A shock wave pulse generating device

Abstract

The present invention discloses a shock wave pulse generating device, comprising a microprocessor, a first power supply, a second power supply, a third power supply, a shock wave generator, a first energy storage device and a second energy storage device, as well as a gas discharge tube switch and a low-voltage electronic switch, wherein the microprocessor is used to control the first power supply to charge the first energy storage device and the second power supply to charge the second energy storage device in a first time period and a second time period; in the second time period, the third power supply is controlled to act on both ends of the electrodes of the shock wave generator to activate the fluid between the electrodes; in the third time period, the low-voltage electronic switch is triggered to close, and the gas discharge tube switch is turned on under the action of the second energy storage device, so that the first energy storage device acts on both ends of the electrodes of the shock wave generator to generate shock waves. The present invention uses a gas discharge tube triggering method to generate shock waves, which can reduce costs, reduce the size of the device, and is simple to control.

Description

Technical Field

[0001] The present application belongs to the technical field of medical devices, and in particular, relates to a shock wave pulse generating device. Background Art

[0002] Electrohydraulic lithotripsy has been widely used in the treatment of calcified deposits in the urethra and bile duct, and has also been gradually applied to the treatment of calcified lithotripsy in coronary and peripheral blood vessels in recent years. When driven by a high-voltage pulse, an arc is formed between the metal electrodes in the saline solution, which instantly ionizes the saline solution to produce plasma and gas, and also generates a shock wave. The calcification inside the blood vessel absorbs the shock wave and causes the calcification to break into tiny pieces.

[0003] The electrohydraulic lithotripsy device usually includes a shock wave generator in the form of a pair of electrodes, an energy storage device and a pulse generator. The energy storage device usually uses a high-voltage capacitor, and the pulse generator usually uses a high-voltage electronic switching device (IGBT). High-voltage electronic switching devices are used to generate narrow voltage pulses from nS to uS levels. To achieve a certain shock wave pulse energy, a higher voltage is often required. Generally, it is above 3kV to have a better shock wave pulse treatment effect, and the pulse instantaneous current is at least one hundred amperes. Therefore, it is required to use an electronic switching device with a withstand voltage of at least 3kV and a high current of several hundred amperes. However, the single-tube electronic switching device that meets this use condition is very expensive and has a large size. At present, there are multiple electronic switches in parallel and series to cope with high withstand voltage and high current applications. The cost and volume of such solutions are still not advantageous, and the control is more complicated.

[0004] In addition, the energy of each high-voltage pulse is stored in advance on a high-voltage capacitor. Part of the energy stored in the high-voltage capacitor is consumed before the spark discharge, and part of the energy is retained in the capacitor. Only about 1 / 2 of the energy is used to generate electric sparks and form shock waves. Due to the low energy conversion efficiency, it is generally required to pre-store excess energy on the high-voltage capacitor. If a single high-voltage electronic switch fails (cannot be disconnected after being turned on), this excess energy is likely to be directly applied to the electrode, which is likely to cause the electrode to burst, the balloon to rupture, and the blood vessel to be damaged. Of course, designing large-sized electrodes can improve the energy tolerance of the electrode and improve the problem of electrode bursting. However, large-sized electrodes have an adverse effect on the permeability of the balloon in the blood vessel. Small-diameter balloon catheters are currently in general demand in the market. Summary of the invention

[0005] The purpose of the present application is to provide a shock wave pulse generating device to overcome the problems of high cost and large size of high-voltage electronic switching devices in the prior art, and to overcome the problems of low storage energy conversion efficiency and excessive energy easily causing electrode bursting in the prior art.

[0006] In order to achieve the above purpose, the technical solution of this application is as follows:

[0007] A shock wave pulse generating device, comprising a microprocessor, a first power supply, a second power supply, a third power supply, a shock wave generator, a first energy storage device and a second energy storage device, and a gas discharge tube switch for connecting the first energy storage device to the shock wave generator and a low-voltage electronic switch for connecting the second energy storage device to the gas discharge tube switch, wherein:

[0008] The microprocessor is used to control the first power supply to charge the first energy storage device and the second power supply to charge the second energy storage device in a first time period and a second time period; control the third power supply to act on both ends of the electrodes of the shock wave generator in the second time period to activate the fluid between the electrodes; and trigger the low-voltage electronic switch to close in the third time period, and turn on the gas discharge tube switch under the action of the second energy storage device, so that the first energy storage device acts on both ends of the electrodes of the shock wave generator to generate a shock wave.

