Operable arm for use in endoscopic surgery

Abstract

A steerable arm (301) for use in endoscopic surgery. The steerable arm (301) is cut from a tube of Nitinol, with the structure into which the tube is cut providing flexibility and resilience. Typically, the cut tube has a helical coil (707) whose loops meet on one side of the tube, and the tube is bent to open the loops on the other side. The material of the tube is capable of retaining memory of the bend. This provides a bias to restore the tube to the bend whenever the force bending the tube is removed.

Description

Technical Field

[0001] The present invention relates to the field of endoscopic surgical instruments.

Background Art

[0002] Gastrointestinal (GI) cancer is the most common cancer worldwide. According to the cancer statistics of the World Health Organization (WHO), colorectal cancer and gastric cancer are the second and third most common causes of cancer-related deaths in the world, respectively, and the number of deaths in 2018 reached 862,000 and 783,000, respectively. The prognosis of GI cancer is significantly favorable. The 5-year survival rate of early-stage GI cancer is over 90% worldwide.

[0003] Conventional treatment of GI cancer is surgery involving resection and anastomosis, which is associated with significant morbidity and mortality.

[0004] Preferred surgical methods for the gastrointestinal (GI) tract include guiding surgical instruments through the instrument / biopsy channel of an endoscope. A flexible endoscope is inserted through the mouth into the stomach to reach the target position or through the anus into the large intestine to reach the target position. The distal end of the endoscope is operated by a surgeon using the control handle at the proximal end of the endoscope. The endoscope has at least one biopsy channel, into which a long and flexible instrument with a surgical tool at the distal tip is inserted from the proximal end of the endoscope. The most common flexible endoscope is made by Olympus, and the diameter of the biopsy channel is as large as 3.7 mm, but it can also be 2.8 mm or less.

[0005] Medrobotics has proposed a semi - automatic robotic endoscope with channels for manual surgical instruments (described in U.S. Patent No. 10016187 B1 (Patent Document 1)). The diameter of the surgical instrument is assembled from many separate joints to enable articulation when pulled by a pair of antagonistic wires (two wires on opposite sides pulling in opposite directions). To bend a joint in one direction, it is necessary to pull one wire and release or push the other wire. The individual joints are complex in design and assembly and require a wide diameter with a thickness of 4 mm. Therefore, the main drawback of this surgical instrument is that it does not fit into the biopsy channel of a typical flexible endoscope.

[0006] Endomaster has proposed a similar robotic surgical instrument, which is also assembled from a separate joint - based mechanism with similar drawbacks (described in US20210186309A1 (Patent Document 2)).

[0007] Lumendi has proposed an endoscopic surgical instrument with a flexible backbone made from a single body of a flexible material such as a nickel - titanium (nitinol) tube, with separate unconnected slots cut along the sides of the tube (described in US20200305906A1 (Patent Document 3)). The straight tube can be bent in either direction by pulling wires attached to both sides of the tube. Even with this design, a complex operation of pulling one wire while releasing the wire on the opposite side is required. Furthermore, this surgical instrument is too thick to be used in the biopsy channel of a typical endoscope and needs to be used in combination with its own accessory system.

[0008] Endotheia has proposed a surgical instrument that can be used with a general endoscope (described in US10441371B2 (Patent Document 4)). This design consists of nested concentric Nitinol tubes that are each pre-curved. These tubes have an overall diameter that can be extended through the biopsy channel of a general endoscope. To bend the surgical instrument towards the target location, each of the nested tubes is extended to an appropriate extent to create the necessary Bend bending. No wire is required to bend the tubes. However, complex calculations are needed to determine how much each curved tube should be expanded, and control by software and robots is rather necessary. Even when manual override is required in some situations, it seems unlikely. Furthermore, the lifting force of the thin tubes is too weak for some procedures. Also, the tubes cannot be bent at sharp angles, and to provide sufficient Bend bending and extend the tubes long enough, the endoscope needs to be placed relatively far from the target site. As a result, the camera at the tip of the endoscope may be too far from the distal end of the surgical instrument, making it impossible to properly visualize the surgery. If the target site is too close to the tip of the endoscope, the lateral and longitudinal reach of the instrument may be limited.

[0009] Therefore, it is desirable to propose a surgical instrument that is suitable for use with a general endoscope, provides dexterous tissue manipulation, and offers the possibility of better control by the surgeon.

Prior Art Documents

Patent Documents

[0010]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

[0011] In a first aspect, the present invention is a manipulable arm for use in endoscopic surgery, comprising: a tubular member having a proximal end and a distal end, the distal end being suitable for attaching a surgical end effector, the tubular member being made of an elastic material; and a wire extending from the proximal end into the interior of the tubular member, the wire being attached to the distal end and the side surface of the tubular member, and the tubular member being capable of having a Bend length in the longitudinal direction; and when the distal end of the tubular member is pulled by the wire, Bend changes, and the elasticity of the elastic material biases the tubular member such that the Bend change is reversed when the pulling of the distal end is released. A manipulable arm for use in endoscopic surgery is proposed, which is characterized in that.

[0012] Advantageously, the present invention provides the possibility of returning the manipulable arm to its rest shape by releasing the tensile force, thereby causing the biasing force to be exerted. This eliminates the need for a second wire in prior art manipulable techniques. This one-wire approach is easier than the prior art two-wire approach, which requires additional adjustment between pulling one wire and releasing the other, and saves space within the manipulable arm for other components or wires.

[0013] The tubular member need not be a tube with a filled wall and may be any elongated member, such as a coil of loops, that provides the necessary features and functions.

