JP5500891B2 - Remote control type actuator - Google Patents

Description

  The present invention relates to a remotely operated actuator that can change the posture of a tool by remote operation and is used for medical use, machining, and the like.

  There are remote-operated actuators that are used for bone processing for medical purposes and drilling and cutting for mechanical processing. The remote operation type actuator remotely controls a tool provided at the end of a long and narrow pipe portion having a linear shape or a curved shape. However, since the conventional remote control actuator only controls the rotation of the tool by remote control, in the case of medical use, it was difficult to process a complicated shape or a part that is difficult to see from the outside. Further, in drilling, it is required that not only a straight line but also a curved shape can be processed. Furthermore, in the cutting process, it is required that a deep part inside the groove can be processed. Hereinafter, taking the medical use as an example, the prior art and problems of the remote control type actuator will be described.

  In the field of orthopedics, there is an artificial joint replacement operation in which a joint that has become worn out due to bone aging or the like is replaced with a new artificial one. In this operation, it is necessary to process the patient's living bone so that the artificial joint can be inserted. In order to increase the adhesive strength between the living bone and the artificial joint after the operation, the shape of the artificial joint is required. It is required to process with high accuracy.

  For example, in hip joint replacement surgery, an artificial joint insertion hole is formed in the medullary cavity at the center of the femur bone. In order to maintain the contact strength between the artificial joint and the bone, it is necessary to increase the contact area between them, and the hole for inserting the artificial joint is processed into an elongated shape extending to the back of the bone. As a medical actuator used for such a bone cutting process, a tool is rotatably provided at the distal end of an elongated pipe portion, and by driving a rotational drive source such as a motor provided on the proximal end side of the pipe portion, There exists a thing of the structure which rotates a tool via the rotating shaft arrange | positioned inside (for example, patent document 1). In this type of medical actuator, the rotating part exposed to the outside is only the tool at the tip, so that the tool can be inserted deep into the bone.

  Artificial joint replacement surgery involves skin incision and muscle cutting. That is, the human body must be damaged. In order to minimize the scratches, the pipe part may not be straight but may be appropriately curved. In order to cope with such a situation, there are the following conventional techniques. For example, in Patent Document 2, an intermediate portion of a pipe portion is bent twice, and the axial center position on the distal end side and the axial center position on the proximal end side of the pipe portion are shifted. There are other known cases where the axial position of the pipe portion is shifted between the tip end side and the axial center side. In Patent Document 3, the pipe portion is rotated 180 degrees.

JP 2007-301149 A U.S. Pat. No. 4,466,429 US Pat. No. 4,265,231 JP 2001-17446 A

  If there is a wide gap between the living bone and the artificial joint with the artificial joint inserted in the artificial bone insertion hole of the living bone, the adhesion time after the operation becomes longer, so the gap is as narrow as possible. desirable. It is also important that the contact surface between the living bone and the artificial joint is smooth, and high accuracy is required for processing the hole for inserting the artificial joint. However, no matter what the shape of the pipe part, the operating range of the tool is limited by the shape of the pipe part. It is difficult to process the artificial joint insertion hole so that the gap is narrow and the contact surface of both is smooth.

  Generally, bones of patients undergoing artificial joint replacement surgery are often weakened due to aging or the like, and the bones themselves may be deformed. Therefore, it is more difficult to process the artificial joint insertion hole than is normally conceivable.

  Therefore, the present applicant tried to make it possible to remotely change the posture of the tool provided at the tip for the purpose of relatively easily and accurately processing the hole for inserting the artificial joint. . This is because, if the posture of the tool can be changed, the tool can be held in an appropriate posture regardless of the shape of the pipe portion. However, since the tool is provided at the tip of the elongated pipe portion, there are many restrictions in providing a mechanism for changing the posture of the tool, and a device for overcoming it is necessary. Further, it is desirable that the posture of the tool is always stable so that machining can be performed with high accuracy.

  In addition, some remote operation type actuators that do not have an elongated pipe portion can change the posture of the portion where the tool is provided with respect to the portion gripped by the hand (for example, Patent Document 4). No changes have been proposed.

  An object of the present invention is to provide a remote operation type actuator in which the posture of a tool provided at the tip of an elongated pipe portion can be changed by remote operation, and the posture of the tool is always stable.

A remote operation type actuator according to the present invention includes an elongated spindle guide part, a tip member attached to the tip of the spindle guide part via a tip member connecting part so that the posture can be freely changed, and the tip member being rotatable. A tool rotation drive source for rotating the tool; and a posture change drive source for operating the posture of the tip member. The tip member rotatably supports a spindle that holds the tool. The spindle guide portion penetrates at both ends, a rotation shaft for transmitting the rotation of the tool rotation drive source to the spindle, and a plurality of rolling bearings for rotatably supporting the rotation shaft in the spindle guide portion . and a guide pipe inner diameter hole is a guide hole having the inside of the outer shell of the spindle guide part, the gas part of the outer surface of the plurality of rolling bearings Supported by Dopaipu, tip inserted retractably attitude operation member changing the position the tip member by advancing and retracting operation in a state of being in contact directly or indirectly to the tip member into the guide hole, for the posture change Provided is a drive mechanism portion that transmits the operation of the drive source to the posture operation member, and the drive mechanism portion is fixed to a male screw portion formed at a base end of the posture operation member and a drive portion housing that houses the drive mechanism portion. A screw mechanism including a female screw portion screwed into the male screw portion, the drive portion housing is coupled to a proximal end of the spindle guide portion, and the posture changing drive source is a rotary actuator, By rotating the base end of the posture operation member with an actuator, the posture operation member is advanced and retracted by the action of the screw mechanism.

