Joint

Abstract

An elastically deformable joint (2) having a proximal end (4), a distal end (6), and an axis (8), the elastically deformable joint including a helical structure, the helical structure (12) including a plurality of integrally formed body portions (10), each body portion including a turn of the helical structure and movable relative to an adjacent body portion, the elastically deformable joint further including a plurality of body joint members (14), each formed on a respective body portion, adjacent body joint members being capable of abutting each other to form a body joint, and the elastically deformable joint further including first and second guides (22, 24) extending axially from the distal end to the proximal end of the elastically deformable joint. [Selected figure] Figure 3

Description

Technical Field

[0001] The present invention relates to joints, and more particularly to joints for surgical devices used in minimally invasive surgery (MIS) procedures, and methods of manufacturing such joints. The present invention particularly relates to elongate flexible joints forming part of a device for use in endoscopic procedures. It should be noted that the joints of the present invention can be used for other applications, and the methods of the present invention can be used for manufacturing similar devices having different applications.

Background Art

[0002] MIS has been introduced to improve postoperative scarring and shorten recovery times. In MIS, a small incision is made in the abdominal wall (e.g., laparoscopic surgery) or it is necessary to introduce through a narrow natural opening such as the esophagus. For MIS, there is a requirement mainly for the function of sufficiently observing and operating on the target anatomical structure from an access site that is not most directly and ergonomically optimally positioned. To provide the surgeon with appropriate visual feedback and dexterous tissue manipulation, endoscopes and other surgical instruments need to be provided with a bendable and controllable section, also called an elastically deformable joint. The elastically deformable joint usually needs to provide a large central lumen without control tendons that would interfere with the incorporation of lighting means such as glass fiber cords and electric wires for the optical unit and camera unit. In the case of surgical tools acting at the distal end of large surgical instruments, the internal space can serve to install the flushing of the suction unit that may be required. Another essential characteristic of such an elastically deformable joint is that its bending direction is controllable by control tendons. To achieve planar bending, a pair of tendons is often used. To achieve spatial bending, 3 out of 4 tendons are often used.

[0003] It is known to use one capstan to control a pair of tendons with one degree of freedom (DOF) of curvature. The two tendons are configured antagonistically, and an increase in one tendon is equal to a decrease in the other tendon. The axial channels within the elastically deformable joint are for guiding the tendons. According to the principle for realizing controllable curvature, known elastically deformable joints can be classified into two categories. According to the principle for realizing controllable curvature, known elastically deformable joints can be classified into two categories.

[0004] <Curved joint> The first category is curved joints that utilize the elasticity of materials. These joints are compliant mechanisms driven by tendons. The tendons pass through channels within the bendable part and reach the distal end of the elastically deformable joint. By pulling the tendons, the elastically deformable joint bends in the corresponding direction. The curved joint completely depends on the dimensions of the curved part and the material properties of the joint such as rigidity and yield strength. These geometric and material properties also determine the torsional rigidity of the joint and how much it can withstand axial and lateral forces. In these designs, often laser profiling technology or electrical discharge matching technology is used to notch metal tubes. In these designs, nitinol or other materials with low elastic modulus may be selected. The design principle is to cut away unnecessary materials to create space for bending. This type of joint is often designed as a combination of thin and thick sections, so stress concentration often occurs in the corner regions. As a result, there is a concern that plastic deformation and fatigue may occur after long-term use. It is also difficult to open tendon guide channels in this type of elastically deformable joint. Conventional methods include cutting channels from a small inlet using wire EDM or inserting a tendon guide plate into slots formed in the wall of the tube. The former is difficult to manufacture, and the latter is difficult to assemble.

