Method for manufacturing a movable surgical arm in endoscopic surgery

Abstract

The present invention relates to a method for manufacturing a tubular body of a movable arm used in an endoscopic surgical procedure, comprising the steps of: providing a metal piece configured into a plurality of coils that define a tubular body; inserting at least one wire into the tubular body; bending the wire inside the tubular body and rods; and heating the bent tubular body while the wire is inside the rods, thereby allowing the tubular body and wire to memorize the bend.

Description

[Technical Field]

[0001] The present invention relates to the field of endoscopic surgical instruments, and in particular to a method for manufacturing a miniature robotic arm for performing surgery through or in parallel with an endoscope. [Background technology]

[0002] A preferred method of gastrointestinal (GI) surgery involves minimally invasive surgery, such as the use of small surgical instruments to manipulate tissue. An endoscope has been proposed with a biopsy channel through which two flexible surgical instruments are inserted for surgical manipulation of tissue. Each surgical instrument has a small, movable robotic arm at its distal end. The distal end of each movable arm is then fitted with an end effector. End effectors come in a variety of types, including forceps, high-frequency scalpels, syringe needles, and suture instruments. The end effector determines the intended use of each surgical instrument.

[0003] The movable arm is fitted with a hollow tube that controls the arm's bending and reach. When a surgical instrument is attached to the endoscope, the hollow tube is passed through the biopsy channel with the movable arm slightly extended from the tip of the endoscope.

[0004] The most common flexible endoscopes are manufactured by Olympus® and have biopsy channels with a diameter of approximately 3.7 mm. Some are as small as 2.8 mm. Therefore, the diameter of the moving arm must be reduced to fit through these biopsy channels.

[0005] During surgery, the surgeon manipulates the endoscope using a control handle at the proximal end of the endoscope to guide the tip of the endoscope, which has a movable arm, to the target tissue. Surgical instruments are disposable and are discarded after surgery.

[0006] One type of moving arm of interest for this application is a curved moving arm made from a continuous piece of Nitinol. A wire is threaded through the hollow core of the curved moving arm, and the end of the wire is anchored at a point on the inner surface defining the core. By pulling on the wire, the curved moving arm can be straightened.

[0007] Due to their complex structure, movable arms tend to be manufactured by hand. Typically, movable arms are cut from small hollow tubes, with a gap on one side of the tube. The cut hollow tube is then bent over to the non-gap side to open the gap and heated. This permanently bends the movable arm. Once cooled, the movable arm is held straight in the craftsman's fingers. A wire is then threaded through the distal end of the movable arm on the gaped side of the hollow tube and secured in place. Pulling the wire closes the gap, straightening the movable arm. Further pulling further closes the gap and causes the movable arm to bend in the opposite direction. Releasing the wire returns the movable arm to its original bend. Despite best efforts, the bends between different movable arms tend to vary, with some having a less pronounced bend than others. The problem with a gradual bend is that it limits the range of motion at the tip of the movable arm. A surgeon may pull the wire just a little before the movable arm is fully extended, preventing further extension. More importantly, the large variability in bending impairs the surgeon's manipulation skills and prevents him from relying entirely on experience when manipulating the next moving arm.

[0008] It is therefore desirable to provide a movable arm with reduced bending variability, and a method for manufacturing such a movable arm. Summary of the Invention

[0009] In a first aspect, the present invention provides a method for manufacturing a tubular body of a movable arm for use in endoscopic surgery, the method comprising the steps of: providing a hollow metal tube and configuring the hollow metal tube into a tubular body having a plurality of ribs along at least one side, the ribs extending from a spine portion; inserting at least one wire into the tubular body and bending the tubular body inward with the wire; and heating the bent tubular body with the bent wire therein, so that the tubular body and the wire memorize their respective bends.

[0010] In the prior art, the internal, nearly straight wire resisted bending of the movable arm, resulting in large bending variations between movable arms. Heating the wire inside the bent hollow tube permanently bends both the hollow tube and the wire. The wire no longer resists bending. After multiple wires are passed through the bent, heated movable arms experience a more pronounced reduction in the wire's resistance to bending. This reduces bending variations between the movable arms and improves product quality consistency.

[0011] Another problem that the present invention solves is variability in stiffness, which refers to how easily the movable arm "bounces back" when the force that straightens it is released.

[0012] Preferably, the method further comprises the steps of: cutting the hollow metal tube to form a plurality of loops connected in series, one edge of each loop defining a rib of the tubular body and the other edge of the loop becoming part of the spine portion.

[0013] Preferably, the method further includes the steps of cutting two slits in at least one of the ribs to form a strip along the rib, pushing the strip down towards the core wire of the tubular body to form an eyelet, inserting at least one wire into the tubular body, and inserting the wire into the eyelet.

[0014] "Eyelet" includes any device that can be welded or glued to the surface of each rib, and any device cut out of the rib and / or formed from the rib itself by permanently / plastically deforming a localized portion of the rib. Eyelets may be free, unattached, or hooks with endless hoops.

[0015] Passing the wire through an eyelet increases the likelihood that the bend imparted by the wire will match as closely as possible to the curvature of the side of the hollow tube into which the wire is expected to straighten, thereby further reducing variability.

[0016] Preferably, the method further includes the steps of forming a plurality of eyelets on the plurality of ribs, aligning the plurality of eyelets to form a channel in the tubular body, inserting at least one wire into the tubular body, and inserting the wire into the channel.

[0017] Optionally, the method further includes the steps of providing a plurality of eyelets of different sizes and arranging the eyelets to expand the diameter of the channel along the length of the tubular body.

[0018] In embodiments where there are two such channels with enlarging eyelets, the channels can be located on opposite sides of the inner surface of the tubular body, with one channel located at one portion along the length of the tubular body and the other channel located at another portion along the length of the tubular body, and the larger eyelet of each channel can be located toward the center of the tubular body to allow a single wire to easily pass through both channels.

[0019] Preferably, the channel is a first channel, and the method further includes the steps of: forming a plurality of eyelets on another plurality of ribs, each eyelet being formed in a respective one of the other plurality of ribs; aligning the plurality of eyelets to form a second channel; and inserting at least one wire into the hollow tube, the step including inserting a second wire into the second channel. This feature enables embodiments in which two or more wires are heated simultaneously with the tubular body to memorize a bend. Generally, the more unbent wires there are within the tubular body, the greater the resistance of the tubular body to bending. Therefore, heating multiple wires within the tubular body significantly reduces the likelihood of the wires straightening in response to bending of the tubular body.

[0020] Optionally, the first and second channels are angularly offset about the axis of the tubular body, such that the wire in the second channel can be used to bend the tubular body in a different planar direction than the wire in the first channel. The spine and ribs in which the first channel is provided may or may not be angularly offset relative to the spine and ribs in which the second channel is provided.

[0021] Preferably, the method further comprises the steps of punching an eyelet to form the first channel with a punch having a first dimension suitable for giving the eyelet a size suitable for passing a wire of a first diameter; and punching an eyelet to form the second channel with another punch having a second dimension suitable for giving the eyelet a second size suitable for passing a wire of a second diameter. The wires can be identified by their diameter, and therefore the portions of the movable arms that each wire controls can also be identified.

