Intravascular lithotripsy device and system for detecting electrical interference

Abstract

Fault detection in electrical circuits including intravascular lithotripsy (IVL) devices and one or more emitters. A balanced current circuit includes a high-voltage source, a control unit or console, and at least one emitter having a pair of electrodes through which a spark is generated. Under normal operating conditions, there is a closed-loop electrical circuit, with a voltage applied through two conductors, and a current flowing between them when a spark is established. Under normal conditions, the current IC on the first conductor from the console to the emitter is the same as the current IR returning from the emitter to the high-voltage source on the second conductor. In this case, the circuit is in a balanced state. In such a balanced state, there is no indication of current leakage from the circuit. In an unbalanced state of the circuit, the comparison of current IC with current IR indicates a difference in the amplitude of current over time and across pulses. Specifically, when current IR is smaller than current IC, there is circuit unbalance, suggesting loss or leakage of current IF.

Description

Technical Field

[0001] Cross - reference to Related Applications This application claims the priority and benefit of U.S. Provisional Patent Application No. 63 / 455,805, filed Mar. 30, 2023.

[0002] The present invention is directed to a catheter system for treating blood vessel thrombi or calcified lesions, etc., by utilizing energy waves generated by electrodes in a conductive fluid medium.

Background Art

[0003] Catheter systems having angioplasty balloons are widely used to apply physical force by expanding the balloon against calcified lesions in the vasculature and pushing the calcification back against the vessel wall. Among such calcified lesions and thrombi, there are those that cannot be effectively destroyed by the use of angioplasty balloons.

[0004] In recent years, catheter systems have been developed that include a balloon similar to an angioplasty balloon filled with a conductive liquid medium, such as saline, for expanding the balloon in situ of a lesion or thrombus. This catheter system includes one or more electrode pairs operably disposed within the conductive liquid medium. The electrodes cause a spark to jump across the gap between the two electrodes with each pulse when a high - voltage direct current is supplied in a pulsed manner. The spark in the conductive medium generates an energy wave that propagates through the liquid medium and physically provides a force against the lesion or thrombus from the balloon. The energy propagation also includes the generation of microbubbles that also facilitate physical forces. Such devices are known to provide energy waves that act on lesions or thrombi for the purpose of destroying calcifications or clots.

[0005] Current catheter systems include a treatment sequence that includes a maximum number of consecutive pulses, a subsequent minimum delay time, and a strict maximum total number of pulses associated with a particular catheter. One such product has the following specifications:

[0006] [Table 1]

[0007] If treatment is not yet complete after the maximum total pulses per catheter, the doctor must replace the catheter, which is undesirable as it involves costs, delays, and distractions.

[0008] Intravascular lithotripsy (IVL) devices can be used for some calcification patterns. Disposable IVL balloon devices are available in various designs and sizes for peripheral or coronary artery applications. All designs utilize reusable power sources such as IVL generators. One reusable DC generator has the following specifications:

[0009] [Table 2]

[0010] One such disposable device consists of a fluid-filled balloon angioplasty catheter compatible with a 0.014-inch guidewire, with two fragmentation emitters integrated into the axis of a 12 mm long balloon section of the catheter. The fluid-filled balloon (e.g., 50 / 50 saline contrast agent) is inflated to approximately 4 atmospheres, and then an electrical pulse is supplied to the emitters, causing them to generate a high-voltage spark to provide treatment. Acoustic waves are generated, and calcium is destroyed. [Overview of the project]

[0011] The present invention is directed toward fault detection in electrical circuits including IVL devices and one or more emitters (each emitter comprising a pair of spaced electrodes). A balanced current circuit includes a high-voltage source, a control unit or console, and at least one emitter comprising a pair of electrodes between which a spark is generated. As described above, electrical energy of several thousand volts and tens or even hundreds of amperes is used in IVL devices. Under normal operating conditions, there is a closed-loop electrical circuit in which a voltage is applied through two conductors and a current flows between them when a spark is established. Under normal conditions, the current IC on the first conductor from the console to the emitter is the same as the current IR returning from the emitter to the high-voltage source on the second conductor. In this case, the circuit is in a balanced state. In such a balanced state, there is no indication of current leakage from the circuit. In an unbalanced state of the circuit, the comparison of current IC with current IR indicates the difference in the amplitude of the current over time and across the pulses. Specifically, when current IR is smaller than current IC, it indicates a circuit imbalance suggesting loss or leakage of current IF.