[0014] Preferably, the tubular member has a first side and a second side along the axis of the tubular member, the first side is relatively more compressible than the second side, and the second side is relatively less compressible than the first side. The side of the tubular member to which the wire is attached is the first side. When the wire is pulled, the first side is compressed and the curvature of the tubular member changes. Advantageously, the greater compressibility of the first side accommodates bending and buckling of the second side, enabling the entire manipulable arm to bend and flex. The greater compressibility of the first side and the lesser compressibility of the second side can be provided by making the first side and the second side of different materials, or by structural design.

[0015] Preferably, to further provide compressibility on the first side, the manipulable arm further comprises a gap on the first side. Due to the pulling of the wire, the gap closes, and the second side bends towards the first side, thereby changing the Bend of the tubular member. This feature relates to the structurally provided compressibility and improves the inherent compressibility provided by the material of the tubular member.

[0016] Preferably, the manipulable arm further comprises a wire guide inside the tubular member to guide the translation of the wire.

[0017] Preferably, the tubular member is curved in the stationary state, with a concave surface and a convex surface existing on the tubular member, and the convex surface of the tubular member is the first side. Advantageously, this allows the manipulable arm to be bent from bending in one direction to bending in the opposite direction, and potentially to swing across a plane, with a single wire, to the extent that the compressibility of the first side enables this.

[0018] In applications where a tubular member is used within the biopsy channel of an endoscope, the curvature of the tubular member provides the advantage that the camera at the tip of the endoscope can be positioned closer to the target tissue compared to a straight, non-curved, steerable arm of the same length. Also, due to the curvature, the body of the steerable arm is positioned away from the center of the endoscope's field of view, so the field of view of the camera is not blocked.

[0019] Preferably, the tubular member is a tubular coil of a helical loop, and the Bend ends of the loops on the first side are spaced apart to form a gap, and the ends of each loop on the second side abut against the ends of adjacent loops, where the first side and the second side are on opposite sides of the tubular member. The abutting ends prevent compression and provide the lever action for bending the steerable arm.

[0020] Due to the advantages of the helical loop structure, it is possible to cut a steerable arm from a single original tube, which is economical and provides a continuous structure. This also provides the possibility of bending the steerable arm by utilizing the flexibility of the loop structure while providing biasing depending on the rigidity of the material constituting the tubular member. In an embodiment, the loops on the first side are described as ribs that can open and close, and the second side is described as a backbone.

[0021] As an option, the loops have variations in different helical pitches and / or spacings along different portions to give different flexibilities to different portions of the steerable arm.

[0022] Preferably, the distal portion is more flexible than the proximal portion, and pulling a wire attached to a more distal portion of the steerable arm advantageously prevents the more proximal portion from being unintentionally deformed. This allows the bending of the more distal portion to be controlled without affecting the bending of other more proximal portions, improving the control of the steerable arm.

[0023] Preferably, the loops are created by making at least one helical cut in the tube.

[0024] Preferably, the manipulable arm further comprises at least one slit at the edge of at least one loop on the second side. Advantageously, the slit allows for a certain degree of expansion and contraction of the backbone, increasing flexibility.

[0025] Alternatively, the tubular member is a tubular coil of a helical loop, and the manipulable arm further has two rows of opposing connecting joints arranged along the opposite sides of the tubular member, each connecting joint in each row rotatably connecting two adjacent loops, the opposing rows of connecting joints providing the second side, the tubular member being located at the center of the cross-section of the tubular member and having an axis along its length, and the first side and the second side being arranged orthogonally to each other with respect to the axis of the tubular member.

[0026] Preferably, the tubular member is manufactured from a single material and the tubular member is a continuous structure (i.e., remains in a monolithic structure). For example, the single material is a single tube. Advantageously, the continuous structure offers the possibility of relying entirely on the inherent strength and rigidity of the material constituting the structure without the need for additional connections or couplings to join separate parts.

[0027] Alternatively, it further has an elongated spring piece attached to the length of the second side to provide additional structural robustness, and the elongated spring piece enhances the biasing force.

[0028] Preferably, the tubular member includes at least two sections, with a respective number of wires extending from the proximal end into the interior of the tubular member, each wire being attached to the distal end of each section, the distal end of the most distal section being the distal end of the tubular member, and each section can have a longitudinal direction in the tubular member. Bend When the distal ends of each section are pulled by their respective wires, the... of each section changes, where the elasticity of the elastic material is the... of each section when the pull on the distal end of each section is released. Bend ... changes, where the elasticity of the elastic material is the... of each section when the pull on the distal end of each section is released. Of the bendApply a bias to the tubular member such that the change is reversed.

[0029] Advantageously, each section can contribute to a different plane of motion, thereby increasing the degrees of freedom of movement of the distal end of the manipulable arm.

[0030] Preferably, for each of at least two sections The section of Bend the change is in different planes Exists .

[0031] Preferably, the stiffness of each section is different such that the section located closer to the proximal end of the manipulable arm is larger in order to reduce the mechanical coupling effect between sections when pulling the wires of different sections.

[0032] Generally, the manipulable arm is disposed at the distal end of a transmission tube, the transmission tube includes a channel through which a wire is passed, the proximal end of the wire is connected to a knob and / or lever for pulling the wire, and when the distal end of the tubular member is pulled by the wire at the proximal end of the transmission tube, the curvature changes.

[0033] In a second aspect, the present invention proposes a method of fabricating a manipulable arm for use in endoscopic surgery from a hollow tube, the method comprising the following steps: a) providing a hollow tube having a proximal end and a distal end, the distal end being suitable for attaching a surgical end effector, the hollow tube being made of an elastic material; b) cutting the hollow tube circumferentially and along the length of the tube to make a helical cut, the helical cut creating a gap along at least one side of the hollow tube; c) inserting a wire into the proximal end of the hollow tube; and d) attaching the wire to the hollow tube, the attachment being: i) on the side of the tube with the gap; and ii) very distally from the proximal end such that the wire extends across the gap.

