WO2019039362A1 - Medical manipulator bending structure - Google Patents

Abstract

Provided is a medical manipulator bending structure that is excellent in terms of withstand load and bendability while realizing size reduction. The present invention comprises: a flexible tube 15 that is formed from a super elastic alloy; and a guide part 17 that is disposed inside the flexible tube 15 and guides a driving wire of a medical manipulator. The flexible tube 15 comprises: a plurality of ring parts 21 that are consecutively provided along an axial direction of the flexible tube 15; tube connection parts 23a, 23b that connect, at some parts in a circumferential direction, ring parts 21 that are adjacent to each other in the axial direction; and tube slits 25 that are defined on both circumferential sides of the tube connection parts 23a, 23b between ring parts 21 adjacent to each other in the axial direction and that permit bending of the flexible tube 15 facilitated by bending of the tube connection parts 23a, 23b. The bending rigidity of the guide part 17 is set so as to be smaller than the bending rigidity of the tube connection parts 23a, 23b of the flexible tube 15.

Description

Flexure structure of medical manipulator

The present invention relates to a bending structure applicable to a bending portion of a medical manipulator such as a surgical robot.

In recent medical care, medical manipulators such as a robot forceps of a surgical robot and a manual forceps, which can reduce the burden on both a patient and a doctor at the time of surgery, have become widespread.

Medical manipulators such as robot forceps and manual forceps insert an endoscopic camera and arm from a patient's small wound and perform surgery with the sense that the forceps are actually moved while the doctor looks at the surgical field with a 3D monitor. Make it possible to

Among such medical manipulators, as in Patent Document 1, there is a manipulator which can secure a high degree of freedom and can perform more precise surgical operation by providing the arm with a joint function by a bending portion.

In this medical manipulator, a coil spring is used at a bending portion of the arm, and the coil spring is bent by pulling a drive wire passing therethrough.

The arm of such a medical manipulator is desired to be miniaturized in order to make the patient's wound smaller and to alleviate the mental and physical burden. In accordance with this, it is also desired to miniaturize the bent portion used for the arm.

However, in the technique of Patent Document 1, since the bent portion is configured by a coil spring, there is a limit to the size reduction because of the need to secure load resistance and flexibility.

Such problems exist not only in medical manipulators such as robot forceps and manual forceps as described above, but also in other medical manipulators such as endoscopic cameras.

JP, 2014-38075, A

The problem to be solved is that there was a limit in securing load resistance and flexibility while achieving miniaturization.

According to a first aspect of the present invention, there is provided a flexible tube made of a superelastic alloy, and a medical manipulator which is disposed in the flexible tube and which is made of a superelastic alloy in order to achieve miniaturization and excellent load resistance and flexibility. And a guide portion for guiding a drive wire, wherein the flexible tube is a part of a circumferential direction between a plurality of ring portions continuously provided in the axial direction of the flexible tube and the ring portions adjacent in the axial direction. And a slit which is defined on both sides in the circumferential direction of the tube connection between the adjacent ring portions in the axial direction and which allows bending of the flexible tube by bending of the tube connection. A bending structure in which at least a bending rigidity between the ring portions of the flexible tube is set smaller than a bending rigidity of the tube coupling portion of the flexible tube. To provide.

A second aspect of the present invention is a flexible tube of a medical manipulator made of super elastic alloy, which comprises a plurality of ring portions arranged in a row in the axial direction and a ring portion adjacent in the axial direction. A tube joint portion joined in a circumferential direction and a ring joint portion adjacent in the axial direction are divided on both sides in the circumferential direction of the tube joint portion, and allowing bending of the flexible tube by bending of the tube joint portion The tube coupling portion is gradually reduced in size in the circumferential direction from one side in the axial direction that is the fixed side during the bending to the other side in the axial direction that is the movable side during the bending Provide a flexible tube.

A third aspect of the present invention is a flexible tube of a medical manipulator made of super elastic alloy, which comprises: a plurality of ring portions provided continuously in the axial direction; and a ring portion adjacent in the axial direction A tube joint portion joined in a circumferential direction and a ring joint portion adjacent in the axial direction are divided on both sides in the circumferential direction of the tube joint portion, and allowing bending of the flexible tube by bending of the tube joint portion The ring portion provides a flexible tube whose dimension in the axial direction is equal to or less than the dimension in the circumferential direction of the largest tube coupling portion.

In the first to third aspects of the present invention, a flexible tube made of a superelastic alloy is formed by connecting a plurality of ring portions in the axial direction by a tube joint, and bending is possible by bending the tube joint. Since it has become, it can be made excellent in load resistance and flexibility while achieving miniaturization.

Moreover, in the first aspect, the bending stiffness of the guide portion at least between the ring portions of the flexible tube is set smaller than the bending stiffness of the tube joint portion of the flexible tube, so that the bending of the flexible tube is prevented. Instead, the drive wire can be held in an appropriate position to perform a stable and accurate bending operation.

In the second aspect, the size of the circumferential direction is gradually reduced from one side in the axial direction, which is the fixed side during bending, to the other side in the axial direction, which is the movable side during bending. Also on the other side, it is possible to generate sufficient strain during bending of the tube connection.

As a result, it is possible to relieve the strain at the tube coupling portion on one side in the axial direction, to make the strain uniform, and to be further excellent in load resistance and flexibility.

In the third aspect, when the flexible tube is bent, the ring portion is deformed together with the tube connection portion by the configuration in which the axial dimension of the ring portion is equal to or smaller than the circumferential dimension of the largest tube connection portion. It is possible to generate strain in the entire structure of the flexible tube, and as a result, to relieve the strain.

FIG. 1A is a perspective view from the front side showing a robot forceps using a bending structure, and FIG. 1B is a perspective view from the back side (Example 1). 2 (A) and 2 (B) show the robot forceps of FIG. 1, FIG. 2 (A) is a side view, and FIG. 2 (B) is a front view (Example 1). FIG. 3 is a perspective view showing a bending structure of the robot forceps of FIG. 1 (Example 1). FIG. 4 is a front view of the bending structure of FIG. 3 (Example 1). FIG. 5 is a perspective view showing a flexible tube used in the bending structure of FIG. 3 (Example 1). 6 is a front view showing the flexible tube of FIG. 5 (Example 1). 7 is a partially enlarged front view of the flexible tube of FIG. 5 (Example 1). FIG. 8 is a perspective view showing a guide portion used in the bending structure of FIG. 3 (Example 1). FIG. 9 is a front view showing the guide part of FIG. 8 (Example 1). FIG. 10 is a plan view showing the guide part of FIG. 8 (Example 1). FIG. 11 is a graph showing the relationship between the load and the bending angle of the flexible tube used for the bending structure (Example 1). FIG. 12 is a front view showing a bending structure (Example 2). FIG. 13 is a plan view of the bent structure of FIG. 12 (Example 2). FIG. 14 is a perspective view showing a bending structure (Example 3). FIG. 15 is a side view showing the bent structure of FIG. 14 (Example 3). FIG. 16 is a plan view showing the bent structure of FIG. 14 (Example 3). FIG. 17 is a perspective view showing a bending structure (Example 4). FIG. 18 is a side view showing the bent structure of FIG. 17 (Example 4). FIG. 19 is a plan view showing the bent structure of FIG. 17 (Example 4). FIG. 20 is a perspective view showing a bending structure (Example 5). FIG. 21 is a side view showing the bent structure of FIG. 20 (Example 5). FIG. 22 is a plan view showing the bent structure of FIG. 20 (Example 5). FIG. 23 is a partially enlarged front view showing a flexible tube of a bending structure (Example 6). FIG. 24 is a partially enlarged front view showing a flexible tube of a bent structure according to a modification (Example 6). FIG. 25 is a partially enlarged front view showing a flexible tube of a bending structure (Example 7). FIG. 26 is a side view showing a flexible tube of a robot forceps (Example 8). FIG. 27 is a front view showing a flexible tube at the time of bending (Example 8). FIGS. 28 (A) and 28 (B) are side views of a flexible tube showing strain distribution, and FIG. 28 (A) is Example 8 and FIG. 28 (B) is a comparative example. (Example 8). FIG. 29 is a graph showing the relationship between the maximum value of strain and the bending angle (Example 8). FIGS. 30 (A) and 30 (B) are graphs showing the relationship between the bending angle and the increase and decrease of the load value, FIG. 30 (A) shows Example 8, and FIG. 30 (B) shows Comparative Example (Example 8). 31 (A) and 31 (B) are graphs showing the relationship between the bending angle and the spring constant, and FIG. 31 (A) is Example 8 and FIG. 31 (B) is a comparative example (Example 8). . FIG. 32 is a graph showing the relationship between the load of the flexible tube and the bending angle (Example 8). FIG. 33 is a front view showing a bending structure using a flexible tube (Example 9). FIG. 34 is a front view showing the guide portion of the bent structure of FIG. 33 (Example 9). FIG. 35 is a front view showing a bending structure using a flexible tube (Example 10). FIG. 36 is a side view showing a bending structure using a flexible tube (Example 11). FIG. 37 is a side view showing a bending structure using a flexible tube (Example 12). FIG. 38 is a side view showing a bending structure using a flexible tube (Example 13). 39 (A) and (B) show a flexible tube of robot forceps, FIG. 39 (A) is a front view, and FIG. 39 (B) is a side view (Example 14). FIGS. 40 (A) and 40 (B) are front views of a flexible tube showing strain distribution, FIG. 40 (A) shows Example 14, and FIG. 40 (B) shows a comparative example (Example 14). . 41 (A) and 41 (B) are perspective views of a flexible tube showing distribution of strain, FIG. 41 (A) shows Example 14, and FIG. 41 (B) shows a comparative example (Example 14). . FIG. 42 (A) is an enlarged view of an essential part of FIG. 41 (A), and FIG. 42 (B) is an enlarged view of an essential part of FIG. 41 (B) (Example 14). FIG. 43 is a graph showing the relationship between the maximum value of strain and the bending angle (Example 14). FIG. 44 is a graph showing the relationship between the load of a flexible tube and the bending angle (Example 14). 45 (A) and 45 (B) show a flexible tube, FIG. 45 (A) is a side view, and FIG. 45 (B) is a front view (Example 15). 46 (A) and 46 (B) are front views of a flexible tube showing distribution of strain, FIG. 46 (A) is Example 15, and FIG. 46 (B) is a comparative example (Example 15) . 47 (A) and (B) are perspective views of a flexible tube showing distribution of strain, FIG. 47 (A) shows Example 15, and FIG. 47 (B) shows a comparative example (Example 15). . FIG. 48 is an enlarged view of a portion of XLVIII in FIG. 47 (A) (Example 15). 49 (A) and 49 (B) show a flexible tube, FIG. 49 (A) is a side view, and FIG. 49 (B) is a front view (Example 16). FIG. 50 is a front view showing a bending structure (Example 17). FIG. 51 is a front view showing the guide portion of the bent structure of FIG. 50 (Example 17). FIG. 52 is a front view showing a bending structure using a flexible tube (Example 18). FIG. 53 is a side view showing a bending structure using a flexible tube (Example 19). FIG. 54 is a side view showing a bending structure using a flexible tube (Example 20). FIG. 55 is a side view showing a bending structure using a flexible tube (Example 21).

