A connector

Abstract

The elastically deformable joint (2) has a proximal end (4), a distal end (6) and an axis (8), the elastically deformable joint includes a helical structure (12), the helical structure (12) includes a plurality of integrally formed main body parts (10), each of the main body parts includes a turn of the helical structure and is movable relative to an adjacent main body part, the elastically deformable joint further includes a plurality of main body joint components (14), each of the main body joint components is formed on a corresponding main body part so that adjacent main body joint components can be adjacent to each other to form a main body joint, the elastically deformable joint further includes a first guide portion (22) and a second guide portion (24) extending axially from the distal end of the elastically deformable joint to the proximal end.

Description

Technical Field

[0001] The present invention relates to connectors, and particularly, but not exclusively, to connectors for use in surgical devices for use in minimally invasive surgery (MIS) procedures, and to methods of making such connectors. The present invention is particularly directed to flexible, elongated connectors that form part of devices for use in endoscopic procedures. However, the connectors can be used in other applications, and the method can be used to make similar devices having different applications. Background Art

[0002] MIS was introduced to improve postoperative scarring and shorten recovery time. MIS requires a small incision in the abdominal wall (such as laparoscopic surgery), or access through a narrow natural orifice (such as the esophagus). The main requirement for MIS is the ability to fully observe and manipulate the target anatomical structure from a misaligned entry site in the most direct and ergonomically optimal position. In order to provide the surgeon with adequate visual feedback and dexterous tissue manipulation, endoscopes and other surgical instruments are required to have a bendable and steerable section, also known as an elastically deformable joint.

[0003] Elastically deformable joints generally need to provide a large central lumen free of control cables, which would otherwise hinder the incorporation of lighting components (such as glass fiber filaments and wires for optical units and camera units). For surgical tools that work at the distal ends of large surgical instruments, the internal space can also help install a suction unit that may require flushing. Another basic property of this elastically deformable joint is that it can be controlled via a control cable with respect to its bending direction. A pair of cables is generally used to achieve planar bending. Three or four cables are generally used to achieve spatial bending.

[0004] It is known to use a capstan to control a pair of cables for one bending degree of freedom (DOF). The two cables are constructed in an antagonistic manner, and an increase in one cable is equivalent to a decrease in the other cable. An axial channel in the elastically deformable joint is required to guide the cables. Depending on the principle of achieving controllable bending, the known elastically deformable joints can be classified into two categories.

[0005] Bend joints: The first category is bend joints that use material elasticity. These joints are cable-driven compliant mechanisms. The cable passes through a channel inside the bendable portion and terminates at the distal end of the elastically deformable joint. By pulling the cable, the elastically deformable joint bends in the corresponding direction. Bend joints depend entirely on the size of the flexible portion and the material properties of the joint, such as stiffness and yield strength. These geometric and material properties also determine how the joint resists torsion and how well the joint can resist axial and lateral forces. These designs typically involve using laser profiling technology or electrospark machining technology to form notches on the metal tube. Nitinol and other materials with a lower elastic modulus are typically selected for these designs. The design principle is to cut away unnecessary material, thereby forming a gap for the bend. Since this type of joint is designed as a combination of thin and thick sections, it typically introduces stress concentration in the corner area. This means that plastic deformation and fatigue may be a major concern for long-term use. The difficulty in drilling cable guide channels in this type of elastically deformable joint is another disadvantage. Current methods include using wire EDM to cut a channel through a small entrance, or inserting a cable guide plate through a slot formed in the wall of the tube. The former presents difficulties in manufacturing, and the latter presents difficulties in assembly.

[0006] Rigid joints: Other types of elastically deformable joints use multiple small rigid joints to achieve bending. This type of elastically deformable joint is constructed by stacking a series of small tubular segments instead of using a single continuous entity. The movement between two adjacent segments is constrained by the connecting components formed on the surface of the tube segment. These connecting components include rolling joints and hinged harness joints. The two parts of the rolling joint rotate relative to each other along a circular trajectory defined by the curvature of the joint, while the two parts of the hinged harness joint rotate relative to a common pivot point. The connecting components are usually designed as puzzle pieces that fit together to limit movement in unwanted directions. For small tubular segments, it is not difficult to form cable guide channels, and they do not have the fatigue problems associated with curved joints. However, friction and backlash are introduced into this design type. Due to the nonlinear nature of friction and backlash, this type of flexible joint has a smooth body curvature and less accurate tip positioning compared to curved joints. In addition, compared with the unified design of curved joints, this type of joint introduces difficulties in assembly. Summary of the invention

[0007] 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, the elastically deformable joint comprising a helical structure, the helical structure comprising a plurality of integrally formed main body parts, each of the main body parts comprising turns of the helical structure and being movable relative to an adjacent main body part, the elastically deformable joint further comprising a plurality of main body joint components, each of the main body joint components being formed on a corresponding main body part so that adjacent main body joint components can be adjacent to each other to form a main body joint, the elastically deformable joint further comprising a first guide portion and a second guide portion extending axially from the distal end of the elastically deformable joint to the proximal end.