[0009] Furthermore, the first power supply provides a charging voltage of 500V-10000V.

[0010] Furthermore, the second power supply provides a charging voltage of 50V-1200V.

[0011] Furthermore, the third power supply provides an activation voltage of 10V-100V.

[0012] Furthermore, a load resistor is provided between two electrodes of the shock wave generator.

[0013] Furthermore, the third power supply is connected to both ends of the electrodes of the shock wave generator through a high-voltage diode.

[0014] Furthermore, a freewheeling diode is arranged between two electrodes of the shock wave generator.

[0015] Furthermore, the first energy storage device is also connected in series with a current sensing resistor, and the current sensing resistor is connected to the microprocessor through a current limiting circuit and a first isolation optical coupler.

[0016] Furthermore, the low-voltage electronic switch is connected to the microprocessor via a second isolation optical coupler.

[0017] The present application proposes a shock wave pulse generating device, which activates the physiological saline solution in advance, and then generates shock waves by triggering a gas discharge tube. The use of a gas discharge tube trigger can reduce costs, reduce the size of the device, and simplify control. The physiological saline solution is activated in advance, and when the high voltage on the first energy storage device is directly applied to the electrode, the physiological saline solution between the electrodes can be immediately ionized to generate sparks, and shock waves are released at the same time, which can improve energy conversion efficiency, reduce energy storage requirements for the first energy storage device, reduce the cost of the first energy storage device, and avoid electrode bursts, balloon ruptures, and blood vessel damage. And the shock wave is generated instantly after the trigger, the speed is fast, and it is easy to operate. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is the circuit schematic diagram of the shock wave pulse generating device of this application.

[0019] Figure 2 This is a working timing diagram of the shock wave pulse generating device of this application. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0021] An embodiment of the present application, such as Figure 1 As shown, a shock wave pulse generating device is provided.

[0022] The shock wave pulse generating device comprises a microprocessor, a first power supply, a second power supply, a third power supply, a shock wave generator, a first energy storage device and a second energy storage device, and a gas discharge tube switch for connecting the first energy storage device to the shock wave generator and a low-voltage electronic switch for connecting the second energy storage device to the gas discharge tube switch, wherein:

[0023] The microprocessor is used to control the first power supply to charge the first energy storage device and the second power supply to charge the second energy storage device in a first time period and a second time period; control the third power supply to act on both ends of the electrodes of the shock wave generator in the second time period to activate the fluid between the electrodes; and trigger the low-voltage electronic switch to close in the third time period, and turn on the gas discharge tube switch under the action of the second energy storage device, so that the first energy storage device acts on both ends of the electrodes of the shock wave generator to generate a shock wave.

[0024] Specifically, the present embodiment uses a gas discharge tube to replace a conventional high-voltage electronic switch device (IGBT) to reduce costs, reduce the size of the device, and simplify control.

[0025] The gas discharge tube is connected in series between the first power supply and the shock wave generator. The shock wave generator is an electrode type, and two electrodes of the shock wave generator are in a fluid (usually a physiological saline solution).

[0026] This embodiment uses a second power supply to charge the second energy storage device, and the second energy storage device is connected to the triggering pole of the gas discharge tube through a low-voltage electronic switch. When the low-voltage electronic switch is closed, the gas discharge tube is triggered to conduct, so that the first energy storage device acts on both ends of the electrodes of the shock wave generator to generate shock waves. When the high voltage on the first energy storage device is directly applied to the electrodes, the physiological saline solution between the electrodes can be immediately ionized to generate sparks and release shock waves at the same time.

[0027] In this embodiment, the second power supply, the second energy storage device and the low-voltage electronic switch are linked to trigger the gas discharge tube to conduct, so that the shock wave generator generates a shock wave. This method can avoid the use of traditional high-voltage electronic switch devices.

[0028] In order to solve the problem of low energy conversion efficiency, this embodiment uses a third power source to act on both ends of the electrodes of the shock wave generator to pre-activate the fluid between the electrodes. Specifically, the third power source is added to both ends of the electrodes of the shock wave generator to activate the fluid. After the fluid is activated, when the low-voltage electronic switch is closed, the high voltage on the first energy storage device is directly applied to the electrodes, which can immediately ionize the physiological saline solution between the electrodes to generate sparks and release shock waves. Since the high voltage on the first energy storage device is directly used to generate sparks and release shock waves, the energy conversion efficiency of the first energy storage device is improved, the energy storage requirements of the first energy storage device are reduced, and the occurrence of electrode bursts, balloon ruptures, and blood vessel damage is avoided.

