Wire ropes, forceps, and medical robots

Abstract

The present invention provides a wire rope with improved pushing ability (pushing capability), forceps equipped with a wire rope, and a medical robot equipped with forceps. [Solution] The wire rope 1 comprises an inner stranded body 11 including a stranded wire C11 formed of multiple metal strands w11, an outer stranded body 21 including a stranded wire C21 formed of multiple metal strands w21 and wound spirally around the outer circumference of the inner stranded body 11, and a wrapping wire 31 made of strands w31 with a flattened cross-section and wound spirally between the inner stranded body 11 and the outer stranded body 21.

Description

Technical Field

[0001] The present disclosure relates to wire ropes, forceps, and medical robots.

Background Art

[0002] As a wire rope for driving, for example, a wire rope in which filaments are wound around a core is known (see, for example, Patent Document 1).

[0003] In such a wire rope, the tensile strength (tensile property) is increased by forming the wire from metal, and the flexibility is also increased by making it a stranded wire.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The above-described wire rope has high flexibility and tensile property, but there is room for improvement in the pushing-in ability (push-in property).

Means for Solving the Problems

[0006] The wire rope of the present disclosure includes an inner stranded wire body including a stranded wire formed of a plurality of metal strands, an outer stranded wire body spirally wound so as to cover the outer periphery of the inner stranded wire body and including a stranded wire formed of a plurality of metal strands, and a wrapping wire spirally wound between the inner stranded wire body and the outer stranded wire body using a strand having a flat cross-sectional shape.

Brief Description of the Drawings

[0007] [Figure 1] It is a schematic cross-sectional view showing a first embodiment. [Figure 2] This is a schematic cross-sectional view of the strands used in the wrapping wire shown in Figure 1. [Figure 3] This is a schematic cross-sectional view showing a second embodiment. [Figure 4] This is a schematic cross-sectional view showing a third embodiment. [Figure 5] This is a schematic cross-sectional view showing one aspect of the strands used in wrapping wire. [Figure 6] This is a schematic cross-sectional view showing one aspect of the strands used in wrapping wire. [Figure 7] This is an explanatory diagram of the tensile test method. [Figure 8] This is an explanatory diagram of the method for measuring the indentation force. [Figure 9] This is a schematic diagram showing an example of tensile test results. [Figure 10] This is a schematic diagram showing an example of the results of a force measurement. [Modes for carrying out the invention]

[0008] The wire rope of this disclosure is (1) The device comprises an inner stranded body containing strands formed of multiple metal wires, an outer stranded body spirally wound around the outer circumference of the inner stranded body and containing strands formed of multiple metal wires, and a wrapping wire made of wires with a flattened cross-section, spirally wound between the inner stranded body and the outer stranded body. This configuration allows for improved pushability while maintaining high flexibility and tensile strength. As a result, it can exhibit excellent operability, for example, as a drive rope where pushability is required.

[0009] (2) In the wire rope described in (1) above, the wrapping wire may be curved in a wavy manner along the circumferential direction. This configuration effectively enhances the ability to push the object in.

[0010] (3) In the wire ropes of (1) and (2) above, the outer periphery of the inner stranded wire body may be covered with the wrapping wire over the entire length. According to this configuration, the pushing-in property can be effectively enhanced.

[0011] (4) In the wire ropes of (1) to (3) above, the winding direction of the wrapping wire and the winding direction of the stranded wires in the outer stranded wire body may be opposite to each other. According to this configuration, when the wire rope is pulled, it is possible to suppress unnecessary rotation of the wire rope in the circumferential direction.

[0012] (5) In the wire ropes of (1) to (4) above, the outer stranded wire body includes a plurality of stranded wires, and the wire diameter of the outermost peripheral stranded wire among the stranded wires forming at least one of the plurality of stranded wires may be larger than the wire diameter of any of the stranded wires located inside the outermost peripheral stranded wire. According to this configuration, for example, it is possible to suppress the repulsion of the stranded wires (the stranded wires in the inner stranded wire body, the wrapping wire, and the stranded wires in the outer stranded wire body) in the wire rope after swaging processing toward the radially outer side. As a result, a wire rope having a desired shape can be easily obtained. In addition, since the rigidity is enhanced by the stranded wire having a large wire diameter, the pushing-in property can also be improved.

