Stiffening Device

Abstract

The stiffening system includes an elongated stiffening device configured to be stiffened from a flexible configuration to a rigid configuration by vacuum or pressure, and an outer tube configured to be disposed around the stiffening device, the outer tube including a plurality of expandable channels therein configured to allow a working tool to pass therethrough.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Patent Application No. 63 / 030,252, entitled "RIGIDIZING DEVICES," filed May 26, 2020, U.S. Provisional Patent Application No. 63 / 128,769, entitled "RIGIDIZING DEVICES," filed December 21, 2020, and U.S. Provisional Patent Application No. 63 / 165,721, entitled "RIGIDIZING DEVICES," filed March 24, 2021, each of which is incorporated by reference in its entirety into this specification.

[0002]

[0002] This application may also be related to International Application No. PCT / US2020 / 013937, filed January 16, 2020, entitled "DYNAMICALLY RIGIDIZING COMPOSITE MEDICAL STRUCTURES," which is incorporated herein by reference in its entirety. [Background technology]

[0003]

[0003] During a medical procedure, an interventional medical device may bend or loop through the anatomy, which can make advancing the medical device difficult.

[0004]

[0004] Gastrointestinal loops, which occur when an endoscope cannot be advanced due to excessive curvature or looping of the gastrointestinal tract, are a particularly well-known clinical challenge in endoscopy. In fact, one study found that loops occurred in 91 out of 100 patients undergoing colonoscopy [Shah et al., "Magnetic Imaging of Colonoscopy: An Audit of Looping, Accuracy, and Ancillary Maneuvers," Gastrointest Endosc 2000;52:1-8]. Gastrointestinal loops can prolong the procedure and cause pain to the patient because they can stretch the blood vessel walls and mesentery. In addition, bowel loops are associated with an increased incidence of perforation. In serious cases of bowel loops, a complete colonoscopy is impossible because the loop extends the length of the colon, preventing the colonoscope from reaching its end. Bowel loops also impede precise tip control, preventing the user from achieving the desired one-to-one relationship between the handle and the endoscope tip. Such problems commonly occur across a wide range of endoscopic procedures, including colonoscopy, esophagogastroduodenoscopy (EGD), enteroscopy, endoscopic retrograde pancreatography (ERCP), interventional endoscopic procedures (including endoscopic submucosal dissection (ESD) and endoscopic mucosal resection (EMR)), robotic flexible endoscopy, transoral robotic surgery (TORS), endoscopic bowel procedures (including Roux-en-Y anastomosis), and NOTES (transluminal endoscopic surgery) procedures. Therefore, devices that help prevent gastrointestinal loops are needed to provide more successful access to the gastrointestinal tract.

[0005] Similar difficulties in advancing medical instruments can arise, for example, during interventional procedures in the lungs, kidneys, brain, epigastric region, and other anatomical regions. Thus, there is a need for devices that can provide safe, efficient, and precise access to anatomical regions that are normally difficult to reach. Summary of the Invention

[0006] In general, in one embodiment, a stiffening system includes an elongated stiffening device configured to be stiffened from a flexible configuration to a rigid configuration by vacuum or pressure, and an outer tube configured to be disposed around the stiffening device, the outer tube including a plurality of expandable channels therein configured to allow for the passage of a working tool therethrough.

[0007]

[0007] The above and other embodiments may include one or more of the following features. The stiffening system may further include at least one guide configured to be removably inserted into a channel of the plurality of expandable channels. The at least one guide may include a lumen configured to allow a working tool to pass therethrough. The channel may be configured to expand upon insertion of the at least one guide. The channel may be configured to collapse upon removal of the at least one guide. The at least one guide may include an atraumatic distal end. The lumen may be configured to point radially inward toward the elongated stiffening device when the at least one guide is disposed within the channel. The lumen may include a 30° to 60° bend at its distal end such that the lumen points radially inward. The at least one guide may include an asymmetric cross-section configured to enable rotational alignment of the at least one guide relative to the elongated stiffening device. The at least one guide may include an angled or curved surface configured to substantially follow the circumference of the elongated stiffening device. The at least one guide can have a stiffness greater than that of the stiffening device in its flexible configuration and less than that of the stiffening device in its rigid configuration. The ratio of the outer diameter of the elongate stiffening device to the inner diameter of each of the expandable channels of the plurality of channels can be between 1:1 and 6:1. The outer tube can be a sleeve having a wall thickness of 0.076 cm (0.03 inches). The outer tube can comprise an elastomer, plastic, or fabric structure. The outer tube can be permanently attached to the elongate stiffening device. Each channel can include a proximal marker thereon configured to indicate a distal circumferential position of the working tool relative to the stiffening device when the working tool is inserted into the channel. The elongate stiffening device can be configured to be stiffened by applying a vacuum or pressure within a wall of the elongate stiffening device. The wall can include a braided layer.The working tool can have a stiffness greater than that of the stiffening device in the flexible configuration and a stiffness less than that of the stiffening device in the rigid configuration. The elongate stiffening device can be part of an overtube, the overtube being configurable for an endoscope to pass through.

[0008]

[0008] Generally, in one embodiment, a method of placing a working tool within a body lumen includes inserting a stiffening device and an outer tube having a plurality of expandable channels therein into the body lumen when the stiffening device is in a flexible configuration, applying vacuum or pressure to the stiffening device to transition the stiffening device from the flexible configuration to a rigid configuration, inserting a working tool through one of the expandable channels when the stiffening device is in the rigid configuration, and performing a medical procedure in the body lumen with the working tool.

[0009]

[0009] The above and other embodiments may include one or more of the following features. The method further includes inserting a guide into a channel of the plurality of expandable channels when the stiffening device is in the rigid configuration and before inserting the working tool. The method may further include detaching the working tool from the guide and removing the guide from the channel. Removing the guide from the channel may cause the channel to collapse radially inward. The shape of the stiffening device in the rigid configuration may remain fixed during the guide insertion step. The guide may be asymmetric. The guide insertion step may include inserting the guide such that an angled or curved surface substantially follows the periphery of the stiffening device. The working tool insertion step may include inserting the working tool such that the working tool extends through a preset bend in the lumen of the guide and points toward the central axis of the stiffening device. Inserting the guide into the channel may cause the channel to expand radially outward from the collapsed configuration to the expanded configuration. At least one guide may have a stiffness greater than that of the stiffening device in the soft configuration and a stiffness less than that of the stiffening device in the rigid configuration. The step of applying vacuum or pressure to the stiffening device can include applying vacuum or pressure to a wall of the stiffening device. The step of performing the medical procedure can be performed while the stiffening device is in the rigid configuration. The working tool can have a higher stiffness than the stiffening device in the soft configuration and a lower stiffness than the stiffening device in the rigid configuration. The method can further include passing a scope through the stiffening device while it is in the rigid configuration. The shape of the stiffening device in the rigid configuration can remain fixed during the step of inserting the working tool. The method can further include selecting a channel from the plurality of channels before inserting the guide. Selecting the channel can include selecting based on a proximal marker indicating a distal periphery position of the channel.

[0010] In general, in one embodiment, a stiffening system includes an elongated stiffening device configured to be stiffened by vacuum or pressure, and a plurality of rails extending longitudinally along the length of the stiffening device, each of which is configured to slidably engage an elongated tubular guide.

[0011]

[0011] These and other embodiments may include one or more of the following features: When the elongated tubular guide engages a rail of the plurality of rails, the elongated tubular guide can be parallel to the elongated stiffening device. Each rail of the plurality of rails can be a T-shaped rail. The stiffening device can further include a tubular guide. The tubular guide can include a T-shaped slot therein configured to engage with a rail of the plurality of rails. The plurality of rails can include male extensions. The stiffening device can further include a tubular guide, the tubular guide including a female slot therein configured to engage with a rail of the plurality of rails. The plurality of rails can include female slots therein. The stiffening device can further include a tubular guide, the tubular guide including a male extension thereon configured to engage with a rail of the plurality of rails. One or more rails of the plurality of rails can be serrated. The plurality of rails can be equidistantly positioned around the circumference of the stiffening device.

[0012] In general, in one embodiment, a stiffening system includes a first stiffening device, a second stiffening device radially disposed within the first stiffening device, and a plurality of tool channels extending longitudinally along an exterior of the first stiffening device. The second stiffening device is axially slidable relative to the first stiffening device. The first stiffening device and the second stiffening device are configured to be alternately stiffened by vacuum or pressure.

[0013]

[0013] These and other embodiments may include one or more of the following features: The multiple tool channels may be positioned substantially adjacent to one another. The multiple tool channels may be positioned along less than 120 degrees of the circumference of the first stiffening device. The multiple tool channels may be configured to move around the circumference of the stiffening device after insertion of the stiffening system into the body lumen. At least one tool channel may be configured to hold an articulating camera therein. The multiple tool channels may have cutouts therein to increase flexibility. The stiffening system may further include an outer sheath surrounding the outside of the first stiffening device and the multiple tool channels, and a vacuum supply port between the outer sheath and the first stiffening device. The supply port may be configured to apply a vacuum to suction the outer sheath against the tool channel. The multiple tool channels may include a spiral-cut tube or coil. The stiffening system may further include a mount configured to slidably move along the first stiffening device. The multiple tool channels may be attached to the mount. The stiffening system can further include a plurality of cables configured to move the attachment distally when pulled proximally. The plurality of tool channels can be an integral part of an outer tube configured to slide over the first stiffening device. The outer tube can include a bend along the outer tube. The outer tube can include a longitudinal slit to allow the outer tube to snap over the first stiffening device. An inner or outer wall of the outer tube can be configured to be stiffened by application of pressure or vacuum.

[0014] In general, in one embodiment, a stiffening device includes an elongated flexible tube having a tubular wall with a proximal and distal portion, a braided layer extending within the proximal portion, a plurality of linkages extending within the distal portion, a plurality of cables extending through or parallel to the proximal and distal portions and attached to the linkages for steering the distal portion, and a clamping mechanism at the junction of the proximal and distal portions. The clamping mechanism includes a plurality of clamp engagements disposed around the plurality of cables. Application of vacuum or pressure to the tubular wall stiffens the braided layer to transition the proximal portion from a flexible to a rigid configuration and activates the clamping mechanism to lock the shape of the distal portion.

[0015]

[0015] These and other embodiments can include one or more of the following features: A distal portion of each of the cables of the plurality of cables can include a plurality of cable engagement portions configured to engage with clamp engagement portions. The clamp engagement portions can be female engagement portions, and the plurality of cable engagement portions can be male engagement portions. The stiffening device can further include an outer layer extending over the braid layer and the plurality of links. The clamping mechanism can further include a clamp bladder configured to compress the clamp engagement portions when a vacuum or pressure can be applied to the tubular wall.

[0016] In general, in one embodiment, a stiffening device includes an elongated flexible tube having a tubular wall with a proximal and distal portion, a braided layer extending within the proximal portion, a plurality of linkages extending within the distal portion, a plurality of steering cables extending through the proximal and distal portions attached to the linkages for steering the distal portion, a plurality of locking cables extending through the distal portion, and a clamping mechanism at a junction between the proximal and distal portions including a plurality of clamp engagements disposed about the plurality of locking cables. Applying vacuum or pressure to the tubular wall stiffens the braided layer to transition the proximal portion from a flexible configuration to a rigid configuration and activates the clamping mechanism to lock the shape of the distal portion.

[0017] These and other embodiments can include one or more of the following features: A distal portion of each cable of the plurality of locking cables can include a plurality of cable engagement portions configured to engage with the clamp engagement portions.

[0018] In general, in one embodiment, a stiffening device includes an elongated flexible tube having a tubular wall including a proximal portion and a distal portion, a plurality of connectors extending within the distal portion, a plurality of channels extending through or parallel to the connectors, and a plurality of pressure lines extending through channels of the plurality of channels, each of the plurality of pressure lines configured to expand against a plurality of connectors to transition the distal portion from a flexible configuration to a rigid configuration.

[0019]

[0019] The above and any other embodiments may include one or more of the following features: The stiffening vise may further include a plurality of support members extending through the channels of the plurality of channels. Expansion of a pressure line within the channels may urge the support members against the plurality of connectors. Each of the channels may include an engagement element on an inner periphery thereof. Each of the support members may include a mating engagement member on an outer periphery thereof configured to engage upon application of pressure from the pressure line. Each of the support members may include a wire. The stiffening device may further include a plurality of cables extending through or parallel to the proximal and distal portions and attached to the plurality of connectors for steering the distal portion. Each of the plurality of pressure lines may have a diameter of less than 0.06 inches. The distal portion may be configured to form a bend with a radius of curvature of less than 1 inch. The plurality of pressure lines may be configured to support a pressure in excess of 5 atmospheres. Each of the pressure lines can have a smaller outer circumference in the flexible configuration than the outer circumference in the rigid configuration. Each of the pressure lines can include a resilient material. Each of the pressure lines can have a larger outer circumference in the flexible configuration than the outer circumference in the rigid configuration. Each of the pressure lines can include a non-resilient material. The proximal portion can include a braided layer extending within the proximal portion. Applying a vacuum or pressure to the tubular wall can stiffen the braided layer to transition the proximal portion from the flexible configuration to the rigid configuration. The pressure lines can include a braided layer surrounding it.

[0020] The novel features of the invention are set forth with particularity in the appended claims. A better understanding of the features and advantages of the present invention will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the invention are utilized, and the accompanying drawings of which: [Brief explanation of the drawings]

[0021] [Figure 1]FIG. 1 illustrates a stiffening device. [Figure 2A]

[0022] 1A-1C illustrate exemplary stiffened shapes of stiffening devices. [Figure 2B] 1A-1C illustrate exemplary stiffened shapes of stiffening devices. [Figure 3A]

[0023] FIG. 1 illustrates an exemplary vacuum stiffening device. [Figure 3B] FIG. 1 illustrates an exemplary vacuum stiffening device. [Figure 3C] FIG. 1 illustrates an exemplary vacuum stiffening device. [Figure 3D] FIG. 1 illustrates an exemplary vacuum stiffening device. [Figure 4A]

[0024] 1 illustrates an exemplary pressure stiffening device. [Figure 4B] 1 illustrates an exemplary pressure stiffening device. [Figure 5]

[0025] FIG. 1 shows a stiffening device having a distal end. [Figure 6]

[0026] FIG. 10 shows a stiffening device with a distal end having a braid pattern separate from the proximal portion of the device. [Figure 7]

[0027] FIG. 10 illustrates a stiffening device with a distal end having multiple passive links. [Figure 8]

[0028] FIG. 1 shows a stiffening device with a distal end having multiple actively controlled links. [Figure 9A]

[0029] FIG. 1 illustrates multiple actively controlled links. [Figure 9B] FIG. 1 illustrates multiple actively controlled links. [Figure 9C] FIG. 1 illustrates multiple actively controlled links. [Figure 9D] FIG. 1 illustrates multiple actively controlled links. [Figure 9E]FIG. 1 illustrates multiple actively controlled links. [Figure 10]

[0030] FIG. 10 illustrates an embodiment of a stiffening device including cables extending within a layered wall. [Figure 11]

[0031] FIG. 10 illustrates an embodiment of a stiffening device including cables extending within a layered wall. [Figure 12]

[0032] FIG. 10 illustrates an embodiment of a stiffening device including cables extending within a layered wall. [Figure 13]

[0033] FIG. 10 illustrates an embodiment of a stiffening device including cables extending within a layered wall. [Figure 14]

[0034] FIG. 10 illustrates an embodiment of a stiffening device including cables extending within a layered wall. [Figure 15]

[0035] FIG. 10 illustrates an embodiment of a stiffening device including cables extending within a layered wall. [Figure 16]

[0036] FIG. 10 illustrates an embodiment of a stiffening device including cables extending within a layered wall. [Figure 17]

[0037] FIG. 10 illustrates a stiffening device including a cable extending through a central lumen. [Figure 18]

[0038] FIG. 10 illustrates an embodiment of a stiffening device that includes a cable that spirals around the periphery. [Figure 19]

[0039] FIG. 10 illustrates an embodiment of a stiffening device having a cable spirally surrounding it. [Figure 20A]

[0040] FIG. 10 illustrates an embodiment of a stiffening device having a cable spirally surrounding it. [Figure 20B] FIG. 10 illustrates an embodiment of a stiffening device having a cable spirally surrounding it. [Figure 21A]

[0041] FIG. 10 shows a stiffening device having a cable spiraling through it. [Figure 21B] FIG. 10 shows a stiffening device having a cable spiraling through it. [Figure 22A]

[0042] 10A-10C show exemplary connections for the distal end. [Figure 22B] 10A-10C show exemplary connections for the distal end. [Figure 22C] 10A-10C show exemplary connections for the distal end. [Figure 22D] 10A-10C show exemplary connections for the distal end. [Figure 23A]

[0043] FIG. 10 shows a stiffening device with a distal end having a coupling portion on the stiffening portion. [Figure 23B] FIG. 10 shows a stiffening device with a distal end having a coupling portion on the stiffening portion. [Figure 24]

[0044] FIG. 10 shows a steerable stiffening tip. [Figure 25A]

[0045] FIG. 10 shows a stiffening device with a distal end having a coupling portion within the stiffening portion. [Figure 25B]

[0046] FIG. 10 shows a stiffening device with steering cables attached to the wall near the distal end. [Figure 26A]

[0047] FIG. 1 shows a stiffening device with an actively deflecting distal end. [Figure 26B] FIG. 1 shows a stiffening device with an actively deflecting distal end. [Figure 26C] FIG. 1 shows a stiffening device with an actively deflecting distal end. [Figure 27]

[0048] FIG. 1 illustrates a nested stiffening system. [Figure 28]

[0049] FIG. 10 shows a nested stiffening system with a cover between the inner and outer stiffening devices. [Figure 29A]

[0050] FIG. 10 illustrates a nested stiffening system in which an outer stiffening device includes steering and imaging functions. [Figure 29B] FIG. 10 illustrates a nested stiffening system in which an outer stiffening device includes steering and imaging functions. [Figure 30A]

