WO2024220780A1

WO2024220780A1 - Intravascular lithotripsy devices and systems including sizing measurement

Info

Publication number: WO2024220780A1
Application number: PCT/US2024/025369
Authority: WO
Inventors: Matthew W. Tilstra; Joseph P. Higgins
Original assignee: Cardiovascular Systems Inc
Current assignee: Cardiovascular Systems Inc
Priority date: 2023-04-21
Filing date: 2024-04-19
Publication date: 2024-10-24
Anticipated expiration: 2025-10-21
Also published as: CN120981206A

Abstract

Systems and methods for performing both an intravascular lithotripsy (IVL) operation and a sizing operation within vasculature of a subject. A system can comprise a catheter having a distal end provided with an inflatable balloon and a plurality of electrodes within the balloon, wherein at least a first electrode is provided as a component of a first emitter and is electrically connected with both a high voltage pulse generator for performing an IVL operation and a conductance excitation module for performing the sizing operation. A method can include exciting a first electrode and sensing conductance or admittance at a second electrode for performing a sizing operation within the balloon as positioned in a vasculature of a subject, and creating a spark between the first electrode, as provided as one electrode component of a first emitter pair of electrodes, and another electrode component of the first emitter pair of electrodes by providing a high voltage pulse from a high voltage pulse generator for performing an IVL operation.

Description

INTRAVASCULAR LITHOTRIPSY DEVICES AND SYSTEMS INCLUDING SIZING MEASUREMENT

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to and the benefit of U.S. Provisional Patent Application No. 63/461,085, filed April 21, 2023, the entire contents of which is incorporated herein by reference in its entirety.

Technical Field

[0002] The present invention is directed to a catheter system for treating a vascular thrombus or calcified lesion or the like utilizing energy waves that may be generated by electrodes within a conductive fluid medium.

Background

[0003] Catheter systems having an angioplasty balloon are commonly used to apply a physical force by expansion of the balloon against a calcified lesion within vasculature to force the calcification back into and against the blood vessel wall. Certain such calcified lesions and thrombi are not effectively broken up by the use of an angioplasty balloon alone.

[0004] More recently, catheter systems have been developed that include a balloon similar to an angioplasty balloon that is filled with a conductive liquid medium, such as a saline solution, for expanding the balloon in position at the lesion or thrombus, wherein the catheter system includes one or more pair(s) of electrodes operatively positioned within the conductive liquid medium. The electrodes are pulsed with high voltage direct current so as to create a spark that jumps over a gap between the two electrodes at each pulse. The spark within the conductive medium creates an energy wave that propagates through the liquid medium causing the balloon to physically provide a force against the lesion or thrombus. The energy propagation includes the creation of micro-bubbles that also facilitate the physical force. Such devices are known to provide an energy wave to act against a lesion or thrombus for purposes of breaking up the calcification or clotting.

[0005] Current catheter systems include a therapy sequence that includes a maximum number of continuous pulses, followed by a minimum delay time and a hard maximum total pulses associated with a particular catheter. One such product specifies:

[0006] If a therapy is not yet completed after the maximum total pulse per catheter count, the physician must replace the catheter with the attendant undesirable, cost, delay and distraction.

[ 0007] Intravascular lithotripsy (IVL) devices are available for some calcification patterns. Disposable IVL balloon devices are provided in different designs and sizes for peripheral or coronary indications. All designs utilize a reusable power source such as an IVL generator. One reusable DC generator comprises the following specification:

[0008] One such disposable device consists of a 0.014-inch guidewire-compatible, fluid-filled balloon angioplasty catheter w ith two lithotripsy emitters incorporated into the shaft of the 12-mrn-long balloon segment. A fluid filled balloon (e.g. a 50/50 saline contrast medium) is inflated to about 4 atm and then electrical pulses are provided to the emitters that create high voltage sparks to provide the therapy . Acoustic waves are created and the calcium is fractured.

