Method and apparatus for navigating using a pair of stiffening devices - Patents.com

Abstract

Disclosed herein are systems and methods for navigating a system through a body lumen, the system including a pair of nested stiffening devices configured to alternately stiffen, transition between stiffened and soft states, and copy the shape of the device as it advances or retreats. Also described herein are examples of apparatus for automatically or semi-automatically screening a body lumen using a pair of nested stiffening devices.

Description

[Technical field]

[0001] Priority claim

[0001] This patent application claims priority to U.S. Provisional Patent Application No. 63 / 324,011, entitled "METHODS AND APPARATUSES FOR NAVIGATING USING A PAIR OF RIGIDIZING DEVICES," filed March 25, 2022, and is incorporated by reference in its entirety herein.

[0002] Incorporation by Reference

[0002] The publications and patent applications mentioned in this specification are herein incorporated by reference in their entirety to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference. [Background technology]

[0003]

[0003] During medical procedures, nested or telescopic instruments may be advanced by coordinated movement of both an inner device (e.g., an inner member, catheter, endoscope, etc.) and an outer device (e.g., an outer member, overtube, etc.). However, coordinating the movement of the inner and outer members can be particularly difficult when navigating through curved or tortuous anatomy, including body regions within which the device may bend, curve, or even loop or double over. This can make both the advancement and / or retraction of the medical device difficult.

[0004]

[0004] These problems can be particularly acute in anatomical regions such as the gastrointestinal tract region that may be tortuous and may form loops. Gastrointestinal loops, which occur when conventional endoscopes cannot advance any further due to excessive curvature or looping of the gastrointestinal tract, are a particularly well-known clinical challenge in endoscopy. Gastrointestinal loops can prolong the procedure and cause pain for the patient as they may stretch the vascular walls and mesentery. Gastrointestinal loops also lead to an increased incidence of perforation. Similar problems commonly occur across a wide range of endoscopic procedures, including colonoscopy, esophagogastroduodenoscopy (EGD), small intestinal endoscopy, endoscopic retrograde pancreatography (ERCP), interventional endoscopic procedures (including ESD (endoscopic submucosal dissection) and EMR (endoscopic mucosal resection)), robotic flexible endoscopy, transoral robotic surgery (TORS), enterointestinal cases (including Roux-en-Y anastomosis), and NOTES (transluminal endoscopic surgery) procedures. Thus, there is a need for a device that can prevent gastrointestinal loops and / or otherwise provide more successful access to the gastrointestinal tract. Specifically, there is a need for a method and device that can safely and efficiently coordinate the movement of all of the telescoping members of a nested device having both inner and outer stiffening members during advancement and retraction of the device. Summary of the Invention

[0005]

[0005] Described herein are methods and apparatus (e.g., devices, systems, etc.) for controlling a pair of nested selectively stiffening members during advancement and retraction within a body lumen. One or both of the selectively stiffening members can be steerable at the distal end region of the member by tensioning one or more tendons to cause bending of the distal end region in a desired direction. In some examples, the apparatus can include a pair of nested stiffening devices that can be alternately stiffened and advanced (or retracted) distally or proximally through a body lumen. In the absence of constraints, the transition between the stiffened and soft states can involve significant shape changes that, in some circumstances, can be detrimental to the surrounding anatomy. There is a need for methods and systems that can provide such devices with a safe and smooth transition between the stiffened and soft states.

[0006]

[0006] In general, these methods and devices may involve estimating the current shape of the nested set by storing a sequence of commanded articulations and copying, and / or using the estimated shape to improve control of guiding (e.g., steering) the device in a space, such as within a body lumen. The memory of the current shape can be reproduced ("stored") by using a first, flexible device to copy the shape of a second, rigid (e.g., locked) device nested with the first device.

[0007] In some embodiments, the methods and apparatus may, for example, allow an apparatus including a pair of nested devices to be withdrawn (proximally) while maintaining the orientation of the distal tip of the apparatus such that a camera on the distal face of the first or second stiffening device can maintain its orientation (e.g., maintaining the net articulation angle). This may be advantageous as it may allow these devices to smoothly transition between rigid and non-rigid states without significant deflection. For example, a method of controlling a nested pair of stiffening devices includes retracting a first stiffening device of the nested pair of stiffening devices relative to a second stiffening device of the nested pair of stiffening devices with the first stiffening device in a soft state and the second stiffening device in a stiffened state, stiffening the first stiffening device, and actuating a steering member within the second stiffening device to maintain an orientation of a distal end face of the second stiffening device constant relative to an exterior region before and / or during transition of the second stiffening device from the rigid state to the soft state.

[0008] Any of these methods or apparatus may include, after actuating the steering member, retracting the second stiffening device relative to the first stiffening device while the second stiffening device is in a soft state. These methods and apparatus may be further configured to stiffen the second stiffening device and retract the first stiffening device over the second stiffening device while the first stiffening device is in a soft state. Retracting the second stiffening device may include retracting the second stiffening device at least partially within the first stiffening device. In any of these methods and apparatus (e.g., systems), actuating the steering member within the second stiffening device to maintain an orientation of a distal end face of the second stiffening device may include maintaining a net articulation angle of a distal end of the second stiffening device relative to a proximal portion of the second stiffening device. In any of these methods and apparatus, actuating a steering member within the second stiffening device to maintain the orientation of the distal end face of the second stiffening device constant relative to the exterior region can include maintaining the orientation of the distal end face of the second stiffening device relative to the lumen wall. For example, actuating a steering member within the second stiffening device to maintain the orientation of the distal end face of the second stiffening device constant relative to the exterior region can include maintaining the orientation of the distal end face of the second stiffening device such that the angular orientation of the distal end face of the second stiffening device varies by less than ±15 degrees. Actuating the steering members can include tensioning at least one of the steering members. In an example, actuating the steering members can include displacing at least one of the steering members. Any of these methods and apparatus can include actuating the steering members by automatically actuating the steering members.

[0009] The methods and apparatus described herein may include retracting the first stiffening device proximally relative to the second stiffening device.

[0010]

[0010] The first stiffening device may be nested within the second stiffening device, or the second stiffening device may be nested within the first stiffening device.

[0011]

[0011] The methods and apparatus described herein can include imaging the exterior area from a sensor at a distal end face of the second stiffening device.

[0012] Also described herein are apparatus (e.g., systems) configured to perform any of the methods described herein. These apparatuses may include a nested pair of stiffening devices including a first stiffening device and a second stiffening device, one or more processors, and a memory coupled to the one or more processors, the memory storing computer program instructions that, when executed by the one or more processors, perform a computer-implemented method of controlling the nested pair of stiffening devices.

[0013]

[0013] Also described herein is a method for automatic (or semi-automatic) shape copying. Specifically, described herein is a method for automatic shape copying when triggered by a user activating a control, and for the automatic shape copying to continue while the user continues to activate the control, but to stop if the user stops activating the control. For example, the control can be activated by pressing a button or switch, and the shape copying procedure can be automatic while the user holds down the button, but can stop when the user stops pressing the button.

[0014]

[0014] For example, a method for controlling a pair of nested stiffening devices may include receiving a copy command from a user input and automatically performing a shape copy sequence, the shape copy sequence including advancing a first stiffening device of the nested pair of stiffening devices relative to a second stiffening device of the nested pair of stiffening devices with the first stiffening device in a soft state and the second stiffening device in a rigidified state, wherein the first stiffening device is initially proximal to the second stiffening device such that the first stiffening device copies a shape of the second stiffening device, and preventing the first stiffening device from advancing distal to the second stiffening device.

[0015] Any of these methods can include continuing to advance the first stiffening device until a distal end of the first stiffening device reaches a distal end of the second stiffening device.

[0016]

[0016] As mentioned above, advancing the first stiffening device can include advancing the first stiffening device only while the copy command continues to be received. Any of these methods (or apparatus) can additionally or alternatively be configured to prevent the first device (e.g., the first stiffening device) from going beyond the distal end region of the second device (e.g., the second stiffening device). These features allow for rapid and efficient operation of these nested systems while maintaining a high degree of user control that would not be possible without preventing overshoot and / or partial stalls throughout the automated shape-copying procedure.

[0017]

[0017] The shape copy sequence may include stiffening the second stiffening device to a rigid state before advancing the first stiffening device relative to the second stiffening device. In some embodiments, the shape copy sequence may further include de-stiffening the first stiffening device to a soft state before advancing the first stiffening device relative to the second stiffening device. The shape copy sequence may further include stiffening the first stiffening device to a rigid state after the first stiffening device has been advanced relative to the second stiffening device. In any of these methods and apparatus, prior to receiving a copy command, the method may include advancing the second stiffening device in a soft state while steering a distal end region of the second stiffening device, wherein the first stiffening device is in a rigid state.

[0018]

[0018] For example, a method for controlling a pair of nested stiffening devices includes receiving a copy command from a user input and automatically performing a shape copy sequence while the user input is received, the shape copy sequence including advancing a first stiffening device of the nested pair of stiffening devices relative to a second stiffening device of the nested pair of stiffening devices with the first stiffening device in a soft state and the second stiffening device in a rigidified state, wherein the first stiffening device is initially proximal to the second stiffening device such that the first stiffening device copies a shape of the second stiffening device.

[0019]

[0019] Also described herein are methods and apparatus (e.g., systems) for automatically shape copying upon detection of an automatic copy trigger, which can be, for example, a distal extension of one of the first or second nested stiffening devices relative to the other stiffening device, a time delay longer than a set threshold when moving one of the nested stiffening devices relative to the other, a delay in the movement of one or the other stiffening device, etc.

[0020]

[0020] For example, a method for controlling a nested pair of stiffening devices including a first stiffening device and a second stiffening device, the method including automatically performing a shape copy sequence when an auto-copy trigger event is detected by a control circuit, the method including receiving, in a controller, one or more of sensor data and / or user movement inputs, comparing the one or more of the sensor data and / or user movement inputs to an auto-copy trigger threshold, and triggering the shape copy sequence when the auto-copy trigger threshold is detected, the shape copy sequence including advancing the first stiffening device relative to the second stiffening device with the first stiffening device in a soft state and the second stiffening device in a stiffened state.

[0021]

[0021] As mentioned above, in some embodiments, the auto-copy trigger threshold can be a relative axial movement distance between the first stiffening member and the second stiffening member. The auto-copy trigger threshold can include exceeding a time delay after movement of the second stiffening member relative to the first stiffening member. Automatically performing the shape copy sequence can include advancing the first stiffening device relative to the second stiffening device until a distal end region of the first stiffening device is adjacent to a distal end region of the second stiffening device.

[0022] The first stiffening device may be nested above the second stiffening device.

[0023]

[0023] The shape copy sequence may further include stiffening the second stiffening device to a rigid state before advancing the first stiffening device. In some embodiments, the shape copy sequence may further include de-stiffening the first stiffening device to a soft state before advancing the first stiffening device relative to the second stiffening device. The shape copy sequence may further include stiffening the first stiffening device to a rigid state after advancing the first stiffening device relative to the second stiffening device.

[0024]

[0024] A method for controlling a pair of nested stiffening devices includes advancing a second stiffening device of the nested pair of stiffening devices distally relative to a first stiffening device of the nested pair of stiffening devices with the second stiffening device in a soft state and the first stiffening device in a stiffened state, and automatically performing a shape copy sequence when the second stiffening member extends a predetermined travel distance relative to the first stiffening member, the shape copy sequence including advancing the first stiffening device relative to the second stiffening device with the first stiffening device in a soft state and the second stiffening device in a stiffened state.

[0025]

[0025] The predetermined travel distance may be a maximum distance. Advancing the second stiffening device may include advancing and steering.

[0026]

[0026] As described above, automatically performing the shape copy sequence may include advancing the first stiffening device relative to the second stiffening device until a distal end region of the first stiffening device is adjacent to a distal end region of the second stiffening device. The shape copy sequence may further include stiffening the second stiffening device to a rigid state before advancing the first stiffening device relative to the second stiffening device. The shape copy sequence may further include de-stiffening the first stiffening device before advancing the first stiffening device relative to the second stiffening device. The shape copy sequence may further include stiffening the first stiffening device to a rigid state after the first stiffening device has been advanced relative to the second stiffening device.

[0027]

[0027] Any of the methods and apparatus described herein may also include controlling the timing of release of tension on an actuated steering member at the steerable distal end of the nested stiffening device when transitioning from a rigid state to a flexible state, for example, by actuating the steering member to maintain curvature as the device transitions to the flexible state.

[0028]

[0028] For example, a method of controlling a pair of nested stiffening devices may include advancing a first stiffening device of the nested pair of stiffening devices distally relative to a second stiffening device of the nested pair of stiffening devices, where the first stiffening device is in a soft state and the second stiffening device is in a rigid state, transitioning the first stiffening device from the soft state to a rigid state, and transitioning the second stiffening device from the rigid state to the soft state while actuating a steering member of the second stiffening device to maintain a curvature of a distal end of the second stiffening device as the second stiffening device transitions to the soft state.

[0029] Any of these methods can include distally advancing a soft second stiffening device while the first stiffening device remains in a rigid state, and further actuating a steering member to steer a distal end of the second stiffening device. Actuating the steering member within the second stiffening device can include tensioning one or more tendons. Actuating the steering member can include tensioning at least one of the steering members. Actuating the steering member can include automatically actuating the steering member.

[0030] In some embodiments, the first stiffening device is nested within the second stiffening device. Any of these methods can include imaging the exterior area from a sensor at a distal end face of the second stiffening device, and / or advancing the second stiffening device in a soft state, steering the second stiffening device while advancing, and then repeating the steps of advancing the first stiffening device distally, transitioning the first stiffening device to a stiff state, and transitioning the second stiffening device to a soft state.

[0031] Also described herein are methods of advancing or retracting a system including a pair of nested stiffening devices along a body lumen, any of which may include advancing or retracting a first stiffening device in a soft state relative to a second stiffening device in a stiff state, steering the first stiffening device using a steering member coupled to the first stiffening device, stiffening the first stiffening device, advancing or retracting the second stiffening device in a soft state at least partially over the stiffened first stiffening device, stiffening the second stiffening device, actuating the steering member to correspond to the curvature of the stiffened second stiffening device, and transitioning the first stiffening device to a soft state.

[0032]

[0032] Actuating the steering member within the first stiffening device may include maintaining a previously commanded curvature of the first stiffening device throughout the advancement or retraction and stiffening of the second stiffening device. In some embodiments, actuating the steering member within the first stiffening device includes adjusting the steering member prior to transitioning the first stiffening device to a soft state to accommodate a new curvature of the stiffened second stiffening device that differs from the curvature prior to stiffening the first stiffening device. In some embodiments, actuating the steering member occurs prior to transitioning the first stiffening device to a soft state. Actuating the steering member may occur during transitioning the first stiffening device to a soft state.

[0033] In any of these methods, the system can be configured to automatically maintain existing curvature command control over the steering member while advancing or retracting and stiffening the second stiffening device.

[0034]

[0034] Advancing or retracting the second stiffening device can include advancing the second stiffening device such that a distal end of the second stiffening device is generally aligned with a distal end of the first stiffening device. In some embodiments, the system can be configured to automatically maintain existing curvature command control over the steering member while advancing or retracting and stiffening the second stiffening device.

[0035]

[0035] The system can be configured to automatically actuate the steering members while the first stiffening device transitions to the soft state. Actuating the steering members can include tensioning at least one of the steering members. Actuating the steering members can include displacing at least one of the steering members. The system can be configured to automatically actuate the steering members to impart a curvature to the first stiffening device that is a predetermined percentage less than a previously commanded curvature imparted by the steering member.

[0036] Advancing or retracting the first and second stiffening devices can include advancing distally. Advancing or retracting the first and second stiffening devices can include retracting proximally.

[0037] In some embodiments, actuating the steering member can include actuating the steering member to correspond to a shape of a portion of the first stiffening device exposed upon retracting the second stiffening device proximally over the first stiffening device. Actuating the steering member can include approximating an angle between a distal face of the first stiffening device and a cross-section of the first stiffening device at a proximal end of the portion of the first stiffening device. For example, actuating the steering member can include maintaining an orientation of a distal end of the first stiffening device relative to a proximal end of the portion of the first stiffening device.

[0038]

[0038] For example, a method of advancing a system including a pair of nested stiffening devices along a body lumen may include advancing a first stiffening device in a soft state through the body lumen and steering a distal end region of the first stiffening device using a steering member coupled to the first stiffening device, stiffening the first stiffening device, advancing a second stiffening device in a soft state at least partially over the stiffened first stiffening device, stiffening the second stiffening device, actuating the steering member to correspond to a new curvature of the stiffened second stiffening device that is different from the curvature before stiffening the first stiffening device before transitioning the first stiffening device to the soft state, and transitioning the first stiffening device to the soft state.

[0039]

[0039] A method of retracting a system including a pair of nested stiffening devices along a body lumen may include retracting a first stiffening device in a soft state through the body lumen relative to a second stiffening device in a stiffened state, steering a distal end region of the first stiffening device using a steering member coupled to the first stiffening device, stiffening the first stiffening device, retracting the second stiffening device in a soft state at least partially over the stiffened first stiffening device, stiffening the second stiffening device, actuating the steering member to maintain an orientation of the distal end of the first stiffening device relative to a proximal portion of the second stiffening device, and retracting the first stiffening device into the second stiffening device while the first stiffening device is in the soft state.