[0022] Preferably, the step of forcing the strip down towards the core of the tubular body to form the eyelet includes punching the strip with a punch having a concave surface, the bend of the concave surface extending from one slit to the other slit.

[0023] Preferably, the cutting of each rib is completed before cutting the next rib along the hollow metal tube.

[0024] Typically, the method includes the further step of connecting the end effector to the distal end of at least one wire. This feature also relates to the wire for operating the end effector, which is also bent and heated to acquire the curvature of the bent movable arm. Therefore, inside the movable arm, there may be a wire for straightening the movable arm and another wire for operating the end effector.

[0025] Preferably, a plurality of eyelets are formed at the apex of each rib.

[0026] In a second aspect, the present invention provides a tubular body of a movable arm for use in endoscopic surgery, the tubular body comprising a plurality of ribs, the ribs extending from a spine portion, and at least one wire passing through the tubular body, the tubular body having a bent portion in a resting state, and the at least one wire having a bent portion corresponding to the bent portion of the tubular body in a resting state.

[0027] Preferably, the tubular body further comprises at least one translation guide for guiding the movement of each of the at least one wire, the at least one translation guide being located inside the tubular body.

[0028] Preferably, the at least one translation guide comprises at least one eyelet formed in the inner surface of the tubular body.

[0029] Preferably, the edge of at least one eyelet is bent towards the core or axis of the hollow tube, to prevent the edge of the eyelet from rubbing against the wire during translation of the wire.

[0030] In some embodiments, although less preferred, the eyelets may be formed on the exterior surface of the tubular body, in these embodiments the slits may be pulled out by a pick.

[0031] Preferably, there are a plurality of translation guides, each corresponding to at least one of the plurality of eyelets, each corresponding to a respective wire within the tubular body, the eyelets for each translation guide being different in size from the eyelets for at least one other translation guide, and the wires for the different translation guides having different diameters depending on the size of the corresponding eyelets.

[0032] Preferably, at least one of the plurality of eyelets is formed at the apex of each rib, so that the eyelet formed at the apex of the rib provides a greater leverage for moving the rib by pulling the wire to bend the tubular body, thereby enabling more precise guidance of the rib movement. [Brief explanation of the drawings]

[0033] To further describe the present invention, it is convenient to refer to the accompanying drawings, which illustrate possible configurations of the invention, and in which like reference numerals refer to like parts. The invention is susceptible to other embodiments, and therefore the specificity of the accompanying drawings does not supersede the generality of the foregoing description of the invention. [Figure 1] 1 illustrates an apparatus including one embodiment of the present invention. [Figure 2] 2A and 2B show two of the devices of FIG. 1 in use with an endoscope. [Figure 3] 3 is an enlarged view of one embodiment, a portion of that shown in FIG. 2. [Figure 4] FIG. [Figure 5] FIG. 5 is a schematic diagram illustrating the operation of the embodiment of FIG. [Figure 6] 5A to 5C are diagrams illustrating a method for manufacturing the embodiment of FIG. 4. [Figure 7] 5A to 5C illustrate a second manufacturing method of the embodiment of FIG. [Figure 8] 5A to 5C illustrate a third manufacturing method of the embodiment of FIG. [Figure 9] 5A to 5C are diagrams illustrating a part of a method for manufacturing the embodiment of FIG. 4. [Figure 10a-b] 5A to 5C are diagrams illustrating a part of a method for manufacturing the embodiment of FIG. 4. [Figure 10c] 5A to 5C are diagrams illustrating a part of a method for manufacturing the embodiment of FIG. 4. [Figure 10d] 5A to 5C are diagrams illustrating a part of a method for manufacturing the embodiment of FIG. 4. [Figure 10e] 5A to 5C are diagrams illustrating a part of a method for manufacturing the embodiment of FIG. 4. [Figure 10f] 5A to 5C are diagrams illustrating a part of a method for manufacturing the embodiment of FIG. 4. [Figure 10g] 5A to 5C are diagrams illustrating a part of a method for manufacturing the embodiment of FIG. 4. [Figure 10h-j] 5A to 5C are diagrams illustrating a part of a method for manufacturing the embodiment of FIG. 4. [Figure 11] 10(j) is a technical drawing corresponding to FIG. [Figure 12] 10(j) is a technical drawing corresponding to FIG. [Figure 13a] 10A to 10C are diagrams illustrating a manufacturing method of another embodiment. [Figure 13b] 10A to 10C are diagrams illustrating a manufacturing method of another embodiment. [Figure 13c] 10A to 10C are diagrams illustrating a manufacturing method of another embodiment. [Figure 13d] 10A to 10C are diagrams illustrating a manufacturing method of another embodiment. [Figure 13e] 10A to 10C are diagrams illustrating a manufacturing method of another embodiment. [Figure 13f] 10A to 10C are diagrams illustrating a manufacturing method of another embodiment. [Figure 13g] 10A to 10C are diagrams illustrating a manufacturing method of another embodiment. [Figure 13h] 10A to 10C are diagrams illustrating a manufacturing method of another embodiment. [Figure 14a] 10A to 10C are diagrams illustrating a manufacturing method of another embodiment. [Figure 14b] 10A to 10C are diagrams illustrating a manufacturing method of another embodiment. [Figure 14c]10A to 10C are diagrams illustrating a manufacturing method of another embodiment. [Figure 14d] 10A to 10C are diagrams illustrating a manufacturing method of another embodiment. [Figure 15] FIG. 10 illustrates yet another embodiment. [Figure 16] 10A to 10C are diagrams illustrating a manufacturing method according to yet another embodiment. [Figure 17] FIG. 10 illustrates yet another embodiment. [Figure 18] FIG. 18 is a perspective view of the embodiment of FIG. [Figure 19] FIG. 18 is another view of the embodiment of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0034] FIG. 1 shows a flexible surgical instrument 100 that is insertable into an endoscope 200 .

[0035] The flexible surgical instrument 100 includes a transmission hollow tube 107 that occupies most of the overall length of the flexible surgical instrument 100. A movable arm 101 is provided at the distal end 103 of the transmission hollow tube 107. A surgical end effector 203 (see the inset in FIG. 2), such as forceps, a high-frequency scalpel, a syringe needle, or a suture tool, is attached to the distal end of the movable arm 101. FIG. 2 shows an endoscope 200 with two flexible surgical instruments 100 inserted therein.

[0036] The endoscope 200 is an optical instrument that can be inserted into the gastrointestinal (GI) tract through the mouth or anus to observe a target site within the GI tract. The endoscope 200 has a video display connected to the proximal end and a light source and a wide-field-of-view camera at the distal end 211. Images are transmitted from the camera to the video display via a fiber optic system or a sensor chip system.

[0037] Endoscopes 200 for gastrointestinal surgery are typically over 1 meter in length. The core of the most common gastrointestinal endoscope 200 is provided with one or two movement channels with a diameter of 2.8 mm to 3.7 mm, which are typically referred to as biopsy channels 205 or instrument channels. The biopsy channel 205 has a channel inlet 213 at the proximal end of the endoscope 200 and a channel outlet 211 at the distal end 211 of the endoscope 200. A flexible surgical instrument 100 can be inserted through the channel inlet and passed through the biopsy channel 205.

