Reinforced central lumen for steerable device

Abstract

A catheter sheath includes: a central lumen extrusion having an inner layer defining a central lumen, a reinforcing structure surrounding the inner layer, and an outer layer surrounding the reinforcing structure; a plurality of rings disposed on the outer layer of the central lumen extrusion at predetermined distances from each other in a distal segment of the sheath; and an outer sheath encapsulating the rings and the central lumen extrusion. The reinforcing structure includes one or more of a braid, coil, and laser-cut tube embedded between the inner and outer layers. The central lumen extrusion is bonded with adhesive, laser-welded, or pressure-fitted into one or more of the rings. The reinforcing structure is offset toward an inner or outer surface, and the rings have chamfered, beveled, or rounded inner edges.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to U.S. Provisional Application No. 63 / 112931, filed November 12, 2020, and U.S. Provisional Application No. 63 / 104935, filed October 23, 2020. The disclosures of the above-listed provisional applications are incorporated herein by reference in their entirety for all purposes. Priority is claimed pursuant to 35 U.S.SC §119(e). Technical Field

[0003] This disclosure relates to medical devices. More specifically, this disclosure illustrates embodiments of reinforced central lumen extrusions suitable for tubular sheaths of manipulable medical devices, such as endoscopes or catheters. Background Technology

[0004] Medical devices configured for minimally invasive surgery (MIS) include catheters and endoscopic probes. Some of these devices are guided through disposable or limited-use flexible tubular bodies (often referred to as sleeves or sheaths or introducer sheaths). Some of these introducer sheaths or sleeves are robotically controlled. Robotically controlled catheters or endoscopes have catheter sheaths with a steerable distal segment and a non-steerable proximal segment. The proximal segment is connected to an actuator unit via an electromechanical connector, and the size of the distal segment is configured to be introduced into the patient's anatomy through natural cavities or small surgical incisions. Similar catheters or endoscopes that can be inserted into the patient can be manually operated by the user without automation or robotic control. In either case, one or more channels extend along the central lumen of the sheath to allow access for imaging devices (miniature cameras or fiber optic probes) and / or end effectors (biopsy tools or treatment probes) and / or fluids (contrast agents, gases, or irrigation fluids).

[0005] To reduce exposure to fluids and minimize interaction with instruments passing through the lumen, sheaths typically include a liner. The inner surface of the liner is configured to meet certain requirements, such as lubricity, hydrophobicity, and flexibility. The liner can be a thermoplastic or fluoropolymer material (such as...) in the form of a thin-walled tube with an inner diameter sized according to design requirements. Nylon, polyimide, high-density polyethylene (HDPE) Extrusions of urethane resin (or combinations thereof). See, for example, U.S. Patent Nos. 7,550,053, 7,553,387, 10,821,264 and pre-grant disclosure US 2009 / 0126862, the disclosures of which are incorporated herein by reference.

[0006] For robot-controlled sheaths, multiple drive lines or tendons extend along the sheath wall to allow actuator units to selectively manipulate (bend) the distal segment of the sheath. In some designs, the distal segment of the sheath has multiple bendable sections comprising rings made of biocompatible polymers such as polytetrafluoroethylene (PTFE) or polyethylene (PE). These rings are joined to the outer surface of the liner. Drive lines or tendons, typically made of metallic materials such as nickel-titanium (NiTi) alloys (NiTiN) or stainless steel or other similar metals, are guided through through-holes (secondary lumens) provided in the walls of the rings. This type of manipulable medical device for medical examination or treatment of internal body structures is described in numerous patent publications (including, for example, pre-grant publication US 2016 / 0067450, international publication WO / 2020 / 092097, and US Patent Nos. 8365633, 9144370, and 10687694, the disclosures of which are incorporated herein by reference in their entirety).

[0007] During use, because the sheath structure bends sharply within the patient's convoluted anatomy, the gap between the rings increases on the outer radius of the bend and decreases on the inner radius. This causes the liner to stretch on the outer radius of the bend and curl on the inner radius, creating a ridge. Thus, when the instrument passes through the central lumen of the sheath, it can deflect sufficiently so that the tip can catch on a ring and protrude from the sheath in the space between the two rings. On the other hand, for some inserted instruments, the tip can become stuck on the "ridge" between the guide rings. These problems can cause damage to the catheter and to the instruments or tools that are retracted to pass through it, and because the instrument cannot pass through, the intended use of the instrument cannot be performed.

[0008] Therefore, there is a need for improved maneuverable medical devices, particularly robotically maneuverable catheters or endoscopes with reduced overall diameters, which require thinner, more flexible, but torsion-resistant central lumens. Summary of the Invention

[0009] According to at least one embodiment of this disclosure, an apparatus is provided comprising a catheter sheath having a reinforced central lumen extrusion. The catheter sheath, extending longitudinally from a proximal end to a distal end along a sheath axis, includes: a central lumen extrusion having multiple layers, the multiple layers comprising, sequentially and substantially concentrically with the sheath axis, an inner layer defining a central lumen, a reinforcing structure surrounding the inner layer, and an outer layer surrounding the reinforcing structure; and a plurality of rings disposed on the outer layer of the central lumen extrusion, wherein the plurality of rings are arranged at a predetermined distance from each other in a direction from the distal end to the proximal end, wherein the reinforcing structure of the central lumen extrusion includes one or more of a braided structure, a coil structure, and a laser-cut tube structure embedded between the inner and outer layers, and wherein the central lumen extrusion is bonded to, laser-welded to, or pressure-fitted to one or more of the plurality of rings.

[0010] According to one embodiment, the catheter sheath includes: an elongated tubular body having a proximal end and a distal end, and defining a central lumen extending along the length of the tubular body along the sheath axis; the tubular body includes a maneuverable segment formed by guide rings commonly disposed in the longitudinal direction of the tubular body, the guide rings being spaced apart from each other by a predetermined distance to create a gap therebetween. A central lumen extruder has an inner surface, a reinforcing structure, and an outer surface arranged sequentially between the tubular body and the central lumen, substantially concentric with the central lumen; the reinforcing structure includes one or more of a braided structure, a coil structure, and a laser-cut tube structure embedded between the inner and outer surfaces. The reinforcing structure is offset toward either the inner or outer surface.

[0011] According to one embodiment, the steerable sheath includes: an elongated tubular body having a proximal end and a distal end, and defining a central lumen extending the length of the tubular body, wherein the tubular body includes a steerable segment formed by guide rings commonly disposed in the longitudinal direction of the tubular body, wherein the guide rings are spaced apart from each other by a predetermined distance to create a gap between each pair of consecutive guide rings, wherein the guide rings include wire sleeves arranged substantially parallel to and equidistant from the central lumen; at least one control line slidably disposed in each wire sleeve, the distal end of the at least one control line being attached to the steerable segment of the tubular body, the proximal end of the at least one control line being configured to be mechanically connected to an actuator unit; and a central lumen extruder having an inner surface, a reinforcing structure, and an outer surface arranged sequentially between the tubular body and the central lumen, substantially concentric with the central lumen, wherein the reinforcing structure includes one or more of a braided structure, a coil structure, and a laser-cut tube structure embedded between the inner and outer surfaces.

[0012] According to some embodiments, the central lumen extrusion includes inner and outer layers concentric with each other, and one or more of a braided reinforcement structure, a coil reinforcement structure, and a laser-cut tube reinforcement structure are encapsulated between the inner and outer layers of the central lumen extrusion.

[0013] According to some embodiments, both the inner and outer layers are made of an elastic polymer material, and the inner layer includes or is coated with a lubricating material that is not included in the outer layer.

[0014] According to some embodiments, the outer layer is made of thermoplastic elastomer (TPE) and the inner layer is made of thermoplastic polyurethane (TPU).

[0015] In some embodiments, the inner layer is thicker than the outer layer. Alternatively, the outer layer is thicker than the inner layer.

[0016] In some embodiments, the hardness of the inner layer differs from that of the outer layer. For example, the hardness of the inner layer is higher than that of the outer layer. Alternatively, the hardness of the inner layer is lower than that of the outer layer.

[0017] According to certain embodiments, the coil reinforcement structure included in the central lumen extrusion is a first coil reinforcement structure made of metal wire and / or polymer wire wound in a first direction relative to the lumen axis, and the outer sleeve includes a second coil reinforcement structure made of metal wire and / or polymer wire wound in a second direction relative to the lumen axis, the first direction being opposite to the second direction.

[0018] According to some embodiments, the outer layer is made of an elastic polymer combined with a carbon black additive material, and the inner layer is made of an elastic polymer combined with or coated with a lubricating additive.

[0019] These and other objects, features, and advantages of this disclosure will become clear when read in conjunction with the accompanying drawings and the provided claims in the following detailed description of exemplary embodiments of this disclosure. Attached Figure Description

[0020] Figure 1A This illustration depicts an example embodiment of a medical system 1000 that includes an operable medical device 11 in its applicable medical environment. Figure 1B An example embodiment of the medical system 1000 is illustrated in the form of a block diagram;

[0021] Figure 2A and Figure 2B The structural details of a steerable catheter sheath 100 are illustrated, the steerable catheter sheath 100 having a central lumen extrusion 200 and a plurality of guide rings arranged on the central lumen extrusion. Figure 2C An example is shown with a guide ring for a wire guide sleeve; Figure 2DExamples illustrating ring components with alternative structures or functions;

[0022] Figure 3 An example embodiment is illustrated, including a central lumen extrusion 200 with a reinforced structure made of braided fibers;

[0023] Figure 4 An example embodiment is illustrated, including a central cavity extrusion 200 with a reinforcing structure made of wound wire;

[0024] Figure 5 The illustration includes an example embodiment of a central cavity extrusion 200 with a reinforced structure made of a laser-cut tube;

[0025] Figure 6A An example embodiment of the central lumen extruder 200 is shown. Figure 6B As shown along Figure 6A The cross-sectional view of the reinforced central cavity extrusion 200 seen in section BB. Figure 6C and Figure 6D Show them separately as along Figure 6A The cross-sectional view of the reinforced central cavity extrusion 200 seen in section BB, wherein the reinforcing structure 200 is offset relative to the inner and outer layers;

[0026] Figure 7 An example embodiment of a reinforced central lumen extrusion 200 is illustrated, wherein a thin-walled ring 720 (reinforcing ring) is located on the outer surface of the central lumen extrusion 200;

[0027] Figure 8A An example embodiment illustrating the reinforced central lumen extrusion 200 is provided. Figure 8B Show Figure 8A Detailed view of area B. Figure 8C An example embodiment of a guide ring 120 having a chamfered, beveled, or rounded edge 825 on its inner surface is shown;

[0028] Figure 9A and Figure 9B An example embodiment of a reinforced central lumen extrusion with different gap distances between consecutive guide rings in a curved section is illustrated.

[0029] Figure 10 An example embodiment of a steerable catheter sheath 100 having a reinforced central lumen extrusion 200 and an outer sheath 800 is illustrated.

[0030] Figure 11A A cross-sectional view of the catheter sheath 100 is shown as seen from a plane perpendicular to the lumen axis Ax. Figure 11B A cross-sectional view of the catheter sheath 100 is shown, wherein the outer sheath 800 includes a reinforcing structure similar to the reinforcing structure of the central lumen extruder;

[0031] Figure 12 This illustration depicts an exemplary manufacturing process for producing a catheter sheath with a central lumen extrusion having a reinforcing structure; and

[0032] Figure 13 It is a graph showing the experimental results of bending a catheter sheath with a central lumen extruder having a reinforced structure. Detailed Implementation

[0033] The following paragraphs describe some illustrative embodiments of a robotic medical system configured to use a manipulable medical device with a reinforced central lumen. Other embodiments may include alternatives, equivalents, and modifications. Additionally, illustrative embodiments may include several features, and certain features may not be essential for some embodiments of the devices, systems, and methods described herein.

[0034] Throughout the accompanying drawings, where possible, unless otherwise stated, the same numbers and characters are used to denote similar features, elements, components, or portions of the illustrative embodiments. Furthermore, while the subject matter disclosure is described in detail with reference to the accompanying drawings, this is done in relation to illustrative exemplary embodiments. It is intended that changes and modifications may be made to the described exemplary embodiments without departing from the true scope of the subject matter disclosure as defined by the appended claims. Although the drawings illustrate some possible configurations and methods, they are not necessarily drawn to scale, and certain features may be enlarged, removed, or partially cut to better illustrate and explain certain aspects of this disclosure. The description set forth herein is not intended to be exhaustive or to otherwise limit or bind the claims to the precise forms and configurations shown in the drawings and disclosed in the following detailed description.