[0040]

[0040] For example, a method of retracting a system including a pair of nested stiffening devices along a body lumen may include retracting a first stiffening device in a soft state through the body lumen relative to a second stiffening device in a stiffened state, steering a distal end region of the first stiffening device using a steering member coupled to the first stiffening device, stiffening the first stiffening device, retracting the second stiffening device in a soft state at least partially over the stiffened first stiffening device, stiffening the second stiffening device, actuating the steering member to maintain a constant curvature, and retracting the first stiffening device into the second stiffening device while the first stiffening device is in the soft state.

[0041]

[0041] Also described herein is a system including a first stiffening device disposed within a second stiffening device, a controller including one or more processors, and a memory coupled to the one or more processors, the memory storing computer program instructions that, when executed by the one or more processors, perform a computer-implemented method of advancing inner and outer stiffening devices within a body lumen, the method including advancing or retracting the first stiffening device in a soft state relative to a second stiffening device in a rigid state, steering the first stiffening device using a steering member coupled to the first stiffening device, stiffening the first stiffening device, advancing or retracting the second stiffening device in the soft state at least partially over the stiffened first stiffening device, stiffening the second stiffening device, actuating the steering member to correspond to the curvature of the stiffened second stiffening device, and transitioning the first stiffening device to a soft state.

[0042] In any of these apparatus and methods, the inner stiffening device may be referred to as an inner member, a catheter, an endoscope, etc., and the outer stiffening device may be referred to as an outer member, a tube, an overtube, etc. The outer stiffening device may be referred to as a first stiffening device, and the inner stiffening device may be referred to as a second stiffening device. Alternatively, the outer stiffening device may be referred to as a second stiffening device, and the inner stiffening device may be referred to as a first stiffening device. In general, the inner stiffening device is nested within the outer stiffening device, and the outer stiffening device is nested over the inner stiffening device, such that the two stiffening devices can move longitudinally (distally or proximally) relative to one another.

[0043]

[0043] In any of these embodiments, the first (inner) stiffening device can be retracted into a non-linear (e.g., curved, bent, etc.) distal portion of the second (outer) stiffening member, and the non-linear region can be addressed, for example, by articulating the bent portion to match the curvature as the first stiffening device retracts into the second stiffening device.

[0044] In any of these apparatus, actuating the steering member within the first stiffening device may include maintaining a curvature commanded prior to the first stiffening device throughout the advancement and stiffening of the second stiffening device. In some embodiments, actuating the steering member within the first stiffening device may include adjusting the steering member to a stiffened shape of the second stiffening device to correspond to a shape of the first stiffening device. Actuating the steering member may occur prior to transitioning the first stiffening device to a soft state. Actuating the steering member may occur during transitioning the first stiffening device to a soft state.

[0045] Any of these systems can be configured to automatically maintain existing curvature command control over the steering member while advancing and stiffening the second stiffening device.

[0046]

[0046] In some embodiments, advancing the second stiffening device can include advancing the second stiffening device such that a distal end of the second stiffening device is generally aligned with a distal end of the first stiffening device. The system can be configured to automatically maintain existing curvature command control over the steering member while advancing and stiffening the second stiffening device. In some embodiments, the system is configured to automatically actuate the steering member while the first stiffening device transitions to the soft state.

[0047] In any of these embodiments, actuating the steering members includes tensioning at least one of the steering members. For example, actuating the steering members can include displacing at least one of the steering members. The system can be configured to automatically actuate the steering members to impart a curvature to the first stiffening device that is a predetermined percentage less than a previously commanded curvature imparted by the steering members. In some embodiments, advancing the first and second stiffening devices includes advancing distally. Advancing the first and second stiffening devices may include advancing proximally.

[0048]

[0048] Actuating the steering member can include actuating the steering member to correspond to a shape of a portion of the first stiffening device exposed upon retracting the second stiffening device proximally over the first stiffening device. Actuating the steering member can include approximating an angle between a distal face of the first stiffening device and a cross-section of the first stiffening device at a proximal end of the portion of the first stiffening device. In some embodiments, actuating the steering member can include maintaining a position of the distal end of the first stiffening device relative to the proximal end of the portion of the first stiffening device.

[0049] Also described herein is a method of screening a body lumen of a patient, the method including: navigating a system through the body lumen including a first stiffening device disposed within a second stiffening device, the first stiffening device including a camera at a distal end; articulating a distal portion of the first stiffening device to perform a circular pass (e.g., perform a looping motion with the tip) that provides camera visualization around a first portion of the body lumen; retracting the system a selected length such that the distal portion of the first stiffening device is exposed; and articulating a distal portion of the first stiffening device to perform a loop (e.g., perform a looping motion with the tip) that provides camera visualization around a second portion of the body lumen, the second portion being at least partially proximal to the first portion. A circular pass motion as used herein may be a loop motion, and is not limited to a circular pass, and may be elliptical or irregular, but may describe a line radially around the circumferential lumen. The circular pass motion may start and stop at approximately the same location. In some embodiments, the circular passing motion extends beyond the radial starting position.

[0050]

[0050] In any of these embodiments, the system can be retracted (or configured to be retracted) as described above, including retracting a selected length to expose a distal portion of the first stiffening device.

[0051]

[0051] In general, the devices described herein may include a controller. The controller may include control circuitry, e.g., one or more processors (microprocessors), memory and timers (e.g., registers), and control logic, which may be software, hardware, and / or firmware. These controllers are equivalently referred to herein as "control circuitry." The controller may be implemented in software, firmware, hardware, or any suitable combination of at least two of the three.

[0052]

[0052] In some embodiments, the system can be configured to perform the method automatically. For example, the system can include a controller including one or more processors and a memory coupled to the one or more processors, the memory storing computer program instructions that, when executed by the one or more processors, perform a computer-implemented method of advancing inner and outer stiffening devices within a body lumen, the method being performed by the system. The selected length can be calculated based on a desired distance from a portion of the lumen already visualized by the camera. In some embodiments, the first and second portions can overlap.

[0053] Any of these methods can include compiling data received by the camera to generate a model of at least a portion of the lumen. The method can include machine sensing to provide positioning information regarding the center of the lumen.

[0054]

[0054] For example, described herein is a system including a first stiffening device disposed within a second stiffening device, a controller including one or more processors, and a memory coupled to the one or more processors, the memory storing computer program instructions which, when executed by the one or more processors, perform a computer-implemented method of screening a body lumen, the method including exposing a distal portion of the first stiffening device, articulating the distal portion of the first stiffening device to perform a circular passing motion resulting in camera visualization around a first portion of the body lumen, retracting the system a selected length such that the distal portion of the first stiffening device is exposed, and articulating the distal portion of the first stiffening device to perform a circular passing motion (e.g., performing a rotational motion by the tip) resulting in camera visualization around a second portion of the body lumen, wherein at least a portion of the second portion is located proximal to the first portion.

[0055]

[0055] The length selected may be calculated based on the desired distance from the portion of the lumen already visualized by the camera. The first and second portions may overlap.

[0056]

[0056] The system can also include compiling the data received by the camera to generate a model of at least a portion of the lumen. Any of these systems can include machine sensing to provide positioning information regarding the center of the lumen.

[0057] All of the methods and apparatus described herein in any combination are contemplated herein and can be used to achieve the advantages as described herein.

[0058]

[0058] The novel features of the invention are set forth with particularity in the appended claims. A better understanding of the features and advantages of the present invention will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the invention are utilized, and the accompanying drawings of which: [Brief description of the drawings]

[0059] [Figure 1] FIG. 13 shows a stiffening device. [Figure 2A]

[0060] 1A-1C show exemplary stiffening geometries of the stiffening device. [Figure 2B] 1A-1C show exemplary stiffening geometries of the stiffening device. [Figure 3A]

[0061] FIG. 2 illustrates an example embodiment of a portion of a vacuum stiffening device described herein, showing a cross-section of an example vacuum stiffening member of the device. [Figure 3B] FIG. 3B is an enlarged view of a portion of the cross section of the embodiment of FIG. 3A, showing the arrangement of layers in a non-rigidified configuration. [Figure 3C]

[0062] FIG. 1 illustrates an example of a portion of a vacuum stiffening device having multiple stiffening layers as described herein, showing a perspective view of a vacuum stiffening member with the outer layer removed (showing the outermost blade layer). [Figure 3D] FIG. 3D is an enlarged view of a portion of FIG. 3C. [Figure 3E] FIG. 3D is a longitudinal cross-sectional view of the vacuum stiffening device of FIG. 3C. [Figure 3F] FIG. 3D shows a cross-section of the stiffening member of FIG. 3C. [Figure 4A]

[0063] FIG. 1 illustrates an exemplary pressure stiffening device. [Figure 4B] FIG. 1 illustrates an exemplary pressure stiffening device. [Diagram 5]

[0064] FIG. 1 illustrates a stiffening device having a distal end. [Figure 6]

[0065] FIG. 1 illustrates a stiffening device having a distal end with multiple actively controlled links. [Figure 7]

[0066] FIG. 1 illustrates a nested stiffening system. [Figure 8]

[0067] FIG. 13 shows a nested stiffening system having a cover between an inner stiffening device and an outer stiffening device. [Figure 9A]

[0068] FIG. 13 illustrates a nested stiffening system in which an outer stiffening device includes steering and imaging functions. [Figure 9B] FIG. 13 illustrates a nested stiffening system in which an outer stiffening device includes steering and imaging functions. [Figure 10]

[0069] FIG. 13 illustrates an example of the use of a nested stiffening system. [Figure 10B] FIG. 13 illustrates an example of the use of a nested stiffening system. [Figure 10C] FIG. 13 illustrates an example of the use of a nested stiffening system. [Figure 10D] FIG. 13 illustrates an example of the use of a nested stiffening system. [Figure 10E] FIG. 13 illustrates an example of the use of a nested stiffening system. [Figure 10F] FIG. 13 illustrates an example of the use of a nested stiffening system. [Figure 10G] FIG. 13 illustrates an example of the use of a nested stiffening system. [Figure 10H] FIG. 13 illustrates an example of the use of a nested stiffening system. [Figure 11]

[0070] Fig. 11A is a schematic diagram of an example of the use of an actuating steering member of a stiffening device to assist in the transition of the stiffening device from a stiffened state to a soft state; Fig. 11B is a schematic diagram of an example of the use of an actuating steering member of a stiffening device to assist in the transition of the stiffening device from a stiffened state to a soft state; Fig. 11C is a schematic diagram of an example of the use of an actuating steering member of a stiffening device to assist in the transition of the stiffening device from a stiffened state to a soft state; Fig. 11D is a schematic diagram of an example of the use of an actuating steering member of a stiffening device to assist in the transition of the stiffening device from a stiffened state to a soft state; Fig. 11E is a schematic diagram of an example of the use of an actuating steering member of a stiffening device to assist in the transition of the stiffening device from a stiffened state to a soft state; [Figure 12]

[0071] Fig. 12A is a schematic diagram of an example of the use of an actuating steering member of a stiffening device to assist in the transition of the stiffening device from a stiffened state to a soft state; Fig. 12B is a schematic diagram of an example of the use of an actuating steering member of a stiffening device to assist in the transition of the stiffening device from a stiffened state to a soft state; Fig. 12C is a schematic diagram of an example of the use of an actuating steering member of a stiffening device to assist in the transition of the stiffening device from a stiffened state to a soft state; Fig. 12D is a schematic diagram of an example of the use of an actuating steering member of a stiffening device to assist in the transition of the stiffening device from a stiffened state to a soft state; Fig. 12E is a schematic diagram of an example of the use of an actuating steering member of a stiffening device to assist in the transition of the stiffening device from a stiffened state to a soft state; [Figure 13]

[0072] Fig. 13A is a schematic diagram of an example of the use of an actuating steering member of a stiffening device to assist in the transition of the stiffening device from a stiffened state to a soft state; Fig. 13B is a schematic diagram of an example of the use of an actuating steering member of a stiffening device to assist in the transition of the stiffening device from a stiffened state to a soft state; Fig. 13C is a schematic diagram of an example of the use of an actuating steering member of a stiffening device to assist in the transition of the stiffening device from a stiffened state to a soft state; Fig. 13D is a schematic diagram of an example of the use of an actuating steering member of a stiffening device to assist in the transition of the stiffening device from a stiffened state to a soft state; Fig. 13E is a schematic diagram of an example of the use of an actuating steering member of a stiffening device to assist in the transition of the stiffening device from a stiffened state to a soft state; [Figure 14A]

[0073] 1A-1C illustrate an exemplary method of performing a screening procedure within a body lumen using a nested stiffening system. [Figure 14B] 1A-1C illustrate an exemplary method of performing a screening procedure within a body lumen using a nested stiffening system. [Figure 14C] 1A-1C illustrate an exemplary method of performing a screening procedure within a body lumen using a nested stiffening system. [Figure 14D] 1A-1C illustrate an exemplary method of performing a screening procedure within a body lumen using a nested stiffening system. [Figure 14E] 1A-1C illustrate an exemplary method of performing a screening procedure within a body lumen using a nested stiffening system. [Figure 14F] 1A-1C illustrate an exemplary method of performing a screening procedure within a body lumen using a nested stiffening system. [Figure 15]

[0074] Figures 15A, 15B and 15C show an example of a method for copying shapes between a pair of nested stiffening devices. [Figure 16]

[0075] FIG. 16A illustrates a method for controlling a pair of nested stiffening devices to advance the nested shape distally by performing multiple shape copy sequences. FIG. 16B illustrates a method for controlling a pair of nested stiffening devices to advance the nested shape distally by performing multiple shape copy sequences. FIG. 16C illustrates a method for controlling a pair of nested stiffening devices to advance the nested shape distally by performing multiple shape copy sequences. FIG. 16D illustrates a method for controlling a pair of nested stiffening devices to advance the nested shape distally by performing multiple shape copy sequences. [Figure 17]

[0076] FIG. 17A illustrates a method of controlling a nested pair of stiffening devices to retract the nested pair proximally, including controlling the inner stiffening device to assume a memorized shape to facilitate withdrawal of the inner stiffening device. FIG. 17B illustrates a method of controlling a nested pair of stiffening devices to retract the nested pair proximally, including controlling the inner stiffening device to assume a memorized shape to facilitate withdrawal of the inner stiffening device. FIG. 17C illustrates a method of controlling a nested pair of stiffening devices to retract the nested pair proximally, including controlling the inner stiffening device to assume a memorized shape to facilitate withdrawal of the inner stiffening device. FIG. 17D illustrates a method of controlling a nested pair of stiffening devices to retract the nested pair proximally, including controlling the inner stiffening device to assume a memorized shape to facilitate withdrawal of the inner stiffening device. [Figure 18]

[0077] FIG. 18A illustrates a method of controlling a pair of nested stiffening devices, including controlling tension on one or more steering actuators when transitioning between a rigid state and a non-rigid state. FIG. 18B illustrates a method of controlling a pair of nested stiffening devices, including controlling tension on one or more steering actuators when transitioning between a rigid state and a non-rigid state. FIG. 18C illustrates a method of controlling a pair of nested stiffening devices, including controlling tension on one or more steering actuators when transitioning between a rigid state and a non-rigid state. FIG. 18D illustrates a method of controlling a pair of nested stiffening devices, including controlling tension on one or more steering actuators when transitioning between a rigid state and a non-rigid state. FIG. 18E illustrates a method of controlling a pair of nested stiffening devices, including controlling tension on one or more steering actuators when transitioning between a rigid state and a non-rigid state. FIG. 18F illustrates a method of controlling a pair of nested stiffening devices, including controlling tension on one or more steering actuators when transitioning between a rigid state and a non-rigid state. [Figure 19]

[0078] 19A and 19B are diagrams illustrating an automatic shape-copying method between a pair of nested stiffening devices when one of the pair of nested stiffening devices is advanced; [Figure 20]

[0079] Figure 20A is a diagram showing a method for linking the rolls of one stiffening device of a pair of nested stiffening devices, Figure 20B is a diagram showing a method for linking the rolls of one stiffening device of a pair of nested stiffening devices, and Figure 20C is a diagram showing a method for linking the rolls of one stiffening device of a pair of nested stiffening devices. [Figure 21]

[0080] 21A and 21B show examples of methods for controlling the operation of a nested pair of stiffening devices, including automatically controlling the movement of the nested pair; [Figure 22]

[0081] 22A and 22B illustrate an example of a method for controlling the movement of a pair of nested stiffening devices that may cause conflicting movements. [Diagram 23]

[0082] 23A and 23B illustrate an example of a method for controlling the operation of a pair of nested stiffening devices, including automatic detection and compensation of conflicting motions. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0060]

[0083] Generally, described herein are nested stiffening apparatus (e.g., devices, systems, etc.) that can be configured to navigate and / or assist in transporting a scope (e.g., endoscope) or other medical instrument through a curved or looped portion of the body, such as, but not limited to, a portion of the gastrointestinal tract, including, but not limited to, the large intestine, and methods of using the same. Specifically, described herein are methods and apparatus for navigating curves in a body region, such as the large intestine, including both forward and backward movement, using a pair of nested stiffening apparatus.

