Dynamically stiffening medical composite structures

Abstract

The stiffening device includes an elongated flexible tube, a braided layer disposed over the elongated flexible tube, an outer layer over the flexible tube and the braided layer, and an inlet between the elongated flexible tube and the outer layer configured to be attached to a vacuum or pressure source. The braided layer has a plurality of strands braided together at a braid angle of 5 to 40 degrees relative to a longitudinal axis of the elongated flexible tube when the elongated flexible tube is straight. The stiffening device is configured to have a stiffened configuration when vacuum or pressure is applied through the inlet and a flexible configuration when vacuum or pressure is not applied through the inlet. The braid angle is configured to change as the stiffening device flexes when in the flexible configuration. [Selected figure] Figure 1

Description

[Technical field]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This application is a continuation of U.S. Provisional Patent Application No. 62 / 835,101, filed April 17, 2019, entitled “DYNAMICALLY RIGIDIZING COMPOSITE MEDICAL STRUCTURES,” U.S. Provisional Patent Application No. 62 / 854,199, filed May 29, 2019, entitled “DYNAMICALLY RIGIDIZING COMPOSITE MEDICAL STRUCTURES,” U.S. Provisional Patent Application No. 62 / 780,820, filed December 17, 2018, entitled “DYNAMICALLY RIGIDIZING COMPOSITE MEDICAL STRUCTURES,” and U.S. Provisional Patent Application No. 62 / 780,820, filed December 17, 2018, entitled “BRAIDED DYNAMICALLY RIGIDIZING COMPOSITE MEDICAL STRUCTURES.” This application claims priority to U.S. Provisional Patent Application No. 62 / 700,760, filed July 19, 2018, entitled "METHOD FOR USE IN HYDRAULIC SYSTEMS AND METHOD FOR USE IN A HYDRAULIC SYSTEM ...

[0002] This application also claims priority to U.S. Provisional Patent Application No. 62 / 672,444, filed May 16, 2018, entitled “DYNAMICALLY RIGIDIZING OVERTUBE,” and is related to International Patent Application No. PCT / US2018 / 042946, filed July 19, 2018, entitled “DYNAMICALLY RIGIDIZING OVERTUBE,” and U.S. Provisional Patent Application No. 62 / 535,134, filed July 20, 2017, entitled “DYNAMICALLY RIGIDIZING OVERTUBE,” both of which are incorporated by reference in their entireties.

[0003] This application also relates to a device for endoscopy advancement through the small intestine, now U.S. Patent Application Publication No. 2018 / 0271354, which is a national stage application under 35 U.S.C. 371 of International Patent Application No. PCT / US2016 / 050290, filed September 2, 2016, entitled "DEVICE FOR ENDOSCOPIS ADVANCEMENT THROUGH THE SMALL INTESTINE," now WO 2017 / 041052, which claims priority to U.S. Provisional Patent Application No. 62,339,593, filed May 20, 2016, entitled "DEVICE FOR ENDOSCOPIS ADVANCEMENT THROUGH THE SMALL INTESTINE." No. 15 / 757,230, filed March 2, 2018, entitled "DEVICE FOR ENDOCSOPIS ADVANCEMENT THROUGH THE SMALL INTESTINE," and U.S. Provisional Patent Application No. 62 / 213,908, filed September 3, 2015, entitled "DEVICE FOR ENDOCSOPIS ADVANCEMENT THROUGH THE SMALL INTESTINE," both of which are incorporated by reference in their entireties.

[0004] (Incorporated by reference) All publications and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference.

[0005] The present invention relates to dynamically stiffening medical composite structures. [Background technology]

[0006] During a medical procedure, an interventional medical device may bend or loop within the anatomy, making entry of the medical device difficult.

[0007] Digestive looping, which occurs when an endoscope cannot be advanced any further due to excessive curves or loops in the digestive tract, is a particularly well-known clinical challenge for endoscopes. In fact, one study found that looping occurred in 91 out of 100 patients undergoing colonoscopy (Non-Patent Document 1). Digestive looping can prolong the procedure and cause pain to the patient because it stretches the blood vessel walls and mesentery. Furthermore, digestive looping leads to an increased incidence of perforation. In severe cases of digestive looping, complete colonoscopy is not possible because the looping extends the length of the colon and the colonoscope is not long enough to reach the end. Digestive looping is an obstacle to precise tip control, depriving the user of the desired one-to-one operating relationship between the handle and the endoscope tip. Such problems commonly occur during colonoscopy, esophagoduodenoscopy (EGD), enteroscopy, endoscopic retrograde cholangiopancreatography (ERCP), interventional endoscopic procedures (including ESD (endoscopic submucosal dissection) and EMR (endoscopic mucosal resection)), robotic flexible endoscopy, transoral robotic surgery (TORS), cases of abnormal anatomy (including Roux-en-Y), and across a wide range of endoscopic procedures, and during NOTES (natural orifice transluminal endoscopic surgery) procedures. Thus, there is a need for a device that helps prevent the formation of gastrointestinal loops and provides better access to the gastrointestinal tract. [Prior art documents] [Non-patent literature]

[0008] [Non-Patent Document 1] Shah et al., "Magnetic Imaging of Colonoscopy: An Audit of Looping, Accuracy and Ancillary maneuvers." Gastrointest. Endosc. 2000;52:1-8. Summary of the Invention [Problem to be solved by the invention]

[0009] Similar challenges in advancing medical devices can arise during interventional procedures, for example, in the lungs, kidneys, brain, epigastric region, and other anatomical locations. Thus, there is a need for devices that provide safe, efficient, and precise access to reach otherwise difficult to reach anatomical locations. [Means for solving the problem]

[0010] Generally, in one embodiment, the stiffening device includes an elongated flexible tube, a braided layer disposed over the elongated flexible tube, an outer layer over the flexible tube and the braided layer, and an inlet between the elongated flexible tube and the outer layer configured to be attached to a vacuum or pressure source. The braided layer has a plurality of strands braided together at a braid angle of 5 to 40 degrees relative to a longitudinal axis of the elongated flexible tube when the elongated flexible tube is straight. The stiffening device is configured to have a stiffened configuration when vacuum or pressure is applied through the inlet and a flexible configuration when vacuum or pressure is not applied through the inlet. The braid angle is configured to change as the stiffening device flexes when the stiffening device is in the flexible configuration.

[0011] These and other embodiments may include one or more of the following features: The braid angle may be between 10 and 35 degrees. The braid angle may be between 15 and 25 degrees. The stiffened device in the stiffened configuration may be at least two times stiffer than the stiffened device in the flexible configuration. The stiffened device in the stiffened configuration may be at least five times stiffer than the stiffened device in the flexible configuration. The stiffening may further include a sliding layer adjacent the braided layer having a lower coefficient of friction than the braided layer. The elongated flexible tube may include a reinforcing element extending therethrough. The reinforcing element may include a coil or a plurality of hoop elements. The plurality of strands may be braided together at a picks per inch count of 4 to 60. The strands may include polyethylene terephthalate or stainless steel. The braided layer may provide a coverage of 30 to 70% for the elongated flexible tube. The plurality of strands may include 96 or more strands. The inlet may be configured to be attached to a pressure source and the stiffening device may further include an air reservoir therein. The reservoir layer may be configured to be pressed against the braided layer when pressure is applied from the inlet. The outer layer may further include a plurality of reinforcing elements therein. The inlet is configured to be attached to a vacuum source and the outer layer may be a thin flexible sheath. The stiffening device may further include a radial gap between the braided layer and the outer layer. The gap may have a thickness of 0.00002" to 0.04". The stiffening device may further include a steerable distal end. The stiffening device may further include a sealed channel between the elongated flexible tube and the outer layer. The sealed channel may include a working channel, a cable guide, or an inflation lumen.

[0012] Generally, in one embodiment, a method of advancing a stiffening device through a body lumen includes (1) inserting the stiffening device into the body lumen while the stiffening device is in a flexible configuration, the stiffening device including an elongated flexible tube, a braided layer having a plurality of strands braided together at a braid angle of 5-40 degrees when the stiffening device is straight, and an outer layer, the braid angle changing when the flexible tube is in the flexible configuration, and (2) manipulating a vacuum or pressure between the flexible tube and the outer layer when the stiffening device reaches a desired location in the body lumen to transition the stiffening device to a stiffening configuration that is more rigid than the flexible configuration.

[0013] These and other embodiments may include one or more of the following features. The method may further include releasing the vacuum or pressure after operating the vacuum or pressure to transition the stiffening device back to the flexible configuration. The braid angle may be between 10 and 35 degrees. The braid angle may be between 15 and 25 degrees. The method may further include passing a scope through the stiffening device while the stiffening device is in the stiffening configuration. The method may include steering the steerable distal end of the stiffening device through the body lumen. The body lumen may be in the digestive tract. The body lumen may be in the heart. The body lumen may be in the kidney. The body lumen may be in the lung. The body lumen may be in the brain.

[0014] In general, in one embodiment, the stiffening device includes an elongated flexible tube, a braided layer disposed over the elongated flexible tube, an outer layer over the flexible tube and the braided layer, and an inlet between the elongated flexible tube and the outer layer configured to be attached to a vacuum or pressure source. The stiffening device is configured to have a stiffened configuration when vacuum or pressure is applied through the inlet and a flexible configuration when vacuum or pressure is not applied through the inlet. A stiffness ratio between the stiffening device in the stiffened configuration and the stiffening device in the flexible configuration is greater than 5.

[0015] These and other embodiments may include one or more of the following features: The ratio is greater than 6. The ratio is greater than 10. The braided layer has a plurality of strands braided together at a braid angle of 5 to 40 degrees relative to a longitudinal axis of the elongated flexible tube when the elongated flexible tube is straight. The braid angle may be between 10 and 35 degrees. The stiffening device may further include a sliding layer proximate the braided layer having a lower coefficient of friction than the braided layer. The elongated flexible tube may include a reinforcing element extending therethrough. The reinforcing element may include a coil or a plurality of hoop elements. The braided layer may include a plurality of strands braided together at a picks per inch of 4 to 60. The braided layer includes a plurality of strands braided together, the strands may include polyethylene terephthalate or stainless steel. The braided layer may provide a coverage of 30 to 70% for the elongated flexible tube. The braided layer may include 96 or more strands braided together. The inlet may be configured to be attached to a pressure source. The stiffening device may further include a reservoir layer therein, the reservoir layer configured to be pressed against the braided layer when pressure is provided from the inlet. The outer layer may further include a plurality of reinforcing elements therein. The inlet may be configured to be attached to a vacuum source. The outer layer may be a thin flexible sheath. The stiffening device may further include a radial gap between the braided layer and the outer layer. The gap may have a thickness of 0.00002" to 0.04". The stiffening device may further include a steerable distal end. The stiffening device may further include a sealed channel between the elongated flexible tube and the outer layer. The sealed channel may include a working channel, a cable guide, or an inflation lumen.

[0016] Generally, in one embodiment, a method of advancing a stiffening device through a body lumen includes (1) inserting the stiffening device into the body lumen while the stiffening device is in a flexible configuration, the stiffening device including an elongated flexible tube, a braided layer, and an outer layer, and (2) when the stiffening device reaches a desired location in the body lumen, manipulating a vacuum or pressure between the flexible tube and the outer layer to transition the stiffening device to a stiffened configuration that is stiffer than the flexible configuration, the ratio of stiffness in the stiffened configuration to stiffness in the flexible configuration being greater than 5.

[0017] These and other embodiments may include one or more of the following features. The method may further include releasing the vacuum or pressure after manipulating the vacuum or pressure to transition the stiffening device back to the flexible configuration. The ratio may be greater than 6. The ratio may be greater than 10. The method may further include passing a scope through the stiffening device while the stiffening device is in the stiffening configuration. The method may further include steering the steerable distal end of the stiffening device through the body lumen. The body lumen may be in the GI tract. The body lumen may be in the heart. The body lumen may be in the kidney. The body lumen may be in the lung. The body lumen may be in the brain.

[0018] In general, in one embodiment, the stiffening device includes an elongated flexible tube, a braided layer disposed radially outward of the elongated flexible tube, a sliding layer adjacent the braided layer, an outer layer, and a vacuum or pressure inlet between the elongated flexible tube and the outer layer. The outer layer overlies the flexible tube, the braided layer, and the sliding layer. The inlet is configured to be attached to a vacuum or pressure source. The stiffening device is configured to have a stiffened configuration when vacuum or pressure is applied from the inlet and a flexible configuration when vacuum or pressure is not applied from the inlet. The sliding layer is configured to reduce friction between the braided layer and the elongated flexible tube or the outer layer when the stiffening device is in the flexible configuration.

[0019] These and other embodiments may include one or more of the following features: The sliding layer may have a lower coefficient of friction than the braided layer. The sliding layer may include a powder. The cured device in the cured configuration may be at least two times stiffer than the cured device in the flexible configuration. The cured device in the cured configuration may be at least five times stiffer than the cured device in the flexible configuration. The braided layer may have a plurality of strands braided together at a braid angle of 5 to 40 degrees relative to a longitudinal axis of the elongated flexible tube when the elongated flexible tube is straight. The braid angle may be between 10 and 35 degrees. The elongated flexible tube may include a reinforcing element extending therethrough. The reinforcing element may include a coil or a plurality of hoop elements. The braided layer may include a plurality of strands braided together at a picks per inch of 4 to 60. The braided layer may include a plurality of strands braided together, the strands may include polyethylene terephthalate or stainless steel. The braided layer may provide 30-70% coverage for the elongated flexible tube. The braided layer may include 96 or more strands braided together. The inlet may be configured to be attached to a pressure source. The stiffening device may further include a reservoir layer therein. The reservoir layer may be configured to be pressed against the braided layer when pressure is provided from the inlet. The outer layer may further include a plurality of reinforcing elements therein. The inlet may be configured to be attached to a vacuum source. The outer layer may be a thin flexible sheath. The stiffening device may further include a radial gap between the braided layer and the outer layer. The gap may have a thickness of 0.00002" to 0.04". The stiffening device may further include a steerable distal end. The stiffening device may further include a sealed channel between the elongated flexible tube and the outer layer. The sealed channel may include a working channel, a cable guide, or an inflation lumen.

[0020] Generally, in one embodiment, a method of advancing a stiffening device through a body lumen includes (1) inserting the stiffening device into the body lumen while the stiffening device is in a flexible configuration, the stiffening device including an elongated flexible tube, a braided layer, a sliding layer adjacent to the braided layer, and an outer layer, the sliding layer reducing friction between the braided layer and the elongated flexible tube or the outer layer while the stiffening device is in the flexible configuration, and (2) manipulating a vacuum or pressure between the flexible tube and a sheath to transition the stiffening device to a stiffening configuration that is more rigid than the flexible configuration when the stiffening device reaches a desired location in the body lumen.

[0021] These and other embodiments may include one or more of the following features: The method may further include releasing the vacuum or pressure after operating the vacuum or pressure to transition the stiffening device back to the flexible configuration. The sliding layer may have a lower coefficient of friction than the braided layer. The sliding layer may include a powder. The method may further include passing a scope through the stiffening device while the stiffening device is in the stiffened configuration. The method may further include steering the steerable distal end of the stiffening device through the body lumen. The body lumen may be in the digestive tract. The body lumen may be in the heart. The body lumen may be in the kidney. The body lumen may be in the lung. The body lumen may be in the brain.

[0022] In general, in one embodiment, the stiffening device includes an inner elongated flexible tube including a reinforcing element and a substrate, a braided layer disposed radially outward of the elongated flexible tube, an outer layer over the braided layer, and a vacuum or pressure inlet between the elongated flexible tube and the outer layer configured to be attached to a vacuum or pressure source. The reinforcing element has an aspect ratio of width to thickness greater than 5:1. The stiffening device is configured to have a stiffened configuration when vacuum or pressure is applied from the vacuum inlet and a flexible configuration when vacuum or pressure is not applied from the vacuum inlet.

[0023] These and other embodiments may include one or more of the following features: The reinforcing element may be a coil. The reinforcing element may include a plurality of closed rings. The closed rings may include a plurality of pockets and notches. The reinforcing element may include a wavy wire. The reinforcing element may be a fabric or a metal wire. The aspect ratio may be greater than 10:1. The aspect ratio may be greater than 11:1. The elongated flexible tube may include a plurality of reinforcing elements. The spacing between each reinforcing element may be 0.0006" or less. The elongated flexible tube may further include a substrate in which the reinforcing elements are embedded. The substrate may include TPU or TPE.

[0024] Generally, in one embodiment, a method of advancing a stiffening device in a body lumen includes (1) inserting the stiffening device into the body lumen while the stiffening device is in a flexible configuration, the stiffening device including an elongated flexible tube having a reinforcing element and a substrate, a braided layer, and an outer layer, the reinforcing element having an aspect ratio of width to thickness greater than 10:1, and (2) when the stiffening device reaches a desired location in the body lumen, manipulating a vacuum or pressure between the flexible tube and the outer layer to transition the stiffening device to a stiffening configuration that is more rigid than the flexible configuration.

[0025] These and other embodiments can include one or more of the following features: The elongated flexible tube can resist compression when a vacuum or pressure is applied.

[0026] Generally, in one embodiment, the stiffening device includes an elongated flexible tube, a braided layer disposed over the elongated flexible tube, an outer layer over the flexible tube and the braided layer, and an inlet between the elongated flexible tube and the outer layer configured to be attached to a vacuum or pressure source. The braided layer has a plurality of strands braided together. The stiffening device is configured to have a stiffened configuration when vacuum or pressure is applied through the inlet and a flexible configuration when vacuum or pressure is not applied through the inlet. Each end is embedded or surrounded by an annular ring that allows relative movement of the ends of the strands when the stiffening device is in the flexible configuration.

[0027] These and other embodiments may include one or more of the following features: The annular ring may include a material coating. The annular ring may include silicone or urethane. The annular ring may be approximately 0.005 to 0.250 inches thick.

[0028] Generally, in one embodiment, a method of advancing a stiffening device in a body lumen includes (1) inserting the stiffening device into the body lumen while the stiffening device is in a flexible configuration, the stiffening device including an elongated flexible tube, a braided layer having a plurality of strands braided together, and an outer layer, and (2) manipulating a vacuum or pressure between the flexible tube and a sheath to transition the stiffening device to a stiffened configuration that is more rigid than the flexible configuration when the stiffening device reaches a desired location in the body lumen. Each end of the strands is embedded or surrounded by an annular ring such that the ends move relative to each other while the stiffening device is in the flexible configuration. The ends are substantially fixed relative to each other while the stiffening device is in the stiffened configuration.

[0029] In general, in one embodiment, the stiffening device includes an elongated flexible tube, a braided layer disposed over the elongated flexible tube, an outer layer sealed over the flexible tube and the braided layer, and an inlet between the elongated flexible tube and the outer layer configured to be attached to a vacuum source. The braided layer has a plurality of strands braided together and a plurality of hoop fibers woven into the braid. The stiffening device is configured to have a stiffened configuration when a vacuum is applied through the inlet and a flexible configuration when a vacuum is not applied through the inlet.

[0030] Generally, in one embodiment, a method of advancing a stiffening device through a body lumen includes (1) inserting the stiffening device into the body lumen while the stiffening device is in a flexible configuration, the stiffening device including an elongated flexible tube, a braided layer, and an outer layer, and (2) when the stiffening device reaches a desired location in the body lumen, operating a vacuum between the flexible tube and the outer layer to transition the stiffening device to a stiffened configuration that is more rigid than the flexible configuration. The braided layer has a number of strands that are braided together and a number of hooped fibers woven into the braid.

[0031] Generally, in one embodiment, the stiffening device includes an elongated flexible tube, an air reservoir layer disposed over the elongated flexible tube, a braided layer disposed over the air reservoir layer, an outer layer disposed over the flexible tube and the braided layer, a pressure inlet between the air reservoir layer and the elongated flexible tube, and a vent outlet between the air reservoir layer and the outer layer. The pressure inlet is configured to be attached to a pressure source. The braided layer includes a plurality of strands braided together. The stiffening device is configured to achieve a stiffened configuration when pressure is applied from the pressure inlet and a flexible configuration when pressure is not applied from the pressure inlet. When the stiffening device transitions from the flexible configuration to the stiffened configuration, fluid or gas surrounding the strands exits through the vent outlet.

[0032] These and other embodiments may include one or more of the following features: The curing device may further include a handle attached to the elongated flexible tube. The handle may include a vent port in communication with the vent outlet.

[0033] Generally, in one embodiment, a method of advancing a stiffening device through a body lumen includes (1) inserting the stiffening device into the body lumen while the stiffening device is in a flexible configuration, the stiffening device including an elongated flexible tube, an air reservoir, a braided layer having a plurality of strands braided together, and an outer layer; and (2) when the stiffening device reaches a desired location in the body lumen, applying pressure from an inlet between the elongated flexible tube and the air reservoir while venting gas or fluid surrounding the strands through a vent outlet to transition the stiffening device to a stiffened configuration that is more rigid than the flexible configuration.

[0034] In general, in one embodiment, the stiffening device includes an elongated flexible tube, a braided layer disposed over the elongated flexible tube, an outer layer over the flexible tube and the braided layer, a channel extending between the outer layer and the elongated flexible tube, and an inlet. The inlet is between the elongated flexible tube and the outer layer and is configured to be attached to a vacuum or pressure source. The channel includes a working channel, a steering cable channel, or an inflation lumen. The stiffening device is configured to have a stiffened configuration when vacuum or pressure is applied from the inlet and a flexible configuration when vacuum or pressure is not applied from the inlet.

[0035] Generally, in one embodiment, a method of advancing a medical tool through a body lumen includes (1) inserting a stiffening device into the body lumen while the stiffening device is in a flexible configuration, the stiffening device including an elongated flexible tube, a braided layer, and an outer layer; (2) manipulating a vacuum or pressure between the flexible tube and the outer layer when the stiffening device reaches a desired location in the body lumen to transition the stiffening device to a stiffened configuration that is more rigid than the flexible configuration; and (3) passing a medical tool through a sealed working channel disposed between the elongated flexible tube and the outer layer.

[0036] Generally, in one embodiment, a method of advancing a medical tool through a body lumen includes (1) inserting a stiffening device into the body lumen while the stiffening device is in a flexible configuration, the stiffening device including an elongated flexible tube, a braided layer, and an outer layer; (2) when the stiffening device reaches a desired location in the body lumen, manipulating a vacuum or pressure between the flexible tube and the outer layer to transition the stiffening device to a stiffened configuration that is more rigid than the flexible configuration; and (3) manipulating at least one cable disposed between the elongated flexible tube and the outer layer to orient a distal end of the stiffening device.

[0037] Generally, in one embodiment, a method of advancing a medical tool through a body lumen includes: (1) inserting a stiffening device into the body lumen while the stiffening device is in a flexible configuration, the stiffening device including an elongated flexible tube, a braided layer, and an outer layer; (2) when the stiffening device reaches a desired location in the body lumen, manipulating a vacuum or pressure between the flexible tube and the outer layer to transition the stiffening device to a stiffened configuration that is more rigid than the flexible configuration; and (3) inflating a balloon with the stiffening device by passing an inflation medium through a sealed inflation lumen disposed between the elongated flexible tube and the outer layer.

[0038] In general, in one embodiment, the stiffening device includes an elongated flexible tube having a central lumen, a braided layer disposed over the elongated flexible tube, an outer layer over the flexible tube and the braided layer, a plurality of sealed working channels extending into the central lumen, and an inlet between the elongated flexible tube and the outer layer configured to be attached to a vacuum or pressure source. The stiffening device is configured to have a stiffening configuration when vacuum or pressure is applied through the inlet and a flexible configuration when vacuum or pressure is not applied through the inlet.

[0039] Generally, in one embodiment, a method of advancing multiple medical tools through a body lumen includes: (1) inserting a stiffening device into the body lumen while the stiffening device is in a flexible configuration, the stiffening device including an elongated flexible tube, a braided layer, and an outer layer; (2) manipulating a vacuum or pressure between the flexible tube and the outer layer when the stiffening device reaches a desired location in the body lumen to transition the stiffening device to a stiffened configuration that is more rigid than the flexible configuration; (3) passing a first medical tool through a first sealed working channel of the stiffening device; and (4) passing a second medical tool through a second sealed working channel of the stiffening device.

[0040] In general, in one embodiment, the overtube includes an elongate tube and a distal tip attached to the elongate tube, the distal tip having an annular distal surface with one or more vacuum holes extending therethrough, the one or more vacuum holes configured to draw tissue toward the annular distal surface upon application of vacuum.

[0041] This and other embodiments may include one or more of the following features: The elongate tube may be a stiffening device, and the stiffening device may be configured to have a stiffened configuration when a vacuum or pressure is applied to the wall and a flexible configuration when no vacuum or pressure is applied to the wall. The elongate tube may include a braided layer and an outer layer thereon. The annular distal surface may be angled relative to a longitudinal axis of the elongate tube.

[0042] In general, in one embodiment, the stiffening device includes an elongated flexible tube, a braided layer disposed over the elongated flexible tube, an outer layer over the flexible tube and the braided layer, and a distal tip attached to the elongated flexible tube. The braided layer has a plurality of strands braided together at a first braid angle relative to a longitudinal axis of the elongated flexible tube when the elongated flexible tube is straight. The distal tip includes a second braided layer having a plurality of strands braided together at a second braid angle different than the first braid angle. An inlet between the elongated flexible tube and the outer layer is configured to be attached to a vacuum or pressure source. The stiffening device is configured to have a stiffened configuration when vacuum or pressure is applied from the inlet and a flexible configuration when vacuum or pressure is not applied from the inlet.

[0043] These and other embodiments can include one or more of the following features: The second braid angle is greater than the first braid angle The first and second braided layers can be joined to one another.

[0044] In general, in one embodiment, the stiffening device includes an elongate flexible tube having a plurality of reinforcing elements therein. The elongate flexible tube includes a proximal section and a distal section. A braided layer is disposed over the proximal section but not the distal section. The braided layer has a plurality of strands braided together at a first braid angle relative to a longitudinal axis of the elongate flexible tube when the elongate flexible tube is straight. An outer layer is disposed over the braided layer. A plurality of steering linkages extend over the distal section but not the proximal section. An inlet is between the elongate flexible tube and the outer layer and is configured to be attached to a vacuum or pressure source. The stiffening device is configured to have a stiffened configuration when vacuum or pressure is applied from the inlet and a flexible configuration when vacuum or pressure is not applied from the inlet.

[0045] These and other embodiments may include one or more of the following features: The stiffening device may further include a plurality of cables attached to the steerable linkage. The cables may extend between the elongated flexible tube and the outer layer.

[0046] In general, in one embodiment, the stiffening device includes a stiffening assembly and a plurality of linkages. The stiffening assembly includes an elongated flexible tube, a braided layer disposed over the elongated flexible tube, an outer layer over the flexible tube and the braided layer, and an inlet. The inlet is between the elongated flexible tube and the outer layer and is configured to be attached to a vacuum or pressure source. The plurality of steerable linkages are mounted on a distal portion of the stiffening assembly. The stiffening assembly is configured to have a stiffened configuration when vacuum or pressure is applied from the inlet and a flexible configuration when vacuum or pressure is not applied from the inlet.

[0047] These and other embodiments may include one or more of the following features: The stiffening device may further include a plurality of cables attached to the steerable linkage. The cables may extend between the elongated flexible tube and the outer layer.

[0048] In general, in one embodiment, the stiffening device includes an elongated flexible tube, a plurality of steerable linkages, and an outlet. The elongated flexible tube includes a proximal section and a distal section. The elongated flexible tube includes a plurality of reinforcing elements therein, a braided layer disposed over the proximal and distal sections, and an outer layer including the plurality of reinforcing elements. The plurality of steerable linkages extend over the distal section but not the proximal section. The inlet is between the elongated flexible tube and the outer layer and is configured to be attached to a vacuum or pressure source. The braided layer has a plurality of strands braided together at a first braid angle relative to a longitudinal axis of the elongated flexible tube when the elongated flexible tube is straight. The outer layer is disposed over the proximal section but not the distal section. The stiffening device is configured to have a stiffened configuration when a vacuum or pressure is applied from the inlet and a flexible configuration when a vacuum or pressure is not applied from the inlet.

[0049] These and other embodiments may include one or more of the following features: The stiffening device may further include a plurality of cables attached to the steerable linkage, the cables extending between the elongated flexible tube and the outer layer.