The embodiment of the present invention has the object of providing a guide portion in a superelastic alloy flexible tube with the object of achieving compactness, excellent load resistance and flexibility, and enabling stable and accurate bending operation. It was realized.

Specifically, the bending structure includes a flexible tube made of a superelastic alloy, and a guide portion disposed in the flexible tube and guiding a drive wire of the medical manipulator.

The flexible tube has a plurality of ring portions arranged in the axial direction, a tube coupling portion connecting the ring portions adjacent in the axial direction in a part of the circumferential direction, and a tube between the ring portions adjacent in the axial direction And a slit defined on both sides in the circumferential direction of the joint to allow bending of the flexible tube due to bending of the tube joint.

The guide portion is set such that the bending stiffness at least between the ring portions of the flexible tube is smaller than the bending stiffness of the tube coupling portion of the flexible tube.

Moreover, in the embodiment, the above object is achieved by connecting a plurality of ring portions provided in a row in the axial direction by means of the tube connecting portion, and the circumferential dimension of the tube connecting portion is fixed from the one side in the axial direction. It is realized by a flexible tube made of a superelastic alloy which is gradually reduced toward the other side in the axial direction which becomes the movable side at the time of bending.

Furthermore, in the embodiment, the above object is achieved by connecting a plurality of axially arranged ring portions by a tube coupling portion, and reducing the axial dimension of the ring portion to the largest dimension of the largest tube coupling portion. This is realized by a flexible tube made of a superelastic alloy.

[Structure of robot ladder]
1 (A) is a perspective view from the front side showing a robot forceps using a bending structure, FIG. 1 (B) is a perspective view from the same back side, and FIG. 2 (A) is the same side view, FIG. 2 (B) is a front view of the same. In addition, in FIG.1 and FIG.2, illustration of the guide part 17 of the bending structure 3 mentioned later is abbreviate | omitted.

The robot forceps 1 constitute a robot arm tip of a surgical robot that is a medical manipulator. The robot forceps 1 is an example of a medical manipulator. The medical manipulator to which the bending structure 3 can be applied is manually operated by a doctor or the like regardless of whether it is attached to a surgical robot or not, provided that it has a bending portion that performs bending operation. It is not a thing. Therefore, the medical manipulator also includes an endoscopic camera and a manual forceps which are not attached to the surgical robot.

The robot forceps 1 is composed of a shaft portion 5, a bending portion 7 and a gripping portion 9.

The shaft portion 5 is formed in a cylindrical shape. A drive wire 11 (FIG. 10) for driving the bending portion 7 and a push-pull cable 13 (FIG. 10) for driving the grip 9 pass through the shaft portion 5. A grip portion 9 is provided at the tip of the shaft portion 5 via the bending portion 7.

The bending portion 7 is configured by the bending structure 3 of the present embodiment, and can be bent by the operation of the drive wire 11. The details of the bending structure 3 will be described later.

The forceps portion 9 b is pivotally supported by a base portion 9 a attached to the tip of the bending portion 7. The forceps portion 9b is adapted to be opened and closed by advancing and retracting operation (push-pull operation) of the push-pull cable 13.

The drive of the grip portion 9 is not limited to the push-pull cable 13, and an air tube or a plurality of drive cables may be used.

[Structure of bending structure]
3 is a perspective view showing a bending structure 3 of the robot forceps 1 of FIG. 1, FIG. 4 is a front view of the same, and FIG. 5 is a perspective view showing a flexible tube 15 of the bending structure 3 of FIG. 6 is the same front view, FIG. 7 is the same part enlarged front view. The bent structure 3 shown in FIGS. 3 to 7 is slightly different in shape from FIGS. 1 and 2, but the same one is simplified.

The bending structure 3 includes a flexible tube 15 and a guide portion 17, and can be bent with one side (base end side) in the axial direction as the fixed side and the other side (tip side) in the axial direction as the movable side. ing. In FIGS. 3 to 7, the proximal end side is the lower side, and the distal end side is the upper side.

The flexible tube 15 is made of a super elastic alloy, and is constituted by the connecting portions 19a and 19b, the ring portion 21, the tube connecting portions 23a and 23b, and the tube slit 25. The superelastic alloy is a titanium-based alloy such as NiTi alloy (nickel-titanium alloy), rubber metal (registered trademark), Cu-Al-Mn alloy (copper-based alloy), Fe-Mn-Al-based alloy (iron-based alloy) And so on.

The connecting portions 19a and 19b are ring-shaped provided at both ends, and are portions connected to the robot forceps 1 side. A plurality of ring portions 21 are located between the connecting portions 19a and 19b.

The plurality of ring portions 21 are arranged in parallel at equal intervals in the axial direction. The distance d between the adjacent ring portions 21 in the axial direction is held constant, and the diameter r1 of each ring portion 21, the axial width w1 as the dimension in the axial direction, and the thickness t are also constant. . The thickness t is constant in the entire flexible tube 15 including the connecting portions 19a and 19b and the tube connecting portions 23a and 23b.

Adjacent ring portions 21 are coupled by tube coupling portions 23a and 23b in a part of the circumferential direction. The ring portions 21 at both ends are coupled to the coupling portions 19a and 19b by tube coupling portions 23a and 23b.

The tube coupling portions 23a and 23b are integrally provided in the ring portion 21 and couple between the ring portions 21 adjacent in the axial direction at two circumferentially opposing positions in the radial direction.

In each ring portion 21, the tube coupling portions 23a and 23b positioned on one side (base end side) in the axial direction and the tube coupling portions 23b and 23a positioned on the other side (tip end side) are 180 / N degrees in the circumferential direction It is placed out of alignment. The deviation of the tube coupling portions 23a and 23b here means the deviation between the center lines of the tube coupling portions 23a and 23b (the same applies hereinafter). N is an integer of 2 or more. In the present embodiment, N = 2 and the tube coupling portions 23a and 23b are disposed 90 degrees apart.

The deviation between the tube coupling portions 23a and 23b may be 60 degrees or the like, but is preferably 90 degrees. This is because the number of ring portions 21 required for bending the flexible tube 15 can be reduced, and the overall length can be made compact.

Each of the tube coupling portions 23 a and 23 b has a rectangular plate shape extending in the axial direction, and has a slight curvature according to the ring portion 21. Both end portions of the tube coupling portions 23 a and 23 b transition to the ring portion 21 via the arc portion 26. Thereby, between the tube coupling portions 23a and 23b and the ring portion 21 is tangentially continuous.

In the radial direction of the ring portion 21, the inner and outer peripheries of the tube coupling portions 23a and 23b and the ring portion 21 are transitioned without any step. However, it is also possible to make the tube joint portions 23a and 23b thicker or thinner than the ring portion 21 to have a step.

The circumferential width w2 of the tube coupling portions 23a and 23b is smaller than the axial width w1 of the ring portion 21. The radius of curvature r2 of the arc portion 26 is smaller than the axial width w1 of the ring portion 21 and is the same as or slightly different from the circumferential width w2 of the tube coupling portions 23a and 23b.

The tube coupling portions 23a and 23b allow bending of the flexible tube 15 by compressing one side in the circumferential direction bordering on the neutral axis and bending so as to extend the other side. In this embodiment, bending in the circumferential direction by the tube coupling portions 23a and 23b shifted by 90 degrees enables bending in two different intersecting directions X and Y.

The tube slit 25 which permits bending of the flexible tube 15 by bending of tube connection part 23a, 23b is provided in the circumferential direction both sides of each tube connection part 23a, 23b.

That is, the tube slits 25 are divided on both sides in the circumferential direction of the tube coupling portions 23a and 23b between the ring portions 21 adjacent in the axial direction. Each tube slit 25 has a rectangular shape with rounded corners according to the shapes of the ring portion 21 and the tube coupling portions 23a and 23b.

The axial width d of the tube slit 25 (the same as the distance d between the ring portions 21) is formed larger than the axial width w1 of the ring portion 21.

