Overtube devices and assemblies for elongated surgical tools

Abstract

An overtube assembly is provided. The overtube assembly includes a primary tubular body defining a primary lumen configured to receive a first elongated medical device, and a secondary lumen extending along the primary tubular body, configured to receive a second elongated medical device. The primary tubular body has a length extending from a proximal end oriented to receive the first elongated medical device to a distal end. The secondary lumen is coupled along the length of the primary tubular body. When a torque force is applied to the proximal end of the primary tubular body, causing the proximal end to rotate by a first amount of rotation, the distal end of the primary tubular body responds by rotating by a second amount of rotation, lagging behind the first amount of rotation by a rotational lag of less than 90 degrees. TIFF2026524940000002.tif122134

Description

Technical Field

[0001] Cross - Reference to Related Applications This application claims priority to U.S. Provisional Patent Application No. 63 / 514,407, filed on July 19, 2023, the entire content of which is incorporated herein by reference for all purposes.

[0002] Government Funding This invention was made with government support under Grant No. (2129152) awarded by the National Science Foundation of the United States. The government has certain rights in this invention.

[0003] Technical Field Aspects of the present disclosure are directed to over - tube assemblies for use in medical procedures, specifically over - tube assemblies for use with endoscopes and other elongated surgical tools.

Background Art

[0004] Background Surgical procedures inside the gastrointestinal (GI) tract can be difficult to perform due to limited access to the target tissue and / or the serpentine removal of the target tissue. For example, larger lesions that occur in the colon, rectum, esophagus, and / or stomach require highly invasive and costly surgeries for removal, and can result in a more difficult recovery for patients who may then be left with a non - fully functional GI tract.

[0005] Endoscopic procedures involving resection and / or dissection of larger lesions inside the GI tract have been an advancement in medicine. However, these procedures, such as endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD), can be time - consuming for the endoscopist and may be difficult considering the instability of the GI tract during the procedure and the restricted access to surgical tools.

[0006] Therefore, there is a need for improved access to medical tools for endoscopic procedures within the GI tube. Specifically, there is a need for over-tube devices and assemblies for elongated surgical tools to be used in intraluminal surgery to remove lesions inside the GI tube. [Overview of the Initiative]

[0007] overview In one aspect, an overtube assembly is provided. The overtube assembly is for use with a first elongated medical device and a second elongated medical device inside a patient's physiological lumen. The overtube assembly includes a primary tubular body defining a primary lumen configured to receive the first elongated medical device, and a secondary lumen extending along the primary tubular body. The primary tubular body has a length extending from a proximal end oriented to receive the first elongated medical device to a distal end. The secondary lumen is coupled along the length of the primary tubular body. When a torque force is applied to the proximal end of the primary tubular body, causing the proximal end to rotate by a first amount of rotation, the distal end of the primary tubular body responds by rotating by a second amount of rotation, lagging behind the first amount of rotation by a rotational lag of less than 90 degrees.

[0008] In another aspect, an overtube assembly is provided. The overtube assembly is for use with a first elongated medical device and a second elongated medical device inside a patient's physiological lumen. The overtube assembly includes a primary tubular body including a first circumferential outer wall and a primary lumen configured to receive the first elongated medical device, as well as at least one of a fluid tubular body or a secondary tubular body. The primary tubular body has a length extending from a proximal end oriented to receive the first elongated medical device to a distal end. The first circumferential outer wall (5711a-c) includes a first radially inner circumferential surface, a first radially outer circumferential surface, and a first radial wall thickness (T1+T2+T3) of approximately 0.126 mm to approximately 7.75 mm. The first radially inner circumferential surface defines the primary lumen and has a first internal diameter (D3) of approximately 5.5 mm to approximately 17.5 mm. The first radially outer circumferential surface has a first outer diameter (D2) of approximately 15 mm to approximately 19 mm. Each of the fluid tubular body and the secondary tubular body extends along the primary tubular body, is coupled to the primary tubular body, and is helically wound around the primary tubular body at a helical pitch of approximately 1 turn per 165 mm to approximately 1 turn per 170 mm. The fluid tubular body includes a second radially inner circumferential surface, a second radially outer circumferential surface, and a second radial wall thickness defined between the second radially inner circumferential surface and the second radially outer circumferential surface. The second radially inner circumferential surface defines the fluid transport lumen and has a second internal diameter (D4) of approximately 0.5 mm to approximately 3.25 mm. The second radially outer circumferential surface has a second outer diameter (D5) of approximately 0.75 mm to approximately 6.5 mm. The secondary tubular body includes a third radially inner circumferential surface, a third radially outer circumferential surface, and a third radial wall thickness defined between the third radially inner circumferential surface and the third radially outer circumferential surface. The third radially inner circumferential surface defines the secondary lumen and has a third internal diameter (D6) of approximately 1.5 mm to approximately 4 mm. The third radially outer circumferential surface has a third external diameter (D7) of approximately 1.75 mm to approximately 7.5 mm, and the secondary lumen is configured to receive a second elongated medical device.The distance (R1) between the center of the primary lumen and the center of the fluid transport lumen is approximately 3.25 mm to approximately 12.5 mm. The distance (R2) between the center of the primary lumen and the center of the secondary lumen is approximately 3.5 mm to approximately 13.5 mm. [Brief explanation of the drawing]

[0009] Simple explanation The above summary, as well as the following detailed description of preferred embodiments, will be better understood in conjunction with the accompanying drawings. For illustrative purposes, currently preferred embodiments are shown in the drawings. However, it should be understood that this disclosure is not limited to the exact aspects and means shown.

[0010] [Figure 1] This is a perspective view of a device used in an operating environment according to one or more aspects of the present disclosure. [Figure 2A] A front view of an example of an environment in which the apparatus and system described herein may be used. [Figure 2B] This is an overtube assembly for use in the environment shown in Figure 2A. [Figure 3A] Figures 3A to 3C are perspective views of an overtube assembly according to one or more embodiments of the present disclosure. [Figure 3B] Refer to the explanation in Figure 3A. [Figure 3C] Refer to the explanation in Figure 3A. [Figure 4A] Figures 4A and 4B are perspective views of a system including a tool coupled to an overtube assembly according to one or more embodiments of the present disclosure. [Figure 4B] See the explanation in Figure 4A. [Figure 5] This is an isometric projection view of an overtube assembly according to one or more embodiments of the present disclosure. [Figure 6] Figure 6A is an isometric projection view of an overtube assembly according to one or more embodiments of the present disclosure. Figures 6B and 6C are isometric projection views of the overtube assembly shown in Figure 6A being subjected to rotation or torque. [Figure 7] Figures 7A - 7D are isometric projection views of a section of an overtube according to one or more aspects of the present disclosure. [Figure 8A] Figures 8A - 8M are cross - sectional views of an overtube having a primary lumen and a secondary tube according to one or more aspects of the present disclosure. [Figure 8B] Refer to the description of Figure 8A. [Figure 8C] Refer to the description of Figure 8A. [Figure 8D] Refer to the description of Figure 8A. [[ID=第15]] [Figure 8E] Refer to the description of Figure 8A. [Figure 8F] Refer to the description of Figure 8A. [Figure 8G] Refer to the description of Figure 8A. [Figure 8H] Refer to the description of Figure 8A. [Figure 8I] Refer to the description of Figure 8A. [Figure 8J] Refer to the description of Figure 8A. [Figure 8K] Refer to the description of Figure 8A. [Figure 8L] Refer to the description of Figure 8A. <第38]] [Figure 8M] Refer to the description of Figure 8A. [Figure 9A] Figures 9A - 9C are isometric projection views of an overtube assembly including a primary tube and a secondary tube according to one or more aspects of the present disclosure. [Figure 9B] Refer to the description of Figure 9A. [Figure 9C] Refer to the description of Figure 9A. [Figure 10-1] Figures 10A - 10F are isometric projection views and end - face views of an overtube assembly including a primary tube and a secondary tube having an operable end according to one or more aspects of the present disclosure. [Figure 10-2] Refer to the description of Figure 10 - 1. [Figure 10-3] Refer to the description of Figure 10 - 1. [Figure 11A]Figures 11A to 11E are isometric and side views of an overtube assembly comprising a primary tube and a secondary tube having a steerable end, according to one or more embodiments of the present disclosure. [Figure 11B] Refer to the explanation in Figure 11A. [Figure 11C] Refer to the explanation in Figure 11A. [Figure 11D] Refer to the explanation in Figure 11A. [Figure 11E] Refer to the explanation in Figure 11A. [Figure 12] Figures 12A and 12B are isometric projection views of an overtube assembly, including a primary tube and a second tube, according to one or more embodiments of the present disclosure. [Figure 13A] Figures 13A to 13C are isometric projection views of an overtube assembly, comprising a primary tube and a secondary tube integrally formed with the primary tube, according to one or more embodiments of the present disclosure. [Figure 13B] Refer to the explanation in Figure 13A. [Figure 13C] Refer to the explanation in Figure 13A. [Figure 14] Figures 14A and 14B are isometric projection views of a sheathed overtube assembly according to one or more embodiments of the present disclosure. [Figure 15] Figures 15A and 15B are isometric projection views of an overtube assembly, comprising a primary tube and a secondary tube integrally formed with the primary tube, according to one or more embodiments of the present disclosure. [Figure 16] Figures 16A and 16B are isometric projections of the helical deformation of the overtube assembly shown in Figures 15A and 15B. [Figure 17] Figure 17A is a cross-sectional view of an overtube assembly including a primary tube and one secondary tube, according to one or more embodiments of the present disclosure. Figure 17B is a cross-sectional view of an overtube assembly including a primary tube and multiple secondary tubes, according to one or more embodiments of the present disclosure. [Figure 18A]Figures 18A to 18C are isometric and cross-sectional views of an overtube assembly, including a primary tube and a plurality of secondary tubes, according to one or more embodiments of the present disclosure. [Figure 18B] See the explanation in Figure 18A. [Figure 18C] See the explanation in Figure 18A. [Figure 19A] Figures 19A to 19C are isometric and cross-sectional views of an overtube assembly, including a primary tube and a plurality of secondary tubes, according to one or more embodiments of the present disclosure. [Figure 19B] See the explanation in Figure 19A. [Figure 19C] See the explanation in Figure 19A. [Figure 20A] Figures 20A to 20C are isometric and cross-sectional views of an overtube assembly, including a primary tube and a plurality of secondary tubes, according to one or more embodiments of the present disclosure. [Figure 20B] Refer to the explanation in Figure 20A. [Figure 20C] Refer to the explanation in Figure 20A. [Figure 21] Figures 21A to 21C are isometric projection views of an overtube assembly having a primary tube and secondary tubes at different longitudinal positions, according to one or more embodiments of the present disclosure. [Figure 22] Figures 22A and 22B are isometric projection views of an overtube assembly, including a primary tube and a secondary tube assembly, according to one or more embodiments of the present disclosure. [Figure 23] Figures 23A and 23B are isometric and side views of an overtube assembly, comprising a primary tube and a secondary tube extending along the primary tube, according to one or more embodiments of the present disclosure. [Figure 24] Figures 24A and 24B are isometric projection views of an overtube assembly, including a primary tube, a secondary tube, and a balloon, according to one or more embodiments of the present disclosure. [Figure 25]Figures 25A and 25B are isometric projection views of an overtube assembly, including a primary tube, a secondary tube, a balloon, and a handle, according to one or more embodiments of the present disclosure. [Figure 26] Figure 26A is an isometric projection of an overtube assembly, including a balloon and a handle, in a first state in which torque is applied to the handle, according to one or more embodiments of the present disclosure. Figures 26B and 26C are isometric projections of the overtube assembly shown in Figure 26A, in a subsequent state in which torque is applied to the handle and the balloon. [Figure 27] This is a partial cross-sectional view of an overtube assembly including a locking mechanism according to one or more aspects of the present disclosure. [Figure 28] Side view and isometric projection view of an overtube assembly coupled to an elongated tool, according to one or more embodiments of the present disclosure. [Figure 29] Side view and isometric projection view of an overtube assembly coupled to an elongated tool, according to one or more embodiments of the present disclosure. [Figure 30] Figures 30A–30C are isometric projections of an overtube assembly, including a primary tube, a secondary tube, a balloon, and a handle, according to one or more embodiments of the present disclosure, with a tool extending through the secondary tube. [Figure 31] This is an isometric projection view of an overtube assembly including two balloons, according to one or more embodiments of the present disclosure. [Figure 32] Figures 32A to 32C are isometric projections of the overtube assembly shown in Figure 31 under various expansion conditions. [Figure 33] Figures 33A and 33B are isometric projections of an overtube assembly including a balloon in an alternative position, according to one or more embodiments of the present disclosure. [Figure 34] Figures 34A and 34B are isometric and side views of an overtube assembly including a primary tube, a secondary tube, and a balloon, according to one or more embodiments of the present disclosure. [Figure 35] Figures 35A and 35B are isometric and side views of an overtube assembly including a primary tube, a secondary tube, and an asymmetrical balloon, according to one or more embodiments of the present disclosure. [Figure 36A] Figures 36A to 36C are cross-sectional and isometric projection views of an overtube assembly including an integrally formed air supply lumen according to one or more embodiments of the present disclosure. [Figure 36B] Refer to the explanation in Figure 36A. [Figure 36C] Refer to the explanation in Figure 36A. [Figure 37A] Figures 37A to 37F are cross-sectional and isometric projection views of an overtube assembly including separately formed air supply tubing, according to one or more embodiments of the present disclosure. [Figure 37B] Refer to the explanation in Figure 37A. [Figure 37C] Refer to the explanation in Figure 37A. [Figure 37D] Refer to the explanation in Figure 37A. [Figure 37E] Refer to the explanation in Figure 37A. [Figure 37F] Refer to the explanation in Figure 37A. [Figure 38] This is a side view of a balloon assembly for use with an overtube assembly according to one or more embodiments of the present disclosure. [Figure 39] This is a side view of another balloon assembly for use with an overtube assembly according to one or more embodiments of the present disclosure. [Figure 40] This is a side view of yet another balloon assembly for use with an overtube assembly according to one or more embodiments of the present disclosure. [Figure 41] Figures 41A and 41B are isometric projections of an overtube assembly for use with an endoscope, according to one or more embodiments of the present disclosure. [Figure 42] Figures 42A and 42B are side views of the overtube assembly shown in Figures 41A and 41B. [Figure 43]This is a side view of an overtube assembly for use with an endoscope, according to one or more embodiments of the present disclosure. [Figure 44] Figure 43 is an isometric projection view of the overtube assembly shown. [Figure 45] Figures 45A and 45B are side views of the overtube assembly shown in Figure 43. [Figure 46] Figures 46A to 51B are isometric and end views of end caps for use with an overtube, according to one or more embodiments of the present disclosure. [Figure 47] Figures 46A to 51B are isometric and end views of end caps for use with an overtube, according to one or more embodiments of the present disclosure. [Figure 48] Figures 46A to 51B are isometric and end views of end caps for use with an overtube, according to one or more embodiments of the present disclosure. [Figure 49] Figures 46A to 51B are isometric and end views of end caps for use with an overtube, according to one or more embodiments of the present disclosure. [Figure 50] Figures 46A to 51B are isometric and end views of end caps for use with an overtube, according to one or more embodiments of the present disclosure. [Figure 51] Figures 46A to 51B are isometric and end views of end caps for use with an overtube, according to one or more embodiments of the present disclosure. [Figure 52] Figures 52A and 52B are side and assembly views of a handle assembly for use with an overtube assembly, according to one or more embodiments of the present disclosure. [Figure 53A] Figures 53A to 53C are side and isometric views of a handle assembly for use with an overtube assembly, according to one or more embodiments of the present disclosure. [Figure 53B] Refer to the explanation in Figure 53A. [Figure 53C] Refer to the explanation in Figure 53A. [Figure 54] This is a top perspective view of an overtube assembly including a handle assembly according to one or more embodiments of the present disclosure. [Figure 55] This is a side perspective view of an overtube assembly according to one or more embodiments of the present disclosure. [Figure 56] Figures 56A and 56B are cross-sectional and side perspective views, and respectively, of an overtube having a primary lumen, a secondary tube, and an air tube, according to one or more embodiments of the present disclosure. [Figure 57A] Figures 57A and 57B are a top perspective view and a side view of an overtube assembly including a handle assembly, according to one or more embodiments of the present disclosure. [Figure 57B] Refer to the explanation in Figure 57A. [Figure 58A] This is the same figure as Figure 57B, except that it is enlarged. [Figure 58B] This is a longitudinal cross-section of the overtube assembly taken along the cross-sectional line DD in Figure 58A. [Figure 58C] Figure 58B shows an enlarged view of the region of the overtube assembly in the longitudinal cross-section, circled as detail E. [Figure 58D] This is a cross-section of the overtube assembly taken along the cross-sectional line GG in Figure 57B. [Modes for carrying out the invention]

[0011] Detailed explanation Hereinafter, we refer in detail to the exemplary embodiments illustrated in the attached drawings. Wherever possible, the same reference numerals are used throughout the drawings to refer to the same or similar parts.

[0012] There is a need for improved medical tool access for endoscopic procedures within the GI tube. Specifically, there is a need for overtube devices and assemblies for elongated surgical tools to be used in endoluminal surgery to remove lesions inside the GI tube. Balloon overtubes may be used in such procedures to provide the endoscopist with an additional working channel access through the overtube, while enabling deeper access and / or greater stability of the GI tube wall. The overtube may include an inner coating and / or inner layer with reduced friction response for easier advancement of surgical tools, such as endoscopes or catheters, through the overtube, specifically through the curved and bent sections of the highly tortuosic GI tube.

[0013] In addition to the working channel for insertion and manipulation of the endoscope, the overtube devices and assemblies described herein also include a second working channel for insertion and manipulation of a second surgical tool, such as forceps, knives, scissors, or clamps, not limited to this. Thus, the overtube devices and assemblies described herein allow (1) insertion and rotation of the endoscope within the working channel, (2) insertion and rotation of a second surgical tool within the second working channel, and (3) rotation of the second surgical tool relative to the endoscope within the working channel. Independent rotation of the second surgical tool relative to the endoscope may facilitate improved surgical visibility and access to target tissue.

[0014] Figure 1 is a perspective view of an operating environment 100 corresponding to an example of application of the apparatus and system according to the present disclosure. More specifically, the operating environment 100 illustrates a patient's colon 110, which generally includes a colonic wall 112 defining a physiological lumen 114. In a particular procedure illustrated in the operating environment 100, a lesion 116 is in the process of being surgically removed from the colon 110 using a tool assembly 200.

[0015] As shown in Figure 1, the tool assembly 200 generally includes an endoscope 202, which is located inside and extends through the overtube assembly 210. To facilitate the removal of the lesion 116, the tool assembly 200 includes a first tool 206 (illustrated as a snare tool) and a second tool 222 (illustrated as a forceps tool). More specifically, the first tool 206 is shown to be inserted through the endoscope 202 and extending out of a first opening 218 at the distal end 204 of the endoscope 202. Similarly, the second tool 222 is shown to be inserted through the overtube assembly 210 and extending out of a second opening 220 at the distal end 216 of the overtube assembly 210.

[0016] The overtube assembly 210 generally includes an overtube 212 that defines a primary lumen through which an endoscope 202 or similar elongated tool can be inserted. The overtube assembly 210 further includes a balloon 214 that is coupled to the overtube 212 and is selectively inflatable by a clinician to secure the overtube assembly 210 to the colonic wall 112 of the colon 110. More generally, and considering other applications, the inflatable balloon is selectively inflatable to secure the overtube assembly to the wall of a physiological lumen in which the overtube assembly is located.

[0017] The balloon 214 can also be selectively inflated to position the endoscope 202 and tool inside the physiological lumen as desired. In some applications, selective inflation of the balloon allows the user to then "rock" the overtube assembly forward and / or backward (which causes the endoscope and tool to rock). In other applications, selective inflation of the balloon allows the user to slightly rotate the balloon assembly to apply tension to the tissue in contact with the secondary lumen 224 (e.g., the working channel), as shown in Figure 1.

[0018] In addition to providing a firm support to the endoscope 202, the attachment of the overtube assembly 210 to the colon wall 112 facilitates pulling and straightening the colon wall 112, for example, to flatten or smooth out folds in the colon wall 112. Although not shown in Figure 1, the balloon 214 is generally connected to the proximal air supply via an air lumen extending through the overtube assembly 210 (e.g., defined within the wall of the overtube 212; or in the form of a separate tubular tube coupled to or integrated within the overtube 212).

[0019] The overtubes according to this disclosure include auxiliary or secondary lumens (also referred to herein as “working channels”) to provide clinicians performing surgery with additional functionality and capabilities. For example, Figure 1 illustrates an overtube assembly 210 including a secondary lumen 224 terminating at a second opening 220 at the distal end 216 of the overtube assembly 210. In the illustrated application, a second tool 222 (e.g., in the form of a grasping tool) is inserted through the secondary lumen 224 and extends out of the second opening 220 to provide clinicians with additional capabilities.

[0020] Generally, the secondary lumen 224 provides a channel between the proximal end of the overtube assembly 210 and a somewhat distal location on the overtube assembly 210. Although shown as an opening at the distal end 216 of the overtube assembly 210, the opening of the secondary lumen 224 may be located anywhere along the overtube 212, depending on the procedure being performed. Furthermore, although the secondary lumen 224 is generally described as being used to guide and hold a secondary tool, the secondary lumen 224 is, more generally, a conduit / channel that may be used for other purposes. For example, and not limited to, in certain implementations, the secondary lumen 224 may be used to provide irrigation, suction, inflation, blowing, and other similar actions involving fluid communication to or from a physiological lumen. Also, although Figure 1 illustrates the overtube assembly 210 as containing a single secondary lumen, the overtube according to this disclosure may contain multiple secondary lumen.