[0051] FIG. 1 illustrates an example of the use of a nested stiffening system. [Figure 30B] FIG. 1 illustrates an example of the use of a nested stiffening system. [Figure 30C] FIG. 1 illustrates an example of the use of a nested stiffening system. [Figure 30D] FIG. 1 illustrates an example of the use of a nested stiffening system. [Figure 30E] FIG. 1 illustrates an example of the use of a nested stiffening system. [Figure 30F] FIG. 1 illustrates an example of the use of a nested stiffening system. [Figure 30G] FIG. 1 illustrates an example of the use of a nested stiffening system. [Figure 30H] FIG. 1 illustrates an example of the use of a nested stiffening system. [Figure 31A]

[0052] FIG. 1 illustrates a robotic control stiffening system. [Figure 31B] FIG. 1 illustrates a robotic control stiffening system. [Figure 31C] FIG. 1 illustrates a robotic control stiffening system. [Figure 31D] FIG. 1 illustrates a robotic control stiffening system. [Figure 32A]

[0053] FIG. 1 illustrates the mechanism for operating the robotic controlled stiffening system. [Figure 32B] FIG. 1 illustrates the mechanism for operating the robotic controlled stiffening system. [Figure 33]

[0054] FIG. 1 illustrates a drive unit of a robotic control stiffening system. [Figure 34]

[0055] FIG. 1 illustrates a guide for a robotic control stiffening system. [Figure 35A]

[0056] FIG. 10 illustrates another embodiment of a guide for a robotically controlled stiffening system. [Figure 35B] FIG. 10 illustrates another embodiment of a guide for a robotically controlled stiffening system. [Figure 36]

[0057] FIG. 10 illustrates another embodiment of a mounting for a robotically controlled stiffening system. [Figure 37]

[0058] FIG. 1 illustrates a tool for use with a robotically controlled stiffening system. [Figure 38]

[0059] FIG. 1 illustrates a slide for use with a robotically controlled stiffening system. [Figure 39A]

[0060] FIG. 1 illustrates a robotic control stiffening system. [Figure 39B] FIG. 1 illustrates a robotic control stiffening system. [Figure 40]

[0061] FIG. 1 illustrates a pivot arm for a robotic controlled stiffening system. [Figure 41A]

[0062] FIG. 10 shows a stiffening device with a rail system for attachment of the working channel. [Figure 41B] FIG. 10 shows a stiffening device with a rail system for attachment of the working channel. [Figure 41C] FIG. 10 shows a stiffening device with a rail system for attachment of the working channel. [Figure 42]

[0063] FIG. 10 illustrates a stiffening device with working channels positioned adjacent to each other around the periphery of the stiffening device. [Figure 43]

[0064] FIG. 43 shows the stiffening device of FIG. 42 with the working channels moved to a more spread-out position around the circumference. [Figure 44]

[0065] FIG. 10 shows a stiffening device with an attached serrated working channel. [Figure 45]

[0066] FIG. 10 shows a stiffening device with a telescoping working channel attached. [Figure 46]

[0067] FIG. 10 shows a stiffening device with one or more working channels that move freely within an outer sheath configured for vacuum actuation. [Figure 47]

[0068] FIG. 10 shows a stiffening device fitted with a spiral cut working channel. [Figure 48]

[0069] FIG. 10 shows a stiffening device with an attached coiled working channel. [Figure 49A]

[0070] FIG. 10 shows a fixture including a flexible guide. [Figure 49B] FIG. 10 shows a fixture including a flexible guide. [Figure 50A]

[0071] FIG. 10 shows the distal end of a stiffening device having a lumen for passage of a working tool. [Figure 50B] FIG. 10 shows the distal end of a stiffening device having a lumen for passage of a working tool. [Figure 50C] FIG. 10 shows the distal end of a stiffening device having a lumen for passage of a working tool. [Figure 51A]

[0072] FIG. 10 shows a stiffening device with a separated stiffening distal end. [Figure 51B] FIG. 10 shows a stiffening device with a separated stiffening distal end. [Figure 51C] FIG. 10 shows a stiffening device with a separated stiffening distal end. [Figure 51D]FIG. 10 shows a stiffening device with a separated stiffening distal end. [Figure 51E] FIG. 10 shows a stiffening device with a separated stiffening distal end. [Figure 52A]

[0073] FIG. 10 shows a stiffening device including a flexible outer tube with a working channel. [Figure 52B] FIG. 10 shows a stiffening device including a flexible outer tube with a working channel. [Figure 53]

[0074] FIG. 10 shows a stiffening device including an alternative outer tube with a working channel. [Figure 54]

[0075] FIG. 10 shows another stiffening device having a separated stiffening distal end. [Figure 55]

[0076] FIG. 10 shows a stiffening distal tip. [Figure 56A]

[0077] FIG. 10 shows a stiffening distal end containing multiple pressure channels therein. [Figure 56B] FIG. 10 shows a stiffening distal end containing multiple pressure channels therein. [Figure 56C] FIG. 10 shows a stiffening distal end containing multiple pressure channels therein. [Figure 56D] FIG. 10 shows a stiffening distal end containing multiple pressure channels therein. [Figure 57]

[0078] FIG. 1 shows a pressure channel with a rectangular pressure line and a support member. [Figure 58]

[0079] FIG. 1 shows a pressure channel with pressure lines and cable support lines. [Figure 59]

[0080] FIG. 1 shows a pressure channel with a pressure line and multiple support members. [Figure 60]

[0081] FIG. 10 shows a support member wrapped around a pressure line. [Figure 61]

[0082] FIG. 10 shows a pressure channel with a pressure line having a circumference smaller than the circumference of the pressure line. [Figure 62]

[0083] FIG. 10 shows a pressure channel with a pressure line having a circumference larger than the circumference of the pressure line. [Figure 63A]

[0084] 13A-13C show an overmolded support member for use with a pressure channel. [Figure 63B] 13A-13C show an overmolded support member for use with a pressure channel. [Figure 64A]

[0085] 13A-13C show alternative overmolded support members for use with pressure channels. [Figure 64B] 13A-13C show alternative overmolded support members for use with pressure channels. [Figure 65]

[0086] 13A-13C show alternative overmolded support members for use with pressure channels. [Figure 66A]

[0087] FIG. 1 shows an inflatable pressure line with a blade around it. [Figure 66B] FIG. 1 shows an inflatable pressure line with a blade around it. [Figure 67]

[0088] FIG. 10 shows another stiffening distal end including multiple pressure channels therein. [Figure 68A]

[0089] 10A-10C show examples of pressure line passage through pressure channels. [Figure 68B] 10A-10C show examples of pressure line passage through pressure channels. [Figure 69]

[0090] FIG. 10 shows another stiffening distal end including multiple pressure channels therein. [Figure 70]

[0091] FIG. 1 shows a pressure channel with a frictionless layer therein. [Figure 71A]

[0092] FIG. 10 shows a stiffening distal end with a support member extending along the joint. [Figure 71B]FIG. 10 shows a stiffening distal end with a support member extending along the joint. [Figure 72]

[0093] FIG. 1 shows a stiffening device having a clamping mechanism for its distal end. [Figure 73A]

[0094] 10A-10C illustrate a stiffening system having an outer tube with a removable guide configured to allow insertion of a working tool. [Figure 73B] 10A-10C illustrate a stiffening system having an outer tube with a removable guide configured to allow insertion of a working tool. [Figure 73C] 10A-10C illustrate a stiffening system having an outer tube with a removable guide configured to allow insertion of a working tool. [Figure 73D] 10A-10C illustrate a stiffening system having an outer tube with a removable guide configured to allow insertion of a working tool. [Figure 73E] 10A-10C illustrate a stiffening system having an outer tube with a removable guide configured to allow insertion of a working tool. [Figure 73F] 10A-10C illustrate a stiffening system having an outer tube with a removable guide configured to allow insertion of a working tool. [Figure 73G] 10A-10C illustrate a stiffening system having an outer tube with a removable guide configured to allow insertion of a working tool. [Figure 73H] 10A-10C illustrate a stiffening system having an outer tube with a removable guide configured to allow insertion of a working tool. [Figure 73I] 10A-10C illustrate a stiffening system having an outer tube with a removable guide configured to allow insertion of a working tool. [Figure 73J]10A-10C illustrate a stiffening system having an outer tube with a removable guide configured to allow insertion of a working tool. [Figure 73K] 10A-10C illustrate a stiffening system having an outer tube with a removable guide configured to allow insertion of a working tool. [Figure 73L] 10A-10C illustrate a stiffening system having an outer tube with a removable guide configured to allow insertion of a working tool. [Figure 73M] 10A-10C illustrate a stiffening system having an outer tube with a removable guide configured to allow insertion of a working tool. [Figure 74A]

[0095] 10A-10C illustrate another stiffening system having an outer tube with a removable guide configured to allow insertion of a working tool. [Figure 74B] 10A-10C illustrate another stiffening system having an outer tube with a removable guide configured to allow insertion of a working tool. [Figure 74C] 10A-10C illustrate another stiffening system having an outer tube with a removable guide configured to allow insertion of a working tool. [Fig. 74D] 10A-10C illustrate another stiffening system having an outer tube with a removable guide configured to allow insertion of a working tool. [Figure 74E] 10A-10C illustrate another stiffening system having an outer tube with a removable guide configured to allow insertion of a working tool. [Figure 74F] 10A-10C illustrate another stiffening system having an outer tube with a removable guide configured to allow insertion of a working tool. [Figure 75A]

[0096] FIG. 10 illustrates an alternative outer tube with removable guides for use with a stiffening system. [Figure 75B]FIG. 10 illustrates an alternative outer tube with removable guides for use with a stiffening system. DETAILED DESCRIPTION OF THE INVENTION

[0022]

[0097] Generally, described herein are stiffening devices (e.g., overtubes) configured to assist in transporting a scope (e.g., endoscope) or other medical instrument through curves or loops in the body (e.g., body canals). The stiffening devices can be long, thin, hollow, and can rapidly transition from a soft configuration (i.e., a relaxed, flexible, or pliable configuration) to a rigid configuration (i.e., a configuration that is stiff and / or retains its shape when stiffened). Multiple layers (e.g., a coil or reinforcing layer, a slip layer, a braid layer, a bladder layer, and / or a sealing sheath) can combine to form the walls of the stiffening device. The stiffening device can transition from a soft configuration to a rigid configuration, for example, by applying vacuum or pressure to or within the walls of the stiffening device. With the vacuum or pressure removed, the layers can easily shear or move relative to one another. With the vacuum or pressure applied, the layers can transition to a state that exhibits substantially enhanced resistance to shear, movement, bending, torque, and buckling, thereby providing stiffness to the system.

[0023]

[0098] The stiffening devices described herein can provide stiffening for a variety of medical applications, including catheters, sheaths, scopes (e.g., endoscopes), wires, overtubes, trocars, or laparoscopic instruments. The stiffening devices can function as separate add-on devices or can be incorporated into the body of the catheter, sheath, scope, wire, or laparoscopic instrument. The devices described herein can also provide stiffening to non-medical structures.

[0024]

[0099] An exemplary stiffening device system is shown in FIG. 1. The system includes a stiffening device 300 having a wall with multiple layers, including a braid layer, an outer layer (portion of which is cut away to reveal the underlying braid), and an inner layer. The system further includes a handle 342 having a vacuum or pressure inlet 344 for applying vacuum or pressure to the stiffening device 300. An actuation element 346 can be used to turn the vacuum or pressure on and off, thereby transitioning the stiffening device 300 between its flexible and rigid configurations. The distal tip 339 of the stiffening device 300 can be smooth, flexible, and atraumatic to facilitate distal movement of the stiffening device 300 through the body. Additionally, the tip 339 can be tapered from the distal end to the proximal end to further facilitate distal movement of the stiffening device 300 through the body.

[0025]

[0100] An exemplary stiffening device in a stiffened configuration is shown in FIGS. 2A and 2B. When the stiffening device is stiffened, it is stiffened in the shape it had before the vacuum or pressure was applied, i.e., the stiffening device does not straighten, bend, or otherwise substantially change its shape (e.g., it may be stiffened in a looped configuration as shown in FIG. 2A or a serpentine configuration as shown in FIG. 2B). This is possible because the air-stiffening effect on the inner or outer layer (e.g., made of coiled tubing) can be a small percentage (e.g., 5%) of the maximum load capacity of the stiffening device in the bent state, thereby allowing the stiffening device to resist straightening. When the vacuum or pressure is released, the braids or strands unlock relative to each other and can again move to allow the stiffening device to bend. Again, when the stiffening device is made more flexible by the release of vacuum or pressure, it becomes flexible in the shape it had before the vacuum or pressure was released, i.e., the stiffening device does not straighten, bend, or otherwise substantially change its shape. Thus, the stiffening devices described herein can transition from a flexible, less rigid configuration to a more rigid, stiff configuration by restricting movement between the strands of the braid (e.g., by applying a vacuum or pressure).

[0026]

[0101] The stiffening devices described herein can switch between rigid and flexible configurations rapidly, in some embodiments, with an indefinite number of transition cycles. As interventional medical devices become longer and inserted deeper into the human body, and as they are expected to perform more precise therapeutic procedures, the need for precision and control increases. The selective stiffening devices (e.g., overtubes) described herein advantageously provide both the benefits of flexibility (when needed) and stiffness (when needed). Additionally, the stiffening devices described herein can be used with conventional endoscopes, colonoscopes, robotic systems, and / or navigation systems, such as those described in International Patent Application No. PCT / US2016 / 050290, filed September 2, 2016, and entitled "DEVICE FOR ENDOSCOPIC ADVANCEMENT THROUGH THE SMALL INTESTINE," which is incorporated herein by reference in its entirety.

[0027]

[0102] The stiffening devices described herein may additionally or alternatively be any of International Patent Application Nos. PCT / US2016 / 050290, filed September 2, 2016, entitled "DEVICE FOR ENDOSCOPIC ADVANCEMENT THROUGH THE SMALL INTESTINE," published as WO2017 / 041052; International Patent Application Nos. PCT / US2018 / 042946, filed July 19, 2018, entitled "DYNAMICALLY RIGIDIZING OVERTUBE," published as WO2019 / 018682; and International Patent Application Nos. PCT / US2018 / 042946, filed July 19, 2018, entitled "DYNAMICALLY RIGIDIZING COMPOSITE MEDICAL DEVICE," published as WO2020 / 018934. The present invention may include any of the features described in connection with International Patent Application No. PCT / US2019 / 042650, filed July 19, 2019, entitled "DYNAMICALLY RIGIDIZING COMPOSITE MEDICAL STRUCTURE," and International Patent Application No. PCT / US2020 / 013937, filed January 16, 2020, entitled "DYNAMICALLY RIGIDIZING COMPOSITE MEDICAL STRUCTURE," which are incorporated herein by reference in their entireties.

[0028]

[0103] The stiffening devices described herein can be provided in multiple configurations, including different lengths and diameters. In some embodiments, the stiffening device can include a working channel (e.g., to allow passage of typical endoscopic tools within the body of the stiffening device), a balloon, a nesting element, and / or a side-loading mechanism.

[0029]

[0104] 3A-3D, in one embodiment, a tubular stiffening device 100 can include a wall having multiple layers disposed about a lumen 120 (e.g., for placement of an instrument or endoscope therethrough). A vacuum can be applied between the layers to stiffen the stiffening device 100.

[0030]

[0105] The innermost layer 115 can be configured to provide an inner surface against which the remaining layers can be compacted, for example, when a vacuum is applied within the wall of the stiffening device 100. This structure can be configured to minimize bending forces / maximize flexibility in non-vacuum conditions. In some embodiments, the innermost layer 115 can include reinforcing elements 150z or coils within a matrix, as described above.

[0031]

[0106] The layer 113 above (ie, radially outward from) the innermost layer 115 may be a slip layer.

[0032]

[0107] Layer 111 can be a radial void (i.e., space) that can provide space for the braided layer above it to move inward (when no vacuum is applied) and space for the braided or woven layer to move radially inward (when a vacuum is applied).

[0033]

[0108] Layer 109 can be a first braided layer including braided yarns 133 similar to those described elsewhere herein. The braided layer can be, for example, 0.001 inch to 0.040 inch thick. For example, the braided layer can be 0.001 inch, 0.003 inch, 0.005 inch, 0.010 inch, 0.015 inch, 0.020 inch, 0.025 inch, or 0.030 inch thick.

[0034]

[0109] In some embodiments, the braid can have tension or hoop fibers 137, as shown in FIG. 3B. The hoop fibers 137 can be spiraled and / or woven into the braid layer. The hoop fibers 137 can be arranged in 2-50, e.g., 20-40, hoops per inch. The hoop fibers 137 can advantageously exhibit high compressive stiffness in the radial direction (resisting buckling or bending) while remaining flexible along the longitudinal axis 135 of the stiffening device 100. That is, when compression is applied to the stiffening device 100, the braid layer 109 attempts to expand in diameter as it compresses. The hoop fibers 137 can withstand this diametric expansion and, therefore, can withstand compression. Thus, the hoop fibers 137 can provide a system that is flexible when bent yet can withstand both tension and compression.

[0035]

[0110] Layer 107 may be another radially gapped layer similar to layer 111 .

[0036]

[0111] In some embodiments, the stiffening devices described herein can have multiple braided layers. For example, the stiffening devices can include two, three, or four braided layers. With reference to FIG. 3C , layer 105 can be a second braided layer 105. The second braided layer 105 can have any of the features described in connection with the first braided layer 109. In some embodiments, the braid of the second braided layer 105 can be the same as the braid of the first braided layer 109. In other embodiments, the braid of the second braided layer 105 can be different from the braid of the first braided layer 109. For example, the braid of the second braided layer 105 can include fewer twists and have a larger braid angle α than the braid of the first braided layer 109. The fewer strands may facilitate increased flexibility of the stiffening device 100 (compared to a second strand having an equal or greater number of strands), and the larger braid angle α may facilitate contraction of the diameter of the first braided layer 109 (e.g., when the first braided layer is compressed) while increasing / maintaining the flexibility of the stiffening device 100. As another example, the braid of the second braided layer 105 may include more strands and have a larger braid angle α than the braid of the first braided layer 109. Having a larger number of strands results in a relatively strong and smooth layer, while having a larger braid angle α may facilitate contraction of the diameter of the first braided layer 109.

