Medical device with segmented bendable section

Abstract

An articulated medical instrument having a hollow core that can be maneuvered with a high degree of maneuverability through small spaces of a patient to reach a target minimally invasively, and once the medical instrument reaches the target, allows medical tools, including an endoscope, a camera, and a flexible medical device, to be guided through the hollow chamber to facilitate a medical procedure at the target.

Description

[0001] Cross-references to Related Patent Applications

[0002] This application claims priority to U.S. Provisional Patent Application No. 62 / 925,101 filed in the U.S. Patent and Trademark Office on October 23, 2019, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0003] The present disclosure generally relates to apparatus and methods for medical applications. More specifically, the present disclosure relates to an articulated medical device having a hollow chamber, wherein the device can be manipulated within a patient's body to reach a desired target and allows a medical tool to be guided through the hollow chamber, thereby allowing a medical procedure to be performed at the target site. The medical tool may include an endoscope, a camera, a flexible medical device, or other medical implement. Background Art

[0004] Flexible medical instruments (such as endoscopic surgical instruments and flexible medical devices) are well known and have long been accepted in the medical field. Flexible medical instruments generally include a flexible body, commonly referred to as a sleeve or sheath. One or more tool channels extend along the flexible body (typically within the flexible body) to allow access to a target located at the distal end of the body.

[0005] The device is intended to provide a flexible pathway within the patient's body having at least one bend or more bends leading to a desired target while maintaining torsional and longitudinal stiffness so that a physician can control tools located at the distal end of the medical device by manipulating the proximal end of the device.

[0006] Recently, in order to enhance the maneuverability of the distal end of the instrument, a robotized instrument that controls the distal portion has appeared. In those robotized instruments, different technologies have been disclosed in order to locally generate bending at the distal portion by a robot.

[0007] For example, U.S. Patent Publication No. 2018 / 0243900 provides a multi-segment articulated bendable medical device with bendable segments, wherein all segments comprise multiple individual nodes / guide loops. Prior patents have involved fully "skeleton" segments composed of many individual guide loops or single-piece segments made of multi-hole tubing.

[0008] In either case, the art provides multiple catheters to maintain the shape of the proximal portion while simultaneously actuating tendons to bend the distal portion of the medical device. The multiple catheters are selectively controlled in a binary manner by constraining or unconstraining the proximal ends of the catheters. By selecting a constrained catheter, the length of the curved distal segment of the bendable medical device can be varied by varying the stiffness of the bendable medical device based on the region of catheter deployment.

[0009] However, existing medical devices have several shortcomings that severely limit their use and efficacy. Namely, the column stiffness necessary to propel the device through difficult areas without collapsing is already particularly challenging, especially when minimizing the overall diameter of the device. In addition, the use of medical devices with a single-structure proximal segment lacks the flexibility to maneuver through sharp bends. Since the length of the segment also plays a role, a short bendable segment for a single-structure proximal segment would require much greater force than is feasible to bend the device to the desired output angle. A short length skeleton structure can provide optimal maneuverability, but the aforementioned passive segment needs to be rigid to allow the skeleton structure to bend correctly and to withstand the forces placed on it when bending, which makes it difficult to navigate a tortuous path.

[0010] Finally, the implementation of the proximal segment with both the skeleton structure and the multi-porous tubing is not robust enough to transmit the thrust required to navigate through the lung airways. While the skeleton portion of the proximal segment can navigate through certain bifurcations of the lung, the multi-porous tubing following the skeleton structure often cannot turn to the same bifurcation, but instead begins to buckle and prolapse into the other opening of the bifurcation. When this happens, the robotic system cannot transmit thrust to the distal end of the flexible medical device, and the prolapse limits the accessibility of the flexible medical device to nodules in the peripheral areas of the lung. If this problem is further exacerbated, prolapse of the flexible medical device often causes permanent damage, rendering the medical device unusable.

[0011] Some attempts to address this deficiency have included using longer bendable segments, however, these attempts suffer from the large displacements required when bending, making it difficult to control the bendable medical device, which could potentially cause injury to the patient.