[0021] In the example in Figure 1, the overtube assembly 210 is described to assist in surgery and tissue manipulation, but the overtube assembly 210 also serves as a conduit for the endoscope 202. In some embodiments, the overtube assembly 210 remains in place while the endoscope 202 is partially or completely removed from the patient. The endoscope or other instrument can then be reinserted and easily advanced to the surgical site. That is, the size, shape, and / or material of the overtube assembly 210 may facilitate its retention of its position within the physiological lumen without collapsing or buckling.

[0022] The overtube assembly 210 is designed to maintain the primary lumen without significant bending, even in highly tortuosic environments, when the endoscope 202 is withdrawn. These tortuosic environments are known to cause other overtubes, as is known in the prior art, to buckle or twist when the endoscope is withdrawn. Withdrawal of the endoscope during or after the procedure can facilitate the removal of tissue without dissecting larger tissue portions or using additional nets or baskets. That is, the entire tissue portion can be withdrawn in one piece via the endoscope and tools through the endoscopic gripper, facilitating easier analysis of the withdrawn tissue and allowing determination of whether all diseased tissue has been removed with appropriate margins.

[0023] Removing the endoscope 202 without having to remove the overtube assembly 210 can also facilitate simplified instrument changes, such as changing the endoscope or other instruments during the procedure without losing its position within the physiological lumen or wasting time moving back to the surgical site. In practice, the procedure may begin with one endoscope, perhaps a larger diameter and stiffer one, to establish the surgical site and field of view. During the procedure, the endoscope may then be removed, and a second endoscope, perhaps a thinner one with a smaller diameter, may be introduced. A larger and stiffer endoscope may facilitate improved advancement through serpentine anatomical structures, while a thinner and more flexible endoscope may facilitate greater maneuverability for surgical dissection and tissue removal.

[0024] The specific application illustrated in Figure 1 is provided primarily for illustrative purposes and is an unrestricted example intended to provide context for the disclosure. Throughout the disclosure, applications to the gastrointestinal tract, more specifically to the lower intestinal tract / lower bowel, are relied upon as primary examples, but the disclosure assumes that various features and concepts contained herein can be readily adapted to other applications, including, but not limited to, procedures and applications based on esophagogastroduodenoscopy (EGD) and small bowel endoscopy.

[0025] While not strictly limited to gastrointestinal applications, such applications present unique challenges, partly due to the morphological dimensions and tissue of the large intestine. Figure 2A is a diagram of an example of the large intestine 118 illustrating the typical morphological dimensions and relative positioning of the cecum, colon, and rectum. As shown, the large intestine 118 contains several bends / curves of approximately 90 degrees. Therefore, for tools (e.g., endoscopes) used to perform surgical procedures such as lesion removal inside the large intestine, the tool and overtube must have the ability to move through the bends of the large intestine required to reach the target of the procedure. For procedures to be performed inside the ascending colon, for example, the tool and overtube must be sufficiently flexible to move through four 90-degree bends. Figure 2B illustrates an overtube assembly 210 in a state corresponding to a procedure performed, for example, in the ascending colon.

[0026] Conventional overtube assemblies generally rely on increasing the flexibility of the overtube to move through anatomical bends such as the curves of the large intestine; however, this common approach of increasing flexibility can create challenges when a secondary lumen / working channel is incorporated into the overtube.

[0027] As a first example, during a particular procedure, a clinician may want to reposition a second opening 220 of the secondary lumen 224, for example, to provide better access to a lesion or similar target. To do so, the overtube assembly 210 may be rotated, thereby rotating the second opening 220 around the endoscope 202, and altering the location of the second opening 220 and the approach of the second tool 222. During the procedure, the clinician is generally limited in applying the torque required for such rotation at the proximal end of the overtube assembly 210 due to the remainder of the overtube assembly 210 positioned inside the patient. However, conventional flexible overtube assemblies generally lack sufficient torsional rigidity to reliably transmit the torque applied at the proximal end of the overtube assembly to cause rotation at the distal end. Among other things, this results in an unpredictable rotational response of the overtube assembly when torque is applied to the proximal end. In certain cases, a conventional overtube assembly may even act as a torsional spring when torque is applied from the proximal end. For example, when torque is applied to the proximal end of an overtube assembly, frictional engagement between the distal portion of the overtube assembly and the wall of the physiological lumen may prevent rotation of the distal portion. In such cases, when torque is applied and the overtube of the overtube assembly twists, energy is stored within the overtube of the overtube assembly. Once the stored energy becomes sufficient to overcome the frictional forces on the overtube assembly, the overtube assembly may suddenly, unpredictably, and undesirably unravel, resulting in a loss of control by the physician, loss of procedure progress, and potential harm to the patient.

[0028] A related phenomenon called "snap-through" may also be observed in certain over-tube applications. Snap-through generally refers to a type of buckling that can occur in elastic systems, where the system spontaneously and abruptly transitions between non-adjacent equilibrium shapes. Thus, for example, a structure may be bent or manipulated into a first equilibrium shape, but may experience a sudden and rapid change to an inverted shape. Jumping popper toys are a common example of the snap-through phenomenon. Such toys are generally dome-shaped and made of elastic material so that they can be inverted into their initial stable shape. If left alone, the toy will eventually experience a snap-through, abruptly returning to its original shape and releasing the energy stored within it, propelling it upwards.

[0029] In the medical field, snap-through is a known phenomenon in applications involving elongated tools and related devices such as catheters, overtubes, and endoscopes. Generally, the snap-through effect becomes more pronounced as the length of the device and the meandering of the device's passages increase, and this phenomenon is most likely to occur at bends within the device. Snap-through has also been observed to be more likely to occur in devices with asymmetric cross-sections. Like the torsional spring effect described above, snap-through can result in a sudden, unpredictable, and undesirable release of stored energy.

[0030] To address the above-mentioned problems, in particular, this disclosure provides a variety of novel overtube assemblies and improvements to conventional overtube assemblies. The implementation of this disclosure covers overtube assemblies for use with, for example, endoscopes or similar elongated tools, which include a secondary lumen / working channel and simultaneously address the various above-mentioned problems related to torsional performance and snap-through.

[0031] The overtube devices and assemblies further described herein provide an overtube for housing a series of endoscopes, in addition to a second working channel for housing a second surgical tool for accessing target tissue inside the GI tube. To effectively advance through the GI tube, the overtube devices and assemblies described herein are laterally flexible, while minimizing rotational lag and snap-through, while maintaining sufficient torsional rigidity for stable rotation at the distal end when torque is applied to the proximal end. For example, the disclosure includes overtubes reinforced with an inner layer such as a laser-cut thin-walled steel tube, wire braid, or wire coil for flexible overtubes having consistent torqueability along their length. The torqueability of the overtube can be further improved by reducing the coefficient of friction between the endoscope and the inner surface of the overtube, such as by using a hydrophilic coating.

[0032] In addition, for example, this disclosure includes an overtube assembly having an overtube and a second working channel. Some of the overtube assemblies described herein integrate the overtube and the second working channel into a common cross-section along the length of the assembly. While these overtube assemblies are sufficiently flexible laterally to move the GI tube, the relatively linear second working channel along the overtube may lead to energy accumulation and release through “snap-through” motion when the assembly rotates. Therefore, other overtube assemblies described herein position the second working channel radially offset from the overtube and arrange the second working channel in a symmetrical cross-sectional layout along the length of the overtube, thereby maintaining the flexibility of the overtube assembly while simultaneously maintaining stable torque transmission along its length and minimizing rotational lag between the proximal and distal ends.

[0033] Figures 3A to 3C illustrate the overtube assembly 300 according to this disclosure. Specifically, Figure 3A is a distal perspective view of the overtube assembly 300, Figure 3B is an elevation view of the overtube assembly 300, and Figure 3C is a proximal perspective view of the overtube assembly 300.

[0034] As shown, the overtube assembly 300 generally includes a handle assembly 302 and a primary tube 304 extending distally from the handle assembly 302. The overtube assembly 300 further includes a secondary tube 306 (also referred to herein as a working channel) extending parallel to the primary tube 304.

[0035] The primary tube 304 defines a primary lumen 308, which is molded and configured to receive an endoscope or similar elongated tool in endoscopic applications, and terminates at a distal opening 309. The primary lumen 308 is sized to accommodate an elongated tool, such as an endoscope, having a diameter (or cross-sectional width) of approximately 6 mm to 15 mm. In other embodiments, the primary lumen 308 is sized for an elongated tool having a diameter (or cross-sectional width) of approximately 2 mm to 7 mm. In other embodiments, the primary lumen 308 is sized for an elongated tool having a diameter (or cross-sectional width) of approximately 12 mm to 20 mm. The secondary tube 306 defines a secondary lumen 310, through which an auxiliary tool, fluid, or other element may be inserted to complement the endoscope. Similarly, the secondary tube 306 terminates at a distal opening 311. The secondary lumen 310 is sized to accommodate elements having a diameter (or cross-sectional width) of approximately 1.5 mm to approximately 3.8 mm. In other embodiments, the secondary lumen 310 is sized for elements having a diameter (or cross-sectional width) of approximately 1 mm to approximately 2 mm. In other embodiments, the secondary lumen 310 is sized for elements having a diameter (or cross-sectional width) of approximately 2.2 mm to approximately 6.5 mm.

[0036] As described later in this disclosure, a particular embodiment may include multiple secondary tubes having various configurations. However, for the purposes of this introductory embodiment, the overtube assembly 300 includes a single working channel, for example, a secondary tube 306 extending longitudinally and parallel to the primary tube 304, so that the secondary lumen 310 of the secondary tube 306 and the primary lumen 308 of the primary tube 304 are substantially parallel. Also in this introductory embodiment, the distal opening 309 of the primary tube 304 and the distal opening 311 of the secondary tube 306 are located at the distal end 301 of the overtube assembly 300, so that the working space for the overtube assembly 300 is generally in the region distal to the distal end 301.

[0037] In at least one particular embodiment, the primary tube 304 and the secondary tube 306 may be formed from at least one of nylon, PFA, PET, PTFE, FEP, HDPE, TPPE, silicone, PVC, other thermopolymers, or any other suitable material. In one embodiment, the primary tube 304 is extruded from 70 Shore A silicone. In other embodiments, the primary tube 304 may be 20 Shore A or 80 Shore A. In one embodiment, the primary tube 304 and the secondary tube 306 may be formed from the same material. In other embodiments, the lumen and / or corresponding tube may be formed from one or more different materials. When in use, the entire assembly generally exhibits bendability and indentation stiffness comparable to that of an endoscope.

[0038] Non-limitingly, the materials of each tube, such as the primary tube 304 and / or secondary tube 306, may also contain additives to reduce or increase surface friction of the corresponding lumen. For example, in one particular embodiment, the primary tube 304 may be formed from a Hytrel thermoplastic polyester elastomer containing Everglide. In another particular embodiment, both the primary tube 304 and the secondary tube 306 may be coated with a hydrophilic coating to reduce friction when an elongated tool is inserted and advanced through the corresponding lumen. Not limited to such embodiments, but according to this disclosure, thinner-walled tubular bodies may generally be formed from a harder polymer than thicker-walled tubular bodies so that the thinner-walled tubular body has sufficient rigidity to advance inside the patient's physiological lumen (e.g., GI tube). In one particular embodiment, the wall thickness of the primary lumen 308 may be about 0.75 mm. In a particular embodiment, the primary tube 304 and the secondary tube 306 may have wall thicknesses between about 0.25 mm and about 1.0 mm. In another embodiment, the primary tube 304 and the secondary tube 306 may have a wall thickness of approximately 0.75 mm or more and approximately 5.0 mm or less.

[0039] In a particular implementation, the overtube assembly 300 may also include one or more inflatable balloons, e.g., balloon 312, which can be selectively inflated from the handle assembly 302 and used to secure the overtube assembly 300 inside the patient's physiological lumen, as shown, for example, in Figure 1. To facilitate the inflation and deflation of balloon 312, the overtube assembly 300 may further include an air supply lumen 314 (shown in Figure 3A) extending from the handle assembly 302 to balloon 312.

[0040] Balloons used with an overtube assembly, such as balloon 312 for the overtube assembly 300, may have uniform or non-uniform wall thicknesses. In some embodiments, the wall thickness of balloon 312 may be about 0.05 mm to about 0.35 mm. In other embodiments, the wall thickness of balloon 312 may be about 0.25 mm to about 0.95 mm.

[0041] The uninflated, stationary cross-sectional width of balloon 312 can be approximately 20 mm to 55 mm. In certain implementations, the cross-sectional width of balloon 312 can be approximately 5 mm to 25 mm. In other implementations, the uninflated cross-sectional width of balloon 312 can be approximately 50 mm to 85 mm. When inflated, the volume of balloon 312 can increase by approximately 5% to 50%. In certain implementations, balloon 312 can be designed to conform to and match the shape and dimensions of a physiological lumen. In other implementations, when inflated, the volume of balloon 312 can increase by more than approximately 50% compared to its uninflated state, up to a maximum of approximately 200%.

[0042] Balloons used with an overtube assembly, such as balloon 312 for the overtube assembly 300, can be inflated to a pressure of about 1 kPa to about 10 kPa. For example, balloon 312 can be inflated to a pressure of 7 kPa. In other embodiments, balloon 312 can be inflated to a pressure of about 0.1 kPa to about 1 kPa or about 10 kPa to about 100 kPa. Balloon 312 can be made from at least one non-rigid material. For example, in one embodiment, balloon 312 may be formed from a material comprising one or more of low-density polyethylene (LDPE), latex, polyether block amide (e.g., PEBAX®), silicone, polyethylene terephthalate (PET / PETE), nylon, polyurethane, and any other thermoplastic elastomer, siloxane, or other similar non-rigid materials. In a particular embodiment, balloon 312 may be formed from one material. In other embodiments, balloon 312 may be formed from multiple materials.

[0043] While not limited to specific dimensions, in at least one particular embodiment, the air supply lumen 314 may have a cross-sectional width of approximately 0.8 mm and a wall thickness of approximately 0.33 mm. In other embodiments, the cross-sectional width of the air supply lumen 314 may be approximately 0.5 mm to approximately 3.5 mm, and the wall thickness may be approximately 0.10 mm to approximately 1.75 mm. However, generally, the diameter and / or wall thickness of the air supply lumen 314 may be made as small and thin as possible to minimize the size of the primary tube 304 and, as a result, minimize the volume that penetrates into the physiological lumen. Similarly, other features of the primary tube 304 may be formed to be as thin and small as possible. This is because thinner and smaller features generally result in the primary tube 304 being more flexible and able to pass more easily through any bends in the physiological lumen in which it is deployed. Nevertheless, with respect to certain materials (e.g., silastic polymers), the minimum wall thickness and other dimensions may be limited by manufacturing. The air supply lumen 314 may be manufactured using the same or similar material as the primary tube 304. If the air supply lumen 314 is intended to deliver and / or remove a fluid other than air, the diameter of the air supply lumen 314 may need to be larger than the diameter required to move air, taking into account the increased viscosity of the fluid. Thus, during use of the overtube assembly 300, the balloon 312 can be selectively inflated and deflated by injecting air through the air supply lumen 314 or by deflating air from the balloon 312, respectively. While air can be used, balloon inflation can also be performed using other gases such as carbon dioxide, as well as liquids including saline and water.

[0044] Figure 3C illustrates the handle assembly 302 in more detail. The handle assembly 302 is intended as a non-limiting example of a handle assembly. Nevertheless, the handle assembly 302 includes various feature parts and elements intended to illustrate certain functions and aspects of the overtube assembly of this disclosure. The handle assembly 302 may be manufactured using the same or similar material as the primary tube 304. In some embodiments, the handle assembly 302 may be manufactured using a more rigid material, such as a material containing ABS or polycarbonate. With respect to embodiments in which the handle assembly 302 and the primary tube 304 are formed from the same or similar material, the handle assembly 302 may have a different durometer, thereby allowing the handle assembly 302 to retain greater rigidity compared to the primary tube 304 to facilitate easier forward and rotation of the device.

[0045] As shown in Figure 3C, the handle assembly 302 may include a handle body 316 that terminates at the port assembly 318 and has a pistol-style configuration. When in use, the handle assembly 302 is designed to allow easy forward, backward, and / or rotation of the entire device within a physiological lumen. The port assembly 318 includes proximal inlets for various lumens of the overtube assembly 300. For example, as shown, the port assembly 318 includes a primary tube inlet 320 and a secondary tube inlet 322, respectively. Generally, the primary tube inlet 320 is sized and shaped to accept a primary tool such as an endoscope, while the secondary tube inlet 322 is sized and shaped to accept an auxiliary tool.

[0046] The port assembly 318 further includes a water inlet 324 which communicates with the primary lumen 308 and can be used to introduce fluid into the primary lumen 308 to flush out or remove air bubbles inside the primary lumen 308. The introduction of fluid may also help to smooth the interface between the endoscope (or other elements inside the primary tube) and the primary lumen 308.

[0047] In the specific embodiment illustrated, the handle assembly 302 also includes a lever 326 and a valve switch 328 to facilitate the selective inflation and deflation of the balloon 312. More specifically, the lever 326 is pressurized to actuate a pump mechanism (not shown) located inside the handle body 316, and is configured to selectively inject air into or out of the air supply lumen 314, depending on the position of the valve switch 328. Thus, for example, when the valve switch 328 is in the first position, the lever 326 results in air being injected into the air supply lumen 314 and the corresponding inflation of the balloon 312. Conversely, when the valve switch 328 is in the second position, the lever 326 results in air being drawn out of the air supply lumen 314, thereby deflating the balloon 312.

[0048] In other embodiments, inflation and deflation may be controlled within the surgical area by an external air supply unit, such as an automatic air pump. In such embodiments, the lever 326 and valve switch 328 may be omitted or selectively disabled, and the port assembly 318 may further include an air supply port (not shown) adapted to be coupled to an external air supply unit to facilitate the discharge and introduction of air from the balloon 312 through the air supply lumen 314. The inflation and / or deflation time of the balloon may range from about 1 to 5 seconds. In other embodiments, the inflation and / or deflation time of the balloon may range from about 0.1 seconds to about 1 second, or from about 4 seconds to about 25 seconds.

[0049] Figures 4A and 4B illustrate a system 400 in which the endoscope 402 and associated tools are inserted into / coupled to the overtube assembly 300. As shown in the figures, during use, the endoscope 402 is generally inserted through the primary lumen 308 of the primary tube 304 and exits through the distal opening 309. Similarly, an auxiliary tool 404 may be inserted through the secondary lumen 310 or secondary tube 306 and exits through the distal opening 311. In the specific implementation shown in Figures 4A and 4B, the auxiliary tool 404 is a gripper-type tool. Among other things, as shown, the endoscope 402 further includes a tool lumen 406 through which the tool 408 (e.g., a cutter tool) extends. Thus, the auxiliary tool 404 may be used to complement and enhance the tool-related features and functions of the endoscope 402.

[0050] Figure 5 is an isometric projection of an overtube assembly 500 according to another embodiment of the present disclosure. The overtube assembly 500 includes a handle assembly 502 and a tube assembly 501 which includes a primary tube 504 extending distally from the handle assembly 502. The tube assembly 501 further includes a secondary tube 506 extending parallel to the primary tube 504. In contrast to the pistol-style handle appearance of the handle assembly 302, the handle assembly 502 has a cylindrical or barrel-shaped grip that extends substantially parallel to the primary tube 504. In some applications, the cylindrical grip allows for easier rotation during clinical use.

[0051] Similar to the previous implementation, the primary tube 504 defines a primary lumen 508, which is shaped and configured to receive an endoscope or similar elongated tool and terminates at a distal opening 509. The secondary tube 506 defines a secondary lumen 510, which may be inserted through to complement the endoscope by an auxiliary tool, fluid, or other element such as an auxiliary tool 550. Similarly, the secondary tube 506 terminates at a distal opening 511.

[0052] The overtube assembly 500 further includes a balloon 512 that can be inflated by one or more air supply tubules, for example, an air supply tubule (not shown). For example, the handle assembly 502 may include a pressurizable pump mechanism and corresponding valves to direct air into and out of the balloon 512 via the air supply tubule. Alternatively, the handle assembly 502 may include a port configured to connect to an external supply source and communicate air or other fluids with the external supply source.

[0053] Similar to the handle assembly 302, the handle assembly 502 is generally configured to receive an endoscope or similar tool via a primary tube inlet 520 (not shown in Figure 5), for example, located on the proximal end of the primary tube 504. The handle assembly 502 is further configured to receive an auxiliary tool 550 within the proximal opening or port of the secondary tube 506. Although not specifically shown in Figure 5, the handle assembly 502 may also include a fluid / flush port that communicates with the primary lumen 508 and is configured to facilitate the injection and circulation of fluid inside the primary lumen 508 and at the distal end of the overtube assembly 500.

[0054] As described above in relation to Figures 2A and 2B, procedures that rely on overtubes often involve moving the overtube through complex / serpentine passages. Such applications often require and result in bending, twisting, and other similar operations of the overtube. Conventional overtubes are generally formed from flexible / elastic materials and experience a "rotational lag" between the rotation applied at the proximal end of the overtube and the corresponding rotation occurring at the distal end of the overtube. Thus, for example, a half-turn applied at the proximal end of a conventional overtube may result in less than a half-turn at the distal end of the overtube. This is especially true for softer and more flexible materials.