[0034] Cutting the entire hollow tube to form a manipulable arm allows for the possibility that the manipulable arm has a continuous structure.

[0035] By this method, a single tube of material can be preselected according to the diameter of the tube, and the dimensions of the manipulable arm can be adjusted according to the channel dimensions of the endoscope. In contrast, in prior art methods that rely on assembling different parts together, it is more difficult to manufacture a small manipulable arm.

[0036] Preferably, the method further comprises the steps of holding the hollow tube in a bent position; and causing the hollow tube to remember the bend in a stationary state by plastic deformation or heat treatment.

[0037] Preferably, the method further comprises the step of cutting the hollow tube so as to leave a coupler on each loop for coupling to an adjacent loop.

Brief Description of the Drawings

[0038] It is convenient to further describe the present invention with reference to the accompanying drawings showing possible configurations of the present invention. In the drawings, like integers refer to like members. Other embodiments of the present invention are also possible, and thus the particularity of the accompanying drawings should not be understood as substituting for the generality of the foregoing description of the present invention.

Figure 1-2

Figure 3-4

Figure 5

Figure 5a

Figure 5b

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12-13

Figure 14

Figure 15

Figure 16

Figure 17

Figure 18

Figure 19

Figure 20

Figure 21

Figure 21a

Figure 22

Figure 23

Figure 24

Figure 25

Figure 26

Figure 27

Mode for Carrying Out the Invention

[0039] FIG. 1 shows the prior art for comparison. The prior art is a manipulable arm that can be used in endoscopic surgery. This manipulable arm is composed of nested curved segments and can be telescopically extended. The end of the thinnest part can extend to the farthest point and is fixed with an end effector such as a pair of forceps or a diathermy knife. Each segment can contribute to the overall bending of the manipulable arm by fully or partially expanding to reach the target area. The bending of the manipulable arm is not achieved by pulling a wire.

[0040] FIG. 2 shows another manipulable arm of the prior art. This manipulable arm is generally an elongated member 201 having a series of portions cut from the side of the elongated member. Two wires within the elongated member are fixed on both sides of the distal end of the elongated member. To bend the elongated member to one side, it is necessary to pull one wire and release the other wire as a pair of operating and antagonistic wires.

[0041] FIG. 3 shows an embodiment of the present invention, a flexible surgical instrument 300 for use with an endoscope 400.

[0042] The flexible surgical instrument 300 includes a transmission tube 307 that occupies most of the length of the flexible surgical instrument 300. A manipulable arm 301 is attached to the distal end 303 of the transmission tube 307. At the tip of the manipulable arm 301, a surgical end effector 403 (see the inset in FIG. 4) that determines the function of the flexible surgical instrument 300, such as forceps, a diathermy knife, an injection needle, or a suturing instrument, is attached.

[0043] Figure 4 shows an endoscope 400 with two flexible surgical instruments 300 inserted therein. The endoscope 400 is an optical instrument that can be extended into the gastrointestinal (GI) tract through the mouth or anus and can be manipulated to reach a target position within the tract to provide a view. The endoscope 400 may include a video display connected to its proximal end and a light source and camera having a wide field of view on the distal end 411. Image transmission from the camera to the video display can be provided by an optical fiber system or a sensor chip system.

[0044] Endoscopes 400 for gastrointestinal procedures are typically over 1 m in length. The outer diameter of an endoscope 400 having two biopsy channels is typically greater than 1.2 cm. One or two channels, typically called biopsy channels 405 or instrument channels, having a diameter of 2.8 mm to 3.7 mm, may be provided in the core of the most common GI endoscope 400. The biopsy channel 405 has a channel inlet 413 at the proximal end of the endoscope 400 and a channel outlet at the distal end 411 of the endoscope 400. The flexible surgical instrument 300 can be inserted into the biopsy channel 405 through the channel inlet. The endoscope 400 of FIG. 4 has two biopsy channels 405, one for each of the two flexible surgical instruments 300.

[0045] FIG. 5 is an enlarged view of the drawing insert of FIG. 4 and shows an exemplary arrangement of a camera 501 and a light source 503 on a cap 401 at the distal end 411 of the endoscope 400. The camera 501 provides a live view of the surgical site, the manipulable arm 301, and the end effector 403, guiding the surgeon in operating the manipulable arm 301.

[0046] FIG. 5a shows a manipulable arm 301 having forceps 505 as an end effector provided at its distal end. FIG. 5b shows a manipulable arm 301 having a diathermy knife 507 as an end effector provided at its distal end. Other end effectors, such as injection needles and suturing instruments, can be attached to the distal end of the manipulable arm 301 to determine the ultimate function of the arm.

[0047] FIG. 6 is a photograph that can be taken by the camera 501, showing two manipulable arms 301, each having an end effector 403 attached thereto and performing a treatment on the tissue. The two manipulable arms 301 in FIG. 6 are attached with an outer sheath that reduces friction when the flexible surgical instrument 300 is inserted into the biopsy channel 405 and provides electrical insulation.

[0048] In a preferred embodiment, the delivery tube 307 and the manipulable arm 301 have an outer diameter of 2.7 mm or less to fit into most biopsy channels 405 provided by a general GI endoscope 400. The length of the delivery tube 307 can be varied. This is determined by the design and depends on the length of the endoscope 400 in which the flexible surgical instrument 300 is used.