[0029] The first power supply, the second power supply and the third power supply of this embodiment are all DC power supplies with current limiting function. Among them, the first power supply charges the first energy storage device and provides a charging voltage of 500 volts to 10,000 volts, that is, between 500 volts and 10,000 volts, which will not be repeated below. The second power supply charges the second energy storage device and provides a charging voltage of 50 volts to 1,200 volts. The third power supply acts on both ends of the electrode of the shock wave generator to activate the fluid and provides an activation voltage of 10 volts to 100 volts.

[0030] The microprocessor of this embodiment is used to control the working time of each power supply and to control the working timing of the low-voltage electronic switch.

[0031] During operation, the first power supply charges the first storage device, and the second power supply charges the second storage device. The third power supply acts on both ends of the electrodes of the shock wave generator to activate the fluid. Before the first power supply acts on the electrodes, the third power supply is first used to act on both ends of the electrodes to activate the physiological saline solution between the electrodes to ensure that the first power supply can instantly generate sparks once it acts on the electrodes. The second energy storage device is connected to the triggering pole of the gas discharge tube through a low-voltage electronic switch. Under the control of the microprocessor, after the low-voltage electronic switch is closed, the voltage of the second energy storage device acts on the triggering pole of the gas discharge tube to trigger the gas discharge tube to turn on. After the gas discharge tube is turned on, when the voltage of the first storage device acts on the electrodes in the physiological saline solution, the physiological saline solution between the two ends of the electrodes is instantly ionized, sparks are generated, and shock wave pulses occur at the same time.

[0032] In a specific embodiment, Figure 1 As shown, the first power supply charges the first energy storage device, and the first energy storage device uses a high-voltage capacitor C1, which acts on the two electrodes (HV+, HV-) of the shock wave generator through the gas discharge tube GDT1. The second power supply charges the second energy storage device, and the second energy storage device uses a capacitor C2, which is connected to the trigger pole T of the gas discharge tube GDT1 through a low-voltage electronic switch.

[0033] For example, the gas discharge tube GDT1 can be TG-244 of CPclare, which has an actual withstand voltage of 1.2-4.2kV (can be used for the first power supply 3kV application). The gas discharge tube is small in size, with the widest part not exceeding 30mm, which can effectively reduce the volume of the entire device. The T pole (trigger pole) of GDT1 is connected to the low-voltage electronic switch, and the other two poles of GDT1 (A pole and O pole, A pole is the adjacent electrode, O pole is the opposite electrode), where A pole is connected to the ground (GND), and O pole is connected to the HV-electrode of the shock wave generator.

[0034] The third power supply is connected to both ends of the electrodes of the shock wave generator through a high-voltage diode D2. The high-voltage diode D2 provides a unidirectional channel for the voltage generated by the third power supply, and is reversely cut off to prevent the high voltage of the first power supply from damaging the third power supply.

[0035] The microprocessor is also connected to the low-voltage electronic switch via an isolation optical coupler 2 to control the closing or opening of the low-voltage electronic switch.

[0036] A load resistor R2 is also provided between the two electrodes of the shock wave generator to provide a minimum maintaining current for the gas discharge tube to ensure reliable conduction of the gas discharge tube.

[0037] Due to the characteristics of the gas discharge tube GDT1, it needs a certain minimum holding current to maintain the on state after being excited. In some special cases, such as when the electrode or electrode is disconnected, there will be no current loop flowing through GDT1, and the gas inside GDT1 will be extinguished, and the on state cannot be guaranteed. Therefore, in the case of electrode or electrode disconnection, as long as GDT1 is excited, the load resistor R2 ensures that a current flows through GDT1 between HV+ and HV- to maintain GDT1 in the on state. For example, if the load resistor R2 is 1KΩ and the first power supply is 3kV, when GDT1 is excited, a holding current of about 3A is generated on the load resistor R2 to maintain GDT1 reliable conduction.

[0038] A freewheeling diode D1 is also provided between the two electrodes of the shock wave generator. The electrode load is inductive to a certain extent, and the freewheeling diode D1 provides a current freewheeling channel.

