JP4984280B2 - Drive mechanism - Google Patents

Description

  The present invention relates to a drive mechanism that changes the direction of a member by bending or bending a connecting portion, for example, a drive mechanism of forceps used in minimally invasive surgery, a drive mechanism of a machine for architectural civil engineering used in architectural civil engineering, and a toy The present invention relates to a driving mechanism used. The present invention also relates to a minimally invasive surgical manipulator provided with the drive mechanism.

  Various drive mechanisms for realizing a bending motion at the connecting portion have been proposed. For example, there are Patent Documents 1 to 3 as mechanisms for bending a connecting portion between a shaft portion and a distal end portion of a forceps for minimally invasive surgery.

  In Patent Documents 1 and 2, a bending motion is realized by a so-called slider-link mechanism. That is, a slider / link mechanism is provided at a connecting portion that connects the shaft portion and the distal end portion of the forceps, and a drive shaft inserted through the shaft portion of the forceps is connected to the link. By directly moving the drive shaft by a motor from the outside of the patient, the forceps connecting portion is bent. In addition, what uses a wire instead of a drive shaft is also known.

In Patent Document 3, a forceps called a tripod platform type is disclosed. In this forceps, three legs are formed at the tip of the forceps. The three legs are respectively supported by three drive shafts inserted through forceps shafts penetrating from the outside to the inside of the patient via ball joints. By rotating the three drive shafts independently in the axial direction by a motor from outside the patient, the tip of the forceps changes direction.
JP 2004-154877 A JP 2005-169011 A JP 2004-187798 A

  The above techniques have problems inherent to each technique. For example, when the link is driven by a wire, it is difficult to ensure the rigidity and durability of the wire, and the wire may be extended or cut. Therefore, it is possible to bend the bent portion with a relatively large force. difficult. When a bending motion with multiple degrees of freedom is realized by the slider-link mechanism, the bending point in one direction and the bending point in the other direction are provided at different positions in the axial direction. The rotation trajectory in the direction and the rotation trajectory in the other direction have different rotation radii, and the movement range of the tip is an aspherical surface. In a tripod platform type drive mechanism, a plurality of joint parts constituted by the drive mechanism cannot be connected, so that the bending angle cannot be expanded.

  In various technical fields, in consideration of the advantages and disadvantages of various drive mechanisms, an appropriate drive mechanism is selected and used from the currently proposed drive mechanisms. Therefore, if another drive mechanism is proposed, the degree of freedom in design is improved, which is desirable. Here, any of the above-described techniques inputs a linear motion from the shaft portion of the forceps to the connecting portion, and a drive mechanism for inputting rotation to the connecting portion has not yet been proposed.

  It is an object of the present invention to provide a drive mechanism and a minimally invasive surgical manipulator that can input rotation to a connecting portion to bend or curve the connecting portion.

  A drive mechanism according to a first aspect of the present invention is a drive mechanism that bends a connecting portion that connects a first connected member and a second connected member, and the connecting portion includes the first connected member and the first connected member. A restricting universal joint for connecting the second connected member and a driving universal joint are provided, and the restricting universal joint is not movable in the axial direction with respect to the first connected member and the second connected member. A first male threaded portion that is threadedly engaged with a first female threaded portion formed on the first connected member is formed on one shaft portion of the universal driving joint, and the other universal shaft for the driving universal joint is formed. The shaft portion is formed with a second male screw portion that is screwed into a second female screw portion formed on the second connected member, and the first male screw portion and the second male screw portion are the driving universe. The first connected member and the second connected member are brought close to each other when the joint is rotated in one direction, and the first connected member and the second connected member are moved when rotated in the other direction. They are formed in opposite directions so as to be separated from each other, and are formed at the same pitch.

  The drive mechanism according to the second aspect of the present invention is configured such that the first connected member, the second connected member, the first position of the first connected member, and the second position of the second connected member are close to each other. And a regulation link that couples the first and second members to be regulated, a third position that is different from the first position of the first connected member, and a fourth position that is different from the second position of the second connected member. A drive link to be coupled, and at least one of a first connection portion between the drive link and the first connected member and a second connection portion between the drive link and the second connected member. When the drive link is rotated in one direction, the first connected member and the second connected member are brought close to each other, and when the drive link is rotated in the other direction, the first connected member and the second A feed screw mechanism is configured to separate the connected members, and the drive link is It can be bent or curved in all directions around the rotation axis.

  Preferably, the feed screw mechanism is configured in each of the first connection portion and the second connection portion, and the feed screw mechanism of the first connection portion and the feed screw mechanism of the second connection portion are used for the driving. The feed directions for the rotation of the link in one direction are opposite to each other, and the feed amounts for the rotation of the drive link are the same.

  Preferably, the two driving links are provided at different positions.

  Preferably, the restriction link has the same configuration as the drive link.

  Preferably, one joint part is configured including the first connected member, the regulating link, and the driving link, and the first connected member of one joint part is adjacent to the other connected part. The rotation of the driving link of the one joint portion and the plurality of joint portions connected so as to function as a second connected member of the joint portion are transmitted to the driving link of the other adjacent joint portion. A transmission unit.

  Preferably, the transmission portion connects the driving link of the one joint portion and the driving link of the other adjacent joint portion so that they can be brought close to and away from each other and relatively unrotatable. A link connecting member.

  Preferably, one joint part is configured including the first connected member, the regulating link, and the driving link, and the first connected member of one joint part is adjacent to the other connected part. A plurality of joints connected so as to function as second connected members of the joints; and a plurality of drive sources that rotate and drive the driving links of the joints independently of each other.

  Preferably, the second connected member is provided with a movable member movable with respect to the second connected member, and the restriction link includes the first connected member and the second connected member. And can be bent or curved in all directions around the rotation axis, and the movable member is driven by the rotation of the restriction link.

  Preferably, the movable member is connected to the other member so as to be able to open and close with respect to the other member so as to be swingable around a predetermined rotation axis, and is opened and closed by rotation of the restriction link. Is done.

  Preferably, the movable member holds a member that can be opened and closed, and is driven to rotate with respect to the second connected member together with the member that can be opened and closed by the rotation of the restriction link.

  Preferably, the second connected member is provided with a movable member movable with respect to the second connected member, and the movable member is driven by the tension of the wire guided by the restriction link. The

  A minimally invasive surgical manipulator according to a third aspect of the present invention includes a hollow shaft member inserted from the outside to the inside of a patient, a tip member provided at a tip of the hollow shaft member, and the hollow shaft member A restricting link for connecting the first position of the tip member and the second position of the tip member so as to be able to restrict proximity and separation, a third position different from the first position of the hollow shaft member, and the tip member A drive link for connecting a fourth position different from the second position so as to be close to or away from each other and a hollow shaft member rotatably inserted therein, and the drive link connected to the drive link rotatably. And at least one of a first connection portion between the drive link and the first connected member and a second connection portion between the drive link and the second connected member, The drive link was rotated in one direction A feed screw mechanism that causes the first connected member and the second connected member to move away from each other when the first connected member and the second connected member are brought close to each other and rotated in the other direction. The driving link can be bent or curved in all directions around the rotation axis.

  According to the present invention, rotation can be input to the connecting portion to bend or curve the connecting portion.

(First embodiment)
FIG. 1 is a perspective view showing an appearance of a forceps 1 for minimally invasive surgery according to the first embodiment. The forceps 1 includes a base 2, a shaft portion 3 extending from the base 2, and a working portion 4 provided at the tip of the shaft portion 3.