[0005] <Rigid joint> Other elastically deformable joints achieve curvature using multiple small rigid joints. This type of elastically deformable joint is constructed by stacking a series of small tubular segments rather than using a single continuum. The movement between two adjacent segments is restricted by connection means provided on the surface of the tube segments. These connection means include rolling joints and hinge joints. The two parts of a rolling joint rotate relative to each other along a circular track defined by the curvature of the joint, while the two parts of a hinge joint rotate relative to a common pivot point. The connection means are typically designed as jigsaw puzzle pieces that fit together to limit movement in unwanted directions. Creating tendon guide channels is not difficult for small tubular segments, and there are no fatigue problems associated with the curvature of the joint. However, friction and backlash are introduced in this design category. Due to the non-linear characteristics of friction and backlash, this type of flexible joint has a less smooth body curvature and lower chip positioning accuracy compared to a curved joint. Furthermore, this type of joint is difficult to assemble compared to the single design of a curved joint. Summary of the Invention

[0006] According to a first aspect of the present invention, there is provided an elastically deformable joint having a proximal end, a distal end, and an axis, wherein the elastically deformable joint includes a helical structure, the helical structure includes a plurality of integrally formed body portions, each body portion includes a turn of the helical structure and is movable relative to an adjacent body portion, the elastically deformable joint further includes a plurality of body joint members, each body joint member is formed on a respective body portion, and adjacent body joint members can contact each other to form a body joint, and the elastically deformable joint further includes first and second guides that extend axially from the distal end to the proximal end of the elastically deformable joint.

[0007] Forming an elastically deformable joint using a helical structure means that stress is more evenly distributed along the body of the elastically deformable joint during bending. Since the helical structure represents an aggregate of an infinite number of bending points, it is difficult to control it completely and reliably. However, due to the presence of the body joint, the elastically deformable joint can be accurately controlled.

[0008] In an embodiment of the present invention, the helical structure includes a spring, has good torsional rigidity, and very low axial rigidity and bending rigidity. The body joint restricts the number of degrees of freedom (DOF) and improves the axial rigidity of the elastically deformable joint.

[0009] The helical structure may have a substantially constant pitch along the length of the elastically deformable joint. In other embodiments of the present invention, the pitch of the helical structure may vary along the length of the elastically deformable joint. In some embodiments of the present invention, the pitch of the helical structure decreases along the length of the flexible joint.

[0010] In such an embodiment of the present invention, the size of the body joint also changes in response to the change in the pitch of the helical structure.

[0011] In an embodiment of the present invention, the pitch of the helical structure decreases along the length of the flexible joint, and the size of the body joint member also decreases along the length of the flexible joint.

[0012] In an embodiment of the present invention, the elastically deformable joint is made of a single material. In other embodiments of the present invention, the elastically deformable joint is made of a plurality of materials.

[0013] The specific material for making the elastically deformable joint is determined by the use to which the surgical instrument including the elastically deformable joint is put.

[0014] The helical structure may be a single, double, or triple helical structure. When this structure is a double helical structure, a plurality of pairs of body joint portions constituting the body joint are symmetrically arranged.

[0015] When the axial length is constant, the double helix design has higher bending stiffness compared to the single helix design.

[0016] Generally, when the pitch distance is constant, a helical structure using more strands (i.e., double or triple helix) has increased overall stiffness compared to a helical structure using fewer strands.

[0017] When the helical structure has an even number of strands, for example, when the helical structure is a double or quadruple structure and the starting points of the strands are evenly assigned, a plurality of pairs of body joint portions constituting the body joint are symmetrically arranged with respect to the bending surface of the flexible joint. As a result, when this structure is twisted clockwise or counterclockwise, the torsional stiffness is the same.

[0018] On the other hand, in a helical structure having an odd number of strands, for example, a single helical structure, when this structure is twisted about its central axis, the torsional stiffness when twisted clockwise is different from that when twisted counterclockwise.

[0019] The specific helical structure of the elastically deformable joint is determined by the use to which the surgical instrument including the deformable joint is put.

[0020] The elastically deformable joint according to an embodiment of the present invention includes a plurality of body portions integrally formed with each other. This means that the disadvantages associated with the assembly of a plurality of individual body portions are overcome.

[0021] The elastically deformable joint according to an embodiment of the present invention can be curved by using a pair of antagonistic tendons. The tendons are guided through the elastically deformable joint by first and second guides.

[0022] In an embodiment of the present invention, the first and second guides each include a first and a second channel, and each channel extends from the distal end to the proximal end of the elastically deformable joint.

[0023] The channels are formed at any convenient portion of the elastically deformable joint and can guide and protect the tendon during use of the elastically deformable joint.

