Medical devices

Abstract

To properly arrange a plurality of actuators.SOLUTION: A medical device comprises: a manipulator which includes a first bent part that can be bent by driving a first transmission member in a base axial direction and a second bent part that is located on a distal side relative to the first bent part in the base axial direction and can be bent by driving a second transmission member in the base axial direction; a first driving unit which drives the first transmission member in the base axial direction; and a second driving unit which drives the second transmission member in the base axial direction. The first driving unit and the second driving unit are arranged so as to be offset in the base axial direction.SELECTED DRAWING: Figure 2

Description

[[Technical Field]]

[0001] The embodiments disclosed in the present specification and drawings relate to a medical device. [[Background Art]]

[0002] Patent Document 1 discloses a bendable medical device configured by driving a plurality of wires with a plurality of actuators. [[Prior Art Documents]] [[Patent Documents]]

[0003] [[Patent Document 1]] US Patent Publication No. 2021 / 0121051 [[Summary of the Invention]] [[Problem to be Solved by the Invention]]

[0004] One of the problems to be solved by the embodiments disclosed in the present specification and drawings is to appropriately arrange a plurality of actuators. However, the problem to be solved by the embodiments disclosed in the present specification and drawings is not limited to the above problem. Problems corresponding to the respective effects achieved by each configuration shown in the embodiments described later can be regarded as other problems. [[Means for Solving the Problem]]

[0005] A medical device according to an embodiment comprises: a manipulator including a first bendable portion that is bendable by driving a first transmission member in a base axis direction, and a second bendable portion that is located distal to the first bendable portion in the base axis direction and is bendable by driving a second transmission member in the base axis direction; a first driving unit that drives the first transmission member in the base axis direction; and a second driving unit that drives the second transmission member in the base axis direction, wherein the first driving unit and the second driving unit are arranged offset in the base axis direction. [[Brief Description of the Drawings]]

[0006] [Figure 1] A schematic diagram showing an example of a continuum robot 101. [Figure 2] A schematic diagram showing an example of actuator unit 7A. [Figure 3] A schematic diagram showing an example of the drive unit 24. [Figure 4] A schematic diagram showing an example of the drive unit 25. [Figure 5] A schematic diagram showing an example of actuator unit 7B. [Figure 6] A schematic diagram showing an example of actuator unit 7C. [Figure 7] A schematic diagram showing an example of actuator units 7D to 7K. [Figure 8] A schematic diagram showing an example of a continuum manipulator 11. [Modes for carrying out the invention]

[0007] The following description of this embodiment will be made in detail with reference to the attached drawings and reference numerals, and the explanation of common reference numerals will be omitted. Note that the coordinate axes in the embodiment are common to all embodiments. Furthermore, the present invention is not limited to the configuration of the following embodiments, but also includes embodiments derived from combinations of the embodiments described.

[0008] This embodiment will be described using Figures 1 to 8. Figure 1 is a schematic perspective view of the continuum robot 101 of this embodiment. The continuum robot 101 is composed of a continuum manipulator 11 and an actuator unit 7 for driving the continuum manipulator 11. The continuum manipulator 11 is, for example, a catheter, and in this case, the continuum robot 101 is a medical device. First, the configuration of the continuum manipulator 11 will be described. As shown in Figure 1, the continuum manipulator 11 is composed of a connector 5 for attachment to the actuator unit 7, a base 19, and three independent curved parts 12, 13, and 14. Note that the number of curved parts is not limited to three. In this embodiment, the positive direction of the z-axis (continuum manipulator side) is referred to as the distal side, and the negative direction of the z-axis (actuator unit side) is referred to as the proximal end side.

[0009] Next, an example of the specific configuration of the base 19 and curved sections 12-14 of the continuum manipulator 11 will be explained using Figure 8. Figure 8 is a schematic perspective view of the curved structure 3 having a tubular structure as described below. The curved structure 3, with a base axis O parallel to the z-axis as its central axis, includes a base 19 and three curved sections: a distal curved section 12, an intermediate curved section 13, and a proximal curved section 14. The intermediate curved section 13 or the proximal curved section 14 is an example of a first curved section, and the distal curved section 12 or the intermediate curved section 13 is an example of a second curved section. In the figure, the base 19, proximal curved section 14, intermediate curved section 13, and distal curved section 12 are arranged in that order along the base axis (z-axis) O, from the proximal end to the distal end. The distal curved section 12 is composed of a tip member 120A and a plurality of wire guides 120. One end of three linear members (drive wires) 115 is fixed to the tip member 120A, and the three linear members 115 are slidably positioned relative to the rear wire guides 120, 130, 140 and the base 19. Similarly, the intermediate curved section 13 is composed of a plurality of wire guides 130. One end of the three linear members 115 is fixed to the most distal wire guide 130, and the three linear members 115 are used as the tip member. The three linear members 115 are slidably positioned relative to the rear wire guides 130, 140 and the base 19. Similarly, the base curved section 14 is composed of multiple wire guides 140, and by fixing one end of three linear members 115 to the most distal wire guide 140, it is used as a tip member, and the three linear members 115 are slidably positioned relative to the rear wire guide 140 and base 19. With this configuration, by applying z-axis thrust (F1, F2...) to a total of nine linear members 115 extending from the base end of the base 19, each curved section 12 to 14 can be given two degrees of freedom: curvature with respect to the z axis and rotation around the z axis, excluding extension and contraction in the z axis direction. With this configuration, the continuous manipulator 11 is a continuous manipulator with a total of six degrees of freedom, excluding extension and contraction in the z axis direction. A linear member 115 connected to the wire guide 130 or wire guide 140 is an example of a first transmission member, and a linear member 115 connected to the tip member 120A or wire guide 130 is an example of a second transmission member.The continuous manipulator 11 is an example of a manipulator that includes a first bending section that can be bent by driving a first transmission member in the direction of the base axis, and a second bending section located distal to the first bending section in the direction of the base axis, and that can be bent by driving a second transmission member in the direction of the base axis.

