Nasal balloon catheter for stabilizing an ultrasound probe

Abstract

Provided herein is a transnasal transesophageal balloon catheter (10) comprising at least one compliant balloon (30) attached to an outer surface of a tubular body (12). An arrangement (41) of structures (42) extends away from an inner surface of the tubular body (12), and exposed probe guide surfaces (44A) on the structures (42) form a lumen (46) of less than about 15 French (Fr) (5 mm) in diameter extending from a proximal end (13) to a distal end (15) of the tubular body (12), and the lumen (46) is configured to slidably and rotatably receive an ultrasound probe. An arrangement (43) of elongated fluid channels (48A) is interlaced with the structures (42). The fluid channels (48A) are in fluid communication with the lumen (46) and convey fluid between a fluid inlet port (18) and fluid outlet ports (24, 26) to at least partially inflate or deflate the balloon (30).

Description

[0001] This application claims the benefit of U.S. Patent Application 17 / 500,738, filed October 13, 2021, and U.S. Provisional Patent Application 63 / 092,332, filed October 15, 2020, the entire contents of each of which are incorporated herein by reference. Background Technology

[0002] Transthoracic echocardiography (TTE) is a relatively inexpensive and less invasive form of ultrasound imaging. However, to provide good quality images, TTE requires an acoustic window—a region of the anatomical structure unobstructed by bone and air (lungs)—that allows sound to travel from and from the ultrasound probe to the target tissue. The variability of the acoustic window limits the practicality and widespread applicability of TTE in procedures such as cardiac imaging.

[0003] In intracardiac echocardiography (ICE) imaging procedures, a relatively small catheter is advanced through the patient's vein, and an ultrasound transducer is moved through the catheter and placed directly into the heart, largely eliminating any imaging problems related to the patient's anatomy. However, ICE uses disposable probes, which are either discarded or collected and reprocessed after each procedure, increasing costs.

[0004] In transesophageal echocardiography (TEE) procedures, the ultrasound probe is positioned in the patient's esophagus near the heart, thus the TEE procedure is less obstructed by the acoustic window. However, due to the gag reflex (when the patient is intubated), high levels of sedation or general anesthesia are often required during the procedure to ensure patient comfort. Increased anesthesia introduces additional patient risks and procedural costs. Furthermore, because the TEE probe involves a large, relatively rigid catheter, it may be more prone to causing trauma and other complications in some patients. Additionally, image quality during a TEE procedure can be compromised if good contact between the probe and the esophageal wall is not maintained across the entire transducer surface. Gaps between the transducer and the esophageal wall can introduce air, which can block almost 100% of acoustic energy transmission, resulting in noticeable shadows in the ultrasound image.

[0005] In some cases, TEE imaging can be performed while the probe is inserted into the esophagus through the patient's nose rather than through their mouth. This procedure (which has been referred to as transnasal TEE (TNTEE)) aims to eliminate vomiting associated with the oral route, which in turn reduces or eliminates the need for additional anesthesia and improves patient comfort. TNTEE procedures have been performed using pediatric miniature TEE probes with rectangular tip dimensions of approximately 7.5 mm × 5.55 mm, or an average of approximately 18 French (Fr). Images produced by TNTEE using pediatric TEE probes are generally comparable to those obtained using conventional TEE.

[0006] However, while the probe in a TNTEE is smaller than that of a full-size TEE probe, a miniature TEE is still quite large relative to the nasal passages of some patients. In some TNTEE procedures, particularly in patients who have previously taken anticoagulants, nasal bleeding may occur during probe insertion. Furthermore, practitioners may find it more difficult to maintain contact between the smaller probe and the esophageal or stomach wall, potentially resulting in lower quality images. Additionally, while imaging during ICE-guided procedures can be performed by the implant physician, both TEE and TNTEE typically require specialized users to manipulate and position the probe, which can increase the cost and complexity of the procedure. Summary of the Invention

[0007] Generally, this disclosure relates to an ultrasound imaging system comprising a slender, flexible tubular catheter that improves image quality in transnasal transesophageal echocardiography (TNTEE) procedures. The catheter includes an internal lumen configured to hold a small and maneuverable three-dimensional ultrasound probe, suitable for use, for example, in intracardiac echocardiography (ICE) procedures. ICE ultrasound probes have a diameter of less than about 15 Fr (5 mm), and in some cases even less than 10 Fr (3.3 mm). This reduction in catheter size, compared to the 18 Fr (6 mm) diameter catheters typically used in TNTEE procedures, provides easy, non-invasive access through almost the entire nasal passage of the patient.

[0008] In some cases, as mentioned above, it may be difficult for physicians to maintain contact between a small-diameter ultrasound probe and the esophageal wall, which may hinder the formation of the acoustic window and reduce imaging results.

[0009] To form and more easily maintain a more consistent acoustic window and improve TNTEE images of cardiac structures such as, for example, the atrial septum, the catheter in the imaging system of this disclosure includes a distal end with a compliant balloon. When inflated with fluid, the balloon forms a conformal interface with a selected area of ​​esophageal wall tissue, providing a substantially air-free path between at least one transducer on the ultrasound probe and the target tissue area to be imaged by the ultrasound probe. The inflated balloon also stabilizes the catheter within the esophagus, eliminating the need for operator-assisted catheter stabilization. In various embodiments, the balloon may have a circular profile to symmetrically fill the esophagus, or, for improved patient comfort, the balloon may extend only a portion of the tubular body of the catheter to allow saliva passage during the imaging procedure.

[0010] To more effectively stabilize a small-diameter ultrasound probe within the tubular body of the catheter, an arrangement of structures extending away from the inner surface of the catheter body provides a lumen with a probe guiding surface. This guiding surface is configured to contact the probe, track selected imaging sites within the esophagus using the probe, and rotate the probe to ensure an unobstructed view of the target tissue to be imaged by one or more transducers on the probe. Structures on the inner surface of the catheter lumen are interspersed with arrangements of fluid channels forming a fluid delivery network that delivers fluid to inflate or deflate the balloon and expel trapped air without interfering with probe movement within the lumen.

[0011] The catheter body has a sealed distal end for insertion into the patient's nasogastric region and esophagus. This prevents fluid or tissue contaminants from contacting the ultrasound probe, and similarly prevents probe material from contacting the patient. This closed system provides a safety benefit to the patient and, in some cases, allows for probe reuse without extensive resterilization, reducing the cost of ultrasound imaging procedures.