[0008] The use of a helical structure to form an elastically deformable joint means that, during bending, stresses are more evenly distributed along the body of the elastically deformable joint. Since the helical structure represents an assembly of numerous flexure points, it may be difficult to fully and reliably control. However, the presence of the body joint results in an elastically deformable joint that can be accurately controlled.

[0009] In an embodiment of the invention, the helical structure comprises a spring and has excellent torsional stiffness, but very low axial and bending stiffness.The body joint serves to limit the number of degrees of freedom (DOF) and also to increase the axial stiffness of the elastically deformable joint.

[0010] The helical structure may have a substantially constant pitch along the length of the elastically deformable joint. In other embodiments of the invention, the pitch of the helical structure may vary along the length of the elastically deformable joint. In some embodiments of the invention, the pitch of the helical structure will decrease along the length of the flexible joint.

[0011] In such an embodiment of the invention, the size of the body joint may also vary with the varying pitch of the helical structure.

[0012] In embodiments of the invention where the pitch of the helical structure decreases along the length of the flexible joint, the size of the body joint member may also decrease along the length of the flexible joint.

[0013] In embodiments of the invention, the elastically deformable joint is formed from a single material. In other embodiments of the invention, the elastically deformable joint is formed from more than one material.

[0014] The particular material or materials selected to form the resiliently deformable joint will depend on the use to which the surgical instrument including the resiliently deformable joint will be put.

[0015] The helical structure may comprise a single helical structure, a double helical structure or a multi-helical structure. When the structure comprises a double helical structure, the multiple pairs of body joint parts forming the body joint are arranged symmetrically.

[0016] For a given axial length, the double helix design has a higher bending stiffness than the single helix design.

[0017] In general, for a given pitch distance, if a helical structure uses more bundles of wires, ie it is a double helix or a triple helix, the overall stiffness increases compared to a helical structure using fewer bundles of wires.

[0018] When the helical structure has an even number of strands, so for example when the helical structure is a double or quadruple structure and the starting points of the strands are equally distributed, the multiple pairs of body joint parts forming the body joint will be arranged symmetrically with respect to the bending plane of the flexible joint. This feature can provide equal torsional stiffness to the structure when the structure is twisted clockwise or counterclockwise.

[0019] In contrast, for a helical structure having an odd number of strands, such as a single helix, when the structure is twisted about its central axis, the structure has a different torsional stiffness when twisted clockwise than when twisted counterclockwise.

[0020] The particular helical configuration of the elastically deformable joint will be determined by the use to which the surgical instrument incorporating the deformable joint will be put.

[0021] The elastically deformable joint according to an embodiment of the present invention comprises a plurality of body parts which are integrally formed with each other. This means that the disadvantages associated with the assembly of a plurality of separate body parts are overcome.

[0022] The elastically deformable joint according to an embodiment of the present invention can be bent by using a pair of opposing cables. The cables are guided through the elastically deformable joint by means of a first guide portion and a second guide portion.

[0023] In an embodiment of the present invention, the first guide portion and the second guide portion include a first channel and a second channel, respectively, each channel extending from a distal end to a proximal end of the elastically deformable joint.

[0024] The channel may be formed in any convenient part of the resiliently deformable joint and serves to guide and protect the cables during use of the resiliently deformable joint.

[0025] In an embodiment of the invention, the first channel and the second channel are radially spaced apart from the body joint portion. This enables bending to occur at the body joint when bending is activated by means of antagonistic cables extending through the first channel and the second channel, respectively.

[0026] In an embodiment of the invention, each body portion comprises two body joint members radially spaced substantially 180 degrees from each other.

[0027] The first guide portion and the second guide portion may also be radially spaced 180 degrees from each other, and in an embodiment of the present invention, the first guide portion and the second guide portion are radially spaced substantially 90 degrees from each of the body joint portions.

[0028] This configuration ensures that when opposing cables are seated within the first and second guide portions, bending can be achieved via the cables due to the positions of the first and second guide portions relative to the body joint portion.

[0029] The body joint may be arranged to extend in a direction substantially coaxial with the axis of the elastically deformable joint. In other arrangements, the body joint may extend along a helical path.