[0055] The amount of rotational lag between the proximal and distal ends of an overtube is unpredictable and can depend heavily on several factors, including the structure of the overtube, its cross-sectional shape, and its configuration. For example, an overtube may have minimal lag when torque is applied in a substantially linear configuration, but significant lag can occur when it is bent (e.g., when moving through various curves in the colon).

[0056] In particular, in certain cases, the overtube can act like a torsion spring, storing torsional energy, which can cause a torsional lag to accumulate within the overtube. When enough lag has accumulated, the overtube can suddenly release the stored energy and move abruptly to become a straight line, which can result in a sudden and uncontrolled movement of the overtube.

[0057] In general, the lack of continuous and reliable control, as well as the possibility of uncontrolled torsional release associated with rotational lag, present significant safety concerns. Accordingly, implementation of the present disclosure may include an overtube configured to be flexible in bending to move through a variety of anatomical curves and bends in a patient, while simultaneously having sufficient torsional stiffness to reduce rotational lag or to provide a predictable relationship between the rotation applied to the proximal end of the overtube and the resulting rotation at the distal end of the overtube.

[0058] Figure 6A is an isometric projection of the overtube assembly 600 according to the present disclosure. As shown, the overtube assembly 600 includes a tube assembly 601A which further includes a primary tube 602A and a secondary tube 604A, respectively. Figure 6A illustrates the overtube assembly 600A with the tube assembly 601A in a neutral rotational state before the application of torque (indicated by arrow 650) at the proximal end 606A of the tube assembly 601A. As illustrated by arrow 652, such torque generally results in a corresponding rotation or torque at the distal end 608A of the overtube assembly 600A.

[0059] Figure 6A illustrates an example of an overtube assembly according to the present disclosure, with the tube assembly intended to be in the start / neutral position. Figures 6B and 6C, respectively, illustrate the respective overtube assemblies following a 180-degree rotation of the proximal end of each tube assembly from the neutral position shown in Figure 6A.

[0060] Referring to Figure 6B, an over-tube assembly 600B is shown, which includes tube assembly 601B to provide a one-to-one relationship between the rotation applied at the proximal end 606B of tube assembly 601B and the resulting rotation at the distal end 608B of tube assembly 601B. In other words, tube assembly 601B of over-tube assembly 600B is configured such that the rotation at the proximal end 606B results in an equal rotation at the distal end 608B (i.e., 180 degrees in the illustrated example).

[0061] Figure 6C, in contrast, illustrates an over-tube assembly 600C that includes tube assembly 601C to provide a 2:1 relationship between the rotation applied at the proximal end 606C of tube assembly 601C and the resulting rotation at the distal end 608C of tube assembly 601C. In other words, tube assembly 601C of over-tube assembly 600C is configured such that a rotation at the proximal end 606C results in a half rotation at the distal end 608C (i.e., a 180-degree rotation applied at the proximal end 606C results in a 90-degree rotation at the distal end 608C).

[0062] Figures 7A–7D are isometric projections of overtube sections illustrating different internal structures for the overtube according to this disclosure. Generally, each structure is provided to increase the torsional stiffness of the overtube while minimizing its impact on the bending stiffness. As described above, such configurations allow the overtube to have sufficient flexibility to move the patient's anatomical structures, while also having sufficient torsional stiffness to avoid problems associated with rotational lag.

[0063] The overtubes according to this disclosure may include any one of the structures illustrated in Figures 7A–7D or structures that implement similar concepts. Alternatively, the overtubes may include more than one of the structures in a layered configuration and / or a segmented configuration (for example, a first longitudinal segment of the overtube having a first structure, while a second longitudinal segment having a second structure). Furthermore, the overtubes according to this disclosure may include any of the structures as an inner layer, but may further include additional layers of material applied to the inner or outer surface of that layer. For example, a layer providing torsional reinforcement may include inner and outer layers formed from a low-friction material or coating to improve interaction with the tool inserted through the overtube and the surface of the physiological lumen, respectively.

[0064] Figure 7A is an isometric projection of an overtube segment 700A including a torsional resistance feature as an embodiment of the present disclosure. As shown, the overtube segment 700A includes a primary tube 702A along which a spine element 704A extends longitudinally.

[0065] The spine element 704A may be formed integrally with the primary tube 702A, co-formed with the primary tube 702A (e.g., by co-extrusion or co-molding processes), or formed separately from the primary tube 702A and subsequently bonded to the primary tube 702A (e.g., by adhesive, ultrasonic welding, or other bonding techniques). The spine element 704A may be fabricated using the same or similar material as the primary tube 702A, the same or similar material with different durometers or stiffnesses, or different materials. The spine element 704A may extend substantially along the entire primary tube 702A, or along one or more individual segments of the primary tube 702A. Furthermore, although Figure 7A illustrates it extending longitudinally along only one side of the primary tube 702A, the spine element 704A may alternatively extend partially circumferentially; or the overtube segment 700A may include multiple spine elements extending along the primary tube 702A.

[0066] Generally, the spine element 704A is formed using a material and / or in a structure such that the spine element 704A provides increased torsional resistance compared to the material / structure of the primary tube 702A. For example, while the primary tube 702A may be formed from a first material, the spine element 704A may be formed from one or more second substantially rigid materials. As another example, the spine element 704A may be formed from substantially the same material as the primary tube 702A, but the overtube segment 700A may have a greater thickness or an alternative orientation (e.g., in the case of anisotropic or composite materials) so that it has greater torsional resistance than if the spine element 704A were absent.

[0067] Although shown in Figure 7A as extending in the longitudinal direction, in certain embodiments, the spine element 704A may be configured to extend at least partially around the primary tube 702A. For example, the spine element 704A may extend helically around the primary tube 702A along at least a portion of its length (or be wrapped around it in a different way). In such embodiments, the torsional properties of the overtube segment 700A may be further controlled by modifying the pitch of the helical spine (e.g., a relatively low pitch results in lower torsional stiffness, and vice versa). Furthermore, although shown as including a single spine element, the disclosure also envisions embodiments that may include one or more additional spine elements.

[0068] Figure 7B is an isometric projection of the overtube segment 700B, which includes an alternative torsional resistance feature in the form of a braided reinforcement. More specifically, the overtube segment 700B includes a primary tube 702B in which a braided element 706B is embedded inside or wrapped around the periphery. For example, in a particular embodiment, the braided element 706B may be formed from one or more braided wires (e.g., nitinol wire and / or other metallic and polymer materials (e.g., polyamide materials) fibers or wires formed from other materials) embedded inside the primary tube 702B. Alternatively, the braided element 706B may be braided to cover the primary tube 702B, or formed as a separate sheet co-formed with the primary tube 702B, or formed separately from the primary tube 702B and then attached to the primary tube 702B.

[0069] The torsional properties of the overtube segment 700B, such as torsional stiffness, can be selectively controlled by modifying the properties of the braided element 706B. For example, and not limited to, the torsional stiffness of the overtube segment 700B can be selectively controlled by modifying the number of braided wires, the thickness of one or more braided wires, the material of one or more braided wires, the braid density (e.g., a programmable picks per inch (PPI) value), the braid pattern, etc. The properties of the matrix (e.g., material, wall thickness, etc.) to which the braid can be embedded or to which the braid can be bonded can also be modified to selectively control the torsional properties of the overtube segment 700B.

[0070] Figure 7C is an isometric projection of an alternative torsional resistance feature in the form of a laser-cut tube 700C, such as a hypo tube. As shown, the laser-cut tube 700C includes a tubular body 702C, and the cuts can be distributed along the tubular body 702C to selectively impart flexibility to the laser-cut tube 700C. The laser-cut tube 700C can be integrated into the overtube according to this disclosure by, for example, overlaying or extruding a flexible overtube body onto the laser-cut tube 700C, such that the laser-cut tube 700C is embedded within the overtube body or otherwise forms an internal layer of the overtube body assembly. The laser-cut tube 700C can also be embedded inside the overtube body and sandwiched between two or more layers of other materials.

[0071] As illustrated, the cuts to the tubular body 702C include a first set of cuts 704C extending along the first side surface 706C of the tubular body 702C, and a second set of cuts 708C extending along the second side surface 710C of the tubular body 702C. In the illustrated embodiment, each cut of the tubular body 702C extends laterally, i.e., along a plane perpendicular to the longitudinal axis of the tubular body 702C, and extends to approximately the midline of the tubular body 702C. The two sets of cuts are also shown to be offset from each other such that the cuts of the first set of cuts 704C are staggered longitudinally from the cuts of the second set of cuts 708C. Although these cuts are shown to be perpendicular to the longitudinal axis of the tubular body 702C, these cuts may also represent a pitch, in which case they are cut in a helical pattern along the longitudinal axis. The pitch of the helical cuts can be varied, and the length of the cuts can be varied to affect the torsional rigidity and bending flexibility.

[0072] The lateral cuts of the tubular body 702C substantially increase the relative flexibility of the tubular body 702C when bending, compared to the case where the tubular body 702C is substantially uncut / a solid-walled tube. Despite this decrease in bending stiffness, the lateral cuts have only a very slight, if any, effect on the torsional stiffness of the tubular body 702C. Therefore, by introducing the tubular body 702C into the overtube assembly, the overtube assembly can be rotationally stiff and yet remain quite flexible when bent.

[0073] As a final non-limiting example, Figure 7D is an isometric projection of an overtube segment 700D that includes an alternative torsional resistance feature in the form of a variable material segment. More specifically, the overtube segment 700D includes a primary tube 702D having separate segments formed from different materials and / or having different dimensional characteristics (e.g., wall thickness) so that selected portions of the primary tube 702D have different bending and torsional stiffnesses. For example, the proximal segment 704D may be formed from a relatively rigid material to facilitate torque transmission, while the intermediate segment 706D and distal segment 708D may be formed from one or more relatively flexible / softer materials to allow the primary tube 702D to move through a bend in a physiological lumen such as a GI tube.

[0074] In at least one particular implementation, the overtube segment 700D may be configured to transition from a relatively hard / rigid material at the proximal end to a relatively soft / flexible material at the distal end. Thus, for example, the proximal segment 704D may be formed from a first, most rigid material, the intermediate segment 706D from a second material having intermediate rigidity, and the distal segment 708D from a third, most flexible material.

[0075] One or more of the various flexibility and torsional control features illustrated in Figures 7A to 7D can be combined within a given overtube. Similarly, an overtube according to this disclosure may include different longitudinal sections, each of which may have its own structure and torsional properties. For example, one or more types of features (e.g., spine, braid, hypotube, etc.) may vary across multiple sections. As another (not necessarily mutually exclusive) example, one or more sections may include the same general type or feature, but the specific configuration of the feature in different sections of the overtube may vary. For example, one implementation of an overtube may include a braided element to provide torsional rigidity, but the density, weave pattern, etc., of the braid may be varied along the sections of the overtube to modify and control the rigidity within the sections.

[0076] Figures 8A–8M are cross-sectional views of different overtubes for use in the overtube assembly according to this disclosure.

[0077] Generally, each of the overtube designs illustrated in Figures 8A–8M includes a primary tubular structure defining a primary lumen that is sized and shaped to receive a tool such as an endoscope. The primary tubular structure may be formed integrally with or coupled to one or more secondary tubular structures that provide their respective secondary lumens. Each primary and / or secondary lumen may be coated with a coating that alters the frictional properties of the lumen surface. In one particular implementation, both the primary and secondary lumens are coated with a hydrophilic coating to reduce friction when an elongated tool is inserted and advanced through their corresponding lumens.

[0078] The overtube according to this disclosure may have a layered structure in which the primary and secondary tubular structures are further supplemented by layers that provide reinforcement, joinability, protective surfaces, surfaces with enhanced friction properties, and the like. In at least certain embodiments, the layers are assembled using a mandrel-based technique in which the overtube layers are applied to and supported by a mandrel before undergoing a reflow operation to join the layers together. Depending on the number and appearance of the layers, a given overtube may require multiple assembly steps, each step involving the application of one or more layers and the corresponding joining / reflow operation. In other embodiments, a more flexible outer layer is expanded to accommodate the inner layers.

[0079] A given layer can be applied in various ways during assembly. For example, a given layer may have a tubular or sleeve-like shape and may slide over any layer placed inside the mandrel and overtube. As another example, the layer may be in the form of a strip wound around the mandrel (e.g., spirally wound) and any layer placed inside the overtube. Similarly, the layer may be wound or braided on the mandrel, as in the case of the braided structure shown in Figure 7B.

[0080] In another implementation, the layer can be assembled by immersing the apparatus in order to apply a coating to the outside or inside of one of the lumens. The layer can also be added by pouring a material (such as silicone) onto the inner or outer surface.

[0081] The structure of the overtube may also include the placement of other components along the overtube, and in some implementations, between the layers of the overtube. For example, each of the implementations illustrated in Figures 8D–8F includes separately formed tubular structures that form the secondary lumen of their respective overtubes. Thus, such an assembly of overtube structures may include positioning the tubular structures along the length of the lower overtube layer and, optionally, bonding or otherwise joining the tubular structures to the lower overtube layer before applying one or more additional layers.

[0082] The thickness of the layers is generally designed to be thin in order to minimize the overall size of the device for insertion into a physiological lumen. In one embodiment, the wall thickness of the primary tube, secondary tube, and / or air lumen is approximately 0.1 mm to approximately 0.5 mm. In another embodiment, the wall thickness is approximately 0.25 mm to approximately 1.25 mm. In yet another embodiment, the primary tube has a wall thickness of approximately 0.25 mm, while the secondary lumen has a wall thickness of approximately 1.25 mm, and the air lumen has a wall thickness of approximately 0.50 mm.

[0083] Figure 8A is a cross-sectional view of the overtube 800A. The overtube 800A includes a primary tube 802A defining a primary lumen 804A (for example, for an endoscope or similar elongated tool). The overtube 800A further includes a secondary tube 806A or working channel defining a secondary lumen 808A. In the illustrated embodiment, the secondary tube 806A is positioned on the outer surface of the primary tube 802A and is formed integrally with the primary tube 802A by, for example, an extrusion process.

[0084] Since the secondary tube 806A extends along the outer surface of the primary tube 802A, the primary lumen 804A is generally unobstructed and substantially concentric with any scope / tool ​​inserted through the primary tube 802A. Among other advantages, such concentricity can help minimize or control the gap between the inner wall of the primary tube 802A and the scope / tool ​​inserted through the primary tube 802A, and reduce the possibility of tissue being trapped or pinched between the scope / tool ​​and the inner wall of the primary tube 802A.

[0085] In certain implementations, the overtube 800A may correspond to a one-piece overtube that has general advantages related to ease of manufacture (e.g., suitable for extrusion-type processes). Considering the offset of the secondary lumen 808A from the secondary tube 806A, the overtube 800A may be suitable for applications where the overall length of the overtube 800A is relatively short and / or torsional stiffness is not so critical (e.g., procedures with relatively linear / non-serpentine physiological lumens or tool passages), particularly when the secondary lumen 808A extends substantially longitudinally along the secondary tube 806A. As discussed throughout this disclosure, the torsional and snap-through properties of the overtube 800A may be improved, for example, by winding the secondary tube 806A helically or otherwise around the primary tube 802A.

[0086] The primary tube is sized to accommodate elongated tools, such as endoscopes, with a diameter (or cross-sectional width) of approximately 6 mm to 15 mm. In other embodiments, the primary tube is sized for elongated tools with a diameter (or cross-sectional width) of approximately 2 mm to 7 mm. In yet another embodiment, the primary tube is sized for elongated tools with a diameter (or cross-sectional width) of approximately 12 mm to 20 mm. The secondary tube is sized to accommodate elements with a diameter (or cross-sectional width) of approximately 1.5 mm to 3.8 mm. In other embodiments, the secondary tube is sized for elements with a diameter (or cross-sectional width) of approximately 1 mm to 2 mm. In yet another embodiment, the secondary tube is sized for elements with a diameter (or cross-sectional width) of approximately 2.2 mm to 6.5 mm.

[0087] The distance between the centers of the primary and secondary tubes can be constant along the length of the assembly or can vary along the length. In one embodiment, the distance between the centers is approximately 1.75 mm to approximately 5 mm. In another embodiment, the distance between the centers is approximately 4 mm to approximately 13.25 mm.

[0088] Figure 8B is a cross-sectional view of the overtube 800B, which includes a primary tube 802B defining a primary lumen 804B and a secondary tube 806B defining a secondary lumen 808B. In contrast to the overtube 800A, the secondary tube 806B is positioned on the inner surface of the primary tube 802B and consequently extends through 804B. As with the overtube 800A, the primary tube 802B and the secondary tube 806B are formed integrally, for example, by an extrusion process.

[0089] Like the overtube 800A, the overtube 800B may correspond to a one-piece overtube that has general advantages related to ease of manufacture (e.g., suitable for extrusion-type processes), and may be particularly suitable for applications where the overall length of the overtube 800B is relatively short and / or torsional stiffness is not so important (e.g., procedures with relatively linear / non-serpentine physiological lumens or tool passages). However, like the overtube 800A, the torsional properties of the overtube 800B can be improved, for example, by forming a secondary lumen 808B having a helical or other non-linear passage along the inner surface of the primary tube 802B. Furthermore, by placing the secondary tube 806B inside the primary tube 802B, the outer surface of the primary tube 802B can be made relatively consistently, for example, circular. In particular, such an outer shape may be beneficial in manufacturing, more specifically, for attaching additional elements (e.g., inflatable balloons) to the outer surface of the overtube 800B. A smooth, cylindrical outer surface may be beneficial in medical applications where advancing or rotating a tube with an asymmetrical outer surface is undesirable.

[0090] Figure 8C is a cross-sectional view of an overtube 800C comprising multiple layers. More specifically, the overtube 800C includes a primary tube 802C defining a primary lumen 804C. Similar to the implementation in Figure 8B, the overtube 800C further includes a secondary tube 806C defining a secondary lumen 808C extending through the primary lumen 804B. The primary tube 802C includes additional layers in the form of a reinforcing layer 810C and a jacket 812C. For example, the reinforcing layer 810C may be a layer of braided material (such as that shown in Figure 7B) or a laser-cut tube layer (such as that shown in Figure 7C) adapted to provide torsional rigidity to the primary tube 802C. The jacket 812C, in contrast, may be formed from a low-friction material or otherwise may provide a protective barrier between the overtube 800C and the physiological lumen in which the overtube 800C is used internally. In one embodiment, the reinforcing layer 810C has a thickness of less than approximately 0.25 mm, while the jacket 812C has a thickness of approximately 0.25 mm, and the primary tube 802C has a thickness of approximately 0.75 mm.

[0091] The primary tube 802C and secondary tube 806C of the overtube 800C are substantially similar to the corresponding elements of the overtube 800B, and as a result, offer similar advantages in terms of ease of manufacture. The substantially circular outer shape of the primary tube 802C also facilitates the application of the reinforcing layer 810C and jacket 812C during manufacturing.

[0092] The reinforcing layer 810C (and similar reinforcing layers in other implementations discussed in this section) provides a variety of benefits, including, but not limited to, improved torsional performance, resistance to twisting, and the ability to use softer materials for other layers of the overtube 800C (e.g., the primary tube 802C and the jacket 812C). In particular, the improved torsional performance provided by the reinforcing layer 810C enables overtube structures suitable for longer overtube structures and / or more serpentine tool passages. The reinforcing layer 810C may have a variety of structures; however, in at least certain implementations, the reinforcing layer 810C may be formed using hypotube, a layer of braided material, or a similar reinforced tubular structure.

[0093] Jacket 812C (and similar jackets in other implementations discussed in this section) may be formed from any suitable biocompatible material and may be selected to have a variety of properties and characteristics based on the intended application of the overtube 800C. For example, in a particular implementation, jacket 812C may be selected to provide a smooth or other low-friction outer surface to the overtube 800C and to have resistance to a variety of chemicals (e.g., body fluids, sterile fluids, etc.).

[0094] Figure 8D is a cross-sectional view of the overtube 800D, which includes a primary tube 802D defining a primary lumen 804D. In contrast to the earlier implementations shown in which the secondary tube is integrally formed with the overtube body, the implementation of the overtube 800D includes a secondary tube shaft 806D defining a secondary lumen 808D located within an external recess 809D of the primary tube 802D. The retention of the secondary tube shaft 806D on the primary tube 802D is further facilitated by a jacket 812D. Similar to the jacket 812C of the overtube 800C, the jacket 812D of the overtube 800D may also be selected to provide a protective layer between the overtube 800D and the physiological lumen, in addition to facilitating the retention of the secondary tube shaft 806D on the primary tube 802D. In alternative implementations, the secondary tube shaft 806D may be bonded to the primary tube 802D using, for example, adhesive, welding, etc., and thus the primary purpose of the jacket 812D is as a protective layer. As illustrated, the secondary tube shaft 806D is a separate component assembled together with the primary tube 802D. Therefore, the secondary tube shaft 806D may be formed from a different material than that of the primary tube 802D, or it may be constructed using a different technique than that of the primary tube 802D.

[0095] Figure 8E is a cross-sectional view of the overtube 800E, which includes a primary tube 802E defining the primary lumen 804E. Similar to the overtube 800D in Figure 8D, the overtube 800E includes a secondary tube shaft 806E that defines the secondary lumen 808E and is held within the external recess 809E of the primary tube 802E. In contrast to the overtube 800D, the overtube 800E further includes a reinforcing layer 810E, for example, to provide the overtube 800E with additional torsional rigidity. As shown, the outer surface of the overtube 800E is also covered by a jacket 812E.

