Coupling joint of tubular helical annulus for steerable arm of endoscopic instrument channel

Abstract

A coil forming a helical loop of a steerable arm (301) has a male coupling joint on one side of each loop or rib (909) and a female coupling joint on the other side of the rib (909). The male coupling joint (1401) is a neck-free small round head, and the female coupling joint (1403) is a shallow frame. As the male coupling joint has no neck, the female coupling joint does not need to buckle the head of the male coupling joint.

Description

Technical Field

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

[0002] Gastrointestinal (GI) cancers are the most common cancers 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 globally, reaching 862,000 cases and 783,000 cases respectively in 2018. Although advanced GI cancers are difficult to cure, early-stage GI cancers have significantly better prognoses. The 5-year survival rate of GI cancers at the early stage exceeds 90% worldwide.

[0003] The conventional treatment method for GI cancers is surgical operation, including resection and anastomosis, and is associated with significant morbidity and mortality.

[0004] The preferred method for gastrointestinal (GI) surgery involves guiding surgical instruments through the instrument / biopsy channel of an endoscope. The surgeon manipulates the distal end of the endoscope using a control handle on the proximal end of the endoscope, inserts the flexible endoscope through the mouth into the stomach to reach the target position, or inserts it upward from the anus into the large intestine to reach the target position. The endoscope has at least one biopsy channel, and a long and flexible instrument with a surgical appliance at the distal tip is inserted into this biopsy channel from the proximal end of the endoscope. The most common flexible endoscope is manufactured by Olympus and has a biopsy channel with a diameter as large as 3.7 mm, but it can also be as small as 2.8 mm or smaller.

[0005] Medrobotics proposed a semi-robotic endoscope with a channel for manual surgical instruments (as described in US10016187B2). The diameter of the surgical instrument is assembled from multiple discrete joints so as to allow joint connection when pulled by a pair of opposing wires (two wires on opposite sides are pulled in opposite directions). To bend the joint in one direction, one wire rope must be pulled, while the other wire rope must be released or pushed. The design and assembly of the discrete joints are complex and require a wide diameter of 4 mm thick. Therefore, a major drawback of this surgical instrument is that it cannot fit into the biopsy channel of a common flexible endoscope.

[0006] Endomaster proposed a similar robotic surgical instrument, which is also assembled from a discrete joint-based mechanism (as described in US20210186309A1), and it has the same drawback.

[0007] Lumendi proposes an endoscopic surgical instrument that includes a flexible backbone made of a single-piece flexible material such as a nitinol (nitinol) tube, with unconnected, discrete slots cut along the sides of the tube (described in US20200305906A1). By pulling on cords fixed to each side of the tube, the straight tube can be bent in any direction. Also, this design requires complex manipulation of releasing the opposite cord while pulling on one cord. Additionally, this surgical instrument is too thick to be used with the biopsy channel in a regular endoscope and must be used with its proprietary accessory system.

[0008] Endotheia proposes a surgical instrument that can be used with a regular endoscope, as described in US10441371B2. This design includes nested concentric nitinol tubes, each of which is pre-bent. These tubes have a total diameter that allows them to extend through the biopsy channel of a regular endoscope. To bend the surgical instrument towards the target location, each nested tube is extended to an appropriate extent to form the desired curvature. There is no need to use cords to bend the tubes. However, determining how far each bent tube should be extended requires complex calculations, making software and robotic control quite necessary and unreliable even when manual override is required. Additionally, the lifting force on the thin tubes is too weak for some surgical procedures. Also, the tubes cannot provide sharp bends, and the endoscope must be placed relatively far from the target site so that the tubes can extend far enough to provide sufficient curvature. As a result, the camera at the tip of the endoscope may be too far from the distal end of the surgical instrument to provide good visualization for the operation; if the target site is too close to the tip of the endoscope, the lateral and vertical accessibility of the instrument may be limited.

[0009] Accordingly, there is a desire to propose a surgical instrument that both provides dexterous tissue manipulation and is suitable for use with a regular endoscope, and offers the possibility of better control for the surgeon. Summary of the Invention

[0010] In a first aspect, the present invention proposes a manipulable arm for an endoscopic surgical procedure, comprising: a tubular member having a proximal end and a distal end; the distal end being adapted to be fitted with a surgical end effector; the tubular member being made of an elastic material; a cord extending from the proximal end inside the tubular member; the cord being attached to the distal end of the tubular member and to the side of the tubular member; the tubular member being capable of having a curvature in the longitudinal direction; wherein when the distal end of the tubular member is pulled by the cord, the curvature changes; and the elasticity of the material provides a bias for the tubular member such that when the pull on the distal end is released, the change in curvature is reversed.

[0011] Advantageously, the present invention provides the possibility that releasing the traction can make the bias manifest and restore the manipulable arm to the shape in the natural state. This makes the second wire rope in the prior art manipulable techniques redundant. This single wire rope solution is easier than the double wire rope solution in the prior art, which requires additional coordination between pulling one wire rope and releasing the other wire rope, and the single wire rope solution saves space for other components or wire ropes inside the manipulable arm.

[0012] The tubular member does not necessarily have to be a tube with a solid wall, but can be any elongate member that provides the required characteristics and functions, such as a coil of a ring.

[0013] 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; the second side is relatively less compressible than the first side; wherein the side to which the wire rope is attached of the tubular member is the first side; and pulling the wire rope compresses the first side to change the curvature of the tubular member. Advantageously, the greater compressibility of the first side will accommodate the bending and kinking of the second side, allowing the entire manipulable arm to bend and kink. The greater compressibility of the first side and the lesser compressibility of the second side can be provided by using different materials for the first side and the second side, or by structural design.

[0014] Preferably, the manipulable arm further includes a gap within the first side to provide compressibility of the first side; wherein pulling the wire rope changes the curvature of the tubular member by making the gap closer together and causing the second side to bend towards the first side. This feature relates to structurally provided compressibility, which improves the inherent compressibility provided by the material of the tubular member.