According to this configuration, bone or the like is cut by the rotation of the tool provided on the tip member. In this case, when the posture operation member is advanced or retracted by the posture change drive source, the tip of the posture operation member directly or indirectly acts on the tip member, so that the tip member connecting portion is attached to the tip of the spindle guide portion. The tip member attached so as to be freely changeable via the posture changes its posture. Since the posture operation member is inserted into the guide hole, the posture operation member does not shift in the direction intersecting the longitudinal direction, and can always act properly on the tip member, and the posture change operation of the tip member Is done accurately.
When an external force is applied to the tool or the tip member, an axial force is applied from the tip member to the posture operation member. However, the posture change drive source is a rotary actuator, and by rotating the base end of the posture operation member with this rotary actuator, the posture operation member is moved forward and backward by the action of the screw mechanism. Does not move in the axial direction unless it rotates. Therefore, the posture stability of the tip member with respect to external force is good.
The posture changing drive source is provided at a position away from the tip member, and the posture of the tip member can be changed by remote control. Further, since the rotary actuator is used as the posture changing drive source, it is only necessary to transmit the rotation output of the rotary actuator as it is to the base end of the posture operating member, and the posture changing drive mechanism can be simply configured.

In the present invention, both or one of the tool rotation drive source and the attitude change drive source may be provided in the drive unit housing.
If either or both of the tool rotation drive source and the attitude change drive source are provided in the drive unit housing, the number of parts provided outside the drive unit housing is reduced, and the overall configuration of the remote operation type actuator is simplified. Can be.

Further, the tool rotation drive source and the posture change drive source may be provided outside the drive unit housing.
If the tool rotation drive source and the posture change drive source are provided outside the drive unit housing, the drive unit housing can be reduced in size. Therefore, the handleability when operating the remote control type actuator with the drive unit housing can be improved.

When both or one of the tool rotation drive source and the posture change drive source is provided outside the drive unit housing, the tool rotation drive source and the posture change drive source are outside the drive unit housing. It is preferable that the driving force of the provided driving source is transmitted to the rotating shaft or the posture operation member with a flexible cable.
If the driving force of the drive source provided outside the drive unit housing is transmitted to the rotary shaft or the attitude control member with a flexible cable, the flexibility of the positional relationship between the drive source provided outside the drive unit housing and the drive unit housing The remote control type actuator is easy to operate.

The posture operation member may change the posture of the tip member by operating on the side pressing the tip member, or change the posture of the tip member by operating on the side of pulling the tip member. It may be.
In any case, the posture of the tip member can be favorably changed by the posture operation member.

  In the present invention, the guide hole and the posture operation member inserted into the guide hole are provided in only one place, a restoring elastic member for urging the tip member toward a predetermined posture is provided, and the posture operation member is The posture of the tip member can be changed against the biasing force of the restoring elastic member. Further, the guide hole and the posture operation member inserted into the guide hole are provided at two positions, the posture change drive source is provided individually for each posture operation member, and the posture control members of the two positions are provided. You may change and maintain the attitude | position of the said front-end | tip member by the balance of the acting force to a front-end | tip member. In these cases, the posture of the tip member can be changed around one posture changing axis. In the latter, since the tip member is pressurized by two posture operation members, the posture stability of the tip member can be improved as compared with the former in which pressure is applied by only one posture operation member.

  Further, the tip member connecting portion supports the tip member so that the tip member can tilt in an arbitrary direction, and the guide hole and the posture operation member inserted into the guide hole are arranged around the tilt center of the tip member. The posture changing drive source is provided individually for each posture operation member, and the posture of the tip member is adjusted by balancing the acting forces of the posture operation members of the three or more locations on the tip member. It may be changed and maintained. In this case, the posture of the tip member can be changed around the two posture change axes. In this configuration, since the tip member is pressurized by three or more posture operation members, the posture stability of the tip member can be further improved.

In this invention, you may provide the deceleration rotation transmission mechanism which decelerates rotation of the said rotary actuator and transmits to the base end of the said attitude | position operation member.
Providing the decelerating rotation transmission mechanism allows the base end of the posture operation member to be rotated at a low speed even with a small rotary actuator that rotates at high speed, so that a small rotary actuator can be used.

In the present invention, the outer shell may be an outer pipe.
With this configuration, it is possible to reduce the weight by making the spindle guide hollow while protecting the inside of the spindle guide by the outer pipe.

In the case of the above configuration, the rotating shaft is arranged at the center in the outer pipe, and a plurality of reinforcing shafts and the guide pipe are arranged in a circumferential direction between the rotating shaft and the inner diameter surface of the outer pipe. It is good to provide.
By providing the reinforcing shaft and the guide pipe in this manner, they can be arranged in a well-balanced manner in the spindle guide portion, and the rigidity of the spindle guide portion can be improved.

In the above structure, the outer surface of the plurality of rolling bearings can be supported by the plurality of reinforcing shafts and said guide pipe.
By using the reinforcing shaft and the guide pipe, the outer diameter surface of the rolling bearing can be supported without using an extra member.

Moreover, when providing the several rolling bearing which supports the said rotating shaft in the said spindle guide part rotatably, it is desirable to provide the spring element which gives a preload with respect to these rolling bearings between adjacent rolling bearings.
In order to improve the finish of processing, it is preferable to rotate the spindle at high speed. When the spindle is rotated at a high speed, there is an effect of reducing cutting resistance acting on the tool. Since the rotational force is transmitted to the spindle through a thin rotating shaft made of a wire or the like, it is necessary to preload the rolling bearing that supports the rotating shaft in order to realize high-speed rotation of the spindle. If a spring element for this preload is provided between adjacent rolling bearings, the spring element can be provided without increasing the diameter of the spindle guide portion.

In the present invention, the spindle guide portion may have a curved portion.
Since the posture operation member is flexible, even if there is a curved portion in the spindle guide portion, it can be advanced and retracted in the guide hole.