[0030] The arrangement of the body joints will be determined by the use to which the surgical instrument including the resiliently deformable joint will be put.

[0031] Regardless of the arrangement of the body joint, the first guide portion and the second guide portion may extend generally parallel to the body joint.

[0032] During bending, the body joint portions will abut each other and move relative to each other to thereby allow bending to occur.

[0033] The body joint member may have any suitable shape to form any suitable body joint.

[0034] In an embodiment of the invention, each body joint comprises a rolling joint.

[0035] In such an embodiment of the invention, adjacent body joint members will abut during bending of the elastically deformable joint and the contact surface of each body joint member will be tortuous.

[0036] In an embodiment of the invention, each body joint portion is substantially cylindrical in shape, the axis of the cylinder being substantially perpendicular to the axis of the elastically deformable joint. The contact surface of each body joint will then comprise the tortuous surface of the cylinder.

[0037] In an embodiment of the invention, the elastically deformable joint comprises a third guide portion and a fourth guide portion extending through a neutral bending line of the elastically deformable joint.

[0038] In an embodiment of the present invention, the third guide portion and the fourth guide portion include a third channel and a fourth channel, respectively.

[0039] Embodiments of the present invention thus provide a combination of a compliant or elastically deformable joint structure in the form of a helical spring together with a rigid structure in the form of a body joint. This results in a joint that is softer than known similar joints and distributes its stress more evenly along its entire body when bent. In addition, due to the compliant structure of the spring, the overall elasticity becomes the dominant force affecting the bending shape, rather than local friction between the body joint parts, as is the case in known similar joints. For this reason, all body joints will present an equal rotation angle, resulting in a constant bending curvature for the elastically deformable joints according to embodiments of the present invention.

[0040] In an embodiment of the invention, the elastically deformable joint has a diameter of approximately 9 mm and an axial length of approximately 18 mm.

[0041] The elastically deformable joint has an inner diameter of approximately 5 mm.

[0042] In one embodiment of the present invention, the elastically deformable joint is made of 316 stainless steel.

[0043] According to a second aspect of the present invention, an elastically deformable joint structure is provided, which includes a first elastically deformable joint and a second elastically deformable joint, each according to the first aspect of the present invention, wherein the first elastically deformable joint and the second elastically deformable joint are connected in series with each other, the proximal end of the first elastically deformable joint is connected to the distal end of the second elastically deformable joint to form a connecting portion, the connecting portion includes a first connecting guide portion and a second connecting guide portion, the first connecting guide portion and the second connecting guide portion respectively connect the first guide portion and the second guide portion of the first elastically deformable joint with the first guide portion and the second guide portion of the second elastically deformable joint to respectively form a first structural guide portion and a second structural guide portion, wherein the second elastically deformable joint includes a third guide portion and a fourth guide portion extending through the neutral bending line of the second elastically deformable joint.

[0044] In an embodiment of the present invention, the first elastically deformable joint and the second elastically deformable joint forming the elastically deformable joint structure are formed integrally with each other.

[0045] In an embodiment of the invention, the first elastically deformable joint may be radially offset from the second elastically deformable joint by substantially 90 degrees.This structure results in a spatially flexible joint by using two pairs of cables.

[0046] In such an embodiment, the first and second guide portions of the first elastically deformable joint are radially offset from the first and second guide portions of the second elastically deformable joint by approximately 90 degrees and are substantially co-linear with the third and fourth guide portions of the second elastically deformable joint.

[0047] In this embodiment of the invention, the first connecting guide and the second connecting guide extend substantially axially within the connecting portion.

[0048] In other embodiments of the present invention, the first elastically deformable joint has substantially the same radial orientation as the second elastically deformable joint. This results in a structure that can achieve an S-bend by using two pairs of cables.

[0049] In this embodiment of the invention, the first and second connecting guides extend along a substantially helical path. This enables the first and second guides of the first elastically deformable joint to connect with the third and fourth guides of the second flexible portion, respectively.

[0050] Thus, in use, the cable associated with the first resiliently deformable joint is guided to extend along the neutral bending line of the second resiliently deformable joint. In other embodiments, the first and second connecting guides may define different paths and may not be helical, but will nonetheless follow a generally zigzag or stepped path so that the first and second guides of the first resiliently deformable joint can merge with the third and fourth guides of the second resiliently deformable joint.

[0051] An advantage of this arrangement is that it is not necessary to use Bowden cables or the like for guiding the cables as is the case in the prior art.

