WO2025265090A1 - Steerable balloons - Google Patents

Abstract

An endoscope includes a balloon arranged at a distal end of the endoscope, wherein the balloon is configured to be inflated by a fluid, an imaging system arranged to obtain an image through at least a portion of the balloon; and a working channel extending along a length of the endoscope, wherein the working channel is configured to receive an interventional tool and a bending angle of the balloon is adjustable based on a volume of the fluid in the balloon. Maneuvering the endoscope includes inserting the endoscope into a human subject, and while the endoscope is inside the human subject, adjusting a volume of the fluid in the balloon, wherein the adjustment of the volume of the fluid causes a bending angle of the balloon to change.

Description

STEERABLE BALLOONS

CLAIM OF PRIORITY

[0001] This application claims the benefit of U.S. Provisional Patent Application Serial No. 63/663,002, filed on June 21, 2024. The entire contents of the foregoing application are hereby incorporated by reference.

STATEMENT OF GOVERNMENT SUPPORT

[0002] This invention was made with government support under Grant Nos. R01HL124020 and T32HL007572, awarded by the National Institutes of Health (NIH). The government has certain rights in the invention.

TECHNICAL FIELD

[0003] This disclosure relates to devices and method for surgical imaging and tool navigation, such as during an intracardiac procedure.

BACKGROUND

[0004] Cardioscopes use an optically clear distal cap or optical window encapsulating an imaging element. When the window is not in contact with the anatomy, the image is entirely red. However, when pressed in contact with tissue, the window displaces the blood and enables direct visualization of the contacted region. Cardioscopic imaging can decrease procedures times and can allow automation of procedures, reducing X-ray exposure times and simplifying procedures.

SUMMARY

[0005] This disclosure is based, at least in part, on the discovery⁷ that surgical procedures, such as intracardiac procedures, can be guided by an instrument (e.g.. endoscope) with steerable balloons (e.g., cardioscopic balloons) that can be inserted percutaneously in a deflated state to pass through the vasculature and subsequently inflated inside the blood-filled heart to provide direct visualization of tissue such as cardiac tissue. The instrument introduces a flexural degree of freedom corresponding to an inflation level of the balloon to steer the working channel, which enables reliable tool positioning. Once the instrument is positioned, interventional procedures within the beating heart can be carried out under image guidance, and the result of the procedure can be visualized in vivo and in real time. The instrument can include a working channel configured to receive an interventional tool. Imaging at the surgical site (e.g.. within the heart) before, during, and after procedure provides for image-guided positioning of tools (e.g., cutting tools). The tunable balloon molding method enables balloons to be designed for a range of intracardiac tasks. For example, a balloon can be designed to meet target metric parameters for steering a cutting tool to bum a hole through the base of aortic leaflets to enable simpler transcatheter leaflet laceration.

[0006] In a first general aspect, an endoscope includes a balloon arranged at a distal end of the endoscope, wherein the balloon is configured to be inflated by a fluid, an imaging system arranged to obtain an image through at least a portion of the balloon, and a working channel extending along a length of the endoscope, wherein the working channel is configured to receive an interventional tool, and wherein a bending angle of the balloon is adjustable based on a volume of the fluid in the balloon.

[0007] Implementations of the first general aspect can include one or more of the follow features.

[0008] A first wall portion of the balloon has a first thickness, a second wall portion of the balloon has a second thickness, the second thickness different from the first thickness, and the first wall portion is opposite the second wall portion along a diameter of the balloon. [0009] The first thickness is greater than the second thickness and the balloon is configured to bend toward the first wall portion as the volume of the fluid in the balloon increases.

[0010] The first thickness is at least 0.03 mm greater than the second thickness.

[0011] A third wall portion of the balloon has a third thickness that is less than the first thickness and the second thickness, wherein the third wall portion is at a distal end of the balloon and in a field of view of the imaging system.

[0012] The third wall portion of the balloon has the third thickness, a fourth wall portion of the balloon has a fourth thickness, wherein the third wall portion is opposite the fourth wall portion along a diameter of the balloon, wherein a difference between the third thickness and the fourth thickness is less than a difference between the second thickness and the fourth thickness, and wherein the third wall portion and fourth wall portion are more distal than the first wall portion and the second wall portion.

[0013] An uninflated outer diameter of the balloon is less than 6 mm, and wherein the balloon is expandable to have a diameter greater than 8 mm. [0014] The first general aspect includes one or more clips that attach the imaging system to the working channel.

[0015] The bending angle of the balloon is adjustable over a range of at least 30° based on the volume of the fluid in the balloon.

[0016] A diameter of a distal face of the balloon changes by less than 20% as the bending angle adjusts over the range of at least 30° based on the volume of the fluid in the balloon. [0017] The imaging system is disposed in an interior of the balloon.

[0018] The first general aspect includes a steerable sheath, wherein the balloon is arranged at a distal end of the steerable sheath.

[0019] The balloon is rotatable with respect to the steerable sheath.

[0020] In a second general aspect, an endoscope system includes the endoscope of the first general aspect and a control feedback system configured to obtain an image captured by the imaging system and adjust the volume of the fluid in the balloon based on the image.

[0021] Implementations of the second general aspect can include one or more of the follow features.

[0022] The control feedback system is configured to identify a predetermined feature in the image and adjust the volume of the fluid in the balloon based on identification of the predetermined feature.

[0023] The control feedback system is configured to adjust the volume of the fluid to achieve a target bending angle of the balloon.

[0024] In a third general aspect, maneuvering an endoscope includes inserting the endoscope into a human subject, and while the endoscope is inside the human subject, adjusting a volume of the fluid in the balloon, wherein the adjustment of the volume of the fluid causes a bending angle of the balloon to change. The endoscope includes a balloon arranged at a distal end of the endoscope, wherein the balloon is configured to be inflated by a fluid, an imaging system arranged to obtain an image through at least a portion of the balloon, and a working channel extending along a length of the endoscope, wherein the working channel is configured to receive an interventional tool.

[0025] Implementations of the third general aspect can include one or more of the follow features.

[0026] The third general aspect can include capturing the image using the imaging system, identifying a predetennined feature in the image, and adjusting the volume of the fluid in the balloon based on the identification of the predetermined feature. [0027] Adjusting the volume of the fluid can include adjusting the volume of the fluid to achieve a target bending angle of the balloon.

[0028] The third general aspect can include providing the interventional tool through the working channel and performing an interventional procedure on the human subject using the interventional tool.

[0029] The details of one or more examples of the subject matter of this disclosure are set forth in the accompanying drawings and the description. Other features, aspects, and advantages of the subject matter will become apparent from the description, the drawings, and the claims.

BRIEF DESCRIPTION OF DRAWINGS

[0030] FIG. 1 is a schematic diagram of the interior of a heart illustrating placement of one of the endoscopes described herein.