[0010] Next, an overview of how to use the continuum robot 101 of the present invention will be described. As shown in Figure 1, various tools can be inserted from the proximal end toward the distal curved portion using the access port 55 provided on the side of the connector 5. In Figure 8, the curved structure 3 has a tip member 120A and a tool channel 150 composed of wire guides 120, 130, 140 and the inner wall of the base 19, thus forming a tube structure with a hollow path running through its interior. The access port 55 has a configuration equivalent to, for example, the access port 55 described in Patent Document 1, allowing access to the tool channel 150 from outside the continuum manipulator 11 via the access port 55. Using this path from the access port 55 to the tool channel 150, it is possible to observe and treat objects near the tip of the distal curved portion 12 by inserting a small camera, forceps, biopsy tools, etc., as in Patent Document 1. In addition, by inserting an irrigation suction tube and spraying or sucking liquid through the irrigation suction tube from the tip of the curved section 12, it is possible to clean objects near the tip of the curved section 12 or administer chemicals.

[0011] In this embodiment, an example of a continuum robot driving a 6-degree-of-freedom manipulator using 9 drive units is described, but the present invention is not limited to this. For example, the present invention is applicable to any form of continuum manipulator having multiple curved sections (joints) with one or more degrees of freedom, each having at least one drive unit.

[0012] Next, the configuration of the actuator unit 7 for driving the continuum manipulator 11 described above will be specifically explained using embodiments of actuator units 7A to 7K described below.

[0013] (Example 1) Embodiment 1 will be described using Figures 2 to 4. Figure 2 shows (a) a schematic perspective view, (b) a schematic perspective view with the exterior member 21 omitted, (c) a schematic perspective view with the drive board 23 omitted, and (d) a schematic front view of the actuator unit 7A. In Figures 2(b) and (d), the central axis of the actuator unit 7A is positioned on the same straight line as the base axis O shown in Figure 8. Note that in each of the following embodiments, the actuator unit will be treated as an actuator unit regardless of the presence or absence of the exterior member 21 and the drive board 23. In Figures 2(b) and (c), the actuator unit 7A includes two types of drive units: a 6-axis drive unit 22A and a 3-axis drive unit 22B. The 6-axis drive unit 22A includes 6 drive units 24, and the 3-axis drive unit 22B includes 3 drive units 25. In addition, a drive board 23 is provided so as to surround the 3-axis drive unit 22B. Here, the drive board 23 is the control electronic equipment for the DC motor and encoder described later, and includes, for example, a servo amplifier and a control controller for position control. As shown in Figure 2(b), the drive board 23 is provided around the drive units, which are fewer in number. The drive board 23 is, for example, a board that controls the drive of at least one of the drive units 24 and 25.

