and the communication between the ARM processor and the host computer is realized through the third control chip.

[0028] In one embodiment, the control unit further includes a CAN communication module, the input of which is connected to the FPGA, and the output of which is connected to the ARM processor, for realizing communication between the ARM processor and the FPGA.

[0029] In one embodiment, the control unit further includes a wireless communication module, which includes a receiver and a transmitter. The receiver is connected to a host computer, and the transmitter is connected to the FPGA to enable wireless communication between the FPGA and the host computer.

[0030] The CT high-voltage generator according to the above embodiment includes a control unit, a power inverter unit, and a high-voltage tank. The control unit employs a dual-core processor (ARM processor and FPGA), and converts the digital value of the first voltage output by the ARM processor into an analog value through a digital-to-analog conversion module. The input terminal of the high-speed analog switch module receives the analog value of the first voltage output by the ARM processor, and the control terminal receives the control signal output by the FPGA. The FPGA controls the high-speed analog switch module to generate the reference operating voltage of the X-ray tube based on the analog value of the first voltage. The voltage control module outputs a PWM signal and adjusts the duty cycle of the PWM signal according to the tube voltage and the reference operating voltage. The power inverter unit generates the corresponding output power according to the duty cycle of the PWM signal, and the high-voltage tank updates the tube voltage according to the output power. This application utilizes the high computing speed of the FPGA to control the on / off state of the high-speed analog switch module, thereby rapidly generating the reference operating voltage of the X-ray tube and achieving rapid switching of the tube voltage at the microsecond level. Attached Figure Description

[0031] Figure 1 A schematic diagram of the structure of a CT high-voltage generator according to one embodiment. Figure 1 ;

[0032] Figure 2 This is a schematic diagram of the control unit of a CT high-voltage generator according to one embodiment;

[0033] Figure 3 This is a schematic diagram of an ARM processor according to one embodiment;

[0034] Figure 4 This is a circuit connection diagram of the first MAX5815 chip in one embodiment;

[0035] Figure 5 This is a circuit connection diagram of the second MAX5815 chip in one embodiment;

[0036] Figure 6 This is a schematic diagram of an FPGA according to one embodiment;

[0037] Figure 7This is a circuit connection diagram of a high-speed analog switch module according to one embodiment;

[0038] Figure 8a This is a circuit connection diagram of a voltage control module according to one embodiment;

[0039] Figure 8b This is a schematic diagram of a voltage control module chip according to one embodiment;

[0040] Figure 9 This is a circuit connection diagram of a current warning module according to one embodiment;

[0041] Figure 10 This is a circuit connection diagram of a voltage warning module according to one embodiment;

[0042] Figure 11 This is a circuit connection diagram of an optocoupler isolation circuit according to one embodiment;

[0043] Figure 12 This is a schematic diagram of the circuit connection of a transistor output circuit according to one embodiment;

[0044] Figure 13 This is a circuit connection diagram of an analog voltage regulator module according to one embodiment;

[0045] Figure 14 This is a circuit connection diagram of a third step-down module according to one embodiment;

[0046] Figure 15 This is a circuit connection diagram of a CAN communication module according to one embodiment;

[0047] Figure 16 This is a circuit connection diagram of a wireless communication module according to one embodiment;

[0048] Figure 17 A schematic diagram of the structure of a CT high-voltage generator according to one embodiment. Figure 2 . Detailed Implementation

[0049] The present invention will now be described in further detail with reference to specific embodiments and accompanying drawings. Similar elements in different embodiments are referred to by associated similar element reference numerals. In the following embodiments, many details are described to facilitate a better understanding of this application. However, those skilled in the art will readily recognize that some features may be omitted in different situations, or may be replaced by other elements, materials, or methods. In some cases, certain operations related to this application are not shown or described in the specification. This is to avoid obscuring the core parts of this application with excessive description. For those skilled in the art, detailed description of these related operations is not necessary; they can fully understand the related operations based on the description in the specification and general technical knowledge in the art.

[0050] Furthermore, the features, operations, or characteristics described in the specification can be combined in any suitable manner to form various embodiments. At the same time, the steps or actions in the method description can be rearranged or adjusted in a manner obvious to those skilled in the art. Therefore, the various orders in the specification and drawings are only for the clear description of a particular embodiment and do not imply a necessary order, unless otherwise stated that a particular order must be followed.

