Nanosecond pulse generator based on FPGA control and medical equipment

Abstract

The utility model discloses a nanosecond pulse generator based on FPGA control and medical equipment. The nanosecond pulse generator comprises a power supply system, a DC-DC module, a pulse forming system, an FPGA control system and a man-machine interaction system, the power supply system comprises a filtering isolation module and a program-controlled direct-current power supply; the pulse forming system comprises an energy storage capacitor and an LTD high-voltage circuit module; the output end of the FPGA control system controls the pulse forming module to respectively control charging of the energy storage capacitor and discharging of the LTD high-voltage circuit module through a photoelectric isolation circuit, and the input end of the FPGA control system is in communication connection with the program control direct-current power supply and the man-machine interaction system. The nanosecond pulse generator designed by the utility model can output nanosecond high-voltage pulses, and does not generate too high voltage at an equipment end.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the bio -electromagnetic technology field, concretely relates to nanosecond pulse generator and medical equipment based on field programmable gate array (FPGA) control. BACKGROUND

[0002] Electroporation refers to the phenomenon that cell membrane permeability changes and nanoscale small pores are generated under the action of high-voltage pulsed electric field. When the electric field intensity is increased to a certain intensity or the pulsed voltage is continuously applied, the electroporation formed cannot be restored, and this phenomenon is called irreversible electroporation (IRE). IRE tumor ablation technology is a treatment method for destroying tumors by inducing tumor cell apoptosis through electric pulses. Studies have shown that when a pulsed electric field with a rising edge of ns level, a pulse width of μs level and an amplitude of kV / cm acts on tumor cells, the tumor cells will undergo irreversible electroporation apoptosis.

[0003] In the research of IRE ablation equipment, the research of high-voltage pulse generator is one of the focuses, and the high-voltage pulse generator is used to emit the pulse parameters required by IRE. At present, there are two forms of high-voltage pulse generators required for IRE ablation. One is a capacitor discharge pulse generator, which mainly generates exponential decay pulses, and an air spark switch is commonly used. The other is a square wave pulse generator, which generates square wave pulses, and high-voltage pulse generators composed of Blumlein transmission line, MOSFET, IGBT, etc. are commonly used.

[0004] The existing high-voltage pulse generator, such as the "full solid-state high-voltage nanosecond square wave pulse generator based on FPGA control" with the application number 201110195350.4, discloses a nanosecond square wave pulse generator based on FPGA control. Based on the principle of Marx generator, a group of capacitors are connected in parallel for charging, and then the initial pulse generated by discharging the capacitors in series through solid-state switching devices is chopped to obtain the required high-voltage nanosecond square wave pulse. The FPGA control system realizes human-computer communication through a portable computer, sends high-voltage DC module and Marx circuit control signals, receives measurement signals obtained by the pulse measurement system, controls the operation of the entire generator and handles burst accidents, and plays a role in overall control of the system. The main disadvantage of this system is that in the steep pulse circuit, the FPGA chip is directly connected with the photoelectric transducer, and due to the influence of electric field inductance, the photoelectric signal is unstable. Moreover, the Marx circuit is used, and since each stage of the Marx circuit is at a different potential and the voltage of the later stage is very high, the circuit is complex and requires the use of expensive isolation transformers, which poses a certain safety hazard for medical use. In addition, since all the switches and capacitors of the Marx circuit are connected in series, the output impedance is high, which limits the output current. SUMMARY

[0005] The utility model provides a nanosecond pulse generator and medical equipment based on FPGA control, aims at solving the problems of unstable photoelectric signal and complex Marx circuit, high output impedance and the like of the traditional FPGA pulse generation circuit.

[0006] The principle of the utility model is as follows: based on the principle of solid-state linear transformer driver (LTD), the operator sets the output pulse amplitude, pulse width, pulse frequency and pulse number through the man-machine interaction system, and after being processed by the single-chip microcomputer module and FPGA operation module of the FPGA control system, the electric signal is converted into an optical signal through the photoelectric isolation circuit and transmitted to the power supply system and the pulse forming system. The power supply system automatically converts the voltage of the program-controlled DC power supply according to the pulse amplitude set by the man-machine interaction system to charge the energy storage capacitor. After the charging is completed, the charging circuit is cut off through the FPGA control program, the pulse forming system is connected, and the energy storage capacitor releases the boosted voltage to the load through the magnetic core coupling discharge in the LTD high-voltage circuit module. MOSFET switch 1 and MOSFET switch 2 switch according to the pulse width, pulse frequency and pulse number set by the man-machine interaction system to control the output pulse width, pulse frequency and pulse number.