[0015] Preferably, the manipulable arm further includes a wire rope guide or eyelet within the tubular member for guiding the translation of the wire rope.

[0016] Preferably, the tubular member is bent in the natural state such that the tubular member has a concave side and a convex side; and the convex side of the tubular member is the first side. Advantageously, this allows a single wire rope to bend the manipulable arm to change its bending direction from one direction to the opposite direction up to the extent allowed by the compressibility of the first side, and it is possible to swing the manipulable arm on a plane.

[0017] In the application where the tubular member is used in the biopsy channel of an endoscope, compared with a straight manipulable arm of the same length without curvature, the curvature of the tubular member advantageously allows the camera on the tip of the endoscope to be closer to the target tissue. In addition, the field of view of the camera will not be blocked because the curvature moves the body of the manipulable arm away from the center of the field of view of the endoscope.

[0018] Preferably, the tubular member is a tubular coil of a helical annulus; the curvature of the tubular member is set such that: the edges of the annulus on the first side are spaced apart to provide a gap; the edges of each of the annuli on the second side abut the edges of each adjacent annulus; wherein the first side and the second side are located on opposite sides of the tubular member. The abutting edges prevent compression and provide a leverage around which the manipulable arm can bend.

[0019] The advantages of the helical annulus structure are the possibility of cutting the manipulable arm from a single original tube, which is economically beneficial and provides a continuous structure. This also provides the possibility of utilizing the flexibility of the annular structure to bend the manipulable arm while relying on the stiffness of the material forming the tubular member to provide a bias. In an embodiment, the annuli on the first side are described as ribs that can be separated or brought closer together, while the second side is described as a ridge.

[0020] Optionally, the annuli have different helical pitches and / or interval variations along different parts of the manipulable arm in order to provide different flexibilities for different parts.

[0021] Preferably, the distal part is more flexible than the proximal part, advantageously preventing the pulling of a cord attached to the more distal part of the manipulable arm from causing an accidental deformation of the more proximal part; this allows for the control of the bending of the more distal part without affecting the bending of other more proximal parts, providing better control of the manipulable arm.

[0022] Preferably, the annulus is made by performing at least one helical cut on the tube.

[0023] Preferably, the manipulable arm further includes at least one notch in at least one of the edges of the annulus on the second side. Advantageously, the notch allows the ridge to have a certain degree of stretchability, thereby increasing flexibility.

[0024] Optionally, the tubular member is a tubular coil of a helical annulus; and the manipulable arm further includes two opposing rows of coupling joints, each row being arranged along opposite sides of the tubular member; each of the coupling joints in each row is rotatably connected to two corresponding adjacent annuli; such that the coupling joints of the opposing rows provide the second side; the tubular member has an axis located at the center of the cross-section of the tubular member and along its length; and the first side and the second side are arranged orthogonally to each other with respect to the axis of the tubular member.

[0025] Preferably, the tubular member is made of a single piece of material; such that the tubular member is a continuous structure (i.e., remains an integral structure). For example, the single piece of material is a single tube. Advantageously, the continuous structure provides the possibility of relying only on the inherent strength and stiffness of the material forming the structure without requiring additional connections or couplings to join separate parts.

[0026] Optionally, there is a longitudinally extending elastic member attached to the length of the second side; the longitudinally extending elastic member enhances the bias by providing additional structural stiffness.

[0027] Preferably, the tubular member includes at least two segments; a corresponding number of cords extending from the proximal end within the tubular member; each cord being fixed to the distal end of each segment, the distal end of the farthest segment being the distal end of the tubular member; each segment being capable of having a curvature in the longitudinal direction of the tubular member such that when the corresponding cord pulls on the distal end of each segment, the curvature of each segment changes; wherein the elasticity of the material provides a bias to the tubular member such that when the pull on the distal end of each segment is released, the change in curvature of each segment is reversed.

[0028] Advantageously, each segment can contribute to movement in different planes, such that the distal tip of the manipulable arm has better degrees of freedom of movement.

[0029] Preferably, the change in curvature of each of at least two segments lies in different planes.

[0030] Preferably, each segment has a different stiffness, such that the segments near the proximal end of the manipulable arm are larger, in order to reduce the mechanical coupling effect between the segments when the cords of different segments are pulled.

[0031] Typically, the manipulable arm is disposed at the distal end of a delivery tube; the delivery tube has minimal compressibility and extensibility in its axial direction and has a high torsional stiffness to provide effective torque and force transmission, the force transmission including the transmission of force from the pulling cords to the manipulable arm and the end effector, the delivery tube includes a channel through which the cords and other necessary components, such as electrical connections or surgical functions, such as a suction tube or an injection tube, are threaded together; the proximal ends of the cords are connected to a knob and / or a control lever for pulling the cords; such that when the distal end of the tubular member is pulled by the cords at the proximal end of the delivery tube, the curvature changes.

[0032] In a second aspect, the present invention provides a method of making a hollow tube into a manipulable arm for use in endoscopic surgical procedures, comprising the steps of:

[0033] a) providing a hollow tube having a proximal end and a distal end;

[0034] the distal end being adapted to be fitted with a surgical end effector; and the hollow tube being made of an elastic material;

[0035] b) cutting the hollow tube longitudinally and circumferentially along the length of the tube to form a helical cut;

[0036] the helical cut forming a gap along at least one side of the tube;

[0037] c) inserting cords into the proximal end of the hollow tube; and

[0038] d) Attach the cord to the hollow tube, attaching at:

[0039] i. The side where the gap of the tube is located; and

[0040] ii. Away from the proximal end such that the cord extends beyond the gap.

[0041] Cutting the entire hollow tube to form a manipulable arm provides the possibility that the manipulable arm has a continuous structure.

[0042] This method allows for pre-selecting a single tube material for the diameter of the tube and tailoring the size of the manipulable arm to match the channel size of the endoscope. In contrast, with the prior art methods that rely on assembling different components together, it is relatively difficult to manufacture small manipulable arms.

