Balloon catheter system

Abstract

A catheter system (108) includes a balloon (112) and a control circuit (128) configured to control a size of the balloon by at least controlling an inflation pressure of the balloon. For example, the control circuitry may be configured to control inflation pressure by controlling at least a flow of fluid through an interior volume of the balloon. In some examples, the control circuit is configured to control the size of the balloon based on input provided by a user, such as based on user input indicative of a pressure setpoint or a particular balloon size. Additionally, in some examples, the control circuit is configured to control the treatment element based on the size of the balloon.

Description

Technical Field

[0001] The present technology involves a catheter. Background Art

[0002] Catheters have been proposed for various medical procedures. For example, catheters can be configured to deliver neuromodulation therapy to a target tissue site to change the activity of nerves at or near the target tissue site. Nerves can be, for example, sympathetic nerves. The sympathetic nervous system (SNS) is a major involuntary body control system that is usually associated with a stress response. Chronic overactivation of the SNS is a maladaptive response that can drive the progression of many disease states. For example, overactivation of the renal SNS has been confirmed in experiments and humans as a possible cause of the complex pathophysiology of arrhythmias, hypertension, volume overload states (e.g., heart failure) and progressive nephropathy. Summary of the invention

[0003] The present disclosure describes a catheter system, which includes an elongated body and a balloon, which is configured to be positioned within a patient's blood vessel to deliver therapy to the patient. The therapy may include, for example, neuromodulation therapy, such as renal denervation. The catheter system includes a treatment element (e.g., an ultrasonic element), which is configured to deliver therapy to the patient's blood vessel wall or other tissue. The balloon is configured to expand within the blood vessel, such as during a medical procedure to help occlude the blood vessel, help maintain the elongated body within the blood vessel, help displace the elongated body and the blood vessel wall, help position the treatment element within the blood vessel and / or for other reasons. For example, the expanded balloon can be configured to center the treatment element approximately within the blood vessel, help keep the treatment element in place relative to the blood vessel wall, and / or otherwise help. In addition, in some examples, the fluid used to expand the balloon (also referred to as inflation in this article) is configured to change the temperature at or near the target tissue site. For example, the treatment element can be configured to heat the fluid, which then heats the target tissue site at the interface between the balloon and the target tissue site.

[0004] In some examples, the catheter system is configured to control the size of the balloon by at least controlling the inflation pressure of the balloon. The catheter system is configured so that the inflation pressure depends on the flow rate (e.g., a function of the flow rate) of the fluid (e.g., saline) through the internal volume of the balloon. The catheter system includes a control circuit, which is configured to control the inflation pressure by at least controlling the flow of the fluid through the internal volume. In some examples, the control circuit is configured to associate the size (e.g., diameter) of the balloon with a specific inflation pressure value or inflation pressure value range. The control circuit can be configured to control the flow of the fluid to substantially maintain a specific inflation pressure (or inflation pressure range), which enables the control circuit to control the size of the balloon. In some examples, the control circuit is configured to control the size of the balloon based on the input provided by a clinician or other user.

[0005] When the balloon is inflated within the vessel, the size of the balloon defines the displacement between the therapeutic element and the vessel wall. Due to this spacing between the therapeutic element and the vessel wall, for larger vessels, more energy may need to be delivered via the therapeutic element to achieve the desired therapeutic outcome compared to smaller vessels. Therefore, in some examples, the amount of energy (e.g., ultrasound energy or microwave energy) delivered by the therapeutic element can be selected based on the size of the vessel in which the catheter system is positioned. Because the clinician can select the size of the balloon (when inflated) so that the balloon is juxtaposed with the vessel wall, in some examples, the control circuit is configured to control the power of the therapeutic element based on information indicating the size of the inflated balloon. Such information can be provided by the user or can come from another source.

[0006] In an example, a catheter system includes: an elongated body configured to be positioned within a patient's blood vessel; a balloon defining an internal volume; a sensor configured to generate a pressure signal indicating a pressure of a fluid within a flow path, the flow path including the internal volume and at least one lumen defined by the elongated body; a valve configured to define a flow area for the fluid; and a control circuit configured to: determine a pressure set point, receive a pressure signal from the sensor, and position the valve to adjust the flow area based on the pressure set point and the pressure indicated by the sensor signal.

[0007] In an example, a catheter system includes: a slender body; a balloon defining an internal volume; a therapeutic element mechanically supported by the slender body, wherein the therapeutic element is configured to emit energy; and a control circuit configured to: receive an input indicating a pressure within the internal volume of the balloon, determine a power level based on the indicated pressure, and cause the therapeutic element to emit energy based on the determined power level.

[0008] In an example, a method includes: receiving, by a control circuit, a sensor input from a pressure sensor indicating a pressure of a fluid within a flow path for the fluid flowing through an internal volume of a balloon, the flow path being defined by a slender body of a catheter, wherein the slender structure is configured to be positioned with an anatomical lumen of a patient; and positioning, using the control circuit, a valve configured to throttle the flow of the fluid through the flow path based on a difference between a pressure set point and a pressure indicated by the sensor input.

[0009] In an example, a method includes: receiving, by a control circuit, an input indicative of a pressure within an interior volume of a balloon of a catheter, wherein the elongated body of the catheter defines a flow path for a fluid flowing through the interior volume of the balloon, and wherein at least a distal portion of the catheter is configured to be positioned with an anatomical lumen of a patient; determining, by the control circuit, a power level of an energy emitting element of the catheter based on the indicative input; and causing the energy emitting element to emit energy based on the power level using the control circuit.

[0010] Also disclosed herein is a catheter system comprising a balloon and a control circuit configured to control the size of the balloon by at least controlling the inflation pressure of the balloon, wherein, for example, the control circuit can be configured to control the inflation pressure by at least controlling the flow of a fluid through an interior volume of the balloon, wherein the control circuit can be configured to control the size of the balloon based on input provided by a user (e.g., based on user input indicating a pressure set point or a particular balloon size), and wherein the control circuit can be configured to control a therapeutic element based on the size of the balloon.

[0011] The details of one or more aspects of the present disclosure are set forth in the following drawings and description. Other features, objectives, and advantages of the techniques described in the present disclosure will be apparent from the description and drawings, and from the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is a schematic diagram of an exemplary medical system including a catheter system.

[0013] Figure 2 yes Figure 1 Schematic diagram of the catheter system in a patient's blood vessel.

[0014] Figure 3 yes Figure 1 Schematic diagram of the catheter system approaching a patient's renal artery.

[0015] Figure 4 yes Figure 1 Schematic diagram of the catheter system in the delivery configuration.

[0016] Figure 5 yes Figure 1 Schematic diagram of the catheter system in an expanded configuration.

[0017] Figure 6 It is a depiction Figure 1 Example illustration of the pressure within a balloon of a catheter system and the size defined by the balloon.

[0018] Figure 7 is an example illustration depicting the parameters of the balloon and the energy levels of the treatment elements.

[0019] Figure 8It is shown that the use Figure 1 Flow chart of an exemplary technique for controlling the inflation pressure of a balloon using a catheter system.

[0020] Fig. 9 It is shown that the use Figure 1 A flow chart of an exemplary technique for controlling the power level of a therapeutic element of a catheter system. DETAILED DESCRIPTION

[0021] The present disclosure describes an exemplary catheter system, which includes an elongated body configured to be positioned in a patient's body, at least one balloon carried by the elongated body, and at least one therapeutic element configured to deliver treatment to a target tissue site of the patient to achieve a therapeutic result. The catheter system and the system including the catheter system and the method using the catheter system can be used for any suitable medical procedure including delivering therapy (e.g., ultrasonic energy, microwave energy and / or radio frequency (RF) energy) to a target tissue site via a therapeutic element, such as neuromodulation (e.g., denervation). The catheter system is configured to be positioned (e.g., by a clinician) in a patient's blood vessel or other anatomical lumen. The at least one balloon is configured to expand in the anatomical lumen, for example, to help occlude the anatomical lumen, to help maintain the elongated body in the anatomical lumen, to help displace the wall of the elongated body and the anatomical lumen, to help position the therapeutic element in the anatomical lumen and / or for other reasons. For example, the catheter system can be configured so that the expanded balloon helps keep the therapeutic element in place relative to the vessel wall, such as by making the therapeutic element roughly centered in the blood vessel.

[0022] The balloon of the catheter is configured to deliver (e.g., circulate) a fluid relative to the vessel wall to change the temperature at or at the target tissue site. This temperature change can be used to provide a therapeutic result (e.g., cryotherapy or heat-based therapy) or can be used to help protect the vessel wall or other anatomical lumen wall. For example, to help achieve a therapeutic result, the therapeutic element can be configured to heat the fluid, which then causes damage to the target tissue site. As another example, the fluid can be configured to cool the vessel wall or a therapeutic element inside or outside the balloon to help protect the vessel wall from the heat generated by the therapeutic energy delivery (e.g., the therapeutic energy delivery performed by an ultrasonic transducer).

[0023] Although mainly referring to blood vessels throughout this disclosure, the devices, systems and techniques described herein are also applicable to other target tissue sites. In addition, although mainly referring to a single balloon catheter throughout this disclosure, the catheter system described herein may include more than one balloon, such as two, three, four or more balloons.

[0024] In some examples, the balloon is configured to expand to a certain range of sizes (e.g., diameters). For example, the balloon can be a compliant balloon. The balloon is configured to expand to a specific size within the range based on the inflation pressure within the balloon. In an example, the expanded size of the balloon is selected by a clinician based on the size of the blood vessel, for example, selected so that the balloon can contact the blood vessel wall.

[0025] In some examples described herein, the control circuit of the catheter system is configured to control the size of the balloon (also referred to herein as size, such as diameter) by at least controlling the inflation pressure of the balloon. In this way, the control circuit can be configured to adjust the size of the balloon to take into account the size of the blood vessel in which the elongated body and the balloon are positioned. For example, in some examples, the catheter system is configured to receive an input (e.g., from a clinician) indicating the size (e.g., diameter) of the blood vessel in which the procedure is to be performed. Once positioned in the blood vessel, the control circuit of the catheter system is configured to inflate the balloon to a specific inflation pressure based on the input so that the diameter of the inflated balloon enables the balloon to be juxtaposed with the vessel wall during the procedure. In some examples, the control circuit is configured to at least partially shrink the inflated balloon (e.g., based on the user input received) so that the clinician can reposition the catheter system in the patient's body. As used herein, the pressure of a fluid can refer to the static pressure of the fluid, the dynamic pressure of the fluid, or the total pressure of the fluid.

[0026] Thus, the catheter system is configured such that the balloon defines one of a plurality of sizes, such that the catheter system can be used in vessels of different sizes. This can be advantageous in intravascular procedures where treatment (e.g., renal neuromodulation) needs to be delivered in multiple vessels having different vessel diameters. The catheter system enables the clinician to control the inflation size of the balloon to accommodate the different sizes of each of the multiple vessels, such that the catheter system can be guided to deliver treatment to each of the multiple vessels without the need to remove the catheter system from the patient's vasculature and without the need to use multiple catheters with different inflation balloon sizes.

[0027] For example, a clinician can guide a catheter to a first target treatment site in a first blood vessel of a patient. The clinician can deliver the first treatment to the first target treatment site by providing at least a first input, which causes the catheter system to expand the balloon to adapt to the diameter of the first blood vessel. The clinician can then partially or completely shrink the balloon to guide the catheter system through the vascular system to a second treatment site in a second blood vessel with different diameters. The clinician can then inflate the catheter system to adapt to the different diameters of the second blood vessel so that the second treatment can be delivered to the second treatment site. In a similar manner, the clinician can deliver the treatment to other sites in other blood vessels, so that treatment at each blood vessel in multiple blood vessels can be performed without removing the catheter system from the patient's vascular system and without using two different catheters with different expansion balloon sizes.

[0028] The catheter system is configured to provide a flow path for a fluid (e.g., saline) to flow through the internal volume of the balloon to generate inflation pressure in the balloon. For example, the catheter system can be configured to maintain the flow of the fluid through the flow path so that heat can be transferred to the tissue wall or from the tissue wall to the saline (e.g., to provide cooling or heating to the tissue wall during treatment). In some examples, the catheter system is configured to maintain the flow of the fluid through the flow path so that heat can be transferred from the therapeutic element (e.g., ultrasonic element) supported in the internal volume of the balloon. The catheter system is configured to control the flow of fluid to control the inflation pressure in the balloon, and thus control the expansion size of the balloon in the blood vessel. For example, the control circuit of the catheter system can change the flow of fluid to cause the reduction of the inflation pressure in the balloon, thereby causing the size (e.g., diameter) of the balloon to decrease. As another example, the control circuit can change the flow of fluid to cause the increase of the inflation pressure in the balloon, thereby causing the size (e.g., diameter) of the balloon to increase. In some examples, the catheter system is configured to control fluid flow to substantially maintain (e.g., maintain or nearly maintain to the extent allowed by manufacturing tolerances) inflation pressure within the balloon so that the balloon defines substantially the same size (e.g., diameter).

[0029] In an example, the catheter system includes a valve configured to control the flow of fluid flowing through the balloon. The valve is configured to control the flow area in the flow path for the fluid leaving the balloon to control the flow of the fluid leaving the balloon. In some examples, the valve is configured so that the adjustment of the valve will change the back pressure of the fluid flow upstream of the valve. For example, adjusting the valve in the closing direction can increase the back pressure of the fluid flow upstream of the valve. Adjusting the valve in the opening direction can reduce the back pressure of the fluid flow upstream of the valve. In some examples, the valve is positioned downstream of the internal volume of the balloon so that the back pressure generated by the valve acts on the internal volume of the balloon. In an example, the catheter system is configured to control the inflation pressure in the internal volume of the balloon by at least adjusting the valve to control the back pressure generated by the fluid flow. Therefore, in an example where the inflation pressure in the balloon corresponds to the size of the balloon, the catheter system can be configured to control the flow of the fluid through the flow path to control the size (e.g., diameter) of the balloon. The flow path can include, for example, the internal volume of the balloon and one or more lumens defined by the elongated body of the catheter system.

[0030] In some examples, the catheter system includes a sensor (e.g., a pressure sensor) configured to generate a pressure signal indicating the pressure of the fluid in the flow path. The pressure of the fluid in the flow path can indicate the inflation pressure within the internal volume of the balloon. The catheter system can be configured so that the pressure sensed by the sensor is at least proportional to the pressure of the fluid within the internal volume of the balloon. In some examples, the control circuit is configured to adjust the flow area of ​​the flow path of the fluid (e.g., using a valve) based on the pressure signal generated by the sensor to increase, decrease and / or substantially maintain the inflation pressure within the balloon. Therefore, in an example where the inflation pressure within the balloon corresponds to the size of the balloon, the catheter system can be configured to regard the pressure indicated by the pressure signal as a representative of the size (e.g., diameter) of the balloon so that the control circuit can control the size of the balloon.

[0031] In some examples, the control circuit is configured to receive information indicating the pressure within the internal volume of the balloon, such as by directly or indirectly receiving a pressure signal from a sensor, and cause adjustment of the flow area of ​​the flow path based on the information (e.g., by adjusting the position of the valve). In some examples, the control circuit is configured to receive an input indicating a pressure set point for the internal volume of the balloon, and cause adjustment of the flow area based on the pressure indicated by the pressure signal and the pressure set point (such as based on the difference between the pressure and the pressure set point). For example, the control circuit can be configured to cause adjustment of the flow area of ​​the fluid by at least changing the position of the valve (e.g., closing, further closing, opening, and / or further opening). The positioning of the valve caused by the control circuit can change the back pressure generated by the fluid flow (e.g., generated upstream of the valve), and thereby change the inflation pressure within the internal volume of the balloon, thereby causing the inflation pressure to approach and / or equal the pressure indicated by the pressure set point. Thus, because the inflation pressure within the balloon corresponds to and affects the size of the balloon, the control circuit can use the pressure sensed by the sensor as a representative of the size (e.g., diameter) of the balloon, and use the input indicative of a pressure set point as a representative of the desired size (e.g., desired diameter) of the balloon, and thereby control the flow path of the fluid so that the balloon achieves and / or substantially maintains the desired size.

