A synchronous bipolar pulsed electric field tissue ablation device

Abstract

The present invention provides a synchronous bipolar pulse electric field tissue ablation device, comprising a control module, a charging module, a high-voltage pulse forming module, and a transmission line, wherein the charging module is composed of a main board and a transformer, and the transformer in the charging module suspends and charges the high-voltage capacitor in the high-voltage pulse forming module, and after charging, the ground potentials at both ends of the high-voltage capacitor are opposite in polarity and equal in amplitude, and the two ends of the high-voltage capacitor are respectively connected to the inner conductors at the input ends of the two transmission lines through an integrated twin multi-gap spark switch, and the twin multi-gap spark switch can be automatically and synchronously turned on to form bipolar high-voltage pulses with equal amplitude and opposite polarity at both ends of the load through the transmission line. The present invention also provides an operation The method of using a bipolar pulse generating device to ablate tissue can be widely used in minimally invasive treatment of various tumors and lesion tissues in the human body. Compared with the existing technology, its advantage in specific implementation is that the proposed charging method with the reverse reset function of energy recovery can greatly improve the working range of the transformer hysteresis loop, improve the transformer pulse energy transmission capacity and efficiency, and facilitate the miniaturization of the transformer; the unique pulse forming circuit can make the twin multi-gap spark switch automatically synchronized without the need for additional synchronization circuits or devices, output synchronous bipolar high-voltage pulses, reduce the equipment insulation requirements to the ground, realize the integrated integration of the device, and facilitate clinical practical application.

Description

Technical Field

[0001] The present invention relates to the field of electromagnetic field tumor treatment in medical devices, and particularly to high-voltage pulsed electric field tumor tissue ablation and cell processing. Background Art

[0002] Malignant tumors seriously endanger human life and health. In recent years, the ablation therapy based on irreversible electroporation is a new type of non-thermal ablation technology. This technology uses high-voltage pulsed electric fields to damage cell membranes, causing irreversible perforations, disrupting cell homeostasis, and ultimately leading to cell death. Compared with thermal ablation technology, its ablation boundary is clear, and it can effectively avoid damaging important structures such as blood vessels, bile ducts, and nerves, enabling more tumor patients to obtain treatment opportunities and achieving remarkable clinical effects.

[0003] Research has found that nanosecond pulsed electric fields also have an impact on cell viability. When the nanosecond pulsed electric field acting on cells is strong enough, it can stimulate the release of calcium ions from intracellular calcium stores, cause cell membrane swelling and vesiculation, and damage the cytoskeleton such as actin, resulting in cell apoptosis or death. Compared with microsecond pulsed electric fields, nanosecond pulsed electric fields can rapidly ablate tumors with less energy and significantly reduce side effects such as muscle tremors. However, the field strength threshold required for nanosecond pulsed ablation is relatively high (8 - 10 kV / cm), and the insulation strength requirement is high, which is not conducive to the stability and miniaturization of the device. In response to this, it has been proposed to use synchronous bipolar nanosecond pulses without changing the field strength between the electrode needles to reduce the insulation requirements and ensure the reliability of the device. The generation of synchronous bipolar pulses can be based on a single high-voltage switch or a dual switch. The pulse symmetry of the dual switch is better. The main problem is how to achieve the synchronization of positive and negative pulses in the nanosecond range, usually requiring an external synchronization circuit or other synchronization components such as cables and magnetic rings, resulting in a complex and large-sized device with poor reliability. Summary of the Invention

[0004] In view of the above technical deficiencies existing in pulsed ablation, the present invention creatively proposes a synchronous bipolar pulsed electric field tissue ablation device, including a control module, a charging module, a high-voltage pulse formation module, and a transmission line, wherein the charging module is composed of a main board and a transformer.

[0005] Capacitor A 48 on the main board of the charging module is connected in series with switch A49 and then connected in parallel with the primary side of pulse transformer 5 to form an energy recovery and reset circuit, which improves the energy transferred by the transformer in a single pulse and is conducive to the miniaturization of the transformer;

[0006] The switch in the high-voltage pulse forming module is an integrated twin multi-gap spark switch, which is integrated by multiple electrode plates with the same structure. Each electrode plate includes an insulating plate 18 and two metal electrodes 19. The two metal electrodes 19 are embedded in two corresponding holes of the insulating plate 18, and a creepage groove is arranged between the two metal electrodes 19. Two groups of multiple equally spaced parallel metal electrodes respectively form the corresponding twin multi-gap spark switch B 77 and spark switch C 78. The working gas medium of the integrated twin multi-gap spark switch is air, nitrogen or hydrogen, and it works in a closed or open cavity, in a blowing or non-blowing state, at atmospheric pressure, high pressure or low pressure;