  In the case of minimally invasive surgery, the shaft portion 3 and the working portion 4 are inserted into the patient's body, and the base 2 is disposed outside the patient's body. The driving force generated in the base 2 is transmitted to the working unit 4 via the shaft portion 3 and the working unit 4 operates to perform various operations such as organ maintenance.

  Specifically, the base 2 includes a first bending motor 41A, a second bending motor 41B, and a gripping motor 41C (in FIG. 1, the gripping motor 41C is connected to the first bending motor 41A and the second bending motor 41B). The gripping motor 41C is referred to in Fig. 8. Hereinafter, the motor 41C is simply referred to as "the motor 41", which may not be distinguished from each other.) And the rotation of the motor 41 at an appropriate reduction ratio or speed increase ratio, respectively. And a transmission mechanism (not shown) that transmits the gear by shifting.

  The shaft portion 3 includes a hollow shaft member 43 and three drive shafts 44A, 44B, and 44C inserted through the hollow shaft member 43 (shown schematically by dotted lines in FIG. 1. Hereinafter, simply referred to as “drive shaft 44”. And may not distinguish between these). The three drive shafts 44A to 44C are rotationally driven by motors 41A to 41C independently of each other. The working unit 4 operates by transmitting the rotation of the drive shaft 44 to the working unit 4.

  FIG. 2 is a perspective view showing an appearance of the working unit 4. The working unit 4 includes a gripping portion 6 and a bending portion 7 that connects the gripping portion 6 and the shaft portion 3 and directs the gripping portion 6 with respect to the shaft portion 3 by bending. The bent portion 7 is configured by connecting three joint portions 9L, 9M, and 9N. Hereinafter, it is simply referred to as “joint portion 9”, which may not be distinguished.

  FIG. 3A is an external perspective view of the joint portion 9M, and FIG. 3B is an exploded perspective view of the joint portion 9M. As will be described later, since the main components of the joint portions 9L and 9N are the same as those of the joint portion 9M, the additional symbol M is omitted in the description of FIG.

  The joint portion 9 includes universal joints 11A, 11B, and 11C. In the following, it is simply referred to as “universal joint 11”, and these may not be distinguished. The universal joint 11 includes a first shaft 11a and a second shaft 11b, and the first shaft 11a and the second shaft 11b form an arbitrary angle within a predetermined angle range in an arbitrary direction around the axis. Linked to get.

  The joint portion 9 includes first screws 12A and 12B, spline hollow members 13A and 13B, and second screws 14A and 14B coaxially with the universal joints 11A and 11B. In the following description, additional symbols A and B indicating that the joints correspond to the universal joints 11A and 11B, respectively, may be omitted.

  As for the 1st screw 12, the front-end | tip of the external thread part 12a is penetrated by the hole formed in the 2nd axis | shaft 11b of the universal joint 11. As shown in FIG. The tip of the male screw portion 12a of the first screw 12 is fixed to the second shaft 11b so as not to rotate and to move in the axial direction. For example, it is fixed by being press-fitted into the second shaft 11b, or is fixed by an adhesive or solder.

  The spline hollow member 13 is generally formed in a cylindrical shape and has a hole 13a. The hole 13 a has a shape that fits with the bolt head 12 b of the first screw 12 and the bolt head 14 b of the second screw 14. In other words, a key groove is formed in the spline hollow member 13. Therefore, the first screw 12 and the second screw 14 can be close to and separated from each other in the axial direction by the bolt heads 12b and 14b being inserted into the hole 13a of the spline hollow member 13, and are not relatively rotatable. Connected. The cross-sectional shapes of the bolt heads 12b and 14b and the hole 13a are, for example, hexagons.

  As for the 2nd screw 14, the front-end | tip of the external thread part 14a is penetrated by the hole formed in the 1st axis | shaft 11a of the universal joint 11 of the other adjacent joint part 9. FIG. The tip of the male screw portion 14a of the second screw 14 is fixed with respect to the first shaft 11a so that it cannot rotate and cannot move in the axial direction. For example, it is fixed by being press-fitted into the first shaft 11a, or is fixed by an adhesive or solder.

  In the following, a member in which the second screw 14, the universal joint 11, and the first screw 12 are fixed to each other may be referred to as a bending link 21 (see FIG. 4).

  The first screw 12 and the second screw 14 have the same diameter and the same length, and the male screw portion 12a and the male screw portion 14a have the same diameter, the same length, and the same pitch. However, the directions of the male screw portion 12a and the male screw portion 14a are opposite (for example, if the first screw 12 is a right screw, the second screw 12 is a left screw). That is, the first screw 12 and the second screw 14 are the same except in the direction in which the male screw is cut.

  A female screw portion 16 a of the first plate 16 is screwed into the male screw portion 12 a of the first screw 12 between the second shaft 11 b of the universal joint 11 and the bolt head 12 b of the first screw 12. In other words, the first screw 12 and the first plate 16 constitute a feed screw mechanism that sends the first plate 16 in the axial direction by the rotation of the first screw 12.

  The female screw portion 14a of the second plate 17 is screwed into the male screw portion 14a of the second screw 14 between the first shaft 11a of another adjacent universal joint 11 and the bolt head 14b of the second screw 14. is doing. In other words, the second screw 14 and the second plate 17 constitute a feed screw mechanism that sends the second plate 17 in the axial direction by the rotation of the second screw 14.

  A fixing member 15 that fixes the first plate 16 and the second plate 17 to each other is disposed between the first plate 16 and the second plate 17. The fixing member 15 is formed, for example, in a columnar shape having an appropriate cross section. The first plate 16 abuts on one end surface, the second plate 17 abuts on the other end surface, and is inserted into the first plate 16 and the second plate 17. The first screw 16 and the second plate 17 are fixed to each other by screwing a not-shown screw into a female screw portion formed on the end face of the fixing member 15.

  In the following, a member in which the first plate 16, the second plate 17, and the fixing member 15 are fixed to each other may be referred to as a connected member 23.

  The fixing member 15 has a semicircular recess into which the spline hollow member 13 and the like are inserted. Further, bearing holes through which the spline hollow member 13 is inserted are formed concentrically with the female screw portions 16a and 17a on the mutually opposing surfaces of the first plate 16 and the second plate 17. The spline hollow member 13 is pivotally supported by the concave portion of the fixing member 15 and the bearing holes of the first plate 16 and the second plate 17.

  The joint portion 9 includes a fixed shaft 18 coaxially with the universal joint 11C. The fixed shaft 18 includes, for example, a large-diameter portion 18a having the same diameter as the spline hollow member 13, a first small-diameter portion 18b and a second small-diameter portion 18c extending from the large-diameter portion 18a to both sides and having a smaller diameter than the large-diameter portion 18a. It has.

  The first small diameter portion 18b has, for example, the same diameter as the first screw 12, is inserted through the washer 19, and is then inserted into the hole formed in the second shaft 11b of the universal joint 11C. The second shaft 11b is fixed so as not to move in the direction. For example, it is fixed by being press-fitted into the second shaft 11b, or is fixed by an adhesive or solder.

  The second small diameter portion 18c has a diameter equivalent to that of the second screw 14, for example, and is inserted through a washer (not shown) and then formed in the first shaft 11a of the universal joint 11C of the other joint portion 9 adjacent thereto. It is fixed to the first shaft 11a so as not to rotate and move in the axial direction. For example, it is fixed by being press-fitted into the first shaft 11a, or is fixed by an adhesive or solder.