[0031] FIGS. 2A, 2B, and 2C are schematic diagrams of an example balloon for an endoscope.

[0032] FIGS. 3A, 3B, and 3C are schematic diagrams illustrating a balloon molding process.

[0033] FIG. 3D is a schematic diagram of an example assembly of an endoscope.

[0034] FIG. 3E is a schematic diagram of an example balloon for an endoscope.

[0035] FIG. 3F is a schematic diagram illustrating a balloon blow molding process.

[0036] FIG. 3G is a schematic diagram illustrating a cross-sectional view of an example of an asymmetric tube.

[0037] FIG. 4 is a schematic diagram illustrating an example of balloon endoscope control.

[0038] FIG. 5 is a flow chart of an example method of maneuvering an endoscope.

[0039] FIG. 6A is a plot showing the optical face diameter and bending angle as a function of balloon inflation volume.

[0040] FIG. 6B is a plot showing the optical face diameter and bending angle as a function of balloon inflation volume, with and without tool insertion.

[0041] FIG. 7 is a schematic diagram illustrating an example of a computer system.

DETAILED DESCRIPTION

[0042] Cardiac endoscopy presents challenges relating to the limited open volume in the vasculature. To provide an endoscope having an imaging system into the heart, the endoscope should preferably be small to limit interference with cardiac function. However, once the endoscope is in the heart, the optical window of the endoscope should preferably be large, so that a wide field of view can be captured (e.g., a field of view substantially limited to an area of contact between the optical window and tissue). As such, inflatable balloons that include optical windows have been proposed for inclusion in endoscopes.

[0043] In addition, cardiac imaging and interventions may benefit from steerability at or very close to the endoscope tip. Conventional steering mechanisms may overly complicate the structure of the endoscope and/or may fail to provide the fine, targeted steering that is desired.

[0044] Some implementations according to the present disclosure provide endoscopes having balloons that are bendable through their inflation. For example, a bending angle of a balloon (where the balloon is or includes an optical window for imaging) can be a function of a volume of an inflating fluid in the balloon.

[0045] As such, the inflation level of the balloon can be controlled to precisely steer the end of the endoscope and image and/or operate on targeted areas of tissue.

[0046] For example, leaflet laceration typically involves cutting a leaflet down its middle before a transcatheter aortic valve replacement to prevent coronary obstruction. The bioprosthetic or native aortic scallop intentional laceration (BASILICA) procedure is one method for this, using catheters to guide an electrosurgical wire to the base of a coronary leaflet. The wire bums a hole through the leaflet, then forms a loop to cut the leaflet by pulling it out through the aorta. However, heavily calcified leaflets can make the initial step difficult, as electrosurgical tools struggle to penetrate calcified tissue.

[0047] Referring to FIG. 1, an endoscope 100 including a balloon 102 can be delivered through the femoral artery to an aortic valve of an aorta 104. Based on the balloon characteristics described herein, the balloon 102 can be steered directly into contact with the leaflet 106 to image calcified and non-calcified tissue and subsequently position a tool 108 that extends through the balloon 102 to avoid calcified regions. The tool 108 can bum through the targeted non-calcified tissue, enabling laceration of an aortic valve leaflet. The precise positioning of the tool 108, facilitated by the inflation-based bending of the balloon 102, allows for removal of the non-calcified tissues, improving the traversal step of the procedure.

[0048] It will be understood that in some implementations, the tool 108 is not included. For example, some endoscopes according to the present disclosure lack a tool channel extending through the balloon (e.g., are, or are operated as, imaging-only endoscopes). Endoscope Components

[0049] FIGS. 2A-2C illustrate an example of an endoscope 201 that can be used for procedures including, but not limited to, cardiac interventions. For example, the endoscope 201 can be used as described for the endoscope 100 of FIG. 1. FIG. 2A illustrates the outer balloon structure of the endoscope 201. FIG. 2B illustrates inner components of the endoscope 201. FIG. 2C illustrates bending of a balloon 200 of the endoscope 201.

[0050] Referring to FIG. 2A, a balloon 200 is arranged at a distal end of the endoscope 201. The balloon 200 is a hollow, inflatable (e.g., flexible) member formed of a transparent, compliant, biocompatible material, such as a polymer (e.g., silicone, silicone rubber, castable resins such as acrylic resins or polyurethanes, elastomer, or another polymer), or another transparent, compliant material. The transparency of the balloon 200 allows for imaging through the balloon 200, using the balloon 200 as an optical window. As a specific example, the balloon 200 can be formed of an optically clear silicone.

[0051] The balloon 200 is configured to be inflated by a fluid. The fluid can be biocompatible. A suitable example of the fluid is saline. A compliance of the transparent material is such that the transparent material is configured to confirm with irregular surfaces of tissue pressed against the transparent material. “Transparent” here need not refer to absolute transparency. For example, the transparency can be sufficient to permit imaging through at least a portion of the balloon 200. Moreover, in some implementations, only a portion of the balloon 200 (e.g., a portion within a field of view of an imaging system) is transparent.

[0052] The balloon 102, such as the balloon 200, can have one or more sets of opposing wall portions (e.g., wall portions opposite along a cross-section or diameter of the balloon) with different wall thicknesses, such that the balloon bends controllably when inflated. For example, the thicknesses can be different by at least 0.02 mm, at least 0.03 mm, or at least 0.05 mm. Other thickness differences are also within the scope of this disclosure.

[0053] In the example of FIG. 2A, balloon 200 includes a first section 202, a second section, 204, a third section 206. and a fourth section 208. described in more detail below. The first section 202 is arranged near a proximal end of the balloon and the fourth section 208 is arranged near a distal end of the balloon. It will be understood that the number of sections, their ordering, and their characteristics are provided as an example, and that the scope of this disclosure is not limited thereto. [0054] The first section 202 of the balloon 200 has a first wall portion 209 that has a first thickness The second section 204 of the balloon 200 has a second wall portion 210 that has a second thickness t₂ an d a third wall portion 212 that has a third thickness t₃. The third section 206 of the balloon 200 has a fourth wall portion 214 that has a fourth thickness t₄. The fourth section 208 of the balloon 200 has a fifth wall portion 216 that has a fifth thickness t₅ and a sixth wall portion 218 that has a sixth thickness t₆. Although, in this example, the second wall portion 210 is illustrated as extending in both the second and third sections 204, 206, the balloon is not limited to this configuration. For example, separate sections may (though need not) have distinct wall portions having distinct thicknesses.

[0055] In some implementations, the third thickness t₃ is greater than the second thickness t₂ and the fourth thickness t₄. In some implementations, the second thickness t₂ and the fourth thickness t₄ are equal. In some implementations, the second thickness t₂ and the fourth thickness t₄ are greater than the sixth thickness t₆. In some implementations, the sixth thickness t₆ is greater than the fifth thickness t₅. In some implementations, the fifth thickness t₅ is greater than the first thickness t₁₃ which is the thinnest. In some implementations, the third thickness t₃ is the thickest.