[0013] The forceps of the present disclosure (6) includes the wire rope of the present disclosure. According to this configuration, since the wire rope is excellent in the pushing-in property, for example, the opening force of the gripping portion or the shearing blade portion provided on the forceps can be increased, and the gripping portion or the shearing blade portion can be surely separated from the tissue piece in the body.

[0014] The medical robot of the present disclosure (7) includes the forceps of the present disclosure. According to this configuration, for example, the opening force of the gripping portion or the shearing blade portion provided on the forceps can be increased, and the gripping portion or the shearing blade portion can be surely separated from the tissue piece in the body.

[0015] In this specification, the "circumferential direction" means the direction around the long axis of the wire rope. The "radial direction" means the radial direction perpendicular to the long axis of the wire rope. The "single wire" means a single line (solid wire). The "strand" means a bundle of wires formed by twisting a plurality of single wires together in advance.

[0016] The first to third embodiments of the present disclosure will be described with reference to the drawings. The present disclosure is not limited only to the embodiments and examples described in the drawings. The dimensions of each part shown in the drawings are the dimensions shown for the purpose of facilitating understanding of the implementation content, and do not necessarily correspond to the actual dimensions.

[0017] <Wire rope> [First Embodiment] FIG. 1 is a schematic cross-sectional view showing the first embodiment. As shown in FIG. 1, the wire rope 1 includes an inner stranded wire body 11, an outer stranded wire body 21, and a wrapping wire 31.

[0018] The inner stranded wire body 11 is a member including the stranded wire C11. The inner stranded wire body 11 can include one or two or more stranded wires C11.

[0019] Each of the stranded wires C11 of the inner stranded wire body 11 is formed of a plurality of single wires w11. Each of the stranded wires C11 can be formed, for example, of a core wire a1 composed of one or two or more single wires w11 arranged at the center, and side wires b1 formed by twisting one or two or more single wires w11 around the core wire a1.

[0020] The inner stranded wire body 11 of the present embodiment includes seven stranded wires C11 formed of a core wire a1 composed of one single wire w11 and side wires b1 composed of six single wires w11.

[0021] The outer stranded wire body 21 is a member including a stranded wire C21 spirally wound so as to cover the outer periphery of the inner stranded wire body 11. The outer stranded wire body 21 can include one or two or more stranded wires C21.

[0022] Each strand C21 of the outer stranded body 21 is formed from multiple strands w21. Each strand C21 can be formed, for example, from a core wire a2 consisting of one or more strands w21 positioned in the center, and side wires b2 arranged around the core wire a2 and made by twisting one or more strands w21 together.

[0023] The outer stranded wire body 21 of this embodiment includes eight stranded wires C21 formed from a core wire a2 consisting of 7 strands w21 and a side wire b2 consisting of 12 strands w21.

[0024] The strands w11 and w21 of the inner stranded body 11 and the outer stranded body 21 are made of metal. Examples of metals that form the strands w11 and w21 include stainless steel such as SUS304, SUS302, and SUS316, and superelastic alloys such as Ni-Ti alloys.

[0025] The wrapping wire 31 is a component that is spirally wound between the inner stranded wire body 11 and the outer stranded wire body 21.

[0026] The wrapping wire 31 uses a single strand w31 with a flattened cross-section. The wrapping wire 31 may be wound in a single strip using one strand w31, or it may be wound in multiple strips using multiple strands w31. In this embodiment, a C-shaped wrapping wire 31 wound in a single strip using one strand w31 with a rectangular cross-section, as shown in Figure 2, is exemplified.