  Hereinafter, the portion where the second small diameter portion 18c of the fixed shaft 18, the universal joint 11C, and the first small diameter portion 18b of the fixed shaft 18 are fixed to each other may be referred to as a grip link 22 (see FIG. 4).

  The two female screw portions 16a of the first plate 16 and the hole portion that pivotally supports the first small diameter portion 18b are arranged so as to form an equilateral triangle, for example. The same applies to the holes that pivotally support the two female screw portions 17a and the second small diameter portion 18c of the second plate 17. That is, the two bent links 21 and the grip links 22 are arranged at equal positions.

  As shown in FIG. 2, the joint portion 9L includes all the components of the joint portion 9 shown in FIG. However, the 2nd screw 14 screwed in the internal thread part formed in the holding plate 25 of the holding part 6 is penetrated and fixed to the universal joints 11A and 11B of the joint part 9L. Further, a grip driving shaft 26 that is rotatably supported by the grip plate 25 and is not movable in the axial direction is inserted and fixed to the universal joint 11C of the joint portion 9L.

  The joint portion 9N includes a universal joint 11, a first screw 12, a spline hollow member 13 (not shown in FIG. 2), and a first plate 16 among the components of the joint portion 9 shown in FIG. ing. The first plate 16 is provided at the tip of the hollow shaft member 43. The two spline hollow members 13A and 13B corresponding to the universal joints 11A and 11B of the joint portion 9N are fixed to the drive shafts 44A and 44B (see FIG. 1), respectively, and are respectively rotated by the rotation of the drive shafts 44A and 44B. Driven. A shaft member 46 pivotally supported by the first plate 16 of the joint portion 9N is inserted and fixed to the universal joint 11C of the joint portion 9N. The shaft member 46 is fixed to the drive shaft 44C and is driven by the rotation of the drive shaft 44C.

  In FIG. 3, the description has been made by defining from the universal joint 11 to the second screw 14 via the first screw 12 and the spline hollow member 13 as one joint portion. However, in FIG. 3, for the convenience of illustration, only one joint portion is defined so as to include the length equivalent to the fixed shaft 18. Which part is defined as one joint part can be appropriately determined. For example, from the second screw 14 through the universal joint 11 and the first screw 12 to the spline hollow member 13, in other words, from the bent link 21 to the spline hollow member 13 may be defined as one joint portion. it can. In the present embodiment, the range shown in FIG. 3 is basically described as one joint part, but for convenience, the second screw 14 of one joint part 9 and the universal joint 11 of the other joint part 9 and The bending link 21 constituted by the first screw 12 may be described as the bending link 21 of the other joint portion 9 (the joint portion 9 including the universal joint 11).

FIG. 4 is a side view illustrating the operation of the joint portion 9 and is a side view of the joint portion 9 in the direction in which the universal joints 11A and 11B overlap. FIG. 4A shows a neutral state where the joint portion 9 is straight, and FIG. 4B shows a bent state where the joint portion 9 is bent to the maximum bending angle σ _max . In FIG. 4, the washer 19 is omitted.

  As shown in FIG. 4A, in the neutral state, the universal joints 11A to 11C are straight, and the first plate 16 and the second plate 17 are parallel to each other. The position of the first screw 12 with respect to the first plate 16 and the position of the second screw 14 with respect to the second plate 17 are planes (in a straight line Lc) including the intersections of the first shaft 11a and the second shaft 11b of the universal joints 11A to 11C. Is set to be orthogonal to the universal joints 11 </ b> A to 11 </ b> C in a straight state and positioned at an intermediate position between the first plate 16 and the second plate 17.

  When the universal joints 11A and 11B are rotated in one direction from the neutral state of FIG. 4A, the first screw 12 and the second screw 14 are formed in opposite directions to each other. As shown in b), the first plate 16 and the second plate 17 are close to each other at the positions of the universal joints 11A and 11B. On the other hand, at the position of the universal joint 11C, the proximity and separation of the first plate 16 and the second plate 17 are restricted. Accordingly, the joint portion 9 is bent toward the universal joints 11A and 11B (the right side in FIG. 4).

  At this time, the first screw 12 and the second screw 14 are formed with male threads at the same pitch, and the feed amount with respect to the rotation of the bending link 21 is the same. Move so that σ is divided into two. That is, in the universal joints 11A to 11C, the first shafts 11a and the second shafts 11b are kept parallel to each other even after being bent. If the feed amounts of the first screw 12 and the second screw 14 are not the same, the universal joints 11A to 11C have the first shafts 11a and the second shafts 11b not kept parallel to each other. Only the amount of inclination generated by the backlash between the first screw 12 and the second screw 14 and the first plate 16 and the second plate 17 can be bent.

  Although illustration is omitted, when the universal joints 11A and 11B are rotated in the other direction from the neutral state in FIG. 4A, the first plate 16 and the second plate 17 are connected to the universal joints 11A and 11B. The joints 9 are separated at the positions, and the joint portion 9 bends to the opposite side to FIG. Further, if the rotation amount of the universal joint 11A and the rotation amount of the universal joint 11B are different from each other, the joint portion 9 bends toward the universal joint 11A or toward the universal joint 11B. That is, the joint portion 9 can be bent in all directions around the universal joint 11.

The maximum bending angle σ _max of the joint portion 9 is defined by the maximum bending angle of the universal joint 11. 4B, the universal joint 11A abuts on the first plate 16 and the second plate 17, and the feed of the first screw 12 and the second screw 14 is restricted. It is also defined by the movable range of the first screw 12 and the second screw 14 with respect to the first plate 16 and the second plate 17. Therefore, in order to increase the maximum bending angle σ _max of the joint portion 9, it is desirable to set the movable range of the first screw 12 and the second screw 14 to be equivalent to the maximum bending angle of the universal joint 11. In addition, the movable range of the 1st screw 12 and the 2nd screw 14 is the length which protrudes from the universal joint 11 of the external thread part 12a of the 1st screw 12, and the external thread part 14a of the 2nd screw 14, and is shown to Fig.4 (a). The position is determined by the screwing position of the first screw 12 and the second screw 14 with respect to the first plate 16 and the second plate 17 in the neutral position.

  FIG. 5 is a diagram for explaining the operation of the entire bent portion 7. As shown in FIGS. 2 to 4, the rotation of the drive shaft 44A (not shown in FIG. 5) causes the first screw 12A, the universal joint 11A, the second screw 14, the spline hollow member 13, and the first screw 12A again. , Universal joints 11A,... Are transmitted in order from joint 9N to joint 9L. The same applies to the rotation of the drive shaft 44B. Therefore, the joint portions 9L to 9N bend in the same direction at the same bending angle. Then, the gripping portion 6 that is an end effector swings with respect to the shaft portion 3 while changing its direction by an angle corresponding to the total bending angle of the joint portions 9L to 9N.

In addition, the bending angle θ of the entire bending portion 7 is as follows. As shown in FIG. 4, when viewing the joint portion 9, if the distance between the links is x and the feed amount of the first screw 12 or the second screw 14 is y, the bending angle σ of each joint portion 9 Is
σ = 2 tan ⁻¹ (y / x) (1)
It becomes.

Accordingly, the bending angle θ of the entire bending portion 7 is N, where N is the number of joint portions 9 of the bending portion 7.
θ = σ × N (2)
It becomes.