[0043] Preferably, the method further includes the steps of: holding the hollow tube in a bent position; and causing the hollow tube to have a memory of the bend in its natural state through plastic deformation or heat treatment.

[0044] Preferably, the method further includes the step of: cutting the hollow tube such that a coupler is left on each of the rings for coupling with an adjacent ring. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Referring to the drawings that illustrate possible arrangements of the present invention will facilitate a further description of the present invention, where like numerals refer to like components. Other embodiments of the present invention are also possible, and thus the particularity of the drawings should not be construed as substituting for the generality of the previous description of the present invention.

[0046] Figure 1 The prior art is shown for purposes of comparison;

[0047] Figure 2 The prior art is shown for purposes of comparison;

[0048] Figure 3 An apparatus including an embodiment of the present invention is shown;

[0049] Figure 4 Is shown Figure 3 Two views of the shown apparatus in use with an endoscope;

[0050] Figure 5 A close-up view of an embodiment is shown, which is Figure 4 A part of the shown;

[0051] Figure 5a An embodiment equipped with pliers is shown Figure 5 Of the shown embodiment;

[0052] Figure 5bShows the one equipped with an electrosurgical knife Figure 5 The illustrated embodiment;

[0053] Figure 6 Is for Figure 5 A photo taken by the camera of the prototype endoscope corresponding to the illustrated embodiment;

[0054] Figure 7 Is for Figure 5 An illustration of a more specific embodiment found in the illustrated embodiment;

[0055] Figure 8 Is for Figure 7 A schematic illustration of the operation of the illustrated embodiment;

[0056] Figure 9 Is for Figure 7 A schematic illustration of the manufacture of the illustrated embodiment;

[0057] Figure 10 Shows Figure 7 A part of the illustrated embodiment;

[0058] Figure 11 Shows Figure 7 A part of the illustrated embodiment;

[0059] Figure 12 Is for Figure 7 An alternative embodiment of the illustrated embodiment;

[0060] Figure 13 Shows Figure 12 An alternative view of the illustrated embodiment;

[0061] Figure 14 Shows Figure 12 An alternative view of the illustrated embodiment;

[0062] Figure 15 Shows Figure 12 A variant of the illustrated embodiment;

[0063] Figure 16 Shows an embodiment based on Figure 7 The illustrated embodiment;

[0064] Figure 17 Is for Figure 16 A schematic illustration of the manufacture of the illustrated embodiment;

[0065] Figure 18 Is for Figure 16 The technical drawing of the illustrated embodiment;

[0066] Figure 19 Is a schematic diagram showing how Figure 16 The illustrated embodiment operates;

[0067] Figure 20 Schematic diagram of the operation of another embodiment;

[0068] Figure 21 Shows Figure 20 Variations of the illustrated embodiment;

[0069] Figure 21a Shows Figure 20 Another variation of the illustrated embodiment;

[0070] Figure 22 Shows Figure 7 Variations of the illustrated embodiment;

[0071] Figure 23 Shows Figure 22 Schematic illustration of the manufacture of the illustrated embodiment;

[0072] Figure 24 Shows Figure 22 How the illustrated embodiment operates;

[0073] Figure 25 Shows Figure 7 Possible features in the illustrated embodiment;

[0074] Figure 26 Shows Figure 25 Variations of the illustrated features; and

[0075] Figure 27 Shows a more general embodiment of the present invention. Detailed Description

[0076] Figure 1 Shows the prior art for comparison purposes. The prior art is a manipulable arm that can be used in endoscopic surgery. The manipulable arm includes nested curved segments that can extend telescopically. The end of the thinnest segment can extend the farthest and is fixed with an end effector, such as a pair of forceps or an electrothermal knife. Each segment can extend fully or partially, contributing to the overall bending of the manipulable arm to reach the target area. The bending of the manipulable arm is not achieved by pulling a wire rope.

[0077] Figure 2 Shows another manipulable arm of the prior art. The manipulable arm is generally a longitudinal member 201, which has a series of components cut out from the lateral side of the longitudinal member. Two wire ropes within the longitudinal member are fixed to opposite lateral sides at the distal end of the longitudinal member. To bend the longitudinal member to one side, as a shrinkage rib - counter wire pair, one wire rope must be pulled while the other wire rope must be released.

[0078] Figure 3An embodiment of the present invention is shown, which is a flexible surgical instrument 300 for use with an endoscope 400.

[0079] The flexible surgical instrument 300 includes a transmission tube 307, which constitutes most of the length of the flexible surgical instrument 300. A manipulable arm 301 is mounted at the distal end 303 of the transmission tube 307. Accordingly, a surgical end effector 403 (see the illustration in Figure 4 ) that determines the function of the flexible surgical instrument 300 is fixed to the distal end of the manipulable arm 301, such as forceps, an electrosurgical knife, an injection needle, a suturing tool, etc.

[0080] Figure 4 An endoscope 400 into which two flexible surgical instruments 300 are inserted is shown. The endoscope 400 is an optical instrument that can be inserted into the gastrointestinal tract (GI) through the mouth or anus and is manipulated to reach a target position within the gastrointestinal tract to provide a view. The endoscope 400 may include a video display connected to its proximal end, as well as a light source and a camera with a large field of view located at the distal end 411. The image transmission from the camera to the video display may be provided by an optical fiber system or a sensor chip system.

[0081] The endoscope 400 for GI surgical operations is typically greater than 1 m. The outer diameter of the endoscope 400 with two biopsy channels is usually greater than 1.2 cm. The inner core of the most common GI endoscope 400 is provided with one or two channels that may have a diameter of 2.8 mm to 3.7 mm, typically referred to as a biopsy channel 405 or an instrument channel. 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. Figure 4 The shown endoscope 400 has two biopsy channels 405, and each of the two flexible surgical instruments 300 uses one biopsy channel 405.

