Patent Application
20240238620
Certain embodiments of the present technology generally relate to catheters (also known as probes) configured to be inserted into a biological lumen (e.g., a renal artery) and used for obtaining neural measurements, and related apparatuses, systems and methods. Certain embodiments generally related to minimally invasive apparatuses, systems and methods that provide energy delivery to a targeted anatomical location of a subject, and more specifically, to catheter-based, intraluminal apparatuses, systems and methods including or utilizing an ultrasound transducer configured to emit ultrasonic energy for the treatment of tissue, such as nerve tissue.
Proper operation of the nervous system is an important part of proper organ function. It is desired to be able to monitor and change nervous system function in the human body to characterize and correct nervous system regulation of internal human organs. New medical therapies have been practiced whereby a probe such as a needle, catheter, wire, etc. is inserted into the body to a specified anatomical location and destructive means are conveyed to nerves by means of the probe to irreversibly damage tissue in the nearby regions. The objective is to modulate (e.g., abolish) nerve function in the specified anatomic location. The result is that abnormally functioning physiological processes can be terminated or modulated back into a normal range. An alternative objective can be to increase a physiologic process or modulate it to an abnormal range.
An example is renal nerve ablation to relieve hypertension. Various studies have confirmed the relationship of renal nerve activity with blood pressure regulation. In various renal ablation procedures, a catheter is introduced into a hypertensive patient's arterial vascular system and advanced into the renal artery. Destructive means are delivered proximate to the renal artery wall to an extent intended to cause destruction of nerve activity. Destructive means include energy such as radio frequency (RF), microwave, cryotherapy, ultrasound, laser or chemical agents. The objective is to abolish the renal nerve activity. Such nerve activity is an important factor in the creation and/or maintenance of hypertension and abolishment of the nerve activity reduces blood pressure and/or medication burden.
The present technology is defined in the independent claims. Further embodiments of the technology are defined in the dependent claims.
A catheter for use in analyzing neural activity of nerves that surround a biological lumen includes a handle and a shaft extending from the handle. The shaft configured to be inserted into the biological lumen. The selectively inflatable balloon is located on the shaft. The distal electrode and the proximal electrode are longitudinally spaced apart from one another on the shaft. Each of the distal electrode and the proximal electrode is configured to be selectively transitioned between a non-intussuscepted position and an intussuscepted position.
A catheter for use in analyzing neural activity of nerves that surround a biological lumen includes a handle and a shaft extending from the handle. The shaft configured to be inserted into the biological lumen. The selectively inflatable balloon is located on the shaft. The distal spiral electrode is at least partially encircling a distal portion of the balloon. The proximal spiral electrode is at least partially encircling a proximal portion of the balloon. Each of the distal and proximal spiral electrodes is configured to be selectively transitioned between a non-deployed and a deployed position in response to the balloon being at least partially inflated.
A catheter for use in analyzing neural activity of nerves that surround a biological lumen includes a handle and a shaft extending from the handle. The shaft configured to be inserted into the biological lumen. The selectively inflatable balloon is located on the shaft and made for a non-electrically conductive material. The distal coated electrode is formed on and encircling the circumference of a distal portion of the balloon. The proximal coated electrode is formed on and encircling a circumference of a proximal portion of the balloon.
A method for use with a catheter including a handle, a shaft extending from the handle, a selectively inflatable balloon located on the shaft, and a distal electrode and a proximal electrode longitudinally spaced apart from one another. The method includes inserting at least a portion of the shaft into a biological lumen while the balloon is not inflated. At least partially inflating the balloon while the at least the portion of the shaft is inserted into the biological lumen. Causing the distal and proximal electrodes to come into contact respectively with first and second longitudinally spaced apart portions of the biological lumen while the distal and proximal electrodes respectively surround distal and proximal portions of the balloon. Sensing neural activity of nerves within the tissue surrounding the biological lumen using at least one of the distal and proximal electrodes that respectively surround the distal and proximal portions of the balloon and are in contact respectively with the first and second longitudinally spaced apart portions of the biological lumen.
This summary is not intended to be a complete description of the embodiments of the present technology. Other features and advantages of the embodiments of the present technology will appear from the following description in which the preferred embodiments have been set forth in detail, in conjunction with the accompanying drawings and claims.
The various features of the present disclosure and the manner of attaining them will be described in greater detail with reference to the following description, claims, and drawings, wherein reference numerals are reused, where appropriate, to indicate a correspondence between the referenced items, and wherein:
FIG. 3A1 illustrates a cross-sectional view of a catheter shaft, along the line A-A in
FIG. 3A2 illustrates a cross-sectional view of the catheter shaft, along the line A-A in
In the following detailed description of example embodiments, reference is made to specific example embodiments by way of drawings and illustrations. These examples are described in sufficient detail to enable those skilled in the art to practice what is described, and serve to illustrate how elements of these examples may be applied to various purposes or embodiments. Other embodiments exist, and logical, mechanical, electrical, and other changes may be made. Features or limitations of various embodiments described herein, however important to the example embodiments in which they are incorporated, do not limit other embodiments, and any reference to the elements, operation, and application of the examples serve only to define these example embodiments. Features or elements shown in various examples described herein can be combined in ways other than shown in the examples, and any such combination is explicitly contemplated to be within the scope of the examples presented here. The following detailed description does not, therefore, limit the scope of what is claimed.
Regulating operation of the nervous system to characterize nerve signaling and modulate organ function includes in some examples introduction of a probe such as a needle, catheter, wire, or the like into the body to a specified anatomical location, and partially destroying or ablating nerves using the probe to destroy nerve tissue in the region near the probe. By reducing nerve function in the selected location, an abnormally functioning physiological process can often be regulated back into a normal range. It would also be possible to modulate nerve function to purposely cause an abnormally functioning physiological process that is beneficial to the patient.
Unfortunately, not all patients respond to this therapy. One reason is that the delivery of destructive means towards the arterial wall does not have a feedback mechanism to assess the destruction of the nerve activity. As a consequence, an insufficient quantity of destructive means may be delivered, and nervous activity may not be abolished. Clinicians, therefore, require a means of improving the probe/tissue interface and better targeting of nerves, and an improved technology to monitor the integrity of the nerve fibers in order to confirm destruction of nerve activity prior to terminating therapy. Currently, nerve destructive means are applied empirically, without knowledge of whether the desired effect has been achieved.
Current autonomic nerve ablation procedures are performed in a ‘blind’ fashion; the clinician performing the procedure does not know where the nerves are located; and further, whether the nerves have truly been ablated. Instead, surrogates such as calf muscle sympathetic activity (MSNA) or catecholamine spillover into the circulating blood have been used to attempt to evaluate the reduction in organ specific autonomic activity such as renal nerve activity. It is entirely likely that this deficiency could at least partly be responsible for the current variability in clinical responses coming from clinical trials.
Unfortunately, it is typically very difficult to estimate the degree to which nerve activity has been reduced, which makes it difficult to perform a procedure where it is desired to ablate all nerves, or to ablate some, but not all, nerves to bring the nervous system response back into a desired range without destroying the nervous system response entirely.
One such example is renal nerve ablation to treat hypertension. Various studies have confirmed that renal nerve activity has been associated with hypertension, and that ablation of the nerve can improve renal function and reduce hypertension. In a typical procedure, a catheter is introduced into a hypertensive patient's arterial vascular system and advanced into the renal artery. Renal nerves located in the arterial wall and in regions adjacent to the artery are ablated by destructive means such as radio frequency waves, microwave, cryotherapy, ultrasound, laser or chemical agents to limit the renal nerve activity, thereby reducing hypertension in the patient.
Unfortunately, renal nerve ablation procedures are sometimes ineffective, such as due to either insufficiently ablating the nerve or destroying more nerve tissue than is desired. Also, it may be desirable to avoid ablating other off-target tissues. Clinicians often estimate based on provided guideline estimates or past experience the degree to which application of a particular ablative method will reduce nerve activity, and it can take a significant period of time (e.g., 3-12 months) before the clinical effects of the ablation procedure are fully known.
Some attempt has been made to monitor nerve activity in such procedures by inserting very small electrodes into or adjacent to the nerve body, which are then used to electrically monitor the nerve activity. Such microneurography practices are not practical in the case of renal ablation because the renal arteries and nerves are located within the abdomen and cannot be readily accessed, making monitoring and characterization of nerve activity in a renal nerve ablation procedure a challenge.
Prior methods such as inserting electrodes into the arteries of a patient's heart and analyzing received electrical signals are not readily adaptable to renal procedures. In the heart, the ablated tissue is heart muscle which itself is electrically conductive. Further, the cardiac electrical signals emitted from the heart are generally large and slow-moving relative to electrical signals near the renal arteries, which tend to be smaller in size and produce smaller signals that propagate more quickly through the nerves. In the case of renal denervation, the target of the ablation is renal nerves which lie outside the lumen of the blood vessel, and the blood vessel tissue is different from myocardium and acts as a barrier to adequately sense nerve firing. As such, intracardiac techniques used in heart measurements are not readily adaptable to similar renal procedures.
Because nerve activity during procedures to ablate or neuromodulate enervation of organs such as renal nerve ablation cannot be readily measured, it is also difficult to ensure that an ablation probe is located at the most appropriate sites along the renal artery, or to measure the efficiency of the nerve ablation process in a particular patient.