[0007] The utility model solves the technical problem, adopts the technical scheme:

[0008] The utility model provides a kind of nanosecond pulse generator and medical equipment based on FPGA control, including power supply system, pulse forming system, FPGA control system and man-machine interactive system;Power supply system includes filter isolation module and program-controlled DC power supply, pulse forming system includes energy storage capacitor and LTD high voltage circuit module, the output end of FPGA control system controls pulse forming module, and energy storage capacitor charging and LTD high voltage circuit module discharge are controlled respectively by photoelectric isolation circuit, and the input end of FPGA control system is connected with program-controlled DC power supply and man-machine interactive system communication.

[0009] Power supply system includes power supply, filter isolation module, power switch and program-controlled DC power supply.Power supply is 110~220V network power supply on sale, is connected with filter isolation module by wire, is used to filter EMI electromagnetic interference signal that network power supply transmits into and prevents the EMI signal that nanosecond pulse generator generates from entering network, to ensure the safety of nanosecond pulse generator and power supply environment.Filter isolation module can effectively protect equipment from various electrical noise and interference in network, improve the performance and reliability of equipment, while also can isolate the pulse electric field generated by equipment, prevent pulse electric field from interfering or destroying other network power supply line equipment.Program-controlled DC power supply converts 100~220V alternating current into direct current, is connected with energy storage circuit by circuit, and charges energy storage capacitor.Meanwhile program-controlled DC power supply provides 5V, 6V, 7V, 8V, 9V or 10V direct current voltage for power enhancement circuit.Power supply system provides safe and stable power supply for pulse forming system, FPGA control system and man-machine interactive system, guarantees the normal operation of entire equipment.

[0010] Pulse forming system includes energy storage capacitor and LTD high voltage circuit module, and direct current power supply is used to charge energy storage capacitor, and the closure of charging circuit is realized by the conduction of MOSFET switch 1.Then MOSFET switch 2 in LTD high voltage circuit module is turned on (MOSFET switch 1 is disconnected), and the voltage in energy storage capacitor is discharged and boosted by magnetic core coupling discharge, and the turns ratio of primary coil and secondary coil in magnetic core coupling can be 1:1, 1:2, 1:3, 1:4 or 1:5.In order to obtain higher voltage of pulse amplitude, LTD high voltage circuit module can be composed of multiple groups of LTD circuit.

[0011] Further photoelectric isolation circuit includes photoelectric coupling unit, the input end of photoelectric coupling unit is connected with FPGA control system, the output end of photoelectric coupling unit is connected with pulse forming system, and photoelectric coupling unit is used for unidirectional transmission of switch control signal to pulse forming system by photoelectric conversion.

[0012] The further nanosecond pulse is realized by the FPGA control system through photoelectric isolation circuit to control the first MOSFET switch to be turned on, and the program-controlled direct current power supply charges the energy storage capacitor, and the second MOSFET switch is controlled to be turned on to realize the discharge of the LTD high-voltage circuit module, and then a pulse voltage is output.

[0013] The FPGA control system comprises a synchronous trigger module and a single-chip microcomputer module, the FPGA is connected with the input end of the synchronous trigger module, the output end of the synchronous trigger module is connected with a photoelectric isolation module, the photoelectric signal conversion of the photoelectric isolation module is connected with the control end of the LTD high-voltage circuit module in the pulse forming system, and the synchronous pulse signal sent by the synchronous trigger module to the MOSFET switch is converted into an optical signal for transmission. The main function of the FPGA control system is to convert the setting parameters of the man-machine interaction system into circuit system operation parameters, to control the work of each component in the control circuit, to realize the output of the set pulse voltage, pulse width, pulse frequency and pulse number.

[0014] The nanosecond pulse generator can output a pulse amplitude of 0-50kv, a pulse width of 200-600ns, a pulse frequency of 1-2000Hz, a falling edge of 20-60ns and a pulse number of 1-1000, and the specific parameters can be set on the man-machine interaction system according to actual requirements.

[0015] The man-machine interaction system is a conventional computer, a tablet computer, a microcomputer or other electronic equipment, is connected with the single-chip microcomputer module of the FPGA control system through a serial cable or Bluetooth, and the operator sets required parameters through the user interface of the control program, sends a command to the FPGA control system, and thus realizes man-machine interaction communication.

[0016] On the other hand, the utility model also provides a kind of medical equipment, including ablation electrode needle, it is characterized in that, still bag nanosecond pulse generator of above, the ablation electrode needle is connected with the pulse generator, to release nanosecond pulse signal.

[0017] The beneficial effects of the technical solutions of the utility model include, for example: the utility model uses FPGA as control system, can accurately control pulse parameter and program-controlled direct current power supply. The utility model uses LTD high-voltage circuit module to carry out voltage step-up, compared with the Max circuit of conventional use, simple design, does not need to use expensive and complex electrical components and is safer. The utility model is equipped with power enhancement circuit in the periphery of FPGA control system, can ensure that the instruction of FPGA control system is timely and accurate and ensures that synchronization is transmitted to pulse forming system, avoids that each switch in parallel circuit will produce delay difference. BRIEF DESCRIPTION OF DRAWINGS

[0018] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the principle of this utility model;

[0020] Figure 2 This is a schematic diagram of an FPGA control pulse circuit.