[0012] In some implementations, the closed distal end of the catheter may include a non-invasive tip because the tubular catheter body does not require a specific shape or torque, and in some cases, the tip may taper to have a dilating effect on the nasal passage. In some cases, a tapered non-invasive tip can reduce nasal bleeding and lower the incidence of complications in the TNTEE imaging procedure.

[0013] In one aspect, this disclosure relates to a transnasal transesophageal balloon catheter comprising an elongated flexible tubular body having an inner surface, an outer surface, and an orifice extending from a proximal end to a distal end thereof. The proximal end of the tubular body includes a valve and a fluid inlet port for introducing an ultrasound probe, and the distal end of the tubular body includes a closed tip and a fluid outlet port. The fluid outlet port is fluidly connected to at least one compliant balloon attached to the outer surface of the tubular body, and the at least one balloon covers an imaging area of ​​the tubular body. An arrangement of structures extends away from the inner surface of the tubular body and into the orifice, wherein an exposed probe guiding surface on the structure forms a lumen with a diameter less than about 15 French (Fr) (5 mm), the lumen extending from the proximal end to the distal end of the tubular body and configured to slidably and rotatably receive the ultrasound probe. The structure is interspersed with an arrangement of elongated fluid channels, wherein the fluid channels are in fluid communication with the lumen and deliver fluid between the fluid inlet port and the fluid outlet port to at least partially inflate or deflate the balloon.

[0014] In another aspect, this disclosure relates to a system including a balloon catheter. The balloon catheter includes an elongated, flexible tubular body having an inner surface, an outer surface, and an opening extending from its proximal end to its distal end. The proximal end of the tubular body includes a valve and a fluid inlet port configured to sealably receive an ultrasound probe. The distal end of the tubular body includes a closed tip and a fluid outlet port fluidly connected to at least one compliant balloon attached to the outer surface of the tubular body, and wherein the at least one balloon covers an imaging region of the tubular body. An arrangement of structures extends away from the inner surface of the tubular body and into the opening, wherein an exposed probe guiding surface on the structure forms a lumen with a diameter less than about 15 Fr (5 mm), the lumen extending from the proximal end of the tubular body to the distal end and configured to slidably receive the ultrasound probe. An arrangement of elongated fluid channels resides within the structure, wherein the fluid channels are in fluid communication with the lumen and deliver fluid between the fluid inlet port and the fluid outlet port to at least partially inflate or deflate the balloon in the imaging region. An intracardiac echocardiography probe is located within the lumen and is linearly translatable and rotatable within the lumen.

[0015] In another aspect, this disclosure relates to a method for ultrasound imaging of target tissue. The method includes inserting a balloon catheter into an esophageal region, wherein the balloon catheter includes an elongated flexible tubular body having an inner surface, an outer surface, and an opening extending from its proximal end to its distal end. The proximal end of the tubular body includes a valve and a fluid inlet port configured for sealably introducing an intracardiac echocardiographic probe, and the distal end of the tubular body includes a closed tip and a fluid outlet port. The fluid outlet port is fluidly connected to at least one compliant balloon attached to the outer surface of the tubular body, and wherein the at least one balloon covers the imaging region of the tubular body. An arrangement of structures extends away from the inner surface of the tubular body and into the opening, wherein an exposed probe guiding surface on the structure forms a lumen with a diameter less than about 15 Fr (5 mm), the lumen extending from the proximal end of the tubular body to the distal end and configured to slidably and rotatably receive the probe. An arrangement of elongated fluid channels resides within the structure, wherein the fluid channels are in fluid communication with the lumen and deliver fluid between the fluid inlet port and the fluid outlet port. The method includes: linearly translating and rotating the balloon catheter to a selected region of esophageal wall tissue; and inserting fluid into the fluid inlet port such that the fluid enters the fluid channel and the lumen and flows out from the fluid outlet port, thereby fully inflating the balloon in the imaging region to form a conformal interface with the selected region.

[0016] Details of one or more embodiments of the invention are set forth in the accompanying drawings and description below. Other features, objects, and advantages of the invention will be apparent from the description, drawings, and claims. Attached Figure Description

[0017] Figure 1 This is a schematic cross-sectional side view of an embodiment of the catheter according to the present disclosure.

[0018] Figures 2A to 2B yes Figure 1 The implementation scheme of the structure and fluid flow channel in the conduit along Figure 1 A schematic cross-sectional view showing the direction of arrow A.

[0019] Figures 2C to 2D This is when the catheter is in the patient's esophagus and the ultrasound probe is in the catheter. Figure 1 Implementation scheme of balloon configuration in catheter along Figure 1 A schematic cross-sectional view showing the direction of arrow A.

[0020] Figures 3A to 3B This is a schematic diagram of an imaging system having a catheter of the present disclosure in the patient's esophagus.

[0021] Figure 4A This is a schematic cross-sectional view of one embodiment of the catheter of this disclosure, including a catheter body having a tapered distal end and an ablation tip.

[0022] Figure 4B This is a schematic cross-sectional view of an embodiment of the catheter of this disclosure, including a tapered, non-invasive dilating tip.

[0023] Figure 5 This is a schematic diagram of an implementation scheme of an imaging system incorporating the catheter disclosed herein.

[0024] Figure 6 It includes Figure 5 A flowchart illustrating an exemplary implementation of an ultrasound imaging method for an imaging system.

[0025] The same symbols in the diagram represent the same components. Detailed Implementation

[0026] Figure 1This is a schematic diagram (not drawn to scale) of a catheter 10 used to stabilize and guide an ultrasound imaging probe in an imaging system suitable for performing transnasal transesophageal echocardiography (TNTEE) imaging procedures. The catheter 10 includes an elongated, flexible tubular body 12 having a proximal end 13 and a distal end 15. The catheter body 12 can be made of any flexible material and is typically formed by extrusion of a polymeric material, including but not limited to polyethylene (PE), nylon, polypropylene (PP), polyether block amide (PEBA), polybutylene terephthalate (PBT), and combinations thereof. In various embodiments, the catheter body 12 can be formed from a single layer of polymeric material or multiple layers of the same or different polymeric materials. In some examples, not intended to be limiting, for a transnasal transesophageal catheter, the catheter body 12 may have an outer diameter do of about 12 Fr (4 mm) to about 25 Fr (8.3 mm). In some embodiments, the catheter body may optionally include reinforcing materials, such as, for example, metal strands, bands, wires, etc. Figure 1 (Not shown in the image).

[0027] In various embodiments, the distal end 15 of the catheter body 12 can be straight (e.g., Figure 1 (as shown), or it may be tapered. The catheter body 12 includes an outer surface 17, an inner surface 19, and an opening longitudinal hole 14 extending along its length from the proximal end 13 to the distal end 15.