As an example, in the bending portion 7 having the three joint portions 9, in order to set the maximum bending angle θ _max = 90 °, the maximum bending angle σ _max of the joint portion 9 needs to be 30 °. When the two bent links 21 and the grip links 22 are arranged in a circle having a diameter of 6 mm in increments of 120 ° when viewed from the upper side of FIG. 4, one side of an equilateral triangle formed by the two bend links 21 and the grip links 22 is displayed. The distance is 5.2 mm, and the distance from the apex to the facing side is 4.5 mm. Substituting σ _max = 30 ° and x _max = 5.2 mm into equation (1) yields y _max of about 1.4 mm. That is, when the first screw 12 (second screw 14) is moved by 1.4 mm with respect to the first plate 16 (second plate 17), the maximum bending angle θ _max of the bending portion 7 including the three joint portions 9 is 90 °.

  Hereinafter, the inverse kinematics for obtaining the amount of rotation of the bending link 21 from the bending angle θ and the bending direction φ in an arbitrary bending state of the bending portion 7 of the forceps 1 will be described.

  FIG. 6 shows the definition of the coordinate system in the bent portion 7. The grip plate 25 (see also FIG. 2) of the grip portion 6 is provided with female screw portions 25a and 25b into which the bending link 21 of the joint portion 9L is screwed, and a bearing hole 25c for supporting the grip drive shaft 26. It has been. The female screw portions 25a and 25b and the bearing hole 25c form, for example, an equilateral triangle. The origin O of the coordinate system is the center of the gripping plate 25 (the center of the female thread portions 25a and 25b and the bearing hole 25c). The bending direction φ of the bent portion 7 is defined with reference to the position of the axis X1 extending from the origin O toward the bearing hole 25c around the axis Z1 parallel to the axial direction of the bent portion 7 in the neutral state. The bending angle θ of the bending portion 7 is defined by an inclination angle from the axis Z1 to the bending direction φ.

Assuming that the pitch of the second screw 14 and the first screw 12 and the first screw 14 of each joint portion 9 to be screwed into the female screw portions 25a and 25b is p and the maximum moving distance at the bending angle θ is y _θmax , the bending angle The maximum rotation amount δ when θ is
δ = y _θmax / p (3)
It becomes.

From the equations (1) and (2), the maximum moving distance _yθmax is
y _θmax = x _max tan (σ / 2) = x _max tan (θ / 2 / N) (4)
It becomes.

The amount of rotation of the two bent links 21 is respectively
α = δcos (φ-30 °) (5)
β = δcos (φ + 30 °) (6)
It becomes. Therefore, if the bending angle θ and the bending direction φ are determined, the rotation amounts α and β of the bending link 21 can be obtained.

  FIG. 7 is a perspective view showing the configuration of the gripping part 6, FIG. 7A shows the closed state of the gripping part 6, and FIG. 7B shows the open state of the gripping part 6.

  The grip portion 6 includes a first grip piece 28 and a second grip piece 29. The first gripping piece 28 and the second gripping piece 29 are connected so as to be rotatable about the shaft member 30 as a rotation axis by inserting the shaft member 30.

  The first grip piece 28 and the second grip piece 29 are driven in the opening / closing direction by a slider / link mechanism. Specifically, a slit is formed in each of the first grip piece 28 and the second grip piece 29 on the grip plate 25 side of the shaft member 30 (only the slit 29a of the second grip piece 29). (Illustrated). The first grip piece 28 and the second slit are positioned so that the slit is located on the inner side (the lower side of the drawing surface of FIG. 7 for the first holding piece 28 and the upper side of the drawing surface of FIG. 7 for the second holding piece 29). Each of the grip pieces 29 is inclined with respect to the longitudinal direction. A sliding shaft 31 a provided on the link member 31 is inserted into the slit. Therefore, when the link member 31 moves in the axial direction (left and right direction in FIG. 7), the sliding shaft 31a slides in the slit, and the first gripping piece 28 and the second gripping piece 29 open and close.

  The link member 31 is driven by the rotational motion of the grip drive shaft 26 being converted into translational motion by the feed screw mechanism and transmitted to the link member 31. Specifically, a female screw member 32 fixed to the link member 31 and formed with a female screw portion, and a feed screw 33 fixed coaxially to the gripping drive shaft 26 and screwed into the female screw member 32. A feed screw mechanism is configured.

  In the gripping drive shaft 26, the rotation of the drive shaft 44C (see FIG. 1) is performed in the order of the shaft member 46 (see FIG. 2), the universal joint 11C, the fixed shaft 18 (see FIG. 3), the universal joint 11C again. Thus, it is driven by being transmitted from the joint portion 9N to the joint portion 9L.

  FIG. 8 is a block diagram showing the configuration of the signal processing system of the surgical system 51 including the forceps 1. However, symbols such as α and β attached to various signals are used for conceptual description of information included in the signals, and do not accurately indicate signals input / output from each element.

  The surgical system 51 includes an operation device 52 for controlling the operation of the forceps 1. The operating device 52 is electrically connected to the forceps 1. For example, the operating device 52 includes a base, and the base 2 of the forceps 1 is fixed to the base, and is configured integrally with the forceps 1 and connected to the forceps 1. Alternatively, part or all of the operation device 52 is provided at a location away from the forceps 1 and is connected to the forceps 1 via a network such as the Internet.

  The operating device 52 receives a user's operation, a control unit 55 that outputs a control signal to the forceps 1 based on a signal output from the operation unit 54, and predetermined information based on a signal from the control unit 55. A display unit 56 for displaying is provided.

  FIG. 9A is a side view showing the appearance of the operation unit 54. The operation unit 54 includes a joystick 58 and a controller forceps 59 that is provided on a lever 58a of the joystick 58 and imitates a lever side portion of a normal forceps (not a manipulator forceps). The controller forceps 59 may be configured by inserting a normal forceps into the lever 58a.

  The user can specify the bending angle θ of the bending portion 7 by the degree to which the lever 58a is tilted, can specify the bending direction φ of the bending portion 7 by the direction to tilt the lever 58a, and depends on the degree of opening / closing of the controller forceps 59 The degree of opening / closing of the grip 6 can be specified.

  That is, as shown in FIG. 8, the operation unit 54 uses the signal according to the inclination angle of the lever 58a as information for specifying the bending angle θ, and the signal according to the inclination direction of the lever 58a as information for specifying the bending direction φ. Then, a signal corresponding to the degree of opening / closing of the controller forceps 59 is output to the control unit 55 as information for designating the degree of opening / closing of the gripping part 6 (for example, displacement d from the axis).

  The control unit 55 is configured by a computer, for example, and includes a CPU, a ROM, a RAM, an external storage device, and the like (not shown). The control unit 55 calculates the rotation amount corresponding to the bending angle θ and the bending direction φ specified from the signal from the operation unit 54 based on the equations (4), (3), (5), and (6). α and β are calculated. Further, the rotation amount γ of the feed screw 33 of the gripping portion 6 corresponding to the displacement d is calculated based on the pitch of the feed screw 33 and the like. The rotation amount α, β, γ or the rotation amount α, β, γ converted into the rotation amount of the motors 41A to 41C in consideration of the speed increasing ratio or the speed reducing ratio of the transmission mechanism is first bent. The signals are output to the driving unit 61A, the second bending driving unit 61B, and the gripping driving unit 61C (hereinafter simply referred to as “driving unit 61”, which may not be distinguished).

  The drive unit 61 outputs drive power corresponding to the input signal to the motor 41. Further, based on the number of rotations detected by an encoder (not shown) provided in the motor 41, feedback control is performed so that the amount of rotation of the motor 41 converges to a target value. The feedback control is, for example, PI control.