A remote control type actuator according to the present invention is provided with an elongated spindle guide portion, a tip member attached to the tip of the spindle guide portion via a tip member connecting portion so that the posture can be freely changed, and rotatably provided on the tip member. A tool rotation drive source for rotating the tool, and a posture change drive source for manipulating the posture of the tip member. The tip member rotatably supports a spindle holding the tool. The spindle guide portion penetrates at both ends, a rotation shaft for transmitting the rotation of the tool rotation drive source to the spindle, a plurality of rolling bearings rotatably supporting the rotation shaft in the spindle guide portion . and a guide pipe inner diameter hole is a guide hole having the inside of the outer shell of the spindle guide part, a portion of the outer surface of the plurality of rolling bearings the guide Supported by the type, the tip is inserted retractably attitude operation member changing the position the tip member by advancing and retracting operation in a state of being in contact directly or indirectly to the tip member into the guide hole, for the posture change Provided is a drive mechanism portion that transmits the operation of the drive source to the posture operation member, and the drive mechanism portion is fixed to a male screw portion formed at a base end of the posture operation member and a drive portion housing that houses the drive mechanism portion. A screw mechanism including a female screw portion screwed into the male screw portion, the drive portion housing is coupled to a proximal end of the spindle guide portion, and the posture changing drive source is a rotary actuator, By rotating the proximal end of the posture operation member with an actuator, the posture operation member is advanced and retracted by the action of the screw mechanism. The attitude of the tool provided at the distal end of the guide portion can be changed by remote control, always pose of the tool is stable.

It is a figure which shows schematic structure of the remote control type actuator concerning embodiment of this invention. (A) is a sectional view of a part of the distal end member, spindle guide portion, and drive portion housing of the remote control type actuator, (B) is a sectional view taken along the line IIB-IIB, and (C) is a sectional view of the distal end member and the rotating shaft. It is a figure which shows a connection structure. It is the figure which combined and displayed the control system on the front view of the drive part of the same remote control type actuator. (A) is the front view of the deceleration rotation transmission mechanism of the remote operation type actuator, (B) is the side view. It is a figure which shows schematic structure at the time of providing a cooling means in the remote control type actuator. (A) is sectional drawing of the front-end | tip member and spindle guide part of the remote control type actuator which is a modification of embodiment shown in FIG. 1 thru | or FIG. 4, (B) is the VIB-VIB sectional drawing. Furthermore, sectional drawing of the front-end | tip member and spindle guide part of the remote control type actuator which is a different modification, (B) is the VIIB-VIIB sectional drawing. It is sectional drawing of the connection part of a different spindle guide part and a drive part housing. (A) is a front view of a different deceleration rotation transmission mechanism, and (B) is a side view thereof. (A) is a front view of still another reduced rotation transmission mechanism, and (B) is a side view thereof. (A) is sectional drawing of the front end member and spindle guide part of the remote control type actuator concerning different embodiment of this invention, (B) is the XIB-XIB sectional drawing. (A) is sectional drawing of the front-end | tip member and spindle guide part of the remote control type actuator concerning further different embodiment of this invention, (B) is the XIIB-XIIB sectional drawing. (A) is a sectional view of a part of a tip member, a spindle guide portion, and a drive portion housing of a remote operation type actuator having different posture operation members, and (B) is a sectional view taken along XIIIB-XIIIB. (A) is a sectional view of a tip member and a spindle guide portion of a remote operation type actuator having different posture operation members, and (B) is a sectional view of XIVB-XIVB. It is a figure which shows schematic structure of the remote control type actuator from which the shape of a spindle guide part differs. It is a figure which shows schematic structure of the remote control type actuator concerning further different embodiment of this invention. It is a figure which shows the structure of the drive mechanism for a tool rotation of the remote control type actuator, and the drive mechanism for attitude | position change. It is sectional drawing of the cable for tool rotation of the drive mechanism for the tool rotation. It is sectional drawing of the cable for attitude | position change of the drive mechanism for the attitude | position change.

  An embodiment of the present invention will be described with reference to FIGS. In FIG. 1, the remote control type actuator includes a tip member 2 for holding a rotary tool 1, an elongated spindle guide portion 3 having the tip member 2 attached to the tip so that the posture can be freely changed, and the spindle guide. A drive unit housing 4a to which the base end of the unit 3 is coupled, and a controller 5 for controlling the tool rotation drive mechanism 4b and the attitude change drive mechanism 4c in the drive unit housing 4a are provided. The drive unit housing 4a constitutes the drive unit 4 together with the built-in tool rotation drive mechanism 4b and posture changing drive mechanism 4c.

  As shown in FIG. 2, the tip member 2 has a spindle 13 rotatably supported by a pair of bearings 12 inside a substantially cylindrical housing 11. The spindle 13 has a cylindrical shape with an open end, and the shank 1a of the tool 1 is inserted into the hollow portion in a fitted state, and the shank 1a is non-rotatably coupled by the rotation prevention pin 14. The tip member 2 is attached to the tip of the spindle guide portion 3 via the tip member connecting portion 15. The tip member connecting portion 15 is a means for supporting the tip member 2 so that the posture thereof can be freely changed, and includes a spherical bearing. Specifically, the distal end member connecting portion 15 includes a guided portion 11 a that is a reduced inner diameter portion of the proximal end of the housing 11 and a hook-shaped portion of a retaining member 21 that is fixed to the distal end of the spindle guide portion 3. It is comprised with the guide part 21a. The guide surfaces F1 and F2 that are in contact with each other 11a and 21a are spherical surfaces having a center of curvature O located on the center line CL of the spindle 13 and having a smaller diameter toward the proximal end side. As a result, the tip member 2 is prevented from being detached from the spindle guide portion 3 and is supported so as to be freely changeable in posture. In this example, since the tip member 2 is configured to change the posture around the X axis passing through the center of curvature O, the guide surfaces F1 and F2 may be cylindrical surfaces having the X axis passing through the point O as an axis. .