[0012] The difference in length between the distal section and the proximal section causes inaccurate path following and large tip motion during advancement of the device into the patient. This tip misalignment causes the user to attempt to adjust the tip to realign with the original trajectory. However, this motion should not be necessary for the flexible medical device to follow the path of advancement into the patient, so as the instrument advances, the middle section and the proximal section will bend in directions that are not along the desired path. This process will cause the tip to move in an undesirable direction, and the derailment cycle will continue, being exacerbated with each step. The stiffness of the proximal section causes poor and inconsistent advancement of the medical device because the bending output does not match the output of the middle portion of the proximal section, which means it will not reach the desired angle and could potentially cause harm to the patient. Summary of the Invention

[0013] Therefore, to address this exemplary need in the industry, the device disclosed in the present invention teaches a medical device, comprising: a flexible body having a hollow chamber that extends the length of the flexible body; a first flexible section; an intermediate flexible section; at least two guide rings, the at least two guide rings being disposed in the first flexible section and spaced a distance apart from each other to form a cavity; at least two guide holes, the at least two guide holes in the flexible body, the guide holes extending the length of the flexible body and parallel to the hollow chamber; and at least one drive wire slidably disposed in at least one of the at least two guide holes and attached to the distal end of the flexible body, wherein the intermediate flexible section has a stiffness gradient that is different from the stiffness gradient of the first flexible section.

[0014] In another embodiment, the intermediate bendable section of the device comprises at least two sections, wherein each section has a different stiffness gradient.

[0015] In another embodiment, the device further comprises a flexible wall extending the length of the bendable body. It is also contemplated that the inner diameter of the at least two guide rings is attached to at least a portion of the wall. Additionally, the wall may further comprise an elastic outer lining for enclosing the at least two guide rings.

[0016] In other embodiments, the subject apparatus further comprises an actuator attached to a proximal end of the at least one drive wire, wherein the actuator is configured to actuate the drive wire.

[0017] In yet further embodiments, the intermediate bendable section is uniform.Additionally, the intermediate bendable section may comprise at least two adjacent sections, wherein each of the at least two sections has a different stiffness gradient.

[0018] In further embodiments, the apparatus includes an intermediate drive wire slidably disposed in the guide bore and attached to the flexible body, wherein attachment locations of the first drive wire and the intermediate drive wire are different along an axial direction of the flexible body.

[0019] In yet further embodiments, the at least two guide holes are configured in each of the at least two guide rings.

[0020] It is also contemplated that either or both of the drive wire and the guide hole may be constructed of a radiopaque material.

[0021] The present innovation also teaches a medical device, which includes a flexible body having a distal segment and a proximal segment, the flexible body being constructed to bend together with a drive wire, the distal segment having a skeleton structure, the skeleton structure including: a plurality of guide rings arranged at intervals to maintain the position of the drive wire; and an inner liner and an outer liner, the inner liner and the outer liner being attached to the guide rings, and the proximal segment including: a preferential bendable segment having a skeleton structure and connected to the distal segment; a transition skeleton segment including a skeleton structure and connected to the preferential bendable segment; and a passive segment including a multi-lumen tubing and connected to the transition skeleton segment, wherein the guide rings, the inner liner and the outer liner form a hollow chamber.

[0022] In various embodiments, the transition backbone segment includes a support line that terminates at a distal end of the transition backbone segment, wherein at the distal end, bending stiffness increases in the order of the preferentially bendable segment, the transition backbone segment, and the passive segment.

[0023] In other embodiments, the preferentially bendable zone further comprises a second set of support wires, wherein the transitional skeleton zone comprises a greater number of support wires than the preferentially bendable zone.

[0024] In yet another embodiment, the passive section comprises a third set of support wires disposed in a middle portion of the passive section.

[0025] The present innovation also teaches a flexible body having a hollow chamber extending the length of the flexible body; a first flexible section; an intermediate flexible section; at least two guide rings disposed in the first flexible section and spaced a distance apart from each other to form a cavity; at least two guide holes in the flexible body extending the length of the flexible body and parallel to the hollow chamber; and at least one drive wire slidably disposed in at least one of the at least two guide holes and attached to the distal end of the flexible body, wherein the intermediate flexible section has a stiffness gradient different from the stiffness gradient of the first flexible section.

[0026] These and other objects, features and advantages of the present disclosure will become apparent when the following detailed description of exemplary embodiments of the present disclosure is read in conjunction with the accompanying drawings and the provided paragraphs. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Additional objects, features and advantages of the present invention will become apparent from the following detailed description when taken in conjunction with the accompanying drawings which illustrate exemplary embodiments of the present invention.

[0028] Figure 1 is a block diagram of an exemplary bendable medical device including various ancillary components according to one or more embodiments of the subject apparatus, methods, or systems.

[0029] Figure 2 A cutaway perspective view of an exemplary bendable medical device according to one or more embodiments of the subject apparatus, method, or system is provided.

[0030] Figure 3 is a cut-away perspective view of an exemplary bendable medical device according to one or more embodiments of the subject apparatus, method, or system.

[0031] Figures 4a to 4d Side profiles (4a) and front cross-sectional views (4b-4d) of exemplary bendable medical devices according to one or more embodiments of the subject apparatus, methods, or systems are provided.