[0032] In addition to or in lieu of controlling the flow area of ​​the fluid used to inflate the balloon based on a pressure set point, in some examples, the control circuit is configured to control the energy level of the treatment element based on the size (e.g., diameter) of the balloon. In some examples, the control circuit is configured to control the flow area of ​​the fluid based on the power level setting of the treatment element. The catheter system can be configured so that the displacement between the treatment element and the vessel wall is proportional to and / or dependent on the size of the inflated balloon within the vessel. For example, the treatment element may be positioned within the internal volume of the balloon. Due to this spacing between the treatment element and the vessel wall, for larger vessels, more energy may need to be delivered via the treatment element to achieve the desired treatment result compared to smaller vessels. For example, a larger spacing between the treatment element and the vessel wall (e.g., corresponding to a larger vessel) may increase the distribution area of ​​the energy from the treatment element, making it possible to increase the energy emitted by the treatment element in order to provide a sufficient amount of energy to the vessel wall. Therefore, in some examples, the control circuit is configured to determine the size (e.g., diameter) and / or inflation pressure of the inflated balloon, and determine the power level of the treatment element based on the size of the inflated balloon. In an example, the control circuit is also configured to determine the power level based on the type of medium through which the therapeutic element transmits energy upon resulting displacement (e.g., saline to inflate the balloon), as different mediums may heat or otherwise transfer thermal energy differently.

[0033] In some examples, the control circuit is configured to control the inflation of the balloon based on an assessment that the inflated balloon has been sufficiently inflated to contact the vessel wall. For example, the balloon can be configured such that when the balloon is inflated in a substantially unconstrained state within the vessel (e.g., before contacting the vessel wall), the inflation pressure within the interior volume of the balloon defines an ascending trend curve. In some examples, the control circuit uses a pressure signal from a sensor configured to sense the inflation pressure to determine the trend curve. In an example, the control circuit is configured to identify a deviation from the trend curve (e.g., identifying a relatively sudden, more dramatic increase in internal pressure, etc.), which indicates that the size of the balloon may have increased sufficiently to cause the vessel wall to at least partially resist continued inflation of the balloon. The control circuit can be configured to change the flow rate of the fluid passing through the balloon in response to the deviation from the trend curve. For example, the control circuit can be configured to change the flow rate so that the inflation pressure within the balloon substantially stops increasing, so that once the balloon is inflated to contact the vessel wall, the size of the balloon can remain relatively stable.

[0034] Therapeutic elements as described herein can be used to provide any suitable type of therapy, such as denervation therapy.Such as arrhythmia, hypertension, volume overload state (for example, heart failure) and the progressive nephropathy caused by the overactivation of the sympathetic nervous system (SNS) can be relieved by regulating the activity (neuromodulation) of overactive nerves, for example, by denervation or reducing the activity of overactive nerves.Some sympathetic nerves (such as the sympathetic nerves of kidney) are located near blood vessels, so that these overactive nerves can be denervated chemically, thermally or electrically by ablating the sympathetic nerve tissue in or near the blood vessels (for example, renal blood vessels).Chemical substances, thermal energy (thermal energy) (for example, thermal energy (heat energy) or cryotherapy energy) or electrical energy can be delivered to the sympathetic nerve tissue and / or produced in the sympathetic nerve tissue via the therapeutic element carried by the catheter and positioned in the patient's vascular system.

[0035] In neuromodulation, one or more therapeutic elements may be introduced near one or more target nerves. For example, in renal neuromodulation, one or more therapeutic elements may be introduced near the renal nerves located between the patient's aorta and the kidney. In some examples, the one or more therapeutic elements may be carried by or attached to a catheter, and the catheter may be introduced intravascularly, such as into the renal artery via a brachial, femoral, or radial artery approach. In other examples, the one or more therapeutic elements may be introduced extravascularly, such as using laparoscopic techniques.

[0036] Although the present technology is described herein in many instances with reference to renal nerves and blood vessels, the present technology is also applicable to neuromodulation at other anatomical sites and their associated nerves (e.g., spinal neuromodulation, cardiac neuromodulation, cranial neuromodulation, sacral neuromodulation, urinary neuromodulation, and / or neuromodulation techniques involving other parts of the body), and such devices and systems can be configured (e.g., with a suitable shape and size) for use at such sites. For example, a catheter can be configured to deliver energy with a portion of the catheter carrying a therapeutic element positioned with a specific anatomical lumen or specific tissue (e.g., a renal artery, an external iliac artery, an internal iliac artery, an internal pudendal artery, a celiac artery, a mesenteric artery, a superior mesenteric artery, an inferior mesenteric artery, a hepatic artery, a splenic artery, a gastric artery, a left gastric artery, a pancreatic artery, a uterine artery, an ovarian artery, a testicular artery, and / or their associated arterial branches, appendages, veins, and / or other hollow anatomical structures).

[0037] As used herein, the terms "distal" and "proximal" define a position or direction relative to a treating clinician or a clinician's controls (e.g., a handle assembly). "Distal" or "distalwardly" may refer to a position away from or in a direction away from a clinician or a clinician's controls. "Proximal" and "proximally" may refer to a position close to or in a direction toward a clinician or a clinician's controls.

[0038] Figure 1 is a partially schematic perspective view showing a medical system 100 configured according to some examples of the present disclosure. Figure 2 is a schematic diagram of a portion of a medical system 100 within a blood vessel 102 of a patient 106 , the blood vessel 102 having a blood vessel wall 104 . Figure 3 Medical system 100 is shown being guided through the vasculature of patient 106 to a target treatment site within blood vessel 102. Figure 2 and Figure 3 In the example of , blood vessel 102 is a renal artery and blood vessel wall 104 is a renal artery wall. However, in other examples, medical system 100 is configured to deliver therapy to other blood vessels, anatomical lumens, and / or other tissues, such as the external iliac artery, the internal iliac artery, the internal pudendal artery, the celiac artery, the mesenteric artery, the superior mesenteric artery, the inferior mesenteric artery, the hepatic artery, the splenic artery, the gastric artery, the left gastric artery, the pancreatic artery, the uterine artery, the ovarian artery, the testicular artery, and / or their associated arterial branches, appendages, veins, and / or other hollow anatomical structures of a patient.

[0039] The medical system 100 includes a catheter system 108 that defines an elongated body 110 that is configured to be positioned (e.g., by a clinician) within a blood vessel 102 of a patient 106. The catheter system 108 includes one or more expandable elements, such as a balloon 112 ("balloon 112"), that are configured to expand (e.g., by inflating) when the elongated body 110 is positioned within the blood vessel 102. The balloon 112 can be configured to expand to, for example, help occlude the blood vessel 102 during a procedure, help maintain the elongated body 110 within the blood vessel 102, help displace and / or maintain displacement between the elongated body 110 and the blood vessel wall 104, and / or for other reasons. The elongated body 110 defines a longitudinal axis L. The balloon 112 can be configured to expand radially outward relative to the longitudinal axis L (e.g., substantially perpendicular to the longitudinal axis L) when the balloon 112 is inflated within the blood vessel 102 of the patient 106.

[0040] The catheter system 108 includes a therapeutic element 114 configured to deliver therapy to tissue, for example, to perform neuromodulation or another procedure on the vessel wall 104 and / or other tissue associated with the vessel 102. Although the therapy is primarily referred to herein as energy (e.g., acoustic, radiofrequency, pulsed field, heat, or direct current), in other examples, the therapy can be in the form of any suitable therapeutic modality.

[0041] The balloon 112 is configured to help position the therapeutic element 114 within the vessel 102 during the procedure. For example, the catheter system 108 can be configured such that inflation of the balloon 112 helps hold the therapeutic element 114 in place relative to the vessel wall 104 (e.g., approximately centered within the vessel 102), helps maintain displacement between the therapeutic element 114 and the vessel wall 104, and / or otherwise assists. In some examples, the elongated body 110 supports (e.g., mechanically supports) the balloon 112. The elongated body 110 can also support (e.g., mechanically supports) the therapeutic element 114. For example, the therapeutic element 114 can be positioned within the interior volume 116 of the balloon 112 or outside of the balloon 112, such as on an outer surface of the balloon 112.

[0042] The catheter system 108 is configured to control the inflation pressure PI within the interior volume 116 of the balloon 112 to control the size (e.g., diameter) of the balloon 112. The catheter system 108 is configured to control the inflation pressure PI by at least controlling the pressure of the fluid (e.g., saline) flowing within the interior volume 116. In some examples, the catheter system 108 is configured to enable the fluid to flow substantially continuously (e.g., continuously or nearly continuously) through the interior volume 116 to achieve the desired inflation pressure PI. The catheter system 108 can be configured to adjust and / or establish the flow rate (e.g., mass flow) through the interior volume 116 in order to adjust and / or establish the inflation pressure PI within the interior volume 116, and thus adjust and / or establish the size of the balloon 112.

[0043] For example, the catheter system 108 can be configured such that a fluid can flow into the fluid inlet 118 (e.g., flow F1), through the inlet lumen defined by the elongated body 110, through the interior volume 116, and then through the outlet lumen defined by the elongated body 110, and then out through the fluid outlet 120 (e.g., flow F2). Thus, the inlet lumen, the interior volume 116, and the outlet lumen can define a flow path for the fluid flowing through the catheter system 108. The catheter system 108 includes a valve 122 configured to control a flow area of ​​the fluid (e.g., by throttling the flow of the fluid). The flow area can be, for example, a flow area defined by the valve 122 (e.g., defined by the position of a restriction element of the valve 122 relative to a valve seat of the valve 122). The position of the valve 122 can thus control the pressure of the fluid flowing within at least a portion of the flow path (e.g., a portion upstream of the valve 122). The catheter system 108 can be configured such that the pressure within the portion of the flow path affects the inflation pressure PI within the interior volume 116, such that the inflation pressure PI of the balloon 112 can be adjusted and / or established by the position of the valve 122. Thus, the catheter system 108 is configured such that the position of the valve 122 controls the size of the balloon 112.

[0044] In an example, the conduit system 108 includes a pump 124 configured to drive a fluid flow through a flow path defined by the conduit system 108. The conduit system 108 may include a fluid container 125 that defines a reservoir 127 configured to hold a volume of fluid. The pump 124 may be configured to extract fluid from the reservoir 127 and discharge the fluid into the flow path. In some examples, the pump 124 is a positive displacement pump, such as a peristaltic pump, a diaphragm pump, a cam pump, a piston pump, a screw pump, a gear pump, a rotary vane pump, or other positive displacement pumps. In an example, the pump 124 is a dynamic pump, such as a centrifugal pump, a cantilever pump, a vertical centrifugal pump, a multistage centrifugal pump, or other dynamic pumps. In an example, the pump 124 is an axial flow pump or a radial flow pump.

[0045] In some examples, valve 122 is located in a portion of the flow path downstream of interior volume 116 of balloon 112. Valve 122 can be configured such that adjusting valve 122 in a closing direction increases the pressure of the fluid flowing upstream of valve 122 (e.g., increases back pressure), thereby causing an increase in inflation pressure PI within interior volume 116, and such that adjusting valve 122 in an opening direction decreases the pressure of the fluid flowing upstream of valve 122 (e.g., decreases back pressure), thereby causing a decrease in inflation pressure PI within interior volume 116. Valve 122 is configured such that when the position of valve 122 is substantially unchanged (e.g., unchanged or unchanged to the extent permitted by manufacturing tolerances), the pressure of the fluid flowing upstream of valve 122 (e.g., back pressure) and / or the inflation pressure PI within interior volume 116 are substantially unchanged. Thus, when the size of balloon 112 is a function of the inflation pressure PI within interior volume 116 , catheter system 108 may be configured to control the inflation pressure PI within balloon 112 using valve 122 in order to control the size (eg, diameter) of balloon 112 .

[0046] In some examples, catheter system 108 includes sensor 126 configured to sense a parameter indicative of inflation pressure PI of balloon 112 and to generate a pressure signal indicative of inflation pressure PI. For example, sensor 126 may include a pressure sensor configured to generate a pressure signal indicative of pressure within interior volume 116 or at another location along the flow path described above, such as in the lumen of elongated body 110 or at another location. In an example, the parameter indicative of inflation pressure PI sensed by sensor 126 is a flow area (e.g., flow area A) of valve 122. Figure 4 , Figure 5 The catheter system 108 may be configured to adjust the position of the valve 122 based on the pressure signal generated by the sensor 126 to increase, decrease and / or maintain the inflation pressure PI within the balloon 112.

[0047] The catheter system 108 may include a control circuit 128 configured to control the inflation pressure PI of the balloon 112. In some examples, the control circuit 128 is configured to receive the pressure signal and cause adjustment of the inflation pressure PI within the balloon 112 based on the pressure signal. For example, the control circuit 128 may be configured to receive an input indicating a pressure set point and cause adjustment of the position of the valve 122 based on the pressure indicated by the pressure signal and the pressure set point (such as based on the difference between the pressure and the pressure set point). Thus, in the case where the size of the balloon corresponds to the inflation pressure PI within the interior volume 116 of the balloon 112, the control circuit 128 may treat the pressure sensed by the sensor 126 as a representative of the size (e.g., diameter) of the balloon 112, treat the input indicating the pressure set point as a representative of the desired size (e.g., desired diameter) of the balloon 112, and control the position of the valve 122 so that the balloon 112 achieves and / or substantially maintains the desired size.

[0048] In an example, the catheter system 108 can be configured to substantially determine the flow rate through the interior volume 116 of the balloon 112. For example, the catheter system 108 can include a flow sensor 129 configured to sense a parameter indicating the flow rate through the interior volume 116 of the balloon 112. The catheter system 108 can be configured to substantially determine the flow rate through the interior volume 116 based on the speed of the pump 124 or using another indication. The control circuit 128 can be configured to adjust one or more of the position of the valve 122 or the flow rate provided by the pump 124 to control the inflation pressure PI. In an example, the control circuit 128 is configured to adjust one or more of the position of the valve 122 or the flow rate provided by the pump 124 to maintain the flow rate through the interior volume 116 above a flow threshold, such as above 5 ml / min. In some examples, control circuit 128 is configured to optimize (eg, substantially maximize) a flow rate through interior volume 116 (eg, based on a pressure signal from sensor 126 ) for a given inflation pressure PI within interior volume 116 .

[0049] The control circuit 128 and other processors, processing circuits, controllers, control circuits, etc. described herein may include any combination of the following: integrated circuits, discrete logic circuits, analog circuits, such as one or more microprocessors, digital signal processors (DSPs), application specific integrated circuits (ASICs), or field programmable gate arrays (FPGAs). In some examples, the control circuit 128 may include multiple components, such as any combination of one or more microprocessors, one or more DSPs, one or more ASICs, or one or more FPGAs, as well as other discrete or integrated logic circuits and / or analog circuits.

[0050] Although not in Figure 1As shown in , the system 100 may also include a memory 44 configured to store program instructions (such as software), which may include one or more program modules that can be executed by the control circuit 128. When executed by the control circuit 128, such program instructions can cause the control circuit 128 to provide the functionality attributed to the control circuit 128 herein. The program instructions may be embodied in software and / or firmware. The memory may include any volatile medium, non-volatile medium, magnetic medium, optical medium, or electrical medium, such as random access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), electrically erasable programmable ROM (EEPROM), ferroelectric RAM (FRAM), flash memory, or any other digital medium.