  The spindle guide portion 3 has a rotating shaft 22 that transmits the rotational force of the tool rotation drive source 41 (FIG. 3) in the drive portion housing 4 a to the spindle 13. In this example, the rotating shaft 22 is a wire and can be elastically deformed to some extent. As the material of the wire, for example, metal, resin, glass fiber or the like is used. The wire may be a single wire or a stranded wire. As shown in FIG. 2C, the spindle 13 and the rotary shaft 22 are connected so as to be able to transmit rotation via a joint 23 such as a universal joint. The joint 23 includes a groove 13 a provided at the closed base end of the spindle 13 and a protrusion 22 a provided at the distal end of the rotating shaft 22 and engaged with the groove 13 a. The center of the connecting portion between the groove 13a and the protrusion 22a is at the same position as the center of curvature O of the guide surfaces F1 and F2.

  The spindle guide section 3 has an outer pipe 25 that is an outer shell of the spindle guide section 3, and the rotation shaft 22 is located at the center of the outer pipe 25. The rotating shaft 22 is rotatably supported by a plurality of rolling bearings 26 that are arranged apart from each other in the axial direction. Between each rolling bearing 26, spring elements 27A and 27B for generating a preload on the rolling bearing 26 are provided. The spring elements 27A and 27B are, for example, compression coil springs. There are an inner ring spring element 27A for generating a preload on the inner ring of the rolling bearing 26 and an outer ring spring element 27B for generating a preload on the outer ring, which are arranged alternately. The retaining member 21 is fixed to the pipe end portion 25a of the outer pipe 25 by a fixing pin 28, and rotatably supports the distal end portion of the rotating shaft 22 via the rolling bearing 26 at the inner peripheral portion of the distal end. The pipe end portion 25a may be joined by welding or the like with the outer pipe 25 as a separate member.

  Between the inner diameter surface of the outer pipe 25 and the rotary shaft 22, one guide pipe 30 penetrating at both ends is provided, and the posture operation member 31 advances and retreats in the guide hole 30 a which is the inner diameter hole of the guide pipe 30. It is inserted freely. In this example, the posture operation member 31 includes a posture operation wire 31a and a columnar pin 31b provided on the distal end side of the posture operation wire 31a. The distal end of the columnar pin 31 b is spherical and is in contact with the proximal end surface of the distal end member housing 11.

  A compression spring is positioned between the proximal end surface of the housing 11 of the distal end member 2 and the distal end surface of the outer pipe 25 of the spindle guide portion 3 at a position 180 degrees relative to the circumferential position where the posture operation member 31 is located. A restoring elastic member 32 is provided. The restoring elastic member 32 acts to urge the tip member 2 toward a predetermined posture.

  In addition to the guide pipe 30, a plurality of reinforcing shafts 34 are arranged on the same pitch circle C as the guide pipe 30 between the inner diameter surface of the outer pipe 25 and the rotary shaft 22. These reinforcing shafts 34 are for ensuring the rigidity of the spindle guide portion 3. The intervals between the guide pipe 30 and the reinforcing shaft 34 are equal. The guide pipe 30 and the reinforcing shaft 34 are in contact with the inner diameter surface of the outer pipe 25 and the outer diameter surface of the rolling bearing 26. Thereby, the outer diameter surface of the rolling bearing 26 is supported.

  A male screw portion 36a is formed at the proximal end of the posture operation wire 31a, and this male screw portion 36a is screwed with a female screw portion 36b formed in the drive portion housing 4a. The male screw portion 36a and the female screw portion 36b constitute a screw mechanism 36. By rotating the base end of the posture operation wire 31a by driving the posture change drive source 42 (FIG. 3), the posture operation wire 31a is advanced and retracted by the action of the screw mechanism 36.

  FIG. 3 shows a tool rotation drive mechanism 4b and a posture change drive mechanism 4c in the drive unit housing 4a. The tool rotation drive mechanism 4 b includes a tool rotation drive source 41 controlled by the controller 5. The tool rotation drive source 41 is, for example, an electric motor, and its output shaft 41 a is coupled to the proximal end of the rotation shaft 22. The posture changing drive mechanism 4 c includes a posture changing drive source 42 controlled by the controller 5. The posture changing drive source 42 is, for example, an electric rotary actuator, and the rotation of the output shaft 42 a is transmitted to the proximal end of the posture operation wire 31 a through the decelerating rotation transmission mechanism 43 at a reduced speed. The posture changing drive mechanism 4 c includes the posture changing drive source 42 and the drive mechanism 83. The drive mechanism unit 83 includes the screw mechanism 36 and the deceleration rotation transmission mechanism 43.

  As shown in FIGS. 3 and 4, the reduced rotation transmission mechanism 43 is rotated by a circular spur gear 43a attached to the output shaft 42a of the attitude changing drive source 42 and a support member 60 fixed to the drive section housing 4a. A sectoral spur gear 43b that is freely supported and meshes with the circular spur gear 43a. A rotary sliding portion 62 provided on the rotation center shaft 61 of the sectoral spur gear 43b is used to rotate the posture operation wire 31a from the sector spur gear 43b. The rotation is transmitted to the proximal end extension 63. The sector spur gear 43b has a larger pitch circle diameter than the circular spur gear 43a, and the rotation of the output shaft 42a is decelerated and transmitted to the proximal end of the posture operation wire 31a. The rotary sliding portion 62 includes a grooved hole 62a formed in the sector spur gear 43b and a protruding shaft 62b of the proximal end extension 63, and the protruding shaft 62b is provided with respect to the grooved hole 62a. It is fitted so as to be movable in the axial direction while being rotationally restricted. Providing the decelerating rotation transmission mechanism 43 can rotate the base end of the attitude operation wire 31a at a low speed even with a small rotary actuator that rotates at a high speed. Therefore, a small rotary actuator can be used as the attitude changing drive source 42. It becomes possible. Further, since the rotary actuator is used as the posture changing drive source 42, the rotation output of the rotary actuator may be transmitted as it is to the proximal end of the posture operating wire 31a, and the posture changing drive mechanism 4c can be simplified.