[0039] In practical applications, there is a certain inductive reactance between electrodes and electrode wires. In some special cases, such as when a pulse occurs, the pulse circuit is suddenly disconnected (for example, the electrode and electrode wire are suddenly disconnected), and the instantaneous current generated on the electrode will have nowhere to be released, which will form high voltage and damage other components. The addition of D1 can provide a sub-instantaneous large current follow-up channel; at the moment the pulse discharge circuit is disconnected, the instantaneous large current can flow through the circuit in the direction of HV+, electrode, HV-, and D1 for follow-up, thus protecting the components from high voltage damage.

[0040] The working sequence of the device in this embodiment is as follows: Figure 2 As shown, Figure 2 The top graph shows the relationship between the voltage of the first power supply, the second power supply and the third power supply and time, the middle graph shows the relationship between the working state of the gas discharge tube GDT1 and time, and the bottom graph shows the relationship between the current I4 and time. The working process includes three time periods, namely, the t0-t1 preparation stage, the t1-t2 activation stage and the t2-t3 spark excitation stage.

[0041] The first time period, t0-t1 preparation stage:

[0042] The microprocessor controls the first power supply to start and keep working, and its output current I1 slowly charges the high-voltage capacitor C1, and charges to the target voltage V1 and maintains it before time t1.

[0043] The microprocessor controls the second power supply to start up and keep working with the first power supply at the same time, allowing a certain time difference. The output current I2 charges C2 slowly, and charges to the target voltage V2 and maintains it before time t1.

[0044] During this period of time, the low-voltage electronic switch is in the off state, and the gas discharge tube is not triggered and is in the high-blocking off state ( Figure 2During this period, the third power supply has been in the off state.

[0045] In a specific embodiment, the time length of t0-t1 is between 100ms-1S.

[0046] The second time period, t1-t2 activation phase:

[0047] The microprocessor controls the operation of the third power supply to generate an adjustable V3 voltage of 10-100V, which acts on both ends of the electrode through the high-voltage diode D2. Under the action of the voltage V3, a current I3 is formed. Part of the current I3 flows through the load resistor R2, and the other part flows through the electrode to form a current I4 on the electrode. The current I4 is typically 10-50mA. The physiological saline solution is slowly electrolyzed to produce charged ions and tiny bubbles. The solution between the electrodes forms a conductive channel. This process is called the activation of the physiological saline solution. The size of the bubbles generated is related to the voltage size, the solubility of the solution, and the time of application of the V3 voltage. In order to ensure that the bubble size is controllable and the physiological saline solution between the electrodes can be reliably activated, the application time of V3 is preferably 1mS-50mS;

[0048] During this period of time, the second power supply is always in the working state, but the low-voltage electronic switch is always in the disconnected state, so C2 always maintains the target voltage V2.

[0049] During this period of time, the first power supply is always in working state, and the gas discharge tube is in disconnected state ( Figure 2 Therefore, the high-voltage capacitor C1 always maintains the target voltage V1.

[0050] The third time period: t2-t3 spark excitation stage:

[0051] When the third power supply is applied to the expected time t3, the salt water between the electrodes is fully activated and the conditions for sparking are met. At this time, the microprocessor controls the low-voltage electronic switch to close through the isolation optical coupler 2. The energy stored in the capacitor C2 will act on the trigger level (T level) of the gas discharge tube through the low-voltage electronic switch. The gas in the entire gas discharge tube is activated, and the O and A poles are turned on ( Figure 2 In the working state of GDT1 (on), the voltage on the high-voltage capacitor C1 directly acts on the electrodes. Since the salt water at both ends of the electrodes is likely to be in an activated state at this time, the high voltage on the high-voltage capacitor C1 can immediately ionize the salt water between the electrodes to generate sparks when it is directly applied to the electrodes, and release shock waves at the same time until the energy of the high-voltage capacitor C1 is exhausted.

[0052] The duration of the t2-t3 stage is about 0.5-5uS. During this period of time, the energy on the high-voltage capacitor C1 is released to both ends of the electrode, forming an instantaneous spark discharge current I4 between the electrodes, and at the same time forming a current I7 on the load resistor R2, but I7 is much smaller than I4, and the instantaneous current of I4 is 50-500A. After the resistor R1 detects the spark discharge current I6, I6 is approximately equal to I4. Feedback to the microprocessor through the current limiting circuit and the isolation optocoupler 1 indicates that the spark triggering is successful.

[0053] In a specific embodiment, the first energy storage device is further connected in series with a current sensing resistor, and the current sensing resistor is connected to the microprocessor via a current limiting circuit and a first isolation optical coupler.