[0051] In some examples, the catheter system 108 includes a user interface 130, which is configured to receive an input indicating a pressure set point from a user and provide the input to the control circuit 128. The user interface 130 can be configured to receive an input indicating a pressure set point from a clinician and / or other user so that the clinician and / or other user can specify the desired size of the balloon 112. The user interface 130 can have any suitable configuration sufficient to receive input from the user. For example, the user interface 130 may include a button or a keypad, a touch screen, a speaker configured to receive a voice command from a user, and / or a display (such as a liquid crystal (LCD), a light emitting diode (LED) or an organic light emitting diode (OLED)). In some examples, the user interface 130 includes a device body 132 and a positioning member 134, which is configured to move (e.g., rotate) relative to the device body 132 to limit the desired size of the balloon 112. In these examples, the user interface 130 may include one or more markings 136 indicating the position of the positioning member 134 relative to the device body 132 so that the clinician can place the positioning member 134 in a specific position relative to the device body 132 to specify the desired size of the balloon 112. In some examples, the user interface 130 is configured to display information such as one or more desired sizes and / or set points (e.g., the current desired size and / or set point being used by the control circuit 128, or one or more predetermined desired sizes and / or set points from which the user can select to input a desired size of the balloon 112).

[0052] In some examples, the elongated body 110 is configured to support the therapeutic element 114 at a fixed longitudinal position (measured along the longitudinal axis L) on the elongated body 110 relative to the balloon 112. For example, Figure 1 and Figure 2As shown, the elongated body 110 can support the therapeutic element 114 such that the therapeutic element 114 is positioned within the interior volume 116 of the balloon 112. In examples, the elongated body 110 is configured to support the therapeutic element 114 such that the balloon 112 extends substantially over (e.g., substantially around) the therapeutic element 114. In some examples, the elongated body 110 supports the therapeutic element 114 such that the therapeutic element 114 is positioned distal to (e.g., displaced from) the balloon 112 in a direction D or proximal to (e.g., displaced from) the balloon 112 in a direction P. In some examples, the balloon 112 supports the therapeutic element 114 such that, for example, inflation of the balloon 112 reduces displacement between the therapeutic element 114 and the vessel wall 104. For example, the therapeutic element 114 can be supported by the outer surface 138 of the balloon 112 ("balloon outer surface 138"), the inner surface 140 of the balloon 112 ("balloon inner surface 140"), and / or a portion of the balloon body 142 between the balloon outer surface 138 and / or the balloon inner surface 140 and / or defining the balloon outer surface and / or the balloon inner surface.

[0053] The elongated body 110 defines a distal portion 110A ("distal body portion 110A") and a proximal portion 110B ("proximal body portion 110B"). Figure 1 In the example shown, the therapeutic element 114 and / or the balloon 112 are positioned on the distal portion 110A. In an example, the catheter system 108 is configured to present a relatively low-profile delivery configuration, wherein at least one of the distal portion 110A and / or the balloon 112 defines a dimension C1 (e.g., a diameter) that can be measured in a direction perpendicular to the longitudinal axis L. The dimension C1 can define a displacement sufficient to allow at least the distal body portion 110A and the balloon 112 to pass through the vasculature of the patient 106 to reach a target treatment site in the patient 106. In some examples, the distal body portion 110A is configured to position the therapeutic element 114 at an intraluminal (e.g., intravascular) position. In an example, the catheter system 108 is configured such that in the delivery configuration, the dimension C1 measures 2Fr (French), 3Fr, 4Fr, 5Fr, 6Fr, or 7Fr, or another suitable size. The balloon 112 is configured to expand from the delivery configuration to the expanded configuration ( Figure 2 ), for example, to position and / or stabilize the distal body portion 110A and / or the therapeutic element 114 when the distal body portion 110A positions the therapeutic element 114 at a target treatment site.

[0054] The medical system 100 may include a generator 144 that is configured to control, monitor, supply and / or otherwise support the operation of the catheter system 108. In other examples, the catheter system 108 may be self-contained and / or otherwise configured to operate independently of the generator 144. When the generator 144 is present, the generator may be configured to generate energy of a selected form and / or amount for delivery to tissue at the treatment site via the catheter system 108 (e.g., the therapeutic element 114). For example, the generator 144 may be configured to generate energy (e.g., pulsed field, current, microwave, radio frequency, monopolar energy and / or bipolar energy). In other examples, the generator 144 may be another type of device that is configured to generate another suitable type of energy and deliver it to the catheter system 108.

[0055] The medical system 100 includes a cable 147 configured to deliver power from the generator 144 and the catheter system 108. Along the cable 147 or at another suitable location within the medical system 100, the medical system 100 may include a control device 145 that is configured to initiate, terminate, and / or adjust the operation of one or more components of the catheter system 108 directly and / or via the generator 144. In some examples, the generator 144 may be configured to execute an automated control algorithm 146 and / or receive control instructions from an operator. Similarly, in some implementations, the generator 144 is configured to provide feedback to the operator via an evaluation / feedback algorithm 148 before, during, and / or after a treatment procedure. In an example, the control circuit 128 is configured to execute the automated control algorithm 146 and / or the evaluation / feedback algorithm 148, and / or communicate with processing circuitry within the generator 144 to cause execution of the automated control algorithm 146 and / or the evaluation / feedback algorithm 148.

[0056] In some examples, the catheter system 108 is configured to receive energy (e.g., from the generator 144) and convert the energy (e.g., electric current) into acoustic energy (e.g., acoustic pressure waves). For example, the therapeutic element 114 may include an ultrasonic transducer configured to transmit the acoustic energy to the vessel wall 104 or another anatomical location of the patient 106. In an example, the therapeutic element 114 is configured to transmit acoustic energy in a frequency range from about 20 kilohertz (kHz) to about 200 megahertz (MHz). The catheter system 108 (e.g., the therapeutic element 114) can be configured so that the acoustic energy tends to induce molecular vibration and friction in the tissue at the target site at the anatomical location of the patient 106, thereby causing absorptive heating within the target tissue. In an example, the catheter system 108 can be configured so that the acoustic energy tends to heat the fluid within the interior volume 116 of the balloon 112 to transfer thermal energy to the tissue at the target site. The system 100 is configured to control the power and / or wavelength of the acoustic energy transmitted from the treatment element 114 to, for example, control the temperature of tissue at a target site receiving the acoustic and / or thermal energy.

[0057] In an example, the catheter system 108 is configured to inflate the balloon 112 with a fluid (eg, saline). The catheter system 108 can be configured such that the fluid serves as a transmission medium for the acoustic energy transmitted from the treatment element 114 to the target tissue.

[0058] In some examples, the medical system 100 (e.g., the proximal body portion 110B) includes a handle portion 150 that is configured to remain external to the patient's vasculature while the distal body portion 110A is within the patient's vasculature. The handle portion 150 can be configured to allow a clinician to guide at least the distal body portion 110A through the vasculature, allow inflation and / or deflation of the balloon 112, allow transmission and / or control of energy delivered to the therapeutic element 114, and / or implement other functions of the medical system 100 that can assist in delivering therapy (e.g., neuromodulation) to the patient 106. At least some portion of the catheter system 108 (e.g., the distal body portion 110A) can be substantially flexible such that the catheter system 108 can be flexed and / or bent en route to substantially position the therapeutic element 114 at a target location within a patient's blood vessel. Thus, despite the fact that the distal body portion 110A is located within the patient's vasculature, the handle portion 150 can be configured to allow a clinician to guide at least the distal body portion 110A through the vasculature, allow inflation and / or deflation of the balloon 112, allow transmission and / or control of energy delivered to the therapeutic element 114, and / or implement other functions of the medical system 100 that can assist in delivering therapy (e.g., neuromodulation) to the patient 106. Figure 1 108 is shown as being substantially linear, but the catheter system 108 (or a portion thereof) can be configured to present a linear, curved and / or curvilinear shape. Correspondingly, the longitudinal axis L defined by the catheter system 108 (and / or a portion thereof) can be linear, curved and / or curvilinear.

[0059] Figure 2Schematically illustrated is a portion of a medical system 100 (e.g., distal body portion 110A, balloon 112, and therapeutic element 114) within a blood vessel 102 defined by a blood vessel wall 104 of a patient 106. The catheter system 108 is configured to enable the balloon 112 to be inflated when the distal body portion 104A is positioned within the blood vessel 102 to move the catheter system 108 from a delivery configuration ( Figure 1 ) to an expanded configuration. In an example, the catheter system 108 is configured to expand the balloon 112 so that the balloon 112 defines a dimension C2 (e.g., diameter) in the expanded configuration. The dimension C2 defined in the expanded configuration can be larger than that in the delivery configuration ( Figure 1 ) In an example, the balloon 112 is configured to define the dimension C1, the dimension C2, and / or another dimension (eg, a dimension substantially perpendicular to the longitudinal axis L) based on the inflation pressure PI of the fluid within the interior volume 116.

[0060] The catheter system 108 is configured to control the inflation pressure PI such that the dimension C2 can be adjusted to accommodate the size of the vessel 102. For example, the catheter system 108 can be configured to inflate the balloon 112 such that the balloon 112 (e.g., the balloon outer surface 138) contacts the vessel wall 104. The distal body portion 110A can support the balloon 112 such that when the balloon 112 defines the dimension C2, the catheter system 108 defines a displacement B2 substantially between the therapeutic element 114 and the balloon outer surface 138. The displacement B2 can, for example, define a displacement between the therapeutic element 114 and the vessel wall 104 when the balloon outer surface 138 contacts the vessel wall 104. In an example, the catheter system 108 is configured to substantially center the therapeutic element 114 within the vessel 102 (e.g., centered or as close to centered as the vessel symmetry allows) when the balloon 112 is inflated to contact the vessel wall 104.

[0061] Treatment element 114 ( Figure 1 ) can deliver energy and / or cause thermal energy to be delivered to tissue of the patient 106 to induce one or more desired effects (e.g., neuromodulatory effects) at a localized region of the vessel 102 and an area adjacent to the vessel 102. For example, when the vessel 102 defines a renal artery associated with the kidney 152, the therapeutic element 114 can induce one or more desired neuromodulatory effects to a portion of the renal plexus (RP) 154 located within or adjacent to the adventitia of the renal artery.

[0062] Figure 3 A portion of a medical system 100 is shown positioned within the vasculature of a patient 106 to place a therapeutic element 114 within a blood vessel 102 . Figure 3The description is primarily with reference to the renal artery, however similar devices, systems, and techniques may be adapted to access other anatomical lumens or tissues within the patient 106 .

[0063] The catheter system 108 (e.g., the elongated body 110) can provide access to the renal plexus (RP) through an intravascular path (P), such as a percutaneous access site in the femoral artery (shown), the brachial artery, the radial artery, or the axillary artery to a target treatment site within the blood vessel 102. By manipulating the proximal body portion 110B of the elongated member 110 from outside the intravascular path (P), a clinician can advance at least the distal body portion 110A through the sometimes tortuous intravascular path (P) and remotely manipulate the distal body portion 110A. In an example, the distal body portion 110A can be remotely manipulated by a clinician using a handle portion 150.

[0064] exist Figure 3 In the illustrated example, the balloon 112 is delivered intravascularly to the treatment site using a guidewire 156 in an OTW technique. The catheter system 108 (e.g., the elongated body 110) may define a channel for receiving the guidewire 156 to deliver the elongated body 110 (e.g., the distal body portion 110A) using an OTW or RX technique. At the treatment site, the guidewire 156 may be at least partially withdrawn or removed, and the balloon 112 may be moved from the delivery configuration ( Figure 1 ) expands to the expanded configuration ( Figure 2 ). The balloon 112 can generally position the therapeutic element 114 relative to the blood vessel 102 to deliver energy to the blood vessel 102 and / or other anatomical lumens or tissues in the patient 106. In other examples, the balloon 112 and / or the therapeutic element 114 can be positioned within a guide sheath ( Figure 3 In some embodiments, the elongated body 110 may be delivered to the treatment site within a different guide device (not shown) in the embodiment of the present invention. In examples where the medical system 100 includes a guide sheath, when the balloon 112 and / or the therapeutic element 114 are at the target treatment site, the guide sheath may be at least partially withdrawn or retracted, and the balloon 112 may be transformed into an expanded configuration. In still other examples, the elongated body 110 itself may be steerable so that the balloon 112 and / or the therapeutic element 114 may be delivered to the treatment site without the aid of the guide wire 156 and / or the guide sheath.

[0065] Figure 4 is a schematic diagram of a medical system 100 having a catheter system 108 in a delivery configuration within a blood vessel 102 , wherein the catheter system 108 defines a dimension C1 . Figure 5 1 is a schematic diagram of a medical system 100 having a catheter system 108 in an expanded configuration within a blood vessel 102, wherein the catheter system 108 defines a dimension C2. Dimension C2 is greater than dimension C1. In an example, as Figure 5, the catheter system 108 is configured such that the balloon 112 contacts the vessel wall 104 in the expanded configuration. Dimension C1 and / or dimension C2 can be a cross-sectional dimension of the catheter system 108 (e.g., balloon 112), the cross section being taken perpendicular to the longitudinal axis L of the elongated body 110. In an example, dimension C1 and dimension C2 define displacement in a direction substantially perpendicular to the longitudinal axis L. In an example, the longitudinal axis L extends through the catheter system 108 and through the distal end 158 ("distal body end 158") of the elongated body 110. The longitudinal axis L can extend through at least some portion of the distal body portion 110A and / or the proximal body portion 110B.

[0066] The catheter system 108 is configured to control the size defined by the balloon 112 by at least controlling the inflation pressure PI in the interior volume 116. The catheter system 108 is configured to generate the inflation pressure PI using a fluid flowing through the interior volume 116 of the balloon 112. In an example, the catheter system 108 is configured such that the fluid flows from the fluid inlet 118 to the interior volume 116 and from the interior volume 116 to the fluid outlet 120. The catheter system 108 can adjust the flow area A ( Figure 5 ) and / or adjusting the flow rate provided by pump 124 to control inflation pressure PI. In an example, catheter system 108 controls inflation pressure PI based on a pressure signal provided by sensor 126 (eg, by adjusting flow area A).

[0067] In some examples, the control circuit 128 is configured to receive the pressure signal and position the valve 122 (e.g., to adjust the flow area A) and / or adjust the flow rate provided by the pump 124 based on the pressure signal. For example, the control circuit 128 can receive input (e.g., from a clinician) via the user interface 130 indicating a desired size (e.g., diameter) of a blood vessel in which a procedure is to be performed. Thus, where the size of the balloon 112 corresponds to the inflation pressure PI within the interior volume 116, the control circuit 128 can treat the pressure sensed by the sensor 126 as representative of the size (e.g., diameter) of the balloon 112, treat the input indicating the pressure set point as representative of the desired size, and control the position of the valve 122 so that the balloon 112 achieves and / or substantially maintains the desired size.

[0068] Dimension C1 and / or dimension C2 may define any suitable displacement. Furthermore, catheter system 108 may be configured such that dimension C1 and / or dimension C2 may define any one of a range of possible displacements. For example, catheter system 108 may be configured such that balloon 112 and / or elongated body 110 define a minimum cross-sectional dimension (e.g., a minimum diameter) and a maximum cross-sectional dimension (e.g., a maximum diameter) based on, for example, an inflation pressure PI within interior volume 116. Thus, although for clarity in FIG. Figure 4 and Figure 5 1 and 2 as corresponding to only one displacement value, but the catheter system 108 is configured such that dimensions C1 and C2 can define any displacement greater than or equal to the minimum cross-sectional dimension and less than or equal to the maximum cross-sectional dimension.