[0082] Figure 5 For Figure 4 is an enlarged view of the illustration in, showing an exemplary arrangement of a camera 501 and a light source 503 on a cover body 401 at the distal end 411 of the endoscope 400. The camera 501 provides a real-time view of the surgical site, the manipulable arm 301, and the end effector 403 to guide the surgeon in operating the manipulable arm 301.

[0083] Figure 5a The manipulable arm 301 is shown, and forceps 505 serving as an end effector are provided at its distal end. Figure 5bShows a manipulable arm 301, with an electrothermal knife 507 as an end effector disposed at its distal end. Other end effectors can be mounted at the distal tip of the manipulable arm 301 to determine the ultimate function of the arm, such as injection needles and suture tools.

[0084] Figure 6 Shows a picture that can be taken by a camera 501, showing two manipulable arms 301, each fixed with an end effector 403 and performing a surgical operation on tissue. Figure 6 The two manipulable arms 301 in are equipped with outer sheaths, which can reduce friction and provide electrical insulation when the flexible surgical instrument 300 is inserted into the biopsy channel 405.

[0085] In a preferred embodiment, the transfer tube 307 and the manipulable arm 301 have an outer diameter of 2.7 mm or less to fit into most of the biopsy channels 405 provided by a general GI endoscope 400. The length of the transfer tube 307 can vary with the design and depends on the length of the endoscope 400 intended to be used with the flexible surgical instrument 300.

[0086] By pulling a cord passing through at least one channel in the transfer tube 307, the manipulable arm 301 can be moved or bent. The distal ends of some cords are fixed to different parts inside the manipulable arm 301. The distal ends of the remaining cords are connected to the end effector 403.

[0087] The end of a cord 309 extending 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, a pulley, or a control lever (not shown), to which the end of the cord is individually connected. The rotation or translation of each knob, pulley, or control lever causes the pulling of the respective cord. Pulling the proximal end of the cord moves or bends the manipulable arm 301 or actuates the end effector 403. The adapter can be robotically operated through electronic components and software to control the movement of the manipulable arm 301 and the end effector 403.

[0088] During surgery, the surgeon inserts the endoscope 400 into the patient's body and navigates the endoscope 400 to a desired position in the gastrointestinal tract. The adapter can pull or release the cord 309 extending from the proximal end of the endoscope 400.

[0089] Figure 7Shows the main part of the manipulable arm 301, which is a metal tube that is formed into a looped shape as a tubular coil 707 or a helical metal strip. The manipulable arm 301 is bent in its natural state and thus has a convex side 703 and a concave side 701. On the concave side 701, the edges of the loops come close together, with each edge abutting the corresponding edge of each adjacent loop, thereby preventing compression of the loops on the concave side 701. This provides a ridge on the concave side 701 of the tubular coil 707. On the convex side 703, the edges of the loops are spaced apart from each other, which forms ribs that extend from the ridge. The edges of the ribs on the concave side 701 can be moved closer to or further apart from each other to allow the ridge to bend. The manipulable arm 301 can be bent to make it straight or, alternatively, even bent to the opposite side. However, metal is an elastic material that provides a bias in the manipulable arm 301 so that it returns to its original shape when the bending force is removed.

[0090] Figure 8 A series of schematic diagrams of the joint connection of the manipulable arm 301. The figure shows the end of the cord 309 for controlling the manipulable arm 301 extending through the inner core of the manipulable arm 301 and connected to a rib located at or near the distal end of the manipulable arm 301. For clarity, the cord 309 is shown as a solid line, but those skilled in the art will understand that, since it is inside the manipulable arm 301, the cord 309 is largely visually concealed. The distal end of the cord 309 can be fixed to the rib by knotting, crimping or other means to ensure that the cord 309 remains fixed to the rib. The manipulable arm can be made of helical loops or can be made of a tube with sections cut out along the side of the tube.

[0091] The leftmost figure shows the manipulable arm 301 in its natural state, which is bent such that the ridge is concave ( Figure 8 a). The ribs are located on the convex side and are spread apart to accommodate the bend. When the cord 309 is pulled, some of the ribs are brought closer together, bending and straightening the ridge ( Figure 8 b). When the cord 309 is pulled further, the ribs are pulled even closer together such that the curvature of the manipulable arm 301 is reversed and it now bends in the direction away from the initial bending direction ( Figure 8 c). Releasing the pull allows the bias to manifest and the manipulable arm 301 to return to the shape of its natural state. It is this bias that makes a second cord for pulling the manipulable arm back to its initial natural state redundant.

[0092] Thus, the steerable arm 301 can be moved from bending in one direction to bending in another direction within a plane. This allows the end effector 403 on the steerable arm 301 to operate on tissue. This single wire rope scheme is easier than the prior art double wire rope scheme, which requires additional coordination between pulling one wire rope and releasing the other. Additionally, the presence of the second wire rope takes up space within the steerable arm 301.

[0093] Figure 9 A preferred way of manufacturing the steerable arm 301 is schematically shown. First, a tube 901 made of a superelastic material is provided, which is small enough in diameter to pass through the biopsy channel 405 of the endoscope 400 on which the steerable arm 301 is intended to be used. Typically, for general applications, a diameter of 2.7 mm or less is preferred. The traction transmission tube 307 can have a similarly small diameter, which is not a challenging issue for passing through the biopsy channel. Superelastic materials are those materials that have the ability to withstand large deformations and immediately return to their undeformed shape after removal of an external load, such as Nitinol (nickel-titanium alloy) and the following alloys: Cu-Zn, Cu-Al-Ni, Au-Cd, Au-Cu-Zn, and In-TI.

[0094] As Figure 9 shown in a, the tube 901 is made into a tubular coil 707 by helically cutting along the length of the tube 901. The cutting can be performed by precision machining, such as laser cutting, computer numerical control (CNC) milling, or other means. Figure 9 A laser source 903 for cutting the tube 901 is shown.