[0035] When a feature or element is referred to herein as “on another feature or element,” such a feature or element may be directly on said other feature or element, or there may be an intermediate feature and / or element. Conversely, when a feature or element is referred to herein as “directly on another feature or element,” it will be understood that there is no intermediate feature or element. It will also be understood that when a feature or element is referred to as “connected,” “attached,” “coupled,” etc., to another feature or element, it may be directly connected, attached, or coupled to said other feature or element, or there may be an intermediate feature or element. Conversely, when a feature or element is referred to as “directly connected,” “directly attached,” or “directly coupled” to another feature or element, it will be understood that there is no intermediate feature or element. Although described or illustrated relative to one embodiment, features and elements so described or illustrated in one embodiment may be applicable to other embodiments. Those skilled in the art will also recognize that discussions of structures or features arranged “adjacent” to another feature may include portions that overlap with or are located below the adjacent feature.

[0036] Ordinal numbers such as first, second, third, etc., may be used in this document to describe various elements, components, regions, parts, and / or segments. It should be understood that these elements, components, regions, parts, and / or segments are not limited by these nomenclature terms. These nomenclature terms are only used to distinguish one element, component, region, part, or segment from another. Therefore, for the purpose of distinction only, and not limitation, and without departing from structural or functional meaning, the first element, component, region, part, or segment discussed below may be referred to as the second element, component, region, part, or segment.

[0037] As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should be further understood that the terms “comprising,” “including,” and “containing,” when used in this specification and claims, specify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof not expressly stated. Furthermore, in this disclosure, particularly when used in claims, the transitional phrase “consisting of…” excludes any element, step, or component not specified in the claim. It should be further noted that some claims or features of claims may be drafted to exclude any optional elements; one or more such claims may use proper terms such as “only,” “merely,” etc., in relation to the recitation of the claim elements, or it may use the limiting term “negative.”

[0038] As used herein, the terms “approximately” or “roughly” mean, for example, within 10%, within 5%, or less of a given quantity. In some embodiments, the term “approximately” may mean within measurement error or manufacturing tolerance. For this purpose, all figures, whether described or claimed, may be interpreted as if preceded by the words “approximately” or “roughly”, even if the term is not explicitly stated. The phrase “approximately” or “roughly” may be used to describe a quantity and / or location indicating that the described value and / or location is within a reasonably expected range of the value and / or location. For example, a numerical value may have values ​​of + / -0.1%, + / -1%, + / -2%, + / -5%, + / -10%, etc., of the value (or range). If recorded herein, any numerical range is intended to include the given limit and all subranges to which it falls. As used herein, the term "substantially" is intended to allow deviations from the descriptor that do not negatively impact the intended purpose. For example, deviations from limits in measurement, differences within manufacturing tolerances, or variations of less than 5% can be considered to be within substantially the same range. The specified descriptor can be an absolute value (e.g., substantially spherical, substantially perpendicular or parallel, substantially concentric, etc.) or a relative term (e.g., substantially similar, substantially identical, etc.).

[0039] This disclosure generally relates to medical devices, and specifically illustrates embodiments of steerable catheter sheaths for guiding catheters and / or optical probes that can be applied to imaging devices (e.g., endoscopes). Imaging devices may use miniature cameras based on chip-on-tip (COT) technology for imaging, or may provide some other form of imaging, such as spectral-coded endoscopy (SEE) imaging technology (see, for example, U.S. Patents 10,288,868 and 10,261,223). In some embodiments, the imaging device may include optical coherence tomography (OCT) equipment, spectroscopic devices, or combinations of such devices (e.g., multimodal imaging probes).

[0040] Embodiments of manipulable instruments and their parts are described in relation to their position / orientation in three-dimensional space. As used herein, the term "position" refers to the location of an object or part of an object in three-dimensional space (e.g., three translational degrees of freedom along Cartesian X, Y, Z coordinates); the term "orientation" refers to the rotational placement of an object or part of an object (three rotational degrees of freedom—e.g., roll, pitch, and yaw); the term "pose" refers to the position of an object or part of an object in at least one translational degree of freedom, and the orientation of that object or part of an object in at least one rotational degree of freedom (up to six degrees of freedom in total); the term "shape" refers to a set of poses, positions, and / or orientations measured along the elongated body of an object. As is known in the field of medical devices, the terms "proximal" and "distal" are used with reference to manipulation of the end of an instrument extending from the user to a surgical or diagnostic site. In this respect, the term "proximal" refers to the portion of the instrument closer to the user, and the term "distal" refers to the portion of the instrument further away from the user and closer to the surgical or diagnostic site.

[0041] As used herein, the term "catheter" generally refers to a flexible, thin tubular instrument made of medical-grade materials designed to be inserted through a narrow opening into a body cavity (e.g., a blood vessel) to perform a wide range of medical functions. A catheter can be simply an imaging device, or it can include tools used in therapeutic or diagnostic procedures. The more specific term "optical catheter" refers to a medical instrument comprising a long bundle of one or more flexible optical fibers housed within a protective sheath made of medical-grade materials and possessing optical imaging capabilities. A specific example of an optical catheter is a fiber optic catheter that includes a sheath, coil, protector, and optical probe. In some applications, a catheter may include a "guide catheter" that functions similarly to a sheath.

[0042] As used in this article, the term "endoscope" refers to a rigid or flexible medical instrument that uses light guided by an optical probe to visualize the inside of a body cavity or organ. The medical procedure in which an endoscope is inserted through a natural opening is called an endoscopic examination. Specialized endoscopes are generally named according to how or where they are intended to be used, such as bronchoscopes (mouth), sigmoidoscopes (rectum), cystoscopes (bladder), nephroscopes (kidneys), bronchoscopes (bronchus), laryngoscopy (larynx), otoscopes (ears), arthroscopy (joints), laparoscopes (abdomen), and gastrointestinal endoscopes.

[0043] Tactile medical instruments provide flexible access to the intended lesion or other internal site (e.g., an approach with one or more curves) while maintaining torsional and longitudinal stiffness, allowing the physician to control an end effector positioned distally (the end closest to the internal site) by manipulating the proximal end of the instrument (the end furthest from the internal site and closest to the physician). Some tactile medical instruments are robotic and use kinematic principles to actuate a flexible catheter sheath, wherein the sheath has a drive line actuated in the push-pull direction to bend a portion of the flexible body. However, as noted above, for access to deep lesions and other sites, it is necessary to minimize the outer diameter (OD) and maximize the inner diameter (ID) of the central lumen (or tool channel) of the catheter sheath. Therefore, some tactile medical instruments may include a sheath with minimal wall thickness that can be improved by strengthening the central lumen as described in this disclosure.

[0044] First, refer to Figure 1A , Figure 1B and Figure 2A-2C The structural components of a robotic medical system 1000 are described below. The robotic medical system 1000 includes a flexible body 3 detachably attached to an actuator unit 7 via a connector assembly 5. The robotic medical system 1000 may include a continuous robot or a multi-segment robot with a geometry configured to form a continuous curve by actuating one or more bending segments of the flexible body 3. Examples of continuous robots are snake-like endoscope devices as described in the applicant's previously published U.S. Patent No.: US9144370 and patent applications US 2015 / 0088161, US 2018 / 0243900, US 2018 / 0311006, and US 2019 / 0015978, which are incorporated herein by reference for all purposes.

[0045] Most of these manipulable medical devices feature polymer rings and metal wires arranged around a central lumen to create a flexible spine for serpentine joint connections. Therefore, this type of manipulable medical instrument is called a serpentine or continuum robot. A serpentine continuum robot has a unique distal structure in which polymer rings are attached to the central lumen at predetermined intervals to form a skeletal structure with specific bending properties. The central lumen can be a single-lumen extrusion made of a low-stiffness material to reduce the forces required to bend the skeletal structure. A single-lumen skeletal structure made of a low-stiffness material allows for relatively sharp bending radii. When the catheter sheath is bent into a curved shape, the gaps between the rings increase at the outer radius of the curved structure and decrease at the inner radius. Thus, as the instrument passes through the curved central lumen, the low stiffness of the central lumen extrusion allows the lumen walls to deflect or contract sufficiently so that the instrument tip can grip the rings and become locked. Specifically, the low stiffness of the central lumen extrusion does not provide sufficient circumferential strength to resist the radial expansion or contraction (ellipticization) of the central lumen. Therefore, there are situations where the central lumen cannot prevent instrument deflection and cannot prevent the instrument from getting caught on the rings of the scaffold structure. This situation can cause damage to the catheter sheath and / or the instrument inserted through the central lumen, and may also compromise patient safety.

[0046] According to this disclosure, one or more embodiments relate to a central lumen extrusion formed by a liner having an inner surface, a reinforcing structure, and an outer surface arranged substantially concentrically with the central lumen in the following order. The reinforcing structure includes one or more of a braided structure, a coil structure, and a laser-cut tube structure embedded between the inner and outer surfaces of the liner. In at least one embodiment, the reinforcing structure is offset toward either the inner or outer surface. According to this disclosure, one or more embodiments relate to a catheter sheath including a central lumen extrusion and having a plurality of rings arranged longitudinally on the outer surface of the central lumen extrusion in a direction from proximal to distal, spaced at predetermined distances from each other. At least some of the rings have secondary lumens serving as sheaths for actuating the distal end of the catheter sheath as control or support lines. The outer surface of the central lumen extrusion and / or the inner surface of the rings are specifically designed to allow for sharp bends of the catheter sheath with curvatures greater than 90 degrees in tortuous anatomical structures.

[0047] < Figure 1A-1B Robotic Medical Systems

[0048] Will be by reference Figure 1A and Figure 1B To describe robotic medical systems. Figure 1AAn example embodiment of a medical system 1000 in a medical environment (such as an operating room (OR)) is illustrated. The medical system 1000 uses a manipulable instrument 11 (manipulable medical device) to treat a patient 8 under interactive commands from a user (e.g., a physician) 10. The medical system 1000 includes at least a navigation system 1, a controller system 2, and the manipulable instrument 11. The manipulable instrument 11 includes an actuation unit 7 and a manipulable catheter sheath 100. The manipulable catheter sheath 100 includes multiple distal segments 3 and a single proximal segment 4. The proximal segment 4 is connected to the actuation unit 7 via a connector assembly 5. Figure 1A As shown in detail in small figure A, the actuation unit 7 is configured to be detachably attached to the robot platform (support platform) 9.

[0049] The maneuverable instrument 11 can be configured for a variety of medical and / or industrial applications. In medical applications, the maneuverable instrument 11 can be configured as a robotic endoscope, a maneuverable catheter, or a surgical insertion sheath or sleeve that uses kinematic (robotic) navigation principles to guide medical tools through tortuous body cavities. Robotic endoscopes can be used for a wide range of diagnostic and interventional procedures, including but not limited to colonoscopy, bronchoscopy, laparoscopy, and video endoscopy. In the case of video endoscopy, the maneuverable instrument 11 will be equipped with a miniature camera, such as a CCD or CMOS camera positioned at the distal portion of the flexible body 3, as well as electronic wiring and illumination optics (fiber optics) extending along the tool channel.

[0050] Figure 1B An example embodiment of the medical system 1000 is illustrated using a functional block diagram. The catheter sheath 100 has a proximal unmanageable segment 4 and a distal manageable segment 3, the distal manageable segment 3 being composed of a plurality of curved segments (e.g., curved segments 14, 13, 12) arranged longitudinally along a longitudinal axis (Ax). At least one central lumen or tool channel extends along the length of the catheter sheath 100 and passes through a portion of a connector assembly 5. In at least some embodiments, the manageable instrument 11 is controlled by a robot controller system 2 via an actuation unit 7; the actuation unit 7 is a handheld controller (handle) connected to the proximal segment 4 of the catheter sheath 100 via the connector assembly 5. The actuation unit 7 may include any force-generating device and mechanical element for generating and transmitting an actuating force sufficient to bend at least one curved segment of the manageable segment 3. In this respect, the actuation unit 7 may include any device capable of generating and transmitting an actuating force (including, for example, mechanical force, hydraulic pressure, magnetic force, or pneumatic force). The support platform 9 may include, for example, a robotic arm and a linear stage 91 for guiding the maneuverable instrument 11 (control unit 7, connector assembly 5 and catheter sheath 100) in the direction of movement for inserting and / or retracting the catheter sheath 100 relative to the patient 8.