[0061]

[0084] The stiffening devices described herein can be long, thin, hollow (or solid) and can transition rapidly from a soft form (i.e., relaxed, pliable, or flexible) to a rigid form (i.e., a form that is stiff and / or retains its shape when stiffened). These stiffening devices can include multiple layers (e.g., coiled or reinforcing layers, slip layers, stiffening layers, bladder layers, and / or sealing sheaths) that can combine to form the walls of the stiffening device, which may be referred to as a "layered stiffening device." Unless the context makes clear otherwise, the methods and devices described herein may refer to any suitable stiffening device, including a layered stiffening device. For example, the stiffening devices (members, devices, etc.) described herein can be stiffened by jamming particles, by a phase change, by a connecting component (e.g., a cable with a disk or cone, etc.), or by any other stiffening mechanism. The stiffening device can transition from a soft form to a rigid form, for example, by applying a vacuum or pressure to or within the walls of the stiffening device. With the vacuum or pressure removed, the layers can easily shear or move relative to one another, and with the vacuum or pressure applied, the layers can transition to a state that exhibits substantially enhanced resistance to shear, movement, bending, torque and buckling, thereby providing stiffness to the system.Any of the devices described herein may be used to treat or diagnose various disease including the neurovascular system (e.g., aortic arch, subclavian artery, carotid artery, vertebral, basilar, posterior cerebral artery, circle of Willis, middle cerebral, protocerebral, etc.), upper gastrointestinal tract (e.g., mouth, esophagus, stomach, pylorus, bile duct, and pancreatic duct), small intestine (e.g., small intestine, duodenum, jejunum, iliac, etc.), lower gastrointestinal tract (rectum, colonic regions such as sigmoid colon, descending, transverse, ascending, cecum, ileocecal valve, etc.), urinary tract (urethra, bladder, kidneys, ureters, etc.), peripheral vasculature (e.g., femoral , iliac, mesenteric, lumbar, renal, celiac, hepatic, thoracic, etc.), heart (e.g., aorta, right coronary artery, left coronary artery, etc.), left heart (e.g., aorta, aortic valve, left ventricle, etc.), right heart (e.g., vena cava, right atrium, left atrium, mitral valve, coronary sinus, tricuspid valve, right ventricle, pulmonary valve, pulmonary vasculature, etc.), and / or right pulmonary (e.g., mouth, pharynx, trachea, bronchial tree and lobes, etc.).

[0062]

[0085] Any of the stiffening devices described herein may include a stiffening layer or region that engages a compression layer (which may be or include a bladder) that applies a force to the stiffening layer to stiffen or, in some cases, to destiffen (e.g., release) the stiffening layer. In some embodiments, these stiffening devices may include a stiffening layer that may include braids, knits, weaves, shreds, randomly distributed or randomly oriented fibers or strands, engagers, links, scales, plates, segments, particles, granules, crossed fibers, or other materials that form a stiffening layer. For example, the stiffening layer may include multiple strands or strand segments that cross each other (e.g., as part of a braid, knit, weave, etc.). The compression layer may apply a force to drive the crossed strands or strand segments against each other. While many of the embodiments shown herein are braids, any of these devices may instead or in addition include a generalized stiffening layer that includes crossed strands or strand segments.

[0063]

[0086] The stiffening device embodiments described herein can use pressure (positive pressure) and / or negative pressure to selectively or controllably stiffen, and in some embodiments, the methods described herein can be used with any suitable stiffening device.

[0064]

[0087] The stiffening (e.g., selective stiffening) devices described herein can provide stiffening for a variety of medical applications, including catheters, sheaths, scopes (e.g., endoscopes), wires, overtubes, trocars, or laparoscopic instruments. The stiffening devices can function as separate add-on devices or can be incorporated into the body of the catheter, sheath, scope, wire, or laparoscopic instrument. The devices described herein can also provide stiffening to non-medical structures.

[0065]

[0088] An exemplary stiffening apparatus is shown in FIG. 1. The system includes a stiffening device 300 having a wall with multiple layers, including a stiffening layer, an outer layer (part of which is cut away to show the underlying stiffening layer, configured as a braided layer in this example), and an inner layer. The system further includes a handle 342 having a vacuum or pressure inlet 344 for applying vacuum or pressure to the stiffening device 300. An actuation element 346 can be used to turn the vacuum or pressure on and off, thereby transitioning the stiffening device 300 between the soft and rigid 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 through the body. Additionally, the tip 339 can be tapered from the distal end to the proximal end to further facilitate distal movement of the stiffening device 300 through the body. In this example, the stiffening device is configured as an overtube, although other configurations can be used.

[0066]

[0089] An exemplary stiffening device in an exemplary stiffened configuration is shown in Figures 2A and 2B. When the stiffening device is stiffened, it is locked in the shape it had before the vacuum or pressure was applied, i.e., the stiffening device does not straighten, bend, or otherwise substantially change its shape (e.g., it may be stiffened in a looped configuration as shown in Figure 2A or a serpentine configuration as shown in Figure 2B). The air stiffening effect on the inner or outer layer (e.g., made of coiled tubing) can be a small percentage (e.g., 5%) of the maximum load capacity of the stiffening device in the bent state, thereby resisting the stiffening device from straightening out. When the vacuum or pressure is released, the strands in the stiffening layer of the device unlock relative to each other and can again move to allow bending of the stiffening device. Again, when the stiffening device is made softer by the release of the vacuum or pressure, it becomes soft in the shape it had before the vacuum or pressure was released, i.e., the stiffening device does not straighten, bend, or otherwise substantially change its shape. Thus, the stiffening devices described herein can transition from a soft, less rigid configuration to a stiffer, more rigid configuration by application of vacuum or pressure by restricting movement between overlapping yarns of a stiffening layer (e.g., a braided layer).

[0067]

[0090] The stiffening devices described herein can be switched between stiff and soft configurations quickly, in some embodiments with an indefinite number of transition cycles. In some embodiments, it is also possible to adjust the stiffening (e.g., stiffness) of the device, for example, by adjusting the positive pressure (in positive pressure stiffening embodiments) or vacuum (in vacuum stiffening embodiments). As interventional medical devices become longer and inserted deeper into the human body, and as they are expected to perform more precise therapeutic procedures, the need for precision and control increases. The selective stiffening devices described herein (including selective stiffening overtubes) are advantageous because they can provide both the benefits of flexibility (when needed) and stiffness (when needed). Additionally, the stiffening devices described herein can be used with conventional endoscopes, colonoscopes, robotic systems and / or navigation systems, such as those described in U.S. patent application Ser. No. 17 / 644,758, filed December 16, 2021, entitled “DEVICE FOR ENDOSCOPIC ADVANCEMENT THROUGH THE SMALL INTESTINE,” which is incorporated by reference in its entirety.

[0068]

[0091] The stiffening devices described herein may additionally or alternatively be any of the following: U.S. patent application Ser. No. 17 / 644,758, entitled "DEVICE FOR ENDOSCOPIC ADVANCEMENT THROUGH THE SMALL INTESTINE," filed on December 16, 2021; U.S. patent application Ser. No. 16 / 631,473, entitled "DYNAMICALLY RIGIDIZING OVERTURE," filed on July 19, 2018; U.S. patent application Ser. No. 17 / 604,203, entitled "DYNAMICALLY RIGIDIZING COMPOSITE MEDICAL STRUCTURES," filed on January 16, 20020; U.S. patent application Ser. No. 17 / 902,770, entitled "NESTED RIGIDIZING DEVICES," filed on September 2, 2022; U.S. patent application Ser. No. 17 / 902,770, entitled "LAYERED RIGIDIZING DEVICES," filed on March 29, 2021; all of which are incorporated by reference in their entireties. No. 17 / 995,294, entitled "DYNAMICALLY RIGIDIZING GUIDERAIL AND METHODS OF USE," filed on September 3, 2021, and entitled "DYNAMICALLY RIGIDIZING GUIDERAIL AND METHODS OF USE," filed on September 3, 2021.

[0069]

[0092] The stiffening devices described herein can be provided in multiple configurations, including different lengths and diameters. In some embodiments, the stiffening devices can include a working channel (e.g., to allow passage of typical endoscopic tools within the body of the stiffening device), a balloon, a nesting element, and / or a side-loading mechanism.

[0070]

[0093] For example, the stiffening device 100 (also referred to as an apparatus, e.g., system and / or device, including a stiffening member) can be configured to be stiffened by application of a vacuum, e.g., negative pressure. These devices can generally consist of layers configured to form a laminated structure upon application of negative pressure such that one or more stiffening layers reversibly coalesce to a softer outer layer driven against a stiffer inner layer. Figures 3A-3B show an example of a cross-section of a stiffening member of an apparatus (e.g., device, system) that is stiffened by application of a vacuum. Figure 3B shows a close-up view of the arrangement of layers of Figure 3A in a non-rigidified form. In this example, the stiffening member includes an innermost layer 115 configured to provide an inner surface against which the remaining layers can be consolidated (e.g., upon application of a vacuum). The innermost layer 115 can include a reinforcing element or coil. The stiffening member can also include a slip layer 113 on (e.g., radially outward of) the innermost layer. The slip layer may be, for example, a lubricant, coating and / or powder (e.g., talcum powder) on the outer surface of the inner layer 115 and / or within the gap layer 111. A radial gap layer 111 may separate the slip layer 113 from the stiffening layer (shown in this example as a braided or woven layer) 109 (referred to herein for convenience as the "stiffening layer"), providing a space between the stiffening layer and the slip layer within which the stiffening layer above may move, for example, when no vacuum is applied. This space or gap is removed when a vacuum is applied, thereby allowing the stiffening layer (e.g., the braided or woven layer in some examples) to move radially inward upon application of the vacuum. A second gap layer 107 may be present between the stiffening layers 109 and may be similar to layer 111. As described with reference to Figures 3C-3F, multiple stiffening layers may be included (e.g., two, three, four or more stiffening layers may be included), separated by additional gap layers and / or slip layers. The outermost layer 101 may be separated from the stiffening layer by a gap layer and may be configured to move radially inward and conform to the surface of the stiffening layer when a vacuum is applied to pull down against the stiffening layer.The outermost layer 101 can be soft, atraumatic, and can be sealed at both ends to form a vacuum-tight chamber with the innermost layer 115. The outermost layer 101 can be made of an elastomer, such as urethane. The hardness of the outermost layer 101 can be, for example, 30A to 80A. Also, the outermost layer 101 can have a thickness of about 0.0001 inch to 0.01 inch, such as about 0.001 inch, 0.002 inch, 0.003 inch, or 0.004 inch. Alternatively, the outermost layer can be a plastic, including, for example, LDPE, nylon, or PEEK.

[0071]

[0094] 3C-3F show an embodiment of a tubular stiffening member of device 100 that includes multiple stiffening layers. As in FIGS. 3A-3B, the device includes a tube having a wall made of multiple layers disposed about a lumen 120 (e.g., for placement of an instrument or endoscope therethrough). A vacuum can be applied between the layers to stiffen stiffening device 100. Any of the tubular devices described herein may instead include a solid core forming an inner layer 115.

[0072]

[0095] The innermost layer 115 can be configured to provide an inner surface against which the remaining layers can be compacted, for example, when a vacuum is applied within the walls of the stiffening device 100. This structure can be configured to minimize bending forces and / or maximize flexibility in a non-vacuum state. In some embodiments, the innermost layer 115 can include reinforcing elements 150z or coils in a matrix as described above. In the embodiment shown in FIG. 3E, the layer 113 above (i.e., radially outward from) the innermost layer 115 can be a slip layer. The layer 111 can be a radial void (i.e., space). The void layer 111 can provide space for the stiffening layer above it to move inward (when no vacuum is applied) and space for the stiffening layer to move radially inward (when a vacuum is applied).

[0073]

[0096] Layer 109, in this embodiment, can be a first stiffening layer including braided yarns 133 similar to those described elsewhere herein. The stiffening layer can be, for example, 0.001 inch to 0.040 inch thick. For example, the stiffening layer can be 0.001 inch, 0.003 inch, 0.005 inch, 0.010 inch, 0.015 inch, 0.020 inch, 0.025 inch, or 0.030 inch thick. In some embodiments, the stiffening layer can include braids having tensile or hoop fibers 137, as shown in FIG. 3D. The hoop fibers 137 can be spiraled and / or woven to provide a stiffening layer. Also, the hoop fibers 137 can be arranged in 2-50, e.g., 20-40, hoops per inch. The hoop fibers 137 can advantageously exhibit high compressive stiffness in the radial direction (resisting buckling or bending) but remain flexible in the direction of the longitudinal axis 135 of the stiffening device 100. That is, when compression is applied to the stiffening device 100, the stiffening layer 109 will attempt to expand in diameter as it compresses. The hoop fibers 137 can withstand this diametric expansion and therefore can withstand compression. Thus, the hoop fibers 137 can provide a system that is flexible when bent but still resists both tension and compression.

[0074]

[0097] Layer 107 may be another radially gapped layer similar to layer 111 .

[0075]

[0098] In some embodiments, the stiffening devices described herein can have multiple stiffening layers. For example, the stiffening devices can include two, three, or four stiffening layers. With reference to FIG. 3E, layer 105 can be a second stiffening layer 105. The second stiffening layer 105 can have any of the features described in connection with the first stiffening layer 109. In some embodiments, the second stiffening layer 105 can be the same as the first stiffening layer 109. In other embodiments, the second stiffening layer 105 can be different from the first stiffening layer 109. For example, in some embodiments, the stiffening layer is a braided layer, and in FIG. 3E, the braid of the second braided layer 105 can include fewer twists and have a larger braid angle α than the braid of the first braided layer 109. The fewer number of strands may facilitate increased flexibility of the stiffening device 100 (compared to a second strand having an equal or greater number of strands), and the larger braid angle α may facilitate contraction of the diameter of the first braided layer 109 (e.g., when the first braided layer is compressed) while increasing / maintaining flexibility of the stiffening device 100. As another example, the braid of the second braided layer 105 may include more strands and have a larger braid angle α than the braid of the first braided layer 109. Having a larger number of strands results in a relatively tough and smooth layer, while having a larger braid angle α may facilitate contraction of the diameter of the first braided layer 109.

[0076]

[0099] Layer 103 may be another radial gap similar to layer 111. Void layer 103 may have a thickness of 0.0002 inches to 0.04 inches, such as about 0.03 inches. A thickness within this range may ensure that the stiffening layer strands 133 can easily slip and / or bulge relative to one another to ensure flexibility when stiffening device 100 is bent.

[0077]

[0100] The outermost layer 101 can be configured to move radially inward and conform to the surface of the stiffening layers 105, 109 when a vacuum is applied to pull it down against the stiffening layers 105, 109. The outermost layer 101 can be soft and atraumatic and can be sealed at both ends to form a vacuum tight chamber with the layer 115. The outermost layer 101 can be made of an elastomer, such as urethane. The hardness of the outermost layer 101 can be, for example, 30A to 80A. Also, the outermost layer 101 can have a thickness of about 0.0001 inch to 0.01 inch, such as about 0.001 inch, 0.002 inch, 0.003 inch, or 0.004 inch. Alternatively, the outermost layer can be a plastic, including, for example, LDPE, nylon or PEEK.

[0078]

[0101] In some embodiments, the outermost layer 101 can have, for example, tensile or hoop fibers 137 extending therethrough. The hoop fibers 137 can be, for example, aramid (e.g., Technora, Nylon, Kevlar), Vectran, Dyneema, carbon fiber, fiberglass, or plastic. Additionally, the hoop fibers 137 can be arranged at 2-50 hoops per inch, for example, 20-40 hoops per inch. In some embodiments, the hoop fibers 137 can be laminated within an elastomeric sheath. Hoop fibers can be advantageously more rigid 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 stiffening device). Additionally, the hoop fibers can be advantageously less rigid until placed under a tensile load where the hoop fibers can suddenly exhibit a higher hoop stiffness.

[0079]

[0102] In some embodiments, the outermost layer 101 may include a lubricant, coating and / or powder (e.g., talcum powder) on its exterior surface to enhance sliding of the stiffening device through the anatomy. The coating may be hydrophilic (e.g., Hydromer® coating or Surmodics® coating) or hydrophobic (e.g., fluoropolymer). The coating may be applied, for example, by dipping, painting or spraying the coating on.

[0080]

[0103] The innermost layer 115 may likewise include a lubricant, a coating (e.g., a hydrophilic or hydrophobic coating) and / or a powder (e.g., talcum powder) on its interior surface to maximize flexibility, particularly configured to allow the boundary layers to shear against one another more easily when no vacuum is applied to the stiffening device 100.

[0081]

[0104] In some embodiments, the outermost layer 101 may be loose on the radially inner layer. For example, the inner diameter of layer 101 (assuming it constitutes a tube) may have a diameter gap of 0 inches to 0.200 inches between the next radially inner layer (e.g., stiffening layer). This allows the vacuum stiffening system to be more flexible when not under vacuum while still maintaining a high stiffening factor. In other embodiments, the outermost layer 101 may be stretched somewhat over the next radially inner layer (e.g., stiffening layer). For example, the zero strain diameter of the tube constituting layer 101 may be 0 inches to 0.200 inches smaller in diameter than the next radially inner layer and may then be stretched over it. When not under vacuum, this system may have less flexibility than a system with a looser outer layer 101. However, it may also have a smoother appearance and be less likely to tear during use.