[0024] In an embodiment of the present invention, the first and second channels are arranged with a body joint portion interval in the radial direction. Thus, when curvature is activated by the antagonistic tendons extending through the first and second channels respectively, curvature occurs at the body joint.

[0025] In an embodiment of the present invention, each body portion includes two body joint members arranged at a substantially 180-degree interval from each other in the radial direction.

[0026] The first and second guides are arranged 180 degrees apart from each other in the radial direction. In an embodiment of the present invention, the first and second guides are arranged at a substantially 90-degree interval from each of the body joint portions in the radial direction

[0027] With such a configuration, when the antagonistic tendons are arranged within the first and second guides, curvature can be achieved via the tendons depending on the positions of the first and second guides with respect to the body joint portion.

[0028] The body joint is arranged to extend in a direction substantially coaxial with the axis of the elastically deformable joint. In other arrangements, the body joint can extend along a helical path.

[0029] The arrangement of the body joint is determined by the application in which the surgical instrument including the elastically deformable joint is used

[0030] The first and second guides can extend substantially parallel to the body joint regardless of the arrangement of the body joint.

[0031] During bending, the body joint portions are adjacent to each other and move relative to each other to enable the occurrence of bending.

[0032] The body joint member has any suitable shape for forming any suitable body joint.

[0033] In an embodiment of the present invention, each body joint includes a rolling joint.

[0034] In such an embodiment of the present invention, adjacent body joint members contact each other during the bending of the elastically deformable joint, and the contact surfaces of each body joint member curve.

[0035] In an embodiment of the present invention, each body joint portion is substantially cylindrical and has an axis of a cylinder that is substantially perpendicular to the axis of the elastically deformable joint. The contact surface of each body joint includes the curved surface of the cylinder.

[0036] In an embodiment of the present invention, the elastically deformable joint includes third and fourth guides, and the third and fourth guides extend along the neutral bending line of the elastically deformable joint.

[0037] In an embodiment of the present invention, the third and fourth guides each include a third and a fourth channel.

[0038] In an embodiment of the present invention, a combination of a compliant or elastically deformable joint structure in the form of a helical spring and a rigid structure in the form of a body joint is provided. Thereby, a joint is obtained that is more flexible than known similar joints and in which stress is more evenly distributed throughout when bent. Further, due to the compliant structure of the spring, the overall elasticity becomes the dominant force affecting the curved shape, rather than local friction between the body joint portions of the body, as in the case of known similar joints. As a result, all body joints exhibit equal rotation angles, and the elastically deformable joint according to an embodiment of the present invention has a constant bending curvature.

[0039] In an embodiment of the present invention, the elastically deformable joint has a diameter of about 9 mm and an axial length of about 18 mm.

[0040] The elastically deformable joint has an inner diameter of about 5 mm.

[0041] In one embodiment of the present invention, the elastically deformable joint is made of 316 stainless steel.

[0042] According to a second aspect of the present invention, an elastically deformable joint structure including first and second elastically deformable joints according to the first aspect of the present invention is provided. The first and second elastically deformable joints are connected in series with each other such that the proximal end of the first elastically deformable joint is connected to the distal end of the second elastically deformable joint to form a connection portion. The connection portion includes first and second connection guides, and the first and second guides of the first elastically deformable joint are coupled to the first and second guides of the second elastically deformable joint, respectively, to form first and second structural guides. The second elastically deformable joint includes third and fourth guides extending along the neutral bending line of the second elastically deformable joint.

[0043] In an embodiment of the present invention, the first and second elastically deformable joints constituting the elastically deformable joint structure are integrally formed with each other.

[0044] In an embodiment of the present invention, the first elastically deformable joint is offset by approximately 90 degrees radially from the second elastically deformable joint. In such a structure, the joint can bend spatially by using two pairs of tendons.

[0045] In such an embodiment, the first and second guides of the first elastically deformable joint are offset by approximately 90 degrees radially from the first and second guides of the second elastically deformable joint and are substantially collinear with the third and fourth guides of the second elastically deformable joint.

[0046] In such an embodiment of the present invention, the first and second connection guides extend substantially axially within the connection portion.