The dimensions of each part of the flexible tube 15 of the present embodiment are the total length L 22.4 mm, the diameter r1 of the ring portion 21 6 mm, the axial width w1 0.8 mm, the thickness t 0.4 mm, and the tube The circumferential width w2 of the coupling portions 23a and 23b is 0.2 to 0.5 mm, the curvature radius r2 of the arc portion 26 is 0.3 mm, and the axial width d of the tube slit 25 is 1.0 mm.

However, the dimensions of these parts are only an example, and can be appropriately changed according to the required size and characteristics. For example, the thickness t of the ring portion 21 and the tube coupling portions 23a and 23b, the diameter r1 of the ring portion 21, and the axial width w1 may not be constant depending on the characteristics required of the flexible tube 15. Further, the relative sizes of the diameter r1 of the ring portion 21, the axial width w1, the circumferential width w2 of the tube coupling portions 23a and 23b, the curvature radius r2 of the arc portion 26, and the axial width d of the tube slit 25 It is also possible to change

8 is a perspective view showing the guide portion 17 of the bending structure 3 of FIG. 3, FIG. 9 is a front view thereof, and FIG. 10 is a plan view thereof.

The guide portion 17 of the present embodiment is disposed in at least a central portion of the flexible tube 15 and suppresses movement of the drive wire 11 beyond the central portion. The central portion means an axial center portion where the insertion hole 33b is located in the present embodiment and a region surrounding the axial center portion.

The guide portion 17 is made of a material having a smaller Young's modulus than the flexible tube 15. As a material of the guide part 17, it is possible to use resin, such as a polypropylene. Further, the guide portion 17 of the present embodiment is formed in a shape corresponding to the flexible tube 15, and is in phase with the flexible tube 15.

However, the guide portion 17 is disposed in the flexible tube 15, and at least the bending rigidity of the guide portion 17 between the ring portions 21 of the flexible tube 15 is the bending rigidity of the tube coupling portions 23a and 23b of the flexible tube 15. The shape and the material are not particularly limited as long as the configuration is set smaller than that.

The guide portion 17 of the present embodiment includes a guide body 27, guide coupling portions 29 a and 29 b, and a guide slit 31.

The guide body 27 is formed in a disk shape that is positioned on the inner periphery of the plurality of ring portions 21 of the flexible tube 15. The thickness T in the axial direction of the guide body 27 of the present embodiment is set so as to be within the range of the ring portion 21 of the flexible tube 15. The guide body 27 is set to have a diameter r3 so as to fit on the inner periphery of the ring portion 21. The guide body 27 can be loosely fitted on the inner periphery of the ring portion 21.

Each guide body 27 has insertion holes 33 a and 33 b for inserting the drive wire 11 and the push-pull cable 13. The drive wire 11 is fixed to the tip end side of the bending structure 3 after the guide portion 17 is inserted. The push-pull cable 13 is coupled to the grip 9.

The insertion hole 33 b for inserting the push-pull cable 13 is provided at the axial center portion. Four insertion holes 33a for inserting the drive wire 11 are provided at every 90 degrees in the circumferential direction in the present embodiment, and each is arranged to be biased radially outward with respect to the insertion holes 33b. There is. As a result, the drive wire 11 is held in a well-balanced manner every 90 degrees in the circumferential direction. By this holding, the guide portion 17 suppresses movement of each drive wire 11 beyond the central portion of the flexible tube 15.

The movement beyond the central portion of the flexible tube 15 means that the drive wire 11 moves to the opposite side across the central portion by the movement toward the central portion. In the present embodiment, the drive wire 11 does not move from the holding portion to the central portion side.

The guide body 27 does not have to be located on the inner periphery of each ring portion 21 of the flexible tube 15. For example, the guide body 27 may be located on the inner periphery of the ring portion 21 only at every other portion or in the axial direction middle portion of the flexible tube 15. It is also possible to position.

The adjacent guide bodies 27 are coupled by the guide coupling portions 29a and 29b. The guide coupling portions 29a and 29b are integrally provided to the guide body 27, and couple the adjacent guide bodies 27 in a part of the circumferential direction corresponding to the tube coupling portions 23a and 23b of the flexible tube 15.

The guide coupling portion 29 a of the present embodiment is provided between the ring coupling portions 21 of the flexible tubes 15 axially adjacent to each other and between the tube coupling portions 23 a of the flexible tubes 15 opposed in the radial direction. The guide coupling portion 29b is similarly provided across the tube coupling portions 23b.

Thus, the guide coupling portions 29a and 29b are formed in a belt shape extending in the radial direction, and lightening holes 35a, 35b and 35c are provided at the central portion in the radial direction and on both sides thereof.

The guide coupling portions 29a and 29b are shaped so as to overlap the tube coupling portions 23a and 23b in the radial direction, and like the tube coupling portions 23a and 23b, both end portions in the axial direction are guide members through the arc portion 37. The state transitions to 27, and the tangent to the ring portion 21 is continuous.

The guide coupling portions 29a and 29b, together with the tube coupling portions 23a and 23b, compress one side in the circumferential direction and bend so as to extend the other side, thereby enabling the bending of the guide portion 17. The bending stiffness of the guide coupling portions 29 a and 29 b is set to be lower than the bending stiffness of the tube coupling portions 23 a and 23 b of the flexible tube 15.

Therefore, in the present embodiment, at least the bending rigidity of the guide portion 17 between the ring portions 21 of the flexible tube 15 is set smaller than the bending rigidity of the tube coupling portions 23 a and 23 b of the flexible tube 15. ing.

Guide slits 31 which allow bending of the guide portion 17 due to bending of the guide coupling portions 29a and 29b are provided on both circumferential sides of each of the guide coupling portions 29a and 29b.

That is, the guide slit 31 is divided on both sides in the circumferential direction of the guide coupling portions 29a and 29b between the ring portions 21 adjacent in the axial direction. Each guide slit 31 has a rectangular shape with rounded corners according to the shapes of the guide body 27 and the guide coupling portions 29a and 29b.

[Motion of bending structure]
When the doctor operates the robot forceps 1, the bending structure 3 as the bending portion 7 pulls any one of the drive wires 11 to move the holding portion 9 to the fixed side located on the shaft 5 side. The movable side located is bent. And by combining and pulling several drive wires 11, it becomes possible to make it bend in 360 degrees omnidirectional.

When one of the drive wires 11 is pulled and bent, one of the tube coupling portions 23a and 23b (tube coupling portion 23b in the embodiment) located on the neutral axis as shown in FIG. It bends so as to compress the flexing inner part relative to the neutral axis and extend the flexing outer part.

When the tube coupling portion 23b is bent, the ring portion 21 on the tip side with respect to the tube coupling portion 23b is displaced so as to close the tube slit 25 with the tube coupling portion 23b as a fulcrum. On the other hand, the tube coupling portion 23a which is shifted by 90 degrees in the circumferential direction from the tube coupling portion 23b on the neutral axis holds the posture of the ring portion 21 without bending.

Thus, the flexible tube 15 is bent as a whole by bending the tube coupling portion 23b located on the neutral axis.

The bending of the flexible tube 15 is not impeded by the guide portion 17. That is, as in the flexible tube 15, the guide portion 17 is bent as a whole by bending one of the guide coupling portions 29a and 29b located on the neutral axis (the guide coupling portion 29b in this embodiment).

At this time, since the guide coupling portion 29b has a bending rigidity smaller than that of the tube coupling portion 23b, the guide coupling portion 29b does not hinder the bending of the tube coupling portion 23b. In particular, in the guide portion 17 of the present embodiment, the guide coupling portion 29b has a shape corresponding to the tube coupling portion 23b of the flexible tube 15, and the material is significantly smaller in Young's modulus than the flexible tube 15 by about 1/50. It is. For this reason, the bending rigidity of the guide coupling portion 29b is significantly smaller than the bending rigidity of the tube coupling portion 23b, and the bending rigidity of the flexible tube 15 is not hindered.

Note that the guide portion 17 omits the guide coupling portion 29b so as not to have a portion located between the ring portions 21 of the flexible tube 15, thereby preventing the flexible tube 15 from being bent. It is also possible.

In this case, the bending rigidity of the guide portion 17 between the ring portions 21 of the flexible tube 15 becomes zero, so the bending rigidity of the guide portion 17 becomes smaller than the bending rigidity of the tube coupling portion 23b of the flexible tube 15.

Since the drive wire 11 is maintained at an appropriate position by the guide portion 17 at the time of such bending, the bending structure 3 as the bending portion 7 can perform a stable and accurate bending operation according to the operation of the doctor.

Load capacity
FIG. 11 is a graph showing the relationship between the load and the bending angle of the flexible tube 15 used in the bending structure 3 according to the first embodiment.

In FIG. 11, in the case where the circumferential width w2 of the tube coupling portions 23a and 23b of the flexible tube 15 is 0.2 mm, 0.3 mm and 0.4 mm, the tube is bent until the bending angle becomes 0 degree to 90 degrees. Then, the load when returning to 0 degrees is plotted. In the present embodiment, a linear characteristic in which the load is 10 N when the bending angle is 90 degrees is taken as an ideal line IS indicating an ideal load resistance characteristic.

When the circumferential width w2 of the tube couplings 23a and 23b is 0.2 mm and 0.3 mm, although the load as a whole is lower than the ideal line IS, hysteresis is small between bending and returning, and linearity is low. high. For this reason, the risk of breakage of the tube connection portions 23a and 23b can be reduced, and the load resistance is excellent.

When the circumferential width w2 of the tube coupling portions 23a and 23b is 0.4 mm, although the linearity is lowered, the load at a bending angle of 90 degrees is about 15 N, which is higher than the ideal line IS, and the load resistance is Is an excellent one.