[0095] Additional cuts are made on one side of the tube 901 to cut and remove a portion 907 of each ring. This provides a gap 905 between every two adjacent rings on that side of the tube 901, which provides ribs 909 ( Figure 9 b). The gap 905 allows the ribs 909 to move closer together to accommodate bending of the ridge 911 towards the rib side. Additionally, the ribs 909 can move further apart separately to accommodate bending of the ridge 911 towards the ridge side ( Figure 9 c). The other side of the tube 901 forming the ridge 911 is cut with small gaps 905 between the rings.

[0096] It should be noted that the helical cutting is performed around the circumference of the tube 901, including the side of the tube 901 that becomes the ridge 911. Thus, the edges of the rings on the ridge 911 are also cut and separated. However, the edge of each ring on the ridge side abuts against the edge of each adjacent ring. When the steerable arm 301 is bent by pulling the wire rope 309, the abutment can prevent compression of the ridge 911.

[0097] Optionally, in other embodiments, only one side of the tube 901 may be cut to provide a gap 905 for forming the rib 909, without performing a circumferential spiral cut, such that the side of the tube 901 forming the ridge 911 remains integral and is not cut at all.

[0098] Optionally, the manipulable arm 301 is then held in a desired shape and heat treated or plastically deformed to cause the material to memorize the shape.

[0099] Figure 10 and Figure 11 A technical drawing showing the rib 909 and the ridge 911, with the ridge 911 not shown as being curved. Figure 10 The left figure in [reference] shows an external view of the manipulable arm 301, while Figure 10 the right figure in [reference] is a corresponding cross-sectional view in the direction marked h-h. Figure 11 The left figure in [reference] is a cross-sectional view in the direction of j-j, while Figure 11 the right figure in [reference] shows the corresponding appearance of the manipulable arm 301.

[0100] The spiral pattern can be varied to change the spiral pitch (L), pitch variation (M), number of turns, cut thickness, cut shape, position and size of the slots. These parameters can be adjusted to change the bending profile, range of motion and stiffness of the ridge 911, and can be selected according to the requirements of surgical applications. Thus, the degree and shape of the pre-bending can be changed to meet different surgical requirements, such as a specific disposition angle of the instrument tip manipulator 403.

[0101] The stiffness, flexibility and elasticity of the manipulable arm can be adjusted by changing the structure of the gaps and the rings. For example, if the rings are thicker, the manipulable arm has less flexibility and is stiffer. Optionally, if the rings are narrower, the manipulable arm has greater flexibility. The size of the gaps between the rings, the width of each gap, the inclination of the gaps (spiral pitch), the density of the gaps, these can all affect the flexibility and elasticity. Generally speaking, the larger the gaps and the greater the density of the rings, the stronger the deformability or flexibility of the tube. Even in embodiments where the manipulable arm is not a coil of rings but merely a tube with gaps, the gaps are cut into the side wall of the tube, and the same changes in the gaps can produce similar changes in the flexibility of the tube. Therefore, it is possible to make 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 have more fine rings or more cut-out portions, and making the proximal end have fewer finely cut-out rings or fewer cut-out portions. Advantageously, this prevents pulling on the cords attached to the more distal part of the manipulable arm, causing unintentional deformation of the more proximal part; this allows the distal end to not lose more control sensitivity than the proximal end, thus making the manipulable arm more flexible and maneuverable.

[0102] The manipulable arm 301 is made of a single piece of metal that provides a continuous structure. A continuous structure refers to an object that bends in a continuous manner and is integral by causing the material to deform plastically rather than through the movement between separate but connected joints. In other words, a continuous structure is typically made from a single piece of material. Additionally, a continuous structure does not have sharp creases or folding bends that can create high stress concentrations and may only have gradually curved or straight sides. In this way, the molecular or elemental structure of the material can provide strength, stiffness, elasticity, and flexibility to the continuous structure.

[0103] The continuous structure avoids assembling separate parts to the manipulable arm 301 and overcomes the challenges found in the prior art where manipulable instruments require the assembly of complex separate parts or interconnected joints in a labor-intensive manner, and the complexity of the parts can lead to a size that is too large to be used in conjunction with the biopsy channel 405 of some endoscopes 400. Additionally, this also reduces manufacturing time, complexity, and cost. In comparison to this embodiment, the prior art manipulable arms made of separate parts cannot be bent in their natural state because the separate parts cannot be heated to retain a position memory. Moreover, the material used in the continuous structure can provide sufficient strength and stiffness to the manipulable arm 301 to traction / lift tissue in a surgical environment, which an assembled structure made of separate parts cannot do with the strength of the material.

[0104] Preferably, holes 2201 for guiding the cable 309 are provided on the inner surface of the rib (see Figure 22 ). These holes allow the cable 309 to translate axially to facilitate actuation of the ridge 911 while also constraining the cable 309 to the inner side of the manipulable arm 301. These holes can be provided by additional parts manufactured separately and assembled with the manipulable arm.

[0105] Figure 12 A second embodiment is shown where a coupling joint 1201 is provided between each adjacent rib 909 to prevent the rib 909 from widening or sliding radially or from twisting about the longitudinal axis of the manipulable arm. Figure 13 and Figure 14 corresponds to Figure 12 except that the version in Figure 12 is shown with a biased bend in its natural state.

[0106] In Figure 13As can be seen in a, the coupling joint 1201 is provided on the opposite side of the manipulable arm 301. The edges of the ribs 909 are spaced apart on both the convex and concave sides of the bend. Thus, unlike the above-described embodiment, abutting the ribs on the concave side does not define the ridge. Instead, the coupling joint 1201 that prevents compression of the ribs 909 defines the ridge, and the coupling joints 1201 are arranged in columns along the length of the manipulable arm 301 such that the coupling joints 1201 provide a pivot about which the ribs 909 can rotate, and the ridge can bend to either side. In other words, the ribs 909 and the ridge are arranged orthogonally to each other with respect to the axis of the tube 901.