[0028] The proximal end 13 of the catheter body 12 includes a valve 16 adapted for introducing an ultrasound imaging probe device, such as a TNTEE transducer and shaft ( Figure 1 (Not shown in the diagram, but will be shown in more detail below). Valve 16 can vary widely and should be configured to include a sealing member such as, for example, an O-ring, a gasket, a sealable diaphragm, etc., which receives the TNTEE transducer and shaft and then forms a liquid-tight seal with the TNTEE probe shaft, preventing liquid from passing through. The proximal end 13 of the catheter body 12 also includes a fluid inlet port 18. In some exemplary embodiments, the fluid inlet port 18 includes a Luer lock connector 20, but any type of connector can potentially be used to connect the catheter body 12 to a fluid source. In some embodiments, the catheter body may include multiple fluid inlet ports 18.

[0029] The distal end 15 of the catheter body 12 includes a sealing tip 22 that seals the catheter body 12 to prevent fluid leakage and to prevent contact between the ultrasound probe therein and the patient's bodily fluids. Figure 1In some embodiments, the tip 22 is integral with the catheter body 12; however, in others, the tip 22 may be made of a non-invasive polymer material that is softer and more compliant than, for example, the polymer material used to form the catheter body 12. In some embodiments, the tip 22 may be tapered to provide a dilation effect and facilitate passage of the tip 22 through the patient's nasal passage and esophagus. The distal end 15 of the catheter body 12 also includes at least one fluid outlet port, and... Figure 1 The implementation includes dual fluid outlet ports 24, 26. However, in some examples, the catheter body 12 may include multiple lumens and channels, each having multiple fluid outlet ports.

[0030] The distal end 15 of the catheter body 12 also includes at least one compliant balloon 30 covering the fluid outlet ports 24, 26. In some exemplary embodiments, not intended to be limiting, the balloon 30 is formed of a soft, flexible, compliant polymeric material, such as a polyethylene (PE) / ethylene vinyl alcohol (EVA) blend, silicone, polyurethane, polyether block amide, and combinations thereof. The balloon 30 includes a balloon wall 32 that may be formed of a single or multiple layers of polymeric material and may optionally include reinforcing material to enhance strength and burst resistance. In some exemplary embodiments, the balloon 30 has a length along the catheter body 12 of about 2 cm to about 10 cm. The balloon wall 32 may be attached to the outer surface 17 of the catheter body 12 by any suitable technique, including, for example, adhesive, fusion, etc.

[0031] Now for reference Figure 1 and Figures 2A to 2B The catheter body 12 also includes an internal fluid delivery system 40, which can be used to inflate and deflate the balloon 30 when fluid is delivered to or exits from the fluid outlet ports 24, 26. The fluid delivery system 40 includes an arrangement 41 having a plurality of structures 42 extending away from the inner surface 19 of the catheter body 12 and into the orifice 14. In various embodiments, the structures 42 may be integrally formed with the catheter body 12 or may be formed as separate units or inserts for placement in the orifice 14. In various embodiments, the structures 42 may be formed of the same or different polymeric materials as the catheter body 12.

[0032] Not intended to be restrictive Figures 2A to 2B In the exemplary implementation shown, when along Figure 1When viewed from below hole 14 in the direction of arrow A, structure 42A may have a rectangular cross-sectional shape. Structure 42B has a generally trapezoidal cross-sectional shape, but in various embodiments, structure 42 may have cross-sectional shapes including triangular, pyramidal, semi-circular, I-beam, etc. The structure may include substantially straight or curved walls. Although Figures 2A to 2B The embodiments shown in the diagram illustrate an arrangement of structures 41 comprising multiple substantially similar structures 42A, 42B, but in some embodiments, structures 42 in arrangement 41 may have different shapes. In various examples, these structures may be present along the length of the orifice 14 on all or a portion of the inner surface 19 of the catheter body 12, and may occupy all or a portion of the circumference of the inner surface 19. In various embodiments, structures 42A, 42B may be integrally formed with the inner surface 19, or may be formed as inserts for placement in the orifice 40 of the catheter 12.

[0033] In various embodiments, which are not intended to be limiting, structures 42A-42B have a height h above the inner surface 19 of about 0.1 mm to about 5 mm, or about 1 mm to about 3 mm, or about 1 mm to about 1.5 mm, or about 1 mm to about 1.25 mm. In various non-limiting embodiments, structures 42A-42B have a width w of about 0.1 mm to about 5 mm, or about 0.5 mm to about 2 mm, or about 0.8 mm to about 1 mm. In various embodiments, the number of structures 42A-42B present along the inner surface 19 can be 1 to 10, or 2 to 8, or 4 to 8. In some examples, multiple small structures 42A-42B may be present to form a rough inner surface 19, wherein these structures allow fluid to flow and circulate therebetween.

[0034] Structures 42A-42B include exposed probe guiding surfaces 44A-44B that form a lumen 46 therebetween. In some embodiments, the lumen 46 extends along the orifice 14 from the proximal end 13 to the distal end 15 of the catheter body 12 and is configured to receive small ultrasound probes or probe arrays, such as probes sized for use in intracardiac echocardiography (ICE) imaging procedures. In various embodiments, the probe guiding surfaces 44A-44B may be configured to slidably receive and stabilize a selected ICE probe configuration, allowing the ICE probe to translate more efficiently linearly and rotationally within the lumen 46. For example, in some embodiments, the probe guiding surfaces 44A-44B may be concave (…). Figure 2A or basically flat ( Figure 2BIn various examples that are not intended to be limiting, lumen 46 is configured to accept and allow linear translation and rotation of probes with diameters from about 3 mm to about 6 mm. For example, in various embodiments, lumen 46 has a diameter D of less than about 15 Fr (5 mm), or less than about 12 Fr (4 mm), or less than 10 Fr (3.3 mm), or even less than about 8 Fr (2.7 mm).

[0035] The arrangement 43 of the elongated fluid channels 48A-48B is interspersed with structures 42A-42B. One or more of the fluid channels 48A-48B are in fluid communication with the lumen 46 and transport fluid along the inlet direction I between the fluid inlet port 18 and the fluid outlet ports 24, 26. Figure 1 or Figures 2A to 2B (Not shown) to at least partially inflate or deflate the balloon 30. One or more of the elongated fluid channels 48A-48B may also be used to expel air from the lumen 46 or the balloon 30 along the outlet direction E during the inflation or deflation procedure.