[0049] The manipulable arm 301 can be moved or bent by pulling a wire passed through at least one channel in the delivery tube 307. The distal ends of some of the wires are attached to different parts within the manipulable arm 301. One of the remaining wires is connected to the end effector 403.

[0050] The end of the wire 309 protruding from the proximal end 305 of the flexible surgical instrument 300 is coupled to an adapter (not shown) located outside the endoscope 400. The adapter includes a knob, pulley, or lever (not shown), and the ends of the wires are connected separately. By rotating or moving each knob, pulley, or lever, the respective wire is pulled. Pulling the proximal end of the wire causes the manipulable arm 301 to move or bend, or the end effector 403 to operate. The adapter can be robotically operated via electronics and software to control the movement of the manipulable arm 301 and the end effector 403.

[0051] In surgery, the surgeon inserts the endoscope 400 into the patient's body and guides the endoscope 400 to a desired position within the digestive tract. The wire 309 extending from the proximal end of the endoscope 400 can be pulled or released by an adapter.

[0052] FIG. 7 shows the main part of the steerable arm 301, which is a metal tube formed into a tubular coil 707 of a loop or helical metal ribbon. The steerable arm 301 has a convex surface 703 and a concave surface 701 because it bends when at rest. On the concave surface 701, the ends of the loops are closed and each end abuts against the corresponding end of each adjacent loop. This prevents compression of the loops on the concave side 701. Thereby, a backbone is formed on the concave side 701 of the tubular coil 707. On the convex side 703, the ends of the loops are spaced apart, thereby forming ribs extending from the backbone. The ends of the ribs on the concave side 701 can be brought closer to or farther away from each other to expand and contract the backbone. The steerable arm 301 is flexible and can be straightened or bent to the opposite side. However, the metal is an elastic material and the steerable arm 301 is biased to return to its original shape when the bending force is removed.

[0053] FIG. 8 is a series of schematic views of the articulation of the steerable arm 301. The drawing shows the end of the wire 309 that extends through the core of the steerable arm 301 and is connected to a rib at or near the center of the steerable arm 301 for controlling the steerable arm 301. The wire 309 is shown as a solid line for clarity, but a skilled reader will understand that most of the wire 309 is not visible because it is inside the steerable arm 301. The wire 309 can be fixed to the rib at or near its distal end via a knot, crimping, or other means that ensures the wire 309 remains fixed to the rib. The steerable arm can also be made of a loop helix or a tube having sections cut along the side of the tube.

[0054] The leftmost figure shows the manipulable arm 301 in a stationary state, bent so that the backbone is concave (Figure 8a). The ribs are on the convex side and spread out to fit the bend. When the wire 309 is pulled, a part of the ribs approach each other, and the backbone bends or straightens (Figure 8b). When the wire 309 is pulled further, the ribs are pulled closer to each other, and the Bend manipulable arm 301 is reversed and bends away from the original bending direction (Figure 8c). When the pull is released, the biasing force is exerted, and the manipulable arm 301 can be returned to the shape of the stationary state. Due to this biasing force, the second wire for returning the manipulable arm to the original stationary state becomes redundant.

[0055] Therefore, the manipulable arm 301 One can move from bending in one direction to bending in another direction within a plane. This enables the end effector 403 on the manipulable arm 301 to manipulate tissue. This one-wire approach is easier than the prior art two-wire approach that requires additional adjustment between pulling one wire and releasing the other wire. Also, the presence of the second wire would occupy space within the manipulable arm 301.

[0056] Figure 9 schematically shows a preferred method of manufacturing the manipulable arm 301. First, a tube 901 made of a superelastic material is prepared, and this tube 901 has a diameter small enough to be sent through the biopsy channel 405 of the endoscope 400 where the manipulable arm 301 is expected to be used. Generally, a diameter of 2.7 mm or less is preferred for general use. The subsequent transfer tube 307 also has a similarly small diameter and has no problem passing through the biopsy channel. A superelastic material is a material that can undergo large deformations and can immediately return to its original undeformed shape when the external stress is removed, and includes, for example, nitinol (nickel titanium) and the following alloys: Cu-Zn, Cu-Al-Ni, Au-Cd, Au-Cu-Zn, In-Tl.

[0057] As shown in FIG. 9a, the tube 901 is cut spirally along the length of the tube 901 to produce the tube 901 into a tubular coil 707. This cutting can be performed by, for example, laser cutting, precision machining such as computer numerical control (CNC) milling, or other means. FIG. 9 shows a laser source 903 used to cut the tube 901.

[0058] Other cuts are made on the side surface of the tube 901 to slice and remove a part 907 of each loop. As a result, a gap 905 is formed for every two adjacent loops on that side of the tube 901, and ribs 909 are formed (FIG. 9b). The gap 905 allows the ribs 909 to approach each other and adapt to the bending of the backbone 911 towards the rib side. Also, the ribs 909 can move further apart to adapt to the bending of the backbone 911 towards the backbone side (FIG. 9c). The other side of the tube 901 forming the backbone 911 is cut with the gap 905 between the loops minimized.

[0059] Note that the spiral cutting is performed over the entire circumference of the tube 901, including the side surface of the tube 901 that becomes the backbone 911. Thus, the ends of the loops on the backbone 911 are also cut and separated. However, the back ends of each loop are adjacent to the ends of each adjacent loop. The abutting portion prevents compression of the backbone 911 when the steerable arm 301 bends by pulling the wire 309.

[0060] As an option, in other embodiments, only one side of the tube 901 can be cut to provide the gap 905 that forms the ribs 909 without performing a spiral cut over the entire circumference. As a result, the side of the tube 901 that forms the backbone 911 remains integral and no cutting is done.