  The posture change drive mechanism 4c is provided with an operation amount detector 45 for detecting the operation amount of the posture change drive source 42. The detection value of the movement amount detector 45 is output to the posture detection means 46. The posture detection means 46 detects the tilt posture of the tip member 2 around the X axis (FIG. 2) based on the output of the movement amount detector 45. The posture detection means 46 has relationship setting means (not shown) in which the relationship between the tilt posture and the output signal of the motion amount detector 45 is set by an arithmetic expression or a table, and the relationship is determined from the input output signal. The tilting posture is detected using setting means. This posture detection means 46 may be provided in the controller 5 or may be provided in an external control device.

  Further, the posture changing drive mechanism 4 c is provided with a supply wattmeter 47 for detecting the amount of power supplied to the posture changing drive source 42, and the detected value of the supplied wattmeter 47 is output to the load detecting means 48. The The load detection means 48 detects the load acting on the tip member 2 based on the output of the wattmeter 47. The load detection means 48 has relation setting means (not shown) in which the relation between the load and the output signal of the supplied wattmeter 47 is set by an arithmetic expression or a table, and the relation setting means is determined from the input output signal. The load is detected using. The load detecting means 48 may be provided in the controller 5 or may be provided in an external control device.

  The controller 5 controls the tool rotation drive source 41 and the posture change drive source 42 based on the detection values of the posture detection means 46 and the load detection means 48.

The operation of this remote control type actuator will be described.
When the tool rotation drive source 41 is driven, the rotational force is transmitted to the spindle 13 via the rotation shaft 22, and the tool 1 rotates together with the spindle 13. The load acting on the tip member 2 when the tool 1 is rotated to cut bone or the like is detected by the load detection means 48 from the detection value of the supply wattmeter 47. By controlling the feed amount of the entire remote operation type actuator and the posture change of the distal end member 2 described later according to the load value thus detected, the load acting on the distal end member 2 can be appropriately maintained while maintaining the load. Cutting can be performed.

  At the time of use, the posture changing drive source 42 is driven to change the posture of the tip member 2 by remote control. For example, when the posture operating member 31 is advanced to the distal end side by the posture changing drive source 42, the housing 11 of the distal end member 2 is pushed by the posture operating member 31, and the distal end member 2 is directed downward in FIG. The posture is changed along the guide surfaces F1 and F2 toward the side. On the other hand, when the posture operation member 31 is retracted by the posture changing drive source 42, the housing 11 of the tip member 2 is pushed back by the elastic repulsive force of the restoring elastic member 32, and the tip member 2 is shown in FIG. The posture is changed along the guide surfaces F1 and F2 to the side facing upward. At that time, the pressure of the posture operation member 31, the elastic repulsive force of the restoring elastic member 32, and the reaction force from the retaining member 21 act on the tip member connecting portion 15, and the balance of these acting forces The posture of the tip member 2 is determined. The posture of the tip member 2 is detected by the posture detection means 46 from the detection value of the movement amount detector 45. Therefore, the posture of the tip member 2 can be appropriately controlled by remote operation.

  Since the posture operation member 31 is inserted through the guide hole 30a, the posture operation member 31 does not shift in the direction intersecting the longitudinal direction, and can always act properly on the tip member 2, and the tip member 2 posture change operation is performed accurately. Further, since the posture operation member 31 includes a posture operation wire 31a and a columnar pin 31b and is flexible as a whole, even when the spindle guide portion 3 has a curved portion, the posture change operation of the tip member 2 is reliably performed. Is called. Furthermore, since the center of the connecting portion between the spindle 13 and the rotating shaft 22 is at the same position as the center of curvature O of the guide surfaces F1 and F2, a force for pushing and pulling against the rotating shaft 22 by changing the posture of the tip member 2 is increased. Accordingly, the posture of the tip member 2 can be changed smoothly. The posture changing drive source 42 is provided at a position away from the tip member 1, and the posture of the tip member 1 can be changed by remote control.

  When an external force is applied to the tool 1 or the tip member 2, an axial force is applied from the tip member 2 to the posture operation member 31, but the posture operation member 31 is advanced and retracted by the screw mechanism 36. 31 does not move in the axial direction unless it rotates in the rotational direction. Therefore, the posture stability with respect to the external force of the tip member 2 is good.

  This remote control type actuator is used, for example, for cutting the medullary cavity of bone in artificial joint replacement surgery. During the operation, all or part of the distal end member 2 is inserted into the patient's body. The For this reason, if the posture of the tip member 2 can be changed by remote control as described above, the bone can be processed while the tool 1 is always held in an appropriate posture, and the artificial joint insertion hole is finished with high accuracy. Can do.

  The elongated spindle guide portion 3 needs to be provided with the rotating shaft 22 and the posture operation member 31 in a protected state. The rotating shaft 22 is provided at the center of the outer pipe 25, and the outer pipe 25, the rotating shaft 22, Since the guide pipe 30 accommodating the posture operation member 31 and the reinforcing shaft 34 are arranged side by side in the circumferential direction, the rotary shaft 22 and the posture operation member 31 are protected and the interior is hollow. It is possible to secure rigidity while reducing the weight. Also, the overall balance is good.