[0038] The endoscope 200 of Figure 2 has two biopsy channels 205, one for each of the two flexible surgical instruments 100. The outer diameter of an endoscope 200 with two biopsy channels is typically greater than 1.2 cm.

[0039] 3 is an enlarged view of the insert portion of FIG. 2, illustrating an example of the placement of a camera 301 and a light source 303 on the cap 201 at the distal end 211 or tip of the endoscope 200. The camera 301 provides a live view of the surgical site, the movable arm 101, and the end effector 203, and serves as a guide for the surgeon in manipulating the movable arm 101. One end of the movable arm 101 is shown to be equipped with forceps as the end effector 203, and the other end is shown to be equipped with a suturing tool.

[0040] Typically, the outer diameter of the transmission hollow tube 107 and the movable arm 101 is 2.7 mm or less, which is compatible with most biopsy channels 205 provided in common gastrointestinal endoscopes 200. The length of the movable arm 101 is approximately 3 cm. The length of the transmission hollow tube 107 varies depending on the design and is dependent on the length of the endoscope 200 in which the flexible surgical instrument 100 is used. The movable arm 101 can be moved or extended by pulling a wire threaded through the transmission hollow tube 107.

[0041] Specifically, one end of the end effector wire 109a is connected to the end effector 203 in order to operate the end effector 203. The body of the end effector wire 109a passes through the hollow core of the movable arm 101 and the transmission hollow tube 107. The other end of the end effector wire 109a exits from the proximal end of the transmission hollow tube 107.

[0042] Similarly, a straightening wire 109b is provided within the hollow core of the movable arm 101. The distal end of the straightening wire 109b is connected to a point on the inner surface defining the hollow core of the movable arm 101 and near or at the distal end of the movable arm 101. The remaining length of the straightening wire 109b passes through the transmission hollow tube 107 and exits the proximal end of the transmission hollow tube 107.

[0043] The movable arm 101, and portions of the end effector wire 109a and straightening wire 109b within the movable arm 101, are permanently curved in a resting state. By "permanently," we do not mean that the movable arm 101 and wires 109 are rigid and inflexible. The movable arm 101 is made of a resilient and flexible metal, such as Nitinol, which allows the movable arm 101 to bend and deform, but quickly return to its original shape when the bending force is released.

[0044] Pulling the straightening wire 109b moves the proximal portion of the straightening wire 109b into the transmission hollow tube, causing the movable arm 101 to bend against the bend and straighten the movable arm 101. Further pulling may reverse the bend in the movable arm 101.

[0045] The ends of the wires 109 protruding from the proximal end 105 of the flexible surgical instrument 100 are coupled to an adapter (not shown) located outside the endoscope 200. The adapter includes knobs, pulleys, or levers (not shown) to which the wire ends are individually connected. Rotating or moving each knob, pulley, or lever either pulls or releases the corresponding wire, depending on the direction of rotation or movement. Pulling the proximal end of the wire moves or extends the movable arm 101 or actuates the end effector 203. The adapter can be operated manually or robotically via electronics and software to control the movement of the movable arm 101 and the end effector 203.

[0046] 4 shows the end effector 203 and the movable arm 101 without any wires inside. The movable arm 101 is a tubular body made of a spiral strand or coil of metal ribbon. The tubular body 407 has a long, slender tubular shape with multiple loops arranged in series.

[0047] The movable arm 101 is curved when at rest, and the tubular body 407 has a convex side 403 and a concave side 401. On the concave side 401, the edges of the loops of the tubular body 407 are closed, and the edges of each loop abut against the edges of adjacent loops, preventing compression of the loops on the concave side 401. This forms a spine 711 on the concave side 401. On the convex side 403, the edges of the loops are spaced apart, forming ribs 709 extending from the spine 711. The edges of the ribs 709 on the concave side 401 can move toward or away from each other as the spine 711 is curved. Thus, the curved movable arm 101 can be bent to straighten itself or even bent in the opposite direction to reverse the original curve. However, metal is an elastic material, and when the bending force is removed, it provides a structural bias to the movable arm 101, returning it to its original bent state.

[0048] 5 shows three diagrams that schematically illustrate the bending stages of the movable arm 101. These diagrams show how the end of the wire 109 for controlling the movable arm 101 passes through the core of the movable arm 101 and connects to a rib 709 at or near the distal end of the tubular body 407. The wire 109 is shown as a solid line for clarity, but one skilled in the art will understand that the wire 109 is inside the tubular body 407. The distal end of the wire 109 is secured to the tubular body 407 by a knot, crimp, or any means that keeps the wire 109 secured to the inner surface of the tubular body 407.

[0049] The leftmost image shows the movable arm 101 at rest, curved so that the spine 711 is concave (FIG. 5a). The ribs 709 on the convex side flare to accommodate bending. Pulling the wire 109 moves some of the ribs 709 closer together, bending the spine 711 and straightening it (FIG. 5b). Pulling the wire 109 further moves the ribs 709 closer together, reversing the curvature of the movable arm 101 and bending it away from its original bending direction (FIG. 5c). When the pull is released, a bias is exerted, returning the movable arm 101 to its original bend. This bias eliminates the need for a separate wire to return the straightened movable arm 101 to its original bend. This one-wire approach to moving the movable arm 101 in two directions is simpler than a two-wire approach, which requires coordinating pulling one wire while releasing the other.

[0050] Thus, the movable arm 101 can move in a plane and from bending in one direction to bending in another direction, thereby moving the end effector 203 on the movable arm 101 towards the tissue to be treated.

[0051] The proximal portion of the straightening wire 109b inside the movable arm 101 has a permanent bend that follows the bend of the movable arm 101, but accommodates the curvature of the transmission hollow tube 107 when retracted into the transmission hollow tube 107. The coupler connecting the movable arm and the transmission hollow tube 107 provides the necessary physical leverage. When the tension is released, the movable arm 101 springs back to its permanent bend, retracting the proximal portion of the straightening wire 109b back into the movable arm 101. The permanent bend of the straightening wire 109b also returns into the movable arm 101. Typically, but not necessarily, the elastic force of the straightening wire 109b is less than the elastic force of the movable arm. Similarly, the end effector wire 109a can follow the shape of the movable arm 101 and the transmission hollow tube 107 during movement.

[0052] (The entire manufacturing process of the movable arm) 6 shows an example of an overall process for manufacturing the movable arm 101. The illustrated process primarily relates to the manufacturing method of the tubular body 407 and the method of threading the wires through the tubular body 407. The manufacturing of the end effector 203 is outside the scope of this application.

[0053] First, a hollow metal tube 601 made of Nitinol is cut to create the tubular body 407. Next, a steel wire 109b is threaded through the hollow core of the tubular body 407. If necessary, the distal end of the steel wire 109b is fixed to the inner surface of the tubular body 407. To control the distal end of the tubular body 407, the fixing position is preferably near or at the distal end of the tubular body 407. The length of the steel wire 109b is longer than the length of the transmission hollow tube 107. Therefore, the portion of the steel wire 109b protruding from the tubular body 407 is threaded through the transmission hollow tube 107, with the excess length emerging from the proximal end of the transmission hollow tube 107 (not shown). This excess length of the wire 109b can be manipulated by a control adapter to which the wire 109b is fixed. This wire, or any wire having the same purpose, will be referred to below as a straightening wire 109b.