[0096] Figure 8F is a cross-sectional view of the overtube 800F, which includes a primary tube 802F defining the primary lumen 804F. Similar to the above overtube, the overtube 800E includes a secondary tube shaft 806F that defines the secondary lumen 808F and is held within the external recess 809F of the primary tube 802F. The overtube 800F further includes a reinforcing layer 810F, for example, to provide additional torsional rigidity to the overtube 800E. The overtube 800F also includes an internal jacket 812F radially inside the reinforcing layer 810F and an external jacket 814F radially outside the reinforcing layer 810F.

[0097] In at least certain implementations, the structure illustrated in Figure 8F offers additional benefits in terms of manufacturability. More specifically, the inner jacket 812F can facilitate assembly by holding the secondary tube shaft 806F relative to the primary tube 802F during the application of the reinforcing layer 810F. Thus, for example, the secondary tube shaft 806F may be positioned on the primary tube 802F. The inner jacket 812F is then positioned to cover the secondary tube shaft 806F and the primary tube 802F and can be reflowed to bond the secondary tube shaft 806F to the primary tube 802F, thereby maintaining the secondary tube shaft 806F aligned in the appropriate position during the application of the reinforcing layer 810F and the outer jacket 814F.

[0098] Figure 8G is a cross-sectional view of the overtube 800G. The overtube 800G includes a primary tube 802G defining a primary lumen 804G and a secondary tube 806G defining a secondary lumen 808G. The secondary tube 806G is positioned on the outer surface of the primary tube 802G and is shown to be formed integrally with the primary tube 802G. In contrast to previous implementations in which layers are added to the outer surface of the overtube body, the overtube 800G includes internal layers in the form of a liner 816G and an internal reinforcement layer 818G. In certain implementations, the liner 816G may be formed from a low-friction / smoothed material or a material suitable for the application of a smooth layer in order to facilitate the insertion and translational movement of an elongated tool (e.g., an endoscope) into the primary tube 802G. As shown, the liner 816G also provides a base layer or substrate for supporting the internal reinforcement layer 818G.

[0099] Figure 8H is a cross-sectional view of the overtube 800H, which includes a secondary tube shaft 806H defining the primary lumen 804H and the secondary lumen 808H. In contrast to the previous implementation in which the overtube included a primary tube defining the primary lumen 804H, the overtube 800H is formed from only an auxiliary layer to the primary tube of the previous implementation. More specifically, the overtube 800H includes a liner 816H surrounded by a reinforcing layer 818H, such that the liner 816H defines the primary lumen 804H. As a result, the overtube 800H has a generally lower profile compared to the structures illustrated in Figures 8A–8G. The secondary tube shaft 806H is positioned on the outer surface of the reinforcing layer 818H, with both the secondary tube shaft 806H and the reinforcing layer 818H surrounded by a jacket 812H.

[0100] Figure 8I is a cross-sectional view of the overtube 800I, which includes a primary lumen 804I and a secondary tube shaft 806I defining a secondary lumen 808I. Similar to the overtube 800H, the overtube 800I includes a liner 816I surrounded by a reinforcing layer 818I such that the liner 816I defines the primary lumen 804I. In contrast to the overtube 800H, the overtube 800I includes a first jacket 820I surrounding the reinforcing layer 818I and in contact with the secondary tube shaft 806I. The overtube 800I further includes the first jacket 820I and a second jacket 822I surrounding the secondary tube shaft 806I.

[0101] In particular, the structure shown in Figure 8I provides a jacket material that completely encloses and wraps around the secondary tube shaft 806I. By doing so, an improved coupling of the secondary tube shaft 806I to the underlying overtube structure can be provided.

[0102] Figure 8J is a cross-sectional view of the overtube 800J, which includes a primary lumen 804J and a secondary tube shaft 806J defining the secondary lumen 808J. The overtube 800J is substantially similar to the overtube 800H in Figure 8H, except that the reinforcing layer is omitted. In other words, the overtube 800J includes a liner 816J, with the secondary tube shaft 806H positioned on the outer surface of the liner 816J, both of which are surrounded by a jacket 812J.

[0103] Figure 8K is a cross-sectional view of the overtube 800K, which includes a primary lumen 804K and a secondary tube shaft 806K defining a secondary lumen 808K. Similar to the overtube 800J in Figure 8J, the overtube 800K includes an internal liner 816K, in contact with which the secondary tube shaft 806K is positioned. The 800K further includes a reinforcing layer 818K extending around both the secondary tube shaft 806K and the reinforcing layer 818K, and a further jacket layer 812K positioned around the reinforcing layer 818K.

[0104] Figure 8L is a cross-sectional view of the overtube 800L, which includes a primary lumen 804L and a secondary tube shaft 806L defining the secondary lumen 808L. The overtube 800L is substantially similar to the overtube 800H in Figure 8H, except that the liner is omitted. In other words, the overtube 800J includes a reinforcing layer 818L defining the primary lumen 804L. Thus, the structure shown in Figure 8L may be best suited to an implementation where the reinforcing layer 818L is a standalone tubular structure (e.g., a hypotube) rather than a braid or similar structure that must be wrapped around, wound around, or otherwise applied to the underlying foundation / substrate layer. The secondary tube shaft 806L is positioned on the outer surface of the reinforcing layer 818L, and both are surrounded by a jacket 812L.

[0105] Finally, Figure 8M is a cross-sectional view of the overtube 800M, which includes a primary lumen 804M and a secondary tube shaft 806M defining the secondary lumen 808M. Similar to the overtube 800L, the overtube 800M includes a reinforcing layer 818M defining the primary lumen 804M. The overtube 800M includes a first jacket 820M surrounding the reinforcing layer 818M, with the secondary tube shaft 806M positioned adjacent to it. The overtube 800M further includes a second jacket 822M surrounding the first jacket 820M and the secondary tube shaft 806M.

[0106] The various structures illustrated in Figures 8A–8M are intended merely as examples and should be considered non-limiting. For example, the overtubes according to this disclosure may be a combination of various structural aspects, or the structures illustrated may be modified in other ways for a given application or overtube. The various structures may also be modified to include additional structures and features, such as additional secondary lumens, to provide an additional working channel through which air can be delivered to a balloon coupled to the overtube, for irrigation / suction, or through which other tools can be inserted.

[0107] Prior implementations of this disclosure generally include an overtube assembly in which a secondary tube extends through a primary tube. The secondary tube may extend along either the inner or outer surface of the primary tube and may be formed integrally with the primary tube or coupled to it. Prior implementations also include a configuration in which the primary tube includes a separate tubular structure (e.g., an extruded primary tubular body) which optionally includes an internal or external functional layer formed on the primary tubular body. In yet another implementation, the overtube excludes the primary tubular body and is formed by various liners, reinforcements, and jacket layers. Unless otherwise noted, the features and concepts discussed later may be adapted to include any suitable overtube structure, including, but not limited to, the general structural concepts illustrated in Figures 8A–8M.

[0108] For the purposes of brevity and clarity, subsequent implementations of this disclosure will generally refer to a primary tube as defining the primary lumen of an overtube assembly, and one or more secondary tubes defining their respective secondary lumens. Unless otherwise specified, such terms should not be considered limiting to any particular structure of an overtube assembly. In other words, the various concepts and structures provided in this disclosure can be adapted and combined in any suitable combination.

[0109] Prior implementations of this disclosure generally included an overtube assembly in which a single secondary tube extends along and parallel to the primary tube. In other implementations of this disclosure, the secondary tube may extend along the primary tube in a non-linear manner. Such implementations include those that include a helically wound secondary tube, as illustrated in Figures 9A–9C.

[0110] Through testing, the implementation of an overtube assembly including a helically wound secondary tube demonstrated improved resistance to snap-through action compared to one containing a substantially longitudinally oriented secondary tube. As previously mentioned, snap-through action has been found to be more pronounced in tubular structures with non-axisymmetric cross-sections. By helically winding a secondary tube around a primary tube, the average cross-section of the overtube assembly across the pitch of the secondary tubes is approximately axisymmetric, which likely results in improved resistance to snap-through action.

[0111] Experimental tests have shown that, to eliminate snap-through, the helical pitch of the secondary tube can be reduced by an amount proportional to the narrowest bending radius through which the part of the device passes. In other words, to maintain the same level of snap-through, a narrower physiological bend leads to greater snap-through, so to minimize snap-through, additional helical winding of the secondary tube is required.

[0112] The secondary tube helical pitch can be defined as the axial distance over which the secondary tube completes one full circumferential turn along the primary tube. In one implementation, the secondary tube pitch is consistently about 20 cm along the length of the assembly. In another implementation, the secondary pitch is about 20 cm on average along the length of the assembly, but has a variable pitch, such as about 10 cm in some parts and about 25 cm in others. In yet another implementation, the helical pitch is about 10 cm on average for some parts of the assembly's length, about 20 cm on average for other parts, and about 30 cm on average for yet another part.

[0113] Figure 9A is an isometric projection of the overtube assembly 900A, which includes a primary tube 902A with a secondary tube 904A helically wound around it. As shown, the secondary tube 904A is wound around the primary tube 902A at a constant pitch along the entire length of the primary tube 902A.

[0114] Figure 9B is an isometric projection of the overtube assembly 900B, which includes a primary tube 902B with a secondary tube 904B spirally wound around it. In contrast to the overtube assembly 900A, the secondary tube 904B of the overtube assembly 900B is wound around the primary tube 902B with a variable pitch. More specifically, the overtube assembly 900B includes a proximal section 906B with a first pitch and a distal section 908B with a second pitch, the second pitch being shorter than the first pitch. The pitch can be varied to more easily accommodate the expected physiological lumen meandering. It is desirable to maintain the overall amount of secondary tube winding to a minimum. An assembly with significant secondary tube winding can hinder the advance of the tool through the working channel (secondary lumen). Significant winding can also hinder the operation and use of the tool. Thus, there is a trade-off between minimizing snap-through and maintaining the effective use of the working channel tool.

[0115] This disclosure assumes that the pitch may vary in any suitable manner along the length of the primary tube 902B and may include any number of suitable sections, each having its own helical pitch. In at least one particular embodiment, portions of the secondary tube 904B may have a relatively small pitch in areas of the overtube assembly 900B that are typically bent during a given application, thereby providing increased torsional stiffness and snap-through resistance in these areas.

[0116] Figure 9C is an isometric projection of an overtube assembly 900C, which includes a primary tube 902C with a secondary tube 904C helically wound around it. More specifically, the secondary tube 904C is coupled to the primary tube 902A such that the secondary tube 904C is partially wound around the primary tube 902C. More specifically, the secondary tube 904C includes a proximal section 910C, an intermediate section 912C, and a distal section 914C. The proximal section 910C and the distal section 914C each extend longitudinally and parallel to the primary tube 902C, while the primary tube 902B includes a single helical winding around the primary tube 902C.

[0117] Similar to the previous implementation, the helical segments of the primary tube 902C correspond to portions of the overtube assembly 900C that would experience bending in a particular application of the overtube assembly 900C, thereby potentially providing additional torsional rigidity and resistance to snap-through action in those areas. Furthermore, while the intermediate section 912C includes a complete helical winding of the primary tube 902C, the helical segments of the primary tube 902C may alternatively include only partial windings, multiple windings, left-handed windings, right-handed windings, or any combination thereof.

[0118] Prior implementations of this disclosure have generally illustrated overtube assemblies in which the secondary tube is coterminated with the primary tube such that the distal opening of the secondary tube is substantially coplanar with the distal opening of the primary tube. The distal opening of the secondary tube may also be oriented in a different direction from the distal opening of the primary tube and, in some implementations, may be maneuverable from the proximal end of the overtube assembly. Orienting the secondary tube in a direction other than coaxial with the primary tube allows for "biasing" of a tool to exit the secondary tube in a non-coaxial manner. This may facilitate easier interaction with the physiological lumen when advancing and rotating the overtube assembly.

[0119] One example of an overtube assembly including a maneuverable secondary tube is shown in Figures 10A–10F. More specifically, Figures 10A–10F illustrate the distal section of an overtube assembly 1000, which includes a primary tube 1002 and a secondary tube 1004 extending along the outer surface of the primary tube 1002. The secondary tube 1004 includes a distal tip 1006 that is maneuverable to direct a tool, fluid, or other object introduced into and through the secondary tube 1004.

[0120] To facilitate the manipulation of the distal tip 1006, the distal portion 1008 of the secondary tube 1004 is not connected to the primary tube 1002. Therefore, when the user manipulates the distal tip 1006, the distal portion 1008 can bend freely relative to the primary tube 1002.

[0121] In one particular implementation, the distal tip 1006 is maneuverable using a cable or wire-based system. More specifically, the distal tip 1006 includes a pull ring 1010 to which one or more cables (not shown) are attached. The cables extend to a proximal control assembly (not shown) which includes various control elements for selectively applying and releasing tension to the cables / wires.

[0122] Figures 10A and 10B illustrate, for example, a first cable 1012 extending from a pull ring 1010, which is pulled / tensioned so that its distal end 1006 is pulled laterally away from the primary tube 1002. Figures 10C and 10D similarly illustrate a second cable 1014 extending from a pull ring 1010, which is pulled / tensioned so that its distal end 1006 is pulled in a first direction along a plane parallel to the longitudinal axis of the primary tube 1002. Finally, Figures 10E and 10F illustrate a third cable 1016 extending from a pull ring 1010, which is pulled / tensioned so that its distal end 1006 is pulled in a second direction opposite to the direction shown in Figures 10C and 10D.

[0123] Figures 11A–11E illustrate an alternative steering mechanism for the distal tip of the secondary tube of the overtube assembly 1100. Figures 11A and 11B are isometric and cross-sectional views of the distal portion 1150 of the overtube assembly 1100. As shown, the overtube assembly 1100 includes a primary tube 1102 and a secondary tube assembly 1152 extending along the primary tube 1102. The secondary tube assembly 1152 includes a secondary tube 1104 that defines a secondary lumen 1106 through which a secondary tube shaft 1154 extends, the secondary tube shaft 1154 being hollow and defining a shaft lumen 1155. The distal tip 1156 is coupled to the distal end of the secondary tube shaft 1154 so that the distal tip 1156 protrudes beyond the distal limit of the primary tube 1102.

[0124] During use, the secondary tube shaft 1154 is rotatable from a corresponding control unit (e.g., a knob or handle) located at the proximal end of the overtube assembly 1100, and the rotation of the secondary tube shaft 1154 results in a corresponding rotation of the distal tip 1156. As shown, the distal tip 1156 has a curved shape, and therefore, when the secondary tube shaft 1154 is rotated, the outlet 1158 of the distal tip 1156 changes direction, thereby changing the direction of the secondary tube assembly 1152 and any tools, fluids, etc., introduced through the secondary tube assembly 1152.

[0125] Figures 11C–11E are additional isometric projections of the overtube assembly 1100, illustrating a 180-degree rotation of the secondary tube shaft 1154 and the distal tip 1156.

[0126] In certain embodiments of this disclosure, the overtube assembly may include a secondary tube that extends along the primary tube and is either integrally formed with the primary tube or bonded to the primary tube substantially along its entire length. In other embodiments, the secondary tube may be bonded to the primary tube only partially.

[0127] Figure 12A is an isometric projection of the overtube assembly 1200A, including the selective coupling of the secondary tube 1204A to the primary tube 1202A. More specifically, the secondary tube 1204A is illustrated to include a proximal section 1206A, an intermediate section 1208A, and a distal section 1210A. In contrast to previous implementations shown in which the secondary tube is coupled to the primary tube substantially along the entire length of the secondary tube, the secondary tube 1204A is coupled to the primary tube 1202A at selective locations. For example, the proximal section 1206A and the distal section 1210A are each coupled to the primary tube 1202A, while the intermediate section 1208A is detached from the primary tube 1202A and can generally move relative to the primary tube 1202A.

[0128] Figure 12B is an isometric projection of the overtube assembly 1200B, including a single connection point for the secondary tube 1204B to the primary tube 1202B. More specifically, the secondary tube 1204A is shown to include a distal section 1210B that is connected to the primary tube 1202B, but otherwise is separated from the primary tube 1202B.

[0129] As previously stated, the overtube assemblies according to this disclosure may include a secondary tube that is integrally formed with or coupled to the primary tube. Figure 13A is an isometric projection of an overtube assembly 1300A, which includes, for example, a secondary tube 1304A integrally formed with the primary tube 1302A. In particular, the secondary tube 1304A is also shown in Figure 13A as an enclosed structure that completely defines a secondary lumen 1306A extending through the secondary tube 1304A.

[0130] Figures 13B and 13C illustrate alternative implementations in which the secondary tube is only partially defined and includes open sides or slits along its length. For example, Figure 13B is an isometric projection of an overtube assembly 1300B including a primary tube 1302B. In contrast to the secondary tube 1304A of the overtube assembly 1300A, the overtube assembly 1300B uses an open channel 1308B instead of an enclosed tube. As shown, the open channel 1308B is generally in the form of a U-shaped tube with open sides. As with the enclosed tube in the previous implementation, the secondary tool can be inserted into the open channel 1308B from its proximal end and translated longitudinally along the primary tube 1302B. Alternatively, the open channel 1308B allows the secondary tool to be inserted into the open channel 1308B from the side. In at least some implementations, the opening channel 1308B may have an opening with a width less than the diameter of the secondary tool, so that the secondary tool can be snap-fitted into the opening channel 1308B and securely held inside the opening channel 1308B.

[0131] Figure 13C is an isometric projection of the overtube assembly 1300C, including the primary tube 1302C. In contrast to the secondary tube 1304A of the overtube assembly 1300A, the overtube assembly 1300C uses a slit tube 1308C instead of an enclosed tube. As shown, the slit tube 1308C is in the form of a C-shaped tube with open sides. As with the enclosed tube in the previous implementation, the secondary tool can be inserted into the slit tube 1308C from its proximal end and translated longitudinally along the slit tube 1308C. Alternatively, the secondary tool can be inserted laterally through the slit in the slit tube 1308C. Similar to the case of the opening channel 1308B of the overtube assembly 1300B, the slit in the slit tube 1308C may have a width less than the diameter of the secondary tool so that the secondary tool can be snap-fitted into the slit tube 1308C and securely held inside the slit tube 1308C.

[0132] The overtube assemblies according to this disclosure may include an external sheath, or may be used otherwise with it. In certain embodiments, such an external sheath may simply provide another protective layer between the overtube assembly and the wall of the physiological lumen into which the overtube assembly is inserted. However, in other embodiments, the sheath may also facilitate the retention of the secondary tube, particularly when the secondary tube is only partially connected to the primary tube (for example, in the embodiments of Figures 12A and 12B).

[0133] For example, Figures 14A and 14B are isometric projections of the respective sheathed overtube assemblies. More specifically, Figure 14A illustrates an overtube assembly 1400A in which the sheath 1450A is fitted to cover the primary tube 1402A and secondary tube 1404A of the overtube assembly 1400A. In this configuration, the sheath 1450A may be loose along the entire length of the overtube assembly 1400A.

[0134] Figure 14B illustrates the overtube assembly 1400B, including a sheath 1450B fitted to cover the primary tube 1402B and secondary tube 1404B of the overtube assembly 1400B. In contrast to the sheath 1450A of the overtube assembly 1400A, the sheath 1450B of the overtube assembly 1400B is coupled to the primary tube 1402B at its distal end. Thus, the sheath 1450B forms a space around the primary tube 1402B through which the secondary tube 1404B extends and through which the secondary tube 1404B is held internally. Therefore, an implementation in which the sheath 1450B is partially coupled to the primary tube 1402B can be particularly useful when the secondary tube 1404B is only partially coupled to the primary tube 1402B, since the sheath 1450B and the space it defines provide loose constraint on the secondary tube 1404B.

[0135] The overtube assemblies according to this disclosure may include a primary tube along which a secondary tube extends. For example, Figure 15A is an isometric projection of an overtube assembly 1500A, which includes a primary tube 1502A formed integrally with a secondary tube 1504A. Similarly, Figure 15B is an isometric projection of an overtube assembly 1500B, which includes a primary tube 1502B and a separately formed secondary tube 1504B. As previously discussed, in an embodiment in which the separately formed secondary tube 1504B is formed separately from the primary tube 1502B, the separately formed secondary tube 1504B may be joined to the primary tube 1502B, completely or partially, by means of adhesive or welding. The retention of the separately formed secondary tube 1504B on the primary tube 1502B may be further enhanced by an auxiliary jacket or sheath (not shown) positioned around the primary tube 1502B and the separately formed secondary tube 1504B.

[0136] In the implementations shown in Figures 15A and 15B, the secondary tube is depicted as substantially linear. In contrast, Figures 16A and 16B illustrate implementations in which the secondary tube extends helically around the primary tube. For example, Figure 16A illustrates an overtube assembly 1600A, which is a helical variation of the overtube assembly 1500A in Figure 15A. More specifically, the overtube assembly 1600A includes a primary tube 1602A, around which a secondary tube 1604A extends in a helical configuration. Similar to the case of the secondary tube 1504A in the overtube assembly 1500A, the secondary tube 1604A is formed integrally with the primary tube 1602A.

[0137] Figure 16B illustrates the overtube assembly 1600B, which is a helical variation of the overtube assembly 1500B in Figure 15B. More specifically, the overtube assembly 1600B includes a primary tube 1602B, around which a secondary tube 1604B extends in a helical configuration. Similar to the secondary tube 1504B of the overtube assembly 1500B, the secondary tube 1604B is formed separately but is coupled to the primary tube 1602B.

[0138] Prior implementations of this disclosure generally include a single secondary tube and a single corresponding secondary lumen defined through the secondary tube; however, the overtube assembly according to this disclosure may alternatively include multiple secondary tubes.