[0036] In various embodiments, fluid channel 48A has a generally trapezoidal cross-sectional shape, while fluid channel 48B has a generally arcuate or hemispherical shape when viewed in cross-section. However, similar to structures 42A-42B, in various embodiments, fluid channels 48A-48B may have cross-sectional shapes including triangular, pyramidal, etc. Although Figures 2A to 2B The embodiments shown depict fluid channels 43 arranged with several substantially similar structures 42A-42B, but in some embodiments, the fluid channels within the arrangement 43 may have different shapes. In various examples, fluid channels 48A-48B may exist along the length of the orifice 14 on all or part of the inner surface 19 of the conduit body 12, and may occupy all or part of the circumference of the inner surface 19.

[0037] In various embodiments, fluid channels 48A-48B have a depth r below the probe guide surfaces 44A-44B, which is approximately 0.5 mm to approximately 5 mm, approximately 1 mm to approximately 2 mm, or approximately 1 mm to approximately 1.5 mm. In various embodiments, fluid channels 48A-48B have a width x of approximately 0.1 mm to approximately 5 mm, approximately 0.2 mm to approximately 1.5 mm, or approximately 0.2 mm to approximately 1.25 mm. In various embodiments, fluid channels 48A-48B include walls 49A-49B that are substantially perpendicular to the outer surface 19 of the outer surface 19 of the catheter body 12, or may be arcuate. In various embodiments, which are not intended to be limiting, the number of fluid channels 48A-48B present can be 1 to 10, 2 to 8, or 4 to 8.

[0038] Now for reference Figure 2CIn some examples, the balloon 30 extends around the entire circumference of the tubular catheter body 12. When placed in the patient's esophagus 60, the balloon 30 can be filled with fluid via the fluid channel 48 and expand to symmetrically fill the esophagus 60. An ultrasound probe 70 (such as, for example, an ICE probe) can be slidably and rotatably inserted into the lumen 46 and contact the probe guide surface 44 on the structure 42.

[0039] exist Figure 2D In another embodiment shown, the balloon 30 extends only a portion of the circumference of the tubular catheter body 12. When placed in the patient's esophagus 60, the balloon 30 can be filled with fluid via the fluid channel 48 and expand to fill a portion of the esophagus 60, while leaving an unobstructed esophageal region 62 for saliva to pass through. The probe 70 can be slidably inserted into the lumen 46 and contact the probe guide surface 44 on the structure 42.

[0040] Now for reference Figures 3A to 3B The diagram above illustrates that, in use, the above... Figure 1 and Figures 2A to 2D The catheter 10, shown in detail, can be inserted into the patient's nasal passage and advanced into the channel 64 in the patient's esophagus 60. The catheter body 12 can be advanced along the esophageal wall 66 to the appropriate position to obtain an image of an area of ​​target tissue (not shown), which includes, but is not limited to, cardiac tissue, vascular tissue, or retrosternal tissue. A fluid suitable for the desired ultrasound imaging protocol (in various embodiments, it may be an ultrasound-transparent fluid such as water or saline, a non-ultrasound-transparent fluid such as a radiopaque contrast agent, or a mixture or combination thereof) can be introduced into the fluid inlet port ( Figures 3A to 3B Not shown in the image, please refer to [link / reference]. Figure 1 (Example in the text). Fluid flows through the fluid channel and the working lumen 46 formed by the structure within the orifice of the catheter body 12, inflating the balloon 30. The wall 32 of the inflated balloon 30 contacts the wall 66 of the esophagus 60 and forms a conformal interface 68 therewith.

[0041] A suitably sized ultrasound probe device 70 (such as, for example, an intracardiac echocardiography (ICE) probe) can be inserted into a lumen 46 formed within the catheter body 12. The ultrasound probe device 70 includes a shaft 72, which optionally contains a drawwire that can be manually or automatically manipulated to linearly and rotationally translate a transducer stack 74, including one or more transducers 76, to a desired location within the esophagus 60. The transducers 76 are manipulated within the esophagus to reside within an imaging region 82 defined by a conformal interface 68 formed by the walls 32 of the balloon 30. Due to the small size and flexibility of the probe device 70, the probe guiding surface defining the lumen 46 provides stability and precise guidance as the transducer stack 74 is linearly translated and rotated to the desired location. In various embodiments, not intended to be limiting, suitable probe devices include ultrasound probes available from General Electric (GE), Philips, Siemens, etc.

[0042] In some cases, the enhanced stability provided by catheter 12 allows surgeons to easily manipulate the transducer stack 74 and securely anchor it in place, potentially eliminating the need for multiple users to perform imaging procedures and reducing the cost per procedure. In some embodiments, catheter 12 may optionally include additional features to aid in transducer stack placement, such as, for example, guidewires, braids, coils, etc.

[0043] In various embodiments provided by way of example, the transducer 76 operates in a frequency range of about 1 MHz to about 60 MHz or about 3 MHz to about 10 MHz for use in transesophageal imaging procedures. In some examples, a suitable transducer 76 has a focal length of about 1 cm to about 4 cm, or about 2 cm to about 3 cm. Transmission line ( Figures 3A to 3B (Not shown) The transducer stack 74 is electrically connected to the control electronics ( Figures 3A to 3B (Not shown in the image, see below). Transducer 76 transmits ultrasound signal 80 to target tissue 90 within imaging region 82. The conformal interface 68 within imaging region 82 formed by balloon 30 reduces or eliminates air gaps along the path of ultrasound signal 80, which reduces shadowing effects in ultrasound images of target tissue 90. The magnified imaging region 82 also provides transducer 76 with a wider field of view.

[0044] For example, if an air gap exists near a portion of the transducer 76, the observer will only be able to use a portion of the field of view, while the other portion is blocked by air. By eliminating the air gap, the useful field of view is effectively increased.

[0045] Additionally, ultrasound images are typically (though not always) created in such a way that they spread out with increasing depth, and the field of view becomes larger / wider at deeper depths. By incorporating a balloon 30 at the distal end of catheter 12, ultrasound probe 76 is effectively retracted from the esophagus by a small offset (e.g., about 1 cm). Therefore, the tissue to be imaged is at this offset compared to imaging with probe 76 against the esophageal wall. Because the tissue to be imaged is deeper, the field of view becomes wider, resulting in a broader field of view.