[0027] The arrangement of the wrapping wires 31 with respect to the inner stranded body 11 and the outer stranded body 21 is not particularly limited. The flattened surface of the strands w31 (the relatively flat surface of the outer surface of the strands w31) may be arranged to face the inner stranded body 11 and the outer stranded body 21. The strands w31 may be in contact with the inner stranded body 11 and the outer stranded body 21. The arrangement of the wrapping wires as described above stabilizes the shape of the wire rope 1. The sides of the wound wrapping wires 31 (the opposing surfaces of adjacent wrapping wires 31 in the longitudinal direction of the wire rope 1) may be substantially in contact in the axial direction or separated in the axial direction. That is, the wrapping wires 31 may be tightly wound or loosely wound.

[0028] The portion of the inner stranded wire 11 covered by the wrapping wire 31 may be the entire inner stranded wire 11 or only a part of the inner stranded wire 11. In this embodiment, the outer circumference of the inner stranded wire 11 is covered by the wrapping wire 31 over its entire surface. The larger the proportion of the inner stranded wire 11 covered by the wrapping wire 31 (area of ​​the outer surface of the inner stranded wire 11 covered by the wrapping wire 31 / area of ​​the outer surface of the entire inner stranded wire 11), the more effectively the indentation performance can be improved.

[0029] By adjusting the thickness of the wrapping wire 31, the ease of pushing in and the resistance to breakage of the wire rope 1 when pushed in can also be adjusted. Making the wrapping wire 31 thicker results in a wire rope with higher ease of pushing in. From the viewpoint of further improving ease of pushing in, the thickness of the wrapping wire 31 may be 0.2 to 1.0 mm. Making the wrapping wire 31 thinner results in a wire rope that is less likely to break. From the viewpoint of making a wire rope that is less likely to break, the thickness of the wrapping wire 31 may be 0.01 to 0.1 mm.

[0030] The winding direction of the wrapping wire 31 and the winding direction of the stranded wire C21 in the outer stranded body 21 may be the same direction (forward winding) or opposite directions (reverse winding). In the case of reverse winding, the stranded wire C21 in the outer stranded body 21 that is wound in the opposite direction to the winding direction of the wrapping wire 31 may be all of the stranded wire C21 in the outer stranded body 21 or only a part of it. In the case of reverse winding, when the wire rope 1 is pulled, it is possible to suppress the wire rope 1 from rotating unnecessarily in the circumferential direction. As a result, it is possible to suppress the application of unnecessary force to a driven object (for example, the gripping part or scissors part of forceps) driven by the wire rope 1.

[0031] Examples of materials used to form the strands w31 of the wrapping wire 31 include stainless steel such as SUS304, SUS302, and SUS316, and superelastic alloys such as Ni-Ti alloys. The material of strand w31 may be the same as or different from that of strands w11 and w21.

[0032] As described above, the wire rope 1, having the above configuration, can improve its pushability while maintaining high flexibility and tensile strength. As a result, it can exhibit excellent operability, for example, as a drive rope where pushability is required.

[0033] [Second Embodiment] Figure 3 is a schematic cross-sectional view showing a second embodiment. As shown in Figure 3, the wire rope 2 comprises an inner stranded body 11, an outer stranded body 21, and a wrapping wire 32. The second embodiment differs from the first embodiment in that it includes a wrapping wire 32. The configuration of the inner stranded body 11 and the outer stranded body 21 is the same as in the first embodiment. Therefore, the same parts are denoted by the same reference numerals and their detailed descriptions are omitted. The configuration of the wrapping wire 32, other than the configuration of the wrapping wire 32 shown below, is the same as in the first embodiment.

[0034] The wrapping wire 32 is a component made of flattened wires w32, wound spirally between the inner stranded body 11 and the outer stranded body 21. In this embodiment, the wrapping wire 32 is curved in a wave-like manner along the circumference. In other words, the distance from the long axis of the wire rope 2 to the wrapping wire 32 changes periodically along the circumference.

[0035] The wrapping wire 32 can be formed, for example, by placing a flattened wire w32, before it is processed into a wavy wrapping wire 32, between the inner stranded body 11 and the outer stranded body 21, and then subjecting it to a swaging process. When such processing is performed, the wrapping wire 32 can be processed into a wavy shape so as to follow the outer surface of the inner stranded body 11.