Acoustic-based tissue treatment transducers, apparatuses, systems, and portions thereof, are provided herein. Preferably, the systems are catheter-based and may be delivered intraluminally (e.g., intravascularly) so as to place a transducer within a target anatomical region of the subject, for example, within a suitable body lumen such as a blood vessel. Once properly positioned within the target anatomical region, the transducer can be activated to deliver unfocused ultrasonic energy radially outwardly so as to suitably heat, and thus treat, tissue within the target anatomical region. The transducer can be activated at a frequency, duration, and energy level suitable for treating the targeted tissue. In one nonlimiting example, the unfocused ultrasonic energy generated by the transducer may target select nerve tissue of the subject, and may heat such tissue in such a manner as to neuromodulate (e.g., fully or partially ablate, necrose, or stimulate) the nerve tissue. Neuromodulating renal nerves may be used to treat various conditions, e.g., hypertension, chronic kidney disease, atrial fibrillation, etc. However, it should be appreciated that the transducers suitably may be used to treat other nerves and conditions, e.g., sympathetic nerves of the hepatic plexus within a hepatic artery responsible for blood glucose levels important to treating diabetes, or any suitable tissue, e.g., heart tissue triggering an abnormal heart rhythm, and is not limited to use in treating (e.g., neuromodulating) renal nerve tissue.
In an intraluminal system, an ultrasound transducer may be disposed within a balloon that is filled with a cooling fluid before and during treatment. In certain embodiments, a balloon may surround the transducer, and the balloon may contact the interior surface (e.g., intima) of the body lumen BL. In certain embodiments, the transducer may be used to output an acoustic signal when the balloon fully occludes a body lumen BL, and the cooling fluid within the balloon may be used to cool both the body lumen and the transducer. In certain embodiments, the balloon may surround the transducer in order to cool the transducer during sonications, but the balloon may not contact or occlude the body lumen, and the blood within the body lumen may be relied upon to cool the body lumen instead of the cooling fluid. The term body lumen is also referred to herein interchangeably as the term biological lumen.
In the embodiment shown in
Referring now to
The catheter 102 may be coupled to the controller 120 by connecting the electrical coupling(s) 232 to the connection cable 140. The connection cable 140 may be removably connected to the controller 120 and/or the catheter 102 via a port on the controller 120 and/or the catheter 102, in order to permit use of multiple catheters during a procedure. In certain embodiments, e.g., where only one catheter 102 needs to be used during a procedure, the connection cable 140 may be permanently connected to the controller 120. As will be described in additional detail below, electrical cabling (represented by the dashed line 282 in
In certain embodiments, the proximal portion 220 of the catheter 102 may further include one or more fluidic ports, e.g., a fluidic inlet port 234a and a fluidic outlet port 234b, via which the balloon 112 may be fluidly coupled to the cartridge 130 (shown in
The transducer 111 may be disposed partially or completely within the balloon 112, which may be inflated with a cooling fluid 213 so as to contact the interior surface (e.g., intima) of the body lumen BL. In certain embodiments, the transducer 111 may be used to output an acoustic signal when the balloon 112 fully occludes a body lumen BL. The balloon 112 may center the transducer 111 within the body lumen BL. In certain embodiments, e.g., suitable for renal denervation, the balloon 112 is inflated while inserted in the body lumen BL of the patient during a procedure at a working pressure of about 1.4 to 2 atm using the cooling fluid 213. The balloon 112 may be or include a compliant, semi-compliant or non-compliant medical balloon. The balloon 112 is sized for insertion in the body lumen BL and, in the case of insertion into the renal artery, for example, the balloon 112 may be selected from available sizes including outer diameters of 3.5, 4.2, 5, 6, 7, or 8 mm, but not limited thereto. In some embodiments, as shown in
Referring again to
As shown in
As illustrated in
In order to permit liquid cooling along both the inner and outer electrodes 202, 203, the backing member 218 may include one or more stand-off assemblies 230a and 230b. The stand-off assemblies 230a, 230b may define one or more annular openings through which cooling fluid 213 may enter the space of the transducer 111 (which may be selectively insulated) between the backing member 218 and the inner electrode 202. Accordingly, the backing member 218 may serve as a fluid barrier between the cooling fluid 213 circulated within the balloon 112 and the lumen of the backing member 218 that receives the guidewire 216. As shown schematically in
In accordance with certain embodiments, the stand-off assemblies 230a, 230b are electrically conductive, so as to electrically couple the inner electrode 202 of the ultrasound transducer 111 to the backing member 218. One or more conductors of the electrical cabling 282 may be electrically coupled to the backing member 218. Thus, as the controller 120 is activated, current may be delivered from the electrical cabling 282 to the inner electrode 202 of the ultrasound transducer 111 via the backing member 218 and the stand-off assemblies 230a, 230b, which advantageously eliminates the need to couple the cabling 282 directly to the inner electrode 202 of the transducer 111. In other embodiments, the backing member 218 and the stand-off assemblies 230a, 230b are made of one or more electrical insulator material(s), or if made of an electrically conductive material(s) are coated with one or more electrical insulator material(s). In certain embodiments, one or more electrical conductors of the cabling 282 are directly coupled (e.g., soldered) to the inner electrode 202 of the transducer 111.
Moreover, as illustrated in
As illustrated in
As illustrated in FIGS. 3A1 and 3A2, the catheter shaft 214 includes one or more lumens that can be used as fluid conduits, electrical cabling passageways, guidewire lumen, and/or the like. For example, as illustrated in FIGS. 3A1 and 3A2, the catheter shaft 214 may comprise a guidewire lumen 325 that is shaped, sized and otherwise configured to receive the guidewire 216. In certain embodiments, as illustrated in FIG. 3A1, the guidewire lumen 325 is located in the center of the catheter shaft 214 in order to center the transducer 111 within the catheter shaft 214. Alternatively, the guidewire lumen 325 can be offset from the center of the catheter shaft 214, e.g., as shown in FIG. 3A2. The catheter shaft 214 may also include a cable lumen 326 for receiving electrical cabling 282. Further, the catheter shaft 214 can include one or more fluid lumens 327, 328 for transferring the cooling fluid 213 (e.g., water, sterile water, saline, 5% dextrose (D5 W)), other liquids or gases, etc., from and to a fluid source, e.g., the reservoir 110 and cartridge 130, at the proximal portion 220 of the catheter 102 (external to the patient) to the balloon 112 under control of the controller 120. Active cooling of about the first millimeter of tissue is designed to preserve the integrity of the blood vessel wall, e.g., the renal arterial wall. The guidewire lumen 325 can extend longitudinally through the entire catheter shaft 214, parallel to the fluid lumens 327, 328. Alternatively, the guidewire lumen 325 may extend longitudinally through only a portion of the catheter shaft 214, e.g., where the catheter 102 is a rapid exchange (Rx) type of catheter.
The catheter 102 may include only a single fluid lumen or two or more fluid lumens (e.g., 3, 4, more than 4, etc.), as desired or required. As illustrated in FIG. 3A1, in an embodiment, the fluid lumens 327 and 328 and the cable lumen 326 all have a kidney-shaped or D-shaped cross-sections configured to maximize efficiency of fluid flow delivery and distribute fluid uniformly across the ultrasound transducer 111 by maximizing area, while minimizing the perimeter of the fluid lumens 327 and 328. In certain embodiments, each of the fluid lumens 327 and 328 and the cable lumen 326 are substantially symmetrical, the same size, the same geometry, and/or are interchangeable, e.g., as shown in FIG. 3A1. Changes in fluid flow rate within the catheter can lead to delayed, incomplete, or over treatment. In certain embodiments, the catheter shaft 214 is configured to enable a fluid flow rate of about 40 mL/min. In certain embodiments, the catheter shaft 214 is configured to enable a fluid flow rate of about 35 to 45 mL/min. In certain embodiments, the catheter shaft 214 is configured to enable a fluid flow rate of about 20 to 45 mL/min. In certain embodiments, e.g., suitable for radial delivery during a renal denervation procedure, the catheter shaft 214 is configured to enable a fluid flow rate of about 10 to 20 mL/min. Each of one or more lumens (e.g., 328) may be in fluid communication with the same or separate, individual fluid sources external to the patient at the proximal portion 220 of the catheter 102.
In certain embodiments, as illustrated in FIG. 3A2, the guidewire lumen 325 is located proximal to and/or shares a wall with the catheter shaft 214 so as to enable expedited exchange of catheters during a procedure. In such embodiments, the cable lumen 326 may be located opposite the guidewire lumen 225 and also share a wall with the catheter shaft 214. The cable lumen 326 may be, e.g., triangular or rectangular in shape, and may be configured to maximize the area available for and minimize the perimeter of the fluid lumens 327 and 328, thereby enabling a higher flow rate for the same pressure. The fluid lumens 327 and 328 may be shaped so as to optimize flow rate and reduce, and preferably minimize, fluidic friction. In such embodiments, the area of fluid lumens 327 and 328 may not be maximized, but instead the walls of the fluid lumens 327 and 328 may be rounded to avoid pockets that may otherwise cause fluidic friction, thereby optimizing flow rate of the cooling fluid 213 within the fluid lumens 327 and 328.
The catheter shaft 214 may include within at least the cable lumen 326, the electrical cabling 282 (e.g., a coaxial cable, parallel coaxial cables, a shielded parallel pair cable, one or more wires, or one or more other electrical conductors) coupling the inner and outer electrodes 202, 203 of the ultrasound transducer 111 to the controller 120, such that the controller 120 may apply a suitable voltage across such electrodes so as to cause the piezoelectric material of the transducer 111 to emit ultrasonic energy to a subject. In certain embodiments, the cable lumen 326 is shaped, sized and otherwise configured to receive the electrical cabling 282 (e.g., coaxial cable(s), wire(s), other electrical conductor(s), etc.). The electrical cabling 282 permits the electrodes 202, 203 of the ultrasound transducer 111 to be selectively activated in order to emit acoustic energy to a subject. More specifically, the electrical cabling 282 can allow for the communication of transducer information, such as operating frequency and power, from the catheter 102 to the controller 120 and/or vice versa, as well as the transfer of electrical energy to the ultrasound transducer 111 during a procedure.