[0051] The serial numbers assigned to components in this document, such as "first" and "second," are used only to distinguish the described objects and have no sequential or technical meaning. Unless otherwise specified, the terms "connection" and "linkage" used in this application include both direct and indirect connections (linkages).

[0052] CT scans utilize X-rays emitted from an X-ray tube to perform a spiral scan of a specific thickness of the human body. Simultaneously, detectors collect the X-rays that pass through the body. X-ray tubes are generally divided into two types: fixed anode tubes and rotating anode tubes. Current medical X-ray devices typically use rotating anode tubes. A rotating anode tube mainly consists of positive and negative electrodes and an outer shell; the positive and negative electrodes are generally referred to as anode and cathode. The anode section comprises mechanical components that allow it to rotate. A crucial component is the anode target, which receives the electrons that bombard the emitted X-rays. When a DC voltage (tens of thousands to hundreds of thousands of volts) is applied between the cathode and anode of the tube, a large number of ionized electrons emitted from the cathode collide with the rotating anode. The energy carried by the electron beam is largely lost as heat after being sharply blocked, with the remaining portion effectively exciting the anode target to produce X-rays. The electron beam emitted from the cathode to the anode is the current flowing through the X-ray tube (tube current). The magnitude of the tube current depends on the filament current and the voltage applied to the X-ray tube (tube voltage). Therefore, to obtain precise and controllable X-ray energy, the filament current and tube voltage must be precisely controlled. The high-voltage generator provided in this application is a power supply device for supplying power to this special load, the X-ray tube. The high-voltage generator is mainly used to provide a stable tube voltage and tube current to the CT X-ray tube under the control of the CT main control unit. After the high-voltage generator is started, a corresponding tube voltage is applied to the X-ray tube, thus generating a corresponding tube current.

[0053] Please refer to Figure 1 Some embodiments provide a CT high-voltage generator 100, including a control unit 200, a power inverter unit 300, and a high-voltage oil tank 400.

[0054] Please refer to Figure 2 In some embodiments, the control unit 200 includes an ARM processor 201, an FPGA 202, a digital-to-analog converter 203, a high-speed analog switch module 204, and a voltage control module 205.

[0055] Please refer to Figure 3 In some embodiments, the ARM processor 201 is the processor in the STM32F microcontroller, which, in addition to outputting the digital quantity of the first voltage, also issues logic control instructions during the operation of the CT high voltage generator.

[0056] Please refer to Figure 4In some embodiments, the digital-to-analog converter module 203 uses a MAX5815 chip. The input terminals SDA and SCL of the MAX5815 control chip are the data input terminal and clock input terminal, respectively. The MAX5815 chip receives the digital value of the first voltage sent by the ARM processor 201 through the data input terminal, converts the digital value of the first voltage into an analog value within the MAX5815 chip, and utilizes the four output terminals VoutA, VoutB, VoutC, and VoutD (i.e., ...) Figure 4 The Ref_A, Ref_B, Ref_C, and Ref_D output analog values ​​of the first voltage. In some embodiments, the voltages output by the four terminals may be the same or different, depending on the specific circumstances.

[0057] Please refer to Figure 5 In some embodiments, the digital-to-analog conversion module 203 further includes a MAX5815 chip. This MAX5815 chip receives the digital value of the first voltage sent by the ARM processor 201 via its data input terminal, converts the digital value of the first voltage into an analog value internally, and outputs the analog value of the first voltage via two output terminals, VoutA and VoutC. Resistors R134 and R244 are connected to the output terminals of the MAX5815 chip to generate the filament current based on the analog value of the first voltage.

[0058] Please refer to Figure 6 In some embodiments, the FPGA202 is used to output control signals. The FPGA202 consists of hardware resources such as logic units, RAM, and multipliers. By rationally organizing these hardware resources, hardware circuits such as multipliers, registers, and address generators can be implemented. The FPGA202 can be reprogrammed indefinitely during the calculation process, thus its calculation speed is extremely fast.