[0047] In another embodiment of the present invention, the first elastically deformable joint has substantially the same radial direction as the second elastically deformable joint. This results in a structure in which an S-shaped curve can be realized by using two pairs of tendons.

[0048] In such an embodiment of the present invention, the first and second connection guides extend along a substantially helical path. As a result, the first and second guides of the first elastically deformable joint are respectively connected to the third and fourth guides of the second flexible portion.

[0049] Thus, in use, the tendons associated with the first elastically deformable joint are guided to extend along the neutral bending line of the second elastically deformable joint. In other embodiments, the first and second connection guides may define different paths and may not be helical, but still generally follow a curved or stepped path to couple the first and second guides of the first elastically deformable joint to the third and fourth guides of the second elastically deformable joint.

[0050] The advantage of this arrangement is that there is no need to use a Bowden cable or the like to arrange the tendon as in the prior art.

[0051] In another embodiment of the second aspect of the present invention, the elastically deformable joint structure may include two or more elastically deformable joints. In such an embodiment, adjacent elastically deformable joints of the present invention may have the same radial direction as each other, or one elastically deformable joint may be rotated 90 degrees radially with respect to the adjacent joint. There can be different combinations of orientations in an elastically deformable joint structure including a plurality of elastically deformable joints.

[0052] In such an embodiment, the elastically deformable joint structure includes a plurality of connecting portions that connect the distal end of one elastically deformable joint and the proximal end of the adjacent elastically deformable joint.

[0053] All elastically deformable joints constituting such an elastically deformable joint structure include third and fourth guides that extend along the neutral bending line of each elastically deformable joint, separately from the first elastically deformable joint. This ensures that the elastically deformable joints constituting the elastically deformable joint structure can be separated from each other. That is, by ensuring that the tendon associated with one elastically deformable joint extends along the neutral bending lines of all other elastically deformable joints constituting the elastically deformable joint structure, the operation of these tendons causes bending only of the elastically deformable joints associated with these tendons.

[0054] In some embodiments of the present invention, the first elastically deformable joint includes the third and fourth guides even if not necessary. This is because the manufacturing process can be simplified.

[0055] In an embodiment of the present invention, all guides include channels formed in the body portion of each elastically deformable joint.

[0056] In an embodiment of the present invention, the elastically deformable joint structure further includes a gimbal connected in series to the elastically deformable joint.

[0057] In an embodiment of the present invention, the gimbal is located between the distal end of the elastically deformable joint structure and the distal end of the first elastically deformable joint.

[0058] In another embodiment of the present invention, the gimbal may be located between two elastically deformable joints. In another embodiment of the present invention, the gimbal may be located between the proximal end of the elastically deformable joint and the proximal end of the elastically deformable joint structure.

[0059] According to a third aspect of the present invention, there is provided a surgical instrument including a proximal end, a distal end, and an elastically deformable joint according to the second aspect of the present invention.

[0060] According to a fourth aspect of the present invention, there is provided a surgical instrument including a proximal end, a distal end, and an elastically deformable joint structure according to the second aspect of the present invention.

[0061] According to a fifth aspect of the present invention, there is provided a method for forming an elastically deformable joint according to the first aspect of the present invention, including the step of forming a member of the elastically deformable joint by an additive manufacturing technique.

Brief Description of the Drawings

[0062] Hereinafter, the present invention will be described with reference to the drawings and examples.

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Embodiments for Carrying Out the Invention

[0063] As shown in FIG. 1, the elastically deformable joint according to the embodiment of the present invention is indicated by reference numeral 2. The joint 2 is shown in a neutral or unbent position in FIG. 1.

[0064] The joint includes a proximal end 4, a distal end 6, and an axis 8. The joint includes a plurality of integrally formed body portions 10, including turns of the helical spring 12 in this embodiment. The joint further includes a plurality of body joint portions 14 formed on the body portion 10. In this embodiment, each body portion or turn of the helical spring includes two body joint portions 14 arranged in diametrically opposite positions, that is, separated from each other by 180 degrees in the radial direction. Each body joint portion 14 is arranged so as to be adjacent to the body joint portion on the adjacent body portion 10. The adjacent body joint portions 14 jointly constitute the body joint 16. In this embodiment, the body joint 16 includes a rolling joint. However, in other embodiments, the body joint may be other joints such as a hinge joint or a pivot joint.