[Flexibility]
In the present embodiment, as shown in FIG. 11, when the bending angle is 90 degrees, the load is about 3N, 5.5N, 15N, there is no breakage of the tube connection parts 23a, 23b, and the bending radius R is about 14.2. It could be as small as 3 mm. The bending radius R refers to the bending radius of the neutral axis (the same applies hereinafter).

As described above, in the present embodiment, even if the bending structure 3 is miniaturized, it can be bent easily and reliably with a small bending radius, and can be excellent in flexibility.

[Effect of Example 1]
As described above, the bending structure 3 of the present embodiment includes the flexible tube 15 made of superelastic alloy, and the guide portion 17 disposed in the flexible tube 15 and guiding the drive wire 11 of the medical manipulator. Have.

The flexible tube 15 is a tube coupling portion 23a, 23b which couples the plurality of ring portions 21 continuously provided in the axial direction of the flexible tube 15 and the ring portion 21 adjacent in the axial direction in a part of the circumferential direction. And a tube slit 25 defined on both sides in the circumferential direction of the tube coupling portions 23a and 23b between the axially adjacent ring portions 21 and allowing bending of the flexible tube 15 by bending of the tube coupling portions 23a and 23b.

Further, at least the bending rigidity of the guide portion 17 between the ring portions 21 of the flexible tube 15 is set smaller than the bending rigidity of the tube coupling portions 23 a and 23 b of the flexible tube 15.

Therefore, in the bending structure 3 of the present embodiment, the flexible tube 15 made of superelastic alloy is formed by connecting the plurality of ring portions 21 in the axial direction by the tube connecting portions 23a and 23b, and the tube connecting portion 23a, 23 By the structure which can be bent by bending of 23b, it can be made excellent in load resistance and flexibility, achieving size reduction.

Moreover, the bending structure 3 of the present embodiment can be made to be excellent in torsional rigidity by the configuration in which the flexible tube 15 couples the ring portions 21 with each other by the tube coupling portions 23a and 23b.

Further, in the bending structure 3 of the present embodiment, the bending rigidity of the guide portion 17 at least between the ring portions 21 of the flexible tube 15 is set smaller than the bending rigidity of the tube coupling portions 23 a and 23 b of the flexible tube 15 As a result, the drive wire 11 can be held at an appropriate position and a stable and accurate bending operation can be performed without preventing the bending of the flexible tube 15.

Further, in the present embodiment, the tube coupling portions 23a and 23b couple the ring portions 21 adjacent in the axial direction at two positions in the circumferential direction facing each other in the radial direction, and one tube of one ring direction of each ring portion 21 The coupling portion 23b and the tube coupling portion 23a on the other side in the axial direction are shifted 180 / N degrees, particularly 90 degrees in the circumferential direction, and differ depending on the bending of the tube coupling portions 23b and 23a on one side and the other side in the axial direction The bending of the flexible tube 15 in the direction is enabled.

Therefore, in the bending structure 3 of the present embodiment, it is possible to make it possible to bend in all directions through 360 degrees through the operation of the drive wire 11, and it is possible to suppress the anisotropy of bending.

The guide portion 17 of the present embodiment is made of a material having a Young's modulus smaller than that of the flexible tube, is positioned on the inner periphery of the plurality of ring portions 21 of the flexible tube 15, and has insertion holes 33a through which the drive wire 11 is inserted. Guide connecting portions 29a and 29b which connect between a plurality of disk-shaped guide bodies 27 and the guide bodies 27 adjacent in the axial direction in a circumferential direction corresponding to the tube connecting portions 23a and 23b of the flexible tube 15 And guide slits 31 partitioned on both sides of the guide coupling portions 29a and 29b between the guide bodies 27 adjacent in the axial direction.

Therefore, the guide portion 17 of this embodiment can be phased with the flexible tube 15, and the stability and accuracy of the operation can be secured.

FIG. 12 is a front view showing a bending structure according to a second embodiment of the present invention, and FIG. 13 is a plan view thereof. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and redundant description will be omitted.

The bending structure 3 of the present embodiment is such that the guide portion 17 has a cylindrical shape. The flexible tube 15 has the same configuration as that of the first embodiment.

In the guide portion 17, groove portions 33 c for guiding the drive wire 11 every 90 degrees in the circumferential direction are provided in the cylindrical guide body 27 along the axial direction. Each groove 33 c radially extends from the outer peripheral surface of the guide body 27 toward the axial center in a plan view. The axial center portion is provided with an insertion hole 33 b for inserting the push-pull cable 13.

Also in the second embodiment, the same function and effect as the first embodiment can be obtained.

FIG. 14 is a perspective view showing a bending structure according to a third embodiment of the present invention, FIG. 15 is a side view thereof, and FIG. 16 is a plan view thereof. In the third embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and redundant description will be omitted.

The bending structure 3 of the present embodiment is one in which the guide portion 17 is a coil spring of superelastic alloy. Others are the same shape as Example 1.

The guide portion 17 has a coil-like inner diameter equal to the outer diameter of the push-pull cable 13, and the push-pull cable 13 is inserted into the coil-like inner peripheral portion. The drive wire 11 is disposed on the outer peripheral side of the guide portion 17.

Therefore, in the present embodiment, while the push-pull cable 13 is held in an appropriate position by the guide portion 17, the drive wire 11 is prevented from extremely moving beyond the central portion, and a stable and accurate bending operation is performed. Can.

In addition, also in the present embodiment, the same function and effect as in the first embodiment can be obtained.

FIG. 17 is a perspective view showing a bending structure according to a fourth embodiment of the present invention, FIG. 18 is a side view thereof, and FIG. 19 is a plan view thereof. In the fourth embodiment, the same components as those in the third embodiment are given the same reference numerals, and duplicate explanations will be omitted.

The bending structure 3 of the present embodiment is such that the coil-like inner and outer diameters of the guide portion 17 are larger than those of the third embodiment. Others are the same as in the third embodiment.

Specifically, the inner diameter of the guide portion 17 is larger than the outer diameter of the push-pull cable 13, and the coiled outer diameter of the guide portion 17 is correspondingly larger.

Even with this configuration, the same effects as those of the third embodiment can be obtained.

FIG. 20 is a perspective view showing a bending structure according to a fifth embodiment of the present invention, FIG. 21 is a side view thereof, and FIG. 22 is a plan view thereof. In the fifth embodiment, the same components as those in the first embodiment will be assigned the same reference numerals and overlapping descriptions will be omitted.

In the bending structure 3 of the present embodiment, the guide portion of the first embodiment is a first guide portion 17, and a coil spring-like guide portion made of the same superelastic alloy as that of the third embodiment is formed on the first guide portion 17. 2 is added as the guide portion 18. Others are the same as in the first embodiment.

The insertion hole 33 b of the axial center portion of the first guide portion 17 has a diameter larger than that of the first embodiment. The second guide portion 18 is inserted into the insertion hole 33b. The drive wire 11 is inserted into the insertion hole 33 a of the first guide portion 17, and the push-pull cable 13 is inserted into the inner circumferential portion of the second guide portion 18.

Therefore, also in the present embodiment, the same function and effect as the first embodiment can be obtained.

FIG. 23 is a partially enlarged front view showing a flexible tube of a bending structure according to a sixth embodiment of the present invention. In the sixth embodiment, the same components as those in the first embodiment are denoted by the same reference numerals and the description will not be repeated.

In the present embodiment, the shape of the ring portion 21 of the flexible tube 15 is changed with respect to the first embodiment. The guide portion 17 may have a shape corresponding to the flexible tube 15 as in the first embodiment, but a cylindrical shape as in the second embodiment, a coil spring shape as in the third and fourth embodiments, and an embodiment It is also possible to adopt a combination of a guide portion having a shape corresponding to the flexible tube 15 and a guide portion in the form of a coil spring, as in 5, or another shape.

Each ring portion 21 is axially biased such that a portion in the circumferential direction narrows the tube slit 25 in the axial direction at an intermediate portion in the circumferential direction. Specifically, the ring portion 21 is configured by the parallel portion 21a and the inclined portion 21b. The tube coupling portions 23a and 23b are integrally provided on the parallel portion 21a.

FIG. 24 is a partially enlarged front view showing a flexible tube of a bending structure according to a modification.

The ring portion 21 of the modified example has a wave shape so as to expand the tube slit 25 in the axial direction at the circumferential middle portion, contrary to the sixth embodiment of FIG.

Also in the sixth embodiment and the modification example, the same function and effect as those of the first embodiment can be obtained.

FIG. 25 is a partially enlarged front view showing a flexible tube of a bending structure according to a seventh embodiment of the present invention. In the seventh embodiment, the same components as those in the first embodiment will be assigned the same reference numerals and overlapping descriptions will be omitted.

The bending structure 3 of the present embodiment is different from the first embodiment in that the number of tube coupling portions 23 a and 23 b of the flexible tube 15 is changed. The guide portion 17 may have a shape corresponding to the flexible tube 15 as in the first embodiment, but a cylindrical shape as in the second embodiment, a coil spring shape as in the third and fourth embodiments, and an embodiment It is also possible to adopt a combination of a guide portion having a shape corresponding to the flexible tube 15 and a guide portion in the form of a coil spring, as in 5, or another shape.

In the present embodiment, three tube coupling portions 23a and 23b are disposed at every 60 degrees in the circumferential direction between the adjacent ring portions 21.

Even if the number of tube coupling portions 23a and 23b is changed as described above, the same function and effect as those of the first embodiment can be obtained.