[0069] The balloon 112 is configured to expand radially outward in a direction away from the longitudinal axis L of the elongated body 110 when an inflation pressure PI sufficient to cause expansion acts within the interior volume 116. In an example, the interior volume 116 is at least partially defined by a balloon inner surface 140. The balloon 112 (e.g., the balloon body 142) can be configured to elastically expand based on the inflation pressure PI within the interior volume 116, such that an increase in the inflation pressure PI causes the balloon 112 to increase its cross-sectional diameter (e.g., from size C1 to size C2) and a decrease in the inflation pressure PI causes the balloon 112 to decrease its cross-sectional size (e.g., from size C2 to size C1). Thus, the medical system 100 is configured such that when the catheter system 108 is guided (e.g., by a clinician) to and / or from a target site within the vessel 102, the catheter system 108 can define a first size (e.g., size C1), and when delivering therapy (e.g., neuromodulation) at the target site, the catheter system can define a second size (e.g., size C2) that is greater than the first size.

[0070] In an example, the balloon 112 is configured to expand radially based on the inflation pressure PI within the internal volume 116 to define a specific size. The balloon 112 can be configured so that the specific size increases with the increase of the specific inflation pressure PI. In an example, the specific size is a function of the inflation pressure PI. The catheter system 108 (e.g., the control circuit 128) can be configured to define the specific size of the balloon 112 based on the pressure indicating the inflation pressure PI, so that the catheter system 108 can use the inflation pressure PI as a representative of the size (e.g., diameter) of the balloon 112. The specific size of a given inflation pressure can be a single value for a given inflation pressure, or can be a value defined within a range of values ​​for a given inflation pressure. For example, the specific value of a specific inflation pressure can be the minimum cross-sectional dimension of the balloon 112, the maximum cross-sectional dimension of the balloon 112, or a value between the minimum cross-sectional dimension and the maximum cross-sectional dimension.

[0071] As an example, Figure 6 An exemplary relationship between a specific value defined by the balloon 112 and a specific inflation pressure within the interior volume 116 of the balloon 112 is shown. In this example, the balloon 112 is configured to define one or more specific dimensions such as D1, D2, D3 ... DN when the catheter system 108 causes a specific pressure such as P1, P2, P3 ... PN within the interior volume 116, respectively (e.g., when the inflation pressure PI is one of P1, P2, P3 ... PN). For example, the balloon 112 can be configured such that a specific inflation pressure P1 causes the balloon 112 to define a specific dimension D1, a specific inflation pressure P2 causes the balloon 112 to define a specific dimension D2, a specific inflation pressure P3 causes the balloon 112 to define a specific dimension D3, a specific inflation pressure PN causes the balloon 112 to define a specific dimension DN, and so on. In an example, the specific dimension D1 is a dimension within a range R1, the specific dimension D2 is a dimension within a range R2, the specific dimension D3 is a dimension within a range R3, and / or the specific dimension DN is a dimension within a range RN.

[0072] In an example, the specific dimensions D1, D2, D3 ... DN increase as the specific inflation pressures P1, P2, P3 ... PN increase. In some examples, the specific dimensions D1, D2, D3 ... DN are described by a correlation C1 that associates the specific dimensions with the specific inflation pressures. In some examples, the correlation C1 is continuous, such that the correlation C1 describes the specific dimensions for any specific pressure between and including the specific pressure P1 and the specific pressure PN. The correlation C1 can be discrete, such that when the specific pressure defines or is assigned (e.g., assigned by the control circuit 128) a discrete value (e.g., 1 or P1, P2, P3 ... PN), the correlation C1 describes the specific dimensions. In some examples, the correlation C1 is defined by a coordinate data structure (e.g., a table) that describes a plurality of ordered pairs that describe a set of coordinates (e.g., coordinates that describe a specific inflation pressure and coordinates that describe a specific dimension).

[0073] In some examples, the correlation C1 is defined by a plurality of separate correlations defined over one or more intervals (e.g., an interval between P1 and P2, an interval between P2 and P3, and / or another interval). The correlation C1 may define any curvature and / or slope over any interval, and may be a linear function over one or more intervals. The catheter system 108 may be configured such that the inflation pressure PI substantially reaches a specific inflation pressure (e.g., one of P1, P2, P3, ... PN) within the interior volume 116, such that the balloon 112 defines a specific size (e.g., one of D1, D2, D3, ... DN) associated with the specific inflation pressure.

[0074] One or more specific dimensions, such as D1, D2, D3, ... DN, may be cross-sectional dimensions of the balloon 112, such as dimensions that are substantially perpendicular (e.g., perpendicular or nearly perpendicular to the extent permitted by manufacturing tolerances) to the longitudinal axis L. One or more specific dimensions, such as D1, D2, D3, ... DN, may be dimensions C1 ( Figure 4 )、Dimension C2( Figure 5 ) or one of the dimensions other than dimension C1 or dimension C2. One or more specific dimensions, such as D1, D2, D3, ... DN, may define the minimum cross-sectional dimension of balloon 112, the maximum cross-sectional dimension of balloon 112, or a cross-sectional dimension other than the minimum cross-sectional dimension and the maximum cross-sectional dimension.

[0075] The balloon 112 has any suitable configuration. In an example, the balloon 112 is configured so that an imaging system (e.g., an imaging system outside the patient 106) can capture an image of the balloon 112 while the balloon 112 is inside the patient 106. In an example, the balloon 112 (e.g., the balloon body 142) includes silicone. In some examples, the balloon 112 is a dipped balloon manufactured using a dip molding process. The balloon 112 (e.g., the balloon body 142) can be made of any compliant, semi-compliant, or non-compliant material, typically a plastic such as polyurethane, nylon, polyethylene, PET, or PEBAX.

[0076] The catheter system 108 is configured to provide a flow path for a fluid (e.g., saline) through the interior volume 116 of the balloon 112. The catheter system 108 is configured such that when the fluid flows through the interior volume 116, the fluid flowing through the interior volume 116 exerts an inflation pressure PI on the balloon inner surface 140. The catheter system 108 can be configured to control the flow of the fluid to control the inflation pressure PI, and thereby control the size of the balloon 112. For example, the catheter system 108 can provide fluid flow to induce an inflation pressure PI, such as one of a particular pressure P1, P2, P3, ... PN, so that the balloon 112 defines one of the corresponding sizes D1, D2, D3, ... DN, respectively ( Figure 6 ). The control circuit 128 can adjust the flow area A by at least Figure 5 ) to control the inflation pressure PI. In addition, and as discussed, the flow of fluid through the flow path can provide one or more other functions, such as facilitating heat transfer to or from the vessel wall 104, to or from the therapeutic element 114, and / or for other reasons.

[0077] In an example, the catheter system 108 (e.g., the elongated body 110) defines an inlet lumen 162 and an outlet lumen 164 that are configured to provide at least a portion of a flow path. The inlet lumen 162 and the outlet lumen 164 are fluidly coupled to the interior volume 116 such that a fluid can flow into the interior volume 116 via the inlet lumen 162, flow through a portion of the interior volume 116, and flow out of the interior volume 116 via the outlet lumen 164. For example, the inlet lumen 162 can be configured to provide an inlet flow F1 ( Figure 5 ). The outlet lumen 164 can be configured to provide a flow path for an outlet flow F2 from the interior volume 116 to the fluid outlet 120. The inlet flow F1 can be a portion or substantially all of the pump flow FP provided by the pump 124 to the fluid inlet 118. The outlet flow F2 can be a portion or substantially all of the valve flow FV flowing out of the fluid outlet 120 and flowing through the valve 122.

[0078] In an example, the inlet lumen 162 defines a proximal opening 166 ("inlet proximal opening 166") and a distal opening 168 ("inlet distal opening 168") fluidly coupled to the inlet proximal opening 166. The inlet distal opening 168 leads to the interior volume 116. The outlet lumen 164 may define a distal opening 170 ("outlet distal opening 170") and a proximal opening 172 ("outlet proximal opening 172") leading to the outlet distal opening 170. The outlet distal opening 170 may be fluidly coupled to the interior volume 116. In an example, the catheter system 108 includes an inlet conduit 174 fluidly coupling the inlet proximal opening 166 and an outlet 176 of the pump 124 ("pump outlet 176") and an outlet conduit 176 fluidly coupling the outlet proximal opening 172 and an inlet 180 of the valve 122 ("valve inlet 180") . Inlet conduit 174 and outlet conduit 176 may be respective lumens of elongated body 110 in some examples, or may be separate from elongated body 110 in other examples.

[0079] The catheter system 108 can be configured such that when the catheter system 108 (e.g., the distal body portion 110A) is positioned within the blood vessel 102, fluid flowing through the inlet conduit 174, the inlet lumen 162, the interior volume 116, the outlet lumen 164, and / or the outlet conduit 176 is fluidly isolated from the blood vessel 102. In examples, the flow path defined by the catheter system 108 includes at least the inlet lumen 162, the interior volume 116, and the outlet lumen 164. In some examples, the flow path defined by the catheter system 108 includes the inlet conduit 174 and / or the outlet conduit 178.

[0080] The conduit system 108 defines a flow area A ( Figure 5) so that the fluid in the flow path applies an inflation pressure PI within the interior volume 116. The catheter system 108 is configured so that the flow area A presents a flow restriction to the fluid flow, so that when the fluid flows through the flow area A, the flow area A causes the fluid to generate a pressure differential across the flow area A. The catheter system 108 can be configured so that the pressure differential controls the inflation pressure PI within the interior volume 116. The control circuit 128 is configured to adjust the flow area A and / or the flow rate provided by the pump 124 to adjust the pressure differential generated by the fluid flow, thereby, for example, controlling the inflation pressure PI applied by the fluid within the interior volume 116. Therefore, the catheter system 108 can be configured to control the size (e.g., diameter) defined by the balloon 112 by at least adjusting the defined flow area A.

[0081] In some examples, when the fluid flows upstream from the inlet proximal opening 166 through the interior volume 116 and reaches the outlet proximal opening 172, the flow area A is located downstream of the interior volume 116. The flow area A is configured such that when the fluid flows through the flow area A, the fluid generates a pressure PB (e.g., back pressure) within the outlet conduit 178 and / or the outlet lumen 164 ( Figure 5 ). The catheter system 108 can be configured such that the pressure PB affects the inflation pressure PI. In an example, the catheter system 108 is configured such that the fluid flowing downstream of the internal volume 116 transmits at least some portion of the pressure PB to the internal volume 116. Thus, the control circuit 128 can control the inflation pressure PI (and the corresponding size of the balloon 112) by at least controlling the pressure PB generated by the fluid when the fluid flows through the flow area A. In other examples, the flow area A is upstream of the internal volume 116, within the internal volume 116, or within some other location within the flow path defined by the catheter system 108.

[0082] The control circuit 128 is configured to adjust the flow area A and / or the flow rate provided by the pump 124 to adjust the inflation pressure PI within the internal volume 116. For example, the conduit system 108 can be configured so that changing the defined flow area A changes the flow restriction of the fluid passing through the flow area A, thereby changing the pressure PB. The conduit system 108 can be configured so that changing the flow rate provided by the pump 124 changes the mass flow rate through the defined flow area A, thereby changing the pressure PB. Changing the pressure PB can change the inflation pressure PI applied by the fluid within the internal volume 116. For example, the conduit system 108 can be configured so that a decrease in the area described by the flow area A increases the flow restriction of the fluid passing through the flow area A, thereby increasing the pressure PB and causing an increase in the inflation pressure PI. In addition, the conduit system 108 can be configured so that an increase in the area described by the flow area A reduces the flow restriction of the fluid passing through the flow area A, thereby reducing the pressure PB and causing a decrease in the inflation pressure PI. The catheter system 108 can be configured such that a decrease in the flow provided by the pump 124 decreases the pressure PB and results in a decrease in the inflation pressure PI, and / or such that an increase in the flow provided by the pump 124 increases the pressure PB and results in an increase in the inflation pressure PI. In an example, the control circuit is configured to control one or both of the valve 122 and / or the pump 124 to adjust the inflation pressure PI. Thus, the control circuit 128 can be configured to control the inflation pressure PI within the interior volume 116 by at least controlling the size of the flow area A defined by the catheter system 108, and thus controlling the size (e.g., diameter) defined by the balloon 106.

[0083] In some examples, valve 122 defines a flow area A. In some examples, valve 122 is fluidly coupled to outlet lumen 164 and / or outlet conduit 178 such that valve flow FV flows into valve inlet 180 and at least partially passes through flow area A before being discharged from outlet 182 of valve 122 ("valve outlet 182"). In an example, valve outlet 182 is configured to direct valve flow FV to a discharge reservoir (not shown). Valve inlet 180 and / or valve outlet 182 may be defined by a body 184 ("valve body 184") of valve 122. Valve 122 may have any suitable configuration configured to control fluid flow. In an example, valve 122 includes a restriction element 186 (e.g., a valve disc) configured to at least partially define flow area A. Restriction element 186 may be configured to move relative to a portion of valve body 184 (e.g., relative to a valve seat) to define flow area A. In an example, valve 122 is configured such that the size (e.g., area) of flow area A is a function of the position of restriction element 162 relative to valve body 184. Thus, control circuit 128 may be configured to control the position of valve 122 (e.g., the position of restriction element 186 relative to valve body 184) to control flow area A, and thus control inflation pressure PI within interior volume 116 based on the position of valve 122.

[0084] In an example, the valve 122 includes an actuator 188 configured to position the valve 122 (e.g., configured to position the restriction element 162 relative to the valve body 184). In an example, the actuator 188 is configured to position and / or change the position of the valve 122 based on a valve signal (e.g., an electrical signal, an electronic signal, a hydraulic signal, a pneumatic signal, or another type of signal) received from the control circuit 128 via a signal link 190.

[0085] The valve 122 can be any type of valve sufficient to define and / or change the flow area A. The valve 122 can be, for example, a ball valve, a lift valve, a needle valve, a gate valve, a sliding valve, or some other mechanism or combination of mechanisms sufficient to define the flow area A. In an example, the valve 122 can be a remotely actuated valve. The actuator 188 can be any type of actuator sufficient to make the valve 122 (e.g., the restriction element 186) define and / or change the flow area A. In an example, the actuator 188 includes a solenoid actuator configured to affect the position of the valve 122. The actuator 188 can be configured to position and / or change the position of the valve 122 in response to received electrical or electronic communications (e.g., received via a signal link 190). In some examples, the actuator 188 is configured to position and / or change the position of the valve 122 based on the supply of the control fluid. For example, the valve 122 can be a hydraulically or pneumatically operated valve. The valve 122 may include a control circuit configured to control components of the valve 122 in response to a received valve signal. The control circuit may be some portion of the control circuit 128 or may be substantially separate from the control circuit 128. The valve 122 may be configured to provide communication to other devices in data communication with the control circuit 128.

[0086] The conduit system 108 can be configured to enhance the effect of changing the flow area A on the inflation pressure PI applied within the internal volume 116. In an example, the conduit system 108 defines a flow path for the fluid such that different segments of the flow path define different resistance coefficients, where the resistance coefficient describes the resistance to the flow of the fluid through the corresponding segment. The resistance coefficient (e.g., resistance coefficient K) of a given segment can be, for example, proportional to the length of the given segment, proportional to the friction coefficient of the given segment, and / or inversely proportional to the diameter and / or equivalent diameter of the given segment. The conduit system 108 can define the flow area A (e.g., using valve 122) at a specific location within the flow path to enhance the effect of changing the flow area A on the inflation pressure PI based on different resistance coefficients. For example, the conduit system 108 can define the flow path such that the valve 122 is located upstream of a segment of the flow path with a lower flow coefficient, so that the increase and decrease of the flow area A has a greater effect on the inflation pressure PI than positioning the valve 122 upstream of a segment with a higher flow coefficient.