[0037]

[0112] Layer 103 can be another radially voided layer similar to layer 111. Voided layer 103 can have a thickness of 0.0002 inches to 0.04 inches, such as about 0.03 inches. A thickness within this range can ensure that the braided layer strands 133 can easily slip and / or expand relative to each other to ensure flexibility when stiffening device 100 is bent.

[0038]

[0113] The outermost layer 101 can be configured to move radially inward and conform to the surface of the braid layers 105, 109 when a vacuum is applied to pull it down against the braid layers 105, 109. The outermost layer 101 can be soft and atraumatic and can be sealed at both ends to form a vacuum-tight chamber with the layer 115. The outermost layer 101 can be made of an elastomer, such as urethane. The hardness of the outermost layer 101 can be, for example, 30A to 80A. The outermost layer 101 can also have a thickness of between 0.0001 inches and 0.01 inches, such as approximately 0.001 inches, 0.002 inches, 0.003 inches, or 0.004 inches. Alternatively, the outermost layer may be a plastic, including, for example, LDPE, nylon, or PEEK.

[0039]

[0114] In some embodiments, the outermost layer 101 can have, for example, tensile or hoop fibers 137 extending therethrough. The hoop fibers 137 can be made of, for example, aramid (e.g., Technora, nylon, Kevlar), Vectran, Dyneema, carbon fiber, fiberglass, or plastic. The hoop fibers 137 can be arranged at 2 to 50 hoops per inch, e.g., 20 to 40 hoops per inch. In some embodiments, the hoop fibers 137 can be laminated within an elastomeric sheath. Hoop fibers can advantageously exhibit higher stiffness in one direction compared to other fibers (e.g., very stiff in the hoop direction but very flexible in the direction of the longitudinal axis of the stiffening device). Furthermore, hoop fibers can advantageously exhibit low hoop stiffness until placed under a tensile load, at which point the hoop fibers can suddenly exhibit high hoop stiffness.

[0040]

[0115] In some embodiments, the outermost layer 101 can include a lubricant, coating, and / or powder (e.g., talcum powder) on its exterior surface to enhance sliding of the stiffening device through the anatomy. The coating can be hydrophilic (e.g., Hydromer® coating or Surmodics® coating) or hydrophobic (e.g., fluoropolymer). The coating can be applied, for example, by dipping, painting, or spraying the coating on.

[0041]

[0116] The innermost layer 115 may likewise include a lubricant, coating (e.g., a hydrophilic or hydrophobic coating) and / or powder (e.g., talcum powder) on its interior surface to maximize flexibility, particularly configured to allow the boundary layers to shear more easily against each other when no vacuum is applied to the stiffening device 100.

[0042]

[0117] In some embodiments, the outermost layer 101 may be looser than the radially inner layer. For example, the inner diameter of layer 101 (assuming it comprises a tube) may have a diameter gap of 0 cm (0 in) to 0.200 in (0.508 cm) between it and the next radially inner layer (e.g., braided layer). This allows the vacuum-stiffened system to be more flexible when not under vacuum while maintaining a high stiffening factor. In other embodiments, the outermost layer 101 may be stretched somewhat over the next radially inner layer (e.g., braided layer). For example, the zero-strain diameter of the tube comprising layer 101 may be 0 cm (0 in) to 0.200 in (0.508 cm) smaller in diameter than the next radially inner layer and then stretched over it. When not under vacuum, this system may have less flexibility than a system with a looser outer layer 101. However, it may also have a smoother appearance and be less likely to tear during use.

[0043]

[0118] In some embodiments, the outermost layer 101 may be loose above the radially inner layers. A slight positive pressure may be applied underneath the layer 101 to gradually expand the layer 101 and allow the stiffening device to bend more freely in the flexible configuration. In this embodiment, the outermost layer 101 may be elastomeric and may maintain a compressive force on the braid, thereby providing stiffness. After positive pressure (sufficient to nominally expand the sheath away from the braid, e.g., 2 psi) is applied, the outermost layer 101 no longer contributes to stiffness, thereby enhancing baseline flexibility. Once stiffening is needed, the positive pressure may be replaced by negative pressure (vacuum) to provide stiffness.

[0044]

[0119] A vacuum can be maintained within the stiffening device 100 from a minimum to a full atmospheric vacuum (e.g., approximately 14.7 psi). Some embodiments may include a bleed valve, regulator, or pump control to release the vacuum to any intermediate level for variable stiffness capability. This vacuum pressure can be advantageously used to stiffen the stiffening device structure by compressing layers of the braided sleeve against adjacent layers. The braid naturally flexes during bending (i.e., when bending perpendicular to its longitudinal axis), and as the sleeve is bent, the lattice structure formed by the interwoven strands deforms so that the braid conforms to the bent shape while resting on the inner layer. This results in a lattice geometry in which the corner angle of each lattice element changes as the braided sleeve bends. When compressed between conformal materials, such as the layers described herein, the lattice elements are fixed at their current corners and have an enhanced ability to resist deformation during application of a vacuum, thereby stiffening the overall structure during bending when a vacuum is applied. Additionally, in some embodiments, the hoop fibers in or on the braid can carry tensile loads that help prevent localized buckling of the braid at high applied bending loads.

[0045]

[0120] The stiffness of stiffening device 100 can increase by 2 to more than 30 times, e.g., 10 times, 15 times, or 20 times, when transitioning from the flexible to the rigid configuration. In one particular example, the stiffness of a stiffening device similar to stiffening device 100 was tested. The test stiffening device had a wall thickness of 1.0 mm and an outer diameter of 17 mm, and a force was applied to the end of a 9.5 cm long cantilevered portion of the stiffening device until the stiffening device deflected 10 degrees. This required only 30 grams of force in the flexible mode, while the force required to do this in the rigid (vacuum) mode was 350 grams.

[0046]

[0121] Some embodiments of the vacuum stiffening device 100 may have only one braid layer. Other embodiments of the vacuum stiffening device 100 may include two, three, or more braid layers. In some embodiments, the stiffening device 100 may eliminate one or more of the radial gap layers or slip layers. In some embodiments, the stiffening device 100 may eliminate some or all of the slip layers.

[0047]

[0122] The braid layer described herein can serve as a variable stiffness layer. The variable stiffness layer can include one or more variable stiffness elements or structures that, when activated (e.g., when a vacuum is applied), increase bending stiffness and / or shear resistance, resulting in higher stiffness. Other variable stiffness elements can be used in addition to or instead of the braid layer. In some embodiments, an engagement portion can be used as a variable stiffness element, as described in International Patent Application No. PCT / US2018 / 042946, filed July 19, 2018, entitled "DYNAMICALLY RIGIDIZING OVERTUBE," which is incorporated herein by reference in its entirety. Alternatively or additionally, the variable stiffness element can include particles or granules, jamming layers, flakes, stiffening shafts, stiffening pieces, longitudinal members, or substantially longitudinal members.

[0048]

[0123] In some embodiments, the stiffening devices described herein can be stiffened by the application of pressure rather than a vacuum. For example, with reference to Figures 4A-4B, stiffening device 2100 can be similar to stiffening device 100, except that it can be configured to hold pressure (e.g., greater than 1 atmosphere) rather than a vacuum for stiffening. Thus, stiffening device 2100 can include multiple layers disposed about lumen 2120 (e.g., for placement of an instrument or endoscope therethrough). The stiffening device 2100 may include an innermost layer 2115 (similar to innermost layer 115), a slip layer 2113 (similar to slip layer 113), a pressure void 2112, a bladder layer 2121, a void layer 2111 (similar to void layer 111), a braid layer 2109 (similar to braid layer 109) or other variable stiffness layer as described herein, a void layer 2107 (similar to layer 107), and a confining outermost layer 2101.

[0049]

[0124] The pressure void 2112 can be a sealed chamber that provides a space for application of pressure to the layers of the stiffening device 2100. Pressure can be supplied to the pressure void 2112 using a fluid or gas expansion / pressure medium. The expansion / pressure medium can be water or saline, or a lubricating fluid such as, for example, earth or glycerin. The lubricating fluid can, for example, allow the layers of the stiffening device 2100 to move easily over each other in the flexible configuration. The expansion / pressure medium can be supplied to the void 2112 when stiffening the stiffening device 2100 and can be partially or completely evacuated to transform the stiffening device 2100 back to the flexible configuration. In some embodiments, the pressure void 2112 of the stiffening device 2100 can be connected to a pre-filled pressure source, such as a pre-filled syringe or a pre-filled inhaler, thereby reducing the preparation time required by the physician.

[0050]

[0125] The bladder layer 2121 can be made of, for example, a low durometer elastomer (e.g., Shore 20A-70A) or a thin plastic sheet. The bladder layer 2121 can be formed from a thin sheet of plastic or rubber sealed longitudinally to form a tube. The longitudinal seal can be, for example, a butt joint or a lap joint. For example, a lap joint can be formed longitudinally in the rubber sheet by melting the rubber at the lap joint or by using an adhesive. In some embodiments, the bladder layer 2121 can be 0.0005 cm (0.0002 inches) to 0.0508 cm (0.020 inches) thick, such as approximately 0.0127 cm (0.005 inches) thick. The bladder layer 2121 can be soft, high friction, stretchy, and / or wrinkle-resistant. In some embodiments, the bladder layer 2121 is polyolefin or PET. The bladder 2121 can be formed, for example, using methods used to form heat shrink tubing, such as extrusion of a substrate, followed by wall thinning with heat, pressure, and / or radiation. When pressure is supplied through the pressure void 2112, the bladder layer 2121 can expand through the void layer 2111 and press the braid layer 2109 against the confining outermost layer 2101 such that relative movement of the braided yarns is reduced.

[0051]

[0126] The outermost containment layer 2101 can be a tube, such as an extruded tube. Alternatively, the outermost containment layer 2101 can be a tube with a reinforcing member (e.g., a metal wire with a round or rectangular cross-section) encapsulated in an elastomeric matrix, similar to that described in connection with the innermost layer of other embodiments described herein. In some embodiments, the outermost containment layer 2101 can include a helical spring (e.g., made of round or flat wire) and / or a tubular braid (e.g., made of round or flat metal wire) and a thin elastomeric sheet not bonded to other elements in the layer. The outermost containment layer 2101 can be a tubular structure with a continuous, smooth surface. This can favor an outer member sliding against it with close proximity and locally high contact loads (e.g., in a nesting configuration as described further herein). The outer layer 2101 can also be configured to support compressive loads, such as pinching. Additionally, the outer layer 2101 (eg, with the reinforcing elements therein) can be configured to prevent the stiffening device 2100 from changing diameter when pressure is applied.

[0052]

[0127] Because both the outer layer 2101 and the inner layer 2115 contain reinforcing elements therein, the braid layer 2109 may be moderately restricted from both shrinking in diameter (under tensile load) and increasing in diameter (under compressive load).

[0053]

[0128] Using pressure rather than vacuum for transition from the flexible state to the rigid state can increase the stiffness of the stiffening device 2100. For example, in some embodiments, the pressure supplied to the pressure void 2112 can be between 1 and 40 atmospheres, such as between 2 and 40 atmospheres, between 4 and 20 atmospheres, or between 5 and 10 atmospheres. In some embodiments, the pressure supplied is about 2 atmospheres, about 4 atmospheres, about 5 atmospheres, about 10 atmospheres, or about 20 atmospheres. In some embodiments, the stiffening device 2100 can exhibit a change in relative bending stiffness from the flexible to the rigid configuration (as measured in a simple cantilever configuration) of 2 to 100 times, such as 10 to 80 times, 20 to 50 times, or more. For example, the stiffening device 2100 can have a change in relative bending stiffness from the flexible to the rigid configuration of about 10 times, 15 times, 20 times, or 25 times, 30 times, 40 times, 50 times, or more than 100 times.

[0054]

[0129] Any of the stiffening devices described herein can have a distal end or portion that is designed differently from the elongate body of the stiffening device. For example, as shown in FIG. 5, a stiffening device 5500 can have an elongate body 5503z and a distal end 5502z. Only the distal end 5502z, only the elongate body 5503z, or both the distal end 5502z and the elongate body 5503z can be stiffened as described herein (e.g., by vacuum and / or pressure). In some embodiments, one portion 5502z, 5503z is pressure actuated and the other portion 5502z, 5503z is vacuum actuated. In other embodiments, both portions 5502z, 5503z are pressure or vacuum actuated.

[0055]

[0130] Referring to FIG. 6 , in some embodiments, the distal portion 5702z can include stiffening blades that are different from the blades of the elongate body portion 5703z. For example, in one embodiment, the blade angle relative to the longitudinal axis at the distal end 5702z can be greater than the blade angle of the elongate body 5703z. For example, the blade angle at the distal portion can be 40 degrees and the blade angle at the elongate body can be 20 degrees. The blades can overlap slightly and be joined by a flexible adhesive. These designs can provide the distal end 5702z with greater bending flexibility than the elongate body 5703z in a non-rigidified state. Having a more flexible distal tip can be advantageous, for example, to prevent buckling and drag at the tip (caused by fixing the blade ends) and / or provide flexibility when navigating through a body lumen to prevent trauma to the anatomy. In another embodiment, the blade angle relative to the longitudinal axis at the distal end 5702z can be less than the blade angle of the elongate body 5703z. This can provide the distal end 5702z with relatively greater stiffness in the rigid state compared to the elongate body 5703z. Having more stiffness in the distal end 5702z can be advantageous, for example, by providing a stable platform for movement or delivery of a medical device through the central lumen of the stiffening device 5700 and out the distal end.

[0056]

[0131] Referring to FIG. 7 , in some embodiments, the distal end 5802z can include multiple passively actuated links 5804z. The links 5804z can be connected together at one or more pivot points, advantageously providing deterministic bending (i.e., bending in a specific, predetermined direction). Additionally, the links 5804z can advantageously provide torsional stiffness to the distal end 5802z while providing high flexibility for bending. The links 5804z can be passively actuated, for example, by bending as the device 5800 moves through the anatomy. The distal end 5802z can include 1 to 100 links 5804z, such as 1, 2, 4, 6, 8, 10, 16, 20, 30, or 40 links 5804z. In some embodiments, the links 5804z can be formed by passively cutting and bending a material, such as a laser-cut tube or stent.

[0057]

[0132] Referring to FIG. 8 , in other embodiments, the distal end 7602z can include multiple links 7604z that are actively controlled, such as via cables 7624, for steering the stiffening device 7600. The device 7600 is similar to the device 5800, except that it includes cables 7624 configured to control the movement of the device. While FIG. 26 does not show the passage of the cables 7624 through the elongate stiffening body 7603z (i.e., comprising the outer wall 7601, the braid layer 7609, and the inner layer 7615), the cables 7624 can extend in any manner as described elsewhere herein. In some embodiments, one or more layers of the elongate stiffening body 7603z can continue into the distal end 7602z. For example, as shown in FIG. 26 , the inner layer 7615 can continue into the distal end 7602z, e.g., be located radially inward of the links 7604z. Similarly, any additional layers from the stiffening proximal portion (e.g., the braid layer 7609 or the outer layer 7601) may continue into the distal portion 7602z and / or may be located radially inward of the coupling portion 7604z. In other embodiments, none of the layers of the elongate stiffening body 7603z continue into the distal portion 7602z. The coupling portion 7604z (and any coupling portion described herein) may include a coating 7627z thereon. The coating 7627z may be advantageous because it can make the distal portion 7602z atraumatic and / or smooth. The coating 7627z may be a film, such as expanded PTFE. Expanded PTFE is advantageous because it can provide a smooth, low-friction surface that is less resistant to bending but more resistant to buckling.

[0058]

[0133] 9A-9E show another example distal end 4302z including multiple links 4304z that are actively controlled, such as via cables 4324, for steering the stiffening device. In some embodiments, the pivots of the links 4304z can be involutes, similar to gear teeth, as shown in FIGS. 9A-9E, to reduce local contact drag. The cables 4324 can be disposed within cable guides (e.g., jackets or coil pipes) that extend the length of the stiffening device. In some embodiments, the cables 4324 (and cable guides) can extend within the walls of the stiffening device. Cable guides are advantageous because they can ensure that tensile loads are supported through the cable guides rather than through the walls of the stiffening device, so as not to adversely deflect the wall structure when tensile loads are applied to the links 4304z. In some embodiments, the cable guides and cables 4324 can have excess length to allow for flexing of the stiffening device. This excess length can be woven or coiled within the wall of the stiffening device, for example. Alternatively, the cables 4324 can be threaded through openings and / or grooves in the links 4304z (see FIG. 9C), with the remainder free-floating within the wall (thereby allowing room for flexing of the stiffening device). When the cables 4324 are actuated, the links 4304z pivot relative to each other, thereby imparting steering to the distal end of the stiffening device. Articulation of the links 4304z and the cables 4324 for steering can be achieved by actuators (e.g., localized motors, current-activated (heat) nitinol wires, proximal actuators (typically stainless steel, tungsten, or composites), hydraulics, and / or EAPs (electroactive polymers)). Such steering mechanisms are advantageous because they can improve clinical utility. They also allow devices (e.g., endoscopes or guidewires) placed through the central lumen to be steered toward and more easily reach desired anatomical sites.

[0059]

[0134] When cables are used for distal end steering, the cables (which may or may not be housed in cable guides) can be routed through the walls of the stiffening devices described herein in several different ways. FIGS. 10-21B illustrate example configurations of stiffening devices with cable guides (some wall layers are omitted from FIGS. 10-21B for clarity). For example, FIG. 10 illustrates a stiffening device 6200 having cables 6224 extending within cable guides 6299 within the outer radial void layer 6207 (and thus between the braid layer 6209 and the outer layer 6201). In some embodiments, each of the cables 6224 and cable guides 6299 can be approximately equally spaced around the circumference (i.e., approximately 90 degrees apart from adjacent cables if four cables are used). In other embodiments, one or more of the cables 6224 and cable guides 6299 can be closely spaced (e.g., in the same quadrant) rather than spaced apart. Additionally, in some embodiments, the cables 6224 and / or guides 6299 can be arranged asymmetrically around the circumference of the stiffening device 6200.