[Flexible tube]
FIG. 26 is a side view showing a flexible tube of a robot forceps according to an eighth embodiment of the present invention, and FIG. 27 is a front view showing the flexible tube at the time of bending. In the eighth embodiment, the same components as those in the first embodiment are denoted by the same reference numerals and the description will not be repeated.

The flexible tube 15 of the present embodiment is used in place of the bending structure 1 of the first embodiment. For this reason, in the present embodiment, the guide portion 17 is omitted.

The flexible tube 15 has basically the same structure as the flexible tube 1 of the bending structure 1 of the first embodiment. However, the circumferential width w2 of the tube coupling portions 23a and 23b of the flexible tube 15 gradually decreases from the proximal end side to the distal end side. In the present embodiment, in each ring portion 21, the circumferential width w2 of the tube coupling portions 23b and 23a positioned on the distal end side of the tube coupling portions 23a and 23b positioned on the proximal end side is smaller.

Thus, the circumferential width w2 of the tube coupling portion 23a located at the most distal end side is the smallest, and the circumferential width w2 of the tube coupling portion 23b located at the most proximal side is the largest. The axial width w1 of each ring portion 21 is set to about twice the circumferential width w2 of the smallest tube coupling portion 23a located on the tip end side.

The circumferential width w2 in each tube coupling portion 23a, 23b is constant. The circumferential width w2 of the two tube coupling portions 23a and 23b opposed to each other in the radial direction between the ring portions 21 is the same.

In addition, the circumferential direction width w2 of tube joint part 23a, 23b may be constant from base end to the middle, and a fixed section may exist after that it becomes small gradually to a tip after that. As described above, even if a certain section exists, the circumferential width w2 of the tube coupling portions 23a and 23b is gradually reduced from the proximal end side to the distal end side.

The circumferential width w2 of the tube coupling portions 23a and 29b of the present embodiment can be expressed by the following equation.

@ 0001

Here, hX is a dimension of the circumferential width w2 of the tube coupling portions 23a and 29b, LX is a distance from the tip in the axial direction to the center of the tube coupling portions 23a and 29b, w is a load, and εmin is The strain at the first tube joint 23a from the tip in the axial direction.

The strain ε min can be expressed by the following equation.

@ 0002

Here, Lmin is the distance from the tip in the axial direction to the center of the first tube coupling portion 23a, and hmin is the dimension of the circumferential width w2 of the first tube coupling portion 23a.

The tube coupling portions 23a and 23b allow bending of the flexible tube 15 by compressing one side in the circumferential direction and bending so as to extend the other side. In this embodiment, bending in the circumferential direction by the tube coupling portions 23a and 23b shifted by 90 degrees enables bending in two different intersecting directions X and Y.

When the flexible tube 15 of the present embodiment is bent as a whole by bending the tube coupling portion 23b located on the neutral axis, distortion due to bending occurs in each tube coupling portion 23b. Here, in the present embodiment, since the circumferential direction width of the tube coupling portions 23a and 23b gradually decreases from the proximal end side to the distal end side, the distal end side tube coupling portion 23b is easily bent.

Thereby, in the present embodiment, it is possible to sufficiently generate distortion due to bending in the tube coupling portion 23b not only at the proximal end side but also at the distal end side of the flexible tube 15 at the time of bending.

As a result, the strain can be alleviated by suppressing the maximum value of the strain of the proximal tube coupling portions 23a and 23b. Therefore, in the flexible tube 15 of the present embodiment, the uniformity of strain at the time of bending is improved from the proximal tube coupling portion 23b to the distal tube coupling portion 23b, and the anisotropy of the bending operation is suppressed. The stability and accuracy of the bending motion can be improved.

28 (A) and 28 (B) are side views of the flexible tube 15 showing strain distribution, and FIG. 28 (A) is Example 8 and FIG. 28 (B) is a comparative example. In the comparative example, the tube coupling portions 23a and 23b have the same circumferential width from the proximal end to the distal end, and the other configuration is the same as that of the eighth embodiment. In FIG. 28, the relatively large strain is shown thick and the relatively small strain is shown thin.

As shown in FIG. 28A, in the flexible tube 15 of the present embodiment, strain can be sufficiently generated in the tube coupling portions 23a and 23b also on the distal end side, and the tube coupling portions 23a and 23b on the proximal end side Strain can be alleviated.

As a result, in the present embodiment, the uniformity of strain is improved from the proximal end side to the distal end side tube coupling portion 23b, and when bending the bending portion 7 of the robot forceps 1, the anisotropy of the bending operation can be suppressed. It is possible to secure the stability and accuracy of the bending operation and in turn the bending operation by the doctor.

On the other hand, in the comparative example, as shown in FIG. 28B, strain can not be sufficiently generated in the distal end side tube coupling portion 23b, and distortion of the proximal end tube coupling portion 23b is large, The strain of the distal end side tube coupling portion 23b is gradually reduced.

As a result, in the comparative example, the condition of strain is different between the tube coupling portions 23a and 23b at positions shifted by 90 degrees, and when bending the bending portion 7 of the robot forceps 1, an anisotropy of the bending operation is caused and the bending operation is performed. It is difficult compared with Example 1 to ensure the stability and accuracy of the

FIG. 29 is a graph showing the relationship between the maximum value of strain and the bending angle. FIG. 29 is a plot of the load when bent from 0 ° to 90 ° in Example 8 and Comparative Example.

As shown in FIG. 29, in the present example, although the maximum value of strain is higher than that of the comparative example at the initial stage of bending in which the bending angle is about 0 to 30 degrees, compared to the comparative example from 30 to 90 degrees. It is also possible to lower the maximum value of strain.

Thereby, in the present embodiment, even if the bending is in different directions, the load characteristics hardly change, and the hysteresis of the load is small between the bending time and the return time, and the risk of breakage of the tube connection portions 23a and 23b Can be reduced.

FIGS. 30 (A) and 30 (B) are graphs showing the relationship between the bending angle and the increase and decrease of the load value, and FIG. 30 (A) is Example 8 and FIG. 30 (B) is a comparative example.

As shown in FIG. 30A, in the present embodiment, even if the bending angle changes from 0 degrees to 90 degrees, the change rate of the load value changes from -0.3% to 100%, with 0 degrees being 100%. It is 7% and can control the fluctuation of the load value. For this reason, the flexible tube 15 of the present embodiment has less load anisotropy, can suppress the sense of anisotropy at the time of bending operation by a doctor, and enables stable and accurate operation.

FIG. 31 is a graph showing the relationship between the bending angle and the spring constant, and FIG. 31 (A) shows Example 8, and FIG. 31 (B) shows a comparative example.

As shown in FIG. 31A, in the flexible tube 15 of the present embodiment, even if the bending angle is 90 degrees, the rate of increase of the spring constant with respect to the case where the bending angle is 0 degree is about 6%. .

Therefore, in the present embodiment, the variation of the spring constant during the bending operation can be reduced, and the stability and accuracy of the operation can be improved from this point as well.

On the other hand, in the comparative example, as shown in FIG. 31B, when the bending angle is 90 degrees, the increasing rate of the spring constant is about 14% with respect to the case where the bending angle is 0 degree. Therefore, in the comparative example, the spring constant is larger than that of the present example as the bending angle is larger.

Load capacity
FIG. 32 is a graph showing the relationship between the load and the bending angle of the flexible tube 15 according to the eighth embodiment.

In FIG. 32, the load is plotted when the bending angle is bent from 0 degrees to 90 degrees, and then returned to 0 degrees. In the present embodiment, a linear characteristic in which the load is 10 N when the bending angle is 90 degrees is taken as an ideal line IS indicating an ideal load resistance characteristic.

In this embodiment, the load at a bending angle of 90 degrees is about 16 N, which is higher than the ideal line IS, and moreover, the hysteresis is small and the linearity is high between the bending time and the return time. For this reason, the flexible tube 15 of the present embodiment can reduce the risk of breakage of the tube coupling portions 23a and 23b, can increase the load, and is excellent in load resistance.

On the other hand, in the comparative example, the load at a bending angle of 90 degrees is slightly lower than that of this embodiment, and the hysteresis is also large and the linearity is low. Therefore, it is understood that the comparative example is inferior in load resistance to the present example.

[Flexibility]
In this embodiment, as shown in FIG. 32, when the bending angle is 90 degrees, the load is about 16 N, there is no breakage of the tube connection parts 23a and 23b, and the bending radius R is reduced to about 10.2 mm. did it. The bending radius R refers to the bending radius of the neutral axis (the same applies hereinafter).

On the other hand, in the comparative example, when the bending angle is 90 degrees, the load is about 15.5 N, and the bending radius R is about 14.3 mm although there is no breakage of the tube connection parts 23a and 23b.

Therefore, in this embodiment, even if the flexible tube 15 is miniaturized, it can be bent easily and reliably with a small bending radius, and can be excellent in flexibility.

[Effect of Example 8]
The flexible tube 15 of the present embodiment is a flexible tube of a medical manipulator made of super elastic alloy, and between a plurality of ring portions 21 continuously provided in the axial direction and the ring portions 21 adjacent in the axial direction The tube coupling portions 23a and 23b coupled in part in the circumferential direction and the ring coupling portions 21 adjacent in the axial direction are divided on both sides in the circumferential direction of the tube coupling portions 23a and 23b, and bending of the tube coupling portions 23a and 23b is possible And a slit for allowing bending of the flexible tube 15.

Therefore, the flexible tube 15 of the present embodiment can be made compact with excellent load resistance and flexibility.

In the present embodiment, the tube connecting portions 23a and 23b are gradually reduced from one side in the axial direction in which the circumferential width w2 is fixed on bending to the other side in the axial direction moving on flexing.