[0051] The controller system 2 generally includes electronic components, such as PID controllers and / or digital signal processor (DSP) devices, along with suitable software, firmware, and peripheral hardware that are generally known to those skilled in the art. The controller system 2 may be part of or connected to the navigation system 1 (e.g., a computer or system console). The navigation system 1 includes necessary software (computer-executable code, programs, and applications) executable by a central processing unit (CPU) 190 to control the operable instrument 11 based on user interaction with the system 1000 via a user interface 194. Operation of the CPU 190 may be implemented by one or more processors in a computer that load and execute programs, or by special-purpose circuitry (FPGAs and ASICs). The user interface 194 may include, for example, a display device 192 (LCD, LED, or OLED display), which may include a graphical user interface (GUI) and / or pointing devices and a keyboard (not shown) or a touchscreen.

[0052] The navigation system 1, controller system 2, and actuation unit 7 are operably connected to each other via a network connection or cable bundle 199 and data bus system 195. Among other functions, the navigation system 1 can provide surgeons or other users with a GUI and other information displayed on the image display device 192, allowing users to interact with and remotely operate the manipulable instrument 11.

[0053] The controller system 2 is configured to control the actuation unit 7, which includes multiple actuation motors (or actuators) 70-1, 70-2, ..., 70-M. The number of actuators or motors 70 will depend on the design of the actuation unit 7, and it may include a single actuator or motor capable of independently actuating all drive lines, or it may include several actuators or motors equal to the number of drive lines 115, such that each actuator or motor can actuate each drive line individually.

[0054] The controller system 2 may also include or be connected to one or more sensors 74. Sensors 74 may include strain sensors and / or position sensors configured to detect and / or measure compressive or tensile forces (actuation forces) applied to the drive line 115 to bend one or more of segments 12, 13, and 14. Sensors 74 may output a signal 75 corresponding to the amount of compressive or tensile force (amount of strain) applied to the drive line 115 at any given time. Signals 75 from the sensors 74 (strain sensors and / or position sensors) for each drive line are fed into the controller system 2 to individually control each actuator. In this way, each drive line can be actively controlled via a feedback loop to achieve axial guidance suitable for navigating the maneuverable segment 3 through a tortuous path within the lumen of the patient's anatomy.

[0055] < Figure 2A-2B : Duct sheath structure >

[0056] Figure 2A and Figure 2B Additional details of the catheter sheath 100 according to an embodiment of the present disclosure are illustrated. Figure 2A This is a 3D rendering of a catheter sheath 100 consisting of an unmanageable proximal segment 4 and a manageable distal segment 3. Figure 2B This is a perspective view. The operable segment 3 includes multiple curved segments, including a proximal curved segment 14, an intermediate curved segment 13, and a distal curved segment 12. (Example) Figure 2B As shown, each curved segment is formed by two or more rings (multiple rings) arranged cooperatively in the longitudinal direction to form a tubular structure. Figure 2A As shown, the tubular structure also includes an outer jacket 80 and a central lumen extrusion 200. The central lumen extrusion 200 includes a liner 210 reinforced by a reinforcing structure 220. The liner 210 has an inner surface and an outer surface, the inner surface defining a central lumen or tool passage 150, and a plurality of rings arranged on the outer surface. The rings include a plurality of tubular sleeves (secondary lumens) through which drive lines 115 and / or support lines 116 pass. Drive lines 115 are moved by an actuation force to bend one or more segments of the operable section; support lines 116 are not actuated.

[0057] Figure 2B An example is illustrated where the catheter sheath 100 lacks a central lumen compression element 200 and an outer sheath 80. For example... Figure 2BAs shown, multiple drive lines 115 pass through the proximal segment 4, advance through the sleeve of the line guide ring 140 of the proximal bend segment 14, through the sleeve of the line guide ring 130 of the intermediate bend segment 13, and through the sleeve of the line guide ring 120 of the distal bend segment 12. Each bend segment of the operable section is actuated by a set of opposing drive lines 115, which are operated by tension or thrust (actuation force) to bend each bend segment independently of each other. Forces F1 and F2 of different magnitudes can be applied in the longitudinal direction to the separate drive lines to bend various bend segments in the desired direction. Combinations of forces F1 and F2 can also be applied to bend a given bend segment in an additional direction. Therefore, the first set of drive lines 115 can be anchored at the anchoring ring 120A at the distal end of the distal segment 12, the second set of drive lines 115 can be anchored at the anchoring ring 130A at the intermediate curved segment 13, and the third set of drive lines 115 can be anchored at the anchoring ring 140A at the proximal curved segment 14.

[0058] According to one embodiment, three drive lines 115 can be used to actuate each curved segment. In this case, the distal end of the drive line 115 in the first set of drive lines can be anchored to anchoring ring 120A, the second set of drive lines can be anchored to anchoring ring 130A, and the third set of drive lines can be anchored to anchoring ring 140A. In such an example, nine drive lines 115 will pass through the proximal segment 4 of the steerable sheath. At each anchoring member, it may be advantageous to arrange (anchor) the drive lines 115 circumferentially around each anchoring member at the strategic location to actuate each curved segment independently in the desired direction. For example, each drive line 115 can be anchored to the anchoring member at equal intervals, for example, when each curved segment is actuated by three lines, the drive lines will be anchored at 120-degree intervals to enable actuation of each curved segment in substantially any direction (any angle relative to the lumen axis Ax).

[0059] like Figure 2A and 2B As shown, within the catheter sheath, each curved segment 12, 13, and 14 includes multiple annular guiding members (guide rings), while the proximal unmanageable segment 4 is a single, elongated tubular assembly. Here, the tubular proximal segment 4 and the central lumen extrusion 200 can be made of similar biocompatible polymeric materials, such as polyether block amide copolymers (e.g., manufactured by Arkema), well-known polymers used in the fabrication of catheter shafts. (Brand). Other medical-grade thermoplastic polyurethane (TPU) and thermoplastic elastomer (TPE) materials can also be used as tubing extrusion materials for medical catheters and endoscopic devices requiring precision and consistency. In addition, other well-known catheter tubing materials can be used, including PVC, HDPE, polyurethane, nylon, FEP, PFA, ETFE, PTFE (lining), PEEK, TPE, etc. Lubricating films, and many other materials.

[0060] < Figures 2C-2D Ring structure >

[0061] Each wire guide member (each guide ring) has multiple wire sleeves (or through holes) along the wall of the guide ring. The through holes serve as sleeves through which the wire is guided along the wall of the tubular shaft. Again, wire sleeves may also be formed on the outer surface of each guide ring. The number of wire sleeves in each wire guide member depends on the curved section in which the wire guide member is arranged. The distal curved section 12 includes multiple wire guide rings 120; the intermediate curved section 13 includes multiple wire guide rings 130; and the proximal curved section 14 includes multiple wire guide rings 140. The distal curved section 12 is engaged to the intermediate curved section 13 by anchoring rings 130A; the intermediate curved section 13 is connected to the proximal curved section 14 by anchoring rings 140A. The proximal section 4 is a non-manipulated section, but it includes multiple wire sleeves extending through the wall (or extending on the outer surface of the wall). Here, it should be noted that the wire sleeves are not limited to through holes or sleeves within the wall itself. In some embodiments, wire sleeves may be formed on the outer or inner surface of a single ring. Moreover, at least some rings can be formed without through holes or sleeves.

[0062] Figure 2C An exemplary representation of an annular guide ring is shown, having a central opening or tool channel 150, and secondary lumens or conduits (151, 152, 153, 154, 155, 156, 157, 158, 159, etc.) formed on the walls of the ring surrounding the tool channel 150. For ease of illustration, the outer and inner surfaces of each guide ring are shown as circular, but actual implementations are not limited to this. The outer and inner surfaces of each guide ring structure may have substantially symmetrical and closed polygonal shapes, such as hexagons, octagons, etc.

[0063] Figure 2CA wire guide ring 120, a wire guide ring 130, and a wire guide ring 140 are shown. Wire guide ring 120 includes three wire guide sleeves (151, 154, 157); wire guide ring 130 includes six wire guide sleeves (152-153, 155-156, 158-159); and wire guide ring 140 includes nine wire guide sleeves (151, 152, 153, 154, 155, 156, 157, 158, and 159). In this embodiment, the nine drive lines 115 can be arranged to pass through the tubular wall of the proximal end segment 4. The drive lines then continue through the wire sleeves of the proximal bend segment 14 and are anchored to the anchoring member of each bend segment. Anchoring rings 120A, 130A, and 140A are substantially similar in structure to the corresponding wire guide rings 120, 130, and 140, respectively. All wire guide components and anchoring components include a central opening or tool channel 150 and have a predetermined number of through holes (wire guide sleeves or secondary lumens) arranged around the tool channel 150 that are substantially parallel to and equidistant from the instrument axis Ax.

[0064] The number of through holes in each ring or line guide member depends on the bend to which each ring belongs. However, in at least some embodiments, some rings may not have any through holes at all. For example, Figure 2D An illustration shows a first ring 120 and a second ring 130 with different structures or functions. The first ring 120 has a tool channel 150 but no through holes. Instead, the first ring 120 includes a groove 121 on its outer surface. The second ring 130 includes a tool channel 150, a plurality of through holes 151 (secondary lumens) surrounding the tool channel 150, and it also includes an opening groove 131 on its outer surface. The groove 121 in the first ring 120 or the opening groove 131 on the second ring 130 can be used to arrange electronic components (e.g., EM sensors) or radiopaque materials (radiopaque markers). EM sensors or radiopaque markers can be used as references, for example, during image guidance processes. The axis Ax of each line guide ring (120, 130, 140) or guide ring is arranged to be substantially coaxial with the sheath axis Ax. Although in geometry, the term "coaxial" technically means two or more three-dimensional linear forms sharing a common axis, in Figure 2B In the steerable sheath illustrated in the other accompanying figures disclosed herein, "coaxial" means that two or more components (e.g., liner, ring, and outer sheath) share substantially the same axis. In some cases, some components may be off-axis (i.e., have axes parallel to each other) rather than completely coaxial. However, for off-axis components with small distances between their axes, the axes of such components can be considered effectively coaxial.

[0065] In reference Figures 2A-2DIt should be understood that not all through-holes are used for drive lines 110. At least some of these through-holes are used to allow cables to pass through, some through-holes are empty, and some have support lines that are not drive lines. That is, according to at least one embodiment, the through-holes of each guide ring can have several uses; for example, some through-holes can contain control lines (drive lines), some can contain support lines that do not transmit force, some are left empty, some allow optical fibers to pass through, some can contain cables, and some can contain electronic components such as load cells or sensors. The rings used for the actuated segment 3 can be made of a biocompatible thermoplastic polymer similar to the thermoplastic polymer used for the central lumen extruder or proximal segment 4.

[0066] In at least some embodiments, rings 120, 130, and 140 are made of a transparent or translucent material that facilitates bonding to the central lumen extrusion 200. For example, rings 120, 130, and 140 are made of natural clear Pebax. Using a transparent material, the rings can be bonded to the central lumen extrusion using bonding processes associated with light energy transfer. Thus, even micro-rings can be bonded with consistent bonding quality as part of the manufacturing process. For example, UV adhesives can be used to bond the rings to the central lumen extrusion. In another design example, rings 120, 130, and 140 are made of natural clear Pebax, while the central lumen extrusion includes carbon black on its outer layer, black being beneficial for more efficient laser absorption. This particular combination of rings and the central lumen extrusion allows the rings to be bonded to the central lumen extrusion using laser welding without affecting the inner surface of the central lumen. Laser welding provides a consistent, strong bond between the rings and the central lumen extrusion. To minimize unnecessary heating from the joint area to other parts, it is preferable that the central lumen extrusion includes carbon black only in the outer layer of the central lumen extrusion. Other examples of biocompatible medical-grade translucent materials are described in pre-grant patent application publication US 20160220735, which is incorporated herein by reference for all purposes.