[0021] Figure 3 This is the LTD circuit topology diagram for the pulse forming system;

[0022] Figure 4 This is a circuit diagram for photoelectric signal conversion;

[0023] Figure 5 For fiber optic board input circuit;

[0024] Figure 6 This is a circuit diagram for a DC-DC converter. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0026] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0027] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0028] In the description of this utility model, it should be noted that if terms such as "upper," "lower," "inner," or "outer" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the utility model product is usually placed during use, they are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0029] Furthermore, the terms "first" and "second" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0030] It should be noted that, where there is no conflict, the features in the embodiments of this utility model can be combined with each other.

[0031] Example 1

[0032] like Figures 1-6 As shown, a nanosecond pulse generator and medical device based on FPGA control mainly consists of a power supply system, a DC-DC module, a pulse forming system, and an FPGA control system.

[0033] The power system includes a filter isolation module and a programmable DC power supply. The filter isolation module is... EMI filter (Commercially available components); The programmable DC power supply can be selected from 500V to 5000V DC power as needed, for charging the energy storage capacitor.

[0034] The LTD high-voltage circuit module consists of n cascaded LTD circuits, such as... Figure 4 As shown, the charging terminals C1, C2, C3...C in each LTD circuit are... n By using a parallel connection and then connecting the superimposed voltage in series at the load end, the advantages of this setup are that each LTD charging circuit does not need to withstand excessively high voltages, which helps extend the lifespan and safety of circuit components. The load end directly outputs the voltage, without any electrical components. Another advantage is that this setup keeps the overall voltage and current of the device relatively low, improving both safety and reliability for medical devices.

[0035] like Figure 3 As shown, the timing signals generated by the FPGA control switches Q0 and Q1-Q N The switching on and off of the circuit can be achieved using a MOSFET switch. When only a MOSFET switch is used, the Q0 switch is equivalent to... Figure 2 The first MOSFET switch in the circuit, Q1-Q N The switch is equivalent to a second MOSFET switch. When the LTD circuit needs to be charged, switch Q0 is turned on, and Q1-Q... NWhen the switch is off, DC power is supplied to capacitors C1-C. N Charging; when discharging, Q1-Q N When the switch is on, Q0 is off, and diodes D0 and D1-D... N The discharge of the control capacitor is transmitted to the load through the primary coil and then through electromagnetic coupling isolation. N electromagnetic couplers are connected in series at the load end, and the voltage is superimposed to 10kV-50kV.

[0036] The FPGA chip requires a drive voltage of 3.3V. To obtain a stable 3.3V voltage, this application employs a DC-DC converter circuit. Specifically, as follows... Figure 6 As shown, the AMS1117 has an input bypass capacitor C16 of 10uF / 50V, an output capacitor C12 of 10uF / 50V, a resistor R11 of 3000 ohms, and an avalanche diode D20 to prevent reverse power connection. The AMS1117's OUT terminal can output a stable 3.3V voltage.

[0037] This application converts the timing signals of the FPGA into optical signals through an opto-isolation module, which can transmit high-frequency timing signals with maximum fidelity and avoid interference from electrical signals by using optical signal transmission.

[0038] Example 2

[0039] like Figures 1-6 As shown, a nanosecond pulse generator and medical device based on FPGA control mainly consists of a power supply system, a DC-DC module, a pulse forming system, an FPGA control system, and a human-computer interaction system.

[0040] The human-machine interface system (HMI) is connected to the FPGA control system via RS-485 communication. The HMI can be a tablet or a microcomputer. The set pulse parameters can be input into the FPGA system through the HMI for controlling and adjusting the pulse output.

[0041] The power system includes a filter isolation module and a programmable DC power supply. The filter isolation module is... EMI filter (Commercially available components); The programmable DC power supply can be selected from 500V to 5000V DC power as needed, for charging the energy storage capacitor.

[0042] The LTD high-voltage circuit module consists of n cascaded LTD circuits, such as... Figure 4 As shown, the charging terminals C1, C2, C3...C in each LTD circuit are... nBy using a parallel connection and then connecting the superimposed voltage in series at the load end, the advantages of this setup are that each LTD charging circuit does not need to withstand excessively high voltages, which helps extend the lifespan and safety of circuit components. The load end directly outputs the voltage, without any electrical components. Another advantage is that this setup keeps the overall voltage and current of the device relatively low, improving both safety and reliability for medical devices.