Therefore, in the present embodiment, strain can be sufficiently generated in the tube coupling portions 23a and 23b not only at the proximal end side but also at the distal end side of the flexible tube 15 during bending, and the proximal end tube coupling portion 23a, The strain of 23b can be relieved.

As a result, in the present embodiment, the uniformity of strain at the time of bending is improved from the proximal tube coupling portion 23b to the distal tube coupling portion 23b, and the load resistance and the flexibility are further improved. It is possible to improve the stability and accuracy of the bending operation and hence the bending operation by the doctor.

Moreover, the flexible tube 15 of the present embodiment can be made to be excellent in torsional rigidity by the configuration in which the flexible tube 15 is connected between the ring portions 21 by the tube coupling portions 23a and 23b.

Further, in the present embodiment, in each ring portion 21, the tube coupling portion 23b on the proximal end side has a smaller dimension in the circumferential direction with respect to the tube coupling portion 23a on the distal end side. The load resistance and the flexibility can be further improved, and the stability and accuracy of the bending operation and the bending operation can be further improved.

The tube coupling portions 23a and 23b couple the ring portions 21 adjacent to each other in the axial direction at two circumferentially opposing positions in the radial direction, and the tube coupling portion 23b on the proximal end side of each ring portion 21 and the distal end side And the tube coupling part 23a of the above are shifted by 180 / N degrees in the circumferential direction, particularly 90 degrees, and bending of the flexible tube 15 in different directions is possible by bending the tube coupling parts 23a and 23b on the distal end side and the proximal end side. And

With this configuration, it is possible to suppress the anisotropy of the bending operation by the uniformity of strain at the time of bending while enabling bending in different directions by the single flexible tube 15.

Further, in the present embodiment, the fluctuation of the spring constant during the bending operation can be reduced, and the stability and accuracy of the bending operation and the bending operation can be improved from this point as well.

In the eighth embodiment, as shown in FIG. 23 of the sixth embodiment, each ring portion 21 may be configured by the parallel portion 21a and the inclined portion 21b. Further, the ring portion 21 may have a wave shape as shown in FIG. 24 of the sixth embodiment. Furthermore, as in the seventh embodiment, the number of tube coupling portions 21a and 23b may be changed to three or the like.

FIG. 33 is a front view showing a bending structure using a flexible tube according to a ninth embodiment of the present invention, and FIG. 34 is a front view showing a guide portion of the bending structure of FIG. In the ninth embodiment, the same components as those in the first and eighth embodiments will be assigned the same reference numerals and overlapping explanations will be omitted.

In the present embodiment, as in the first embodiment, the bending portion 7 of the robot forceps 1 is constituted by the bending structure 3 in which the guide portion 17 is inserted in the flexible tube 15. The flexible tube 15 has the same configuration as that of the eighth embodiment.

The guide portion 17 basically has the same configuration as that of the first embodiment. However, the guide coupling portions 29a and 29b of the guide portion 17 correspond to the tube coupling portions 23a and 23b, and the dimension in the circumferential direction becomes the fixed side at the time of bending. The other side gradually becomes smaller.

Therefore, in the present embodiment, the same effects as those of the first and eighth embodiments can be obtained.

FIG. 35 is a front view showing a bending structure according to Example 10 of the present invention. In the tenth embodiment, the same components as those in the second and ninth embodiments are denoted by the same reference numerals and the description will not be repeated.

The bent structure 3 of the present embodiment is, as in the second embodiment, formed into a cylindrical shape of the guide portion 17. The flexible tube 15 has the same configuration as that of the eighth embodiment.

Therefore, in this embodiment, the same function and effect as those of the second and ninth embodiments can be obtained.

FIG. 36 is a side view showing a bent structure according to Example 11 of the present invention. In the eleventh embodiment, the same components as those in the third and ninth embodiments will be assigned the same reference numerals and overlapping descriptions will be omitted.

As in the third embodiment, the bending structure 3 of the present embodiment is the one in which the guide portion 17 is a coil spring of superelastic alloy. Others are the same shape as Example 9.

Therefore, in the present embodiment, the same function and effect as the third and ninth embodiments can be obtained.

FIG. 37 is a side view showing a bent structure according to Example 12 of the present invention. In the twelfth embodiment, the same components as those in the fourth, ninth, and eleventh embodiments are denoted by the same reference numerals, and redundant description will be omitted.

The bent structure 3 of the present embodiment is, as in the fourth embodiment, the coil-shaped inner and outer diameters of the guide portion 17 larger than those of the eleventh embodiment. Others are the same as in the eleventh embodiment.

Therefore, also in the present embodiment, the same function and effect as the fourth and eleventh embodiments can be obtained.

FIG. 31 is a side view showing a bent structure according to Example 13 of the present invention. In the thirteenth embodiment, the same components as those in the fifth, ninth, and eleventh embodiments are denoted by the same reference numerals, and redundant description will be omitted.

Like the fifth embodiment, the bending structure 3 of the present embodiment uses the guide portion of the ninth embodiment as the first guide portion 17, and the first guide portion 17 is a coil made of the same superelastic alloy as that of the eleventh embodiment. A spring-like guide portion is added as a second guide portion 18. Others are the same as that of the ninth embodiment.

Therefore, also in the present embodiment, the same function and effect as the fifth, ninth, and eleventh embodiments can be obtained.

[Flexible tube]
39 (A) and 39 (B) show a flexible tube of a robot forceps according to a fourteenth embodiment of the present invention, FIG. 39 (A) is a front view, and FIG. 39 (B) is a side view. In the fourteenth embodiment, the same components as those in the first embodiment will be assigned the same reference numerals and overlapping descriptions will be omitted.

The flexible tube 15 of the present embodiment is used in place of the bending structure 1 of the first embodiment. For this reason, in the present embodiment, the guide portion 17 is omitted.

The flexible tube 15 has basically the same structure as the flexible tube 1 of the bending structure 1 of the first embodiment.

However, the axial direction width w1, which is the dimension in the axial direction of each ring portion 21, is equal to or less than the circumferential width w2 of the largest tube coupling portions 23a and 23b described later. In the present embodiment, the circumferential width w2 of the tube coupling portions 23a and 23b is constant, and the circumferential width w2 and the axial width w1 are the same.

In addition, it is important that the axial width w1 be made deformable when the ring portion 21 bends, and it is sufficient that the axial width w1 be equal to or less than the circumferential width w2 of the largest tube coupling portions 23a and 23b.

When the flexible tube 15 of the present embodiment is bent as a whole by bending the tube coupling portion 23b positioned on the neutral axis, the ring portion 21 has the same axial direction as the circumferential width w2 of the tube coupling portions 23a and 23b. Because of the width w1, not only the tube coupling portion 23b but also the ring portion 21 is deformed by bending.

For this reason, distortion due to bending is generated in the tube joint portion 23b and the ring portion 21, thereby generating distortion in the entire structure of the flexible tube 15, reducing the maximum value of distortion and relieving distortion. Is possible.

40 (A) and 40 (B) are front views of the flexible tube 15 showing strain distribution, and FIG. 40 (A) is Example 14 and FIG. 40 (B) is a comparative example. 41 (A) and 41 (B) are perspective views of the flexible tube 15 showing the distribution of strain, FIG. 41 (A) shows Example 14, and FIG. 41 (B) shows a comparative example. FIGS. 42 (A) and (B) are the principal part enlarged views of FIG. 41 (A) and (B) respectively. In FIG. 40 to FIG. 42, the portion with large strain is thin, and the portion with small strain is thick.

As shown in FIGS. 40 (A), 41 (A) and 42 (A), in the flexible tube 15 of this embodiment, the ring portion 21 is deformed together with the tube coupling portion 23b at the time of bending, and the tube coupling portion 23b It is also understood that the ring portion 21 is distorted.

On the other hand, in the comparative example, as shown in FIG. 40 (B), FIG. 41 (B) and FIG. 42 (B), the ring portion 21 is hardly deformed and the strain is large only at the tube connecting portion 23b. It turns out that it has become.

FIG. 43 is a graph showing the relationship between the maximum value of strain and the bending angle. FIG. 43 is a plot of the load at the time of bending from 0 degree to 90 degrees in Example 14 and the Comparative Example.

As shown in FIG. 43, in the present embodiment, the maximum value of strain can be made lower than in the comparative example in the range of 0 degrees to 90 degrees.

Thereby, in the present embodiment, even if the bending is in different directions, the load characteristics hardly change, and the hysteresis of the load is small between the bending time and the return time, and the risk of breakage of the tube connection portions 23a and 23b Can be reduced.

Load capacity
FIG. 44 is a graph showing the relationship between the load and the bending angle of the flexible tube 15 according to the fourteenth embodiment.

FIG. 44 shows the fluctuation of the load when the bending angle is changed from 0 degrees to 90 degrees.

In the present embodiment, the load at a bending angle of 90 degrees is as high as about 9N. Further, by reducing the fluctuation of the maximum value of strain as described above, the hysteresis of the load is reduced between the bending time and the return time.

For this reason, the flexible tube 15 of the present embodiment can reduce the risk of breakage of the tube coupling portions 23a and 23b, can increase the load, and is excellent in load resistance.

On the other hand, in the comparative example, the load when the bending angle is 90 degrees is about 6 N, which is lower than that of the present example, and moreover, as shown in FIG. Therefore, it is understood that the comparative example is inferior in load resistance to the present example.

[Flexibility]
In this embodiment, as shown in FIG. 44, when the bending angle is 90 degrees, the load is about 9 N, there is no breakage of the tube connection parts 23a and 23b, and the bending radius R is reduced to about 8.6 mm. did it.