The distal portion 210 of the catheter 102 may be percutaneously delivered to the target anatomical location (e.g., at a specified location within the body lumen BL) via any suitable intraluminal access route, e.g., via a gastrointestinal route or via an intravascular route such as the femoral or radial route. In certain embodiments, the controller 120 is configured so as to fill the balloon 112 with the cooling fluid 213 only after the distal portion 210 of the catheter 102 is suitably positioned at the target anatomical location. The catheter 102 may be delivered through the body lumen BL with or without the assistance of a commercially available guidewire. For example, the catheter 102 and the balloon 112 may be delivered over the guidewire 216 (shown in
It will be appreciated that the frequency, power, and amount of time for which the transducer 111 is actuated suitably may be selected based on the treatment to be performed. For example, the frequency optionally is in a range of from 1 to 20 MHz, e.g., 1-5 MHz, 5-10 MHz, 8.5-9.5 MHz, 10-15 MHz, 15-20 MHz, or 8-10 MHz, for example, about 9 MHz. Or, for example, the frequency optionally is in a range of below 1 MHz, e.g., 0.1-0.2 MHz, 0.2-0.3 MHz, 0.3-0.4 MHz, 0.4-0.5 MHz, 0.5-0.6 MHz, 0.6-0.7 MHz, 0.7-0.8 MHz, 0.8-0.9 MHz, or 0.9-1.0 MHz. Or, for example, the frequency optionally is in a range of above 20 MHz, e.g., 20-25 MHz, 25-30 MHz, or above 30 MHz. Optionally, the power may be in a range of 5 to 80 W (e.g., 5 to 50 W, 5 to 10 W, 12.1-16.6 W, 10 to 20 W, 20 to 30 W, 30 to 40 W, 40 to 50 W, 50 to 60 W, 60 to 70 W, or 70 to 80 W, or may be more than 80 W). For example, the power may be 20 to 40 W with 20 to 30 W for balloons with smaller diameters (e.g., 3.5 to 5 mm) and 30 to 40 W for balloons with larger diameters (e.g., 5 to 8 mm). The period of time during which the transducer 111 is actuated may be sufficient to complete the particular treatment being performed, and may depend on factors such as the power at the transducer, the frequency of ultrasonic energy emitted, the size of the tissue region being treated, the age, weight and gender of the patient being treated, and/or the like. Illustratively, in some configurations the time period for which the transducer 111 may be actuated may be in a range of about 3 seconds to 5 minutes, e.g., 3-10 seconds, 3-30 seconds, 30 seconds to 1 minute, 30 seconds to 5 minutes, 1 to 3 minutes, about 2 minutes, 10 seconds to 1 minute, 1 to 2 minutes, 2 to 3 minutes, 3 to 4 minutes, or 4 to 5 minutes. Or, for example, the transducer 111 may be actuated for less than 10 seconds (s), e.g., 0.1-10 s, 1-2 s, 2-3 s, 3-4 s, 4-5 s, 5-6 s, 6-7 s, 7-8 s, 8-9 s, or 9-10 s. Or, for example, the transducer 111 may be actuated for more than 5 minutes (m), e.g., 5-6 m, 6-7 m, 7-8 m, 8-9 m, 9-10 m, 10-15 m, 15-20 m, or for more than 20 minutes.
In various configurations, the delivery of ultrasound energy during the treatment may be continuous or substantially continuous, e.g., without any interruptions or fluctuations in frequency, power, duty cycle and/or any other parameters. Alternatively, one or more of the frequency, power, duty cycle, or any other parameter may be modified during the treatment. For example, in some configurations, the delivery of ultrasonic energy is modulated, e.g., between on and off, or between a relatively high level and a relatively low level, so as prevent or reduce the likelihood of overheating of adjacent (e.g., targeted or non-targeted) tissue. For examples of such modulation, see U.S. Pat. No. 10,499,937 to Warnking, the entire contents of which are incorporated herein by reference.
In example configurations in which nerve tissue is to be treated, e.g., the nerves N illustrated in
Additional options regarding designs and uses of ultrasound transducers and catheter-based ultrasound delivery systems are provided in the following patents and published applications, the entire contents of each of which are incorporated by reference herein: U.S. Pat. Nos. 6,635,054; 6,763,722; 7,540,846; 7,837,676; 9,707,034; 9,981,108; 10,350,440; 10,456,605; 10,499,937; and PCT Publication No. WO 2012/112165.
In accordance with certain embodiments of the present technology, the piezoelectric transducer body of the ultrasound transducer comprises a hollow tube of piezoelectric material having an inner surface and an outer surface. In certain such embodiments, a first electrode is disposed on one of the inner and outer surfaces of the hollow tube of piezoelectric material, and a second electrode is disposed on the other one of the inner and outer surfaces of the hollow tube of piezoelectric material. The hollow tube of piezoelectric material can be cylindrically shaped, such that it has a circular shaped radial cross-section. In certain embodiments suitable, e.g., for renal denervation, the piezoelectric material, of which the piezoelectric transducer body is made, is lead zirconate titanate 8 (PZT8), which is also known as Navy III Piezo Material. Raw PZT transducers may be plated with layers of copper, nickel and/or gold to create electrodes on surfaces (e.g., the inner and outer surfaces) of the piezoelectric transducer body. In alternative embodiments the hollow tube of piezoelectric material can have other shapes besides being cylindrical with a circular cross-section. Other cross-sectional shapes for the hollow tube of piezoelectric material, and more generally the piezoelectric transducer body, include, but are not limited to, an oval or elliptical cross-section, a square or rectangular cross-section, pentagonal cross-section, a hexagonal cross-section, a heptagonal cross-section, an octagonal cross-section, and/or the like. In still other embodiments, the piezoelectric transducer body is not hollow, e.g., can have a generally solid rectangular shape, or some other solid shape. The piezoelectric transducer body can be configured, e.g., to deliver acoustic energy in a frequency range of 8.5 to 9.5 MHz, but is not limited thereto. In accordance with certain embodiments, the piezoelectric transducer body is configured to produce an acoustic output power within a range of 5 to 45 Watts in response to an input electrical power within a range of 10 to 80 Watts, but is not limited thereto.
In the illustrated embodiment of
In some embodiments, the ECU 402 can include a switching network configured to interchange which of electrodes of a catheter (e.g., 102) are coupled to which portions of the ECU. In some such embodiments, a user can manually switch which inputs receive connections to which electrodes of the catheter 102. Such configurability allows for a system operator to adjust the direction of propagation of the elicited potential as desired. For example, the switching network, or more generally switches, can be used to select which electrodes of a catheter connect to the stimulator during a period of time during which stimulation pulses are to be emitted by the catheter 102, and the switches can then be used to select which electrodes of the catheter are connected to the amplifier 412 during a period of time during which the elicited response to the stimulation pulses are to be sensed. More generally, the switching network can be used to select which two or more electrodes of a catheter are being used as sense electrodes, and which two or more electrodes of the catheter are being used as stimulation electrodes. It is noted that one or more electrodes that are used as stimulation electrodes during a period of time can be used as sense electrodes during another period of time, and/or vice versa.
The amplifier 412 can include any appropriate amplifier for amplifying desired signals or attenuating undesired signals. In some examples, the amplifier has a high common-mode rejection ratio (CMRR) for eliminating or substantially attenuating undesired signals present at the sensing electrodes. In some embodiments, the amplifier 412 can be adjusted, for example, via an adjustable capacitance or via other attributes of the amplifier.
In the example system 400 of
At least one of amplification and filtering of the signal received at the sense electrodes can allow for extraction of the desired signal at 416. In some embodiments, extraction 416 comprises at least one additional processing step to isolate desired signals from the signal sensed using the sense electrodes such as preparing the signal for output at 418. In some embodiments, the functionalities of any combination of amplifier 412, filter 414, and extraction 416 may be combined into a single entity. For instance, the amplifier 412 may act to filter undesired frequency content from the signal without requiring additional filtering at a separate filter.
In some embodiments, the ECU 402 can record emitted stimuli and/or received signals. Such data can be subsequently stored in permanent or temporary memory 420. The ECU 402 can comprise such memory 420 or can otherwise be in communication with external memory (not shown). Thus, the ECU 402 can be configured to emit stimulus pulses to electrodes of the catheter, record such pulses in a memory, receive signals from the catheter, and also record such received signal data. The memory 420 in or associated with the ECU 402 can be internal or external to any part of the ECU 402 or the ECU 402 itself.
The ECU 402 or separate external processor can further perform calculations on the stored data to determine characteristics of signals either emitted or received via the catheter. For example, in various embodiments, the ECU 402 can determine any of the amplitude, duration, or timing of occurrence of the received or emitted signals. The ECU 402 can further determine the relationship between the received signal and the emitted stimulus signal, such as a temporal relationship therebetween. In some embodiments, the ECU 402 performs signal averaging on the signal data received from the catheter. Such averaging can act to reduce random temporal noise in the data while strengthening the data corresponding to any elicited potentials received by the catheter.
Averaging as such can result in a signal in which temporally random noise is generally averaged out and the signal present in each recorded data set, such as elicited potentials, will remain high. In some embodiments, each iteration of the process can include a synchronization step so that each acquired data set can be temporally registered to facilitate averaging the data. That is, events that occur consistently at the same time during each iteration may be detected, while temporally random artifacts (e.g., noise) can be reduced. In general, the signal to noise ratio (SNR) resulting in such averaging will improve by the square root of the number of samples averaged in order to create the averaged data set.
The ECU 402 can further present information regarding any or all of the applied stimulus, the signal, and the results of any calculations to a user of the system, e.g., via output 418. For example, the ECU 402 can generate a graphical display providing one or more graphs of signal strength vs. time representing the stimulus and/or the received signal.
In some embodiments, the ECU 402 can include a controller 422 in communication with one or both of stimulator 406 and SENS subsystem 410. The controller 422 can be configured to cause stimulator 406 to apply a stimulation signal to a catheter, e.g., the catheter 102. Additionally or alternatively, the controller 422 can be configured to analyze signals received and/or output by the SENS subsystem 410. In some embodiments, the controller 422 can act to control the timing of applying the stimulation signal from stimulator 406 and the timing of receiving signals by the SENS subsystem 410. The controller 422 can be implemented, e.g., using one or more processors, field programmable gate arrays (FPGAs), state machines, and/or application specific integrated circuits (ASICs), but is not limited thereto.