[0032] Figure 5 Depicted is a side cutaway view of an exemplary bendable medical device according to one or more embodiments of the subject apparatus, methods, or systems.

[0033] Figure 6 Provided are one or more embodiments of a subject device, method, or system. Figure 5 A close-up side cutaway view of an exemplary bendable medical device is shown.

[0034] Figures 7a to 7e Side profiles (7a) and front cross-sectional views (7b-7e) of exemplary bendable medical devices according to one or more embodiments of the subject apparatus, methods, or systems are provided.

[0035] Figure 8 Depicted is a side cutaway view of an exemplary bendable medical device according to one or more embodiments of the subject apparatus, methods, or systems.

[0036] Figures 9a to 9e Side profiles (9a) and front cross-sectional views (9b-9e) of exemplary bendable medical devices according to one or more embodiments of the subject apparatus, methods, or systems are provided.

[0037] Figures 10a to 10f Side profiles (10a) and front cross-sectional views (10b-10f) of exemplary bendable medical devices according to one or more embodiments of the subject apparatus, methods, or systems are provided.

[0038] Figure 11Depicted is a side cutaway view of an exemplary bendable medical device according to one or more embodiments of the subject apparatus, methods, or systems.

[0039] Throughout the drawings, unless otherwise indicated, the same reference numerals and characters are used to designate similar features, elements, components or parts of the illustrated embodiments. In addition, reference numerals preceded by a "'" (e.g., 101' or 24') denote intermediate elements and / or references of the same nature and / or kind. Furthermore, although the present disclosure will now be described in detail with reference to the accompanying drawings, this is done in conjunction with exemplary embodiments. It is intended that changes and modifications may be made to the described embodiments without departing from the true scope and spirit of the present disclosure as defined in the accompanying paragraphs.

[0040] As used herein, the term "substantially" means that deviations from the description are permissible and do not adversely affect the intended purpose. For example, deviations from measurement limits, differences within manufacturing tolerances, or variations of less than 5% may be considered to be within the substantially identical range. The specified description may be absolute (e.g., substantially spherical, substantially vertical, etc.) or relative (e.g., substantially no different waist profile, substantially identical, etc.). DETAILED DESCRIPTION

[0041] Analysis of this innovation showed that adding the intermediate stiffness segment resulted in a significant change in the occurrence of prolapse, reducing failures (where there was no transition at all) by approximately 30%. This innovation allows for more insertion force to be applied to overcome friction elsewhere in the flexible medical device, rather than being limited by the bending stiffness limits of the skeleton segments, thereby allowing the flexible medical device to be advanced further and deeper into the patient's anus. Furthermore, this innovation enables improved navigation by allowing the user to incorporate the newfound flexibility in the flexible medical device to reach parts of the lung more quickly and with fewer problems.

[0042] With Example 1, the advantages of using skeleton segments over tube segments (flexibility and bend radius) can be maintained while also closing large rigidity gaps.

[0043] For Example 2, the advantages result in increased stiffness of all backbone segments to reduce the risk of buckling through the length of the bendable medical device, while also reducing the relative stiffness differences between the backbone segments and the tube segments.

[0044] In the third embodiment, the advantage results in the ability to create multiple stiffness transitions, which may permit the less stiff tube segments 115 to bend at smaller radii due to the short segment lengths.

[0045] The present innovation will now be conveyed in detail through a description of exemplary figures, beginning with a general system associated with a bendable medical device.

[0046] Figure 1 FIG1 is a system block diagram of an exemplary flexible medical device system 10 including various auxiliary components intended to be assembled into a complete medical system. The flexible medical device system 10 includes a drive unit 12, a flexible medical device 13, a positioning cart 14, an operating console 15, and navigation software 16. The exemplary flexible medical device system 10 is capable of interacting with external system components and a clinical user to facilitate use within a patient.

[0047] The navigation software 16 and the drive unit 12 are communicatively connected via a bus to transmit / receive data between each other. In addition, the navigation software 16 is connected to and can communicate with a CT scanner, a fluoroscope, and an image server (not shown) as auxiliary components of the flexible medical device system 10. The image server may include, but is not limited to, a DICOM system connected to a medical imaging device. TM The navigation software 16 processes the data provided by the drive unit 12 and the images stored on the image server and / or the images from the CT scanner and fluoroscope to display the images on the image display.

[0048] Images from a CT scanner can be provided to navigation software 16 preoperatively. Using the navigation software, a clinical user creates an anatomical computer model from the images. In this specific embodiment, the anatomical structure is the anatomy of the lungs with associated airways. From the chest images from the CT scanner, the clinical user can segment the lung airways for clinical treatment, such as a biopsy. After generating a map of the lung airways, the user can also create a plan for approaching the lesion for biopsy. The plan includes the airway for inserting and maneuvering the flexible medical device 13 toward the desired target (in this example, the lesion).