[0054] The drawing also shows the end effector 203 fixed to the distal end of the tubular body 407. In this example, the end effector 203 is a pair of forceps. The end effector 203 is provided with an end effector wire 109a for operating the end effector 203, for example, for closing the forceps when pulled. Thus, the end effector wire 109a is connected to the end effector 203 at its distal end and has a length sufficient to pass through the tubular body 407 and the transmission hollow tube 107, with an excess portion protruding from the proximal end of the transmission hollow tube 107. This excess portion can be operated by a control adapter (not shown) to operate the forceps.

[0055] Once the forceps, end effector wire 109a, and straightening wire 109b are in place, the entire assembly becomes a movable arm and is assembled into a mold. The mold is made of three small, stackable metal plates. The middle section 609 is cut to form an elongated groove 613 with a curved portion. The tubular body 407 can be removably fitted into the groove 613 with sufficient airtightness. The tubular body 407 is held firmly in its bent state with little or no wiggle. While the portions of the wires 109a, 109b outside the tubular body are very long, only the portions of the wires inside the tubular body 407 are bent along with the tubular body 407 within the groove 613.

[0056] The mold is assembled by placing an upper metal piece 607 and a lower metal piece 611 on either side of the middle section 609. The mold is then placed in an oven to heat. Optionally, the middle section 609 has a small groove 615 into which a needle thermometer 617 can be inserted to observe the temperature of the mold.

[0057] The mold is heated above the recrystallization temperature of the hollow tubing material (approximately 500°C if the material is Nitinol). At this temperature, the Nitinol recrystallizes, relieving stress in the tubular body 407, and upon cooling, the tubular body 407 permanently remembers the bent shape. In this way, the bent shape becomes the permanent shape of the tubular body 407, i.e., the shape that the tubular body 407 has when at rest.

[0058] The material used to fabricate the end effector wires 109a and straightening wires 109b inside the tubular body 407 also recrystallizes and stress-relieves, memorizing the same bent shape in the process. These wires do not necessarily have to be made of Nitinol. In some embodiments, steel wires are suitable because they have similar or overlapping recrystallization temperatures to Nitinol.

[0059] Steel wires have the advantage of being elastically flexible, allowing them to bend and return to a memorized bent state in response to the movement of the movable arm 101. Steel wires also have the advantage of exhibiting relatively low elongation depending on the conditions of use. The wires 109a, 109b for operating the movable arm 101 cannot be significantly stretched or contracted, as pulling the wires would increase the nonlinearity of the movement of the movable arm 101, making precise control of the device more difficult.

[0060] It should be noted that flexible means, among other things, the ability to bend or stretch, and resilient means, among other things, having the ability to return to a previous or original state.

[0061] Because the tubular body 407 and wires are made of a resilient material, pulling the straightening wire 109b straightens the tubular body 407, but releasing the tension causes the tubular body 407 to return to the memorized bent state. Similarly, the forceps are designed to close when the end effector wire 109a is pulled and automatically open when the tension is released.

[0062] Although not described in detail herein, in some embodiments, the material may not be Nitinol and steel. Furthermore, there are many different types of steel. Whatever material is used, the mold temperature should be above the highest recrystallization temperature of all materials used, but not near the melting point of any of the materials.

[0063] FIG. 7 shows another method for heating the tubular body 407. In this method, both ends of the assembled movable arm 101 are held with tools such as tweezers. The end effector wire 109a and straightening wire 109b are already threaded through the movable arm. The distance and placement of the tools are precisely set. The tools are then brought close together to create a bend in the center of the tubular body 407. A heating device 713, such as a heat gun, heats the tubular body 407 and the wires inside it to the appropriate temperature for the appropriate time. The tubular body 407 is held in the bent state while it cools. After cooling, the tubular body 407 and the internal wires 109b, 109a are permanently bent into that shape.

[0064] Figure 8 shows a variation of the method of Figure 6, with the difference being that the end effector wire 109a is passed through the tubular body 407 without fixing the end effector 203 before heat treatment. The tubular body 407 has the straightening wire 109b and the end effector wire 109a inside, and the end effector 203 is placed in a groove in a mold and heated without being fixed. After cooling, the tubular body 407 and a portion of the wire inside the tubular body 407 are bent. The end effector 203 is then fixed to the end effector wire 109a, completing the movable arm.

[0065] Before being heated and bent, the wire is straight. By "straight," we mean relatively or reasonably straight over the length of the movable arm 101 (approximately 3 cm). A straight wire makes it easier to thread the wire through the unbent tubular body 407. However, a meter-long metal wire will typically exhibit a gentle curve or bend. This gentle curve is not an issue in this application and is considered straight within the context of this application.

[0066] When the tubular body 407 is held in a bent position, the internal wires bend with the tubular body 407. By having the wires within the tubular body 407 permanently bend with the tubular body 407, the tendency of the wires to straighten and counter the bending of the tubular body 407 is eliminated. In this manner, this embodiment alleviates one of the reasons why conventional movable arms have large bending variations.

[0067] Furthermore, the bent wire reinforces the bend of the tubular body 407, helping the movable arm overcome the transmission friction and more elastically restore the bend when the tension on the straightening wire 109b is released.

[0068] (Cutting a hollow metal tube into tubular bodies) The tubular body 407 is made from a hollow tube 601 of a superelastic material, which is a material that has the resilience to be significantly deformed by a force and quickly return to its original shape when the force is removed, examples of which include, but are not limited to, Nitinol (nickel titanium) and alloys such as Cu-Zn, Cu-Al-Ni, Au-Cd, Au-Cu-Zn, and In-Tl.

[0069] The diameter of hollow tube 601 is preferably small enough to allow the movable arm to be inserted into the biopsy channel of most endoscopes. This typically means a diameter of 2.7 mm or less. Hollow tube 601 is approximately 3 cm long. The delivery hollow tube 107 attached to movable arm 101 is also of a similar diameter. Alternatively, hollow tube 601 may have a diameter suitable for insertion through an external instrument channel (usually of larger diameter) attached along the length of the endoscope.

[0070] 9(a)-9(c) show schematic diagrams of hollow tube 601 being helically cut at 903 to form a helical coil of metal ribbon 905 with serially arranged loops while maintaining the elongated shape of hollow tube 601. The cut can be made by precision machining, such as laser cutting with a laser source 703, a computer numerically controlled (CNC) milling machine, or similar device.

[0071] Figure 9(a) shows a side view of hollow tube 601 before cutting. Figure 9(b) shows the laser cuts along the length of hollow tube 601 and around the circumference of hollow tube 601. Finally, as shown in Figure 9(c), hollow tube 601 becomes tubular body 407, which is made of a metal ribbon with a series of loops 905 formed into it. This can be thought of as a flat, thin, wide ribbon formed into a helical structure that maintains the overall tubular shape. The gaps between loops 905 are exaggerated.

[0072] The procedure shown in Figures 9(a) to 9(c) is an overly simplified example and is shown only to illustrate how a spiral cut is made in hollow tube 601 to form tubular body 407. A more specific method of cutting hollow tube 601 is shown in Figures 10(a) to 10(j).