[0082]

[0105] In some embodiments, the outermost layer 101 may be loose on the radially inner layer. A slight positive pressure may be applied under the layer 101 to gradually expand the layer 101 and allow the stiffening device to bend more freely in the soft configuration. In this embodiment, the outermost layer 101 may be elastomeric and may maintain a compressive force on the stiffening layer, thereby providing stiffness. After positive pressure (sufficient to nominally expand the sheath away from the stiffening layer, e.g., 2 psi) is applied, the outermost layer 101 no longer contributes stiffness, thereby enhancing baseline flexibility. After stiffening is required, the positive pressure may be replaced by negative pressure (vacuum) to provide stiffness.

[0083]

[0106] A vacuum can be maintained within the stiffening device 100 from a minimum to a full atmospheric vacuum (e.g., about 14.7 psi). In some embodiments, a bleed valve, regulator, or pump control can be provided so that the vacuum can be released to any intermediate level to provide variable stiffness capabilities. This vacuum pressure can be advantageously used to stiffen the stiffening device structure by compressing layers of a stiffening layer (e.g., a braided sleeve) against adjacent layers. A stiffening layer, such as a braid, knit, or woven, can naturally flex when flexed (i.e., when flexed perpendicular to its longitudinal axis), and the lattice structure formed by the interwoven strands deforms as the sleeve is bent such that the stiffening layer conforms to the bent shape while resting on the inner layer. In some embodiments, this results in a lattice geometry in which the corner angles of each lattice element change as the braided sleeve bends. When compressed between conformal materials such as layers described herein, the lattice elements are fixed at their current corners and have an enhanced ability to resist deformation upon application of a vacuum, thereby stiffening the entire structure in flexion when a vacuum is applied. Also, in some embodiments, the hoop fibers in or on the braid can carry tensile loads that help prevent localized buckling of the braid at high applied bending loads.

[0084]

[0107] The stiffness of stiffening device 100 can increase by 2 to more than 30 times, for example 10 times, 15 times, or 20 times, when transitioned from the soft to the rigid configuration. In one particular embodiment, the stiffness of a stiffening device similar to stiffening device 100 was tested. The test stiffening device had a wall thickness of 1.0 mm and an outer diameter of 17 mm, and a force was applied to the end of a 9.5 cm long cantilever section of the stiffening device until the stiffening device deflected 10 degrees. Only 30 grams of force was required to do this in the soft mode, while 350 grams of force was required to do this in the rigid (vacuum) mode.

[0085]

[0108] In some embodiments of the vacuum stiffening device 100, there may be only one stiffening layer. Other embodiments of the vacuum stiffening device 100 may include two, three or more stiffening layers. In some embodiments, one or more of the radial gap layers or slip layers of the stiffening device 100 may be eliminated. In some embodiments, some or all of the slip layers of the stiffening device 100 may be eliminated.

[0086]

[0109] The stiffening layer described herein can act as a variable stiffness layer. The variable stiffness layer can include one or more variable stiffness elements or structures that, when activated (e.g., when a vacuum is applied), increase bending stiffness and / or shear resistance, resulting in higher stiffness. Other variable stiffness elements can be used in addition to or instead of the stiffening layer. In some embodiments, an engagement portion can be used as a variable stiffness element, as described in International Patent Application No. PCT / US2018 / 042946, filed July 19, 2018, entitled "DYNAMICALLY RIGIDIZING OVERTUBE," which is incorporated herein by reference in its entirety. Alternatively or additionally, the variable stiffness element can include particles or granules, jamming layers, flakes, stiffening shaft members, stiffening parts, longitudinal members or substantially longitudinal members.

[0087]

[0110] The stiffening devices described herein can also be stiffened by application of positive pressure rather than a vacuum. For example, with reference to Figures 4A-4B, a stiffening device (e.g., device or system) 2100 can be similar to the stiffening device 100 described above, except that it can be configured to hold pressure (e.g., greater than 1 atmosphere) rather than a vacuum for stiffening. The pressure-activated stiffening device 2100 can also include multiple layers disposed about a lumen 2120 (e.g., for placement of an instrument or endoscope therethrough).

[0088]

[0111] For example, Figures 4A-4B show longitudinal and radial cross sections of an embodiment of a stiffening member actuated by pressure from a stiffening device. Stiffening device 2100 shown in Figures 4A-4B can include an innermost layer 2115 (similar to innermost layer 115), a slip layer 2113 (similar to slip layer 113), a pressure void 2112, a bladder layer 2121, a void layer 2111 (similar to void layer 111), a stiffening layer 2109 (e.g., a braid layer, similar to stiffening layer 109) or other variable stiffness layer as described herein, a void layer 2107 (similar to layer 107), and a containment outermost layer 2101.

[0089]

[0112] The pressure void 2112 can be a sealed chamber that provides a void for the application of pressure to the layers of the stiffening device 2100. Pressure can be supplied to the pressure void 2112 using a fluid or gas expansion / pressure medium. The expansion / pressure medium can be water or saline, or a lubricating fluid, such as oil or glycerin. The lubricating fluid can, for example, facilitate the layers of the stiffening device 2100 moving over each other in the soft configuration. The expansion / pressure medium can be supplied to the void 2112 upon stiffening of the stiffening device 2100, and can be partially or completely evacuated to transform the stiffening device 2100 back to the soft configuration. In some embodiments, the pressure void 2112 of the stiffening device 2100 can be connected to a pre-filled pressure source, such as a pre-filled syringe or a pre-filled inhaler, thereby reducing preparation time required by the physician.

[0090]

[0113] Bladder layer 2121 may be made of, for example, a low durometer elastomer (e.g., shore hardness 20A-70A) or a thin plastic sheet. Bladder layer 2121 may be formed from a thin sheet of plastic or rubber sealed lengthwise to form a tube. The lengthwise seal may be, for example, a butt joint or a lap joint. For example, a lap joint may be formed lengthwise in the rubber sheet by melting the rubber at the lap joint or by using an adhesive. In some embodiments, bladder layer 2121 may be 0.0002 inches to 0.020 inches thick, such as about 0.005 inches thick. Bladder layer 2121 may be soft, high friction, stretchy, and / or wrinkle-resistant. In some embodiments, bladder layer 2121 is polyolefin or PET. The bladder 2121 can be formed, for example, using methods used to form heat shrink tubing, such as extrusion of a substrate, followed by wall thinning by heat, pressure and / or radiation. When pressure is supplied through the pressure void 2112, the bladder layer 2121 can expand through the void layer 2111 and press the stiffening layer 2109 against the confining outermost layer 2101 such that relative motion of the stiffening layer yarns is reduced.

[0091]

[0114] The outermost containment layer 2101 can be a tube, such as an extruded tube. Alternatively, the outermost containment layer 2101 can be a tube with a reinforcing member (e.g., a metal wire with a circular or rectangular cross section) encapsulated in an elastomeric matrix, similar to those described in connection with the innermost layer of other embodiments described herein. In some embodiments, the outermost containment layer 2101 can include a helical spring (e.g., made of round or flat wire) and / or a tubular stiffening layer (e.g., made of round or flat metal wire) and a thin elastomeric sheet that is not bonded to other elements in the layer. The outermost containment layer 2101 can be a tubular structure with a continuous smooth surface. This can favor an outer member that slides against it with a close and locally high contact load (e.g., a nesting configuration as described further herein). The outer layer 2101 can also be configured to support a compressive load, such as pinching. Additionally, the outer layer 2101 (eg, with the reinforcing elements therein) can be configured to prevent the stiffening device 2100 from changing diameter when pressure is applied.

[0092]

[0115] Because both the outer layer 2101 and the inner layer 2115 contain reinforcing elements therein, the stiffening layer 2109 may be moderately restricted from both shrinking in diameter (under tensile load) and increasing in diameter (under compressive load).

[0093]

[0116] By using pressure rather than vacuum for transition from the soft to the rigid state, the stiffness of the stiffness imparting device 2100 can be increased. For example, in some embodiments, the pressure supplied to the pressure void 2112 can be between 1 and 40 atmospheres, such as between 2 and 40 atmospheres, between 4 and 20 atmospheres, between 5 and 10 atmospheres. In some embodiments, the pressure supplied is about 2 atmospheres, about 4 atmospheres, about 5 atmospheres, about 10 atmospheres, about 20 atmospheres. In some embodiments, the stiffness imparting device 2100 can exhibit a change in relative bending stiffness from the soft to the rigid configuration (as measured in a simple cantilever configuration) of 2 to 100 times, such as 10 times to 80 times, 20 times to 50 times. For example, the stiffness imparting device 2100 can have a change in relative bending stiffness from the soft to the rigid configuration of about 10 times, 15 times, 20 times, or 25 times, 30 times, 40 times, 50 times, or more than 100 times.

[0094]

[0117] Any of the stiffening devices described herein can have a distal end or a portion that is designed differently from the elongated body of the stiffening device. For example, as shown in FIG. 5, the stiffening device 5500 can have an elongated body 5503z and a distal end 5502z. Only the distal end 5502z, only the elongated body 5503z, or both the distal end 5502z and the elongated body 5503z can be stiffened (e.g., by vacuum and / or pressure) as described herein. In some embodiments, one portion 5502z, 5503z is actuated by pressure and the other portion 5502z, 5503z is actuated by vacuum. In other embodiments, both portions 5502z, 5503z are actuated by pressure or vacuum, respectively.

[0095]

[0118] Any of the stiffening devices (e.g., inner and / or outer stiffening devices) can be configured to be steered (e.g., bend or curve controllably), particularly at their distal end regions. Any of these devices can, in fact, include one or more actuated steering members configured to steer the device, for example, from the proximal end of the device. The actuated steering members can be any suitable steering members, including mechanical steering (e.g., one or more tendons, cables, wires, actuators, etc.), pneumatic steering, magnetic steering, thermal steering (e.g., using shape memory alloys or polymers, etc.). Although the examples described herein primarily include actuated steering members including one or more cables, any suitable steering members can be used in any of these devices and methods.

[0096]

[0119] Referring to FIG. 6, in other embodiments, the distal end 7602z can include multiple links 7604z that are actively controlled, such as via actuated steering members (e.g., cables 7624) for steering the stiffening device 7600. The device 7600 is similar to the device 5800, except that the device 7600 includes cables 7624 configured to control the movement of the device. Although FIG. 26 does not show the passage of the cables 7624 through the elongated stiffening body 7603z (i.e., comprising the outer wall 7601, the stiffening layer 7609, and the inner layer 7615), the cables 7624 can extend in any manner as described elsewhere herein. In some embodiments, one or more layers of the elongated stiffening body 7603z can continue into the distal end 7602z. For example, as shown in FIG. 26, the inner layer 7615 can continue into the distal end 7602z, e.g., radially inward of the links 7604z. Similarly, any of the additional layers from the stiffening proximal portion (e.g., stiffening layer 7609 or outer layer 7601 may continue into the distal portion 7602z and / or may be located radially inward of the coupling portion 7604z). In other embodiments, none of the layers of the elongated stiffening body 7603z continue into the distal portion 7602z. The coupling portion 7604z (and any coupling portion described herein) may include a coating 7627z thereon. The coating 7627z may be advantageous because it may make the distal portion 7602z atraumatic and / or smooth. The coating 7627z may be a film, such as expanded PTFE. Expanded PTFE may be advantageous because it may provide a smooth, low-friction surface that is less resistant to bending but more resistant to buckling.

[0097]

[0120] In some embodiments, the stiffening devices described herein can be used with one or more of the other stiffening devices described herein. For example, an endoscope can include a stiffening mechanism described herein, and a stiffening device can include a stiffening mechanism described herein. Used together, they can form a nested system that can be advanced one after the other, thereby allowing one of the elements to remain stiff at any given time such that loops are reduced or eliminated (i.e., a sequentially advanced nested system can be formed).

[0098]

[0121] An exemplary nested system 2300z is shown in FIG. 7. The system 2300z can include an outer stiffening device 2300 and an inner stiffening device 2310 (here configured as a stiffening scope) that can be axially moved relative to each other concentrically or non-concentrically. The outer stiffening device 2300 and the inner stiffening device 2310 can include any of the stiffening mechanisms as described herein. For example, the outer stiffening device 2300 can include an outermost layer 2301a, a stiffening layer 2309a, and an inner layer 2315a that includes a wound coil. The outer stiffening device 2300 can be configured to receive a vacuum between the outermost layer 2301a and the inner layer 2315a to provide stiffening, for example. Similarly, the inner scope 2310 can include an outer layer 2301b (e.g., coiled), a stiffening layer 2309b, a bladder layer 2321b, and an inner layer 2315b (e.g., coiled). The inner scope 2310 can be configured to receive pressure between the bladder 2321b and the inner layer 2315b to provide stiffening, for example. Also, an air / water channel 2336z and a working channel 2355 can extend through the inner stiffening device 2310. Additionally, the inner stiffening scope 2310 can include a distal portion 2302z with a camera 2334z, a light 2335z, and a steerable linkage 2304z. A cover 2327z can extend over the distal portion 2302z. In another embodiment, the camera and / or illumination can be delivered in a separate assembly (e.g., the camera and illumination may be bundled within a catheter and delivered through working channel 2355 and / or additional working channels to the distal-most end 2333z).

[0099]

[0122] An interface 2337z can be disposed between the inner stiffening device 2310 and the outer stiffening device 2300. The interface 2337z can be an air gap having a dimension d (see FIG. 5) of 0.001 inch to 0.050 inch, for example, with a thickness of 0.0020 inch, 0.005 inch, or 0.020 inch. In some embodiments, the interface 2337z can be low friction, for example, including powders, coatings, or laminations to reduce friction. In some embodiments, there can be a sealant between the inner stiffening device 2310 and the outer stiffening device 2300, and the intervening space can be pressurized, for example, with a fluid or water, to form a hydrostatic bearing. In other embodiments, there may be a sealant between the inner stiffening device 2310 and the outer stiffening device 2300, and the intervening space may be filled with small balls to reduce friction.

[0100]

[0123] The inner stiffening device 2310 and the outer stiffening device 2300 can be moved relative to each other and alternately stiffened to impart a bend or shape along the length of the nested system 2300z. For example, the inner device 2310 can be inserted into a lumen and bent or steered to a desired shape. Pressure can be applied to the inner stiffening device 2310 to engage and lock the stiffening layer elements to the inner stiffening device 2310 in this configuration. The stiffening device 2300 (e.g., in a soft state) can then be advanced over the stiff 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 engage and lock the layers to fix the shape of the stiffening device. The inner device 2310 can transition to a soft state and be advanced, and the process is repeated. It should be understood that while the system 2300z is described as including a stiffening device and an inner device configured as a scope, 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.

[0101]

[0124] FIG. 8 illustrates another exemplary nested system 2700z. The system 2700z is similar to the system 2300z, except that it includes a cover 2738z attached to both the inner and outer stiffening devices 2710, 2700. The cover 2738z may be low durometer and thin walled, for example, to allow elasticity and stretchability. The cover 2738z may be a rubber, such as urethane, latex or silicone. The cover 2738z may protect the interface / radial gap between the inner and outer devices 2710, 2700. The cover 2738z may prevent contaminants from entering the space between the inner and outer tubes. The cover 2738z may further prevent tissue and other material from being trapped in the space between the inner and outer tubes. The cover 2738z may stretch within the elastic limits of the material to allow the inner and outer devices 2710, 2700 to move independently of each other. The cover 2738z may be adhered or otherwise attached to the stiffening device 2710, 2700 such that the cover 2738z is always in a minimal slightly stretched state. This embodiment may be wipeable on the outside for cleaning. In some embodiments, the cover 2738z may be configured as a "rolling" seal, such as that disclosed in U.S. Pat. No. US6,447,491, the entire disclosure of which is incorporated herein by reference.

[0102]

[0125] 9A-9B show another exemplary nested system 9400z. In this system 9400z, the outer stiffening device 9400 includes steering and imaging functions (e.g., similar to a scope), while the inner device includes only stiffening functions (but 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 therein) for accessing 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 a time, while the other may follow stiffening and / or move through the anatomy. Here, the outer device 9400 can guide the inner device 9410 (in FIG. 9A the inner device 9410 is shown retracted relative to the outer device 9400, and in FIG. 7B it is extended approximately equal to the outer device 9400). Advantageously, the system 9400z can provide a smooth outer surface to avoid pinching anatomy and / or avoiding fluid flow between the inner and outer devices 9410, 9400. Having steering capabilities on the outer device 9400 can also provide additional leverage for steering the tip. The outer device can also facilitate better imaging capabilities due to the larger diameter of the outer device 9400 and the ability to accommodate larger cameras.