[0060]

[0135] 11 shows a stiffening device 6300 in which cables 6324 and cable guides 6399 are disposed within an inner radial void layer 6311 (thus between a braided layer 6309 of the stiffening device and an inner layer, such as a bladder 6321). For example, when pressure is supplied to the pressure void 6312, the bladder 6321 can push against the braided layer 6309, which can correspondingly push against the outer layer 6301 without the braided layer 6309 squeezing or otherwise affecting the cables 6324. Again, the cables 6324 and cable guides can be equally spaced or asymmetrically spaced around the circumference of the stiffening device 6300.

[0061]

[0136] 12 , in some embodiments, the stiffening device 6400 can have the cables 6424 and cable guides 6499 at least partially isolated from the pressurized or vacuum compartment. For example, as shown in FIG. 12 , a tubular bladder layer 6421 can surround the pressure void 6412. Some or all of the cables 6424 and cable guides 6499 can be positioned circumferentially adjacent to the tubular bladder layer 6421 within the void 6407 between the inner layer 6415 and the braid layer 6409. Advantageously, this configuration minimizes the effect of pressurization of the bladder layer 6421 on both the cables 6424 and cable guides 6499, and does not substantially add additional stack height or thickness to the wall.

[0062]

[0137] Referring to FIG. 13, in some embodiments, the stiffening device 6500 can include multiple tubular bladders 6521 spaced apart circumferentially such that each cable 6524 and cable guide 6599 can fit within the gap 6507 between adjacent tubular bladders 6521.

[0063]

[0138] Referring to FIG. 14, stiffening device 6600 is similar to device 6500, except that the cables 6624 and guides 6699 are paired together to reduce the number of tubular bladders 6621 required (e.g., there may be two tubular bladders 6621 with two pairs of cables 6624 and guides 6699 positioned therebetween).

[0064]

[0139] 15 , stiffening device 6700 is similar to device 6500, except that each tubular bladder 6721 includes a tubular braid layer 6709 around its periphery (i.e., rather than having a single braid layer 6509 as in device 6500). When pressurized medium is supplied to pressure void 6712, bladders 6721 can expand to press against each individual tubular braid 6709, which in turn can expand to press against inner layer 6715 and outer layer 6701. Alternatively, not all of the bladders may be pressurized simultaneously (e.g., only one or two may be pressurized) so that the device is only partially stiffened around its periphery. This allows stiffening along only portions of the device while other portions remain flexible, thereby allowing selective movement when the device is subjected to a bending load.

[0065]

[0140] 16 , in some embodiments, the stiffening device 6800 can include strips of braided layer 6809 (i.e., flat braids rather than tubular braids). Each strip of braided layer 6809 and each cable 6824 and cable guide 6899 can be disposed in the radial void 6807. Additionally, the strips of braided layer 6809 can alternate with the cables 6824 / 6899 to minimize the wall thickness of the stiffening device 6800. A bladder 6821 can be disposed radially outward of the strips of braided layer 6809 and cables 6824 / guides 6899. When pressure medium is supplied to the pressure void 6812, the bladder 6821 can press the strips of braided layer 6809 radially inward against the innermost layer 6815 to stiffen the device 6800. In other embodiments, the bladder 6821 may be radially inward of the strip of braided layer 6809 (and cables 6824 / guides 6899 ) and may be configured to press the strip of braided layer 6809 against the outer layer 6801 .

[0066]

[0141] In some embodiments, and with reference to FIG. 17, the cable 6924 and cable guide 6999 can be positioned to extend through the central lumen 6920 of the stiffening device 6900 .

[0067]

[0142] 18 , the cables 7024 and cable guides 7099 can be positioned radially outward of the outer layer 7001. The cables 7024 and cable guides 7099 can be positioned within a sheath 7009z that can, for example, extend only over the cables 7024 or can completely encase the outer layer 7001. The guides 7099 can be positioned with minimal constraint within the sheath 7009z to allow them to flex freely during movement of the device 7000 (e.g., to curl or fully extend as the stiffening device 7000 flexes, depending on whether the guides 7099 are positioned inside or outside the stiffening device 7000).

[0068]

[0143] 19, in some embodiments, a cable guide 7199 (with one or more cables therein) can spiral around the outside of the outer layer 7101 of the stiffening device 7100. Additional cable guides can similarly spiral around. In some embodiments, the cable guide 7199 can spiral around other layers of the stiffening device 7100, such as around an inner layer.

[0069]

[0144] 20A-20B, in some embodiments, cable guides 7299 (with one or more cables therein) and tubular elements 7210z can be wrapped around the inner layer 7215 in an alternating spiral fashion (i.e., such that the cable guides 7299 and tubular elements 7210z form a substantially single layer along the length of the stiffening device 7200). The tubular elements 7210z can include an outer tubular braid 7209 with an inner tubular bladder 7221. When pressurized medium is supplied to the pressure void 7212, the bladder 7221 can expand to push the tubular braid 7209 outward, and the tubular braid 7209 can push the outer layer (not shown for clarity) outward.

[0070]

[0145] 21A-21B, stiffening device 7300 may be similar to device 7200, except that only cable guide 7399 and tubular bladder 7321 may be spirally wrapped around inner layer 7315 within void 7311 (note that cable guide 7399 and tubular bladder 7321 are not shown in FIG. 21B for clarity). Braided layer 7309 may then be wrapped radially around void 7311. When a pressure medium is supplied to tubular bladder 7321, bladder 7321 may expand to compress braided layer 7309 against outer layer 7301 (not shown in FIG. 21A for clarity).

[0071]

[0146] It should be understood that the cable configurations described in connection with FIGS. 10-21B can be used with any number of cables (e.g., 1, 2, 3, 4, 5, 6, 8, 12, or 16 cables). Additionally, the cables can be used for steering any tip or stiffening device and / or steering any distal end (e.g., a joint or a section with a different blade angle). Additionally, the cable guides described herein can be round with round cables, flat, rectangular with flat ribbon tension elements, or combinations thereof. Additionally, in some embodiments, other steering elements (e.g., pneumatic mechanisms, hydraulic mechanisms, shape memory alloys, EAPs (electroactive polymers), or motors) can be used in addition to or in place of the cables. By intentionally separating the elements required for steering from the elements required for stiffening, the structure can continuously exhibit high stiffening performance as a function of length, even when the forces available for steering are significantly lower than those required for stiffening the nested system.

[0072]

[0147] Additionally, it should be understood that the cable configurations and arrangements described in connection with Figures 10-21B can be similarly used for the arrangement of working channels or other lumens (e.g., inflation lumens for balloons) within stiffening devices.

[0073]

[0148] 22A-22D, in some embodiments, the distal end 5902z may include a series of links 5904z (active or passive) specifically designed to be stiffened by the application of pressure or vacuum. For example, the links 5904z may be connected to one another via pivot points 5928z (which may be wire pivot points, for example). Each pivot point 5928z may allow one degree of freedom of bending between the links. The links 5904z may also be alternated, with every other link connected to a pivot point 5928z spaced 90 degrees from the previous link. Each link 5904z may have notches 5975z at its proximal and distal ends extending from the pivot point 5928z to allow the links 5904z to bend relative to one another. Each link 5904z may also be connected to an adjacent link 5904z by a respective tension member 5930z. The tension member 5930z can be fixed relative to one link and can be at least partially movable within the track 5931z of an adjacent link (e.g., within the track 5931z of link 5904z). The movement of the link 5904z can cause the tension member 5930z to lengthen when on the outside of the curve and shorten when on the inside of the curve when the stiffening device is bent. The proximal end 5902z can also include two slide clamps 5932z attached to the tension member 5930z along opposite axes (i.e., spaced 90 degrees from each other). The two tension members 5930z extend from each of the slide clamps 5932z to the distal-most end of the distal portion 5902z. When the distal end 5902z is bent, one cable element of each slide clamp 5932z shortens and one cable element of each slide clamp 5932z lengthens, resulting in circumferential movement of the slide clamps 5932z. When a vacuum or pressure is applied, the outer sleeve can press the slide clamps 5932z against the track 5931z surface. The slide clamp 5932Z and track 5931z surfaces can be smooth, rough, or toothed.This compressive force may lock slide clamp 5932Z in place relative to linkage 5904z, thereby immobilizing that portion of tension member 5930z and causing the distal end to become stiffer in its current shape. Other stiffening links and / or engagements are described in International Patent Application No. PCT / US2018 / 042946, entitled "DYNAMICALLY RIGIDIZING OVERTUBE," filed July 19, 2018, now PCT Publication No. WO2019 / 018682, which is incorporated herein by reference in its entirety.

[0074]

[0149] 23A-23B, in some embodiments, the distal end 6002z can include a linkage 6004z (active or passive) disposed above a portion 6007z that is stiffened by vacuum or pressure as described elsewhere herein (i.e., above a stiffening wall comprising the inner layer 6015, pressure cavity 6012, bladder 6021, braid layer 6009, and outer layer 6001). Locating the linkage 6004z above the stiffening portion can provide the benefits of a coupled system (e.g., bending flexibility and torsional stiffness) with a steering tip or deterministic bending tip that can be stiffened as the remaining structure is stiffened. Alternatively, the linkage can be disposed radially inward of the stiffening member, as shown in FIG. 71A. Also shown in FIG. 71A (and FIG. 71B), a support member 7493y can extend radially outward of the linkage 7404z (i.e., between the braid layer 7409 and the linkage 7404z). The support member 7493y can be configured to slide relative to the linkage 7404z when the distal end 7402z is in the flexible configuration. When pressure is supplied to a pressure void 7412 in the bladder 7421 (disposed between the outer layer 7401 and the blade 7409), the blade 7409 can stiffen against the support member 7493y, thereby forcing the support member 7493y against the linkage 7404z and reinforcing the shape of the distal end 7402z in the rigid configuration. As shown in FIG. 23B , a cable 6024 in a cable guide 6099 can extend through the linkage 6400z to provide optional active steering of the linkage 6400z.

[0075]

[0150] 24 , in some embodiments, the distal end 8907z can include a link 8904z disposed radially inward of a vacuum- or pressure-stiffening portion 8907z as described elsewhere herein. For example, the link 8904z (and corresponding cable 8924) can be disposed radially inward of the inner layer 8915 (and thus the bladder 8921, braid layer 8909, and outer layer 8901). When radially inward of the inner layer 8915, the link 8904z can make the inner layer 8915 (e.g., a coil-wrapped tube) less crushable. Also, in such embodiments, the distal portion of the inner layer 8915 coextensive with the link 8904z can be thinner and / or more flexible than the proximal portion of the inner layer 8915 not coextensive with the link 8904z. Having a thinner and / or more flexible distal portion of the inner layer 8915 can provide maneuverability, flexibility and bending at the tip.

[0076]

[0151] In one exemplary use of distal end portion 8907z (or distal end portion 6002z in FIGS. 23A-23B), when stiffening portion 8907z is in a flexible configuration, linkage 8904z and cable 8924 can be used to steer the stiffening device. Conversely, when the stiffening portion is in a rigid configuration, linkage 8904z can be prevented from moving, thereby holding linkage 8904z in a fixed shape. In some embodiments, portion 8907z can be separately stiffenable relative to the proximal portion of the stiffening device.

[0077]

[0152] 55, in some embodiments, the distal end 5507z can include a link 5504z and a stiffening wall including dual braids and dual bladders above the link 5504z. Thus, the distal end 5507z can include two braided layers 5509, 5505 sandwiching two bladders 5521, 5517 (and / or a single bladder). When pressure is applied to a pressure gap 5512 between the bladders 5521, 5517, the outer braided layer 5505 can be forced radially against the outer layer 5501, while the inner braided layer 5509 can be forced radially inward against the link 5504z, thereby stiffening the device and the distal end 5507z. Similar to the distal end 8907z, the link 5504z and cable 5524 can be used for steering the stiffening device when the stiffening portion 5507z is in its flexible configuration. Conversely, when the stiffening portion 5507z is in a rigid configuration, the linking portion 5504z is prevented from moving, thereby holding the linking portion 5504z in a fixed shape. In some embodiments, one or both of the braid layers 5509, 5505 can include longitudinal fibers running through or adjacent the layer.

[0078]

[0153] 51A-51E, in one embodiment, the stiffening device 5100 can include a distal end 5102z having a linkage 5104z, one or more cables 5124 for actuating the linkage 5104z for steering, and an outermost layer 5101 (which can be continuous with the outermost layer of the elongate body 5103z). A clamp 5157y can be immediately adjacent to the distal end 5102z and can be disposed within the outermost layer 5101, braid layer 5109, and bladder 5121 of the elongate body 5103z. As shown in FIG. 51C, the clamp 5157y can include, for example, multiple female engagement portions 5128 extending therefrom. The clamp 5157y can be surrounded on its outer surface by a clamp bladder 5164y (see FIG. 51B). Additionally, the distal portion of each of the cables 5124 may include multiple male engaging portions 5114 extending around the cable 5124 and along its distal length. Alternatively, the male engaging portions 5114 may be part of a single continuous piece rather than multiple separate pieces as shown. Each of the female engaging portions 5128 may include an outer flange 5127 and an inner flange 5129 configured to receive the male engaging portion 5114 of the cable 5124 therebetween. When the stiffening device 5100 is in the flexible configuration, the cables 5124 are free to move through the clamps 5157y (e.g., the male engaging portions 5114 of the cables 5124 can freely pass through the female engaging portions 5128 of the clamps 5157y), thereby allowing the cables 5124 to steer the engaging portions 5104z as desired. When pressure (or vacuum) is applied to the walls of the elongate body 5103z, the clamp bladder 5164y tightens onto the clamp 5157y, thereby forcing the female engagement portions 5128 closer together circumferentially, thereby tightening onto the male engagement portion 5114 of the cable 5124 and locking the cable 5124 in place, thus stiffening the elongate body 5103z while simultaneously locking the distal end portion 5102z in place.

[0079]

[0154] The clamp 5157y advantageously allows for improved stiffening of the distal portion 5102z due to the shorter length of the cables 5124 required to maintain the shape (i.e., due to the effective separation of the cables 5124 in the distal portion 5102z from the cables in the elongate body 5103z). Additionally, locking with the clamp 5157y advantageously allows for the distal end 5102z to be stiffened by the same actuation mechanism (e.g., pressure or vacuum) as the elongate body 5103z, while still maintaining the distal end 5102z thin-walled (i.e., the wall may include only the thin outer layer 5101 and the linking portion 5104z).

[0080]

[0155] As best shown in FIG. 51B , the clamp 5157y can include a sheath termination block 5158y into which a cable pipe 5159y terminates. The cable pipe 5159y can be connected to the proximal end of the cable guide 5199. Similar to the cable guide 5199, the cable pipe 5159y can accommodate the cable 5124. However, because the cable pipe 5159y is at the distal end of the cable 5124 and therefore accommodates the portion of the cable 5124 having the male engagement portion 5114 therearound, the cable pipe 5159y can have a larger diameter that can accommodate the male engagement portion 5114. As shown in FIG. 51B , the cable pipe 5159y can extend further proximally than the male engagement portion 5114 when the stiffening device 5100 is straight to accommodate proximal movement of the cable 5124 when the stiffening device 5100 is flexed.

[0081]

[0156] Examples of engagement portions that can be used in addition to or instead of engagement portions 5128, 5114 are described in International Patent Application No. PCT / US2018 / 042946, entitled "DYNAMICALLY RIGIDIZING OVERTUBE," filed July 19, 2018, the entire contents of which are incorporated herein by reference.

[0082]

[0157] In some embodiments, referring to FIG. 54 , rather than using a steering cable 5424 to connect to the linkage 5404z to stiffen the distal end 5402z, a separate locking cable 5460y including a male stiffening element can extend through the distal end 5402z along with the standard steering cable 5424. The locking cable 5460y can extend a short distance proximally beyond the clamp 5457y (to accommodate elongation of the locking cable 5460y upon bending of the distal end 5402z). In some embodiments, for example, the locking cable 5460y can alternate with the steering cable 5424 (and the surrounding cable guide 5499) around the circumference of the stiffening device 5400. Upon activation of vacuum or pressure, the locking cable 5460y can be locked in place by the clamp bladder 5164y and the engagement portion 5428.

[0083]

[0158] 56A-56D, in some embodiments, the stiffening distal end 5602z of the stiffening device 5600 can include an engagement portion 5604z having multiple pressure channels 5690y extending therethrough, such as along the inner circumference of the linkage 5604z. Each of the pressure channels 5690y can further include an expandable pressure line 5691y and a support member 5693y disposed therethrough. As with the other stiffening distal ends described herein, the linkages 5604z can be connected to one another via one or more pivot points 5628z. A cable 5624 extending within a cable guide 5699 can control the bending of the linkage 5604z at the pivot point 5628z. An outer layer 5698y (not shown in FIG. 56A for clarity) can extend over the linkage 5604z. The outer layer 5698z can be continuous with or separate from the outer layer 5601 of the stiffening body 5603z. In some embodiments, the outer layer 5698z can include ePTFE.

[0084]

[0159] Each inflatable pressure line 5691y can have a small diameter (e.g., a diameter of less than 0.060 inches, such as less than 0.050 inches, less than 0.040 inches, etc.) and a thin wall thickness (e.g., a wall thickness of less than 0.002 inches, such as less than 0.001 inches, less than 0.0005 inches, less than 0.00025 inches, etc.). The pressure line 5691y can run from the proximal end of the stiffening device 5600, through the stiffening body 5603z, and into the distal end 5602z. Each pressure line 5691y can be the same material throughout the entire length of the stiffening device 5600, or can be a different material (e.g., only the distal end 5602z may be expandable, but not within the stiffening body 5603z), and the pressure lines 5691y can be connected to the same pressure line as the stiffening body 5603z, or can be separately actuated and controlled.