[0073] FIG. 10(a) shows the cuts beginning at one end of the hollow tube 601. The horizontal drawing at the top of FIG. 10(a) shows the cuts in more detail. In particular, the horizontal drawing shows that two cuts are required to provide the gaps 705 below each rib 709. First, a first spiral cut 1009 is made around the circumference of the hollow tube 601 to define the bottom of the first rib 709. "Bottom" here refers to the orientation of the drawing. The first cut is shown as a solid line. The first cut 1009 is an incomplete spiral, making it around most, but not all, of the circumference of the hollow tube 601. The start of the first cut 1009 is shown above the hollow tube 601, and the end of the first cut 1009 is shown below the hollow tube.

[0074] Next, a second spiral cut 1011 is made around the circumference of hollow tube 601, as shown by the dashed line. The second cut 1011 is made at a less steep angle than the first cut 1009 and is made directly below the first cut 1009. The second cut 1011 meets the first cut 1009 on both ends, cutting away a portion 707 of the hollow tube. This creates a gap 705 between adjacent loops.

[0075] The same process is repeated down hollow tube 601 to form the next loop and gap. The "second cuts" in each loop are made at an angle and length such that each second cut connects to the upper second cut at one end and to the lower second cut at the other end, forming a continuous spiral cut around the circumference and along the length of hollow tube 601.

[0076] Finally, as shown in FIG. 10(b), a series of loops separated by gaps are formed on one side of the hollow tube 601. These independent loops are the ribs 709 of the movable arm. The spine 711 side of the hollow tube 601 is also cut evenly along the hollow tube, but no hollow tube material is removed. All loops on the spine side of the tubular body 407 are in contact with adjacent loops. When the movable arm 101 is bent by pulling the straightening wire 109b, the struts prevent compression of the spine 711, and the gaps 705 between the ribs 709 move the ribs 709 closer together, straightening the bent movable arm 101.

[0077] To cut an object cleanly, the cut surface must have sufficient structural strength to withstand overall deformation due to the cutting force, except at the cut surface that separates the object in two. However, Nitinol is a superelastic material and therefore easily deforms. Therefore, to ensure a certain degree of structural strength, the hollow tube 601 is cut from one end to the other, with the distal cut being made before the proximal cut. The next rib 709 is cut into the hollow tube 601 only after the previous rib 709 and gap have been cut. This leaves as much of the hollow tube 601 as possible uncut and ensures structural strength. Conversely, if the hollow tube 601 were cut continuously in a spiral pattern throughout the entire hollow tube 601 before cutting the gap 705, the structure of the hollow tube 601 may be too weak to cut the gap 705. This could result in inaccurate or imprecise cuts and potentially damage to the hollow tube 601.

[0078] Finally, all the necessary ribs 709 and spines 711 are formed. The next step is to provide eyelets 715 on the inner surface of the ribs 709. The eyelets 715 act as travel guides for the straightening wire 109b. The entire row of eyelets forms the travel path.

[0079] Preferably, each eyelet 715 is positioned on the inner surface below the apex of the corresponding rib 709. This holds the straightening wire 109b as close as possible to the apex of the rib so that when the tubular body 407 is bent and heated, the bend imparted to the straightening wire 109b matches the curve that crosses the apex of the rib 709. This reduces the mismatch in bending between the movable arm 101 and the straightening wire 109b, further reducing the reaction to the bending of the movable arm 101. Furthermore, operating the rib 709 with the apex of the rib 709 provides greater leverage when closing the rib 709 and straightening the movable arm.

[0080] In some embodiments, hollow tube 601 is cut on only one side to create gaps 705 that define ribs 709. No spiral cut is made around the entire circumference. Thus, the sides that form the spine 711 of hollow tube 601 remain intact and integral and are not cut.

[0081] FIG. 10(c) is a cross-sectional view of the tubular body 407 as viewed from the proximal end, showing four eyelets 715 punched around the circumference of the tubular body 407 towards the core.

[0082] In a basic method, eyelets 715 are formed one at a time. Figures 10(d), 10(e), and 10(f) show how a single eyelet 715 is created near the distal end of hollow tube 601 before the first rib 709 is cut into hollow tube 601. Figure 10(e) is a close-up view of the portion of hollow tube 601 being machined in Figure 10(d). First, two slits are made in hollow tube 601 using a laser. The slits are preferably parallel to the edges of the rib 709 to be formed. The section of hollow tubing between the two slits becomes the strip, with both ends of the strip connected to hollow tube 601. The strip is heated to the recrystallization temperature of the hollow tubing using a suitable heater. After sufficient heating, the center of the strip is punched toward the center of hollow tube 601 using puncher 717. Both sides of the strip remain connected to hollow tube 601, and the pressed strip becomes eyelet 715. Upon cooling, eyelet 715 becomes permanently fixed onto hollow tube 601 .

[0083] The upper left diagram in Figure 10(f) is a cross-sectional view of the end of hollow tube 601. It shows the state in which the puncher has punched the circumference of hollow tube 601. The upper right diagram is a side view of hollow tube 601. The lower diagram is a perspective view of hollow tube 601 in the state in which the puncher has punched the hollow tube 601.

[0084] The puncher is a metal block with an end called face 719. The face has a rectangular cross section that punches against the strip. Preferably, face 719 is concave rather than flat in side view. The edges of face 719 cause the sides of the recessed strip to bend toward the core of hollow tube 601. This reduces the chance that sharp edges of eyelet 715 will scratch or impede the movement of straightened wire 109b through eyelet 715. Such scratches could lead to poor performance and a shortened lifespan of the movable arm 101.

[0085] A preferred method over punching the eyelets one by one is to punch all of the eyelets 715 on one side of the tubular body 407 at once, rather than making each eyelet 715 individually. To punch the eyelets 715 at once, the ribs 709 must first be formed. Then, each rib 709 is laser cut to form strips on the ribs 709. Multiple punches can then be precisely positioned on the punching tool to punch all of the strips simultaneously.

[0086] Figure 10(g) shows an example of a bulk punching tool. The bulk punching tool consists of a metal die that can be opened into two halves 719. Each half 719 is a rectangular metal plate with a long, narrow, straight groove 721 running the entire length of the metal plate. The groove 721 is used to tightly position the tubular body 407 after the ribs 709 and spine 711 have been created on the tubular body 407.

[0087] The bottom of each groove 721 has a series of through holes. Each through hole is sized and shaped to allow a punching tool to extend from the outside of the die and punch a trip into the die. When placing tubular body 407 into groove 721, the strips on ribs 709 must be aligned with the through holes to ensure accurate punching.

[0088] Punchers 717 are disposed on punching blocks 723. Two punching blocks 723 are shown, one for each groove 721. The upper punching block 723 has five punchers 717, the number and positions of which correspond to the through holes in the upper mold half 719. The lower punching block 723 also has five punchers 717, the number and positions of which correspond to the through holes in the lower mold half 719. It is possible for either punching block 723 to have a different number of punchers.

[0089] When the mold is assembled, the two grooves close to encase the tubular body 407, and the two punching blocks are attached to either side of the mold by inserting punches into the corresponding through-holes. The assembled mold is then heated in an oven to the recrystallization temperature of the tubular material. After sufficient heating, a punching machine is used to impact the punching blocks 723, punching the strip into eyelets 715.