  The display unit 56 is configured by, for example, a CRT or a liquid crystal display. The control unit 55 generates image data based on the calculated θ, φ, d, converts the image data into a video signal, and outputs the video signal to the display unit 56. The display unit 56 displays an image based on the video signal from the control unit 55.

  FIG. 9B shows an example of an image I1 displayed on a part or all of the screen of the display unit 56. A vector I2 is displayed in the image I1. The vector I2 indicates the bending angle θ input to the operation unit 54 by the length, and the bending direction φ input to the operation unit 54 by the pointing direction. A scale I3 for measuring the length and direction of the vector I2 is displayed in the display area of the vector I2. In addition, a table I4 indicating θ, φ, and d input to the operation unit 54 by numbers is also displayed in the image I1.

  According to the first embodiment described above, as shown in FIG. 4, the grip link 22 moves the connected member 23 of one joint part 9 and the connected member 23 of the other joint part 9 closer to and away from each other. On the other hand, the bending link 21 is screwed into the connected member 23 of one joint portion 9 and the connected member 23 of the other joint portion 9 to form a feed screw mechanism and bendable in all directions. Therefore, the joint portion 9 can be bent by rotating the bending link 21. In other words, rotation can be input to the joint portion 9 to bend or curve the joint portion 9.

  The feed screw mechanism of the bending link 21 is configured on each of the first shaft 11a side and the second shaft 11b side of the universal joint 11, and these feed screw mechanisms are feed directions with respect to rotation in one direction of the bending link 21. Are opposite to each other, and the feed amount for the rotation of the bending link 21 is the same, as shown in FIG. 4, the universal joints 11A to 11C have the first shafts 11a and the second shafts 11b connected to each other. Kept parallel to each other. Therefore, it is possible to bend even if the fitting backlash of the bending link 21 is reduced, and precise position control of the gripping portion 6 that is an end effector is possible.

  Since the two bent links 21 are provided at different positions, the two bent links 21 can be independently controlled to bend in all directions, that is, bend with multiple degrees of freedom. Multi-degree-of-freedom bending is possible even if three or more bending links 21 are provided. However, the number of the two bending links 21 is the smallest, and the control is the simplest. Further, as in the conventional case, when bending with multiple degrees of freedom is realized by a slider / link mechanism, bending in one direction and bending in a direction perpendicular to the one direction are performed using different positions as fulcrums, Although the end effector cannot be moved in a spherical shape, in the joint portion 9 of this embodiment, the bending in one direction and the bending in the direction orthogonal to the one direction are the same position (universal joint 11C of the grip link 22). (The intersection of the first axis 11a and the second axis 11b) is used as a fulcrum, so that the end effector and the like can be moved in a spherical shape. Since the end effector can be moved in a spherical shape, for example, the base 2 can be rotated while keeping the posture of the bending portion 7 with respect to the patient the same while the bending portion 7 is inserted into the patient.

  A plurality of joint parts 9 are connected, and the bending link 21 of one joint part 9 and the bending link 21 of the other joint part 9 are connected to each other by a spline hollow member 13 so as to be close to and away from each other and not relatively rotatable. Therefore, the joint portions 9 that are connected can be bent at the same time, and the bending angle θ of the entire bending portion 7 can be increased. That is, the position and orientation of the grip portion 6 that is an end effector can be greatly changed.

  Since the gripping part 6 is driven to open and close by the rotation of the gripping link 22, the gripping link 22 for realizing bending can also be used as a part of the drive mechanism of the gripping part 6. That is, the number of members can be reduced and the configuration can be simplified. Moreover, it is easy to obtain the rigidity and durability required for gripping compared to the case of opening and closing by the tension of the wire. Since the feed screw mechanism is provided in the grip portion 6 as an end effector, the rotation of the grip link 22 can be input to the end effector to perform an appropriate operation.

  The drive shaft 44 of this embodiment is rotationally driven. In a conventional manipulator for minimally invasive surgery, the drive shaft is linearly moved in the axial direction. Since the drive shaft that is linearly driven and the drive shaft that is rotationally driven have different required strengths, the selection range of the material and diameter of the drive shaft is expanded, and the degree of freedom in design is improved. Further, for example, a mechanism for converting rotation of the motor 41 or the like into translational motion and transmitting it to the drive shaft 44 can be omitted.

  In the first embodiment, regarding the drive mechanism according to the first aspect of the present invention, the mechanism constituting the bent portion 7 is an example of a drive mechanism, and the bent link 21 is an example of a drive universal joint. The grip link 22 is an example of a universal joint for restriction, the combination of the bent link 21 and the grip link 22 is an example of a connecting portion, and the male screw portion 12a of the first screw 12 and the male screw portion 14a of the second screw 14 are It is an example of a 1st external thread part and a 2nd external thread part.

  In the first embodiment, regarding the drive mechanism according to the second aspect of the present invention, the mechanism constituting the bent portion 7 is an example of the drive mechanism, the bent link 21 is an example of the drive link, and the grip link. 22 is an example of a restriction link, the connection position of the grip link 22 and the connected member 23 is an example of the first position and the second position, and the connection position of the bent link 21 and the connected member 23 is The feed screw mechanism constituted by the first screw 12 and the first plate 16 and the feed screw mechanism constituted by the second screw 14 and the second plate 17 are examples of the third position and the fourth position. It is an example of a feed screw mechanism configured in the first connection part and the second connection part, and the combination of the connected member 23, the bending link 21, and the grip link 22 is an example of a joint part, and the spline hollow member 13 is a transmission part. And link connection Is an example of a timber, first gripping piece 28 and the second gripping piece 29 of the grip portion 6 is an example of the movable member.

  The first embodiment relates to a minimally invasive surgical manipulator according to the third aspect of the present invention. The forceps 1 is an example of a minimally invasive surgical manipulator, and the gripping plate 25 of the gripper 6 is a tip member. It is an example.

(Second Embodiment)
FIG. 10 is a side view showing the appearance of the working unit 104 of the forceps 101 according to the second embodiment of the present invention. As in the first embodiment, the working unit 104 includes a gripping unit 106 and a bent portion 107, and the bent portion 107 is configured by connecting three joint portions 109. The principle of bending the joint 109 is the same as in the first embodiment. In other words, the joint portion 109 can be bent in all directions and functions as a feed screw, and the bending link 121 that moves the connected members 123 closer to or away from each other, and the restriction link that restricts the proximity or separation of the connected members 123 to each other. (Not shown).

  However, in the second embodiment, the configuration of the bent link 121 and the configuration of the connected member 123 are simplified and the number of parts is reduced. The configuration of the restriction link may be the same as that of the first embodiment.

  FIG. 11 is a partially exploded perspective view of the joint 109. Note that illustration of some members such as the restriction link is omitted, and some members of other joint portions 109 are shown for convenience.

  In other words, the bent link 121 has a configuration in which the second screw 14, the universal joint 11, and the first screw 12 of the first embodiment are integrated. That is, the bending link 121 has a first shaft 121a and a second shaft 121b, and the first shaft 121a and the second shaft 121b are connected so as to be bendable in all directions to form a universal joint, The first shaft 121a and the second shaft 121b are respectively formed with a first male screw portion 121c and a second male screw portion 121d having the same thread pitch direction and the same pitch. The first male screw portion 121c and the second male screw portion 121d are each formed with three first spline grooves 121e and three second spline grooves 121f extending in the axial direction.