[0050] In general, in one embodiment, the stiffening device includes a stiffening assembly and a plurality of linkages. The stiffening assembly includes an elongated flexible tube, a braided layer disposed over the elongated flexible tube, an outer layer over the flexible tube and the braided layer, and an inlet between the elongated flexible tube and the outer layer configured to be attached to a vacuum or pressure source. A back portion extends from a distal section of the stiffening assembly. The back portion is configured to effect bending of the stiffening assembly in a set orientation. A plurality of steerable linkages are distal to the stiffening assembly. The stiffening assembly is configured to have a stiffened configuration when vacuum or pressure is applied from the inlet and a flexible configuration when vacuum or pressure is not applied from the inlet.

[0051] These and other embodiments may include one or more of the following features: The stiffening device may further include a pull wire configured to bend the device at its back when actuated. The stiffening device may further include a plurality of cables attached to the steerable linkage. The cables may extend between the elongated flexible tube and the outer layer.

[0052] In general, in one embodiment, the stiffening device includes a stiffening assembly and a distal tip. The stiffening assembly includes an elongated flexible tube, a braided layer disposed over the elongated flexible tube, an outer layer over the flexible tube and the braided layer, and an inlet between the elongated flexible tube and the outer layer configured to be attached to a vacuum or pressure source. The distal tip is attached to the elongated flexible tube. The distal tip includes a plurality of linkages connected together at pivot points. The stiffening assembly and distal tip are configured to assume a stiffened configuration when vacuum or pressure is applied from the inlet and a flexible configuration when vacuum or pressure is not applied from the inlet.

[0053] In general, in one embodiment, a handle for use with a curing device includes a handle body configured to be attached to the curing device, a vacuum delivery line attached to the handle body and configured to be connected to a vacuum source, a vacuum port in communication with a wall of the curing device, and an operating element on the handle body configured to move between a first position and a second position, the operating element in the first position connecting the vacuum delivery line to the vacuum port to provide a vacuum to the wall of the curing device and the operating element in the second position disconnecting the vacuum delivery line from the vacuum port to evacuate the wall of the curing device.

[0054] These and other embodiments may include one or more of the following features: The operating element may include a magnetic element. The magnetic element may be configured to hold the operating element in the first position or the second position. The vacuum delivery line may be coiled within the handle.

[0055] Generally, in one embodiment, a method of advancing a stiffening device through a body lumen includes: (1) holding a handle of the stiffening device; (2) inserting an elongate body of the stiffening device into the body lumen while the stiffening device is in a flexible configuration; (3) when the stiffening device reaches a desired location in the body lumen, moving a manipulating element in a first direction to connect a vacuum delivery line of the handle with a vacuum port to a wall of the elongate body such that vacuum flows into the wall of the elongate body to transition the elongate body to the stiffened configuration; and (4) moving the manipulating element in a second direction to disconnect the vacuum delivery line from the vacuum port to vent the elongate body to transition the elongate body to the flexible configuration.

[0056] In general, in one embodiment, a handle for use with a curing device includes a handle body configured to attach to the curing device, a fluid chamber within the handle body, an outlet in fluid communication with the fluid chamber and a wall of the curing device, and an operating element configured to move between a first position and a second position, the operating element configured to transfer fluid from the fluid chamber to the wall of the curing device when moving from the first position to the second position, and to transfer fluid back to the fluid chamber when moving from the second position to the first position.

[0057] These and other embodiments may include one or more of the following features: The handle may further include an overflow chamber in the handle body and a pressure relief valve between the fluid chamber and the overflow chamber. The pressure relief valve may be configured to open to allow fluid to enter the overflow chamber when pressure in the fluid chamber reaches a predetermined maximum pressure. The handle may further include a piston and a rolling diaphragm in the handle body. The piston may be configured to press against the rolling diaphragm as the operating element moves between the first position and the second position.

[0058] Generally, in one embodiment, a method of advancing a stiffening device through a body lumen includes (1) holding a handle of the stiffening device; (2) inserting an elongated body of the stiffening device into the body lumen while the stiffening device is in a flexible configuration; (3) when the stiffening device reaches a desired location in the body lumen, moving the operating element in a first direction to move fluid from a fluid chamber in the handle to a wall of the stiffening element and transition the stiffening device to the stiffening configuration; and (4) moving the operating element in a second direction to again move fluid from the wall of the stiffening element to the handle and transition the stiffening device to the flexible configuration.

[0059] In general, in one embodiment, the nesting system includes a first curing device and a second curing device radially disposed within the first curing device, the second curing device being axially slidable relative to the first curing device, the first and second curing devices configured to be alternately cured by vacuum or pressure.

[0060] These and other embodiments may include one or more of the following features: The pressure is greater than 1 atm. The first stiffening device may be configured to be cured by a vacuum and the second stiffening device may be configured to be cured by a pressure greater than 1 atm. Each of the first and second stiffening devices may include multiple layers. The vacuum or pressure may be configured to be applied between the multiple layers. At least one of the multiple layers may be a braided layer.

[0061] Generally, in one embodiment, a method of advancing in a body lumen includes (1) inserting a first stiffening device into the body lumen while the first stiffening device is in a flexible configuration; (2) applying a vacuum or pressure to the first stiffening device to transition the first stiffening device to a stiffening configuration that is more rigid than the flexible configuration; (3) inserting a second stiffening device in a flexible configuration into the first stiffening device while the first stiffening device is in the stiffening configuration such that the second stiffening device assumes the shape of the first stiffening device in the stiffening configuration; and (4) applying a vacuum or pressure to the second stiffening device to transition the second stiffening device from the flexible configuration to the stiffening configuration.

[0062] These and other embodiments may include one or more of the following features: Each stiffening device may include an elongated flexible tube and a braided layer. Application of vacuum or pressure may compress the braided layer to transition the stiffening device into the stiffening configuration.

[0063] Generally, in one embodiment, a method of advancing within a body lumen includes: (1) moving a first stiffening device in a flexible configuration until it reaches a desired location; (2) transitioning the first stiffening device to a stiffening configuration by applying a vacuum or pressure to the first stiffening device after the first stiffening device reaches the desired location; (3) moving a second stiffening device in a flexible configuration over the first stiffening device in the stiffening configuration after the first stiffening device has hardened; (4) transitioning the second stiffening element to the stiffening configuration by applying a vacuum or pressure to the second stiffening device; (5) transitioning the first stiffening device to the flexible configuration by removing the vacuum or pressure; and (6) moving the first stiffening device in the flexible configuration through the second elongated stiffening device until the first stiffening device reaches the desired location.

[0064] These and other embodiments may include one or more of the following features: The method may include cyclically moving both the first and second stiffening devices to a flexible configuration to increase the curvature of the first and second stiffening devices to conform to the surrounding anatomy.

[0065] Generally, in one embodiment, the stiffening rod includes an inner reservoir layer, a braided layer disposed over the inner reservoir layer, an outer sheath sealed over the inner reservoir layer and the braided layer, and an inlet between the outer sheath and the inner reservoir layer configured to be attached to a vacuum source. The stiffening rod is configured to have a stiffened configuration when vacuum is applied through the inlet and a flexible configuration when no vacuum or pressure is provided through the inlet. The stiffening rod does not have a through lumen extending therethrough.

[0066] Generally, in one embodiment, a method of advancing a stiffening device through a body lumen includes: (1) advancing the stiffening device through the body lumen; (2) inserting a rod, having an elongated flexible tube, a braided layer, and an air reservoir, into a lumen of the stiffening device while the rod is in a flexible configuration; (3) when the rod reaches a desired location in the lumen of the stiffening device, delivering a pressure greater than 1 atm to a central sealed lumen of the rod to press the braided layer against the elongated flexible tube and transition the stiffening device to a stiffened configuration that is more rigid than the flexible configuration; and (4) advancing the stiffening device further over the rod while the rod is in the stiffened configuration.

[0067] Generally, in one embodiment, a method of performing a cholangioscopy includes (1) inserting an overtube into the colon while the overtube is in a flexible configuration, the overtube including an elongated flexible tube, a braided layer having a plurality of strands braided together, and an outer layer; (2) steering a distal end of the overtube toward the papilla; (3) manipulating a vacuum or pressure between the flexible tube and the outer layer to transition the overtube to a stiffened configuration that is more rigid than the flexible configuration; (4) advancing a guidewire through the overtube into the bile or pancreatic duct while the overtube is in the stiffened configuration; and (5) advancing a scope over the guidewire into the bile or pancreatic duct.

[0068] Generally, in one embodiment, a method of accessing a cardiac anatomy includes (1) inserting a sheath into the cardiac anatomy while the sheath is in a flexible configuration, the sheath including an elongated flexible tube, a braided layer having a plurality of strands braided together, and an outer layer; (2) steering a distal end of the sheath to a desired final location; (3) manipulating a vacuum or pressure between the flexible tube and the outer layer to transition the overtube to a stiffened configuration that is more rigid than the flexible configuration; and (4) passing a cardiac device through the stiffening sheath.

[0069] These and other embodiments may include one or more of the following features: The desired end location may be the aortic valve. The cardiac device may be a transcatheter aortic valve replacement. The desired end location may be the mitral valve. The cardiac device may be a mitral valve replacement or mitral valve repair element.

[0070] Any of the devices described herein may include one or more of the following: The stiffened device may further include a sliding layer adjacent to the braided layer. The sliding layer may have a lower coefficient of friction than the braided layer. The stiffened device in the stiffened configuration may be at least two times stiffer than the stiffened device in the flexible configuration. The stiffened device in the stiffened configuration may be at least five times stiffer than the stiffened device in the flexible configuration. The braided layer may have a plurality of strands braided together at a braid angle of 5 to 40 degrees relative to a longitudinal axis of the elongated flexible tube when the elongated flexible tube is straight. The braid angle may be between 10 and 35 degrees. The elongated flexible tube may include a reinforcing element extending therethrough. The reinforcing element may include a coil or a plurality of hoop elements. The braided layer may include a plurality of strands braided together at a picks per inch of 4 to 60. The braided layer may include a plurality of strands braided together. The strands may include polyethylene terephthalate or stainless steel. The braided layer may provide 30-70% coverage for the elongated flexible tube. The braided layer may include 96 or more strands braided together. The inlet may be configured to be attached to a pressure source. The stiffening device may further include a reservoir layer therein. The reservoir layer may be configured to be pressed against the braided layer when pressure is provided from the inlet. The outer layer may further include a plurality of reinforcing elements therein. The inlet may be configured to be attached to a vacuum source. The outer layer may be a thin flexible sheath. The stiffening device may further include a radial gap between the braided layer and the outer layer. The gap may have a thickness of 0.00002" to 0.04". The stiffening device may further include a steerable distal end. The stiffening device may further include a sealed channel between the elongated flexible tube and the outer layer. The sealed channel may include a working channel, a cable guide, or an inflation lumen.

[0071] Any of the methods described herein may include one or more of the following. The method may further include releasing the vacuum or pressure after manipulating the vacuum or pressure to transition the stiffening device back to the flexible configuration. The method may be performed in the gastrointestinal tract. The method may be performed in the heart. The method may be performed in the kidney. The method may be performed in the lung. The method may be performed in the brain. [Brief description of the drawings]

[0072] The novel features of the invention are set forth with particularity in the following 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: [Figure 1] 1 shows a curing device. [Figure 2A] ~ [Figure 2B] 1 shows a portion of the braided layer of a cured device. [Diagram 3] 1 is a graph of bending force versus braid angle when the cured device is placed under vacuum. [Figure 4A] ~ [Figure 4D] 1 illustrates an exemplary braid configuration. [Figure 5A] ~ [Figure 5B] 1 illustrates an exemplary braid configuration. [Figure 6A] ~ [Figure 6D] Various designs for the termination of the braided layer of the stiffening device. [Figure 7] 1 shows the inner layer of the cured device. [Figure 8A] ~ [Figure 8F] 1 illustrates various coil designs for layers of the cured device. [Figure 9A] ~ [Figure 9B] 1 shows a corrugated reinforcing element for a layer of a stiffening device. [Figure 10A] ~ [Figure 10E] 1 shows notch and pocket reinforcement elements for layers of the stiffening device. [Figure 11A] ~ [Figure 11B] 1 shows cut tubing reinforcement elements for layers of the stiffening device. [Figure 12A] ~ [Figure 12B] 1 illustrates an exemplary curing configuration of a curing device. [Figure 13A] ~ [Figure 13D] 1 illustrates an exemplary vacuum curing device. [Figure 14A] ~ [Figure 14B] 1 illustrates an exemplary pressure curing device. [Figure 15] 1 is a graph of flexural strength versus pressure for a cured device. [Figure 16A] ~ [Figure 16O] 1 shows various examples of pressure curing devices. [Figure 17A] ~ [Figure 17D] 1 shows a stiffening device incorporating a working channel. [Figure 18A] ~ [Figure 18B] 1 shows a curing device with a spiral working channel. [Figure 19A] ~ [Figure 19B] 1 shows a curing device with multiple spiral working channels. [Figure 20A] ~ [Figure 20B] 1 illustrates a curing device with multiple working channels extending into a central lumen. [Figure 21] 13 shows a curing device with a working channel that extends to the side. [Figure 22] 1 illustrates a tool that may be used with a working channel of a device such as a curing device. [Figure 23] 1 shows a stiffening device with a distal end section. [Figure 24] 13 illustrates a stiffening device with a distal end section having a different braid pattern than the proximal section of the stiffening device. [Diagram 25] 1 illustrates a stiffening device with a distal end section having multiple passive linkages. [Figure 26] 1 illustrates a stiffening device with a distal end section having multiple active control linkages. [Figure 27A] ~ [Figure 27E] 1 shows multiple active control linkages. [Figure 28] 1 illustrates an embodiment of a stiffening device that includes a cable extending into a laminated wall. [Figure 29] 1 illustrates an embodiment of a stiffening device that includes a cable extending into a laminated wall. [Diagram 30] 1 illustrates an embodiment of a stiffening device that includes a cable extending into a laminated wall. [Diagram 31] 1 illustrates an embodiment of a stiffening device that includes a cable extending into a laminated wall. [Diagram 32] 1 illustrates an embodiment of a stiffening device that includes a cable extending into a laminated wall. [Diagram 33] 1 illustrates an embodiment of a stiffening device that includes a cable extending into a laminated wall. [Diagram 34] 1 illustrates an embodiment of a stiffening device that includes a cable extending into a laminated wall. [Diagram 35] 1 shows a stiffening device including a cable extending through a central lumen. [Diagram 36] 1 illustrates an embodiment of a curing device including a helically wound cable. [Figure 37] 1 illustrates an embodiment of a curing device comprising a helically wound cable. [Figure 38A] ~ [Figure 38B] 1 illustrates an embodiment of a curing device comprising a helically wound cable. [Figure 39A] ~ [Figure 39B] 1 shows a curing device with a helically wound cable. [Figure 40A] ~ [Figure 40D] 1 illustrates an exemplary linkage for the distal end section. [Figure 41A] ~ [Figure 41B] 1 illustrates a stiffening device with a distal end section having a linkage over the stiffening section. [Figure 42A] 1 illustrates a stiffening device with a distal end section having a linkage within the stiffening section. [Figure 42B] 13 shows a stiffening device with steering cables attached to the wall near the distal end. [Figure 43A] ~ [Figure 43C] 1 shows a stiffening device having an actively bending distal end section. [Figure 44A] ~ [Figure 44C] 1 shows a curing device with separate curing chambers along its length. [Figure 45A] ~ [Figure 45D] 1 shows a stiffening device with a balloon and an inflation lumen. [Figure 46A] ~ [Figure 46B] 1 illustrates an embodiment of a suction tip for a device such as a sclerosing device. [Figure 47A] ~ [Figure 47B] 1 illustrates an embodiment of a suction tip for a device such as a sclerosing device. [Figure 48A] ~ [Figure 48B] 1 illustrates an embodiment of a suction tip for a device such as a sclerosing device. [Figure 49A] ~ [Figure 49D] 1 illustrates an embodiment of a handle for use with a curing device. [Figure 50A] ~ [Figure 50B] 13 shows an embodiment of a manipulation element for a handle of a curing device. [Figure 51A] ~ [Figure 51C] 13 shows an embodiment of a manipulation element for a handle of a curing device. [Figure 52A] ~ [Figure 52C] 13 shows an embodiment of an operating element with a coupling for a handle of a curing device. [Figure 53A] ~ [Fig. 53D] 1 illustrates an embodiment of a handle for use with a curing device. [Figure 54A] ~ [Figure 54B] 1 illustrates an embodiment of a handle for use with a curing device. [Figure 55A] ~ [Figure 55C] 13 shows an embodiment of a manipulation element for a handle of a curing device. [Figure 56A] ~ [Figure 56G] 1 illustrates an embodiment of a handle for use with a vacuum curing device. [Figure 57A] ~ [Figure 57C] 1 illustrates an embodiment of a handle for use with a pressure curing device. [Figure 58A] ~ [Figure 58E] 1 shows a preloading handle for use with a pressure curing device. [Figure 59] 1 shows a curing device with a side-mounted imaging element. [Figure 60] 1 shows a sclerosing introducer needle. [Figure 61A] ~ [Figure 61B] 1 shows a curing device with side access. [Figure 62] 1 shows a nested curing system. [Figure 63] 1 shows a nested curing system with a cover between inner and outer curing devices. [Fig. 64A] ~ [Figure 64B] 1 illustrates a nested curing system where the outer curing device includes steering and imaging. [Figure 65A] ~ [Fig. 65H] 1 illustrates an exemplary use of a nested curing system. [Figure 66] 1 shows a cured rod. [Figure 67] 1 shows a stiffening rod in use with a colonoscope. [Figure 68A] ~ [Figure 68B] 1 illustrates an exemplary curing device with a scope. [Figure 69A] ~ [Figure 69B] 1 illustrates the use of a sclerosing device in the gastrointestinal tract. [Figure 70A] ~ [Figure 70B] We demonstrate how to use a hardening device for ERCP. [Figure 71A] ~ [Figure 71B] We demonstrate how to use a hardening device for ERCP. [Figure 72A] ~ [Fig. 72D] We demonstrate how to use a hardening device for ERCP. [Figure 73A] ~ [Figure 73B] 1 illustrates the use of a stiffening device in the heart to access the left atrium. [Fig. 74A] ~ [Fig. 74B] 1 illustrates the use of a cardiac stiffening device to perform a branched vessel procedure. [Fig. 75A] ~ [Fig. 75C] 1 illustrates the use of a stiffening device in a heart for mitral valve repair. [Figure 76A] ~ [Figure 76B] 1 illustrates the use of a dual-cure device in the heart. [Figure 77] 1 shows a stiffening device used as a trocar. [Figure 78] 1 shows the stiffened device in use at the aortic bifurcation. [Figure 79] 1 shows a stiffening device for mitral valve repair. [Figure 80] 1 shows a stiffening device with a distal payload for mitral valve repair. [Figure 81A] ~ [Fig. 81F]1 illustrates the use of a hardening device to control a working tool. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0073] Generally described herein is a stiffening device (e.g., an overtube) configured to aid in the transport of a scope (e.g., an endoscope) or other medical device through a curved or looped portion of the body (e.g., a blood vessel). The stiffening device is long, thin, hollow, and can be rapidly transitioned from a flexible configuration (i.e., flaccid, pliable, or soft) to a stiffened configuration (i.e., rigid and / or retains the shape it assumes upon stiffening). Multiple layers (e.g., a coiled or reinforcing layer, a sliding layer, a braided layer, an air reservoir layer, and / or a sealing sheath) can together form the walls of the stiffening device. The stiffening device can transition from the flexible configuration to the stiffened configuration, for example, by applying a vacuum or pressure to or within the walls of the stiffening device. When the vacuum or pressure is removed, the layers can easily twist or move relative to one another. When the vacuum or pressure is applied, stiffening of the system occurs by transitioning the layers to a state that has a substantially increased ability to resist twisting, moving, bending, or buckling.

[0074] The stiffening devices described herein may provide stiffening for a variety of medical applications, including catheters, sheaths, scopes (e.g., endoscopes), wires, or laparoscopic instruments. The stiffening devices may function as separate add-on devices and may be incorporated into the body of a catheter, sheath, scope, wire, or laparoscopic instrument. The devices described herein may also provide stiffening for non-medical structures.

[0075] 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 braided layer, an outer layer (partially cut away to show the braid underneath), and an inner layer. The system further includes a handle 342 having a vacuum or pressure inlet 344 that provides vacuum or pressure to the stiffening device 300. A manipulation element 346 can be used to turn the vacuum or pressure on and off to transition the stiffening device 300 between the flexible and stiffened configurations. A distal tip 339 of the stiffening device 300 can be smooth, flexible, and atraumatic to facilitate distal movement of the stiffening device 300 within the body. Additionally, the tip 339 is tapered from the distal end to the proximal end to further facilitate distal movement of the stiffening device 300 within the body.

[0076] A portion of an exemplary braided layer 209 for a cured device similar to device 300 is shown in Figures 2A-2B. Braided layer 209 can include braided strands 233. Braided layer 209 can be, for example, a tubular braid.

[0077] The braid angle α of the strands 233 relative to the longitudinal axis 235 of the stiffened device (e.g., device 300) when the stiffened device is in a straight (non-flexed) configuration can be less than 45 degrees, less than 35 degrees, less than 25 degrees, or less than 45 degrees. With reference to FIG. 3, as the braid angle α (when the stiffened device is in a straight or non-flexed configuration) increases, the flexural strength of the stiffened device decreases. That is, the flexural strength under vacuum of a stiffened device with a 45 degree braid angle (the minimum angle typical for torque or twist braids). A larger angle, typically used for catheter shaft reinforcement under vacuum, is 27% of the flexural strength under vacuum of a stiffened device with a 25 degree braid angle. Thus, having a lower braid angle (e.g., less than 40 degrees, less than 35 degrees, or less than 45 degrees) is advantageous because it ensures that the stiffened device (e.g., device 300) remains rigid (resists configurational changes) when flexed under vacuum (and similarly under pressure). Additionally, the braid angle α when the stiffened device is in a straight (unbent) configuration is greater than 5 degrees, such as greater than 8 degrees, greater than 10 degrees, 15 degrees or more. Having a braid angle α within this range ensures that the braid remains flexible enough to bend when in a flexible configuration (i.e., not cured under vacuum or pressure). Thus, the braid angle α of the strands 233 relative to the longitudinal axis 235 of the stiffened device when the stiffened device is in a straight configuration can be 5 to 40 degrees, such as 10 to 35 degrees, 15 to 25 degrees, approximately 5, 10, 15, 20, 25, 30, 35, 40 degrees. A braid angle α of the strands 233 relative to the longitudinal axis 235 of the stiffened device when the stiffened device is in a straight (unbent) configuration of 5 to 40 degrees ensures that the stiffened device is flexible enough to bend when in a stiffened configuration (i.e., when placed under vacuum or pressure) while still in a rigid flexible configuration (e.g., not in a vacuum / pressure state). Additionally, it should be appreciated that the yarns 233 are configured to slide over one another, thus changing the braid angle α to cause the stiffening device to flex or bend. Having an angle α that is between 5 and 40 degrees is advantageous as it also ensures that the yarns 233 can move freely relative to one another without the fibers colliding with one another and preventing further angle change.

[0078] Additionally, the braid for braided layer 209 can be between 4 and 60 picks per inch, such as 8, 10, 12, 14, 16, 18, 20, or 25 picks per inch. In one embodiment, the tube formed by layer 209 has a diameter of 0.578" and the braid is between 12 and 14 picks per inch.

[0079] In some embodiments, braided layer 209 (or any braided layer described herein) may be configured such that the stiffened devices described herein have a high stiffness ratio (i.e., the ratio of stiffness in a stiffened configuration, such as when a vacuum or pressure is applied, to stiffness in a flexible configuration, such as when no vacuum or pressure is applied). For example, the stiffness ratio is greater than 5, such as greater than 6, greater than 9, greater than 9, greater than 10, etc. Referring to Table 1 below, six vacuum-cured devices (Samples A-F) were constructed and tested for cantilever bending stiffness at atmospheric pressure (flexible configuration) and vacuum (cured configuration) at 4" length and ½" deflection. As shown, as the braid angle decreases, the stiffness of the stiffened device increases. Samples E and F in particular show the stiffness difference between a braid at a typical torque angle (Sample E, 47.7 degrees and 0.529 lbf stiffness at curing) and a low angle braid (Sample F, 27.2 degrees and 1.455 lbf stiffness at curing). As also shown in Table 1, stiffening devices with low angles (e.g., angles less than 45 degrees or 35 degrees, such as Samples A-D and F) can have much higher stiffness ratios (e.g., ratios greater than 5, greater than 6, greater than 9, or greater than 10) than stiffening devices with high angles (e.g., angles greater than 45 degrees, such as Sample F), which have stiffness ratios less than 5. It can also be seen from Table 1 that both Samples A and B have stiffness ratios greater than 5. Sample B, with a braid angle of 14.9 degrees, has a lower stiffness ratio than Sample A because the twisted yarns in Sample B have an orientation closer to the longitudinal axis, but the absolute stiffness is higher (hence Sample B has a higher stiffness in the flexible configuration).

[0080] [Table 1]

[0081] Referring to Table 2 below, three pressure stiffening devices (samples G-I) were constructed and tested for cantilever bending stiffness at atmospheric pressure (flexible configuration) and at 4 atm pressure (stiffened configuration) at 4" length and 1 / 2" deflection. All samples included 35-45% coverage and a braid with 96 strands and 1 monofilament per strand. As shown, decreasing the braid angle increases stiffness of the stiffening device. As also shown in Table 2, low angle stiffening devices can have a higher stiffness ratio than high angle stiffening devices. In some embodiments, the pressure stiffening devices described herein have a stiffness ratio greater than 10, such as greater than 15, greater than 20, etc.

[0082] [Table 2]

[0083] Further, in some embodiments, the braid of braided layer 209 has a coverage area of ​​30% to 70%, such as 40% to 60%, e.g., 30%, 40%, 50%, 60%, or 70%, where the coverage area is the percentage of the underlying surface that is covered or shielded by the braid.

[0084] In some embodiments, the braided layer 209 may be formed by helically winding each individual strand around an inner tube or stiffening device and / or separate mandrel such that the strands 233 are intertwined with one another. In one embodiment, the braided layer 209 may be heat formed on a 0.50"-0.60", e.g., 0.56", mandrel. Additionally, in some embodiments, the braided layer may be attached to a tube or mandrel during manufacture such that the braided layer has a diameter smaller than the core diameter (i.e., smaller than the diameter the braid was originally manufactured with). Radially compressing the braid in this manner may reduce the braid angle (as well as reduce the PPI, increase the overall length of the tubular braided layer, and increase the braid coverage percentage) to an extent that provides a high stiffening factor.

[0085] Yarns 233 may be rectangular / flat (e.g., long sides between 0.001" and 0.060", such as 0.005", 0.007", 0.010", 0.012", and short sides between 0.0003" and 0.030", such as 0.001", 0.002", 0.003"), round (e.g., diameter between 0.001" and 0.020", such as 0.005", 0.01", 0.012"), or elliptical. In some embodiments, some of yarns 233 may be flat and some of yarns 233 may be round.

[0086] In some embodiments, the threads 233 may be made of metal filaments (e.g., stainless steel, aluminum, nitinol, tungsten, titanium), plastics (e.g., aramid, ultra-high molecular weight UHMW polyethylene, or liquid crystal polymers such as Vectran). In some embodiments, the threads 233 may be made of multi-layer composites, such as a metal core with a thin elastomeric coating. In one particular example, the threads 233 may include 0.010" diameter round nylon (or 0.003" diameter metal filaments) woven with aluminum-coated PET having cross-sectional dimensions of 0.002" x 0.002". In some embodiments, the material of the braided threads 233 may be any known high coefficient of friction material. For example, the threads 233 may be of unitary construction or may have a coating such that the threads include aluminum on aluminum, copper on copper, silver on silver, or gold on gold. As another example, the threads 233 may be coated with an elastomeric material (e.g., a low durometer elastomer may be coated over a high modulus substrate.) As another example, the threads 233 may be made of a styrene copolymer, polycarbonate, or acrylic.

[0087] There may be between 12 and 800 strands 233, such as 24, 48, 96, 120, 144 or more strands 233 extending within the braided layer 209. In some embodiments, there may be 96 or more strands, 120 or more strands, 200 or more strands, or 240 or more strands. A large number of strands is advantageous because it helps stiffen the braid due to increased interaction between the strands.