[0052] In other embodiments of the second aspect of the invention, the elastically deformable joint structure may include more than two elastically deformable joints. In such embodiments of the invention, adjacent elastically deformable joints may have the same radial orientation as each other, or one elastically deformable joint may be radially rotated by 90 degrees relative to an adjacent radial joint. In an elastically deformable joint structure having a plurality of elastically deformable joints, different combinations of orientations may exist.

[0053] In such an embodiment, the elastically deformable joint structure will include a plurality of connecting portions connecting the distal end of one elastically deformable joint to the proximal end of an adjacent elastically deformable joint.

[0054] All elastically deformable joints forming such an elastically deformable joint structure, except the first elastically deformable joint, will have a third guide and a fourth guide extending along the neutral bending line of the corresponding elastically deformable joint. This is to ensure that the elastically deformable joints forming the elastically deformable joint structure can be decoupled from each other. In other words, by ensuring that the cables associated with one elastically deformable joint extend along the neutral bending line of all other elastically deformable joints forming the elastically deformable joint structure, the operation of those cables will result in bending of only the elastically deformable joints associated with those cables.

[0055] In some embodiments of the present invention, the first elastically deformable joint may have the third guide portion and the fourth guide portion even if they are not required. This can simplify the manufacturing process.

[0056] In an embodiment of the invention, all guides comprise channels formed in the body portion of each elastically deformable joint.

[0057] In an embodiment of the present invention, the elastically deformable joint structure further comprises a universal joint connected in series to the elastically deformable joint.

[0058] In an embodiment of the present invention, the universal joint is positioned between the distal end of the elastically deformable joint structure and the distal end of the first elastically deformable joint.

[0059] In other embodiments of the present invention, the universal joint may be positioned between two elastically deformable joints. In still other embodiments of the present invention, the universal joint may be positioned between the proximal end of the elastically deformable joint and the proximal end of the elastically deformable joint structure.

[0060] According to a third aspect of the present invention, there is provided a surgical instrument having a proximal end and a distal end and a resiliently deformable joint according to the first aspect of the present invention.

[0061] According to a fourth aspect of the present invention, there is provided a surgical instrument having a proximal end and a distal end and a resiliently deformable joint structure according to the second aspect of the present invention.

[0062] According to a fifth aspect of the present invention, there is provided a method of forming an elastically deformable joint according to the first aspect of the present invention, the method comprising the step of forming components of the elastically deformable joint using additive manufacturing techniques. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] The present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0064] Figure 1 is a schematic representation of a first embodiment of an elastically deformable joint according to the first aspect of the present invention in a neutral position;

[0065] Figure 2 It is in a curved structure Figure 1 A detailed representation of a portion of an elastically deformable joint;

[0066] Figure 3 is a schematic representation of a first embodiment of an elastically deformable joint structure according to the second aspect of the present invention, wherein the orientation of the first elastically deformable joint is radially offset by 90 degrees relative to the second elastically deformable joint, thereby forming a composite elastically deformable joint;

[0067] Figure 4 is a schematic representation of a second embodiment of an elastically deformable joint structure according to the second aspect of the present invention, wherein the orientation of the first elastically deformable joint is radially aligned with the second elastically deformable joint to form an S-bend type elastically deformable joint structure;

[0068] Figure 5 is shown in an "S" configuration Figure 4 Schematic representation of the elastically deformable joint structure;

[0069] Figure 6 is shown in a "C" configuration Figure 4 Schematic representation of a composite elastically deformable joint;

[0070] Figure 7 is a schematic representation showing a portion of another embodiment of an elastically deformable joint according to the first aspect of the invention comprising a double helix structure;

[0071] Figure 8 is a schematic representation of a portion of another embodiment of an elastically deformable joint according to the first aspect of the invention showing a different type of rolling joint;

[0072] Fig. 9 and Fig.10 is a schematic representation showing a portion of yet another embodiment of the present invention, wherein a channel has been formed in a body joint member;

[0073] Fig.11 is a schematic representation of an elastically deformable joint according to an embodiment of the first aspect of the present invention, comprising a helical structure having a varying pitch along the length of the elastically deformable joint;

[0074] Fig.12 is a schematic representation of another embodiment of an elastically deformable joint structure according to another embodiment of the second aspect of the present invention, comprising three integrally formed joints;

[0075] Fig.13 is a schematic representation of a surgical instrument comprising a flexible endoscope and having an elastically deformable joint structure according to an embodiment of the second aspect of the present invention;

[0076] Fig.14 The joint structure with an S-shaped bend is shown Fig.13 Schematic representation of a surgical device;

[0077] Fig.15 It shows how the cables are routed through the instrument. Fig.13 and Fig.14 Schematic representation of the surgical instrument shown in . DETAILED DESCRIPTION

[0078] First reference Figure 1 , an elastically deformable joint according to an embodiment of the present invention is generally indicated by reference numeral 2. The joint 2 is Figure 1 is shown in a neutral or non-flexed position.