[0009] Sizing balloons are known that utilize conductance for measurement of the size of a portion of a patient’s vasculature and, in particular, for determining a proper stent size to be implanted. A known sizing balloon is shown in Fig. 1 . In this example, an inflated balloon A is shown filled with saline and positioned at a distal end of a catheter C. Four electrodes (El , E2, E3, and E4) are provided at controlled spacing along the catheter within the balloon. For a DC connection, positive voltage in the order of tens of volts or less is provided to electrodes El and E4 and electrical conductance is measured at electrodes E2 and E3 connected with the negative voltage. For an AC connection, the hot side is provided to the electrodes El and E4 and the electrodes E2 and E3 are connected with neutral. Electrical conductance is determined based on the ratio of current/voltage drop, which directly relates to the balloon cross-sectional area through Ohms law. For measurement, the outer two electrodes El and E4 are excited while the inner two electrodes E2 and E3 sense and measure a voltage signal. This system can be excited with AC and/or DC power for determining a difference between liquid and tissue. For more details of such a sizing balloon and sizing determination, see the article of Svendsen, et al titled “Conductance sizing balloon for measurement of peripheral artery minimal stent area” Journal of Vascular Surgery, September 2014. which article is incorporated herein by reference in its entirety.

[0010] The article describes a method for accurately measuring the minimal stent area (MSA) in peripheral arteries using a conductance sizing balloon (CSB). The CSB measures the electrical conductance of the artery to determine its diameter and thus the MSA. Other methods for measuring MSA in peripheral arteries are compared to CSB, such as intravascular ultrasound and angiography, both of which have limitations and may not provide accurate measurements. The CSB offers several advantages over these methods, including its ability to measure the MSA in real-time and without the need for contrast dye. The article discusses a study to evaluate the performance of the CSB in measuring MSA in peripheral arteries. They found that the CSB provided accurate and reliable measurements of MSA, with a correlation coefficient of 0.96 compared to intravascular ultrasound measurements.

Summary

[0011] In accordance with an aspect of the present invention, a system for performing both an intravascular lithotripsy (IVL) operation and a sizing operation within vasculature of a subject is disclosed. A system can comprise a catheter having a distal end provided with an inflatable balloon and a plurality of electrodes within the balloon, wherein at least a first electrode is provided as a component of a first emitter and is electrically connected with both a high voltage pulse generator for performing an IVL operation and a conductance excitation module for performing the sizing operation.

[0012] Preferably, the sizing operation comprises a conductance sizing operation that uses at least the first electrode as operatively connected with the conductance excitation module and a spaced second electrode that is operatively connected with a conductance sensor for determining at least one of a cross-sectional area or an internal volume of the balloon as inflated within a vasculature. The first electrode can be one of a pair of electrodes comprising the first emitter for an IVL operation so that when a high voltage pulse is generated, a spark will be created across the electrode pair through a conductive medium within the balloon.

[0013] A third electrode can be provided as a component of a second emitter that is electrically connected with the high voltage pulse generator for performing an IVL operation in parallel with the first emitter. Moreover, the third electrode can be operatively connected with conductance excitation module for performing the sizing operation and the second emitter is electrically in parallel with the first emitter.

[0014] A fourth electrode can be operatively connected with the conductance sensor for performing the sizing operation along with the third electrode as can be connected with the conductance excitation module.

[0015] The system can preferably include a control system, wherein two (e.g. the first and third) electrodes can be electrically connected to be excited by the conductance excitation module in parallel with one another by a sizing excitation and sensing control module, and the second and fourth electrodes can be electrically connected to provide feedback information to the sizing excitation and sensing control module for determining the at least one of a cross-sectional area or an internal volume of the balloon as inflated within a vasculature.

[0016] In another aspect of the present invention, the sizing excitation and sensing control module further can comprise an AC power source so that admittance is sensed and a DC power source so that conductance is sensed, each for providing information regarding fluid and tissue of the vasculature.

[0017] Preferably, the high voltage pulse generator can be operatively connected with the control system and at least the first and second emitters so that the IVL operation can be controllably performed independent of the sizing operation. In one embodiment, at least one- electrode in an electrode pair used to create a spark to emit an acoustic wave can also serve as an excitation or sensing electrode for the sizing excitation and sensing control module. [0018] In another aspect of the present invention, a method of performing an intravascular lithotripsy (IVL) operation and a sizing operation within vasculature of a subject can include a catheter having a distal end provided with an inflatable balloon and a plurality of electrodes within the balloon, and the method can include exciting a first electrode and sensing conductance or admittance at a second electrode for performing a sizing operation within the balloon as positioned in a vasculature of a subject, and creating a spark between the first electrode, as provided as one electrode component of a first emitter pair of electrodes, and another electrode component of the first emitter pair of electrodes by providing a high voltage pulse from a high voltage pulse generator for performing an IVL operation.