[0065] The elastically deformable joint 2 includes a bendable portion in the form of a helical spring 12. Axial compression of this bendable portion is constrained by the body joints 16. In this embodiment, the body joints 16 each include a rigid rolling contact joint located at each body portion 10. Each body joint portion 14 is cylindrical, and the axis of each cylinder is substantially orthogonal to the axis 8 of the joint 2. In this embodiment, the body joints 16 are arranged on two lines that extend axially 180 degrees apart on the surface of the elastically deformable joint 2. Due to the restraint of the joints 16, the spring 12 has only one bending DOF that is controlled by the antagonistic tendons 18, 20. Details will be described later.

[0066] The elastically deformable joint 2 further includes first and second guides in the form of channels 22, 24. The first and second guides guide the tendons 18, 20 to pass through the joint 2. The tendons 18, 20 are attached to the distal end 6 of the elastically deformable joint 2 by the punch points 26 and extend through the elastically deformable joint 2 and the proximal end 4. The tendons 18, 20 are a pair of antagonistic tendons and can be used to control the bending of the joint 2 in a known manner. In particular, by pulling one of the tendons 18, 20, each body joint 16 deflects at a small angle. Due to these small angles, the elastically deformable joint 2 can bend at a large angle of up to 180 degrees or more.

[0067] As shown in FIG. 2, a part of the elastically deformable joint 2 is shown in a curved state. This curved state is realized by pulling the tendon 18.

[0068] The elastically deformable joint 2 shown in FIGS. 1 and 2 bends only in a 2D plane.

[0069] As shown in FIG. 3, an elastically deformable joint structure according to an embodiment of the second aspect of the present invention is denoted by reference numeral 30. The elastically deformable joint structure 30 includes a first elastically deformable joint 32 and a second elastically deformable joint 34. The first elastically deformable joint 32 and the second elastically deformable joint 34 are connected in series such that the proximal end 36 of the first elastically deformable joint 32 is connected to the distal end 38 of the second elastically deformable joint 34 to form a connection portion 40.

[0070] The portions of the first and second elastically deformable joints 32 and 34 corresponding to the portion of the elastically deformable joint 2 shown in FIG. 1 are denoted by corresponding reference numerals for convenience of explanation.

[0071] The first elastically deformable joint 32 is driven by tendons 18, 20 guided through the first elastically deformable joint 32 by the first and second channels 22, 24. The tendons 18, 20 are fixed to the distal end 6 of the first elastically deformable joint 32 by the punch points 26. The second elastically deformable joint 34 is driven by tendons 180, 200 guided through the second elastically deformable joint 34 by the first and second channels 220, 240, and is fixed to the distal end 38 of the second elastically deformable joint 34 by the punch points 26. The second elastically deformable joint 34 further includes third and fourth guides in the form of channels 50, 52. The channels 50, 52 guide the tendons 18, 20 through the second elastically deformable joint 34. When the tendons 18, 20 are activated to bend the first elastically deformable joint 32, the second elastically deformable joint includes third and fourth guides in the form of channels 50, 52 that extend along the neutral bending line in the second elastically deformable joint 34 to ensure that the second elastically deformable joint 34 does not bend. In this embodiment, the channels 50, 52 extend through the body joint portion 14 in the second elastically deformable joint 34. This means that when the tendons 18, 20 are pulled to bend the first elastically deformable joint 32, it does not affect the second elastically deformable joint 34. Thereby, the joints 32, 34 are separated from each other.

[0072] The connection part 40 includes first and second connection guides in the form of channels 60, 62. The first and second connection guides are connected to the channels 22, 24 in the first elastically deformable joint and to the channels 50, 52, thereby forming structural channels 64, 66 that extend from the distal end 6 of the first elastically deformable joint 32 to the proximal end 4 of the second elastically deformable joint 34. Thereby, the tendons 22, 24 are guided from the distal end 6 of the first elastically deformable joint 32 through both joints 32, 34.