[0007] In the high-voltage pulse forming module, diode A 73 and diode B 75 are used for floating charging of high-voltage capacitor B 74 by the secondary side of transformer 5; both ends of high-voltage capacitor B 74 are respectively connected to the inner conductors of the input ends of transmission line A 91 and transmission line B 92 through switch B 77 and switch C 78; the outer conductors of the input ends of transmission line A 91 and transmission line B 92 are connected in parallel to the ground;

[0008] The inner conductors of the output ends of transmission line A 91 and transmission line B 92 are connected to both ends of the load, and the outer conductors of the output ends of transmission line A 91 and transmission line B 92 are connected together;

[0009] The control module outputs a continuous pulse control signal or an intermittent pulse control signal through an external trigger or internal setting by the control chip.

[0010] The switch in the high-voltage pulse forming module is an integrated twin spark gap switch, semiconductor switch, thyratron switch or magnetic switch.

[0011] Capacitor B 74 in the high-voltage pulse forming module is a high-voltage ceramic capacitor, artificial transmission line, transmission line or Blumlein line.

[0012] The power supply 40 on the main board included in the charging module is a DC power supply, AC power supply or battery;

[0013] Switches D 42, E 47, and A 49 on the main board in the charging module are IGBTs, MOSFETs or thyratrons.

[0014] The transmission line is composed of a single or multiple transmission lines connected in series and parallel.

[0015] The charging module is composed of a main board and a transformer, or is composed of a DC charging, AC charging, or charging circuit based on a full-bridge inverter.

[0016] The load is biological tissue, tumor, cell or microorganism.

[0017] The present invention creatively proposes a synchronous bipolar pulsed electric field tissue ablation device, and its advantages are as follows: An innovative charging module with an energy recovery and reset circuit is designed to improve the energy and efficiency of single-pulse transfer of the transformer, which is beneficial to the miniaturization of the transformer; The integrated structure innovation design of the twin multi-gap spark switch and the unique pulse formation circuit can achieve the automatic synchronization of two groups of switches without additional circuits or devices, and output synchronous bipolar nanosecond high-voltage steep pulses on the load, reducing the insulation requirement of the transmission line by half and greatly improving the reliability of the device; In addition, the transformer performs floating charging on the high-voltage capacitor with opposite charging voltage polarities and equal amplitudes, also reducing the insulation requirement of the transformer and the line by half, thus realizing the overall integration and miniaturization of the device. When used for tissue ablation, the ablation electrodes with opposite potential polarities can act synergistically. On the premise of ensuring the ablation range, the ground voltage of the ablation electrodes is reduced by half, greatly reducing the insulation requirement of the insulation layer of the electrode needles, reducing the manufacturing difficulty of the ablation electrode needles. This pulse generator uses high-frequency and high-efficiency fast charging. Through the setting of the control module, the twin multi-gap spark switch can achieve high-frequency intermittent operation greater than 500Hz without blowing air. During the actual ablation process, a smaller amount of energy can achieve a larger ablation range, and multiple nanosecond steep pulses can be output within the cardiac refractory period. Description of the Drawings

[0018] Figure 1 Schematic diagram of the structure of the integrated bipolar pulse generator.

[0019] Figure 2 Circuit schematic diagram of the bipolar pulse generator.

[0020] Figure 3 Typical output pulse waveform diagram of the bipolar pulse device.

[0021] Figure 4 Schematic diagram of the structure of the integrated twin multi-gap spark switch.

[0022] Figure 5 Example of using the bipolar pulse generator to drive parallel electrodes to ablate liver tissue.

[0023] Figure 6 Example of using the bipolar pulse generator to drive coaxial electrodes to ablate liver tissue.

[0024] Figure 7 Typical schematic diagram of the intermittent pulse control signal output by the control module.

[0025] In the figure: 1. Pulse generating device; 2. Touch control screen; 3. Control module; 4. Main board; 5. Pulse transformer; 6. Isolation transformer; 7. High-voltage pulse forming module; 8. BNC connector; 91. Transmission line A; 92. Transmission line B; 10. Load; 11. Grounding; 12. Electrode plate A; 13. Electrode plate B; 14. Electrode plate C; 15. Electrode plate D; 16. Electrode plate E; 17. Trigger electrode; 18. Insulating plate; 19. Metal electrode; 20. Ablation electrode needle A; 21. Ablation electrode needle B; 22. Tissue; 23. Coaxial ablation electrode needle C; 24. Coaxial ablation electrode needle D; 25. Pulse control signal; 40. Power supply; 41. Capacitor C; 42. Switch D; 43. Inductor; 44. Diode C; 45. Capacitor D; 46. Diode D; 47. Switch E; 48. Capacitor A; 49. Switch A; 71. Resistor A; 72. Diode E; 73. Diode A; 74. High-voltage capacitor B; 75. Diode B; 76. Resistor B; 77. Switch B; 78. Switch C. Detailed implementation mode

[0026] In order to describe the present invention more specifically, the technical solutions of the present invention will be described in detail below with reference to the accompanying drawings and specific implementation modes.