[0019] The sizing operation can be performed prior to any creation of a spark for the IVL operation to provide initial sizing information. Likewise, one or more sizing operation(s) can be performed after at least one IVL cycle or pulse cycle to provide progress information or confirmation of the IVL operation. Moreover, a sizing operation can be performed after the IVL operations are complete to provide or confirm size information for an implant, such as a stent.

[0020] The sizing operation can comprise a conductance sizing operation that uses at least the first electrode as operatively connected with the conductance excitation module and a spaced second electrode that is operatively connected with a conductance sensor, and the method can further comprise determining at least one of a cross-sectional area or an internal volume of the balloon as inflated within a vasculature.

[0021] A third electrode can be provided as a component of a second emitter that is electrically connected with the high voltage pulse generator, and the method can further comprises performing an IVL operation in parallel with the first emitter. The third electrode can be operatively connected with a conductance excitation module, and the method can further comprise performing the sizing operation with the second emitter electrically in parallel with the first emitter.

[0022] A fourth electrode can be operatively connected with the conductance sensor, and the method can further comprise performing the sizing operation along with the third electrode as connected with the conductance excitation module. [0023] Preferably, such a method includes the use of a control system, wherein the first and third electrodes can be electrically connected to be excited by the conductance excitation module in parallel with one another by a sizing excitation and sensing control module, and the second and fourth electrodes can be electrically connected to provide feedback information to the sizing excitation and sensing control module, and the method can further comprise determining the at least one of a cross-sectional area or an internal volume of the balloon as inflated within a vasculature.

[0024] The method can further comprise exciting with both an AC power source so that admittance is sensed and exciting with a DC power source so that conductance is sensed, each for providing information regarding fluid and tissue of the vasculature.

[0025] Preferably, the high voltage pulse generator can be operatively connected with the control system and at least the first and second emitters so that the IVL operation can be controllably performed independent of the sizing operation.

Brief Description of the Drawings

[0026] FIG. 1 shows a sizing balloon including plural electrodes for excitation and sensing of conductance for cross-sectional sizing of the balloon.

[0027] FIG. 2 illustrates a system for providing intravascular lithotripsy according to an aspect of the present invention.

[0028] FIG. 3 illustrates an inflated balloon in a vessel for providing intravascular lithotripsy according to an aspect the present invention.

[0029] FIG. 4 schematically illustrates dual-purpose IVL and balloon sizing system of the present invention including at least one electrode that is part of an emitter for spark generation and that is also electrically connected with a conductance excitation module.

[0030] FIG. 5 is schematic illustration of an alternative circuit for IVL operation of a system of the present invention.

[0031] FIG. 6 is a schematic illustration of a circuit for a sizing operation utilizing conductance excitation and sensing. [0032] FIG. 7 is a graphical representation of an exemplary manner of conducting sizing operations along with IVL operations for IVL treatment of a lesion.

Detailed Description

[0033] The present invention is directed to IVL devices of the type that includes electrodes or lithotripsy emitters that create acoustic waves by arcing discharges between electrode components but may also include devices that create acoustic energy within the balloon via laser energy sources. Examples of such laser systems are described in U.S. Pat. Nos. 11,058,492 and 11,246,569 (the entire contents of which are incorporated by reference). Examples of electrically induced systems are described in U.S. Pat. Nos. 8,728,091, 9,642,673 and 10,850,078 and Published U.S. Pat. AppL No. 2022-0054194 (the entire contents of which are incorporated by reference).

[0034] With reference to the Figures, Figs. 2 and 3 show a system 10 according to the present invention comprising a console or power source 12 (in the form of an electrical generator, but alternatively in the form of a laser system), a handle 14 with therapy delivery control 15 and a catheter 20 with two lithotripsy emitters 22 (shown in the form of a pair of arcing electrodes, but alternatively they could comprise optical or laser emitters), and a fluid filled balloon 24. Optional marker bands B may be provided. The catheter 20 preferably includes a central tube 26 defining a guide wire lumen 27 through which a guide wire G passes for delivering the balloon 24 at the desired location along the guide wire G. A sheath 28 surrounds the central tube 26 and defines a delivery lumen 29 through which saline can be controllably delivered for balloon 24 inflation. The lumen 29 provides a concentric space around the central tube 26 within with electrode wires (not shown) can be run from the control 15 to the emitters 22 among other components in accordance with the present invention and discussed below. The sheath 28 is connected at a proximal end to a hub 17 that can include any number of ports allowing electrode wires to pass into the lumen 29 along with saline for inflation, the guide wire G, and any number of other components as desired.