[0036] As described above, the wire rope 2 has the above configuration, which effectively enhances its ability to be pushed in. This is presumed to be because, by making the wrapping wire 32 wavy, the rigidity of the wrapping wire 32 in the longitudinal direction can be increased while maintaining the bending rigidity (flexibility) of the wrapping wire 32, thereby improving its ability to be pushed in.

[0037] [Third Embodiment] Figure 4 is a schematic cross-sectional view showing a third embodiment. As shown in Figure 4, the wire rope 3 comprises an inner stranded body 11, an outer stranded body 23, and a wrapping wire 31. The third embodiment differs from the first embodiment in that it includes an outer stranded body 23. The configuration of the inner stranded body 11 and the wrapping wire 31 is the same as in the first embodiment. Therefore, the same parts are denoted by the same reference numerals and their detailed descriptions are omitted. The configuration of the outer stranded body 23, other than the configuration of the outer stranded body 23 shown below, is the same as in the first embodiment.

[0038] The outer stranded body 23 is a component that includes a stranded wire C23 formed of multiple metal strands, which is wound spirally to cover the outer circumference of the inner stranded body 11.

[0039] The outer stranded body 23 of this embodiment includes a plurality of stranded wires C23. The diameter of the outermost strand w23 (the strand that becomes the side wire b2) among the strands forming at least one stranded wire C23 is greater than the diameter of any of the strands w21 (the strand that becomes the core wire a2) located inside the outermost strand w23.

[0040] In the wire rope 3, the outer stranded body 23 contains eight strands C23, and each strand C23 is formed from a core wire a2 consisting of seven strands w21 and a side wire b2 consisting of twelve strands w23. The wire diameter D23 of the strands w23 in the side wire b2 located on the outermost periphery of the stranded wire C23 is greater than the wire diameter D21 of any strand w21 in the core wire a2 located inside the side wire b2.

[0041] The fact that the wire diameter D23 is larger than the wire diameter D21 generally means that the stiffness of the strands w23 is greater than that of the strands w21. The stiffness of a strand is proportional to its cross-sectional area. Therefore, if all the strands in the stranded wire C23 are made of the same material, the stiffness of the strands w23 in the side wire b2, which has a larger cross-sectional area, will be greater than the stiffness of the strands w21 in the core wire a2. In this embodiment, since the strands w23 with greater stiffness are arranged on the outer circumference of the wire rope 3, the outer shape of the wire rope 3 is easier to maintain.

[0042] As described above, since the wire rope 3 has the above configuration, for example, the strands in the wire rope 3 after swaging (specifically, the strands w11 in the inner strand body 11, the strands w31 that become the wrapping wire 31, and the strands w21 and w23 in the outer strand body 23) can be prevented from repelling outward in the radial direction. As a result, a wire rope 3 of the desired shape can be easily obtained. In addition, the rigidity is increased by the strands w23 with a larger diameter, so the tensile strength can also be improved.

[0043] <forceps> The disclosure also includes forceps comprising the wire ropes 1, 2, and 3 described above. More specifically, the forceps of the disclosure comprises wire ropes 1, 2, and 3, a cylindrical body provided on the outer circumference of the wire ropes 1, 2, and 3, and a gripping portion (jaws) or a shearing portion (scissors) connected to the end of the wire ropes. For example, in the case of forceps with a mechanism in which the gripping portion opens by pushing the wire rope, if the pushability is poor, there is a risk that a tissue fragment inside the body will not separate from the gripping portion or shearing portion. The wire ropes 1, 2, and 3 of the disclosure have excellent pushability, so for example, the force required to open the gripping portion or shearing portion can be increased, and the gripping portion or shearing portion can be reliably separated from a tissue fragment inside the body.

[0044] <Medical robots> This invention further includes a medical robot equipped with the forceps described above. This allows, for example, to increase the opening force of the gripping or scissor portion of the forceps, thereby ensuring that the gripping or scissor portion is reliably separated from a tissue fragment inside the body.

[0045] This disclosure is not limited to the configurations of the embodiments described above, but is intended to include all modifications within the meaning and scope of the claims as indicated by the claims. Some of the configurations of the embodiments described above may be deleted or replaced with other configurations, or other configurations may be added to the configurations of the embodiments described above.