[0088] 4A-4D, the braid of any of the cured devices described herein may be in a variety of different braid patterns. For example, with reference to FIG. 4A, the braid of layer 1709 may be a diamond full load pattern with two adjacent strands 1733a,b extending over two strands and then under two strands. With reference to FIG. 4B, the braid of layer 1709 may be a full load pattern with each strand 1733a extending over two strands and then under two strands in opposition to the adjacent strand 1733b. With reference to FIG. 4C, the braid of layer 1709 may be a diamond half load pattern with each strand 1733a extending over one strand and under one strand in opposition to the adjacent strand 1733b. With reference to FIG. 4D, the braid of layer 1709 may include one or more longitudinal strands 1733c extending within the crossed strands 1733a,b.

[0089] 5A-5B, each yarn 1833 may include one monofilament 1818 (FIG. 5A) or multiple monofilaments 1818a-c (FIG. 5B shows three monofilaments 1818a-c in each yarn 1833). The monofilaments 1818 may be selected (i.e., diameter, spacing, and modulus may be specifically tailored) to reduce crimp (single filament undulation or bending). Reducing crimp helps the system to have increased compression buckling resistance, which translates to increased system stiffness.

[0090] Specific braided layer embodiment examples JN are shown in Table 3.

[0091] [Table 3]

[0092] In use, a vacuum or pressure is applied between the walls of the stiffening devices described herein to cause the braided layer and adjacent layers to contract and / or separate, transitioning between the flexible and stiffened configurations. Thus, the stiffening devices described herein are advantageously capable of transitioning from highly flexible to highly stiff upon manipulation by a user. When vacuum or pressure is applied, the braids or strands may contract or expand radially and become mechanically fixed or locked in place relative to one another. As a result, when vacuum or pressure is applied, the stiffening device transitions from a flexible configuration to a stiffened configuration (thereby fixing the stiffening device in the shape it was in immediately prior to application of the vacuum or pressure).

[0093] 6A-6D, in some embodiments, one or both ends of the braided layer 5609 of a stiffening device 5600 described herein can be bonded to another layer of the device 5600 to prevent fraying of the braided yarns 5633. Additionally, the ends of the yarns 5633 are bonded to allow for relative movement of the yarns 5633 during flexion of the stiffening device 5600 when in a flexible configuration (i.e., to prevent stiffening or buckling of the device 5600, which could result in traction at the tip 5629, as may occur if the yarns 5633 were restrained).

[0094] For example, as shown in FIG. 6A, the tip 5629 of the braided layer 5609 may include a coating 5634 of a low durometer material, such as silicone or urethane, that is stretchable and / or flexible. As a result, the ends of the strands 5633 are encapsulated in the coating 5634 (and thus prevented from fraying), yet move with the coating 5634 as they stretch and / or flex. The coating 5634 is thin, such as between 0.005-0.250 in thickness (e.g., approximately 1 / 32″ thick).

[0095] As another example, as shown in FIG. 6B, the distal end 5629 of the braided layer 5609 may include an annular ring 5601z therearound. In some embodiments, the ring 5601z may be formed by melting the distal end of the strand 5633. In other embodiments, the ring 5601z may be a separate element that is bonded to the strand 5633 (e.g., bonded to less than 20%, less than 10%, or less than 5% of the strand 5633). In some embodiments, the two bond locations are approximately 180 degrees apart from each other. The ring 5601z is advantageous because it ensures that the strands 5633 can move substantially relative to each other under the ring 5601z without fraying. The ring 5601z may be made of, for example, rubber, Kapton, PTFE, silicone, urethane, latex, or ePTFE.

[0096] As another example, as shown in FIG. 6C, the tip 5629 of the braided layer 5609 has a varying pick count along the tip 5629, with a higher pick count at the tip and a lower pick count toward the center. As a result, the strands 5633 may have a larger angle with respect to the longitudinal axis at the tip 5629 than in other portions of the layer 5609. For example, the strands 5633 at a central portion of the device 5600 may have an angle of 45 degrees or less with respect to the longitudinal axis of the device 5600 (e.g., 40 degrees or less, 35 degrees or less, 25 degrees or less, 20 degrees or less), while the strands 5633 at the tip 5629 may have an angle of more than 45 degrees with respect to the longitudinal axis (e.g., 35 degrees, 45 degrees, or 55 degrees), such as between 45 degrees and 60 degrees. The change in braid angle may be a continuous change at the tip 5629 and / or may occur by joining two separate braids together. The larger angle yarns 5633 are bonded to the innermost layer at the tip 5629. Providing a larger angle braid at the tip 5629 allows the tip 5629 to remain flexible when curved or bent even when the yarns 5633 are secured to the inner layer 5615. In some embodiments, the increased braid angle at the tip 5629 is achieved by varying the rate at which the inner core of the tubular braid is pulled during manufacture.

[0097] 6D , tip 5629 of braided layer 5609 can be everted and bonded to innermost layer 5615 (and / or other layers radially inward of braided layer 5609). Tip 5629 can be more flexible than a non-everted tip 5629 because it includes extra (inverted) length that allows movement of strands 5633.

[0098] In some embodiments, the proximal and distal ends of the braided layer 5609 may undergo different treatments (e.g., the distal end may undergo a first treatment as described in Figures 6A-6D, while the proximal end may undergo a second treatment as described in Figures 6A-6D).

[0099] In some embodiments, the cured devices described herein (e.g., cured device 300) may include one or more sliding layers adjacent to the braided layer (e.g., braided layer 209). The sliding layer may be configured to reduce friction between the braid and adjacent layers to allow adjacent layers (especially braided layers) to easily twist or move relative to one another to maximize flexibility in the flexible configuration, especially when no vacuum or pressure is applied to the cured device. The sliding layer is advantageous because it increases the basic flexibility of the cured device to allow the layers to move relative to one another. In one embodiment, the sliding layer may include a powder such as talc or cornstarch. In particular, a powder sliding layer is advantageous because it increases the flexibility of the cured device in the cured configuration by reducing friction without adding significant thickness to the device. The sliding layer may be fabricated from a material with a low coefficient of friction, such as a thin fluoropolymer (FEP, Chemifilm, PTFE, 2-50 microns thick). In one embodiment, the sliding layer may be a coating. In one embodiment, the sliding layer may be a lubricant added to an elastomer. In one embodiment, the sliding layer can be a sheath of a thin plastic film with inherent lubricity, such as low density polyethylene (LDPE). In one embodiment, the sliding layer can be made of a thin spiral wound film, such as .0005" FEP or .00025" Chemfilm (St. Gobain). In one embodiment, the sliding layer can be made of grease, oil, or other liquid.

[0100] The curing devices described herein may include an innermost layer configured to provide an inner surface to which additional layers (e.g., braided layers) may be integrated, for example, when a vacuum or pressure is applied within the walls of the curing device. This layer may further provide a seal (i.e., leak-proof) to the walls and may be strong enough to resist radial collapse during flexing of the curing device and / or compression of the curing device during curing. With reference to FIG. 7, in some embodiments, the innermost layer 8815 may include a reinforcing element 8850z or coil within a substrate 8851z. The reinforcing element 8850z may be a continuous helical coil or closed ring with gaps therebetween (exhibiting a higher resistance to crushing than a helical coil). Additionally, the inner layer 8801 may include an inner membrane 8852z and an outer membrane 8853z on one or both sides thereof. In some embodiments, each of the elements 8853z, 8852z, 8850z / 8851z may have a thickness of 0.0002″-0.015″.

[0101] The reinforcing element 8850z can be, for example, a metal wire, such as a metal wire made of stainless steel, nitinol, or tungsten. The reinforcing element 8850z can be, for example, a high strength fiber (e.g., Kevlar, Dyneema, Vectran, Technora, or carbon fiber). The reinforcing element 8850z can be, for example, a stent, a structure cut from a tube, or a braid. In some embodiments, the reinforcing element 8850z can be a round wire (e.g., a diameter of 0.0005" to 0.030", such as a diameter of 0.001", 0.003", 0.005", 0.007", 0.009"). In some embodiments, the reinforcing element 8850z can be a rectangular wire (e.g., having a width of 0.001" to 0.100" inches, e.g., 0.010", 0.020", 0.030", 0.040", 0.050", 0.060", 0.070", 0.080", 0.090", 0.100", and / or the rectangular wire can have a thickness of 0.0003" to 0.020", e.g., 0.001", 0.003", 0.005", 0.007", 0.010"). In other embodiments, the reinforcing element 8850z may have an elliptical cross-section, and / or may have multiple individual strands, and / or may have a rectangular cross-section with four rounded sharp corners. In some embodiments, the reinforcing element 8850z may be cut from a single tube, for example using a laser to create a gap. In some embodiments, no reinforcing element is used.

[0102] In some embodiments, the reinforcing elements 8850z can be high aspect ratio elements (e.g., having a high RE width relative to the RE height, such as an aspect ratio of more than 5:1, more than 10:1, more than 11:1, approximately 12:1, etc.). Note that in FIG. 7, the RE width is the width of the reinforcing elements 8850z, the RE height is the height or thickness of the reinforcing elements 8850z, and the RE gap is the distance between the reinforcing elements 8850z. A high ratio of the width to the height of the reinforcing elements 8850z is advantageous because it helps prevent external pressure from causing a parallelogram-type collapse of the reinforcing elements 8850z in the innermost layer 8815. A parallelogram-type collapse occurs when the helix of the coil moves from approximately perpendicular to the central axis of the coil to parallel to the central axis of the coil (the helix essentially "flips"). Further, the RE gap between the reinforcing elements 8850z is advantageous to prevent parallelogramming if it is less than or equal to 3 times the RE height, such as less than or equal to 2 times the RE height, less than or equal to 1.5 times the RE height, etc. Additionally, a ratio of the inner diameter of the hollow tube with the innermost layer 8815 to the width of the reinforcing elements 8850z at the innermost layer 8815 less than 4.5, such as about 4.3, less than 5 also helps to prevent parallelogram type collapse.

[0103] The substrate 8851z is of very low durometer, such as TPU or TPE, with a durometer of 60A, 50A, 40A, 30A, 20A, 10A or less. In some embodiments, the substrate 8851z can be TPU, TPE, PET, PEEK, Mylar, urethane, or silicone. The inner and outer membranes 8852z, 8853z can similarly include TPU, TPE, PET, PEEK, Mylar, urethane, silicone. In some embodiments, the inner and outer membranes 8852z, 8853z can be formed by spraying, dipping, wrapping as a sheet or tube, drawing in a solvent bath, melting, and / or consolidation. In some embodiments, the layer 8815 can be free of inner and / or outer membranes 8852z, 8853z and / or can include additional membranes. The inner and / or outer membranes 8852z, 8853z may provide smooth inner and outer surfaces.

[0104] In a specific example of an innermost layer 8815 for a pressure system, the layer is fabricated as a hollow tube with an inside diameter of 0.260" with an RE width of 0.050", an RE height of 0.008", and an RE gap of 0.010". The membranes 8853z are omitted on both sides. All of the membranes 8852z (on either side of the substrate 8851z and reinforcement elements 8850z) are fabricated from urethane (100% strain from 600 psi). The thickness of both the substrate 8851z and each membrane 8852z is approximately 0.006", resulting in a total wall thickness of 0.018". This structure is capable of resisting collapse at external pressures in excess of 10 atm.

[0105] In a second specific example of the innermost layer 8815 for a pressure system, the membrane 8853z is omitted on both sides. The RE width is 0.050", the RE height is 0.008", and the RE gap is 0.010". The membrane 8852z is a high durometer elastomer, for example, with a stress of 2000 psi @ 100% strain and a thickness of about 0.001" thick. The substrate 8851z can be a 50A urethane. The substrate 8851z can be applied as a thermoplastic elastomer braid stock, for example, with a rectangular cross section of .008" or a circular cross section of .010". The braid stock can be applied with a high axial modulus (but not a high transverse modulus) by co-extrusion of a stock with a wire (e.g., .001" diameter) or fiber core.

[0106] In a third specific example of an innermost layer 8815 for a pressure system, the reinforcing elements 8850z can be wires with high aspect ratios. For example, layer 8815 can be a square stainless steel wire with an RE height of 0.005", an RE width of 0.060" and an RE gap of 0.006". The inner diameter of the tube formed with the innermost layer 8815 is 0.26". Elements 8852z and 8851z can be 80A urethane with a thickness of approximately 0.002". Additionally, layer 8851z can be 50A urethane (e.g., deposited from a heated tank with molten urethane and an orifice for precise dispensing via pressure). This exemplary innermost layer 8815 structure can resist collapse at external pressures of greater than 10 atm, such as pressures of greater than 12 atm, greater than 13 atm, etc.

[0107] In a specific example of an innermost layer 8815 for a vacuum system, the outer membrane 8853z on one side (e.g., outside or top) is omitted, the membrane 8852z above (outside) the reinforcement / substrate comprises 0.005" 50A urethane, the substrate 8851z is made of 0.005" thick 50A urethane, the reinforcement elements 8850z are stainless steel wire, the membrane 8852z below (inside) the reinforcement / substrate is 0.0025" thick 50A urethane, and the bottom outer membrane 8853z is 0.004" thick 80A urethane. The RE width is 0.020", the RE height is 0.005", and the RE gap is 0.010". The bottom outer membrane 8853z has a hydrophilic coating. The inside diameter of the tube formed by layer 8815 is 0.551".

[0108] 7 as symmetrical, it should be understood that the innermost layer 8815 need not have a symmetrical arrangement of membranes 8852z, 8853z. For example, neither layer could be at the bottom (inside the substrate / reinforcement) and both layers could be on the top. Additionally, it should be understood that the material of both innermost membranes 8852z need not be the same, and the material of both outermost membranes 8853z need not be the same.

[0109] The reinforcing elements of the innermost layer can be in various configurations. As shown in Figures 8D-8F, the reinforcing elements 9205z can be multi-start coil windings (e.g., two starts as shown in Figure 8F, three starts as shown in Figure 8E, or four starts as shown in Figure 8D). When multi-start coil windings are used, the spacing between the reinforcing elements on the longitudinal axis can be the same as with a single coil, but the number of starts can be 2, 3, 4, 5, 6, 7, 8, 9, or more. A single start results in a wire angle that is nearly perpendicular (e.g., 2 degrees away from perpendicular), whereas a multi-start approach results in a wire angle that biases the coil to tilt in one direction further away from perpendicular (e.g., 4, 6, 10, 15, or 20 degrees). This larger angle is less likely to tilt the innermost layer and structurally collapse under pressure, since coils with larger pitches tend to support each other for stability. Figures 8A-8C show individual start points (coils) of the multi-start reinforcing element 9205z, with Figure 8C showing one coil from Figure 8F, Figure 8B showing one coil from Figure 8E, and Figure 8A showing one coil from Figure 8D.

[0110] In some embodiments, referring to Figures 9A-9B, the reinforcing element 8950z can be a series of wavy or corrugated wires (or wavy wires that are coiled as described herein). As shown in Figure 9B, when the device is loaded, the corrugated reinforcing element 8950z moves to impinge on itself to compress the substrate 8851z between the wires and resist a parallelogram type crush. In one particular embodiment, an innermost layer including such wavy wires can have an RE height of 0.005", an RE width of 0.060", and an RE gap of just 0.006". The wavy waves can vary from the centerline by + / - 0.03" (i.e., have a wave amplitude of 0.060"). The waves can repeat every 0.3" (i.e., have a wavelength of 0.3").

[0111] 10A-10C, in some embodiments, the reinforcing element 9050z can include alternating pocket wires 9052z and notch wires 9053. Upon ejection, the pockets and notches of each element are spaced apart (as shown in FIG. 10D). Upon loading, however, the notches of the wires 9053z move (as shown in FIG. 10E) and collide with the pockets of the wires 9052z, compressing the substrate 8851z between the wires to resist a parallelogram-type crush.

[0112] In some embodiments, referring to Figures 11A-11B, the reinforcing element 9150z can be of a bent design, for example cut from a laser tube.

[0113] In some instances, the reinforcing element is separate from the inner layer. For example, the reinforcing element may be disposed radially inward or outward of the inner layer. The innermost layer may have a hardness of, for example, 30A to 80A. Additionally, the innermost layer may have a wall thickness between 0.0005" and 0.060". In some embodiments, the innermost layer may include a lubricant or coating (e.g., a hydrophilic coating) on ​​its inner surface to enhance sliding of the endoscope or other instrument. The coating may be hydrophilic (e.g., a Hydromer® coating or a Surmodics® coating) or hydrophobic (e.g., a fluoropolymer). The coating may be applied, for example, by dipping, painting, or spraying the coating. The innermost layer may be a low coefficient of friction laminate.

[0114] An exemplary stiffening device in a stiffened configuration is shown in Figures 12A and 12B. As the stiffening device stiffens, it does so in the shape it had before the vacuum or pressure was applied, i.e., it does not straighten, bend, or otherwise substantially change its shape (e.g., it sets in a looped configuration as shown in Figure 12A, or in a serpentine shape as shown in Figure 12B). This is because the stiffening device resists straightening due to the air stiffening action on the inner or outer layers (e.g., by coiled tubing) being a small percentage (e.g., 5%) of the stiffening device's maximum load capacity when bent. Upon release of the vacuum or pressure, the braids or strands disengage from one another and move again to allow bending of the stiffening device. Again, as the stiffening device becomes more flexible through the release of the vacuum or pressure, it becomes flexible in the shape it had before the vacuum or pressure was released, i.e., it does not straighten, bend, or otherwise substantially change its shape. Thus, the stiffening devices described herein can be transitioned from a flexible, non-rigid configuration to a highly rigid, stiffened configuration by constraining the movement of the strands of the braid (eg, by applying a vacuum or pressure).

[0115] The stiffening devices described herein rapidly switch between stiffening and flexible configurations, with an infinite number of transition cycles in some embodiments. Because interventional medical devices are long and inserted deep into the human body, and because they are expected to perform more precise therapeutic procedures, the need for precision and control is high. The selective stiffening devices (e.g., overtubes) described herein can provide both the benefits of flexibility (when needed) and rigidity (when needed). Furthermore, the stiffening devices described herein can be used with traditional endoscopes, colonoscopes, robotic systems, and / or guidance systems, such as those described in International Patent Application No. PCT / US2016 / 050290, filed September 2, 2016, entitled "DEVICE FOR ENDOSCOPIC ADVANCEMENT THROUGH THE SMALL INTESTINE," which is incorporated by reference in its entirety.

[0116] The stiffening devices described herein can be provided in a number of configurations, including different lengths and diameters, and in some embodiments, the stiffening devices can include a working channel (e.g., to allow passage of common endoscopic tools within the body of the stiffening device), a balloon, a nesting element, and / or a side-loading feature.

[0117] 13A-13D, in one embodiment, a tubular stiffening device 100 includes a wall having multiple layers disposed about a lumen 120 (e.g., for placing an instrument or endoscope therein). A vacuum may be applied between the layers to stiffen the stiffening device 100.

[0118] For example, the innermost layer 115 may be configured to provide an inner surface that is integrated with the remaining layers when a vacuum is applied within the walls of the curing device 100. This structure may be configured to minimize bending forces / maximize flexibility in non-vacuum conditions. In some embodiments, the innermost layer 115 may include reinforcing elements 150z or coils within the substrate as described above.

[0119] The layer 113 above (ie, radially outward from) the innermost layer 115 may be a sliding layer.

[0120] Layer 111 can be a radial gap (i.e., space) that provides space for the braided layer above it to move in (when no vacuum is applied) and space that the braided or woven layer can move radially inward (when a vacuum is applied).

[0121] Layer 109 may be a first braided layer including braided strands 133 similar to those described elsewhere herein. The braided layer may be, for example, 0.001" to 0.040" thick. For example, the braided layer may be 0.001", 0.003", 0.005", 0.010", 0.015", 0.020", 0.025", 0.030" thick.

[0122] In some embodiments, as shown in FIG. 13B, the braid may have tensile or hoop fibers 137. The hoop fibers 137 may be helical and / or woven into the braided layer. Additionally, the hoop fibers 137 may be arranged as 2-50, e.g., 20-40, hoops per inch. The hoop fibers 137 are advantageous because they provide high radial compression stiffness (resistance to buckling or bursting), but remain flexible in the direction of the longitudinal axis of the stiffening device 100. That is, when compression is applied to the stiffening device 100, the braided layer 109 will attempt to expand in diameter upon compression. The hoop fibers 137 may resist compression by resisting this radial expansion. Thus, the hoop fibers 137 may provide a system that is flexible upon bending, yet resists both tension and compression.

[0123] Layer 107 may be another radially spaced layer similar to layer 111 .

[0124] In some embodiments, the stiffening devices described herein may have more than one braided layer. For example, the stiffening devices may include two, three, or four braided layers. With reference to FIG. 13C, layer 105 may be a second braided layer 105. The second braided layer 105 may have any of the properties described with respect to the first braided layer 109. In some embodiments, the braid of the second braided layer 105 may be the same as the braid of the first braided layer 109. In other embodiments, the braid of the second braided layer 105 may be different from the braid of the first braided layer 109. For example, the braid of the second braided layer 105 may include fewer twists and have a larger braid angle α than the braid of the first braided layer 109. A lower number of strands may help increase the flexibility of the stiffening device 100 (relative to having a second strand with an equal or higher number of strands), while a higher braid angle α may help to constrict 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 higher braid angle α than the braid of the first braided layer 109. A higher number of strands may result in a relatively stronger and smoother layer, while a higher braid angle α helps to constrict the diameter of the first braided layer 109.

[0125] Layer 103 may be another radially spaced layer similar to layer 111. Spaced layer 103 may have a thickness of 0.0002-0.04", such as approximately 0.03". A thickness within this range ensures that the strands 133 of the braided layer can slide and / or bulge relative to one another to ensure flexibility during bending of stiffened device 100.

[0126] The outermost layer 101 may be configured to move radially inward when a vacuum is applied, drawing toward and conforming to the surfaces of the braided layers 105, 109. The outermost layer 101 is soft and atraumatic and is sealed at both ends to form a vacuum sealed chamber with layer 115. The outermost layer 101 may be elastic, for example made of urethane. The hardness of the outermost layer 101 may be, for example, 30A to 80A. Additionally, the outermost layer 101 may have a thickness of 0.0001 to 0.01", such as approximately 0.001", 0.002", 0.003", 0.004". Alternatively, the outermost layer may be plastic, including, for example, LDPE, nylon, or PEEK.

[0127] In some embodiments, the outermost layer 101 may have, for example, tensile or hoop fibers 137 extending therethrough. The hoop fibers 137 may be made of, for example, aramid (e.g., Technora, Nylon, Kevlar), Vectran, Dyneema, carbon fiber, fiberglass, or plastic. Additionally, the hoop fibers 137 may be arranged at 2-50, e.g., 20-40 hoops per inch. In some embodiments, the hoop fibers 137 may be laminated within an elastomeric sheath. Hoop fibers may be advantageous because they may provide high stiffness in one direction compared to another fiber (e.g., very stiff in the hoop direction, but very flexible in the direction of the longitudinal axis of the cured device). Additionally, hoop fibers may be advantageous because they may provide low hoop stiffness until the fiber is placed under tensile load, at which point the hoop fibers may suddenly exhibit high hoop stiffness.

[0128] In some embodiments, the outermost layer 101 includes a lubricant, coating, and / or powder (e.g., talc powder) on its outer surface to enhance sliding of the cured device through the anatomical structures. The coating can be hydrophilic (e.g., a Hydromer® coating or a Surmodics® coating) or hydrophobic (e.g., a fluoropolymer). The coating can be formed, for example, by dipping, painting, or spraying the coating.

[0129] The innermost layer 115 may likewise include a lubricant, coating (e.g., a hydrophilic or hydrophobic coating) and / or powder (e.g., talc powder) on its inner surface that is configured to maximize flexibility, particularly when no vacuum is applied to the curing device 100, by allowing adjacent layers to easily twist relative to one another.

[0130] In some embodiments, the outermost layer 101 may be loose on the layer radially inward. For example, the inner diameter of layer 101 (assuming it comprises a tube) may have a radial gap of 0"-0.200" from the next layer radially inward (e.g., a braided layer). This allows the vacuum cure system to be more flexible when not under vacuum, but still maintain a high cure factor. In other embodiments, the outermost layer 101 may stretch slightly radially inward over the next layer (e.g., a braided layer). For example, the zero strain diameter of the tube that comprises layer 101 may be 0-0.200" smaller in diameter than the next layer radially inward, and then stretch over this layer. When not under vacuum, this system may be less flexible than one in which the outer layer 101 is looser; however, it may have a smoother appearance and be less likely to tear during use.

[0131] In some embodiments, the outermost layer 101 may be loose above the radially inner layer. A slight positive pressure may be applied underneath layer 101 to gently expand layer 101 and allow the stiffened device to bend more freely in a flexible configuration. In this embodiment, the outermost layer 101 is elastic and may provide stiffness by maintaining a compressive force on the braid. When positive pressure (nominally sufficient to expand the sheath away from the braid, e.g., 2 psi) is applied, the outermost layer 101 no longer contributes stiffness and may increase basic flexibility. Once stiffening is desired, the positive pressure is replaced with negative pressure (vacuum) to provide stiffness.

[0132] Vacuum is delivered within the curing device 100 from lowest to highest ambient vacuum conditions (e.g., approximately 14.7 psi). In some embodiments, a bleed valve, regulator, or pump control may be provided so that the vacuum can be lowered to some intermediate level to provide variable stiffness performance. Advantageously, vacuum pressure may be used to stiffen the cured device structure by compressing layers of the braided sleeve to adjacent layers. The braid has a natural flexibility when bent (i.e., when bent perpendicular to the longitudinal axis), and the lattice structure formed by the interlacing yarns distorts as the sleeve bends to conform to the bent shape while the braid abuts the inner layer. This results in a lattice geometry in which the corner angles of each lattice element change as the braided sleeve bends. When compressed between similar materials, such as the layers described herein, the lattice elements are locked at their current angles and have a high ability to resist deformation when a vacuum is applied, thereby stiffening the entire structure when bent when a vacuum is applied. Additionally, in some embodiments, hoop fibers in or on the braid may carry tensile loads that help prevent localized buckling of the braid when high bending loads are applied.

[0133] Upon transition from the flexible to the rigid configuration, the stiffness of the curing device 100 may increase by 2 to 30 times or more, such as 10 times, 15 times, 20 times, etc. In one particular example, the stiffness of a curing device similar to the curing device 100 was tested. The tested curing 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 beam portion of the curing device until the device flexed 10 degrees. The force required to achieve this bending in the flexible mode was only 30 grams, whereas the force required to achieve this bending in the rigid (vacuum) mode was 350 grams.

[0134] In some embodiments of the vacuum curing device 100, only one braided layer may be provided. In other embodiments of the vacuum curing device 100, two, three or more braided layers may be provided. In some embodiments, one or more of the radial gap layer or the sliding layer of the curing device 100 may be eliminated. In some embodiments, some or all of the sliding layers of the curing device 100 may be eliminated.

[0135] The braided layer described herein may act as a variable stiffness layer. The variable stiffness layer may include one or more variable stiffness elements or structures that increase bending stiffness and / or torsional deformation resistance during operation (e.g., when a vacuum is applied), resulting in high stiffness. Other variable stiffness elements may be used in addition to or instead of the braided layer. In some embodiments, a fitting is 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 by reference in its entirety. Alternatively or additionally, the variable stiffness element may include particles or granules, obstruction layers, flakes, stiffening axial members, stiffening devices, longitudinal members, or substantially longitudinal members.

[0136] In some embodiments, the curing devices described herein may be cured through application of pressure rather than vacuum. For example, referring to FIGS. 14A-14B, the curing device 2100 may be similar to the curing device 100, except that the curing device 2100 may be configured to hold a pressure (e.g., greater than 1 atm) rather than a vacuum for curing. Thus, the curing device 2100 may include multiple layers disposed around the lumen 2120 (e.g., for placement of an instrument or endoscope). The curing device 2100 may include an innermost layer 2115 (similar to the innermost layer 115), a sliding layer 2113 (similar to the sliding layer 113), a pressure gap 2112, an air reservoir layer 2121, a gap layer 2111 (similar to the gap layer 111), a braided layer 2109 (similar to the braided layer 109) or other stiffness variable layers described herein, a gap layer 2107 (similar to layer 107), and an outermost encapsulating layer 2101.

[0137] The pressure gap 2112 may be a sealed chamber that provides a gap for application of pressure to the layers of the cured device 2100. Pressure may be supplied to the pressure gap 2112 using a fluid or gas expansion / pressure medium. The expansion / pressure medium may be water or saline, or a lubricating fluid such as soil or glycerin. The lubricating fluid may, for example, help the layers of the cured device 2100 flow over each other in a flexible configuration. The expansion / pressure medium may be supplied to the gap 2112 during curing of the cured device 2100 and may be partially or completely drained to transform the cured device 2100 back into a flexible configuration. In some embodiments, the pressure gap 2112 of the cured device 2100 may be connected to a pre-filled pressure source, such as a pre-filled syringe or injector, to reduce the setup time required by the physician.