[0012] In one aspect of the present invention, a method for determining a malfunction of an intravascular lithotripsy (IVL) device, the IVL device comprising: a catheter having at least one emitter distal to a control module; a first conductor electrically extending from the control module to the emitter and connected to the emitter; and a second conductor electrically extending from the emitter to the control module and connected to the emitter, wherein the first and second conductors are electrically connected to a high-voltage pulse generator via the control module as a system having the IVL device, the method comprising: generating a high-voltage pulse in the high-voltage pulse generator; measuring a supply current through the first conductor and measuring a return current through the second conductor; and comparing the supply current to the return current to find a possible imbalance of the supply current with respect to the return current.

[0013] Each emitter has a pair of electrodes spaced apart from each other, and includes another pair of electrodes to create a spark across the electrode pairs when a high-voltage pulse is generated. Often, multiple electrode pairs are arranged electrically in series with each other. Preferably, the measurement step is performed on the return current through a second conductor from the last electrode pair to the control module. In another preferred configuration, the measurement step may be performed within the control module.

[0014] In another preferred configuration, multiple electrode pairs can be arranged electrically in parallel with one another, each of which has a parallel portion of the first conductor, and furthermore, the supply current is measured with respect to multiple parallel portions of the first conductor.

[0015] The step of measuring the supply current can be performed for the first conductor using a supply current sensor, and the step of measuring the return current can be performed for the second conductor using a return current sensor, and the comparison step can be performed using the values ​​obtained from the supply current sensor and the return current sensor, respectively.

[0016] The measuring and comparing steps can be alternatively performed by passing a first conductor and a second conductor through an iron coil such that the current through the first conductor generates a current in one direction within the iron coil, and the current through the second conductor generates a canceling current in the opposite direction within the iron coil, with the unidirectional current within the iron coil indicating an imbalance.

[0017] Even if the supply current and return current are determined not to be in an unbalanced state, if the measurement results show a decrease in supply current and return current compared to the measurement results over time, such a determination may indicate wear and tear on the electrode pair.

[0018] The method may further utilize a differential amplifier circuit that receives measurement results from a supply current sensor and a return current sensor, amplifies the difference between them, and then compares the amplified difference to a threshold to determine if there is an imbalance.

[0019] Alternatively, the method could further utilize a sense amplifier that receives a current value from an iron coil and amplifies that current value, and the amplified current value is then compared to a threshold to determine if there is an imbalance.

[0020] In another aspect of the present invention, a system can determine a malfunction of an intravascular lithotripsy (IVL) device, the IVL device comprising: a catheter having at least one emitter distal to a control module; a first conductor electrically extending from the control module to the emitter and connected to the emitter; and a second conductor electrically extending from the emitter to the control module and connected to the emitter, wherein the first and second conductors are electrically connected to a high-voltage pulse generator via the control module as a system having the IVL device, the system is connectable to a high-voltage pulse in the high-voltage pulse generator to cause a spark at the emitter by the high-voltage pulse, and the system further comprises a sensor for measuring a supply current through the first conductor and a sensor for measuring a return current through the second conductor, thereby allowing the supply current to be compared to the return current to find a possible imbalance of the supply current with respect to the return current.

[0021] Each emitter has a pair of electrodes spaced apart from each other, and includes another pair of electrodes to create a spark across the electrode pairs when a high-voltage pulse is generated. Often, multiple electrode pairs are arranged electrically in series with each other. Preferably, the measurement step is performed on the return current through a second conductor from the last electrode pair to the control module. In another preferred configuration, the measurement step may be performed within the control module.

[0022] In such a system, multiple electrode pairs can be arranged electrically in parallel with one another, each of which has a parallel portion of the first conductor, and a sensor for the supply current is provided on at least one of the multiple parallel portions of the first conductor.

[0023] Specifically, it is possible to perform a sensor of the supply current on the first conductor, it is possible to perform sensing of the return current on the second conductor, and the values obtained from each of the sensor of the supply current and the sensor of the return current can be used for comparison.

[0024] In an alternative configuration, the first conductor and the second conductor are passed through an iron coil so that the current passing through the first conductor generates a current in one direction within the iron coil and the current passing through the second conductor generates a canceling current in the opposite direction within the iron coil, and an imbalance is indicated by the current in one direction within the iron coil.