[0035] The balloon 24 may be placed in a deflated position so as to more readily pass through a patient’s vasculature to arrive at the scene of calcification. In use, the balloon 24 will be inflated to a common pressure for angioplasty procedures (e.g. 4 atm) and the therapy actuated via the delivery control 15. [0036] Figure 3 shows the balloon 24 inflated to a therapy delivery state where the lithotripsy emitters 22 may be “fired” to disrupt the vessel calcification C. Optional indicator bands B may be provided to afford visualization and proper positioning by use of known imaging techniques. The balloon 24 is inflated to a typical angioplasty pressure (e.g. 4 atm) and therapy is delivered. The balloon 24 may naturally expand during or just after the therapy is delivered to clear the vessel for passage of blood. While two pairs of electrode pair emitters 22 are shown in Fig.’s 2 and 3, in alternative embodiments the number of electrode pair emitters can comprise only 1 pair or 4, 5, 6 or even more emitter pairs to address longer lesions, such as those encountered in the peripheral vasculature.

[0037] The control 15 is used to produce one or a series of voltage pulses in accordance with a treatment scheme. A high voltage pulse is provided to one of the emitters 22 comprising a pair of spaced electrodes and, in accordance with the illustrated embodiment, then in series to a second emitter 22 also comprising a pair of spaced electrodes. The high voltage pulse causes a spark across the first electrode pair then or also across the second electrode pair sequentially within the balloon 24. The somewhat conductive saline solution within the balloon 24 permits the high voltage spark across each electrode pair, thus creating an energy wave that propagates within the balloon toward the vessel calcification.

[0038] Any spark created within a balloon 24 that is located within a patient’s vasculature will also create a visible, or detectable, light event. Such light event can be detected at wavelengths other than that of visible light. Moreover, it is understood that a visible or detectable light leader can emanate from the ground connected electrode of any electrode pair when a high voltage pulse is initiated on the hot electrode pair prior to the actual spark event. Such a leader is similar to that seen to occur from conductive objects prior to a lightning strike. Monitoring of detectable light for looking at spark timing is the subject of co-owned pending US provisional patent application number 63/434912 filed December 22, 2022, the entire contents of which are incorporated herein by reference.

[0039] It is also contemplated that a catheter can be utilized in accordance with the present invention that does not include a balloon. Such a catheter would preferably include a lumen 29 that delivers saline to a controlled volume including the one or more emitters 22. Such a controlled volume can be created by structure of the vasculature of a patient along with the catheter distal end in the area of the emitters. Saline can be provided to fill such a controlled volume or may flow within and from such controlled volume at a controlled flow rate. A partial balloon is also contemplated from which saline fluid flow can weep from an open distal end of a partial balloon. Such a partial or open balloon design can be useful with a forward facing electrode system such as disclosed within pending US provisional patent application number 63/416,231 filed October 14, 2022, the entire contents of which are incoiporated herein by reference. In the case of a catheter 20 having a balloon 24, the controlled volume is provided within the volume of the balloon 24.

[0040] A schematic of a combined IVL and sizing system in accordance with the present invention is shown in Fig. 4. Specifically, a catheter 120 extends to an inflatable balloon 124, in a similar manner as above described. Within the balloon 124, four or more electrodes are preferably provided, such as shown at El, E2, E3, and E4. In accordance one example of the present invention, two of the electrodes El and E4 can comprise two emitters 122 that are used as described above for the purpose of generating plural high voltage sparks within the balloon 124 to create energy waves for breaking up a lesion within the vasculature. Specifically, each emitter 122 would include an electrode pair with a pair of wires running from a control system (discussed below) to each emitter 122 with one wire to each one of the electrode pair for creating a high voltage spark as discussed above. Wires 134 as schematically illustrated each represent such a pair of electrical wires for connection with the emitters 122 as comprising electrodes El and E4. As noted within an example within the Background section, such a high voltage pulse can be provided at a voltage of three thousand volts or higher, or even up to ten thousand volts or more.