[0138] The air reservoir 2121 may be made of, for example, a low durometer elastomer (e.g., Shore 20A to 70A) or a thin plastic sheet. The air reservoir 2121 may be formed from a thin sheet of plastic or rubber that is sealed lengthwise to form a tube. The longitudinal seal may be, for example, a butt or lap joint. For example, a lap joint may be formed lengthwise in a rubber sheet by melting the rubber at the lap joint or by using an adhesive. In some embodiments, the air reservoir 2121 may be 0.0002 to 0.020" thick, such as approximately 0.005" thick. The air reservoir 2121 may be soft, high friction, stretchable, and / or easily pleated. In some embodiments, the air reservoir 2121 is a polyolefin or PET. The air reservoir 2121 may be formed using methods used to form heat shrink tubing, such as, for example, extrusion of a base material followed by thinning by heat, pressure, and / or radiation. When pressure is supplied through the pressure gap 2112, the air reservoir layer 2121 expands through the gap layer 2111 and presses the braided layer 2109 against the outermost encapsulating layer 2101, thereby preventing relative movement of the braided strands.

[0139] The outermost encapsulating layer 2101 can be a tube, such as an extruded tube. Alternatively, the outermost encapsulating layer 2101 can be a tube in which a reinforcing element (e.g., a metal wire with a circular or rectangular cross section) is encapsulated in an elastomeric substrate, similar to that described for the innermost layer for other embodiments described herein. In some embodiments, the outermost encapsulating layer 2101 can include a helical spring (e.g., made of circular or flat wire) and / or a tubular braid (e.g., made of circular or flat metal wire) and a thin elastomeric sheet that is not bonded to other elements of the layer. The outermost encapsulating layer 2101 can be a tubular structure with a continuous smooth surface. This can facilitate the outer members to slide in close proximity with locally high contact loads (e.g., a nested configuration as described further herein). Additionally, the outer layer 2101 can be configured to support compressive loads, such as a clamping load. Additionally, the outer layer 2101 (eg, comprising reinforcing elements) may be configured to prevent the stiffening device 2100 from changing diameter even when pressure is applied.

[0140] Because both the outer layer 2101 and the inner layer 2115 contain reinforcing elements therein, the braided layer 2109 can be reasonably inhibited from both diametric contraction (under tensile load) and diametric increase (under compressive load).

[0141] By using pressure rather than vacuum to transition from the flexible state to the rigidized state, the rigidity of the stiffening device 2100 may be increased. For example, in some embodiments, the pressure supplied to the pressure gap 2112 may be between 1 and 40 atm, such as between 2 and 40 atm, between 4 and 20 atm, between 5 and 10 atm. In some embodiments, pressure is supplied at approximately 2 atm, approximately 4 atm, approximately 5 atm, approximately 10 atm, approximately 20 atm. In some embodiments, the stiffening device 2100 experiences a change in relative bending stiffness (measured in a simple cantilever beam configuration) from the flexible configuration to the rigidized configuration that is between 2 and 100 times, such as between 10 and 80 times, such as between 20 and 50 times. For example, the stiffening device 2100 may have a change in relative bending stiffness from the flexible configuration to the rigidized configuration that is between approximately 10, 15, 20, or 25, 30, 40, 50, or 100 times or more. FIG. 15 shows a graph of bending strength versus pressure for the stiffening devices described herein. As shown, the flexural strength of the cured device increases as the pressure applied to the wall increases.

[0142] Simple configurations of the walls of various pressure curing devices similar to curing device 2100 are shown in Figures 16A-16O. For example, curing device 2200a in Figure 16A includes innermost layer 2215a, pressure gap 2212a, air reservoir layer 2221a sealed to outermost layer 2201a, braided layer 2209a, and outer encapsulation layer 2201a (similar to that described with respect to curing device 2100). Curing device 2200a further includes end caps 2292a at the proximal and distal ends that seal pressure therein. When pressure is supplied to pressure gap 2212a via inlet 2293a, air reservoir layer 2221a is pressed against braided layer 2209a, and the braided layer is pressed against outermost layer 2201a to prevent the strands of the braid from moving relative to each other.

[0143] Referring to FIG. 16J, the cured device 2200j is similar to the cured device 2200a, except for the addition of a sliding layer 2213j and a rigid layer 2298j. The layer 2213j can be a sliding layer as described herein, including, for example, a coating or a powder. The layer 2298j can be a rigid layer similar to the layers 2201j and 2215j, and can include the reinforcing elements 2250z as described elsewhere herein. The additional rigid layer 2298j can work together with the inner layer 2215j. For example, the two layers 2215j and 2298j can slide easily over each other in the flexible configuration (via the sliding layer 2213j) and bond to each other in the cured configuration (i.e., under pressure) to form a rigid composite structure. The layer 2298j can be a high durometer elastomeric rubber, such as a TPU or TPE with a durometer greater than or equal to 60A, 70A, 80A, or 90A. When the tube is in a flexible state, layers 2215j and 2298j can easily twist or move relative to one another (e.g., by sliding layer 2213j), so the flexibility of the system is less than if the layers were bonded together. When the tube is in a cured state (e.g., when pressure is applied), layers 2215j, 2298j, 2213j can lock together and act like a single bonded layer to resist collapse of the walls of the cured device 2200j. As with the other embodiments, braided layer 2205j can be pressed against outer layer 2201j when pressure is applied to gap 2212j to cure device 2200j.

[0144] 16B, stiffening device 2200b is similar to stiffening device 2200a, except that pressure gap 2212b is surrounded by inverted reservoir 2221b (or double layer reservoir), i.e., reservoir 2221b includes one side adjacent to braided layer 2205b and one side adjacent to innermost layer 2215b. When pressure is applied to pressure gap 2212b (inside both sides of reservoir 2221b), reservoir 2221b expands into both innermost layer 2215b and braid 2209b (and the braid is pressed into outermost layer 2201b).

[0145] 16C, stiffening device 2200c is similar to stiffening device 2200a, except that air reservoir 2221c is sealed to innermost layer 2215c rather than outermost layer 2201c. When pressure is supplied to pressure gap 2212c via inlet 2293c, air reservoir 2221c is pressed against braided layer 2209c, which is pressed against outermost layer 2201c.

[0146] 16D, stiffening device 2200d is similar to stiffening device 2200b, except that innermost layer 2215d is a spring element rather than a coiled tube. Because pressure exists in inverted reservoir 2221d, inner layer 2215d does not need to be sealed to itself.

[0147] Referring to FIG. 16E, curing device 2200e is similar to curing device 2200a, except that the innermost layer 2215a is replaced with an inner payload 2294e that is sealed at both the proximal and distal ends and may contain multiple lumens (e.g., working channel 2291e, pressure channel 2292e, irrigation channel 2293e).

[0148] Referring to FIG. 16F, stiffening device 2200f is similar to stiffening device 2200a, except that braided layer 2209f is inside pressure gap 2212f and air reservoir 2221f such that pressure supplied to pressure gap 2212f presses air reservoir 2221 inwardly against braided layer 2209f, pressing the braided layer against innermost layer 2215f.

[0149] In some embodiments, a pressure stiffening device may include two braided layers (e.g., of the same or different braiding characteristics). For example, an exemplary stiffening device 2200m comprising two braided layers 2209m and 2205m is shown in FIG. 16M. The two braided layers 2209m and 2205m sandwich two reservoirs 2221m and 2217m (and / or a single annular reservoir). When pressure is supplied to the pressure gap 2212m between the two reservoirs, the outer braided layer 2205m is forced radially outwardly towards the outer layer 2201m, while the inner braided layer 2209m is forced radially inwardly towards the inner braided layer 2215m, stiffening the device 2200m.

[0150] Another exemplary stiffening device 2200n is shown in FIG. 16N, which includes two braided layers 2209n, 2205n. The two braided layers 2209n, 2205n are disposed adjacent to each other between the air reservoir 2221n (not shown) and the outer tube 2201n. When pressure is applied to the pressure gap 2212n, the air reservoir 2221n presses the two braided layers 2209n, 2205n together against the outer tube 2201n. The braided layers 2209n, 2205n interdigitate with each other when pressure is applied, thereby enhancing the stiffness of the device 2200n.

[0151] 16K, the stiffening device 2200k is similar to the stiffening device 2200a, except that an annular ring 2219k, comprising, for example, a fiber and adhesive, is disposed around each of the ends of the braided layer 2209k and the air reservoir layer 2221k to attach the air reservoir layer 2221k to the innermost layer 2215k (and thereby maintain pressure in the pressure gap 2212k when pressure is provided from the inlet 2293k). The annular ring 2219k may comprise, for example, a high strength fiber such as Kevlar or Dyneema. Additionally, the adhesive may be, for example, a cyanoacrylate. In some embodiments, the adhesive is also applied to the ends between the innermost layer 2215k and the air reservoir layer 2221k, and also surrounds the inlet tube.

[0152] FIG. 16G shows a curing device 2200g with gap inlet 2293g and vent inlet 2223g. Inlet 2293g is connected to pressure gap 2212g (via pressure line 2294g). Inlet 2223g is connected to gap 2206g around braided layer 2209g (between reservoir 2221g and outermost layer 2201g). Device 2200g may be cured in one or more different configurations. In a first curing configuration, pressure is applied to inlet 2293g while vent inlet 2223g is opened or vented to atmospheric pressure. Pressure supplied from inlet 2293g to pressure gap 2212g thus presses braid 2209g against outermost layer 2201g, which in turn pushes air in gap 2206g out of vent inlet 2223g. Releasing air from the vent inlet 2223g allows for a tighter mechanical fit between the braided layer 2209g and the outer layer 2201g, thereby enhancing stiffening of the device 2200g. In the second stiffening configuration, pressure can be applied to the inlet 2293g and a vacuum can be applied to the vent inlet 2223g. This makes the stiffening device 2200g more rigid than in the first configuration, as the vacuum assists the movement of the braided layer 2209g to the outer layer 2201g. The device 2200g can be flexible as well in one or more different configurations. In the first flexible configuration, both the inlet 2293g and the vent inlet 2223g can be open to atmospheric pressure. This can free the braided layer 2209g relative to the outer layer 2201g, making the stiffening device 2200g flexible as the braided layer 2209g can move freely relative to the outer layer 2201g. In the second flexible configuration, a low pressure (e.g., 5-10% above atmospheric pressure) may be provided to both the inlet 2293g and the vent inlet 2223g. This may cause the outermost layer 2201g and the innermost layer 2215g to separate slightly, providing additional area for the braided layer 2209g to move freely. As a result, this may cause the stiffening device 2200g to be more flexible than in the first stiffening configuration. Additionally, providing a low pressure above atmospheric pressure in the flexible configuration may allow the stiffening device 2200g to be introduced into a body of a very small diameter (e.g., such that the pressure gap 2212g is essentially zero) and then providing a low pressure to both the inlet 2293g and the vent inlet 2223g to expand the pressure gap 2212g slightly, providing additional room for the braided layer 2209g to move freely.

[0153] FIG. 16H shows the stiffening device 2200h with a bellows 2243h connected to a pressure line 2294h. The pressure gap 2212h, the pressure line 2294h and the bellows 2243h may all be configured to be filled with a sealed pressure transmission medium, such as distilled water or saline solution or oil. The pressure transmission medium may be a radiopaque fluid, which is advantageous as it shows the stiffening device more clearly during a procedure using fluoroscopy. The pressure transmission medium may be added to the stiffening device just prior to use and / or when the device is manufactured. In use, actuation of the actuator 2288h compresses the bellows 2243h, thereby reducing the volume of the pressure medium in the bellows 2243h, which flows down the pressure line 2294h to the pressure gap 2212h, causing an increase in pressure in the pressure gap 2212h and movement of the braided layer 2209h to the outer layer 2201h. The vent inlet 2223h is open to the atmosphere to allow gas to escape from the space 2206h around the braided layer 2209h. Additionally, reversing the action of the actuator 2288h causes the pressure in the pressure gap 2212h to drop as the pressure medium returns to the bellows 2243h. The actuator 2288h can be, for example, a solenoid, a voice coil, a lead screw, a valve, or a rotary cam. In some embodiments, the pressure line 2294h is clamped or flattened to increase the pressure in the pressure gap 2212h without the use of the bellows 2243h.

[0154] FIG. 16I shows the curing device 2200i including sumps 2230i and 2228i, respectively. The sumps 2230i and 2228i may contain fluid media, such as water and gaseous media, such as air. Pressure or vacuum, or a combination thereof, may be applied to the inlets 2293i, 2223i. The use of the sump configuration shown means that no air or gas is provided to the curing device, regardless of the pressurization state (pressure, vacuum, or elevated atmospheric pressure) of the respective gaps 2206i or 2212i. In the event of leakage from the gaps during the procedure, this may mean that only the fluid media flows to the patient. Patient protection from gas (e.g., air) embolism is thus obtained.

[0155] In some embodiments, the stiffening devices described herein may include multiple separate reservoirs that extend longitudinally across the length of the device. For example, referring to FIG. 16O, the device 2200o includes four distinct circumferential reservoirs 2221o that surround the pressure gap 2212o. In this embodiment, the braided layer is similarly divided into four longitudinal flat braids 2209o, each of the braids disposed radially outward of the reservoir 2221o. In other embodiments, the braided layer may include a tubular braid wrapped around the reservoir 2221o (similar to that described with respect to FIG. 67 below). Additionally, the outer and inner layers 2201o, 2215o are connected by a split 2236o. In some embodiments, the split 2236o may be formed by an element of the outer or inner layer 2201o, 2215o (e.g., may be a continuous element of one or both of the layers 2201o, 2215o). In some embodiments, the split section 2230o can be configured to help maintain the wall thickness. When pressure is applied to the pressure gap 2212o, the air reservoir 2221o expands to press the flat braided layer 2209o against the outer layer 2201o.

[0156] In some embodiments, referring to FIG. 16L, the pressure curing device described herein does not include an innermost layer (e.g., does not include an innermost layer with a reinforcing element therein). Rather, the curing device 2200l may include an outer layer 2201l, a gap layer 2206l, a braided layer 2209l, and an inverted or tubular reservoir 2221l (with a pressure gap 2212l therein). The tubular reservoir 2221l may be configured to be disposed around an inner device (such as a scope 229l). When the pressure gap 2212l is filled with a pressurized medium, the reservoir 2221l may extend into the scope 229l and the braided layer 2209l. It should be understood that any of the features described herein with respect to the vacuum curing device may be alternated or substituted for any of the features described with respect to the pressure curing device.

[0157] In some embodiments, the stiffening devices described herein incorporate a tool or working channel. The working channel may be designed so as not to significantly add to the bending stiffness of the stiffening device. With reference to FIGS. 17A-17C, in one embodiment, the stiffening device 500 may include a working channel 555 extending therethrough. The working channel 555 may include a central lumen 571z (e.g., for passage of a working element) formed by alternating stretchable tubular sections that are locally necked or tapered from a larger diameter end 569z to a smaller diameter end 570z. Each of the sections is connected to an underlying layer of the wall (e.g., a sliding layer 513 above the innermost layer 515) at discrete points or anchoring points 568z, or is otherwise free to move. As the stiffening device 500 bends, the smaller diameter end 570z may move within the larger diameter end 559z of the adjacent section to allow bending of the working channel 555. The working channel 555 is disposed within a wall of the curing device 500, such as the radial gap 511 between the sliding layer 513 and the first braided layer 509 (and therefore may also be disposed under the radial gap layer 507, the second braided layer 505, the radial gap layer 503, and the outermost layer 501). The working channel 555 may therefore be disposed within a sealed vacuum (or pressure chamber) of the curing device 500. In some embodiments, the working channel 555 itself may be disposed within a sealed bag or layer 572z to ensure that there is no vacuum or pressure leak path. In other embodiments, the sections may include sliding seals between them to ensure that there is no vacuum or pressure leak path. In some embodiments, rather than having tapered sections, as shown in FIG. 17D, there may be alternating large diameter sections 525a and small diameter sections 525b. During bending in the curing device 500, the small diameter section 525b may move within the large diameter section 525a. The working channel may be located within the enclosed space formed by layers 501 and 515, or may be located outside of this enclosed space, such as above layer 501.

[0158] 18A-18B, in some embodiments, the stiffening device 7800 can include a working channel 7855 that spirals around a portion of the elongated body 7803z of the stiffening device 7800. For example, the working channel 7855 can spiral at an angle of 40-50 degrees, such as approximately a 45 degree angle, relative to the longitudinal axis of the device 7800. A spiral working channel 7855 is advantageous because it can deform into a curved path as the stiffening device 7800 bends without resisting bending and / or requiring path length adjustment along its length. The working channel 7855 can include a proximal port 7840z that is integral with the handle 7831 and a distal port 7841z (which is the exit port for the working tool) that is molded into the end of the tip 7833z of the stiffening device 7800. The spiral working channel 7855 can be disposed on the outermost layer 7801, on top of the outer layer 7801 (as shown in Figures 18A-18B, where the outer layer 7801 has been removed for clarity), or further within the wall layers (i.e., below the braided layer).

[0159] 19A-19B, in some embodiments, the stiffening device 4500 can include a plurality of working channels 4555 spirally disposed on the outside. As shown in FIG. 19A-19B, the working channels 4555 can form, for example, a helical shield around the stiffening device 4500. In some embodiments, the working channels 4555 can be configured together to form a second stiffening element that can be stiffened separately from the inner stiffening device 4500. The second stiffening element can advantageously be more flexible due to the relative movement of the individual helical working channels 4555. In some embodiments, the working channels 4555 can include a thin flexible ring and / or a thin flexible sheath that accommodates the working channels 4555 in a circular cross section. In some embodiments, the device 4500 can further include a steerable distal tip 4547 to aid in the placement of, for example, a tool extending within the working channel 4555.

[0160] 20A-20B, in some embodiments, the stiffening device 8000 may include a stiffening elongate body 8003z with multiple working channels 8055a-d (e.g., 1-10, 3-5, 4-5 working channels) extending from a central lumen 8020 to a distal end 8033z. The working channels 8055a-d may be used for multiple different tools throughout a procedure. For example, one of the working channels 8055a-d may be used for a catheter with a camera and lighting, another working channel may be used for traction, another working channel may be used for cutting, another working channel may be used for suction, etc. Elements extending into the working channels 8055a-d may be replaced throughout a procedure. In some embodiments, the stiffening elongate body 8003z is disposable, but the tools may be cleaned and / or sterilizable. In some embodiments, the stiffening device 8000 may further include a passive or active linkage 8004z.

[0161] 21, in some embodiments, the stiffening device 8100 can include a first working channel 8155a and a second working channel 8155b. The first working channel 8155b can extend into the central lumen 8120 (or into the wall of the elongate body 8103z) to the distal end 8133z. The second working channel similarly extends into the central lumen 8120 or into the wall of the elongate body 8103z, but exits from a side of the elongate body 8103z proximal to the distal section 8102z (e.g., before the linkage 8104z). Having the tool channel 8155b exit proximal to the distal section is advantageous as it limits interference with steering or bending of the linkage 8104z.

[0162] 22, in some embodiments, the tool 7942z may be specifically designed for use with the working channel of the stiffening device described herein. The tool 7942z may include a flexible shaft 7943z and an expandable atraumatic tip 7944z. The atraumatic tip 7944z may be an expandable balloon or a nitinol cage with foam therearound. In some embodiments, the expandable tip 7944z may be configured to collapse (e.g., sheath) for delivery in the working channel and to self-expand after withdrawal and placement of the sheath through the working channel. The atraumatic tip 7944z may be sized, for example, to not fill the lumen of the GI tract and therefore not contact the walls of the GI tract. The tool 7942z may further include a flexible loop 7945z attached to the tip 7944z or the shaft 7943z. In some embodiments, the loop 7945z can be attached to an endoscopic clip (used mostly to close various defects in the digestive tract) to provide traction during an ESD procedure. By sliding the shaft 7943z longitudinally, the user can provide traction to the clip. Advantageously, the expandable atraumatic clip 7944z allows the tool 7942z to be freely advanced in front of the curing device without concern of causing trauma or getting stuck in the digestive tract. By hooking the flexible loop 7945z onto the clip, the tool 7942z can provide good traction with a simple back and forth movement of the flexible shaft 7943z.

[0163] Any of the stiffening devices described herein may have one or more distal end sections with a different design than the main elongate body of the stiffening device. For example, as shown in FIG. 23, stiffening device 5500 may have a main elongate body 5503z and a distal end section 5502z. Only the distal end section 5502z, only the main elongate body 5503z, or both the distal end section 5502z and the main elongate body 5503z may be stiffened as described herein (e.g., by vacuum and / or pressure). In some embodiments, one section 5502z, 5503z is operated by pressure and the other section 5502z, 5503z is operated by vacuum. In other embodiments, both sections 5502z, 5503z are operated by pressure or vacuum, respectively.

[0164] 24, in some embodiments, the distal section 5702z may include a stiffened braid that is different from the braid of the main elongate section 5703z. For example, in one embodiment, the braid angle of the distal end section 5702z relative to the longitudinal axis is greater than the braid angle of the main elongate body 5703z. For example, the braid angle of the distal section may be 40 degrees, while the braid angle of the main elongate body may be 20 degrees. The braids may overlap somewhat and be bonded with a flexible adhesive. These designs provide the distal end section 5702z with greater bending flexibility than the main elongate section 5703z in an unhardened state. Providing a more flexible distal tip may be advantageous, for example, to prevent buckling and traction at the tip (caused by braid end sticking) and / or provide flexibility during navigation through the body lumen to prevent trauma to the anatomy. In another embodiment, the braid angle of the distal end section 5702z relative to the longitudinal axis is less than the braid angle of the main elongate body 5703z. This provides the distal end section 5702z with a higher stiffness in a cured state than the main elongate body 5703z. A higher stiffness of the distal end section 5702z may be advantageous, for example, because it may provide a stable platform for movement or delivery of a medical device from the distal end of the cured device 5700 through the central lumen.

[0165] 25, in some embodiments, the distal end section 5802z may include a plurality of passively operated linkages 5804z. The linkages 5804z may be connected together at one or more pivot points to advantageously provide deterministic flexure (i.e., flexure in a specific and predetermined direction). Additionally, the linkages 5804z may advantageously provide high flexibility for flexure while providing torsional stiffness to the distal end section 5802z. The linkages 5804z may be passively operated, e.g., through flexure, as the device 5800 moves within the anatomy. The distal end section 5802z may include 1-100 linkages 5804z, e.g., 1, 2, 4, 6, 8, 10, 16, 20, 30, 40 links 5504z. In some embodiments, the linkages 5804z may be formed by passively cutting flexures, such as laser-cut tubes or stents.

[0166] 26, in other embodiments, the distal section 7602z can include multiple linkages 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. Although the passage of the cables 7624 through the stiffening elongate body 7603z (i.e., including the outer wall 7601, the braided layer 7609, and the inner layer 7615) is not shown in FIG. 26, the cables 7624 can extend in any manner described elsewhere herein. In some embodiments, one or more layers of the stiffening elongate body 7603z can continue to the distal section 7602z. For example, as shown in FIG. 26, the inner layer 7615 can be placed radially inward of the linkages 7604z, for example, that continue to the distal section 7602z. Similarly, any additional layers from the stiffened proximal section (e.g., braided layer 7609 or outer layer 7601) may continue to the distal section 7602z and / or may be disposed radially inward of the linkage 7604z. In other embodiments, none of the layers of the stiffened elongate body 7603 may continue to the distal section 2702z. The linkage 7604z (and any linkages described herein) may include a coating 7627z thereon. The coating 7627z may be advantageous because it may make the distal section 7602z atraumatic and / or lubricious. The coating 7627z may be a membrane, such as expanded PTFE. Expanded PTFE is advantageous because it may provide a smooth, low friction surface that has low bending resistance but high buckling resistance.

[0167] 27A-E show another exemplary distal end section 4302z including multiple linkages 4304z that are actively controlled, such as via cables 4324, for steering the stiffening device. In some embodiments, the pivot points for the linkages 4304z may be spiral, similar to gear teeth, as shown in FIG. 27A-E, to reduce local contact drag. The cables 4324 may be disposed within a cable guide (e.g., a jacket or coil pipe) that extends the length of the stiffening device. In some embodiments, the cables 4324 (and cable guide) may extend within the wall of the stiffening device. The cable guide is advantageous because it may ensure that the structure of the wall does not flex adversely when a load is applied to the linkages 4304z, since tensile loads are transferred through the cable guide and not through the wall of the stiffening device. In some embodiments, the cable guide and cables 4324 may have excess length to offset bending of the stiffening device. This excess length may be woven or wound, for example, within the wall of the stiffening device. Additionally, the cables 4324 extend through holes and / or grooves in the linkages 4304z (see, e.g., FIG. 27C), but otherwise remain free-floating within the wall (and thereby counteract bending of the stiffening device). When the cables 4324 are manipulated, the linkages 4304z pivot relative to one another, thereby steering the distal end section of the stiffening device. Articulation of the linkages 4304z and the cables 4324 for steering can be accomplished by actuators (e.g., local motors, current activated (heat) nitinol wires, proximal actuators (typically stainless steel, tungsten, or composites), hydraulic devices, and / or EAPs (electroactive polymers). Such steering mechanisms are advantageous because they can provide high clinical utility. Additionally, such steering allows devices (e.g., endoscopes or guidewires) positioned in the central lumen to be steered to and more easily reach the desired anatomical location.

[0168] When cables are used to steer the distal end section, the cables (whether in cable guides or not) may be routed within the walls of the stiffening devices described herein in several different ways. FIGS. 28-39B show example configurations of stiffening devices with cable guides (several wall layers have been omitted from FIGS. 28-39B for clarity). For example, FIG. 28 shows a stiffening device 6200 having cables 6224 extending to cable guides 6299 in the outer radial gap layer 6207 (and thus between the braided layer 6209 and the outer layer 6201). In some embodiments, each of the cables 6224 and cable guides 6299 may be positioned approximately equidistant around the circumference (i.e., approximately 90 degrees away from neighboring cables when four cables are used). In other embodiments, one or more of the cables 6224 and cable guides 6299 may be grouped nearby (e.g., in the same quadrant) rather than spaced apart. Additionally, in some embodiments, the cables 6224 and / or guides 6299 may be asymmetrically positioned around the curing device 6200.

[0169] 29 illustrates a stiffening device 6300 in which the cables 6324 and cable guides 6399 are disposed in the inner radial gap layer 6311 (and thus between the braided layer 6309 and the inner layer of the stiffening device, such as the air reservoir 6321). For example, when pressure is provided to the pressure gap 6312, the air reservoir 6321 presses against the braided layer 6309, which in turn presses against the outer layer 6301, such that the braided layer 6309 does not twist or otherwise affect the cables 6234. Again, the cables 6324 and cable guides may be disposed equidistantly or asymmetrically around the stiffening device 6300.

[0170] 30, in some embodiments, the curing device 6400 can have cables 6424 and cable guides 6499 at least partially isolated from a pressurized or vacuum zone. For example, as shown in FIG. 30, the tubular air reservoir 6421 can surround the pressure gap 6412. Some or all of the cables 6424 and cable guides 6499 can be disposed in the gap 6407 between the inner layer 6415 and the braided layer 6409, and in close proximity to the tubular air reservoir 6421. In this configuration, both the cables 6424 and cable guides 6499 are minimally affected by the pressurization of the air reservoir 6421, and substantially no stack height or thickness is added to the wall.

[0171] Referring to FIG. 31, in some embodiments, the curing device 6500 may include multiple circumferentially spaced tubular air reservoirs 6521 such that each of the cables 6524 and cable guides 6599 fits into a gap 6507 between adjacent tubular air reservoirs 6521.

[0172] Referring to FIG. 32, the curing device 6600 is similar to device 6500, except that the cables 6624 and guides 6699 are grouped in pairs to reduce the number of tubular air reservoirs 6621 required (e.g., there are two tubular air reservoirs 6621 with two pairs of cables 6624 and guides 6699 disposed therebetween).

[0173] 33, stiffening device 6700 is similar to device 6500, except that each tubular reservoir 6721 includes a tubular braided layer 6709 therearound (i.e., rather than having a single braided layer 6509 as in device 6500). When a pressurized medium is provided to pressure gap 6712, reservoir 6721 expands and presses against each individual tubular braid 6709, which in turn expands and presses against inner and outer layers 6715, 6701. Alternatively, not all of the reservoirs may be pressurized at the same time (e.g., only one or two), such that the device is only stiffened around a portion of its circumference. This results in stiffness in only a portion of the device, while still remaining flexible among other portions, allowing for dominant motion if the device were subjected to a bending load.