[0073] In this embodiment of the present invention, the first elastically deformable joint 32 is substantially offset by 90 degrees in the radial direction from the second elastically deformable joint 34. This means that when the channels 22, 24 are axially aligned with the channels 50, 52, the connecting channels 60, 62 extend substantially coaxially with the axis 8 of the first and second elastically deformable joints 32, 34.

[0074] As shown in FIG. 4, an elastically deformable joint structure according to a second embodiment of a second aspect of the present invention is denoted by reference numeral 400. Parts of the structure 400 corresponding to the parts of the structure 30 shown in FIG. 3 are denoted by corresponding reference numerals for convenience of explanation.

[0075] In this embodiment, the first elastically deformable joint 32 is radially aligned with the second elastically deformable joint 34. Since the channels 22, 24 are axially offset from the channels 50, 52 in the second elastically deformable joint 34, the connecting channels 60, 62 need to follow a helical path in order to connect the channels 22, 24 and the channels 60, 62 to form the structural channels 64, 66.

[0076] In both of the elastically deformable joint structures 30, 400, the third and fourth guides are in the form of channels 50, 52, which guide the tendons 18, 20 that drive the first elastically deformable joint 32 along the neutral bending line in the second elastically deformable joint 34 and separate the first elastically deformable joint from the second elastically deformable joint. This is facilitated by the connection portion 40 including the connecting channels 60, 62 that guide the tendons 18, 20 from the channels 18, 20 to the channels 50, 52.

[0077] According to the present invention, a wide range of curved shapes can be curved and controlled. FIG. 5 shows a flexible structure 400 in an S-curved shape. FIG. 6 shows a flexible structure 400 in a C-curved shape.

[0078] In other embodiments of the present invention, the flexible structure may be composed of two or more elastically deformable joints 2. In such an embodiment, adjacent joints 2 are connected by a connecting portion 40 as described above (FIGS. 3 and 4). In such an embodiment, by transporting the tendons used to activate the first elastically deformable joint along the neutral bending lines of the elastically deformable joints with respect to each other, it is ensured that all elastically deformable joints are separated from each other.

[0079] All of the above elastically deformable joints 2 have a single helical structure. In other embodiments, the joint 2 may have a double or multiple helical structure. FIG. 7 shows a part of an elastically deformable joint 70 having a double helical structure according to another embodiment of the present invention.

[0080] Other body joints are also possible. FIG. 8 shows an elastically deformable joint 80 according to another embodiment of the present invention. The elastically deformable joint 80 includes a body joint 82 composed of a first body joint portion 84. The first body joint portion 84 includes a recess 86 adapted to receive a protrusion 88 that constitutes a part of the second body joint 90. The body joint 82 includes a rolling joint having a circular contact surface, respectively. Such an arrangement requires more space than a double convex rolling joint, but further restricts the bending movement and also increases the torsional rigidity. Other configurations are also possible.

[0081] In order to allow the tendons 18, 20 to pass along the neutral bending line, it may be necessary to pass the tendons through the center of the joint 16. In such an embodiment, the relative rigidity of the tendon may prevent the movement of the joint.

[0082] Figures 9 and 10 show an elastically deformable joint 900 according to a further embodiment of the present invention. A gap 902 is formed in the rolling joint 16. These gaps 902 can form third and fourth guides. The third and fourth guides guide a tendon along the neutral bending line of the joint 900 from other elastically deformable joints that form part of the flexible structure according to the embodiment of the present invention.

[0083] As shown in FIG. 11, an elastically deformable joint according to an embodiment of the first aspect of the present invention is indicated by reference numeral 110. The parts of the joint 110 corresponding to the parts of the above joint are indicated by corresponding reference numerals for convenience of explanation. In this embodiment of the present invention, the helical spring 12 has a pitch that increases from the proximal end 4 to the distal end 6 of the joint 110. Also, the size of the body joint portion 14 increases from the proximal end 4 to the distal end 6. The size of the body joint portion 14 changes corresponding to the change in the pitch of the helical spring 2.