[0025] The system can further include a differential amplifier circuit that receives the measurement results of the supply current sensor and the return current sensor and amplifies the difference between them, and the amplified difference can then be compared with a threshold value to determine whether there is an imbalance.

[0026] Alternatively, the system can further use a sense amplifier that receives a current value from the iron coil and amplifies the current value, and the amplified current value can then be compared with a threshold value to determine whether there is an imbalance.

[0027] In yet another aspect of the present invention, a system for determining a malfunction of an intravascular lithotripsy (IVL) device can include a catheter having at least one emitter distal to a control module, the emitter comprising an electrode pair having electrodes spaced apart from each other for generating a spark across the electrode pair when a high voltage pulse is generated, the IVL device further comprising a first conductor electrically extending from the control module to the emitter and connected to the emitter, and a second conductor electrically extending from the emitter to the control module and connected to the emitter, the first and second conductors being electrically connected to a high voltage pulse generator via the control module as a system having the IVL device, the system being connectable to the high voltage pulse in the high voltage pulse generator to cause a spark at the emitter with the high voltage pulse, the system further comprising a sensor for measuring a supply current passing through the first conductor and a sensor for measuring a return current passing through the second conductor, whereby an possible imbalance of the supply current with respect to the return current can be found by comparing the supply current with the return current, either (a) the supply current sensor is made with respect to the first conductor, the return current sensing is made with respect to the second conductor, and values obtained from each of the supply current sensor and the return current sensor can be used in the comparison, or (b) the first and second conductors are passed through an iron coil such that a current passing through the first conductor generates a current in one direction within the iron coil and a current passing through the second conductor generates a cancelling current in the opposite direction within the iron coil, and an imbalance is indicated by the current in one direction within the iron coil.

Brief Description of the Drawings

[0028] [Figure 1] FIG. is a diagram of a system for providing intravascular lithotripsy according to one aspect of the present invention. [Figure 2] FIG. is a diagram of an inflated balloon within a blood vessel for providing intravascular lithotripsy according to one aspect of the present invention. [Figure 3] FIG. is a schematic diagram of a current circuit of an IVL device according to one aspect of the present invention, in which a first conductor and a second conductor are balanced with respect to current. [Figure 4] This graph, similar to Figure 3, shows a balanced circuit and represents the high-voltage pulse over time. [Figure 5] This is a schematic diagram of a current circuit of an IVL device according to one embodiment of the present invention, in which the first conductor and the second conductor are unbalanced with respect to current. [Figure 6] This graph, similar to Figure 5, shows the high-voltage pulse over time, illustrating an unbalanced circuit. [Figure 7] This is a graph of a series of high-voltage pulses over time, showing a balanced circuit with multiple peaks followed by detected disequilibrium. [Figure 8] This is a schematic diagram of a subcircuit according to one embodiment of the present invention for determining balanced or unbalanced current within an IVL device circuit. [Figure 9] This is a graph of a series of high-voltage pulses over time, showing the distinction between a balanced circuit, wear and tear on the balanced circuit, and detected imbalance. [Figure 10] This is a schematic diagram of another current circuit of an IVL device according to another aspect of the present invention, in which a first conductor and a second conductor pass through an iron coil to detect circuit imbalance. [Figure 11] Similar to Figure 10, this is a schematic diagram of the current circuit of an IVL device, in which multiple conductors run from the console to the IVL emitter. [Figure 12] Similar to Figures 10 and 11, this is a schematic diagram of the current circuit of an IVL device, where multiple circuits are directed towards and exit the IVL emitter. [Modes for carrying out the invention]

[0029] The present invention is directed toward an IVL apparatus of the type that includes an electrode or fragmentation emitter that generates acoustic waves by arc discharge between electrode components, but may also include an apparatus that generates acoustic energy in a balloon via a laser energy source. Examples of such laser systems are described in U.S. Patent Nos. 11,058,492 and 11,246,569. Examples of electric induction systems are described in U.S. Patent Nos. 8,728,091, 9,642,673 and 10,850,078, and U.S. Patent Application Publication No. 2022 / 0054194.