[0046] Now for reference Figure 4A As illustrated in the schematic diagram, in an alternative embodiment, the distal end 115 of catheter 110 includes a catheter body 112 having a tapered region 121 and a closed tip 122. The tapered region 121 works in conjunction with the non-invasive tip 122, which has an expanding shape, to facilitate insertion into a patient's nasal passage and esophagus. As described above, in some embodiments, the non-invasive tip 122 may be made of a polymeric material that is softer and more compliant than the polymeric material of the catheter body 112. The tip 122 may be integrally formed with the catheter body 112 or may be separately molded and attached to the catheter body 112 using any suitable technique.

[0047] The catheter 110 also includes a plurality of balloons 130A-130B, each balloon having a corresponding wall 132A, 132B that engages with the outer surface 117 of the catheter body 112. The balloons 130A, 130B are inflated and deflated via fluid flow through corresponding fluid outlet ports 124, 126.

[0048] The longitudinal hole 114 within the catheter body 112 includes the protrusions described above. Figure 4A An arrangement (not shown) is used to form a working lumen 146 to linearly translate and rotate the catheter shaft 172, thereby precisely positioning an ultrasound imaging device 170, such as, for example, an ICE probe. Fluid channels with protrusions are interspersed. Figure 4A (Not shown) Fluid is supplied to fluid outlet ports 124, 126 to inflate and deflate balloons 130A, 130B.

[0049] When balloons 130A and 130B contact the esophageal wall to form a conformal interface, multiple balloons 130A and 130B can provide a larger imaging area 182 and improved tissue contact. The large conformal interface formed by the balloons 130A and 130B effectively provides a large acoustic window to facilitate signal transmission to and from the transducers 176 in the transducer stack 174.

[0050] Now for reference Figure 4BIn another embodiment shown in the schematic diagram, the distal end 215 of catheter 210 includes a catheter body 212 having a closed tip 222. Tip 222 includes a tapered region 222A and a non-invasive dilation region 222B. Tip 222 facilitates insertion of catheter 210 into a patient's nasal passage and esophagus. As described above, in some embodiments, one or both portions of tip 222 may be made of a polymeric material that is softer and more compliant than the polymeric material of catheter body 212. Tip 222 may be integrally formed with catheter body 212 or may be separately molded and attached to catheter body 212 using any suitable technique.

[0051] The catheter 210 also includes a balloon 230 having a wall 232 that engages with the outer surface 217 of the catheter body 212. The balloon 230 is inflated and deflated by a flow of fluid through a fluid outlet port 224.

[0052] The longitudinal hole 214 within the catheter body 212 includes the protrusions described above. Figure 4B An arrangement (not shown) is used to form a working lumen 246 for linear translation and rotation of the catheter shaft 272, thereby precisely positioning an ultrasound imaging device 270, such as, for example, an ICE probe. Fluid channels with protrusions are interspersed. Figure 4B (Not shown) Fluid is supplied to fluid outlet port 224 to inflate and deflate bladder 230.

[0053] The large conformal interface formed by the balloon 230 effectively provides a large acoustic window to provide signal transmission to and from the transducer 176 in the transducer stack 174.

[0054] Now for reference Figure 5 A schematic diagram of an exemplary embodiment of system 300 includes a catheter 310 having a catheter body 312 and a closed tip 322. The distal end 315 of catheter 310 includes a balloon 330 having a body 332 attached to the outer surface 317 of catheter body 312. The balloon 330 is inflated and deflated by fluid delivered to a fluid inlet port 318, which passes through a network of fluid channels as described above. Figure 5 (Not shown in the image) The fluid is supplied to the fluid outlet port 324 through the longitudinal hole 314 of the conduit body 312.

[0055] The longitudinal hole 314 within the catheter body 312 includes the protrusions described above. Figure 5 An arrangement (not shown) is used to form a working lumen 346 for linearly translating and rotating the catheter shaft 372, thereby precisely positioning an ultrasound imaging device 370, such as an ICE probe.

[0056] In some embodiments, system 300 includes a controller or patient interface module 390. The catheter body 312 may be manually operated by a user, or in some examples, the patient interface module 390 is configured to automatically control various functions of movement of the ultrasound imaging device 370 within the working lumen 346 of the catheter 312. For example, the patient interface module 390 may be configured to control at least one of linear translation or rotation of the ultrasound imaging device 370 via the catheter axis 372. In another embodiment, the imaging device 370 may include an optical system to observe the position of the ICE probe in the patient's esophagus, and the patient interface module 390 may be configured to control or capture and process images from the optical system. In another embodiment, the patient interface module 390 may be configured to control a fluid supply system 392, which includes suitable fluid pumps, reservoirs, temperature and pressure sensors, etc.

[0057] The patient interface module 390 includes a processor 396 in a computing device 394 to process signals from the imaging device 370 and the fluid supply system 392. In various embodiments, the processor 396 may be integrated with the imaging device 370 or the fluid supply system 392, or it may be a remote processor.

[0058] The processor 396 in the computing device 394 can be any suitable software, firmware, hardware, or a combination thereof. The processor 396 may include any one or more microprocessors, controllers, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or discrete logic circuit systems. The functionality attributable to the processor 396 may be provided by the processing circuitry system of the hardware device, such as by software and / or firmware.

[0059] In some examples, processor 396 may be coupled to memory 397, which may be part of or remote from computing device 394. Memory 397 may include any volatile or non-volatile media, such as random access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), electrically erasable programmable ROM (EEPROM), flash memory, etc. Memory 397 may be a storage device or other non-transitory media. Processor 396 may use memory 397 to, for example, store imaging data related to ultrasound scanning procedures, or to retrieve other patient information during or after the imaging procedure.

[0060] In some implementations, processor 396 is coupled to user interface 398, which may include a display, user inputs and outputs, etc. Figure 5(Not shown). Suitable display devices include, for example, monitors, PDAs, mobile phones, tablets, etc. In some examples, user input may include components for user interaction (such as a keyboard) and a display (such as a cathode ray tube (CRT) display, liquid crystal display (LCD), or light-emitting diode (LED) display), and the keyboard may take the form of an alphanumeric keypad or a reduced set of keys associated with a specific function. In some examples, the display may include a touchscreen display, and the user may interact with the user input via the display's touchscreen. In some examples, the user may also interact with the user input remotely via a networked computing device.

[0061] In some embodiments, the patient interface module 390 may include a controller 394 that generates control signals for, for example, linear translation or rotation of the ultrasound imaging device 370, fluid pressure in the fluid supply system 392, etc. The controller 394 may be adjusted via a variety of manual and automatic means. The automatic means may utilize any number of control algorithms, such as adaptive algorithms, or so-called "machine learning" algorithms. In some embodiments, the controller 394 may utilize information from other sources such as infrared cameras, previous imaging data, etc., to determine the control actions determined by the algorithm or machine learning scheme.