[0059] In some embodiments, the input of the high-speed analog switch module 204 is connected to an analog quantity of a first voltage, and the control terminal of the high-voltage analog switch module 204 receives a control signal sent by the FPGA 202. The FPGA 202 controls the switching of the high-speed analog switch module 204 to generate the reference operating voltage for the X-ray tube.

[0060] Please refer to Figure 7In some embodiments, the high-speed analog switch module 204 includes NAND gates U2A, U2B, U2C, and U2D, and a non-inverting amplifier OP8. The input terminals of NAND gates U2A, U2B, U2C, and U2D are connected to the analog quantity of the first voltage, i.e., connected to the four output terminals VoutA, VoutB, VoutC, and VoutD of the MAX5815 control chip. The control terminals of NAND gates U2A, U2B, U2C, and U2D are connected to the control signals issued by the FPGA 202. The FPGA 202 controls the switching of NAND gates U2A, U2B, U2C, and U2D according to the different voltages required by the X-ray tube of the CT high-voltage generator 100, to output the analog quantity of the first voltage with a set number of outputs. The non-inverting amplifier OP8 amplifies and integrates the analog signals of the first voltage from a set number of channels to generate the reference operating voltage for the X-ray tube. For example, when the X-ray tube of the CT high-voltage generator 100 requires a high voltage, the required number of NAND gates can be determined based on the required high voltage. Therefore, the FPGA200 controls the corresponding number of NAND gates to open. The opened NAND gates can output the analog signal of the first operating voltage. The analog signals of the first operating voltage output from each opened NAND gate are input to the non-inverting amplifier OP8. The non-inverting amplifier OP8 amplifies and integrates the analog signals of the first operating voltage output from each NAND gate to output the operating reference voltage.

[0061] Since all four NAND gates can output analog quantities of the first voltage, by using the FPGA to control the on and off of the four NAND gates instantaneously, different reference working voltages can be output in a short time. Based on the different reference working voltages output in a short time, the switching of different peak voltages in a microsecond time can be realized.

[0062] Please refer to Figure 8a In some embodiments, the first input terminal of the voltage control module 205 (i.e. Figure 8a Pins 4 and 6 of the voltage control module 205 receive the tube voltage feedback from the X-ray tube (since the tube voltage feedback from the X-ray tube has positive and negative voltages, the first input terminal receives the positive and negative voltages of the X-ray tube respectively), and the second input terminal of the voltage control module 205 (i.e., Figure 8a The KVREF terminal is connected to the output of voltage comparator OP8 to receive the reference operating voltage of the X-ray tube.

[0063] In some embodiments, the voltage control module 205 includes a first amplifier module 205a, a second amplifier module 205b, a first comparator module 205c, and a first control chip 205d. The first input terminal of the voltage control module 205 is connected to the non-inverting input terminal of the first amplifier module 205a to amplify the tube voltage of the X-ray tube. The inverting input terminal of the second amplifier module 205b receives the reference operating voltage of the X-ray tube and amplifies it. The output terminals of the first amplifier module 205a and the second amplifier module 205b are connected to the input terminal of the first comparator module 205c for comparing the tube voltage of the X-ray tube with the reference operating voltage of the X-ray tube.

[0064] Please refer to Figure 8b In some embodiments, the first control chip 205d is an SG3525 chip. The SG3525 chip outputs a PWM signal, and its input terminal (IN+) is connected to the output terminal of the first comparator module 205c. The SG3525 chip adjusts the duty cycle of the PWM signal based on the comparison result output by the first comparator module 205c. That is, the duty cycle of the corresponding PWM signal is adjusted according to the tube voltage and the reference operating voltage of the X-ray tube. The SG3525 chip is a high-performance, feature-rich, and versatile monolithic integrated PWM control chip. It is simple, reliable, and easy to use. Its output drive is push-pull output, increasing the driving capability. Furthermore, the SG3525 chip internally contains an undervoltage lockout circuit, a soft-start control voltage, and a PWM latch, providing overcurrent protection, adjustable frequency, and the ability to limit the maximum duty cycle.

[0065] In some embodiments, the voltage control module 205 also includes a third input terminal, namely pins 3 and 1 in Figure 8, for receiving the tube current of the X-ray tube (since the tube current fed back by the X-ray tube has both positive and negative currents, the third input terminal receives the positive and negative currents of the X-ray tube current, respectively). The tube current of the X-ray tube is amplified by the third amplifier module 205e.