[0030] Referring to the figures, Figures 1 and 2 show a system 10 according to the present invention, which comprises a console or power supply 12 (in the form of a generator, but alternatively in the form of a laser system), a handle 14 with a treatment execution control device 15, a catheter 20 with two fragmentation emitters 22 (illustrated in the form of a pair of arc electrodes, but alternatively consisting of optical or laser emitters), and a fluid-filled balloon 24. An optional marker band B may be provided. The catheter 20 preferably includes a central tube 26, which defines a guidewire lumen 27 through which the guidewire G passes to deliver the balloon 24 to a desired position along the guidewire G. A sheath 28 surrounds the central tube 26, which defines a delivery lumen 29 through which saline solution can be controlledly delivered to inflate the balloon 24. The lumen 29 provides a concentric space around the central tube 26 through which an electrode wire (not shown), among the various components according to the present invention, can pass from the control device 15 to the emitter 22. The sheath 28 is connected to the hub 17 at its proximal end, and the hub 17 may include any number of ports through which the electrode wire can pass into the lumen 29, along with saltwater for expansion, a guidewire G, and any number of other components as needed.

[0031] The balloon 24 may be placed in a deflated position to allow it to pass more easily through the patient's vascular system and reach the site of calcification. When used, the balloon 24 is inflated to a general pressure for angioplasty (e.g., 4 atmospheres), and the treatment is performed via the implementation control device 15.

[0032] Figure 2 shows the balloon 24 inflated to a therapeutic state in which the fragmentation emitter 22 can "fire" to break down the calcification C in the blood vessel. An optional indicator band B may be provided for visualization and proper positioning to be used by known imaging techniques. The balloon 24 is inflated to a typical angiogenic pressure (e.g., 4 atmospheres) and the treatment is performed. The balloon 24 may spontaneously expand during or immediately after the treatment, widening the vessel to allow blood to pass through.

[0033] The control device 15 is used to generate a single voltage pulse or a sequence of voltage pulses according to the treatment scheme. A high-voltage pulse is supplied to one of the emitters 22, which have spaced-apart pairs of electrodes, and, according to the illustrated embodiment, then in series to a second emitter 22, which also has spaced-apart pairs of electrodes. The high-voltage pulse sequentially generates sparks in the balloon 24, across the first pair of electrodes and then across the second pair of electrodes. The slightly conductive saline solution in the balloon 24 enables the high-voltage sparks across each pair of electrodes, thereby generating energy waves that propagate within the balloon toward vascular calcification. When used in the IVL apparatus of the present invention, the "high" voltage is preferably above 500V, more preferably above 1000V, and more preferably above 2000V.

[0034] Sparks generated within the balloon 24, located within the patient's vascular system, also produce visible or detectable optical events. Such optical events can be detected at wavelengths other than those of the visible light spectrum. Furthermore, it is understood that when a high-voltage pulse is initiated at a high-temperature electrode pair prior to the actual spark event, a visible or detectable optical leader may be emitted from the electrode connected to ground among any electrode pair. Such a leader is similar to that seen emanating from a conductive object prior to a lightning strike. An object of the present invention is to monitor this visible or detectable optical event as feedback to the controlled generation of the high-voltage spark. Understanding the timing of such a leader and the actual spark generation at one or more electrode pairs after the generation of the high-voltage pulse may lead to modifications in the design of the electrode pair and other components for the propagation of energy waves within the balloon. An object of the present invention is to better predict the timing of spark generation from the time the high-voltage pulse is delivered by sensing an optical event that can predict when the spark will actually occur.

[0035] Furthermore, it is intended that catheters without balloons may be used in accordance with the present invention. Such catheters preferably include a lumen 29 for delivering saline solution to a controlled volume containing one or more emitters 22. Such a controlled volume may be created by the structure of the patient's vascular system together with the distal end of the catheter in the region of the emitters. Saline solution may be supplied to fill such a controlled volume, or it may flow through and out of such a controlled volume at a controlled flow rate. Partial balloons are also intended, from which a saline solution flow may flow out of an open distal end of the partial balloon. Such partial balloon or open balloon designs may be useful in forward electrode systems, such as those disclosed in U.S. Provisional Patent Application No. 63 / 416,231, filed October 14, 2022, which is incorporated herein by reference in its entirety. In the case of a catheter 20 having a balloon 24, the controlled volume is provided within the volume of the balloon 24.