[0067] Refer back Figure 1A and Figure 1BThe handle or connector assembly 5 provides an electromechanical interface between the proximal segment 4 and the actuator in the actuation unit 7. For example, the connector assembly 5 can provide mechanical, electrical, and / or optical connections and other data / digital connections for connecting the operable instrument 11 to the controller system 2 and navigation system 1 via the interface. The handle or connector assembly 5 can also provide an access port 55, which can be used by a surgeon or other operator to insert an instrument or end effector through the tool channel 150. For example, the access port 55 can be used to insert small instruments such as small forceps, needles, or electrocautery instruments. Additionally, the connector assembly 5 can include one or more dials or control wheels 52 for manual control (bending or manipulating) of at least one segment of the operable segment. In some embodiments, the bendable body 3 can include more than one tool channel 150, wherein at least one of these channels can be used to allow fluid and / or gaseous fluid to pass through, and another channel can be used to allow tools or imaging devices to pass through.

[0068] During operation, navigation system 1 and controller system 2 are communicatively coupled via data bus 199 to send and receive data between them. Navigation system 1 is also connected to external devices outside the medical system 1000, such as computed tomography (CT) scanners, fluorescence imagers, and image servers. Figure 1A (not shown in the image) and communicate with it. Image servers may include, but are not limited to, DICOM devices connected to PACS (Picture Archiving and Communication Systems) or medical imaging systems. TM The server, medical imaging system, may include, but is not limited to, one or more of a CT scanner, magnetic resonance imaging (MRI) scanner, or fluoroscope. Navigation system 1 processes data provided by controller system 2, data provided by images stored on the image server, or data provided by images from the CT scanner or fluoroscope. Navigation system 1 displays images and other medical information in image display device 192 to assist the user in performing medical procedures.

[0069] For medical procedures that require the use of maneuverable instrument 11, medical images (e.g., from a CT scanner) are provided to navigation system 1 preoperatively. Using navigation system 1, the clinical user creates an anatomical computer model from the images. Figure 1A In a specific example embodiment, the anatomical structure may be the lung airways of patient 8. Based on chest images received from a CT scanner or PACS system, a clinical user can segment the lung airways for clinical treatment, such as biopsy. After the navigation system 1 generates a map of the lung airways, the user can also use a navigation software system to create a plan to enter the lesion for biopsy. The plan includes the target lesion and the trajectory (navigation path) of the flexible body 3 (manipulated sheath) of the manipulated instrument 11 inserted through the airway.

[0070] The controller system 2 includes firmware, control circuitry, and peripheral hardware for controlling the operable instrument 11, the insertion unit 9, and the field generator 6 (e.g., an electromagnetic (EM) field generator). The controller system 2 is integrated with the actuation unit 7, the insertion unit 9, the EM field generator 6, and the human-machine interface (e.g., [missing information]). Figures 1A-1B The controller system 2 (not shown) is communicatively coupled with the navigation system 1. In this way, the controller system 2 cooperates with the navigation system 1 to control the overall function of the operable instrument 11 and the insertion unit 9.

[0071] The operable instrument 11 includes a bendable body 3, a handle or connector assembly 5, and an actuation unit 7. The actuation unit 7 is configured to bend one or more of the proximal bending segment 14, the intermediate bending segment 13, and the distal segment 12 via the connector assembly 5 according to commands from the controller system 2 and based on navigation plans provided by the navigation system 1.

[0072] According to one embodiment, during the insertion or retraction of the manipulable instrument 11, the controller system 2 can control the linear stage 91 of the insertion unit 9 to move along the centerline of the lumen (e.g., airway) in a desired trajectory, followed by active control of the curved segments. This is similar to axis-guided techniques used to control robot-guided catheters or endoscopes with the goal of forcing the flexible axis of the sheath to follow a desired trajectory. In one example, when using the navigation system 1, the manipulable instrument 11 is robotically controlled to advance the sheath through the lumen while sensors 74 measure the actuation force, insertion depth, angle, etc., of the user-controlled manipulable segments to obtain trajectory information. The trajectory information is stored in the system's memory and is continuously updated. After a brief advance in the insertion or retraction distance, the shape of the flexible body 3 is corrected by adjusting one or more of the curved segments (one or more of the actuated curved segments) in such a way that the new shape closely matches the desired trajectory. This process is repeated until the target area is reached. The same process can be applied when the manipulable instrument is controlled to withdraw the flexible body 3 from the patient. This process is similar to the navigation process described, for example, in US 2007 / 0135803, which is incorporated herein by reference for all purposes. Additional details for driving the snake-like robot include control methods for actuation as described in the applicant's previous patent applications, US 2015 / 0088161, US 2018 / 0243900, US 2018 / 0311006, and US 2019 / 0015978, which are also incorporated herein by reference for all purposes. To improve the navigation process, it is advantageous to reinforce the lining of the central lumen or tool channel 150.

[0073] < Figure 3-5 : Central cavity extrusion component with reinforced structure >

[0074] According to an example embodiment, the maneuverable sheath of the flexible body 3 includes a central lumen extruder with a reinforced structure. The central lumen extruder is a liner made of one or more polymeric materials and is reinforced by adding a reinforcing structure made of metal, metal alloy, polymeric materials, or combinations thereof to improve its circumferential strength, propulsion, maneuverability, and kink resistance. The increased circumferential strength reduces the deflection of the liner, thereby preventing instruments passing through the central lumen from gripping the sheath's rings. The reinforcing structure can be designed to enhance circumferential strength without affecting the overall flexibility of the central lumen extruder. The material used for the reinforcing structure can be any biocompatible metal or polymer. The reinforcing structure for the central lumen extruder includes one or more of a braided structure, a coiled structure, or a laser-cut tube (hypotube) structure combined with one or more polymers (preferably elastic polymers). In this way, the central lumen structure can include one or more of a braided reinforced liner, a coiled reinforced liner, and a laser-cut tube reinforced liner.

[0075] Figure 3 An example embodiment of a central cavity extrusion 200 reinforced by a braided reinforcement structure 320 is illustrated. Figure 3 The central lumen extrusion 200 shows a liner 210 with a braided reinforcement structure 320 and a plurality of guide rings 120, which are collectively arranged (engaged) to the outer layer of the liner 210 to form one or more curved sections. Each guide ring 120 includes a plurality of wire guide sleeves (wire sleeves or secondary lumens). Figure 3 In the example, each guide ring 120 is illustrated to have a first wire guide sleeve 151 and a second wire guide sleeve 157 (see reference). Figure 2C Two consecutive guide rings 120 are arranged such that they are spaced apart by a distance D1 to form a gap between them. The gap distance D1 is substantially equal to or less than the length L1 of each guide ring 120. Here, the length L1 and the gap distance D are measured in the longitudinal direction (i.e., parallel to the longitudinal axis Ax).

[0076] According to one or more embodiments, the ratio of the guide ring length L1 to the gap distance D can be customized to achieve desired sheath properties (including circumferential strength and flexural flexibility). For example, the length L1 of each guide ring and the gap distance D between each pair of consecutive guide rings are in the range of 0.5 mm to 1.5 mm, or in the range of 0.75 mm to 1 mm. The ratio of the length of each guide ring to the gap distance between consecutive guide rings (L1 / D) is in the range of 3 to 0.3, or in the range of 2 to 0.5, or in the range of 1.5 to 1. Furthermore, the length L1 of each guide ring and the gap distance D between each pair of consecutive guide rings are 1 mm and 0.5 mm, or 0.75 mm and 0.75 mm, or 0.75 mm and 0.5 mm, respectively. These dimensions (unless otherwise noted) apply to all embodiments.

[0077] exist Figure 3 In this context, the reinforcing structure 320 is made of braided strands (filaments or filaments) of metal and / or rigid polymer materials. As used herein, the term "braid" or "woven" refers to a structure or pattern formed by interlacing or weaving two or more strands or two or more flexible materials (such as flexible threads). The strands may have a circular (round) or rectangular (flat) cross-section. The liner 210 is reinforced by the braided structure 320 to have sufficient thickness and circumferential strength to allow for easy bending, while maintaining torsional resistance and preventing the instrument from gripping the guide ring 120.

[0078] For braided reinforced central lumen extrusions, various materials can be used to reinforce the properties of the tubular shaft, depending on the performance characteristics to be achieved (e.g., torsional and kinking resistance, improved flexibility, enhanced circumferential strength, etc.). According to at least one embodiment of this disclosure, the reinforced central lumen extrusion of the liner 200 has three components: an inner layer, a braided structure, and an outer layer. These components are combined to obtain specific properties in terms of circumferential strength, flexibility, and kinking and torsional resistance. Simultaneously, the three components must be combined to meet desired dimensions (e.g., the wall thickness of the reinforcing liner) and manufacturing / assembly tolerances. In this regard, it must be noted that the size of the total outer diameter (OD) and inner diameter (ID) of the steerable sheath may necessarily limit the number of polymer layers and the type / thickness of the reinforcing structure that can be used. For example, because the braided filaments (braided yarns) must repeatedly cross each other to form the braided structure, the total thickness of the liner 200 will be determined by the thickness of the inner layer plus at least twice the diameter of the braided yarns plus the thickness of the outer layer. Therefore, larger diameter braided yarns can provide greater stiffness and torsional resistance, but they can increase the minimum wall thickness, which will affect flexibility. On the other hand, flat yarns woven to form a reinforcing structure can maintain the minimum wall thickness and provide some improvement in flexibility, but may not provide significant torsional resistance.

[0079] Another aspect to consider for the braided reinforcement structure 320 is the warp and weft density. Warp and weft density is expressed in warp and weft per inch (PPI), and it represents the number of intersections of the braided threads per inch of axial length. According to an example embodiment, the braided threads used in the current prototype are 0.0005 × 0.003 inch cross-section 304 stainless steel (304SS) flat wires. The braided pattern used is 130 PPI; meaning there are 130 repeating units (warp and weft) per inch of the braid. The higher the warp and weft density, the more flexible the braid is when bent. Typical braided patterns have 70-80 PPI. In this disclosure, because the central lumen extruder must be bendable with relatively low force input, much higher warp and weft densities have been prototyped and have yielded good results. The braided density will depend on the size of the flat wires and the size of the central lumen extruder (inner and outer diameters). For catheter sheaths with a central lumen extrusion having an ID of 6 to 10 French, the braid density will therefore range between approximately 50 PPI and approximately 200 PPI. Additionally, to provide greater flexibility near the distal end of the central lumen extrusion and greater axial stiffness towards the proximal end, the warp and weft ratio can vary along the length of the central lumen. For example, depending on the application, the braided reinforcement 320 can have 50-200 warp and weft per inch, a value that can vary along the length of the liner 210 to create increasingly flexible sections from proximal to distal.

[0080] Figure 4 An example embodiment of a central cavity extrusion 200 reinforced by a coil reinforcement structure 420 is illustrated. Figure 4 The central tube extrusion 200 shows a liner 210 having a coil reinforcement structure 420 and a plurality of guide rings arranged together to form one or more curved segments. The coil reinforcement structure 420 is made of wound wire of metallic material and / or wound rod of polymeric material. The polymeric material rod may comprise single strands of polymeric fibers wound in a specific pattern (e.g., wound at varying spacing) to obtain desired properties of circumferential strength and flexural flexibility, and / or spool-stranded multifiber rods. The coil reinforcement structure 420 can be manufactured using various wires, filaments, strands, or threads having flat, rectangular, square, and / or circular cross-sections, and can be made of metallic materials or polymer-based materials such as stainless steel, nitinol, fiberglass, carbon fiber, nylon, fluorocarbons, PEEK, PET, PEN, etc. Other materials. The arrangement of guide ring 120 and about Figure 3The arrangement of the guide rings is the same as described in the other embodiments. According to one example embodiment, the wire used in the coil reinforcement structure 420 is 0.001” × 0.003” 304SS wire (basically flat wire), but round or circular wire of similar size may also be used. The coil reinforcement structure 420 provides the necessary circumferential strength and is more flexible than the braided reinforcement structure, although the braided reinforcement structure provides better torsional stiffness. Therefore, in some embodiments, the catheter sheath 100 may have more than one type of reinforcement structure.