[0062] exist Figure 6 In another embodiment shown in the flowchart, this disclosure relates to a method 400 for imaging a target tissue.

[0063] Method 400 includes inserting a balloon catheter into a region of the patient's esophagus (402). The balloon catheter includes a distal end having a closed tip and at least one compliant balloon, wherein the orifice of the catheter body includes an arrangement of structures having exposed probe guiding surfaces that form a lumen with a diameter less than about 15 Fr (5 mm). Method 400 includes inserting fluid into an arrangement of elongated fluid channels located between the structures, wherein the fluid channels are in fluid communication with the lumen and deliver fluid to adequately inflate the balloon, thereby forming a conformal interface with a selected region of the esophageal wall tissue (404).

[0064] Method 400 includes providing an ultrasound probe in a lumen and linearly translating and rotating the probe in the lumen to establish an acoustic window (406) between a transducer on the probe and a target area of ​​the tissue to be imaged by the probe.

[0065] In some embodiments, a balloon catheter is first inserted into the patient's nasal passage, manipulated to the desired location in the patient's esophagus, and then an ultrasound probe is inserted into the catheter and moved to a position within the catheter lumen to reach a preferred viewing location. The catheter may optionally include braided material, coils, threads, etc., to improve overall rigidity and enable more precise positioning within the esophagus. In some embodiments, the catheter may also be used with an optional guide or dilator to facilitate movement through the patient's nasal passage and esophagus.

[0066] In some implementations, an ultrasound probe is first inserted into the catheter lumen before the catheter lumen is inserted into the patient's nasal passage. The catheter and probe are then manipulated together through the patient's anatomy to a preferred viewing location. In some examples, an optional dilator or guide may be used to navigate the patient's anatomy, or the catheter may be reinforced with braids, coils, etc., to provide axial mechanical means that can be pushed through the anatomy and twisted to move the system to a preferred viewing location.

[0067] In exemplary TNTEE imaging procedures using the catheter of this disclosure in conjunction with an ICE probe, ultrasound images of the internal chambers of the heart, such as the left atrium, can be obtained. Sufficient contact and improved near-field visualization facilitate overall visualization of other cardiac structures, such as all four pulmonary veins entering the left atrium. In some embodiments, the improved visualization provided by the catheter of this disclosure can be used to guide ablation procedures in the pulmonary veins, on the interatrial septum, etc.

[0068] In some additional examples, not intended to be limiting, the catheter of this disclosure can be used to visualize patient anatomy during the delivery of implantable medical devices, such as leads, valves, leadless pacemakers, cardiac closure devices, etc. The catheter can be used to deliver the implantable medical device not only to the left atrium, but also to the left ventricle (e.g., mitral valve, aortic valve, left ventricular assist device), right atrium (e.g., right atrial pacing leads, leadless pacemakers), and right ventricle (e.g., defibrillator leads, leadless pacemakers). Anatomical structures that can be visualized using the catheter of this disclosure for delivery of the implantable medical device include, but are not limited to, the superior vena cava (SVC), inferior vena cava (IVC), tricuspid valve, mitral valve, aortic valve, pulmonary valve, atrial septum, interventricular septum, coronary sinus, foramen ovale, fossa ovale, left atrial appendage, and right atrial appendage.

[0069] Implementation Plan

[0070] Implementation Scheme A. A transnasal transesophageal balloon catheter, comprising:

[0071] An elongated flexible tubular body has an inner surface, an outer surface, and a hole extending from its proximal end to its distal end, wherein the proximal end of the tubular body includes a valve and a fluid inlet port for introducing an ultrasound probe, and the distal end of the tubular body includes a closed tip and a fluid outlet port, wherein the fluid outlet port is fluidly connected to at least one compliant balloon attached to the outer surface of the tubular body, and wherein at least one balloon covers the imaging area of ​​the tubular body;

[0072] An arrangement of a structure extending away from the inner surface of the tubular body and into the orifice, wherein an exposed probe guiding surface on the structure forms a lumen with a diameter less than about 15 French (Fr) (5 mm), the lumen extending from the proximal end to the distal end of the tubular body and configured to slidably and rotatably receive the ultrasound probe; and

[0073] An arrangement of elongated fluid channels interspersed with the structure, wherein the fluid channels are in fluid communication with the lumen and deliver fluid between the fluid inlet port and the fluid outlet port to at least partially inflate or deflate the balloon.

[0074] Implementation Scheme B. The catheter according to Implementation Scheme A, wherein the balloon is configured to inflate in the imaging region to form a conformal interface with a selected area of ​​esophageal wall tissue and to provide a substantially airless path between the transducer on the ultrasound probe and the target area of ​​the tissue to be imaged by the ultrasound probe.

[0075] Implementation Scheme C. The catheter according to Implementation Scheme A or B, wherein the lumen is configured to receive an intracardiac echocardiography probe.

[0076] Implementation scheme D. The catheter according to any one of implementation schemes A to C, wherein the lumen has a diameter of less than about 12 Fr (4 mm).

[0077] Implementation scheme E. The catheter according to any one of implementation schemes A to D, wherein the lumen has a diameter of less than about 10 Fr (3.3 mm).

[0078] Implementation F. The conduit according to any one of Implementations A to E, wherein the structure has a trapezoidal cross-sectional shape and the fluid channel has a hemispherical cross-sectional shape when viewed downward from the orifice of the tubular body along the longitudinal axis of the tubular body.

[0079] Implementation scheme G. The catheter according to implementation scheme F, wherein the probe guiding surface is substantially flat.

[0080] Implementation scheme H. The catheter according to implementation scheme F or G, wherein the probe guiding surface is concave.

[0081] Implementation Scheme I. The conduit according to any one of Implementation Schemes A to H, wherein the structure has a rectangular cross-sectional shape and the fluid channel has a trapezoidal cross-sectional shape when viewed downward from the orifice of the tubular body along the longitudinal axis of the tubular body.

[0082] Implementation Scheme J. The catheter according to Implementation Scheme I, wherein the probe guiding surface on the structure is concave.

[0083] Implementation scheme K. The catheter according to any one of implementation schemes A to J, wherein the probe guiding surface has a height of about 0.5 mm to about 5 mm above the inner surface of the tubular body.

[0084] Implementation Scheme L. The catheter according to any one of Implementation Schemes A to K, wherein the fluid channel has a depth of about 0.5 mm to about 5 mm below the probe guide surface on the structure.