[0087] For example, the conduit system 108 can define a flow path such that a first segment 189 of the flow path defines a first resistance coefficient K1 and a second segment 191 of the flow path defines a second resistance coefficient K2. The second resistance coefficient K2 can be less than the first resistance coefficient K1. The conduit system 108 can be configured such that when the fluid flows in a direction from the inlet conduit 174 and / or the inlet lumen 162 to the outlet lumen 164 and / or the outlet conduit 178, the flow area A is defined (e.g., by the valve 122) upstream of the second segment 191. In an example, the second segment 191 is located upstream of the interior volume 116. In an example, the first segment 189 is defined by at least a portion of the inlet lumen 162 and / or at least a portion of the inlet conduit 174. The second segment 191 can be defined by at least a portion of the outlet lumen 164 and / or at least a portion of the outlet conduit 178.

[0088] In some examples, conduit system 108 is configured such that pump 124 (e.g., pump outlet 176) is located downstream of first section 189. Conduit system 108 can be configured such that flow (e.g., flow FP and / or flow F1) from pump 124 flows through first section 189 before entering interior volume 116. Positioning pump 124 downstream of first section 189 can enhance the effect of changing flow area A on inflation pressure PI. For example, when pump 124 is located downstream of first section 189 and the fluid within the flow path is an incompressible fluid (e.g., saline or another incompressible fluid), defining flow area A upstream of second section 191 can allow changes in flow area A to have a greater effect on back pressure PB, such that changes in flow area A have a greater effect on inflation pressure PI.

[0089] The catheter system 108 can be configured such that the first segment 189 defines a first resistance coefficient K1 in any manner and / or such that the second segment 191 defines a second resistance coefficient K2 in any manner. For example, the first cross-sectional dimension (e.g., first diameter) of the inlet lumen 162 can be smaller than the second cross-sectional dimension (e.g., second diameter) of the outlet lumen 164. In addition to or in lieu of the cross-sectional dimensions of the lumens 162, 164, in some examples, the first length of the first segment 189 (e.g., the length of the flow path for the flow F1) is greater than the second length of the second segment 191 (e.g., the length of the flow path for the flow F2). In some examples, the first friction coefficient of the first segment 189 is greater than the second friction coefficient of the second segment 191. The catheter system 108 can include one or more flow restrictions (e.g., orifices, baffles, or other flow restrictions) configured to cause the first resistance coefficient K1 to exceed the second flow resistance coefficient K2. For example, the catheter system 108 can include one or more flow restrictions within the inlet lumen 162 and / or the inlet conduit 174. Any of the aforementioned techniques for controlling the drag coefficients K1 , K2 may be used alone or in combination with one or more other techniques.

[0090] The sensor 126 is configured to sense a parameter indicating the inflation pressure PI within the internal volume 116 and generate a pressure signal indicating the inflation pressure PI. The pressure indicating the inflation pressure PI may be a pressure at a certain position along the flow path defined by the catheter system 108. In an example, the pressure indicating the inflation pressure PI is the pressure of the fluid within the internal volume 116 and / or fluidically coupled to the internal volume. For example, the sensor 126 may be configured to generate a pressure signal indicating the pressure of the fluid within the internal volume 116, the outlet lumen 164, the outlet conduit 178, the valve 122, the inlet lumen 162, the inlet conduit 174, and / or a certain fluid fluidically coupled to the internal volume 116. The catheter system 108 may be configured to adjust the flow area A (e.g., using the position of the valve 122) based on the pressure signal generated by the sensor 126 to increase, decrease, and / or maintain the inflation pressure PI within the balloon 112.

[0091] The sensor 126 can be configured to generate a pressure signal according to the fluid pressure applied to a certain part of the sensor 126. The sensor 126 can be configured to sense the outlet pressure using any type of force collector, including, for example, a diaphragm, a piston, a Bourdon tube, a bellows, or some other collector. The sensor 126 can use, for example, a piezoresistive strain gauge, a capacitor, an electromagnet, an optical fiber, a potentiometer slide, or other devices to convert the pressure into an electrical signal. The sensor 126 can be configured to sense static pressure, dynamic pressure, and / or total pressure. The sensor 126 can be configured to sense absolute pressure or gauge pressure. The pressure signal generated by the sensor 126 can be an analog electrical signal or a digital signal. In some examples, the sensor 126 includes a processing circuit configured to interpret the response of the force collector and generate a pressure signal, and / or the control circuit 128 can be configured to interpret the response of the force collector and generate a pressure signal. The sensor 126 can be configured to provide a pressure signal to other devices of the medical system 100 that communicate data with the sensor 126 and / or transmit the pressure signal in other ways.

[0092] The control circuit 128 is configured to receive a pressure signal from the sensor 126 and cause an adjustment of the inflation pressure PI within the internal volume 116 based on the pressure signal. In an example, the control circuit 128 is configured to receive the pressure signal from the sensor 126 via the communication link 192. The control circuit 128 may be configured to receive a signal indicating a flow rate from the sensor 129 via the communication link 193. In an example, the control circuit 128 is configured to receive an input signal indicating a pressure set point from the user interface 130 (e.g., via the communication link 194). The control circuit 128 may be configured to cause an adjustment of the flow area A to adjust the inflation pressure PI based on a comparison of the pressure indicated by the pressure signal with the pressure set point indicated by the input signal (e.g., the difference between the two). In an example, the control circuit 128 is configured to adjust the position of the valve 122 (e.g., the restriction element 186) based on the difference between the pressure indicated by the pressure signal and the pressure set point indicated by the input signal. The control circuit 128 may be configured to communicate with the actuator 188 (eg, via a signal link 190 ) to cause the actuator 188 to position the valve 122 .

[0093] In an example, the input signal indicates a specific size of the balloon 112 (eg, one of the specific sizes D1, D2, D3, ..., DN ( Figure 6 )). The control circuit 128 can be configured to define a pressure set point using an input signal indicating a specific balloon size. For example, the control circuit 128 can be configured to define the pressure set point to be one of the specific pressures corresponding to the specific size indicated by the input signal (e.g., one of the specific pressures P1, P2, P3, ... PN). For example, the control circuit 128 can be configured to use the correlation C1 ( Figure 6) to define a specific pressure. As an example, the control circuit 128 can be configured to define a specific size using a table stored in a memory, wherein the table associates a specific size with a specific pressure.

[0094] The control circuit 128 may be configured to cause adjustment of the flow area A to adjust the inflation pressure PI acting within the internal volume 116 based on the defined pressure set point. For example, when the sensor 126 indicates that the inflation pressure PI is less than the pressure set point, the control circuit may adjust the flow area A (e.g., using the valve 122) to increase the inflation pressure PI. When the sensor 126 indicates that the inflation pressure PI is greater than the pressure set point, the control circuit 128 may adjust the flow area A (e.g., using the valve 122) to decrease the inflation pressure PI. The control circuit 128 may be configured to substantially maintain (e.g., maintain or nearly maintain to the extent allowed by manufacturing tolerances) the inflation pressure PI when the inflation pressure PI is substantially equal to the pressure set point or within a range of values ​​defined around the pressure set point. For example, the control circuit 128 may be configured to maintain the inflation pressure PI within 1% to about 30% of the pressure set point, such as within 30% of the pressure set point, within 20% of the pressure set point, within 10% of the pressure set point, within 5% of the pressure set point, or within 1% of the pressure set point. In the example, the control circuit 128 positions the valve 122 to adjust the pressure PB caused by the position of the valve 122 ( Figure 5 ) in order to increase, decrease and / or substantially maintain the inflation pressure PI.

[0095] As described above, in some examples, the system 100 includes a user interface 130 configured to receive an input indicating a pressure set point (e.g., from a user) and provide an input signal to the control circuit 128 based on the indicated input (e.g., via a communication link 196). For the size (e.g., diameter or other size) of the balloon 112, the indicated input may be a pressure value or some other input indicating a pressure set point. The user interface 130 may be configured to receive the indicated input via a button or keypad, a touch screen, a speaker configured to receive voice commands from a user, and / or a display. In some examples, the user interface 130 may include a mobile phone, a smart phone, a tablet computer, a personal computer, a desktop computer, a personal digital assistant, a router, a modem, a remote server or a cloud computing device and / or related equipment, or be configured to be used in combination therewith. In some examples, the positioning member 134 is configured to move (e.g., rotate) relative to the device body 132 so that the user interface 130 provides an indicated input (e.g., the desired size of the balloon 112, the pressure value, and / or some other input indicating a pressure set point). In some examples, the user interface 130 is configured to display information, such as one or more desired sizes and / or set points (e.g., the current desired size and / or set point being used by the control circuit 128, or one or more predetermined desired sizes and / or set points from which a user can select to input a desired size for the balloon 112).

[0096] Communication links 192, 193, 194, 196 and / or signal link 190 may be hardwired and / or wireless communication links. In some examples, communication links 192, 193, 194, 196 and / or signal link 190 may include some portion of control circuit 128. In some examples, communication links 192, 193, 194, 196 and / or signal link 190 include a wired connection, a wireless Internet connection, such as a wireless LAN, Bluetooth, or the like. TM , Wi-Fi TM Direct wireless connection and / or infrared connection. Communication links 192, 193, 194, 196 and / or signal link 190.

[0097] In some examples, control circuit 128 is configured to control inflation of balloon 112 based on an assessment that balloon 112 has been sufficiently inflated to contact vessel wall 104. For example, balloon 112 may be configured such that when balloon 112 is inflated in a substantially unconstrained state (e.g., prior to contacting vessel wall 104), inflation pressure PI within interior volume 116 defines a pressure profile, such as that defined by correlation C1( Figure 6) The control circuit 128 may be configured to determine and / or monitor a trend of the inflation pressure PI ("inflation pressure trend") to determine whether the balloon 112 may have contacted the vessel wall 104, and / or whether the expansion of the balloon 112 is otherwise constrained. In an example, the control circuit 128 is configured to receive and / or request a plurality of pressure signals from the sensor 126 over a period of time, and to determine the inflation pressure trend using at least the plurality of pressure signals.

[0098] In an example, instead of or in addition to receiving an input signal from the user interface 130 indicating a pressure set point, the control circuit 128 is configured to establish a pressure set point for the inflation pressure PI based on an assessment that the balloon 112 has been sufficiently inflated to contact the vessel wall 104. The control circuit 128 can be configured to determine the resulting inflation pressure (e.g., using a pressure signal from the sensor 126) when the control circuit 128 assesses that the balloon 112 has contacted the vessel wall 104, and to base the pressure set point on the resulting inflation pressure. Thus, in some examples, the control circuit 128 is configured to establish a pressure set point for the inflation pressure PI without requiring an input signal from the user interface 130, potentially facilitating the performance of a medical procedure within the vessel 102.

[0099] The control circuit 128 may be configured to identify a deviation from the inflation pressure trend (e.g., a relatively sudden increase) to assess that the balloon 112 may have been sufficiently inflated to contact the vessel wall 104 (e.g., to assess that the vessel wall 104 may be constraining continued inflation of the balloon 112). In some examples, the control circuit 128 assesses that the balloon 112 is constrained by the vessel wall 104 based on a deviation between the inflation pressure trend and the pressure trend curve described by the correlation C1. The control circuit 128 may be configured to change the flow area A (e.g., the position of the valve 122) in response to the deviation from the inflation pressure trend and / or the pressure trend curve of the correlation C1. In an example, the control circuit 128 is configured to identify the inflation pressure PI when the deviation occurs, and to establish a pressure set point based on the identified inflation pressure so that, for example, the catheter system 108 substantially maintains the inflation pressure PI within the interior volume 116 sufficient to keep the balloon 112 in contact with the vessel wall 104.

[0100] For example, the control circuit 128 can be configured to receive and / or request a first plurality of pressure signals from the sensor 126, the first plurality of pressure signals indicating pressures such as S1, S2, S3, and S4 occurring substantially within the time period T ( Figure 6). The control circuit 128 may use two or more of the inflation pressures S1, S2, S3, and S4 and the time period T1 to determine the inflation pressure trend PT. The control circuit 128 may receive and / or request one or more additional pressure signals from the sensor 126 after receiving S1, S2, S3, S4 to assess whether a deviation from the inflation pressure trend PT has occurred. The control circuit 128 may be configured to extrapolate the inflation pressure trend PT (e.g., extrapolate in time sequence) and compare the additional pressure signals with the extrapolated inflation pressure trend to assess whether the balloon 112 may have been sufficiently inflated to contact the vessel wall 104.

[0101] For example, the control circuit 128 can be configured to receive and / or request additional pressure signals indicative of inflation pressures (such as S5 and / or S6), and compare the inflation pressures S5, S6 to the inflation pressure trend PT, and determine that the inflation pressures S5, S6 substantially match (e.g., match within a limited range) the pressures expected based on the extrapolation of the pressure trend line PT. The control circuit 128 determines that the balloon 112 is continuing to expand in an unconstrained manner (e.g., not in contact with the vessel wall 104) based on the inflation pressures S5, S6 substantially matching the extrapolated pressure trend of the pressure trend line PT.

[0102] Alternatively, the control circuit 128 may receive and / or request an additional pressure signal indicating an inflation pressure (such as S7 and / or S8), and compare the inflation pressures S7, S8 with the inflation pressure trend PT, and determine an extrapolated pressure trend that the inflation pressures S7 and / or S8 deviate (e.g., fall outside a defined range) from the pressure trend line PT1. The control circuit 128 may be configured to determine that the expansion of the balloon 112 may be constrained (e.g., in contact with the vessel wall 104) based on the extrapolated pressure trend that the inflation pressures S7 and / or S8 deviate from the pressure trend line PT.

[0103] In some examples, the control circuit 128 defines the inflation pressure trend PT using the correlation C1. For example, the control circuit 128 may define the inflation pressure trend PT1 over an interval defined by two or more inflation pressures of S1, S2, S3, S4, S5, S6, S7, and S8. The control circuit 128 may be configured to determine that the balloon 112 is continuing to expand in an unconstrained manner (e.g., not in contact with the vessel wall 104) based on the inflation pressures S1, S2, S3, S4, S5, S6, S7, and / or S8 substantially matching (e.g., matching within a defined range) the pressure expected by the correlation C1. The control circuit 128 may be configured to determine that the expansion of the balloon 112 may be constrained (e.g., in contact with the vessel wall 104) based on the inflation pressures S1, S2, S3, S4, S5, S6, S7, and / or S8 deviating (e.g., falling outside a defined range) from the pressure expected by the correlation C1.

[0104] In an example, the control circuit 128 is configured to define a pressure trend PT determined according to the correlation C1 based on the flow rate of the fluid flowing through the inlet conduit 174, the inlet lumen 162, the internal volume 116, the outlet lumen 164, and / or the outlet conduit 178. The control circuit 128 can be configured to determine the flow rate of the fluid using, for example, a flow detector within the catheter system 108, the speed of the pump 124, the position of the valve 122, and / or other parameters. The control circuit 128 can be configured to map the correlation C1 to the flow rate and / or a time axis defined by the flow rate, so as to, for example, correlate the inflation pressure trend PT defined by the correlation C1 with the flow rate through the inlet conduit 174, the inlet lumen 162, the internal volume 116, the outlet lumen 164, and / or the outlet conduit 178.