[0085]

[0160] Each support member 5693y can extend the length of the stiffening device 5600, for example, running parallel to the inflation pressure line 5691y within each channel 5690y. The support members 5693y can advantageously bridge gaps between the links 5604z to prevent buckling of the distal ends 5602z under compression (e.g., when the distal ends 5602z are in a rigid configuration). The support members 5603y can be wire. In one embodiment, the wire can be 0.010 inch stainless steel spring wire. The channels 5690y and / or support members 5693y can be, for example, circular (as shown in FIG. 56B), rectangular, square, or oval (as shown in FIG. 57). In some embodiments, as shown in FIG. 58, the support member 5693y can include multiple filaments 5602x (e.g., formed as a cable). In some embodiments, each channel 5690y can include multiple support members 5693y (and the channels 5690y can have corresponding conformal shapes), as shown in Figure 59. In some embodiments, the support members 5693y can coil around the inflation pressure line 5691y rather than running parallel to the inflation pressure line 5691y, as shown in Figure 60.

[0086]

[0161] In the flexible configuration, the coupling portion 5604z can allow the distal end 5602z to be flexibly bendable (e.g., forming a curved surface having a radius of curvature less than 1 inch, such as less than 0.5 inches, less than 0.25 inches, etc.). In the flexible configuration, the inflatable pressure line 5691y and / or the support member 5693y are slidable within the pressure line 5690y. When pressure is supplied to the inflatable pressure line 5691y, the pressure line 5691y expands within the pressure channel 5690y, filling the pressure channel 5690y and thereby pressing the support member 5693y against the coupling portion 5604z, preventing the coupling portions 5604z from moving relative to each other and transitioning the distal end 5602z to the rigid configuration. Small diameter pressure line 5691y is advantageous because it can withstand extremely high pressures, such as 3 atmospheres to 60 atmospheres or even greater than 5 atmospheres, thereby providing improved stiffening.

[0087]

[0162] 61 , in some embodiments, pressure conduit 5691y can have a smaller circumference in its flexible configuration than the circumference of pressure channel 5690y. In this embodiment, pressure conduit 5691y can be made of a resilient material such as, for example, nylon, Pebax, or urethane. Upon application of pressure, the resilient material of pressure conduit 5691y can expand to fill pressure channel 5690y.

[0088]

[0163] 62, in some embodiments, pressure conduit 5691y can be oversized relative to the diameter of pressure channel 5690y (e.g., it can have a larger circumference than pressure channel 56906, but can be folded or pleated within pressure channel 5690y). In this embodiment, pressure conduit 5691y can be made of a non-elastic material such as, for example, PET. Upon application of pressure, the non-elastic material of pressure conduit 5691y can expand to fill pressure channel 5690y.

[0089]

[0164] In some embodiments, the pressure line 5691y and the support member 5693y can slide freely relative to each other, hi other embodiments, the pressure line 5691y and the support member 5693y can be adhered to each other.

[0090]

[0165] 63A and 63B, in some embodiments, the support member 5693y may be overmolded with, for example, a male engaging portion 5695y (e.g., similar to male engaging portion 1554 in FIGS. 51A-51E). The pressure channel 5690y may include a corresponding mating female engaging portion 5692y (e.g., similar to female engaging portion 5128) on its inner periphery. Alternatively, the support member 5693y may include a female engaging portion and a male engaging portion of the pressure channel 5690y. When pressure is supplied to the pressure line 5691y, the extension line 5691y applies pressure to the support member 5693y, thereby locking the male 5695y and female 5692y engaging portions together and providing enhanced rigidity. As shown in FIGS. 64A and 64B, in some embodiments, the engaging portions 5695y, 5692y are sharp or pointed. Referring to FIG. 65, in some embodiments, each engagement portion 5695y, 5692y can include multiple extensions or elements configured to engage with corresponding elements on the inner circumference of the pressure channel 5690y.

[0091]

[0166] Referring to Figures 66A-66B, in some embodiments, rather than including a support member 5693y, the inflatable pressure line 5691y may be surrounded by a braid layer 5694y configured to stiffen against the engagement portion 5604z.

[0092]

[0167] 67, in some embodiments, channel 5690y may be recessed within and / or through linkage 5604z (rather than running along the inner periphery). Note that linkage 5604z in FIG. 67 also has a different shape and configuration than the linkages in FIGS. 56A-56C. It should be understood that any of linkages 5604z shown in any of the figures may be substituted or interchangeable with any of the other linkages described herein.

[0093]

[0168] The channel 5690y in any of the embodiments described herein can also be oval (as shown in FIG. 67) or circular (as shown in FIG. 56A).

[0094]

[0169] 68A-68B, in some embodiments, pressure lines 5691y can be separate from one another (as shown in FIG. 68A) or continuous with one another (as shown in FIG. 68B).

[0095]

[0170] In some embodiments, the distal end 5602z can include between 2 and 10 channels 5690y, such as 4 channels (as shown in FIGS. 56A and 67). In other embodiments, the distal end 5602z can include more channels 5690y, such as 10 to 20 channels 5690y (as shown in FIG. 69).

[0096]

[0171] Referring to FIG. 70, in some embodiments, the inner diameter of channel 5690y may be coated with a friction layer 5697y configured to enhance stiffness when pressure is applied to inflatable pressure line 5691y.

[0097]

[0172] In some embodiments, the link 5904z may be passive and may not include the cable 5624. The link 5904z may be made of plastic or metal.

[0098]

[0173] In some embodiments, the entire stiffening device can include the stiffening system (e.g., linkage 5604z, channel 5690y, etc.) described in connection with Figures 56A-70 (i.e., instead of a separate stiffening body 5603z). In some embodiments, the body can be unstiffened while the distal end 5602z is stiffened.

[0099]

[0174] 72, in some embodiments, similar to FIG. 54, the distal end 4702z can include multiple links 4704z, multiple locking cables 4760y extending alongside the links 4704z, and a clamp 4757y. In this embodiment, the clamp 4757y can include a circumferential member having multiple channels 4790y extending therethrough (only one channel 4790y is shown for clarity). The locking cables 4760y and an inflation pressure line 4591y (e.g., similar to the inflation pressure line described in connection with FIGS. 56A-70) can extend through the channels 4790y. The clamp 4757y can further include multiple channels 4799 (again, only one channel 4799 is shown for clarity) through which the cables 4724 can extend. The pressure channel 4790y can further include male or female mating portions (similar to those described in connection with FIGS. 64A-65B) along its inner circumference, while the locking cable 4760y can include corresponding mating portions along at least the portion of the cable 4760y that extends through the channel 4790y (although the mating portion 4795y can extend along its entire length). When pressure is applied to the pressure line 4790y, the pressure line 4790y can expand within the clamp 4757y, locking the mating portions together and stiffening the distal end 4702z. As with the embodiment of FIGS. 51A-51E, these separate locking cables 4760y can also be replaced with cables 4724 having mating portions thereon.

[0100]

[0175] 25A , in some embodiments, the distal end 6102z can include a series of links 6104z (active or passive) encapsulated within a thin layer of material 6108z (e.g., comprised of elastomer, PVC, or PEEK). The links 6104z and thin layer of material 6108z can be positioned, for example, above (i.e., radially outward from) the braid layer 6109 and can be continuous with the coil wound tube 6101 of the elongate body 6103z. In this embodiment, when pressure or vacuum is applied to the void 6112, the braid layer 6109 can be compressed and stiffened by the bladder 6121 against the coil wound tube 6101 in the elongate body 6103z and against the link sheath 6108z at the distal end 6102z. The link sheath 6108z is supported by the links 6104z so that it can resist the pressure of braid expansion. This design is advantageous because it provides both stiffening and coupling while maintaining a small wall thickness and / or diameter. The distal end 6102z can include, for example, a cable 6124 extending within a cable guide to actuate the coupling 6104z.

[0101]

[0176] In some embodiments, the stiffening structure can be steered from within the wall of the stiffening structure, optionally without any connections. Figure 25B shows a cross section of pressure stiffening structure 2500 with cable guide 2599 disposed within pressure void 2512 and attachable to inner layer 2515. Cable 2524 extends from cable guide 2599 into distal end 2502z and is secured to inner layer 2515 at anchor point 2568. Pulling on cable 2524 causes distal end 2502z (distal to the end of cable guide 2599) to flex. In some embodiments, cable guide 2599 can be omitted and stiffening device 2500 will flex along its entire length as cable 2524 is pulled. In some embodiments, the device 2500 can be formed with a distal end 2502z that is less bendingly stiff than the elongated proximal body 2503z (e.g., by varying the braid angle or by using more flexible reinforcing elements in the inner or outer layers, as described herein) so that the distal end 2502z is more flexible than the proximal body 2503z. The cable guides 2599 and cables 2524 can be positioned between the bladder 2521 and the braid 2509 or between the braid 2509 and the outer layer 2501. The cable guides 2599 and / or cables 2524 can be attached to the outer wall 2501. Alternatively, in a vacuum stiffening configuration, the cable guides 2599 and cables 2524 can be positioned between the inner layer and the braid or between the braid and the outer layer. In some embodiments, the bladder 2521 and braiding of the braided layer 2509 may be omitted where there are no cables 2524 within the cable guide 2599, leaving only the inner and outer layers 2515, 2501, or only the outer layer, or only the inner layer.

[0102]

[0177] 26A-26C, in some embodiments, the distal end 4602z can include an active flexure 4646. The flexure 4646 can include a ribbon or spine extending therethrough that, when actuated, imparts bending only in one or more predetermined directions. The active flexure 4646 can be deflected into a predetermined shape, for example, using the introduction of one or more cables, bladders, pull wires, and / or guide wires. The active flexure 4646 can thus impart bending in a fixed direction at a fixed location of the stiffening device 4600. In some embodiments, a marker (e.g., a radiopaque marker) can be placed in or near the active flexure 4646 to indicate where bending occurs and / or the direction in which the active flexure 4646 bends. Bending of the stiffening device 4600 using the active flexures 4646 can be advantageous, for example, when bending is required without assistance from the anatomy (i.e., when the anatomical path of the stiffening device 4600 is not predefined or constrained by the anatomy). For example, such bending may be useful to create bending across the open or relatively unconstrained space between the inferior vena cava (IVC) and the atrial septum during a transseptal procedure on the mitral valve. The active flexures 4646 can be configured to be stiffened (i.e., with pressure or vacuum) as described herein to fix or lock the active flexures 4646 in a bent configuration. The stiffening device 4600 can also include a steerable distal portion 4647 (e.g., using a linkage) in addition to the active flexures 4646. The steerable distal portion 4647 can be used to point or orient the distal end of the stiffening device 4646 in a desired direction (e.g., with a cable and / or along four axes) as described elsewhere herein.

[0103]

[0178] In some embodiments, the stiffening devices described herein can be used in conjunction with one or more other stiffening devices described herein. For example, an endoscope can include a stiffening mechanism described herein, and a stiffening device can include a stiffening mechanism described herein. When used together, they can form a nested system that can be advanced one after the other, thereby ensuring that one of the elements remains stiff at all times so that loops are reduced or eliminated (i.e., a sequentially advanced nested system can be formed).

[0104]

[0179] An exemplary nested system 2300z is shown in FIG. 27. The system 2300z can include an outer stiffening device 2300 and an inner stiffening device 2310 (here configured as a stiffening scope) that can be axially movable relative to one another concentrically or non-concentrically. The outer stiffening device 2300 and the inner stiffening device 2310 can include any of the stiffening mechanisms as described herein. For example, the outer stiffening device 2300 can include an outermost layer 2301a, a braid layer 2309a, and an inner layer 2315a including a wound coil. The outer stiffening device 2300 can be configured, for example, to receive a vacuum between the outermost layer 2301a and the inner layer 2315a to provide stiffening. Similarly, the inner scope 2310 can include an outer layer 2301b (e.g., coiled), a braid layer 2309b, a bladder layer 2321b, and an inner layer 2315b (e.g., coiled). The inner scope 2310 can be configured to receive pressure between the bladder 2321b and the inner layer 2315b, for example, to provide stiffening. Additionally, an air / water channel 2336z and a working channel 2355 can extend through the inner stiffening device 2310. Additionally, the inner stiffening scope 2310 can include a distal portion 2302z with a camera 2334z, a light 2335z, and a steerable linkage 2304z. A cover 2327z can extend over the distal portion 2302z. In another embodiment, the camera and / or light can be delivered in a separate assembly (e.g., the camera and light can be bundled within the catheter and delivered to the distal-most end 2333z through the working channel 2355 and / or additional working channels).

[0105]

[0180] An interface 2337z can be disposed between the inner stiffening device 2310 and the outer stiffening device 2300. The interface 2337z can be an air gap having a dimension d (see FIG. 5 ) of 0.0025 cm (0.001 inch) to 0.127 cm (0.050 inch), for example, with a thickness of 0.0020 cm (0.0020 inch), 0.005 inch, or 0.020 inch. In some embodiments, the interface 2337z can be low-friction, for example, can include a powder, coating, or lamination to reduce friction. In some embodiments, there can be a sealant between the inner stiffening device 2310 and the outer stiffening device 2300, and the intervening space can be pressurized, for example, with a fluid or water, to form a hydrostatic bearing. In other embodiments, there may be a seal between the inner stiffening device 2310 and the outer stiffening device 2300, and the intervening space may be filled with small spheres to reduce friction.

[0106]

[0181] The inner stiffening device 2310 and the outer stiffening device 2300 can be moved relative to one another and alternately stiffened to impart a bend or shape along the length of the nested system 2300z. For example, the inner device 2310 can be inserted into a lumen and bent or steered to a desired shape. Pressure can be applied to the inner stiffening device 2310 to engage and lock the inner stiffening device 2310 in this configuration with the blade elements. The stiffening device 2300 (e.g., in a flexible state) can then be advanced over the rigid inner device 2310. Once the outer stiffening device 2300 reaches the distal end of the inner device 2310, a vacuum can be applied to the stiffening device 2300 to engage and lock the layers to fix the shape of the stiffening device. The inner device 2310 can transition to a flexible state and be advanced, and the process can be repeated. While the system 2300z is described as including a stiffening device and an inner device configured as a scope, it should be understood that other configurations are possible. For example, the system may include two overtubes, two catheters, or a combination of an overtube, a catheter, and a scope.

[0107]

[0182] FIG. 28 illustrates another exemplary nested system 2700z. The system 2700z is similar to the system 2300z, except that it includes a cover 2738z attached to both the inner and outer stiffening devices 2710, 2700. The cover 2738z may be low durometer and thin-walled, for example, to allow for elasticity and stretchability. The cover 2738z may be a rubber, such as urethane, latex, or silicone. The cover 2738z may protect the interface / radial gap between the inner and outer devices 2710, 2700. The cover 2738z may prevent contaminants from entering the space between the inner and outer tubes. The cover 2738z may also prevent tissue and other materials from becoming trapped in the space between the inner and outer tubes. The cover 2738z may stretch within the elastic limits of the material to allow the inner and outer devices 2710, 2700 to move independently of each other. The cover 2738z may be glued or otherwise attached to the stiffening device 2710, 2700 such that the cover 2738z is always in a minimal, slightly stretched state. This embodiment may be wipeable on the outside for cleaning. In some embodiments, the cover 2738z can be configured as a "rolling" seal, such as that disclosed in U.S. Pat. No. 6,447,491, the entire disclosure of which is incorporated herein by reference.

[0108]

[0183] 29A-29B illustrate another exemplary nested system 9400z. In this system 9400z, the outer stiffening device 9400 includes steering and imaging functions (e.g., similar to a scope), while the inner device includes only stiffening functions (although it may include additional steering elements as described elsewhere herein). Thus, the outer device 9400 includes a linkage or other steering means 9404z as disclosed herein, a camera 9434z, and a light 9435z. The outer device 9400 may further include a central passage 9439z (e.g., a lumen such as a working channel therein) for accessing the inner device 9410. In some embodiments, a bellows or loop of tubing may connect the passage 9439z to the lumen of the inner device 9410. As with other nested systems, at least one of the devices 9410, 9400 may be stiffened at a time, while the other may follow the stiffening and / or move through the anatomy. Here, the outer device 9400 can guide the inner device 9410 (in FIG. 29A the inner device 9410 is shown retracted relative to the outer device 9400, and in FIG. 7B it is extended approximately equal to the outer device 9400). Advantageously, the system 9400z can provide a smooth outer surface to avoid pinching anatomy and / or avoiding fluid flow between the inner and outer devices 9410, 9400. Steering capabilities on the outer device 9400 can also provide additional leverage for tip steering. The outer device can also facilitate better imaging capabilities due to the larger diameter of the outer device 9400 and the ability to accommodate larger cameras.

[0109]

[0184] 30A-30H illustrate an example use of a nested system 2400z as described herein. In FIG. 30A, the inner stiffening device 2410 is positioned within the outer stiffening device 2400 such that the distal end of the inner stiffening device 2410 extends outside the outer stiffening device 2400. In FIG. 30B, the distal end of the inner stiffening device 2410 is bent to a desired direction / orientation and then stiffened (e.g., using vacuum or pressure as described herein). In FIG. 30C, the outer stiffening device 2400 (in its soft form) is advanced over the stiffened inner stiffening device 2410 (including over the bent distal portion). After the distal end of the outer stiffening device 2400 has been fully advanced over the distal end of the inner stiffening device 2410, the outer stiffening device 2400 can be stiffened (e.g., using vacuum or pressure as described herein). In FIG. 30D, the inner stiffening device 2410 can then be transitioned to a flexible state (e.g., by removing the vacuum or pressure as described herein and allowing the steering cables to slacken so the tip can move easily) and can be advanced and directed / aimed / steered as desired. Alternatively, in FIG. 30D, the inner stiffening device 2410 can be actively steered (manually or computer controlled) as it emerges to minimize the load on the stiffened outer tube. Minimizing the load on the outer stiffening device 2400 helps this tube retain its stiffened shape. After the inner stiffening device 2410 is stiffened, the outer stiffening device 2400 can be transitioned to a flexible state and advanced over it (as shown in FIG. 30E). This process can then be repeated as shown in FIGS. 30F-30H.