[0090] The tubular body 407 is hollow but is sufficiently impact resistant to allow the strips to be punched out, this impact resistance being provided by the walls of the close fitting groove 721 which supports the coil structure.

[0091] The mold is then opened to remove the tubular body 407. On both sides of the tubular body 407, eyelets 715 are provided on the inner surface of the ribs 709. This allows the straightening wire 109b and the end effector wire 109a to be threaded through the tubular body 407.

[0092] FIG. 10(h) shows the straightening wire 109b being inserted. The distal end of the straightening wire 109b has a stopper or knot 1015 that is too large to pass through the eyelets 715, and the proximal end is inserted through the eyelets 715. Once the proximal end of the straightening wire 109b has been threaded through all of the eyelets 715, the straightening wire 109b can be pulled through the tubular body 407 until the knot abuts the distal-most eyelet 715 and stops the pulling, as shown in FIG. 10(i). The knot prevents the straightening wire 109b from being pulled through the eyelets 715. As an alternative to a knot, the end of the straightening wire 109b can be crimped, fused, welded, or otherwise secured to a point near the distal end of the hollow tube 601.

[0093] FIG. 10(j) shows the hollow tube 601 bent into the desired shape and heated, with the straightened wire 109b loaded into the eyelet 715, as described above.

[0094] When the straightening wire 109b is pulled to straighten the movable arm 101 during surgery, and when the straightening wire 109b is released to return the movable arm 101 to its original bent state, the eyelet 715 acts as a guide to ensure smooth movement of the straightening wire 109b.

[0095] An eyelet 715 may be provided for each rib 709, with the eyelets 715 forming a path for movement of the straightening wire 109b. However, in other embodiments, an eyelet 715 may be provided for every other rib 709 (not shown). In still other embodiments, a single eyelet is sufficient as a movement guide.

[0096] In embodiments in which the eyelets 715 form a path of travel for the straightening wire 109b, the eyelets help straighten the straightening wire 109b when the ribs are closed, which in turn helps straighten the movable arm 101. Furthermore, when the straightening wire 109b is pulled, the eyelets guide further movement of the straightening wire 109b, helping the straightening wire 109b to bend in the opposite direction as the bending direction of the movable arm 101 is reversed. These bending functions are illustrated in FIG. 5 above and are even more pronounced if each rib in FIG. 5 has an eyelet 715 at its apex. Releasing the straightening wire 109b returns both the movable arm 101 and the straightening wire 109b to their original, permanently bent states.

[0097] Figures 11 and 12 show technical drawings of the ribs 709 and spine 711, which simply repeat what was shown in Figure 10(j).

[0098] The left side view of FIG. 11 shows a side view of the movable arm 101, and the right side view is a corresponding cross section in the hh direction.

[0099] The left side of Figure 12 is a cross-sectional view in the jj direction, and the right side of Figure 12 shows the corresponding exterior view of the movable arm 101. In Figures 11 and 12, the straightening wire 109b can be seen threaded through a travel channel defined by a series of eyelets 715. The straightening wire 109b is secured in place by a knot tied at the distal end of the straightening wire 109b to prevent the straightening wire 109b from slipping out of the eyelets 715.

[0100] (Tubular body with different bending sections) The movable arm described thus far can be straightened and bent in a plane of motion using only a single straightening wire 109b inside the movable arm 101. However, in other embodiments, the movable arm can be constructed from different sections, each capable of moving in a different plane.

[0101] The sections of such a movable arm can be thought of in a modular manner. Figure 13(a) shows a tubular body 407 cut from a single hollow tube 601, with the tubular body 407 having two sections 801 and 803. The two sections 801 and 803 function as if two tubular bodies 407, as shown in Figure 4, were connected in series. The two sections 801 and 803 are coaxial, sharing the same axis, but are angularly offset. The spine and ribs of one section face one direction, while the spine and ribs of the other section face a different direction. With an angular offset of 180 degrees, the two sections 801 and 803 can move in opposite directions within the same plane.

[0102] The upper section 801 is driven by one straightening wire 109b fixed to the distal end of the upper section 801, and the lower section 803 is driven by another straightening wire 109b fixed to the distal end of the lower section 803 located approximately in the middle of the tubular body 407.

[0103] However, when the lower section 803 is bent, the upper section 801 swings over a wide range because it extends from the lower section 803. This increases the reach of the end effector 203 fixed to the tip of the upper section 801.

[0104] Here, coaxiality does not necessarily mean a straight axis. The axis may be the center of the movable arm 101, but may also be a curved axis along the bend of the movable arm. These bends can be permanently obtained by bending the movable arm in two places and then heating the movable arm, according to the method described above.

[0105] The process for cutting the tubular body 407 in Figure 13(a) is similar to the process already described with respect to Figure 10, except that the process is performed once for the upper section 801 and again for the lower section 803, as shown in Figures 13(b)-13(d). First, the upper section of the hollow tube 601 is cut to create the tubular body 407. That is, the tubular body 407 forms the spine from which the ribs extend. Next, similar cuts are made in the lower section of the hollow tube 601, but the resulting tubular body 407 is oriented in the opposite direction. Figure 13(d) shows two rows of eyelets 715 punched into the apexes of the ribs 709 of each section 801, 803. Each row of eyelets provides a travel channel through which a respective straightening wire 109b is threaded.

[0106] The inset in Figure 13(e) shows two channels positioned 180 degrees apart on opposite sides of the tubular body 407, with the same plane of travel. Figure 13(g) is a set of technical drawings provided to complement the schematic diagram illustrating the same concept, showing how the ribs 709 and spines 711 of the upper and lower sections 801 and 803 are oriented in different directions. A cross section of the eyelet 715 on the inner surface at the apex of the rib 709 is visible. The mold (not shown) used to heat the tubular body 407 has grooves with two bends, one in each section, to impart the bends shown in Figure 13(f) to the movable arm.

[0107] As shown in the axial view of tubular body 407 in Figure 13(h), if the two sections 801, 803 are offset by an angle less than 180 degrees (angular displacement θ), the movement of the two sections 801, 803 will be in different planes. In this case, tubular body 407 cannot be inserted into a flat groove in a heated mold. To accommodate the angular offset, the groove (not shown) must have different reliefs or slopes for each section.

[0108] 7 can also be applied by separately and sequentially heating the two sections. First, the upper section 801 is held in a bent state within a plane defined by its spine 711 and ribs 709 and heat-treated to memorize the bend. Next, the lower section 803 is held in a bent state within a plane defined by the spine 711 and ribs 709 of the lower section 803 and heat-treated. This heating method is effective for a movable arm with multiple sections that each move within a different plane.

[0109] 14(a)-14(c) show embodiments in which the size and arrangement of the eyelets inside the movable arm are varied. The eyelets 715 in the upper section 801 and the lower section 803 of the tubular body 407 are located on opposite sides. However, in both sections 801 and 803, the size of the eyelets 715 gradually increases toward the center of the tubular body 407. Therefore, a single straightening wire 109b can be passed through the eyelets in both the upper section 801 and the lower section 803. Before heating, the tubular body 407 is held so that the two sections 801 and 803 are bent in opposite directions. The tubular body 407 then permanently retains the two bent shapes.