[0105] Thus, the catheter system 108 can be configured to control the size (e.g., dimensions) of the balloon 112 by at least controlling the inflation pressure PI acting within the internal volume 116. In this way, the catheter system 108 can adjust the size of the balloon 112 to take into account the size of the elongated body 110 and the blood vessel 102 in which the balloon 112 is positioned. The catheter system 108 can receive an input indicating the size (e.g., diameter) of the blood vessel in which the procedure will be performed (e.g., received from a clinician via the user interface 130). Once positioned within the blood vessel, the control circuit 128 can be configured to inflate the balloon 112 to a specific inflation pressure PI based on the input, so that the size of the balloon 112 enables the balloon 112 to be juxtaposed with the blood vessel wall during the procedure. In an example, the control circuit 128 is configured to at least partially deflate the balloon 112 (e.g., based on the received user input) to enable the clinician to reposition the catheter system 108 within the patient 106.

[0106] In addition to or in lieu of controlling the inflation pressure PI to control the size of the balloon 112, in some examples, the control circuit 128 is configured to control the energy level of the therapeutic element 114 based on the size of the balloon 112. The catheter system 108 can be configured such that the displacement B2 ( Figure 2 and Figure 5 ) is proportional to and / or substantially dependent on the size of the balloon 112 within the vessel 102. For example, the catheter system 108 can be configured to support the therapeutic element 114 within the interior volume 116 or at some other location, wherein the displacement B2 is proportional to and / or substantially dependent on the size of the balloon 112.

[0107] In an example, the therapeutic element 114 is configured to transmit energy (e.g., acoustic energy, microwave energy, RF energy, or another form of energy) to deliver therapy to the vessel wall 103. The energy transmitted can be a function of the power level of the therapeutic element 114. In an example, the therapeutic element 114 can be configured so that the power level necessary to deliver therapy depends on the displacement B2 defined by the balloon 112. Therefore, in some examples, the control circuit 128 is configured to determine the size (e.g., diameter) and / or inflation pressure of the inflated balloon 112, and determine the power level of the therapeutic element 114 based on the size and / or inflation pressure. In some examples, the control circuit 128 is also configured to determine the power level based on the type of medium through which the therapeutic element 114 transmits energy over the displacement B2 (e.g., saline that inflates the balloon 112).

[0108] In an example, the control circuit 128 is configured to control the energy level of the therapeutic element 114 using an input signal (e.g., from the user interface 130) that indicates a particular size of the balloon 112 (e.g., one of the particular sizes D1, D2, D3, ... DN). For example, the control circuit 128 may be configured to control the energy level of the therapeutic element 114 based on the particular size and / or a parameter determined using the particular size (e.g., the volume of the internal volume 116). In some examples, the control circuit 128 is configured to control the energy level of the therapeutic element 114 based on a pressure signal from the sensor 126 (e.g., when the pressure signal indicates the size of the balloon 112). For example, the control circuit 128 may be configured such that an indication of a larger size of the balloon 112 causes the control circuit 128 to control the energy level of the therapeutic element 114 to a relatively higher power level. The control circuit 128 may be configured such that an indication of a smaller size of the balloon 112 causes the control circuit 128 to control the energy level of the therapeutic element 114 to a relatively lower power level (e.g., a power level that is less than the higher power level).

[0109] As an example, Figure 7 An exemplary relationship between a parameter S indicating the size of the balloon 112 and a power level of the therapeutic element 114 is shown. In some examples, the control circuit 128 is configured to define the parameter S based on, for example, a specific size of the balloon 112, a parameter determined using the specific size (e.g., volume), a pressure signal from the sensor 126, an input signal from the user interface 130, and / or other indications. The specific parameter S can be proportional to the size (e.g., specific size) of the balloon 112. In an example, when the size of the balloon 112 increases, the specific parameter S increases. The control circuit 128 can be configured to control the power level of the therapeutic element 114 based on the parameter S.

[0110] The control circuit 128 may be configured to define one or more specific power levels such as E1, E2, E3, ... EN when the parameter S describes specific parameters such as S1, S2, S3, ... SN, respectively. For example, the control circuit 128 may be configured such that the specific parameter S1 causes the control circuit 128 to control the power level of the treatment element 114 at about the specific power level E1, the specific parameter S2 causes the control circuit 128 to control the power level of the treatment element 114 at about the specific power level E2, the specific parameter S3 causes the control circuit 128 to control the power level of the treatment element 114 at about the specific power level E3, the specific parameter SN causes the control circuit 128 to control the power level of the treatment element 114 at about the specific power EN, etc. In an example, the specific power level E1 is a power level within a range RE1, the specific power level E2 is a power level within a range RE2, the specific power level E3 is a power level within a range RE3, and / or the specific power level E4 is a size having a range REN.

[0111] In an example, a specific power level E1, E2, E3 ... EN increases with an increase in a specific parameter S1, S2, S3 ... SN. In some examples, the specific power level E1, E2, E3 ... EN is described by a correlation C2 that relates a specific parameter S to a specific power level. In some examples, the correlation C2 is continuous, so that the correlation C2 describes a specific power level for any specific parameter S that is between and including the specific parameter S1 and the specific parameter SN. The correlation C2 can be discrete, so that when the specific parameter S defines or is assigned (e.g., assigned by the control circuit 128) a corresponding discrete value (e.g., 1 or S1, S2, S3 ... SN), the correlation C2 describes a specific power level. In some examples, the correlation C2 can be defined by a data structure (such as a coordinate table) that describes a plurality of ordered pairs, which describe a set of coordinates (e.g., coordinates describing a specific parameter S and corresponding coordinates describing a specific power level).

[0112] In an example, the correlation C2 may be defined by a plurality of separate correlations defined on one or more intervals, such as an interval between E1 and E2, an interval between E2 and E3, and / or another interval. The correlation C2 may define any curvature and / or slope on any interval, and may be a linear function on one or more intervals. The control circuit 128 may be configured to control the power level such that when the balloon 112 defines a specific parameter S, the therapeutic element 114 substantially achieves a specific power level (e.g., one of E1, E2, E3, ... EN).

[0113] In some examples, control circuit 128 is configured to use input signals from user interface 130 and / or pressure signals from sensor 126 to determine a power level for therapeutic element 114 to deliver therapy. For example, control circuit 128 may be configured to use input signals from user interface 130, pressure signals from sensor 126, and / or correlation C1( Figure 6 ) determines a specific parameter S (e.g., one of S1, S2, S3, ..., SN), and determines a specific power level (e.g., one of specific power levels E1, E2, E3, ..., EN) corresponding to the specific parameter S. For example, the control circuit 128 may be configured to use the correlation C2 ( Figure 7 ) to determine the specific power level. The control circuit 128 may be configured to determine the specific power level using a table (or other data structure) stored in a memory, wherein the table relates a specific parameter S to a specific power level.

[0114] In these examples, the control circuit 128 is configured to adjust the power level of the therapeutic element 114 based on the defined specific power level. For example, the control circuit 128 may increase the power level when the input signal from the user interface 130 and / or the pressure signal from the sensor 126 indicates that the power level is less than a specific power level (or range of levels) associated with the parameter S defined by the balloon 112. The control circuit 128 may be configured to decrease the power level when the input signal from the user interface 130 and / or the pressure signal from the sensor 126 indicates that the power level is greater than the specific power level associated with the parameter S defined by the balloon 112. The control circuit 128 may be configured to substantially maintain (e.g., maintain or nearly maintain to the extent permitted by manufacturing tolerances) the power level when the power level is substantially equal to the specific power level associated with the parameter S defined by the balloon 112. For example, the control circuit 128 can be configured to maintain the power level of the therapeutic element 114 within 1% to about 30% of a specific power level, such as within 30% of a specific power level, within 20% of a specific power level, within 10% of a specific power level, within 5% of a specific power level, or within 1% of a specific power level.

[0115] In an example, the control circuit 128 is configured to communicate with the control treatment element 114 (e.g., via the communication link 194) to cause the treatment element 114 to change and / or substantially maintain the power level. In an example, the catheter system 108 (e.g., the treatment element 114 or the generator 144) includes the element circuit 198 ( Figure 4 and Figure 5), the element circuit is configured to cause the therapeutic element 114 to emit energy at a particular energy level (e.g., up to about 50 watts, up to about 100 watts, or another power level). The control circuit 128 can be configured to transmit a signal indicating the particular power level to the element circuit 198 (e.g., via the communication link 194). The element circuit 198 is configured to cause the therapeutic element 114 to emit a certain amount of power based on the signal indicating the particular power level. In some examples, the control circuit 128 is configured to communicate with the generator 144 ( Figure 1 ) to cause the therapeutic element 114 to change and / or substantially maintain the power level provided to the therapeutic element 114. The power level can define the level of any type of energy, including pulsed field, current, microwave, radio frequency, monopolar, bipolar energy, and / or other energy. In an example, the control circuit 128 is configured to communicate with the automated control algorithm 146 and / or the evaluation / feedback algorithm 148 to change and / or substantially maintain the power level.

[0116] Exemplary techniques for controlling the size of balloon 112 are described in Figure 8 Although the main reference Figures 1 to 5 The technology is described with reference to medical system 100 , but the technology can be applied to other medical systems in other examples and in other medical systems through control circuit 128 alone or in combination with other control circuits in other examples.

[0117] The technique includes receiving, by the control circuit 128 of the catheter system 108, a pressure signal from the sensor 126 indicating the pressure of the fluid flowing through the interior volume 116 of the balloon 112 (802). In some examples, the pressure indicates the pressure of the fluid within the interior volume 116 or elsewhere along the flow path of the fluid through the interior volume 116. The balloon 112 can be positioned within the blood vessel 102 of the patient 106 using the elongated body 110 (e.g., the distal body portion 110A) supporting the balloon 112. The fluid flowing through the interior volume 116 can exert an inflation pressure PI within the interior volume 116 (e.g., exerting the inflation pressure PI on the balloon inner surface 140).

[0118] The technique includes adjusting a flow area A of the fluid flow using the control circuit 128 to adjust an inflation pressure PI within the interior volume 116 (804). The control circuit 128 can control the inflation pressure PI to control the size of the balloon 112. For example, the control circuit 128 can position the valve 122 to control the flow area A. In an example, when the fluid flows through the interior volume 116, the valve 122 defines the flow area A downstream of the interior volume 116.

[0119] The sensor 126 can sense a parameter indicating the inflation pressure PI of the balloon 112 and generate a pressure signal indicating the inflation pressure PI. The control circuit 128 can adjust the position of the valve 122 to increase, decrease and / or maintain the inflation pressure PI in the balloon 112 based on the pressure signal generated by the sensor 126. In an example, the control circuit 128 receives an input indicating a pressure set point from the user interface 130. The control circuit 128 can control the flow area A based on a comparison of the pressure signal with the pressure set point. In some examples, the input indicating the pressure set point describes the size (e.g., diameter) of the balloon 112. In some examples, the input indicating the pressure set point describes the pressure (e.g., inflation pressure PI) used for the balloon 112. The user interface 130 can receive an input indicating a pressure set point from a user and provide the input to the control circuit 128.

[0120] The control circuit 128 may receive a pressure signal from the sensor 126 and cause an adjustment of the inflation pressure PI within the internal volume 116 based on the pressure signal. The control circuit 128 may cause an adjustment of the flow area A to adjust the inflation pressure PI based on a comparison of the pressure indicated by the pressure signal with a pressure set point indicated by the input signal. In an example, the control circuit 128 adjusts the position of the valve 122 (e.g., the restriction element 186) based on a difference between the pressure indicated by the pressure signal and the pressure set point indicated by the input signal. In an example, the control circuit 128 communicates with the actuator 188 to cause the actuator 188 to position the valve 122.

[0121] In an example, the control circuit 128 may define the pressure set point as a specific pressure corresponding to a specific size (e.g., one of the specific pressures P1, P2, P3, ... PN). The control circuit 128 defines the specific pressure using the correlation C1 or a table stored in a memory or using some other method. The control circuit 128 may cause the adjustment of the flow area A to adjust the inflation pressure PI acting within the internal volume 116 based on the defined pressure set point. For example, when the sensor 126 indicates that the inflation pressure PI is less than the pressure set point, the control circuit may adjust the flow area A (e.g., using the valve 122) to increase the inflation pressure PI. When the sensor 126 indicates that the inflation pressure PI is greater than the pressure set point, the control circuit may adjust the flow area A (e.g., using the valve 122) to reduce the inflation pressure PI. The control circuit 128 may be configured to substantially maintain (e.g., maintain or nearly maintain to the extent allowed by manufacturing tolerances) the inflation pressure PI when the inflation pressure PI is substantially equal to the pressure set point or within a range of values ​​defined around the pressure set point.

[0122] In an example, the control circuit 128 establishes a pressure set point for the inflation pressure PI instead of or in addition to receiving an input signal indicating a pressure set point from the user interface 130. The control circuit 128 may establish the pressure set point based on an assessment that the balloon 112 has been sufficiently inflated to contact the vessel wall 104. When the control circuit 128 assesses that the balloon 112 has contacted the vessel wall 104, the control circuit 128 may determine the resulting inflation pressure (e.g., using the pressure signal from the sensor 126) and base the pressure set point on the resulting inflation pressure.

[0123] The control circuit 128 may identify a deviation from the inflation pressure trend (e.g., a relatively sudden increase) to assess that the balloon 112 may have been sufficiently inflated to contact the vessel wall 104. In an example, the control circuit 128 assesses that the balloon 112 is constrained by the vessel wall 104 based on a deviation between the inflation pressure trend and the pressure trend curve described by the correlation C1. The control circuit 128 may change the flow area A (e.g., the position of the valve 122) in response to the deviation from the inflation pressure trend and / or the pressure trend curve of the correlation C1. The control circuit 128 may identify the inflation pressure PI when the deviation occurs, and establish a pressure set point based on the identified inflation pressure so that, for example, the catheter system 108 substantially maintains the inflation pressure PI within the interior volume 116 sufficient to keep the balloon 112 in contact with the vessel wall 104. In an example, the control circuit 128 determines the inflation pressure trend PT using any of the above-described techniques.

[0124] Fig. 9 An exemplary technique for controlling the power level of the therapeutic element 114 is shown. Although primarily referring to Figures 1 to 5 The technology is described with reference to medical system 100 , but the technology can be applied to other medical systems in other examples and in other medical systems through control circuit 128 alone or in combination with other control circuits in other examples.

[0125] The technique includes receiving, by the control circuit 128, a pressure signal indicating a pressure in the interior volume 116 of the balloon 112 (902). The control circuit 128 may receive the pressure signal from the sensor 126. The control circuit 128 may use the pressure signal to determine the size (e.g., diameter) of the balloon 112 and control the energy level of the therapeutic element 114 based on the size of the balloon 112. As described above, in some examples where the therapeutic element 114 is positioned within the interior volume 116, the displacement B2 is proportional to and / or substantially dependent on the size of the balloon 112. The power level necessary for the therapeutic element 114 to deliver therapy may depend on the displacement B2 defined by the balloon 112. In some examples, the power level necessary to deliver therapy also depends on the type of medium through which the therapeutic element 114 transmits energy over the displacement B2 (e.g., saline that inflates the balloon 112).

[0126] In an example, the control circuit 128 uses an input signal (e.g., from the user interface 130) indicating a particular size of the balloon 112 (e.g., one of the particular sizes D1, D2, D3, ... DN) to control the energy level of the therapeutic element 114. The control circuit 128 can control the energy level of the therapeutic element 114 based on the particular size and / or a parameter determined using the particular size (e.g., the volume of the interior volume 116). In some examples, the control circuit 128 controls the energy level of the therapeutic element 114 based on a pressure signal from the sensor 126. The control circuit 128 can control the energy level of the therapeutic element 114 to a relatively higher power level for a larger sized balloon 112, and to a relatively lower power level for a smaller sized balloon 112.