[0056] In the example of FIG. 2A, the first section 202 can be used to bond the balloon 200 to a shaft and may have negligible influence on the bending or inflation of the balloon 200. The first thickness t_r can be small (e.g., less than one, some, or all more-distal wall thicknesses discussed below) to avoid adding unnecessary thickness to the overall assembly. [0057] The fifth thickness t₅ and/or the sixth thickness t₆ can be less than the second thickness t₂ and/or the third thickness t₃ to allow the fourth section 208 to open and expand first before the balloon 200 experiences a large degree of bending in the second section 204. This helps to avoid a dead zone in the center of the workspace (e.g., not being able to inflate the cardioscope while remaining straight). When the fifth thickness t₅ and/or the sixth thickness t₆ is less than the second thickness t₂ and/or the third thickness t₃, it causes more strain in the fourth section 208 for the same input stress (e.g., volume input, creating internal pressure) than in the thicker sections, causing the fourth section 208 to expand first. The fifth thickness t₅ and/or the sixth thickness t₆ can be thicknesses at a distal tip or distal end of the balloon 200, e.g., in a field of view of a camera of the imaging system 228.

[0058] The third section 206 serves as a buffer region between the fourth section 208 and the second section 204 section, so that, as the fourth section 208 expands and the balloon material stretches thinner across its length, the bending from the second section 204 is sequentially delayed. In some implementations, a difference in opposite wall thicknesses in the third section 206 (e.g., between t₂ and t₄) is less than a difference in opposite wall thickness in the second section 204 (e.g., between t₂ and t₃), helping the third section 206 sen e this buffer function.

[0059] The second wall portion 210 with the second thickness t₂ is opposite the third wall portion 212 with the third thickness t₃ along a diameter of the balloon 200. The asymmetric thickness of the second wall portion 210 and the third wall portion 212 of the balloon 200 causes the balloon 200 to bend when inflated. In some implementations, the second thickness t₂ is less than the third thickness t₃. This thickness difference can cause the balloon 200 to bend toward the third wall portion 212 (downward) as the volume of the fluid in the balloon 200 increases. For example, a thinner wall may stretch more under inflation, and a thicker wall may stretch less under inflation, resulting in bending towards the thicker wall. Accordingly, a bending angle (a) of the balloon 200 is adjustable based on a volume of the fluid in the balloon 200. A greater difference in wall thickness can provide a greater degree of bending.

[0060] In some implementations, the first thickness t_r is in a range from 0. 1 mm to 0.4 mm. In some implementations, the second thickness t₂ is at least 0.02 mm less than the third thickness t₃, at least 0.03 mm less than the third thickness t₃, or at least 0.05 mm less than the third thickness t₃. In some implementations, the second thickness t₂ is in a range from 0.7 mm to 1.0 mm. In some implementations, the third thickness t₃ is in a range from 0.8 mm to 1.1 mm. In some implementations, the first wall portion 209 has a longitudinal length Z₄ of at least 2 mm, at least 3 mm. at least 5 mm, or at least 8 mm. In some implementations, a length h of the second wall portion 210 opposite the third wall portion 212 (e.g., a length of the second section 204) is at least 2 mm, at least 3 mm, at least 5 mm, at least 8 mm, or at least 10 mm. In some implementations, a length h of the second wall portion 210 opposite the fourth wall portion 206 (e.g., a length of the third section 206) has a length of at least 2 mm, at least 3 mm, or at least 5 mm. In some implementations, the length of the third section 206 is less than the length of the second section 204.

[0061] The fifth wall portion 216 is opposite the sixth wall portion 218 along a diameter of the balloon 200. In some implementations, the fifth wall portion 216 and the sixth wall portion have longitudinal lengths h of at least 0.5 mm or at least 1 mm. In some implementations, a difference between the fourth thickness t₄ and the fifth thickness t₅ is less than a difference between the third thickness t₃ and the fifth thickness t₅. In some implementations, the fifth thickness t₅ is at least 0. 15 mm less than the fourth thickness t₄. In some implementations, the fifth thickness t₅ is at least 0. 15 mm less than the sixth thickness t₆. In some implementations, the fourth thickness t₄ is in a range from 0.7 mm to 1.0 mm. In some implementations, the fifth thickness t₅ is in a range from 0.4 mm to 0.8 mm. In some implementations, the sixth thickness t₆ is in a range from 0.65 mm to 1.05 mm. It will be understood that these and other specific lengths and length ranges described herein are provided as examples, and that other lengths and length ranges are within the scope of this disclosure.

[0062] In some implementations, the fourth wall portion 214 and the fifth wall portion 216 are more distal than the second wall portion 210 and the third wall portion 212. An uninflated inner diameter 220 of the balloon 200 can be less than 6 mm. In some implementations, the balloon 200 is expandable to have a diameter greater than 8 mm. In some implementations, a distal neck inner diameter 222 is in a range from 0.2 mm to 3 mm. [0063] In some implementations, such as in the example of FIG. 2B, the endoscope 201 includes the sheath 226, where the balloon 200 is arranged at a distal end of the sheath 226. The sheath 226 can be formed of a polymer tube (e.g., Pebax 5533). The sheath 226 can include, for example, a shaft having at least one lumen extending longitudinally through the shaft. For example, the balloon 200 can be attached to a second shaft that extends through a lumen of the sheath, such that the balloon 200 or a distal portion of the second shaft protrudes from the distal end of the sheath 226. The sheath 226 can be bendable/ steerable using any one or more suitable mechanisms, e.g., a pull wire mechanism, a motorized actuator, and/or the like. In some implementations, the sheath 226 is configured to rotate independent of the volume of fluid in the balloon 200, e.g., independent of bending of the balloon 200. In some implementations, a sheath approach angle 240 (shown in FIG. 2C below) is independent of the bending angle of the balloon 200.

[0064] The endoscope 201 includes an imaging system 228 arranged to obtain an image through at least a portion of the balloon 200 and a working channel 230 extending along a length of the endoscope, where the working channel 230 is configured to receive an interventional tool. In some implementations, the working channel 230 is defined by a tube extending through the balloon 200, e.g., a transparent silicone tube with a 1 mm inner diameter and a 0.5 mm wall thickness. A fluid-tight seal (e.g., a glued seal) can be provided between the balloon 200 and the working channel 230. For example, the balloon 200 can be inverted into the working channel 230 and glued to the working channel 230. In some implementations, the imaging system 228 is disposed in an interior of the balloon 200. In some implementations, the working channel is not present in the endoscope 201.