[0014] Here, the two types of drive units 24 and 25 used in the actuator unit 7A will be described using Figures 3 and 4, respectively. Figure 3 is (a) a schematic perspective view of the drive unit 24 and (b) a schematic cross-sectional view taken by the yz plane passing through the center of the drive unit 24. In the figure, a rotary DC motor 29 equipped with an encoder 30 used for drive control is fixed to a bracket 32. On the other hand, the lead screw 35 is supported so as to be rotatable around the z axis by a combination angular contact ball bearing 38 supported by the bracket 32. The shaft of the DC motor 29 and the lead screw 35 are fixed to a coupling 31, making it possible to transmit the rotational power of the DC motor 29 to the lead screw 35. The lead screw 35 meshes with a nut 37 fixed to the tractor 33 via screw surfaces, and the nut 37 is movable in the base axis (z axis) direction in accordance with the rotation of the lead screw 35. In addition, a linear bush 36 is fixed to the tractor 33, and the rod 34 is supported so as to be slidable in the z axis direction relative to the linear bush 36. Furthermore, one end of the rod 34 is fixed to the bracket 32, forming a linear guide that allows the tractor 33 to slide in the z-axis direction. Instead of the linear bush 36 and rod 34, a ball spline with high rigidity around the axis can be used. Also, a ball screw can be used instead of the lead screw 35 and nut 37. The above configuration is a rotary-to-linear motion conversion mechanism that converts the rotational power of the DC motor 29 into z-axis power of the tractor 33. An output end 27 having a mechanically engageable shape (a hole in the figure) is provided at the end of the tractor 33 that is slidable in the z-axis direction by the rotary-to-linear motion conversion mechanism. The output end 27 can output z-axis thrust (driving force) to the linear member 115 via a known structure, such as the connection unit 107 described in Patent Document 1. The output end 27 only needs to be able to transmit thrust to the linear member 115 and is not limited to the shape shown in the figure. The linear member 115 may be directly connected to the output end 27, or it may be connected via any structure. The same applies to the output terminal 28, which will be described later.

[0015] Similarly, FIG. 4 is (a) a schematic perspective view of the driving unit 25, and (b) a schematic cross-sectional view taken along the y-z plane passing through the center of the driving unit 25. In the figure, a rotary DC motor 39 provided with an encoder 30 used for drive control is fixed to a bracket 32. Here, the DC motor 39 is larger and has a higher output than the DC motor 29 used in the driving unit 24. The description of the rotary-linear conversion mechanism that converts the power in the rotational direction of the DC motor 39 into the power in the z-axis direction of the tractor 43 is omitted because it is the same as that in the case of the driving unit 24. Similar to the case of the driving unit 24, an output end 28 having a mechanically engageable shape is provided at an end portion of the tractor 43 slidable in the z-axis direction. The output end 28 can output a thrust (driving force) in the z-direction to the linear member (115) via a known structure such as the connection unit 107 described in Patent Document 1, for example.

[0016] The brackets 33 and 43 of the driving units 24 and 25 described above are fixed to the support column 26 in FIG. 2. The support column 26 has a shape having six flat fixable surfaces in a region where the 6-axis drive unit 22A is arranged, and three flat fixable surfaces in a region where the 3-axis drive unit 22B is arranged. Therefore, as illustrated in FIG. 2(d), the six driving units 24 constituting the 6-axis driving unit 22A are arranged at equal intervals of 60 degrees around the z-axis, and the three driving units 25 constituting the 3-axis driving unit 22B are arranged at equal intervals of 120 degrees around the z-axis. As shown in FIG. 2(d), at least a part of the driving unit 24 and the driving unit 25 overlap each other in a vertical projection plane along the base axis direction.

[0017] Further, the output end 28 of the driving unit 25 is exposed in the z-direction from between the driving units 24, and together with the output end 27 of the driving unit 24, all nine output ends 27 and 28 are exposed in the z-axis direction. Further, the nine output ends 27 and 28 are arranged at the same distance with respect to the base axis (z-axis) O.

[0018] A method for load connection to each output end for driving a continuum manipulator 11 having nine input shafts using the actuator unit 7A having the above configuration will be described. In the present embodiment, consideration is given to a case where the distal bending portion 12 and the intermediate bending portion 13 are driven using the 6-axis drive unit 22A, and the proximal bending portion 14 is driven using the 3-axis drive unit 22B. A total of six linear members 115 extending from the distal bending portion 12 and the intermediate bending portion 13 are engaged with the output end 27 via a known structure such as the connection unit 107 described in Patent Document 1, for example. Similarly, a total of three linear members 115 extending from the proximal bending portion 14 are engaged with the output end 28 via a known structure such as the connection unit 107 described in Patent Document 1, for example. The drive unit 25 included in the 3-axis drive unit 22B is an example of a first drive unit that drives a first transmission member in the base axis direction, and the drive unit 24 included in the 6-axis drive unit 22A is an example of a second drive unit that drives a second transmission member in the base axis direction. The output end 28 is an example of a first output end, and the output end 27 is an example of a second output end. As shown in FIG. 2(d), the first output end is disposed between the plurality of second drive units within a vertical projection plane in the base axis direction.

[0019] According to the present embodiment, various effects as described below can be obtained by offsetting the nine drive units 24 and 25 in the base axis direction (z-axis direction) and arranging them in a divided manner. As a first effect, it becomes possible to reduce the outer diameter dimension of the actuator unit 7A compared to a case where nine drive units 24 and 25 are arranged circumferentially around the base axis (z-axis) at the same position in the base axis direction. By making the outer diameter of the actuator unit 7A as small as possible, the outer diameter of the exterior member 21 can also be reduced, which facilitates manual gripping, installation, transportation and the like.