[0061] As an option, thereafter, the steerable arm 301 is held in the desired shape and heat-treated or plastically deformed to cause the material to remember that shape.

[0062] Figures 10 and 11 are technical diagrams of rib 909 and backbone 911, and the backbone 911 is shown in a non-bent state. The left diagram in Figure 10 shows the external image of the manipulable arm 301, and the right diagram in Figure 10 is the corresponding cross-sectional view from the direction marked h-h. The left side of Figure 11 is the cross-sectional image in the j-j direction, and the right side of Figure 11 shows the external appearance of the corresponding manipulable arm 301.

[0063] The helical pattern can be changed to vary the helical pitch (L), change in spacing (M), number of turns, cut thickness, cut shape, and slot position and size. These parameters can be adjusted to change the bending profile, range of motion, and stiffness of the backbone 911 and can be selected according to the requirements of surgical applications. Thus, the range and shape of the pre-curvature can be changed to meet different surgical requirements such as a specific approach angle of the end effector 403 of the instrument.

[0064] The stiffness, flexibility, and elasticity of the manipulable arm can be adjusted by changing the structure of the gaps and loops. For example, when the loop is thick, the flexibility of the manipulable arm decreases and it becomes stiffer. Alternatively, when the loop is narrow, the flexibility of the manipulable arm increases. The size of the gaps between the loops, the width of each gap, the inclination of the gaps (helical pitch), and the proximity of the gaps can all potentially affect the flexibility and restoring force. Generally, the larger the gap and the higher the loop density, the higher the deformability and flexibility of the tube. In an embodiment where the manipulable arm is not a loop of coils but simply a tube with gaps sliced into the tube along the side of the tube, the same changes in the gaps can result in similar changes in the flexibility of the tube. Therefore, it is possible to manufacture a manipulable arm that is more flexible at the distal end and less flexible at the proximal end by simply cutting the distal end more finely to provide finer loops or more cutout portions. At the end, the finely cut loops and cutout portions are reduced. Advantageously, this prevents the wire attached to the more distal portion of the manipulable arm from being pulled and the more proximal portion from being inadvertently deformed. This prevents the distal end from losing control sensitivity more than the proximal end and makes the manipulable arm more dexterous.

[0065] The manipulable arm 301 is manufactured from a single metal body that provides a continuous structure. By a continuous structure, it is meant not the movement between separate but connected joints, but rather something that is integrated by actually deforming the material and bends continuously. In other words, a continuous structure is typically made of a single material. Further, the continuous structure has no sharp folds or bends that can cause high stress concentrations, and the sides of the continuous structure only gradually curve or become straight. In this way, the molecular or elemental structure of the material can give the continuous structure strength, stiffness, elasticity, and flexibility.

[0066] The continuous structure avoids the need to assemble separate parts onto the manipulable arm 301, overcoming the problems seen in prior art where the manipulable instrument requires labor-intensive assembly of complex individual parts or interconnecting joints, and where the complexity of the parts can have a resultant impact. Further, this reduces manufacturing time, complexity, and cost. In contrast to this embodiment, prior art manipulable arms composed of individual parts cannot be bent in a stationary state because the individual parts cannot be heated to retain a memory of their position. Further, the materials used in the continuous structure can provide the manipulable arm 301 with sufficient strength and rigidity to retract / lift tissue in a surgical environment, whereas in an assembled structure composed of separate parts, the strength of the materials cannot be utilized for this purpose.

[0067] Preferably, an eyelet 2201 (see FIG. 22) for guiding the wire 309 is provided on the inner surface of the rib. The eyelet enables axial translation of the wire 309 to facilitate actuation of the backbone 911 and also constrains the wire 309 relative to the inside of the manipulable arm 301. The eyelet may be provided as an additional part that is manufactured separately and assembled with the manipulable arm.

[0068] FIG. 12 shows a second embodiment where a connection joint 1201 is provided for each adjacent rib 909 to prevent the rib 909 from spreading or sliding radially, or from twisting about the long axis of the manipulable arm. FIGS. 13 and 14 correspond to FIG. 12, except that the version of FIG. 12 is shown biased to bend in a stationary state.

[0069] The connecting joint 1201 is shown in Fig. 13a as being provided on both sides of the manipulable arm 301. The edges of the rib 909 are spaced apart on either the convex or concave side of the curved portion. Thus, unlike the previous embodiment, the backbone is not defined by adjacent ribs on the concave side. Instead, the backbone is defined by the connecting joint 1201 that prevents the rib 909 from being compressed, the connecting joint 1201 is arranged in a row along the length of the manipulable arm 301, and the connecting joint 1201 provides a pivot about its periphery. The rib 909 may rotate and the backbone may bend to either side. In other words, the rib 909 and the backbone are arranged perpendicular to the axis of the tube 901.

[0070] The connecting joint 1201 minimizes bending or twisting outside the rotational plane of the joint and prevents the loop forming the rib 909 from loosening or expanding radially. Generally, the connecting joint 1201 does not provide additional rigidity to the manipulable arm 301 for it to return to its original shape when the manipulable arm 301 is bent. Elasticity and biasing are still provided by the choice of material forming the manipulable arm 301 and by the manipulable arm 301 being a continuous structure.

[0071] A wire 309 (not shown in this figure) extends within the manipulable arm 301 and is fixed to one edge of the most distal rib 909, which edge is on the convex side portion of the rib 909. Pulling on the wire 309 rotates each rib 909 about each connecting joint 1201 and, by bending the manipulable arm 301, the rib 909 can be made to articulate. Bending simply means Bend changing the shape of the arm. Bending may mean bending the arm from a straight configuration or straightening the arm from a bent configuration. The ends of the rib 909 on the convex side of the backbone close and the ends of the rib 909 on the concave side open. Further pulling on the wire 309 reverses the bend and the manipulable arm 301 bends in the opposite direction (not shown). The manipulable arm 301 naturally returns to its memorized shape when the pulling on the wire 309 is released.