[0139] For example, Figure 17A is a cross-section of an overtube assembly 1700A, which includes a primary tube 1702A and one secondary tube 1704A. In contrast, Figure 17B is a cross-section of an overtube assembly 1700B, which includes a primary tube 1702B with multiple secondary tubes distributed around it. More specifically, the overtube assembly 1700B includes four secondary tubes (e.g., secondary tube 1704B) distributed around the primary tube 1702B. As shown, the secondary tubes are substantially identical and are evenly distributed around the primary tube 1702B such that the secondary tubes are positioned at approximately a 90-degree offset.

[0140] More generally, the overtube assemblies according to this disclosure may include any number of secondary tubes distributed around the external or internal surface of the primary tube. In particular, the inclusion of multiple secondary tubes / working channels may improve the axial symmetry of the overtube assembly, thereby reducing snap-through action and improving the torsional properties of the overtube assembly. In embodiments including multiple secondary tubes, the secondary tubes may be evenly distributed and substantially similar (as in the case of overtube assembly 1700B). More broadly, this disclosure assumes that the distribution, size, orientation, etc., of the secondary tubes may vary within a given overtube assembly.

[0141] Figures 18A-18C illustrate an overtube assembly 1800 that includes a primary tube 1802 and a plurality of secondary tubes arranged around the outer surface of the primary tube 1802. More specifically, as in overtube assembly 1700B, the overtube assembly 1800 also includes four secondary tubes 1804-1810 evenly distributed around the primary tube 1802.

[0142] Figure 18A illustrates an overtube assembly 1800 in a first configuration in which secondary tubes 1804-1810 extend linearly along the primary tube 1802. On the other hand, Figure 18C illustrates an overtube assembly 1800 having secondary tubes 1804-1810 having a helical configuration.

[0143] Figures 19A–19C illustrate an alternative implementation of an overtube assembly 1900, configured to include a primary tube 1902 and a plurality of secondary tubes arranged around the outer surface of the primary tube 1902. More specifically, the overtube assembly 1900 includes four channels 1904–1910 evenly distributed around the primary tube 1902. In a particular implementation, each of the channels 1904–1910 may be configured to hold a corresponding secondary tool. Alternatively, one or more of the channels 1904–1910 may be configured to receive a secondary tube shaft or similar structure providing a secondary lumen, for example, as shown in Figures 8D–8F.

[0144] Figure 19A illustrates the overtube assembly 1900 in a first configuration in which channels 1904-1910 extend linearly along the primary tube 1902. On the other hand, Figure 19C illustrates the overtube assembly 1900 having channels 1904-1910 having a helical configuration.

[0145] Figures 20A–20C illustrate an alternative implementation of the overtube assembly 2000, which includes the primary tube 2002. The overtube assembly 2000 includes the secondary tube 2004 and channels 2006–2010, each distributed around the outer surface of the primary tube 2002. As in the previous implementation, each of the channels 2006–2010 may be configured to hold the corresponding secondary tool. Alternatively, one or more of the channels 2006–2010 may be configured to receive a secondary tube shaft or similar structure providing a secondary lumen, for example, as shown in Figures 8D–8F.

[0146] Figure 20A illustrates the overtube assembly 2000 in a first configuration in which the secondary tube 2004 and channels 2006-2010 extend linearly along the primary tube 2002. On the other hand, Figure 20C illustrates the overtube assembly 2000 having a helical configuration of the secondary tube 2004 and channels 2004-2010.

[0147] Figures 21A–21C are isometric projections of various overtube sections according to this disclosure, illustrating different longitudinal positions of secondary tube openings. First, Figure 21A is an isometric projection of an overtube assembly 2100A, which comprises a primary tube 2102A and a secondary tube 2104A, the secondary tube 2104A may be integrally formed with or coupled to the primary tube 2102A. As shown, the primary tube 2102A includes a distal opening 2106A, and the secondary tube 2104A includes a distal opening 2108A which is substantially co-terminated.

[0148] In contrast, Figure 21B is an isometric projection of the overtube assembly 2100B, which includes the primary tube 2102B and the secondary tube 2104B. The primary tube 2102B includes a distal opening 2106B, and the secondary tube 2104B includes a distal opening 2108B. In contrast to the previous implementation, the primary tube 2102B and the secondary tube 2104B are configured such that the distal opening 2106B of the primary tube 2102B is proximal to the distal opening 2108B of the secondary tube 2104B. In other words, the secondary tube 2104B extends distally beyond the distal limit of the primary tube 2102B.

[0149] As yet another example, Figure 21C is an isometric projection of an overtube assembly 2100C, which includes a primary tube 2102C and a secondary tube 2104C. The primary tube 2102C includes a distal opening 2106C, and the secondary tube 2104C includes a distal opening 2108C. In the overtube assembly 2100C, the primary tube 2102C and the secondary tube 2104C are configured such that the distal opening 2108C of the secondary tube 2104C is proximal to the distal opening 2108B. In other words, the primary tube 2102C extends distally beyond the distal limit of the secondary tube 2104C.

[0150] Prior implementations of this disclosure generally include a secondary tube that is substantially continuous along the length of the primary tube. In contrast, Figures 22A and 22B illustrate implementations that include a discontinuous secondary tube.

[0151] First, Figure 22A is an isometric projection of the overtube assembly 2200A, which includes the primary tube 2202A and the secondary tube assembly 2204A. As shown, the secondary tube assembly 2204A includes a series of discontinuous but linearly aligned tubules (e.g., tubule 2206A) that are coupled to and distributed along the primary tube 2102A. Collectively, the tubules of the secondary tube assembly 2204A approximate a continuous tubular structure through which a secondary tool can be inserted.

[0152] Figure 22B is an isometric projection of the overtube assembly 2200B, which includes the primary tube 2202B and the secondary tube assembly 2204B. In contrast to the tubular secondary tube assembly 2204A, the secondary tube assembly 2204B is formed from a series of linearly aligned rings (e.g., ring 2208B) that are connected to and distributed along the primary tube 2202B. Similar to the tubular secondary tube assembly 2204A, the rings of the secondary tube assembly 2204B approximate a continuous tubular structure through which a secondary tool can be inserted.

[0153] In general, the discontinuous structure of the secondary tube assembly illustrated in Figures 22A and 22B reduces any bending stiffness that may be imparted to the primary tube by an alternative continuous secondary tube. As with other embodiments of this disclosure, the discontinuous structure illustrated in Figures 22A and 22B has been demonstrated to provide improved torsional properties and reduced snap-through action. In other words, the discontinuous secondary tube assemblies of overtube assembly 2200A and overtube assembly 2200B effectively function as living hinges that provide reduced resistance to bending. In particular, in certain embodiments, a jacket, sheath, or similar external layer may be applied around the secondary tube assembly to form a substantially continuous internal space of the secondary tube assembly. In such embodiments, the jacket, sheath, etc., may be formed from a thin or alternative flexible material to reduce any influence on the flexibility of the overtube assembly.

[0154] As previously stated in the implementation of this disclosure, the overtube assembly according to this disclosure may include a secondary tube having a steerable distal end. As an alternative to the steerable configuration, the distal end of the secondary tube may be fixed so that tools and materials exiting the distal end of the secondary tube are directed in a particular direction.

[0155] For example, Figures 23A and 23B are isometric and side elevation views of an overtube assembly 2300, which includes a primary tube 2302 and a secondary tube 2304 coupled to and extending along the primary tube 2302. The secondary tube 2304 terminates with a distal tip 2306 that extends distally beyond the distal limit of the primary tube 2302. As shown, the distal tip 2306 is angled such that the distal opening 2308 of the secondary tube 2304 is oriented toward the longitudinal axis 2310 of the primary tube 2302. More generally, the distal tip 2306 can be rotated from the orientation shown in Figures 23A and 23B to bias any tool or material exiting the distal opening 2308 in a desired direction. Orienting the secondary tube in a direction other than coaxial with the primary tube allows for the “biasing” of the tool to exit the secondary tube in a non-coaxial manner. This may facilitate easier interaction with the physiological lumen when the overtube assembly is advanced and rotated.

[0156] The overtube assemblies according to this disclosure may include one or more inflatable balloons to facilitate retention of the overtube assembly within the physiological lumen. Generally, the overtube assembly includes, or can be coupled to, a source of air or other fluid, and also includes one or more air supply lumens extending through the overtube assembly from the source to the balloon to facilitate controlled inflation and deflation of the balloon.

[0157] When contained within a physiological lumen, the balloon can substantially resist both longitudinal and rotational motion. Therefore, certain implementations of this disclosure include bearings or similar support elements that allow rotation of the inflatable balloon over the tube.

[0158] Figures 24A and 24B are isometric projections of, for example, an overtube assembly 2400. The overtube assembly 2400 includes a primary tube 2402, a secondary tube 2404 coupled to the primary tube 2402, and a balloon 2406 coupled to the distal portion of the overtube assembly 2400. Figure 24A illustrates the overtube assembly 2400 in a first state before the rotation of the primary tube 2402 and secondary tube 2404 relative to the balloon 2406, while Figure 24B illustrates the overtube assembly 2400 in a second state after the rotation of the primary tube 2402 and secondary tube 2404 relative to the balloon 2406.

[0159] To facilitate the rotation of the primary tube 2402 and secondary tube 2404 relative to the balloon 2406, the overtube assembly 2400 may include one or more bearings or similar elements that fix the balloon 2406 longitudinally. For example, the overtube assembly 2400 includes a proximal bearing 2408 coupled to the proximal end of the balloon 2406, and a distal bearing 2410. In a particular embodiment, each of the proximal bearing 2408 and the distal bearing 2410 may include an inner race shaped to receive the primary tube 2402 and secondary tube 2404, or shaped to engage with the tubular structure of the overtube assembly 2400 in a manner that is otherwise fixed longitudinally. Each of the proximal bearing 2408 and the distal bearing 2410 may also include an outer race or similar bearing element that is longitudinally constrained relative to the inner race but freely rotatable relative to the inner race. The external race is further coupled to the balloon 2406, thereby constraining the balloon 2406 in the longitudinal direction while simultaneously allowing the balloon 2406 to rotate relative to the primary tube 2402 and the secondary tube 2404. Each of the proximal bearing 2408 and the distal bearing 2410 may be sealed or otherwise include a sealing element to prevent air from leaking out of the balloon 2406 through the bearing.

[0160] Figures 25A and 25B illustrate an overtube assembly 2500, including an alternative handle design for the overtube assembly according to this disclosure. The overtube assembly 2500 is substantially similar to the overtube assembly 500 discussed above in relation to Figure 5.

[0161] Referring first to Figure 25A, the overtube assembly 2500 includes a tube assembly 2501, which includes a primary tube 2502 and a secondary tube 2504, with the balloon 2506 coupled to the distal portion of the tube assembly 2501. The handle assembly 2508 is coupled to the proximal end of the tube assembly 2501. In particular, the handle assembly 2508 includes a control element 2510 configured to modify the inflation and deflation of the balloon 2506, more specifically to control an air supply unit communicating with the internal space of the balloon 2506.

[0162] As shown in Figure 25A, the overtube assembly 2500 is a standalone overtube assembly in which the control element 2510 is in the form of a lever or switch. During operation, the user can press down the control element 2510 to control the airflow into or out of the balloon 2506, resulting in the inflation and deflation of the balloon 2506, respectively. For example, in a particular implementation, the handle assembly 2508 may include an internal mechanical pump mechanism driven by pressing down the control element 2510. In such an implementation, the user can repeatedly press down the control element 2510 to activate the pump mechanism and cause airflow into / out of the balloon 2506. Alternatively, the handle assembly 2508 may include an electromechanical pump, and the control element 2510 functions as a switch for selectively activating and deactivating the electromechanical pump. In yet another implementation, the handle assembly 2508 may contain pressurized air or other fluid, and the operation of the control element 2510 may mechanically or electromechanically actuate a valve element inside the handle assembly 2508 to release the pressurized fluid into the balloon 2506.

[0163] Figure 25B illustrates an alternative implementation in which the overtube assembly 2500 is coupled to an external air supply system (not shown) by an air supply line 2512. In such an implementation, the control element 2510 may also facilitate mechanical or electromechanical control of the airflow into and / or out of the balloon 2506. For example, the air supply line 2512 may communicate with an air supply lumen extending through the tube assembly 2501, and a valve element may be positioned along the airflow passage. In such an implementation, the control element 2510 may mechanically or electromechanically open and close the valve, thereby allowing airflow into or out of the balloon 2506 in accordance with the airflow direction of the external air supply system.

[0164] Alternatively, the handle assembly 2508 may include an interface for communicating with suitable electronic equipment and an external air supply system. For example, the handle assembly 2508 may connect to and communicate with an external air supply system by a wired or wireless link. In such an implementation, when the control element 2510 is operated or otherwise activated by the user, the handle assembly 2508 may transmit corresponding control signals to the external air supply system to control the operation of the air supply system (e.g., to start or stop the flow to the balloon 2506, to change the direction of the flow, to change the amount of flow, etc.), and the control element 2510 may act as a control input.

[0165] As previously discussed in relation to Figures 24A and 24B, certain embodiments of the present disclosure may include an inflatable balloon that can rotate independently of a tube assembly to which the balloon is coupled. The present disclosure assumes that in at least certain embodiments, the balloon and the tube assembly may be coupled together by a ratchet coupling such that rotation of the tube assembly in a first direction results in the tube assembly rotating independently of the balloon, while rotation of the tube assembly in a second direction results in torque transmission from the tube assembly to the balloon, thereby driving the rotation of the balloon.

[0166] This ratchet concept is illustrated in Figures 26A–26C, which are isometric projections of the overtube assembly 2600 at various stages of ratchet rotation. The overtube assembly 2600 includes a tube assembly 2601, which includes a primary tube 2602 and a secondary tube 2604 extending from the handle assembly 2608. The tube assembly 2601 is fixed to the handle assembly 2608 both longitudinally and rotationally, such that the longitudinal motion of the handle assembly 2608 causes the tube assembly 2601 to translate, and the rotation of the handle assembly 2608 imparts torque to the tube assembly 2601. The overtube assembly 2600 further includes a balloon 2606 coupled to the distal end of the tube assembly 2601. The balloon 2606 is fixed longitudinally to the tube assembly 2601 but includes a ratchet bearing that allows for selective rotation of the balloon 2606 relative to the tube assembly 2601.

[0167] Referring first to Figure 26A, the overtube assembly 2600 is illustrated in a first state where a clockwise torque (relative to the operator's viewpoint) is applied to the handle assembly 2608, as indicated by arrow 2620. Figure 26B illustrates the overtube assembly 2600 after the application of the torque corresponding to arrow 2620, showing the handle assembly 2608 and tube assembly 2601, although the balloon 2606 remains stationary.

[0168] Figure 26B further shows a second torque applied in a counterclockwise direction to the handle assembly 2608 (e.g., indicated by arrow 2622). Due to the ratchet-like coupling of the balloon 2606 to the tube assembly 2601, the torque applied to the handle assembly 2608 is transmitted to the balloon 2606, as indicated by arrow 2624, resulting in rotation of the handle assembly 2608, the tube assembly 2601, and the balloon 2606.

[0169] In general, during use of the overtube assembly of this disclosure with an elongated tool such as an endoscope, the elongated tool extends through at least a portion of the handle assembly of the overtube assembly. To improve the utility of the overtube assembly and the control of the elongated tool, in at least certain embodiments, the handle assembly may include a mechanism for attaching or otherwise locking the elongated tool to the overtube assembly.

[0170] As a non-limiting example, Figure 27 is a partial cross-sectional top view of an overtube assembly 2700 including a pinch-type locking mechanism. More specifically, the overtube assembly 2700 includes a tube assembly 2701, which further includes a primary tube 2702 and a secondary tube (hidden). The tube assembly 2701 is coupled at its proximal end to a handle assembly 2708 and supports an inflatable balloon 2706 at its distal end.

[0171] An overtube assembly 2700 in use with an elongated tool 2750 is illustrated. More specifically, the elongated tool 2750 is shown partially inserted into the handle assembly 2708 and before further insertion through the tube assembly 2701. As shown, the handle assembly 2708 includes a pinch lock 2710 which can be selectively engaged by the user of the overtube assembly 2700. In a particular embodiment, the pinch lock 2710 may be configured to engage with a corresponding locking feature of the elongated tool 2750; however, in other embodiments, the pinch lock 2710 may include one or more blocks or similar elements configured to frictionally engage with the elongated tool 2750, thereby preventing or at least providing substantial resistance to the longitudinal movement of the elongated tool 2750 relative to the overtube assembly 2700.

[0172] In certain implementations, the pinch lock 2710 may be engaged and disengaged using a cam mechanism. As another example, the pinch lock 2710 may include a spring-loaded mechanism that engages with the pinch lock 2710 when pressed down once and disengages it when pressed down a second time. Other locking mechanisms suitable for use in the overtube assembly 2700 may include a wedge-type lock that selectively frictionally engages with the elongated tool 2750, and a Touhy Borst-type clamping mechanism.

[0173] Figures 28 and 29 are a side view and an isometric projection view, respectively, of the overtube assembly 2800 coupled to the elongated tool 2850. As shown, the overtube assembly 2800 includes a tube assembly 2801 coupled to the handle assembly 2808 and extending distally from the handle assembly 2808.

[0174] As most clearly illustrated in Figure 29, the tube assembly 2801 can be coupled to the handle assembly 2808 such that the proximal end and opening of the tube assembly 2801 are co-terminated with the proximal end of the handle assembly 2808. Next, the elongated tool 2850 is inserted into the proximal opening of the tube assembly 2801.

[0175] During operation, the elongated tool 2850 may be susceptible to bending and other motions, which can impart strain and stress to the overtube assembly 2800, particularly to the proximal portion of the tube assembly 2801. In the implementations illustrated in Figures 28 and 29, a considerable portion of the typically strain-prone proximal portion of the tube assembly 2801 is received inside the handle assembly 2808 and firmly supported by the handle assembly 2808. In other words, the handle assembly 2808 functions as a strain-relieving mechanism for the tube assembly 2801.

[0176] As described throughout this disclosure, the overtube assemblies according to this disclosure generally include a primary lumen through which an endoscope or similar elongated tool may be placed, and an auxiliary working channel / secondary tube through which an auxiliary tool may extend. In implementations involving a working channel / secondary tube, the overtube assemblies may include a proximal control assembly that includes a control element adapted to selectively control the extension and retraction of the auxiliary tool relative to the distal end of the overtube assemblies.

[0177] As a non-limiting example, Figures 30A–30C are isometric projections of the overtube assembly 3000. The overtube assembly 3000 includes a primary tube 3002 defining a primary lumen 3003 and a secondary tube 3004 defining a secondary lumen 3005, through which a tool 3006 is shown to extend. More specifically, the tool 3006 is shown protruding from the distal end 3008 of the overtube assembly 3000.

[0178] As shown, the overtube assembly 3000 includes a proximal handle assembly 3010 shaped to receive and engage with the primary tube 3002. Among other features, the proximal handle assembly 3010 includes a control element 3012 configured to selectively extend and retract the tool 3006 from the secondary lumen 3005 of the secondary tube 3004.

[0179] In a particular implementation, the control element 3012 may be in the form of a slider configured to engage with the proximal portion of the tool 3006 and move longitudinally relative to the primary tube 3002. As illustrated, the control element 3012 is generally positioned to be easily operated by an operator of the overtube assembly 3000, for example, using the thumb. By translating the slider distally, the tool 3006 can be retracted relative to the distal end 3008 of the overtube assembly 3000 (for example, as shown in Figure 30B), and by translating the slider proximal, the tool 3006 can be extended relative to the distal end 3008 of the overtube assembly 3000 (for example, as shown in Figure 30A). In an alternative implementation, the control element 3012 may be in the form of a rotatable handle that frictionally engages with the tool 3006, such that rotation of the control element 3012 toward its distal end 3008 results in distal extension of the tool 3006 relative to the primary tube 3002, and rotation of the control element 3012 proximal away from its distal end 3008 results in proximal retraction of the tool 3006 relative to the primary tube 3002.

[0180] Figure 31 is an isometric projection of an overtube assembly 3100 containing multiple balloons. More specifically, the overtube assembly 3100 includes a first balloon 3106A located at a first location corresponding to the distal end of the overtube assembly 3100, and a second balloon 3106B located proximal to the first balloon 3106A. As further shown in Figure 31, the overtube assembly 3100 includes a primary tube 3102 and a secondary tube 3104, each extending through each of the inflatable balloons to the distal end of the overtube assembly 3100.

[0181] As previously discussed, implementations of the present disclosure may include, or be connectable to, an air supply unit for selectively inflating and deflating an inflatable balloon of an overtube assembly. More specifically, the proximal portion of the overtube assembly may include an air supply port connectable to an air supply mechanism (e.g., a manual pump) or external air supply equipment for providing air to one or more air supply lumens. The air supply lumens extend through the overtube body of the overtube assembly and communicate with the internal space of the inflatable balloon. Thus, to selectively control the inflation of the balloon, air can be injected or withdrawn through the air supply lumens by an air supply mechanism or air supply equipment.

[0182] This disclosure assumes that an overtube assembly containing multiple balloons may include various mechanisms for ordering the inflation of the balloons. For example, in one particular embodiment, two or more balloons may be configured to be able to inflate simultaneously by sharing an air supply lumen. In other embodiments, the inflatable balloons of an overtube assembly may be divided into subsets of one or more balloons, each subset of which is able to inflate by its respective air supply lumen. In embodiments containing multiple air supply lumens, the proximal portion of the overtube assembly may include a respective air supply mechanism or port for each air supply lumen, or a switch / valve mechanism configured to selectively direct air from the air supply mechanism or port to a subset of air supply lumens.