[0174] 34, in some embodiments, the stiffening device 6800 may include a strip of braided layer 6809 (i.e., a flat braid rather than a tubular braid). Each strip of braided layer 6809 and each cable 6824 and cable guide may be disposed in a radial gap 6807. Additionally, the strips of braided layer 6809 may alternate with the cables 6824 / 6899 to minimize the wall thickness of the stiffening device 6800. The air reservoir 6821 may be disposed radially outward of the strips of braided layer 6809 and the cables 6824 / guides 6899. When pressure media is provided to the pressure gap 6812, the air reservoir 6821 presses the strip of braided layer 6809 radially inward toward the innermost layer 6815 to stiffen the device 6800. In other embodiments, the air reservoir 6821 may be configured to be radially inward of the strip of braided layer 6809 (and cable 6824 / guide 6899 ) and press the strip of braided layer 6809 against the outer layer 6801 .

[0175] In some embodiments, with reference to FIG. 35 , the cable 6924 and cable guide 6999 can be positioned to extend into a central lumen 6920 of the stiffening device 6900 .

[0176] 36, the cables 7024 and cable guides 7099 may be disposed radially outward of the outer layer 7001. The cables 7024 and guides 7099 may be disposed in a sheath 7009z, for example, which may extend only to the cables 7024 or may completely surround the outer layer 7001. There is only minimal constraint of the guides 7099 within the sheath 7009z so that they are free to flex during movement of the device 7000 (e.g., to curl or extend their full length depending on whether the guides 7099 are disposed inside or outside the curing layer of the device 7000 during flexion).

[0177] 37, in some embodiments, the cable guide 7199 (and one or more cables therein) may be spirally wound around the outside of the outer layer 7101 of the curing device 7100. Additional cable guides may be spirally wound around as well. In some embodiments, the cable guide 7199 may be spirally wound around other layers of the curing device 7100, such as around an inner layer.

[0178] 38A-38B, in some embodiments, the cable guide 7299 (and one or more cables therein) and the tubular element 7210z can be alternately spirally wound around the inner layer 7215 (i.e., such that the cable guide 7299 and the tubular element 7210z form approximately a single layer along the length of the stiffening device 7200). The tubular element 7210z can include an outer tubular braid 7209 with an inner tubular reservoir 7221. When a pressurized medium is provided to the pressure gap 7212, the reservoir 7221 can expand outwardly into the tubular braid 7209, and the braid can press outwardly against the outer layer (not shown for clarity).

[0179] 39A-39B, stiffening device 7300 is similar to device 7200, except that only cable guide 7399 and tubular reservoir 7321 are spirally wound around inner layer 7315 within gap 7311 (note that cable guide 7399 and tubular reservoir 7321 are not shown in FIG. 39B for clarity), and braided layer 7309 may be radially wound around gap 7311. When pressure media is supplied to tubular reservoir 7321, reservoir 7321 expands and presses braided layer 7309 against outer layer 7301 (not shown in FIG. 39A for clarity).

[0180] The cable configurations described with respect to FIGS. 28-39B may be used with any number of cables (e.g., 1, 2, 3, 4, 5, 6, 8, 12, 16 cables, etc.). Additionally, the cables may be used to steer any tip or stiffening device and / or to steer a distal end section (e.g., a section with linkages with different braid angles). Additionally, the cable guides described herein may be round with round cables, flat, rectangular with flat ribbon tensile elements, or combinations thereof. Additionally, in some embodiments, other steering elements (e.g., pneumatic devices, hydraulic devices, shape memory alloys, EAPs (electroactive polymers), or motors) may be used in addition to or in place of the cables. Even if the forces available for steering are significantly lower than the forces required for stiffening the nested system, the intentional separation of the elements required for steering and the elements required for stiffening may result in a structure that exhibits continuous high stiffening performance over length.

[0181] Additionally, it should be understood that the cable configurations and placements described with respect to Figures 28-39B may similarly be used for placement within the stiffening device in the working channel or other lumen (e.g., an inflation lumen for a balloon).

[0182] 40A-40D, in some embodiments, the distal end section 5902z may include a series of linkages 5904z (active or passive) specifically designed to stiffen through application of pressure or vacuum. For example, the linkages 5904z may be connected to one another through pivot points 5928z (which may be wire pivot points, for example). Each pivot point 5928z allows for bending in one degree of freedom between the linkages. Furthermore, the linkages 5904z may be arranged in an alternating fashion with every other linkage located 90 degrees away from the previous linkage and connected to a pivot point 5928z. Each linkage 5904z has cutouts 5975z at the proximal and distal ends extending from the pivot points 5928z to allow bending of the linkages 5904z relative to one another. Furthermore, each linkage 5904z may be connected to an adjacent linkage 5904z by a respective tension member 5930z. The tension member 5930z may be fixed to one linkage and at least partially movable within the track 5931z of a neighboring linkage (e.g., within the track 5931z of linkage 3203b). Movement of the linkage 5904z causes the tension member 5930z to lengthen when on the outside of the curve and shorten when on the inside of the curve during bending of the stiffening device. Additionally, the proximal end section 5902z may include two sliding clamps 5932z attached to the tension member 5930z on opposite axes (i.e., 90 degrees apart from each other). The two tension members 5930z extend from each of the sliding clamps 5932z to the most distal end of the distal section 5902z. When the distal end section 5902z is bent, one cable element of each sliding clamp 5932z shortens and one cable element of each sliding clamp 5932z lengthens, resulting in circumferential movement of the sliding clamps 5932z. When vacuum or pressure is applied, the outer sleeve can compress the sliding clamp 5932z against the surface of the track 5931z. The surfaces of the sliding clamp 5932z and track 5931z can be smooth, textured, or have teeth. This compressive force locks the sliding clamp 5932z in place relative to the link 5904z, thereby fixing the position of the tension member 5930z and rigidifying the distal end section in its current shape.Additional stiffening linkages and / or fittings are described in International Patent Application No. PCT / US2018 / 042946, filed July 19, 2018, entitled “DYNAMICALLY RIGIDIZING OVERTUBE,” now PCT Publication No. WO2019 / 018682, which is incorporated herein by reference in its entirety.

[0183] 41A-41B, in some embodiments, the distal end section 6002z may include a linkage 6004z (active or passive) that rests on top of a section 6007z that is stiffened via vacuum or pressure as described elsewhere herein (i.e., on top of stiffened walls including inner layer 6015, pressure gap 6012, air reservoir 6021, braided layer 6009, and outer layer 6001). Locating the linkage 6004z on top of the stiffened section provides the benefits of a linked system (e.g., bending flexibility and torsional stiffness) along with a steerable or deterministic bending tip that may be stiffened when the remaining structure is stiffened. Alternatively, the linkage may be located radially inward of the stiffened section. As shown in FIG. 41B, a cable 6024 in a cable guide 6099 extends to the linkage 6004z to provide any active steering of the linkage 6004z.

[0184] 42A, in some embodiments, the distal end section 6102z may include a series of linkages 6104z (active or passive) sealed to a thin layer of material 6108z (e.g., made of elastomer, PVC, or PEEK). The linkages 6104z and thin layer of material 6108z may, for example, be disposed above (i.e., radially outward of) the braided layer 6109 and be continuous with the coiled tube 6101 of the main elongated body 6103z. In this embodiment, when pressure or vacuum is applied to the gap 6112, the braided layer 6109 is compressed and hardened by the air reservoir 6121 against the coiled tube 6101 of the main elongated body 6103z and the linkage sheath 6108z of the distal end section 6102z. The linkage sheath 6108z is supported by the linkage 6104z so that it can resist the expansion pressure of the braided body. This design is advantageous as it provides both stiffness and linkage while maintaining a small wall thickness and / or diameter. The distal end section 6102z can include a cable 6124, for example, that extends into a cable guide to operate the linkage 6104z.

[0185] In some embodiments, the stiffening structure may be steered from within the wall of the stiffening structure, and optionally without links. FIG. 42B shows a cross-sectional view of a pressure stiffening structure 2500 with a cable guide 2599 placed in the pressure gap 2512 and attached to the inner layer 2515. The cable 2524 extends from the cable guide 2599 to a distal end section 2502z and is anchored to the inner layer 2515 at an anchor point 2568. Pulling on the cable 2524 causes the distal end section 2502z (distal from the end of the cable guide 2599) to flex. In some embodiments, the cable guide 2599 may be omitted and the stiffening device 2500 will bend over its entire length when the cable 2524 is pulled. In some embodiments, the device 2500 may be constructed with a distal end section 2502z having a lower bending stiffness than the proximal elongated body 2503z such that the distal end section 2502z is more flexible than the body 2503z (e.g., by varying the braid angle or using more flexible reinforcing elements in either the inner or outer layer, as described herein). The cable guide 2599 and cables 2524 may be placed between the reservoir 2521 and the braid 2509, or between the braid 2509 and the outer layer 2501. The cable guide 2599 and / or cables 2524 may be attached to the outer wall 2501. Alternatively, in a vacuum cured construction, the cable guide 2599 and cables 2524 may be placed between the inner layer and the braid, or between the braid and the outer layer. In some embodiments, the air reservoir 2521 and the braid of the braided layer 2509 are omitted in sections where the cable 2524 is not inside the cable guide 2599, leaving only the inner and outer layers 2515, 2501, or only the outer layer, or only the inner layer.

[0186] 43A-43C, in some embodiments, the distal end section 4602z can include an active flex segment 4646. The flex segment 4646 can include a ribbon or spine extending therein that, upon manipulation, flexes in only one or more predetermined directions. The active flex segment 4646 can flex to a predetermined shape, for example, using the introduction of one or more cables, air reservoirs, pull wires, and / or guide wires. The active flex segment 4646 can thus flex the stiffening device 4600 at fixed locations and directions. In some embodiments, markers (e.g., radiopaque markers) are placed in or proximal to the active flex segment 4646 to indicate where the flex occurs and / or in which direction the active flex segment 4646 will flex. Bending of the stiffening device 4600 using the active bending segment 4646 may be advantageous, for example, when bending is required without assistance from anatomy (i.e., the anatomical path for the stiffening device 4600 is not predefined or constrained by anatomy). For example, such bending may be useful to provide a bend in the open or relatively unconstrained space between the inferior vena cava (IVC) and the atrial septum during a transseptal procedure at the mitral valve. The active bending segment 4646 may be configured to be stiffened (i.e., via pressure or vacuum) as described herein to fix or lock the active bending segment 4646 in a bent configuration. Furthermore, the stiffening device 4600 may include a steerable distal section (e.g., comprising a linkage) in addition to the active bending segment 4646. As described elsewhere herein, the steerable distal section 4647 may be used to point or orient the distal end of the stiffening device 4646 in a desired direction (e.g., via a cable and / or on four axes).

[0187] Any of the curing devices described herein may include one or more sections that are separately cured. For example, with reference to FIGS. 44A-44C, in some embodiments, the curing device 900 may have separate vacuum / pressure chambers 975a-d (e.g., four vacuum or pressure chambers) along its length. Each chamber 975a,b,c,d may have its own vacuum / pressure line 927a-d extending therethrough for separate curing of the chamber 975a,b,c,d. Pressure seals 929 may extend between and / or at the distal end of each chamber. A curing device 900 with separate curing chambers 975a,b,c,d may, in some embodiments, include a steerable distal section 902z (e.g., with a linkage as described elsewhere herein). Cables 924a-d that control the steerable distal section 902z may be managed using cable guides 999 (e.g., at least one may be provided for each vacuum chamber 975, such as 1-4 cable guides 999). In some embodiments, as shown in FIG. 44B, the cables 924a-d, cable guides 999a-d, and / or vacuum / pressure lines 927a-d may extend into the radial gap 911 between the innermost layer 915 and the braided layer 909 (and thus under the outermost layer 901). In other embodiments, as shown in FIG. 44C, the cables 924a-d, cable guides 999a-d, and / or vacuum / pressure lines 927a-d may extend into the central lumen 920 of the stiffening device 900. During use of the stiffening device 900, any of the chambers 975a-d in the flexible state may be steered or flexed in the cable pulling direction, while the stiffened chambers 975a-d remain in position and do not flex. This design is advantageous because the chambers 975a-d in the vacuum / pressure state and / or steering direction may take on a variety of complex shapes to navigate within the anatomy with minimal loop formation.

[0188] In some embodiments, the distal end section of the stiffening device described herein may include elements for localized tissue stabilization, such as suction, balloon, or cage elements. For example, referring to FIGS. 45A-45D, in one embodiment, the stiffening device 600 may include a balloon 666 and a balloon inflation lumen or tube 667 that extends to the balloon. As shown in FIGS. 45B-45D (with the outer layer removed in 6B-6C for clarity), the balloon inflation tube 667 may extend along the working channel 655 (and thus within the radial gap between the sliding layer 613 and the first braided layer 609). As shown in FIGS. 45B-45C, the inflation tube 667 may be configured to include a service loop 668 that can vary in length (i.e., be straight as in FIG. 45B or have a large bend as in 45C) to accommodate bending of the stiffening device 600. In some embodiments, the balloon inflation tube may be spiraled about an axis to accommodate bending. In some embodiments, the vacuum curing device can include a balloon inflation tube between the innermost layer and the braid, between the braid and the outer layer, radially inward of the inner layer, or radially outward of the outer layer. In some embodiments, the pressure curing device can include an inflation lumen in the pressure gap between the reservoir and the braid, between the braid and the outer layer, radially inward of the inner layer, or radially outward of the outer layer. For example, the inflation lumen can be positioned similarly as described herein with respect to the working channel and / or cable.

[0189] As another example, FIGS. 46A-46B show an exemplary vacuum tip 5354 for use with a sclerosing device. The vacuum tip 5354 may include a circumferential array of vacuum holes 5358 at a distal-most surface 5359. Additionally, the array of vacuum holes 5358 may be connected to a vacuum line 5356 that extends to the sclerosing device (i.e., in or along the laminar wall of the sclerosing device). The vacuum line 5356 may be connected to a vacuum source such that during operation, a vacuum is provided through the vacuum line 5356 (e.g., from annular inlet 5319z) to each of the holes 5358 in the array. As a result, suction may be provided at the distal-most surface 5359 of the tip 5354 (and thus the distal-most surface of the sclerosing device). Such suction may be useful, for example, for aspirating tissue (e.g., for stabilization during an interventional procedure such as cannulation of the nipple, e.g., for access to the pancreatic or bile duct). Suction may also be useful, for example, in endoscopic submucosal dissection (ESD) or endoscopic full thickness mucosal resection (EFTR).

[0190] In some embodiments, the vacuum tip 5354 is located just distal to the steerable section of the curing device, which is advantageous as it can be used to orient the vacuum tip 5354 in a desired direction. Additionally, in some embodiments, a tool (e.g., a guidewire or scope) can be passed through a central lumen 5320z of the tip 5354 and between the array of vacuum holes 5358 to allow for the procedure to be performed while suction is being applied.

[0191] 47A-47B, in some embodiments, the vacuum tip 5254 can include a semi-annular array of holes 5238 on the distal-most surface 5259 rather than a circumferential array of holes.

[0192] 48A-48B, in some embodiments, the vacuum tip 5454 can have a beveled distal surface 5459 (e.g., beveled 30-80 degrees, such as 30, 45, 60, 70, 80 degrees, relative to the longitudinal axis of the tip 5454). The beveled distal surface is advantageous because it can help access beveled anatomical structures to more easily adhere to topical surfaces.

[0193] The vacuum tips described herein are advantageous because they can deliver suction without causing "red-out" of the endoscope lens because the suction occurs locally (e.g., at hole 5358) and not at the lens of the scope. Thus, the scope allows visualization of the tissue even as suction is being delivered.

[0194] In some embodiments, the vacuum tips described herein may include metallized portions and / or have co-bonded wires such that the vacuum tips can conduct electrical current that can be used, for example, to cut or coagulate the aspirated tissue.

[0195] In some embodiments, the vacuum tips described herein can be used with standard endoscopes or endoscopic type devices that do not include stiffening.

[0196] Any of the curing devices described herein may be used with a handle configured to allow for manual handling and / or manipulation of the device.

[0197] An exemplary handle 1031 is shown in Figures 49A-49D. The handle 1031 includes an operating element 1048 in the form of a button configured to operate a vacuum or pressure (the button is shown OFF in Figures 49A and 49C and ON in Figures 49B and 49D). Additionally, the flow path in the handle 1031 may include a vacuum or pressure inlet port 1049 configured to be attached to a vacuum or pressure source, a curing device port 1050 connected to the curing device via an outlet 1073z, and a vent port 1051 connected to the atmosphere. As shown in Figure 49A, when the operating element 1048 is in a distal "off" position (i.e., such that the vacuum or pressure for curing to the curing device is off), the vent port 1051 and the curing device port 1050 are in communication with each other to vent the curing pressure or vacuum to the air and to cause the curing device to be in a flexible configuration. As shown in FIG. 49B, when the operating element 1048 is in the proximal "on" position (i.e., such that the vacuum or pressure to the curing device is on), the curing device port 1050 and the vacuum or pressure inlet port 1049 are in communication with each other to provide pressure or vacuum to the curing device to enable curing of the device. In some embodiments, the handle 1031 can be configured to be joined to the curing device (e.g., to the inner coiled tubing on the curing device) at the joining area 1053. As shown in FIGS. 49C-D, the handle includes a status indicator element 1067z that indicates whether the curing device is in a flexible or cured configuration. In this embodiment, the status indicator 1067z is such that the word "on" indicates when the button is placed in the "on" position and the word "off" indicates when the button is placed in the "off" position. In other embodiments, the status indicator can be a symbol, a color, a light, or a moving indicator.

[0198] The operating elements for the stiffening device handles described herein can be buttons, switches, toggle switches, sliders, screw connections, squeeze handles, and stopcocks. Additionally, the operating elements can be planar, sector-shaped, or omni-directional. The indicator elements can include words, lights, or elements that rotate with vacuum or pressure flow. For example, referring to FIGS. 50A-50B, in some embodiments, the operating element 1548 can be a slider element. The operating element 1548 can include a connection element 1574z (e.g., a hollow tube or a snap-fit ​​element) configured to slide over the handle. An indicator element 1567z can be incorporated into the slider (e.g., indicating "stiff" when the slider is in one position and "flexible" when the slider is in another position). A similar slider operating element 1648 (which is orthogonal) is seen in FIGS. 51A-51C.

[0199] In some embodiments, rather than including the operating element and indicator element in the handle, either or both may be on separate elements. For example, the operating element may be located in a vacuum or pressure line between the handle and a vacuum or pressure pump, may be operated by a foot pedal, may be located on a scope umbilical, a scope shaft, or may be clipped to a patient bed. In some embodiments, the operating element is separate from the handle, but is clipped to the handle for part of the procedure. For example, FIGS. 52A-52C show an operating element 1448 that includes an attachment mechanism 1452 (e.g., a c-shaped clip) for releasably coupling to the handle 1431. Providing an indicator element and / or operating element separate from the handle may be advantageous because the actuators and indicators are more clearly visible (i.e., not obscured by human anatomy) and / or may be more easily controlled / used by additional personnel (e.g., a procedure assistant).

[0200] 53A-D show a handle 1131 designed to allow manipulation of the curing device but does not include manipulation or indicator elements. The handle 1131 includes a large stop or flange 1161 at the distal end which may act as an insertion stop for the handle 1131 (i.e., stops the handle 1131 from moving into the anatomy) and also acts as a surface for the operator to press against during use. The curing device may be connected at a junction region 1153. Additionally, the handle 1131 may include an input 1165 from a remote manipulation element to the curing device that is connected to an output 1173z.

[0201] In some embodiments, a handle for use with a vacuum curing device may include a vent port to vent the curing device when vacuum is not applied (i.e., when the curing device is in a flexible configuration). For example, FIGS. 54A-54B show a handle 1231 having a spool valve operating element 1248 that operates the vacuum in the curing device when moved in one direction and stops operating the vacuum or pressure when moved in the opposite direction. When operating the curing device with vacuum or pressure is stopped, the operating element 1248 may vent through a vent port 1251. The operating element 1248 may be positioned 4″-8″, e.g., 6″, away from the handle in the vacuum or pressure line 1232 leading to the handle. As shown in FIG. 54A, a spool valve with end button indicator element 1267z indicates that the curing device is in the curing configuration (as shown) or the curing configuration (when pushed in the opposite direction).

[0202] 55A-55C, the operating element 1348 is a rotary valve (e.g., connected to a handle or other location as described herein) and a sliding indicator 1367z on the rotary valve operating element 1348 indicates whether the vacuum or pressure is on (as shown in FIGS. 55A and 55C) or off and being vented (as shown in FIG. 55B).

[0203] In some embodiments, a handle for use with a vacuum curing device may include a mechanism configured to automatically lock the handle in a vacuum or vent configuration. For example, a handle 7531 for use with a vacuum curing device 7500 is shown in FIGS. 56A-56G. The handle 7531 includes a handle body 7515z configured to be attached to the curing device 7500. The handle 7531 further includes an operating element 7548 in the form of a switch ring for applying vacuum to the curing device 7500. The switch ring operating element 7548 may include a magnet 7522z configured to engage either a proximal magnet 7523z (shown in FIG. 56D) or a distal magnet 7524z (shown in FIG. 56E). When the switch ring magnet 7522z engages with the proximal magnet 7523z, the vacuum feed line 7532 in the handle 7531 is disconnected from the vacuum port 7550 to the curing device and both the curing device and vacuum are evacuated or vented to atmosphere (as shown in FIG. 56F). When the switch ring magnet 7522z engages with the distal magnet 7523z, the vacuum feed line 7532 in the handle 7531 is connected to the vacuum port 7550 to the curing device to provide vacuum (as shown in FIG. 56G). The magnets 7522z, 7523z, 7524z advantageously lock the switch ring 7548 in a vacuum or vent configuration, thereby preventing harm to the patient that may occur in an unintended configuration (e.g., attempting to move the device 7500 in the anatomy when in the curing configuration which may damage the anatomy). In some embodiments, the magnets 7522z may be ferrous while the magnets 7523z, 7524z may be magnets, or vice versa. As shown in FIGS. 56A-56B, the handle 7531 may further include a user grip 7521z for a user's hand, comprising a grip cover 7525z configured to cover the vacuum feed tube line 7532 of the handle 7531. Further, the vacuum feed tube line 7532 may be directly connected to the switch ring operating element 7548. The vacuum feed line 7532 may have a spiral or coiled shape under the grip cover 7525z to allow the switch ring operating element 7548 to move proximally and distally without motion constraints caused by the vacuum feed line 7532.The spiral of the vacuum delivery line 7532 is from 30 to about 1440 degrees. For example, it can be 90 degrees, 180 degrees, 360 degrees, 720 degrees (as shown in FIG. 56C with the grip cover removed for clarity). The grip cover 7525z can be designed to cover the entire vacuum delivery line 7532 even as it spirals all the way around the handle 7531. The handle 7531 can further include a stop flange 7561 to prevent movement of the handle 7531 into the anatomy (e.g., the stop flange can prevent the device from passing through an anal or oral bite guard), a proximal handle port 7526z for insertion of a scope or other working tool, and / or an indicator element 7567z. The indicator element 7567z is a band that is visible only when the switch ring operating element 7548 is in the distal position. The indicator element 7567z has a different color or value than the rest of the handle, preferably a color that provides sharp contrast and is visible in low lighting configurations. For example, the handle 7531 is white and the indicator element 7567z is a medium or dark blue. The indicator element 7567z band may have a different texture than the rest of the handle 7531. For example, it may have raised protrusions or cross-hatching. In this way, the physician can easily sense the status of the handle 7531.

[0204] In some embodiments, a handle for use with a pressure stiffening device may include a pressure gap inlet and a vent gap inlet. An exemplary handle 6231 attached to a pressure stiffening device 6200 is shown in FIGS. 57A-57C. The handle includes a gap inlet 6293 and a vent gap inlet 6223. The pressure gap inlet 6293 is connected to the pressure gap 6212 (via a pressure line 6294). The vent gap inlet 6223 (which runs through the handle and has outlets on both sides) is connected to the gap 6206 around the braided layer 2209 (between the reservoir 6221 and the outermost layer 6201). The vent inlet 6223 is open to the atmosphere, while the gap inlet 6293 may be connected to a pressure source (e.g., operated with an operating element). The handle 6231 may be used to operate the device 2200g, for example, as described with respect to FIG. 16G. In some embodiments, a fitting can be added to the gap entrance 6293 so that a handle 6231 can be used to actuate the device 2200i, as described with respect to FIG. 16I.

[0205] In some embodiments, a handle for use with a pressure stiffening device may include a pre-filled pressure media. For example, an exemplary handle 7431 attached to a pressure stiffening device 7400 is shown in FIGS. 58A-58E. The handle 7431 includes a handle body 7415z and a grip / lever 7411z that may be manipulated to provide a pressure media to the stiffening device 7400, such as a pressure media pre-filled or stored in a fluid chamber 7412z of the handle 7431. The chamber 7412z may be adjacent to a rolling diaphragm 7416z, for example. The grip / lever 7411z may include teeth 7476z that engage with a rack 7414z of a piston 7413z. As the grip / lever 7411z moves toward the handle body 7415z, the piston 7413z may move distally toward the rolling diaphragm 7416z of the fluid chamber 7412z. When the rolling diaphragm 7416z is pressed distally, it allows pressure media to flow from the chamber 7412z through the gap inlet 7493 into the pressure gap 7412 outside the reservoir 7421 for stiffening (and air or other fluids similarly flow out around the braided layer 7409 via the vent 7423). In some embodiments, the handle 7431 includes a locking mechanism (e.g., via a click-on / click-off mechanism as found in ballpoint pens), and the spring 7477z and feeler 7778z are configured to lock the grip / lever 7411z to the body 7415z to lock the stiffening device 7400 in the stiffened configuration. Similarly, when the grip / lever 7411z is pressed against the body again, the grip / lever 7411 is released and fluid returns to the fluid chamber 7412z via the inlet 7493.

[0206] In some embodiments, the handle 7431 may further include a pressure relief valve 7417z between the chamber 7412z and the overflow chamber 7418z. When the pressure in the fluid chamber 7412z reaches a predetermined maximum pressure (e.g., 5 atm), the pressure relief valve 7417z opens and transfers fluid to the overflow chamber 7418z. The fluid chamber 7412z may be overflowed during manufacturing so that the valve 7417 is always open upon initial actuation of the grip / lever 7411z, thus ensuring calibration of the handle 7431 to the desired pressure. One exemplary method of filling the fluid chamber 7412z may include: (1) attaching the handle 7431 to a fill fitting that is attached to a tube leading to a pressure system; (2) applying a vacuum to the handle to remove air from the fill fitting; (3) while maintaining the vacuum, introducing water, DI, saline, oil, or another incompressible fluid into the system through the fill fitting; and (4) crimping and sealing the tube distal to the pressure fitting (via mechanical crimping, via melting the tubing, etc.), and then removing the pressure fitting and leaving the crimped / sealed tube in the handle.

[0207] Any of the handles described herein may incorporate a pressure indicating feature. For example, the handle may have a pressure gauge. The handle may include a feature such as a piston that displaces to provide a visual indication that the device is pressurized. The handle may have a feature that can be flipped or turned to display different colors, for example, displaying a green dot at atmospheric pressure and a red dot when set. In some embodiments, the visual indication is viewed under fluoroscopy.

[0208] Any of the pressure cure handles described may have an emergency vent feature in case the handle passage becomes clogged for any reason. The emergency vent feature may, for example, allow the device to be cut open, thereby breaking the pressure cavity. The emergency vent feature may, for example, be a valve (e.g., a wipe valve) distal to the handle that, when operated, allows the device to vent pressure, thus ending cure.

[0209] Any of the curing devices described herein may include an integrated camera, lighting, etc. for in-situ imaging. In some embodiments (such as shown in FIG. 63 below), the camera and lighting may be located at the distal tip of the device. In other embodiments, as shown in FIG. 59, the curing device 8200 may include a camera 8234z and lighting 8235z attached to an elongated body 8203z proximal to the distal end 8202z of the device (e.g., proximal to the steering linkage 7204z).

[0210] In some embodiments, the stiffening devices described herein may be configured as introducer needles (i.e., instruments for introduction of flexible devices, such as introducer sheaths for interventional cardiology procedures). For example, with reference to FIG. 60, stiffening device 8700 may include stiffening elongate body 8703z with tapered tip 8733z. Device 8700 may further include hemostasis valve 8749z and outflow conduit 8748z.