[0049] The drive unit 12 includes an actuator and control circuitry. The control circuitry is communicatively coupled to an operating console 15. The drive unit 12 is connected to the flexible medical device 13 so that the actuators in the drive unit 12 operate the flexible medical device 13. Thus, a clinical user can control the flexible medical device 13 via the drive unit 12. The drive unit 12 is also physically connected to a positioning cart 14. The positioning cart 14 includes a positioning arm and positions the drive unit 12 and the flexible medical device 13 at a desired location relative to the target / patient. The clinical user can insert, manipulate, and withdraw the flexible medical device 13 to perform a medical procedure, in this case, a lung biopsy, on the patient.

[0050] The flexible medical device 13 can be navigated to a target within the patient's body based on the plan by a clinical user. The flexible medical device 13 includes a tool channel 108 for various tools (e.g., a biopsy tool). The flexible medical device 13 can guide the tools to the patient's lesion. In one example, the clinical user can use the biopsy tool to obtain a biopsy sample from the lesion.

[0051] like Figure 2 and Figure 3 As depicted, the distal section 101 of the flexible medical device 13 includes a plurality of guide rings 109, wherein the guide rings 109 are configured to be spaced apart from each other and not in contact with each other. The guide rings 109 are held in place by a cylindrical wall 18, which includes an inner liner 111 and an outer liner 110. This provides flexible support for the flexible body 17 while maintaining the guide rings 109 in a constant position along the axial direction of the flexible body 17. The inner liner 111 creates an inner diameter 40, and the outer liner 110 creates an outer diameter 42, wherein the inner diameter 40 establishes the tool channel 108. The edges of the flexible body 17 can be rounded by the atraumatic tip 26 to further reduce any damage to the patient's internal elements as the flexible body 17 is advanced.

[0052] Adjacent guide rings 109 are attached to the inner liner 111 and / or the outer liner 110, wherein cavities 113 are created between the adjacent guide rings 109, distributed along the longitudinal direction of the flexible body 17. When the flexible body bends, the cavities 113 create evenly distributed wrinkles in both the inner liner 111 and the outer liner 110. Thus, the cavities 113 avoid fatal kinks that could crush the tool channel 108.

[0053] Each guide ring 109 contains at least two guide holes 112 that extend the length of the guide ring 109 parallel to the length of the flexible body 17 to slidably accommodate the drive wires 105-106. In addition, each guide hole 112 within the guide ring 109 is configured to receive an anchor 21 that is displaced at the end of the drive wire 105-106 to be embedded in the guide ring 109. Figure 2 , the proximal drive line 106 depicts the anchor 21, which is configured at the distal end of the intermediate bendable section 103. The space between adjacent guide loops 109, in conjunction with the elastomeric inner liner 111 and outer liner 110, allows the bendable body 17 to achieve a greater range of bending motion without kinking due to the open space between the guide loops 109.

[0054] The tool channel 108 is configured to extend the length of the flexible body 17, wherein the proximal end of the flexible body 17 provides a path for a clinician user to insert / withdraw medical tools. For example, a clinician user can insert and withdraw a biopsy tool through the tool channel 108 at the distal end of the flexible medical device 13.

[0055] like Figures 4b to 4d As shown in the cross-sectional view in FIG, the flexible body 17 includes a set of distal drive wires 105, a set of intermediate drive wires 106, and a set of support wires 107 housed in the flexible body 17, wherein each of the set of drive wires 105 and the set of drive wires 106 corresponds to the distal bendable section 101, the intermediate bendable section 103, and the proximal bendable section 104, respectively. The cylindrical wall 18 is formed by an inner liner 111 and an outer liner 110, which are consistent and combined with each other at the distal end of the medical device 13 to enclose the flexible body 17. The wall 18 provides flexible support to the flexible body 17 while maintaining a constant position of the guide ring 109 along the axial direction of the flexible body 17. The inner liner 111 creates the inner diameter 40 of the wall and establishes the tool channel 108, while the outer liner 110 creates the outer diameter 42 of the flexible body 17.