[0183] Figures 32A–32C are isometric projections of the overtube assembly 3100 in various inflation states, demonstrating the selective inflation of balloons in the multi-balloon implementation of this disclosure. First, Figure 32A illustrates the overtube assembly 3100 with the first balloon 3106A and the second balloon 3106B each in a deflated or low-inflated state. In contrast, Figure 32B illustrates both the first balloon 3106A and the second balloon 3106B in a fully or substantially inflated state, while Figure 32C illustrates the first balloon 3106A in a fully / substantially inflated state and the second balloon 3106B in a deflated or low-inflated state. Although not specifically shown, the overtube assembly 3100 may also be configured such that the first balloon 3106A is in a deflated or low-inflated state and the second balloon 3106B is in a fully / substantially inflated state.

[0184] As discussed previously, in certain embodiments of the present disclosure, the first balloon 3106A and the second balloon 3106B may be configured to inflate and deflate simultaneously, for example, using a single air supply lumen and a single air supply source (e.g., a manual pump or auxiliary air supply device) communicating with both balloons. In such embodiments, the overtube assembly 3100 may transition between the states shown in Figures 32A and 32B by simultaneous addition of air or simultaneous removal of air from the first balloon 3106A and the second balloon 3106B.

[0185] In an embodiment in which the first balloon 3106A and the second balloon 3106B are independently controllable, the overtube assembly 3100 can be easily transitioned between any of the states shown in Figures 32A-32C, as well as between states not shown in Figures 32A-32C, in which the first balloon 3106A is deflated and the second balloon 3106B is substantially inflated. For example, each of the first balloon 3106A and the second balloon 3106B may be coupled to its respective air supply unit and its respective control unit (e.g., a valve or switch) adapted to control whether air is supplied to or discharged from the corresponding balloon. Alternatively, the proximal control assembly of the overtube assembly 3100 may include a first control unit for selecting a particular balloon and a second control unit for modifying the direction of the airflow for that balloon.

[0186] Previous examples of overtube assemblies included in this disclosure generally include at least one inflatable balloon located at or near the distal end of the overtube assembly. The implementation of this disclosure is not limited to such configurations, and the disclosure assumes that the balloon may be positioned or distributed in any manner suitable for the intended application of the overtube assembly. As a non-limiting example, Figure 33A is an isometric projection of an overtube assembly 3300A illustrating a first alternative balloon position. More specifically, the overtube assembly 3300A illustrates an example of an implementation in which an inflatable balloon 3306A is located in the distal portion of the overtube assembly 3300A, but is offset proximal to the distal ends of the primary tube 3302A and secondary tube 3304A of the overtube assembly 3300A. Figure 33B illustrates an example of a more common implementation of the overtube assembly 3300B, in which the inflatable balloon 3306B is positioned at any suitable position and any suitable proximal offset relative to the distal ends of the overtube body 3302B and secondary tube 3304B of the overtube assembly 3300B.

[0187] As illustrated in the figures and as discussed in earlier portions of this disclosure, the overtube assembly according to this disclosure may include one or more inflatable balloons arranged along the length of the overtube body.

[0188] Generally, each of the preceding examples of implementations included a balloon configured to inflate symmetrically around the overtube body of the overtube assembly. For example, Figures 34A and 34B are isometric and side elevation views of an overtube assembly 3400. The overtube assembly 3400 includes an overtube body 3402 defining a primary channel adapted to receive an elongated tool such as an endoscope, and a secondary tube 3404 extending along the primary channel and configured to receive an auxiliary tool. The overtube assembly 3400 further includes a balloon 3406 that can be selectively inflated from a proximal port (not shown) of the overtube assembly 3400. As shown in Figures 34A and 34B, the balloon 3406 is coupled to the overtube body 3402 such that the balloon 3406 extends substantially evenly around the overtube body 3402. Therefore, when inflated, deflated, and in the absence of obstruction, the balloon 3406 generally inflates and collapses uniformly and symmetrically around the overtube body 3402.

[0189] In contrast, Figures 35A and 35B are isometric and side elevation views of the overtube assembly 3500, which includes an asymmetric balloon. More specifically, the overtube assembly 3500 includes an overtube body 3502 defining a primary channel adapted to receive an elongated tool such as an endoscope, and a secondary tube 3504 extending along the primary channel and configured to receive an auxiliary tool. The overtube assembly 3500 further includes a balloon 3506 that can be selectively inflated from a proximal port (not shown) of the overtube assembly 3500. In contrast to the balloon 3406 of the overtube assembly 3400, which is symmetrically mounted around the overtube body 3402 and configured to inflate / deflate substantially uniformly, the balloon 3506 is asymmetrically mounted on the side of the overtube body 3502, so that when the balloon 3506 is inflated and deflated, it extends substantially laterally from one side of the overtube body 3502.

[0190] More generally, the implementation of the present disclosure may include a balloon configured to inflate and deflate unevenly around an overtube body to which the balloon is bonded. Such unevenness can be achieved in a variety of ways, not limited to, asymmetrically bonding a given balloon to its overtube and selectively modifying the properties of the balloon around its periphery (e.g., material choice / elasticity, thickness, etc.) such that certain portions of the balloon have different strain characteristics.

[0191] As discussed, the implementation of the overtube assembly according to the present disclosure may include an inflatable balloon that can be selectively inflated from the proximal end of the overtube assembly by a pumping mechanism such as a manual, hand-operated pump, or by connection to an auxiliary air / fluid supply system. To do so, the overtube assembly includes one or more air supply lumens (or more generally, fluid supply lumens) that extend from the proximal end of the overtube assembly and communicate with the internal space of one or more inflatable balloons of the overtube assembly.

[0192] The overtube assemblies according to this disclosure may include one or more air supply lumens. The air supply lumens may be formed integrally with the primary tube of the overtube assembly (e.g., as secondary tubes in the overtube examples illustrated in Figures 8A-8C and 8G), or they may be formed separately and coupled to the primary tube (e.g., as secondary tubes in the overtube examples illustrated in Figures 8D-8F and 8H-8M). Furthermore, similar to the secondary tubes discussed above, the air supply lumens may be routed along the primary tube in the longitudinal direction, helically, or in any combination thereof. When helically wound, the pitch of the air supply lumens may be constant or variable and may be smaller, for example, in sections of the overtube assembly that are generally more susceptible to bending in order to reduce potential snap-through effects.

[0193] Further details regarding the air supply lumen and examples of configurations of the air supply lumen with an inflatable balloon can be found in U.S. Patent Application No. US17 / 721,157, which is incorporated herein by reference for all purposes.

[0194] Figure 36A is a cross-sectional view of an overtube 3600 including an integrally formed air supply lumen. Specifically, the overtube 3600 includes a primary tube 3602 defining a primary lumen 3604 (for example, for an endoscope or similar elongated tool). The overtube 3600 further includes a secondary tube 3606 or working channel defining a secondary lumen 3608, the secondary tube 3606 being positioned on the outer surface of the primary tube 3602 and integrally formed with the primary tube 3602 by, for example, an extrusion process. The overtube 3600 further includes an air supply lumen 3610 integrally formed with the primary tube 3602.

[0195] As shown in Figure 36A, the air supply lumen 3610 is positioned at a 90-degree offset from the secondary tube 3606; however, the implementation of this disclosure is not limited to any position of the air supply lumen 3610 relative to the secondary tube 3606 or the primary tube 3602. Furthermore, although the overtube 3600 includes only the air supply lumen 3610, it may include a plurality of air supply lumens, each of which may be formed integrally with the primary tube 3602 or formed using separate tubular structures (for example, as shown and discussed in Figures 37A and subsequent figures). More generally, Figure 36A is intended to illustrate one embodiment in which the air supply lumen is formed integrally with another tubular structure of the overtube assembly. Although shown as being formed integrally with the primary tube 3602, in multilayer implementations, the air supply lumen 3610 (and additional air supply lumens) may be integrated with other layers of the overtube assembly.

[0196] Referring to Figure 36B, a first configuration is illustrated in which the air supply lumen 3610 extends substantially longitudinally along the primary tube 3602. In contrast, Figure 36C illustrates an alternative configuration in which the air supply lumen 3610 is configured to spirally wrap around the primary tube 3602. Other embodiments of the present disclosure may include a configuration in which the air supply lumen 3610 is divided into a plurality of sections that vary between longitudinal, spiral, or other passages.

[0197] Figure 37A is a cross-sectional view of the overtube 3700, which includes a separately formed air supply capillary defining an air supply lumen. Specifically, the overtube 3700 includes a primary lumen 3704 and a secondary tube shaft 3706 defining a secondary lumen 3708. The overtube 3700 includes a liner 3716 surrounded by a reinforcing layer 3718, such that the liner 3716 defines the primary lumen 3704. The secondary tube shaft 3706 is positioned on the outer surface of the reinforcing layer 3718. The overtube 3700 further includes an air supply shaft 3720 defining an air supply lumen 3710. Similar to the secondary tube shaft 3706, the air supply shaft 3720 is separately formed and positioned on the outer surface of the reinforcing layer 3718. The secondary tube shaft 3706, the air supply shaft 3720, and the reinforcing layer 3718 are bundled together and enclosed by a jacket 3712.

[0198] As in the previous example, the overtube 3700 is intended to be illustrative only. Therefore, for example, the present disclosure assumes that the overtube assembly of the present disclosure may include additional air supply shafts and air supply lumens. Furthermore, although shown substantially adjacent to the secondary tube shaft 3706, the air supply shaft 3720 may be located elsewhere around the overtube 3700, relative to the secondary tube shaft 3706.

[0199] In certain implementations, each of the secondary tube shaft 3706 and the air supply shaft 3720 may extend longitudinally; however, in at least certain implementations, one or both of the secondary tube shaft 3706 and the air supply shaft 3720 may be helically wound at least partially. For example, Figure 37B illustrates a first configuration example of an overtube 3700 in which the air supply shaft 3720 extends longitudinally, while the secondary tube shaft 3706 is helically wound around a reinforcing layer 3718 (for clarity, the jacket 3712 is removed and the internal layer defining the primary lumen 3704 is combined). As previously discussed, helically wound tubular structures (e.g., the secondary tube shaft 3706 and / or air supply shaft 3720 in subsequent examples) can promote improved torsional strength and snap-through properties. To the extent that the tubular structure is spirally wound around the primary lumen, the pitch of the spiral tubular structure may vary along the length of the overtube assembly and / or may include both spiral and non-spiral divisions.

[0200] Figures 37C–37F illustrate alternatives to the overtube 3700, intended to illustrate alternative but non-limiting configurations of the overtube 3700 with different routing settings for the secondary tube shaft 3706 and the air supply shaft 3720. Figure 37C illustrates one implementation in which, for example, the air supply shaft 3720 and the secondary tube shaft 3706 are both helically wound with substantially similar pitch and direction. In the illustrated implementation, the air supply shaft 3720 runs adjacent to the secondary tube shaft 3706. In other words, the air supply shaft 3720 has a slight angular offset from the secondary tube shaft 3706 around the longitudinal axis of the overtube 3700. In contrast, Figure 37D illustrates a configuration in which the angular offset between the secondary tube shaft 3706 and the air supply shaft 3720 is larger, for example, approximately 180 degrees. More generally, the angular offset between the secondary tube shaft 3706 and the air supply shaft 3720 may vary in the implementation of this disclosure and is not limited to the adjacent configuration and 180-degree offset configuration shown in Figures 37C and 37D.

[0201] Figure 37E illustrates an implementation of the overtube 3700 in which the secondary tube shaft 3706 and the air supply shaft 3720 are helically wound in the same direction but have different pitches. Specifically, the air supply shaft 3720 is shown to have a shorter pitch than the secondary tube shaft 3706. In such an implementation, the air supply shaft 3720 may intersect the secondary tube shaft 3706 by, for example, extending below or above the secondary tube shaft 3706.

[0202] As a final non-limiting example, Figure 37F illustrates an implementation of the overtube 3700 in which the secondary tube shaft 3706 and the air supply shaft 3720 are helically wound in opposite directions but at approximately the same pitch. Similar to the previous configuration, such opposite windings of the secondary tube shaft 3706 and the air supply shaft 3720 result in periodic intersections of the secondary tube shaft 3706 and the air supply shaft 3720.

[0203] The above-described implementations of the overtube, including secondary lumens / working channels and air lumens, are provided merely as non-limiting examples. The general concepts relating to secondary and air supply lumens can be readily adapted to overtubes and overtube assemblies, including other features and concepts discussed throughout this disclosure. For example, while Figures 36A–37F illustrate an implementation of an overtube assembly including only one secondary lumen and one air supply lumen, implementations of this disclosure may include one or more secondary lumens and one or more air supply lumens, each of which is constructed according to one of the implementations included in this disclosure. Thus, for example, implementations may include combinations of integrally formed secondary lumens and / or air supply lumens and separately formed secondary lumens and / or air supply lumens.

[0204] In some examples, the secondary lumen / working channel and / or air lumen may be attached to the overtube only at its proximal and distal ends. That is, the secondary lumen / working channel and / or air lumen may not be attached to the overtube along its entire length, but only at its ends, with the remaining length hanging freely. The secondary lumen / working channel and / or air lumen attached only at its ends may extend longitudinally along the overtube or spirally wrap around the overtube. In other examples, the secondary lumen / working channel and / or air lumen may be attached to the overtube at several points by rigid means (e.g., via one or more rivets) or semi-rigid means (e.g., via one or more rubber bands). In other examples, the secondary lumen / working channel and / or air lumen may be adjacent to the overtube but not attached, so that the secondary lumen / working channel and / or air lumen may float freely within the overtube and the sleeve surrounding the secondary lumen / working channel and / or air lumen. The fact that the secondary lumen / working channel and / or air lumen are not attached to the overtube along their entire length may facilitate easier rotation of the overtube and / or reduced snap-through of the overtube. That is, the free movement of the secondary lumen / working channel and / or air lumen relative to the outside of the overtube, even if limited, may improve the rotation and snap-through of the overtube.

[0205] Figure 38 is a side view of a balloon assembly 3800 for use with an overtube assembly according to the present disclosure. The balloon assembly 3800 includes a balloon 3814 having balloon shoulders 3862 and balloon necks 3864 at each end of the balloon 3814. The balloon assembly 3800 is positioned around an overtube 3812, and the balloon shoulders 3862 and balloon necks 3864 may form a tapered diameter at the ends of the balloon 3814 toward the overtube 3812 (e.g., radially inward). In some examples, the balloon assembly 3800 may be positioned at one end of the overtube 3812. In other examples, the balloon assembly 3800 may be positioned such that the overtube 3812 extends out through each end of the balloon 3814. In other words, the overtube 3812 may extend so as to exit through the balloon shoulder 3862 and balloon neck 3864 at each end of the balloon 3814.

[0206] The thickness of the balloon assembly 3800 is greatest (e.g., thickest) at the balloon neck 3864, and the thickness may decrease radially inward from the balloon neck 3864 to the balloon shoulder 3862 and then to the balloon 3814. Tapering the thickness of the balloon assembly 3800 from the minimum diameter at the balloon neck 3864 to the maximum diameter at the center of the balloon 3814 may promote improved stability of the balloon assembly 3800 and / or greater diameter expansion of the balloon 3814 under low inflation pressure.

[0207] The tapering of the thickness of the balloon assembly 3800 may be uniform as shown in Figure 38 or non-uniform as shown in Figure 39. Figure 39 is a side view of the balloon assembly 3900 for use with an overtube assembly according to the present disclosure. The balloon assembly 3900 includes a balloon 3914 having balloon shoulders 3962 and balloon necks 3964 at each end of the balloon 3914. The balloon assembly 3900 is positioned around the overtube 3912, and the balloon shoulders 3962 and balloon necks 3964 may form a tapering diameter at the ends of the balloon 3914, toward the overtube 3912 (e.g., radially inward).

[0208] The balloon assembly 3900 is similar to the balloon assembly 3800 shown in Figure 38, but a difference is that the balloon assembly 3900 may have a non-uniform tapering thickness. Specifically, the thickness of the balloon shoulder 3962 varies based on the shape of the balloon shoulder 3962. In some embodiments, the balloon shoulder 3962 is finger-shaped, as shown in Figure 39, and the thickness of the balloon shoulder 3962 may vary between the finger-shaped portions. For example, the thickness of the balloon shoulder 3962 may taper from the vicinity of the balloon neck 3964 to the tip of the finger shape. In other embodiments, the balloon shoulder 3962 is formed into one or more alternative shapes, and the thickness of the balloon shoulder 3962 may vary between the portions of the alternative shapes. The non-uniform tapering thickness of the balloon assembly 3900, specifically the balloon shoulder 3962, may facilitate improved folding of the balloon assembly 3900 when it is deflated (for insertion, etc.) while maintaining the required stability. In some examples, the balloon shoulder 3962 may be visually distinct from the surface of the balloon 3914. In other examples, the balloon shoulder 3962 may be integrated into the surface of the balloon 3914 for a seamless appearance.

[0209] Figure 40 is a side view of a balloon assembly 4000 for use with an overtube assembly according to the present disclosure. The balloon assembly 4000 includes a balloon 4014 having balloon shoulders 4062 and balloon necks 4064 at each end of the balloon 3814. The balloon assembly 4000 is positioned around an overtube 4012, and the balloon shoulders 4062 and balloon necks 4064 can form a tapered diameter at the ends of the balloon 4014, toward the overtube 4012 (for example, radially inward).

[0210] The balloon assembly 4000 is similar to the balloon assemblies 3800 and 3900 shown in Figures 38 and 39, except that the balloon assembly 3900 may have a non-uniform thickness. Specifically, the balloon 4014 may have one or more raised portions 4066 and one or more recessed portions 4068 around its circumference, formed by varying the thickness of the balloon 4014 around its circumference. In some examples, the thickness of the balloon 4014 may be greater at one or more raised portions 4066 than at one or more recessed portions 4068. Although shown extending laterally around the balloon 4014 in Figure 40, one or more raised portions 4066 and one or more recessed portions 4068 may also extend longitudinally along the length of the balloon 4014.

[0211] Figures 41A and 41B are isometric projections of the overtube assembly 4100 for use with an endoscope 4102. The overtube assembly 4100 includes a collar 4170 for attachment to the distal end of the endoscope 4102. This distinguishes the overtube assembly 4100 from the overtube assemblies of the present disclosure described earlier that receive the entire length of the endoscope through the overtube. The overtube assembly 4100 also includes a balloon 4114, a secondary tube 4106 (also referred to herein as a working channel), and an air supply lumen 4172. In some examples, when the distal end of the endoscope 4102 is received by the collar 4170, a securing mechanism 4174 may be used to attach the secondary tube 4106 and / or the air supply lumen 4172 to the endoscope 4102. The securing mechanism 4174 may, among other things, be a strap, a band, or a helical wrapping. In other examples, when the distal end of the endoscope 4102 is received by the collar 4170, the secondary tube 4106 and / or air supply lumen 4172 may float freely alongside the endoscope 4102. Figures 42A and 42B are side views of the overtube assembly 4100 for use with the endoscope 4102.

[0212] Figure 43 is a side view of the overtube assembly 4300. The overtube assembly 4300 includes an overtube 4312 and a balloon 4314, the overtube 4312 having one or more protrusions 4376 extending radially outward from the outer surface of the overtube 4312. An overtube assembly having a balloon as described herein may include texture on the balloon to facilitate improved fastening of the overtube to the wall of the surrounding lumen. The protrusions 4376 of the overtube assembly 4300 may be alternative features to improve the fastening of the overtube 4312 to the wall of the surrounding lumen. For example, the protrusions 4376 may be smooth, flat, ribbed, or textured to facilitate improved positioning of the overtube 4312 with respect to the lumen. The overtube 4312 may also have one or more air holes 4378 positioned adjacent to the protrusions 4376. To facilitate improved positioning of the overtube 4312 with respect to the lumen, a vacuum may be applied to the air vent 4378 from the inside of the overtube 4312. For example, a vacuum drawn through the air vent 4378 can help remove air pockets between the overtube 4312 and the surrounding lumen, keeping the overtube 4312 in place. The raised portion 4376 may have a radially extending height from the overtube 4312 to minimize tissue suction through the air vent 4378 when a vacuum is applied.

[0213] Figure 44 is an isometric projection of the overtube assembly 4300. The overtube assembly 4300 may include a secondary tube 4306. In some examples, the overtube assembly 4300 may include a balloon 4314 as shown. In other examples, the overtube assembly 4300 may not include a balloon. The overtube assembly 4300 may be used with an endoscope 4302.

[0214] Figures 45A and 45B are isometric and side cross-sectional views of the overtube assembly 4300. The overtube 4312 may include one or more air channels 4380 that are in fluid communication with the air vents 4378. When a vacuum is applied to the air vents 4378 from the inside of the overtube 4312, air may be drawn through the air vents 4378 along the air channels 4380. In some examples, one or more air vents 4378 may be in fluid communication with one or more shared air channels 4380. In other examples, one or more air vents 4378 may have separate air channels 4380.

[0215] The overtube assemblies described herein may include an end cap at the proximal end of the overtube to facilitate easier insertion of the overtube into the patient's lumen. Figures 46A and 46B are end view and isometric projection views of an end cap 4600 for use with an overtube such as one or more of the overtubes described herein. The end cap 4600 on the proximal end of the overtube may facilitate reduced tissue damage when the overtube is inserted into the lumen. The end cap 4600 may be made of a soft durometer material to assist in the insertion of the overtube into the lumen. The end cap 4600 may be formed from at least one of nylon, PFA, PET, PTFE, FEP, HDPE, TPPE, silicone, PVC, other thermopolymers, or any other suitable material. The end cap 4600 may be formed from a material with a Shore A hardness from 20 to a maximum of 80 Shore A. The end cap 4600 may also be formed using multiple materials. The end cap may be coated to allow for desired friction performance. The end cap 4600 may be sized and / or shaped to minimize the gap between the scope and the overtube of the overtube assembly, thereby minimizing tissue intrusion into the gap.