[0027] Embodiment 1

[0028] As Figure 1 Shown on the left, the pulse generating device 1 is an integrated structure and can be placed on a desktop or a conventional medical operation cart in a hospital. The front panel of the pulse generating device 1 has a touch control screen 2 for controlling pulse output. The shell of the pulse generating device 1 is made of metal and grounded. Inside, as shown on the right, it includes a control module 3, a main board 4, a transformer 5, an isolation transformer 6, and a high-voltage pulse forming module 7. The high-voltage pulse forming module 7 generates synchronous positive and negative polarity high-voltage pulses, which are transmitted to the load through two transmission lines connected to the BNC connector 8. Specifically, the isolation transformer 6 isolates the control module 3 from other circuits, plays a shielding and protection role, and reduces electromagnetic interference; the control module 3 provides the control signals required by the main board 4 and the medical staff interaction interface for surgical treatment planning and implementing surgery.

[0029] Embodiment 2

[0030] The circuit schematic diagram of the bipolar steep pulse generating device is as Figure 2As shown, it includes a main board 4, a transformer 5, a high-voltage pulse forming module 7, a transmission line A 91, a transmission line 92, and a load 10. Specifically, the main board includes a power supply 40, a capacitor C 41, a switch D 42, an inductor 43, a diode C 44, a capacitor D 45, a diode D 46, a switch E 47, a capacitor A 48, and a switch A 49; the power supply 40 charges the capacitor C 41, and the power supply 40 can be an AC power supply, a DC power supply or a battery, etc.; the capacitor C 41 charges the capacitor D 45 through the switch D 42, the inductor 43, and the diode C 44, and the diode D 46 is connected in parallel with the capacitor D 45 to prevent the voltage polarity on the capacitor D 45 from being reversed; the capacitor A 48 reversely resets the magnetic core of the transformer 5 through the primary side of the transformer 5 through the switch A 49, thereby increasing the pulse energy transmitted by the pulse transformer 5 and avoiding saturation of the magnetic core of the pulse transformer 5; the capacitor D 45 charges the high-voltage pulse forming module 7 through the switch E 47 and the pulse transformer 5.

[0031] The high-voltage pulse forming module 7 includes a resistor A 71, a diode E 72, a diode A 73, a high-voltage capacitor B 74, a diode B 75, a resistor B 76, a switch B 77, and a switch C 78; the resistor A 71 is connected in series with the diode E 72 and connected in parallel with the secondary side of the transformer 5; the secondary side of the transformer 5 charges the high-voltage capacitor B 74 in a suspended manner through the diode A 73 and the diode B 75; the resistor B 76 is connected in parallel with the high-voltage capacitor B 74; the two ends of the high-voltage capacitor B 74 are connected to the inner conductors of the input ends of the transmission line A 91 and the transmission line B 92 through the switch B 77 and the switch C 78 respectively; the outer conductors of the input ends of the transmission line A 91 and the transmission line B 92 are connected to the metal chassis and grounded 11; the inner conductors of the output ends of the transmission line A 91 and the transmission line B 92 are connected to the two ends of the load 10 respectively, and the outer conductors of the output ends of the transmission line A 91 and the transmission line B 92 are connected together.

[0032] Specifically, when switch B 77 and switch C 78 are spark gap switches, after any one switch is triggered, the other switch automatically breaks down due to overvoltage. After the two switches are synchronized, high-voltage capacitor B 74 starts to discharge, and forms positive and negative polarity high-voltage pulses on transmission line A 91 and transmission line B 92, respectively, which are transmitted to load 10 through the transmission line. The typical voltage waveform of both ends of load 10 to ground is as follows: Figure 3 As shown, +15 kV and -15 kV ground potentials can be obtained respectively, the pulse peak voltage across the load is 30 kV, and the pulse rising edge is about 10 ns.

[0033] Example 3

[0034] Schematic diagram of integrated twin multi-gap spark switch Figure 4As shown, when there are 4 switch gaps, it includes electrode plates A 12, B 13, C 14, D 15, and E 16 with the same structure. Among them, the middle electrode plate C 14 is equipped with a trigger electrode 17. Specifically, taking the electrode plate E 16 as an example, it includes an insulating plate 18 and two metal electrodes 19. The two metal electrodes 19 are embedded in two corresponding holes of the insulating plate 18, and a creepage groove is arranged between the two metal electrodes 19. After the electrode plates A 12, B 13, C 14, D 15, and E 16 are arranged in parallel combination as shown in the figure, two groups of parallel 5 parallel metal electrodes respectively form corresponding multi-gap spark switches B 77 and C 78.