[0081] Figure 5 An example embodiment is illustrated by reinforcing the central cavity extrusion 200 with a laser-cut tube structure 520. Figure 5 The central tube extrusion 200 shows an inner liner 210, which has a laser-cut reinforcement structure 520 and a plurality of guide rings 120 arranged together to form one or more curved sections. The laser-cut reinforcement structure 520 is made of a metal tube or polymer tube 521 that has been laser-cut to form slots 522. The arrangement of the guide rings 120 is consistent with the above. Figure 3 and Figure 4 The arrangement of the guide rings described is the same. According to one example embodiment, tube 521 may be made of 304SS or nitinol, or it may be made of a polymer-like polyimide. In embodiments, tube 521 may be a conventional thiourea tube laser-cut with a specific slot pattern to provide circumferential strength and lateral flexibility. The continuous and / or interrupted helical cut pattern of the slot cut 522 may be gradually formed to provide a desired combination of circumferential strength, bending flexibility, and resistance to torsion of the catheter. Utilizing a laser-cut reinforcement structure 520 with an interrupted laser-cut pattern, the laser-cut tube can make the central lumen extrusion more resistant to compression and elongation than a coil or braided reinforcement structure. Therefore, the catheter sheath 100 of the maneuverable continuum robot may have at least some segments of the catheter sheath made of a central lumen extrusion 200, the central lumen extrusion 200 having, as Figure 5 The illustration shows a multilayer structure reinforced with an embedded laser-cut tube.

[0082] Naturally, the catheter sheath 100 may have a combination of reinforcing structures arranged alternately along the length of the central lumen extrusion 200; the reinforcing structures are selected from the laser-cut tube, coil, and / or braided reinforcement structures described in the foregoing embodiments. In one embodiment, each bend may have a different reinforcing structure. For example, the proximal segment 140 may have a central lumen extrusion 200 reinforced by a laser-cut tube reinforcement structure 520, the intermediate segment 130 may have a central lumen extrusion 200 reinforced by a coil reinforcement structure 320, and the distal segment 120 may have a central lumen extrusion 200 reinforced by a braided reinforcement structure 420. The reinforcing structures can be interchangeably adapted to each bend according to the desired application and the need for circumferential strength and flexibility.

[0083] < Figures 6A-6D Offset central lumen reinforcement structure >

[0084] Figure 6A An example embodiment of a central lumen extrusion 200 is shown. The central lumen extrusion 200 includes an inner layer 210a, a reinforcing structure 220, and an outer layer 210b arranged substantially concentrically and equidistantly with the lumen axis Ac in the following order. The inner layer 210a and the outer layer 210b constitute... Figure 3 , Figure 4 , Figure 5 , Figure 7 Figure 8 Figure 10 and Figure 11A-11B The lining 210 shown.

[0085] The reinforced central lumen extrusion 200 can be made into a plastic package by any known process, but not limited to injection molding, blow molding, or extrusion. For example, the processes described in U.S. Patent Nos. 7,550,053 and 7,553,387 cited above, and in publication US2009 / 0126862, can be used to produce reinforced central lumen extrusions of any embodiment disclosed herein. While the reinforced central lumen extrusion can be produced by a series of processes to form the combined reinforcing structure 220 and the inner / outer polymer layers (210a, 210b) as a whole central lumen extrusion in a single process, the central lumen extrusion can also be produced in separate steps using two or more distinct extrusion portions (e.g., the first portion being the outer layer 210b extruded in the first step, and the second portion being the inner layer 210a extruded in the second step). Subsequently, a third step is performed to sandwich the reinforcing structure 220 between the inner layer 210a and the outer layer 210b.

[0086] The process of creating the inner layer in separate steps can provide configurations that can be combined in a way that benefits the hardness of the resulting central cavity extrusion. For example, the first portion of the outer layer 210b can have a different material and a different hardness than the second portion of the inner layer 210a. Furthermore, the lengths of the inner layer 210a and / or the outer layer 210b can be generated in separate portions with different materials and hardnesses.

[0087] Figure 6B As shown along Figure 6A The cross-sectional view of the reinforced central cavity extrusion 200 seen in section BB. Figure 6B As shown, the reinforcing structure 220 can be arranged between the inner layer 210a and the outer layer 210b, midway (in the middle) of the wall thickness. However, to achieve specific requirements for enhanced circumferential strength and flexibility, the hardness of the materials used for the inner layer 210a and the outer layer 210b can be alternated, adjusted, modified, mixed, doped, etc. For example, according to one embodiment, the inner layer 210a can use a material with a higher hardness than the outer layer 210b, and vice versa. In other words, the central lumen extrusion comprises two layers (inner and outer layers) and a reinforcing structure arranged between these two layers. The two layers are joined by any known process to secure the reinforcing structure (braided or coiled or laser-cut tube layers) between them. The material of the inner layer is or includes a low-friction material; an example of an inner layer material is ePTFE. The outer layer material can be a low- or high-hardness material; an example of an outer layer material is... The beneficial effect is that this combination of features can improve the torsional stiffness of the conduit body as a whole, while maintaining good flexibility and circumferential strength of the inner tube for sharp bending curvature.

[0088] According to one example embodiment, the central lumen extrusion 200 includes an inner layer 210a made of a high-hardness elastomer, an outer layer 210b made of a low-hardness elastomer, and a braided or coiled or laser-cut tube reinforcement structure 220 disposed between the inner and outer layers. The higher-hardness inner layer 210a can be customized to improve lubrication and / or made to improve resistance to damage from tools and instruments passing through the lumen. Advantageously, because the inner layer 210a of the central lumen extrusion is closer to the central axis Ax of the lumen or tool channel 150, the higher-hardness inner layer 210a will experience less bending strain. In this case, the reinforcement structure can be offset towards the inner surface. Therefore, the resulting reinforced central lumen extrusion achieves the desired enhanced circumferential strength and flexibility.

[0089] According to another embodiment, the central lumen extrusion 200 includes an inner layer 210a made of a low-hardness elastomer, an outer layer 210b made of a high-hardness elastomer, and a braided, coiled, or laser-cut tube reinforcement structure 220 disposed between the inner and outer layers. Advantageously, because the outer layer 210b is bonded to the guide ring 120, the higher-hardness outer layer 210b provides enhanced flexural flexibility and sufficient circumferential strength when the sheath bends. Examples of hardness values ​​include high hardness in the range of approximately 63D to 72D Shore, and lower hardness in the range of approximately 25D to 35D Shore.

[0090] Low-hardness polymers tend to have sticky surfaces. Therefore, when a low-hardness material is used in the inner layer 210a, certain measures should be taken. Specifically, due to the sticky surface, the instrument may encounter greater frictional forces during passage through the central lumen or tool channel 150. If this frictional force is reduced, the central lumen extruder 200 will deflect less, and the instrument will have greater passage capacity without gripping the guide ring. Therefore, according to an exemplary embodiment of this disclosure, friction in the inner layer is reduced by selecting different materials that are similar in stiffness but provide improved lubricity. To this end, in an alternative embodiment, lubrication additives can be added only to the inner layer 210a of the central lumen extruder to improve the lubricity of instrument passage. When lubrication additives are added only to the inner layer (or more specifically, the inner surface), the bonding of the outer layer of the reinforced central lumen extruder to the guide ring is not affected. Therefore, according to one embodiment, the inner layer 210a of the central lumen extruder 200 may be made of a material that is more lubricating than the outer layer 210b, or may be coated with a material that is more lubricating than the outer layer 210b. More lubricating materials may include expanded PTFE (ePTFE) or other similar fluoropolymer linings or coatings.

[0091] Further alternative embodiments of this disclosure use lubricating additives mixed into the resin or material of the inner layer 210a of the central lumen extruder 200. In this and other embodiments, the reinforcing structure 220 may be one or more of a braided reinforcing structure 320, a coiled reinforcing structure 420, and a laser-cut tube reinforcing structure 520. For example, the steerable segment of the catheter sheath may have a first curved section reinforced by a braided structure, a second curved section reinforced by a coiled structure, and a third curved section reinforced by a laser-cut tube structure. Regardless of the reinforcing structure used, the lubricating additives mixed into the resin or material of the inner layer 210a improve the lubricity of the reinforced central lumen extruder. Additionally, during surgery, lubricant may be applied to the instrument or flushed through the central lumen extruder to reduce friction. According to at least some embodiments, the inner and outer layers may be made from the same resin (e.g., Extrusion is possible, but the inner layer may contain additives mixed into the base resin to improve lubricity. Various commercially available additives are available, including, for example... (Foster Corp), Mobilize (Compounding Solutions) and (Duke Empirical Inc.) etc.

[0092] In this way, the inner layer 210a provides a central lumen extrusion 200 with high lubricity on its inner diameter. This high lubricity facilitates the passage of diagnostic or therapeutic devices through the central lumen without them being caught by the guide rings of the skeletal structure. The inner layer 210a, made of a more lubricating material, provides a smooth yet rigid inner surface to promote smooth tool manipulation.

[0093] To further enhance circumferential strength and flexural flexibility, the reinforcing structure 220 is offset relative to the central cavity extrusion layer. Figure 6C and Figure 6D Cross-sectional views of the reinforced central lumen extrusion 200 are shown, wherein the reinforcing structure 220 is offset relative to the inner and outer layers. Typically, the reinforcing extrusion shaft has its reinforcing structure at the center of the wall (i.e., at the center between the inner and outer layers), and the stiffness of the shaft can vary in the longitudinal direction of the sheath. Conversely, according to at least one embodiment of this disclosure, the reinforcing structure 220 is either offset toward the outer layer 210b, as... Figure 6C As shown, it either shifts towards the inner layer 210a, as... Figure 6D As shown.

[0094] The offset of the reinforcing structure can be selected based on the desired characteristics of the resulting reinforced central cavity extrusion. For example, according to Figure 6C In one embodiment, the reinforcing structure 220 can be offset toward the outer layer 210b (i.e., the reinforcing structure 220 is closer to the OD than to the ID) to reduce the risk of exposing the braid, coil, or tube to the tool passage 150. This means the inner layer is thicker than the outer layer. This can result in improved lifespan for multiple tool uses. On the other hand, according to Figure 6D In one embodiment, the reinforcing structure 220 can be offset toward the inner layer 210a (i.e., the reinforcing structure 220 is closer to the ID than to the OD) to provide more material for thermally bonding the guide ring of the skeleton structure to the outer layer and to prevent disturbance to downstream processing. In this case, this means that the thickness of the outer layer is greater than that of the inner layer. This can improve compatibility with downstream processes that utilize reflow / laser welding to bond the guide ring to the inner tube. Additionally, providing a reinforcing structure closer to the ID will improve the circumferential strength of the central lumen.

[0095] Furthermore, as discussed in more detail below, both the central lumen extrusion (liner) and the outer extrusion can be reinforced using a reinforcing structure.

[0096] In any of the foregoing embodiments, regardless of whether the reinforcing structure is offset, the central lumen extrusion can be further reinforced when only the outer layer includes a radiation-absorbing additive material (such as carbon black). Carbon black is a form of subcrystalline carbon used as a reinforcing filler in rubber products (especially tires) during extrusion processing. Carbon black is also a radiation-absorbing material that strongly absorbs light from ultraviolet to infrared wavelengths (approximately 350 nm to approximately 1100 nm). Therefore, in this disclosure, the outer layer of the central lumen extrusion is formed using a thermoplastic elastomer mixed with carbon black to improve compatibility with downstream processes that use laser welding or reflow to join the guide ring to the inner layer. In one embodiment, the outer layer of the central lumen extrusion can be formed by extrusion comprising, by weight, from approximately 0.5% to 10% carbon black or a polyurethane elastomer containing approximately 2% to 5% carbon black.

[0097] When the outer layer is made of a thermoplastic elastomer (TPE) in combination with carbon black, the central lumen extrusion in any of the above embodiments can become a blurred (black) colored layer only on the outer layer. This allows for the safe use of laser welding to join the guide ring to the liner. This advantageous effect is achieved because the TPE mixed with carbon black absorbs more laser energy than the TPE alone. In this way, because only the outer layer is blurred (black), the heat from laser welding will join the guide ring to the reinforced central lumen extrusion while preventing heat penetration into the inner layer. The result is that laser welding will provide an effective and secure engagement between the guide ring and the outer surface of the central lumen extrusion, and will keep the inner surface of the lumen smooth for tool passages.