[0079] The joint comprises a proximal end 4, a distal end 6 and an axis 8. The joint comprises a plurality of integrally formed main body portions 10, which in this embodiment comprise a plurality of turns of a coil spring 12. The joint further comprises a plurality of main body joint portions 14 formed on the main body portion 10. In this embodiment, each main body portion or each turn of the coil spring comprises two main body joint portions 14 positioned diametrically opposite to each other, i.e., they are radially spaced apart from each other by 180 degrees. Each main body joint portion 14 is positioned to abut against the main body joint portion on the adjacent main body portion 10. Adjacent main body joint portions 14 together form a main body joint 16. In this embodiment, the main body joint 16 comprises a rolling joint. However, in other embodiments, the main body joint can be other joints such as an articulated joint or a pivot joint.

[0080] The elastically deformable joint 2 thus comprises a bendable portion in the form of a helical spring 12 whose axial compression is constrained by a body joint 16, which in this embodiment each comprises a rigid rolling contact joint positioned on each body portion 10. Each body joint portion 14 is cylindrical in shape, the axis of each cylinder being substantially orthogonal to the axis 8 of the joint 2. In this embodiment, the body joints 16 are arranged in two lines extending axially 180 degrees apart on the surface of the elastically deformable joint 2. As described in more detail below, due to the constraint of the joint 16, the spring 12 has only one bending DOF controlled by the opposing cables 18, 20.

[0081] The elastically deformable joint 2 further comprises a first guide and a second guide in the form of a channel 22, 24 for guiding the cables 18, 20 through the joint 2. The cables 18, 20 are attached to the elastically deformable joint 2 at the distal end 6 by means of a punch point 26 and extend through the elastically deformable joint 2 and through the proximal end 4. The cables 18, 20 are a pair of antagonistic cables and can be used to control the bending of the joint 2 in a known manner. In particular, by pulling one of the cables 18, 20, each body joint 16 is caused to deflect through a small angle. In general, these small angles result in the elastically deformable joint 2 being able to bend through large angles of up to 180 degrees or more.

[0082] Now go to Figure 2 , a portion of the elastically deformable joint 2 is shown in a bent position. The bent position is achieved by pulling the cable 18.

[0083] like Figure 1 and Figure 2 The elastically deformable joint 2 shown in FIG. 1 only bends in a 2D plane.

[0084] Now go to Figure 3 , an embodiment of the elastically deformable joint structure according to the second aspect of the present invention is indicated by reference numeral 30. The elastically deformable joint structure 30 includes a first elastically deformable joint 32 and a second elastically deformable joint 34, which are connected in series with each other so that a proximal end 36 of the first elastically deformable joint 32 is connected to a distal end 38 of the second elastically deformable joint 34 to form a connecting portion 40.

[0085] The first and second elastically deformable joints 32, 34 are Figure 1 Parts corresponding to those of the elastically deformable joint 2 illustrated in FIG. 2 have been given corresponding reference numerals for ease of reference.

[0086] The first elastically deformable joint 32 is driven by cables 18, 20, which are guided through the first elastically deformable joint 32 through the first channel 22 and the second channel 24. The cables 18, 20 are fastened to the distal end 6 of the first elastically deformable joint 32 by means of the punching point 26. The second elastically deformable joint 34 is driven by cables 180, 200, which are guided through the second elastically deformable joint 34 through the first channel 220 and the second channel 240 and fastened to the distal end 38 of the second elastically deformable joint 34 by means of the punching point 26. The second elastically deformable joint 34 further comprises third and fourth guides in the form of channels 50, 52 for guiding the cables 18, 20 through the second elastically deformable joint 34. In order to ensure that when the cables 18, 20 are activated in order to bend the first elastically deformable joint 32, they do not also cause a bend in the second elastically deformable joint 34, the second elastically deformable joint comprises third and fourth guides in the form of channels 50, 52 extending along the neutral bending line in the second elastically deformable joint 34. 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 cables 18, 20 are pulled in order to cause a bend in the first elastically deformable joint 32, the cables 18, 20 will not have an effect on the second elastically deformable joint 34. The two joints 32, 34 are thus decoupled from each other.