[0072] This embodiment is also made by cutting a single tube of nitinol. A portion of the tube is cut away to create spaced-apart helical loop coils, and these loops form the ribs 909 of the steerable arm 301. However, the notch leaves the shape of the male coupling joint on one side of each rib. In this case, "side" refers not to the side of the entire tube, but to the side of each rib 909 of the coil. The male coupling joint on the lower side of each rib 909 shown in the figure mates with the female coupling joint on the upper side of the adjacent rib. After being cut from the tube, the steerable arm 301 is held in the desired bend with all the coupling joints 1201 mated and heat-treated to memorize the bend.

[0073] In some variations of this embodiment, both sides of the tube around the backbone of the coupling joint can be fixed with wires respectively, and the tube can be bent to either side with a single wire. In these variations, the tube may or may not be pre-curved. Of course, using a pre-curved elastic tube, the tube can be bent to the opposite side with only one wire and return to its original shape by the elastic biasing.

[0074] Figure 14 shows the male coupling joint 1401 and the female coupling joint 1403 separately, not mated, and each is provided on the opposite side of the adjacent rib 909. The male coupling joint 1401 has a neck with a round head and can be mated. The female coupling joint 1403 has a jaw that defines a round gap. The round jaw can rotate around the round head to enable the rib 909 to perform an articulating movement. Note that during the manufacture of the continuous structure, the male coupling joint and the female coupling joint are already joined, and Figure 14 is for illustrative purposes only.

[0075] Advantageously, the embodiment of FIG. 12 combines the advantages of a continuous device (an integrated device that does not require assembling different parts offers simplicity in manufacturing, ease of miniaturization, rigidity selectable based on the tube material and / or structure, and inherent resistance to buckling due to compliance) with the advantages of a joint-based bending segment (such as mechanical restraint to minimize axial compression and out-of-plane bending).

[0076] FIG. 15 shows a variation of a connection joint with a more simplified design. In this case, the male connection joint 1401 has simply a small round head without a neck, and the female connection joint 1403 is a shallow receptacle. Since the male connection joint has no neck, the female connection joint does not need to hook the head of the male connection joint.

[0077] The embodiments described so far can bend or stretch only within one moving plane. To provide multiple moving planes, the embodiments can be considered modular and different parts can be cut from the same Nitinol tube as different parts of a larger manipulable arm 301. Thus, FIG. 16 shows a manipulable arm 301 made of a single tube. Similar to that of FIG. 7, this is cut such that two tubular coils 707 are connected in series. The two tubular coils 707 share the same axis but are angled so that each part can be bent in a different plane.

[0078] Thus, the backbone 911 of the upper part 1601 of the tube (the upper part shown in the figure) faces one direction, while the backbone 911 of the bottom part 1603 faces a different direction. The upper part 1601 can be actuated by one wire 309 to bend and move within a first plane, while the bottom part 1603 can be actuated by another wire 309 to bend and move within a second plane. Since the upper part 1601 extends from the lower part 1603, moving the lower part 1603 also moves the upper part 1601. This gives the surgeon greater freedom when orienting the end effector 403 on the manipulable arm 301.

[0079] Note that the meaning of "coaxial" in the embodiments does not require the axis to be straight. The axis is curved along the bending shape of the steering arm 301 and is continuous.

[0080] FIG. 17 shows a method of manufacturing a steerable arm 301 having a plurality of sections. FIG. 17a shows how a helical cut is made along and around the entire tube 901 to produce a looped tubular coil 707. Subsequently, as shown in FIG. 17b, further cuts are made in the side of the tubular coil 707 to remove a portion of each upper loop. This forms a gap 905 between the loops and forms ribs 909. Such further cuts are also made at the bottom of the tube, but also on different sides of the tubular coil 707. As a result, a backbone 911 at the bottom is formed. Thus, the upper part can be bent in one direction as shown in FIG. 17c, while the lower part can be bent in another direction as shown in FIG. 17d. FIG. 18 is a technical drawing of a tube cut to provide a backbone 911 in the upper part 1601 on a side different from the backbone 911 of the bottom 1603. Finally, the upper part 1601 is held in a bent state in a desired shape, the bottom 1603 is held in a bent state in another desired shape, and a heat treatment (not shown) is performed to memorize the overall shape.

[0081] It is optional to cut the tube so that the upper backbone and the lower backbone bend in exactly opposite directions, which means that both the upper and lower parts can bend even if they are in the same plane and in opposite directions. Alternatively, instead, the upper backbone and the lower backbone are angularly offset along the axis.

[0082] FIG. 19 schematically shows how the embodiment of FIG. 16 operates. In the figure, the upper part 1601 of the steerable arm 301 is made to bend in the left direction of the figure when stopped. The lower part 1603 is made to bend to the right when at rest. As a result, the steerable arm 301 has a shape like an inverted S. The upper part 1601 of the steerable arm 301 BendIt can be reduced by pulling a single wire 309 that extends inside and is fixed to the manipulable arm 301. Further pulling can cause the curvature to reverse towards the rib side.

[0083] Similarly, pulling the wire 309 can straighten the lower part 1603. Further pulling the wire 309 can even cause the curvature to reverse towards the rib side. In this case, the wire 309 extends inside the manipulable arm 301 and is fixed to one of the ribs near the distal part of the lower part or, as an option, to the uppermost proximal part. This is because the distal part of the lower part 1603 ends where the proximal part of the upper part 1601 begins. Thus, the most distal rib of the lower part 1603 is the rib just below the backbone 911 of the upper part 1601.