[0098] The use of carbon black additives in the outer layer of the central cavity extrusion is for coloring (blurring) purposes, but achieving proper circumferential strength is considered important. This is because during the assembly process, only the outer layer turns black and absorbs laser energy more efficiently, allowing it to be selectively heated at the point where the guide ring is joined to the central cavity extrusion by welding. Because the inner layer is not heated, the risk of overheating or melting the inner layer is reduced, and the smoothness of the central cavity is prevented from being affected.

[0099] < Figure 7 : Center-cavity extrusion with reinforced outer diameter >

[0100] According to a further example embodiment, the central lumen extrusion can be reinforced by adding a reinforcing structure to its outer diameter (OD) or outer surface. Figure 7An exemplary embodiment of a reinforced central lumen extrusion 200 is illustrated. According to this embodiment, the central lumen extrusion 200 includes a liner 210 made of one or more layers of polymer similar to those described above. In this embodiment, the liner 210 is reinforced by a plurality of thin-walled rings (reinforcing rings) 720 formed between already attached guide rings 120. The thin-walled rings 720 may be provided to supplement or replace the embedding of reinforcing structures (woven fabric, coils, or laser-cut tubes) within the layers of the central lumen extrusion. The thin-walled rings 720 have a smaller diameter and a smaller length than the guide rings. Additionally, the thin-walled rings 720 may be made of a metal with a unique Poisson's ratio, specifically, said unique Poisson's ratio would allow the central lumen extrusion to bend without changing its diameter. The thin-walled rings 720 may be made of a rigid polymer material and manufactured according to a known process, such as that disclosed in U.S. Patent No. 7,815,975, which is incorporated herein by reference. However, to allow sufficient space for catheter sheath bending while providing enhanced circumferential strength, the length L2 of the thin-walled ring 720 must be tailored to achieve the desired flexibility and torsional properties. In this regard, the length L2 is less than the length L1 of the guide ring 120 and less than the gap distance D between consecutive guide rings 120. In at least some embodiments, one or more thin-walled rings 720 made of a radiopaque material (e.g., platinum, gold, or a radiopaque polymer) may be used. This will allow for identification of the central lumen and / or identification of one or more bends during image-guided procedures. The thin-walled ring 720 may be an ePTFE ring arranged in the "ring gap" to improve liner strength and prevent potential damage to the sheath from tools passing through when the catheter sheath bends.

[0101] < Figures 8A-8C Reinforced central lumen extrusion with a grooved outer surface and / or a guide ring with chamfered edges >

[0102] According to a further alternative embodiment, the central cavity extrusion can be reinforced by increasing the wall thickness of the liner and providing a reinforcing structure in such a way as to engage the guide ring to the outer surface of the extrusion. Figure 8A An example embodiment illustrating the reinforced central lumen extrusion 200 is provided. Figure 8B Show Figure 8A A detailed view of area B, which shows an example of how the guide ring can be attached to the central lumen extruder. Figure 8C An example embodiment of a guide ring 120 with a chamfered, beveled, or rounded edge 825 is shown.

[0103] According to this embodiment, the central lumen extruder 200 has a liner 210, which is made of one or more polymer materials similar to those in the previous embodiments. The central lumen extruder 200 is reinforced by slightly increasing the thickness or number of layers constituting the liner 210 and forming a reinforcing structure by attaching the ring 120 to the outer layer of the central lumen extruder. In one embodiment, as in the previous embodiments, the liner 210 is reinforced using one or more of a braid, a coil, or a laser-cut tube. In other embodiments, the liner 210 is modified to form a groove 830 (a grooved section) in which the ring 120 with a chamfered edge 825 is arranged.

[0104] More specifically, to provide the desired characteristics of enhanced circumferential strength and lateral flexibility, a plurality of grooves 830 are formed on the outer surface of the liner 210. For example... Figure 8A As shown in region B (in Figure 8B (As shown in the diagram), the groove 830 may be formed at a specific location where the guide ring 120 is engaged or pressure-fitted into the central cavity extrusion. As an alternative to forming the groove 830 or chamfering the inner edge 825, at least the inner edge 825 of the guide ring 120 may be made of a material that is softer (lower hardness) than the material of the outer layer 210b of the liner 210.

[0105] In this embodiment, the liner 210 can be designed with a groove 830 to achieve the same enhanced performance but with an increased inner diameter (ID). The groove 830 can be fabricated by laser cutting, heat shrinking, or reflowing the outer surface of the liner 210 at the location where the central extruder contacts the guide ring 120's inner diameter. In this way, the wall thickness t2 of the liner 210 decreases to thickness t1 only in the section forming the groove 830 (making it thinner). That is, the wall thickness of the central cavity extruder 200 is thinner where the liner 210 contacts the guide ring 120. This is because the guide ring 120 increases the wall strength of the liner 210, and the wall thickness is thicker where the central cavity extruder does not contact the guide ring 120. The inner diameter (ID) of the central cavity extruder is continuously uniform and smooth, or has no significant dimensional variation along its length. On the other hand, the outer diameter of the liner 210 has a significant variation along its length. The liner “groove or concave” 830 may also have rounded (rounded) or chamfered end surfaces. This will help alleviate strain concentration at a single point where the outer surface of the liner 210 meets the plane of the guide ring 120. Additionally, the ring 120 may have a rounded or chamfered inner edge (the edge of its inner surface) at an angle α of approximately 30 to 45 degrees, such as… Figure 8CAs shown. The chamfered inner edge 825 of the guide ring 120 and / or the rounded end surface of the groove 830 on the outer surface of the liner 210 make the sheath more durable during repeated bending / use, while enhancing circumferential strength and lateral flexibility. Advantageously, the inner edge 825 of the guide ring 120 is chamfered, rounded, or beveled, so that when the catheter sheath bends, instruments passing through the central lumen are less likely to get caught on the edge of the guide ring 120.

[0106] < Figures 9A-9B : Enhance the change in the gap distance between the central tube extrusion component and the guide ring >

[0107] According to at least one embodiment, the circumferential strength and flexibility of the central lumen extruder with a reinforced structure are further enhanced by adjusting (decreasing or increasing) the spacing (D) between successive guide rings in one or more curved segments. According to one example embodiment, the shorter the gap distance between successive guide rings, the greater the improvement in the deflection resistance of the central lumen extruder, and vice versa. Therefore, reducing the gap distance between successive guide rings in at least one curved segment (particularly the distal curved segment) will also minimize the incidence of the instrument gripping the guide rings during surgery. However, careful consideration is necessary to achieve an appropriate amount of bending (radius) for a maneuverable instrument.

[0108] Figure 9A and Figure 9B An example embodiment of a reinforced central lumen extrusion is illustrated, showing different gap distances between consecutive guide rings in a curved section. Figure 9A and Figure 9B In this illustration, for ease of depiction, the central lumen extruder is not shown, as the first guide ring 120-1 and the second guide ring 120-2 are arranged continuously along the lumen axis Ax. A drive line 115 passes through the sheath of each guide ring 120-1 and guide ring 120-2. The drive line 115 is operated to actuate (bend) the tubular body of the catheter sheath 100 by pulling or pushing, such that the gap distance between the successive guide rings decreases along the inner radius and increases along the outer radius, as described elsewhere in this disclosure. Figure 9A The catheter sheath in the embodiment includes a larger than Figure 9B The embodiment in which the gap distance between the small guide rings 120-1 and 120-2 is shown. In this case, according to Figure 9A The catheter sheath of this embodiment has a shorter length between two consecutive guide rings 120-1 and 120-2, with a central lumen compression element. When instruments or tools (e.g., biopsy or camera) are inserted through... Figure 9A When the central lumen or tool channel of the sheath is 150, because Figure 9A The shorter central lumen extrusion component in the middle has the same characteristics as Figure 9BCompared to the previous embodiment, the reduced deflection prevents the tool from gripping the edge of the guide rings. Placing the guide rings closer together makes the central lumen extruder more effectively rigid between the two guide rings. Therefore, a greater force is required to sufficiently deflect the central lumen extruder for the instrument to grip the guide rings. Thus, when the guide rings are placed with a smaller gap distance, an instrument or tool passing through the central lumen extruder is more likely to follow the curvature of the central lumen rather than gripping the edge of the rings and attempting to poke out of the sheath through the space between the guide rings. From the foregoing description, it can be appreciated that by reducing the gap distance between successive guide rings, instrument navigation through the catheter sheath can be improved, and damage to the sheath and / or the tool can be minimized.

[0109] < Figure 10 and Figure 11A-11B Reinforced Outerwear >

[0110] According to yet another further embodiment, both the outer sheath and the inner lining can be reinforced to provide enhanced circumferential strength to the steerable sheath. Figure 10 An exemplary embodiment of a steerable catheter sheath 100 having a reinforced central lumen squeeze 200 and a sheath 800 is illustrated. The catheter sheath 100 includes a central lumen squeeze 200 arranged substantially concentrically with the longitudinal axis Ax, a plurality of rings 120 and a sheath 800, and a plurality of drive lines 115. The central lumen squeeze 200 defines a central lumen or tool channel 150 through which medical tools and devices configured for use in treating a patient's anatomy are passed. The plurality of guide rings 120 include a sheath 151 through which the drive lines 115 pass. The drive lines 115 receive an actuating force (push or pull) that bends at least one curved segment of the steerable sheath 100. According to various embodiments of this disclosure, the catheter sheath 100 can be bent greater than 90 degrees (up to 180 degrees or more), wherein the minimum radius R is approximately 5.0 mm or less.

[0111] Figure 11A A cross-sectional view of the catheter sheath 100 is shown as seen from a plane perpendicular to the lumen axis Ax. According to... Figure 11A A central lumen extrusion 200 defines a central lumen or tool channel 150 encapsulated by a tubular wall made of an inner layer 210a, a reinforcing structure 220, and an outer layer 210b. A guide ring 120 is engaged with the outer surface of the extrusion 200 (outer layer 210b). The guide ring 120 includes a plurality of wire sleeves 151 configured to allow at least one drive wire 115 to pass through one or more wire sleeves. Some wire sleeves 151 may be left unused or may be used to allow other types of wire to pass through. A jacket 800 encapsulates the guide ring 120. Figure 11A In the middle, the reinforcing structure 220 of the central cavity extrusion 200 is offset toward the inner surface so that the inner layer 210a is thinner than the outer layer 210b.

[0112] Figure 11B Showing with Figure 11A The diagram shows a cross-sectional view of a catheter sheath 100, similar to the one shown. According to... Figure 11B The outer jacket 800 is also reinforced by a reinforcing structure 820 similar to the reinforcing structure 220. According to at least one embodiment, the outer jacket 800 includes an inner layer 810a, a wound wire reinforcing structure 820, and an outer layer 810b. In this case, the coils in the reinforced central lumen extrusion 200 (liner) can be wound in the opposite direction to the coils in the reinforced outer jacket 800. For example, the coils in the reinforcing structure 220 are wound in a clockwise (CW) direction, while the coils in the reinforcing structure 820 are wound in a counterclockwise (CCW) direction, as indicated by the opposite arrows. Additionally, similar to the central lumen extrusion 200, the outer jacket 800 may have a reinforcing structure 820 offset towards an inner or outer surface. Figure 11B In the example shown, the reinforcing structure 820 of the sheath is offset toward the outer surface to provide greater resistance to external pressure. The combination of the central lumen extrusion and the oppositely wound coils in the sheath will enhance torsional stiffness while maintaining sufficient circumferential strength and flexibility of the sheath.

[0113] < Figure 12 Exemplary manufacturing process >

[0114] Figure 12 The illustration depicts the overall process for manufacturing a catheter sheath according to one embodiment of the present disclosure. For example, Figure 12 The processing indicates that it is used to create, such as Figure 2A The illustrations illustrate possible steps for a maneuverable duct sheath used in a snake-like continuum robot. Figure 12 The steps can be modified (added or omitted) depending on the type of application for which the catheter sheath is intended. In an exemplary manufacturing process for the catheter sheath, first, a reinforced central lumen extrusion is formed; second, multiple rings are arranged above the central lumen extrusion; and third, an outer sheath is arranged above the multiple rings. The rings may have through-holes or secondary lumens formed and arranged to surround the central lumen. The rings may be pressure-fitted, joined, welded, or attached to the outer surface of the central lumen extrusion and / or the inner surface of the outer sheath in any other manner. To ensure that the catheter sheath meets minimum requirements, the final step of the process is to perform a bending test. These steps can be performed in any type of manufacturing process known to a person of ordinary skill in the art of medical devices.