[0216] The end cap 4600 includes an end cap body 4682, one or more sizing features 4683, one or more directional features 4684, and a body slit 4685 for receiving a tool inserted through the working channel of the overtube assembly. The sizing features 4683 allow various endoscopes to pass through while maintaining a minimum gap between the endoscope and the side surface of the end cap 4600. In one embodiment, endoscopes with cross-sectional widths from about 7.0 mm to a maximum of about 13 mm can be accommodated by the end cap 4600. In another embodiment, the end cap 4600 can accommodate endoscopes with cross-sectional widths from about 3.0 mm to a maximum of about 8 mm. In yet another embodiment, the end cap 4600 can accommodate endoscopes with various cross-sectional widths from about 9 mm to a maximum of about 15 mm. Minimizing this gap prevents potentially tissue from entering the end cap 4600 and being damaged during use. The end cap body 4682 may have a streamlined (e.g., chamfered) profile. The width and / or height of the main body slit 4685 may vary to accommodate the various tools accepted by the work channel. In some examples, the main body slit 4685 may have a width substantially equal to the width of the tool accepted by the work channel. In other examples, the main body slit 4685 may have a width that is small enough to be visually inconspicuous.

[0217] The number, shape, and / or size of the sizing features 4683 can vary to accommodate various scope sizes. In addition, the number, shape, and / or size of the orientation features 4684 can vary. For example, the number, shape, and / or size of the sizing features 4683 and / or orientation features 4684 can accommodate various scope diameters while minimizing the gap between the end cap 4600 and the scope.

[0218] Figures 47A and 47B are end views of the end cap 4700 for use with overtubes, such as one or more overtubes as described herein. The end cap 4700 is similar to the end cap 4600 shown in Figures 46A and 46B, but differs in that it has a less streamlined (e.g., less chamfered) end cap body 4782 and a different number, size, and shape of sizing features 4783.

[0219] Figures 48A and 48B are isometric projections of the end cap 4800 for use with overtubes, such as one or more overtubes as described herein. The end cap 4800 is similar to the end cap 4600 shown in Figures 46A and 46B, but differs in that it has a less streamlined (e.g., less chamfered) end cap body 4882 and different sizes and shapes of body slits 4885.

[0220] Figures 49A and 49B are isometric and end views of the end cap 4900 for use with one or more overtubes as described herein. The end cap 4900 is similar to the end cap 4600 shown in Figures 46A and 46B, except that it has a different size and shape of the sizing feature 4983 and a different size and shape of the body slit 4985.

[0221] Figures 50A and 50B are isometric and end views of the end cap 5000 for use with overtubes, such as one or more overtubes, as described herein. The end cap 5000 is similar to the end cap 4700 shown in Figures 47A and 47B, except that it has a different size and shape of the sizing feature 5084 and a different size and shape of the body slit 5085.

[0222] Figures 51A and 51B are isometric and end views of the end cap 5100 for use with overtubes, such as one or more overtubes, as described herein. The end cap 5100 is similar to the end cap 4700 shown in Figures 47A and 47B, but differs in the size and shape of the sizing feature 5184 and the size and shape of the body slit 5185.

[0223] Figures 52A and 52B are side views of a handle assembly 5200 for use with an overtube assembly, such as one or more overtube assemblies described herein. The handle assembly 5200 includes a handle body 5286 to facilitate improved insertion and rotation of the overtube assembly during use. The proximal end of the handle body 5268 includes a handle seal 5287 to provide a seal to the scope when accepted by the overtube assembly. Figures 53A–53C are side and isometric views of the handle body 5286 and the handle seal 5287 at the proximal end of the handle body 5286.

[0224] The handle assembly 5200 also includes a working channel port 5288 for inserting tools into the working channel of the overtube assembly. The working channel port 5288 may include a tuohy borst 5289 for closing the working channel port 5288. During use, the distal end of the endoscope can be blown (e.g., pressurized), and the tuohy borst 5289 can be closed to prevent air release through the working channel port 5288 from the distal end of the endoscope. In addition, the tuohy borst 5289 can facilitate improved handling of tools inside the working channel. For example, the tuohy borst 5289 can enable the tool to be held in place during use inside the working channel while the tool is being clamped. The handle assembly 5200 further includes an inflation port 5285 and corresponding tubes for connection to a blower, and a flush port 5290 and corresponding tubes that can be used to add saline and / or water to the gap between the overtube and the scope during use. The handle assembly 5200 is designed to keep the inflation port 5285 and flush port 5290 tubes from getting entangled while being gripped. FIG. 54 is a perspective view of an example of an overtube assembly including the handle assembly 5200.

[0225] FIG. 55 is a perspective view of an example of an overtube assembly according to the present disclosure. As shown in FIG. 55, the overtube assembly can be configured to allow inversion of the scope of the overtube assembly during use. That is, a plurality of tools / instruments such as additional tools passing through the scope and the working channel can be used with the overtube assembly such that the scope can be inverted.

[0226] Figures 56A and 56B are cross-sectional and perspective views of the overtube 5600. The overtube 5600 includes a primary tube 5602 defining a primary lumen 5604 (for example, for an endoscope or similar elongated tool). The overtube 5600 further includes a secondary tube 5606 defining a secondary lumen 5608, or an air tube 5605 defining a working channel and air lumen 5607. In the illustrated embodiment, the secondary tube 5606 and the air tube 5605 are positioned on the outer surface of the primary tube 5602 and are formed integrally with the primary tube 5602, for example, by an extrusion process. The overtube 5600 is formed from layers. More specifically, the overtube 5600 includes a liner 5616 defining the primary lumen 5604.

[0227] Since the secondary tube 5606 and air tube 5605 extend along the outer surface of the primary tube 5602, the primary lumen 5604 is generally unobstructed and substantially concentric with any scope / tool ​​inserted through the primary tube 5602. Among other advantages, such concentricity can help minimize or control the gap between the liner 5616 around the inside of the primary tube 5602 and the scope / tool ​​inserted through the primary tube 5602, and reduce the possibility of tissue being trapped or pinched between the scope / tool ​​and the liner 5616.

[0228] In certain embodiments, overtube 5600 may correspond to a one-piece overtube having general benefits related to ease of manufacture (e.g., suitable for an extrusion-type process). Considering the offset of secondary lumen 5608 and air lumen 5607 from primary tube 5602, overtube 5600 may be particularly suitable for applications where the overall length of overtube 5600 is relatively short and / or torsional rigidity is not as critical (e.g., procedures involving relatively straight / non-sinuous physiological lumens or tool passages), particularly when secondary lumen 5608 extends substantially longitudinally along secondary tube 5606. As discussed throughout this disclosure, the torsional and snap-through characteristics of overtube 5600 can be improved, for example, by helically or otherwise winding secondary tube 5606 and / or air tube 5605 around primary tube 5602.

[0229] Primary tube 5602 is sized to accommodate an elongate tool, such as an endoscope, having a diameter (or cross-sectional width) of from about 6 mm to about 15 mm. In other embodiments, primary tube 5602 is sized for an elongate tool having a diameter (or cross-sectional width) of from about 2 mm to about 7 mm. In yet other embodiments, primary tube 5602 is sized for an elongate tool having a diameter (or cross-sectional width) of from about 12 mm to about 20 mm. Secondary tube 5606 is sized to accommodate an element having a diameter (or cross-sectional width) of from about 1.5 mm to about 3.8 mm. In other embodiments, secondary tube 5606 is sized for an element having a diameter (or cross-sectional width) of from about 1 mm to about 2 mm. In yet other embodiments, secondary tube 5606 is sized for an element having a diameter (or cross-sectional width) of from about 2.2 mm to about 6.5 mm.

[0230] The center-to-center spacing between primary tube 5602 and secondary tube 5606 may be invariant along the length of the assembly or may vary along the length. In one embodiment, the center-to-center spacing is from about 1.75 mm to about 5 mm. In another embodiment, the center-to-center spacing is from about 4 mm to about 13.25 mm.

[0231] Figure 57A is a top perspective view of the overtube assembly 5700, and Figure 57B is a side view of the overtube assembly 5700. The overtube assembly 5700 includes an overtube 5712 and a balloon 5714. Overtube assemblies having a balloon, such as the overtube assembly 5700 shown in Figures 57A and 57B, as described herein, may include texture on the balloon to facilitate improved fastening of the overtube assembly to the wall of the surrounding lumen. The overtube assembly 5700 includes a handle assembly 5703, an air tube 5705, a secondary tube 5706, and an end cap 5715.

[0232] Figure 58A is the same as Figure 57B, except that it is enlarged. Figure 58B is a longitudinal cross-sectional view of the overtube assembly 5700 taken along the section line DD of Figure 58A. Figure 58C is an enlarged cross-sectional view of the overtube assembly 5700, specifically detail E of Figure 58B. Figure 58D is a transverse cross-sectional view of the overtube assembly 5700 taken along the section line GG of Figure 57B.

[0233] The overtube assembly 5700 is similar to the overtube assembly described herein, where the overtube assembly 5700 is laterally flexible while minimizing rotational lag and snap-through, while maintaining sufficient torsional rigidity for stable rotation at the distal end when torque is applied to the proximal end. As illustrated with reference to Figures 57A–58D, the air tube 5705 and secondary tube 5706 are positioned radially offset from the overtube 5712 and arranged in a symmetrical cross-sectional layout along the length of the overtube 5712, thereby maintaining the flexibility of the overtube assembly 5700 while simultaneously maintaining torque transmission along its length for stable rotation at the distal end and minimized rotational lag between the proximal and distal ends. Thus, the overtube assembly 5700 can be used in a GI tube to navigate unexpected bends and unpredictable in vivo environments that may require separate advance and / or rotation of the endoscope inside the overtube and the second surgical tool inside the second working channel for proper surgical positioning. The torque transmission along the length of the overtube assembly 5700 facilitates stable and consistent positioning of the overtube 5712 and the endoscope advanced through it, as well as the secondary tube 5706 and the second surgical tool advanced through it.

[0234] As shown in Figure 57B, the overtube 5712 has a length L1, which can range from 20 cm to approximately 120 cm. The balloon 5714 has an inflated balloon length L2a, which can range from 30 mm to approximately 70 mm; a balloon length including the shoulders L2b, which can range from 50 mm to approximately 90 mm; and an uninflated stationary diameter D1, which can range from 40 mm to approximately 80 mm. The handle assembly 5703 has a length L3, which can range from 10 cm to approximately 18 cm; and the total length L4 of the overtube assembly 5700, which can range from 28 cm to approximately 138 cm, is the combined length of the length L3 of the handle assembly 5703 and the length L1 of the overtube 5712. The end cap 5715 has a height H, which can range from 18 mm to approximately 26 mm; and a width W, which can range from 8 mm to approximately 14 mm. The overtube 5712 has a diameter D2, which can range from 15 mm to approximately 19 mm.

[0235] The torque transmission along the length of the overtube assembly 5700 can facilitate stable rotation of the distal end at the end cap 5715 when a torque force of up to 1 N*m is applied to the proximal end relative to the handle assembly 5703. That is, when a torque force is applied to the handle assembly 5703, the proximal end of the overtube 5712 adjacent to the handle assembly 5703 may rotate by a first amount, and the distal end of the overtube 5712 adjacent to the end cap 5715 may rotate by a second amount. The balance between the torsional rigidity and torque transmission of the overtube assembly may result in the second amount of rotation lagging by up to 90 degrees compared to the first amount of rotation.

[0236] For example, the handle assembly 5703 can be rotated 360 degrees by a torque force of up to 1 N*m, applied when the overtube assembly 5700 is free from any torque resistance structure along its length (e.g., when the overtube assembly 5700 is extended straight on a benchtop), which can result in a stable rotation of the end cap 5715 that lags the rotation of the handle assembly 5703 by up to 90 degrees. In some embodiments, the stable rotation of the end cap 5715 may lag the rotation of the handle assembly 5703 by 15 to 90 degrees. In other embodiments, the stable rotation of the end cap 5715 may lag the rotation of the handle assembly 5703 by 15 to 45 degrees. In yet another embodiment, the stable rotation of the end cap 5715 may lag the rotation of the handle assembly 5703 by up to 20 degrees. In addition, further rotation of the handle assembly 5703 beyond the first 360-degree rotation by torque force, for example, with a maximum torque of 1 N*m, may result in further stable rotation of the end cap 5715 with an additional delay of up to 10 degrees. This rotational delay can be applied to an overtube having a length of approximately 1 m.

[0237] The air tube 5705 and secondary tube 5706 are wound around the over tube 5712 in a symmetrical cross-sectional layout along the length L1 of the over tube 5712, and the helical pitch HP is defined as the axial distance it takes to complete one full circumferential rotation around the over tube 5712. Reducing the helical pitch HP and thereby increasing the number of full circumferential rotations along the length L1 may promote improved performance of the over tube 5712. This is because if the over tube 5712 is moved through corners (e.g., bends) in the lumen, the reduced helical pitch HP may reduce snap-through. However, increasing the helical pitch HP and thereby reducing the number of full circumferential rotations along the length L1 may promote improved movement of a tool through the air tube 5705 and / or secondary tube 5706. This is because the tool becomes more susceptible to less friction and change of direction, making forward movement easier. Therefore, the helical pitch HP of the air tube 5705 and / or secondary tube 5706 may vary along the length L1 of the over tube 5712 to balance snap-through performance and tool movement.

[0238] The helical pitch HP of the air tube 5705 and the secondary tube 5706 can range from 14 cm to approximately 19 cm. The helical pitch HP of the air tube 5705 and the secondary tube 5706 may depend on the diameter D2 of the over tube 5712. For example, the helical pitch HP of the air tube 5705 and / or the secondary tube 5706 may be substantially equal to or less than the diameter D2 of the over tube 5712. That is, if the diameter D2 of the over tube 5712 is 15 mm, the helical pitch HP of the air tube 5705 and / or the secondary tube 5706 may be up to approximately 15 mm.

[0239] In some embodiments, the air tube 5705 and / or secondary tube 5706 may be co-extruded with the overtube 5712 at a desired helical pitch HP. In other embodiments, the air tube 5705 and / or secondary tube 5706 may be externally coupled to the overtube 5712. The length of the external coupling may affect the snap-through of the overtube 5712. For example, externally coupling the air tube 5705 and / or secondary tube 5706 along the entire length L1 of the overtube 5712 may increase the snap-through as the overtube assembly 5700 is advanced through the meandering GI tube. Therefore, for such an overtube assembly, the snap-through performance of the overtube assembly 5700 may be improved by reducing the helical pitch HP of the air tube 5705 and secondary tube 5706.

[0240] In addition, externally coupling the air tube 5705 and / or secondary tube 5706 only at separate locations along the length L1 of the overtube 5712 can reduce snap-through by allowing the air tube 5705 and / or secondary tube 5706 to move slightly in relation to the overtube 5712 as the overtube assembly 5700 is advanced through the meandering GI tube. Thus, for such an overtube assembly, the helical pitch HP of the air tube 5705 and secondary tube 5706 can be increased without reducing the snap-through performance of the overtube assembly 5700. In some embodiments, the air tube 5705 and / or secondary tube 5706 can be coupled to the overtube 5712 at its proximal end (e.g., near the handle assembly 5703) and at its distal end (e.g., near the end cap 5715). In other embodiments, the air tube 5705 and / or secondary tube 5706 may be joined to the overtube 5712 segment by segment (e.g., at specific intervals of a particular length) along the length L1 of the overtube 5712. The air tube 5705 and secondary tube 5706 may be joined to the overtube 5712 using any suitable method, including but not limited to adhesives, tapes, rubber bands, and the like.

[0241] As illustrated in Figure 58C, the overtube 5712 may include a plurality of layers 5711 defining the lumen through which it passes, for example, a first layer 5711a, a second layer 5711b, and a third layer 5711c. The first layer 5711a is the outermost layer and has a thickness T1 which may range from 0.10 mm to about 3.75 mm. The second layer 5711b is an intermediate layer and has a thickness T2 which may range from 0.025 mm to about 2.25 mm. The third layer 5711c is the innermost layer and has a thickness T3 which may range from 0.001 mm to about 1.75 mm. The overtube 5712 may have an inner diameter D3 which may range from 5.5 mm to about 17.5 mm, extending to the innermost edge of the third layer 5711c.

[0242] As illustrated in Figure 58D, the center 5705C of the air tube 5705 may be positioned with a radial offset R1 from the center 5717 of the over tube 5712, where R1 may range from 3.25 mm to approximately 12.5 mm. The center 5706C of the secondary tube 5706 may be positioned with a radial offset R2 from the center 5717 of the over tube 5712, where R2 may range from 3.5 mm to approximately 13.5 mm. The air tube 5705 may have an inner diameter D4 which may range from 0.5 mm to approximately 3.25 mm, and an outer diameter D5 which may range from 0.75 mm to approximately 6.5 mm, and the thickness of the air tube 5705 is the difference between the inner diameter D4 and the outer diameter D5. In addition, the secondary tube 5706 may have an inner diameter D6 that can range from 1.5 mm to approximately 4 mm, and an outer diameter D7 that can range from 1.75 mm to approximately 7.5 mm, and the thickness of the secondary tube 5706 is the difference between the inner diameter D6 and the outer diameter D7.

[0243] The dimensions of the overtube assembly 5700 may differ from those described herein, depending on the intended use of the overtube assembly 5700. In one embodiment, the dimensions of the overtube assembly 5700 may be for use with shorter endoscopes and / or for use in shorter patient lumen tubes. For example, smaller dimensions of the overtube assembly 5700 may, due to a shorter overall length and smaller diameter, support more optimal use in the proximal portion of the colon with shorter endoscopes, such as gastroscopy, and / or in the upper gastrointestinal tract for esophageal and gastric procedures. Compared to colonoscopy, gastroscopy is typically smaller in diameter and shorter in length, and at the same time more flexible and easier to control for surgical procedures.

[0244] As illustrated in Figure 57B, the overtube assembly 5700 for use with shorter endoscopes and / or for use in shorter patient lumen tubes may include one or more of the following dimensions: height H of the end cap 5715 of approximately 22.5 mm, width W of the end cap 5715 of approximately 10 mm, uninflated stationary diameter D1 of the balloon 5714 of approximately 56.7 mm to approximately 57 mm, length L2a of the inflated balloon 5714 of approximately 41.1 mm, length L2b of the balloon 5714 including the shoulder of approximately 60 mm, length L1 of the overtube 5712 of approximately 486 mm, length L3 of the handle assembly 5703 of approximately 143 mm, diameter D2 of the overtube 5712 of approximately 15.29 mm, total length L4 of approximately 629 mm, as well as the helical pitch HP of the air tube 5705 and / or secondary tube 5706 of approximately 1 turn per 165 mm to approximately 1 turn per 170 mm.

[0245] As illustrated in Figure 58C, the overtube assembly 5700 for use with shorter endoscopes and / or in shorter patient lumen tubes may include one or more of the following dimensions: a first layer 5711a with a thickness T1 of approximately 0.499 mm, a second layer 5711b with a thickness T2 of approximately 0.405 mm, a third layer 5711c with a thickness T3 of approximately 0.253 mm, and an overtube 5712 with an inner diameter D3 of approximately 12.972 mm.

[0246] As illustrated in Figure 58D, the overtube assembly 5700 for use with shorter endoscopes and / or in shorter patient lumen tubes may include one or more of the following dimensions: a radial offset R1 of the air tube 5705 of approximately 9.6 mm, a radial offset R2 of the secondary tube 5706 of approximately 10.6 mm, an inner diameter D4 of the air tube 5705 of approximately 2 mm, an outer diameter D5 of the air tube 5705 of approximately 4 mm, an inner diameter D6 of the secondary tube 5706 of approximately 3.5 mm, and an outer diameter D7 of the secondary tube 5706 of approximately 6 mm.

[0247] In another embodiment, the dimensions of the overtube assembly 5700 may be for use with larger and / or longer endoscopes. For example, larger dimensions of the overtube assembly 5700, due to a longer overall length and larger diameter, may support more optimal use in the distal portion of the right colon with larger and longer endoscopes, such as colonoscopes. Compared to gastroscopy, colonoscopes are generally less flexible and easier to advance over longer distances in the gastrointestinal tract.

[0248] As illustrated in Figure 57B, the overtube assembly 5700 for use with larger and / or longer endoscopes may include one or more of the following dimensions: height H of the end cap 5715 of approximately 24.2 mm, width W of the end cap 5715 of approximately 10 mm, uninflated stationary diameter D1 of the balloon 5714 of approximately 57 mm, length L2a of the inflated balloon 5714 of approximately 41.1 mm, length L2b of the balloon 5714 including the shoulder of approximately 60 mm, length L1 of the overtube 5712 of approximately 1100 mm, length L3 of the handle assembly 5703 of approximately 143 mm, diameter D2 of the overtube 5712 of approximately 17 mm, total length L4 of approximately 1243 mm, and helical pitch HP of the air tube 5705 and / or secondary tube 5706 with one turn per approximately 165 mm.

[0249] For an overtube assembly 5700 for use with a larger and / or longer endoscope, the helical pitch HP of the air tube 5705 and / or the secondary tube 5706 is reduced proximate to the handle assembly 5703, which can improve tool movement along this segment of the length L1 of the overtube 5712 that is not inserted as far into the patient lumen. Additionally, for an overtube assembly 5700 for use with a larger and / or longer endoscope, the helical pitch HP of the air tube 5705 and / or the secondary tube 5706 can increase either progressively or in segments along the length L1 of the overtube 5712 away from the handle assembly 5703 (e.g., toward the balloon 5714) to improve the snap-through performance of the overtube 5712 as it is further inserted into the patient lumen. The decrease in the helical pitch HP of the air tube 5705 and / or the secondary tube 5706 proximate to the handle assembly 5703 can depend on (e.g., be related to) an increase in the helical pitch HP of the air tube 5705 and / or the secondary tube 5706 at the distal end of the overtube 5712.