[0043] like Figure 3 As shown, the timing signals generated by the FPGA control switches Q0 and Q1-Q N The switching on and off of the circuit can be achieved using a MOSFET switch. When a MOSFET switch is selected, the Q0 switch is equivalent to... Figure 2 The first MOSFET switch in the circuit, Q1-Q N The switch is equivalent to a second MOSFET switch. When the LTD circuit needs to be charged, switch Q0 is turned on, and Q1-Q... N When the switch is off, DC power is supplied to capacitors C1-C. N Charging; when discharging, Q1-Q N When the switch is on, Q0 is off, and diodes D0 and D1-D... N The discharge of the control capacitor is transmitted to the load through the primary coil and then through electromagnetic coupling isolation. N electromagnetic couplers are connected in series at the load end, and the voltage is superimposed to 10kV-50kV.

[0044] The FPGA chip requires a drive voltage of 3.3V. To obtain a stable 3.3V voltage, this application employs a DC-DC converter circuit. Specifically, as follows... Figure 6 As shown, the AMS1117 has an input bypass capacitor C16 of 10uF / 50V, an output capacitor C12 of 10uF / 50V, a resistor R11 of 3000 ohms, and an avalanche diode D20 to prevent reverse power connection. The AMS1117's OUT terminal can output a stable 3.3V voltage.

[0045] This application converts the timing signals of the FPGA into optical signals through an opto-isolation module, which can transmit high-frequency timing signals with maximum fidelity and avoid interference from electrical signals by using optical signal transmission.

[0046] Furthermore, since the FPGA chip's power supply voltage is 3.3V, and the photoelectric conversion circuit using 3.3V has slightly weaker driving force, this application adopts the following design: the timing signal generated by the FPGA is amplified by a 5V power amplifier, then converted into an optical signal by an invisible fiber optic transmitter HFBR-1412, transmitted to the driving circuit, converted back into an electrical signal, amplified, and then drives the power circuit to operate. The specific implementation scheme is as follows... Figure 4 and Figure 5As shown, in some implementations, the timing signals generated by the FPGA are input to the 74HC14 chip via G15 (1A) and J15 (2A). A 5V voltage is input to the VCC terminal of the 74HC14. The 1Y pin of the 74HC14 is connected to pin 2 of the fiber optic board, and the 2Y pin of the 74HC14 is connected to pin 3 of the fiber optic board. When the FPGA chip controls the LTD circuit to charge, the FPGA outputs a high-level signal (3.3V voltage) input to G15 (1A) of the 74HC14. After conversion by the internal circuitry of the 74HC14, a 5V voltage is output to the fiber optic board 2 via the 1Y pin, generating a charging signal. When the FPGA chip controls the LTD circuit to discharge, the FPGA outputs a high-level signal (3.3V voltage) input to J15 (2A) of the 74HC14. After conversion by the internal circuitry of the 74HC14, a 5V voltage is output to the fiber optic board 3 via the 2Y pin, generating a discharging signal.

[0047] Example 3

[0048] A medical device employing the nanosecond pulse generator and medical device of Embodiment 1 or Embodiment 2, wherein the load is an ablation electrode needle.

[0049] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the protection scope of the claims.

Claims

1. A nanosecond pulse generator based on FPGA control, characterized in that The nanosecond pulse generator comprises a power supply system, a DC-DC module, a pulse forming system, an FPGA control system and a man-machine interaction system; the power supply system comprises a filter isolation module and a program-controlled direct current power supply; the pulse forming system comprises an energy storage capacitor and an LTD high-voltage circuit module; the output end of the FPGA control system controls the pulse forming module by controlling the charging of the energy storage capacitor and the discharging of the LTD high-voltage circuit module through an optoelectronic isolation circuit, and the input end of the FPGA control system is in communication connection with the program-controlled direct current power supply and the man-machine interaction system.

2. The nanosecond pulser of claim 1, wherein, The filter isolation module is arranged at a network power supply interface and is used for filtering EMI electromagnetic interference signals transmitted by a network power supply and preventing EMI signals generated by the nanosecond pulse generator from entering the network power supply, so as to ensure the safety of the nanosecond pulse generator and the power supply environment.

3. The nanosecond pulser of claim 1, wherein, The nanosecond pulse is realized by controlling the first MOSFET switch to be turned on through the optoelectronic isolation circuit of the FPGA control system, so that the program-controlled direct current power supply charges the energy storage capacitor, and the second MOSFET switch is controlled to be turned on, so that the LTD high-voltage circuit module discharges, and then a pulse voltage is output.

4. The nanosecond pulser of claim 1, wherein, The LTD high-voltage circuit module is realized by magnetic core coupling discharge voltage boosting.

5. The nanosecond pulser of claim 1, wherein, The LTD high-voltage circuit module can be composed of multiple groups of LTD circuits.

6. A medical device comprising an ablation electrode needle, characterized in that The nanosecond pulse generator also comprises an ablation electrode needle connected with the pulse generator, so as to release the nanosecond pulse signal.

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