[0020] As a second effect, it becomes easier to secure space for arranging components such as a linear bush, a nut, and a tractor used in the rotary-to-linear conversion mechanism, and the risk of interference between components can be reduced.

[0021] A third benefit is that the drive board 23 can be positioned using the space around the 3-axis drive unit 22B. Even with the drive board 23 in place, the outer diameter of the 3-axis drive unit 22B does not become significantly larger than that of the 6-axis drive unit 22A, and the cylindrical exterior member 21 can be attached.

[0022] As a fourth effect, by designating either drive unit 24 or 25 as the drive unit driving the same curved section among the curved sections 12 to 14, and aligning their positions in the base axis direction (z direction), the force transmission path from the DC motor, which is the drive source, to the tip of the curved section can be made identical for the same curved section. This reduces the difference in transmission characteristics of the transmission paths driving the same curved section, and improves the control performance of each curved section. Furthermore, in this embodiment, by arranging the projection positions of all nine output terminals 27, 28 onto a plane normalized to the base axis on the same circumference centered on the base axis, it is advantageous that the continuous manipulator constituting different curved sections 12 to 14 can be easily applied using wire guides 120, 130, 140 having the same outer diameter shape, as shown in Figure 8. This is because, for example, the connection mechanism from the output terminal to the drive wire, which corresponds to the connection unit 107 described in Patent Document 1, can be arranged rotationally symmetrically in the projection cross-section in the base axis direction. Therefore, it is possible to contribute to reducing the diameter of the continuous manipulator 11.

[0023] As a fifth effect, by making the distance from the base axis (z-axis) of the drive unit output terminal 27 or 28 equal in each curved section 12 to 14, and by making the moment arm length in each curved section the same, the control performance of each axis can be similarly improved.

[0024] As a sixth effect, by positioning the 6-axis drive unit 22A, which drives the distal curved section 12 and the intermediate curved section 13, distal to (towards the positive z-axis direction) the 3-axis drive unit 22B, which drives the proximal curved section 14, the force transmission path for driving the distal curved sections 12 and 13 can be shortened, making it suitable for multi-joint manipulators where dexterity and high responsiveness are required for the distal curved sections.

[0025] A seventh effect is that the output of the drive source of the drive unit can be changed for each curved section. By dividing and arranging the drive sources in the base axis (z-axis) direction, the output of the DC motor of the drive source can be increased only for the necessary drive units, thus preventing a significant increase in the size of the actuator unit due to the increase in the size of the drive source. In this embodiment, the output of the drive source used for the 3-axis drive unit 22B that drives the base end curved section 14 is set to be large. That is, the output of the drive unit with fewer units is larger. This is effective when the transmission paths for the distal curved section 12 and the intermediate curved section 13 run parallel to the transmission path that drives the base end curved section 14, and more output from the drive source is required when driving the base end curved section 14 while the distal curved section 12 and the intermediate curved section 13 are under load.

[0026] In this embodiment, an example of using a rotary DC motor and a rotary-to-linear motion conversion mechanism as the drive source for the actuator unit has been described, but the scope of the present invention is not limited to this. For example, the present invention also applies to cases where a rotary-to-linear motion conversion mechanism using a stepping motor driven by applied pulses is used as the drive source, or where a linear motor is used for the drive unit itself. Any known type of motor can be applied as the drive source, and it is also possible to configure the actuator unit with a combination of drive units using different drive sources. Furthermore, in this embodiment, an example of cantilever support of the lead screw 35 of the rotary-to-linear motion conversion mechanism using a pair of combined angular contact ball bearings has been illustrated, but it is also possible to improve rigidity by using a double-ended support configuration where one end is supported by a combined angular contact ball bearing and the other end is supported by a deep groove ball bearing. By increasing rigidity, the positioning performance of the tractor can be improved. Regarding the rotary-to-linear motion conversion mechanism, an example of a guide mechanism in the base axis (z-axis) direction using a linear bush and a rod has been shown, but it is possible to apply a known linear guide on which a block can slide relative to a rail.

[0027] Furthermore, in this embodiment, the effect was explained using an example in which the base axis direction (z direction) position of the drive unit and the distance of the output end of each drive unit from the base axis (z axis) are aligned for each curved section, but the present invention is not limited to this. Even when the base axis direction (z direction) position of each drive unit and the distance of the output end of each drive unit from the base axis (z axis) are different, this embodiment can also achieve miniaturization (reduction in diameter) of the actuator unit.

[0028] In Figure 2(d), the drive units 24 and 25 have overlapping regions in the plane obtained by projecting the actuator unit in the direction of the base axis (z axis), but it is not necessary for each drive unit to necessarily overlap. For example, it is possible to position the drive unit 25 outward away from the base axis (z axis) so that the drive units 24 and 25 do not overlap, thereby increasing the space near the base axis (z axis) and allowing the electronic components corresponding to the drive board 23 to be placed there.