[0087] The connecting portion 40 includes first and second connecting guides in the form of channels 60, 62, which respectively connect the channels 22, 24 in the first elastically deformable joint with the channels 50, 52 to form structural channels 64, 66 extending 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 guiding the cables 22, 24 from the distal end 6 of the first elastically deformable joint 32 through both joints 32, 34.

[0088] In this embodiment of the invention, the first elastically deformable joint 32 is radially offset by substantially 90 degrees from the second elastically deformable joint 34. This means that the passages 22, 24 are axially aligned with the passages 50, 52 and thus the connecting passages 60, 62 extend substantially coaxially with the axis 8 of the first and second elastically deformable joints 32, 34.

[0089] Now go to Figure 4 The elastically deformable joint structure according to the second embodiment of the second aspect of the present invention is generally indicated by reference numeral 400. Figure 3 Corresponding parts of the structure 30 illustrated in FIG. 3 have been given corresponding reference numerals to facilitate reference.

[0090] In this embodiment, the first elastically deformable joint 32 is radially aligned with the second elastically deformable joint 34. This means that the channels 22, 24 are axially offset from the channels 50, 52 in the second elastically deformable joint 34, and thus it is necessary for the connecting channels 60, 62 to follow a helical path so that the channels 22, 24 are connected to the channels 60, 62 to form structural channels 64, 66.

[0091] In both elastically deformable joint structures 30, 400, the third and fourth guides are in the form of channels 50, 52 guiding the cables 18, 20, which drive the first elastically deformable joint 32 along the neutral bending line in the second elastically deformable joint 34, thereby decoupling the first elastically deformable joint from the second elastically deformable joint. This is facilitated by the connecting portion 40 comprising connecting channels 60, 62 guiding the cables 18, 20 from the channels 18, 20 to the channels 50, 52.

[0092] By means of the invention it is possible to control the bending through a wide variety of bending shapes. Figure 5 The flexible structure 400 is shown in an S-bend configuration, while Figure 6 The flexible structure 400 is shown in a C-bend configuration.

[0093] In other embodiments of the present invention, the flexible structure can be formed by more than two elastically deformable joints 2. In such embodiments, adjacent joints 2 will be connected via the above reference Figure 3and Figure 4 The described connection portion 40 is connected. In such an embodiment, the cable for activating the first elastically deformable joint will be carried along the neutral bending line of each elastically deformable joint, so as to ensure that all elastically deformable joints are decoupled from each other.

[0094] The elastically deformable joints 2 described above all have a single helical structure. In other embodiments, the joint 2 can have a double helical structure or a multi-helical structure. Figure 7 A portion of an elastically deformable joint 70 having a double helix structure according to another embodiment of the present invention is shown.

[0095] Other forms of body joints are possible. Figure 8 A portion of an elastically deformable joint 80 according to another embodiment of the present invention is shown, which includes a body joint 82 formed by a first body joint portion 84, the first body joint portion 84 including a recessed portion 86 adapted to receive a protrusion 88 forming a portion of a second body joint 90. The body joint 82 includes a rolling joint, each of which has a circular contact surface. This arrangement provides more constraints on bending motion, which also improves torsional stiffness, although the structure requires more space than a biconvex rolling joint. Other configurations are also possible.

[0096] In order to enable the cables 18, 20 to pass along the neutral bending line, it may sometimes be necessary to pass the cables through the middle of the joint 16. In such an embodiment, there is a risk that the relative rigidity of the cables may interfere with the movement of the joint.

[0097] Fig. 9 and Fig.10 A resiliently deformable joint 900 according to a further embodiment of the invention is illustrated, in which apertures 902 have been formed in the rolling joint 16. These apertures 902 can thus form third and fourth guides that guide cables from another resiliently deformable joint forming part of the flexible structure according to an embodiment of the invention along the neutral bending line of the joint 900.

[0098] Reference now Fig.11 , an elastically deformable joint according to another embodiment of the first aspect of the present invention is generally indicated by reference numeral 110. Portions of the joint 110 corresponding to portions of the joint described above have been given corresponding reference numerals for ease of reference. In this embodiment of the present invention, the coil spring 12 has a pitch that increases from the proximal end 4 to the distal end 6 of the joint 110. In addition, the size of the main body joint portion 14 also increases from the proximal end 4 to the distal end 6, so that the size of the main body joint portion 14 changes in a manner corresponding to the change in the pitch of the coil spring 2.

[0099] The greater the pitch of a particular portion of the coil spring 12, the greater the bending stiffness of that portion of the joint 110. In addition, varying bending curves can be achieved. For example, the distal end of the joint 110 can bend more than the proximal end of the joint 110. This feature results in increased distal flexibility while reducing body movement of the joint 4. This is advantageous because body movement can cause damage to the surrounding environment.