[0036] As also shown in Figure 2, an optical fiber 30 can be passed through the lumen 29 to a desired point within the balloon 24 for the purpose of sensing the generation of light from a spark within the balloon 24. The proximal end of the optical fiber 30 is preferably optically connected to an optical detector that provides an amplified signal of the sensed light. Optical fibers are well known to have an optical core surrounded by an outer sheath, through which light can propagate. The outer sheath may be further surrounded by a protective layer. Light generated by a spark or precursor travels along the optical core and is sensed by a photodetector such as a photodiode. Direct detection of the generation of a spark or precursor by the observed visible or detectable light (via the optical fiber) may improve the lifespan of the IVL device by varying power usage for each spark and optimizing the spark by intensity. Reducing the intensity and duration of the spark may benefit the lifespan of the IVL and is intended to reduce the harmful effects of the heat generated by the spark. Furthermore, understanding the intensity and timing of the spark in relation to high-voltage pulses may improve control and responsiveness.

[0037] The additional option of using optical fibers 30 and optical sensors is the detection of microbubbles in the saline solution of balloon 24 that may interfere with the passage of the shock wave. It is understood that microbubbles are produced by high-voltage sparks and the resulting energy waves. It is also understood that such microbubbles can collapse when a certain amount of energy is applied to them while they are suspended in the solution. Acoustic luminescence is a phenomenon in which both detectable light and sound waves can be produced as a result of the collapse of such microbubbles. In this situation, a first pulse may produce an energy wave and generate microbubbles in the saline solution of balloon 24. A subsequent pulse may produce another energy wave and microbubbles, but may also cause the collapse of the microbubbles in the saline solution produced by the previous pulse. Such events can produce other detectable light that can be detected by optical fibers 30. Such light produced from the collapse of microbubbles may be detectable at a different wavelength than, for example, the detectable light from the spark. Depending on the optical phenomenon to be detected using an understanding of the light emitted therefrom at a particular wavelength, optical filters can be used. For example, the excitation of sodium ions in saline solution can result in the emission of light at a wavelength of 589 nm (yellow-orange). Detecting light at this wavelength exhibits spark properties, which may allow for the control of spark generation.

[0038] If one or more emitters 22 are ignited by the control device 15 and no light is detected by the optical fiber 30, this is an example of a fault condition. Such a fault may result from current leakage, where the current supplied on the electrode wires going to one or more emitters 22 in the balloon 24 is different (in this case, greater) than the current returning from the emitters 22 in the balloon 24 to the control device 15. Thus, one aspect of the present invention is to check for current faults by measuring the current balance on the electrode wires going to and from the emitters 22. If no current flows across the electrode gap between the pairs of electrodes of the emitter and no spark is generated, the current from the emitter 22 may be zero. This may mean that the emitter 22 is damaged or worn out, or that there is current leakage somewhere before the emitter 22. If there is current flow across one or more emitters 22, whether or not a spark is generated, a current difference or imbalance between the current supplied to the emitter and the current from the emitter can also be a fault, suggesting current leakage somewhere along the circuit.

[0039] Referring next to Figures 3 and 4, a balanced current circuit 50 is shown, which includes a high-voltage source 52, a control unit or console 54, and an emitter 56 with a pair of electrodes between which a spark is generated. As described above, electrical energy of several thousand volts and tens or even hundreds of amperes is used in intravascular lithotripsy (IVL) devices. Under normal operating conditions, there is a closed-loop electrical circuit 50, with a voltage applied through two conductors and a current flowing between them when a spark is established. Under normal conditions, the current IC on the first conductor 58 from the console 54 to the emitter 56 is the same as the current IR returning from the emitter 56 to the high-voltage source 52 in the second conductor 60. In this case, the circuit 50 is in a balanced state. In such a balanced state, there is no indication of current leakage from the circuit 50. Figure 4 shows the balanced state of the circuit 50 with amperes of a high-voltage pulse over time, and current IC equal to current IR. Any circuit may have slight fluctuations from IC current to IR current, and it is understood that it is preferable to use a threshold in comparing IC current and IR current based on empirical information or by other means.