[0029] In this embodiment, the output ends 27 and 28 provided at the ends of the tractors 33 and 43 are illustrated as having holes as an example of a shape that can be mechanically engaged, but the present invention is not limited thereto. The output ends include any shape or configuration that can be mechanically engaged with the connection unit 107 described in Patent Document 1. For example, the output ends can be configured to be clamped with a spring-driven clip, configured to be engaged in the base axis (z-axis) direction below a certain threshold using a snap-fit ​​mechanism or plunger, or configured to be physically engaged by magnetic attraction using magnets. Furthermore, the position of the output ends 27 and 28 is not limited to between the rod 34 and the lead screw 35, but may be provided at any other position as long as it can be directly or indirectly connected to the linear member 115.

[0030] In this embodiment, we have explained that control performance can be improved by aligning the placement of the drive units and the output of the drive sources that drive a single curved section. However, the present invention is not limited to this. The present invention also includes cases where a common curved section is driven by a combination of different drive units or by multiple drive units arranged at different distances and positions relative to the base axis.

[0031] (Example 2) Other embodiments will be described with reference to Figure 5. Figure 5 shows (a) a schematic perspective view and (b) a schematic front view of the actuator unit 7B. Similar to Embodiment 1, the central axis of the actuator unit 7B is aligned with the base axis O of the continuum manipulator 11, and the base axis O is not shown in Figure 5. In the figure, the actuator unit 7B consists of two types of drive units, a 6-axis drive unit 22A and a 3-axis drive unit 22B, similar to Embodiment 1, with the 3-axis drive unit 22B positioned on the positive z-axis side (distal side) and the 6-axis drive unit 22A positioned on the negative z-axis side (base end side). Similar to Embodiment 1, the two types of drive units 24 and 25 used in the 6-axis drive unit 22A and the 3-axis drive unit 22B are supported and fixed to appropriately provided support columns via their respective brackets 33 and 43. Furthermore, as shown in Figure 5(b), the nine output terminals 27, 28 of each drive unit 24, 25 are arranged at equidistant distances from the central axis (base axis, z axis) of the actuator unit 7B, and lie on the same circumference centered on the base axis within the xy projection plane (the perpendicular projection plane in the direction of the base axis).

[0032] Next, a method for connecting loads to each output end for driving the continuum manipulator 11 using the actuator unit 7B of this embodiment will be described. In this embodiment, we consider the case where the distal curved portion 12 is driven by a 3-axis drive unit 22B, and the intermediate curved portion 13 and the proximal curved portion 14 are driven by a 6-axis drive unit 22A. A total of three linear members 115 extending from the distal curved portion 12 are engaged with the output end 28 via a known structure, such as the connection unit 107 described in Patent Document 1. Similarly, a total of six linear members 115 extending from the intermediate curved portion 13 and the proximal curved portion 14 are engaged with the output end 27 via a known structure, such as the connection unit 107 described in Patent Document 1. The drive unit 24 included in the 6-axis drive unit 22A is an example of a first drive unit that drives the first transmission member in the direction of the base axis, and the drive unit 25 included in the 3-axis drive unit 22B is an example of a second drive unit that drives the second transmission member in the direction of the base axis.

[0033] The drive unit 24 included in the 6-axis drive unit 22A is an example of a first drive unit that drives the first transmission member in the base axis direction, and the drive unit 25 included in the 3-axis drive unit 22B is an example of a second drive unit that drives the second transmission member in the base axis direction. The output terminal 27 is an example of a first output terminal, and the output terminal 28 is an example of a second output terminal. As shown in Figure 5(b), this second output terminal is arranged between a plurality of first drive units in a vertical projection plane in the base axis direction.

[0034] According to this embodiment, by offsetting and dividing the nine drive units 24 and 25 in the base axis direction (z axis direction), various effects can be obtained, similar to those in Embodiment 1. The first to fifth effects described in Embodiment 1 can also be obtained in this embodiment, so their explanation will be omitted.

[0035] As a sixth effect, by positioning the 3-axis drive unit 22B that drives the distal curved section (12) distal to the 6-axis drive unit 22A that drives the intermediate curved section 13 and the proximal curved section 14 (towards the positive z-axis direction), the force transmission path for driving the distal curved section 12 can be shortened, making it suitable for multi-joint manipulators where dexterity and high responsiveness are required for the distal curved section 12.

[0036] Regarding the seventh effect, similar to Example 1, the output of the drive source of the drive unit can be changed for each curved section without significantly increasing the size and diameter of the actuator unit. In this embodiment, the output of the drive source used for the 3-axis drive unit 22B that drives the distal curved section 12 is set to be large. This is effective when setting the curvature angle of the distal curved section 12 to be larger than that of the other two curved sections. For example, consider a continuous robot that uses a continuous manipulator 11 as a bronchoscope and enters the inside of the bronchus while bending the curved section at its tip. The inside of the bronchus is a complex path with repeated branching, and we can assume a case where the target is a part that is not easily accessible, such as the upper lobe of the right lung located at the back of a path that includes a branch with a large curvature. According to this embodiment, even at branches with a large curvature, it is possible to advance through the bronchus while setting a large curvature angle (small radius of curvature) of the distal curved section 12. This embodiment is suitable for multi-joint manipulators that require a large driving force for the distal curved section 12.