[0110] Figure 14(d) shows a further variation in the eyelets, where the lower set of eyelets are the same size except for the most distal eyelet, and the upper set of eyelets are the same size except for the most proximal eyelet. In this configuration, smaller eyelets are advantageous in ensuring that the straightening wire 109b threaded through the eyelets in both sections follows the curves of both sections as closely as possible. A larger eyelet near the center of the tubular body 407 provides a guide for the straightening wire to pass from one side of the movable arm to the other.

[0111] Figure 15 shows another embodiment, a movable arm 101 having two or more sections. A corresponding number of straightening wires 109b are provided for the different sections, with each straightening wire 109b attached to the distal end of the respective section and threaded through a respective eyelet (not shown) provided in the respective section. The distal-most section shown in this example is straight and unbent in its resting state, and can be bent by alternately pulling the wires attached to either side of it. Figure 15a (left) shows the movable arm 101 in its resting state. Figure 15b (right) shows how each section can be moved or bent in different directions by the action of its respective straightening wire 109b.

[0112] The movable arm 101 of Figure 15 has four sections 1001, 1003, 1005, and 1007. Beneath a first distal section 1001 of the movable arm 101a are a second section 1003 and a third section 1005. The first section 1001 and the second section 1003 are axially offset to allow the first section 1001 to bend in a first plane 1009, and the second section 1003 to bend in a second plane 1011 that is angled relative to the first plane 1009. The second section 1003 and the third section 1005 are also axially offset to allow the third section 1005 to bend in a third plane 1013 that is angled relative to the second plane 1011. Thus, the three sections 1001, 1003, 1005 are movable in different planes 1009, 1011, 1013, providing three degrees of freedom of movement. A fourth section 1007, located below the third section 1005 as shown, is a coupler that attaches to a corresponding coupler on the delivery tube 107. Preferably, this coupler allows the movable arm 101 to rotate when the delivery tube 107 is twisted at the proximal end of the endoscope, adding an additional degree of movement. Figure 10(c) shows a view from the proximal end of this movable arm.

[0113] 16 illustrates the procedure used to thread a tubular body 407 having three sections, each requiring one straightening wire 109b for bending. Eyelets 715 can be seen positioned on different sides of the interior surface of the tubular body 407. A first straightening wire 109b is inserted into a series of eyelets (not shown) defining the distal-most transfer channel, a second straightening wire 109b is inserted into a series of eyelets (not shown) defining the second-most distal transfer channel, and a third straightening wire 109b is inserted into a series of eyelets (not shown) defining the proximal-most transfer channel. In this embodiment, no wire 109 passes through more than one transfer channel.

[0114] The most distal portion of hollow tube 601 is then bent with first straightening wire 109b threaded through the corresponding eyelet and heated.

[0115] The penultimate section is then bent and heated, with the second straightening wire 109b for the penultimate section threaded through the corresponding eyelet, along with the portion of the first straightening wire 109b that passes through the first and second sections. The first straightening wire 109b does not need to be guided by an eyelet as it moves through the penultimate section, but simply passes through the core of the hollow movable arm.

[0116] Next, the third most distal section is bent and heated with the third straightening wire 109b threaded through the corresponding eyelet, and a portion of the first straightening wire 109b and a portion of the second straightening wire 109b passing through the core of the movable arm in this third section.

[0117] Figures 17, 18, and 19 show another embodiment of a modified tubular body 407, in which each rib 709 is rotatably connected to the next rib 709 by a linkage joint 1801. One rib 709 has a male linkage joint 1701, which is a rounded protrusion that can be received as a seat by a corresponding female portion 1703 of the next rib 709, allowing the rounded protrusion to rotate within the seat when the movable arm is flexed. The linkage joint improves the reliability of the movable arm 101 by reducing the possibility of radial expansion of the loop and reducing compressive deformation along the axis of the arm during actuation. The linkage joint 1801 prevents the ribs from spreading or sliding radially or twisting about the long axis of the movable arm. In this embodiment, the spine is not located on one side of the tubular body, while the ribs extend on opposite sides. Instead, the spine is "centered." The spine is comprised of two rows of linkage joints 1801 on opposite sides of the movable arm. However, the ribs extending from one linkage joint join the next linkage joint along the tubular body, and then the next linkage joint, forming a spiral. This allows this embodiment to maintain a continuous structure without any discrete disconnected sections. Therefore, unlike the previous embodiment, the spine is not defined by the abutting ribs on the concave side. Instead, the spine is defined by linkage joints 1801 that prevent the ribs from compressing. The linkage joints 1801 are arranged in two rows along the length of the movable arm, and the linkage joints 1801 act as the axis of rotation for the ribs, allowing the spine to bend in either direction. In other words, the ribs and spine are oriented perpendicular to each other with respect to the axis of the hollow tube. The same procedures as those shown in Figures 6-10 can be used to manufacture the tubular body of this embodiment and form the permanent bends. The only difference is that the hollow metal tube 601 must be cut to form the linkage joints and ribs. The continuous structure allows bending while storing bending memory by inserting a wire and heating it, as described in the previous embodiment.

[0118] Figure 18 is a perspective view of the embodiment before heat bending. It can be seen that slits are provided on different sides of the tubular body 407 to achieve different bending directions or planes. The inset in Figure 18 is a portion of the tubular body, with reference numbers indicating the connection joints on opposite sides of the tubular body.

[0119] FIG. 19 shows the corresponding top view 1901, front view 1903, bottom view 1905, and back view 1907. The four orthogonal sides of the tubular body 407 are notched, forming four different channels on four different sides of the tubular body 407. A straightening wire 109b threaded through the channels can be used to bend the tubular body 407 in different planes or directions. The eyelets punched on the different sides of the tubular body are different sizes, as shown, to accommodate wires of corresponding thicknesses. Therefore, the punch depth is tailored to the required eyelet dimensions. Varying the wire diameter and thickness allows for wires of different tensile strengths to match the stiffness of each section of the movable arm.

[0120] The wire thickness is selected according to the tensile load requirements of the corresponding movable arm section. As a general rule, all wires in the movable arm should be as thin as possible to reduce wire congestion within the transmission body connected to the base of the movable arm. However, different sections of the movable arm require wires with different tensile loads to bend the sections. Wires that are too thin may not have enough tensile strength to bend stiffer sections without breaking them. The force required to bend a section depends on the amount of material removed from the section and the location of the removed material. Therefore, the wire thickness can be estimated from the design of each section. Also, generally, more force is required to bend more proximal sections than more distal sections.

[0121] Typically, the end effector wire 109a is not threaded through any of the eyelets, but simply passes through the core of the tubular body 407 between all of the eyelets. This is because the end effector wire 109a is not used to close the ribs and therefore does not need to travel close to the apex of the eyelets. However, the end effector wire 109a still has a permanent bend imparted by heat treatment so as not to interfere with the bending of the tubular body 407.