[0040] Figures 5 and 6 show circuit 50 with a current IC from console 54 to emitter 56 and a current IR returning from emitter 56 to high-voltage source 52. Under conditions where spark generation is established at emitter 56, IR and IC should be the same or substantially the same as described above. However, a third current is shown as current IF, which is current leakage from circuit 50, which can occur inside or outside console 54, into and within other conductive media. Such current leakage IF still allows spark generation at emitter 56, but as described above, it may have less energy and a reduced energy wave acting against the lesion. Figure 6 shows an unbalanced state of circuit 50, where a comparison of current IC with current IR shows the difference in current amplitude over time and across pulses. Specifically, current IR is smaller than current IC by the amount of current IF in a general sense, taking into account small fluctuations in the system.

[0041] The currents flowing through conductors such as conductor 58 and conductor 60 can be measured by any current sensor, such as commercially available ones. Examples include a current sensing resistance and a voltage amplifier that measures the voltage difference. Other examples include systems that include a magnetic coil or a Hall effect sensor. In one embodiment of the system according to the present invention, as schematically shown in Figure 3, a first current sensor 62 is preferably provided along the first conductor 58 from the console 54 to the emitter 56, and a second current sensor 64 is preferably provided along the second conductor 60 from the emitter 56 to the high voltage source 52. In this way, the current IC and current IR can be directly compared with each other. The current sensors 62 and 64 may be provided in the console 54 or at any point along the length of the first and second conductors 58 and 60.

[0042] In a system according to the present invention that includes current balance monitoring, it is understood that if such an imbalance exists, it can be determined at any time during or after the firing of any number of high-voltage sparks and energy waves. For example, Figure 7 shows three such high-voltage pulses over a period of time, the first two pulses having balanced currents, and the third pulse having a current imbalance. The first two pulses have the same curve as shown superimposed on each other, whereas the third pulse shows its curves separately from each other, with curve IR having a smaller amplitude than the curve of IC with a larger amplitude. This indicates a current imbalance, and the amplitude of that imbalance is shown below the third unbalanced pulse in the graph below. During operation, such an imbalance in a sequence of pulses can therefore be controlled to stop further pulses once the imbalance is determined. It is also intended to terminate the pulse within the pulse if an imbalance is detected during the pulse.

[0043] Figure 8 shows an embodiment of a system subcircuit 70 that can be used to determine imbalance based on a comparison of current IC and current IR. In this example, a current amplifier 72 receives current values ​​from current sensors such as 62 and 64 and amplifies the difference between IC and IR. This difference is then provided to a comparator 74, which compares the amplified difference value to a threshold. If the amplified difference value is greater than the threshold, imbalance is determined. Such amplifiers and comparators are well known and commercially available. It is understood that comparators can also be used alone without amplification, and that the threshold may be as low as zero and may be determined empirically or otherwise.

[0044] It should also be noted that normal wear over time can be detected using the current sensors in both the first and second conductors 58 and 60. As schematically shown in Figure 9, the upper graph shows multiple pulses over time, and the amplitudes of both current curves represent both IC and IR between each pulse. The first pulse, as described above, shows both curves overlapping, indicating no imbalance or other fluctuations. The second pulse also shows both curves overlapping in a similar manner, but with a smaller amplitude than the first pulse. Comparing the first and second pulses, the second pulse indicates wear in the system (console or catheter) that increases resistance within the first and second conductors 58 and 60, possibly over some time and any number of pulses in between. The comparison of pulse amplitudes over time from multiple current sensors is intended to provide feedback information on system wear or electrode wear, which can also facilitate the determination of excessive wear of the system or electrodes that require replacement. The third pulse shows the imbalance described above, and the amplitude difference is graphed below the third pulse.

[0045] In another aspect of the present invention, the system can utilize non-contact measurement to determine imbalance. In the above system, current sensors 62, 64 are provided for comparing current data, amperages at multiple locations with respect to each other. Figure 10 schematically shows a circuit 150 which includes a high-voltage source 152, conductors 158 and 160, an emitter 156 with an electrode pair, and a sub-circuit 170 for determining imbalance. Instead of using current sensors, an iron coil 166 can be provided so as to be operably positioned to pass the first and second conductors 158 and 160 through an open center of the iron coil 166. As shown in Figure 10, the current IC flowing from console 154 to emitter 156 passes through the open center of coil 166 in that direction. The current IR flowing from emitter 156 to high-voltage source 152 passes through the open center of coil 166 in the opposite direction. A current flowing in one direction through the center of the iron coil 166 generates a current in that direction within the iron coil 166 due to the interaction of magnetic flux. A current flowing in the opposite direction through the center of the iron coil 166 similarly generates a current in the opposite direction within the iron coil 166. If both currents flowing through the open center of the iron coil are the same, no current is generated within the coil. If there is a difference in the current in the first conductor 158 compared to the second conductor 160, a current is generated in the iron coil in one direction or the other based on that difference. Such a difference may be the result of leakage IF from the system, which is also shown in Figure 10. As above, the subcircuit 170 can initially amplify the current generated within the iron coil 166 at 172, and its value can be compared to a threshold at 174 to determine imbalance. As above, modifications are intended.