On the other hand, in the comparative example, when the bending angle is 90 degrees, the load is about 6 N, and the bending radius R is about 14.3 mm although there is no breakage of the tube connection parts 23a and 23b.

Therefore, in this embodiment, even if the flexible tube 15 is miniaturized, it can be bent easily and reliably with a small bending radius, and can be excellent in flexibility.

[Effect of Example 14]
As described above, the flexible tube 15 of the present embodiment is a flexible tube of a medical manipulator made of superelastic alloy, and is adjacent in the axial direction to the plurality of ring portions 21 continuously provided in the axial direction. The tube coupling portions 23a and 23b, which couple between the ring portions 21 in the circumferential direction, and the ring coupling portions 21 adjacent in the axial direction, are partitioned on both sides in the circumferential direction of the tube coupling portions 23a and 23b. , 23b, and a tube slit 25 which allows the flexible tube 15 to bend.

Therefore, the flexible tube 15 of the present embodiment can be made compact while achieving excellent torsional rigidity, load resistance, and flexibility.

And as for the ring part 21 of a present Example, the axial direction width w1 which is a dimension in an axial direction is set below the circumferential direction width w2 which is a dimension in the circumferential direction of the largest tube coupling part 23b.

Therefore, the flexible tube 15 of the present embodiment can be deformed into the ring portion 21 together with the tube coupling portions 23a and 23b at the time of bending, and strain can be generated in the entire structure, and the maximum value of strain is reduced to reduce strain. It becomes possible to ease.

As a result, in the present embodiment, the load resistance and the flexibility can be further improved, and the bending operation and hence the stability and accuracy of the bending operation by the doctor can be improved.

Further, in the present embodiment, the tube coupling portions 23a and 23b couple the ring portions 21 adjacent in the axial direction at two positions in the circumferential direction facing each other in the radial direction, and one tube of one ring direction of each ring portion 21 The coupling portion 23b and the tube coupling portion 23a on the other side in the axial direction are shifted 180 / N degrees, particularly 90 degrees in the circumferential direction, and differ depending on the bending of the tube coupling portions 23a and 23b on one side and the other side in the axial direction The bending of the flexible tube 15 in the direction is enabled.

According to such a configuration, it is possible to suppress the anisotropy of the bending operation by the uniformity of strain at the time of bending and the relaxation of the strain while enabling the bending in different directions by the single flexible tube 15.

In the eighth embodiment, as shown in FIG. 23 of the sixth embodiment, each ring portion 21 may be configured by the parallel portion 21a and the inclined portion 21b. Further, the ring portion 21 may have a wave shape as shown in FIG. 24 of the sixth embodiment. Furthermore, as in the seventh embodiment, the number of tube coupling portions 21a and 23b may be changed to three or the like.

45 (A) and 45 (B) show a flexible tube according to Embodiment 15 of the present invention, FIG. 45 (A) is a side view, and FIG. 45 (B) is a front view. In the fifteenth embodiment, the same components as those in the fourteenth embodiment will be assigned the same reference numerals and overlapping descriptions will be omitted.

In the flexible tube 15 of the fifteenth embodiment, as in the eighth embodiment, the circumferential width w2 of the tube coupling portions 23a and 23b gradually decreases from the proximal end side to the distal end side. Also in the present embodiment, in each ring portion 21, the circumferential width w2 of the tube coupling portions 23b, 23a positioned on the distal end side of the tube coupling portions 23a, 23b positioned on the proximal end side is smaller.

Thus, the circumferential width w2 of the tube coupling portion 23a located at the most distal end side is the smallest, and the circumferential width w2 of the tube coupling portion 23b located at the most proximal side is the largest.

The axial width w1 of the ring portion 21 is the same as the circumferential width w2 of the tube coupling portion 23a located closest to the tip end.

Thus, in the present embodiment, the axial width w1 which is the dimension in the axial direction of the ring portion 21 is set to be equal to or less than the circumferential width w2 which is the dimension in the circumferential direction of the largest tube coupling portion 23b.

As in the eighth embodiment, the flexible tube 15 having this configuration has the tube coupling portions 23a and 23b gradually decreasing in width from the proximal end to the distal end, so the distal end tube coupling portion 23b is bent. It will be easy.

Thereby, in the present embodiment, it is possible to sufficiently generate distortion due to bending in the tube coupling portion 23b not only at the proximal end side but also at the distal end side of the flexible tube 15 at the time of bending.

As a result, the strain can be alleviated by suppressing the maximum value of the strain of the proximal tube coupling portions 23a and 23b. Therefore, in the flexible tube 15 of the present embodiment, the uniformity of strain at the time of bending is improved from the proximal tube coupling portion 23b to the distal tube coupling portion 23b, and the anisotropy of the bending operation is suppressed. The stability and accuracy of the bending motion can be improved.

46 (A) and 46 (B) are front views of the flexible tube 15 showing strain distribution, and FIG. 46 (A) is Example 15, and FIG. 46 (B) is a comparative example. 47 (A) and 47 (B) are perspective views of the flexible tube 15 showing the distribution of strain, FIG. 47 (A) is an example 15, and FIG. 47 (B) is a comparative example. FIG. 48 is an enlarged view of a portion of XLVIII in FIG. FIG. 46 shows a portion with large strain thick and a portion with small strain thin. On the contrary, in FIGS. 47 and 48, the portion with large strain is thin and the portion with small strain is thick.

In the comparative example, the tube connecting portions 23a and 23b have the same circumferential width from the proximal end to the distal end, and the other configuration is the same as that of the comparative example used in the first embodiment.

As shown in FIGS. 46A, 47A, and 48, in the flexible tube 15 of the present embodiment, strain can be sufficiently generated in the tube coupling portions 23a and 23b also on the distal end side, The strain of the proximal tube couplings 23a and 23b can be relaxed.

As a result, in the present embodiment, the uniformity of strain is improved from the proximal end side to the distal end side tube coupling portion 23b, and when bending the bending portion 7 of the robot forceps 1, the anisotropy of the bending operation can be suppressed. It is possible to secure the stability and accuracy of the bending operation and in turn the bending operation by the doctor.

On the other hand, in the comparative example, as shown in FIG. 46 (B) and FIG. 47 (B), strain can not be sufficiently generated in the distal end side tube connecting portion 23b, and the proximal end tube connecting portion The strain of 23 b is large, and the strain of the tube coupling portion 23 b on the distal end side is gradually reduced.

As a result, in the comparative example, the condition of strain is different between the tube coupling portions 23a and 23b at positions shifted by 90 degrees, and when bending the bending portion 7 of the robot forceps 1, an anisotropy of the bending operation is caused and the bending operation is performed. It is difficult compared with Example 1 to ensure the stability and accuracy of the

Thus, in the present embodiment, since the axial width w1 of the ring portion 21 is the same as the circumferential width w2 of the smallest tube coupling portion 23a, the ring portion 21 can be reliably deformed during bending. The strain can be reliably relieved.

Further, in the present embodiment, since the uniformity of strain at the time of bending is improved from the proximal tube coupling portion 23b to the distal tube coupling portion 23b, the strain due to the deformation of the ring portion 21 is alleviated. Thus, the load resistance and the flexibility can be further improved, and the bending operation and, in turn, the stability and accuracy of the bending operation by the doctor can be improved.

In addition, also in the present embodiment, the same function and effect as the fourteenth embodiment can be exhibited.

49 (A) and 49 (B) show a flexible tube according to Embodiment 16 of the present invention, FIG. 49 (A) is a side view, and FIG. 49 (B) is a front view. In the sixteenth embodiment, the same components as those in the fourteenth and fifteenth embodiments will be assigned the same reference numerals and overlapping explanations will be omitted.

The flexible tube 15 of the present embodiment is such that the axial width w1 of the ring portion 21 is set to be gradually smaller from the proximal end side to the distal end side with respect to the fifteenth embodiment.

With this configuration, in the present embodiment, the ring portion 21 can be reliably deformed together with the tube coupling portions 23a and 23b at the time of bending, and the strain of the ring portion 21 can be made uniform from the proximal end side to the distal end side. .

Therefore, in the present embodiment, the anisotropy can be more reliably suppressed to enable stable and accurate operation.

In addition, also in the sixteenth embodiment, the same function and effect as the fourteenth embodiment can be exhibited.

FIG. 50 is a front view showing a bent structure using a flexible tube according to Embodiment 17 of the present invention, and FIG. 51 is a front view showing a guide portion of the bent structure of FIG. In the seventeenth embodiment, the same components as those in the first and 14th embodiments will be assigned the same reference numerals and overlapping explanations will be omitted.

In the present embodiment, as in the first embodiment, the bending portion 7 of the robot forceps 1 is constituted by the bending structure 3 in which the guide portion 17 is inserted in the flexible tube 15. The flexible tube 15 has the same configuration as that of the fourteenth embodiment.

The guide portion 17 basically has the same configuration as that of the first embodiment. However, the thickness in the axial direction of the guide body 27 of the present embodiment is set so as to be within the range of the ring portion 21 of the flexible tube 15.

Thereby, the dimension in the axial direction of the guide body 27 is equal to or less than the dimension in the circumferential direction of the largest guide coupling portions 29a and 29b. In this embodiment, the dimensions of the guide coupling portions 29a and 29b in the circumferential direction are constant, and the dimensions of the guide coupling portions 29a and 29b in the circumferential direction are the same as the dimensions of the guide body 27 in the axial direction. .

Therefore, in the present embodiment, the same function and effect as those of the first and fourth embodiments can be obtained.