[0065] If the working channel is present in the endoscope 201, in addition to asymmetric wall thicknesses of the balloon 200, the position and physical properties of the working channel 230 (e.g., material of the working channel, thickness of the working channel) contribute to the degree of bending. For example, placing the working channel 230 near one side of the balloon 200, in proximity to a wall portion, is comparable to increasing the thickness of the wall portion, in terms of the effect of the working channel 230 on bending. The axial stiffness of the working channel 230 resists elongation, causing the balloon 200 to bend in the direction of the working channel 230.

[0066] The endoscope 201 can include one or more clips 232 that attach the imaging system 228 to the working channel 230. The one or more clips 232 can be additively manufactured. In some cases, the one or more clips 232 include one or more straight clips, one or more angled clips, or a combination thereof. In some implementations, the imaging system 228 includes a camera 234 (e.g., Myriad Fiber Imaging). A diameter of the camera can be 1 mm, and the camera can have a 400x400 pixel resolution, though the camera configuration is not limited thereto. The imaging system 228 can include an illumination device 236. A suitable example of the illumination device 236 includes a circumferential light emitting diode. In some implementations, the imaging system 228 includes at least one of the camera 234 or the illumination device 236 in a tube, where the tube is retractable within the balloon 200. The one or more clips 232 attach the imaging system 228 to the working channel at an angle 238. The one or more clips 232 allow for the imaging system to follow the tip deflection of the working channel, which itself follows the bending and rotation of the balloon 200. Accordingly, adjustment of the bending/positioning of the balloon 200 also adjusts the field of view of the imaging system 228.

[0067] In some implementations, a distance between the one or more clips 232 is at least 1 mm. For example, the distance between the one or more clips 232 is in a range from 3 mm to 6 mm. Other distances between the one or more clips 232 are within the scope of this disclosure. In some implementations, a distance between the one or more clips 232 and the distal end of the endoscope 201 is at least 1 mm. For example, the distance between the one or more clips 232 and the distal end is in a range from 2 mm to 5 mm. Other distances between the one or more clips 232 and the distal end are within the scope of this disclosure. As shown in FIG. 2B, the spacing between the one or more clips 232 and the view angle P allow the imaging system 228 to point toward the distal end of the balloon 200. The view angle p can be any suitable angle. In some implementations, the view angle is in a range between 5° and 30° (e.g., 6°, 9°, or 15°). Other view angle p ranges are within the scope of this disclosure.

[0068] The one or more clips 232 connect the imaging system 228 to the working channel 230, allowing a camera of the imaging system 228 to move along with the working channel 230 (e.g., with the fourth section 208) as it bends. An angled clip of the one or more clips 232 can center the camera view on the center of the distal end of the balloon 200. A straight clip of the one or more clips 232 can align the camera for insertion into the angled clip. The one or more clips 232 help prevent the imaging system 228 from sliding out of the clips as the balloon 200 bends.

[0069] Referring to FIG. 2C, in some implementations, the balloon 200 is rotatable with a rotation angle 0. For example, the balloon 200 can be rotatable with respect to the steerable sheath 226. For example, a shaft to which the balloon is attached (where the shaft extends through a lumen of the steerable sheath 226) can be rotatable within the steerable sheath 226. This can provide an additional degree of freedom for steering of the balloon 200, aiding in precise positioning. Rotation can be performed using any suitable mechanism, e.g., a mechanism of the drive system. For example, a motorized rotating actuator of the drive system can be attached (directly or indirectly) to the balloon 200 to rotate the balloon. As another example, the balloon 200 can be attached (directly or indirectly) to a manually- rotatable handle.

[0070] FIG. 2C illustrates three positional states of the balloon 200. In a first state (250a), a bending angle a of the balloon 200 is approximately zero. The bending angle a is an angle of a distal end with respect to a longitudinal axis 252 of a portion of the endoscope 201 immediately proximal to the balloon 200 or an exposed portion of the balloon 200 (e.g., a distal portion of the steerable sheath 226). In a second state (250b), the bending angle a is larger than in the first state, e.g., about 90°. The second state can correspond to a higher level of inflation (higher volume of fluid in the balloon 200) than the first state. In a third state (250c), the bending angle a is the same as in the second state, but the rotation angle 0 of the balloon 200 has been rotated about 180°, such that the balloon 200 points in an opposite direction to the second state. Accordingly, by appropriate adjustment of the rotation angle 0 and the bending angle a. the balloon positioning can be adjusted in an arbitrary direction. [0071] In some implementations, the bending angle a of the balloon 200 is adjustable over a range of at least 5°, at least 10°. at least 15°, at least 20°, at least 30°, at least 45°, at least 60°, at least 75°, or at least 90° based on a volume of the fluid in the balloon 200. Other suitable bending angles are within the scope of this disclosure. In some cases, a diameter of a distal face of the balloon 200 changes by less than 20 % as the bending angle adjusts over a range of at least 45° based on the volume of fluid in the balloon 200.

[0072] In some implementations, infusion/withdrawal of 3mL of fluid can steer the balloon 200 over a bending angle of 80°. This can correspond to steering of the balloon 200 by 60° in less than 1 second.

Endoscope Fabrication

[0073] A schematic diagram depicting an example of manufacture of a balloon (e.g.. balloon 200) is shown in FIGS. 3A-3C. Referring to FIG. 3A, additively manufactured (e.g., 3D printing) mold components are used to manufacture the balloon. The mold components include a mold bottom 302, a mold top 304, a pin 306, and end caps 308. The mold bottom 302, the mold top 304, and end caps 308 are combined to align the pin 306 within the mold bottom 302 and mold top 304, thereby yielding a mold assembly 310. The mold bottom 302 and mold top 304 are mold negatives to create an exterior of the balloon, and the pin 306 creates a positive (interior) of the balloon. The mold components are configured to create a gap of varying thickness between the pin 306 and the mold bottom 302 and the mold top 304. When the mold is used to manufacture a balloon from feedstock in-between the pin 306 and the mold bottom/top 302, 304, walls of the balloon will have different thicknesses, resulting in controllable, inflation-based balloon bending as discussed above. For example, to provide the vary ing gap thickness, the pin 306 can have a varying cross section along its length.

[0074] The pin 306 is placed between the end caps 308 with the proximal end of the balloon 200 keyed by an internal feature to promote longitudinal alignment within the mold bottom 302 and mold top 304. A feedstock is mixed, degassed, and poured into the mold assembly 310 without the mold top 304. In the mold assembly 310, the end caps 308 are bolted to the mold bottom 302. The mold top 304 is placed and bolted to the mold bottom 302 and the end caps 308. The feedstock is left to cure for a length of time (e.g., four hours) at room temperature.