[0046] Figure 11 shows a modification of the system in Figure 10, where multiple conductors 158 and 159 extend in parallel from the console 155 to a pair of emitters 156 and 157. Both emitters 156 and 157 are shown to be electrically connected to a high-voltage source 152 by a return conductor 160. Multiple return conductors are also conceivable. In any case, the current generation within the iron coil 166 is the same as described above, even though multiple conductors for the current IC pass through the iron coil 166.

[0047] In contrast to the system in Figure 11, the system 250 in Figure 12 can include multiple subsystems, each subsystem having a system circuit similar to that in Figure 10. The subsystems can share a high-voltage source 252 and a console 254. Each subsystem may have its own dedicated first conductors 258, 259 that pass through iron coils 266, 267 to emitters 256, 257, and second conductors 260, 261 from emitters 256, 257 to the high-voltage source 252. Each iron coil 266, 267 may have an independent subcircuit (not shown), such as a subcircuit 170 for determining imbalance. The advantage of the system in Figure 12 over the system in Figure 11 is that specific conductors and emitters can be more easily determined from the other. [Explanation of Symbols]

[0048] 10 Systems 12 console, power supply 14 handles 15 Control device 17 Hubs 20 Catheters 22 Emitter 24 Balloons 26 Central tube 27, 29 lumen 28 Sheath 30 Optical Fibers 50 circuits 52 High-voltage sources 54 Control unit, console 56 Emitter 58, 60 Conductor 62, 64 Current Sensor 72 Current Amplifier 74 Comparator 150 circuits 152 High Voltage Source 156, 157 Emitter 158, 159, 160 conductors 166 coils 170 Sub-circuits 250 Systems 252 High Voltage Source 254 Console 256, 257 Emitter 258, 259 First conductor 260, 261 Second conductor 266, 267 Iron coil G guidewire

Claims

1. A method for determining a malfunction of an intravascular lithotripsy (IVL) device, wherein the IVL device comprises a catheter having at least one emitter distal to a control module, a first conductor electrically extending from the control module to the emitter and connected to the emitter, and a second conductor electrically extending from the emitter to the control module and connected to the emitter, wherein the first and second conductors are electrically connected to a high-voltage pulse generator via the control module as a system having the IVL device, and the method is, The steps include generating a high-voltage pulse with the high-voltage pulse generator, The steps include measuring the supply current through the first conductor and measuring the return current through the second conductor, A method comprising the step of comparing the supply current with the return current to find a possible imbalance in the supply current with respect to the return current.

2. The method according to claim 1, wherein the emitter comprises a pair of electrodes spaced apart from each other, and a pair of electrodes for generating a spark across the pair of electrodes when a high-voltage pulse is generated.

3. The method according to claim 2, wherein a plurality of electrode pairs are arranged electrically in series with respect to the return current through the second conductor from the last electrode pair to the control module.

4. The method according to claim 3, wherein the measurement step is performed within the control module.

5. The method according to claim 2, wherein a plurality of electrode pairs are provided electrically in parallel with respect to each other, each of the parallel electrode pairs has a parallel portion of the first conductor, and further, the measurement of the supply current is performed with respect to the plurality of parallel portions of the first conductor.

6. The method according to claim 1, wherein the step of measuring the supply current is performed on the first conductor using a supply current sensor, the measurement of the return current is performed on the second conductor using a return current sensor, and the comparison step uses values ​​obtained from the supply current sensor and the return current sensor, respectively.

7. The method according to claim 1, wherein the measuring and comparing steps are performed by passing the first conductor and the second conductor through an iron coil such that the current through the first conductor generates a current in one direction within the iron coil and the current through the second conductor generates a canceling current in the opposite direction within the iron coil, and the current in one direction within the iron coil indicates an imbalance.