  Since the outer diameter surface of the rolling bearing 26 that supports the rotating shaft 22 is supported by the guide pipe 30 and the reinforcing shaft 34, the outer diameter surface of the rolling bearing 26 can be supported without using extra members. Moreover, since the preload is applied to the rolling bearing 26 by the spring elements 27A and 27B, the rotating shaft 22 made of a wire can be rotated at a high speed. Therefore, machining can be performed by rotating the spindle 13 at a high speed, the machining finish is good, and the cutting resistance acting on the tool 1 can be reduced. Since the spring elements 27A and 27B are provided between the adjacent rolling bearings 26, the spring elements 27A and 27B can be provided without increasing the diameter of the spindle guide portion 3.

  In this embodiment, a tool rotation drive source 41 and a posture change drive source 42 are provided in a common drive unit housing 4a. Therefore, the configuration of the entire remote operation type actuator can be simplified. Only one of the tool rotation drive source 41 and the posture change drive source 42 may be provided in the drive unit housing 4a. Further, as will be described later, the tool rotation drive source 41 and the attitude change drive source 42 may be provided outside the drive unit housing 4a.

  This remote control type actuator can be provided with a cooling means 50 for cooling the tool 1 or the like as shown in FIG. 5 by utilizing the fact that the spindle guide portion 3 is hollow. That is, the cooling means 50 includes a coolant supply device 51 provided outside the remote control type actuator, and a tool that passes from the coolant supply device 51 through the inside of the drive unit housing 4a, the spindle guide portion 3, and the tip member 2. 1 is a coolant supply pipe 52 that guides the coolant to 1, and a portion 52 a of the coolant supply pipe 52 that passes through the spindle guide portion 3 is the outer pipe 25 itself, which is the coolant supply pipe 52. The liquid passes through. The coolant guided to the tool 1 is discharged to the outer periphery of the tool 1. If such a cooling means 50 is provided, the heat generating parts such as the tool 1, the workpiece, the spindle 13, and the rotating shaft 22 can be cooled by the coolant. Since the coolant is allowed to pass through the outer pipe 25, it is not necessary to provide a separate coolant supply pipe, and the spindle guide portion 3 can be simplified and reduced in diameter. Further, the cooling liquid may be used for lubricating the rolling bearings 26 and 29. By doing so, it is not necessary to use grease or the like generally used for bearings, and it is not necessary to provide a separate lubricating device. It is also possible to adopt a circulation type configuration in which the coolant guided to the tool 1 is returned to the coolant supply device 51 without being discharged to the outer periphery of the tool 1. However, when the flow rate of the cooling liquid passing through the outer pipe 25 is small, the cooling liquid may be further supplied from the outside to cool the tool 1 or the workpiece.

  The cooling liquid is preferably water or physiological saline. This is because if the coolant is water or physiological saline, the coolant does not adversely affect the living body when the tip member 2 is inserted into the living body to perform processing. When the coolant is water or physiological saline, it is desirable that the material of the parts in contact with the coolant is stainless steel having excellent corrosion resistance. Other parts constituting the remote control type actuator may also be made of stainless steel.

  In the above example, the posture operation member 31 is composed of the posture operation wire 31a and the columnar pin 31b, and the posture of the tip member 2 is changed by pushing the housing 11 of the tip member 2 with the columnar pin 31b. The posture operation member 31 may be configured by only the wire 31a, and the housing 11 may be directly pressed by the tip of the posture operation wire 31a. In that case, the tip of the posture operation wire 31a is preferably spherical.

  In each of the above examples, the posture operation member 31 pushes the housing 11 to change the posture of the tip member 2. As shown in FIG. 7, the posture operation member 31 includes the posture operation wire 31 a and the posture operation wire. The posture operation wire 31a is moved back to the proximal end side by the posture change drive source 42 (FIG. 3), and the posture operation wire 31a is moved to the housing 11 by a connecting member 31c for connecting the distal end of the housing 31a and the housing 11. You may make it change the attitude | position of the front-end | tip member 2 by pulling. In this case, the restoring elastic member 32 is a tension coil spring.

  FIG. 8 shows a screw mechanism having a configuration different from that of FIG. In the screw mechanism 36, a female screw portion 36 b is formed on the inner periphery of the proximal end of the guide pipe 30. The male screw portion 36a is formed at the proximal end of the posture operation wire 31a as described above. Also in this case, as described above, the posture operation wire 31a can be advanced and retracted by the action of the screw mechanism 36 by rotating the proximal end of the posture operation wire 31a by driving the posture changing drive source 42 (FIG. 3).

  FIG. 9 and FIG. 10 each show a reduced rotation transmission mechanism different from the above. 9 is provided with a gear 43c attached to an output shaft 42a of a posture changing drive source (not shown), and is rotatably supported by a support member (not shown) and meshes with the gear 43c. The worm gear mechanism is composed of a worm 43d. 10 is rotatably supported by a first bevel gear 43e attached to an output shaft 42a of a posture changing drive source (not shown) and a support member (not shown). The bevel gear mechanism includes a second bevel gear 43f that meshes with the first bevel gear 43e. In any case, the same rotation sliding portion 62 provided on the rotation center shaft 61 of the worm 43d or the second bevel gear 43f can be used to extend the proximal end side extension portion of the posture operation wire 31a from the worm 43d or the second bevel gear 43f. Rotation is transmitted to 63.

  FIG. 11 shows a different embodiment. In this remote operation type actuator, two guide pipes 30 are provided at circumferential positions that are 180 degrees in phase with each other in the outer pipe 25, and a posture operation member 31 is placed in a guide hole 30 a that is an inner diameter hole of the guide pipe 30. Has been inserted to move forward and backward. The figure shows an example in which the posture operation member 31 includes a posture operation wire 31a and a columnar pin 31b. Between the two guide pipes 30, a plurality of reinforcing shafts 34 are arranged on the same pitch circle C as the guide pipe 30. The restoring elastic member 32 is not provided. The guide surfaces F1 and F2 are spherical surfaces whose center of curvature is the point O, or cylindrical surfaces whose axis is the X axis passing through the point O.