[0075] After curing, the pin 306 and a preform 312 are removed from the mold assembly 310, as shown in FIG. 3B. The pin 306 is removed from the preform 312. The preform 312 can include a tail 314. A working channel tube 316 is inserted into the tail 314. [0076] Referring to FIG. 3C. to assemble the endoscope 100, at least a portion of the tail 314 and the working channel tube 316 is cut off the preform 312. The remaining portion of the tail 314 is adhered to the balloon 200 at the distal end of the working channel 230 230. In some implementations, to adhere the balloon 200 to the distal end of the working channel 230, at least a portion of the tail 314 and the working channel tube 316 is cut off the preform 312 and inverted into the working channel tube 316. In some implementations, to adhere the balloon 200 to the distal end of the working channel 230, at least a portion of the tail 314 and the working channel tube 316 is cut off the preform 312 and adhered to the outside of the working channel 230. The working channel 230 is bonded to the balloon 200 with an adhesive (e.g., silicone adhesive, SilPoxy™). The one or more clips 232 are placed on the working channel 230. A distal end of the working channel tube 316 and the tail 314 is cut flush with a face of the balloon 200. The steerable sheath 226 is bonded to the balloon 200 with an adhesive (e.g., cyanoacrylate adhesive or a super glue gel) to yield the endoscope 100.

[0077] Referring to FIG. 3D, the endoscope 100 is connected to a connector 350 (hemostasis valve Y connector). The working channel 230 extends through this connector 350 and back out an additional hemostasis valve Y connector 352 (with a male luer slip and female luer lock) connecting to a fluid delivery system 354 and is sealed (e.g., by a tuohy borst connection). The imaging system 228 is inserted into the balloon 200, placed into the one or more clips 232, and proximally sealed (e.g., by a tuohy borst connection), allowing for fluid (e.g., saline) pressurization from volume infusion by the fluid deliver}' system 354. The fluid delivery system 354 is configured to convey fluid to and from the balloon 200. For example, the fluid delivery system 354 can include a controllable syringe, one or more fluid conduits, and/or the like. Saline can be chosen as fluid at least in part because it improves optical clarity through the balloon 200 and is safe if released into the bloodstream. The tool 108 can be passed through the w orking channel 230, as shown in FIG. 3E.

[0078] In some implementations, the balloon is made using blow⁷ molding. As shown in FIG. 3F, in this method, a tube 380 is placed through a hollow⁷ mold (not shown). In some implementations, the hollow mold is asymmetric. The tube 380 can be prepared from feeding a molten material (e.g., molten polymer) to an extruder and squeezing through a die head. For example, the tube 380 can be an extruded tube. The tube 380 is placed in the hollow' mold and is fdled with pressurized gas. In some implementations, the mold is continuously cooled. Pressurized gas can be blown into the tube 380 through a needle or a pin. The tube 380 can be heated (e.g., prior to placement in the mold or in the mold prior to pressurization). As such, filling the tube 380 with pressurized gas (pressurization) causes the tube 380 to expand until it conforms to the shape of the inner surface of the mold. As shown in FIG. 3G, the tube 380 can be filled with pressurized gas in an asymmetric manner. For example, a lumen 386 through which the gas is blown into the tube 380 can be positioned off-center in the tube 380. The mold is set to cool so that the expanded tube 382 can solidify into the desired shape. Once the expanded tube 382 has cooled and solidified, the mold is opened and the expanded tube 382 is removed. The expanded tube 382 typically includes a tail 384. Any excess material (e.g., a portion of tail 384) is trimmed to yield the balloon. The resulting balloon (e.g., based on the asymmetry of pressurization of the tube 380, such as based on the asymmetric location of the lumen 386) can have a first wall portion that is thicker than a second wall portion opposite the first wall portion, resulting in bending in response to inflation, as described above.

Drive System

[0079] As shown in FIG. 3D, for infusion and withdrawal of fluid, the fluid delivery system 354 can be connected to a drive system 356. The drive system 356 is configured to provide fluid into and out of the balloon 200 using/through the fluid delivery system 354. For example, the drive system 356 can include a syringe pump, a linear motorized fluid delivery system, a pneumatic system, and/or the like. The drive system 356 can have multiple additively manufactured (e.g., 3D printed) frame components holding a syringe of the fluid delivery system 354. and a linear guide rail and a threaded rod. The drive system 356 can include a motor connected to the threaded rod, and the threaded rod can be configured to that translate motor input into either incremental volume steps (e.g., incremental increases/decreases in volume of fluid in the balloon) or continuous flow. For example, a threaded nut can be connected to a plunger of the syringe, and the motor can rotate a stationary screw, causing a threaded nut to translate along the screw with respect to the syringe to push/pull fluid out of/into the syringe. Accordingly, the drive system 356 can include a motor configured to drive adjustment of the volume in the balloon. In some implementations, the fluid delivery' system 354 and drive system 356 can modify the volume in the balloon at a rate of 0 mL/s to 3mL/s. In some implementations, a step angle (e.g., 1.8°) provided by the motor can be divided into subdivisions (e.g., 32 subdivisions), allowing for high-resolution volume delivery.

Image-based Sensing

[0080] In some implementations, as shown in FIG. 3D, an endoscope system includes the endoscope 100 and a controller 360 configured to obtain an image captured by the imaging system 228 and adjust the volume of the fluid in the balloon 200 based on the image. The controller 360 can provide motor commands to the drive system 364 to adjust the volume of fluid in the balloon.

[0081] The controller 360 can be configured to identify a predetermined feature in the image and adjust the volume of the fluid in the balloon based on identification of the predetermined feature. In some implementations, the predetermined feature is the working channel 230. As another example, the predetermined feature can be, for example, a marking in and/or on the balloon 200 (e.g., on an inner surface or outer of the balloon 200). The control feedback system can be configured to adjust the volume of the fluid to achieve a target bending angle of the balloon. In some implementations, the target bending angle is a tip deflection angle.

[0082] The controller 360 can use images from the imaging system 228 to track the predetermined feature as the balloon bends and adjust the target bending angle of the balloon based on a detected position of the target feature and/or other characteristic associated with detection of the target feature. As an example of such a process, as shown in FIG. 3D, the controller 360 can control the imaging system 228 to capture an image, e.g., by sending a corresponding command to the imaging system 228. In some implementations, capture of the image is performed absent control by the controller 360, e.g., a separate device can control the imaging system 228 to capture the image. The captured image can be obtained by the controller 360. For example, the obtained image can be a raw image. A region of interest around/including the predetermined feature can be identified. The region of interest can be defined based on prior calibration.

[0083] The predefined region of interest can be brightened to increase contrast, for example, by a factor in a range from 2 to 5. Brightening the predefined region of interest aids in contrasting the pixels. A filter can be applied to remove at least some pixels based on color characteristics of the pixels. For example, a hue, saturation, value (HSV) color space can be utilized to filter and remove pixels based on color. For example, red pixels, corresponding to blood, can be detected and removed. Pixels residing outside the predefined region of interest can also be removed.

[0084] A contour region can be drawn around the predetermined feature, e.g., using any suitable object detection and/or segmentation method can be applied to identify- the predetennined feature in the image. This can allow- for the predetermined feature to be differentiated from the rest of the image. Accordingly, position(s) of the predetennined feature in the image can be obtained, and fluid control can be performed based on the position.