[0035] Example 4

[0036] Specifically, Figure 5 A method for driving parallel electrode needles to ablate tissue using a bipolar pulse generating device is provided. The input ends of transmission line A 91 and transmission line B 92 are connected to the BNC connector 8 of the bipolar steep pulse generating device 1. The input ends of transmission line A 91 and transmission line B 92 are respectively connected to ablation electrode needle A 20 and ablation electrode needle B 21. The ablation electrode needle A 20 and ablation electrode needle B 21 are inserted into the target tissue 22, such as liver tissue, in parallel. According to the surgical plan, the high-voltage pulse signal is controlled to be transmitted into the tissue 22 through the touch control screen 2.

[0037] Example 5

[0038] Specifically, Figure 6 A method for driving coaxial electrode needles to ablate tissue using a bipolar steep pulse generating device is provided. The input ends of transmission line A 91 and transmission line B 92 are connected to the BNC connector 8 of the bipolar steep pulse generating device 1. The input ends of transmission line 91 and transmission line B 92 are respectively connected to coaxial ablation electrode needle C 23 and coaxial ablation electrode needle D 24. The coaxial ablation electrode needle C 23 and coaxial ablation electrode needle D 24 are inserted into the target tissue 22, such as liver tissue, as needed. According to the surgical plan, the high-voltage pulse signal is controlled to be transmitted into the tissue 22 through the touch control screen 2.

[0039] Example 6

[0040] Specifically, Figure 7A typical schematic diagram for providing an intermittent pulse control signal 25 output by a control module is shown. In the figure, the frequency of the pulse control signal is 100 Hz, the intermittent working time is 0.1 s, the number of pulses within 0.1 s is 10, and the cycle period is 1 s. If the frequency of the pulse control signal is set to 500 Hz, then the number of pulses within 0.1 s is 50; if the intermittent working time is set to 0.2 s, then 100 pulse control signals are issued within one cycle period. The frequency, intermittent working time, and cycle period of the pulse control signal are all adjustable. If the pulse output is triggered by an electrocardiogram signal, dozens of high-voltage steep pulses can be selected to be output within the 100 ms electrocardiogram refractory period.

[0041] The specific embodiments described above further elaborate on the purpose, technical solutions, and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not used to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A synchronous bipolar pulse electric field tissue ablation device, comprising a control module, a charging module, a high-voltage pulse forming module, and a transmission line. The charging module consists of a main board and a transformer. It is characterized in that: The capacitor A (48) on the main board in the charging module is connected in series with the switch A (49) and then connected in parallel with the primary side of the transformer (5) to form an energy recovery reverse reset circuit, which improves the transformer pulse energy transfer ability and efficiency and is conducive to the miniaturization of the transformer; The switch in the high-voltage pulse forming module is an integrated twin multi-gap spark switch; The integrated twin multi-gap spark switch is integrated by multiple electrode plates with the same structure. Each electrode plate includes an insulating plate (18) and two metal electrodes (19). The two metal electrodes (19) are embedded in two corresponding holes of the insulating plate (18). A creepage groove is arranged between the two metal electrodes (19). Two groups of parallel multiple equally spaced metal electrodes respectively form the corresponding twin multi-gap spark switch B (77) and spark switch C (78); The working gas medium of the integrated twin multi-gap spark switch is air, nitrogen or hydrogen, which is placed in a closed or open cavity and works in a blowing or non-blowing state, and works at atmospheric pressure, high pressure or low pressure; In the high-voltage pulse forming module, the diode A (73) and the diode B (75) are used for the floating charging of the high-voltage capacitor B (74) by the secondary side of the transformer (5); both ends of the high-voltage capacitor B (74) are respectively connected to the inner conductors of the input ends of the transmission line A (91) and the transmission line B (92) through the spark switch B (77) and the spark switch C (78); the outer conductors of the input ends of the transmission line A (91) and the transmission line B (92) are connected in parallel to the ground; The inner conductors of the output ends of the transmission line A (91) and the transmission line B (92) are connected to both ends of the load, and the outer conductors of the output ends of the transmission line A (91) and the transmission line B (92) are connected together; The power supply (40) on the main board in the charging module is an AC power supply, a DC power supply or a battery; The switch D (42), switch E (47), and switch A (49) on the main board in the charging module are IGBTs, MOSFETs or thyratrons; The control module outputs a continuous pulse control signal or an intermittent pulse control signal through the control chip by external triggering or internal setting.

2. The synchronous bipolar pulsed electric field tissue ablation device according to claim 1, wherein The load is biological tissue or microorganisms.

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