[0211] The braids described herein may include or be replaced by meshes, woven materials, ribbons, or fabrics. In some embodiments, the braids are non-woven (i.e., fibers at different angles do not pass over or under each other, but are on separate layers that do not cross each other). Similarly, the braids may be replaced by structures (e.g., metal structures) cut from stents or hypodermic tubes.

[0212] In some embodiments, the curing devices described herein can be configured to be mounted to the side of a scope or other instrument (e.g., rather than requiring insertion of the scope / instrument into the proximal end of the curing device). For example, as shown in FIGS. 61A-61B, the curing device 400 can be split along its length (i.e., split longitudinally within the wall from the proximal end to the distal end). Additionally, a connecting feature 444 can connect the split walls together. In some embodiments, the connecting feature 444 is reusable. For example, the connecting feature 444 can be a series of magnets that mate (FIG. 61A) to hold the curing device 400 together and disengage (FIG. 61B) to provide side access for the scope / instrument. Other exemplary reusable connecting features include zippers, interlocking ziplock male and female configurations, or reusable tape. In some embodiments, the connecting feature 444 is permanent and not reusable, such as permanent tape or adhesive.

[0213] In some embodiments, the vacuum and pressure multilayer systems described herein can be used to create stiffness for non-cylindrical or non-tubular structures. For example, the systems described herein can be used to prepare a balloon that assumes a desired shape upon pressurization and / or curing. Such structures can be flexible structures that nevertheless contain elements that exhibit high hoop stiffness, such as wires (in tension or compression) or thin (in tension) fiber strands.

[0214] In some embodiments, the stiffening devices described herein may include proximal and distal seals in the innermost layer that provide a space between the scope or instrument and the innermost layer to retain a lubricant.

[0215] In some embodiments, the stiffening devices described herein may be used with other forms of products, for example, an endoscope may include a stiffening mechanism described herein, and a stiffening device may include a stiffening mechanism described herein, when used together they can advance one at a time to form a nested system in which loop formation is reduced or eliminated because one of the elements is always in a rigid state (i.e., forming a sequential advancement nested system).

[0216] An exemplary nesting system 2300z is shown in FIG. 62. The system 2300z may include an outer stiffening device 2300 and an inner stiffening device 2310 (here configured as a stiffening scope) that are axially movable relative to one another in either a concentric or non-concentric manner. The outer stiffening device 2300 and the inner stiffening device 2310 may include any of the stiffening features described herein. For example, the outer stiffening device 2300 may include an outermost layer 2301a, a braided layer 2309a, and a coiled inner layer 2315a. The outer stiffening device 2300 may be configured, for example, to receive a vacuum between the outermost layer 2301a and the inner layer 2315a to effect stiffening. Similarly, the inner scope 2310 may include an outer layer 2301b (e.g., coiled), a braided layer 2309b, an air reservoir layer 2321b, and an inner layer 2315b (e.g., coiled). The inner scope 2310 can be configured to receive pressure between the air reservoir 2321b and the inner layer 2315b, for example, to effect curing. Additionally, an air / water channel 2336z and a working channel 2355 can extend into the inner curing device 2310. Additionally, the inner curing scope 2310 can include a distal section 2302z comprising a camera 2334z, a light 2335z, and a steerable linkage 2304z. A cover 2327z can extend into the distal section 2302z. In another embodiment, the camera and / or lighting can be delivered in a separate assembly (e.g., the camera and lighting can be packaged together in a catheter and delivered through the working channel 2355 and / or additional working channels to the most distal end 2333z).

[0217] An interface 2337z may be disposed between the inner curing device 2310 and the outer curing device 2300. The interface 2327z may be a gap having a dimension d (see FIG. 62) of 0.001″-0.050″, such as a thickness of 0.0020″, 0.005″, or 0.020″. In some embodiments, the interface 2337z may be low friction, such as including a powder, coating, or lamination that reduces friction. In some embodiments, a seal is provided between the inner curing device 2310 and the outer curing device 2300, and the intervening space is pressurized, such as with a fluid or water, to provide a hydrostatic bearing. In other embodiments, a seal is provided between the inner curing device 2310 and the outer curing device 2300, and the intervening space is filled with globules to reduce friction.

[0218] The inner stiffening device 2310 and the outer stiffening device 2300 move relative to each other and alternately stiffen to impart a bend or shape along the length of the nesting system 2300z. For example, the inner device 2310 can be inserted into the lumen and bent or steered into a desired shape. Pressure can be applied to the inner stiffening device 2310 to interlock and lock the braided elements in the inner stiffening device 2310 and its configuration. The stiffening device 2300 (e.g., in a flexible state) can then be advanced over the rigid inner device 2310. When the outer stiffening device 2300 reaches the tip of the inner device 2310, a vacuum can be applied to the stiffening device 2300 to interlock and lock the layers to fix the shape of the stiffening device. The inner device 2310 transitions to a flexible state and is advanced and the process is repeated. Although the system 2300z has been 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.

[0219] FIG. 63 shows another exemplary nesting 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, for example, thin-walled with low durometer to allow elasticity and stretchability. The cover 2728z may be a rubber such as urethane, latex, silicone, etc. The cover 2728z may protect the interface / radial gap 2337z 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 or other material from being trapped in the space between the inner and outer tubes. The cover 2738z stretches to allow the inner device 2710 and the outer device 2700 to move independently of each other within the elastic range of the material. The cover 2738z may be bonded or attached to the curing device 2710, 2700 such that the cover 2738z is always in a minimal slight tension state. This embodiment may be wiped down from the outside for cleaning. In some embodiments, the cover 2738z may be configured as a "rolling" seal as disclosed in U.S. Patent No. 6,447,491, the entire disclosure of which is incorporated by reference.

[0220] 64A-64B show another exemplary nested system 9400z. In this system 9400z, the outer stiffening device 9400 includes steering imaging (e.g., similar to a scope) while the inner device includes only stiffening (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 passageway 9439z (e.g., a lumen such as a working channel) for access to the inner device 9410. In some embodiments, a bellows or loop of tubing may connect the passageway 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 one time while the other may be adapted to stiffen and / or move within the anatomy. Here, the outer device 9400 communicates with the inner device 9410 (inner device 9410 is shown retracted relative to the outer device 9400 in FIG. 64A and extending substantially flush with the outer device 9400 in FIG. 64B). The system 9400z advantageously has a smooth outer surface that avoids pinching of anatomical structures and / or ingress of fluid between the inner and outer devices 9410, 9400. Steering with the outer device 9400 also provides the added benefit of steering the tip. Additionally, the outer device 9400's larger diameter and ability to accommodate a larger camera facilitates better imaging performance.

[0221] 65A-65H illustrate an exemplary use of the nesting system 2400z described herein. In FIG. 65A, the inner stiffening device 2410 is placed into the outer stiffening device 2400 such that the distal end of the inner stiffening device 2410 extends outside of the outer stiffening device 2400. In FIG. 65B, the distal end of the inner stiffening device 2410 is bent into a desired direction / orientation and then stiffened (e.g., using vacuum or pressure as described herein). In FIG. 65C, the outer stiffening device 2400 (in a flexible configuration) is advanced over the stiffened inner stiffening device 2410 (including over the bent distal section). Once the distal end of the outer stiffening device 2400 has been advanced sufficiently over the distal end of the inner stiffening device 2410, the outer stiffening device 2400 may be stiffened (e.g., using vacuum or pressure as described herein). In FIG. 65D, the inner stiffening device 2410 can be transitioned to a flexible state (e.g., by removing the vacuum or pressure as described herein and relaxing the steering cables so that the tip moves easily) and advanced to be guided / oriented / steered as desired. Alternately, in FIG. 65D, the inner stiffening device 2410 can be actively steered (manually or via computer control) as it emerges to minimize load on the stiffened outer tube. Minimizing load on the outer stiffening device 2400 facilitates holding this tube in the stiffened shape. Once the inner stiffening device 2410 has hardened, the outer stiffening device 2400 can transition to a flexible state and advanced over it (as shown in FIG. 65E). The process can then be repeated as shown in FIGS. 65F-H.

[0222] In some embodiments, upon completion of the procedure shown in Figures 65A-H, a third stiffening device may be slid over and stiffened onto the first two stiffening devices (2400, 2410). The stiffening devices 2400, 2410 are then withdrawn. Finally, a fourth stiffening device may be inserted into the lumen of the third tube. This fourth stiffening device has a larger diameter and more features than the stiffening device 2410. For example, it may have a larger working channel, more working channels, a better camera, or a combination of these. This technique allows two smaller tubes, which tend to be more flexible and more maneuverable, to reach deeper into the body while the larger tube is ultimately delivered for therapeutic purposes. Alternately, in the above example, the fourth stiffening device may be a standard endoscope as is well known in the art.

[0223] In some embodiments, once the procedure shown in Figs. 65A-H is completed, the outer stiffening device 2400 is hardened and the inner stiffening device 2410 can then be removed. For example, the stiffening device 2410 can be a "guiding" device that includes a camera, lights, and a distal steering section. The "guiding" device 2410 can be fully sealed to facilitate cleaning between procedures. A second inner device is then placed inside the hardened outer device 2400 and advanced beyond the distal end of the outer device 2400. The second inner device can be a "treatment" tube that includes a camera, lights, water, suction, and various tools. The "treatment" device does not have a steering section or hardening capabilities, and other features, such as additional space in the body of the treatment tube to include tools for performing treatment, can be provided. Once in place, the tools in the "treatment" tube can be used to perform treatment on the body, such as mucosal resection or incision on the person's digestive tract.

[0224] In another embodiment, after or during completion of the procedure shown in Figures 65A-H, a third device may be inserted into the inner inner tube 2410. The third device may be a catheter and / or an endoscope.

[0225] The outer curing device for the nested systems described herein is often referred to as curing via vacuum and the inner scope curing device as curing via pressure, although the reverse is also true (i.e. the outer curing device cures via pressure and the inner curing device cures via vacuum) and / or both may have the same curing source (pressure and / or vacuum).

[0226] Although the inner and outer elements of the nesting system have been generally described as including integral stiffening elements, the stiffening elements may be separate (such that relative sliding movement between the imaging scope element and the stiffening element is possible).

[0227] The stiffening devices of the nesting systems described herein can be designed such 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 splines. The inner surface of the outer stiffening device can have corresponding ridges and grooves that engage with the same features of the outer stiffening device.

[0228] Either or both of the stiffening devices of the nesting systems described herein may be steerable. If both stiffening devices are steerable, an algorithm may be implemented to steer either stiffening device that is flexible and moves longitudinally. The algorithm steers the flexible stiffening device to anticipate the shape of the stiffening device, minimizing the tendency to move the flexible stiffening device to straighten the stiffening device.

[0229] In the case where one stiffening device of the nesting system described herein requires a vacuum and the other stiffening device requires pressure, user control can be established where movement of one and the other (outside and in) involves the operation of a switch, for example, between a first condition where one is pressurized for rigidity while the other is evacuated for flexibility, and a second condition where one is evacuated for flexibility and the other is evacuated for rigidity, which can be, for example, a foot pedal or hand switch.

[0230] In some embodiments, the alternating motion of the nesting systems described herein may be controlled manually, while in other embodiments, the alternating motion may be controlled automatically via a computer and / or by an electronic motion control system.

[0231] Advantageously, the nesting systems described herein may have similar stiffness. This can ensure that the total stiffness of the nesting system is relatively continuous. The nesting systems described herein may be compact to fit a wide variety of anatomical structures. For example, in neurological applications, the outer diameter of the system may be between 0.05" and 0.15", such as approximately 0.1". In cardiac applications, the outer diameter of the system may be between 0.1" and 0.3", such as approximately 0.2". In gastrointestinal applications, the outer diameter of the system may be between 0.3" and 1.0", such as 0.8". Furthermore, the nesting systems described herein may maintain high stiffness even in small profiles. For example, the change in relative stiffness from a flexible configuration to a stiffened configuration may be 10x, 20x, 30x, or more. Additionally, the nesting systems described herein may advantageously move more smoothly relative to one another.

[0232] The nesting system described herein is advantageous because it can be guided through any path or open, complex, or curved space to provide a freestanding range of complex shapes. The nesting system is also advantageous because it allows shape propagation to be performed to impart shape memory from one element to another. In some embodiments, periodically, both tubes are placed in a partial or complete flexible state so that, for example, the radius or curvature of the system increases, and the surrounding anatomical structure supports the system. When the pressure or vacuum used to stiffen the tubes is reduced or stopped, the tubes are placed in a partial or complete flexible state. This temporary relaxation (e.g., 1-10 seconds) allows the system to find a shape that more closely resembles the anatomical shape it will travel through. For example, in the large intestine, this relaxation gently opens up the sharp turns of the anatomical structure.

[0233] In some embodiments, the stiffening properties of the inner and outer stiffening devices can be designed such that the sharp curve formed at the tip by the inner stiffening device when replicated in the outer stiffening device gradually opens up (has a larger radius) as the shape progresses proximally to the outer tube. For example, the outer stiffening device can be designed to have a large minimum radius of curvature when stiffened.

[0234] The Nested System is continuous (i.e., not fragmented), which allows for smooth, continuous movement through the body (e.g., the intestine). The Nested System is disposable and low cost.

[0235] In some embodiments, the outer stiffening device can be a dynamic stiffening overtube (e.g., as described in International Patent Application No. PCT / US18 / 42946, which is incorporated by reference in its entirety). In some embodiments, the inner stiffening device can be a stiffening system or a commercial scope, such as a 5 mm diameter nasal endoscope. The use of a stiffening nesting system allows for the use of a smaller scope, offering greater flexibility if desired, greater stiffness if desired, improved maneuverability, and the ability to articulate at a much smaller radius of curvature, as compared to a duodenoscope.

[0236] In some embodiments, once the destination is reached, the inner stiffening device of the nesting system is withdrawn, while the outer stiffening device remains stiffened and contrast can be introduced into the fluoroscopic image through the spaces of the inner elements.

[0237] An RF coil may be used with any of the nested systems described herein to obtain a 3D representation of whatever shape the nested system may assume, which may be used to reshape or return to a given point (e.g., for follow-up by a physician after an automated colonoscopy).

[0238] In some embodiments, the Nested Systems described herein can be used as a complete endoscope, with internal structures supporting a payload of working channels, pressurized lines, vacuum lines, tip irrigation, and electronics for illumination and imaging (vision systems, ultrasound, x-ray, MRI).

[0239] The nesting systems described herein may be used, for example, for colonoscopy. Such colonoscopy nesting systems may reduce or eliminate loop formation. They may eliminate the need for endoscope reduction. Because there is no loop formation, the procedure may combine the speed and low cost of sigmoidoscopy with the efficiency of colonoscopy. Additionally, the colonoscopy nesting systems may eliminate conscious sedation and its associated costs, time, risks, and equipment requirements. Furthermore, by using the nesting systems described herein, the procedural techniques for such colonoscopic procedures may be significantly reduced. Furthermore, in some embodiments, the nesting systems described herein provide automated colonoscopy, where a vision system automatically advances the nesting system into the center of the colon while searching for polyps. Such an automated system would be advantageous since it would require neither sedation nor a physician for the basic examination, and would allow for follow-up by the physician for subsequent examinations, if necessary.

[0240] In some embodiments, the stiffening devices described herein may be configured as stiffening rods. With reference to FIG. 66, rod 4900 may include an outer layer 4901, a braided layer 4909, and an inner reservoir layer 4921. Additionally, gaps 4912 within the reservoir layer may be sealed and filled (e.g., by pushing reservoir layer 4921 radially outward), for example, with air or water. Outer layer 4901 may be a wire reinforced layer, such as a coil reinforced urethane tube. Braided layer 4901 may include braided strands 4933 and may include any of the features of other braided layers described herein. Inner braided layer 4921 may be fabricated from a low durometer elastomer. Rod 4900 may further include an atraumatic tip that is soft and / or tapered.

[0241] In some embodiments, the distal end of the inner reservoir 4921 is sealed to the outer layer 4901, and the rod 4900 may include an inlet between the outer layer 4901 and the inner reservoir 4921 to provide a vacuum for curing. In other embodiments, the distal end of the inner reservoir 4921 may be sealed to itself or to an atraumatic distal tip, and the proximal end may be configured with an inlet to the inside of the inner reservoir 4921 (i.e., radially inward of the inner reservoir 4921) where pressure curing occurs. When pressure curing is used, the rod 4900 may further include vents at the distal and / or proximal ends to allow for the escape of air from the inner reservoir 4921 to the outer layer 4901 (so that the reservoir 4921 can fully press the braided layer 4909 against the outer layer 4901).

[0242] In some embodiments, the outer surface of the outer layer 4901 is coated to provide a low friction surface including a hydrophilic coating. In some embodiments, the outer diameter of the rod 4900 can be less than 5 mm, less than 4 mm, or less than 3 mm. For example, the outer diameter can be between 2 mm and 5 mm, such as between 2.5 mm and 3 mm, or approximately 2.8 mm. In some embodiments, the angle of the braid of the braided layer 4909 can be less than 25 degrees relative to the longitudinal axis of the tube, such as approximately 5 to 15 degrees. In some embodiments, there can be between 10 and 50 strands, such as 20 to 40 strands extending within the braided layer 4909.

[0243] 67, the rod 4900 may be used, for example, as a stiff wire for colonoscopy. In such use, the colonoscope 5091 may be inserted into the colon of a patient. If looping occurs (thus preventing the colonoscope from advancing), the scope 5091 is left in place, the working channel 5055 of the scope 5091 is flushed, water is sprayed on the outer surface of the rod 4900 to activate the hydrophilic coating, and the rod 4900 is inserted into the working channel 5055 in a flexible (i.e., unstiffened) state. Once the rod 4900 is inserted sufficiently into the endoscope such that the distal end of the rod 4900 is flush with the distal end of the colonoscope 5091, a vacuum or pressure is applied to the rod 4900 (e.g., via a pressure inlet and / or connector 5063z) to stiffen the rod. In some embodiments, the pressure or vacuum may be supplied to the rod 4900 through a syringe or locking injector. The colonoscope 5091 is advanced over the rod 4900 relative to the patient while keeping the rod 4900 stationary relative to the patient. The vacuum or pressure is removed to advance or remove the stiffening rod 4900.

[0244] Thus, the rod 4900 is advantageously inserted into the scope 5091 in a flexible configuration such that it is easily guided around curves as opposed to a standard stiff wire (i.e., a stiff wire with a constant hardness). Furthermore, the rod 4900 conforms to the shape of the looped colon in the flexible configuration, while in the stiffened configuration, it provides a stiff track for the scope to follow. The dynamic transition of the rod 4900 between the flexible and stiff configurations can prevent unwanted straightening of the scope 5091 (which may otherwise occur with standard stiff wires). Furthermore, the atraumatic tip of the rod 4900 can prevent damage to the working channel 5055. The stiffening rod 4900 is also relatively long (e.g., longer than the scope) and does not impede guidance of the scope as it moves over or along the stiffening rod 4900, thus allowing the rod 4900 to function with a variety of scopes regardless of the length of the scope. Similarly, rod 4900 has a diameter of 3.2 mm or less, and therefore can function with a variety of endoscopes regardless of diameter (as most endoscopes have working channels of 3.2 mm or more).

[0245] The sclerosing systems and devices described herein can be used to treat or access a number of different anatomical locations.

[0246] In one method of use, during a surgical procedure, the stiffening devices described herein can be introduced into a patient in a flexible configuration. Once the distal end of the stiffening device is positioned beyond a difficult anatomy (e.g., a portion of the anatomy that may cause looping or is otherwise difficult to traverse with standard instruments), the stiffening device transitions to the stiffening configuration. An instrument (e.g., a scope) is then passed over or through the stiffening device.

[0247] For example, the devices described herein may be used to navigate the gastrointestinal tract, for abdominal access to anatomical locations that would otherwise be blocked by other organs, for interventional endoscopic procedures (including ESD (endoscopic submucosal dissection) and EMR (endoscopic mucosal resection)), for direct cholangioscopy, for endoscopic retrograde cholangiopancreatic imaging, for cardiac applications, for resection or snare of gastrointestinal lesions, for enteroscopy, for EUS to access the lungs or to access the kidneys, for neurological applications, for chronic total occlusions, for laparoscopic manual tools, for contralateral leg access, for ENT applications, during esophagoduodenoscopy, for transoral robotic surgery, for flexible robotic endoscopes, for natural orifice transluminal endoscopic surgery, or for cases of anatomical abnormalities. Specific examples are further described below.

[0248] Additionally, the stiffening devices described herein may have different dimensions depending on the desired application. For example, when designed for gastrointestinal use, the stiffening device may have an inner diameter of approximately 0.3" to 0.8" (e.g., 0.5"), an outer diameter of 0.4" to 1.0" (e.g., 0.6"), and a length of 50 to 200 cm, such as 75 to 150 cm. For example, when designed for cardiovascular use, the stiffening device may have an inner diameter of approximately 0.04" to 0.3" (e.g., 0.2"), an outer diameter of 0.06" to 0.4", and a length of 30 to 130 cm.

[0249] The stiffening devices described herein can be used as an overtube for a scope in at least three different ways: (I) placing the overtube after the scope has reached its destination, (II) the overtube closely trails the scope but is proximal to the tip of the scope until it has reached its destination, and (III) a point-and-shoot method. An exemplary stiffening device 2000 and scope 2091 are shown in Figures 68A-68B.

[0250] In Method I, the scope 2091 is placed on the body at the desired location using standard techniques, and then the stiffening device 2000 is advanced from the proximal end until it adequately supports the scope 2091. For example, to perform a colon resection, the physician advances the colonoscope to the target site and then advances the stiffening device nearly or completely to the tip of the endoscope, and the stiffening device 2000 stiffens. The stiffening device 2000 is advantageous because it improves control during colon resection, for example, by providing a stable surgical platform. The stiffening device 2000 is also advantageous because it may facilitate a good connection between the movement of the shaft of the scope 2091 by the physician's hand outside the patient and the movement of the tip of the scope 2091 (so-called "one-to-one" movement).

[0251] For Method II, the scope 2091 communicates with the stiffening device 2000 (e.g., the distal end of the scope 2091 and the distal end of the stiffening device 2000 are never nearly aligned), and the stiffening device is repeatedly switched between flexible and stiffened states to aid in advancing the scope. For example, as the scope 2091 is advanced, the stiffening device 2000 may be in a stiffened state to help prevent the scope from looping and aid in the transmission of scope forces. Once the scope 2091 has been advanced, the stiffening device becomes flexible again and is advanced distal to the scope. The process can be repeated.

[0252] Method III may include the following steps: (1) the curing device 2000 is placed in a flexible state with the distal end of the curing device 2000 generally aligned with the distal end of the scope 2091; (2) the scope 2091 is steered with the distal end of the curing device 2000 disposed thereon, and therefore steered by the scope 2091; (3) the curing device 2000 is placed in a curing state that is a mirror image of the steered position of the scope 2091; (4) the distal end of the scope 2091 is advanced. This point-and-shoot method is advantageous because it allows the scope 2091 to be advanced in the direction that the tip of the scope 2091 is pointing. In some embodiments, the steps may be repeated to advance the curing device 2000 and the scope 2091 within the body cavity or lumen.

[0253] It should be understood that Methods I-III may be used in combination with one another. Additionally, in some embodiments, the curing device may be steerable to further provide direction for the scope.

[0254] Three different control techniques may be used in the GI tract. For example, as shown in Fig. 69A, these techniques may allow an endoscope 2691a to be placed in the upper GI tract 2646z with a stiffening device 2600a. As another example, as shown in Fig. 69B, a stiffening device 2600b may be used to place an endoscope 2691b in the lower GI tract 2647z. The control techniques described may make the placement shown in Figs. 69A and 69B easier or faster to achieve, while minimizing the risk of complications (such as GI perforation) and reducing or eliminating patient discomfort due to endoscopic loop formation.

[0255] The hardened devices and systems described herein may be used for endoscopic retrograde cholangiopancreatography (ERCP) and / or direct cholangioscopy (DC). The goal of endoscopic retrograde cholangiopancreatography is to diagnose and treat diseases of the bile and pancreatic ducts. This is most commonly performed with a side-viewing duodenoscope by guiding a guidewire into the bile and pancreatic ducts, introducing contrast into the ducts, viewing with fluoroscopy, and passing various tools into the ducts with a wire. It is desirable to directly view the ducts with a camera rather than using radiation and contrast introduction. By passing a miniature endoscope into the bile duct, the ducts can be directly viewed without radiation. However, it is very difficult to navigate such a miniature endoscope through the stomach into the bile duct because the scope has a tendency to form loops.

[0256] Cannulation of the bile and pancreatic ducts is difficult for two reasons. First, the endoscope must be small to fit inside the small ducts, which means that it must be very flexible and buckle inside the stomach as it exits. Second, the entrances to the ducts (papillae) are on the sides of the duodenal wall, which means that the endoscope must bend and advance at an angle to its long axis, which cannot be done without surface flexion. The stiffening devices described herein can be used to create more optimal access and stabilization during ERCP and DC, including the kinematically and clinically challenging task of cannulating the papilla. For example, the devices described herein can be used to both access the papilla (typically performed with a duodenoscope) and cannulate the bile and pancreatic tree ducts.

[0257] 70A-72D, the stiffening devices described herein may be used in a variety of ways for ERCP and direct visualization (cholangioscopy) of the pancreatic and bile ducts. For example, as shown in FIGS. 70A-70B, stiffening device 8300 (similar to the stiffening device of FIG. 25) with steerable distal end 8302z may be used on a cholangioscope 8391. The cholangioscope 8391 may be a flexible endoscope with a camera, lighting, and optionally a tool channel designed to achieve the bend radius and diameter required for navigation into the bile duct. The bending radius of the cholangioscope 8391 is 0.5" and the diameter of the insertion tube at the distal tip is 2mm-6mm. The cholangioscope 8391 is placed inside the stiffening device 8300 and the stiffening device 8300 starts in a flexible state. The two devices 8300, 8391 can be guided together through the upper GI tract to the duodenum 8354z (alternatively, when deemed necessary by the operator, the cholangioscope 8391 advances in front of the stiffening device 8300 and the stiffening device 8300 follows). Once in the duodenum 8354z, the stiffening device 8300 stiffens and is steered to the angle of the cholangioscope 8391 towards the entrance of the duct (papilla 8355z). The steering of the stiffening device 8300 is fixed in position and the cholangioscope 8391 is steered towards the papilla. 70B, the cholangioscope 8391 is advanced over the wire 8385 into the bile duct 8357z to achieve direct cannulation. The stiffening device 8300 in this manner advantageously supports the small cholangioscope 8391 to keep it from buckling in the stomach, and the steering section 8302z of the stiffening device 8300 advantageously flexes the cholangioscope 8391 to direct it towards the papilla. As a result, direct visualization is achieved, reducing the amount of radiation required during ERCP.

[0258] Another exemplary ERCP method is shown in Figures 71A-71B. In this embodiment, a stiffening device 8400 may be used that does not include a steerable distal end. A cholangioscope 8491 may be used to steer the stiffening device 8400 while in a flexible configuration to orient the stiffening device 8400 towards the papilla 8455z. Once correctly oriented, the stiffening device 8400 may be stiffened. The cholangioscope 8491 is then advanced in the same manner as described above with respect to Figures 70A-70B. This method may be referred to as the "point and shoot" method of direct cholangioscopy.

[0259] Another exemplary ERCP method is shown in Figures 72A-72D. In this embodiment, the stiffening device 8500 includes at least two working channels (e.g., similar to the devices of Figures 20A-20B and 21A-21B). The cholangioscope 8591 is initially placed in the first tool channel for navigation and cannulation of the papilla 8555z. Once the guidewire 8585 has traversed the biliary duct 8557z (as shown in Figure 72B) or the pancreatic duct (8556z), the cholangioscope 8591 is removed from the first tool channel, leaving the wire 8585 in place inside the duct 8557z (as shown in Figure 72C). The cholangioscope 8591 can then be placed in the second tool channel (e.g., extending laterally from the wall of the device 8500 as shown in Figure 81) to view the duodenal side of the papilla 8555z (as shown in Figure 72D). The first tool channel may be used to place a larger device such as a stent 8558z that is placed in the vessel 8557z. In some embodiments, it may be useful to have an external (duodenal) view of the papilla 8555z during stent placement since the stent 8558z occupies most of the diameter of the vessel 8557z and a portion of the stent 8558z remains inside the duodenum 8554z.