Example electrical control units have been described. In various embodiments, the ECU 402 can emit stimulus pulses to the catheter 102, receive signals from the catheter 102, perform calculations on the emitted and/or received signals, and present the signals and/or results of such calculations to a user. In some embodiments, the ECU 402 can comprise separate modules for emitting, receiving, calculating, and providing results of calculations. Additionally or alternatively, the functionality of controller 422 can be integrated into the ECU 402 as shown, or can be separate from and in communication with the ECU.
The catheter 102, according to an embodiment of the present technology, is configured to be introduced into a biological lumen, such as an artery, in a location near a body organ, such as a kidney. The catheter 102 can be introduced via a sheath that is advanced to the intended catheter location in the biological lumen, and then withdrawn sufficiently to expose the shaft 214 to the biological lumen (e.g., renal artery).
For example, where the catheter is inserted into a renal artery close to a kidney, the electrodes can be positioned near a nerve bundle that connects the kidney to the central nervous system, as the nerve bundle tends to approximately follow the artery leading to most body organs. The nerve bundle tends to follow the artery more closely at the end of the artery closer to the kidney, while spreading somewhat as the artery expands away from the kidney. As a result, it is desired in some examples that the catheter shaft 214 is small enough to introduce relatively near the kidney or other organ, as nerve proximity to the artery is likely to be higher nearer the organ.
Once the catheter 102 is in place, a practitioner can use instrumentation (e.g., the ECU 402) coupled to stimulation electrodes to stimulate the nerve, and monitor for nerve response signals used to characterize the nervous system response to certain stimulus. In some embodiments, an ablation element (not shown) is included in or on the shaft and configured to ablate nerve tissue, such as by using radio frequency, microwave, cryotherapy, ultrasound, or other energy, such that the catheter can actively stimulate the nerve and sense resulting neural signals in between applications of energy via the ablation element, enabling more accurate control of the degree and effects of nerve ablation. In other examples, a catheter 102 lacking an ablation element can be removed via the sheath, and an ablation probe inserted, with the ablation probe removed and the catheter 102 reinserted to verify and characterize the effects of the ablation probe.
The ECU 402 includes a nerve sensing (SENS) subsystem and a nerve stimulation (STIM) subsystem. The ECU 402 also includes an ultrasound excitation source 426, and a user interface 424. In
The user interface 424 interacts with the controller 422 (and more specifically, e.g., a processor thereof) to cause transmission of electrical signals at selected actuation frequencies to the transducer 111. Wires or other types of electrically conductive traces can electrically couple the transducer 111 to the excitation source 426 of the ECU 402, to thereby enable the controller 422 to control the excitation source 426 to control the amplitude and timing of the electrical signals so as to control the power level and duration of the ultrasound signals emitted by transducer 111. More generally, the controller 422 can control one or more ultrasound treatment parameters that are used to perform sonication. In certain embodiments, the SENS subsystem can also detect electrical signals generated by transducer 111 and communicate such signals to the controller 422. While the ultrasound excitation source 426 in
The user interface 424 can include a touch screen and/or buttons, switches, etc., to allow for an operator (aka user) to enter patient data, select a treatment parameters, view records stored on a storage/retrieval unit (not shown), and/or otherwise communicate with the controller 422. The user interface 424 can include a voice-activated mechanism to enter patient data or may be able to communicate with additional equipment so that control of the controller 422 is through a separate user interface, such as a wired or wireless remote control. In some embodiments, the user interface 424 is configured to receive operator-defined inputs, which can include, e.g., a duration of energy delivery, one or more other timing aspects of the energy delivery pulses (e.g., frequency, duty cycle, etc.), power, and/or mode of operation, or a combination thereof. Example modes of operation can include (but are not limited to): system initiation and set-up, catheter preparation, balloon inflation, verification of balloon apposition, pre-cooling, sonication, post-cooling, balloon deflation, and catheter removal, but are not limited thereto. In certain embodiments, the user interface 424 provides a graphical user interface (GUI) that instructs a user how to properly operate the system 400. The user interface 424 can also be used to process and/or display treatment data for review and/or download, as well as to allow for software updates, and/or the like.
The controller 422 can also control a cooling fluid supply subsystem 428, which can include a cartridge and a reservoir, which are described below with reference to
Example details of the cooling fluid supply subsystem 428, which were introduced above in the above discussion of
The reservoir 510 is fluidically coupled to the cartridge 530 via a pair of fluidic paths, one of which is used as a fluid outlet path (that provides fluid from the reservoir to the cartridge), and the other one of which is used as a fluid inlet path (the returns fluid from the cartridge to the reservoir). The cartridge 530 is shown as including a syringe pump 540, which includes a pressure syringe 542a and a vacuum syringe 542b. The pressure syringe 542a includes a barrel 544a, a plunger 546a, and a hub 548a. Similarly, the vacuum syringe 542b includes a barrel 544b, a plunger 546b, and a hub 548b. The hub 548a, 548b of each of the syringes 542a, 542b is coupled to a respective fluid tube or hose. The cartridge 530 is also shown as including pinch valves V1, V2 and V3, pressure sensors P1, P2, and P3, and a check valve CV. While not specifically shown in
In order to at least partially fill the barrel of the pressure syringe 542a with a portion of the cooling fluid that is stored in the reservoir 510, the pinch valves V1 and V2 are closed, the pinch valve V3 is opened, and the plunger 546a of the pressure syringe 542a is pulled upon to draw cooling fluid 513 into the barrel 544a of the of the pressure syringe 542a. The pinch valve V3 is then closed and the pinch valves V1 and V2 are opened, and then the plunger 546a of the pressure syringe 542a is pushed upon to expel cooling fluid from the barrel 544a of the pressure syringe 542a through the fluid tube attached to the hub 548a of the pressure syringe 542a. The cooling fluid expelled from the pressure syringe 542a enters a fluid lumen (e.g., 327 in the catheter shaft 214), via the fluidic inlet port 234a of the catheter 102, and then enters and at least partially fills the balloon 112. Simultaneously, the plunger 546b of the vacuum syringe 542b can be pulled upon to pull or draw cooling fluid from the balloon 112 into a fluid lumen (e.g., 904b in the catheter shaft 214), through the fluidic outlet port 234b of the catheter 102, and then through fluid tube attached to the hub 548b of the vacuum syringe 542b and into the barrel 544b of the vacuum syringe 542b. In this manner, the cooling fluid can be circulated through the balloon 112. The balloon 112 can be inflated by supplying more cooling fluid to the balloon than is removed from the balloon. One or more of the pressure sensors P1, P2, and P3 can be used to monitor the pressure in the balloon 112 to achieve a target balloon pressure, e.g., of 10 pounds per square inch (psi), but not limited thereto. Once the balloon 112 is inflated to a target pressure, e.g., 10 psi, and/or size, the cooling fluid can be circulated through the balloon 112 without increasing or decreasing the amount of fluid within the balloon by causing the same amount of fluid that is removed from the balloon 112 to be the same as the amount of fluid that is provided to the balloon 112. Also, once the target balloon pressure is reached, the ultrasound transducer 111 can be excited to emit ultrasound energy to treat tissue that surrounds the portion of the body lumen (e.g., a portion of a renal artery) in which the balloon 112 and the transducer 111 are inserted. When the ultrasound transducer 111 is emitting ultrasound energy it can also be said that the ultrasound transducer 111 is performing sonication, or that sonication is occurring. During the sonication, cooling fluid should be circulated through the balloon 112 by continuing to push on the plunger 546a of the pressure syringe 542a and continuing to pull on the plunger 546b of the vacuum syringe 542b.
After the sonication is completed, and the balloon 112 is to be deflated so that the catheter 102 can be removed from the body lumen, the cooling fluid should be returned from the barrel 544b of the vacuum syringe 542b to the reservoir 510. In order to return the cooling fluid from the barrel 544b of the vacuum syringe 542b to the reservoir 510, the pinch valves V1, V2, and V3 are all closed, and the plunger 546b of the vacuum syringe 542b is pushed on to expel the cooling fluid out of the barrel of the vacuum syringe 542b, past the check valve CV, and into the reservoir 510.
The pressure sensors P1, P2, and P3 can be used to monitor the fluidic pressure at various points along the various fluidic paths within the cartridge 530, which pressure measurements can be provided to the controller 422 as feedback that is used for controlling the syringe pump 540 and/or for other purposes, such as, but not limited to, determining the fluidic pressure within the balloon 112. Additionally, flow rate sensors F1 and F2 can be used, respectively, to monitor the flow rate of the cooling fluid that is being injected (aka pushed, provided, or supplied) into the balloon 112, and to monitor the flow rate of the cooling fluid that is being drawn (aka pulled or removed) from the balloon 112. The pressure measurements obtained from the pressure sensors P1, P2, and P3 can be provided to the controller 422 so that the controller 422 can monitor the balloon pressure. Additionally, flow rate measurements obtained from the flow rate sensors F1 and F2 can be provided to the controller 422 so that the controller 422 can monitor the flow rate of cooling fluid being pushed into and pulled from the balloon 112. It would also be possible for one or more pressure sensors and/or flow rate sensors to be located at additional or alternative locations along the fluidic paths that provide cooling fluid to and from the balloon 112.
In the embodiment of
A benefit of using multi-channel sensing is that it enables additional information to be extracted from sensed signals, compared to if single-channel sensing is used. For example, with multi-channel sensing, the signals sensed by different channels can be compared to one another, to enable nerve depths to be quantified, to provide for better discrimination between sensed neural activity originating from afferent nerve fibers and sensed neural activity originating from efferent nerve fibers, and to enable nerve type identification. Additionally, by knowing the distances between the various electrodes that are used to simultaneously sense signals using multiple channels, nerve transmission velocities can be better quantified compared to if single-channel sensing is used.