[0084] When both wires 309 are pulled completely, the reverse S - shape of the manipulable arm 301 is reversed, and all the ribs of both the upper part 1601 and the lower part 1603 of the manipulable arm 301 are closed.

[0085] Figure 20 shows another embodiment including different parts composed from the previous embodiments. To manufacture the embodiment of Figure 20, different parts of the same metal tube are cut in different ways and each part can be bent in a different plane. A corresponding number of wires are provided within the channels of the manipulable arm 301, and each wire 309 is attached to the distal end of its respective section to control the bending of that section.

[0086] Figure 20a on the left side of the drawing shows the manipulable arm 301 in a stationary state. Figure 20b on the right side shows the various directions in which the components are moved or bent by the action of the respective wires 309.

[0087] The manipulable arm 301 of FIG. 20 has four parts 2001, 2003, 2005, 2007. The first distal part 2001 of the manipulable arm 301 is made in the same way as in the embodiment of FIG. 12. Below this first part are a second part 2003 and a third part 2005, which together correspond to the embodiment of FIG. 16.

[0088] The first part 2001 and the second part 2003 are axially offset such that the first part 2001 can bend in a first plane 2009 while the second part 2003 can bend in a second plane 2011 that is at an angle to the first plane. The second part 2003 and the third part 2005 are also axially offset such that the third part 2005 can bend in a third plane 2013 that is at an angle to the second plane 2011. Thus, the three parts 2001, 2003, 2005 can move in different planes 2009, 2011, 2013, providing three degrees of freedom of movement.

[0089] The fourth part 2007, which is below the third part 2005 as shown, is a coupler that attaches to a corresponding coupler on the transmission tube 307 and can be attached by various methods including welding, adhesion, or mechanical means. When the transmission tube is twisted at the proximal end of the endoscope, the manipulable arm 301 can be rotated by the coupling, and some additional movement is added.

[0090] FIG. 21 shows a variant of the embodiment of FIG. 20. The main section of the manipulable arm comprises the embodiment shown in FIG. 16, and at both ends thereof are provided the embodiments of FIG. 12. At the proximal end is provided a coupler that connects the embodiment to the transmission tube. Thus, this manipulable arm 301 has four different sections extending from the coupler, each of which can bend in a different plane.

[0091] In yet another embodiment shown in FIG. 21a, this embodiment comprises a coupler at the bottom, followed by a second section fabricated according to the embodiment of FIG. 12 thereon, and followed by the next two sections of the embodiment of FIG. 16 thereon. The end effector is used by the distal end of the embodiment of FIG. 16. In this embodiment, since the gap between the two parts is larger, the two-section part is more flexible than the second section. Similarly, the embodiment of FIG. 15 has a more flexible distal section connected to a less flexible proximal section.

[0092] FIG. 22 shows a further embodiment in which a slit 2203 is provided in the backbone 911 in the embodiment of FIG. 7. The slit 2203 is not made all around the manipulable arm 301, but is cut into the backbone 911 only from the side of the manipulable arm. Preferably, the slit 2203 is provided by removing a thin portion from the backbone 911. The slit 2203 structurally reduces the resistance of nitinol and allows the backbone 911 to straighten more easily when the wire 309 pulls on the rib side, resulting in improved dynamic performance. Note that in this case as well, the backbone 911 is quite resistant to compression despite the slit 2203. As an option, more cuts can be made in the distal portion of the embodiment to make the distal portion more flexible than the proximal portion.

[0093] Figure 23 shows the process of using the laser 903 to cut the tube 901 in a spiral to provide ribs. The spiral cut shown in Figure 23a is not performed all at once along the entire length of the tube 901. If the spiral were cut along the entire length of the tube 901 all at once, the resulting looped tubular coil would be too thin and would not be able to have a slit put in its backbone. Instead, only a short section of the tube is cut in a spiral each time, and immediately afterwards, the side of the tube that will become the backbone is sliced shallowly. Then, the next spiral cut is made continuously starting from where the first spiral cut ended. Figure 23c shows the state where after the tube is cut satisfactorily, the resulting manipulable arm 301 is bent into the desired shape and heat-treated to memorize that shape, with the backbone on the concave side and the ribs on the convex side.

[0094] Figure 24 shows how the embodiment of Figure 22 operates. Figure 24(a) shows the rest state of the manipulable arm 301 of Figure 22. Figure 24(b) shows the manipulable arm 301 extended straight with the slit open. Figure 24(c) shows the state where the slit in the backbone is further open and the bending is reversed and bent to the opposite side.

[0095] Figure 25 shows a modification of the embodiment of Figure 7, where the rigidity of the backbone 911 is enhanced by attaching a reinforcing element 2501, such as a hard but curved metal piece, to the inner surface of the backbone. The reinforcing element helps the shape of the backbone 911 to quickly recover when the tension of the most distal rib 909 is released, thereby improving the transmission response time and reducing mechanical hysteresis. The reinforcing element 2501 can be considered as a spring. The reinforcing element has sufficient flexibility so that it can straighten the backbone 911 when the wire 309 is actuated. In this embodiment, the wire is not drawn to follow the curve of the manipulable arm to show that in all cases, it is not necessary to provide a wire guide to guide the movement of the wire.

[0096] Such reinforcing elements can be provided in different sections of the backbone 911 in the embodiment of Figure 20 respectively.