[0103]

[0126] 10A-10H show examples of use of the nested system 2400z as described herein. In FIG. 10A, the steerable inner stiffening device 2410 is positioned within the outer stiffening device 2400 such that the distal end of the inner stiffening device 2410 extends outside the outer stiffening device 2400. In FIG. 10B, the distal end of the inner stiffening device 2410 is bent (e.g., via an actuated steering member such as cable 7624) to a desired direction / orientation and then stiffened (e.g., using vacuum or pressure as described herein). In FIG. 10C, the outer stiffening device 2400 (in its soft form) is advanced over the stiffened inner stiffening device 2410 (including over the bent distal portion). After the distal end of the outer stiffening device 2400 has been sufficiently advanced over the distal end of the inner stiffening device 2410, the outer stiffening device 2400 can be stiffened (e.g., using vacuum or pressure as described herein). In FIG. 10D, the inner stiffening device 2410 can then be transitioned to a soft state (e.g., by removing the vacuum or pressure as described herein and allowing the steering cables to slacken so that the tip can move easily) and can be advanced and oriented / pointed / steered as desired. Alternatively, in FIG. 10D, the inner stiffening device 2410 can be actively steered (manually or computer controlled) as it emerges to minimize the load on the stiffened outer tube. Minimizing the load on the outer stiffening device 2400 helps this tube retain its stiffened shape. After the inner stiffening device 2410 is stiffened, the outer stiffening device 2400 can be transitioned to a soft state and advanced over it (as shown in FIG. 10E). The process can then be repeated as shown in FIG. 10F-10H.The repeated process can result in a "shape copy" in which the inner and outer stiffening devices 2410, 2400 in their soft forms successively follow (or copy) the shape of whichever of the devices 2410, 2400 is in its rigid form. In some embodiments, upon completion of the sequence shown in Figures 10A-10H, a third stiffening device can be slid over and stiffened the first two stiffening devices (2400, 2410). The stiffening devices 2400 and 2410 can then be withdrawn. Finally, a fourth stiffening device can be inserted into the inner lumen of the third tube. This fourth stiffening device can have a larger diameter and more features than the stiffening device 2410. For example, the fourth stiffening device can have a larger working channel, more working channels, a more capable camera, or a combination of these. This technique can allow the two smaller tubes, which tend to be more flexible and easier to manipulate, to reach deeper into the body, while the larger tube can ultimately be delivered for therapeutic purposes. Alternatively, in the above example, the fourth stiffening device may be a conventional endoscope as known in the art.

[0104]

[0127] In some embodiments, upon completion of the sequence shown in Figures 10A-10H, the outer stiffening device 2400 may be stiffened and then the inner stiffening device 2410 may be removed. For example, the stiffening device 2410 may be a "navigation" device including a camera, lighting, and a distal steering portion. The "navigation" device 2410 may be sufficiently sealed to facilitate cleaning between procedures. A second inner device may then be placed inside the stiffening outer device 2400 and advanced beyond the distal end of the outer device 2400. The second inner device may be a "treatment" tube including elements such as a camera, lights, water, suction tools, and various tools. The "treatment" device may not have steering portions or stiffening capabilities, thereby providing additional space within the body of the treatment tube to include other features, such as tools for performing treatment. Once in place, the tools on the "treatment" tube may be used to perform treatment on the body, such as mucosal resection or incision in the digestive tract of the human body.

[0105]

[0128] In another embodiment, after or upon completion of the sequence shown in Figures 10A-10H, a third device may be inserted into the inner tube 2410. The third device may be a stiffening device and / or an endoscope.

[0106]

[0129] In some embodiments, after completion of the sequence shown in Figures 10A-10H and any treatment performed in place using the system 2400z, the entire system 2400z can be removed from the anatomy. In one example method of retraction, the system 2400z can be transitioned to a flexible configuration (i.e., both the inner and outer devices 2410, 2400 can be transitioned to a flexible configuration) and the flexible system 2400z can be pulled proximally. In this manner, tension between the patient's body (e.g., anus) and the robotic arm (e.g., arm 1023y, described below) can prevent the system 2400z from falling out of the body as it is removed (e.g., because more of the flexible system 2400z is positioned outside the body than inside the body).

[0107]

[0130] Another example of a retraction method may involve shape copying similar to that described with reference to Figures 10A-10H, but in reverse. In this example, for example, the inner stiffening device 2410 may be stiffened and the outer stiffening device 2400 may be retracted proximally (while in a soft configuration) over the inner stiffening device 2410. The outer stiffening device 2400 may then be stiffened and the inner stiffening device 2410 may be allowed to relax and moved proximally within the outer stiffening device 2400 (e.g., until the distal end of the inner stiffening device 2410 is flush with the distal end of the outer stiffening device 2400). In this example, tension in the steering cables may be kept constant (e.g., low, such as less than ¼ lbs) to ensure that as the inner stiffening device 2410 is retracted into the outer stiffening device 2400, the steerable distal end transitions to the shape of the outer stiffening device 2400 without compromising the fixed shape of the outer stiffening device 2400. Alternatively or additionally, when the outer stiffening device 2400 is stiffened in a straight shape, the inner stiffening device 2410 can be retracted into the outer stiffening device 2400, causing the tension in each of the steering cables to be equal (i.e., the same value, thus causing the child shape to follow the inner shape of the mother shape).

[0108]

[0131] As another example of a withdrawal method, the steerable distal tip of the inner stiffening device 2410 can be actively steered proximally to a known, assumed or measured shape of the outer stiffening device 2400 as or after the distal tip of the inner stiffening device 2410 is retracted into the outer stiffening device 2410. That is, the distal tip of the inner stiffening device 2410 can be steered to match the shape of the portion of the outer stiffening device 2400 immediately proximal to the distal tip of the inner stiffening device 2410. In one particular example, the inner stiffening device 2410 can protrude 4 inches from the outer stiffening device 2400, and the last 4 inches of the outer stiffening device 2400 can form a 90 degree bend along a 2.5 inch radius of curvature. In this embodiment, the inner stiffening device 2410 can be steered into a 90 degree bend along a 2.5 inch radius of curvature and then retracted (in that shape) into the outer stiffening device 2400. This can be advantageous as it can ensure that the inner stiffening device 2410 can be easily retracted into the outer stiffening device 2400 (i.e., because the shapes of the two are matched).

[0109]

[0132] In some embodiments, certain methods, controls, and / or algorithms can be used to enhance the advancement or withdrawal of a nested stiffening device such as those described herein. As described above, when advancing or withdrawing a nested system, the device is alternately softened and stiffened to move along the body lumen. After the soft device is advanced over or within the stiffening device and the soft device copies the shape of the stiffening device, the stiffening device can then be softened to be advanced or withdrawn. In some embodiments, an actuating steering member (such as, for example, steering cable 7624) can be used to control the shape of the stiffening device and / or maintain control of the device during / as the stiffening device transitions to a soft state.

[0110]

[0133] For example, when advancing the nested system, the outer stiffening device (e.g., outer stiffening device 2400) advances over the inner stiffening device and copies its shape before the inner stiffening device (e.g., inner stiffening device 2410) is transitioned to a soft state prior to its advancement. In some embodiments, at the time shown in FIG. 10D, the inner stiffening device can be steered to maintain a previously commanded curvature of the inner stiffening device. The previously commanded curvature may refer to the curvature imparted by the actuated steering member prior to stiffening of the inner device.

[0111]

[0134] Maintaining a previously commanded curvature may have advantages over transitioning the inner stiffening device to a soft state with the steering cables slack. For example, during a partial copy of the inner stiffening device where the outer stiffening device is not fully advanced over the inner stiffening device, it may not be desirable to straighten the exposed length of the inner device upon completion of the partial copy. In some embodiments, in the absence of stiffening or tension on the cables, the inner stiffening device may tend to relax to a non-curved (or less curved) state. As another example, during a full copy of the inner stiffening device where the outer stiffening device is fully advanced over the inner stiffening device in order to advance the inner stiffening device from the outer device, the inner device must first be straightened out of the outer device before it can be articulated.

[0112]

[0135] In some embodiments, the actuating steering member (e.g., cable 7624) can provide a bending moment that is maintained at approximately the same bending moment during shape copying. Maintaining the bending moment can advantageously help the inner stiffening device retain its current shape during the copying process, thereby improving shape copying fidelity. Maintaining the bending moment during shape copying can also reduce artificial "steepening" of the bend due to a shorter exposed length of the inner stiffening device. Furthermore, maintaining the bending moment can allow the desired curvature of the inner stiffening device to be maintained / set / reset with the inner stiffening device positioned within the outer device. When the inner stiffening device is then advanced, it can advance along an arc of constant curvature. This control can, for example, allow the user to bring the inner stiffening device out along the steepest bend possible.

[0113]

[0136] In some embodiments, the system is configured to automatically use the actuated steering members as described above to assist in the transition of the inner device from a stiffened state to a soft state.

[0114]

[0137] In some embodiments, the system may further allow the commanded curvature to be reset to zero upon completion of the shape copy.

[0115]

[0138] For example, the system can be configured to maintain the existing curvature commands for a partial shape copy, and to reset the curvature commands to zero for a full shape copy.

[0116]

[0139] In some embodiments, the operator may choose whether or not to reset the curvature to zero upon completion of a complete shape copy (eg, a partial shape copy, a full shape copy, or both a partial and full shape copy).

[0117]

[0140] In some embodiments, for continuous commanded shape copying, where shape copying progresses incrementally while the operator activates the control (e.g., holds down a button) and stops when the operator releases the control (e.g., releases the button), the previously commanded curvature can be maintained during advancement of the outer stiffening device 2400, and then gradually reduced to zero if the operator continues to activate the control after the outer device has advanced through its entire possible range.

[0118]

[0141] The actuating steering member can use two primary elements to control the inner device distal tip bend. For example, if steering cables (or tendons, etc.) are used, the first element is by imparting a bending moment. The bending moment can be caused by stretching the steering cables. The second element is by imparting a geometric change. The geometric change can be caused by displacing the steering cables, thereby causing different path lengths along different steering cables, resulting in the formation of a bend. The effect of steering cable displacement depends on the overall shape of the bend, including the portion of the bend, if any, that is located within the outer device.

[0119]

[0142] Thus, in some embodiments, the shape of the outer stiffening device can be used to control the shape of the inner stiffening device as it transitions to a soft state. The shape can be known using shape sensing techniques. In some embodiments, tracking the movement of the inner stiffening device can allow for the estimation of a copy shape of the outer device.

[0120]

[0143] The shape of the inner device can be generally maintained during shape copying. This can allow for a smooth completion of the shape copying sequence since there is no change in the actuated steering member control. It can still be important to know the distal shape of the outer device as the inner device is advanced since less and less of the inner device distal tip is subject to the shape constraints of the outer device as the inner device is advanced.

[0121]

[0144] While an ideal shape copy would closely preserve the shape of the copied device, in reality, the process results in a slightly altered shape due to factors such as measurement errors, different radial tolerances between devices, physical effects such as fewer or no bendable portions of the copying device, etc. To take this change in shape into account when estimating the shape of the copying device, the system assumes that the shape loses a certain amount or percentage (e.g., about 10%, 5-10%, 5-20%, etc.) of its current curvature. In such an embodiment, the system may slightly alter the actuated steering member control before transitioning the copied inner device to a soft state in order to maintain the curvature of the outer stiffened device.

[0122]

[0145] Extraction of the nested system can be the reverse of the advancement sequence described above.During extraction of the outer stiffening copy device, the commanded curvature can be maintained or adjusted / controlled.

[0123]

[0146] The difference during withdrawal is that the actuating steering members may not provide enough freedom for the inner device to maintain the previous shape it had in the outer device (e.g., if the shape includes multiple curvatures in different directions). It has been found that maintaining or approximating the shape of the inner device along the portion of the inner device that will be exposed after retraction of the outer device provides the smoothest transition for the inner device as it transitions from the stiffened state.

[0124]

[0147] Different methods of controlling the copied device as it transitions to a soft state after the outer stiffening device (the "mother" or outer stiffening member) is retracted relative to the inner stiffening device (the "child" or inner stiffening member) are shown in Figures 11A-13E.

[0125]

[0148] 11A-11E, various embodiments are shown in which the outer stiffening device 1100 is retracted while actuating the inner device's actuating steering members (e.g., steering cables) to various degrees to adjust and / or maintain the shape of the exposed inner stiffening device 1110. FIG. 11A shows an initial position of the inner stiffening device 1110 and the outer stiffening device 1100. In this embodiment, the inner stiffening device 1110 extends from the outer stiffening device and is curved in one direction and in one plane. The exposed portion 1102 of the inner device is curved by an angle phi and a radius of curvature r c In FIG. 11A, part of the bend of the medial stiffening device is within the outer stiffening device. FIG. 11A also shows the net articulation angle theta, which is the angle of the medial stiffening device 1110 between its distal tip and the proximal point of the medial stiffening device to which the outer device will be retracted. FIG. 11B shows the nested pair of devices 1100, 1110 as the outer stiffening device 1110 is retracted, with the medial stiffening device stiff.

[0126]

[0149] Figure 11C shows the original radius of curvature (r c11B shows an example of an undesirable state indicated by an "X" in which tension is applied to the steering cables to hold the inner stiffening device 1110 at its distal end in a hooked position as shown. Unless impeded by structures within the body lumen, the tip of the inner stiffening device may bend as shown because the tension from the cables drives the flexible distal end region to maintain the radius of curvature at the exposed distal end region. This may also cause the distal face of the inner stiffening member 1110 to point in a different direction, which may change the direction in which the distal end of the inner stiffening device is pointed, including the camera or working channel, if any. As previously mentioned, this may be undesirable within a body lumen. This change in shape occurs because the child (the inner stiffening device 1110) transitions from the rigid configuration of FIG. 11B to the flexible configuration of FIG. 11C with a bending moment applied by the steering cables at the distal end region, further actuating the newly exposed bend as shown.

[0127]

[0150] In some embodiments, the steering cables can alternatively be controlled to maintain the angle phi upon retraction of the outer stiffening device 1100, as shown in FIG. 11D. In FIG. 11D, the apparatus can apply (and adjust) a sufficient bending moment, e.g., tension, to one or more of the steering cables such that the exposed articulation angle (phi) is maintained with the inner stiffening device 1110 unstiffened. In this embodiment, the distal face of the inner stiffening device 1110 remains oriented in the same direction. In some embodiments, the controller can coordinate the application of bending moments by the steering cables to the stiffening devices to maintain the articulation angle (phi). Thus, in some embodiments, the controller can dynamically adjust the steering cables when the inner stiffening member is unstiffened, e.g., by releasing positive or negative pressure stiffening the inner stiffening member.

[0128]

[0151] In some embodiments, the device can be configured to maintain theta angle (e.g., the net articulation angle of the distal end face of the inner stiffening device 1110 relative to the point of the inner stiffening device to which the outer stiffening device is retracted). In the embodiment shown in FIGS. 11A-11D, theta angle is equal to the phi angle. Thus, FIG. 11E illustrates the positions of the outer stiffening device 1100 and the inner stiffening device 1110 when the steering cables are controlled to maintain the theta angle upon retraction of the outer device 1100. As shown in FIGS. 11D and 11E, in this case, maintaining the previously exposed articulation angle phi is equivalent to controlling the net articulation angle of the final exposed length. If the more proximal region of the device is fixed relatively (e.g., relative to the patient's anatomy), as is typical in this case, maintaining the net articulation angle (theta) will maintain the orientation of the distal end face of the inner stiffening member relative to the patient's anatomy (e.g., lumen).

[0129]

[0152] 12A-12E show another embodiment in which the phi and theta angles are not the same. In FIGS. 12A-12E, similar to FIGS. 11A-11E, the apparatus includes an inner stiffening device 1210 (child) and an outer stiffening device 1200 (mother). In FIG. 12A, the inner stiffening device 1210 has a radius of curvature (r c 12A shows the initial position of the medial stiffening device 1210 and the lateral stiffening device 1200. In FIG. 12A, the medial stiffening device 1210 is curved such that it extends distally from the lateral stiffening device 1200 and bends proximally facing in a hook-like fashion. The lateral stiffening member will be withdrawn to approximately the same relative position as shown in FIGS. 11A-11E, but the net articulation angle theta will be different (in this example, larger, e.g., 180 degrees) than the bend angle (phi) of the medial stiffening device 1210 across the initial exposed region 1202. FIG. 12A shows the initial position of the medial stiffening device 1210 and the lateral stiffening device 1200. In FIG. 12A, the medial stiffening device 1210 is curved such that it extends distally from the lateral stiffening device and bends proximally facing in a hook-like fashion.

[0130]

[0153] 12B shows an apparatus including the inner stiffening device 1210 and the outer stiffening device 1200 when the outer stiffening device 1200 is retracted while the inner stiffening device remains stiff. The stiffness of the inner stiffening device can then be released (e.g., by releasing the positive or negative pressure or otherwise) and the bend angle (phi), radius of curvature (r c An actuated steering member (e.g., a steering cable) can be used to maintain one or more of the original curvature r ) and / or the net articulation angle (theta). For example, as shown in FIG. 12C, a steering cable can be controlled by a controller (e.g., software, firmware, etc.) to maintain the original curvature r c 12C, in which the inner stiffening device 1210 remains hooked at its distal end as the outer stiffening device is withdrawn proximally.