[0122] Thus, the embodiment comprises the following steps: 1. Laser cut ribs 709, spine 711, and slits for wire guides into bare hollow tube 601. 2. Punching (while heated) hollow tube 601 to create slits or eyelets 715 to create wire guides. 3. The straightening wires 109b for bending the movable arm 101 are threaded through the corresponding punched eyelets. Meanwhile, the end effector wires 109a are threaded through the core of the tubular body 407 without threading through the eyelets 751. The ends of the straightening wires 109b are attached to the distal ends of the respective sections. The tubular body 407 is secured (e.g., by welding, friction fit, adhesive, or a combination of these methods, or by knotting, etc.). 4. The tubular body 407, end effector 203, and wire 109 are placed in a mold that holds the tubular body 407 in the desired bent shape and heated. 5. The bent movable arm 101 is attached to the hollow transmission tube (for example, by welding, although an intermediate flange can be used to facilitate connection between the arm and the hollow transmission tube). The excess length of wire extending from the proximal end of the movable arm 101 is threaded along the length of the hollow transmission tube 107.

[0123] Accordingly, embodiments include a method for manufacturing a tubular body 407 of a movable arm 101 for use in endoscopic surgery, the method including the steps of providing a hollow metal tube and configuring the hollow metal tube 601 into a tubular body 407 having a plurality of ribs 709 along at least one side, inserting at least one wire 109a, 109b into the tubular body, bending the tubular body 407 with the wire 109a, 109b inside, and heating the bent tubular body 407 with the bent wire 109a, 109b inside, such that the tubular body 107 and the wire 109a, 109b memorize their respective bends.

[0124] In some embodiments, such as that shown schematically in Figure 5, the spine is on the side of the tubular body 407 opposite to at least one side into which at least one wire 109a is inserted. In other embodiments, such as that shown in Figure 18, the spine is centrally located and consists of two rows of linkage joints, with ribs extending from the linkage joints.

[0125] These embodiments also include a tubular body 407 of a movable arm 101 for use in endoscopic surgery, the tubular body 407 having a plurality of ribs 709, the ribs 709 extending from a spine portion, and at least one wire 109a, 109b threaded through the tubular body 407, the tubular body 407 being bent in a resting state. The at least one wire 109a, 109b has a bent portion corresponding to the bent portion of the tubular body 407 in a resting state.

[0126] While the foregoing description describes preferred embodiments of the present invention, those skilled in the art will recognize that many variations or modifications may be made in details of design, construction, or operation without departing from the scope of the present invention.

[0127] For example, while eyelets 715 have been described as recessed strips cut into ribs 709 of tubular body 407, eyelets 715 could also be formed by welding or attaching a hoop to the inside surface of each rib 709. Fabricating eyelets 715 in this different manner does not affect the function of eyelets 715 to guide the movement of straightening wire 109a.

[0128] Additionally, in some embodiments, eyelets 715 can be provided on the interior surface of the spine. Such eyelets bring the straightening wire 109a into close proximity with the spine of one section, allowing the wire to extend in a straight line to the eyelet of the next section on the same side of the tubular body 407 as the spine.

Claims

1. 1. A method for manufacturing a tubular body of a movable arm for use in an endoscopic surgical procedure, comprising: providing a hollow metal tube and configuring the hollow metal tube into a tubular body having a plurality of ribs along at least one side, the ribs extending from a spine portion; inserting at least one wire into the tubular body; bending the tubular body with the wire inside; and heating the bent tubular body with the bent wire inside, thereby causing the tubular body and the wire to memorize their respective bends; 10. A method comprising:

2. further comprising cutting the hollow metal tube to form a plurality of loops connected in series; an edge of each of the loops defines a rib of the tubular body, and another edge of the loop becomes part of the spine portion; 2. A method for manufacturing a tubular body of a movable arm used in endoscopic surgery according to claim 1.

3. cutting two slits in at least one of the ribs to form strips along the rib; and forcing the strip down toward the core of the tubular body to form an eyelet; and the step of inserting at least one of the wires into the tubular body includes inserting the wire into the eyelet.

3. A method for manufacturing a tubular body of a movable arm used in endoscopic surgery according to claim 2.

4. creating a plurality of said eyelets in a plurality of said ribs, each said eyelet being provided in a respective one of said plurality of said ribs, said plurality of said eyelets being aligned to form a channel within said tubular body; and the step of inserting at least one of the wires into the tubular body comprises inserting the wire into the channel; 4. The method for manufacturing a tubular body of a movable arm used in endoscopic surgery according to claim 3.

5. 5. The method of claim 4, further comprising the step of providing a plurality of eyelets of different sizes, the eyelets being arranged to form a channel having an expanding diameter along the length of the tubular body.

6. The channel is a first channel, and the method further comprises: forming a plurality of said eyelets in a plurality of other said ribs, each said eyelet being formed in a respective one of said other plurality of said ribs; and aligning the plurality of eyelets to form a second channel; and the step of inserting at least one of the wires into the tubular body includes inserting a second wire into the second channel.

5. A method for manufacturing a tubular body of a movable arm used in endoscopic surgery according to claim 4.

7. 7. The method of claim 6, wherein the first channel and the second channel are angularly offset about the axis of the tubular body.

8. punching the eyelet forming the first channel with a punch having a first dimension adapted to provide the eyelet sized to accommodate a wire of a first diameter; and punching the eyelet forming the second channel with another punch having second dimensions adapted to provide the eyelet sized to accommodate a wire of a second diameter; 7. The method for manufacturing a tubular body of a movable arm used in endoscopic surgery according to claim 6, further comprising:

9. The step of forcing the strip down towards the core of the tubular body to form the eyelet comprises: punching the strip with a punch having a concave surface; The concave curved surface extends from one of the slits to the other of the slits.

4. The method for manufacturing a tubular body of a movable arm used in endoscopic surgery according to claim 3.

10. 3. The method of claim 2, wherein cutting each rib is completed before cutting the next rib along the hollow metal tube.

11. 2. The method of claim 1, further comprising the step of connecting an end effector to a distal end of at least one of said wires.

12. 5. The method for manufacturing a tubular body of a movable arm used in endoscopic surgical procedures according to claim 4, wherein a plurality of said eyelets are formed at the apexes of each of said ribs.

13. 1. A tubular body of a movable arm for use in an endoscopic surgical procedure, comprising: a plurality of ribs extending from the spine portion; at least one wire threaded through the tubular body; and the tubular body has a bent portion in a static state, the at least one wire has a bend in a resting state corresponding to the bend in the tubular body; A tubular body of a movable arm used in endoscopic surgery.

14. further comprising at least one translation guide for guiding the movement of each of the at least one wire; the at least one translation guide is inside the tubular body; 14. The tubular body of a movable arm used in endoscopic surgical procedures according to claim 13.

15. 15. The tubular body of a movable arm for use in an endoscopic surgical procedure according to claim 14, wherein the at least one translation guide comprises at least one eyelet formed on an inner surface of the tubular body.

16. 16. The tubular body of a movable arm used in an endoscopic surgical procedure according to claim 15, wherein an edge of the at least one eyelet is bent toward the core of the tubular body.

17. a plurality of the translation guides; each translation guide corresponds to at least one of the plurality of eyelets; each said translation guide for a respective wire within said tubular body; the eyelets of each translation guide have a different size than the eyelets of at least one other translation guide; the wires of different translation guides have different diameters depending on the size of the corresponding eyelets; 17. The tubular body of a movable arm used in endoscopic surgical procedures according to claim 15 or 16.

18. 18. The tubular body of a movable arm used in an endoscopic surgical procedure according to claim 15, 16 or 17, characterized in that at least one of the plurality of eyelets is formed at an apex of each of the ribs.

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