[0097] Figure 26 shows yet another embodiment, where the strip 2501 of the reinforcement element is not made of a very flexible material, but springs 2601 are provided at both ends of the reinforcement element. The springs 2601 are fixed at appropriate positions inside the reinforcement element. The springs 2601 can extend when the operable arm 301 bends. However, the springs 2601 enhance the biasing of the operable arm 301 and quickly restore the memorized shape when the tension on the most distal rib 909 is released. This improves the transmission response time and reduces mechanical hysteresis. That is, the effect of the tension of the wire 309 can be more easily seen in the operable arm 301.

[0098] To further improve the responsiveness of the operable arm 301, it is preferable to pre-tension all the wires 309 connected to the operable arm 301. That is, all the wires 309 are tautly pulled in preparation for use, so that as a result, the section of the operable arm 301 can move immediately when the wire 309 is further pulled. If the wires 309 are not pre-tensioned and are slack, backlash may occur, and as a result, a delay will occur before the operable arm 301 responds to the tension of the wire.

[0099] Figure 27 shows a more general embodiment, where the operable arm 301 comprises a hollow elongated member 2701 that is more elastic on one side of the axis marked x and more rigid on the other side of the axis marked y. The elongated member is shaped, molded, or heat-treated to permanently bend towards the more rigid side at rest. The material of the hollow elongated member can remain bent when at rest, but has sufficient elasticity to be straightened or bent back by applying an appropriate force. Similar to the previous embodiment, the bending part Bend and BiasingThis allows the steerable arm 301 to be swung on a plane using a single wire 309. The hollow elongated member can be made from two different polymers co-extruded such that each polymer forms the side surface of the hollow elongated member. In this case, on the convex side, a more rigid material can be provided so that the steerable arm 301 does not shorten when the distal end of the steerable arm 301 is pulled by the wire 309. On the concave side, a more extensible material can be provided to accommodate the bending of the steerable arm 301.

[0100] So far, the foregoing embodiments have been described and illustrated as having a wire 309 fixed to the side surface of the curved tube, i.e., the side surface farthest from the backbone. This provides a more effective lever action when pulling the rib to bend the backbone. However, fixing the wire to the backbone side of the curved tube is within the scope of the intent of this description.

[0101] Accordingly, an embodiment includes a steerable arm 301 for use with an endoscope 400 to operate a surgical tool. The distal end is suitable for attaching a surgical end effector. The tubular member is made of an elastic material, and the wire 309 extends from the proximal end into the interior of the tubular member. The wire is attached to the distal end and the side surface of the tubular member. The tubular member can have a Bend in the longitudinal direction. When the distal end of the tubular member is pulled by the wire, Bend changes. The elasticity of the material biases the tubular member so that the Bend change is reversed when the pull on the distal end is released.

[0102] In the above description, the preferred embodiments of the present invention have been described. However, it will be understood by those skilled in the art that many changes or modifications can be made in the details of the design, structure, or operation without departing from the scope of the present invention as recited in the claims.

[0103] For example, the loop is described as being cut out of a tube, but in some embodiments, the rib could be a simple extension of the curved backbone, a cantilever beam with one end attached to the backbone and the other end free.

[0104] For example, the flexible surgical instrument 300 can be adapted to be used with other types of devices similar to the endoscope 400, such as a transnasal endoscope 400 or a transurethral resectoscope. If these devices do not have an internal channel for inserting the flexible surgical instrument 300, an additional sheath can be created that can be slid over the device to form a channel for the flexible surgical instrument 300.

Claims

1. A steerable arm for attachment to an instrument channel of an endoscope for endoscopic surgery, comprising: a continuous structure in the shape of a hollow tubular member, said tubular member having a proximal end, a distal end and at least two sections, said distal end of said tubular member being suitable for attaching a surgical end effector, and said tubular member being made of an elastic material; each of said sections having one wire extending inside said tubular member from said proximal end of said tubular member; said wire being attached to the distal end of the respective section, the distal end of the most distal said section being the distal end of said tubular member, each of said sections having a bend, the bend of each of said sections changing when the distal end of the respective section is pulled by the wire of the respective section, the elasticity of said elastic material biasing said tubular member such that when the pull on the distal end of each of said sections is released, the change in the bend of the respective section is reversed, and the change in the bend of each of said sections lies in a different one of respective planes, A steerable arm for attachment to an instrument channel of an endoscope for endoscopic surgery, characterized in that.

2. said tubular member being curved in a stationary state, said tubular member having a concave side and a convex side, A steerable arm for attachment to an instrument channel of an endoscope for endoscopic surgery according to claim 1, characterized in that.

3. said tubular member is a metal tube formed by shaping a helical metal ribbon into the shape of a tubular coil, providing two sections, the bend of said tubular member being such that the opposing edges of the adjacent metal ribbons on the convex side are spaced apart from each other to provide a gap, and the opposing edges of the adjacent metal ribbons on the concave side are brought into contact with each other, where the convex side and the concave side are on opposite sides of said tubular member, A steerable arm for attachment to an instrument channel of an endoscope for endoscopic surgery according to claim 2, characterized in that.

4. said steerable arm is disposed at the distal end of a delivery tube, said delivery tube including a channel through which said wire passes, the proximal end of said wire being connected to a knob and / or lever for pulling said wire, when the distal end of said tubular member is pulled by the wire at the proximal end of said delivery tube, the bend changes. A manipulable arm for attachment to an instrument channel of an endoscope for endoscopic surgery, characterized by the above.

5. The manipulable arm for attachment to an instrument channel of an endoscope for endoscopic surgery according to claim 1, wherein the surgical end effector is a forceps, a diathermy knife, an injection needle, or a suture tool.

Images