Additionally, multi-channel sensing can be used to reduce and preferably eliminate noise in sensed signals. For example, two signals sensed by two different channels can be compared to one another to identify signal features (which can be temporal features and/or frequency features) that are common to both of the signals. In other words, noise common to both a first channel signal and a second channel signal can be filtered out, while first signal components unique to the first channel signal, and second signal components unique to the second channel signal, can be retained. As will be appreciated from the following discussion, each channel includes a respective differential amplifier that outputs a respective channel signal indicative of a difference between voltages at the differential inputs of the differential amplifier. Accordingly, a difference between the two channel signals sensed by two different channels is essentially a difference of differences, which difference of differences can be determined and used by an extraction module (1316) of the ECU 702 described below with reference to
Referring again to
In accordance with certain embodiments, as shown in
More generally, in accordance with certain embodiments, each of the amplifiers 712a, 712b includes a respective ground reference terminal that is coupled to a same ground reference electrode. In accordance with certain embodiments, the ground reference electrode comprises one of the electrodes of the catheter that is not electrically coupled to any of the inputs of the amplifiers 712a, 712b. In accordance with certain embodiments, the ground reference electrode comprises one of an external surface electrode configured to be placed against skin of a patient, or an external needle electrode configured to be placed into skin of a patient.
While not specifically shown in
In accordance with certain embodiments, the same electrodes used to deliver the stimulation pulse(s) during a first period of time, can also be used to sense the evoked neural response to the stimulation pulse(s) during a second period of time. In accordance with certain embodiments, in order to mitigate the chance that such electrodes are polarized during the second period of time, as well as to prevent the amplifiers 712a and 712b from being saturated during the second period of time, deblocking and/or switching can be performed to isolate the amplifiers 712a and 712b during the first period of time that the stimulation pulse(s) is/are delivered, as well as for a short temporal window (e.g., a 15 millisecond window) following deliver of the stimulation pulse(s).
As can be appreciated from the above discussion, the nerve sensing subsystem 703 can be used to sense an evoked neural response to one or more electrical stimulation pulses delivered using the nerve stimulation subsystem 704. However, it is also noted that the nerve sensing subsystem 703 can also be used to sense native electrical neural activity, if so desired.
As shown in
As noted above, the filter circuitry 714 is used to remove noise and other signal components that are not of interest. Additional details of the filter circuitry, according to specific embodiments of the present technology, are described below with reference to
Referring now to
In accordance with certain embodiments, the common noise rejection circuitry 804, which can also be referred to as the common noise rejection module 804, includes one or more digital notch filters that filter out noise, intrinsic to the channels, that is within the bandwidth of interest. Noise intrinsic to the channels, which is attenuated using one or more notch filters, can be noise from a known source of noise, such as line noise, but is not limited thereto. An example frequency range that such one or more notch filters can be used to attenuate is from 50 Hz to 60 Hz, but is not limited thereto. It is also noted that each of the differential amplifiers 712a and 712b provides for common noise rejection.
The common noise rejection circuitry 804 can additionally be used to identify signal components of the first and second channel signals that are the same, and/or to identify signal components of the first and second channel signals that differ from one another, depending upon the specific implementation. Examples of type of signal components of the first and second channel signals, which can differ from one another, include signal phases and signal amplitudes, but are not limited thereto. Differences between phases of the first and second channel signals can be due to a longitudinal distance between electrodes used to sense the first and second channel signals. For example, signal phases may differ between the first and second channel signals due to a longitudinal distance between first and second deployable electrodes used, respectively, to sense the first and second channel signals. Signal amplitudes may differ between the first and second channel signals due to variations of the depths of nerve fibers and/or nerve bundles relative to a wall of a biological lumen in which sensing electrodes are located. For example, if nerve fibers are located closer to a portion of the wall of a biological lumen that a first deployable electrode is in contact with, than are nerve fibers located in a portion of the wall of the biological lumen that a second deployable electrode is in contact with, then amplitudes of the first channel signal may be greater than amplitudes of the second channel signal. For the below discussion, it is assumed that noise common to both the first and second channel signals is removed by the common mode noise rejection module 804, such that the first and second channel signals output from the common noise rejection module are substantially devoid of such common noise.
The optional bandpass filter circuitry 806, which can also be referred to as the bandpass filter module 806, if present, attenuates frequencies outside a bandwidth of interest. Explained another way, the bandpass filter circuitry 806 is configured to filter out frequency components of the first and second channel signals outside the bandwidth of interest, and to pass frequency components of the first and second channel signals within the bandwidth of interest. The bandwidth of interest, which is passed by the bandpass filter circuitry 806, can be, e.g., from 150 Hz to 2 kHz, but is not limited thereto. In certain embodiments, each bandpass filter can be implemented by a combination of a low pass filter (that filters out frequencies above an upper limit of the bandpass of interest) followed by a high pass filter (that filters out frequencies below a lower limit of the bandpass of interest), or by one filter that passes frequencies between the lower and upper limits of interest and filters out, aka rejects, frequencies below the lower limit of the bandpass of interest and above the upper limit of the bandpass of interest. The first and second channel signals, which are provided from the filter module 714 to the extraction module 716, can be referred to more specifically herein as filtered first and second channel signals, or equivalently as first and second channel filtered signals.
As noted above, the extraction module 716 is used to extract information of interest from filtered signals received from the filter module 714. Examples of information that can be extracted from the filtered signals include nerve depth information related to the depth of nerves of interest (e.g., renal nerves), nerve fiber type information which can be used to identify nerve fiber types (e.g., A, B, or C type fibers), and discrimination information which can be used to distinguish afferent nerves from efferent nerves, but are not limited thereto.
Nerves can be classified as afferent or efferent depending on the direction in which information travels, with afferent nerves carrying information from an organ (such as a kidney) to the central nervous system (i.e., brain and spinal cord), and efferent nerves carrying information from the central nervous system to an organ (such as a kidney). If a common signal component (e.g., a common evoked neural response component) appears in both the first channel filtered signal and the second channel filtered signal, then the relative phase of the signals can be used to determine whether the signal component originated from either an afferent nerve or an efferent nerve. For a more specific example, if a common evoked neural response component appears in the first channel signal (sensed using a distal deployable electrode) prior to appearing in the second channel signal (sensed using a proximal deployable electrode), then it can be determined that the nerves (whose evoked neural response was sensed) are afferent nerves. Conversely, if a common evoked neural response component appears in the second channel signal (sensed using the proximal deployable electrode) prior to appearing in the first channel signal (sensed using the distal deployable electrode), then it can be determined that the nerves (whose evoked neural response was sensed) are efferent nerves. Morphological analysis can be used to determine whether evoked neural response components included in both the first and second channel signals are a common evoked neural response component. Time stamps, and/or the like, can be used to determine which of the channels a common evoked neural response component initially appears in for the purpose of determining whether the signal component originated from either an afferent nerve or an efferent nerve.
A velocity of a sensed neural signal can be determined based on a time delay between when a common evoked neural response component appears in the second channel signal (sensed using the proximal deployable electrode) and when the common evoked neural response component appears in the first channel signal (sensed using the distal deployable electrode), and knowing the distance between the proximal deployable electrode and the distal deployable electrode. More specifically, since velocity is a rate of change of position with respect to time, the velocity of a neural signal can be determined by dividing the distance between the proximal deployable electrode and the distal deployable electrode, by the time delay between when a common evoked neural response component appears in the second channel signal (sensed using the proximal deployable electrode) and when the common evoked neural response component appears in the first channel signal (sensed using the distal deployable electrode). This is just one example, which is not intended to be all encompassing. Since different nerve fibers carry information at different speeds (aka velocities), the determined velocity of a neural response can be used to identify (aka classify) a type of nerve fiber from which the neural response originated. Accordingly, for example, if there is a desire to identify where C type nerve fibers are positioned about a biological lumen, so that the C type nerve fibers can be targeted for a denervation procedure, then embodiments of the present technology described herein can be used to identify where C type nerve fibers are located. Example details of selectively deployable distal and proximal electrodes are discussed below with reference to
Still referring to
The waveform detection module 814, if present, can be used to detect waveform features of the processed (e.g., filtered, rectified, integrated and/or averaged) first and second channel signals. Such waveform features, which can be detected by the waveform detection module 814, include, but are not limited to, amplitudes, frequency components, phase shifts, polarizations, and/or the like. The waveform feature comparison module 816 compares the first and second channel signals, and/or the features thereof already detected by the waveform feature detection module 814, and outputs information determined based on the comparison. The information output by the waveform feature comparison module 816 can include, e.g., nerve depth information related to the depth of nerves of interest (e.g., renal nerves), nerve fiber type information which can be used to identify nerve fiber types (e.g., A, B, or C type fibers), and discrimination information which can be used to distinguish afferent nerves from efferent nerves, but are not limited thereto. The nerve depth information can be determined by relative signal strengths. In certain embodiments, nerves can be polled to create a reference point based upon a known depth. Alternatively, a signal can be emitted using one or more electrodes from a distant point (e.g., in the abdominal aorta) and then one or more further electrodes can be used to listen for signals from known nerve depths. In certain embodiments, signal strength versus nerve depth from a reference is previously known based on direct coupling study versus depth to get a baseline from which to make inferences. The information output by the waveform feature comparison module 816 can be stored in memory 720 and/or used to display information via the GUI 724, but is not limited thereto.
More generally, in accordance with certain embodiments, the multi-channel nerve sensing subsystem 703 includes one or more analog-to-digital converters configured to convert the first and second channel signals from analog signals to digital signals, and digital signal processing circuitry configured to extract information from the first and second channel signals, based on least in part on the comparison between the first and second channel signals, after the first and second channel signals have been converted to digital signals.
In accordance with certain embodiments, the filter module 714 and the extraction module 716, and the modules thereof, can be implemented using one or more processors, which can include one or more Digital Signal Processors (DSPs). Alternatively, or additionally, the filter module 714 and the extraction module 716, and the modules thereof, can be implemented using one or more field-programmable gate arrays (FPGAs), one or more Signal on Chip (SOCs), and/or one or more application specific integrated circuits (ASICs). More generally, the filter module 714 and the extraction module 716 can be implemented using hardware, software, firmware, and/or combinations thereof.