[0085] It will be understood that the foregoing sequence of operations is an example, and that other operations can be performed and/or one or more of the prior operations (e.g., use of the predefined region of interest, filtering, and/or brightening) can be omitted. For example, one or more suitable algorithms can determine a position of the predetermined feature without using a region of interest, without filtering, and/or without brightening.

[0086] For example, a '‘live’’ pixel ratio can be calculated by dividing the pixels of the predetermined feature by a total pixel count of the image. As the bending angle of the balloon changes, the live pixel ratio can also change as the position of the predetermined feature in captured images changes. Control of the volume of fluid in the balloon can be based on the live pixel ratio. The controller 360 can be configured to adjust the volume of fluid in the balloon to cause the live pixel ratio to match a target pixel ratio, such that the bending angle of the balloon matches the target bending angle. For example, a difference between the live pixel ratio and the target pixel ratio can be used to generate the control input for motor speed and direction for a motor of the drive system 365, which determines whether the endoscope system infuses or withdraws the fluid in the balloon, and the extent of the infusion/withdrawal.

[0087] It will be understood that other methods for controlling the volume of fluid based on detection of the predetermined feature are also within the scope of this disclosure. For example, in some implementations, the volume of fluid is adjusted to cause a “live” position of the predetermined feature in captured images to match a target position.

[0088] Accordingly, closed-loop control can be performed to provide automatic adjustment of bending angle.

[0089] In some implementations, in addition to or instead of automatic control as discussed above, the drive system 365 and/or the controller 360 can receive user input to control bending and steering of the endoscope. For example, a user can operate a knob, a slide on a handle of the endoscope, a computer mouse, a rotary knob labeled with bending angles (e.g., on a separate input device coupled to the endoscope), or a button or joystick on an input device. These inputs can be received and interpreted by the drive system 365 and/or the controller 360, w hich performs corresponding control of the endoscope based on the user inputs. The control can include, for example, adjusting a bending angle of the balloon byadjusting a volume of fluid in the balloon, adjusting a rotation angle of the balloon, and/or adjusting one or more lengths of extension and/or one or more bending angles of a steerable sheath of the endoscope (e g., to provide manual control of a pull wire of the endoscope). Instead or additionally, the endoscope can be integrated with a robotic catheter system. With the robotic catheter system, the bending angle of the balloon can be controlled with a coordinated robotic motion in which multiple degrees of freedom are simultaneously actuated to achieve a desired motion. For example, the bending angle of the balloon and one other parameter of motion of the endoscope can be simultaneously adjusted in a coordinated manner.

[0090] FIG. 4 illustrates an example of the foregoing control process. As shown in FIG. 4, an image-based sensing approach utilizing the imaging system 228 can be used to view and track the working channel position (predetermined feature) as the balloon bends. The imagebased sensing approach can enable closed-loop control and automatic compensation of tip deflections caused by various factors, e.g., tool insertion, which can cause variation in how bending angles correspond to balloon inflation level. A diagram 400 of a closed-loop control feedback diagram is shown in FIG. 4. In the closed-loop control feedback loop, given a target tip deflection angle (a_c), the controller utilizes image processing and control operations to steer the actual angle (a_a) to the target orientation.

[0091] In some implementations, the control operations include capturing a raw image 402 and applying a predefined region of interest around the working channel (based on calibration), as shown in the segmented image 404. Then, the region of interest is brightened by a factor of 3.5, as shown in the brightened image 406. Next, pixels are removed based on color (red pixels, corresponding to blood, are detected in HSV color space using hue thresholds <10 and >160, with saturation values >15), brightness (black pixels, dark background at the camera edge, are removed based on intensity defined as grayscale values <5), or for being outside the region of interest, as shown in filtered image 408. As shown in contoured image 410, a contour region is drawn around the working channel using the image in grayscale and OpenCV’s ‘ indCountours” function. In all, as shown in 412, these steps allow for the region of the image that is the working channel (PA) to be differentiated from the rest of the image (PB) and allows for the determination of the pixel ratio (P) using Equation (1): where P_Totai = 160k pixels. [0092] With the ability to determine P, for a given target tip deflection angle (a_c), a target pixel ratio (P_c) can be compared to the live actual pixel ratio (P_a) determined by the image processing algorithm. As a increases, the working channel shifts within the camera view, thus altering P, which establishes the relationship:

P = f(a) (2)

[0093] This function can be determined via calibration and is used to generate the control input (motor command) co for motor speed and direction based on 3P = P_a — P_c. This can determine whether the system infuses or withdraws saline volume (5V), and an extent of the infusion/withdrawal. c can indicate/provide a motor speed and direction in rotations per minute (rpm), or can be another suitable motor command.

[0094] Referring to FIG. 5, in an example method of maneuvering an endoscope, the endoscope is inserted into a human subject (502). The endoscope can include a balloon, an imaging system, and a working channel. The balloon can include a transparent material arranged at a distal end of the endoscope, where the balloon is configured to be inflated by a fluid. The imaging system can be arranged to obtain an image through at least a portion of the balloon. The working channel extending along a length of the endoscope can be configured to receive an interventional tool. While the endoscope is inside the human subject, a volume of the fluid in the balloon can be adjusted, where the adjustment of the volume of the fluid causes a bending angle of the balloon to change (504).

[0095] The method can include capturing the image using the imaging system, identifying a predetermined feature in the image, and adjusting the volume of the fluid in the balloon based on the identification of the predetermined feature. In some implementations, adjusting the volume of the fluid includes adjusting the volume of the fluid to achieve a target bending angle of the balloon. In some implementations, the method includes providing the interventional tool through the working channel and performing an interventional procedure on the human subject using the interventional tool.

EXAMPLES

[0096] The following describes characterization, calibration, and control methods applied to a balloon, such as the balloon 200.

Example 1 : Balloon inflation and deflection [0097] FIG. 6A depicts optical face diameter and working channel tip deflection angle as functions of inflation volume. With increasing volume, initially the balloon expanded from OmL to 0.8mL, as shown in 602 and 604, respectively. The balloon deflection occurred for higher inflation volumes up to approximately 100° at 4mL, as shown in 608, while optical face diameter leveled off over that range. The decoupling of the degrees of freedom with a single volume input is highlighted in FIG. 6A. showing that a deployed diameter of the balloon was greater than or equal to 8 mm before the bending angle (a) > 0 and that the deployed diameter of the balloon was between 8 mm and 1 1mm. Additionally, a bending angle a > 60° w as achieved in 606, reaching the targeted workspace. The decoupling can be advantageous, because it means that the balloon can be steered about a wide range of bending angles while maintaining a substantially constant optical face diameter, providing consistency in imaging across different bending angles.