[0037] (Example 3) Other embodiments will be described with reference to Figure 6. Figure 6 is a schematic perspective view (a) and a schematic front view (b) of the actuator unit 7C. Similar to Embodiment 1, the central axis of the actuator unit 7C is aligned with the base axis O of the continuum manipulator 11, and the base axis O is not shown in Figure 6. In the figure, the actuator unit 7C consists of three 3-axis drive units 22C, which are arranged in series along the base axis (z axis). The 3-axis drive unit 22C consists of three drive units 45 arranged at equal intervals around the base axis (z axis). The drive unit 45 is a modified version of the drive unit 25, with the DC motor 39 being replaced by a DC motor 29, and the other configurations are the same. Similarly, in each 3-axis drive unit 22C, the three drive units 45 are arranged so that the distance from the base axis (z axis) to the output terminal 28 is equal. Each drive unit 45 is supported and fixed to a support column appropriately provided, similar to Embodiment 1, via its respective bracket 43. In the figure, the three-axis drive unit 22C is arranged such that a part of the rotary-to-linear motion conversion mechanism of the drive unit 45 and a part of the DC motor 29, which is the drive source, overlap in the base axis (z-axis) direction. In this case, it is preferable to determine the position of the drive unit 45 so as to avoid interference between the tractor 43 and the DC motor 29 within the range of motion of the tractor 43.

[0038] Furthermore, as shown in Figure 6(b), the nine output terminals 28 of each drive unit 45 are positioned equidistant from the central axis (base axis, z-axis) of the actuator unit 7C, and lie on the same circumference centered on the base axis in the xy projection plane. In addition, the nine output terminals 28 are arranged at equal intervals of 40 degrees around the base axis in the xy projection plane.

[0039] Next, a method for connecting loads to each output end for driving the continuous manipulator 11 using the actuator unit 7C of this embodiment will be described. In this embodiment, one 3-axis drive unit 22C drives one curved section. The three 3-axis drive units 22C each drive the distal curved section (12), the intermediate curved section (13), and the proximal curved section (14) from the positive z-axis side (distal side). Similar to the embodiment described above, a total of nine linear members 115 extending from each curved section 12 to 14 are engaged with the output end 28 via a known configuration such as the connection unit 107 described in Patent Document 1.

[0040] According to this embodiment, by offsetting and dividing the nine drive units 45 in the base axis direction (z axis direction), various effects can be obtained, similar to those in Embodiment 1. The second to sixth effects described in Embodiment 1 are also obtained in this embodiment, so their explanation will be omitted. Regarding the first effect, since the actuator unit 7C is composed of a three-axis drive unit consisting of three drive units 45, a greater reduction in diameter can be achieved compared to actuator units 7A and 7B. In addition, by arranging the rotation-to-linear motion conversion mechanism of the drive unit 45 and the DC motor 29 to overlap in the z axis direction so as not to interfere with each other, the dimensions of the actuator unit 7C in the base axis direction (z axis) can be kept to a minimum.

[0041] Similarly, the seventh effect in Examples 1 and 2 can also be obtained by appropriately selecting the output of the DC motor for each 3-axis drive unit.

[0042] In this embodiment, an example in which the same drive source 29 is used for all three 3-axis drive units 22C has been described, but the present invention is not limited to the case in which the same drive source 29 is used for all. As in the embodiment described above, it is preferable to appropriately select the drive source necessary to drive the load of each curved section.

[0043] Furthermore, in Examples 1 to 3, the distance from the central axis (base axis) of the output end was set to be the same, but it is also sufficient to set the distance from the central axis to be the same for the output ends of the drive units that drive the same curved section, and some of the effects can be obtained.

[0044] (Example 4) Other embodiments will be described with reference to Figure 7. Figures 7(a) to 7(g) are schematic front views of actuator units 7D to 7K, respectively, and the coordinate axes are common in each figure. Similar to Embodiment 1, the central axes of actuator units 7D to 7K are aligned with the base axis O of the continuum manipulator 11, and the base axis O is not shown in Figures 7(a) to 7(g). In this embodiment, an example of the layout of nine drive units inside the exterior member 21 in the projection plane in the direction of the base axis (z axis) will be described. In this embodiment, an example in which all drive units 24 are used as the layout example will be shown, but new reference numerals 51A to 73C will be assigned to distinguish the position of each drive unit. The drive units 51A to 73C are supported and fixed to appropriate support columns via brackets 32, similar to the embodiments described above. Furthermore, it is assumed that the rotational-to-linear motion conversion mechanisms of each drive unit have appropriate gaps so as not to interfere with each other in their range of motion.