[0046] For example, in the first and third embodiments described above, wire ropes 1 and 3 were exemplified as wrapping wires 31, in which the cross-sectional shape of the strands w31 before spiral winding is rectangular. The cross-sectional shape of the strands of the wrapping wire is not particularly limited as long as it is flattened. The cross-sectional shape of the strands used in the wrapping wire 31 may be, for example, elliptical (see strand w34 in Figure 5) or asymmetrical, such as an egg shape (see strand w35 in Figure 6).

[0047] In the embodiments described above, wire ropes 1, 2, and 3 were described that had wrapping wires 31 and 32 with C-shaped and wavy cross-sections. The cross-sectional shape of the wrapping wire is not particularly limited. The cross-sectional shape of the wrapping wire may be, for example, zigzag. [Examples]

[0048] This disclosure will be described in detail based on examples. This disclosure is not limited to the following examples.

[0049] <Wire rope> The specifications of the wire rope used for evaluation are as follows. Example 1 corresponds to the second embodiment, and Example 2 corresponds to the second embodiment + third embodiment. The wrapping wire was formed into a wavy shape by swaging. • Wire rope diameter: φ0.57mm • Wire material: SUS316 • Inner stranded wire, outer stranded wire, wrapping wire: See Table 1

[0050] [Table 1]

[0051] <Rating> The tensile and compressible properties were evaluated using the wire ropes of the examples and comparative examples shown in Table 1.

[0052] [Tensile] Test specimens t1 were prepared by cutting the wire ropes of the examples and comparative examples to a length of 100 mm. As shown in Figure 7, both ends of the test specimen t1 were gripped using a tensile testing machine E1, and the tensile load was measured with a load cell m1 while the test specimen t1 was pulled in the longitudinal direction. Tensile performance was evaluated using the maximum value of the tensile load as an indicator.

[0053] [Indentation] Test specimens t2 were prepared by cutting the wire ropes of the examples and comparative examples to a length of 30 mm. As shown in Figure 8, test specimen t2 was inserted into the sheath s (inner diameter φ2 mm) of the indentation tester E2, and rods r1 and r2 were placed on both sides of test specimen t2. The input rod r1 was pressed longitudinally at a speed of 10 mm / min using actuator p, and the input load was measured with load cell m21, while the output load transmitted to the output rod r2 was measured with load cell m22. Indentation performance was evaluated using the maximum value of the output load as an indicator.

[0054] The measurement results shown in Figures 9 and 10 indicate that the addition of wrapping lines improves indentation while maintaining tensile strength.

Claims

1. An inner stranded wire body (11) including a stranded wire (C11) formed of multiple metal strands (w11), The outer stranded body (21, 23) includes a stranded wire (C21, C23) formed of multiple metal strands (w21, w23) that is spirally wound to cover the outer circumference of the inner stranded body (11), A wire rope (1, 2, 3) comprising strands (w31, w32) with a flattened cross-section, and wrapping wires (31, 32) spirally wound between the inner stranded body (11) and the outer stranded body (21, 23).

2. The wrapping line (32) is curved in a wavy manner along the circumferential direction, as described in claim 1, for the wire rope (2).

3. The wire rope (1, 2, 3) according to claim 1 or claim 2, wherein the outer circumference of the inner stranded body (11) is covered over the entire surface with the wrapping wire (31, 32).

4. The wire rope (1, 2, 3) according to any one of claims 1 to 3, wherein the winding direction of the wrapping wire (31, 32) and the winding direction of the stranded wire (C21, C23) in the outer stranded body (21, 23) are opposite.

5. The wire rope (3) according to any one of claims 1 to 4, wherein the outer stranded body (23) includes a plurality of strands (C23), and the diameter (w23) of the outermost strand (w21, w23) among the strands (w21, w23) forming at least one strand (C23) in the plurality of strands (C23) is greater than the diameter of any strand (w21) located inside the outermost strand (w23).

6. A forceps comprising wire ropes (1, 2, 3) according to any one of claims 1 to 5.

7. A medical robot comprising the forceps described in claim 6.

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