  The connected member 123 includes a first plate 116 and a second plate 117, and the first plate 116 and the second plate 117 are fixed in contact with each other. That is, the fixing member 115 of the first embodiment is omitted. The first plate 116 has a female screw portion 116a that is screwed to the second male screw portion 121d of the other joint 9, and the second plate 117 has a female screw portion (not shown) that is screwed to the first male screw portion 121c. Is formed. That is, a feed screw mechanism is configured.

  A spline hollow member 113 is accommodated in the connected member 123. In addition, what was shown below the paper surface is the spline hollow member 113 of another adjacent joint part 9. The spline hollow member 113 is formed in a cylindrical shape through which the first male screw portion 121c and the second male screw portion 121d can be inserted, and is fitted to the first spline groove 121e and the second spline groove 121f on the inner peripheral surface. A protruding portion 113a is formed. Accordingly, the first male screw portion 121c and the second male screw portion 121d of the other adjacent joint portion 9 are connected to each other by the spline hollow member 113 so as to be close to each other and away from each other and not relatively rotatable.

  According to the second embodiment described above, the same effect as in the first embodiment can be obtained. Furthermore, cost reduction is expected by reducing the number of parts.

(Third embodiment)
14A and 14B are views showing the appearance of the forceps 301 according to the third embodiment of the present invention. FIG. 14A is a perspective view, FIG. 14B is a side view, and FIG. 14C is FIG. It is the side view seen from the direction different from b). The forceps 301 includes a base 302, a shaft portion 303, and a working portion 304, as in the first embodiment and the second embodiment. As in the first and second embodiments, the working unit 304 includes a grip 306 and a bent portion 307. The bent portion 307 is configured by connecting three joint portions 309. ing. The principle of bending the joint portion 309 is also the same as in the first embodiment and the second embodiment. In other words, the joint portion 309 can be bent in all directions and functions as a feed screw, and the bending link 321 that moves the connected members 323 closer to or away from each other and the grip link that regulates the proximity or separation between the connected members 323. 322.

  However, in the third embodiment, the gripping portion 306 is configured to be rotatable around the rotation axis RA, and the opening / closing operation of the gripping portion 306 is performed by the tension of the wire 331. Different from the second embodiment.

  FIG. 15A is a perspective view showing the grip 306 in an open state, and FIG. 15B is a cross-sectional view in the direction of arrows XVb-XVb in FIG.

  The grip portion 306 includes a grip piece 328, a grip base 329 that pivotally supports the grip piece 328, and a connection base 335 and a support base 325 that hold the grip base 329 rotatably about the rotation axis RA. ing.

  16 (a) is a perspective view showing the grip piece 328, FIG. 16 (b) is a perspective view showing the grip base 329, FIG. 16 (c) is a perspective view showing the connecting base 335, and FIG. 16 (d) is a support base. FIG.

  The gripping piece 328 and the gripping base 329 have a so-called single-scissor structure, and the gripping piece 328 is held by the gripping base 329 so as to be swingable. Specifically, it is as follows.

  As shown in FIG. 16A, the gripping piece 328 is formed in a long shape (for example, a semi-cylindrical shape) as a whole. A shaft support hole 328 a is formed at one end of the grip piece 328. On the other hand, as shown in FIG. 16B, the grip base 329 is formed in a substantially cylindrical support portion 329b and a tip of the support portion 329b. And a gripping protrusion 329c formed in a cylindrical shape. Two support holes 329a facing each other are formed on the side surface of the support portion 329b.

  As shown in FIGS. 15A and 15B, the gripping piece 328 is inserted into the support portion 329b at the portion on the shaft support hole 328a side, and is supported by the shaft support hole 328a and the support hole 329a. The shaft 330 is inserted. The support shaft 330 is rotatably supported with respect to at least one of the shaft support hole 328a and the support hole 329a. Therefore, the grip piece 328 is pivotally supported around the support shaft 330 with respect to the grip base 329, and the grip piece 328 and the grip protrusion 329c are opened and closed by the swing of the grip piece 328.

  The grip base 329 is held by the connection base 335 and the support base 325 so as to be rotatable about the rotation axis RA. Specifically, it is as follows.

  As shown in FIG. 16B, a flange portion 329d that protrudes to the outer peripheral side is formed at the end portion on the opposite side of the gripping projection 329c on the support portion 329b of the grip base portion 329. The outer peripheral edge of the flange portion 329d is circular.

  On the other hand, as shown in FIG. 16D, the support base 325 has a reduced diameter portion 325c on the distal end side (the upper side in the drawing of FIG. 16D), and the reduced diameter portion 325c includes a flange portion. A recess 325a capable of accommodating 329d is formed. The inner peripheral surface of the recess 325a is circular. The bottom surface is, for example, a flat surface. However, the support base 325 has three holes into which the bent links 321 and the grip links 322 are inserted, and the inner peripheral surface of the recess 325a is divided into three.

  Further, as shown in FIG. 16C, the connection base 335 is formed in a substantially cylindrical shape. The inner diameter of the connection base 335 is equal to the outer diameter of the reduced diameter portion 325c of the support base 325. One end surface of the connection base 335 (the lower side in FIG. 16C) is open, and the other end surface has an opening smaller than the outer diameter of the flange portion 329d and larger than the outer diameter of the support portion 329b. A portion 335a is formed.

  Then, as shown in FIGS. 15A and 15B, the flange portion 329 d of the grip base 329 is inserted into the concave portion 325 a of the support base 325. Accordingly, the grip base 329 is supported by the support base 325 so as to be rotatable about the rotation axis RA. The rotation axis RA is parallel to the insertion direction of the bent link 321 and the grip link 322 into the support base 325, and is positioned at the center of the two bend links 321 and the grip link 322.

  The gripping protrusion 329c and the support portion 329b of the grip base 329 are inserted into the opening 335a of the connection base 335, and the flange 329d of the grip base 329 engages with the outer peripheral portion of the connection base 335 of the opening 335a. Further, the reduced diameter portion 325 c of the support base 325 is fitted and inserted into the connection base 335. Accordingly, the grip base 329 is prevented from coming off from the recess 325a.

  The connection base 335 and the support base 325 are fixed by, for example, a connection member capable of releasing the fixing such as a screw. For example, in the connection base 335, a female screw part 335b (see FIG. 16C) is provided on a side surface that covers the reduced diameter part 325c of the support base 325, and a hole part having substantially the same diameter as the female screw part 335b is provided on a side surface of the reduced diameter part 325c. 325b (see FIG. 16D) is formed, and the coupling base 335 and the support base 325 are fixed by inserting the male screw 339 into the female screw part 335b and inserting it into the hole part 325b.

  The grip base 329 is rotationally driven by the rotation of the grip link 322. Specifically, it is as follows.

  As shown in FIGS. 15A and 15B, the support base 325 is provided with a bent link 321 for moving the connected member close to or away from the support base 325, similarly to the grip plate 25 of the first embodiment. In addition, a grip link 322 for restricting the proximity or separation of the connected member is pivotally supported so as to be rotatable and not movable in the axial direction.

  As shown in FIG. 15B, a gear 336 is fixed to the shaft portion inserted into the support base 325 of the grip link 322. A gear 337 that meshes with the gear 336 is inserted and fixed in the hole of the grip base 329. Accordingly, the rotation of the grip link 322 is transmitted to the grip base 329 by the gear device (gear train) including the gear 336 and the gear 337, and the grip base 329 rotates around the rotation axis RA. Note that the grip link 322 rotates in response to the rotation of the motor provided in the base 302 as in the first embodiment.

  The grip piece 328 is driven by the tension of the wire 331. Specifically, it is as follows.