[0110]

[0185] In some embodiments, upon completion of the sequence shown in Figures 30A-30H, a third stiffening device can be slid over and stiffened by the first two stiffening devices (2400, 2410). Next, stiffening devices 2400 and 2410 can be withdrawn. Finally, a fourth stiffening device can be inserted into the inner lumen of the third tube. This fourth stiffening device may have a larger diameter and more features than stiffening device 2410. For example, the fourth stiffening device may have a larger working channel, more working channels, a more powerful camera, or a combination of these. This technique can allow the two smaller tubes, which tend to be more flexible and easier to manipulate, to reach deeper into the body, while ultimately delivering the larger tube for therapeutic purposes. Alternatively, in the above example, the fourth stiffening device may be a conventional endoscope, as known in the art.

[0111]

[0186] In some embodiments, upon completion of the sequence shown in FIGS. 30A-30H , the outer stiffening device 2400 may be stiffened, and then the inner stiffening device 2410 may be removed. For example, the stiffening device 2410 may be a “navigation” device including a camera, lighting, and a distal steering portion. The “navigation” device 2410 may be sufficiently sealed to facilitate cleaning between procedures. In this case, a second inner device may be placed inside the stiffening outer device 2400 and advanced beyond the distal end of the outer device 2400. The second inner device may be a “treatment” tube including elements such as a camera, light, water, suction tools, and various tools. The “treatment” device may not have steering or stiffening capabilities, thereby providing additional space within the body of the treatment tube to include other features, such as tools for performing treatment. Once in place, the tools on the “treatment” tube may be used to perform treatments on the body, such as mucosal resections or incisions in the human digestive tract.

[0112]

[0187] In another embodiment, after or upon completion of the sequence shown in Figures 30A-30H, a third device may be inserted into inner tube 2410. The third device may be a stiffening device and / or an endoscope.

[0113]

[0188] The outer stiffening devices for the nested systems described herein are often referred to as being stiffened by vacuum and the inner scope stiffening devices as being stiffened by pressure, although the reverse is also true (i.e., the outer stiffening device can be stiffened by pressure and the inner stiffening device by vacuum) and / or both can have the same stiffening source (pressure and / or vacuum).

[0114]

[0189] Although the inner and outer elements of the nested system are generally described as including integrated stiffening elements, the stiffening elements can be separate (e.g., to allow relative sliding between the imaging scope element and the stiffening element).

[0115]

[0190] The stiffening systems of the nested systems described herein can be designed so that, when assembled, the inner stiffening device cannot substantially rotate within the outer stiffening device. For example, the outer surface of the inner stiffening device can have longitudinal ridges and grooves that form spines. The inner surface of the outer stiffening device can have corresponding ridges and grooves that mate with the same features on the outer stiffening device.

[0116]

[0191] One or both of the stiffening devices of the nested systems described herein can be steerable. If both stiffening devices are steerable, an algorithm can be implemented to steer the flexible, longitudinally moving stiffening device. The algorithm can steer the flexible stiffening device to predict the shape of the stiffened device, thereby minimizing the tendency of the moving flexible stiffening device to straighten the rigid device.

[0117]

[0192] If one stiffening device of a nested system described herein requires a vacuum and the other stiffening device requires pressure, a user control can be configured such that moving either one or the other (outer or inner) requires the actuation of a switch that toggles between, for example, a first state where one is evacuated to make it flexible and the other is pressurized to make it rigid, and a second state where one is evacuated to make it flexible and the other is evacuated to make it rigid, which can be, for example, a foot pedal or hand switch.

[0118]

[0193] In some embodiments, the rotation of the nested systems described herein can be controlled manually, while in other embodiments, the rotation can be controlled automatically by a computer and / or using a motorized motion control system.

[0119]

[0194] Advantageously, the nested systems described herein can have similar stiffness, ensuring that the overall stiffness of the nested system is relatively continuous. The nested systems described herein can be compact to fit into a variety of different anatomies. For example, for neurological applications, the outer diameter of the system can be between 0.05 inches and 0.15 inches, such as about 0.1 inches. For cardiac applications, the outer diameter of the system can be between 0.1 inches and 0.3 inches, such as about 0.2 inches. For gastrointestinal applications, the outer diameter of the system can be between 0.3 inches and 1.0 inches, such as 0.8 inches. Additionally, the nested systems described herein can maintain high stiffness even at small profiles. For example, the change in relative stiffness from the soft to the rigid configuration can be 10x, 20x, 30x, and even greater. Additionally, the nested systems described herein are advantageous because they can move smoothly relative to one another.

[0120]

[0195] The nested systems described herein advantageously can navigate any path, or open, complex, or tortuous space, forming a series of self-supporting complex shapes. Nested systems are further advantageous because they can provide shape propagation, thereby allowing shape memory to be transferred from one element to another. In some embodiments, both tubes can be periodically forced into a partially or fully flexible state, e.g., as the radius or curvature of the system increases and the surrounding anatomy provides support to the system. The pressure or vacuum used to stiffen the tubes can be reduced or stopped to force the tubes into a partially or fully flexible state. This brief relaxation (e.g., 1-10 seconds) may allow the system to find a shape that more closely matches the anatomy it is passing through. For example, in the colon, this relaxation can gently open sharp bends in the anatomy.

[0121]

[0196] In some embodiments, the stiffening function of the inner or outer stiffening device may be designed so that a sharp curve formed by the inner stiffening device at the distal end, when replicated by the outer stiffening device, gradually opens (has a larger radius) as its shape propagates proximally through the outer tube. For example, the outer stiffening device may be designed to increase its minimum radius of curvature as it is stiffened.

[0122]

[0197] The nested system is continuous (i.e., not segmented), thus providing smooth, continuous movement through the body (e.g., the intestine). The nested system can be disposable and low cost.

[0123]

[0198] In some embodiments, the outer stiffening device can be a dynamically stiffening overtube (e.g., as described in PCT / US18 / 42946, which is incorporated herein by reference in its entirety). In some embodiments, the inner stiffening device can be a stiffening system or a commercially available scope, such as a 5 mm diameter nasal scope. The use of stiffening and telescoping systems allows for the use of smaller scopes that exhibit greater flexibility when needed, greater stiffness when needed, enhanced maneuverability, and the ability to articulate with a much smaller radius of curvature compared to duodenoscopes.

[0124]

[0199] In some embodiments, once the target site is reached, the inner stiffening device of the nested system can be withdrawn, the outer stiffening device can remain stiffened, and contrast can be injected through the space of the inner element for fluoroscopic imaging.

[0125]

[0200] RF coils can be used in any of the nested systems described herein to provide a 3D representation of whatever shape the nested system takes, which can be used to reconstruct the shape (e.g., for review by a physician after an automated colonoscopy) or return to a given point.

[0126]

[0201] In some embodiments, the nested systems described herein may be useful as complete endoscopes, with internal structures carrying a working channel, pressurized lines, vacuum lines, tip irrigation, and a payload of electronics for illumination and imaging (vision systems, ultrasound, x-ray, MRI).

[0127]

[0202] The nested systems described herein can be used, for example, for colonoscopy. Such nested colonoscopy systems can reduce or eliminate loops. The systems can also eliminate the need for endoscopic reduction. Because of the lack of loops, the procedure can combine the speed and low cost of sigmoidoscopy with the effectiveness of colonoscopy. Furthermore, nested colonoscopy systems can eliminate conscious sedation and its associated costs, time, risks, and equipment requirements. Use of the nested systems described herein can also significantly reduce procedural techniques for such colonoscopy procedures. In some embodiments, the nested systems described herein can also enable automated colonoscopy, where a vision system automatically drives the nested system through the center of the colon while searching for polyps. Such automated systems advantageously require neither sedation nor a physician for the basic examination, while allowing the physician to follow up for further examinations if necessary.

[0128]

[0203] In some embodiments, the stiffening devices (e.g., nested systems) described herein are robotically controllable. FIGS. 31A-31D illustrate the use of a nested system 9300z similar to that shown in FIGS. 30A-30H that can be robotically controlled or manipulated (e.g., stiffened, steered, moved, etc.). As shown in FIGS. 31A-31H, the outer stiffening device 9300 and the inner stiffening device 9310 can both terminate in a common structure, such as a cassette 9375. The outer stiffening device 9300 can be moved relative to the inner stiffening device 9310 by rotation of a disk 9389 attached to the cassette 9357. For example, the disk 9389 can be a pinion, and the outer stiffening device 9300 can have an external rack 9382 that includes a plurality of tiny teeth. Rotating the disk 9389 against the teeth 9382 can advance the outer stiffening device 9300 forward or backward relative to the inner stiffening device 9310. In some embodiments, the possible movement or translation of the stiffening devices 9300, 9310 is limited by the size or design of the cassette 9357.

[0129]

[0204] The cassette 9357 may further include additional disks 9371 a, 9371 b connectable to cables 9363 a, 9363 b, respectively, for steering (e.g., bending or flexing) the distal end of the inner stiffening device 9310 (and / or outer stiffening device 9300). Other steering mechanisms (e.g., pneumatic, hydraulic, shape memory alloy, EAP (electroactive polymer), or motor) are also possible. Again, in embodiments with different steering mechanisms, one or more disks (e.g., disks 9371 a, 9371 b) of the cassette 9357 may be used to actuate the steering.

[0130]

[0205] The cassette 9357 can further include bellows 9303a, 9303b connectable to the pressure cavities of the inner stiffening device 9310 and the outer stiffening device 9300, respectively. Squeezing the bellows 9303a, 9303b can drive fluid through pressure line 9305z, thereby increasing the pressure in the pressure cavities of the inner stiffening devices 9310, 9300, causing the stiffening devices 9310, 9300 to become stiff. Actuation of the bellows 9303a, 9303b can be applied sequentially and / or simultaneously. As shown in FIGS. 9A-9D , the cassette 9357 can include eccentric cams 9374a, 9374b for controlling the bellows 9303a, 9303b. Alternatively, as shown in FIG. 32A , one or more linear actuators 9316y (e.g., on cassette 9357 or drive unit 9517y) can be configured to actuate bellows 9303a, 9303b. As another alternative, as shown in FIG. 32B , devices 9300, 9310 can be stiffened and de-stiffened via one or more sumps (as described herein) or pressure sources 9306z (e.g., via pressure lines 9305z). Other mechanisms for causing stiffening of the inner and outer stiffening devices 9310, 9300 are also possible. For example, in some embodiments, cassette 9357 can include a syringe or other container containing a fluid that can be delivered to the inner and outer stiffening devices 9310, 9300 to apply stiffening pressure. In some embodiments, the syringe or other container can be used to withdraw fluid from cassette 9357, thereby creating a vacuum that can be applied to the inner and outer stiffening devices 9310, 9300.

[0131]

[0206] 31A-31D , cassette 9357 can include a connector 9315y for connecting to additional lumens and / or wiring in the inner stiffening device 9310. Connector 9315y can include connections for delivering both suction air and water to the distal end of the inner stiffening device 9310. Connector 9315y can include an electrical connector for connecting a camera mounted at the distal end of the inner stiffening device 9310 to an external monitor and / or video processing unit. Connector 9315y can include a mechanical connector for connecting to a hollow tube (e.g., a working channel) that runs all the way to the distal end of the inner stiffening device 9310. By including connector 9315y, control of all components of system 9300z can be achieved using cassette 9357.

[0132]

[0207] As best shown in the side perspective view of FIG. 93B, the discs 9389, 9371 a, 9371 b and cams 9374 a, 9374 b (or corresponding bellows) may be accessible from the bottom of the cassette 9357. The discs 9389, 9371 a, 9371 b and / or cams 9374 a, 9374 b may have features such as splines, pins, or teeth to transmit torque. These features may allow the discs 9389, 9371 a, 9371 b and / or cams 9374 a, 9374 b to be manipulated (e.g., by a drive unit).

[0133]

[0208] 33 shows an example of a drive unit 9517y that can be used to drive the disks 9389, 9371a, 9371b and / or cams 9374a, 9374b. For example, the drive unit 9517y can include a drive paddle 9519y that can be aligned with the disks 9389, 9371a, 9371b and / or cams 9374a, 9374b of the cassette 9357. The drive paddle 9519y can be driven (i.e., rotated) by one or more motors of the drive unit 9517y to impart torque to the disks 9389, 9371a, 9371b and / or cams 9374a, 9374b of the cassette 9357. Drive paddle 9519y may include a mechanism 9518y (e.g., splines, pins, teeth, etc.) for transmitting torque to discs 9389, 9371a, 9371b and / or cams 9374a, 9374b of cassette 9357. Drive unit 9517y may be coupled to cassette 9357 using, for example, clips, screws, or magnets.

[0134]

[0209] In some embodiments, the stiffening systems described herein can include one or more guides that allow a tool (i.e., a working tool), such as a surgical instrument, a laparoscopic instrument, a grasper, a segment grasper, a fecal cleansing device, or a fecal suction device, to be advanced therethrough. In some embodiments, the tool can be a scope (e.g., to allow for a secondary scope within or alongside the primary scope). The guide can allow the tool to be guided along or through the stiffening device until the distal end of the tool is advanced distally past the distal end of the stiffening device to perform the desired procedure. Also, in some embodiments, the stiffening system can include multiple guides to provide for different placement and / or use of multiple tools. For example, as shown in FIG. 36 , the stiffening device 9800 can include two guides 9821y on opposite sides thereof. The guides 9821y can have the same or different designs. More than two guides and associated tools are also possible. In some embodiments, the guides can be positioned within the volume of the inner stiffening device (e.g., the stiffening device 9310).

[0135]

[0210] The guides described herein can be used with a single stiffening system (e.g., a stiffening scope or overtube) or with a nested stiffening system (e.g., a robotically controlled nested system). When used as part of a nested system, the guide can be included on or within an inner stiffening device or an outer stiffening device. Furthermore, the tool guides described herein can be used when the stiffening system is in a flexible, partially flexible, or fully rigid form.

[0136]

[0211] Referring to FIG. 34 , in some embodiments, a stiffening system (e.g., robotic system 9300z) described herein can include one or more guides 9621y extending along the outer diameter of the outer stiffening device 9600. The guides 9621y can include, for example, a series of atraumatic rings 9622y. The rings 9622y can be spaced apart along the longitudinal axis so that they do not contact each other when the outer stiffening device 9600 is flexed to its maximum bend radius. In some embodiments, the rings 9622y can have an inner diameter of approximately 2-9 mm. In some embodiments, the rings 9622y can be angled at their connection with the stiffening device 9600 so that they can flatten against the device 9600 when inserted into the body, and then angled upward to a position approximately perpendicular to the outer circumference of the device 9600 for use. In some embodiments, the rings 9622y can be pre-biased to self-expand radially outward. In other embodiments, the ring 9622y can be configured to actively expand (eg, by applying tension to a pull wire connected to the ring 9622y).

[0137]

[0212] 35A-35B, the guide 9721y for the stiffening system or device can be, for example, a lay-flat tube adhered along one side to the stiffening device 9700. In a first configuration (shown in FIG. 35A), the lay-flat tube guide 9721y can lie flat against the outside of the stiffening device 9700. In a second configuration, the guide 9721y can expand into its tubular shape. The lay-flat tube guide 9721y can include fibers wrapped around it in a hoop pattern to reinforce its expanded diameter. The fibers can be, for example, an aramid such as Technora, an ultra-high molecular weight polyethylene such as Dyneema, or a liquid crystal polymer such as Vectran. The inner diameter of the guide 9721y in the expanded configuration can be, for example, between 2 mm and 9 mm. The lay-flat tube guide 9721y can assume the second configuration, for example, when a tool is threaded through the lay-flat tube guide 9721y. The lay-flat tube guide 9721y may have a series of perforations along its length to allow a tool to be inserted into the lumen of the tube guide 9721y at any of the perforations along the length of the stiffening device 9700. In one example method of manufacture, the lay-flat tube guide 9721y can be stretched in length and then, while still stretched, can be bonded to the side of the stiffening device 9700. For example, the lay-flat tube guide 9721y can be strained 20%, 30%, 40%, 50% or more before being bonded to the stiffening device 9700. This technique may result in a lay-flat tube guide 9721y with residual strain in its walls. When the stiffening device 9700 (and the associated lay-flat tube guide 9721y) is bent at a curved portion and the lay-flat tube guide 9721y is subjected to a compressive force (for example, when the working channel is inside the bend in the stiffening device 9700), residual strain in the wall of the lay-flat tube guide 9721y results in less compression occurring in the wall, and therefore less wrinkling of the lay-flat tube guide 9721y, which is advantageous.

[0138]

[0213] Advantageously, the tool guides used herein can be designed to be flexible, thereby allowing for bending of the stiffening device during insertion. For example, the rings 9622y can be spaced apart to allow for flexible bending of the stiffening device. Similarly, the lay-flat tube 9721y can be thin and flexible to allow for bending of the stiffening device.

[0139]

[0214] In another embodiment, as shown in FIG. 44, the guide 2221y can be a notched or serrated tube configured to be easily bent when attached to the stiffening device 2200 along its length.

[0140]

[0215] As another example, the guides 2321y can be a series of telescoping stiffening devices, bellow-like shapes, or a combination thereof, as shown in Figure 45. The guides 2321y can be periodically attached to the outer stiffening device 2300 with rings 2353y spaced longitudinally along the length of the outer stiffening device 2300.

[0141]

[0216] 46, the guide 2421y can be a flexible tube attached only to the proximal and distal ends of the outer stiffening device 2400. A device sheath 2454y can be sealed over the outer stiffening device 2400 and the top of the guide 2421y. In some embodiments (e.g., after the device has reached a desired location), a vacuum can be applied to the space between the device sheath 2454y and the outer stiffening device 2400, thereby suctioning the guide 2421y to the stiffening device 2400 for a rigid attachment thereto. Such a rigid attachment can allow tools to pass easily through the guide 2421y.

[0142]

[0217] As another example, the guide 2521y can be made of a spiral cut tube, as shown in Figure 47. The spiral cut guide 2521y can be attached to the external stiffening device 2500 periodically along the length of the guide 2521y, or by a thin sheet of material, such as a thin sheet of highly flexible elastomer.

[0143]

[0218] As another example, the guide 2621y can be a spring (e.g., a metal spring) with gaps between the coils, as shown in Figure 48. The guide 2621y can be periodically attached to the outer stiffening device 2600.