[0066] Please refer to Figure 9In some embodiments, the control unit 200 further includes a current warning module 206, which includes a second comparator module 206a and a second control chip 206b. The tube current of the X-ray tube, amplified by the third amplifier module 205e, is input to the non-inverting input of the second comparator module 206a, and a limiting current is input to the inverting input of the second comparator module 206a. The second comparator module 206a compares the tube current of the X-ray tube with the limiting current. When the tube current of the X-ray tube is greater than the limiting current, it indicates that the tube current of the X-ray tube is too high, and the CT high-voltage generator needs to be shut down. At this time, the second control chip 206b will output an error signal. In some embodiments, the second control chip 206b is a 74HC74 chip. The current warning module 206 can solve the phenomenon of current overshoot, thereby ensuring that the X-ray tube in the CT high-voltage generator can operate under safe conditions.

[0067] Please refer to Figure 10 In some embodiments, the control unit 200 further includes a voltage warning module 207, which includes a third comparator module 207a and a third control chip 207b. The non-inverting input of the third comparator module 207a receives a limiting voltage, and the inverting input receives the tube voltage of the X-ray tube, amplified by the first amplifier module 205a and the second amplifier module 205b. The third comparator module 207a compares the tube voltage of the X-ray tube with the limiting voltage. When the tube voltage of the X-ray tube is greater than the limiting voltage, it indicates that the tube voltage of the X-ray tube is too high, and the CT high-voltage generator needs to be shut down. At this time, the third control chip 207b will output an error signal. In some embodiments, the third control chip 207b is a 74HC74 chip. The voltage warning module 207 can solve the voltage overshoot phenomenon, ensure voltage stability and reliability, and thus ensure that the CT tube in the CT high-voltage generator operates under safe conditions.

[0068] In some embodiments, the control unit 200 further includes a protection signal module 208, which includes an optocoupler isolated input circuit 208a and a transistor output circuit 208b.

[0069] Please refer to Figure 11 In some embodiments, the input terminal of the optocoupler isolated input circuit 208a (i.e. Figure 11 The connection terminals of resistors R36, R38, R40, and R48 receive error signals from the current warning module 206 and the voltage warning module 207, and convert the error signals into a low-level output to the ARM processor 201. The output terminals of the optocoupler-isolated input circuit 208a are connected to LEDs as indicator lights for the error signals.

[0070] Please refer to Figure 12In some embodiments, the input terminal of the transistor output circuit 208b (i.e. Figure 12 The 1-8 ports of the ULN2803 are connected to the ARM processor 201. The ARM processor 201 converts the low level of the error signal sent by the optocoupler isolation circuit 209a to a high level and sends it to the transistor output circuit 208b. The transistor output circuit 209a outputs a high level to shut down the control unit of the entire CT high voltage generator, thus shutting down the entire CT high voltage generator.

[0071] Please refer to Figure 13 In some embodiments, the control unit 200 further includes an analog voltage regulator module 209, which includes a first buck module 209a and a second buck module 209b. Before the analog voltage regulator module 209 performs voltage reduction, the mains voltage is first stepped down to 12V. The first buck module 209a steps down the 12V voltage to 5V, and the 5V operating voltage powers the second buck module 209b. The second buck module 209b steps down the 5V voltage to 3.3V, and the 3.3V voltage powers the ARM processor 201. In some embodiments, the first buck module 209a is a K7805-1000 chip, and the second buck module 209b is a K1117-3.3V chip.

[0072] Please refer to Figure 14 In some embodiments, the analog voltage regulator module 209 further includes a third buck module 209c. The input terminal of the third buck module 209c is connected to the output terminal of the first buck module 209a, and is used to step down the 5V operating voltage to 2.5V, so as to power the FPGA 202 with the 2.5V voltage.

[0073] Please refer to Figure 15 In some embodiments, the control unit 200 further includes a CAN communication module 210. The input terminals of the CAN communication module 210, namely TXD and RXD in the figure, are connected to the FPGA 202. The output terminals of the CAN communication module 210, namely CANH and CANL in the figure, are connected to the ARM processor 201, thereby realizing communication between the ARM processor 201 and the FPGA 202.