[0045] Furthermore, this embodiment differs from the embodiment described above in that the output terminals of the nine drive units are not on the same circumference. Therefore, for the continuous body manipulator driven using the actuator units 7D to 7K described in this embodiment, it is preferable to appropriately change the shape and arrangement of the connection unit 107 and the linear members (driving wires) 115 described in Patent Document 1 to match the arrangement of the output terminals. The drive units of the actuator units described in this embodiment are assigned a code consisting of a number and a single letter of the alphabet, but it is preferable to drive one curved section using three drive units with the same number as a set. Figure 7(a) is a schematic front view of actuator unit 7D, in which the output terminals 27 of drive units 51A to 51C are located on the same circumference G around the base axis, and the output terminals 27 of drive units 52A to 52C and drive units 53A to 53C are located on the same circumference H around the base axis. When drive units 51A to 51C output a driving force to bend the base end curved portion 14, the output terminals 27 of drive units 51A to 51C are an example of first output terminals. Also, when drive units 53A to 53C output a driving force to bend the distal curved portion 12, the output terminals 27 of drive units 53A to 53C are an example of second output terminals. As shown in Figure 7(a), the multiple first output terminals are located at a first distance from the base axis, and the multiple second output terminals are located at a second distance different from the first distance from the base axis.

[0046] Figure 7(b) is a schematic front view of actuator unit 7E, in which the output terminals 27 of drive units 56A to 56C and drive units 57A to 57C are located on the same circumference I around the base axis, and the output terminals 27 of drive units 58A to 58C are located on the same circumference J around the base axis.

[0047] Figure 7(c) is a schematic front view of actuator unit 7F, in which the output terminals 27 of drive units 61A to 61C are located on the same circumference K around the base axis, and the output terminals 27 of drive units 59A to 59C and drive units 60A to 60C are located on the same circumference L around the base axis.

[0048] Figure 7(d) is a schematic front view of actuator unit 7G, in which the output terminals 27 of drive units 64A to 64C are located on the same circumference M around the base axis, the output terminals 27 of drive units 62A to 62C are located on the same circumference N around the base axis, and the output terminals 27 of drive units 63A to 63C are located on the same circumference P around the base axis.

[0049] Figure 7(e) is a schematic front view of actuator unit 7H, in which the output terminals 27 of drive units 65A to 65C and drive units 67A to 67C are located on the same circumference Q around the base axis, and the output terminals 27 of drive units 66A to 66C are located on the same circumference R around the base axis.

[0050] Figure 7(f) is a schematic front view of actuator unit 7J, in which the output terminals 27 of drive units 68A to 68C are located on the same circumference S around the base axis, the output terminals 27 of drive units 69A to 69C are located on the same circumference T around the base axis, and the output terminals 27 of drive units 70A to 70C are located on the same circumference U around the base axis.

[0051] Figure 7(g) is a schematic front view of the actuator unit 7K, in which the output terminals 27 of the drive units 71A to 71C and drive units 72A to 72C are located on the same circumference V around the base axis, and the output terminals 27 of the drive units 73A to 73C are located on the same circumference W around the base axis.

[0052] The actuator units 7D to 7K described above generally have the following characteristics. For example, actuator units 7D, 7F, and 7H have a layout in which a large space is provided near the center of the actuator unit. This space can be used to place support columns or control electronic equipment such as the drive board described above, or to create a path with a different shape from the access port 55 that can access the tool channel 150 of the continuum manipulator 11. On the other hand, actuator units 7E, 7G, 7J, and 7K have a layout in which a relatively large empty space is provided on the outer periphery (outside 58A to 58C, outside 62A to 62C, outside 69A to 69C, and outside 73A to 73C), and can be used in a similar manner. Here, "outside" refers to the direction moving radially from the center of the actuator unit.

[0053] Unlike Embodiments 1 to 3, in which drive units for driving different curved sections were offset in the base axis (z-axis) direction, this embodiment describes a method for arranging drive units without offsetting them from one another. Therefore, according to this embodiment, a structure in which drive units are closely laid out can be realized without increasing the dimensions of the actuator unit in the base axis (z-axis) direction, i.e., a reduction in diameter can be achieved.

[0054] Furthermore, according to this embodiment, although the radial position and orientation from the center of the drive unit vary in each actuator unit 7D to 7K, by treating three drive units of the same number as a set and driving one curved section as shown in the figure, the force transmission path from the DC motor, which is the drive source, to the tip of each curved section can be made identical. This reduces differences in transmission characteristics and improves the control performance of each axis.