[0085] Implementation scheme M. The catheter according to any one of implementation schemes A to L, wherein the tip of the tubular body has a non-invasive shape.

[0086] Implementation scheme N. The catheter according to implementation scheme M, wherein the tip of the tubular body has an expanding shape.

[0087] Implementation scheme O. The catheter according to implementation scheme M or N, wherein the tip of the tubular body is tapered.

[0088] Implementation scheme P. The catheter according to any one of implementation schemes A to O, wherein the tip is integral with the tubular body.

[0089] Implementation Scheme Q. The catheter according to any one of Implementation Schemes A to P, wherein the tubular body comprises a first polymer material and the tip comprises a second polymer material different from the first polymer material.

[0090] Implementation scheme R. The catheter according to any one of implementation schemes A to Q, wherein the fluid is ultrasonically transparent.

[0091] Implementation S. The conduit according to implementation R, wherein the fluid comprises water, saline solution, and mixtures and combinations thereof.

[0092] Implementation scheme T. The catheter according to any one of implementation schemes A to S, wherein the lumen and the fluid passage form a fluid delivery network within the catheter body, such that the ultrasound probe does not come into contact with body fluids during the imaging procedure.

[0093] Implementation scheme U. The catheter according to any one of implementation schemes A to T, wherein the balloon has a length of about 2 cm to about 10 cm and an inflation diameter of about 2 cm to about 4 cm.

[0094] Implementation scheme V. The catheter according to any one of implementation schemes A to U, wherein the balloon extends circumferentially around the outer surface of the tubular body.

[0095] Implementation scheme W. The catheter according to any one of implementation schemes A to V, wherein the balloon extends around a portion of the circumference of the outer surface of the tubular body, and wherein the portion of the circumference is smaller than the entire circumference.

[0096] Implementation scheme X. The catheter according to any one of implementation schemes A to W, wherein the catheter comprises a plurality of balloons.

[0097] Implementation Scheme Y. The catheter according to any one of Implementation Schemes A to X, wherein the tubular body comprises a compliant polymer material selected from polyethylene (PE), nylon, silicone, polyurethane, polyether block amide, and combinations thereof.

[0098] Implementation Scheme Z. The catheter according to any one of Implementation Schemes A to Y, wherein the balloon comprises a polymer material selected from polyethylene (PE), ethylene vinyl alcohol (EVA), silicone, polyurethane, polyether block amide, and mixtures and combinations thereof.

[0099] Implementation scheme AA. The catheter according to any one of implementation schemes A to Z, wherein the tubular body comprises multiple layers of polymer material.

[0100] Implementation Scheme BB. The conduit according to any one of Implementation Schemes A to AA, wherein the tubular body comprises a metal reinforcing material.

[0101] Implementation scheme CC. The catheter according to any one of implementation schemes A to BB, wherein at least one of the tubular body and the balloon includes an ultrasound-enhanced structure.

[0102] Implementation Scheme DD. A catheter according to any one of Implementation Schemes A to C, wherein the structure comprises a first polymer material, and the tubular body comprises a second polymer material different from the first polymer material.

[0103] Implementation scheme EE. The catheter according to any one of implementation schemes A to DD, wherein the catheter body further includes braids, coils, and combinations thereof.

[0104] Implementation scheme FF. The catheter according to any one of implementation schemes A to EE, wherein the catheter body further includes a pull wire.

[0105] Implementation Plan GG. A system comprising:

[0106] A balloon catheter, comprising:

[0107] An elongated flexible tubular body has an inner surface, an outer surface, and an opening extending from its proximal end to its distal end, wherein the proximal end of the tubular body includes a valve and a fluid inlet port configured to sealably receive an ultrasound probe, and the distal end of the tubular body includes a closed tip and a fluid outlet port, wherein the fluid outlet port is fluidly connected to at least one compliant balloon attached to the outer surface of the tubular body, and wherein the at least one balloon covers the imaging area of ​​the tubular body;

[0108] An arrangement of a structure extending away from the inner surface of the tubular body and into the orifice, wherein an exposed probe guiding surface on the structure forms a lumen with a diameter less than about 15 Fr (5 mm), the lumen extending from the proximal end to the distal end of the tubular body and configured to slidably receive the ultrasound probe; and

[0109] An arrangement of elongated fluid channels between the structures, wherein the fluid channels are in fluid communication with the lumen and deliver fluid between the fluid inlet port and the fluid outlet port to at least partially inflate or deflate the balloon in the imaging region; and

[0110] An intracardiac echocardiography probe is located in the lumen, wherein the probe can be linearly translated and rotated within the lumen.

[0111] Implementation scheme HH. The system according to implementation scheme GG, wherein the balloon is capable of being fully inflated in the imaging region to form a conformal interface with a selected region of the esophageal wall tissue and to provide a substantially airless path between the transducer on the probe and the target region of the tissue to be imaged by the probe.

[0112] Implementation Scheme II. The system according to any one of Implementation Schemes GG to HH, the system further includes a controller to provide at least one of linear translation and rotation of the probe in the lumen.

[0113] According to any one of embodiments GG to II, the system further includes at least one display module for displaying an image of the target tissue.

[0114] Implementation scheme KK. The system described in implementation scheme JJ, wherein the target tissue is cardiac tissue, vascular tissue or retrosternal tissue.

[0115] Implementation Scheme LL. A method for performing ultrasound imaging on target tissue, the method comprising:

[0116] A balloon catheter is inserted into the esophageal region, wherein the balloon catheter comprises:

[0117] An elongated flexible tubular body has an inner surface, an outer surface, and an opening extending from its proximal end to its distal end, wherein the proximal end of the tubular body includes a valve and a fluid inlet port configured for sealably introducing an intracardiac echocardiography probe, and the distal end of the tubular body includes a closed tip and a fluid outlet port, wherein the fluid outlet port is fluidly connected to at least one compliant balloon attached to the outer surface of the tubular body, and wherein the at least one balloon covers the imaging area of ​​the tubular body;

[0118] An arrangement of a structure extending away from the inner surface of the tubular body and into the orifice, wherein an exposed probe guiding surface on the structure forms a lumen with a diameter less than about 15 Fr (5 mm), the lumen extending from the proximal end to the distal end of the tubular body and configured to slidably and rotatably receive the probe; and

[0119] An arrangement of elongated fluid channels between the structures, wherein the fluid channels are in fluid communication with the lumen and transport fluid between the fluid inlet port and the fluid outlet port;

[0120] The balloon catheter is linearly translated and rotated to a selected area of ​​the esophageal wall tissue; and

[0121] Fluid is inserted into the fluid inlet port, allowing the fluid to enter the fluid channel and the lumen and flow out from the fluid outlet port, thereby fully inflating the balloon in the imaging region to form a conformal interface with the selected region.