[0107] The coupling joint 1201 minimizes bending or twisting outside the joint rotation plane and prevents the rings forming the ribs 909 from loosening and expanding radially. Generally, the coupling joint 1201 does not provide additional stiffness to the manipulable arm 301 for restoring to the original shape when the manipulable arm 301 is bent. The elasticity and bias are still provided by the material selection for manufacturing the manipulable arm 301, and the manipulable arm 301 is a continuous structure.

[0108] A cord 309 (not shown in the figure) extends within the manipulable arm 301 and is fixed to the edge of one of the ribs 909 at the distal end, and the edge is located on the convex side portion of the rib 909. By pulling the cord 309, the ribs 909 can be articulated by rotating each rib 909 around its respective coupling joint 1201 and bending the manipulable arm 301. Bending only means changing the curvature of the arm. Bending can mean bending the arm from a straight configuration or straightening it from a bent configuration. The edges of the ribs 909 on the convex side of the ridge come closer, while the edges of the ribs 909 on the concave side open. Further pulling the cord 309 can reverse the bending, causing the manipulable arm 301 to bend in the opposite direction at this time (not shown). When the pulling on the cord 309 is released, the manipulable arm 301 naturally returns to the memorized shape.

[0109] This embodiment is also made by cutting a single nitinol tube. Segments of the tube are removed to form coils of a dispersed helical ring, and these rings form the ribs 909 of the manipulable arm 301. However, the removal leaves the shape of a male coupling joint on one side of each rib 909 and the shape of a female coupling joint on the other side of the rib 909. In this case, "side" does not refer to the lateral side of the entire tube, but to the side of each rib 909 of the coil. As shown, the male coupling joint on the lower side of each rib 909 is fitted into the female coupling joint on the upper side of the adjacent rib. After being cut from the tube, the manipulable arm 301 is held in the desired bend, and all the coupling joints 1201 match each other and are heat-treated to memorize the bend.

[0110] In some variations of this embodiment, cords may be fixed to each of two sides of the ridge of the tube surrounding the coupling joint, each cord bending the tube to one side. In these variations, the tube may or may not be pre-bent. Of course, having a pre-bent, flexible tube allows a single cord to bend the tube to the opposite side and bias it back to its original shape through the bias provided by the flexibility.

[0111] Figure 14 The male coupling joint 1401 and the female coupling joint 1403 are shown separated and unmatched, each disposed on the front side of adjacent ribs 909. The male coupling joint 1401 includes a neck having a rounded head thereon that can be fitted into the female coupling joint 1403, which includes jaws defining a circular gap. The circular jaws can rotate around the rounded head to allow rib 909 joint connection. Note that during the manufacturing process of the continuous structure, the male and female coupling joints have been matched with each other, Figure 14 for illustrative purposes only.

[0112] Advantageously, Figure 12 the illustrated embodiment combines the advantages of a continuous device (an integrated device that requires no assembly of any different parts provides advantages such as simple manufacturing, easy miniaturization, selectable stiffness based on the tube material and / or structure, and inherent counteracting force due to compliance) with the advantages of a joint-based curved section (e.g., mechanical constraints that minimize axial compression and out-of-plane bending).

[0113] Figure 15 A variation of the coupling joint with a more simplified design is shown. In this case, the male coupling joint 1401 is just a small rounded head without a neck, and the female coupling joint 1403 is a shallow shelf. Since the male coupling joint has no neck, the female coupling joint does not need to clasp the head of the male coupling joint.

[0114] So far, the described embodiments can only be bent or curved or straightened in one plane of motion. To provide multiple planes of motion, it can be considered to modularize the embodiments of the present invention and cut them from the same nitinol tube into different sections as different parts of a larger manipulable arm 301. Thus, Figure 16 A manipulable arm 301 made of a single tube is shown, the tube being cut such that there are two in series with Figure 7Similar tubular coils 707 as shown. The two tubular coils 707 share the same axis but are angularly offset so that each section can be bent in a different plane. Thus, the ridges 911 of the top portion 1601 of the tube (the top as shown in the figure) face one direction, while the ridges 911 of the bottom portion 1603 face a different direction. The top portion 1601 can be actuated by a cord 309 to bend and move in a first plane, while the bottom portion 1603 can be actuated by another cord 309 to bend and move in a second plane. Movement of the bottom portion 1603 also causes movement of the top portion 1601 since the top portion 1601 extends from the bottom portion 1603. Together, this gives the surgeon greater freedom in the end effector 403 on the steerable arm 301.

[0115] It should be noted that in this embodiment, the meaning of coaxial does not require the axis to be straight. The axis is curved and follows the curved shape of the steerable arm 301.

[0116] Figure 17 A method of manufacturing the steerable arm 301 with multiple sections is shown. Figure 17 Figure a shows how a helical cut is first made along and around the entire tube 901, creating the tubular coils 707 of rings. Subsequently, as Figure 17 shown in Figure b, further cuts are made on the sides of the tubular coils 707 to remove a portion of each ring in the top portion. This provides gaps 905 between the rings, forming ribs 909. This further cutting is also done on the bottom portion of the tube, but on a different side of the tubular coils 707. As a result, the ridges 911 of the bottom portion and the ridges 911 of the top portion are formed on different sides of the tube 901. Thus, the top portion can be bent in one direction as Figure 17 shown in Figure c, while the bottom portion can be bent in another direction as Figure 17 shown in Figure d. Figure 18 A technical drawing of cutting the tube to provide ridges 911 in the top portion 1601 that are on different sides from the ridges 911 in the bottom portion 1603. Finally, the top portion 1601 is bent into a desired shape, the bottom portion 1603 is bent into another desired shape, and it is heat treated (not shown) to form a memory of the overall shape.

[0117] Cutting the tube so that the ridges of the top portion and the ridges of the bottom portion bend in exactly opposite directions is only an option since this means that both the top portion and the bottom portion bend in the same plane, albeit in opposite directions. Alternatively, the ridges of the top portion and the ridges of the bottom portion are instead angularly offset along the axis.