[0084] The greater the pitch of a specific part of the helical spring 12, the greater the bending stiffness of this part of the joint 110. Also, various curved curves can be obtained. For example, the distal end of the joint 110 can bend more than the proximal end of the joint 110. This feature can improve the dexterity of the distal end while suppressing the movement of the body of the joint 4. This is advantageous because the movement of the body may damage the surrounding environment.

[0085] As shown in FIG. 12, an elastically deformable joint structure according to another embodiment of the second aspect of the present invention is indicated by reference numeral 120.

[0086] The elastically deformable joint structure 120 includes first, second, and third elastically deformable joints 122, 124, 126 connected in series with each other. Joint 122 is connected to joint 124 by a connection part 128, and joint 124 is connected to joint 126 by a connection part 130. Joint 122 is driven by tendons 132, 134 guided along the neutral bending lines in the respective joints 124, 126. Joints 122, 124 are oriented relative to each other in the manner described above with reference to joints 32, 34 as shown in FIG. 3 and described above. Accordingly, connection part 128 corresponds to connection part 40 in FIG. 3.

[0087] Joints 124, 126 are oriented in the same manner as joints 32, 34 shown in FIG. 4. Connection part 130 is of the same type as connection part 40 shown in FIG. 4.

[0088] Joint 124 is controlled by tendons 136, 138. These tendons are guided along the neutral bending lines in joint 126. Joint 126 is controlled by tendons 140, 142.

[0089] As shown in FIGS. 13 and 14, a surgical instrument equipped with a flexible endoscope is indicated by reference numeral 200.

[0090] Endoscope 200 includes an elastically deformable joint structure 210 of the type shown in FIG. 4 above. The joint structure 210 forms an "S" when bent, as shown in FIG. 14.

[0091] Flexible endoscope 200 further includes a gimbal connected in series to joint 214 which forms part of joint structure 210.

[0092] This type of endoscope can be used in endoscopic surgery and single-port surgery systems.

[0093] The joint structure 210 allows for an S-shaped curvature as shown in FIG. 14. The gimbal 220 has two degrees of freedom.

[0094] In a single-port surgical system, all surgical instruments include a flexible endoscope such as the flexible endoscope 210 and pass through a single surgical port. The flexible endoscope includes a camera 222. The camera 222 needs to be positioned high to overlook the area to be operated on. This enables an optimal view of the surgical field.

[0095] According to the present invention, these requirements are met.

[0096] With the joint structure 210, the position of the camera can be raised relative to the rest of the surgical instrument. The gimbal 220 is adapted to perform tilting and panning movements of the camera.

[0097] FIG. 15 shows in detail the path of the tendons for controlling the endoscope 200. In a similar manner as described above with reference to other embodiments of the present invention, all tendons used for controlling the gimbal 220 or the joint 214 pass through the other neutral bending lines of those joints when passing through the other one or more joints 214, 212 respectively.

[0098] In this example, the gimbal is controlled by tendons 230, 232, 234, 236. These tendons pass through the neutral bending lines of the joints 212, 214 and emerge from the proximal end 300 of the surgical instrument 200.

[0099] Similarly, the joint 214 is controlled by tendons 240, 242. The tendons 240, 242 are guided along the neutral bending line in the joint 212 and emerge from the proximal end 300 of the device 200.

[0100] Finally, the joint 212 is controlled by tendons 250, 252 in the manner described above with reference to other embodiments of the present invention.

[0101] The resulting flexible endoscope 200 benefits from the fact that the position and orientation of the camera 222 are decoupled from the remaining joints 212, 214. This facilitates the control of the device 200, especially when the user wishes to control only the camera.

[0102] By controlling the curvature of the joints 212, 214, the position of the camera 122 can be changed without changing the viewing angle of the camera.