[0127] In an example, the control circuit 128 uses an input signal from the user interface 130, a pressure signal from the sensor 126, and / or a correlation C1 ( Figure 6 ) determines a specific parameter S (e.g., one of S1, S2, S3, ..., SN). The control circuit 128 may determine a specific power level (e.g., one of specific power levels E1, E2, E3, ..., EN) corresponding to the specific parameter S. In an example, the control circuit 128 uses the correlation C2 ( Figure 7 ) and / or determine a specific power level based on a table or other data structure stored in a memory, where the table or other data structure relates a specific parameter S to a specific power level.

[0128] In some examples, the control circuit 128 adjusts the power level of the therapeutic element 114 based on the defined specific power level. For example, when the input signal from the user interface 130 and / or the pressure signal from the sensor 126 indicates that the power level is less than the specific power level associated with the parameter S defined by the balloon 112, the control circuit 128 may increase the power level. When the input signal from the user interface 130 and / or the pressure signal from the sensor 126 indicates that the power level is greater than the specific power level associated with the parameter S defined by the balloon 112, the control circuit 128 may decrease the power level. When the power level is substantially equal to the specific power level associated with the parameter S defined by the balloon 112, the control circuit 128 may substantially maintain the power level.

[0129] The control circuit 128 can communicate with the therapeutic element 114 to change and / or substantially maintain the power level of the therapeutic element 114. In an example, the control circuit 128 communicates with the element circuit 198 to cause the therapeutic element 114 to emit energy at a specific energy level. In some examples, the control circuit 128 communicates with the generator 144 ( Figure 1) to cause the therapeutic element 114 to change and / or substantially maintain the power level provided to the therapeutic element 114. The power level can define the level of any type of energy, including pulsed field, current, microwave, radio frequency, monopolar, bipolar energy, and / or other energy. In an example, the control circuit 128 communicates with the automated control algorithm 146 and / or the evaluation / feedback algorithm 148 to change and / or substantially maintain the power level.

[0130] In one or more examples, the functions described in the present disclosure 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 codes on a computer-readable medium and executed by a hardware-based processing unit. A computer-readable medium may be an article comprising a non-transitory computer-readable storage medium encoded with instructions. Instructions embedded or encoded in an article comprising an encoded non-transitory computer-readable storage medium may enable one or more programmable processors or other processors to implement one or more of the techniques described herein, such as when instructions included or encoded in a non-transitory computer-readable storage medium are executed by one or more processors. Exemplary non-transitory computer-readable storage media may include RAM, ROM, programmable ROM (PROM), erasable programmable ROM (EPROM), electronically erasable programmable ROM (EEPROM), flash memory, hard disk, compact disk ROM (CD-ROM), ferroelectric RAM, floppy disk, cassette, magnetic medium, optical medium, or any other computer-readable storage device or tangible computer-readable medium.

[0131] In some examples, computer-readable storage media include non-transitory media. The term "non-transitory" may indicate that the storage media is not embodied in a carrier wave or propagating signal. In some examples, non-transitory storage media may store data that can change over time (e.g., in RAM or cache).

[0132] The functionality described herein can be arranged in dedicated hardware and / or software modules. Describing different features as modules or units is intended to highlight different functional aspects, and does not necessarily imply that such modules or units must be implemented by separate hardware or software components. Instead, the functions associated with one or more modules or units can be performed by separate hardware or software components, or integrated in common or separate hardware or software components. In addition, these techniques can be fully implemented in one or more circuits or logic elements.

[0133] In some examples, the disclosure may be summarized in the following numbered clauses.

[0134] Item 1: A catheter system comprising: an elongated body configured to be positioned within a patient's blood vessel; a balloon defining an internal volume; a sensor configured to generate a pressure signal indicating a pressure of a fluid within a flow path, the flow path comprising the internal volume and at least one lumen defined by the elongated body; a valve configured to define a flow area for the fluid; and a control circuit configured to: determine a pressure set point, receive the pressure signal from the sensor, and position the valve to adjust the flow area based on the pressure set point and the pressure indicated by the sensor signal.

[0135] Clause 2: The catheter system of Clause 1, wherein the at least one lumen comprises an inlet lumen and an outlet lumen, and wherein the flow path is defined through the inlet lumen and the outlet lumen.

[0136] Clause 3: The catheter system of Clause 2, wherein the diameter of the outlet lumen is greater than the diameter of the inlet lumen.

[0137] Clause 4: The catheter system of Clause 2 or Clause 3, wherein the pressure signal is indicative of the pressure of the fluid within the outlet lumen.

[0138] Clause 5: The catheter system of any one of clauses 2 to 4, wherein the valve comprises a restriction element configured to define the flow region.

[0139] Clause 6: A catheter system according to any one of clauses 2 to 5, wherein a first segment of the flow path including the inlet lumen defines a first resistance coefficient for the flow, and a second segment of the flow path including the outlet lumen defines a second resistance coefficient, wherein the second resistance coefficient is less than the first resistance coefficient.

[0140] Clause 7: The catheter system of any one of clauses 1 to 6, wherein the elongate body supports the balloon.

[0141] Clause 8: The catheter system of any of clauses 1 to 7, wherein the catheter is configured to receive an input indicative of the pressure set point and to determine the pressure set point using the input.

[0142] Clause 9: The catheter system of any one of clauses 1 to 8, wherein the catheter system is configured to provide continuous flow through the flow path.

[0143] Clause 10: A catheter system according to any one of clauses 1 to 9, wherein the valve comprises: a restriction element configured to define the flow area; and a valve actuator configured to position the restriction element, wherein the control circuit is configured to position the valve to adjust the flow area by at least causing the valve actuator to position the restriction element.

[0144] Clause 11: The catheter system of Clause 10, wherein the pressure signal indicates a pressure of the fluid upstream of the restriction element.

[0145] Clause 12: The catheter system of any of clauses 1 to 11, further comprising a pump configured to flow the fluid through the flow path.

[0146] Clause 13: The catheter system of clause 12, wherein the control circuit is configured to use the pump to regulate a flow rate of the fluid through the flow path based on the pressure set point and the pressure indicated by the sensor signal.

[0147] Clause 14: The catheter system of clause 12 or clause 13, wherein the pump defines a pump outlet configured to discharge the fluid into an inlet lumen defined by the elongated body to cause the fluid to flow through the flow path.

[0148] Clause 15: The catheter system of any one of clauses 12 to 14, further comprising a fluid container defining a reservoir configured to hold a volume of the fluid, wherein the pump is configured to draw the fluid from the reservoir and discharge the fluid into the flow path.

[0149] Clause 16: The catheter system of any of clauses 12 to 15, wherein the pump comprises a centrifugal pump.

[0150] Clause 17: The catheter system of any of clauses 12 to 15, wherein the pump comprises a positive displacement pump.

[0151] Clause 18: The catheter system of any one of clauses 1 to 17, wherein the elongated body defines a longitudinal axis, the catheter system further comprising a therapeutic element mechanically supported by the catheter system, wherein the therapeutic element is configured to emit energy in a direction away from the longitudinal axis.

[0152] Clause 19: The catheter system of clause 18, wherein the therapeutic element is configured to emit ultrasonic energy.

[0153] Clause 20: The catheter system of clause 18 or clause 19, wherein a distal portion of the elongated body supports the therapeutic element.

[0154] Clause 21: The catheter system of any of clauses 18 to 20, wherein the therapeutic element is positioned within the interior volume of the balloon.

[0155] Clause 22: The catheter system of any of clauses 18 to 21, wherein the control circuit is configured to determine a power level and cause the therapeutic element to emit the energy based on the determined power level.

[0156] Clause 23: The catheter system of clause 22, wherein the control circuit is configured to determine the power level based on at least one of the pressure set point or the pressure signal indicative of the pressure of the fluid within the flow path.

[0157] Clause 24: The catheter system of clause 22 or clause 23, wherein the pressure signal indicates the pressure of the fluid within the interior volume, and wherein the control circuit is configured to determine the power level based on the pressure of the fluid within the interior volume.

[0158] Clause 25: The method of any one of clauses 1 to 24, wherein the balloon is a compliant balloon.

[0159] Clause 26: The catheter system of any one of Clauses 1 to 25, wherein the balloon is configured to define a size of the balloon based on a pressure of the fluid within the interior volume.

[0160] Clause 27: The catheter system of Clause 26, wherein the control circuit is configured to determine the pressure set point based on input from a user, wherein the input is indicative of the size of the balloon.

[0161] Clause 28: The catheter system of clause 26 or 27, wherein the dimension of the balloon is a cross-sectional dimension of the balloon perpendicular to the longitudinal axis.

[0162] Clause 29: The catheter system of any of clauses 1 to 28, further comprising a user interface configured to receive input indicative of the pressure set point from a user and to provide the input indicative of the pressure set point to the control circuit.

[0163] Clause 30: The catheter system of any of clauses 1 to 29, wherein the control circuit is configured to determine a pressure trend based on the pressure signals received over a period of time, and to position the valve based on the pressure trend.

[0164] Clause 31: The catheter system of clause 30, wherein the control circuit is configured to position the valve to adjust the flow area in response to determining that the pressure trend deviates from a pressure trend curve.

[0165] Item 32: A catheter system comprising: an elongated body; a balloon defining an internal volume; a therapeutic element mechanically supported by the elongated body, wherein the therapeutic element is configured to emit energy; and a control circuit configured to: receive an input indicating a pressure within the internal volume of the balloon, determine a power level based on the indicated pressure, and cause the therapeutic element to emit the energy based on the determined power level.

[0166] Clause 33: The catheter system of clause 32, wherein the input comprises a pressure set point, the catheter system further comprising a user interface configured to receive the pressure set point from a user, wherein the control circuit is configured to determine the power level based on the pressure set point.

[0167] Item 34: The catheter system of Item 32, further comprising a sensor configured to generate a pressure signal indicative of a pressure of a fluid within a flow path at least partially defined by the elongated body, wherein the pressure of the fluid within the flow path indicates the pressure within the internal volume of the balloon, and wherein the control circuit is configured to: receive the pressure signal from the sensor and determine the power level based on the pressure signal.

[0168] Clause 35: The catheter system of clause 34, wherein the control circuit is configured to determine a pressure trend based on pressure signals received over a period of time, and to adjust a flow area of ​​the fluid based on the pressure trend.

[0169] Clause 36: The catheter system of clause 35, wherein the control circuit is configured to adjust the flow area based on the pressure trend deviating from a pressure trend curve.

[0170] Clause 37: The catheter system of any of clauses 32 to 36, wherein the therapeutic element is configured to emit ultrasonic energy.

[0171] Clause 38: The catheter system of any of clauses 32 to 37, further comprising a generator configured to provide energy to the therapeutic element.

[0172] Clause 39: The catheter system of clause 38, wherein the control circuit is configured to control the generator to control the energy provided so that the therapeutic element emits the energy based on the power level.

[0173] Clause 40: The catheter system of any one of clauses 32 to 39, wherein the therapeutic element comprises an energy control circuit configured to cause the therapeutic element to emit the energy, and wherein the control circuit is configured to control the energy control circuit to cause the therapeutic element to emit the energy at the power level.

[0174] Clause 41: The catheter system of any one of clauses 32 to 40, further comprising a control device configured to receive user input and provide the user input to the control circuit, wherein the control circuit is configured to change the energy emitted by the therapeutic element based on the user input.

[0175] Clause 42: The catheter system of any one of Clauses 32 to 41, wherein the balloon is a compliant balloon.

[0176] Clause 43: The catheter system of any one of clauses 32 to 42, wherein the size of the balloon varies based on the pressure within the interior volume of the balloon, and wherein the input indicative of the pressure within the interior volume of the balloon is indicative of the size of the balloon.

[0177] Clause 44: The catheter system of Clause 43, wherein the elongated body defines a longitudinal axis, and wherein the dimension of the balloon is a cross-sectional dimension of the balloon perpendicular to the longitudinal axis.

[0178] Clause 45: The catheter system of any one of clauses 32 to 44, wherein a distal portion of the elongate body mechanically supports the balloon.

[0179] Clause 46: The catheter system of any of clauses 32 to 45, wherein a distal portion of the elongate body mechanically supports the therapeutic element.

[0180] Clause 47: The catheter system of any of clauses 32 to 46, wherein the therapeutic element is positioned within the interior volume of the balloon.

[0181] Clause 48: The catheter system of any one of clauses 32 to 47, further comprising a valve configured to control the pressure of the fluid within a flow path comprising the internal volume and at least one lumen defined by the elongated body, wherein the control circuit is configured to position the valve based on the input indicative of the pressure within the internal volume of the balloon.

[0182] Clause 49: The catheter system of Clause 48, wherein the pressure of the fluid within the flow path is indicative of a pressure upstream of the restriction element.

[0183] Clause 50: The catheter system of clause 48 or clause 49, wherein the valve comprises: a restriction element configured to limit a flow area of ​​the fluid; a valve actuator configured to position the restriction element, wherein the control circuit is configured to position the valve by at least causing the valve actuator to position the restriction element.

[0184] Clause 51: The catheter system of any of Clauses 47 to 50, wherein the at least one lumen includes an inlet lumen and defines an outlet lumen, and wherein the flow path is defined through the inlet lumen and the outlet lumen.

[0185] Clause 52: The catheter system of Clause 51, wherein the diameter of the outlet lumen is greater than the diameter of the inlet lumen.

[0186] Clause 53: The catheter system of clause 51 or clause 52, wherein the sensor of any of clauses 33 to 51 is configured to determine the pressure of the fluid within the outlet lumen, and wherein the sensor signal is indicative of the pressure of the fluid within the outlet lumen.

[0187] Clause 54: The catheter system of any one of clauses 51 to 53, wherein a first segment of the flow path including the inlet lumen defines a first resistance coefficient for the flow, and a second segment of the flow path including the outlet lumen defines a second resistance coefficient for the flow, wherein the second resistance coefficient is less than the first resistance coefficient.

[0188] Clause 55: The catheter system of any of Clauses 1 to 54, further comprising a pump configured to flow the fluid through the flow path.

[0189] Clause 56: The catheter system of Clause 55, wherein the pump defines a pump outlet configured to discharge the fluid into the inlet lumen of any one of Claims 50 to 54 to cause the fluid to flow through the flow path.

[0190] Clause 57: The catheter system of clause 55 or clause 56, further comprising a fluid container defining a reservoir configured to hold a volume of the fluid, wherein the pump is configured to draw the fluid from the reservoir and discharge the fluid into the flow path.

[0191] Clause 58: The catheter system of any of clauses 55 to 57, wherein the control circuit is configured to use the pump to regulate the flow rate of the fluid through the flow path based on the input indicative of the pressure within the interior volume of the balloon.

[0192] Item 59: A method comprising: receiving, by a control circuit, a sensor input from a pressure sensor, the sensor input indicating a pressure of a fluid within a flow path for fluid flowing through an internal volume of a balloon, the flow path being defined by an elongated body of a catheter, wherein the elongated structure is configured to be positioned with an anatomical lumen of a patient; and positioning, using the control circuit, a valve configured to throttle the flow of the fluid through the flow path based on a difference between a pressure set point and the pressure indicated by the sensor input.

[0193] Clause 60: The method of clause 59, wherein the flow path comprises an inlet lumen and an outlet lumen defined by the elongated structure, and wherein a diameter of the outlet lumen is greater than a diameter of the inlet lumen or the diameter of the inlet lumen is greater than the diameter of the outlet lumen.