  The drive unit 4 (not shown) is provided with two posture change drive sources 42 (not shown) for individually moving the two posture operation members 31 forward and backward, and these two posture change drives. The posture of the tip member 2 is changed by driving the sources 42 in opposite directions. For example, when the upper posture operation member 31 in FIG. 11 is advanced to the distal end side and the lower posture operation member 31 is retracted, the housing 11 of the distal end member 2 is pushed by the upper posture operation member 31. The posture of the tip member 2 is changed along the guide surfaces F1 and F2 to the side where the tip side faces downward in FIG. Conversely, when both posture operation members 31 are moved back and forth, the housing 11 of the tip member 2 is pushed by the lower posture operation member 31, and the tip member 2 is directed upward in FIG. 11A. The posture is changed along the guide surfaces F1 and F2 to the side. At that time, the pressure of the two upper and lower posture operating members 31 and the reaction force from the retaining member 21 are acting on the tip member connecting portion 15, and the posture of the tip member 2 is determined by the balance of these acting forces. Is done. In this configuration, the housing 11 of the tip member 2 is pressurized by the two posture operation members 31, so that the posture stability of the tip member 2 is improved as compared with the embodiment in which the pressure is applied by only one posture operation member 31. Can be increased.

  FIG. 12 shows a further different embodiment. This remote control type actuator is provided with three guide pipes 30 at circumferential positions at a phase of 120 degrees in the outer pipe 25, and the same posture as described above in a guide hole 30 a which is an inner diameter hole of the guide pipe 30. The operating member 31 is inserted so as to freely advance and retract. Between the three guide pipes 30, a plurality of reinforcing shafts 34 are arranged on the same pitch circle C as the guide pipes 30. The restoring elastic member 32 is not provided. The guide surfaces F1 and F2 are spherical surfaces whose center of curvature is a point O, and the tip member 2 can tilt in any direction.

The drive unit 4 is provided with three posture change drive sources 42 (not shown) for individually moving the three posture operation members 31 (31U, 31L, 31R) forward and backward, and these three posture changes. The posture of the tip member 2 is changed by driving the driving source 42 in conjunction with each other.
For example, when the upper one posture operation member 31U in FIG. 12 is advanced to the distal end side and the other two posture operation members 31L and 31R are moved backward, the upper posture operation member 31U causes the housing 11 of the distal end member 2 to move. By being pushed, the tip member 2 changes its posture along the guide surfaces F1 and F2 to the side in which the tip side faces downward in FIG. At this time, each posture changing drive source 42 is controlled so that the amount of advance / retreat of each posture operation member 31 is appropriate. When each posture operation member 31 is moved back and forth, the housing 11 of the tip member 2 is pushed by the left and right posture operation members 31L and 31R, so that the tip member 2 moves to the side where the tip side is upward in FIG. The posture is changed along the guide surfaces F1 and F2.
Further, when the left posture operation member 31L is advanced to the distal end side and the right posture operation member 31R is moved backward while the upper posture operation member 31U is stationary, the distal end member 2 is moved by the left posture operation member 31L. When the housing 11 is pressed, the tip member 2 changes its posture along the guide surfaces F1 and F2 to the right, that is, the side facing the back side of the paper surface in FIG. When the left and right posture operation members 31L and 31R are moved back and forth, the housing 11 of the tip member 2 is pushed by the right posture operation member 31R, so that the tip member 2 moves along the guide surfaces F1 and F2 toward the left side. Change the posture.
Thus, by providing the posture operation member 31 at three positions in the circumferential direction, the tip member 2 can be changed in posture in the directions of the upper, lower, left and right axes (X axis, Y axis). At that time, the pressure of the three posture operating members 31 and the reaction force from the retaining member 21 are acting on the tip member connecting portion 15, and the posture of the tip member 2 is determined by the balance of these acting forces. The In this configuration, since the pressure is applied to the housing 11 of the tip member 2 by the three posture operation members 31, the posture stability of the tip member 2 can be further improved. If the number of posture operation members 31 is further increased, the posture stability of the tip member 2 can be further enhanced.

  As shown in FIGS. 13 and 14, the posture operation member 31 may be composed of a plurality of force transmission members 31 d. FIG. 13 shows an example in which the force transmission member 31d is a ball, and FIG. 14 shows an example in which the force transmission member 31d is a columnar body such as a cylinder. The force transmission members 31d are arranged without a gap along the length direction of the guide hole 30a. In these examples, a columnar pin 31b is provided on the front end side of the line of force transmission members 31d. Further, a male screw member 31e is provided on the proximal end side of the line of force transmission members 31d. And the attitude | position operation member 31 is comprised by 31 d of several force transmission members, the columnar pin 31b, and the external thread member 31e.

  A male screw portion 36a is formed on the outer periphery of the male screw member 31e, and is screwed into the male screw portion 36a with a female screw portion 36b formed in the drive unit housing 4a. The male screw portion 36a and the female screw portion 36b constitute a screw mechanism 36. By rotating the male screw member 31e by driving the posture changing drive source 42 (FIG. 3), the male screw member 31e advances and retreats due to the action of the screw mechanism 36, and the posture operation member 31 as a whole advances and retreats accordingly. The configuration of the posture operation drive mechanism 4c other than the screw mechanism 36 is the same as that of FIG.