[0115] In one example, in step S1202, a thin inner layer 210a is first loaded onto a mandrel (not shown). In step S1204, a reinforcing structure 220 is positioned above the inner layer 210a. As mentioned elsewhere, the reinforcing structure may include one or more of a braided structure, a coil structure, and a laser-cut tube structure, or a combination thereof. In step S1206, an outer layer 210b is positioned above the reinforcing structure 220. At this point, any known processing occurs to join the inner layer 210a, the reinforcing structure 220, and the outer layer 210b together. Depending on the desired conduit structure, the inner layer 210a may be thinner than the outer layer 210b, such that the reinforcing structure 220 is offset toward the inner surface of the central lumen extrusion. Alternatively, the inner layer 210a may be thicker than the outer layer 210b, such that the reinforcing structure 220 is offset toward the outer surface of the central lumen extrusion. Furthermore, the inner layer 210a may have a higher or lower stiffness than the outer layer 210b, or vice versa. In step S1204, any one of a reinforcing structure, including a braided structure, a coil structure, a laser-cut structure, or a combination thereof, can be arranged along the length of the inner layer 210a. In step S1206, the inner layer 210a and the outer layer 210b can be joined to the reinforcing structure therebetween by any known process including one or more of the following: pressure fitting, welding (e.g., ultrasonic or laser), joining using an adhesive material, joining using heat treatment (e.g., reflow, curing using UV energy, or heat shrinking of the outer layer above the reinforcing structure). Furthermore, joining can be performed along the entire length of the central lumen extrusion or only at selected sections where the reinforcing structure is applied.

[0116] In some embodiments, the inner layer 210 may be an off-the-shelf, commercially available reinforced tube. In such embodiments, the liner may be a braided reinforced polymer tube, such as a braided 40DPebax tube. In this case, steps S1202 to S1206 may be optional to add additional reinforcing structural layers only at certain locations on the central lumen extrusion. Alternatively, utilizing an off-the-shelf reinforced liner, the process may begin from step S1208.

[0117] In step S1208, a plurality of first rings 120, a plurality of second rings 130, and a plurality of third rings 140 are arranged above the outer layer 210b of the central cavity extrusion member (e.g., ...). Figure 2B As shown). Figure 2C and Figure 2DAs shown, the ring may have secondary lumens or through-holes 151-159, but at least some of the rings may not have through-holes. Here, when the ring is arranged above the central lumen extruder, the ring can be pressure-fitted above the outer surface (outer layer 210b) of the liner 210. Optionally, in step S1208, the ring may be welded, joined, or otherwise attached to the outer surface of the outer layer 210b. Attaching the ring to the central lumen extruder can be performed by any known process, including one or more of the following: pressure fitting, welding (e.g., ultrasonic or laser welding), joining using adhesive materials, joining using heat treatment (e.g., reflow, curing using UV energy, etc.). As those skilled in the art will understand, laser welding can be considered as part of joining using heat treatment. In some embodiments, special primers and adhesives specifically designed to provide greater bonding strength with polymeric materials (such as PTU or PTE) may be used. An example of a primer material that facilitates bonding to such materials is commercially available from Henkel Corporation. SF 770 (also known as Loctite 770). Elastomer or polymer layers of catheter sheaths that do not typically bond well with conventional adhesives can be coated or encapsulated with epoxy resin or other materials that allow for better bonding.

[0118] In step S1210, one or more lines may be arranged along the wall of the ring in the through-hole of the ring. In some embodiments, lines may be arranged along a slot formed on the outer surface of the ring (e.g., Figure 2D The slot 131 in the loop is used to arrange the wires. In the duct sheath for a snake-like continuum robot, the wires may include one or more of the following: drive wires (control wires that actuate one or more of the bending segments), support wires used as tendons or spines for the robot (not actuated wires), or cables (cables made of one or more metal strands that transmit electrical signals). Additionally, through-holes or slots formed on the loop can be used to arrange elongated sensors such as electromagnetic (EM) sensors, optical fibers, radiopaque markers, and other similar components therein.

[0119] In step S1212, a jacket 80 is arranged over the entire structure, covering the plurality of rings 120, 130, 140 of the steerable distal segment 3, the central lumen extrusion 200, and the non-steerable proximal segment 4. In this step, the rings may be additionally welded or joined or otherwise attached to the inner surface of the jacket 80.

[0120] In step S1214, a bending test is performed to ensure that the newly formed catheter sheath meets the necessary requirements. For example, in step S1213, the bending test confirms that the catheter sheath bends at least 90 degrees (90+ degrees) without causing the tool or instrument to become stuck. To this end, several tests may be performed, such as bending the sheath with different radii of curvature and subjecting the tool or instrument to the central lumen many times to assess whether the sheath can or cannot pass through such drastic use.

[0121] Any or all of the foregoing embodiments can be combined to incrementally improve catheter performance.

[0122] The foregoing embodiments pertain to a single inventive concept of a manipulable sheath with a reinforced central lumen, which possesses enhanced circumferential strength and improved flexibility. The manipulable sheath of a snake-like continuum robot is configured to guide a medical instrument through the reinforced central lumen by manipulating (kinematically actuating) one or more curved segments of the sheath. According to various embodiments, the reinforced central lumen extruder includes one or more of the following features and provides one or more of the following advantages.

[0123] Key features: A flexible catheter sheath includes a central lumen extrusion, guide rings, and an outer sheath. The guide rings are engaged to the central lumen extrusion at predetermined distances from each other. The outer sheath is located outside the guide rings. The central lumen extrusion is a tubular body, the tubular body including braided, coiled, or laser-cut tubular structures within its walls.

[0124] Subordinate Feature 1: The central tube extrusion has an inner layer and an outer layer. The inner layer extends from the inner surface to the braided, coiled, or laser-cut structure, while the outer layer extends from the braided, coiled, or laser-cut structure to the outer surface. The inner layer is made of a material that is more lubricating than the material of the outer layer.

[0125] Dependent feature 2: Same as dependent feature 1, wherein the outer layer is made of thermoplastic elastomer. Dependent feature 2a: Same as dependent feature 1, wherein the outer layer is made of thermoplastic elastomer combined with carbon black.

[0126] Subordinate Feature 3: Same as Subordinate Feature 1, except that the wall thickness of the inner layer is greater than that of the outer layer.

[0127] Subordinate Feature 4: Same as Subordinate Feature 1, except that the wall thickness of the inner layer is less than that of the outer layer.

[0128] Subordinate Feature 5: Same as Subordinate Feature 1, except that the hardness of the inner layer is lower than that of the outer layer.

[0129] Subordinate Feature 6: Same as Subordinate Feature 1, except that the hardness of the inner layer is higher than that of the outer layer.

[0130] Dependent Feature 7: The central lumen extrusion has: a first coil structure in the wall of the tubular body; and a second coil structure in the wall of the outer sleeve. The winding of the first and second coils is performed by winding metal wire over the inner surface (lining) and coating the wound wire with a medical-grade thermoplastic elastomer. The winding directions of the first and second coil structures are opposite to each other.

[0131] Dependent Feature 8: The central lumen extrusion is a reinforced flexible tubular body having multiple layers between an inner surface and an outer surface. These multiple layers include: an inner layer extending from the inner surface to a braided or coiled or laser-cut structure; and an outer layer extending from the braided or coiled or laser-cut structure to the outer surface. The outer layer includes carbon black, while the inner layer does not.

[0132] Dependent feature 9: a catheter sheath comprising a central lumen extrusion according to any one of features 1-8, further comprising a plurality of rings disposed on the outer surface of the central lumen extrusion.

[0133] Dependent Feature 10: Same as Dependent Feature 9, wherein the ring is made of a transparent / semi-transparent material, and wherein the ring is joined to the outer surface of the central lumen extrusion by one or more of the following: pressure assembly, welding (laser welding or ultrasonic welding), joining using adhesive materials, joining using heat treatment (e.g., reflow or UV curing).

[0134] Advantages of adding reinforcing structures: Braided reinforcement provides: increased torsional stiffness; increased circumferential strength; manufacturing over continuous length (lower cost); Coil reinforcement provides: reduced wall thickness of the reinforcement; increased circumferential strength; Laser-cut tube reinforcement provides: higher resistance to compression; increased circumferential strength; increased torsional stiffness.

[0135] The advantage of using multiple materials / multiple hardnesses for the inner lining layers: the lubricity of the ID side of the braid / coil is higher than that of the OD side to help the tool pass through the channel;

[0136] Different materials / stiffness for the lining compared to the outer jacket: A thermoplastic elastomer with optional carbon black is used on the OD side of the braid / coil to allow for reflow / laser welding of the guide rings. A lower stiffness material is used for the outer jacket to provide enhanced navigation (insertion and withdrawal) flexibility;

[0137] In one embodiment, the reinforcing structure (woven fabric, coil, or laser-cut tube) is offset inwards in terms of wall thickness. This provides improved compatibility with downstream processing, including joining the guide ring to the outer surface of the liner via reflow or laser welding. The offset reinforcing structure also provides increased circumferential strength;

[0138] In one embodiment, the reinforcing structure (woven fabric, coil, or laser-cut tube) is offset outwards in terms of wall thickness. This provides a reduced risk of exposing the reinforcing structure to the tool passage and increases the lifespan of the device for multiple tool uses;

[0139] In one embodiment, the inner layer of the central lumen extrusion is made of a low-hardness material, and the outer layer is made of a high-hardness material. This helps maintain good bending flexibility.

[0140] In one embodiment, the inner layer of the central lumen extruder is made of a high-hardness material, and the outer layer is made of a low-hardness material, optionally with an added lubricating coating or lubricating additive. This provides a slippery yet hard inner surface to facilitate smooth tool manipulation;

[0141] In one embodiment, coil reinforcement is added to both the liner and the outer jacket. This provides increased torsional stiffness, improved circumferential strength, and helps maintain flexural flexibility in the central lumen extrusion.

[0142] In one embodiment, only the outer layer of the liner includes a carbon black additive. This improves compatibility with downstream manufacturing processes that use laser welding to join the guide ring to the outer surface of the liner. Because the outer layer includes a carbon black additive, only the outer layer becomes black and can absorb light and be selectively heated. Because the inner layer of the liner is not heated by laser welding, the risk of melting the inner surface or altering the smoothness of the lumen is reduced.

[0143] Other advantages include improved lubricity: reduced insertion force; minimal increase in material cost; reduced gap between guide rings; reduced chance of the instrument gripping the guide rings; and enhanced OD with an annular structure formed between the guide rings on the central lumen extruder: increased circumferential strength of the central lumen.

[0144] The chamfered, beveled, or curved inner edge of the guide ring and / or the grooved outer diameter of the central lumen extrusion reduce the chance of the instrument gripping the ring during insertion.

[0145] < Figure 13 Experimental Results >

[0146] Experiments were conducted to evaluate in various ways how to create an improved flexible body for a manipulable medical instrument with the aforementioned characteristics. Tests were performed to simulate environments in which the flexible medical instrument receives various tools into the tool channel without becoming stuck, particularly when the medical instrument is placed inside a living organism and subjected to invasive conditions, and is required to undergo one or more sharp bends (e.g., bends greater than 90 degrees with a relatively small radius).

[0147] use Figure 3 , Figure 4 or Figure 5 The catheter sheath design shown in any of the examples was experimentally tested, featuring a flexible body with a single central lumen extruder. The central lumen extrusion is manufactured and has an average hardness of 35D Shore, with a tool channel of 0.089 inches ID and 0.099 inches OD. In one embodiment, the central lumen extrusion has a PTFE channel with an ideally smooth surface machined from a PTFE block similar to a prior art catheter structure described by the applicant in publication WO / 2020 / 092097. However, in this disclosure, the central lumen extrusion is reinforced by a braided reinforcement structure. In other embodiments, at least the inner surface (inner layer) of the central lumen extrusion is made of a permeable material such as expanded polytetrafluoroethylene (ePTFE). Because the inner layer is microporous, the inner surface can be augmented with a highly lubricating material to improve the passage of medical instruments without them getting stuck on the ring. In some embodiments, the liner has a lubricating additive to lubricate the inner surface. Such additives include, but are not limited to, Moblize, Pebaslix, and Propell.