8. The method according to claim 2, wherein, after the measurement step, it is determined that the supply current and the return current are not in an unbalanced state, but the measurement results show a decrease in the supply current and return current compared to the measurement results over time, and therefore indicate wear on the electrode pair.

9. The method according to claim 6, further comprising a differential amplifier circuit that receives measurement results from the supply current sensor and the return current sensor and amplifies the difference between them, the amplified difference then being compared with a threshold to determine whether there is an imbalance.

10. The method according to claim 7, further comprising a sense amplifier that receives a current value from the iron coil and amplifies the current value, wherein the amplified current value is then compared with a threshold value to determine whether there is an imbalance.

11. A system for determining a malfunction of an intravascular lithotripsy (IVL) apparatus, wherein the IVL apparatus comprises a catheter having at least one emitter distal to a control module, a first conductor electrically extending from the control module to the emitter and connected to the emitter, and a second conductor electrically extending from the emitter to the control module and connected to the emitter, wherein the first and second conductors are electrically connected to a high-voltage pulse generator via the control module as a system having the IVL apparatus, the system is connectable to the high-voltage pulses in the high-voltage pulse generator to cause a spark at the emitter by the high-voltage pulses, and the system further comprises a sensor for measuring a supply current through the first conductor and a sensor for measuring a return current through the second conductor, thereby enabling the system to compare the supply current with the return current to find a possible imbalance of the supply current with respect to the return current.

12. The system according to claim 11, wherein the emitter comprises a pair of electrodes spaced apart from each other, and a pair of electrodes for generating the spark across the pair of electrodes when a high-voltage pulse is generated.

13. The system according to claim 12, wherein a plurality of electrode pairs are arranged electrically in series with respect to each other, and the sensor for measuring the return current is performed on the return current passing through the second conductor from the last electrode pair to the control module.

14. The system according to claim 13, wherein the sensor for the supply current and the sensor for the return current are located within the control module.

15. The system according to claim 12, wherein a plurality of electrode pairs are provided electrically in parallel with each other, each of the parallel electrode pairs has a parallel portion of the first conductor, and the sensor for the supply current is provided on at least one of the plurality of parallel portions of the first conductor.

16. The system according to claim 11, wherein the sensor for the supply current is performed on the first conductor, the sensing of the return current is performed on the second conductor, and the values ​​obtained from the supply current sensor and the return current sensor can be used for comparison.

17. The system according to claim 11, wherein the first conductor and the second conductor are passed through an iron coil, such that the current passing through the first conductor generates a current in one direction within the iron coil, and the current passing through the second conductor generates a canceling current in the opposite direction within the iron coil, and the current in one direction within the iron coil indicates an imbalance.

18. The system according to claim 16, further comprising a differential amplifier circuit that receives measurement results from the supply current sensor and the return current sensor and amplifies the difference between them, and can then compare the amplified difference with a threshold to determine whether there is an imbalance.

19. The system according to claim 17, further comprising a sense amplifier that receives a current value from the iron coil and amplifies the current value, and which can then compare the amplified current value with a threshold value to determine whether there is an imbalance.

20. A system for determining a malfunction of an intravascular lithotripsy (IVL) device, wherein the IVL device comprises a catheter having at least one emitter distal to a control module, the emitter comprising an electrode pair having spaced electrodes to generate a spark across the electrode pair when a high-voltage pulse is generated, the IVL device further comprises a first conductor electrically extending from the control module to the emitter and connected to the emitter, and a second conductor electrically extending from the emitter to the control module and connected to the emitter, wherein the first and second conductors are electrically connected to a high-voltage pulse generator via the control module as a system having the IVL device, and the system generates the high-voltage pulse in the high-voltage pulse generator to generate a spark at the emitter by the high-voltage pulse. A connectable system further comprising a sensor for measuring a supply current through the first conductor and a sensor for measuring a return current through the second conductor, thereby enabling the system to compare the supply current with the return current to find a possible imbalance of the supply current with respect to the return current, wherein (a) the sensor for the supply current is performed on the first conductor and the sensing for the return current is performed on the second conductor, and the values ​​obtained from the supply current sensor and the return current sensor can be used for comparison, or (b) the first conductor and the second conductor are passed through an iron coil such that the current through the first conductor generates a current in one direction within the iron coil and the current through the second conductor generates a canceling current in the opposite direction within the iron coil, and the imbalance is indicated by the current in one direction within the iron coil.

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