[0194] Clause 61: A method according to clause 59 or clause 60, wherein the outlet inner cavity defines a first flow coefficient for the mass flow rate of the fluid, and the inlet inner cavity defines a second flow coefficient for the mass flow rate of the fluid, wherein the first flow coefficient is less than the second flow coefficient or the second flow coefficient is less than the first flow coefficient.

[0195] Clause 62: The method of any one of clauses 59 to 61, wherein positioning the valve changes a flow area within the flow path.

[0196] Clause 63: The method of clause 62, further comprising sensing the pressure of the fluid upstream of the flow region using the pressure sensor.

[0197] Clause 64: The method of any one of clauses 59 to 63, wherein at least one of the balloon or energy emitting element is positioned on a distal portion of the elongated body, wherein the distal portion is configured to be positioned within the anatomical lumen.

[0198] Clause 65: The method of clause 64, further comprising emitting ultrasonic energy using the energy emitting element.

[0199] Clause 66: The method of clause 64 or clause 65, wherein the energy emitting element is positioned within the interior volume of the balloon.

[0200] Clause 67: The method of any one of clauses 59 to 66, wherein the input indicative of the pressure set point is indicative of a size of the balloon.

[0201] Clause 68: The method of any of clauses 59 to 67, further comprising receiving, by the control circuit, the pressure set point from a user.

[0202] Clause 69: The method of any of clauses 59 to 68, further comprising: determining, using the control circuit, a pressure trend based on a plurality of sensor inputs received over a period of time; and positioning the valve based on the pressure trend.

[0203] Item 70: A method comprising: receiving, by a control circuit, an input indicative of a pressure within an interior volume of a balloon of a catheter, wherein the elongated body of the catheter defines a flow path for a fluid flowing through the interior volume of the balloon, and wherein at least a distal portion of the catheter is configured to be positioned with an anatomical lumen of a patient; determining, by the control circuit, a power level of an energy emitting element of the catheter based on the indicative input; and causing the energy emitting element to emit energy based on the power level using the control circuit.

[0204] Clause 71: The method of clause 70, wherein the input is indicative of a pressure set point received from an input device.

[0205] Clause 72: The method of clause 70, further comprising: receiving, by a control circuit, a sensor input from a pressure sensor, the pressure sensor being configured to sense a pressure of a fluid within the flow path, wherein the pressure of the fluid within the flow path indicates the pressure within the internal volume of the balloon; and determining the power level based on the sensor input.

[0206] Clause 73: The method of clause 72, further comprising: determining, by the control circuit, a pressure trend based on a plurality of sensor inputs received over a period of time; and controlling, by the control circuit, a flow rate of the fluid flowing through the internal volume based on the pressure trend.

[0207] Clause 74: The method of any one of clauses 70 to 73, wherein the energy comprises ultrasonic energy.

[0208] Clause 75: The method of any of clauses 70 to 74, further comprising: receiving, by the control circuit, a user input; and using the control circuit to vary the energy emitted by the energy emitting element based on the user input.

[0209] Clause 76: The method of any one of clauses 70 to 75, wherein the input indicative of the pressure within the interior volume of the balloon is indicative of a size of the balloon.

[0210] Clause 77: The method of any one of clauses 70 to 76, further comprising controlling, by a control circuit, at least one of a valve or a pump based on the input indicative of the pressure within the internal volume of the balloon, wherein the valve or the pump is configured to control a flow rate of a fluid flowing through the internal volume.

[0211] Various examples of the disclosure have been described. Any combination of the described systems, operations, or functions is contemplated. These and other examples are within the scope of the following claims.

[0212] Further disclosed herein are the subject of the following clauses:

[0213] 1. A catheter system, comprising:

[0214] an elongated body configured to be positioned within a blood vessel of a patient;

[0215] a balloon defining an interior volume;

[0216] a sensor configured to generate a pressure signal indicative of a pressure of a fluid within a flow path including the interior volume and at least one lumen defined by the elongated body;

[0217] a valve fluidly coupled to the flow path and configured to define a flow area for the fluid; and

[0218] A control circuit, the control circuit being configured to:

[0219] Determine the pressure set point,

[0220] The pressure signal is received from the sensor, and the valve is positioned to adjust the flow area based on the pressure set point and the pressure indicated by the sensor signal.

[0221] 2. A catheter system according to claim 1, wherein the at least one lumen includes an inlet lumen and an outlet lumen; wherein the flow path is defined as passing through the inlet lumen, the internal volume and the outlet lumen; wherein the diameter of the outlet lumen is greater than the diameter of the inlet lumen.

[0222] 3. The catheter system of clause 2, wherein the pressure signal is indicative of the pressure of the fluid within the outlet lumen.

[0223] 4. The catheter system of any one of clauses 1 to 3, wherein the catheter system is configured to receive an input indicative of the pressure set point and to use the input to determine the pressure set point.

[0224] 5. The catheter system of any one of clauses 1 to 4, wherein the valve comprises:

[0225] a restriction element configured to define the flow region; and

[0226] a valve actuator configured to position the restriction element,

[0227] Wherein the control circuit is configured to position the valve to adjust the flow area by at least causing the valve actuator to position the restriction element.

[0228] 6. The catheter system of clause 5, wherein the pressure signal is indicative of a pressure of the fluid upstream of the restriction element.

[0229] 7. A catheter system according to any one of clauses 1 to 6, wherein the catheter system also includes a pump configured to cause the fluid to flow through the flow path, wherein the control circuit is configured to use the pump to regulate the flow rate of the fluid through the flow path based on the pressure set point and the pressure indicated by the sensor signal, and wherein the pump defines a pump outlet, wherein the pump outlet is configured to discharge the fluid into the inlet tube cavity defined by the slender body to cause the fluid to flow through the flow path.

[0230] 8. The catheter system of clause 7, wherein the pump comprises a centrifugal pump or a positive displacement pump.

[0231] 9. A catheter system according to any one of clauses 1 to 8, wherein the elongated body defines a longitudinal axis, the catheter system further comprising a therapeutic element mechanically supported by the catheter system, wherein the therapeutic element is configured to emit energy in a direction away from the longitudinal axis.

[0232] 10. The catheter system of clause 9, wherein:

[0233] The therapeutic element is configured to emit ultrasonic energy; or

[0234] A distal portion of the elongate body supports the therapeutic element; or

[0235] The therapeutic element is positioned within the interior volume of the balloon.

[0236] 11. A catheter system according to clause 9 or 10, wherein the processing circuit system is configured to:

[0237] Determine the power level, and

[0238] The therapeutic element is caused to emit the energy based on the determined power level.

[0239] 12. The catheter system of clause 11, wherein the control circuit is configured to determine the power level based on at least one of the pressure set point or the pressure signal indicative of the pressure of the fluid within the flow path.

[0240] 13. A catheter system according to any one of clauses 1 to 12, wherein the control circuit is configured to determine the pressure set point based on input from a user, wherein the input indicates a cross-sectional dimension of the balloon perpendicular to the longitudinal axis of the elongated body.

[0241] 14. A catheter system, comprising:

[0242] Slender body;

[0243] a balloon defining an interior volume;

[0244] a therapeutic element mechanically supported by the elongated body, wherein the therapeutic element is configured to emit energy; and

[0245] A control circuit, the control circuit being configured to:

[0246] receiving an input indicative of a pressure within the interior volume of the balloon,

[0247] determining a power level based on the indicated pressure, and

[0248] The therapeutic element is caused to emit the energy based on the determined power level.

[0249] 15. The catheter system of clause 14, wherein the input comprises a pressure set point, the catheter system further comprising a user interface configured to receive the pressure set point from a user, wherein the control circuit is configured to determine the power level based on the pressure set point.

[0250] 16. The catheter system of clause 14, further comprising a sensor configured to generate a pressure signal indicative of a pressure of a fluid within a flow path defined at least in part by the elongated body, wherein the pressure of the fluid within the flow path is indicative of the pressure within the interior volume of the balloon, and wherein the control circuit is configured to:

[0251] receiving the pressure signal from the sensor, and

[0252] The power level is determined based on the pressure signal.

[0253] 17. The catheter system of any one of clauses 14 to 16, wherein the therapeutic element is configured to emit ultrasonic energy, the catheter system further comprising a generator configured to provide energy to the therapeutic element.

[0254] 18. A catheter system according to any one of clauses 14 to 17, wherein the therapeutic element includes an energy control circuit, the energy control circuit is configured to cause the therapeutic element to emit the energy, and wherein the control circuit is configured to control the energy control circuit so that the therapeutic element emits the energy at the power level.

[0255] 19. A catheter system according to any one of clauses 14 to 18, wherein the size of the balloon varies based on the pressure within the internal volume of the balloon, and wherein the input indicative of the pressure within the internal volume of the balloon is indicative of the size of the balloon.

[0256] 20. The catheter system of clause 19, wherein the elongated body defines a longitudinal axis, and wherein the dimension of the balloon is a cross-sectional dimension of the balloon perpendicular to the longitudinal axis.

[0257] 21. The catheter system of any one of clauses 14 to 20, wherein the therapeutic element is positioned within the interior volume of the balloon.

[0258] 22. A method comprising:

[0259] receiving, by the control circuit, a sensor input from a pressure sensor indicative of a pressure of a fluid within a flow path for fluid flowing through an interior volume of the balloon, the flow path being defined by an elongated body of the catheter, wherein the elongated structure is configured to be positioned with an anatomical lumen of a patient; and

[0260] A valve is positioned using the control circuit, the valve being configured to throttle flow of the fluid through the flow path based on a difference between a pressure set point and the pressure indicated by the sensor input.

[0261] 23. A method comprising:

[0262] receiving, by a control circuit, an input indicative of a pressure within an interior volume of a balloon of a catheter, wherein the elongated body of the catheter defines a flow path for a fluid flowing through the interior volume of the balloon, and wherein at least a distal portion of the catheter is configured to be positioned with an anatomical lumen of a patient;

[0263] determining, by the control circuitry, a power level of an energy emitting element of the catheter based on the indicative input; and

[0264] The control circuit is used to cause the energy emitting element to emit energy based on the power level.

Claims

1. A catheter system, comprising: an elongated body configured to be positioned within a blood vessel of a patient; a balloon defining an interior volume; a sensor configured to generate a pressure signal indicative of a pressure of a fluid within a flow path including the interior volume and at least one lumen defined by the elongated body; a valve fluidly coupled to the flow path and configured to define a flow area for the fluid; and A control circuit, the control circuit being configured to: Determine pressure set point; receiving the pressure signal from the sensor, and The valve is positioned to adjust the flow area based on the pressure set point and the pressure indicated by the sensor signal.

2. The catheter system of claim 1 , wherein the at least one lumen comprises an inlet lumen and an outlet lumen; wherein the flow path is defined as passing through the inlet lumen, the internal volume, and the outlet lumen; and wherein the diameter of the outlet lumen is greater than the diameter of the inlet lumen.

3. The catheter system of claim 2, wherein the pressure signal is indicative of the pressure of the fluid within the outlet lumen.

4. The catheter system of any one of claims 1 to 3, wherein the catheter system is configured to receive an input indicative of the pressure set point and to determine the pressure set point using the input.

5. The catheter system according to any one of claims 1 to 4, wherein the valve comprises: a restriction element configured to define the flow region; and a valve actuator configured to position the restriction element, Wherein the control circuit is configured to position the valve to adjust the flow area by at least causing the valve actuator to position the restriction element.

6. The catheter system of claim 5, wherein the pressure signal is indicative of a pressure of the fluid upstream of the restriction element.

7. The catheter system of any one of claims 1 to 6, further comprising a pump configured to cause the fluid to flow through the flow path, wherein the control circuit is configured to use the pump to regulate a flow rate of the fluid through the flow path based on the pressure set point and the pressure indicated by the sensor signal, and wherein the pump defines a pump outlet configured to discharge the fluid into the inlet lumen defined by the elongated body to cause the fluid to flow through the flow path.

8. The catheter system of claim 7, wherein the pump comprises a centrifugal pump or a positive displacement pump.

9. The catheter system of any one of claims 1 to 8, wherein the elongated body defines a longitudinal axis, the catheter system further comprising a therapeutic element mechanically supported by the catheter system, wherein the therapeutic element is configured to emit energy in a direction away from the longitudinal axis.

10. The catheter system of claim 9, wherein: The therapeutic element is configured to emit ultrasonic energy; or A distal portion of the elongate body supports the therapeutic element; or The therapeutic element is positioned within the interior volume of the balloon.

11. The catheter system of claim 9 or 10, wherein the control circuit is configured to: Determine the power level, and The therapeutic element is caused to emit energy based on the determined power level.

12. The catheter system of claim 11, wherein the control circuit is configured to determine the power level based on at least one of the pressure set point or the pressure signal indicative of the pressure of the fluid within the flow path.

13. A catheter system according to any one of claims 1 to 12, wherein the control circuit is configured to determine the pressure set point based on input from a user, wherein the input indicates a cross-sectional dimension of the balloon perpendicular to the longitudinal axis of the elongated body.

14. A catheter system, comprising: Slender body; a balloon defining an interior volume; a therapeutic element mechanically supported by the elongated body, wherein the therapeutic element is configured to emit energy; and A control circuit, the control circuit being configured to: receiving an input indicative of a pressure within the interior volume of the balloon, determining a power level based on the indicated pressure, and The therapeutic element is caused to emit the energy based on the determined power level.

15. The catheter system of claim 14, wherein the input comprises a pressure set point, the catheter system further comprising a user interface configured to receive the pressure set point from a user, wherein the control circuit is configured to determine the power level based on the pressure set point.

16. The catheter system of claim 14, further comprising a sensor configured to generate a pressure signal indicative of a pressure of a fluid within a flow path defined at least in part by the elongated body, wherein the pressure of the fluid within the flow path is indicative of the pressure within the interior volume of the balloon, and wherein the control circuit is configured to: receiving the pressure signal from the sensor, and The power level is determined based on the pressure signal.

17. The catheter system of any one of claims 14 to 16, wherein the therapeutic element is configured to emit ultrasonic energy, the catheter system further comprising a generator configured to provide energy to the therapeutic element.

18. The catheter system of any one of claims 14 to 17, wherein the therapeutic element comprises an energy control circuit configured to cause the therapeutic element to emit the energy, and wherein the control circuit is configured to control the energy control circuit to cause the therapeutic element to emit the energy at the power level.

19. A catheter system according to any one of claims 14 to 18, wherein the size of the balloon varies based on the pressure within the interior volume of the balloon, and wherein the input indicative of the pressure within the interior volume of the balloon is indicative of the size of the balloon.

20. The catheter system of claim 19, wherein the elongated body defines a longitudinal axis, and wherein the dimension of the balloon is a cross-sectional dimension of the balloon perpendicular to the longitudinal axis.

21. The catheter system of any one of claims 14 to 20, wherein the therapeutic element is positioned within the interior volume of the balloon.

22. A method comprising: receiving, by the control circuit, a sensor input from a pressure sensor indicative of a pressure of a fluid within a flow path of the fluid flowing through the interior volume of the balloon, the flow path being defined by the elongated body of the catheter, wherein the elongated structure is configured to be positioned with an anatomical lumen of a patient; as well as A valve is positioned using the control circuit, the valve being configured to throttle flow of the fluid through the flow path based on a difference between a pressure set point and the pressure indicated by the sensor input.

23. A method comprising: receiving, by a control circuit, an input indicative of a pressure within an interior volume of a balloon of a catheter, wherein the elongated body of the catheter defines a flow path for a fluid flowing through the interior volume of the balloon, and wherein at least a distal portion of the catheter is configured to be positioned with an anatomical lumen of a patient; determining, by the control circuitry, a power level of an energy emitting element of the catheter based on the indicative input; as well as The control circuit is used to cause the energy emitting element to emit energy based on the power level.

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