[0056] The flexible body 17 accommodates each of the drive wires 105-106 in a corresponding guide hole 112 configured along the longitudinal direction of the flexible body 17. The guide holes 112 allow the drive wires 105-106 to slidably move along the axial direction of the flexible body 17. The drive wires 105-106 terminate at the distal end of each of the flexible segments 101, 103, and 104. The distal drive wire 105 terminates with an anchor 21 at the distal end of the distal segment 101 and is configured to be approximately 120 degrees apart from one another within the flexible body 17. The distal drive wires 105 are connected to the drive unit 12 at their proximal ends. The drive unit 12 moves the distal drive wires 105 by inducing a push or pull force by actuating the distal drive wires 105, thereby bending the flexible body 17. The proximal drive wire 106 is similarly configured for its corresponding flexible segment 103 and 104, respectively.

[0057] Thus, the bendable medical device 13 may be individually bent in all three dimensions by pushing and pulling the actuation wires 105 - 106 through the proximal, intermediate, and distal bendable sections 104 , 103 , and 101 , respectively.

[0058] Figure 21 , further depicted are support wires 107 disposed within the wall 18 of the flexible body 17. The support wires 107 can provide additional structural support to the wall 18 and can be anchored to the distal ends 24 of the flexible segments 101 to 104. In some embodiments, one or more support wires 107 can be loosely retained within the wall 18, allowing for movement and even removal of the support wires 107 to accommodate bending requirements within the flexible body 17. The support wires 107 can extend through guide holes 112 configured within the wall 18 and can originate at the proximal portion of the flexible medical device 13. In certain embodiments, the support wires 107 can be configured to provide adjustable structural support for the wall 81. Exemplary adjustments for support can include employing various tensile strengths, configurations, and elasticities of the support wires 107. In one embodiment, multiple support wires 107 can extend from the distal end 24 of the flexible medical device 13 to the proximal portion 105 of the flexible medical device 13, thereby allowing all segments 101 to 104 of the flexible body 17 to achieve the anti-kink benefit.

[0059] Figure 4a A side view of an exemplary bendable medical device according to one or more embodiments of the present innovation is provided, wherein Figures 4b to 4d depiction Figure 4a Front cross-section of the device at lines CC, DD, and EE.

[0060] Figure 4a The flexible medical device in FIG. 1 includes a distal section 101 and a proximal section 102 and has a tool channel 108 for delivering a biopsy tool or other tool through the flexible medical device 13 to a target. Distal drive wires 105 terminate in the distal end of the distal section 101 and are arranged equidistantly around the circumference of the device 13, as shown in FIG. Figure 4b In the same manner, the proximal drive wires 106 terminate in the distal end of the proximal section 102 and are also arranged equidistantly around the circumference of the flexible medical device 13, as shown in detail along the line CC. Figure 4a The cross section of line DD Figure 4c shown.

[0061] Furthermore, a proximal drive wire 106 defines the proximal end of the distal segment 101 at position A. By appropriately pulling and pushing those wires, the distal segment 101 and the proximal segment 102 can be bent three-dimensionally. These segments 101 and 102 can be independently controlled by a robotic controller (not shown). Specifically, the proximal segment 102 also includes a middle bendable segment 103 and a proximal bendable segment 104.

[0062] like Figure 5As provided, the middle bendable section 103 has the same mechanical structure as the distal section 101, also known as a skeleton structure, which includes a plurality of guide rings 109 spaced apart from each other, while the proximal bendable section 104 has a simple uniform multi-guide tube.

[0063] Figure 6 Shown Figure 5 A close-up view of the region G in FIG. 1 is provided to better explain the skeleton structure of the distal section 101 and the intermediate bendable section 103. The skeleton structure includes a plurality of guide rings 109 with certain intervals between the guide rings 109. The guide rings 109 have guide holes 112 (see FIG. Figures 4b to 4d ) to slidably retain drive wires 105 and 106 and is surrounded by an inner liner 110 and an outer liner 111. The inner liner 110 forms the tool channel 108, while the outer liner 111 provides a smooth, continuous surface for optimal insertion into the anatomical structure and protects the internal structures of the bendable medical device 13 from external debris. The guide rings 109, inner liner 110, and outer liner 111 form hollow chambers 113 between the respective guide rings 109. These hollow chambers 113 allow the bendable medical device 13 to bend with tight curvatures by causing the inner liner 110 and outer liner 111 to slightly wrinkle and stretch into and around the hollow chambers 113. In addition, the hollow chambers 113 achieve a low bending stiffness compared to the conforming multi-guide tubing section 118. Therefore, in the proximal section 102, the intermediate bendable section 103 having this skeleton structure has a lower bending stiffness than the proximal bendable section 104. This configuration localizes the bend in the intermediate bendable section 103 in the proximal section 102. When the proximal drive wire 106 is pushed or pulled, the intermediate bendable section 103 primarily bends, while the proximal bendable section 104 maintains its posture. However, the joint between the intermediate bendable section 103 and the proximal bendable section 104 (position B) experiences a sharp transition in curvature and is prone to buckling (or kinking). If this buckling occurs, even when the intermediate bendable section 103 turns toward a bifurcation and reaches the next branch, the proximal bendable section 104 behind the intermediate bendable section 103 will not be able to turn toward the bifurcation and will prolapse into the other opening of the bifurcation.