[0100] Now go to Fig.12 , an elastically deformable joint structure according to another embodiment of the second aspect of the present invention is generally indicated by reference numeral 120 .

[0101] The elastically deformable joint structure 120 includes a first elastically deformable joint 122, a second elastically deformable joint 124, and a third elastically deformable joint 126 connected in series with each other. The joint 122 is connected to the joint 124 by means of a connecting portion 128, and the joint 124 is connected to the joint 126 by means of a connecting portion 130. The joint 122 is driven by cables 132, 134 guided along a neutral bending line in each of the joints 124, 126. The joints 122, 124 are described above with reference to Figure 3 The connectors 32, 34 shown in FIG. 1 and described above are oriented relative to each other in the manner described. The connecting portion 128 thus corresponds to Figure 3 The connecting portion 40 in the embodiment of the present invention.

[0102] The connector 124 and the connector 126 are relative to each other in a manner similar to that of the connectors 32 and 34. Figure 4 oriented in the manner shown in the figure, and the connecting portion 130 belongs to Figure 4 The connecting portion 40 shown in FIG.

[0103] The joint 124 is controlled by cables 136 and 138, and these cables are guided along the neutral bending line in the joint 126. The joint 126 is controlled by cables 140,142.

[0104] Now go to Fig.13 and Fig.14 , a surgical instrument including a flexible endoscope is generally indicated by reference numeral 200 .

[0105] The endoscope 200 includes Figure 4 An elastically deformable joint structure 210 of the type illustrated in FIG. 1 and described above is thus suitable for being able to Fig.14 When bent, it forms an "S" as shown in FIG.

[0106] The flexible endoscope 200 further comprises a universal joint which is serially connected to a joint 214 forming part of the joint structure 210 .

[0107] This type of endoscope can be used for endoluminal surgery and is used in single-port surgical systems.

[0108] The joint structure 210 allows Fig.14 The S-shaped bend shown in FIG. 220 has two degrees of freedom.

[0109] For a single-port surgical system, all surgical instruments, including a flexible endoscope such as flexible endoscope 210, pass through a single surgical port. The flexible endoscope includes a camera 222 that is required to assume an elevated position in order to look down at the area where surgery will be performed. This is to allow for optimal observation of the surgical field.

[0110] By means of the present invention, these requirements can be met.

[0111] By means of 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 tilt and pan movements for the camera.

[0112] Now go to Fig.15 , showing in more detail the routing of cables for controlling the endoscope 200. In a manner similar to that described above with reference to other embodiments of the invention, all cables for controlling the gimbal 220 or joint 214 pass through the neutral bending line of the other joint or joints 214, 212, respectively, as they pass through those other joints.

[0113] In this example, the universal joint is controlled by cables 230, 232, 234, and 236. These cables pass through the neutral bend line of joints 212 and 214 before emerging past the proximal end 300 of the surgical instrument 200.

[0114] Similarly, joint 214 is controlled by cables 240 , 242 that are guided along a neutral bend line in joint 212 before emerging from proximal end 300 of device 200 .

[0115] Finally, the joint 212 is controlled by the cables 250, 252 in the manner described above with reference to other embodiments of the invention.

[0116] The resulting flexible endoscope 200 benefits from the fact that the position and orientation of the camera 222 is decoupled from the remaining joints 212, 214. This facilitates control of the device 200, particularly when the user only wishes to control the camera.

[0117] By controlling the bending of joints 212, 214, the position of camera 222 can be changed without changing the viewing angle of the camera.

Claims

1. An elastically deformable joint having a proximal end, a distal end and an axis, the elastically deformable joint comprising a helical structure, the helical structure comprising a plurality of integrally formed main body parts, each of the main body parts comprising a turn of the helical structure and being movable relative to an adjacent main body part, the elastically deformable joint further comprising a plurality of main body joint members, each of the main body joint members being formed on a corresponding main body part so that adjacent main body joint members can abut against each other to form a main body joint, the elastically deformable joint further comprising a first guide portion and a second guide portion extending axially from the distal end of the elastically deformable joint to the proximal end, in, Each body joint comprises a rolling joint in which adjacent body joint components rotate relative to each other along a circular trajectory defined by the curvature of the respective body joint components.

2. The elastically deformable joint according to claim 1, wherein: The pitch of the helical structure varies along the length of the elastically deformable joint.

3. The elastically deformable joint according to claim 2, wherein: The size of the body joint varies with the varying pitch of the helical structure.