[0041] In order to also conduct a sizing technique and determination from elements within the balloon 124, a pair of conductive sensing electrodes 132 can be provided at the distal end of the catheter 120 similarly to the emitters 122. As shown, the conductive sensing electrodes 132 comprise the electrodes E2 and E3 as each are spaced inwardly from the emitter electrodes El and E4. Such spacing is controlled based upon the determination of the balloon 124 cross-sectional area as further based upon a calculation using Ohms law. These electrodes E2 and E3 are spaced relative to one another based upon the desired measurement of the sizing balloon. For a measurement of cross-sectional area, they are closer to one another than for a measurement of an internal volume. lire determination of a balloon’s cross-sectional area is also discussed in the Background section including calculations that are made for such determination. Each of the conductive sensing electrodes 132 electrically connect by way of a wire 136 to a control system discussed below. [0042] In accordance with the present invention, such a balloon catheter system can be utilized as an IVL device for creating energy waves for breaking up a lesion in combination with a sizing device, such as a conductance sizing balloon “CSB”. As part of this combination, electrodes of a pair of the emitters 122 can not only provide functionality for creating a high voltage spark and energy wave, such electrodes can also provide conductance excitation for sizing. Since the electrodes of each emitter 122 require a much higher voltage to create a spark across the electrode pair, as discussed above, an electrode of each emitter 122 can also function as an excitation electrode for sizing. The energy wave pulse production is conducted at such a different voltage regime than the voltage regime of conductive excitation for sizing, and as such there is no chance of spark production when conducting a sizing operation. These dual-purpose electrodes allow sizing and energy wave production by a same dual-purpose system without having to remove one system to be replaced by another. Advantageously, a dual-purpose system of the present invention allows for a sizing determination to be conducted sequentially with energy wave pulses before or after a determined number or series of energy wave pulses. Such a system thus allows for a monitoring of a lesion breakup by conducting a sizing operation at intervals of the IVL process. A final sizing step could indicate to an operator of the system that such a lesion has been successfully broken up. It is noted that a sizing operation with a CSB can include both energizing the CSB system with DC and/or AC power. With DC power, conductance is sensed at the electrodes 132. With AC power, admittance is sensed at the electrodes 132. The combination of DC and AC power provides measurement information of both fluid and tissue, and such excitations with DC and AC power can be done separately or together as known. As used throughout this specification, the term conductance also includes admittance in the same sense as what is sensed for a sizing determination. Moreover, using the same device to both provide the therapy and test for sizing dispenses with the need to use two devices, and the attendant delay of threading into and removing two separate devices in the patient's vasculature.

[0043] In order to perform both sizing and high voltage sparking using at least a pair of electrodes electrically connected for each operation, a control system 200 is provided. As illustrated schematically in Fig. 4, the control system 200 can comprise a pair of switches 202 for activation of either the IVL system or the sizing system. Preferably, the switches 202 are arranged in parallel so that each system can be controlled independent from the other, and more preferably the activation of one switch 202 would deactivate the other switch so that only one system can operate at any given time. It is preferable that the two systems are electrically isolated from one another. Specifically, during a high voltage pulse and spark generation, electrical isolation of the CSB system from the IVL control so as not to damage the sensitive sensor(s) that are used within the CSB system for measuring conductance.

[0044] The portion of the control system 200 indicated at 204 comprises a wire bundle including the two pairs of wires 134 for spark generation and the two wires 136 for conductance sensing. As above, one wire from each wire pair 134 will also be used for excitation for the sizing operation. This wiring bundle 204 includes splitting certain of the wires between a sizing excitation and sensing module 206 and a high voltage pulse generator 212. Specifically, wires 136 would both be electrically routed to the sizing excitation and sensing module 206 to provide a sensing signal to that module from electrodes 132. The two pairs of wires 134 would be routed to the high voltage pulse generator 212 from electrodes 122 for spark generation, while one wire from each wire pair 134 would also be routed to the sizing excitation and sensing module 206 to allow excitation of electrodes 122 during a sizing operation.

[0045] Control of each system can be done including manual manipulation by an operator, such as to switch from an IVL operation to a sizing operation and vice versa. Alternatively, some or all of the steps of each operation and/or switching from one to another operation can be automated. Such control system 200 can include any number of control modules for switching from one operation to another, such as utilizing electronic switches for the switches 202, or for controlling part or all of each sizing and/or IVL system operation. Such a control system can include any number of data processors, memory, and programming provided as software or firmware.