[0064] (Example 1)

[0065] Figure 7a is a side view of the flexible medical device according to the example detailed in Example 1. In addition, Figures 7b to 7e Provided separately Figure 7a Cross-sectional front view at lines CC, DD, HH and KK. In addition, Figure 8 supply Figure 7a The non-uniform side cross-section at line LL is shown as Figures 7b to 7e shown.

[0066] The proximal section 102 now includes a transitional skeleton section 114 between the intermediate bendable section 103 and the proximal bendable section 104. The transitional skeleton section 114 includes the same skeleton structure as the intermediate bendable section 103 and also includes support wires 107. The support wires 107 terminate at the distal end of the transitional skeleton section 114 ( Figure 7a The proximal end of the support wire 107 can be slid in the bendable medical device 13 and specifically pass through the guide hole 112.

[0067] As the bendable medical device 13 bends, the support wires 107 provide additional bending stiffness while adjusting for changes in the length of the channels in the bendable medical device 13. Because the support wires 107 can be constructed between the actuation wires 105 and 106, the walls 18 of the bendable medical device 13 can be made thinner by eliminating a central skeleton structure.

[0068] The transitional backbone section 114 reduces the stiffness variation between the intermediate bendable section 103 and the proximal bendable section 104 (position B), which significantly reduces the risk of prolapse of the proximal section 102. With the reduced stiffness transition, the 'weak point' that causes prolapse is eliminated, resulting in a more flexible bendable medical device with fewer 'weak points' that can cause failure.

[0069] (Example 2)

[0070] Figure 9a is a side view of a flexible medical device according to Example 2. In addition, Figures 9b to 9e Provided Figure 9a Front cross-sectional view of the flexible medical device at lines CC, DD, HH and KK.

[0071] The flexible medical device 13 in this embodiment includes an additional set of support wires 107' that terminate at the distal end of the distal segment 101 and extend through the remainder of the flexible medical device 13. This additional set of support wires 107' increases the bending stiffness of the distal segment 101 and the intermediate flexible segment 103 while maintaining the same order of magnitude. This additional set of support wires 107' also serves to prevent local buckling in areas with a skeletal structure (i.e., the distal segment 101 and the intermediate flexible segment 103). These additional support wires 107' work in conjunction with the original support wires 107 to increase the stiffness of all segments they traverse. Consequently, both the skeletal structure and the conforming tubular segment 117 experience an equal increase in stiffness. However, this means that the overall stiffness difference remains constant, while the relative stiffness difference decreases.

[0072] (Example 3)

[0073] Figures 10a to 10fand Figure 11 Another embodiment of the present invention is shown, wherein Figure 10a A side view of the bendable medical device in Example 3 is provided. Figures 10b to 10f Provided Figure 10a Front cross-section of the device at lines CC, DD, HH, NN, and PP.

[0074] This embodiment differs from embodiment 2 in the starting position of the additional support wire 107 ′, detailing the flexibility of moving the support wire 107 ′ to accommodate structural strength requirements.

[0075] like Figures 10b to 10f As shown, an additional support wire 107' terminates in the middle of the proximal bendable section 104 and creates a transition tube section 115 and a passive tube section 116. The additional support wire 107' can increase bending stiffness at the passive tube section 116 and improve the ability to transmit insertion force to the distal end.

[0076] (Design Example)

[0077] Two different design variations were implemented to address factors that cause prolapse and failure of flexible medical devices.

[0078] The first variation adds a transition section between the segments (here, the proximal priority backbone segment and the proximal passive tubular segment) with a stiffness that falls between the two. The length of this transition section is variable and, here, is selected to prevent the transition between the proximal backbone segment and the tubular segment from reaching the right upper lobe ("RUL").

[0079] In one exemplary embodiment or prototype, a 40 mm length was used to position the transition point 90 mm from the distal end of the flexible medical device. This was selected based on the current model being used, where the deepest point of the RUL is less than 90 mm from the RUL entrance. However, the exact length may require analysis of more patient data, or multiple designs may be available, and the clinician may be instructed to select a specific design / length based on the patient's segment.