[0260] In another exemplary ERCP method, a stiffening device similar to that of FIG. 59 includes a single tool channel that runs the entire length of the device. The stiffening device includes a camera mounted on the exterior of the stiffening device just proximal to the steering section. Cannulation, ERCP, and direct biliary examination can be performed similar to the methods described above. When a stent or large tool is used, the cholangioscope is removed from the tool channel and the stiffening device camera can be used to visualize the exterior of the papilla while the large instrument or stent is being used.

[0261] In another exemplary ERCP method, the stiffening device includes an aspiration tip at its distal end, as depicted in Figures 46A-46B. The aspiration tip surrounds the papilla, and suction can be applied at the tip. This action stabilizes the papilla and makes it easier to orient the cholangioscope at the proper location to cross the wire. Holding the tissue around the papilla can also provide some counter tension when the wire or cholangioscope presses against the papilla. Providing counter tension to the compressive force of the cholangioscope or other tools can reduce the number of sphincterotomes (cutting of the papilla) required.

[0262] Advantageously, the sclerosing devices used in the ERCP described herein are disposable and sterile, reducing the risk of infection or patient-to-patient contamination. This method further results in reduced radiation to the nipple and easier navigation due to steering capabilities of the sclerosing device and / or scope.

[0263] The stiffening devices and systems described herein may be used in cardiology and cardiac surgery, including the aortic and mitral valves.

[0264] Typically, in transcatheter, percutaneous procedures, the clinician influences movement from an access site (e.g., an artery or vein in the groin, arm, etc.) using some type of flexible rod or shaft that is appropriately stiff to advance the catheter to the treatment site, but flexible enough to conform to the anatomy. This means that all of the force or leverage occurs at the remote access site and is reflected from the more local anatomy to (a) bend the flexible rod or shaft for guidance to the treatment site, and (b) provide local forces (linear and torque) at the treatment site. In contrast, the dynamic stiffening device described herein effectively moves the access site to the treatment site by providing a means to both navigate to the treatment site through tortuous anatomy and stiffen and form a stable port at the treatment site, independent of anatomical reflections.

[0265] One advantage of the stiffening devices described herein is their ability to conform to the surrounding anatomical structures (e.g., blood vessels). Devices such as guide catheters need to provide a certain amount of stiffness to advance through the anatomical structures (e.g., blood vessels) and perform the required functions. However, stiffening systems prevent the device from advancing to the target anatomical structure, at least in part, through a very tortuous path to allow the anatomical structure to conform to the device, which leads to trauma to the surrounding tissue and blood vessels. In contrast, the stiffening devices described herein are flexible enough to move through the vasculature and conform to the vasculature rather than reshaping it. The inchworm enabled by the stiffening devices or nesting systems described herein allows for this flexible forward movement. Once the device is advanced to the target site, stiffening allows for the preservation and utilization of the pathway formed in the vasculature. The stiffening devices described herein can be, for example, 1 / 10 as stiff as a typical guide catheter in a flexible state and 5 times as stiff as a typical guide catheter in a stiffened state.

[0266] In some embodiments, the stiffening devices described herein may be used during percutaneous procedures in the heart or vasculature. The stiffening devices can conform to the cardiac anatomy and provide a local distal fulcrum for instrument manipulation. Currently, when performing percutaneous procedures, mechanical fixation and stabilization occurs at the access site (e.g., femoral vein, radial artery, iliac vein, etc.). As described above, this fixation point creates a long moment arm that extends from the access site to the treatment site. Furthermore, as described in more detail below, the mechanical linkage created by typical rigid catheter systems between the access site and the target anatomy relies on anatomical reflexes to direct and transmit forces to the catheter tip to the tool being used. Rigid catheter systems generate latent energy along the access route when they are bent to conform to the anatomy. This energy is released upon voluntary or involuntary patient movement or unintentional movement by the operator at the access site. In contrast, the stiffening devices described herein conform to the anatomical pathway prior to stiffening, eliminating the stored energy associated with rigid catheter systems. Once cured, mechanical fixation is achieved independent of anatomical reflexes, significantly shortening the moment arm and increasing the physician's control over the procedural tool, resulting in more predictable outcomes. In some embodiments, the curing device includes an integrated hemostatic valve, obviating the need for a separate access sheath.

[0267] In some embodiments, the stiffening devices described herein can be used to provide stiffness to guide sheaths in interventional cardiology or structural heart cases. For example, stiffening devices can be used to provide "rails" for transcatheter aortic valve replacement (TAVR) devices, protecting the tip of the TAVR catheter from scratching or tearing the upper part of the aortic arch, which is highly thrombus laden (current systems ride on the outside of the arch and scrape against spots, creating embolic debris). The stiffening devices help enable low paravalvular leakage and optimal placement relative to the pacing node, along with excellent alignment and placement.

[0268] In some embodiments, the stiffened devices described herein may be used as a delivery system passing from the venous circulation through the right atrium and atrial septum to the left atrium and then antegrade through the mitral valve to the left atrial outflow tract and aortic valve. In this way, transcatheter aortic valve implantation (TAVI) may facilitate avoidance of contact with the aortic arch and aortic ascent that is common with retrograde deployment.

[0269] In some embodiments, the stiffening devices described herein may be used in the delivery of mitral valve replacement. That is, crossing the septum during mitral valve replacement can be particularly challenging with multiple curves, a beating heart, and the need for precisely aligned insertion and stabilization prior to delivery of the implant. Current valve delivery platforms are fairly rigid and hazardous to straight anatomical structures (such as the femoral artery, which can be highly calcified and weak). The stiffening devices described herein are advantageous because they can flexibly advance and form a conduit that stiffens a particular person's anatomical structure in any shape, allowing the stiffening device to conform to the entire anatomical trajectory. As a result, the stiffening devices described herein allow the clinician to form a stable mechanical lumen directly into the anatomical structure to place it without significant local anatomical loads, and then to be stabilized with stiffness in that shape as the device is delivered.

[0270] FIG. 73A depicts an embodiment of a stiffening device 3700 advanced through the left atrium from the right atrium RA of the heart. A guidewire or other piercing member and dilator may be used to pierce the atrial septum 3704 to provide access to the left atrium LA. The stiffening device 3700 may be advanced to the treatment site using methods described herein. A cardiac tool 3787 (sclerosing or not) may be advanced within the stiffening device 3700. For example, the cardiac tool 3787 and stiffening device 3700 are advanced as described with respect to the nesting system shown herein as in FIGS. 65A-H. The dynamic nature of the stiffening allows the device 3700 and tool 3787 to be advanced through tortuous anatomy. Once stiffened at the treatment site, the stiffening device 3700 may provide a stable foundation for treatment. Optionally, the sclerosing device 3700 may include an anchoring balloon 3778 near the distal tip that anchors the sclerosing device 3700 to a chamber of the heart, for example, to the atrial septum 3704, to maintain the tip of the tube 3700 in the left atrium LA. The detailed view of FIG. 73B shows the balloon 3778. The balloon 3778 may be positioned anywhere around the circumference of the tube 3700. In some embodiments, the balloon is annular and surrounds the circumference of the tube 3700. The sclerosing device 3700 may include an echogenic tip. Other tips that allow real-time viewing are possible (e.g., an x-ray tip, a scope in a saline filled bag, etc.).

[0271] 74A-74B illustrate an exemplary method for using a dynamic stiffening device to perform treatments in small branching vessels such as coronary arteries. When navigating these small vessels, applying force to these areas often pushes the guide catheter or other advancement device into the area. Sometimes, an access sheath is used in these situations to provide a slight mechanical advantage. Again, using such an access sheath, applying force, for example, to push against an occlusion, pushes the entire device out of the area. FIGS. 74A-74B compare the use of a standard guide catheter to the stiffening device described herein. In FIG. 74A, a standard guide catheter 3886 is used to navigate to an ostium 3845 of one of the main coronary arteries 3842. A guidewire 3885 extends from the tip of the guide catheter 3886 and can be used to perform the procedure (e.g., placement of a stent). The guide catheter 3886 can, in some embodiments, be reflected from nearby anatomical structures 3873 to achieve mechanical advantage, prevent catheter pushback, and / or provide a more localized force. In contrast, Figure 74B shows a sclerosing device 3800 as described herein advanced through an ostium 3845 into a coronary artery 3842. Because of the sclerosing capabilities of the device 3800, it does not need to bounce off local anatomical structures and instead provide inherent stabilization at the treatment site. Additionally, because of the dynamic sclerosing capabilities of the sclerosing device, it may be advanced beyond the ostium 3845 into the coronary artery 3842.

[0272] FIG. 75A shows an exemplary method of using a dynamic stiffening overtube system to perform mitral valve repair. The method illustrates how the stiffening device 3900 is positioned in the left atrium LA so as to solely maintain axial alignment with the treatment site, in this example the mitral valve. As shown in FIG. 75A, the stiffening device 3900 is advanced through the vasculature into the right atrium RA and through the atrial septum into the left ventricle LA. The end of the stiffening device can be steered so that the longitudinal axis 3983 extending to the end 3969 of the tube is aligned with the desired treatment site area (e.g., a portion of the valve). The ability to steer, dynamic stiffening, and tip visualization allows for precise placement of the stiffening device. For example, the axis 3983 extends from the mitral valve MV to the left ventricle LV. Another position 3964 of the stiffening device 3900 is shown in dashed lines, with its axis extending to the leaflets of the mitral valve MV. Current methods of mitral valve repair utilize a guide catheter that is navigated to the left atrium LA and often do not allow for reliable axial alignment. The presently disclosed method of using a stiffening device 3900 to achieve axial alignment in a flexible state prior to stiffening provides significant advantages over currently used methods for positioning during procedures such as mitral valve repair. This type of precise alignment is also beneficial in other areas of the anatomy (e.g., other valves, transseptal access sites, endovascular cavities), including the ability to place sutures, clips, and other devices within the heart with the same precision typically maintained in open chest surgery.

[0273] 75B, the stiffening device 3900 used in a procedure such as that shown in FIG 75A can include a variety of configurations. In some embodiments, the stiffening device 3900 can be steered and positioned using a guidewire 3985. In some embodiments, the stiffening device 3900 can include a nesting system that includes an inner stiffening device 3910.

[0274] As shown in Figure 75C, in one embodiment, a needle tip catheter 3958z is advanced through the stiffening device 3900 and positioned within a cardiac geometry, such as above the mitral valve leaflets. In some embodiments, the needle tip catheter 3958z can house an anchoring device 3962z (pledget, stainless steel pledget, etc.) that is attached to a length of suture 3959z that passes through tissue to provide an anchor for the suture. The suture and anchors delivered within the stiffening device can be used to suture tissue structures together, such as a leaflet plication for mitral valve repair.

[0275] It will be appreciated that a system incorporating one or more of the stiffening devices described herein may be used in cardiac procedures other than mitral valve repair. For example, the system may be used in complex mitral valve procedures where the goal is to perform leaflet repair and mitral valve repair during the same procedure. The system may be used to perform transseptal delivery of aortoplasty (e.g., TAVI). In some embodiments, the system may be used to perform mitral valve repair via transseptal access. A combination of dynamic stiffening overtubes may be used in concert to pass sutures or other devices from one chamber of the heart to another. In any of these procedures, the dynamic stiffening system described herein may be provided with a cannula or access sheath that provides universal access to the various chambers of the heart.

[0276] FIG. 76A shows an exemplary dual stiffening cannula system that may be placed simultaneously in multiple chambers of the heart. The two stiffening cannulas 4000a, 4000b are axially aligned to provide the ability for the clinician to pass instruments from one cannula to the other. In use, the first stiffening cannula 4000a is steered from the right atrium RA to the left atrium LA with the tip 4004 of the cannula facing the mitral valve 4081. The stiffening cannula 4000a may be stiffened in this position. The cannula 4004a may include a bent section near the tip 4004 to properly position the tip and steer the device. The second cannula 4000b may be steered in a retrograde direction from the aorta 4066z to the left ventricle LV. The cannula 4000b may be steered and positioned so that the tip 4039 is positioned below the mitral valve facing the tip 40004 of the first cannula 4000a. The cannula 4000b may be stiffened in this position. The axis 4014 extending between the tip 4004 of the first cannula and the tip 4039 of the second cannula may be aligned with the area to be treated. This dual access allows, for example, sutures to pass from one cannula to the other and / or tools to pass between. Using two cannulas, procedures may be performed with greater precision and accuracy (e.g., the treatment area may be approached from above, below, or both). Examples of procedures that may be performed with such two stiffening cannulas 4000a, 400b include leaflet plication with standard suturing techniques and annuloplasty with conventional rings. Each cannula 4000a, 4000b includes multiple working channels and provides fixed access sites within the heart. Providing these dual fixation sites allows for the repetition of standard open chest procedures through a much less invasive percutaneous access.

[0277] FIG 76B shows the dual stiffening cannula system of FIG 76A being used to pass a suture through tissue. A first stiffening device 4000a is placed on a first side of the tissue 4061z to be sutured. A second stiffening device 4000b is placed on the opposite side of the tissue 4061z. A needle catheter 4058z placed by the first device 4000a may be used in combination with a tool 4065z, such as a grasper, snare, or the like, placed by the second tube 4026 to pass the suture through the tissue 4061z.

[0278] Referring to FIG. 77, in some embodiments, the stiffening devices described herein may be used as trocars during endoscopic procedures. FIG. 77 shows a dynamically stiffening trocar 4141 and a standard trocar 4138. Typically, when using a standard trocar 4138, the initial placement of the trocar 4138 is imprecise, necessitating removal and repositioning. In contrast, the dynamically stiffening trocar 4141 allows for fine adjustments during or after placement of the trocar. As described with respect to other dynamically stiffening devices disclosed herein, the dynamically stiffening trocar 4141 may have steering capabilities. Using this capability, the trocar 4141 may be bent or flexed in a desired direction and then stiffened, allowing for much greater control than a standard trocar. The dynamically stiffening trocar 4141 may be used in cardiac applications and / or elsewhere in the body. Additionally, the trocar 4141 may be provided in different sizes or shapes depending on the application.

[0279] Referring to FIG. 78, the dynamic stiffening device 4200 may be used at the aortic bifurcation 4297. This area of ​​vasculature is commonly diseased and requires complex repairs due to the extremely tortuous anatomy of this site. Currently, many catheters or other delivery devices used to treat this area travel to the apex of the bifurcation and deploy tools from there. As shown in FIG. 78, the dynamic stiffening device 4200 can be navigated around the bifurcation 4297 using a combination of steering and dynamic (e.g., cyclic) stiffening to reach any treatment site in the area. For example, the system shown in FIG. 78 may be used to treat a CTO (chronic total occlusion) in one leg by gaining percutaneous access in the other leg.

[0280] 79, a stiffening device 4700 comprising an active bending segment 4746 and a steerable distal section 4747 may be used in the heart to perform mitral valve repair. The stiffening device 4700 may be positioned in the left atrium LA to solely maintain axial alignment with the treatment site, in this example the mitral valve MV. The stiffening device 4700 is then advanced through the vasculature to the right atrium RA and through the atrial septum to the left atrium LA. The end of the stiffening device may be steered such that the longitudinal axis 4783 extending through the end 4769 of the tube is aligned with the desired treatment area (e.g., a portion of the valve). To achieve the desired positioning, the active bending segment 4746 is bent in the relatively unconstrained space between the IVC and the atrial septum, while the distal steerable section 4747 may be positioned in the left atrium LA and steered or oriented toward the mitral valve MV. In such a position, the curing device 4700 may have a bend at an angle of 90 degrees or greater and with an arc radius of approximately 4-6 cm, such as 5 cm.

[0281] 80, a stiffening device 4800 (with active flexing segment 4846 and steerable distal section 4847) for use in mitral valve repair may include an attached distal payload 4848 (e.g., a mitral valve clip, mitral valve replacement, or annuloplasty ring). While a distal payload 4848 is attached, the incorporation of active flexing segment 4846 and steerable distal section 4847 may also advantageously reduce or eliminate the need for an external large bore guide catheter during such procedures. Catheters 4800 (or 4700) for use in mitral valve procedures may be, for example, 14-40 Fr and 80-120 cm long.

[0282] A method of using the stiffening device 4700 or 4800 may include: (1) introducing the device into the distal circulation; (2) advancing the device to the target anatomical structure (e.g., a heart valve); (3) creating a first bend with the active flexion segment (e.g., passing through the bend between the IVC and the septum, which is approximately 90°); (4) locking the active flexion segment in the bent configuration using pressure or vacuum; (5) reaching the mitral valve plane and the mitral valve using the steerable distal section; and (6) delivering a therapy or payload.

[0283] The stiffening devices with active bending sections and steerable distal sections described herein may also be used, for example, for placement of fenestrated grafts for thoracic arteries and for repair of abdominal aneurysms that contain critical branch vessels requiring treatment.

[0284] The sclerosing devices and systems described herein may be used to resect or snare lesions in the gastrointestinal tract.

[0285] 81A-81F, in some embodiments, the stiffening device 700 can be configured to control the orientation of a working tool 777 extending within the working channel 755. For example, the stiffening device 700 can include a flexible distal section 702z that is more flexible than a proximal stiffening elongate body 703z (which can include stiffening features as described herein) extending proximally. With reference to FIG. 81A, an endoscope 791 with a scope steering section 776 can be placed within the stiffening device 700 in a blood vessel 760z. With reference to FIG. 81B, the stiffening device 700 can be moved distally such that the flexible distal section 702z is positioned over the steering section 776 of the endoscope 791. As shown in FIG. 81C, when the steering section 776 flexes, the flexible distal section 702z and the connected working channel 755 flex with it, thereby steering the tool 777 within the working channel 755 (to a lesion 779 in the blood vessel 736). As shown in FIGURE 81D, a tool 777 is then advanced out of the working channel 755 to the desired location (e.g., lesion 779). With reference to FIGURE 81E, the stiffening device 700 is pulled proximally to move the flexible distal portion 702z out of the steerable section 776 and also move the working channel 755 further proximally. As shown in FIGURE 81F, the scope 791 may thus be steered (by the steerable section 776) without interfering with the placement or orientation of the working tool 777.

[0286] The curing devices and systems described herein may be used in enteroscopy, where navigation is performed throughout substantially the entire small intestine to diagnose and / or treat disease.

[0287] Enteroscopy is kinematically challenging for several reasons, including the relatively small diameter of the scope (9 mm), its great length (2 meters), and the frequent formation of loops when navigating the digestive tract to reach the beginning or end of the small intestine (the pylorus or ileocecal valve, respectively).

[0288] The curing devices and systems described herein may be used for IEUS.

[0289] The sclerosing devices and systems described herein may be used to access the lung. For example, the sclerosing device 2100 and scope 2191 are assembled concentrically (scope inside the sclerosing device) and placed through the mouth into the trachea and into the carina. As detailed herein, a "point and shoot" method is employed at the carina to advance the scope into the left and right main bronchi. The "point and shoot" method may be used iteratively to select additional deeper branches of the lung.

[0290] The stiffening devices and systems described herein may be used to access the kidney. For example, the stiffening device 2100 and scope 2191 are assembled concentrically (scope inside stiffening device) and then placed through the urethra into the bladder. As detailed herein, a "point and shoot" method is employed at the bladder to advance the scope to the left and right urethra. The "point and shoot" method may be used iteratively to help the scope reach the kidney.

[0291] The curing devices and systems described herein can be used for navigation within the neural anatomy.

[0292] The systems described herein may be used to access the carotid artery or distal vessels leading to or within the brain.

[0293] For example, a guidewire can be placed into the carotid artery. A stiffening device or sheath is placed over the guidewire and directed into the carotid artery. When an overtube or sheath is placed at the target site, it reduces the chance of the catheter or guidewire slipping out into the aortic arch during the procedure.

[0294] The curing devices and systems described herein can be used for accessing and / or treating chronic total occlusions (CTOs).

[0295] Thus, in some embodiments, the stiffening device can be incorporated into a catheter for interventional cardiology so that it can be advanced very easily (due to its flexibility) and stiffened when the device is used, for example, to be pushed within the local anatomical structure, such as when treating a CTO.

[0296] The stiffening devices and systems described herein may be used with laparoscopic manual tools.

[0297] The curing devices and systems described herein may be used to access the opposite leg.

[0298] The sclerosing devices and systems described herein can be used in ear, nose and throat (ENT) applications.

[0299] The sclerosing devices and systems described herein may be used to deliver treatment during an esophagoduodenal diagnosis (EGD), for example, at the roof of the stomach.

[0300] The curing devices and systems described herein can be used in TORS (transoral robotic surgery).

[0301] The sclerosing devices and systems described herein may be used in NOTES (Natural Orifice Transluminal Endoscopic Surgery).

[0302] The sclerosing devices and systems described herein may be used in cases of anatomical abnormalities, including Roux-en-Y.

[0303] It should be understood that any feature described herein with respect to one embodiment may be combined or substituted with any feature described herein with respect to another embodiment, for example, various layers and / or features of the cured devices described herein may be combined, substituted, and / or rearranged with respect to other layers.

[0304] Additional details related to the present invention, including materials and manufacturing techniques, may be adopted within the level of one of ordinary skill in the relevant art. The same is true for method-based aspects of the present invention with respect to additional operations generally or logically adopted. It is also contemplated that any feature of the described inventive variation may be described and claimed alone or in combination with one or more of the features described herein. Similarly, reference to a singular item includes the possibility that there are multiple of the same items present. More specifically, as used in this specification and the appended claims, the singular forms "a," "and," "said," and "the" include plural referents unless the context clearly dictates otherwise. It is further noted that the claims may be drafted to exclude any element. As such, this description is intended to serve as a predicate for the use of exclusive terminology such as "solely," "only," and the like in connection with the recitation of claim elements or the use of "negative" limitations. Unless defined elsewhere 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 the invention pertains. It is intended that the scope of the invention be limited not by this specification, but only by the plain meaning of the claim terms used.

[0305] When a feature or element is referred to as being "on" another feature or element, it is either directly on the other feature or element, or intervening features and / or elements may also be present. In contrast, when a feature or element is referred to as being "directly on" another feature or element, there are no intervening features or elements present. When a feature or element is referred to as being "connected," "attached," or "coupled" to another feature or element, it will be understood that it may be directly connected, attached, or coupled to the other feature or element, or intervening features or elements may be present. In contrast, 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, the features and elements so described or illustrated may apply to other embodiments as well. Those skilled in the art will also recognize that a reference to a structure or feature disposed "adjacent" to another feature may have portions that are above or below the adjacent feature.

[0306] 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 as well, unless the context clearly dictates otherwise. It will be further understood that the terms "comprises" and / or "comprising", as used herein, specify the presence of stated features, steps, operations, elements, and / or components, but do not exclude 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 " / ".

[0307] Spatially relative terms such as "under," "below," "lower," "over," "upper," and the like, may be used to facilitate the description of the relationship of one element or feature to another element or feature depicted in the figures. It will be understood that the spatially relative terms are intended to encompass various orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is inverted, an element described as "under" or "beneath" the other element or feature would be oriented "over" the other element or feature. Thus, the exemplary term "under" can encompass both an orientation above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. Similarly, terms such as "upwardly," "downwardly," "vertical," "horizontal," and the like are used herein for descriptive purposes only, unless otherwise specified.

[0308] The terms "first" and "second" may be used herein to describe various features / elements, but these features / elements should not be limited by these terms unless the context dictates otherwise. These terms may be used to distinguish one feature / element from another. Thus, a first feature / element described below may be referred to as a second feature / element, and similarly, a second feature / element described below may be referred to as a first feature / element, without departing from the teachings of the present invention.