4. An elastically deformable joint according to any one of the preceding claims, wherein: The joint is formed from more than one material.

5. The elastically deformable joint according to any one of claims 1 to 3, wherein: The helical structure includes a multi-helical structure.

6. The elastically deformable joint according to any one of claims 1 to 3, wherein: The first guide portion and the second guide portion include a first channel and a second channel, respectively, each channel extending from the distal end to the proximal end of the elastically deformable joint.

7. The elastically deformable joint according to claim 6, wherein: Each body portion includes two body joint members radially spaced substantially 180 degrees from one another.

8. The elastically deformable joint according to claim 7, wherein: The first passage and the second passage are radially spaced substantially 90 degrees from each of the body joint portions.

9. The elastically deformable joint according to any one of claims 1 to 3, wherein: The first guide portion and the second guide portion extend generally parallel to the body joint portion.

10. The elastically deformable joint according to any one of claims 1 to 3, wherein: Each body joint portion is cylindrical, with the axis of the body joint portion being substantially perpendicular to the axis of the elastically deformable joint.

11. The elastically deformable joint according to any one of claims 1 to 3, further comprising a third guide portion and a fourth guide portion extending through a neutral bending line of the elastically deformable joint.

12. The elastically deformable joint according to claim 11, wherein: The third guide portion and the fourth guide portion include a third channel and a fourth channel, respectively.

13. An elastically deformable joint structure, comprising a first elastically deformable joint and a second elastically deformable joint, wherein the first elastically deformable joint and the second elastically deformable joint are elastically deformable joints according to any one of claims 1 to 10, wherein: The first elastically deformable joint and the second elastically deformable joint are connected to each other in series, the proximal end of the first elastically deformable joint is connected to the distal end of the second elastically deformable joint to form a connecting portion, and the connecting portion includes a first connecting guide portion and a second connecting guide portion, and the first connecting guide portion and the second connecting guide portion respectively connect the first guide portion and the second guide portion of the first elastically deformable joint with the first guide portion and the second guide portion of the second elastically deformable joint to form a first structural guide portion and a second structural guide portion respectively, the first structural guide portion and the second structural guide portion extend from the distal end of the first elastically deformable joint to the proximal end of the second elastically deformable joint, and wherein the second elastically deformable joint includes a third guide portion and a fourth guide portion extending through the neutral bending line of the second elastically deformable joint.

14. The elastically deformable joint structure according to claim 13, wherein: The first elastically deformable joint and the second elastically deformable joint are integrally formed.

15. The elastically deformable joint structure according to claim 13, wherein: The first resiliently deformable joint is radially offset from the second resiliently deformable joint by 90 degrees.

16. The elastically deformable joint structure according to claim 15, wherein: The first guide portion and the second guide portion of the first elastically deformable joint are radially offset from the first guide portion and the second guide portion of the second elastically deformable joint by approximately 90 degrees, and wherein the first guide portion and the second guide portion of the first elastically deformable joint are substantially collinear with the third guide portion and the fourth guide portion of the second elastically deformable joint, respectively.

17. The elastically deformable joint structure according to claim 15 or claim 16, wherein: The first connecting guide portion and the second connecting guide portion extend substantially axially.

18. The elastically deformable joint structure according to any one of claims 13 to 16, wherein: The first elastically deformable joint is axially aligned with the second elastically deformable joint.

19. The elastically deformable joint structure according to claim 18, wherein: The first connection guide portion and the second connection guide portion extend helically within the connection portion.

20. The elastically deformable joint structure according to any one of claims 13 to 16, comprises more than two elastically deformable joints, and the plurality of connecting portions connecting the distal end of each of the plurality of connecting portions connect the distal end of one elastically deformable joint to the proximal end of an adjacent elastically deformable joint.

21. The elastically deformable joint structure according to any one of claims 13 to 16, wherein: The first resiliently deformable joint includes a third guide portion and a fourth guide portion extending through a neutral bending line of the first resiliently deformable joint.

22. The elastically deformable joint structure according to any one of claims 13 to 16, further comprising a universal joint connected in series to the elastically deformable joint.

23. A surgical instrument comprising a proximal end and a distal end and a resiliently deformable joint according to any one of claims 1 to 12, the resiliently deformable joint being positioned at the distal end of the instrument.

24. A surgical instrument comprising a proximal end and a distal end and a resiliently deformable joint structure according to any one of claims 13 to 22, the resiliently deformable joint structure being positioned at the distal end of the instrument.

25. A method of manufacturing an elastically deformable joint according to any one of the preceding claims using additive manufacturing techniques.

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