[0118] Figure 19 Is schematically shown Figure 16How the embodiments operate. In the figure, the upper part 1601 of the manipulator arm 301 is bent towards the left side of the figure in its natural state. The lower part 1603 is bent towards the right side in its natural state. As a result, the shape of the manipulator arm 301 is similar to an inverted letter S. By pulling a cord 309 extending inside the manipulator arm 301, the curvature of the upper part 1601 of the manipulator arm 301 can be reduced. The cord 309 is fixed to one of the ribs at the distal most end of the upper part 1601. When further pulled, the curvature can be reversed towards the rib side.

[0119] Similarly, when the cord 309 is pulled, the lower part 1603 can be straightened. If the cord 309 is further pulled, the curvature can even be reversed towards the rib side. In this case, the cord 309 extends inside the manipulator arm 301 and is fixed to one of the ribs near the distal part of the lower part, or alternatively fixed to the proximal most part of the upper part. This is because the distal part of the lower part 1603 ends at the position where the proximal part of the upper part 1601 begins. Therefore, the rib at the distal most end of the lower part 1603 is just the rib below the ridge 911 of the upper part 1601.

[0120] When the two cords 309 are pulled with full force, the inverted S shape of the manipulator arm 301 mutates, and all the ribs on the upper part 1601 and the lower part 1603 of the manipulator arm 301 come closer together.

[0121] Figure 20 Shows another embodiment, which includes different parts composed of the previous embodiments. To manufacture Figure 20 the embodiment in, different sections of the same metal tube are cut in different ways so that each section can be bent in a different plane. A corresponding number of cords are arranged in the channel of the manipulator arm 301, and each cord 309 is attached to the distal end of its respective section to control the bending of that section.

[0122] On the left side of the figure Figure 20 a shows the manipulator arm 301 in its natural state. On the right side Figure 20 b shows the different directions in which each part can move or bend under the action of its respective cord 309.

[0123] Figure 20 The manipulator arm 301 in has four parts 2001, 2003, 2005, 2007. The first distal part 2001 of the manipulator arm 301 is similar to Figure 12 the embodiment shown. Just below this first part are the second part 2003 and the third part 2005, which together correspond to Figure 16 the embodiment of.

[0124] The first part 2001 and the second part 2003 are axially offset such that the first part 2001 can be bent within the first plane 2009, while the second part 2003 can be bent within a second plane 2011 that is angled with respect to the first plane 2009. The second part 2003 and the third part 2005 are also axially offset such that the third part 2005 can be bent within a third plane 2013 that is angled with respect to the second plane 2011. Thus, the three parts 2001, 2003, 2005 can move within different planes 2009, 2011, 2013 and provide three degrees of freedom of movement.

[0125] As shown, the fourth part 2007 located below the third part 2005 is a coupler that is assembled to a corresponding coupler on the transmission tube 307 and can be fixed by various methods including welding, adhesives, or mechanical means. Preferably, this coupler allows the manipulable arm 301 to rotate when the transmission tube twists at the proximal end of the endoscope, adding yet another degree of movement.

[0126] Figure 21 An embodiment is shown Figure 20 of a variant. The main section of the manipulable arm includes Figure 16 the embodiment shown, with Figure 12 shown at both ends. A coupler is provided at the proximal end for connecting this embodiment to the transmission tube. Thus, this manipulable arm 301 has four different sections extending from the coupler and can be bent in different planes respectively.

[0127] In Figure 21a yet another embodiment shown, this embodiment includes a coupler at the bottom and a second section manufactured according to the Figure 12 shown embodiment connected at the top, and this part is then connected at the top to the Figure 16 shown two-section embodiment. The end effector is dominated by the distal end of the Figure 16 shown embodiment. In this embodiment, the two-section part is more flexible than the second section because the gap within the two-section part is larger. Similarly, Figure 15 the embodiment shown has a more flexible distal section that is connected to a less flexible proximal section.

[0128] Figure 22 Another embodiment is shown, in which Figure 7In the illustrated embodiment, the ridge 911 has an open incision 2203. The incision 2203 is not formed around the entire circumference of the steerable arm 301, but is only cut into the ridge 911 from the side of the steerable arm. Preferably, the incision 2203 is formed by removing a thin block from the ridge 911. Structurally, the incision 2203 reduces the resistance of the nitinol to allow the ridge 911 to straighten more easily when the cord 309 pulls on the rib side, thereby improving the dynamic performance. It should be noted that even in this case, despite the incision 2203, the ridge 911 can still significantly resist compression. Optionally, more cuts can be made to the distal portion of this embodiment to make the distal portion more flexible than the proximal portion.

[0129] Figure 23 The process of helically cutting the tube 901 with the laser 903 to form ribs is shown. Figure 23 The helical cut shown in a is not performed in one go along the entire length of the tube 901. If the helix were cut along the entire length of the tube 901 in one go, the tubular coils of the resulting annulus would be too fragile to cut an incision in the ridge. Instead, only a short section of the tube is helically cut each time, and then a shallow cut is immediately made to one side of the tube that will become the ridge. After that, the next part of the helical cut is continued from the position where the first helical cut stopped. Figure 23 c shows how the resulting steerable arm 301 bends into the desired shape after satisfactory cutting of the tube and is heat-treated to produce a memory in that shape, with the ridge on the concave side and the ribs on the convex side.

[0130] Figure 24 The figure shows Figure 22 How the illustrated embodiment operates. Figure 24 (a) shows Figure 22 The natural state of the illustrated steerable arm 301. Figure 24 (b) shows the steerable arm 301 being straightened with the incision open. Figure 24 (c) shows the bending being reversed to bend to the opposite side, with the incision on the ridge opening further.