[0074] Please refer to Figure 16 In some embodiments, the control unit 200 further includes a CAN communication module 211, which includes a receiver 211a and a transmitter 211b. The receiver 211a can receive information from the host computer and also send information from the FPGA 202; the transmitter 211b can also send information from the host computer 201 and also receive information from the FPGA 202. Figure 16The receiver 211a is connected to the FPGA202. Its input terminals TCK, TDO, TMS and TDI are connected to the FPGA202. Its output terminals NC3 and NC2 are wirelessly connected to the input terminals of the transmitter 211a, thereby realizing wireless communication between the FPGA202 and the host computer.

[0075] In some embodiments, the control unit 200 further includes a power-off storage module 212, which includes an FM24C128 chip. The power-off storage module 212 is a storage module inside the STM32F microcontroller, and is used to store the temperature configuration parameters of the CT high-pressure generator and the working status parameters of the cooling system inside the CT high-pressure generator.

[0076] In some embodiments, the control unit 200 also includes a watchdog reset circuit 213 to improve the anti-lock capability of the CT high voltage generator and to improve the anti-interference capability of the CT high voltage generator.

[0077] The control unit 200 of the CT high voltage generator provided in this application uses an ARM processor 201 and an FPGA 202. The FPGA 202 is responsible for processing signals with high real-time requirements, while the ARM processor 201 is responsible for processing functions with low real-time requirements but complex processes. The two work together to solve the problems of slow system response and single function.

[0078] In some embodiments, the power inverter unit 300 is used to obtain the duty cycle of the PWM signal output by the voltage control module 205 and generate the corresponding output power according to the duty cycle of the PWM signal.

[0079] In some embodiments, the high-voltage oil tank 400 acquires the output power from the power inverter unit 300 and updates the tube voltage of the X-ray tube based on this output power. In some embodiments, the voltage corresponding to the output power determined by the power inverter unit 300 based on the PWM duty cycle is 540V, and the high-voltage oil tank 400 outputs a 220KV DC voltage after boost rectification, so that the tube voltage of the X-ray tube is updated to 220KV at this time.

[0080] Please refer to Figure 17 In some embodiments, the CT high-voltage generator 100 also includes a filament control unit 500, a high-speed anode control unit 600, a temperature control unit 700, and a fly-focus control unit 800.

[0081] In some embodiments, the filament control unit 500 is used to acquire the filament current and activate the filament of the X-ray tube when it is necessary to start the X-ray tube. In some embodiments, the filament control unit 500 is connected to the CT high-voltage oil tank 400 in the CT high-voltage generator 100, and the filament current output by the filament control unit 500 is output to the X-ray tube through the LLC resonant circuit of the high-voltage oil tank 400 to start the X-ray tube.

[0082] In some embodiments, the high-speed anode control unit 600 is used to control the start-up, operation, and stop of the anode rotation of the X-ray tube. When the high-speed anode control unit 600 encounters problems such as overcurrent or overvoltage, it feeds back an error signal to the control unit 200 to shut down the entire CT high-voltage generator.

[0083] In some embodiments, the temperature control unit 700 is connected to the power inverter unit 300 and the high-pressure oil tank 400. The temperature control unit 700 includes two parts: dynamic heating and dynamic cooling, to ensure that the CT high-pressure generator operates at the most suitable temperature. During the operation of the temperature control unit 700, temperature configuration parameters and cooling operation status parameters are uploaded at regular intervals.

[0084] The FlyFocus Control Unit 800 is a high-precision digital power supply with a high-speed single-chip microcomputer, connected to the high-voltage oil tank 400, used to precisely control the focal voltage, thereby expanding the heat dissipation of the X-ray tube.

[0085] The above examples illustrate the present invention only to aid in understanding it and are not intended to limit the scope of the invention. Those skilled in the art can make various simple deductions, modifications, or substitutions based on the principles of this invention.