[0055] In this embodiment, the actuator units 7D to 7K were described in an example where they are arranged so that they do not overlap within the projection plane in the direction of the base axis (z axis). However, as in Examples 1 to 3, the drive units may be offset in the direction of the base axis (z axis) and overlapped to further reduce the diameter.

[0056] In this embodiment, an example of forming an actuator unit using nine drive units 24 has been described, but it is not necessary for all drive units to be identical. Drive units with different sizes and power outputs can be combined to achieve close-packing by the drive units.

[0057] In this embodiment, in order to make it easier to compare the mounting state of each actuator unit, an embodiment in which the drive unit is laid out inside a cylindrical exterior member 21 has been described. However, the exterior member can be any shape. For example, a polygonal exterior member that surrounds the outer shape of the drive unit with an enveloping surface can be used. By adopting a polygonal exterior member, not only is miniaturization possible, but it is also possible to prevent the actuator unit body from rolling and falling when the actuator unit is placed on a desk.

[0058] While several embodiments have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These embodiments can be implemented in a variety of other forms, and various omissions, substitutions, modifications, and combinations of embodiments are possible without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims and their equivalents. [Explanation of Symbols]

[0059] 3. Curved Structures 5 Connectors 7.7A~7K Actuator Unit 11. Continuum Manipulator 12. Distal curvature 13. Intermediate curved section 14. Curved base section 19 Base 21 Exterior components 22A 6-axis drive unit 22B, 22C 3-axis drive unit 23 Drive board 24,25,45,51A~73C Drive Unit 26 Posts 27,28 Output terminals 29,39 DC motors 30 encoders 31 Coupling 32 brackets 33,43 tractors 34 rods 35 Lead Screw 36 Linear Bushings 37 Nuts 38 Angular Contact Ball Bearings 55 Access Ports 101 Continuum Robot 115 Linear member 120A Tip component 120, 130, 140 Wire Guides 150 Tool Channels

Claims

1. A manipulator including a first curved portion that can be bent by driving a first transmission member in the direction of the base axis, and a second curved portion located distal to the first curved portion in the direction of the base axis, and which can be bent by driving a second transmission member in the direction of the base axis, A first drive unit that drives the first transmission member in the direction of the base axis, A second drive unit that drives the second transmission member in the direction of the base axis, Equipped with, A medical device characterized in that the first drive unit and the second drive unit are arranged offset in the direction of the base axis.

2. The medical device according to claim 1, characterized in that the second drive unit is arranged distal to the first drive unit.

3. The medical device according to claim 1 or 2, characterized in that at least a portion of the first drive unit and the second drive unit overlap in the vertical projection plane in the direction of the base axis.

4. The first transmission member, the second transmission member, the first drive unit, and the second drive unit are each provided in multiple quantities. Each of the plurality of first drive units is provided with a first output terminal that outputs driving force to the first transmission member, Each of the plurality of second drive units is provided with a second output terminal that outputs driving force to the second transmission member, The medical device according to any one of claims 1 to 3, characterized in that at least one of the plurality of first output terminals or the plurality of second output terminals is arranged at an equidistant distance from the base axis.

5. The medical device according to claim 4, characterized in that the plurality of first output terminals and the plurality of second output terminals are arranged at equidistant distances from the base axis.

6. The medical device according to claim 4 or 5, characterized in that the output of the drive unit with the smaller number among the plurality of first drive units and the plurality of second drive units is greater.

7. The medical device according to any one of claims 4 to 6, characterized in that the plurality of first drive units or the plurality of second drive units are arranged at an equidistant distance from a plane normal to the base axis.

8. Within the vertical projection plane in the direction of the base axis, The medical device according to any one of claims 4 to 7, characterized in that each of the plurality of first output terminals is arranged between the plurality of second drive units.

9. Within the vertical projection plane in the direction of the base axis, The medical device according to any one of claims 4 to 8, characterized in that each of the plurality of second output terminals is arranged between the plurality of first drive units.

10. The medical device according to any one of claims 4 to 9, characterized in that a drive board for controlling the drive of at least one of the first drive units or the second drive units is provided around the drive units that are fewer in number among the plurality of first drive units and the plurality of second drive units.

11. A manipulator including a first curved section that can be bent by driving a plurality of first transmission members in the direction of the base axis, and a second curved section located distal to the first curved section in the direction of the base axis, and that can be bent by driving a plurality of second transmission members in the direction of the base axis, A plurality of first drive units that drive the plurality of first transmission members in the direction of the base axis, A plurality of second drive units that drive the plurality of second transmission members in the base axis direction, Equipped with, Each of the plurality of first drive units is equipped with a first output terminal that outputs driving force to the first transmission member, Each of the plurality of second drive units is provided with a second output terminal that outputs driving force to the second transmission member, The multiple first output terminals are arranged at a first distance from the base axis, A medical device characterized in that a plurality of the second output terminals are arranged at a second distance different from the first distance from the base axis.

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