Balloons with Electrodes
Referring back to
Certain embodiments of the present technology, which are described below, are directed to all-in-one catheters that can be used for both measuring evoke neural activity as well as performing ablation or another neuromodulation procedure. Such all-in-one catheters can be used to reduce the time it takes for an ablation or other type neuromodulation procedure to be performed by reducing and potentially eliminating the need to exchange catheters. The reduction or elimination in catheter exchanges also helps ensure the sensing of neural activity is being performed in substantially the same location that ablation is performed, because the catheter does not have to be moved to allow for the exchange.
As will be described in additional details below, such all-in-one catheters include a transducer (e.g., 111) within a balloon (e.g., 112), as was described above with reference to
In
Beneficially, when the electrodes 903, 905 are in their non-deployed positions (aka non-intussuscepted positions), the overall profile of the shaft 214 of the catheter 102 is reduced, which is desirably when the shaft 214 is being inserted into a biological lumen because it reduces the probability of damaging the biological lumen and surrounding tissue. Furthermore, when the electrodes 903, 905 are in their non-deployed positions (aka non-intussuscepted positions), the electrodes 903, 905 do not block or otherwise adversely affect the emission pattern of the transducer 111.
In additional to including the selectively deployable (aka selectively intussuscepted) electrodes 903 and 905, the catheter shaft 214 can also include one or more ring electrodes and/or a tip electrode that is/are distal to the selectively deployable distal electrode 903 and/or one or more ring electrodes that is/are proximal the selectively deployable proximal electrode 905. As mentioned above, ring electrodes can also be referred to as marker band electrodes, since they can be used as markers when imaging is used to monitor a position of the catheter 102 within a biological lumen.
In accordance with certain embodiments, after the distal portion 210 of the catheter 102 is inserted into a body lumen (e.g., a renal artery), and positioned at a desired position within the body lumen, the balloon 112 can be at least partially filled with a fluid (e.g., a cooling fluid) so that an outer surface of at least a central portion of the balloon 112 comes into contact with an inner surface of the body lumen. For example, the cooling fluid supply subsystem 428, described above with reference to
While the electrodes 903 and 905 are deployed (aka intussuscepted), the electrodes 903 and 905, respectively, contact first and second portions of an inner surface of the body lumen (e.g., renal artery) that are spaced apart from one another by a distance (D) between the deployed electrodes 903 and 905. At this point, the electrodes 903 and 905 can be used in one or more of various different manners. For example, the deployed electrodes 903 and 905 alone, or in combination with one or more additional electrodes (e.g., ring and/or tip electrodes), can be used to sense native electrical neural activity. More specifically, the electrodes 903 and 905 can be coupled to the inputs of the amplifier 412 in
Alternatively, or additionally, the electrodes 903 and 905 can be used (alone, or together with other electrodes, such as one or more ring electrodes, and/or a tip electrode) to selectively deliver the stimulation pulse(s) and sense an evoked neural response to the stimulation pulse(s). For example, during a first period of time, the electrodes 903 and 905 can be coupled to the stimulator 406 in
In certain embodiments, the catheter shaft 214 includes a plurality of nested and concentric tubes, wherein one or more of the tubes can be selectively maneuvered longitudinally using actuators (e.g., 221 in
In accordance with certain embodiments of the present technology, each of the electrodes 903, 905 is made of a unitary nitinol tube that is laser cut to include apertures or openings having a predetermined pattern. The electrodes 903, 905 can alternatively be made of a mesh of braded wires. The use of alternative types of metals, alloys or other electrically conductive materials for the electrodes are also possible and within the scope of the embodiments described herein.
Additional details of the concentric tubes 1031, 1032, 1033, and 1034 of the catheter shaft 214, according to certain embodiments of the present technology, will now be described with reference to
In accordance with an embodiment, the outer diameter OD1 of the first tube 1031 is 0.078 inches, the outer diameter OD2 of the second tube 1032 is 0.063 inches, the outer diameter OD3 of the third tube 1033 is 0.050 inches, and the outer diameter OD4 of the fourth tube 1034 is 0.032 inches. Assuming the wall thickness of each of the tubes 1031, 1032, 1033, and 1034 is 0.006 inches, then the inner diameter ID1 of the first tube 1031 is 0.064 inches (i.e., 0.078−(2×0.006)=0.066), the inner diameter ID2 of the second tube 1032 is 0.51 inches, the inner diameter ID3 of the third tube 1033 is 0.038 inches, and the inner diameter ID4 of the fourth tube 1034 is 0.020 inches. The use of alternative outer and inner diameters, and the use of other wall thicknesses, are also within the scope of the embodiments of the present technology described herein, so long as the outer diameter OD4 of the fourth tube 1034 is less than the inner diameter ID3 of the third tube 1033, the outer diameter ID3 of the third tube 1033 is less than the inner diameter ID2 of the second tube 1032, and the outer diameter ID2 of the second tube 1032 is less than the inner diameter ID1 of the first tube 1031.
As can be appreciated from
As can be appreciated from
In accordance with an embodiment, a proximal end of the distal electrode 903 is physically connected to a distal end of the third tube 1033 (at the region labeled 1041), and a distal end of the distal electrode 903 is physically connected to a distal portion of the fourth tube (at the region labeled 1042) or abuts against a proximal end of the flange 1034′ of the fourth tube 1034. Additionally, a distal end of the proximal electrode 905 is physically connected to in intermediate portion of the third tube 1033 (at the region labeled 1045), and a proximal end of the proximal electrode 1033 is physically connected to a distal portion of the second tube (at the region labeled 1046) or abuts against a distal end of the flange 1032′ of the second tube 1032.
In order to transition the distal electrode 903 from its non-intussuscepted (aka non-deployed) position to its intussuscepted (aka deployed) position, the fourth tube 1034 is moved in the proximal direction indicated by the arrow 1043. This has the effect of causing the distal electrode 903 to initially bulge outward (as shown in
One or more of the tubes 1031, 1032, 1033, and 1034 can each include more than one coiled wire (e.g., 1112) so that one such tube can provide two or more electrically conductive paths. For an example, the tube 1033 can include first and second coiled wires (not specifically shown) that are spaced apart from one another or are otherwise electrically insulated from one another.
Referring briefly back to
In certain embodiments, each of the spiral distal and proximal electrodes 1203, 1205 is made of an electrically conductive material that has shape memory that causes the electrodes to generally conform to a tubular portion of the underlying catheter shaft 214 when the balloon 112 is deflated (aka uninflated). In certain embodiments, the spiral distal and proximal electrodes 1203, 1205 are made of Nitinol, which is a metal alloy of nickel and titanium, that is electrically conductive, has shape memory, and has superelasticity. It is also within the scope of the embodiments of the present technology described herein to manufacture the electrodes 1203, 1205 of another known or future developed alloy or material, besides Nitinol, wherein the material is electrically conductive, has shape memory, and preferably has superelasticity.
In the embodiment of
Beneficially, when the electrodes 1203, 1205 are in their tightly wound non-deployed positions, the overall profile of the shaft 214 of the catheter 102 is reduced, which is desirably when the shaft 214 is being inserted into a biological lumen because it reduces the probability of damaging the biological lumen and surrounding tissue.
In additional to including the spiral distal and proximal electrodes 1203 and 1205, the catheter shaft 214 can also include one or more ring electrodes and/or a tip electrode that is/are distal to the spiral distal electrode 1203 and/or one or more ring electrodes that is/are proximal the spiral proximal electrode 1205. Such ring electrodes can also be referred to as marker band electrodes, since they can be used as markers when imaging is used to monitor a position of the catheter 102 within a biological lumen. For example, a distal ring or tip electrode 1213 is shown in
In accordance with certain embodiments, after the distal portion 210 of the catheter 102 is inserted into a body lumen (e.g., a renal artery), and positioned at a desired position within the body lumen, the balloon 112 can be at least partially filled with a fluid (e.g., a cooling fluid) so that an outer surface of at least a central portion of the balloon 112 comes into contact with an inner surface of the body lumen. For example, the cooling fluid supply subsystem 428, described above with reference to
While the spiral electrodes 1203 and 1205 are at least partially unwound and expanded, the electrodes 1203 and 1205, respectively, contact first and second portions of an inner surface of the body lumen (e.g., renal artery) that are spaced apart from one another by a distance between the electrodes 1203 and 1205. At this point, the electrodes 1203 and 1205 can be used in one or more of various different manners. For example, the spiral electrodes 1203 and 1205 alone, or in combination with one or more additional electrodes (e.g., ring and/or tip electrodes), can be used to sense native electrical neural activity. More specifically, the electrodes 1203 and 1205 can be coupled to the inputs of the amplifier 412 in
Alternatively, or additionally, the electrodes 1203 and 1205 can be used (alone, or together with other electrodes, such as one or more ring electrodes, and/or a tip electrode) to selectively deliver the stimulation pulse(s) and sense an evoked neural response to the stimulation pulse(s). For example, during a first period of time, the electrodes 1203 and 1205 can be coupled to the stimulator 406 in
In the embodiment described above with reference to
In the embodiments of
Each of the electrically conductive coated electrodes 1503, 1505 is electrically coupled to a wire, or insulated strand in a braided jacket, or the like, through the catheter body. Each electrode is electrically connected, and its wire is appropriately insulated or isolated within the catheter body. The electrodes 1503 and 1505 can be used in the same various different manners that the electrodes 1203 and 1205 described above can be used, and thus, such uses need not be described again.