  As shown in FIG. 16 (a), at the end of the gripping piece 328 on the side of the shaft support hole 328a, the gripping protrusion 329c side slightly with respect to the longitudinal direction of the gripping piece 328 (the lower side in the drawing of FIG. 16A). And a closing operation projection 328c projecting to the opposite side of the gripping projection 329c with respect to the longitudinal direction of the gripping piece 328. For example, the closing protrusion 328b and the opening protrusion 328c are provided with holes through which the wire 331 can be inserted so that the wire 331 can be easily fixed.

  As shown in FIGS. 14B and 14C, one end of the wire 331 is fixed to the output shaft of the closing operation motor 332 provided on the base 302, and the closing operation protrusion 328b and the opening operation protrusion 328c. The other end is fixed to the output shaft of the opening operation motor 333 provided on the base 302 via (FIG. 16A).

  Specifically, the wire 331 is inserted from the output shaft of the closing operation motor 332 into the shaft portion 303 while being guided by a pulley or the like, passes through the shaft portion 303, and reaches the bent portion 307. The bent portion 307 reaches the grip portion 306 by being guided by a hole provided at the center of the connected member 323. In the grip portion 306, the wire 331 reaches the grip piece 328 through a hole portion (not shown) provided in the support base 325 and the center hole of the gear 337, as shown in FIG. Then, after being fixed to the closing operation protrusion 328b of the gripping piece 328, it is also fixed to the opening operation protrusion 328c. After that, the wire 331 is fixed to the output shaft of the opening operation motor 333 via the bent portion 307 and the shaft portion 303 as in the forward path.

  Therefore, when the wire 331 is wound by driving the closing operation motor 332, the closing operation protrusion 328b is pulled by the tension of the wire 331, and the gripping piece 328 rotates in the closing direction around the shaft support hole 328a. Conversely, when the wire 331 is wound by driving the opening operation motor 333, the opening operation protrusion 328 c is pulled by the tension of the wire 331, and the gripping piece 328 rotates in the opening direction around the shaft support hole 328 a.

  According to the above embodiment, the same effect as the first embodiment and the second embodiment can be obtained. Furthermore, since the grip 306 is rotated by the rotation of the grip link 322, the posture of the grip 306 can be easily changed and the grip link 322 can be effectively used.

Since the holding portion 306 is opened and closed by the wire 331, the responsiveness of the opening and closing operation can be improved. Further, since only the tip including the grip piece 328 can be removed by separating the connection base 335 and the support base 325, the wire 331 can be easily replaced.
In the third embodiment, the grip base 329 is an example of a movable member that can rotate with respect to the second connected member together with a member that can be opened and closed according to the present invention (for example, the grip piece 328).

  The present invention is not limited to the above embodiment, and may be implemented in various aspects.

  The technical field to which the drive mechanism of the present invention is applied is not limited to a manipulator for minimally invasive surgery, but covers all technical fields. For example, it may be applied to a civil engineering machine such as a power shovel used to dig the ground and transport earth and sand in construction work, or a magic hand finger imitating a human hand or elephant robot nose Etc., and may be used for toys. In addition, when applied to a manipulator, the invention is not limited to those for minimally invasive surgery, and may be applied to manipulators in various fields such as manipulators that perform various operations on nuclear reactors and operations on artificial satellites. When applied to a manipulator for minimally invasive surgery, the application target is not limited to forceps, and may be applied to, for example, a scissors, a knife, a curette, or a needle holder.

  The drive mechanism of the present invention is not limited to a mechanism in which the first connected member and the second connected member are allowed to move relative to each other, and the end effector is set to an appropriate position and orientation. The drive mechanism itself may be the final control target, such as the above-mentioned magic hand finger or elephant robot nose.

  The number of drive links may be set as appropriate and is not limited to two. As can be understood from FIG. 4, which is a view in a direction in which the two bent links 21 overlap, if only one degree of freedom of bending is obtained, one drive link may be used. Further, in order to obtain a multi-degree-of-freedom bend, three or more drive links may be provided.

  The feed screw mechanism may be provided on only one of the ends of the drive link.

  FIG. 12A shows a modified example in which a feed screw mechanism is provided on only one of both ends of the drive link. In this modification, a feed screw mechanism is provided only on the first shaft 201a of the first shaft 201a and the second shaft 201b of the drive link 201. Also in this modification, the drive link 201 is rotated to bring the connected members 203 and 204 close to or away from each other, while the restriction link 202 restricts the proximity and separation of the connected members 203 and 204, Bending motion can be realized.

  However, in the modified example of FIG. 12A, for example, if the restriction link 202 is configured by a universal joint, the drive link and the restriction link cannot be kept parallel (see FIG. 4). Can only be bent at an inclination corresponding to. Therefore, the restricting link 202 is constituted by a member having a plurality of bending points such as a bellows tube, in other words, a member that can be bent into an appropriate shape. The modified example of FIG. 12A can be used in a technical field that does not require precise control, such as a nose of an elephant robot toy.

  The restriction link may have the same configuration as the drive link. In other words, while providing no restriction link, a plurality of drive links may be provided, and one drive link may function as a restriction link with respect to other drive links.

  FIG. 12B shows a modification in which the restriction link has the same configuration as the drive link. In this modification, a bending mechanism having one degree of freedom is constituted by the two drive links 206. By causing one of the drive links 206 to function as a restriction link, that is, by restricting the rotation of one of the drive links 206, a bending operation is performed.

  Furthermore, in this modified example, if one drive link 206 is rotated in a direction in which the connected members 207 and 208 are brought close to each other, and the other drive link 206 is rotated in a direction in which the connected members 207 and 208 are separated from each other. The bending operation can be performed at twice the speed, and the center of the driving links 206 and 207 can be set as the bending point. Further, if both the driving links 206 are rotated in the direction in which the connected members 207 and 208 are brought close to each other, or both the driving links 206 are rotated in the direction in which the connected members 207 and 208 are separated from each other, they are not bent. The distance between the connected members 207 and 208 can be changed. The same applies when a multi-degree-of-freedom bending mechanism is provided by providing three or more drive links.

  The transmission unit that transmits the rotation of the drive link of one joint part to the drive link of the other joint part is not limited to one that rotates the drive links in the same direction. For example, a differential gear may be provided between the driving links, and the rotation of the driving link of one joint portion may be converted into the rotation in the reverse direction and transmitted to the driving link of the other joint portion.

  When connecting a plurality of joint portions, the drive links may be rotatable independently of each other.

  FIG. 13A shows a modification in which the driving links 212 of the two joint portions 211 can be rotated independently of each other. A motor 214 that rotates and drives the drive link 212 is provided on each of the connected members 213 of each joint portion 211. Each motor 214 is supplied with driving power via a cable guided by the driving link 212 or the like, and is controlled independently. In the modified example of FIG. 13A, a complicated operation such as directing a plurality of connected members 213 in different directions is possible.

  The movable member (such as the grip piece in the embodiment) is not limited to one driven by the rotation of the restriction link.

  FIG. 13B shows the closing operation of the gripping piece 218 and the gripping piece 219 by rotating the gripping piece 218 around the rotation shaft 221 with respect to the connected member 220 by the tension of the wire 217 guided by the restriction link 216. The modification in which is performed is shown. The opening operation of the gripping piece 218 and the gripping piece 219 is performed by a biasing means (not shown) such as a spring. The restriction link 216 includes, for example, a cylindrical first shaft 216a and a second shaft 216b, and the wire 217 is guided by being inserted through the restriction link 216. Bends according to the bending. In this modification, the restriction link 216 is also used as a guide member for guiding the wire 217, and the number of parts can be reduced. The guide of the wire 217 by the restriction link 216 is not limited to the guide of the wire 217 inside the restriction link 216, and a ring through which the wire 217 is inserted is formed outside the restriction link 216. Thus, the wire 217 may be guided outside the restriction link 216.