[0122] Implementation scheme MM. According to the method described in implementation scheme LL, the balloon catheter is inserted into the nasogastric feeding area and then into the esophageal area.

[0123] Implementation scheme NN. According to the method of implementation scheme LL or MM, the method further includes inserting an intracardiac echocardiography probe into the lumen of the catheter to establish an acoustic window between a transducer on the probe and a selected target tissue to be imaged by the probe.

[0124] Implementation scheme OO. According to the method described in implementation scheme NN, the probe is inserted into the lumen of the catheter and then the catheter is inserted into the nasogastric feeding area.

[0125] Implementation scheme PP. According to the method described in implementation scheme NN, the probe is inserted into the lumen of the catheter after the catheter is positioned in a selected area of ​​the esophageal wall tissue.

[0126] Implementation scheme QQ. The method according to any one of implementation schemes LL to PP, wherein the target tissue is cardiac tissue, vascular tissue or retrosternal tissue.

[0127] Implementation scheme RR. The method according to any one of implementation schemes LL to QQ, wherein the closed end of the tubular body includes a non-invasive tip with a tapered expansion profile.

[0128] Implementation Scheme SS. The method according to any one of Implementation Schemes LL to RR, wherein the fluid is ultrasonically transparent.

[0129] Implementation scheme TT. The method according to any one of implementation schemes LL to SS, the method further includes delivering an implantable medical device to a selected target tissue.

[0130] Various embodiments of the invention have been described. These and other embodiments are within the scope of the following claims.

Claims

1. A transnasal transesophageal balloon catheter comprising: an elongate flexible tubular body having an inner surface, an outer surface, and a bore extending from a proximal end to a distal end thereof, wherein the proximal end of the tubular body includes a valve for introducing an ultrasound probe and a fluid inlet port, and the distal end of the tubular body includes a closed tip and a fluid outlet port; at least one balloon attached to the outer surface of the tubular body proximate the closed tip and fluidly connected with the fluid outlet port, the at least one balloon covering an imaging region of the tubular body, the at least one balloon extending around a portion of a circumference of the outer surface of the tubular body such that the at least one balloon when inflated is capable of filling a first esophageal region to provide a substantially air-free path between a transducer on the ultrasound probe and a target tissue region to be imaged with the ultrasound probe, and the portion of the circumference is less than the entire circumference such that the at least one balloon when inflated is capable of leaving a second esophageal region unobstructed for saliva to pass through; an arrangement of structures extending away from the inner surface of the tubular body and into the bore, wherein exposed probe guide surfaces on the structures form a lumen less than 15 French in diameter extending from the proximal end to the distal end of the tubular body and configured to slidably and rotatably receive the ultrasound probe; and an arrangement of elongate fluid channels interspersed with the structures, wherein the fluid channels are in fluid communication with the lumen and transport fluid between the fluid inlet port and the fluid outlet port to at least partially inflate or deflate the at least one balloon, the lumen is configured to accept an intracardiac echocardiogram probe.

2. The catheter of claim 1, wherein the lumen has a diameter less than 12 French.

3. The catheter of claim 1 or 2, wherein the structures have a trapezoidal cross-sectional shape, and the fluid channels have a hemispherical cross-sectional shape when viewed down the bore of the tubular body along a longitudinal axis thereof.

4. The catheter of claim 3, wherein the probe guide surfaces are substantially flat or concave.

5. The catheter of claim 1 or 2, wherein the structures have a rectangular cross-sectional shape, and the fluid channels have a trapezoidal cross-sectional shape when viewed down the bore of the tubular body along a longitudinal axis thereof.

6. The catheter of claim 5, wherein the probe guide surfaces on the structures are concave.

7. The catheter of any of claims 1, 2, 4, 6, wherein the lumen and the fluid channels form a fluid transport network within the catheter body such that the ultrasound probe is not in contact with bodily fluids during an imaging procedure.

8. The catheter of claim 3, wherein the lumen and the fluid channels form a fluid transport network within the catheter body such that the ultrasound probe is not in contact with bodily fluids during an imaging procedure.

9. The catheter of claim 5, wherein the lumen and the fluid passageway form a fluid transport network within the catheter body such that the ultrasound probe is not in contact with bodily fluids during an imaging procedure.

10. The catheter of claim 1 or 2, wherein the catheter comprises a plurality of balloons.

11. The catheter of claim 1 or 2, wherein at least one of the tubular body and the balloons comprises an ultrasound enhancing structure.

12. A system comprising: a balloon catheter comprising: an elongate flexible tubular body having an inner surface, an outer surface, and an open bore extending from a proximal end to a distal end thereof, wherein the proximal end of the tubular body comprises a valve configured to sealingly accept an ultrasound probe and a fluid inlet port, and the distal end of the tubular body comprises a closed tip and a fluid outlet port; at least one balloon attached to the outer surface of the tubular body proximate the closed tip and fluidly connected with the fluid outlet port, the at least one balloon covering an imaging region of the tubular body, the at least one balloon extending around a portion of a circumference of the outer surface of the tubular body such that the at least one balloon, when inflated, is capable of filling a first esophageal region to provide a substantially air-free path between a transducer on the ultrasound probe and a target tissue region to be imaged with the ultrasound probe, and the portion of the circumference is less than the entire circumference such that the at least one balloon, when inflated, is capable of leaving a second esophageal region unobstructed for saliva to pass through; an arrangement of structures extending away from the inner surface of the tubular body and into the bore, wherein exposed probe guide surfaces on the structures form a lumen having a diameter of less than 15 French that extends from the proximal end to the distal end of the tubular body and is configured to slidably receive the ultrasound probe; and an arrangement of elongate fluid passageways between the structures, wherein the fluid passageways are in fluid communication with the lumen and transport fluid between the fluid inlet port and the fluid outlet port to at least partially inflate or deflate the at least one balloon in the imaging region; and an intracardiac echocardiogram probe located in the lumen, wherein the probe is capable of linear translation and rotation in the lumen.

13. The system of claim 12, wherein the balloon is capable of being sufficiently inflated in the imaging region to form a conformal interface with a selected region of esophageal wall tissue and to provide a substantially air-free path between a transducer on the probe and a target region of tissue to be imaged with the probe.

14. The system of claim 12 or 13, further comprising a controller to provide at least one of linear translation and rotation of the probe in the lumen.

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