[0080] The intermediate variation also adds transition segments, but reduces the length of each driven skeleton segment to 10 mm each. This improves FTL capabilities using an algorithm based on 'follow-the-leader' angles, as each segment will have the same shape as the segment it follows. This improved FTL performance should reduce instances of the flexible medical device becoming stuck during navigation. The transition segments in this variation are longer than those in the first variation, ensuring that the transition point with the passive tubing segment is also 90 mm away from the end of the flexible medical device.

[0081] The transition section has a skeleton structure, but the stiffness is increased by adding thicker support wires 107 in the five remaining unused guide holes 112. The driven skeleton section already has three support wires 107 with a diameter of 6 mils; the additional support wire 107' in the transition section has a diameter of 105.5 mils. This diameter wire will be suitable for our flexible medical device design without changing any guide hole or flexible medical device diameter, as it is the same diameter as the current drive wires 105 and 106.

[0082] However, there are a number of alternative ways in which this additional stiffness can be achieved. In addition to thicker and additional support wires 107, another material could be used altogether, such as stainless steel.

[0083] Current implementations have the distal portions of the support wires 107 anchored to the distal portion of the transition section, while the proximal portions run into the tube section and are not fixed at the ends so they can slide freely with movement in the bendable medical device 13. This is counterproductive because these support wires will also increase the stiffness of the tube section, which will offset some of the benefits gained by increasing the stiffness of the skeleton section.

[0084] A potential problem could also arise if the support wire ends before entering the adjacent segment. Since the support wire slides as the bendable medical device bends, a shape with a drop in stiffness at the proximal portion of the transition segment will result because the support wire has already slid distally, leaving a gap at the proximal end. Simultaneously, the opposing support wire will slide into the adjacent segment, increasing stiffness at the distal end of that segment. This creates a temporary point of significant stiffness difference, a situation we are trying to avoid.

[0085] One way to address this problem is to have these support wires fixed at both ends. This will produce a much greater increase in stiffness, which may be desirable. Another way to address this problem is to have the support wires fixed at the proximal end of the transition section rather than at the distal end. If we experience the same sliding phenomenon as described above, we will not see any large stiffness transition because the basic transition structure is the same as that of the proximal bendable section, so what we will see is a temporary change in the orientation of the transition point rather than adding a completely new stiffness transition point. However, because these sections have a skeletal structure, there is a risk that the free portion of the drive wire will slip off the guide wire and if the bendable medical device bends, it may not re-enter the guide hole and may inadvertently drill into other structures of the bendable medical device, potentially damaging it. This can be alleviated by having a low stiffness (or high stiffness, if desired) liner extending between all guide rings where this problem may occur.

[0086] Instead of moving the proximal ends of these support wires distally, they can also run all the way to the hub and be fixed in various ways. One way is to fix it to a spring or other type of surface that can be moved with a specific or varying amount of force. Alternatively, it can be fixed in a way that can be switched between 'free to slide' / 'slide under resistance' / 'completely fixed'. One way is to use a set screw that can be screwed in / out to change the resistance. Similarly, the end can be fixed to a motor that can be switched between fixed / free, and have a force feedback system for adjusting the resistance.

[0087] To further expand the liner concept, liners or hypotubes can also be placed along pilot holes currently occupied by other support lines or drive lines, eliminating the limitation of using only empty pilot holes.

[0088] In addition to placing material inside the guide holes of the flexible medical device, additional inner / outer coverings can be applied to this section to increase stiffness. The material and thickness of these coverings can be varied to achieve the desired stiffness. Alternatively, if the outer diameter / inner diameter change is not desired, the pre-existing inner / outer covering for the skeleton structure can be replaced with a different material or with a different thickness pair in this transition section (the guide ring can also be modified to a different inner / outer diameter to ensure that the final diameter does not change). This additional or supplemental material can also have a stiffness transition along its length, such as a variable pitch spring.

[0089] Another way to achieve a stiffness gradient is to adjust the spacing of the guide rings. This can be done gradually or discontinuously. Alternatively, additional material can be placed between the guide rings, and based on the material selection or thickness, the stiffness of this material can be varied gradually or discontinuously along the length of the segment.

[0090] Instead of using a skeleton structure, variations of the tubing segment can be used. A different material with lower stiffness can be used and welded to the 40D section of the tubing segment. Alternatively, instead of welding different materials together, additional inner / outer / intermediate materials can be added to form a composite material and increase stiffness in the proximal direction. Another way to adjust stiffness is to allow the diameter of the flexible medical device to increase gradually or discontinuously. One way to achieve this is through bump extrusion. Alternatively, additional support wires (with the various alternatives described above) can be placed at different points along the length of the tubing segment.