[0131]

[0154] Alternatively, in some embodiments, the controller can maintain the same bend angle (phi), as shown in FIG 12D. In this embodiment, the controller can control (e.g., dynamically control) the actuating steering members to maintain the angle phi as the outer device 1200 is retracted. This may be a less desirable configuration as it may cause the distal tip region to translate as shown, as well as change the orientation and position of the distal face of the device 1210, as shown in this embodiment by the "X".

[0132]

[0155] In some embodiments, the controller can alternatively maintain the net articulation angle (theta) and maintain the approximate orientation (and in some embodiments, position) of the distal end face of the medial stiffening device. In FIG. 12E, the position of the medial stiffening device 1210 (to maintain angle theta) can be maintained by an actuated steering member as the outer stiffening device 1200 is retracted. As shown in FIGS. 12C and 12E, in this embodiment, the radius of curvature r of the medial stiffening member can be adjusted by, for example, controlling the bending moment of the steering cables when pressure (positive or negative) is released. c and / or maintain the net articulation angle (theta) such that the exposed length of the medial stiffening device has essentially the same shape, and the position and orientation of the distal end face of the device 1210 can be substantially maintained, particularly when controlled by simple configurations of the outer and medial stiffening devices.

[0133]

[0156] 13A-13E show an embodiment in which the inner stiffening member 1310 of the device has a compound curvature (curve in multiple directions or planes) at the distal end region (e.g., the region that can be exposed by proximally withdrawing the outer stiffening member) and a radius of curvature (r c ), bend angle (phi), or net articulation angle (theta) during withdrawal of the stiffening device. Again, maintaining the net articulation angle (theta) may be most desirable in order to preserve the position / orientation of the distal face of the medial stiffening device 1310. FIG. 13A shows the effect of controlling the shape during withdrawal of the stiffening device by controlling the distal radius of curvature (r c13B shows a device having a bend angle (phi) and a bend plane (phi). In this example, the bend angle is different from the net articulation angle (theta). In this example, the inner device 1310 extends distally from the outer device and is curved in a first direction, similar to the exposed portion of the device 1110 in FIG. 11A. However, in this example, the more proximal portion of the inner stiffening device 1310 (proximal to the exposed outer distal portion 1302) and the outer stiffening device 1300, which is initially positioned over the inner stiffening device 1310, are curved in a second direction that is different from the first direction. The bend angle and radius of curvature of the second region may be the same or different than the bend angle and radius of curvature of the distal end region. Similarly, the bend plane and bend angle may be different or the same. In this example, the net articulation angle is theta. FIG. 13B shows the inner stiffening device 1310 still in a rigid form while the outer stiffening device 1300 is withdrawn proximally. The device, e.g., a controller, then determines the same radius of curvature (r c ), bending moment applied by the actuating steering member can be coordinated to maintain the bending angle (phi) or net articulation angle (theta).

[0134]

[0157] For example, in FIG. 13C, the controller c 13C ), which when stiffened results in the distal end of the inner stiffening device 1310 being in a different orientation and significantly displaced relative to its original position, as shown in FIG. 13C . Thus, as indicated by the “X” in this example, this may be an undesirable result.

[0135]

[0158] Figure 13D shows an alternative embodiment in which the device's controller maintains a constant bend angle (phi). In this embodiment, both the position of the distal tip of the inner stiffening device 1310 and the orientation of the distal face of this distal tip are significantly different from the initial position (as shown in Figures 13A-13B). Therefore, this embodiment is also marked with an "X" as shown.

[0136]

[0159] In contrast, in Figure 13E, the controller can coordinate the bending moment applied to the actuating steering members to maintain the net articulation angle (theta) following retraction of the outer device 1300 and release of stiffening pressure (positive or negative) on the inner stiffening device 1310. In Figure 13E, the curvature of the inner device 1310 differs from the original shape shown in Figures 13A and 13B, but the orientation of the distal face is maintained.

[0137]

[0160] Thus, in any of these devices, the controller can coordinate the actuation steering members to maintain the net articulation angle (theta) and / or orientation of the distal surface of the medial stiffening device upon retraction of the outer stiffening device. Maintaining the net articulation angle theta can result in a nearly closely matched orientation and position of the distal surface of the medial stiffening device following destiffening of the medial stiffening device. This can allow for a reasonably smooth transition between the stiffened and soft states as the device is retracted (and possibly advanced). As shown by these examples, maintaining the net articulation angle theta results in the orientation of the distal surface of the medial stiffening device being maintained as the medial stiffening device is transitioned from a stiffened state to a less stiff (e.g. soft) state. Maintaining the net articulation angle (theta) or tip orientation can result in a shape of the device after retraction that approximates its shape before retraction.

[0138]

[0161] 11A-13E, an articulation angle theta can be measured between a plane including the distal surface of the medial stiffening device (e.g., device 1110, 1210, 1310, etc.) and a cross section of the medial stiffening device at the point to which the medial stiffening device will be exposed (or at any more proximal point fixed relative to the patient's anatomy). Measuring the articulation angle in this manner can help preserve the orientation of the distal surface of the medial stiffening device (e.g., the direction the medial stiffening device points), which can be useful in applications where the medial device includes a camera to maintain the camera's orientation (e.g., pointing direction) rather than the camera's position. Maintaining the camera's orientation can help provide continuity and precision during the imaging procedure.

[0139]

[0162] It will be appreciated that the net articulation angle can also be measured in a different manner that best preserves the shape of the exposed inner device but does not necessarily maintain the angle of the distal end of the inner device.

[0140]

[0163] As mentioned above, the shapes of the inner and outer devices can be known using shape sensing techniques, and in some embodiments, tracking the movement of the inner stiffening device may allow inference of the copied shape of the outer device.

[0141]

[0164] In any of these embodiments, when transitioning the inner device from a rigidified state to a soft state, the actuation steering member can be adjusted before the device is de-rigidified. This sequence can allow for a smoother and / or more predictable transition between the initial shape of the rigidified inner device and the subsequent shape of the soft child device.

[0142]

[0165] In some embodiments, the actuation steering member is adjusted when the outer stiffening device is advanced or retracted, this sequence can improve user responsiveness as the inner device is ready to be unstiffened as soon as the copying process is complete. Method for screening a body lumen

[0143]

[0166] In some embodiments, the device can be configured to operate in a "screening mode" in which the device performs automated motion of the inner stiffening device to sweep the camera field of view over the interior surface of the lumen (e.g., intestine) to look for abnormalities (e.g., polyps). The automated motion can include circular motion of the inner device. The inner stiffening device can include one or more cameras at the distal end. In some embodiments, the automated motion can occur as the system retracts the device through the lumen. In some embodiments, the controller of the device can include control logic for coordinating the motion of the inner stiffening device to scan in the screening mode described herein.

[0144]

[0167] 14A-14F show schematic diagrams of an embodiment of the apparatus including an inner stiffening device 1410 and an outer stiffening device 1400. In one embodiment of the screening mode, the apparatus 1400z can allow for the selection of an initial orientation of a camera 1434z located at the distal end of the inner stiffening device. At this point, the user can select an orientation of the inner device, such as directing the camera view to the center of the lumen and showing a center point (centered on a loop 1402) within the lumen, as shown in FIG. 14A. The bending portion of the inner device then rotates about the center point in a circular passing motion 1402 to capture images of the area around the center point and its distal walls. FIG. 14B shows the inner stiffening device 1410 at different points during the rotation. The inner stiffening device 1410 is shown in a soft form (e.g., non-rigid), while the outer stiffening device 1400 is stiffened (e.g., by application of positive or negative pressure). In some embodiments, the inner stiffening device 1410 can be advanced distally and / or retracted slightly (e.g., distally / proximally) while navigating in a circular passing motion to maintain the tip in a plane that is transverse to the region of the lumen in which the inner stiffening device 1410 is located. In any of these embodiments, the controller can automatically control the stiffness of the actuating steering member and / or the inner stiffening device and / or the outer stiffening device to coordinate rotation and imaging. The controller can coordinate the rotation and speed of movement of the inner stiffening member tip, which in some embodiments can be based on the capabilities of the image acquisition and analysis module of the device to acquire and process the acquired images. The speed can be constant or variable. For example, the controller can adjust the speed of rotation and / or movement of the tip under automatic or semi-automatic control based on feedback from the image acquisition and / or processing (e.g., image analysis) module.In some embodiments, this can allow the system to image the lumen more quickly than manual review, but can also allow a user (e.g., a physician or technician) to concurrently or later review the imaged lumen, or a model of the lumen (e.g., a data file) generated by the image acquisition and / or processing module.

[0145]

[0168] 14C, once the circular passing motion 1402 is complete, the device 1400z can be operated to retract a selected length (or advance a selected length in some embodiments). In the embodiment shown in FIG. 14C, the inner stiffening device 1410 can be retracted into the outer stiffening device 1400 in a soft / non-rigid form. This embodiment may allow the actuation steering members (e.g., steering cables) to be adjusted to a relaxed or tensioned state so that the inner stiffening device can be easily retracted into the outer stiffening device 1400. Although the embodiments shown in FIGS. 14A-14D show linear devices and lumens, the procedures described herein can also be performed with curved or tortuous lumens.

[0146]

[0169] As shown in FIG. 14D, the outer stiffening device 1400 can then be retracted relative to the inner stiffening device 1410 to expose a portion of the inner device 1410. In some embodiments, the inner stiffening device 1410 can be made rigid (e.g., by application of positive or negative pressure or otherwise) and the outer stiffening device 1400 can be made soft / non-rigid (e.g., by releasing the pressure) so that it can maintain its shape as it extends proximally. The methods and devices described herein can utilize any of the methods and procedures described above when retracting the device. For example, the controller can maintain the net articulation angle by controlling the actuated steering members following withdrawal of the outer stiffening device 1400 and transition of the inner stiffening device 1410 to its soft configuration.

[0147]

[0170] The length 1480 that the external stiffening device is withdrawn can be the same or vary and can depend on how much of the lumen wall is screened by the camera, which can depend at least in part on the field of view of the camera. In some embodiments, the withdrawal length 1480 can depend at least in part on how curved the lumen is. The device 1400z can be configured to retract a selected withdrawal length from a first position where a first portion of the lumen is visible to a second position where a second portion of the lumen is visible. The portions may not overlap or may overlap minimally, e.g., the second portion may be proximal to the first portion. For example, the first portion of the lumen and the second portion of the lumen may be located adjacent to each other such that there is no overlap between the portions. In some embodiments, the adjacent portions may overlap such that the first portion of the lumen and the second portion of the lumen overlap a selected amount (e.g., 0-5 mm, 0-10 mm, etc.), which can help ensure a complete scan.

[0148]

[0171] As shown in FIG. 14D, after the inner stiffening device 1410 is retracted and the outer stiffening device 1400 is exposed, the device 1400z is ready to perform another circular pass of imaging. This process can be repeated over a predetermined or selected (e.g., automatically selected or user selected) length of the lumen. For example, with reference to FIG. 14E and FIG. 14F, after the device 1400z is retracted the withdrawal length, the inner device 1410 can again rotate in a circular pass motion 1402 to image the lumen wall. FIG. 14E and FIG. 14F show a previously scanned first portion 1406 of the lumen (e.g., FIG. 14B) directly adjacent to a second portion 1408 of the lumen proximal to the first portion of the lumen. A camera 1434z is shown at a different point along the circular pass motion 1402 in FIG. 14E and FIG. 14F.

[0149]

[0172] As mentioned above, in some embodiments, image analysis can be performed on the received imaging data to generate a model of the lumen. For example, any of the devices described herein can include an image acquisition and / or analysis module (e.g., an image processing module). A controller can coordinate and / or receive input from the image processing module to repeat imaging (e.g., loop) or reposition the distal tip based on feedback from the image processing module. In any of these embodiments, machine learning can be used to provide information regarding the center of the lumen. This information can be used with the imaging data to generate a model of the lumen. In general, the image processing module can include one or more machine learning agents to determine the position and / or orientation of the tip of the device during a scan or to assist in acquiring scans, locating targets (e.g., polyps) and / or guiding or steering the device. EXAMPLES

[0150]

[0173] As described above, any of the devices and methods may be configured to perform a predetermined series of coordinated actions to improve, simplify, and / or speed up the operation of the pair of nested stiffening devices, which may be collectively referred to herein as a robotic system. These predetermined series or set of coordinated actions may include forward and / or backward, stiffening / unstiffening (e.g., transitioning from a rigid state to a flexible state), and / or rolling movements of one or both of the stiffening devices of the pair of nested stiffening devices. These set of actions may be specific to the operation of the pair of nested (e.g., telescopic) devices, and the stiffening devices may be any of the stiffening devices described herein. These predetermined series or set of coordinated actions may be performed automatically based on one or more sensed or detected parameters (e.g., relative positions of the nested stiffening devices, sensed shapes of one or more of the stiffening devices, positions relative to the patient's body, etc.) and / or may be initiated by a user operating the device.

[0151]

[0174] For example, Figures 11A-11E, 12A-12E, and 13A-13E discussed above show one embodiment of a method for controlling a pair of nested stiffening devices 1100, 1110 such that the distal end face of one of the stiffening devices (e.g., the inner stiffening device 1110) faces approximately the same direction as the device is retracted. This may also be referred to as maintaining approximately the same net articulation angle of the distal end of the second stiffening device relative to the proximal portion of the second stiffening device. As previously discussed, this provides the user with a smooth, clear image as the device is retracted, even through tortuous anatomy. For example, the method may include controlling a pair of nested stiffening devices, the method including: retracting a first stiffening device of the nested pair of stiffening devices relative to a second stiffening device of the nested pair of stiffening devices with the first stiffening device in a soft state and the second stiffening device in a stiffened state; stiffening the first stiffening device; actuating a steering member within the second stiffening device to maintain an orientation of a distal end face of the second stiffening device constant relative to the exterior region before and / or during transitioning the second stiffening device from the rigid state to the soft state; and retracting the second stiffening device relative to the first stiffening device with the second stiffening device in the soft state.

[0152]

[0175] As described above, any of these methods may be implemented as an apparatus (e.g., a system) including a nested pair of stiffening devices including a first stiffening device and a second stiffening device, one or more processors, and a memory coupled to the one or more processors, the memory storing computer program instructions that, when executed by the one or more processors, perform a method (e.g., a computer-implemented method) for controlling the nested pair of stiffening devices.

[0153]

[0176] Any of these methods can include stiffening and destiffening (e.g., transitioning between rigid and flexible states) by controlling pressure, for example, positive and / or negative pressure. As described above, application of positive and / or negative pressure can apply or release a force that drives the bladder layer against the stiffening layer. In some embodiments, the apparatus can include a source of positive and / or negative pressure, and the controller can control and / or coordinate the application of the positive and / or negative pressure to control the transition between rigid and flexible states for each of the nested pair of stiffening devices.

[0154]

[0177] 15A-15C, for example, show an example of an automatic shape-copying method between a pair of nested stiffening devices that can enable continuous copying of the shape of one stiffening device to a second stiffening device. This continuous copying can be triggered, for example, by a user activating a control (e.g., a button, dial, switch, pedal, etc.) to trigger the shape copying. In some examples, the method (or a system performing the method) can be configured to continue continuous and automatic shape copying only as long as the user continues to activate the control (e.g., holding down a button).

[0155]

[0178] For example, in FIG. 15A, a pair of nested stiffening devices includes a first (e.g., outer) stiffening device 1500 and a second (e.g., inner) stiffening device 1510. The second stiffening device may be extended distally and steered at a tip region by controlling one or more actuating steering members (e.g., tendons, pull wires, etc.). In FIG. 15A, a user may then actuate a control, e.g., press and hold a button, to trigger a copy command such that the first stiffening device copies the shape of the second (inner) stiffening device, and in this example, the first stiffening device begins to execute a copy sequence as shown. In this example, the inner stiffening device 1510 may be optionally stiffened (e.g., transitioned from a soft state to a stiff state by applying positive or negative pressure). Tension on the actuating steering members may be maintained at least until the inner stiffening device becomes fully stiff. Similarly, the first (e.g., outer) stiffening device can be in or transition to a soft state (e.g., by releasing positive and / or negative pressure). In FIG. 15B, the user continues to press the copy command input (control) and the outer member continues the copy sequence, with the first stiffening device 1500 advancing distally over the second (inner) stiffening device, which remains in a rigid state, as shown, while the outer stiffening device 1500 remains in a soft state. Each of these steps can be controlled and coordinated by the controller. If at any point during this process the user discontinues the control (e.g., releases the button), the shape copy can stop. For example, the user can release the copy command, and the outer stiffening device 1500 will end the copy sequence there and then, regardless of how much of the inner stiffening device 1510 has been copied.

[0156]

[0179] 15A-15C show a method of controlling a pair of nested stiffening devices, the method including receiving a copy command from a user input and automatically performing a shape copy sequence, the shape copy sequence including advancing a first stiffening device of the nested pair of stiffening devices relative to a second stiffening device of the nested pair of stiffening devices with the first stiffening device in a soft state and the second stiffening device in a rigidified state, the first stiffening device initially proximal to the second stiffening device such that the first stiffening device copies a shape of the second stiffening device, and preventing the first stiffening device from advancing distal to the second stiffening device.