[0098] FIG. 6B depicts the diameter and different deflection angles of the balloon in 610, 612, 614, and 616 with and without a tool (e.g., electrosurgical wire) inserted. The main contrast between the with tool and without tool characterization was a maximum of 13° difference in achieved angle for the same input volumes. This is due at least in part to the tool stiffening the endoscope through the working channel, meaning that, at bending angles a > 50°, the insertion and removal of a tool altered the orientation of the w orking channel from desired targets within the heart. Thus, a closed-loop control approach (as described above) satisfactorily compensated for the tool incorporation.

Example 2: Image-based Control Approach

[0099] To calibrate the image-based sensor and implement a control approach, an acrylic tank was filled with water dyed red using a water-soluble dye to simulate the balloon being in blood while still allowing external visual monitoring of ground truth positions. This ensured the image-processing algorithm would translate to operation in a beating heart. The following describes how the sensing strategy was calibrated to determine its sensitivity and resolution and implemented as a precision closed-loop control feedback sensor for the validation experiments, as described with respect to FIG. 4.

[00100] A multi-threshold bang bang control scheme was utilized for a control approach without instabilities, overshoot, or long settling times. Based on sensor calibration and initial assessments, pixel ratio thresholds for angular velocity (co = [rpm]) steps that promote smooth settling to target angles were identified, with speeds defined as: 100 if [5P] > .006 (3)

I 25 if .002 < [<5P] < .006 W ^— I 5 if .001 < [5P] < .002

I 0 if [<5P] < .001

[00101] This relationship was applied in the closed-loop control feedback process shown in FIG. 4.

[00102] At least in part because pixel ratio is directly monitored by the image-based sensing, controlling angle based on pixel ratio led to variable zone threshold widths depending on the calibration results. In validation tests, difference in volume resulted from fluid infusion or withdrawal at the set speed until the endoscope reached steady state at the target angle (within the dead zone), completing the control loop shown in FIG. 4.

Example 3, Example of a computer system

[00103] FIG. 7 is a block diagram illustrating an example of a computer system 700. In some implementations, the controller 360 is similar to, or is associated with, a computer system such as the computer system 700. The computer system 700 can be configured to perform operations described herein as being performed by the controller 360.

[00104] The computer system 700 may refer to any system including a general purpose or special purpose computing system. For example, the computer system 700 may include a microchip, a microcontroller, a personal computer, a server computer, a cloud computing system, a laptop computer, a home appliance, a tablet, a wearable device, a smart phone, and the like. As shown in FIG. 7, the computer system 700 may include at least one processor 702, a memory 704, a storage system 706. a network adapter 708, an input/output (I/O) interface 710, and/or a display 712. In some implementations, the computer system 700 (e.g., a small computer system implemented as a local controller of a circuit system as described herein) does not include the display 712 and the I/O interface 710.

[00105] The at least one processor 702 may execute a program module including computer system executable instructions. The program module may include routines, programs, objects, components, logic, data structures, and the like, performing a specific task or implementing a specific abstract data type. The memory 704 may include a computer system readable, non-transitory medium in the form of a volatile memory' such as a random access memory (RAM). The at least one processor 702 may access the memory 704 and execute instructions loaded in the memory 704. The storage system 706 may non-volatilely store information and may include at least one program product including a program module configured to perform the operations described herein for the controller.

[00106] The network adapter 708 may provide a connection to a local area network (LAN), a wide area network (WAN), and/or a public network (e.g., the Internet), etc. The I/O interface 710 may provide a communication channel with a peripheral device such as a keyboard, a pointing device, and an audio system. The display 712 may output various pieces of information so that the user may check the information.

[00107] In some implementations, operations described above with respect to the controller are implemented as or using a computer program product. The computer program product may include a non-transitory computer-readable medium (or storage medium) including computer-readable program instructions for causing the at least one processor 702 to perform the disclosed operations. Computer readable instructions may be, but are not limited to, assembler instructions, instruction set architecture (ISA) instructions, machine instructions, machine dependent instructions, microcode, firmware instructions, state setup data, or source code or object code written in at least one programming language.

[00108] The computer-readable medium may be any type of medium capable of non- transitorily holding and storing instructions executed by the at least one processor 702 or any instruction executable device. The computer-readable medium may be an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any combination thereof, but is not limited thereto. For example, the computer readable medium may be a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an electrically erasable read only memory (EEPROM), a flash memory, a static random access memory (SRAM), a compact disc (CD), a digital versatile disc (DVD), a memory stick, a floppy disk, a mechanically encoded device such as a punch card, or any combination thereof.

[00109] The foregoing description provides aspects and methods. For example, the foregoing description provides the following aspects and methods.

[00110] Aspect 1 : An endoscope including: a balloon arranged at a distal end of the endoscope, in which the balloon is configured to be inflated by a fluid; an imaging system arranged to obtain an image through at least a portion of the balloon; and a w orking channel extending along a length of the endoscope, in which the working channel is configured to receive an interventional tool, and in which a bending angle of the balloon is adjustable based on a volume of the fluid in the balloon. [00111] Aspect 2: Aspect 1, in which a first wall portion of the balloon has a first thickness, in which a second wall portion of the balloon has a second thickness, the second thickness different from the first thickness, and in which the first wall portion is opposite the second wall portion along a diameter of the balloon.

[00112] Aspect 3: Aspect 2, in which the first thickness is greater than the second thickness, and in which the balloon is configured to bend toward the first wall portion as the volume of the fluid in the balloon increases.

[001 13] Aspect 4: Aspect 2 3, in which the first thickness is at least 0.03 mm greater than the second thickness.

[00114] Aspect 5: Any one of Aspects 2 to 4, in which a third wall portion of the balloon has a third thickness that is less than the first thickness and the second thickness, in which the third wall portion is at a distal end of the balloon and in a field of view of the imaging system.

[00115] Aspect 6: Any one of Aspects 2 to 5, in which the third wall portion of the balloon has the third thickness, in which a fourth wall portion of the balloon has a fourth thickness, in which the third wall portion is opposite the fourth wall portion along a diameter of the balloon, in which a difference between the third thickness and the fourth thickness is less than a difference between the second thickness and the fourth thickness, and in which the third wall portion and fourth wall portion are more distal than the first wall portion and the second wall portion.

[00116] Aspect 7 : Any one of the foregoing Aspects, in which an uninflated outer diameter of the balloon is less than 5 mm, and in which the balloon is expandable to have a diameter greater than 8 mm.

[00117] Aspect 8: Any one of the foregoing Aspects, including one or more clips that attach the imaging system to the working channel.

[00118] Aspect 9: Any one of the foregoing Aspects, in which the bending angle of the balloon is adjustable over a range of at least 30° based on the volume of the fluid in the balloon.

[00119] Aspect 10: Any one of the foregoing Aspects, in which a diameter of a distal face of the balloon changes by less than 20% as the bending angle adjusts over the range of at least 30° based on the volume of the fluid in the balloon.