Claims

1. A medical device, comprising: A bendable body having a hollow chamber extending the length of the bendable body, wherein the bendable body comprises: a distal bendable section, the distal bendable section comprising: - at least two first guide rings, the at least two first guide rings being spaced apart from each other by a distance to form a cavity; - a plurality of first guide holes in each of the at least two first guide rings; - at least one first drive wire slidably disposed in at least one of the plurality of first guide holes and attached to a distal end of the distal bendable section; and at least one first support wire slidably disposed in at least one of the plurality of first guide holes and proximally unfixedly attached to the distal end of the distal bendable section, a proximal bendable section comprising a middle section comprising: at least two second guide rings, the at least two second guide rings being spaced apart from each other to form a cavity; - a plurality of second guide holes in each of the at least two second guide rings; - at least one intermediate drive wire slidably disposed in at least one of the plurality of second guide holes and attached to a distal end of the intermediate segment; and - wherein the at least one first drive wire is slidably disposed in the at least one of the plurality of second guide holes, and The proximal bendable section has a proximal segment comprising multi-lumen tubing, - wherein the at least one first drive wire and the at least one intermediate drive wire are slidably disposed within the multi-lumen tubing, and - wherein said at least one first support wire is slidably disposed in said multi-lumen tubing.

2. The medical device of claim 1, further comprising a flexible wall extending the length of the bendable body.

3. The medical device of claim 2, wherein inner diameters of the at least two first guide rings and the at least two second guide rings are attached to at least a portion of the flexible wall.

4. The medical device of claim 2, wherein the flexible wall further comprises an elastic outer lining for enclosing the at least two first guide rings and the at least two second guide rings. 5 . The medical device of claim 1 , further comprising an actuator attached to a proximal end of the at least one first drive wire, wherein the actuator is configured to actuate the at least one first drive wire. The medical device of claim 1 , wherein the proximal section is uniform.

7. The medical device of claim 6, wherein the intermediate segment and the proximal segment have different stiffnesses.

8. The medical device of claim 1, wherein attachment locations for the at least one first drive wire and the at least one intermediate drive wire are different along an axial direction of the flexible body. 9 . The medical device of claim 1 , wherein the plurality of first guide holes and the plurality of second guide holes are configured in each of the at least two first guide rings and in each of the at least two second guide rings, respectively.

10. The medical device of claim 1, wherein the at least one first drive wire and the first and second guide rings are constructed of a radiopaque material.

11. A medical device comprising a bendable body having a hollow chamber extending the length of the bendable body, the bendable body comprising: a distal bendable section, the distal bendable section comprising: - at least two first guide rings, the at least two first guide rings being spaced apart from each other by a distance to form a cavity; - a plurality of first guide holes in each of the at least two first guide rings; - at least one first drive wire slidably disposed in at least one of the plurality of first guide holes and attached to a distal end of the distal bendable section; and at least one first support wire slidably disposed in at least one of the plurality of first guide holes and proximally unfixedly attached to the distal end of the distal bendable section, a proximal bendable section comprising a middle section comprising: at least two second guide rings, the at least two second guide rings being spaced apart from each other to form a cavity; - a plurality of second guide holes in each of the at least two second guide rings; - at least one intermediate drive wire slidably disposed in at least one of the plurality of second guide holes and attached to a distal end of the intermediate segment; - wherein the at least one first drive wire is slidably disposed in the at least one of the plurality of second guide holes, and The proximal bendable section has a transitional backbone section comprising: - at least two third guide rings, said at least two third guide rings being spaced apart from each other by a distance to form a cavity; - a plurality of third guide holes in each of the at least two third guide rings; - at least one third support wire slidably disposed in at least one of the plurality of third guide holes and proximally unfixedly attached to the distal end of the transitional skeleton segment; - wherein the at least one first drive wire is slidably disposed in the at least one of the plurality of second guide holes, and The proximal bendable section has a proximal section comprising a multi-lumen tubing, - wherein the at least one first drive wire and the at least one intermediate drive wire are slidably disposed within the multi-lumen tubing, and - wherein said at least one first support wire and said at least one intermediate support wire are slidably disposed in said multi-lumen tubing.

12. The medical device of claim 11, further comprising a flexible wall extending the length of the bendable body.

13. The medical device of claim 12, wherein the at least two first guide rings and the at least two second guide rings are attached to the flexible wall.

14. The medical device of claim 11, further comprising an actuator attached to a proximal end of the at least one first drive wire, wherein the actuator is configured to actuate the at least one first drive wire.

15. The medical device of claim 11, further comprising an actuator attached to a proximal end of the at least one intermediate drive wire, wherein the actuator is configured to actuate the at least one intermediate drive wire.

16. The medical device of claim 11, wherein the at least one first drive wire and the guide ring are constructed of a radiopaque material.

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