[0157]

[0180] Also described herein are a set of predetermined coordinated actions for shape copying when advancing the device and / or when retracting the device. In general, these methods and devices can perform multiple iterative steps of shape copying. Any of these embodiments can include tracking or storing the shape. For example, the method or device can include tracking the angle of the bend (e.g., distal tip region) of the inner stiffening device nested within the outer stiffening device. Figures 16A-16D show multiple shape copying steps when advancing a pair of nested stiffening devices. In Figure 16A, the inner stiffening device 1610 extends distally from the outer stiffening device 1600 and is steered into a curved shape using one or more actuated steering members while being advanced distally from the outer stiffening device 1600. The inner stiffening device is shown bent at an angle of about 90 degrees and bent to the left. When the inner stiffening device is set to a rigid state and the outer stiffening device is set to a soft state, the outer stiffening device can copy this shape as shown in FIG. 16B by advancing distally over the inner stiffening device. After the shape of the inner stiffening device is copied by the outer stiffening device, the outer stiffening device can be made rigid, e.g., changed to a rigid state, and the inner stiffening device can be transitioned to a soft state, e.g., so that it can be advanced distally while being steered by one or more actuating steering members, as shown in FIG. 16C. The apparatus can control the tension applied to the actuating steering members, as described in more detail below with reference to FIGS. 18A-18F. In FIG. 16D, the shape copying described in FIGS. 16A-16B can be repeated, so that the outer stiffening device 1600 can be advanced in a soft state over the inner stiffening device 1610 in a rigid state.Generally, these iterative steps of shape copying as described in Figures 16A-16D can be automated or assisted by a controller of the system, for example using automatic shape copying (e.g. similar to Figures 15A-15C) and / or generally by coordinating transitions between stiff and soft states of the outer and inner stiffening devices.

[0158]

[0181] The method in Figures 16A-16D shows an embodiment of the apparatus and methods described herein that remembers a previously copied shape proximal to the articulating section of the inner member, and this memory, held in the shape of the nested region, allows the inner member to be forced to revert, for example, to a pre-existing stiffened outer member shape when the system is retracted rearward, as described below in Figures 17A-17D. In Figures 16A-16D, the method shows the process of moving forward in an inchworm fashion, where the system retains the shape (history) of the curve it copied. As described below in Figures 17A-17D, these methods can use an actuating steering member (e.g., a steering cable) to gradually bend the articulating distal end region toward a previously memorized shape each time, allowing it to reverse the same curvature that was held when advancing distally, in order to better retain the proximal shape of the system, since if the steerable region did not at least somewhat approximate the shape of the portion, it could drive the previous curvature back while retracting rearward, which would otherwise default to less (or no) articulation as the bent portion retracts into the outer member.

[0159]

[0182] This memorization or retention of curvature thus allows tracking of the entire stiffening length, not just the portion being actively steered, without the need to directly sense its shape. As explained with reference to Figures 11A-11E, 12A-12E, and 13A-132E, the shape of the outer member just proximal to the articulating section is retained (and "known") by these devices. Thus, the curvatures that are set and copied can be retained as an image of what the entire system is shaped like, based on the articulation of the steerable distal end region, without the need to directly sense the shape of those curvatures.

[0160]

[0183] 17A-17C show examples of shape copying when the device is retracted. In general, when reversing or retracting (proximally) the device, the inner stiffening device can shape copy the outer stiffening device, while advancing (distally) can involve the outer stiffening device shape copying the inner stiffening device, as described in FIGS. 16A-16D. In FIG. 17A, the device includes a nested combination of an outer stiffening device 1700 and an inner stiffening device 1710. FIG. 17A shows a pair of nested stiffening devices, with the inner stiffening device 1710 retracted in a soft state into the first stiffening device 1700 held in a rigid state. While in some cases it may be possible to withdraw the entire device from the patient by transitioning both the inner and outer stiffening devices to a soft state (and relaxing the steering members), it may often be more preferable to retract the device from the distal end region of the device, thereby leaving more proximal curves and bends, which may prevent strain on the lumen wall and allow for controllable visualization of the surrounding areas as the device is withdrawn. For example, as shown in Figures 17B-17C, by maintaining the inner stiffening device 1710 in a rigid state, preferably with the steering members in tension and maintaining the curve at the distal tip, the device may be smoothly withdrawn proximally over various bends, and the outer stiffening device may be in a soft state and withdrawn proximally over the most distal bend in the inner stiffening device, as shown. The outer stiffening device 1700 may then be stiffened, and the inner stiffening device 1710 may be transitioned to a soft state and retracted proximally into the now stiff outer stiffening device 1700. These steps can be repeated as shown in Figures 17C-17D.

[0161]

[0184] In any of these steps, it may be useful (and the system can be configured to) steer the distal tip region of the inner stiffening device as it is withdrawn proximally into the outer stiffening device. This can be accomplished, for example, by maintaining a generally constant orientation of the face and / or maintaining the net angle of articulation of the distal end of the second stiffening device relative to the proximal portion of the second stiffening device, as described above.

[0162]

[0185] 18A-18F show one embodiment of a method for controlling the timing of release of tension on a distal tip of an inner stiffening device, which may be steerable at its distal tip region when transitioning from a rigid state to a flexible state by an actuating steering member, so as to maintain curvature as the device transitions to a flexible state. Thus, FIGs. 18A-18F show the timing of the transition of actuation of the inner 1810 and / or outer 1800 stiffening devices after copying has been performed.

[0163]

[0186] For example, Figures 18A-18F show a method of controlling a pair of nested stiffening devices by advancing a first stiffening device 1800 of the nested pair of stiffening devices distally relative to a second stiffening device 1810 of the nested pair of stiffening devices, where the first stiffening device 1800 is in a soft state and the second stiffening device 1810 is in a rigid state, transitioning the first stiffening device 1800 from the soft state to the rigid state, and transitioning the second stiffening device from the rigid state to the soft state while actuating a steering member of the second stiffening device to maintain the curvature of the distal end of the second stiffening device as it transitions to the soft state.

[0164]

[0187] In FIG. 18A, the inner (e.g., second in this example) stiffening device creates a shape (curve) and the actuating steering member can hold the shape. For example, the actuating steering member can be a steel cable. In FIG. 18B, the inner stiffening device 1810 can then be transitioned to a rigid state and the actuating steering member can hold the bend created by the distal end region of the inner stiffening device. In FIG. 18C, the outer stiffening device 1800 can then be advanced over the inner stiffening member in a soft state, with the inner stiffening member remaining in a rigid state and the actuating steering member holding the bend in the steerable tip region. In FIG. 18D, the outer stiffening device can then be stiffened (e.g., by applying pressure) to a rigid state, with the actuating steering member holding the bend in the steerable tip region of the inner stiffening member. In FIG. 18E, the inner member can then be transitioned to a soft state (e.g., by releasing pressure on the inner stiffening member) with the actuating steering member holding the bend in the steerable tip region. Finally, in FIG. 18F, the inner member can be actively steered by controlling an actuated steering member responsive to command inputs.

[0165]

[0188] Any of the methods and apparatus described herein can be configured to cause one of the stiffening devices to automatically (or semi-automatically, e.g., after prompting a user or after the user triggers an automatic mode) copy the shape of the other stiffening device upon detection of an auto-copy trigger event (e.g., upon detection of an auto-copy trigger threshold). For example, the auto-copy trigger event can be when the distance between the distal ends of the two stiffening devices exceeds a threshold, when the user stops moving one (e.g., inner) stiffening device, when the drive performance of the first (e.g., outer) and / or second (e.g., inner) stiffening device drops below a threshold, e.g., based on feedback from a camera and / or shape sensor after a movement command or some other heuristic method.

[0166]

[0189] For example, in some embodiments, the apparatus and method can be configured to automatically copy the shape of one of the stiffening devices to the other stiffening device when the distance between the distal ends of the two stiffening devices exceeds a threshold. Thus, the automatic copy trigger threshold can be the relative axial movement distance between the first stiffening device and the second stiffening device. For example, the automatic shape copy can be triggered when the distance between the distal end of the inner stiffening device and the distal end of the outer stiffening device is at a maximum extension distance (in the "Z" direction), as shown in FIG. 19A. In this embodiment, the method or apparatus can cause the outer stiffening device 1900 to automatically copy the shape of the inner stiffening device 1910. For example, the system can automatically perform the shape copy step without requiring any input from the user. In FIG. 19B, the inner stiffening device 1910 can be maintained in a rigid state while the outer stiffening device is in a soft state and is advanced distally over the inner stiffening device.

[0167]

[0190] 19A-19B show a method of controlling a pair of nested stiffening devices by advancing a second stiffening device of the pair of nested stiffening devices relative to a first stiffening device of the pair of nested stiffening devices with the second stiffening device in a soft state and the first stiffening device in a stiffened state, and automatically performing a shape copy sequence when the second stiffening member extends a predetermined travel distance relative to the first stiffening member, the shape copy sequence including advancing the first stiffening device relative to the second stiffening device with the first stiffening device in a soft state and the second stiffening device in a stiffened state.

[0168]

[0191] An automatic copy trigger event (one example of a) that causes one of the stiffening devices to automatically or semi-automatically copy the shape of the other stiffening device can be controllable by a controller that can receive input (e.g., sensor input) and apply control logic to drive automatic or semi-automatic movement of the stiffening devices.

[0169]

[0192] For example, the auto-copy trigger event may be a stop of movement of one or both of the first and second stiffening devices. Thus, the auto-copy trigger threshold may be a time delay following movement of the second stiffening member relative to the first stiffening member (e.g., copy trigger event time delay). In one example, the device may be configured to detect a stop of movement of the steerable inner stiffening device, where the movement of the inner stiffening device may be detected by a user input moving the inner stiffening device forward and / or backward and / or by a user steering (bending) the inner stiffening device. The auto-copy trigger event may be triggered if the controller does not detect a user input (e.g., forward / backward and / or steering) after the time delay. In some embodiments, the apparatus can be configured (or controlled by user input to be in an automatic or semi-automatic state) to cause the outer stiffening device to shape copy the inner stiffening device as described herein after a time delay period (e.g., an auto-copy trigger event time delay) after the steerable inner stiffening device has been advanced (even if only slightly or by some minimal amount) such that the other stiffening device is proximal to the steerable inner stiffening device, and after the controller no longer detects control inputs driving movement of the inner stiffening device, e.g., steering and advancing (and optionally, the controller also no longer detects movement of the outer stiffening device). The auto-copy trigger event time delay can be a fixed time delay, e.g., 2 seconds or more, 3 seconds or more, 4 seconds or more, 5 seconds or more, 6 seconds or more, 7 seconds or more, 8 seconds or more, 9 seconds or more, 10 seconds or more, etc. Alternatively, the auto-copy trigger event time delay may be determined based on user input (preference) and / or based on previous movement commands, including steering and / or advancing / reversing.Shape copying may include stiffening the inner stiffening device (transforming it to a rigid state while controlling the articulating steering member as described herein), de-stiffening the outer stiffening device (e.g., converting it to a soft state), and advancing the outer stiffening device so that it extends fully or partially to the distal end region of the inner stiffening device.

[0170]

[0193] The controller can receive inputs from one or more sensors (e.g., sensor data) and / or one or more controllers (e.g., forward / reverse and / or steering controls). The control inputs and sensor data can be processed by the controller using control logic as described herein and can be used to identify one or more auto-copy trigger events. Another auto-copy trigger event can be coupled with the controller's analysis of the drive motion, such as detection of motion performance, and as described above, one auto-copy trigger event can be detection of a degradation of the drive motion of the inner and / or outer stiffening devices. The motion degradation can be determined (and an auto-copy trigger event can be triggered) if, for example, the execution of the motion commands (forward / reverse, roll and / or steer) of the inner and / or outer stiffening devices is slower than a threshold speed value. Alternatively or additionally, in some embodiments, the motion degradation can be determined (and an auto-copy trigger event can be triggered) if the drive motion of the inner and / or outer stiffening devices does not perform a sufficient or complete motion, e.g., an "expected" motion, based on position or shape detection (e.g., shape sensing), and in some embodiments, based on a relationship between camera feedback and a commanded pose.

[0171]

[0194] In any of these methods and apparatus, the method may include moving an inner stiffening device of a nested pair of stiffening devices to pan about itself, for example, to image the wall of a lumen 360 degrees or nearly 360 degrees. For example, FIGS. 20A-C show different types of rolls that may be coordinated by the methods and systems described herein. FIG. 20A shows a rotation, e.g., roll 2040, of the distal tip of the inner stiffening device 2010 relative to the distal end of the outer stiffening device 2000. As a result of this first type of roll of the inner stiffening device 2040, the region of the distal tip that is bent and extends from the outer stiffening device swings in a loop 2030. This may be useful for panning around a structure (e.g., a lumen). The inner stiffening device 2010 may be in a rigid or soft state. FIG. 20B shows the use of an actuated steering member to maintain the angle and angular orientation of the inner stiffening device 2010 as it rolls 2040. This results in a rotation (roll) 2035 of the distal surface of the inner stiffening device as shown. The inner stiffening device may be in a flexible state in this example. This may be particularly useful in orienting the field of view of the imaging device forming the distal end region of the inner stiffening device. A similar effect may be achieved by stiffening the outer stiffening device 2000 to be able to support a roll of the inner stiffening device, which may be in a flexible state, such that a roll of the inner stiffening device 2010 results in a roll of only the face of the device.

[0172]

[0195] Thus, for example, if a user wishes to rotate their field of view, the rigid support provided by the outer member allows a commanded rotation of the inner member 2010 to rotate the user's viewpoint about the centerline of the outer member's most proximal face. When the inner member is articulated (FIG. 20B), this can move the user's viewpoint along a path d2030. To rotate about the centerline of the inner member instead, the system can command the articulation steering members (e.g., cables) to coordinate a roll motion and keep the user facing the same direction, or, preferably, copy the outer member flush with the inner member and support the rotation, so that the user's viewpoint is looking in the same direction and simply rotates the field of view as shown in FIG. 20C.

[0173]

[0196] Thus, a method or apparatus can be configured to achieve the roll of the inner stiffening device when inspecting a lesion or other scenario by performing a full shape copy to have the outer stiffening device hold the inner stiffening device in place while rolling, eliminating the need to use an actuated steering member to coordinate the roll while the device is bent at an angle, allowing the distal face of the inner device to rotate about its centerline instead of rotating the entire bend, as shown in FIG.

[0174]

[0197] In general, any of these devices and methods can be configured to operate automatically or semi-automatically and / or to determine when and to what extent the outer stiffening device needs to shape-copy the inner stiffening device (or vice versa). For example, as discussed above with reference to FIG. 19, the device can be configured to automatically copy when the user reaches the end of the allowable insertion length of the inner stiffening device.

[0175]

[0198] For example, in some situations, if the system detects conflicting device movements, it may be advantageous to choose to automatically perform a shape copy to support the inner device movement in a new direction, as shown, for example, in Figures 21A-B (showing a normal scenario), 22A-B (showing conflicting movements), and 23A-B (showing conflicting movement detection and correction).

[0176]

[0199] 21A-B, the inner stiffening device is pointing in the +z direction and there is no articulation of the inner stiffening device. The user wants to reach point c, so inputs a command to move the system forward. This moves both point b and point a (e.g., the distal face of the inner stiffening member, which may correspond to the camera position) in the +z direction, and the user's viewpoint at point a sees movement in the correct direction towards the user's goal.

[0177]

[0200] However, in one situation, shown in Figures 22A-B, the inner stiffening device is pointing in the -z direction and has close to 180 degrees of articulation in the inner stiffening device. The user wants to reach point c, so they input a command to move the system forward. Because of the bend in the inner stiffening device, this moves both points b and a in the +z direction, but now (inconsistently) the user's perspective at point a sees movement away from the user's goal at point c, even though they input the same command as in Figures 21A-B and see what appears to be the same distance from point a to point c. To the user, the system appears to be moving in the opposite direction to that which the user commanded.

[0178]

[0201] Any of the devices described herein can be configured to perform the method described in Figures 22A-22B to correct and / or prevent inconsistent motion. In Figures 23A-23C, the medial stiffening device is facing in the -z direction and the medial member has close to 180 degrees of articulation. The user wants to reach point c and inputs a command to move the system forward. The system can be configured to recognize that the user will not be moving in the desired direction (e.g., by analyzing the change in distance from point c in the image, or by recognizing the angle of articulation and direction of motion that occurs due to it, and / or by identifying the curvature of the stiffening device and knowing where the element 2300 is located) and therefore can automatically perform a shape copy to advance the outer stiffening device to include all of the bends of the medial stiffening device before advancing the outer stiffening device, or the device can suggest that the user perform this shape copy. As shown in Figure 23B, the shape copy can include advancing the outer stiffening device 2300 into the current position of the distal end region of the inner stiffening device 2310. After the shape copy, if the user now inputs a command to move the system forward (as shown in FIG. 23C), the inner stiffening device will slide along the rigid support of the outer stiffening device, causing point a to move in the -z direction toward the goal of point c, and the user's viewpoint will now move toward the user's goal of reaching point c.