[0250] As shown in FIG. 58C, an overtube assembly 5700 for use with a larger and / or longer endoscope can include one or more of the following dimensions: a thickness T1 of the first layer 5711a of about 0.499 mm, a thickness T2 of the second layer 5711b of about 0.5 mm, a thickness T3 of the third layer 5711c of about 0.253 mm, and an inner diameter D3 of the overtube 5712 of about 14.5 mm.

[0251] As illustrated in Figure 58D, the overtube assembly 5700 for use with larger and / or longer endoscopes may include one or more of the following dimensions: a radial offset R1 of the air tube 5705 of approximately 10.5 mm, a radial offset R2 of the secondary tube 5706 of approximately 11.5 mm, an inner diameter D4 of the air tube 5705 of approximately 2 mm, an outer diameter D5 of the air tube 5705 of approximately 4 mm, an inner diameter D6 of the secondary tube 5706 of approximately 3.5 mm, and an outer diameter D7 of the secondary tube 5706 of approximately 6 mm.

[0252] As discussed earlier in this specification, the overtube assembly may require a certain torsional stiffness to reliably transmit the torque applied to the proximal end of the overtube assembly and cause rotation at the distal end of the overtube assembly. In embodiments for use with shorter endoscopes and / or for use in shorter patient lumen tubes, the overtube assembly 5700 may require reduced torsional stiffness to reliably transmit torque due to the shorter length of the overtube assembly 5700 (not limited to, e.g., L1, L2a, L2b, L3, and / or L4), the smaller diameter (not limited to, e.g., D1, D2, D3, D4, D5, D6, and / or D7), and / or the smaller radial offset (not limited to, e.g., R1 and / or R2). Therefore, the overtube 5712, air tube 5705, and / or secondary tube 5706 may, without limitation, be formed from softer materials (e.g., materials with a lower durometer), such as PTFE (polytetrafluoroethylene), other thermopolymers, TPPE (thermoplastic polyolefin elastomer), silastic polymers (variable; typically around here), extruded 70 Shore A silicone, silicone, and / or 20 Shore A.

[0253] To further increase flexibility, the overtube 5712, air tube 5705, and / or secondary tube 5706 may be formed to include, but not limited to, one or more additives, such as a Hytrel thermoplastic polyester elastomer containing Everglide. Alternatively or additionally, the overtube 5712, air tube 5705, and / or secondary tube 5706 may be formed of layers and / or segments of reduced thickness to increase flexibility.

[0254] In embodiments for use with larger and / or longer endoscopes, the overtube assembly 5700 may require increased torsional stiffness to reliably transmit torque due to the longer length of the overtube assembly 5700 (not limited to, e.g., L1, L2a, L2b, L3, and / or L4), the larger diameter (not limited to, e.g., D1, D2, D3, D4, D5, D6, and / or D7), and / or the larger radial offset (not limited to, e.g., R1 and / or R2). Therefore, the overtube 5712, air tube 5705, and / or secondary tube 5706 may be formed from a harder material (e.g., a material with a higher durometer) such as 80 Shore A, PET (polyethylene polyethylene terephthalate), nylon, PFA (perfluoroalkoxyalkane), FEP (fluorinated ethylene propylene), HDPE (high-density polyethylene), and / or PVC (polyvinyl chloride).

[0255] To further increase hardness (e.g., rigidity), the overtube 5712, air tube 5705, and / or secondary tube 5706 may be formed to include, but not limited to, one or more additives such as ABS or polycarbonate. Alternatively or additionally, the overtube 5712, air tube 5705, and / or secondary tube 5706 may be formed with layers and / or segments of increased thickness to increase rigidity. Alternatively or additionally, the overtube 5712, air tube 5705, and / or secondary tube 5706 may be formed to include embedded or wrapped braided reinforcement to increase rigidity.

[0256] Alternatively, or additionally, the overtube 5712 may be formed to include laser-cut sections along the length of the tube. For example, the overtube 5712 may incorporate a laser-cut hypotube placed inside an extruded overtube. The laser-cut hypotube may be a thin-walled metal, such as stainless steel, nitinol, or aluminum, having small laser-cut sections (e.g., windows) around its circumference. The laser-cut sections around the hypotube may allow the hypotube to increase its flexibility while maintaining its rotational rigidity, thereby increasing the flexibility of the overtube 5712.

[0257] The incorporation of laser-cut hypotube into the overtube 5712 may affect the torsional resistance performance of the overtube assembly 5700. The advancement of the overtube assembly 5700 through the meandering GI tube requires that the overtube 5712 has sufficient resistance to torsion (e.g., buckling) when the endoscope is withdrawn from the overtube 5712. That is, when the overtube assembly 5700 is positioned within the GI tube, the endoscope must be able to advance partially or completely, and also be retracted partially or completely, through the overtube 5712. For example, if a force of up to 42 N is applied to advance or retract the endoscope through the overtube 5712, the overtube 5712 may be sufficiently resistant to torsion (e.g., buckling) if it does not compress or stretch by more than 5% when the overtube 5712 is axially loaded. The overtube 5712 may retain sufficient resistance to the torsion described herein when subjected to bending forces applied when the overtube 5712 is free from any bending-resisting structures along its length, and bent at certain radii (for example, when the overtube assembly 5700 is straight on a benchtop and bent): a radius of about 20 mm receiving a maximum bending force of 19 N, a radius of about 25 mm receiving a maximum bending force of 14 N, a radius of about 35 mm receiving a maximum bending force of 8 N, a radius of about 45 mm receiving a maximum bending force of 3.5 N, a radius of about 55 mm receiving a maximum bending force of 1.2 N, a radius of about 65 mm receiving a maximum bending force of 0.5 N, and a radius of about 75 mm receiving a negligible maximum bending force of about 0 N. To modify the torsion resistance performance of the overtube 5712, laser-cut hypo tubing may be added, and / or the thickness or design of the laser-cut hypo tubing may be changed.

[0258] To further increase flexibility, the diameter of the overtube 5712 may be reduced, the external extruded wall thickness of the overtube 5712 may be reduced, the wall thickness of the hypotube incorporated within the overtube 5712 may be reduced, the external extruded durometer may be reduced, the number of cuts in the hypotube incorporated within the overtube 5712 may be increased, and / or the size of the cuts in the hypotube incorporated within the overtube 5712 may be increased. Similarly, to reduce rotational stiffness, the diameter of the overtube 5712 may be increased, the external extruded wall thickness of the overtube 5712 may be increased, the wall thickness of the hypotube incorporated within the overtube 5712 may be increased, the external extruded durometer may be increased, the number of cuts in the hypotube incorporated within the overtube 5712 may be reduced, and / or the size of the cuts in the hypotube incorporated within the overtube 5712 may be reduced.

[0259] As used herein, unless otherwise defined, all technical and scientific terms generally have the same meanings as those commonly understood by those skilled in the art in which this disclosure pertains. Generally, the nomenclature used herein is well known and commonly used in the art.

[0260] As used herein, the articles “a” and “an” refer to one or more than one (i.e., at least one) of the grammatical objects of the article. For example, “an element” means one or more elements.

[0261] Where used herein, the term “about” will be understood by those skilled in the art and will vary to some extent depending on the context in which it is used. Where used herein, “about” refers to a measurable value such as a quantity or a period of time, and means to include a variation of ±20% or ±10%, more preferably ±5%, even more preferably ±1%, and still more preferably ±0.1% from the specified value, provided that such variation is appropriate for practicing the disclosed method.

[0262] Through this disclosure, various aspects of this disclosure may be presented in range form. Range form is for convenience and brevity only and should not be interpreted as an immutable limitation on the scope of this disclosure. Therefore, range forms should be considered to specifically disclose not only possible subranges within that range, but also all individual numbers and, where appropriate, subintegers of the numbers within that range. For example, a range form such as 1–6 should be considered to specifically disclose subranges such as 1–3, 1–4, 1–5, 2–4, 2–6, 3–6, and the individual numbers within that range, such as 1, 2, 2.7, 3, 4, 5, 5.3, and 6. This applies regardless of the breadth of the range.

[0263] Any formulation or combination of the components described or illustrated may be used to practice the exercise of this disclosure unless otherwise noted. Since it is known to those skilled in the art that the same compound may be named differently, any specific names of compounds are intended to be illustrative. Where a compound is described herein in such a way that its specific isomers or enantiomers are not identified, for example, by formula or chemical name, the description is intended to include each isomer and enantiomer of the described compound individually or in any combination.

[0264] The descriptions herein include numerous examples, which should be construed as merely illustrative examples and not as limiting the scope of this disclosure.

[0265] Throughout this disclosure, all references (e.g., patent documents including issued or granted patents or equivalents; patent application publications; and non-patent literature documents or other sources) are incorporated herein by reference as if they were incorporated individually by reference, provided that each reference does not contradict, at least in part, the disclosures herein (for example, partially contradictory references are incorporated by reference with the partially contradictory portion of the reference removed).

[0266] Those skilled in the art will recognize, or can verify by simply using routine experiments, numerous equivalents to the specific procedures, embodiments, claims, and examples described herein. Such equivalents are deemed to be within the scope of this disclosure and to be encompassed by the claims appended herein. In general, the terms and phrases used herein have meanings recognized in their respective art, which can be found by reference to standard literature, journal references, and contexts known to those skilled in the art. Any definitions herein are provided to clarify their specific use in the context of this disclosure.

[0267] Where values ​​and ranges are provided herein, it should be understood that all values ​​and ranges encompassed by these values ​​and ranges are included within the scope of this disclosure. Furthermore, all values ​​included within these ranges, as well as any upper or lower limits on the ranges of values, are also assumed by this disclosure.

[0268] The disclosures of each patent, patent application, and publication cited herein are incorporated herein by reference in their entirety.

[0269] While this disclosure includes references to specific embodiments, it will be apparent that other embodiments and variations of this disclosure can be devised by those skilled in the art without departing from the true spirit and scope of this disclosure. The attached claims are intended to be construed as encompassing all such embodiments and equivalent variations.

Claims

1. An overtube assembly for use with a first elongated medical device and a second elongated medical device inside the physiological lumen of a patient, A primary tubular body having a length extending from a proximal end oriented to a distal end, defining a primary lumen configured to receive the first elongated medical device; and A secondary lumen extending along the length of the primary tubular body and configured to receive the second elongated medical device; Includes, When a torque force is applied to the proximal end of the primary tubular body, causing the proximal end of the primary tubular body to rotate by a first amount of rotation, the distal end of the primary tubular body responds by rotating by a second amount of rotation, which is delayed by less than 90 degrees compared to the first amount of rotation. Overtube assembly.

2. The overtube assembly according to claim 1, wherein the secondary lumen is spirally wound around the primary tubular body.

3. The overtube assembly according to claim 2, wherein the helical pitch of the secondary lumen around the primary tubular body is symmetrical along the length of the primary tubular body.

4. The overtube assembly according to claim 3, wherein the helical pitch is approximately 1 circumferential winding per 165 mm to approximately 1 circumferential winding per 170 mm.

5. The overtube assembly according to claim 1, wherein the torque force applied to the proximal end of the primary tubular body is a maximum torque of 1 N*m.

6. The overtube assembly according to claim 1, wherein the first amount of rotation is 360 degrees.

7. Further rotation of the proximal end of the primary tubular body exceeding the first amount of rotation, The rotation of the distal end of the primary tubular body is delayed by a rotational delay of 10 degrees or less compared to the further rotation. The overtube assembly according to claim 6, corresponding to the above.

8. The overtube assembly according to claim 1, wherein the primary tubular body comprises a low-durometer elastomer.

9. The overtube assembly according to claim 1, wherein the primary tubular body includes a hypotube having one or more cut portions distributed along the length of the primary tubular body.

10. The overtube assembly according to claim 9, wherein the hypotube includes a thin-walled metal.

11. The overtube assembly according to claim 1, wherein the secondary lumen is coupled to the primary tubular body along the entire length of the primary tubular body.

12. The overtube assembly according to claim 1, wherein the secondary lumen is connected to the primary tubular body at separate locations along the length of the primary tubular body.

13. The overtube assembly according to claim 2, wherein, due to the helical winding of the secondary lumen, the secondary lumen remains in close proximity to the primary tubular body along the length of the primary tubular body.

14. The overtube assembly according to claim 1, wherein the first elongated medical device includes one of an endoscope or a catheter.

15. The overtube assembly according to claim 1, wherein the second elongated medical device includes one of forceps, a knife, scissors, or a clamp.

16. The overtube assembly according to claim 1, wherein the rotational delay amount is 15 degrees to 90 degrees.

17. The overtube assembly according to claim 1, wherein the rotational delay amount is 15 to 45 degrees.

18. The overtube assembly according to claim 1, wherein the rotational delay amount is less than 20 degrees.

19. The overtube assembly according to claim 1, wherein the length of the primary tubular body is 20 cm to 120 cm.

20. The overtube assembly according to claim 19, wherein the length of the primary tubular body is 100 cm.

21. The overtube assembly according to claim 1, wherein the center of the secondary lumen is positioned with a radial offset of 3.5 mm to 13.5 mm from the center of the primary lumen.

22. The overtube assembly according to claim 1, wherein the primary tubular body comprises a plurality of layers, and one or more of the plurality of layers have an increased thickness.

23. The overtube assembly according to claim 2, wherein the secondary lumen is wound around the primary tubular body at a first helical pitch close to the proximal end and at a second helical pitch close to the distal end of the primary tubular body, and the first helical pitch is less than the second helical pitch.

24. The overtube assembly according to claim 23, wherein the first helical pitch is based on the second helical pitch.

25. The overtube assembly according to claim 13, wherein the secondary lumen is joined at a first location adjacent to the proximal end of the primary tubular body and at a second location adjacent to the distal end of the primary tubular body.

26. The overtube assembly according to claim 25, wherein the connections of the secondary lumen at the first and second locations along the length of the primary tubular body allow the secondary lumen to move in relation to the primary tubular body.

27. An air cavities extending along the primary tubular body and connected along the length of the primary tubular body The overtube assembly according to claim 1, further comprising:

28. The overtube assembly according to claim 27, wherein each of the secondary lumen and the air lumen is spirally wound around the primary tubular body.

29. The overtube assembly according to claim 28, wherein the helical pitches of the secondary lumen and the air lumen surrounding the primary tubular body are symmetrical along the length of the primary tubular body.

30. The overtube assembly according to claim 29, wherein the helical pitch of the secondary lumen is radially offset from the helical pitch of the air lumen.

31. The overtube assembly according to claim 27, wherein the center of the secondary lumen is positioned at a first radial offset from the center of the primary lumen, and the center of the air lumen is positioned at a second radial offset from the center of the primary lumen, the first radial offset being 3.5 mm to 13.5 mm, and the second radial offset being 3.25 mm to 12.5 mm.

32. A balloon that can be selectively inflated around the primary tubular body and connected to the air lumen for selective inflation and deflation, for securing the overtube assembly to the wall of the patient's physiological lumen, The overtube assembly according to claim 27, further comprising:

33. The overtube assembly according to claim 32, wherein the inflated length of the balloon is 30 mm to 70 mm.

34. The overtube assembly according to claim 33, wherein the inflated length of the balloon is 41.1 mm.

35. The overtube assembly according to claim 32, wherein the uninflated, stationary diameter of the balloon is 40 mm to 80 mm.

36. The overtube assembly according to claim 35, wherein the uninflated, stationary diameter of the balloon is 56.7 mm to 57 mm.

37. An overtube assembly for use with a first elongated medical device and a second elongated medical device inside the physiological lumen of a patient, A first peripheral outer wall comprising a first radially inner peripheral surface defining the primary lumen and having a first internal diameter of approximately 5.5 mm to approximately 17.5 mm, a first radially outer peripheral surface having a first outer diameter of approximately 15 mm to approximately 19 mm, and a first radial wall thickness of approximately 0.126 mm to approximately 7.75 mm, and The primary lumen configured to receive the first elongated medical device A primary tubular body having a length extending from a proximal end to a distal end, oriented to receive the first elongated medical device; and Each of these comprises at least one of a fluid tubular body or a secondary tubular body, extending along the primary tubular body, being coupled to the primary tubular body, and being helically wound around the primary tubular body at a helical pitch of approximately 1 circumferential winding per 165 mm to approximately 1 circumferential winding per 170 mm. Includes, The fluid tubular body is, A second radially inner circumferential surface defining the fluid transport lumen and having a second internal diameter of approximately 0.5 mm to approximately 3.25 mm, a second radially outer circumferential surface having a second outer diameter of approximately 0.75 mm to approximately 6.5 mm, and a second radial wall thickness defined between the second radially inner circumferential surface and the second radially outer circumferential surface. Includes, The aforementioned secondary tubular body, A third radially inner circumferential surface having a third internal diameter of approximately 1.5 mm to approximately 4 mm and defining a secondary lumen configured to receive the second elongated medical device, a third radially outer circumferential surface having a third external diameter of approximately 1.75 mm to approximately 7.5 mm, and a third radial wall thickness defined between the third radially inner circumferential surface and the third radially outer circumferential surface. Includes, The distance between the center of the primary lumen and the center of the fluid transport lumen is approximately 3.25 mm to approximately 12.5 mm, and the distance (R2) between the center of the primary lumen and the center of the secondary lumen is approximately 3.5 mm to approximately 13.5 mm. Overtube assembly.

38. The overtube assembly according to claim 37, wherein the first radial wall thickness is formed from at least one of a first radial layer having a thickness of approximately 0.1 mm to approximately 3.75 mm, a second radial layer having a thickness of approximately 0.025 mm to approximately 2.25 mm, or a third radial layer having a thickness of approximately 0.001 mm to approximately 1.75 mm.

39. The overtube assembly according to claim 37, wherein the first radial wall thickness is formed from at least one of a first radial layer having a thickness of approximately 0.499 mm, a second radial layer having a thickness of approximately 0.405 mm, or a third radial layer having a thickness of approximately 0.253 mm.

40. The overtube assembly according to claim 37, wherein the first internal diameter is approximately 12.972 mm.

41. The overtube assembly according to claim 37, wherein the first outer diameter is approximately 15.29 mm.

42. The overtube assembly according to claim 37, wherein the second internal diameter is approximately 2 mm.

43. The overtube assembly according to claim 37, wherein the second outer diameter is approximately 4 mm.

44. The overtube assembly according to claim 37, wherein the third internal diameter is approximately 3.5 mm.

45. The overtube assembly according to claim 37, wherein the third outer diameter is approximately 6 mm.

46. The overtube assembly according to claim 37, wherein the distance between the center of the primary lumen and the center of the fluid transport lumen is approximately 10.5 mm.

47. The overtube assembly according to claim 37, wherein the distance between the center of the primary lumen and the center of the secondary lumen is approximately 11.5 mm.

48. The overtube assembly according to claim 37, wherein the helical pitch along the primary tubular body is symmetrical along the length of the primary tubular body.

49. The overtube assembly according to claim 37, wherein the helical pitch is equal to or less than the first outer diameter.

50. The overtube assembly according to claim 37, wherein the primary tubular body comprises a low-durometer elastomer.

51. The overtube assembly according to claim 37, wherein the primary tubular body includes a hypotube having one or more cut portions distributed along the length of the primary tubular body.

52. The overtube assembly according to claim 37, wherein at least one of the fluid tubular body or the secondary tubular body is continuously connected along the entire length of the primary tubular body.

53. The overtube assembly according to claim 37, wherein at least one of the fluid tubular body or the secondary tubular body is connected at separate locations along the length of the primary tubular body.

54. The overtube assembly according to claim 37, wherein the first elongated medical device includes one of an endoscope or a catheter.

55. The overtube assembly according to claim 37, wherein the second elongated medical device includes one of forceps, scalpels, scissors, or clamps.

56. The overtube assembly according to claim 37, wherein when a force is applied to the primary tubular body, the compression and expansion of the primary lumen are each 5% or less.

57. The overtube assembly according to claim 56, wherein the force applied to the primary tubular body is a maximum axial load force of 42 N.

58. The overtube assembly according to claim 56, wherein the force applied to the primary tubular body is a maximum bending force of 19 N, and the primary tubular body is bent with a radius of approximately 20 mm.

59. The overtube assembly according to claim 56, wherein the force applied to the primary tubular body is a maximum bending force of 14 N, and the primary tubular body is bent with a radius of approximately 25 mm.

60. The overtube assembly according to claim 56, wherein the force applied to the primary tubular body is a maximum bending force of 8 N, and the primary tubular body is bent with a radius of approximately 35 mm.

61. The overtube assembly according to claim 56, wherein the force applied to the primary tubular body is a maximum bending force of 3.5 N, and the primary tubular body is bent with a radius of approximately 45 mm.

62. The overtube assembly according to claim 56, wherein the force applied to the primary tubular body is a maximum bending force of 1.2 N, and the primary tubular body is bent with a radius of approximately 55 mm.

63. The overtube assembly according to claim 56, wherein the force applied to the primary tubular body is a maximum bending force of 0.5 N, and the primary tubular body is bent with a radius of approximately 65 mm.

64. The overtube assembly according to claim 56, wherein the force applied to the primary tubular body is a negligible bending force of about 0 N, and the primary tubular body is bent with a radius of about 75 mm.

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