[0309] When used in the specification and claims, including in the examples, and unless otherwise specified, all numbers may be interpreted as if preceded by the words "about" or "approximately", even if these words are not explicitly stated. When the words "about" or "approximately" are used to describe a size and / or location, it indicates that the stated value and / or location is within a reasonable expected range of values ​​and / or locations. For example, a numerical value may have a value that is + / -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. Numerical ranges stated herein are intended to include all subranges subsumed therein. [Appendix 1] 1. A curing device comprising: A long flexible tube; a braided layer disposed over the elongated flexible tube, the braided layer having a plurality of strands braided together at a braid angle of 5 to 40 degrees relative to a longitudinal axis of the elongated flexible tube when the elongated flexible tube is straight; an outer layer over the flexible tube and the braided layer; an inlet between the elongated flexible tube and the outer layer configured to be attached to a vacuum or pressure source; Including, a curing device configured to have a curing configuration when a vacuum or pressure is applied through the inlet and a flexible configuration when a vacuum or pressure is not applied through the inlet; wherein the braid angle is configured to change upon bending of the stiffening device when the stiffening device is in the flexible configuration. Hardening device. [Appendix 2] 2. The stiffening device of claim 1, wherein the braid angle is between 10 and 35 degrees. [Appendix 3] 2. The stiffening device of claim 1, wherein the braid angle is between 15 and 25 degrees. [Appendix 4] 2. The stiffening device of claim 1, wherein the stiffening device in the stiffening configuration is at least two times more rigid than the stiffening device in the flexible configuration. [Appendix 5] 2. The stiffening device of claim 1, wherein the stiffening device in the stiffening configuration is at least 5 times more rigid than the stiffening device in the flexible configuration. [Appendix 6] 2. The cured device of claim 1, further comprising a sliding layer adjacent to the braided layer and having a lower coefficient of friction than the braided layer. [Appendix 7] 2. The stiffening device of claim 1, wherein the elongated flexible tube includes a reinforcing element extending therethrough. [Appendix 8] 2. The stiffening device of claim 1, wherein the reinforcing element comprises a coil or a plurality of hoop-shaped elements. [Appendix 9] 2. The stiffening device of claim 1, wherein the plurality of strands are braided together at a picks per inch of between 4 and 60. [Appendix 10] 2. The curing device of claim 1, wherein the yarn is polyethylene terephthalate or stainless steel. [Appendix 11] 2. The cured device of claim 1, wherein the braided layer provides 30-70% coverage over the elongated flexible tube. [Appendix 12] 2. The stiffening device of claim 1, wherein the plurality of strands comprises 96 or more strands. [Appendix 13] 2. The stiffening device of claim 1, wherein the inlet is configured to be attached to a pressure source, the stiffening device further comprising an air reservoir configured to be pressed against the braided layer when pressure is supplied from the inlet. [Appendix 14] 14. The stiffening device of claim 13, wherein the outer layer further comprises a plurality of reinforcing elements therein. [Appendix 15] 2. The curing device of claim 1, wherein the inlet is configured to be attached to a vacuum source and the outer layer is a thin, flexible sheath. [Appendix 16] 2. The stiffening device of claim 1, further comprising a radial gap between the braided layer and the outer layer, the gap having a thickness of 0.00002" to 0.04". [Appendix 17] 2. The hardening device of claim 1, further comprising a steerable distal end. [Appendix 18] 2. The stiffening device of claim 1, further comprising a sealed channel between the elongated flexible tube and the outer layer, the sealed channel comprising a working channel, a cable guide, or an inflation lumen. [Appendix 19] 1. A method of advancing a stiffening device through a body lumen, comprising: inserting a stiffening device into the body lumen while the stiffening device is in a flexible configuration, the stiffening device comprising an elongated flexible tube, a braided layer having a plurality of strands braided together at a braid angle of 5 to 40 degrees when the stiffening device is straight, and an outer layer, the braid angle changing as the flexible tube bends in the flexible configuration; when the stiffening device reaches a desired location in the body lumen, manipulating a vacuum or pressure between the flexible tube and the outer layer to transition the stiffening device to a stiffened configuration that is more rigid than the flexible configuration; The method includes: [Appendix 20] 20. The method of claim 19, further comprising manipulating a vacuum or pressure to transition the curing device back to the flexible configuration, followed by releasing the vacuum or pressure. [Appendix 21] 20. The method of claim 19, wherein the braid angle is between 10 and 35 degrees. [Appendix 22] 20. The method of claim 19, wherein the braid angle is between 15 and 25 degrees. [Appendix 23] 20. The method of claim 19, further comprising passing a scope through the curing device while the curing device is in the curing configuration. [Appendix 24] 20. The method of claim 19, further comprising steering a steerable distal end of the hardening device through the body lumen. [Appendix 25] 20. The method of claim 19, wherein the body cavity is in the digestive tract. [Appendix 26] 20. The method of claim 19, wherein the body cavity is a heart. [Appendix 27] 20. The method of claim 19, wherein the body cavity is a kidney. [Appendix 28] 20. The method of claim 19, wherein the body cavity is a lung. [Appendix 29] 20. The method of claim 19, wherein the body cavity is a brain. [Appendix 30] 1. A curing device comprising: A long flexible tube; a braided layer disposed over the elongated flexible tube; an outer layer over the flexible tube and the braided layer; an inlet between the elongated flexible tube and the outer layer configured to be attached to a vacuum or pressure source; Inclusive of the curing device is configured to have a hardened configuration when a vacuum or pressure is applied through the inlet and a flexible configuration when a vacuum or pressure is not applied through the inlet, and a ratio of a stiffness of the curing device in the hardened configuration to a stiffness of the curing device in the flexible configuration is greater than 5; Hardening device. [Appendix 31] 31. The device of claim 30, wherein the ratio is greater than 6. [Appendix 32] 31. The device of claim 30, wherein the ratio is greater than 10. [Appendix 33] 31. The stiffening device of claim 30, wherein the braided layer comprises a plurality of strands braided together at a braid angle of 5 to 40 degrees relative to a longitudinal axis of the elongated flexible tube when the elongated flexible tube is straight. [Appendix 34] 34. The stiffening device of claim 33, wherein the braid angle is between 10 and 35 degrees. [Appendix 35] 31. The cured device of claim 30, further comprising a sliding layer adjacent to the braided layer and having a lower coefficient of friction than the braided layer. [Appendix 36] 31. The stiffening device of claim 30, wherein the elongated flexible tube includes a reinforcing element extending therethrough. [Appendix 37] 37. The stiffening device of claim 36, wherein the reinforcing element comprises a coil or a plurality of hoop elements. [Appendix 38] 31. The stiffening device of claim 30, wherein the braided layer comprises a plurality of strands braided together at between 4 and 60 picks per inch. [Appendix 39] 31. The curing device of claim 30, wherein the braided layer comprises a plurality of threads braided together, the threads comprising polyethylene terephthalate or stainless steel. [Appendix 40] 31. The stiffening device of claim 30, wherein the braided layer provides 30-70% coverage over the elongated flexible tube. [Appendix 41] 31. The stiffening device of claim 30, wherein the braided layer comprises 96 or more strands braided together. [Appendix 42] 31. The stiffening device of claim 30, wherein the inlet is configured to be attached to a pressure source, the stiffening device containing an air reservoir therein, the air reservoir configured to be pressed against the braided layer when pressure is supplied from the inlet. [Appendix 43] 43. The stiffening device of claim 42, wherein the outer layer further comprises a plurality of reinforcing elements therein. [Appendix 44] 31. The curing device of claim 30, wherein the inlet is configured to be attached to a vacuum source and the outer layer is a thin, flexible sheath. [Appendix 45] 31. The stiffening device of claim 30, further comprising a radial gap between the braided layer and the outer layer, the gap having a thickness of 0.00002" to 0.04". [Appendix 46] 31. The stiffening device of claim 30, further comprising a steerable distal end. [Appendix 47] 31. The stiffening device of claim 30, further comprising a sealed channel between the elongated flexible tube and the outer layer, the sealed channel comprising a working channel, a cable guide, or an inflation lumen. [Appendix 48] 1. A method of advancing a stiffening device in a body lumen, comprising: inserting the stiffening device into the body lumen while the stiffening device is in a flexible configuration, the stiffening device including an elongated flexible tube, a braided layer, and an outer layer; when the stiffening device reaches a desired location in the body lumen, manipulating a vacuum or pressure between the flexible tube and the outer layer to transition the stiffening device to a stiffened configuration that is stiffer than the flexible configuration, wherein the ratio of stiffness in the stiffened configuration to stiffness in the flexible configuration is greater than 5; The method includes: [Appendix 49] 49. The method of claim 48, further comprising manipulating the vacuum or pressure to transition the curing device back to the flexible configuration, followed by releasing the vacuum or pressure. [Appendix 50] 49. The method of claim 48, wherein the ratio is greater than 6. [Appendix 51] 49. The method of claim 48, wherein the ratio is greater than 10. [Appendix 52] 49. The method of claim 48, further comprising passing a scope through the curing device while the curing device is in the curing configuration. [Appendix 53] 49. The method of claim 48, further comprising steering a steerable distal end of the hardening device within the body lumen. [Appendix 54] 49. The method of claim 48, wherein the body cavity is in the digestive tract. [Appendix 55] 49. The method of claim 48, wherein the body cavity is a heart. [Appendix 56] 49. The method of claim 48, wherein the body cavity is a kidney. [Appendix 57] 49. The method of claim 48, wherein the body cavity is a lung. [Appendix 58] 49. The method of claim 48, wherein the body cavity is a brain. [Appendix 59] 1. A curing device comprising: A long flexible tube; a braided layer disposed radially outward of the elongated flexible tube; a sliding layer adjacent to the braided layer; an outer layer over the flexible tube, the braided layer, and the sliding layer; a vacuum or pressure inlet between the elongated flexible tube and the outer layer configured to be attached to a vacuum or pressure source; Inclusive of a curing device configured to have a curing configuration when a vacuum or pressure is applied through the inlet and a flexible configuration when no vacuum or pressure is applied through the inlet; the sliding layer is configured to reduce friction between the braided layer and the elongated flexible tube or the outer layer when the stiffening device is in the flexible configuration. Hardening device. [Appendix 60] 60. The cured device of claim 59, wherein the sliding layer has a lower coefficient of friction than the braided layer. [Appendix 61] 60. The device of claim 59, wherein the sliding layer comprises a powder. [Appendix 62] 60. The stiffening device of claim 59, wherein the stiffening device in the stiffened configuration is at least two times more rigid than the stiffening device in the flexible configuration. [Appendix 63] 60. The stiffening device of claim 59, wherein the stiffening device in the rigid configuration is at least 5 times stiffer than the stiffening device in the flexible configuration. [Appendix 64] 60. The stiffening device of claim 59, wherein the braided layer comprises a plurality of strands braided together at a braid angle of 5 to 40 degrees relative to a longitudinal axis of the elongated flexible tube when the elongated flexible tube is straight. [Appendix 65] 65. The stiffening device of claim 64, wherein the braid angle is between 10 and 35 degrees. [Appendix 66] 60. The stiffening device of claim 59, wherein the elongated flexible tube includes a reinforcing element extending therethrough. [Appendix 67] 67. The stiffening device of claim 66, wherein the reinforcing element comprises a coil or a plurality of hoop elements. [Appendix 68] 60. The stiffening device of claim 59, wherein the braided layer comprises a plurality of strands braided together at between 4 and 60 picks per inch. [Appendix 69] 60. The curing device of claim 59, wherein the braided layer comprises a plurality of threads braided together, the threads comprising polyethylene terephthalate or stainless steel. [Appendix 70] 60. The stiffening device of claim 59, wherein the braided layer provides 30-70% coverage over the elongated flexible tube. [Appendix 71] 60. The stiffening device of claim 59, wherein the braided layer comprises 96 or more strands braided together. [Appendix 72] 60. The stiffening device of claim 59, wherein the inlet is configured to attach to a pressure source, and further comprising an air reservoir therein, the air reservoir configured to be pressed against the braided layer when pressure is supplied from the inlet. [Appendix 73] 72. The stiffening device of claim 71, wherein the outer layer further comprises a plurality of reinforcing elements therein. [Appendix 74] 60. The curing device of claim 59, wherein the inlet is configured to be attached to a vacuum source and the outer layer is a thin, flexible sheath. [Appendix 75] 60. The stiffening device of claim 59, further comprising a radial gap between the braided layer and the outer layer, the gap having a thickness of 0.00002" to 0.04". [Appendix 76] 60. The stiffening device of claim 59, further comprising a steerable distal end. [Appendix 77] 60. The stiffening device of claim 59, further comprising a sealed channel between the elongated flexible tube and the outer layer, the sealed channel comprising a working channel, a cable guide, or an inflation lumen. [Appendix 78] 1. A method of advancing a stiffening device in a body lumen, comprising: inserting the stiffening device into the body lumen while the stiffening device is in a flexible configuration, the stiffening device including an elongated flexible tube, a braided layer, a sliding layer adjacent to the braided layer, and an outer layer, the sliding layer reducing friction between the braided layer and the elongated flexible tube or the outer layer while the stiffening device is in the flexible configuration; when the stiffening device reaches a desired location in the body lumen, manipulating a vacuum or pressure between the flexible tube and the sheath to transition the stiffening device to a stiffening configuration that is more rigid than the flexible configuration; The method includes: [Appendix 79] 80. The method of claim 78, further comprising manipulating the vacuum or pressure to transition the curing device back to the flexible configuration, followed by releasing the vacuum or pressure. [Appendix 80] 80. The method of claim 78, wherein the sliding layer has a lower coefficient of friction than the braided layer. [Appendix 81] 80. The method of claim 78, wherein the sliding layer comprises a powder. [Appendix 82] 80. The method of claim 78, further comprising passing a scope through the curing device while the curing device is in the curing configuration. [Appendix 83] 80. The method of claim 78, further comprising steering a steerable distal end of the hardening device through the body lumen. [Appendix 84] 80. The method of claim 78, wherein the body cavity is in the digestive tract. [Appendix 85] 80. The method of claim 78, wherein the body cavity is a heart. [Appendix 86] 80. The method of claim 78, wherein the body cavity is a kidney. [Appendix 87] 80. The method of claim 78, wherein the body cavity is a lung. [Appendix 88] 80. The method of claim 78, wherein the body cavity is a brain. [Explanation of symbols]

[0310] 100 Hardening Device 101 Outermost layer 103 Interstitial layer 105 Second braided layer 107 Interstitial layer 109 1st braided layer 111 Interstitial layer 113 Sliding layer 115 Innermost layer 120 lumen 133 Braided yarn 137 Circular Fibers 150z Reinforcement elements 209 Braided layer 233 Braided yarn 235 Longitudinal axis 300 Hardening Device 339 Tip 342 Handle 344 Vacuum or pressure inlet 346 Operational Elements 400 Hardening Device 444 Connection Features 500 Hardening Device 501 Outermost layer 503 Radial interstitial layer 505 2nd braided layer 507 Radial interstitial layer 509 1st braided layer 511 Radial clearance 513 Sliding layer 515 Innermost layer 525a Large diameter section 525b Small diameter section 555 Working Channel 568z mooring point 569z Large diameter end 570z small diameter end 571z central lumen 572z sealed layer 600 Hardening Device 609 1st braided layer 611 Radial clearance 613 Sliding layer 655 Working Channel 666 Balloon 667 Inflation tube 668 Service Loop 700 Hardening Device 702z Flexible Distal Section 703z proximal stiffened elongated body 755 Working Channel 760z blood vessels 776 Scope Steering Section 777 Working Tools 779 Lesions 791 Scope 900 Hardening Device 901 Outermost layer 902z Steerable Distal Section 909 Braided layer 911 Radial clearance 915 Innermost layer 920 central lumen 924a,b,c,d cable 927a,b,c,d Vacuum / pressure line 929 Pressure Seal 975a,b,c,d Vacuum / Pressure Chamber 999a,b,c,d Cable guide 1031 Handle 1048 Operational elements 1049 Vacuum Inlet Port 1050 Hardening Device Port 1051 Ventilation port 1053 Junction area 1067z Status Indicator Elements 1073z Output 1131 Handle 1153 Junction area 1161 Large stopper / flange 1165 Input 1173z Output 1231 Handle 1232 Vacuum or pressure lines 1248 Operational Elements 1251 Ventilation port 1267z End Button Indicator Element 1348 Operational elements 1367z Sliding Indicator 1431 Handle 1448 Operational elements 1452 Attachment mechanism 1548 Operational elements 1567z Indicator Element 1574z Connection Elements 1648 Slider Operation Element 1709 layers 1733a,b twisted yarn 1733c Long-hand twisted yarn 1818 Single fiber 1818a,b,c Single fiber 1833 Twisted Yarn 2000 Curing Device 2100 Hardening Device 2101 Outermost encapsulation layer 2107 Interstitial layer 2109 Braided layer 2111 Interstitial layer 2112 Pressure gap 2113 Sliding layer 2115 Innermost layer 2120 Lumen 2121 Reservoir 2200a,b,c,d,e,f,g,h,i,j,k,l,m,n,o Curing Device 2201a,b,c,e,f,g,h,i,j,k,l,m,n,o outermost layer 2205b,d,i,j,m,n, braided layer 2206g,h,i,l gap 2209a,b,c,e,d,f,g,h,k,l,m,n,o Braided layer 2212a,b,c,d,e,f,g,h,i,j,k,l,m,n,o Pressure gap 2213j sliding layer 2215a,b,c,d,f,g,j,k,m,n,o Innermost layer 2217m Air storage section 2219k Annular Ring 2221a,b,c,e,f,g,h,i,j,k,l,m,n,o reservoir 2223g,h,i entrance 2228i,2230i Samp 2236o Split section 2243h Bellows 2250z Reinforcement elements 2288h Actuator 2291e,l working channel 2292a,b,d,e,g,h,i,j,k End Caps 2293a,c,e,g,i,j,k entrance 2294e,g,h Inner Payload 2298j rigid layer 2300 External Hardening Device 2300z System 2301a outermost layer 2301b Outer layer 2302z Distal Section 2304z steering linkage 2309a,b Braided layer 2310 Medial hardening device 2315a,b inner layer 2321b Air reservoir 2327z Boundary surface 2333z distal end 2334z Camera 2335z lighting 2336z Air / Water Channel 2337z cover 2355 Working Channel 2400 External Hardening Device 2400z nesting system 2410 Medial hardening device 2500 Pressure hardened structure 2501 Exterior wall 2502z Distal End Section 2503z Proximal Rectangular Body 2509 Braided body 2512 Pressure gap 2515 Inner layer 2521 Air storage section 2524 Cable 2568 Mooring Point 2599 Cable Guide 2600a,b Curing Device 2646z Upper gastrointestinal tract 2647z lower gastrointestinal tract 2691a,b Endoscope 2700 Outer Device 2700z Nested System 2710 Inner Device 2738z cover 3700 Curing Device 3704 Atrial septum 3778 Balloon 3787 Cardiac Tools 3800 Curing Device 3842 Coronary artery 3845 Heart Gate 3873 Anatomical Structure 3885 Guidewire 3886 Guide Catheter 3900 Hardening Device 3910 Medial Hardening Device 3958z Needle Tip Catheter 3959z Suture 3962z Mooring Device 3964 Another location 3969 Tube End 3983 Longitudinal axis 3985 Guidewire 4000a,b Hardened Cannula 4004 Tip 4014 Axis 4039 Lip 4058z Needle Catheter 4061z Organization 4065z Tools 4066z aorta 4081 Mitral valve 4138 Standard Trocar 4141 Dynamically stiffened trocar 4200 Dynamic Hardening Device 4297 Junction 4302z Distal End Section 4304z linkage 4324 Cable 4500 Curing Device 4547 Steerable Distal Tip 4555 Working Channel 4600 Curing Device 4602z Distal End Section 4646 Flexure Segment 4647 Steerable Distal Section 4700 Curing Device 4746 Active Flexion Segment 4747 Distal Steerable Section 4769 Tube End 4783 Longitudinal axis 4800 Curing Device 4846 Active Flexion Segment 4847 Steerable Distal Section 4848 Distal Payload 4900 Rod 4901 Outer layer 4909 Braided layer 4912 Gap 4933 Braided yarn 5055 Working Channel 5063z Pressure Inlets and / or Connectors 5091 Colonoscopy 5238 hole 5254 Vacuum Tip 5319z Circular entrance 5320z central lumen 5354 Vacuum Tip 5356 Vacuum pipe line 5358 Vacuum hole 5359 Most distal surface 5454 Vacuum Tip 5459 Beveled distal surface 5500 Curing Device 5502z Distal End Section 5503z Main long body 5600 Devices 5601z Ring 5609 Braided layer 5615 Innermost layer 5629 Tip 5633 Twisted yarn 5634 Coating 5700 Curing Device 5702z Distal Section 5703z Main Rectangular Section 5800 Devices 5802z Distal End Section 5804z linkage 5902z Distal End Section 5904z linkage 5928z Turning Point 5929z Distal End Section 5930z Tensile Member 5931z orbit 5932z Sliding Clamp 5975z Excision part 6001 Outer layer 6002z Distal End Section 6004z linkage 6007z Section 6009 Braided layer 6012 Pressure gap 6015 Inner layer 6021 Air storage section 6024 Cable 6099 Cable Guide 6101 Coiled Tube 6102z Distal End Section 6103z Main Rectangular Body 6104z linkage 6108z sheath 6109 Braided layer 6112 Gap 6121 Air storage section 6124 Cable 6200 Curing Device 6201 Outermost layer 6206 Gap 6207 Outer radial interstitial layer 6209 Braided layer 6212 Pressure gap 6221 Air storage section 6223 Ventilation gap inlet 6224 Cable 6231 Handle 6293 Pressure gap inlet 6294 Pressure Pipeline 6299 Cable Guide 6300 Curing Device 6301 Outer layer 6309 Braided layer 6311 Inner radial interstitial layer 6312 Pressure gap 6324 Cable 6321 Air storage section 6399 Cable Guide 6400 Curing Device 6407 Gap 6409 Braided layer 6412 Pressure gap 6415 Inner layer 6421 Tubular reservoir 6424 Cable 6499 Cable Guide 6500 Curing Device 6507 Gap 6521 Pipe-shaped air storage section 6524 Cable 6599 Cable Guide 6600 Curing Device 6621 Pipe-shaped air storage section 6624 Cable 6699 Guide 6700 Curing Device 6701 Outer layer 6709 Tubular braided layer 6712 Pressure gap 6715 Inner layer 6721 Tubular air storage section 6800 Curing Device 6801 Outer layer 6807 Radial clearance 6809 Braided layer 6812 Pressure gap 6815 Innermost layer 6821 Air storage section 6824 Cable 6899 Cable Guide 6900 central lumen 6920 Central lumen 6924 Cable 6999 Cable Guide 7000 devices 7001 Outer layer 7009z sheath 7024 Cable 7099 Cable Guide 7100 Curing Device 7101 Outer layer 7199 Cable Guide 7200 Curing Device 7209 Tubular braided body 7210z tubular element 7212 Pressure gap 7215 Inner layer 7221 Inner pipe type air storage section 7210z tubular element 7212 Pressure gap 7299 Cable Guide 7300 Curing Device 7301 Outer layer 7309 Braided layer 7311 Gap 7315 Inner layer 7321 Tubular air storage section 7399 Cable Guide 7400 Pressure Hardening Device 7411z Grip / lever Room 7412z 7413z piston 7414z Rack 7415z Handle body 7416z Rolling Diaphragm 7417z Pressure Relief Valve 7418z Overflow room 7421 Air storage section 7423 Ventilation section 7431 Handle 7476z Teeth 7493 Entrance 7500 Vacuum Curing Device 7515z Handle body 7521z User Grip 7522z Magnet 7523z Proximal Magnet 7524z Distal Magnet 7525z Grip Cover 7526z Proximal Handle Port 7531 Handle 7532 Vacuum feed line 7548 Switching operation element 7550 Vacuum Port 7561 Stopper flange 7567z Indicator Element 7600 Devices 7601 Exterior wall 7602z Distal Section 7604z linkage 7609 Braided layer 7615 Inner layer 7624 Cable 7627z coating 7778z Fira 7800 Curing Device 7801 Outermost layer 7803z long body 7831 Handle 7833z Tip 7840z Proximal Port 7855 Working Channel 7841z Distal Port 7942 Tools 7943z shaft 7944z atraumatic tip 7945z Flexible Loop 8000 Curing Device 8003z hardened long body 8004z linkage 8020 Central lumen 8033z Tip 8055a,b,c,d working channels 8100 Curing Device 8102z Distal Section 8103z long body 8104z linkage 8120 Central lumen 8155a 1st Working Channel 8155b Second Working Channel 8200 Curing Device 8202z Distal End 8203z long body 8204z Steerable Linkage 8234z Camera 8235z Lighting 8300 Curing Device 8302z Steerable Distal End 8354z Duodenum 8355z nipple 8356z Pancreatic duct 8357z bile duct 8385 Guidewire 8391 Cholangioscope 8400 Curing Device 8455z nipple 8491 Cholangioscope 8500 Curing Device 8554z Duodenum 8555z papillary process 8556z Pancreatic duct 8557z bile duct 8558z stent 8585 Guidewire 8591 Cholangioscope 8700 Curing Device 8733z Tapered Distal Tip 8748z Cleaning Pipe 8749z Hemostasis Valve 8815 Innermost layer 8850z Reinforcement Elements 8055a,b,c,d working channels 8851z Matrix 8852z Intima 8853z adventitia 9050z Reinforcement elements 9052z Pocket Wire 9053z Notch Wire 9150z Reinforcement elements 9400 External Hardening Device 9400z nested system 9404z Steering Elements 9410 Inside Device 9434z Camera 9435z lighting 9439z central aisle IVC inferior aorta LA Left atrium LV left ventricle MV Mitral valve RA right atrium α Braid angle

Claims

1. 1. A curing device comprising: an elongated flexible tube including a reinforcing element extending therethrough; a braided layer disposed over the elongated flexible tube, the braided layer having a plurality of strands braided together at a braid angle of 5 to 40 degrees relative to a longitudinal axis of the elongated flexible tube when the elongated flexible tube is straight; an air storage layer disposed adjacent to the braided layer; an outer layer over the flexible tube and the braided layer; an inlet between the elongated flexible tube and the outer layer configured to be attached to a vacuum or pressure source; Including, a stiffening device configured to have a stiffened configuration when a vacuum or pressure is applied through the inlet and a flexible configuration when a vacuum or pressure is not applied through the inlet, the air reservoir configured to press against the elongated flexible tube and the braided layer when the vacuum or pressure is applied through the inlet; wherein the braid angle is configured to change upon bending of the stiffening device when the stiffening device is in the flexible configuration. Hardening device.

2. The stiffening device of claim 1 , wherein the braid angle is between 10 and 35 degrees.

3. The stiffening device of claim 1 , wherein the braid angle is less than 25 degrees.

4. The curing device of claim 1 , wherein the curing device in the curing configuration is at least twice as stiff as the curing device in the flexible configuration.

5. The curing device of claim 1 , wherein the curing device in the curing configuration is at least five times more rigid than the curing device in the flexible configuration.

6. The curing device of claim 1 further comprising a sliding layer adjacent to said braided layer and having a lower coefficient of friction than said braided layer.

7. The hardening device of claim 1, wherein the reinforcing element comprises a coil or a plurality of ring-shaped elements.

8. The stiffening device of claim 1, wherein the multiple strands are braided together at a picks per inch count of 4 to 60.

9. The hardening device of claim 1, wherein the twisted yarn is polyethylene terephthalate or stainless steel.

10. The curing device of claim 1, wherein the braided layer provides 30-70% coverage over the elongated flexible tube.

11. The stiffening device of claim 1, wherein the plurality of twisted yarns includes 96 or more twisted yarns.

12. The hardening device of claim 1, wherein the inlet is configured to be attached to a pressure source.

13. The curing device of claim 12, wherein the outer layer further includes a plurality of reinforcing elements therein.

14. The curing device of claim 1, wherein the inlet is configured to be attached to a vacuum source and the outer layer is a thin, flexible sheath.

15. The stiffening device of claim 1, further comprising a radial gap between the braided layer and the outer layer, the gap having a thickness of 0.00002" to 0.04".

16. The hardening device of claim 1, further comprising a steerable distal end.

17. The hardening device of claim 1, further comprising a sealed channel between the elongated flexible tube and the outer layer, the sealed channel comprising a working channel cable guide or an inflation lumen.

18. A curing device comprising: an elongated flexible tube including a reinforcing element extending therethrough; a braided layer disposed over the elongated flexible tube; an outer layer over the flexible tube and the braided layer; an air storage layer disposed adjacent to the braided layer; an inlet between the elongated flexible tube and the outer layer configured to be attached to a vacuum or pressure source; Inclusive of the curing device is configured to have a hardened configuration when vacuum or pressure is applied through the inlet and a flexible configuration when vacuum or pressure is not applied through the inlet, a ratio of stiffness of the curing device in the hardened configuration to stiffness of the curing device in the flexible configuration being greater than 5; the air reservoir is configured to press against the elongated flexible tube and the braided layer when the vacuum or pressure is applied through the inlet; the braided layer having a plurality of strands braided together at a braid angle of less than 25 degrees relative to a longitudinal axis of the elongated flexible tube when the elongated flexible tube is straight; Hardening device.

19. The hardening device of claim 18, wherein the ratio is greater than 6.

20. The hardening device of claim 18, wherein the ratio is greater than 10.

21. The curing device of claim 18, further comprising a sliding layer adjacent to the braided layer and having a lower coefficient of friction than the braided layer.

22. The stiffening device of claim 18, wherein the reinforcing element comprises a coil or a plurality of ring-shaped elements.

23. The stiffening device of claim 18, wherein the braided layer comprises a plurality of strands braided together at a pick count of 4 to 60 per inch.

24. The curing device of claim 18, wherein the braided layer comprises a plurality of twisted yarns braided together, the twisted yarns comprising polyethylene terephthalate or stainless steel.

25. The curing device of claim 18, wherein the braided layer provides 30-70% coverage over the elongated flexible tube.

26. The stiffening device of claim 18, wherein the braided layer comprises 96 or more strands braided together.

27. The curing device of claim 18, wherein the inlet is configured to be attached to a pressure source.

28. The curing device of claim 27, wherein the outer layer further comprises a plurality of reinforcing elements therein.

29. The curing device of claim 18, wherein the inlet is configured to be attached to a vacuum source and the outer layer is a thin, flexible sheath.

30. The stiffening device of claim 18, further comprising a radial gap between the braided layer and the outer layer, the gap having a thickness of 0.00002" to 0.04".

31. The hardening device of claim 18, further comprising a steerable distal end.

32. The hardening device of claim 18, further comprising a sealed channel between the elongated flexible tube and the outer layer, the sealed channel comprising a working channel, a cable guide, or an inflation lumen.

33. A curing device comprising: an elongated flexible tube including a reinforcing element extending therethrough; a braided layer disposed radially outward of the elongated flexible tube; a sliding layer adjacent to the braided layer; an outer layer over the flexible tube, the braided layer, and the sliding layer; an air storage layer disposed adjacent to the braided layer; a vacuum or pressure inlet between the elongated flexible tube and the outer layer configured to be attached to a vacuum or pressure source; Inclusive of a curing device configured to have a curing configuration when a vacuum or pressure is applied through the inlet and a flexible configuration when no vacuum or pressure is applied through the inlet; the air reservoir is configured to press against the elongated flexible tube and the braided layer when the vacuum or pressure is applied through the inlet; the sliding layer is configured to reduce friction between the braided layer and the elongated flexible tube or the outer layer when the stiffening device is in the flexible configuration; the braided layer having a plurality of strands braided together at a braid angle of 5 to 40 degrees relative to a longitudinal axis of the elongated flexible tube when the elongated flexible tube is straight; Hardening device.

34. The hardened device of claim 33, wherein the sliding layer has a lower coefficient of friction than the braided layer.

35. The hardening device of claim 33, wherein the sliding layer comprises a powder.

36. The hardening device of claim 33, wherein the hardening device in the hardening configuration is at least twice as rigid as the hardening device in the flexible configuration.

37. The hardening device of claim 33, wherein the hardening device in the hardened configuration is at least 5 times more rigid than the hardening device in the flexible configuration.

38. The hardening device of claim 33, wherein the braid angle is less than 25 degrees.

39. The stiffening device of claim 33, wherein the reinforcing element comprises a coil or a plurality of ring-shaped elements.

40. The stiffening device of claim 33, wherein the braided layer comprises a plurality of strands braided together at a pick count of 4 to 60 per inch.

41. The curing device of claim 35, wherein the braided layer comprises a plurality of twisted yarns braided together, the twisted yarns comprising polyethylene terephthalate or stainless steel.

42. The curing device of claim 33, wherein the braided layer provides 30-70% coverage over the elongated flexible tube.

43. The stiffening device of claim 33, wherein the braided layer comprises 96 or more twisted yarns braided together.

44. The hardening device of claim 33, wherein the inlet is configured to be attached to a pressure source.

45. The hardening device of claim 44, wherein the outer layer further comprises a plurality of reinforcing elements therein.

46. ​​The curing device of claim 33, wherein the inlet is configured to be attached to a vacuum source and the outer layer is a thin, flexible sheath.

47. The stiffening device of claim 33, further comprising a radial gap between the braided layer and the outer layer, the gap having a thickness of 0.00002" to 0.04".

48. The hardening device of claim 33, further comprising a steerable distal end.

49. The hardening device of claim 33, further comprising a sealed channel between the elongated flexible tube and the outer layer, the sealed channel comprising a working channel, a cable guide, or an inflation lumen.

Images