[0179]

[0202] In general, while many of the examples described herein are described in the context of use of these methods and devices within the human (or other mammalian) body, it should be recognized that any of these methods and devices may also be used in non-biological areas, such as, but not limited to, in ducts, pipes, geotechnical or other areas. Single full length stiffening device

[0180]

[0203] While most of the apparatus and methods described herein are described in the context of a pair of nested stiffening devices, both of which have relatively long (longitudinal) lengths, an inner and outer stiffening device that are both stiffened, many of these methods and apparatus may be performed with a single stiffening device having a relatively long stiffening length and a non-rigidifying or partially stiffening steerable device. The second non-rigidifying or partially stiffening steerable device may be stiffened (or at least configured to control or lock the steered distal end region into a selected curvature or shape) over a length of the device that is shorter than the length of the stiffening device having the relatively long stiffening length. In some embodiments, the locked or stiffening length of the second device may be the length of only the steerable distal end region.

[0181]

[0204] Specifically, methods and apparatus are also described herein that include a first stiffening device as described herein that is stiffenable along a majority of its length (e.g., over half the length, over 60% of the length, over 70% of the length, over 80% of the length, over 85% of the length, over 90% of the length, etc.) and a second steerable device whose distal end region is steerable by one or more actuated steering members. This distal end region of the second device can be stiffened or pseudo-stiffened (e.g., locked), but may be significantly shorter than the stiffening length of the first stiffening device. For example, the second stiffening device can be pseudo-stiffened by controlling the actuated steering members such that the shape of the steerable distal end region is held ("locked") in a determined or selected shape, while the region proximal to the steerable distal end region remains soft. The first stiffening device can be stiffened over a majority of its inserted length or at least over a region longer than the steerable end region of the second device (e.g., 1.5 times or more, 2 times or more, 3 times or more, 4 times or more, 5 times or more, 10 times or more, etc.). In some embodiments, the first stiffening device is an outer stiffening device configured as described above. The second (steerable device) can be nested within the outer stiffening device and can include a steerable distal end region that can be stiffened (or equivalently pseudo-stiffened by manipulating an actuating steerable member).

[0182]

[0205] Thus, in some embodiments, the distal tip region of the inner member does not have a stiffening structure, but can be configured to hold its position using an actuating steering member (e.g., a steering cable). Thus, the methods and apparatus described herein can be implemented with a nested pair of devices including a first full-length stiffening device and a second elongated device nested with the first full-length stiffening device, the second elongated device including a steerable distal end region that can be locked to a selected shape. The selected shape can be a user-defined (steering) shape that can be copied by the first full-length stiffening device and / or a shape that can be set by copying the curvature of a region of the first full-length stiffening device. This selected shape can be maintained ("stiffened" or "pseudo-stiffened") by controlling the actuating steering member. In some embodiments, the selected shape can be maintained ("stiffened") by locking a stiffening layer as described above. In some embodiments, the steerable distal end region of the second elongate device is controllable by actuating one or more actuating steering members, alternatively or additionally, the second elongate device may be stiffened only over a distal end region that includes all or a portion of the steerable distal end region. In embodiments in which the second elongate device is stiffened, the stiffening region may be stiffened over a length that is significantly shorter than the stiffening region of the other (e.g., first) stiffening device.

[0183]

[0206] For example, a method of controlling a nested pair of devices (including at least one stiffening device configured to be stiffened over a majority of its length and a second stiffening device configured to be stiffened over a distal steerable region of its length) may include retracting a first stiffening device of the nested pair of devices relative to a second stiffening device of the nested pair of devices with the first stiffening device in a soft state and a distal end region of the second stiffening device in a stiffened (e.g., locked) state, stiffening the first stiffening device, and actuating a steering member within the second device to maintain an orientation of a distal end face of the second device constant relative to the outer region before and / or during the second device transitioning from the rigid state to the soft state.

[0184]

[0207] A method of controlling a nested pair of devices (including at least one stiffening device configured to be stiffened over a majority of its length and a second stiffening device configured to be stiffened over a distal steerable region of its length) can include receiving a copy command from a user input and automatically performing a shape copy sequence, the shape copy sequence can include advancing a first stiffening device of the nested pair of devices relative to a second stiffening device of the nested pair of devices with the first device in a soft state and the second device in a stiffened state with the steerable distal region being stiff, the first stiffening device initially proximal to the second device such that the first stiffening device copies a shape of the second device, and optionally preventing the first stiffening device from advancing distal to the second device. Advancing the first stiffening device can include advancing the first stiffening device only while the copy command is continuously received.

[0185]

[0208] A method of controlling a nested pair of devices (including at least one stiffening device configured to be stiffened over a majority of its length and a second stiffening device configured to be stiffened over a distal steerable region of its length), including automatically performing a shape copy sequence upon detection of an auto-copy trigger event by a control circuit, may include receiving, in a controller, one or more of sensor data and / or user motion inputs, comparing the one or more of the sensor data and / or user motion inputs to an auto-copy trigger threshold, and triggering the shape copy sequence upon detection of the auto-copy trigger threshold, wherein the shape copy sequence includes advancing the first stiffening device relative to the second device with the first stiffening device in a soft state and the second device in a stiffened state.

[0186]

[0209] For example, a method of controlling a nested pair of stiffening devices (including at least one stiffening device configured to be stiffened over a majority of its length and a second stiffening device configured to be stiffened over a distal steerable region of its length) may include advancing a second stiffening device of the nested pair of stiffening devices distally relative to a first stiffening device of the nested pair of stiffening devices with the second stiffening device in a soft state and the first stiffening device in a stiffened state, and automatically performing a shape copy sequence when the second stiffening member extends a predetermined travel distance relative to the first stiffening member, wherein the shape copy sequence may include advancing the first stiffening device relative to the second stiffening device with the first stiffening device in a soft state and the second stiffening device in a stiffened state.

[0187]

[0210] A method of controlling a nested pair of stiffening devices (including at least one stiffening device configured to be stiffened over a majority of its length and a second stiffening device configured to be stiffened over a distal steerable region of its length) can include advancing a first stiffening device of the nested pair of stiffening devices distally relative to a second device of the nested pair of devices, where the first stiffening device is in a soft state and the second device has a distal end region that is rigid (e.g., locked), transitioning the first stiffening device from the soft state to a rigid state, and transitioning the second device from the rigid state to the soft state (unlocking the steerable distal end region to bend freely) by slowly releasing a steering member of the second device to release bending of the distal end of the second stiffening device as the second device transitions to the soft state.

[0188]

[0211] A method of advancing or retracting a system including a pair of nested devices (including at least one stiffening device configured to be stiffened over a majority of its length and a second stiffening device configured to be stiffened over a distal steerable region of its length) along a body lumen can include advancing or retracting a first device in a soft state (wherein a steerable distal end of the first device is free to move) relative to a second stiffening device in a rigid state, steering the first device using a steering member of the first device, stiffening (e.g., locking) the first device such that the steerable distal region is locked in a selected configuration, advancing or retracting the second stiffening device in the soft state at least partially over the stiffened first device, stiffening the second stiffening device, actuating the steering member to accommodate curvature of the stiffened second stiffening device, and transitioning the first device to the soft state (e.g., by releasing tension on the steering member).

[0189]

[0212] Similarly, a method of screening a body lumen of a patient may include navigating a system through the body lumen including a nested pair of devices including a first device nested within a second stiffening device, where the first device includes a camera at a distal end and the distal end region is steerable; exposing a distal portion of the first device; articulating the distal portion of the first device to perform a circular pass-through motion (e.g., a loop) resulting in visualization of a circumference of a first portion of the body lumen by the camera; retracting the system a selected length so that the distal portion of the first device is exposed; and articulating the distal portion of the first device to perform a circular pass-through motion resulting in visualization of a circumference of a second portion of the body lumen by the camera, where at least a portion of the second portion is located proximal to the first portion.

[0190]

[0213] Systems that include any of these methods are also described.

[0191]

[0214] When a feature or element is referred to herein as being "on" another feature or element, it can be directly on the other feature or element, or there may be intervening features and / or elements. 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. Also, when a feature or element is referred to as being "connected," "attached," or "coupled" to another feature or element, it should be understood that it can be directly connected, attached, or coupled to the other feature or element, or there may be intervening features or elements. 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. Although described or illustrated with respect to one embodiment, the features and elements so described or illustrated are applicable to other embodiments. Those skilled in the art will also recognize that when a structure or feature is referred to as being "adjacent" to another feature, it may have portions that overlap or underlie the adjacent feature.

[0192]

[0215] The terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the invention. For example, as used herein, the singular forms "a," "an," and "the" are intended to include the plural unless the context clearly indicates otherwise. It is further understood that the terms "comprising" and / or "including," as used herein, specify the presence of the described features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof. As used herein, the term "and / or" includes any and all combinations of one or more of the associated enumerations and may be abbreviated as " / ."

[0193]

[0216] Spatially relative terms such as "below," "lower," "bottom," "upper," and the like may be used herein to facilitate describing the relationship of one element or feature to another element or feature as depicted in the drawings. It should be understood that these spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the drawings. For example, if the device in the figures were inverted, an element described as being "below" or "below" another element or feature would be oriented "above" that other element or feature. Thus, the illustrative term "below" may 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 "upward," "downward," "vertical," "horizontal," and the like are used herein for descriptive purposes only, unless specifically indicated otherwise.

[0194]

[0217] In this specification, the terms "first" and "second" may be used to describe various features / elements (including steps), but these features / elements should not be limited by these terms unless the context indicates otherwise. These terms may be used to distinguish one feature / element from another. Thus, a first feature / element described below may also be referred to as a second feature / element, and similarly, a second feature / element described below may also be referred to as a first feature / element without departing from the teachings of the present invention.

[0195]

[0218] Throughout this specification and the claims that follow, unless the context requires otherwise, the word "comprise" and variations such as "comprises" and "comprising" mean that various components may be employed together in methods and articles (e.g., devices and compositions and apparatuses that include methods). For example, the term "comprising" should be understood to imply the inclusion of any described elements or steps, but not the exclusion of any other elements or steps.

[0196]

[0219] As used herein and in the claims, including those used in the examples, unless expressly specified otherwise, all numerical values ​​may be interpreted as if they were preceded by "about" or "approximately" even if the words are not explicitly stated. The phrase "about" or "approximately" may be used when describing a size and / or location to indicate that the stated value and / or location is within a reasonable expected range of value and / or location. For example, a numerical value may have a value of + / -0.1% of the stated value (or range of values), + / -1% of the stated value (or range of values), + / -2% of the stated value (or range of values), + / -5% of the stated value (or range of values), + / -10% of the stated value (or range of values), etc. Any numerical value provided herein should also be understood to include "about" or "approximately" that value unless the context indicates otherwise. For example, if the value "10" is disclosed, then "about 10" is also disclosed. Any numerical ranges described herein are intended to include all subranges within that range. Also, when a value is disclosed, it is to be understood that "less than or equal to" that value, "more than or equal to" that value, and possible ranges between the values ​​are also disclosed, as would be understood by one of ordinary skill in the art. For example, if a value "X" is disclosed, "less than or equal to" and "more than or equal to X" (e.g., where X is a number) are also disclosed. It is also to be understood that data are presented in several different forms throughout this application, and that this data represents endpoints and starting points, and ranges for any combination of the data points. For example, when a specific data point "10" and a specific data point "15" are disclosed, it is to be understood that in addition to between 10 and 15, greater than, greater than, less than, less than, and equal to 10 and 15 are also considered to be disclosed. It is also to be understood that each unit between two particular units is also disclosed. For example, when 10 and 15 are disclosed, 11, 12, 13, and 14 are also disclosed.

[0197]

[0220] While various exemplary embodiments have been disclosed above, any of a number of modifications may be made to the various embodiments without departing from the scope of the invention as set forth in the claims. For example, the order in which the various method steps described are performed may often be changed in alternative embodiments, and in other alternative embodiments, one or more method steps may be omitted entirely. Optional features of the various device and system embodiments may be included in some embodiments and not in others. Thus, the foregoing description has been presented primarily for illustrative purposes and should not be construed as limiting the scope of the invention as set forth in the claims.

[0198]

[0221] The examples and illustrations contained herein are illustrative and not limiting of specific examples in which the subject matter may be practiced. As previously mentioned, other examples are available and can be derived therefrom, such that structural and logical substitutions and changes can be made without departing from the scope of the present disclosure. Such examples of the subject matter of the present invention may be referred to herein, individually or collectively, under the term "invention" for the sole convenience and without any intention of spontaneously limiting the scope of the present application to any single invention or inventive concept when in fact multiple inventions or inventive concepts are disclosed. Thus, although specific embodiments have been shown and described herein, any configuration intended to achieve the same purpose may be substituted for the specific embodiment shown. The present disclosure is intended to cover any modifications or variations of the various embodiments. Combinations of the above embodiments and other embodiments not specifically described herein will be apparent to one of ordinary skill in the art upon reviewing the above description.

Claims

1. 1. A method of controlling a pair of nested stiffening devices, comprising: receiving a copy command from a user input; and automatically performing a shape copy sequence, the shape copy sequence comprising: with a first stiffening device of the nested pair of stiffening devices in a softened state and a second stiffening device of the nested pair of stiffening devices in a stiffened state, advancing the first stiffening device relative to the second stiffening device, the first stiffening device initially proximal to the second stiffening device such that the first stiffening device copies the shape of the second stiffening device; and preventing the first stiffening device from advancing distally of the second stiffening device.

2. The method of claim 1 , wherein advancing the first stiffening device comprises advancing the first stiffening device only while the copy commands are continuously received.

3. The method of claim 1 , further comprising continuing to advance the first stiffening device until a distal end of the first stiffening device reaches a distal end of the second stiffening device.

4. The method of claim 1 , wherein the first stiffening device is nested above the second stiffening device.

5. The method of claim 1 , wherein the shape copy sequence further comprises stiffening the second stiffening device to the rigid state before advancing the first stiffening device.

6. 2. The method of claim 1, wherein the shape copy sequence further comprises unstiffening the first stiffening device to the soft state before advancing the first stiffening device relative to the second stiffening device.

7. The method of claim 1 , wherein the shape copy sequence further comprises the step of stiffening the first stiffening device to the rigid state after the first stiffening device advances relative to the second stiffening device.

8. 2. The method of claim 1, further comprising, before receiving the copy command, advancing the second stiffening device in the soft state while steering a distal end region of the second stiffening device, wherein the first stiffening device is in a rigid state.

9. 1. A method of controlling a pair of nested stiffening devices, comprising: receiving a copy command from a user input; and automatically performing a shape copy sequence while the user input is received, the shape copy sequence comprising: The method includes advancing a first stiffening device of the nested pair of rigid devices relative to a second stiffening device with the first stiffening device in a soft state and a second stiffening device of the nested pair of rigid devices in a rigidified state, wherein the first stiffening device is initially proximal to the second stiffening device such that the first stiffening device copies the shape of the second stiffening device.

10. a pair of nested stiffening devices including a first stiffening device and a second stiffening device; one or more processors; a memory coupled to the one or more processors, The memory stores computer program instructions that, when executed by the one or more processors, perform a computer-implemented method for controlling the pair of nested stiffening devices, the method comprising: receiving a copy command from a user input; and automatically performing a shape copy sequence, the shape copy sequence comprising: advancing a first stiffening device relative to a second stiffening device with the first stiffening device in a soft state and the second stiffening device in a stiffened state, the first stiffening device initially proximal to the second stiffening device such that the first stiffening device copies the shape of the second stiffening device; and preventing the first stiffening device from advancing distally of the second stiffening device.

11. The system of claim 10 , wherein advancing the first stiffening device comprises advancing the first stiffening device only while the copy commands are continuously received.

12. 11. The system of claim 10, wherein the computer-implemented method further comprises continuing to advance the first stiffening device until a distal end of the first stiffening device reaches a distal end of the second stiffening device.

13. The system of claim 10 , wherein the first stiffening device is nested above the second stiffening device.

14. The system of claim 10 , wherein the shape copy sequence further comprises stiffening the second stiffening device to the rigid state before advancing the first stiffening device.

15. 11. The system of claim 10, wherein the shape copy sequence further comprises unstiffening the first stiffening device to the soft state before advancing the first stiffening device relative to the second stiffening device.

16. The system of claim 10 , wherein the shape copy sequence further comprises a step of stiffening the first stiffening device to the rigid state after the first stiffening device advances relative to the second stiffening device.

17. 11. The system of claim 10, wherein the computer-implemented method further includes, before receiving the copy command, advancing the second stiffening device in the soft state while steering a distal end region of the second stiffening device, wherein the first stiffening device is in the rigid state.

18. a pair of nested stiffening devices including a first stiffening device and a second stiffening device; one or more processors; a memory coupled to the one or more processors, The memory stores computer program instructions that, when executed by the one or more processors, perform a computer-implemented method for controlling the pair of nested stiffening devices, the method comprising: receiving a copy command from a user input; and automatically performing a shape copy sequence while the copy command is received, the shape copy sequence comprising: a step of advancing the first stiffening device relative to the second stiffening device with the first stiffening device in a soft state and the second stiffening device in a rigidified state, the first stiffening device initially being proximal to the second stiffening device such that the first stiffening device copies a shape of the second stiffening device.

Images