[0144]

[0219] As another example, the guide can be configured to expand and / or collapse outward after placement in the body and / or when a tool is passed through the guide.

[0145]

[0220] In some embodiments, the stiffening system (e.g., a robotically controlled nested system) can be designed to include guides that can be attached after the system is inserted into the body. For example, with reference to FIGS. 41A-41C , the stiffening device 1900 can include a plurality of rails 1949y extending the length of the outer stiffening device 1900. The rails 1949y can include, for example, male extensions such as T-bars (e.g., such that a ledge is formed between the outermost edge 1950y of the rails 1949y and the outer diameter of the outer stiffening device 1900). In some embodiments, as shown in FIG. 41B , the outermost surface of the edge 1950y can include a serrated edge 1951y (e.g., a blunt serrated edge) along its longitudinal length to increase the flexibility of the rails 1949y (e.g., to facilitate bending of the rails 1949y when the outer stiffening device 1900 is flexed). For example, there may be between 1 and 10 rails 1949y spaced (e.g., equidistantly or at different locations) around the circumference of the stiffening device 1900. In one particular embodiment, there may be four rails 1949y spaced approximately 90 degrees apart from one another around the circumference. As shown in FIG. 41C, the guide 1921y may be a tubular body having a female slot 1952y (e.g., a T-slot) extending along the longitudinal length of the guide 1921y and configured to mate with and ride along the rail 1949y.

[0146]

[0221] In use, the stiffening device 1900 can be inserted into a body lumen until it reaches a target site (e.g., a lesion). Once at the site, one or more guides 1921y can be inserted along the rails 1949y. In some embodiments, the proximal end of the guide 1921y can be snapped or broken off after insertion to reduce unnecessary length of the guide 1921y. One or more tools can then be inserted into the guide 1921y as needed (e.g., to treat the lesion).

[0147]

[0222] Having a rail 1949y with a connectable guide 1921y is advantageous because it can reduce the diameter and stiffness of the stiffening system when the system is inserted into place, thereby making it easier to move and / or steer the system to the target area. Also, the connection between the guide 1921y and the rail 1949y can be rigid, and the guide 1921y can be relatively stiff (e.g., without affecting the movement of the system), thereby ensuring that tools can be positioned therethrough for use at the target site (e.g., lesion). Having multiple rails 1949y is further advantageous because it allows a user to select a desired rotational position for the guide 1921y, thereby ensuring that tools are properly oriented relative to the target site (e.g., lesion) without having to substantially rotate the entire system. Finally, having an attachable guide 1921y can allow a user to select a guide 1921y with a diameter or characteristics specific to their treatment plan.

[0148]

[0223] In some embodiments, the rail 1949y can have a female slot and the guide 1921y can have a male extension. In some embodiments, the rail 1949y can have a discrete, separated piece along the longitudinal length of the outer stiffening device 1900 rather than a serrated edge.

[0149]

[0224] In some embodiments, the guides can be part of a unitary structure that slides over the stiffening device after the stiffening device is inserted into the body. For example, as shown in FIGS. 52A-52B, the guides 5221y (for threading example tools 5277a, 5277b) can be incorporated into the outer tube 5261y. The outer tube 5261y can be configured to slide over the external stiffening device 5200. In some embodiments, for example, the outer tube 5261y can have an internal coating to reduce friction during sliding. Also, as shown in FIGS. 52A-52B, the outer tube 5261y can include multiple bends or links to increase the flexibility of the tube 5261y. In other embodiments, the outer tube 5261y can be a solid tube and / or a coiled tube. In some embodiments, the outer tube 5261y can have slits along its longitudinal length and / or can be semicircular to snap onto the external stiffening device 5200. In some embodiments, the proximal end of the outer tube 5261y can be configured to be broken off or snapped off after insertion to shorten unnecessary length. The outer tube 5261y can advantageously have torsional stiffness to allow rotational adjustment of the location of the guide 5221y after the outer tube 5261y is inserted onto the outer stiffening device 5200. In some embodiments, the outer tube 5261y can include an outer sheath thereon so that a vacuum can be applied between the outer sheath and the outer stiffening device 5200 to adhere the guide 5221y to the outer stiffening device 5200.

[0150]

[0225] In another embodiment, as shown in FIGS. 73A-73M, a plurality of guides 7321y can be configured to be removably positioned within an outer tube 7361y to provide liner for the channels 7348x. The outer tube 7361y can be a thin-walled sleeve, such as an elastomeric sleeve, a plastic sleeve, or a fabric sleeve. In some embodiments, the outer tube 7361y can be a fiber-reinforced or wire-reinforced sleeve. In one particular embodiment, the outer tube 7631y can be a fabric material that is inherently somewhat stretchable and / or sewn at a 45° angle (e.g., off-bias to provide elasticity and / or stretch). In some embodiments, the tube 7361y can be permanently attached (e.g., glued, heat-welded, sewn, or ultrasonically welded) to the exterior surface of the stiffening device 7300 (e.g., can be an additional layer in the wall of the stiffening device 7300). The outer tube 7631y can have a wall thickness of, for example, 0.0025 cm (0.001 inch) to 0.0076 cm (0.0030 inch), such as 0.0254 cm (0.010 inch). The outer tube 7361y can include a plurality of channels 7348x (e.g., 2 to 8 channels 7348x, such as 3 channels 7348x) disposed around the circumference of the outer tube 7361y. The channels 7348x can be, for example, lay-flat or expandable channels 7348x. In some embodiments, the channels 7348x can be straight (e.g., axially aligned with the outer tube 7361y). In other embodiments, the channels 7348x can be spiral. In some embodiments, the channels 7348x can be joined to one another by sewing, gluing, or heat sealing. In some embodiments, the channels 7348x may be lined with a hydrophilic, hydrophobic, or low friction (eg, PTFE) coating.

[0151]

[0226] The guide 7321y can be an insert (e.g., a molded or extruded insert) configured to be placed within the channel 7348x for use. For example, the guide 7321y can be configured to be inserted into one or more channels 7348x after the stiffening device 7300 has been positioned and / or stiffened within a body lumen. Each guide 7321y can include a lumen 7350x (configured to pass a tool 7377 therethrough). Each guide 7321y can be sufficiently stiff to open or dilate the channel 7348x when extending therethrough. In some embodiments, the guide can have an inner diameter of 1 mm to 7 mm, such as 3 mm to 5 mm, and a wall thickness of ½ mm to 1 mm. In some embodiments, the guide 7321y can be made of a polymer such as Teflon, FEP, or polyethylene (e.g., HDPE or LDPE). The lumen 7350x can be lubricious to facilitate passage of the tool 7377 therethrough. For example, the lumen 7350x can be made of a material with a low coefficient of friction (e.g., the same material as the guide itself 7321y), such as Teflon, FEP, or polyethylene (e.g., HDPE or LDPE). As another example, the lumen 7350x can be coated with a separate lubricious coating, such as a hydrophilic coating.

[0152]

[0227] As best shown in FIGS. 73E-73L, each guide 7321y can include an atraumatic and / or soft distal end 7349x configured to extend distally beyond the respective channel 7348x (as shown in FIGS. 73K-73L). Also, as best shown in FIGS. 73G-73H, the lumen 7350x can extend substantially axially within the guide 7321y, but can be bent or angled radially inward (e.g., at an angle of 30°-60°, such as 45°) just proximal to the soft distal end 7349x to direct the tool 7377 toward the center of the stiffening device 7300. Directing the tool 7377 toward the center of the stiffening device 7300 can advantageously direct the tool 7377 toward the center of the body lumen as well (e.g., to avoid puncturing the wall of the body lumen with the tool 7377).

[0153]

[0228] As best shown in FIGS. 73C-73D, in some embodiments, guide 7321y can have an asymmetric cross-section. For example, the asymmetric cross-section can have a circular shape with wings 7351x extending from the circle (e.g., rounded triangular wings). In some embodiments, wings 7351x can meet at a central junction to form angled surfaces 7357x (e.g., having an angle of 110°-130°, such as approximately 120°) configured to closely follow the circumference of stiffening device 7300. An asymmetric cross-section can be advantageous because it can ensure proper radial alignment of guide 7321y (e.g., so that the distal end of lumen 7350x points radially inward relative to stiffening device 7300). Additionally, an asymmetric cross-section can be advantageous because it can prevent rotational movement of guide 7321y within channel 7348x. This can be particularly advantageous when the stiffening device is in a rigid configuration, as the asymmetric cross-section can help provide precise and stable access to the desired working area. In other embodiments, guide 7321y can be configured symmetrically and / or otherwise to be rotatable within channel 7348x. In some embodiments, the proximal end of guide 7321y can include indicator markings configured to indicate the rotational position of the distal end of guide 7321y relative to channel 7348x and / or relative to stiffening device 7300.

[0154]

[0229] As best shown in FIGS. 73A-73B and 73M , outer tube 7361y can include a proximal manifold 7353x attached to outer tube 7361y and configured to allow guide 7321y to be inserted therein. For example, manifold 7353x can include ports 7354x that provide access to each channel 7348x. In some embodiments, each port 7354x can include a corresponding marker 7355x configured to allow identification of channel 7348x (and thus identification of the distal circumferential position of tool 7377 to be inserted therein). Marker 7355x can be a shape, number, color, or any one of a variety of input / output matching indicia. In some embodiments, port 7354x can include a valve thereon and / or be vacuum sealed (e.g., to allow guide 7321y within channel 7348x to provide additional rigidity to device 7300).

[0155]

[0230] In some embodiments, guide 7321y can include a handle or stop 5352x (see FIG. 73B) at its proximal end to limit excessive axial movement of guide 7321y within channel 7348x and / or manifold 7353x.

[0156]

[0231] In use, the stiffening device 7300, with the outer tube 7361y attached thereabout, can be placed at a desired anatomical location (see FIG. 73A). For example, the stiffening device 7300 can first be placed at a desired anatomical location and stiffened (e.g., by application of pressure or vacuum as described herein). When it is desired to use the tool 7377, the user can select the desired channel 7348x (based on the marker 7355x and the desired position of the tool 7377). The user can then insert the guide 7321y into the channel 7348x while the stiffening device 7300 is in the rigid configuration. Inserting the guide 7321y can cause the channel 7348x to expand (see FIG. 73B or FIG. 73D). The tool 7377 can then be inserted through the guide 7321y such that the tool 7377 points toward the center of the device 7300 (see FIGS. 73G-73M) and / or the body lumen. After this procedure is complete, the tool 7377 and guide 7321y can be removed and the channel 7348x can collapse back down. The outer tube 7361y described herein is advantageous because it can allow a tool to pass through it, while being thin and flexible (i.e., does not significantly increase the diameter or bending stiffness of the stiffening device 7300) when not in use.

[0157]

[0232] The guide 7321y and / or working tool 7377 can have a higher stiffness than the stiffening device 7300 in its soft configuration, but a lower stiffness than the stiffening device 7300 in its rigid configuration. These relative stiffnesses are advantageous because they allow for the use of stiffer guide 7321y and / or working tool 7377 (e.g., improving access and / or performance at the treatment site) while ensuring that the guide 7321y and / or working tool 7377 do not affect the shape of the stiffened device 7300 (e.g., do not straighten it). Furthermore, these relative stiffnesses can allow for a larger working tool 7377 to be used with the stiffening device 7300 without affecting the shape of the working device. For example, in some embodiments, the ratio of the outer diameter of the stiffening device 7300 to the outer diameter of the expanded guide 7321y can be between 1:1 and 6:1, such as 2:1 and 4:1.

[0158]

[0233] Advantageously, guide 7321y can be provided in different sizes (e.g., with different sized lumens 7350x, e.g., lumens ranging from 1 mm to 7 mm, e.g., 2 mm to 6 mm in diameter) and can be used interchangeably in channel 7348x. In some embodiments, guide 7321y can have a lumen without a bend at its distal end. In other embodiments, the bend and / or asymmetric element of guide 7321y can be configured to direct a tool in a direction other than toward the center of the stiffening device (e.g., to direct the tool radially outward to perform a procedure on the wall of the lumen). In some embodiments, guide 7321y can be steerable (e.g., via a pull wire or other steering mechanism) to allow for further manipulation or orientation of working tool 7377 threaded therethrough.

[0159]

[0234] In some embodiments, guide 7321y can be configured to provide additional stiffening to device 7300. For example, channel 7348x can be sealable, allowing for the application of pressure or vacuum to channel 7348x (either separately from or together with the pressure or vacuum supplied to main stiffening device 7300). When pressure or vacuum is applied to channel 7348x, channel 7348x can seal around guide 7321y, thereby forming a stiffening / stiffening rib for device 7300.

[0160]

[0235] In some embodiments, the channel 7348x can include an elastic cuff or portion configured to maintain the channel 7348x in a collapsed state against the stiffening device 7300 when not in use (i.e., when the guide 7321y is not expanded therein).

[0161]

[0236] Although the outer tube 7361y is described herein as being used in conjunction with the guide 7321y, it should be understood that in some embodiments the outer tube 7361y may allow a working tool to pass through the channel 7348x without the use of a guide.

[0162]

[0237] In some embodiments, the scope can be positioned through the guide 7321y, and in some embodiments, the guide 7321y can be steered or otherwise preset to various angular positions (e.g., between an angle coaxial with the stiffening device 7300 and an angle perpendicular to the scope).

[0163]

[0238] The use of another system similar to that described in connection with FIGS. 73A-73M is illustrated in FIGS. 74A-74F. In FIG. 74A, a stiffening device 7400 is positioned around a scope 7491. The stiffening device 7400 includes an outer tube 7461y (containing multiple lay-flat channels 7448x) therearound. In FIG. 74B, a guide 7421y is inserted into the channel 7448x. In some embodiments, a user can select a channel 7448x based on one or both of a marker 7455x at the proximal end and a corresponding marker 7456x at the distal end (e.g., to select the channel 7448x closest to the desired treatment site). As shown in FIG. 74E, additional guides 7421y can be used simultaneously with the first guide 7421y by placing each guide 7421y in a different channel 7448x. In FIG. 74F, after the guide 7421y is positioned, one or more tools 7477 can be placed therein.

[0164]

[0239] Another example guide 7521y (which may be interchangeable with guide 7321y) is shown in FIGS. 75A-75B. Guide 7521y may have a crescent-shaped, asymmetric cross-section (e.g., angled surface 7357x of guide 7321y may be replaced with curved surface 7558x). Curved surface 7558x may have a curvature that is substantially the same as the curvature of the outer periphery of the stiffening device (and / or the inner periphery of outer tube 7561y). Advantageously, a matching curvature may help ensure a secure coupling of guide 7521y to the stiffening device. Also, guide 7321y may advantageously fit snugly into channel 7548x such that there is an advantageous force holding guide 7521y firmly to the stiffening device (i.e., the outer wall of channel 7548x may provide a force pushing guide 7521y toward the center of the stiffening device). These benefits may further result in advantageous stabilization of the flexible guide 7521y relative to the stiffening device when the stiffening device is in a rigid state. This stabilization may include a reduced tendency of the guide 7521y to bend, twist, or rotate about the center of the stiffening device. This stabilization may provide a more stable lumen 7550x for a tool to pass through, thus improving tool stability and the tool's ability to make precise movements.

[0165]

[0240] For clarity, the walls of channels 7348x, 7548x are shown spaced apart from guides 7321y, 7521y, but it should be understood that some or all of the walls can be positioned flush with guides 7321y, 7521y (i.e., by extension of the walls as guides 7321y, 7521y are passed through channels 7348x, 7548x).

[0166]

[0241] In another embodiment shown in FIG. 53 , multiple guides 5321y can be incorporated into a stiffening outer tube 5361y. One or both of the outer wall 5362y and the inner wall 5363y of the outer tube 5361 can be stiffened as described elsewhere herein. Advantageously, the outer tube 5361y, due to its larger diameter, can be very stiff when stiffened, thereby ensuring that the guides 5321y therein provide a very stable platform for passing tools. In some embodiments, the stiffening system (shown here as including an inner stiffening device 5310 and an outer stiffening device 5300) can be retracted from the outer tube 5361y after placement to allow a different tool or scope (e.g., a very large tool or high resolution) to be placed through the outer tube 5361y.

[0167]

[0242] In some embodiments, rather than incorporating a tool guide into the stiffening device, a guide-free stiffening nested system can be inserted into the body. After the nested system reaches the desired site (e.g., lesion), the guide-free outer stiffening device can be removed from the body, leaving the inner stiffening system still in place. An outer stiffening device including a tool guide (e.g., any of the tool guides described herein) can then be placed over the inner stiffening device.

[0168]

[0243] In some embodiments, the guides can be incorporated within a stiffening device, such as an internal stiffening device or within a single stiffening device. For example, referring to FIGS. 50A-50C , the distal end 2802z of the stiffening device can include a linkage 2804z configured to allow bending of the distal end 2802z. Each linkage 2804z can also include multiple lumens therein. In one embodiment, the lumens can be formed within the linkage 2804z by selective laser sintering (SLS). The lumens within each linkage 2804z can be aligned along the length of the distal end 2802z such that the aligned lumens can combine to form a segmented guide 2821y. As shown, the lumens can be different sizes to accommodate different sized working channels (e.g., for a camera, forceps, etc.).