In
In various embodiments described above, a body of the balloon 112, which is configured to be at least partially filled with a cooling fluid, is made of a non-electrically conductive material, such as nylon, a polyimide film, a thermoplastic elastomer, a medical-grade thermoplastic polyurethane elastomer, pellethane, isothane, or other suitable polymers or any combination thereof, as noted above. While the distal portion 210 of the catheter 102 is positioned within a portion of a biological lumen and the electrically insulated balloon 112 is inflated such that an outer circumference of the electrically insulated balloon contacts an inner circumference of the biological lumen, the balloon 112 restricts blood from flowing from a first location adjacent the distal electrode (e.g., 903, 1203, 1303, 1403 or 1503) to a second location adjacent the proximal electrode (e.g., 905, 1205, 1305, 1405 or 1505), and/or vice versa. This creates an insulating layer between the distal electrode (e.g., 903, 1203, 1303, 1403 or 1503) and the proximal electrode (e.g., 905, 1205, 1305, 1405 or 1505). While the electrically insulated balloon 112 is inflated and restricts blood from flowing past the balloon from the first location adjacent the distal electrode to the second location adjacent the proximal electrode (and thereby creates an insulating layer between the distal and proximal electrodes), stimulation energy can be delivered using the distal electrode and an evoked neural response to the stimulation energy can be sensed using the proximal electrode. Alternatively, or additionally, while the electrically insulated balloon 112 is inflated and restricts blood from flowing past the balloon (and thereby creates an insulating layer between the distal and proximal electrodes), stimulation energy can be delivered using the proximal electrode and an evoked neural response to the stimulation energy can be sensed using the distal electrode. Beneficially, by creating an insulating layer between the distal and proximal electrodes, the electrically insulated balloon, while inflated within the portion of the biological lumen, reduces and preferably prevents the stimulation energy or a portion thereof from traveling through blood (which is electrically conductive) within the biological lumen (e.g., a renal artery) directly from the distal electrode to the proximal electrode, and/or vice versa. Beneficially, such an embodiment should provide for an improved signal-to-noise ratio (SNR) of the sensed evoked neural response signal by allowing more of the stimulation energy to travel via the nerves or neural tissue, compared to if there was no electrically insulated balloon between the distal electrode (e.g., 903, 1203, 1303, 1403 or 1503) and the proximal electrode (e.g., 905, 1205, 1305, 1405 or 1505).
Methods according to certain embodiments of the present technology will now be described below with reference to the high level flow diagram of
Referring to
The neural activity that is sensed at step 1708, using at least one of the distal and proximal electrodes, can be native neural activity. Alternatively, or additionally, evoked neural activity can be sensed. More specifically, the method can also include delivering stimulation energy using one of the distal and proximal electrodes, in which case the neural activity sensed at step 1708 can be an evoked neural response to the stimulation energy.
As explained above, the shaft of the catheter can also include one or more further electrodes (e.g., non-deployable ring electrodes and/or a tip electrode) that is/are located on a portion of the shaft that does not include the balloon. In such an embodiment, the stimulation energy can also be delivered using at least one of the one or more further electrodes (e.g., a ring electrode or a tip electrode). The neural activity that is sensed can also be sensed using at least one of the one or more further electrodes (e.g., a ring electrode or a tip electrode).
As explained above, the shaft of the catheter can also include a transducer (e.g., 111) within the balloon (112). In such an embodiment, the method can also include energizing the transducer, to thereby treat tissue surrounding the biological lumen, wherein the energizing is performed before and/or after sensing the neural activity of the nerves within the tissue surrounding the biological lumen. In certain such embodiments, prior to delivering the stimulation energy using the one of the distal and proximal electrodes, and prior to sensing the evoked neural response to the stimulation energy using the other one of the distal and proximal electrodes, the method can include selectively transitioning each of the distal and proximal electrodes (e.g., 903 and 905) between a non-intussuscepted position (e.g., shown in
In certain embodiments described above, the distal electrode comprises a distal spiral electrode (e.g., 1203) at least partially encircling a distal portion of the balloon, and the proximal electrode comprises a proximal spiral electrode (e.g., 1205) at least partially encircling a proximal portion of the balloon. In certain such embodiments, selectively transitioning each of the distal and proximal spiral electrodes between a non-deployed position and a deployed position occurs in response to the balloon being at least partially inflated while the at least the portion of the shaft is inserted into the biological lumen, as was described above with reference to
In certain embodiments, such as those described above with reference to
The transducers, apparatuses, systems, and methods described herein may be used to treat any suitable tissue, which tissue may be referred to as a target anatomical structure. For example, use of the present systems to treat (e.g., neuromodulate) the renal nerve is described above. It should be appreciated that body lumens, in which the present systems may be positioned for treating tissue, are not necessarily limited to naturally occurring body lumens. For example, the treatment may include creating a body lumen within tissue (e.g., using drilling, a cannula, laser ablation, or the like) and then positioning suitable components within such a body lumen. Other suitable applications for the present system include ablation of pulmonary nerve and tissue responsible veins or cardiac arrhythmia, nerves within that intervertebral disk, nerves within or outside of that intervertebral disk, basivertebral nerves within that vertebral bone, nerves within the brain tissue, tissue responsible for cardiac arrhythmia within the cardiac tissue, nerves along the bronchial tree, one or more esophageal branches of the vagus nerve, and one or more nerves surrounding the bladder.
Advantages of embodiments of the current disclosure include: 1) The ability to determine the appropriate lesion sites along the artery that correspond to the location of nerves; 2) The ability to verify that the destructive devices are appropriately positioned adjacent to the arterial wall, normalizing the tissue/device interface and enabling energy transfer through the vessel wall; and 3) The ability to provide feedback to the clinician intraoperatively to describe lesion completeness or the integrity of the affected nerve fibers.
Example 1. A catheter for use in analyzing neural activity of nerves that surround a biological lumen, the catheter comprising: a handle; and a shaft extending from the handle and configured to be inserted into the biological lumen; a selectively inflatable balloon located on the shaft; and a distal electrode and a proximal electrode longitudinally spaced apart from one another on the shaft; wherein each of the distal electrode and the proximal electrode is configured to be selectively transitioned between a non-intussuscepted position and an intussuscepted position.
Example 2. The catheter of example 1, wherein: the distal electrode is distal to the balloon when the distal electrode is in the non-intussuscepted position; the proximal electrode is proximal to the balloon when the proximal electrode is in the non-intussuscepted position; the distal electrode at least partially overlaps a distal portion of the balloon when the distal electrode is in the intussuscepted position; and the proximal electrode at least partially overlaps a proximal portion of the balloon when the proximal electrode is in the intussuscepted position.
Example 3. The catheter of example 1, wherein: the distal and proximal electrodes are configured to come into contact respectively with first and second longitudinally spaced apart portions of the biological lumen when the shaft is inserted into the biological lumen, the balloon is at least partially inflated, and the distal and proximal electrodes are each in the intussuscepted position; and the balloon is configured to create an insulating layer between the distal electrode and the proximal electrode. This can be achieved at least in part by restricting blood from flowing through the biological lumen from a first location adjacent the distal electrode to a second location adjacent the proximal electrode, and/or vice versa.
Example 4. The catheter of example 3, wherein: at least one of the distal and proximal electrodes is configured to be used to sense neural activity of the nerves that surround the biological lumen.
Example 5. The catheter of example 3, wherein: at least one of the distal and proximal electrodes is configured to be used to stimulate the nerves that surround the biological lumen to thereby evoke a neural response.
Example 6. The catheter of example 3, further comprising: at least one of a non-deployable ring electrode or a tip electrode on the shaft, which can be used together with one or both of the distal and proximal electrodes to sense neural activity of the nerves that surround the biological lumen and/or to stimulate the nerves that surround the biological lumen to thereby evoke a neural response.
Example 7. The catheter of example 1, wherein the handle includes: a first actuator configured to transition the distal electrode between the non-intussuscepted position and the intussuscepted position; and a second actuator configured to transition the proximal electrode between the non-intussuscepted position and the intussuscepted position.
Example 8. The catheter of example 1, further comprising: a transducer within the balloon; wherein the transducer is configured to be selectively energized to treat tissue surrounding the biological lumen; and wherein the balloon is configured to be at least partially filled with a cooling fluid to thereby cool the transducer and/or the tissue surrounding the biological lumen.
Example 9. The catheter of example 8, wherein: the transducer comprises an ultrasound transducer.
Example 10. The catheter of example 8, wherein: the shaft includes a fluid lumen configured to inject fluid into the balloon.
Example 11. A catheter for use in analyzing neural activity of nerves that surround a biological lumen, the catheter comprising: a handle; and a shaft extending from the handle and configured to be inserted into the biological lumen; a selectively inflatable balloon located on the shaft; a distal spiral electrode at least partially encircling a distal portion of the balloon; and a proximal spiral electrode at least partially encircling a proximal portion of the balloon; wherein each of the distal and proximal spiral electrodes is configured to be selectively transitioned between a non-deployed and a deployed position in response to the balloon being at least partially inflated.
Example 12. The catheter of example 11, wherein: each of the distal and proximal spiral electrodes is made from an electrically conductive material having shape memory; each of the distal and proximal spiral electrodes partially unwind in response to the balloon being at least partially inflated; and the shape memory of the distal and proximal spiral electrodes causes each of the distal and proximal spiral electrodes to rewind in response to the balloon being deflated, after the balloon had been at least partially inflated.
Example 13. The catheter of example 11, wherein: the distal and proximal spiral electrodes are configured to come into contact respectively with first and second longitudinally spaced apart portions of the biological lumen when the shaft is inserted into the biological lumen, the balloon is at least partially inflated, and the distal and proximal electrodes are each expanded in diameter; and the balloon is configured to create an insulating layer between the distal electrode and the proximal electrode. This can be achieved at least in part by the balloon restricting blood from flowing through the biological lumen from a first location adjacent the distal electrode to a second location adjacent the proximal electrode, and/or vice versa.
Example 14. The catheter of example 13, wherein: at least one of the distal and proximal spiral electrodes is configured to be used to sense neural activity of the nerves that surround the biological lumen.
Example 15. The catheter of example 13, wherein: at least one of the distal and proximal spiral electrodes is configured to be used to stimulate the nerves that surround the biological lumen to thereby evoke a neural response.