[0054] Specifically, the high-voltage capacitor C1 is also connected in series with a current-sensing resistor R1, 0.1-1 ohm, for detecting the spark current. The current-sensing resistor R1 is connected to the microprocessor through a current-limiting circuit and an isolation optical coupler 1.

[0055] After the resistor R1 detects the spark discharge current I6, it is fed back to the microprocessor through the current limiting circuit and the isolation optocoupler 1, indicating that the spark is triggered successfully.

[0056] In this embodiment, the isolation optocoupler is used for electrical isolation and signal transmission, which will not be described in detail here.

[0057] It should be noted that the first power supply, the second power supply, and the third power supply of the present application are all turned off at time t3. The spark triggering is successful, indicating the arrival of time t3, and the microprocessor controls the three power supplies to be turned off at the same time.

[0058] The shock wave pulse generating device proposed in the present application has the advantages of simple control, stability and reliability, low cost and small size.

[0059] 3kV-4kV withstand voltage IGBT small volume switch tubes, such as TO247 package, generally withstand current within 50A. In actual use, at least two need to be used in parallel to achieve the current withstand capacity. In some applications with higher voltage pulse voltage (such as 5kV-10kV), 2 or 3 series are required, and each tube needs to be used with an isolated suspension drive circuit, which is very complicated to control. Due to the instantaneous high voltage and high current discharge state of IGBT during operation, the instantaneous interference is very large, and the reliable drive of multiple IGBTs in series poses a very big challenge. The conduction of gas discharge tube switches does not require complex and precise drive circuits. The cost of a single gas discharge tube switch is low and the control circuit is simple. IGBT series and parallel use of multiple high-voltage IGBTs, with the isolated suspension drive circuit of the load, is much larger in volume than the gas switch discharge tube solution.

[0060] In addition, because the voltage generated by the third power supply activates the physiological saline solution between the electrodes in advance, the energy on the high-voltage capacitor C1 acts on both ends of the electrodes to stimulate sparks and generate shock waves at the moment the gas discharge tube is turned on. There is no waiting time Td, and all the energy is used to generate shock waves. There is no excess consumption, the temperature rise of the electrodes is lower, and the service life of the electrodes is increased. The voltage acting on both ends of the electrodes each time is controllable and constant, and the stability and consistency of the shock wave pulse generated are improved.

[0061] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A shock wave pulse generating device, characterized in that: The shock wave pulse generating device comprises a microprocessor, a first power supply, a second power supply, a third power supply, a shock wave generator, a first energy storage device and a second energy storage device, and a gas discharge tube switch for connecting the first energy storage device to the shock wave generator and a low-voltage electronic switch for connecting the second energy storage device to the gas discharge tube switch, wherein: The microprocessor is used to control the first power supply to charge the first energy storage device and the second power supply to charge the second energy storage device in a first time period and a second time period; control the third power supply to act on both ends of the electrodes of the shock wave generator in the second time period to activate the fluid between the electrodes; and trigger the low-voltage electronic switch to close in the third time period, and turn on the gas discharge tube switch under the action of the second energy storage device, so that the first energy storage device acts on both ends of the electrodes of the shock wave generator to generate a shock wave.

2. The shock wave pulse generating device according to claim 1, characterized in that: The first power source provides a charging voltage of 500V-10000V.

3. The shock wave pulse generating device according to claim 1, characterized in that: The second power supply provides a charging voltage of 50V-1200V.

4. The shock wave pulse generating device according to claim 1, characterized in that: The third power supply provides an activation voltage of 10V-100V.

5. The shock wave pulse generating device according to claim 1, characterized in that: A load resistor is arranged between the two electrodes of the shock wave generator.

6. The shock wave pulse generating device according to claim 1, characterized in that: The third power supply is connected to both ends of the electrodes of the shock wave generator through a high-voltage diode.

7. The shock wave pulse generating device according to claim 1, characterized in that: A freewheeling diode is arranged between the two electrodes of the shock wave generator.

8. The shock wave pulse generating device according to claim 1, characterized in that: The first energy storage device is also connected in series with a current sensing resistor, and the current sensing resistor is connected to the microprocessor through a current limiting circuit and a first isolation optical coupler.

9. The shock wave pulse generating device according to claim 1, characterized in that: The low voltage electronic switch is connected to the microprocessor via a second isolation optical coupler.

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