  When the movable member is driven by the rotation of the restriction link, the movable member is not limited to one that performs an opening / closing operation or one that performs a rotation operation on the second connected member. For example, it may simply swing on the second connected member, or move forward and backward in the axial direction of the regulating link relative to the second connected member.

  In the case where the movable member is driven to open and close by the rotation of the restriction link, the movable member is connected to the other member so as to be able to open and close with respect to the other member so as to be swingable around a predetermined rotation axis. If it is. Therefore, it may be a double opening as in the first embodiment, or a single opening as in the third embodiment. Further, the movable member is not limited to a member that opens and closes the distal end side in the extending direction of the driving link or the regulating link, in other words, a swinging rotation axis that is orthogonal to the driving link or the regulating link. For example, the swinging rotation axis may be along the extending direction of the drive link or the regulation link. A movable member is not limited to what comprises a holding part, For example, a scissors may be sufficient.

  When the movable member is rotationally driven by the rotation of the restriction link, the movable member is not limited to a member that holds a member that can be opened and closed and changes the posture of the member. For example, the movable member may be a member such as a drill whose movable member itself is an end effector. When the movable member holds another member and changes the posture of the other member, the other member is not limited to a member that can be opened and closed. It may be a member. When the movable member holds a member that can be opened and closed and changes the posture of the member, the direction and type (application) of the opening and closing direction can be appropriately selected as described above. It is.

  The drive link only needs to be able to bend or bend in all directions, and is not limited to a structure including a universal joint. That is, if the drive link has a relatively high axial rigidity and a relatively low bending rigidity, the connected member and the connected member are brought close to or separated from each other, and the relative angle between the connected member and the connected member It bends or curves in accordance with the change in the angle, and a bending operation can be realized. Therefore, the drive link may be configured to include a ball joint instead of the universal joint, for example. You may comprise including the bellows pipe which was illustrated as a link for control in Drawing 12 (a). A relatively hard rubber may be included.

  The restriction link only needs to be able to restrict the proximity and separation between the first connected member and the second connected member at a position different from the connection position by the drive link, and may not be able to rotate or bend. Also good. For example, the restriction link may be formed by one shaft-shaped member, and spheres may be provided at both ends thereof, and the sphere may be supported like a ball joint by the first connected member and the second connected member.

  The feed screw mechanism is not limited to the one in which the male screw portion is formed in the driving link and the female screw portion is formed in the connected member, and the female screw portion may be formed in the driving link and the male screw portion may be formed in the connected member.

The external appearance perspective view of the forceps which concerns on the 1st Embodiment of this invention. The external appearance perspective view of the working part of the forceps of FIG. The external appearance perspective view of the joint part of the operation | work part of FIG. The figure explaining operation | movement of the joint part of FIG. The figure explaining operation | movement of the bending part of the operation | work part of FIG. The figure which shows the definition of the coordinate system of the bending part of the working part of FIG. FIG. 3 is a perspective view illustrating a configuration of a grip portion of the working unit in FIG. 2. The block diagram which shows the structure of the signal processing system of the surgery system containing the forceps of FIG. The figure explaining the interface of the surgery system of FIG. The side view which shows the external appearance of the working part of the forceps of the 2nd Embodiment of this invention. FIG. 11 is a partially exploded perspective view of a joint portion of the working unit in FIG. 10. The figure which shows the modification of this invention. The figure which shows the other modification of this invention. The figure which shows the external appearance of the forceps of the 3rd Embodiment of this invention. The figure which shows the holding part of FIG. The figure which shows some components of the holding part of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Forceps, 11a ... 1st axis | shaft (shaft part), 11b ... 2nd axis | shaft (shaft part), 12a ... Male thread part (1st external thread part or 2nd external thread part), 14a ... External thread part (1st external thread part or 2nd male thread part), 21 ... bending link (universal joint for driving, driving link), 22 ... gripping link (universal joint for regulation, regulating link), 23 ... connected member.

Claims (4)

A first connected member;
A second connected member;
A regulating link that couples the first position of the first coupled member and the second position of the second coupled member so as to regulate proximity and separation; and
A drive link for connecting a third position different from the first position of the first connected member and a fourth position different from the second position of the second connected member;
With
At least one of the first connection portion between the drive link and the first connected member and the second connection portion between the drive link and the second connected member is provided with the drive link in one direction. The first connected member and the second connected member are brought close to each other when rotated, and the first connected member and the second connected member are separated when rotated in the other direction. The screw mechanism is configured,
The driving link Ri bent or bendable der all directions around the rotation axis,
The feed screw mechanism is configured in each of the first connection portion and the second connection portion,
In the feed screw mechanism of the first connection part and the feed screw mechanism of the second connection part, the feed directions with respect to the rotation of the drive link in one direction are opposite to each other, and the feed amount with respect to the rotation of the drive link Drive mechanisms that are identical to each other . A first connected member;
A second connected member;
A regulating link that couples the first position of the first coupled member and the second position of the second coupled member so as to regulate proximity and separation; and
A drive link for connecting a third position different from the first position of the first connected member and a fourth position different from the second position of the second connected member;
With
At least one of the first connection portion between the drive link and the first connected member and the second connection portion between the drive link and the second connected member is provided with the drive link in one direction. The first connected member and the second connected member are brought close to each other when rotated, and the first connected member and the second connected member are separated when rotated in the other direction. The screw mechanism is configured,
The drive link can be bent or curved in all directions around the rotation axis;
The restriction link has the same configuration as the drive link.
Drive dynamic mechanism. A first connected member;
A second connected member;
A regulating link that couples the first position of the first coupled member and the second position of the second coupled member so as to regulate proximity and separation; and
A drive link for connecting a third position different from the first position of the first connected member and a fourth position different from the second position of the second connected member;
With
At least one of the first connection portion between the drive link and the first connected member and the second connection portion between the drive link and the second connected member is provided with the drive link in one direction. The first connected member and the second connected member are brought close to each other when rotated, and the first connected member and the second connected member are separated when rotated in the other direction. The screw mechanism is configured,
The driving link has at most one bending point, and the bending point can be bent in all directions around the rotation axis.
The restriction link has only one bending point or can be bent in all directions around the rotation axis,
Bending between the first position, the second position, the third position and the fourth position, and between the first position and the third position and between the second position and the fourth position. There is no point
Drive mechanism. A first connected member;
A second connected member;
A regulating link that couples the first position of the first coupled member and the second position of the second coupled member so as to regulate proximity and separation; and
A drive link for connecting a third position different from the first position of the first connected member and a fourth position different from the second position of the second connected member;
With
At least one of the first connection portion between the drive link and the first connected member and the second connection portion between the drive link and the second connected member is provided with the drive link in one direction. The first connected member and the second connected member are brought close to each other when rotated, and the first connected member and the second connected member are separated when rotated in the other direction. The screw mechanism is configured,
The drive link can be bent in all directions around the rotation axis;
The restriction link has only one bending point or can be bent in all directions around the rotation axis,
Bending between the first position, the second position, the third position and the fourth position, and between the first position and the third position and between the second position and the fourth position. There is no point
Drive mechanism.

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