FIG. 52 is a front view showing a bending structure according to an eighteenth embodiment of the present invention. In the eighteenth embodiment, configurations corresponding to those in the second and 17th embodiments are denoted by the same reference numerals, and redundant descriptions will be omitted.

The bent structure 3 of the present embodiment is, as in the second embodiment, formed into a cylindrical shape of the guide portion 17. The flexible tube 15 has the same configuration as that of the fourteenth embodiment.

Therefore, in this embodiment, the same function and effect as those of the second and 17th embodiments can be obtained.

FIG. 53 is a side view showing a bent structure according to Example 19 of the present invention. In the nineteenth embodiment, configurations corresponding to those in the third and seventeenth embodiments are denoted by the same reference numerals, and duplicate descriptions will be omitted.

As in the third embodiment, the bending structure 3 of the present embodiment is the one in which the guide portion 17 is a coil spring of superelastic alloy. Others are the same shape as Example 14.

Therefore, in the present embodiment, the same function and effect as in the third and seventeenth embodiments can be obtained.

FIG. 54 is a side view showing a bent structure according to Example 20 of the present invention. In the twentieth embodiment, parts corresponding to those in the fourth and nineteenth embodiments are assigned the same reference numerals and duplicate explanations will be omitted.

The bending structure 3 of the present embodiment is, as in the fourth embodiment, the one in which the coil-shaped inner and outer diameters of the guide portion 17 are larger than those of the nineteenth embodiment. Others are the same as that of the nineteenth embodiment.

Therefore, also in the present embodiment, the same function and effect as in the third and 19th embodiments can be obtained.

FIG. 55 is a side view showing a bent structure according to Example 21 of the present invention. In the twenty-first embodiment, the same components as those in the fifth, seventeenth, and nineteenth embodiments will be assigned the same reference numerals and overlapping descriptions will be omitted.

Like the fifth embodiment, the bending structure 3 of the present embodiment uses the guide of the seventeenth embodiment as the first guide 17, and the first guide 17 has a coil made of the same superelastic alloy as that of the nineteenth embodiment. A spring-like guide portion is added as a second guide portion 18. Others are the same as that of the seventeenth embodiment.

Therefore, also in this embodiment, the same function and effect as those of Embodiments 5, 17 and 19 can be exhibited.

1 Robot forceps (medical manipulator)
DESCRIPTION OF SYMBOLS 3 bending structure 15 flexible tube 17 guide part 21 ring part 23a, 23b tube coupling part 25 tube slit 27 guide body 29a, 29b guide coupling part 31 guide slit

Claims (18)

A flexible tube made of a superelastic alloy,
And a guide unit disposed in the flexible tube and guiding a drive wire of the medical manipulator.
The flexible tube has a plurality of ring portions continuously provided in the axial direction of the flexible tube, a tube coupling portion which couples the ring portions adjacent in the axial direction in a circumferential direction, and the axial direction And a slit defined on both sides in the circumferential direction of the tube coupling portion between adjacent ring portions to allow bending of the flexible tube by bending of the tube coupling portion,
At least the bending stiffness between the ring portions of the flexible tube is set to be smaller than the bending stiffness of the tube coupling portion of the flexible tube.
Bent structure of a medical manipulator characterized in that. The bending structure according to claim 1, wherein
The tube coupling portion couples between the ring portions adjacent in the axial direction at two circumferentially opposite positions in the radial direction,
The tube coupling portion on one side in the axial direction of each ring portion and the tube coupling portion on the other side in the axial direction are circumferentially offset by 180 / N degrees, and the tubes on one side and the other side in the axial direction The bending of the joint enables bending of the flexible tube in different directions, and N is an integer of 2 or more.
Bent structure characterized in that. It is a bending structure of Claim 1 or 2, Comprising:
The guide portion is disposed at least at a central portion of the flexible tube to inhibit movement of the drive wire beyond the central portion.
Bent structure characterized in that. A bending structure according to any one of claims 1 to 3, wherein
The guide unit is
It is made of a material whose Young's modulus is smaller than that of the flexible tube,
A plurality of disc-shaped guide bodies each located on an inner periphery of the plurality of ring portions of the flexible tube and having an insertion hole through which the drive wire is inserted;
A guide coupling portion which couples the axially adjacent guide bodies in a circumferential direction corresponding to the tube coupling portion of the flexible tube;
Slits defined on both sides of the guide coupling portion between the axially adjacent guide bodies;
The bending structure characterized by having. A flexible tube for a medical manipulator made of a superelastic alloy, comprising:
A plurality of ring portions connected in the axial direction;
A tube coupling portion for coupling the axially adjacent ring portions in a circumferential direction;
And a slit defined on both sides in the circumferential direction of the tube coupling portion between the axially adjacent ring portions to allow bending of the flexible tube by bending of the tube coupling portion,
The tube connecting portion is such that the dimension in the circumferential direction is gradually reduced from one side in the axial direction which is a fixed side at the time of bending to the other side in the axial direction which is a movable side at the time of bending.
A flexible tube characterized by The flexible tube according to claim 5, wherein
In each ring portion, the tube coupling portion on one side in the axial direction has a smaller dimension in the circumferential direction than the tube coupling portion on the other side in the axial direction.
A flexible tube characterized by The flexible tube according to claim 5 or 6, wherein
The tube coupling portion couples between the ring portions adjacent in the axial direction at two circumferentially opposite positions in the radial direction,
The tube coupling portion on one side in the axial direction of each ring portion and the tube coupling portion on the other side in the axial direction are circumferentially offset by 180 / N degrees, and the tubes on one side and the other side in the axial direction The bending of the joint allows bending of the flexible tube in different directions,
N is an integer of 2 or more,
A flexible tube characterized by A bending structure comprising the flexible tube according to any one of claims 5 to 7, comprising:
A guide portion disposed in the flexible tube and guiding a drive wire of the medical manipulator;
At least the bending stiffness between the ring portions of the flexible tube is set to be smaller than the bending stiffness of the tube coupling portion of the flexible tube.
Bent structure characterized in that. The bending structure according to claim 8, wherein
The guide portion is disposed at least at a central portion of the flexible tube to inhibit movement of the drive wire beyond the central portion.
Bent structure characterized in that. A bending structure according to claim 8 or 9, wherein
The guide unit is
It is made of a material whose Young's modulus is smaller than that of the flexible tube,
A plurality of disc-shaped guide bodies each located on an inner periphery of the plurality of ring portions of the flexible tube and having an insertion hole through which the drive wire is inserted;
A guide coupling portion which couples the axially adjacent guide bodies in a circumferential direction corresponding to the tube coupling portion of the flexible tube;
And a guide slit partitioned on both sides of the guide coupling portion between the axially adjacent guide bodies,
The dimension of the circumferential direction is gradually reduced from one side in the axial direction which is a fixed side at the time of bending to the other side in the axial direction which is a movable side at the time of bending.
Bent structure characterized in that. A flexible tube for a medical manipulator made of a superelastic alloy, comprising:
A plurality of ring portions connected in the axial direction;
A tube coupling portion for coupling the axially adjacent ring portions in a circumferential direction;
And a slit defined on both sides in the circumferential direction of the tube coupling portion between the axially adjacent ring portions to allow bending of the flexible tube by bending of the tube coupling portion,
The dimension of the ring portion in the axial direction is equal to or less than the dimension of the largest tube coupling portion in the circumferential direction.
A flexible tube characterized by The flexible tube according to claim 11, wherein
The axial dimension of the ring portion is the same as the circumferential dimension of the smallest tube joint.
A flexible tube characterized by The flexible tube according to claim 11, wherein
The dimension of the ring portion in the axial direction is gradually reduced from one side of the axial direction which is a fixed side at the time of bending to the other side of the axial direction which is a movable side at the time of bending.
A flexible tube characterized by The flexible tube according to any one of claims 11 to 13, wherein
The tube connecting portion is such that the dimension in the circumferential direction is gradually reduced from one side in the axial direction which is a fixed side at the time of bending to the other side in the axial direction which is a movable side at the time of bending.
A flexible tube characterized by The flexible tube according to any one of claims 11 to 14, wherein
The tube coupling portion couples between the ring portions adjacent in the axial direction at two circumferentially opposite positions in the radial direction,
The tube coupling portion on one side in the axial direction of each ring portion and the tube coupling portion on the other side in the axial direction are circumferentially offset by 180 / N degrees, and the tubes on one side and the other side in the axial direction The bending of the joint allows bending of the flexible tube in different directions,
N is an integer of 2 or more,
A flexible tube characterized by A bending structure comprising the flexible tube according to any one of claims 11 to 15, wherein
A guide portion disposed in the flexible tube and guiding a drive wire of the medical manipulator;
At least the bending stiffness between the ring portions of the flexible tube is set to be smaller than the bending stiffness of the tube coupling portion of the flexible tube.
Bent structure characterized in that. The bending structure according to claim 16, wherein
The guide portion is disposed at least at a central portion of the flexible tube to inhibit movement of the drive wire beyond the central portion.
Bent structure characterized in that. The bending structure according to claim 16 or 17, wherein
The guide unit is
It is made of a material whose Young's modulus is smaller than that of the flexible tube,
A plurality of disc-shaped guide bodies each located on an inner periphery of the plurality of ring portions of the flexible tube and having an insertion hole through which the drive wire is inserted;
A guide coupling portion which couples the axially adjacent guide bodies in a circumferential direction corresponding to the tube coupling portion of the flexible tube;
And a guide slit partitioned on both sides of the guide coupling portion between the axially adjacent guide bodies,
The dimension of the guide body in the axial direction is equal to or less than the dimension in the circumferential direction of the largest guide coupling portion.
Bent structure characterized in that.

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