Example 16. The catheter of example 13, further comprising: at least one of a non-deployable ring electrode or a tip electrode on the shaft, which can be used together with one or both of the distal and proximal spiral electrodes to sense neural activity of the nerves that surround the biological lumen and/or to stimulate the nerves that surround the biological lumen to thereby evoke a neural response.
Example 17. The catheter of example 11, further comprising: a net that at least partially surrounds the balloon and each of the distal and proximal spiral electrodes to thereby hold the distal and proximal spiral electrodes in place relative to the balloon.
Example 18. The catheter of example 11, wherein: the balloon is made from two layers of non-electrically conductive material including an innermost layer and an outermost layer; one or more portions of each of the distal and proximal spiral electrodes are sandwiched between the two layers of non-electrically conductive material from which the balloon is made; and one or more further portions of each of the distal and proximal spiral electrodes are exposed where the outermost layer has been removed.
Example 19. The catheter of example 11, further comprising: a transducer within the balloon; wherein the transducer is configured to be selectively energized to treat tissue surrounding the biological lumen; and wherein the balloon is configured to be at least partially filled with a cooling fluid to thereby cool the transducer and/or the tissue surrounding the biological lumen.
Example 20. The catheter of example 19, wherein: the transducer comprises an ultrasound transducer.
Example 21. A catheter for use in analyzing neural activity of nerves that surround a biological lumen, the catheter comprising: a handle; and a shaft extending from the handle and configured to be inserted into the biological lumen; a selectively inflatable balloon located on the shaft and made for a non-electrically conductive material; and a distal coated electrode formed on and encircling a circumference of a distal portion of the balloon; a proximal coated electrode formed on and encircling a circumference of a proximal portion of the balloon.
Example 22. The catheter of example 21, wherein: each of the distal and proximal coated electrodes is provided by deposition, printing, or painting via masking.
Example 23. The catheter of example 21, wherein: the distal and proximal coated electrodes are configured to come into contact respectively with first and second longitudinally spaced apart portions of the biological lumen when the shaft is inserted into the biological lumen and the balloon is at least partially inflated; and the balloon is configured to create an insulating layer between the distal electrode and the proximal electrode. This can be achieved at least in part by the balloon restricting blood from flowing through the biological lumen from a first location adjacent the distal coated electrode to a second location adjacent the proximal coated electrode, and/or vice versa.
Example 24. The catheter of example 23, wherein: at least one of the distal and proximal coated electrodes is configured to be used to sense neural activity of the nerves that surround the biological lumen.
Example 25. The catheter of example 23, wherein: at least one of the distal and proximal coated electrodes is configured to be used to stimulate the nerves that surround the biological lumen to thereby evoke a neural response.
Example 26. The catheter of example 23, further comprising: at least one of a non-deployable ring electrode or a tip electrode on the shaft, which can be used together with one or both of the distal and proximal coated electrodes to sense neural activity of the nerves that surround the biological lumen and/or to stimulate the nerves that surround the biological lumen to thereby evoke a neural response.
Example 27. The catheter of example 21, wherein: the distal and proximal coated electrodes each comprises at least one of platinum, gold, or silver.
Example 28. The catheter of example 21, further comprising: a transducer within the balloon; wherein the transducer is configured to be selectively energized to treat tissue surrounding the biological lumen; and wherein the balloon is configured to be at least partially filled with a cooling fluid to thereby cool the transducer and/or the tissue surrounding the biological lumen.
Example 29. The catheter of example 28, wherein: the transducer comprises an ultrasound transducer.
Example 30. The catheter of example 28, wherein: the shaft includes a fluid lumen configured to inject fluid into the balloon.
Example 31. A method for use with a catheter including a handle, a shaft extending from the handle, a selectively inflatable balloon located on the shaft, and a distal electrode and a proximal electrode longitudinally spaced apart from one another, the method comprising: inserting at least a portion of the shaft into a biological lumen while the balloon is not inflated; at least partially inflating the balloon while the at least the portion of the shaft is inserted into the biological lumen; causing the distal and proximal electrodes to come into contact respectively with first and second longitudinally spaced apart portions of the biological lumen while the distal and proximal electrodes respectively surround distal and proximal portions of the balloon; and sensing neural activity of nerves within tissue surrounding the biological lumen using at least one of the distal and proximal electrodes that respectively surround the distal and proximal portions of the balloon and are in contact respectively with the first and second longitudinally spaced apart portions of the biological lumen.
Example 32. The method of example 31, wherein: the neural activity that is sensed using at least one of the distal and proximal electrodes comprises native neural activity.
Example 33. The method of example 31, further comprising: delivering stimulation energy using one of the distal and proximal electrodes; and the sensing neural activity of nerves within tissue surrounding the biological lumen comprises sensing an evoked neural response to the stimulation energy using the other one of the distal and proximal electrodes.
Example 34. The method of example 33, wherein: the shaft also includes one or more further electrodes located on a portion of the shaft that does not include the balloon; and the delivering the stimulation energy is performed also using at least one of the one or more further electrodes.
Example 35. The method of example 34, wherein: the sensing the neural activity is performed also using at least one of the one or more further electrodes.
Example 36. The method of example 31, wherein the shaft also includes a transducer within the balloon, and the method further comprising: energizing the transducer, to thereby treat tissue surrounding the biological lumen, wherein the energizing is performed at least one of before or after the sensing the neural activity of the nerves within the tissue surrounding the biological lumen.
Example 37. The method of example 36, further comprising: prior to delivering the stimulation energy using the one of the distal and proximal electrodes, and prior to sensing the evoked neural response to the stimulation energy using the other one of the distal and proximal electrodes, selectively transitioning each of the distal and proximal electrodes between a non-intussuscepted position and an intussuscepted position and thereby causing the distal and proximal electrodes to come into contact respectively with the first and second longitudinally spaced apart portions of the biological lumen; after delivering the stimulation energy using the one of the distal and proximal electrodes, and sensing the evoked neural response to the stimulation energy using the other one of the distal and proximal electrodes, selectively transitioning each of the distal and proximal electrodes between the intussuscepted position and the non-intussuscepted position; and while each of the distal and proximal electrodes is in the intussuscepted position, performing the energizing the transducer to thereby treat the tissue surrounding the biological lumen.
Example 38. The method of example 36, wherein the distal electrode comprises a distal spiral electrode at least partially encircling the distal portion of the balloon, the proximal electrode comprises a proximal spiral electrode at least partially encircling the proximal portion of the balloon, and the method further comprises: selectively transitioning each of the distal and proximal spiral electrodes between a non-deployed position and a deployed position in response to the at least partially inflating the balloon while the at least the portion of the shaft is inserted into the biological lumen.
Example 39. The method of example 38, wherein each of the distal and proximal spiral electrodes is made from an electrically conductive material having shape memory, and wherein: the selectively transitioning each of the distal and proximal spiral electrodes between the non-deployed position and the deployed position comprises partially unwinding each of the distal and proximal spiral electrodes in response to the balloon being at least partially inflated; and the shape memory causing each of the distal and proximal spiral electrodes to rewind in response to the balloon being deflated, after the balloon had been at least partially inflated.
Example 40. The method of example 31, wherein: the distal and proximal electrodes are at least one of located on or attached to the balloon; and the causing the distal and proximal electrodes to come into contact respectively with first and second longitudinally spaced apart portions of the biological lumen occurs in response to, and simultaneously with, the at least partially inflating the balloon while the at least the portion of the shaft is inserted into the biological lumen.
It is to be understood that the subject matter described herein is not limited in its application to the details of construction and the arrangement of components set forth in the description herein or illustrated in the drawings hereof. The subject matter described herein is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Further, it is noted that the term “based on” as used herein, unless stated otherwise, should be interpreted as meaning based at least in part on, meaning there can be one or more additional factors upon which a decision or the like is made. For example, if a decision is based on the results of a comparison, that decision can also be based on one or more other factors in addition to being based on results of the comparison.
It is to be understood that the above description is intended to be illustrative, and not restrictive. For example, the above-described embodiments (and/or aspects thereof) may be used in combination with each other. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the embodiments of the present technology without departing from its scope. While the dimensions, types of materials and coatings described herein are intended to define the parameters of the embodiments of the present technology, they are by no means limiting and are example embodiments. Many other embodiments will be apparent to those of skill in the art upon reviewing the above description. The scope of the embodiments of the present technology should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. In the appended claims, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein.” Moreover, in the following claims, the terms “first,” “second,” and “third,” etc. are used merely as labels, and are not intended to impose numerical requirements on their objects. Further, the limitations of the following claims are not written in means—plus-function format and are not intended to be interpreted based on 35 U.S.C. § 112(f), unless and until such claim limitations expressly use the phrase “means for” followed by a statement of function void of further structure.
Although several embodiments and examples are disclosed herein, the present application extends beyond the specifically disclosed embodiments to other alternative embodiments and/or uses of the technologies and modifications and equivalents thereof. It is also contemplated that various combinations or subcombinations of the specific features and aspects of the embodiments may be made and still fall within the scope of the technologies. Accordingly, it should be understood that various features and aspects of the disclosed embodiments can be combined with or substituted for one another in order to form varying modes of the disclosed technologies. Thus, it is intended that the scope of the present technologies herein disclosed should not be limited by the particular disclosed embodiments described above, but should be determined only by a fair reading of the claims that follow.
While the technologies are susceptible to various modifications, and alternative forms, specific examples thereof have been shown in the drawings and are herein described in detail. It should be understood, however, that the technologies are not to be limited to the particular forms or methods disclosed, but, to the contrary, the technologies are to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the various embodiments described and the appended claims. Any methods disclosed herein need not be performed in the order recited.
This application claims priority to U.S. Provisional Application No. 63/480,208, filed Jan. 17, 2023, titled CATHETERS WITH BALLOONS ON WHICH ARE LOCATED ELECTRODES, which is incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 63480208 | Jan 2023 | US |