Claims

1. An elastically deformable joint (2) having a proximal end (4), a distal end (6), and an axis (8), wherein the elastically deformable joint (2) includes a helical structure (12), and the helical structure (12) is a structure in which a plurality of body parts (10) are integrally formed, and each of the body parts (10) includes a turn of the helical structure and is movable relative to an adjacent body part (10), the elastically deformable joint (2) further includes a plurality of body joint parts (14), each of the body joint parts (14) is formed on a respective body part (10), and adjacent body joint parts (14) can be in contact with each other to form a body joint (16), the body joint (16) includes a rolling joint, the elastically deformable joint further includes first and second guides extending axially from the distal end (6) to the proximal end (4) of the elastically deformable joint, the first and second guides are paths in which tendons are disposed, the first and second guides each include first and second channels (22, 24) extending from the distal end to the proximal end of the elastically deformable joint, each of the body parts (10) includes two body joint parts (14) spaced radially apart from each other at substantially 180 degrees, the first and second channels are spaced radially apart from each of the two body joint parts (14) at substantially 90 degrees, the pitch of the helical structure varies along the length of the elastically deformable joint, the size of the body joint part (14) varies in response to the change in the pitch of the helical structure, an elastically deformable joint including this.

2. The elastically deformable joint according to claim 1, wherein the joint (2) is formed from a plurality of materials.

3. The elastically deformable joint according to any one of claims 1 or 2, wherein the helical structure (12) includes a plurality of helical structures.

4. The elastically deformable joint according to any one of claims 1 to 3, wherein the first and second guides extend substantially parallel to the body joint part (14).

5. Each of the body joint parts (14) is cylindrical, and the axis of the body joint part (14) is substantially perpendicular to the axis of the elastically deformable joint. The elastically deformable joint according to any one of claims 1 to 4.

6. The elastically deformable joint according to any one of claims 1 to 5, further comprising third and fourth guides extending through the elastically deformable joint (2).

7. The elastically deformable joint according to claim 6, wherein the third and fourth guides each include a third and a fourth channel.

8. An elastically deformable joint structure (30) including first and second elastically deformable joints (32, 34) according to any one of claims 1 to 5, wherein the first and second elastically deformable joints (32, 34) are connected in series with each other such that the proximal end (36) of the first elastically deformable joint (32) is connected to the distal end (38) of the second elastically deformable joint (34) to form a connection part (40), the connection part (40) includes first and second connection guides, and the first and second connection guides connect the first and second guides of the first flexible part and the first and second guides of the second flexible part respectively to form first and second structure guides, and the first and second structure guides extend from the distal end (38) of the first elastically deformable joint (32) to the proximal end (36) of the second elastically deformable joint (34), The second elastically deformable joint (34) includes third and fourth guides extending through the second elastically deformable joint. An elastically deformable joint structure.

9. The elastically deformable joint structure according to claim 8, wherein the first and second elastically deformable joints (32, 34) are integrally formed.

10. The elastically deformable joint structure according to claim 8 or 9, wherein the first elastically deformable joint (32) is offset 90 degrees radially from the second elastically deformable joint (34).

11. The first and second guides of the first elastically deformable joint (32) are offset approximately 90 degrees radially from the first and second guides of the second elastically deformable joint (34), The first and second guides of the first elastically deformable joint (32) are each located substantially in line with the third and fourth guides of the second elastically deformable joint (34), the elastically deformable joint structure according to claim 10.

12. The first and second connection guides extend substantially axially, the elastically deformable joint structure according to claim 10 or 11.

13. The first elastically deformable joint (32) is axially aligned with the second elastically deformable joint (34), the elastically deformable joint structure according to any one of claims 8 to 12.

14. The first and second connection guides extend spirally within the connection portion, the elastically deformable joint structure according to claim 13.

15. Including two or more elastically deformable joints and a plurality of connection portions, The plurality of connection portions connect the distal end of one elastically deformable joint and the proximal end of an adjacent elastically deformable joint, the elastically deformable joint structure according to any one of claims 8 to 14.

16. The first elastically deformable joint (32) includes third and fourth guides extending through the first elastically deformable joint, the elastically deformable joint structure according to any one of claims 8 to 15.

17. Further including a gimbal (220) connected in series to the elastically deformable joint, the elastically deformable joint structure according to any one of claims 8 to 16.

18. A surgical instrument including a proximal end, a distal end, and the elastically deformable joint according to any one of claims 1 to 7 located at the distal end.

19. A surgical instrument including a proximal end, a distal end, and the elastically deformable joint structure according to any one of claims 8 to 17 located at the distal end.

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