[00120] Aspect 11 : Any one of the foregoing Aspects, in which the imaging system is disposed in an interior of the balloon. [00121] Aspect 12: Any one of the foregoing Aspects, including a steerable sheath, in which the balloon is arranged at a distal end of the steerable sheath.

[00122] Aspect 13: Aspect 12, in which the balloon is rotatable with respect to the steerable sheath.

[00123] Aspect 14: An endoscope system, including: the endoscope of Aspect 1; and a controller configured to: obtain an image captured by the imaging system, and adjust the volume of the fluid in the balloon based on the image.

[00124] Aspect 15: Aspect 14, in which the controller is configured to: identify a predetermined feature in the image, and adjust the volume of the fluid in the balloon based on identification of the predetermined feature.

[00125] Aspect 16: Aspect 14 or 15, in which the controller is configured to adjust the volume of the fluid to achieve a target bending angle of the balloon.

[00126] Aspect 17: A method of maneuvering an endoscope, in which the endoscope includes: a balloon arranged at a distal end of the endoscope, in which the balloon is configured to be inflated by a fluid, an imaging system arranged to obtain an image through at least a portion of the balloon, and a working channel extending along a length of the endoscope, in which the working channel is configured to receive an interventional tool, and in which the method includes: inserting the endoscope into a human subject; and while the endoscope is inside the human subject, adjusting a volume of the fluid in the balloon, in which the adjustment of the volume of the fluid causes a bending angle of the balloon to change.

[00127] Aspect 18: Aspect 17, including: capturing the image using the imaging system; identifying a predetermined feature in the image; and adjusting the volume of the fluid in the balloon based on the identification of the predetermined feature.

[00128] Aspect 19: Aspect 17 or 18, in which adjusting the volume of the fluid includes adjusting the volume of the fluid to achieve a target bending angle of the balloon.

[00129] Aspect 20: Any one of Aspects 17 to 19, including: providing the interventional tool through the working channel; and performing an interventional procedure on the human subject using the interv entional tool.

[00130] Although this disclosure contains many specific implementation details, these should not be construed as limitations on the scope of the subject matter or on the scope of what may be claimed, but rather as descriptions of features that may be specific to particular implementation . Certain features that are described in this disclosure in the context of separate implementation can also be implemented, in combination, in a single implementation . Conversely, various features that are described in the context of a single implementation can also be implemented in multiple implementations, separately, or in any suitable sub-combination. Moreover, although previously described features may be described as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can, in some cases, be excised from the combination, and the claimed combination may be directed to a sub-combination or variation of a subcombination.

[00131 ] Particular examples of the subject matter have been described. Other examples, alterations, and permutations of the described examples are within the scope of the following claims as will be apparent to those skilled in the art. While operations are depicted in the drawings or claims in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed (some operations may be considered optional), to achieve desirable results.

[00132] Accordingly, changes, substitutions, and alterations are also possible without departing from the spirit and scope of this disclosure.

Claims

WHAT IS CLAIMED IS:

1. An endoscope comprising: a balloon arranged at a distal end of the endoscope, wherein the balloon is configured to be inflated by a fluid; an imaging system arranged to obtain an image through at least a portion of the balloon; and a working channel extending along a length of the endoscope, wherein the working channel is configured to receive an interventional tool, and wherein a bending angle of the balloon is adjustable based on a volume of the fluid in the balloon.

2. The endoscope of claim 1, wherein a first wall portion of the balloon has a first thickness, wherein a second wall portion of the balloon has a second thickness, the second thickness different from the first thickness, and wherein the first wall portion is opposite the second wall portion along a diameter of the balloon.

3. The endoscope of claim 2, wherein the first thickness is greater than the second thickness, and wherein the balloon is configured to bend toward the first wall portion as the volume of the fluid in the balloon increases.

4. The endoscope of claim 2, wherein the first thickness is at least 0.03 mm greater than the second thickness.

5. The endoscope of claim 2, wherein a third wall portion of the balloon has a third thickness that is less than the first thickness and the second thickness. wherein the third wall portion is at a distal end of the balloon and in a field of view of the imaging system.

6. The endoscope of claim 5, wherein the third wall portion of the balloon has the third thickness, wherein a fourth wall portion of the balloon has a fourth thickness, wherein the third wall portion is opposite the fourth wall portion along a diameter of the balloon, wherein a difference between the third thickness and the fourth thickness is less than a difference between the second thickness and the fourth thickness, and wherein the third wall portion and fourth wall portion are more distal than the first wall portion and the second wall portion.

7. The endoscope of claim 1, wherein an uninflated outer diameter of the balloon is less than 6 mm, and wherein the balloon is expandable to have a diameter greater than 8 mm.

8. The endoscope of claim 1, comprising one or more clips that attach the imaging system to the working channel.

9. The endoscope of claim 1, wherein the bending angle of the balloon is adjustable over a range of at least 30° based on the volume of the fluid in the balloon.

10. The endoscope of claim 9, wherein a diameter of a distal face of the balloon changes by less than 20% as the bending angle adjusts over the range of at least 30° based on the volume of the fluid in the balloon.

11. The endoscope of claim 1, wherein the imaging system is disposed in an interior of the balloon.

12. The endoscope of claim 1 comprising a steerable sheath, wherein the balloon is arranged at a distal end of the steerable sheath.

13. The endoscope of claim 12, wherein the balloon is rotatable with respect to the steerable sheath.

14. An endoscope system, comprising: the endoscope of claim 1 ; and a controller configured to: obtain an image captured by the imaging system, and adjust the volume of the fluid in the balloon based on the image.

15. The endoscope system of claim 14, wherein the controller is configured to: identify a predetermined feature in the image, and adjust the volume of the fluid in the balloon based on identification of the predetermined feature.

16. The endoscope system of claim 15, wherein the controller is configured to adjust the volume of the fluid to achieve a target bending angle of the balloon.

17. A method of maneuvering an endoscope, wherein the endoscope comprises: a balloon arranged at a distal end of the endoscope, wherein the balloon is configured to be inflated by a fluid, an imaging system arranged to obtain an image through at least a portion of the balloon, and a working channel extending along a length of the endoscope, wherein the working channel is configured to receive an interventional tool, and wherein the method comprises: inserting the endoscope into a human subject; and while the endoscope is inside the human subject, adjusting a volume of the fluid in the balloon, wherein the adjustment of the volume of the fluid causes a bending angle of the balloon to change.

18. The method of claim 17, comprising: capturing the image using the imaging system; identifying a predetermined feature in the image; and adjusting the volume of the fluid in the balloon based on the identification of the predetermined feature.

19. The method of claim 17, wherein adjusting the volume of the fluid comprises adjusting the volume of the fluid to achieve a target bending angle of the balloon.

20. The method of claim 18, comprising: providing the interventional tool through the working channel; and performing an interventional procedure on the human subject using the interventional tool.