[0148] One embodiment pertains to a maneuverable catheter with a narrowed-pitch ring. A reinforced central lumen extrusion is used to construct a catheter with... Figure 2A , Figure 9A and Figure 9B The maneuverable catheter shown has a structure similar to that of the one with the reduced ring spacing (up to 30% smaller ring spacing compared to catheters previously disclosed by the applicant).

[0149] An experimental catheter prototype according to the above embodiments was tested and compared with a previously disclosed "existing" serpentine catheter. In the "existing" tested serpentine catheter, the loops were 1 mm wide and the spacing was 1 mm. The novel catheter with reduced-spacing loops was constructed using 0.75 mm loops, with a spacing of 0.75 mm between consecutive loops. In this embodiment, the catheter with 0.75 mm loops and 0.75 mm spacing is smaller than that with 1 mm wide gaps. The results show a significant improvement in insertion performance while maintaining minimal bending radius performance.

[0150] Figure 13 The graphs show experimental results of bending the prototype of the new catheter sheath compared to a previously disclosed catheter sheath (“existing” structure). These experiments were based on a bending radius of 15 mm and a bending curvature of at least 90 degrees to approximately 180 degrees.

[0151] from Figure 13It can be recognized that adding a braided reinforcement structure to the inner layer (dashed line), reducing the interlocking distance by about 30% (dotted line), creating an inner surface of permeable material (ePTFE) (tool channel), and adding lubricating additives (such as Moblize, Pebaslix, and Propell) to the inner layer can reduce the force required for inserting and removing catheters through tortuous paths.

[0152] According to several embodiments, reducing the ring width and gap distance at a 1:1 ratio provides far better results than reducing either the ring width or the gap distance alone. Maintaining a 1:1 ratio of ring width to gap distance is significantly superior in terms of minimum bending radius. For example, reducing only the gap distance (e.g., if you maintain a 1mm ring width and only reduce the gap between rings to 0.5mm), you end up with a minimum bending radius of 10mm compared to the 5mm provided by 0.75×0.75.

[0153] As defined in the applicant's previously filed patent application publication US 2021 / 0259790 (incorporated herein by reference in its entirety), the ring to which the joining / laser welding is performed has a smaller surface area. According to this previous publication, one option is to laser weld the ring to the outer cap (outer jacket) instead of the central lumen extrusion because of the larger surface area and the fact that the surface is already there (easily accessible).

[0154] In terms of tool insertion performance, the catheter with a 1.0 mm ring width and a 0.5 mm gap between the rings performs best. However, this catheter also has the largest bending angle in terms of bending radius. On the other hand, the catheter with a 0.75 mm ring width and a 0.75 mm gap offers lower tool insertion performance but has a much smaller bending radius, making it a preferred embodiment for some applications. The catheter with a 0.75 mm ring width and a 0.5 mm gap also performs well.

[0155] The braided inner tube can be, for example, an off-the-shelf braided reinforced polymer tube, such as braided 40D. The braided inner tube can be attached to the ring structure and outer tube by any known method. For example, laser welding can be used. In some embodiments, laser welding may be biased towards the proximal and / or distal ends of the tool channel. Thicker structures can be provided in these areas to improve laser welding. The braided inner tube can be selected to maintain the flexibility of the snake robot. Additives (e.g., lubricating materials) may be added to the inner diameter, or both the inner and outer diameters. The braided inner tube may be made of separate materials inside and outside the braid. In one embodiment, the inner layer includes lubricating additives, while the outer layer does not.

[0156] The braided inner tube can be, for example, a braided reinforced polymer tube, such as braided 40D Pebax. This braided inner tube can be attached to the ring structure and the outer tube by any known method. For example, laser welding can be used. In some embodiments, laser welding can be biased towards the proximal and / or distal ends of the tool channel. Thicker structures can be provided in these areas to improve laser welding. The braided inner tube can be selected to maintain the flexibility of the snake robot. Additives (e.g., lubricating materials) can be added to the inner diameter, or both the inner and outer diameters. The braided inner tube can be made of separate materials inside and outside the braid. In one embodiment, the inner portion includes lubricating additives, while the outer portion does not.

[0157] Catheters with a low Poisson's ratio inner tube: In some embodiments, the inner tube or liner has a Poisson's ratio less than a defined amount. When the Poisson's ratio is less than this amount, wrinkles in the liner at sharp bend radii are eliminated. Furthermore, because the liner is almost under stress, there are no counteracting forces, thus making it easier to maintain the catheter's posture.

[0158] Other embodiments and modifications

[0159] In the description, specific details are set forth in order to provide a thorough understanding of the disclosed examples. In other instances, well-known methods, processes, components, and circuits are not described in detail so as not to unnecessarily prolong this disclosure. Unless otherwise defined herein, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The breadth of the invention is not limited by the subject matter description, but only by the ordinary meaning of the terminology used in the claims.

[0160] In the exemplary embodiments illustrated in the accompanying drawings, specific terminology has been used for clarity. However, the disclosure of this patent specification is not intended to be limited to the specific terminology chosen so far, and it will be understood that each particular element includes all technical equivalents operating in a similar manner.

[0161] While this disclosure has been described with reference to exemplary embodiments, it will be understood that changes may be made in detail, particularly in the shape, size, and arrangement of components or the content of steps, without departing from the scope of the invention. Therefore, the scope of the claims shall be given the broadest reasonable interpretation to include all such modifications and equivalent structures and functions.

Claims

1. A catheter sheath (100) extending longitudinally from the proximal end to the distal end along a sheath axis (Ax), the catheter sheath comprising: The unmanageable section (4) and the manageable section (3) are arranged sequentially from the proximal end to the distal end. A multi-layered central lumen extrusion (200) comprising, in sequence, an inner layer (210a) defining a central lumen (150) substantially concentric with the sheath axis, a reinforcing structure (220) surrounding the inner layer, and an outer layer (210b) surrounding the reinforcing structure. as well as Multiple rings (120, 130, 140) are arranged on the outer layer (210b) of the central cavity extruder (200) in the operable section (3), wherein the multiple rings are arranged to be spaced apart from each other by a predetermined distance (D) in a direction from the distal end to the proximal end of the operable section. At least one of the plurality of rings is a wire guide ring having at least one wire guide sleeve, such that the control line is slidably arranged in the at least one wire guide sleeve. At least one of the plurality of rings is an anchoring ring for the anchoring control line. The reinforcing structure of the central tube extrusion includes one or more of a braided structure (320), a coil structure (420), and a laser-cut tube structure (520) embedded between the inner and outer layers. The central lumen extrusion (200) is bonded and / or pressure-fitted into one or more of the plurality of rings (120, 130, 140).

2. The catheter sheath according to claim 1, The reinforcing structure is offset toward the inner surface of the central cavity extruder or toward the outer surface of the central cavity extruder, such that the thickness of the inner layer is different from the thickness of the outer layer.

3. The catheter sheath according to claim 1 or 2, Each of the rings has an inner surface and an outer surface made of a thermoplastic polymer. The outer layer of the central lumen extrusion is made of a thermoplastic polymer, and Each of the rings is attached to the outer layer of the central lumen extruder by pressure assembly, adhesive bonding, or heat treatment, such that the inner surface of each ring is fixedly attached to the outer layer of the central lumen extruder.

4. The catheter sheath according to claim 1 or 2, The woven structure includes woven polymer fibers and / or woven metal strands arranged between the inner layer and the outer layer; The coil structure comprises wound metal wire and / or wound polymer filaments arranged between the inner layer and the outer layer; and The laser-cut tube structure comprises a polymer-based tube and / or a metal tube with a slotted pattern, and the laser-cut tube structure is disposed between the inner layer and the outer layer.

5. The catheter sheath according to claim 1 or 2, further comprising: An outer casing that encapsulates at least a portion of the plurality of rings and the central lumen extrusion. Each of the rings has an inner periphery that contacts the outer layer of the central lumen extruder, and an outer periphery that is enclosed by the outer sheath.

6. The catheter sheath according to claim 1 or 2, Each of the rings has an inner surface that contacts the outer layer of the central lumen extruder, and The rings wherein at least two of them have chamfered edges on their inner surfaces such that when the central lumen extruder bends, the chamfered edges of the rings minimize the pressure of the rings against the outer layer of the central lumen extruder.

7. The catheter sheath according to claim 1 or 2, The outer layer of the central lumen extrusion is made of a thermoplastic polymer bonded to carbon black, and The ring is made of a transparent or translucent polymer material.

8. The catheter sheath according to claim 1 or 2, The inner layer of the central tube extrusion is made of an elastic polymer bonded with a lubricating additive.

9. The catheter sheath according to claim 1, Each of the rings has a length in the longitudinal direction, and The length of each of the rings is equal to or less than the predetermined distance at which the rings are arranged.

10. The catheter sheath according to claim 9, The ratio of the length of each ring to the predetermined distance at which the rings are arranged is in the range of 3 to 0.

3.

11. The catheter sheath according to claim 10, The ratio of the length of each ring to the predetermined distance at which the rings are arranged is in the range of 2 to 0.

5.

12. The catheter sheath according to claim 11, The ratio of the length of each ring to the predetermined distance at which the rings are arranged is in the range of 1.5 to 1.

13. The catheter sheath according to claim 9, The length of each ring and the predetermined distance between the rings are 1 mm and 0.5 mm, or 0.75 mm and 0.75 mm, or 0.75 mm and 0.5 mm, respectively.

14. The catheter sheath according to claim 1 or 2, The non-manipulated section has a diameter substantially the same as that of the ring.

15. The catheter sheath according to claim 5, The outer sheath comprises an inner layer, a reinforcing structure, and an outer layer arranged sequentially and substantially concentrically with the sheath axis. The reinforcing structure of the outer jacket is formed by wound metal wire and / or wound polymer wire, and The wound metal wire and / or wound polymer wire of the central tube extrusion is wound in the opposite direction to the wound metal wire and / or wound polymer wire of the outer sleeve.

16. The catheter sheath according to claim 1, The central tube extrusion includes a first polymer layer forming an inner surface and a second polymer layer forming an outer surface, and The reinforcing structure is offset toward the outer surface of the central tube extruder, such that the thickness of the first polymer layer is greater than the thickness of the second polymer layer.

17. The catheter sheath according to claim 1, The central tube extrusion includes a first polymer layer forming an inner surface and a second polymer layer forming an outer surface, and The reinforcing structure is offset toward the inner surface of the central tube extrusion, such that the thickness of the first polymer layer is less than the thickness of the second polymer layer.

18. The catheter sheath according to claim 5, The central tube extrusion includes a first polymer layer forming the inner layer and a second polymer layer forming the outer layer. The outer sheath comprises an inner outer sheath layer, an outer sheath reinforcement structure, and an outer outer sheath layer arranged sequentially and substantially concentrically with the sheath axis. The outer jacket's reinforcing structure is offset toward its inner surface or its outer surface, such that the thickness of the inner layer of the outer jacket is different from the thickness of the outer layer.

19. The catheter sheath according to claim 1, The central tube extrusion comprises a first thermoplastic polyurethane (TPU) layer forming the inner surface and a second thermoplastic elastomer (TPE) layer forming the outer surface, and Only the second thermoplastic elastomer layer includes carbon black additive material, while the first thermoplastic polyurethane layer does not, such that the outer surface of the central lumen extrusion is configured to absorb laser welding heat at a rate greater than that of the inner surface.

20. The catheter sheath according to claim 1, The at least one wire guide ring includes a wire guide sleeve arranged substantially parallel to and equidistant from the sheath axis; At least one wire guide sleeve in each wire guide ring includes at least one control line slidably arranged along the length of the central lumen extruder, the distal end of the at least one control line being attached to the operable section of the operable section, and the proximal end of the at least one control line being configured to be mechanically connected to the actuator unit.

21. The catheter sheath according to claim 1, further comprising: One or more reinforcing rings are disposed on the outer surface of the central lumen extruder in the gap between one or more pairs of line guide rings arranged at the predetermined distance. Each reinforcing ring has a length less than the predetermined distance, and The diameter of each of the reinforcing rings is smaller than the diameter of each of the rings arranged at the predetermined distance.

22. The catheter sheath according to claim 1, The steerable section includes multiple curved sections, and The central tube extrusion corresponding to each curved segment is reinforced by one or more different reinforcing structures, including a braided structure, a coil structure, and a laser-cut tube structure embedded between the inner and outer layers.

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