Claims

1. A CT high-voltage generator, characterized in that, include: Control unit, power inverter unit and high-pressure oil tank; The control unit includes an ARM processor, an FPGA, a digital-to-analog converter module, a high-speed analog switch module, and a voltage control module; The ARM processor is used to output a digital value of the first voltage; The input terminal of the digital-to-analog converter module is connected to the ARM processor and is used to convert the digital value of the first voltage into the analog value of the first voltage. The FPGA is used to output control signals; The high-speed analog switch module includes NAND gates U2A, U2B, U2C, and U2D, and a non-inverting amplifier. The input terminals of NAND gates U2A, U2B, U2C, and U2D are connected to the analog quantity of the first voltage, and the control terminals of NAND gates U2A, U2B, U2C, and U2D are connected to the control signal. The FPGA uses the control signal to control the switching of NAND gates U2A, U2B, U2C, and U2D to output a set number of analog quantities of the first voltage. The non-inverting amplifier acquires the set number of analog quantities of the first voltage and generates the reference operating voltage of the X-ray tube based on the set number of analog quantities of the first voltage. The voltage control module is used to output a PWM signal and adjust the duty cycle of the PWM signal according to the tube voltage of the X-ray tube and the reference operating voltage. The power inverter unit is used to obtain the duty cycle of the PWM signal and generate the corresponding output power according to the duty cycle of the PWM signal. The high-pressure oil tank acquires the output power and updates the tube voltage based on the output power.

2. The CT high-voltage generator as described in claim 1, characterized in that, The voltage control module includes a first amplifier module, a second amplifier module, a first comparator module, and a first control chip; the first control chip is an SG3525 control chip. The non-inverting input terminal of the first amplifier module receives the tube voltage of the X-ray tube, and the inverting input terminal of the second amplifier module receives the reference operating voltage of the X-ray tube. The output terminals of the first amplifier module and the second amplifier module are connected to the input terminal of the first comparator module to compare the tube voltage with the reference operating voltage. The output terminal of the first comparator module is connected to the non-inverting input terminal of the first control chip to adjust the duty cycle of the PWM signal based on the comparison result of the tube voltage and the reference operating voltage.

3. The CT high-voltage generator as described in claim 1, characterized in that, The control unit further includes a current warning module, which includes a second comparator module and a second control chip; the second control chip is a 74HC74 chip. The inverting input of the second comparator module receives a current limit, and the non-inverting input of the second comparator module receives the tube current of the X-ray tube; when the tube current exceeds the current limit, the second control chip outputs an error signal.

4. The CT high-voltage generator as described in claim 1, characterized in that, The control unit also includes a voltage warning module, which includes a third comparator module and a third control chip; the third control chip is a 74HC74 chip. The non-inverting input of the third comparator module receives a limiting voltage, and the inverting input of the third comparator module receives the tube voltage of the X-ray tube; when the tube voltage is greater than the limiting voltage, the third control chip outputs an error signal.

5. The CT high-voltage generator as described in claim 3 or 4, characterized in that, The control unit also includes a protection signal module, which includes an optocoupler isolated input circuit and a transistor output circuit. The input terminal of the optocoupler isolated input circuit acquires the error signal and converts the error signal into a low level output to the ARM processor; The input terminal of the transistor output circuit is connected to the ARM processor. The ARM processor converts the low level of the error signal to a high level and sends it to the transistor output circuit to shut down the CT high voltage generator.

6. The CT high-voltage generator as described in claim 1, characterized in that, The control unit also includes an analog voltage regulator module; The analog voltage regulator module includes a first buck module and a second buck module. The first buck module is used to step down the voltage to determine a first operating voltage, and the first operating voltage is used to power the second buck module. The second buck module is used to step down the first operating voltage to determine a second operating voltage, and the second operating voltage is used to power the ARM processor.

7. The CT high-voltage generator as described in claim 6, characterized in that, The control unit also includes a communication module, which includes a third control chip, namely MAX3232. The communication module is powered by the first operating voltage, and the communication between the ARM processor and the host computer is realized through the third control chip.

8. The CT high-voltage generator as described in claim 1, characterized in that, The control unit also includes a CAN communication module. The input of the CAN communication module is connected to the FPGA, and the output of the CAN communication module is connected to the ARM processor, so as to realize communication between the ARM processor and the FPGA.

9. The CT high-voltage generator as described in claim 1, characterized in that, The control unit further includes a wireless communication module, which includes a receiver and a transmitter. The receiver is connected to a host computer, and the transmitter is connected to the FPGA to realize wireless communication between the FPGA and the host computer.

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