[0046] It should be understood that, depending on the example, certain acts or events of any of the methods described herein can be performed in a different sequence, may be added, merged, or left out altogether (e.g., not all described acts or events are necessary for the practice of the method). Moreover, in certain examples, acts or events may be performed concurrently, e.g., through multi-threaded processing, interrupt processing, or multiple processors, rather than sequentially. In addition, while certain aspects of this disclosure are described as being performed by a single circuit or unit for purposes of clarity, it should be understood that the techniques of this disclosure may be performed by a combination of units or circuits associated with, for example, a medical device. [0047] In one or more examples, the functions described may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored as one or more instructions or code on a computer-readable medium and executed by a hardw'are-based processing unit. Computer-readable media may include computer-readable storage media, which corresponds to a tangible medium such as data storage media (e.g., RAM, ROM, EEPROM, flash memory', or any other medium that can be used to store desired program code in the form of instructions or data structures and that can be accessed by a computer).

[0048] Thus, instructions may be executed by one or more processors.. such as one or more digital signal processors (DSPs), general purpose microprocessors, application specific integrated circuits (ASICs), field programmable logic arrays (FPGAs), or other equivalent integrated or discrete logic circuitry. Accordingly, the term “microprocessor” or “processor,” as used herein may refer to any of the foregoing structure or any other structure suitable for implementation of the techniques described herein. Also, the techniques could be fully implemented in one or more circuits or logic elements.

[0049] Fig. 5 schematically illustrates another circuit for IVL operation. Electrodes 302, 304, 306, and 308 can be arranged in that order along a distal portion of a catheter 310 at controlled spacing as discussed above. Instead of using the outermost two electrodes 302 and 308 for sparking and energy wave generation, one or more of the other electrodes can be used. In the case of firing two emitters, one electrode from any two electrode pairs can be used. For example, as illustrated, a pair of electrodes can comprise emitters at 302 and 304 having a pair of wires electrically connecting the emitters to the high voltage pulse generator 312. It is contemplated that any one, two, or more of the electrodes 302, 304, 306, and 308 can be used for spark generation and IVL operation.

[0050] In Fig. 6, it is schematically illustrated that it is preferable that the outermost two electrodes 302 and 308 be used for excitation within a sizing operation and that the two innermost electrodes 304 and 306 be used for sensing conductance. Electrodes 302 and 308 can be electrically connected with an AC or DC excitation module 314 while electrodes 304 and 306 can be electrically connected with a sensing module 316. Modules 314 and 316 can be integrated together, as above, or as separate functions. In any case. Figs. 5 and 6 illustrate another example of a dual-purpose system for IVL operation and sizing operation. [0051] Fig. 7 is an exemplary graphical illustration 400 plotting a cross-sectional size of an inflated balloon such as within a lesion versus IVL treatments. In this system operational example of the present invention, an initial sizing operation can determine the cross-sectional size of a balloon when first introduced within a lesion and expanded. Such an initial sizing operation can provide a determination of the level of blockage of such a lesion such as indicated at point 402. Portion 404 of this graph shows the conducting of a sizing operation at intervals of IVL operations. For example, a sizing operation can be performed after one or more similar or different series of high voltage pulses at determined intervals. Fig. 7 illustrates a sizing operation at even intervals of IVL operations, wherein the open cross-sectional area of the balloon increases in a substantially even manner. In other examples, the sizing operation may indicate a very different manner of balloon cross-section increase over IVL operations. In any case, an operator is provided with feedback information in real time as to the progress and success of an IVL treatment. Optionally, a specific stent size may also be provided on the Y-axis for the convenience of the physician to confirm stent size for implantation at the site.

[0052] Sensing admittance can be accomplished in a similar manner as that of sensing conductance with four electrodes, as described above. As described in US published patent application 2022/0339428 published October 27, 2022, the entire subject matter of which is hereby incorporated by reference, admittance can be measured for determining volume of a heart chamber. Four electrodes may be spaced for measuring volume along a catheter. The electrodes may be placed on the balloon itself (e.g. by ink printing the electrodes), along the catheter shaft itself, or combinations thereof. Excitation of select electrodes and sensing at other select electrodes is done in a similar manner as that discussed above for sensing conductance and determining sizing with a CSB.

Claims

1 . A system for performing both an intravascular lithotripsy (IVL) operation and a sizing operation within vasculature of a subject comprising a catheter having a distal end provided with an inflatable balloon and a plurality of electrodes within the balloon, wherein at least a first electrode is provided as a component of a first emitter and is electrically connected with both a high voltage pulse generator for performing an IVL operation and a conductance excitation module for performing the sizing operation.