[0169]

[0244] Referring back to FIG. 36 , in some embodiments, the robotically controlled nested system can include a fitting 9823y at its distal end. The guide 9821y can terminate in a port 9824y in the fitting 9823y (or, if a ring is used on the fitting, the ring can be coaxially aligned with the port 9824y when the outer stiffening device 9800 is in a straight configuration). When a tool is threaded through the guide 9821y, the tool can also pass through a corresponding port 9824y and, in some embodiments, can lock into the port 9824y. In some embodiments, two, three, or more tools can be locked into the fitting 9823y. Also, in some embodiments, the fitting 9823y can include additional ports connectable to additional tubular structures to provide suction channels, water channels, imaging channels, and / or channels for additional tools. These additional tubular structures can extend to or beyond a cassette (e.g., cassette 9357). In some embodiments, these additional tubular structures may be omitted from the interior of the inner stiffening device 9310, as they are incorporated into the fitting 9823y. In some embodiments, the fitting 9823y may be permanently attached to the outer stiffening device 9800, but may be temporarily attached to the inner stiffening device (e.g., stiffening device 9310) for use during a particular procedure. The fitting 9823y may include a disposable sheath attached to the fitting 9823y. The disposable sheath may be, for example, a thin plastic stiffening device, such as an inexpensive lay-flat stiffening device. The disposable sheath may cover the inner stiffening device (e.g., device 9310) and the outer stiffening device 9800 and connect to a cassette (e.g., cassette 9357). The disposable sheath may include tubular structures that provide features such as suction channels, water channels, and channels for additional tools, as described herein. In some embodiments, the fitting 9823y may be configured to rotate about the outer stiffening device 9800.For example, a Bowden cable may be attached to the outside of the external stiffening device 9800 and terminate at a distal end in a fitting 9823y and at a proximal end of a stiffening device, such as a handle. Rotating the Bowden cable may apply a torque to the fitting 9823y, thereby rotating the fitting 9823y. The fitting 9823y may have a limited range of motion, for example, + / - 90 degrees or + / - 60 degrees.

[0170]

[0245] 49A-49B, in some embodiments, the attachment 2723y can be moved into position after the nested system is inserted into the body. For example, the outer stiffening device 2700 of the system 2700z can include an attached pulley 2755y with a cable 2756y running therearound. The cable 2756y can extend, for example, between the outer stiffening device 2700 and the inner stiffening device 2710 and be attachable to the attachment 2723y. Thus, when the cable 2756y is pulled proximally, the attachment 2723y (and the flexible guide 2721y attached thereto) can be pulled distally into position. In some embodiments, a stiffening portion along the guide 2721y can be included to help ensure that the guide 2721y is sufficiently stiff after it is in place to allow a tool to be threaded through it. In some embodiments, the entire system 2700z can include an outer sheath that allows a vacuum to be drawn over the guide 2721y to provide additional rigidity.

[0171]

[0246] 42 , a stiffening system 2000z (e.g., a robotically controlled nested system) can include multiple tool guides 2021y as described herein positioned adjacent to one another along the outer stiffening device 2000 (e.g., at 9 o'clock and 10 o'clock) rather than spaced apart from one another (e.g., on opposite sides of the device 2000). In some embodiments, for example, all of the tool guides 2021y can follow an arc of less than 180 degrees, such as less than 120 degrees, 90 degrees or less, around the circumference of the outer stiffening device 2000. Having the tool guides 2021y adjacent to one another can be advantageous because it allows for a smaller total circumference of the system, which can facilitate easier manipulation through the body.

[0172]

[0247] 43 , in some embodiments, adjacent guides 2021y can be moved apart from one another after stiffening device 2000 is positioned within the body, e.g., for better angular positioning relative to the target site. One of the guides 2021y (e.g., the central guide 2021y) can be used, for example, to extend an articulating camera therethrough. An articulating camera may be advantageous because it may allow for a smaller integrated camera in the nested system 2000z (e.g., in the inner stiffening element).

[0173]

[0248] In some embodiments, a guide (e.g., any of the guides described herein) can be attached or otherwise loosely embedded within an outer layer of the stiffening device (e.g., the outer layer of the sheath and / or wall). In this embodiment, when a tool is inserted into the guide, the stiffness of the tool and its tendency to straighten can cause the guide to rotate about the periphery (i.e., central axis) of the stiffening device. This rotation is advantageous because it can place the guide with less resistance to insertion of the tool and / or reduce strain on the guide. In some embodiments, the tool can be inserted while the stiffening device is in its soft form, and when the stiffening device is stiffened, the braid layer can push into the outer layer, thereby securing the guide in place.

[0174]

[0249] In other embodiments (e.g., embodiments in which the guide is fixed relative to the periphery of the stiffening device), the stiffening device can be rotated about its axis to position the guide at the desired low resistance position.

[0175]

[0250] It should be understood that any of the tool guides (and corresponding tools) described herein can be used with nested stiffening systems or with a single stiffening system (e.g., a single overtube). Likewise, it should be understood that any of the tool guides (and corresponding tools) described herein can be used with stiffening or non-stiffening systems.

[0176]

[0251] An exemplary tool 9980 for use with a robotically controlled nested system (e.g., system 9300z) is shown in FIG. 37. The tool 9980 can include a cassette 9925y, a flexible shaft 9926y, a flexure 9927y, and an end effector 9928y (e.g., forceps, grasper, or scissors). The cassette 9925y, similar to a nested system cassette (e.g., cassette 9357), can have a disk that can be rotated to control aspects of the tool 9980. For example, rotating the disk can deflect the flexure 9927y. A separate disk can be used to control the end effector 9928y. Additionally, the tool 9980 can include a locking mechanism 9929y configured to engage with an attachment port (e.g., port 9824y) to lock the tool 9980 in place relative to an outer stiffening device (e.g., stiffening device 9800). The locking mechanism 9929y may include, for example, a spring pin configured to engage with a corresponding slot or hole on the end mount 3060. Other locking mechanisms are possible (e.g., magnetic lock, electronic lock, twist lock, breech lock, bayonet lock, etc.).

[0177]

[0252] In one use example, once the tool 9980 is inserted into the guide 9821y, the tool 9980 can be moved distally until the tool 9980 passes through the port 9824y and the locking mechanism 9929y is aligned with the inner diameter of the port 9824y. In some embodiments, a control on the tool 9980 can be reversibly engaged with the end fitting 9823y to lock the tool 9980 longitudinally. Alternatively, the tool 9980 can automatically lock into place in the fitting 9923y. Aside from the lock in the fitting 9823y, the tool 9980 can otherwise be loosely held or float longitudinally within the guide 9821y.

[0178]

[0253] 38 and back to FIGS. 31A-31D, in some embodiments, a robotic system (e.g., system 9300z including inner and outer stiffening devices 9310, 9300 and cassette 9357) may be disposed on a linear slide 10020y. The linear slide 10020y may further include a drive unit 10017y (similar to drive unit 9517y) configured to control the inner and outer stiffening devices 9310, 9300. The slide 10020y may enable the inner and outer stiffening devices 9310, 9300 to translate together (i.e., simultaneously). In some embodiments, to effect relative movement of the inner stiffening device 9310 relative to the outer stiffening device 9300, the system 9300z can be translated in a first direction (forward or backward along the slide 10020y) while the disk 9389 and rack 9382 on the outer stiffening device 9300 are used to move the outer stiffening device 9300 in a second direction opposite the first direction. That is, to advance the inner stiffening device 9310 relative to the outer stiffening device 9300, the system 9300z, including both stiffening systems 9300, 9310, is advanced along the slide 10020y while the disk 9389 and rack 9382 are used to retract the outer stiffening device 9300. Conversely, to retract the inner stiffening device 9310 relative to the outer stiffening device 9310, the system 9300z including both stiffening systems 9300, 9310 can be retracted along the slide 10020y, and at the same time the outer stiffening device 9033 can be advanced.

[0179]

[0254] Referring to FIG. 38 , the linear slide 10020y can further include a second drive unit 10030y configured to control one or more tools (e.g., tool 9980) used with the inner and outer stiffening devices. In some embodiments, the first drive unit 10017y and the second drive unit 10030y can translate independently along the linear slide 10020y. One, two, or more tools 9980 can be connected to the drive unit 10030y. The linear slide 10020y can advantageously ensure that tools used with the nested stiffening system remain in place at the distal end of the outer stiffening device regardless of any translation of the outer stiffening device. For example, the tool drive unit 10030y can be configured to translate the tool forward when the outer stiffening device advances relative to the slide 10020y. Similarly, the tool drive unit 10030y can be configured to retract the tool when the outer stiffening device is retracted relative to the slide 10020y, which can, for example, ensure that the tool is locked to a fixture (e.g., fixture 9823y).

[0180]

[0255] 39A and 39B show perspective and top views, respectively, of an exemplary robotic system 10100z positioned on a slide 10120y with a cassette 10157 attached to a drive unit 10117y for control of nested stiffening devices 10100, 10110. Two cassettes 10125y are attached to a drive unit 10130y for control of two different tools 10180. The tools 10180 are inserted into guides 1021y and locked into ports 10124y in fittings 10123y.

[0181]

[0256] 40 shows an example pivot arm 10231y that can be connected to the linear slide 10120y to properly orient the slide 10120y, and thus the rest of the robotic system (including the nested stiffening devices 10100, 10110 and / or tool 10180) relative to the patient. Thus, the linear slide 10120y may be positioned vertically, horizontally, or at any angle in between.

[0182]

[0257] The system 10100z may be used in the following exemplary manner: A cassette 10157 is attached to the inner and outer stiffening devices 10110, 10100, and the inner and outer stiffening devices 10110, 10100 are advanced into a patient's body (e.g., as shown in detail in Figures 65A-65H). In some embodiments, the inner and outer stiffening devices 10110, 10100 are advanced into the patient's colon or upper gastrointestinal tract. Reciprocating motion of the inner 10110 and outer stiffening devices 10100 is provided by movement of discs within the cassette 10157 and translation of the stiffening devices 10110, 10100 along the slider 10120y. Stiffening is provided by squeezing a bellows within the cassette 10157. Steering is provided by discs within the cassette 10157. When the medical professional reaches the site within the body where the procedure is to be performed, the tool can be inserted through the guide 10121y and locked into the port 10124y, and the cassette 10125y is then attached to the drive unit 10130y for control of the tool.

[0183]

[0258] The drive units described herein may be connected to a computer (e.g., a computer, tablet, laptop, etc.) for control. The computer communicating with the drive unit may include software that provides a user interface for the clinician to interact with to control the system and any tools being used. Automation, such as by computer control, of the cassettes and / or drive units described herein can be used to facilitate performing repetitive tasks. For example, a program can be developed that automatically moves the distal end of the stiffening device in an arc while releasing water. A second arc can then be formed to aspirate water and material from the gastrointestinal tract. This may be useful for irrigating the gastrointestinal tract. A program can be developed that sequences through the stiffening steps outlined herein, such that the operator only needs to provide input, for example, using a joystick to direct the distal end of the device.

[0184]

[0259] In some embodiments, the inner and outer stiffening devices may be advanced by the robotic systems described herein using small steps (e.g., steps less than 1 inch). Small steps are advantageous because they may allow for more precise control of the placement and orientation of the stiffening devices. For example, a user may steer the inner tube in a desired direction, and when the inner tube advances slightly ahead of the outer tube (e.g., 1 / 2 inch, 3 / 4 inch, or slightly less than 1 inch), a stiffening and advancement or retraction sequence of the outer tube may be automatically triggered. In some embodiments, a current small step sequence can be overridden if desired. In some embodiments, the inner and outer stiffening devices may be advanced by the robotic system using intermediate steps (e.g., steps between 1 inch and 3 inches) or large steps (e.g., greater than 3 inches).

[0185]

[0260] The cassettes and / or tools described herein may be disposable, reusable, or may be used and cleaned for a limited number of cycles.

[0186]

[0261] The linear slides described herein can, in some embodiments, be U-shaped with a corresponding U-shaped tube, or, in some embodiments, the linear slides can be circular with a corresponding circular tube.

[0187]

[0262] In some embodiments, the tip of the external stiffening device may include one or more cameras for viewing the end effector of a tool used with the robotic system, allowing the robotic system's controller to calculate the relationship between control inputs and effector outputs and adjust accordingly to provide the same effector motion regardless of tooth path (e.g., regardless of drag on the tool control cable when bent).

[0188]

[0263] It should be understood that any feature described herein in connection with one embodiment can be combined or substituted with any feature described herein in connection with another embodiment. For example, the various layers and / or features of the stiffening devices described herein can be combined, substituted, and / or rearranged relative to other layers.

[0189]

[0264] Additional details regarding the present invention, including materials and manufacturing techniques, may be employed within the level of one skilled in the relevant art. The same may be true for method-based aspects of the present invention regarding additional acts commonly or logically employed. It is also contemplated that any optional features of the described variations of the present invention may be described and claimed independently or in combination with any one or more of the features described herein. Similarly, reference to the singular includes the possibility that there are plurals of the same being presented. More specifically, as used in this specification and the appended claims, the singular forms "a," "an," "said," and "the" also include plural referents unless the context clearly indicates otherwise. It should also be noted that the claims may be written to exclude optional elements. Therefore, this statement is intended to serve as a predicate for the use of exclusive terms such as "solely," "only," or the use of a "negative" limitation in connection with the description of claim elements. Unless otherwise defined herein, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The scope of the present invention is not limited by this specification, but only by the plain meaning of the claim terms employed.

[0190]

[0265] As used herein, when a feature or element is referred to as being "on" another feature or element, it can be directly on the other feature or element, or intervening features and / or elements may also be present. Conversely, when a feature or element is referred to as being "directly on" another feature or element, there are no intervening features or elements present. Also, when a feature or element is referred to as being "connected," "attached," or "coupled" to another feature or element, it should be understood that it can be directly connected, attached, or coupled to the other feature or element, or there may be intervening features or elements present. Conversely, when a feature or element is referred to as being "directly connected," "directly attached," or "directly coupled" to another feature or element, there are no intervening features or elements present. Although described or illustrated with respect to one embodiment, features and elements so described or illustrated are applicable to other embodiments. Those skilled in the art will also recognize that a structure or feature positioned "adjacent" to another feature may have portions that overlap or underlie the adjacent feature.

[0191]

[0266] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. For example, as used herein, the singular forms "a," "an," and "the" are intended to include the plural forms unless the context clearly indicates otherwise. It should be further understood that the terms "comprising" and / or "comprises," when used herein, specify the presence of stated features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items and may be abbreviated as " / ."

[0192]

[0267] Spatially relative terms, such as "below," "lower," "bottom," "upper," and the like, may be used herein to facilitate describing the relationship of one element or feature to another, as illustrated in the figures. It should be understood that these spatially relative terms are intended to encompass different orientations of the device during use or operation, in addition to the orientation depicted in the figures. For example, if a device in the figures were inverted, an element described as being "below" or "below" another element or feature would then be oriented "above" that other element or feature. Thus, the illustrative term "below" can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations), and the spatially relative descriptors used herein will be interpreted accordingly. Similarly, terms such as "upward," "downward," "vertical," "horizontal," and the like are used herein for descriptive purposes only, unless specifically indicated otherwise.

[0193]

[0268] Although the terms "first" and "second" may be used herein to describe various features / elements, these features / elements should not be limited by these terms unless the context indicates otherwise. These terms may be used to distinguish one feature / element from another. Thus, a first feature / element described below could also be referred to as a second feature / element, and similarly, a second feature / element described below could also be referred to as a first feature / element without departing from the teachings of the present invention.

[0194]

[0269] Unless otherwise expressly stated, all numerical values ​​used in this specification and claims, including those used in the examples, may be interpreted as if preceded by the term "about" or "approximately," even if the term is not explicitly stated. The terms "about" or "approximately" may be used when describing a size and / or location to indicate that the stated value and / or location is within a reasonable expected range of the value and / or location. For example, a numerical value may have a value of + / - 0.1% of the stated value (or range of values), + / - 1% of the stated value (or range of values), + / - 2% of the stated value (or range of values), + / - 5% of the stated value (or range of values), + / - 10% of the stated value (or range of values), etc. Any numerical ranges described herein are intended to include all subranges within that range.

Claims

1. an elongated stiffening device configured to be stiffened from a flexible configuration to a rigid configuration by vacuum or pressure; an outer tube disposed around the stiffening device and permanently attached to an outer surface of the stiffening device, the outer tube including a plurality of expandable channels therein configured to allow a working tool to pass therethrough.

2. 10. The stiffening system of claim 1, further comprising at least one guide configured to be removably inserted into a channel of the plurality of expandable channels, the at least one guide including a lumen configured to allow the working tool to pass therethrough.

3. The stiffening system of claim 2 , wherein the channel is configured to expand when the at least one guide is inserted therein.

4. The stiffening system of claim 2 , wherein the channel is configured to collapse when the at least one guide is removed.

5. The stiffening system of claim 2 , wherein the at least one guide includes an atraumatic distal end.

6. The stiffening system of claim 2 , wherein the lumen is configured to point radially inward toward the elongate stiffening device when the at least one guide is disposed within the channel.

7. The stiffening system of claim 6 , wherein the lumen includes a 30° to 60° bend at its distal end for pointing radially inwardly.

8. The stiffening system of claim 2 , wherein the at least one guide includes an asymmetric cross-section configured to allow rotational alignment of the at least one guide relative to the elongated stiffening device.

9. The stiffening system of claim 8 , wherein the at least one guide comprises an angled or curved surface configured to substantially follow a periphery of the elongate stiffening device.

10. The stiffening system of claim 2 , wherein the at least one guide has a stiffness greater than that of the stiffening device in the flexible configuration and a stiffness less than that of the stiffening device in the rigid configuration.

11. 2. The stiffening system of claim 1, wherein a ratio of an outer diameter of the elongated stiffening device to an inner diameter of each of the expanded expandable channels of the plurality of channels is between 1:1 and 6:

1.

12. The stiffening system of claim 1 , wherein the outer tube is a sleeve having a wall thickness of less than 0.03 inches.

13. The stiffening system of claim 1 , wherein the outer tube comprises an elastomeric, plastic, or fabric structure.

14. 2. The stiffening system of claim 1, wherein each channel includes a proximal marker thereon configured to indicate a distal periphery position of the working tool relative to the stiffening device when the working tool is inserted into the channel.

15. The stiffening system of claim 1 , wherein the elongated stiffening device is configured to be stiffened by applying a vacuum or pressure within a wall of the elongated stiffening device.

16. The stiffening system of claim 15 , wherein the wall comprises a braid layer.

17. The stiffening system of claim 1 , wherein the work tool has a higher stiffness than the stiffening device in the flexible configuration and a lower stiffness than the stiffening device in the rigid configuration.

18. The stiffening system of claim 1 , wherein the elongated stiffening device is part of an overtube, the overtube being configured to pass a scope therethrough.

19. The stiffening system of claim 1 , further comprising a proximal manifold attached to the elongated stiffening device, the proximal manifold including a plurality of ports providing access to the plurality of expandable channels.

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