[0131] Figure 25 shows Figure 7Variations of the illustrated embodiments are where the stiffness of the ridge 911 is enhanced by fixing a reinforcing element 2501, such as a rigid but curved metal piece conforming to the shape of the ridge 911, to the inner surface of the ridge. When the pulling on the most distal rib 909 is released, the reinforcing element helps the shape of the ridge 911 to quickly resume, thus improving the transmission response time and shortening the mechanical hysteresis. The reinforcing element 2501 can be regarded as an elastic member. The reinforcing element has sufficient flexibility to straighten the ridge 911 when the actuating wire rope 309 is actuated. In this embodiment, the wire ropes are not drawn with the curvature of the manipulable arm to show that a wire rope guide is not required in all cases to guide the translation of the wire ropes.

[0132] In Figure 20 the illustrated embodiment, different sections of the ridge 911 can each be provided with such a reinforcing element.

[0133] Figure 26 Another embodiment is shown where the strip of the reinforcing element 2501 is not made of a very flexible material, but elastic members 2601 are provided at both ends of the reinforcing element. The elastic members 2601 are fixed at appropriate positions inside the ridge 911. When the manipulable arm 301 is bent, the elastic members 2601 can stretch. However, the elastic members 2601 enhance the bias of the manipulable arm 301 so that when the pulling on the most distal rib 909 is released, the memorized shape can be quickly resumed. This improves the transmission response time and shortens the mechanical hysteresis, i.e., the effect of pulling the wire rope 309 can be more easily seen in the manipulable arm 301.

[0134] To further improve the response of the manipulable arm 301, all the wire ropes 309 connected to the manipulable arm 301 are preferably pre-tensioned. That is, all the wire ropes 309 are tightened during expected use so that when the wire ropes 309 are further pulled, the sections of the manipulable arm 301 are ready to move. If the wire ropes 309 are not pre-tensioned but are hanging slackly, backlash will occur, resulting in a delay before the manipulable arm 301 responds to the wire rope pull.

[0135] Figure 27Shows a more general embodiment, in which the manipulable arm 301 includes a hollow elongate member 2701 that is more flexible on one side of the axis marked x and more rigid on the other side of the axis marked y. The elongate member is molded, cast, or heat-treated and can be permanently bent towards the more rigid side in its natural state. The material of the hollow elongate member can maintain the bend in its natural state but is elastic enough to be straightened by applying an appropriate force and even bent in the other direction. As in the foregoing embodiments, the degree of bend and the bias of the bend provide the possibility of using a wire rope 309 to swing the manipulable arm 301 in a plane. The hollow elongate member can be co-extruded from two different polymers such that each polymer forms one side of the hollow elongate member. In this case, the convex side can be made of a more rigid material so that when the wire rope 309 pulls on the distal end of the manipulable arm 301, the manipulable arm 301 does not shorten. The concave side can be made of a more extensible material that can stretch to accommodate the bending of the manipulable arm 301.

[0136] So far, the above embodiments have been described and illustrated as fixing the wire rope 309 to the side of the curved tube that is farthest from the ridge. This provides better leverage when pulling the ribs closer together to bend the ridge. However, fixing the wire rope to the ridge side of the curved tube is contemplated in this specification.

[0137] Thus, this embodiment includes a manipulable arm 301 for use in an endoscope 400 to manipulate a surgical tool, comprising: a tubular member having a proximal end and a distal end; the distal end being adapted to be fitted with an end effector for surgery; the tubular member being made of an elastic material; a wire rope 309 extending from the proximal end inside the tubular member; the wire rope being attached to the distal end of the tubular member and to the side of the tubular member; the tubular member may have a degree of bend in the longitudinal direction; wherein, when the wire rope pulls on the distal end of the tubular member, the degree of bend changes; the elasticity of the material provides a bias for the tubular member such that when the pull on the distal end is released, the change in the degree of bend is reversed.

[0138] Although the preferred embodiments of the present invention have been described above, those skilled in the art of this technology will be able to understand that changes or variations can be made to the details of the design, structure, or operation without departing from the scope required by the present invention.

[0139] For example, although the annulus has been mentioned in connection with cutting from the tube, in some embodiments, it is also possible that the rib is merely an extension of the ridge, the rib is bent and one end is connected to the ridge while the other end is a free cantilever.

[0140] For example, the flexible outer-sheath surgical instrument 300 can be adapted for use with other types of devices similar to the endoscope 400, such as a nasal endoscope 400 or a transurethral resection scope. When these devices do not have an internal channel for inserting the flexible surgical instrument 300, an additional outer sheath can be fabricated that can slide over the device to create a channel for the flexible surgical instrument 300.

Claims

1. A steerable arm configured for a biopsy channel of an endoscope, comprising: a continuous structure of an elastic material in the form of a hollow tubular member, the tubular member including a tubular coil of a helical annulus having aligned coupling joints on opposite sides of the tubular coil; each coupling joint being between adjacent annuli, a neckless round head for a male part on one of the adjacent annuli and a shallow shelf for a female part on the other of the adjacent annuli; the tubular member having a curvature that changes when the annulus at the distal end of the tubular coil is pulled closer by a cord; the continuous structure providing a bias such that the change in curvature is reversed when the pull is released.

2. The steerable arm configured for a biopsy channel of an endoscope according to claim 1, wherein, the tubular coil is in two sections, the change in curvature of each section being in a different plane.

3. The steerable arm configured for a biopsy channel of an endoscope according to claim 1 or 2, wherein, the tubular member is curved in its natural state such that the tubular member has a concave side and a convex side; the edges of the annuli on the convex side are spaced apart; the edge of each of the annuli on the concave side abuts the edge of each adjacent annulus.

4. The steerable arm configured for a biopsy channel of an endoscope according to claim 3, wherein, the annuli have different pitch and / or spacing variations along different parts of the steerable arm so as to provide different flexibilities for the different parts.

5. The steerable arm configured for a biopsy channel of an endoscope according to claim 1, wherein, the steerable arm is disposed at the distal end of a delivery tube; the delivery tube includes a channel through which the cord passes; the proximal end of the cord is connected to a knob and / or a control lever for pulling the cord; such that when the distal end of the tubular member is pulled by the cord at the proximal end of the delivery tube, the curvature changes.

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