2. The system of claim 1, wherein the sizing operation comprises a conductance sizing operation that uses at least the first electrode as operatively connected with the conductance excitation module and a spaced second electrode that is operatively connected with a conductance sensor for determining at least one of a cross-sectional area or an internal volume of the balloon as inflated within a vasculature.

3. The system of any of the preceding claims, wherein the first electrode is one of a pair of electrodes comprising the first emitter for an IVL operation so that when a high voltage pulse is generated, a spark will be created across the electrode pair through a conductive medium within the balloon.

4. The system of any of the preceding claims, further comprising a third electrode as a component of a second emitter that is electrically connected with the high voltage pulse generator for performing an IVL operation in parallel with the first emitter.

5. The system of any of the preceding claims, wherein the third electrode is operatively connected with conductance excitation module for performing the sizing operation and the second emitter is electrically in parallel with the first emitter.

6. The system of any of the preceding claims, further comprising a fourth electrode that is operatively connected with the conductance sensor for performing the sizing operation along with the third electrode as connected with the conductance excitation module.

7. The system of any of the preceding claims, further comprising a control system, wherein the first and third electrodes are electrically connected to be excited by the conductance excitation module in parallel with one another by a sizing excitation and sensing control module, and the second and fourth electrodes are electrically connected to provide feedback information to the sizing excitation and sensing control module for determining the at least one of a cross-sectional area or an internal volume of the balloon as inflated within a vasculature.

8. The system of any of the preceding claims, wherein the sizing excitation and sensing control module further comprises an AC power source so that admittance is sensed and a DC power source so that conductance is sensed, each for providing information regarding fluid and tissue of the vasculature.

9. The system of any of the preceding claims, wherein the high voltage pulse generator is operatively connected with the control system and at least the first and second emitters so that the IVL operation can be controllably performed independent of the sizing operation.

10 A method of performing an intravascular lithotripsy (IVL) operation and a sizing operation within vasculature of a subject comprising a catheter having a distal end provided with an inflatable balloon and a plurality of electrodes within the balloon, the method comprising: exciting a first electrode and sensing conductance or admittance at a second electrode for performing a sizing operation within the balloon as positioned in a vasculature of a subject, and creating a spark between the first electrode, as provided as one electrode component of a first emitter pair of electrodes, and another electrode component of the first emitter pair of electrodes by providing a high voltage pulse from a high voltage pulse generator for performing an IVL operation.

11. The method of claim 10, wherein the sizing operation is performed prior to any creation of a spark for the IVL operation to provide initial sizing information.

12. The method according to any of claims 10-11, wherein a sizing operation is performed after at least one IVL operation to provide progress information of the IVL operation.

13. The method according to any of claims 10-12, wherein a sizing operation is performed after the IVL operations are complete to provide size information for an implant, such as a stent.

14. The method according to any of claims 10-13, wherein the sizing operation comprises a conductance sizing operation that uses at least the first electrode as operatively connected with the conductance excitation module and a spaced second electrode that is operatively connected with a conductance sensor, and the method further comprises determining at least one of a cross-sectional area or an internal volume of the balloon as inflated within a vasculature.

15. The method according to any of claims 10-14, further comprising a third electrode as a component of a second emitter that is electrically connected with the high voltage pulse generator, and the method further comprises performing an IVL operation in parallel with the first emitter.

16. The method according to any of claims 10-15, wherein the third electrode is operatively connected with conductance excitation module, and the method further comprises performing the sizing operation with the second emitter electrically in parallel with the first emitter.

17. The method according to any of claims 10-16, further comprising a fourth electrode that is operatively connected with the conductance sensor, and the method further comprises performing the sizing operation along with the third electrode as connected with the conductance excitation module.

18. The method according to any of claims 10-17, having a control system, wherein the first and third electrodes are electrically connected to be excited by the conductance excitation module in parallel with one another by a sizing excitation and sensing control module, and the second and fourth electrodes are electrically connected to provide feedback information to the sizing excitation and sensing control module, and the method further comprises determining the at least one of a cross-sectional area or an internal volume of the balloon as inflated within a vasculature.

19. The method according to any of claims 10-18, wherein the sizing excitation and sensing control module, and the method further comprises exciting with an AC power source so that admittance is sensed and exciting with a DC power source so that conductance is sensed, each for providing information regarding fluid and tissue of the vasculature.

20. The method according to any of claims 10-19, wherein the high voltage pulse generator is operatively connected with the control system and at least the first and second emitters so that the IVL operation can be controllably performed independent of the sizing operation.