  As described above, when the posture operation member 31 is composed of a plurality of force transmission members 31 d, the posture of the tip member 2 is changed only when the tip of the posture operation member 31 is operated to press the tip member 2. . Even if the posture operation member 31 is composed of a plurality of force transmission members 31d, it is possible to reliably act on the tip member 2. Since the force transmission member 31d is arranged in the guide hole 30a, the posture operation member 31 does not shift in the direction intersecting the longitudinal direction, and can always act properly on the tip member 2, The posture changing operation of the member 2 is accurately performed. In addition, even if each force transmission member 31d is a rigid body, the posture operation member 31 as a whole is flexible, so that the posture changing operation of the tip member 2 can be reliably performed even when provided on the bent spindle guide portion 3. Is called.

  FIGS. 13 and 14 show examples in which the posture operation member 31 is provided at three circumferential positions that are in a phase of 120 degrees, but the posture operation member 31 is in two places that are in a phase of 180 degrees with respect to each other. Even when provided at a circumferential position, or when a posture operation member 31 provided at one place in the circumferential direction is combined with a restoring elastic member 32 corresponding thereto, a posture operation constituted by a plurality of force transmission members 31d. The member 31 can be applied.

  In each of the above embodiments, the spindle guide portion 3 has a linear shape. However, the remote operation type actuator of the present invention is such that the posture operation member 31 is flexible and the tip member 2 is bent even when the spindle guide portion 3 is bent. Since the posture changing operation is reliably performed, the spindle guide portion 3 may be curved as shown in FIG. Alternatively, only a part of the spindle guide portion 3 may be curved. If the spindle guide portion 3 is curved, it may be possible to insert the distal end member 2 to the back of the bone, which is difficult to reach in the straight shape, so that the hole for artificial joint insertion can be accurately processed in artificial joint replacement surgery. It becomes possible to finish.

  When the spindle guide portion 3 has a curved shape, the outer pipe 25, the guide pipe 30, and the reinforcing shaft 34 need to have a curved shape. The rotating shaft 22 is preferably made of a material that is easily deformed, and for example, a shape memory alloy is suitable.

  16 to 19 show embodiments in which the configurations of the tool rotation drive mechanism and the posture change drive mechanism are different. In the above embodiment, the tool rotation drive source 41 of the tool rotation drive mechanism 4b and the attitude change drive source 42 of the attitude change drive mechanism 4c are provided in the drive unit housing 4a. In the embodiment of FIG. 19, the tool rotation drive source 41 and the posture change drive source 42 are provided in a drive source housing 70 different from the drive unit housing 4a.

  In the tool rotation drive mechanism 71 of this embodiment, the rotation of the output shaft 41a of the tool rotation drive source 41 provided in the drive source housing 70 is rotated by the inner wire 74 (FIG. 18) of the tool rotation cable 72. It transmits to the base end of the rotating shaft 22 in 4a. The tool rotating cable 72 has a structure shown in FIG. 18, for example. That is, a flexible inner wire 74 is rotatably supported by a plurality of rolling bearings 76 at the center of the flexible outer tube 73. Both ends of the inner wire 74 are connected to the output shaft 41 a of the tool rotation drive source 41 and the base end of the rotation shaft 22, respectively. Between the rolling bearings 76, spring elements 77A and 77B for generating a preload on the rolling bearings 76 are provided. The spring elements 77A and 77B are, for example, compression coil springs. There are an inner ring spring element 77A for generating a preload on the inner ring of the rolling bearing 76 and an outer ring spring element 77B for generating a preload on the outer ring, which are alternately arranged. Thus, the inner wire 74 can be rotated at a high speed by applying a preload to the rolling bearing 76 by the spring elements 77A and 77B. A commercially available flexible shaft may be used.

  Further, the posture changing drive mechanism 81 of this embodiment is configured to drive the rotation of the output shaft 42a of the posture changing drive source 42 provided in the drive source housing 70 through the posture changing cable 82 in the drive unit housing 4a. It transmits to the mechanism part 83. The drive mechanism unit 83 corresponds to the posture change drive mechanism 4c of the above-described embodiment except the posture change drive source 42, and instead of the output shaft 42a of the posture change drive source 42 in the posture change drive mechanism 4c. Further, a gear mounting shaft 85 to which the circular spur gear 43a is mounted is provided. The gear mounting shaft 85 is rotatably supported by the drive unit housing 4a by a rolling bearing 85a. The posture changing drive source 42 is a rotary actuator, and the rotation of the posture changing drive source 42 is transmitted to the gear mounting shaft 85 by the inner wire 84 (FIG. 19) of the posture changing cable 82.

  The attitude changing cable 82 has the same structure as the tool rotating cable 72, for example, the structure shown in FIG. That is, the flexible inner wire 84 is rotatably supported by the plurality of rolling bearings 86 at the center of the flexible outer tube 83. The both ends of the inner wire 84 are connected to the output shaft 42a and the gear mounting shaft 85 of the posture changing drive source 42, respectively. Between the rolling bearings 86, spring elements 87A and 87B for generating a preload in the rolling bearings 86 are provided. The spring elements 87A and 87B are, for example, compression coil springs. There are an inner ring spring element 87A for generating a preload on the inner ring of the rolling bearing 86 and an outer ring spring element 87B for generating a preload on the outer ring, which are arranged alternately. Thus, the inner wire 84 can be rotated at a high speed by applying a preload to the rolling bearing 86 by the spring elements 87A and 87B.

  As shown in FIG. 16, the controller 5 that controls the tool rotation drive source 41 and the attitude change drive source 42 is connected to the drive source housing 60. The tip member 2 and the spindle guide portion 3 have the same configuration as any one of the above embodiments.

  By providing the tool rotation drive source 41 and the posture changing drive source 42 outside the drive unit housing 4a as in this embodiment, the drive unit housing 4a can be reduced in size. Therefore, it is possible to improve the handleability when operating the remote operation type actuator with the drive unit housing 4a.

DESCRIPTION OF SYMBOLS 1 ... Tool 2 ... Tip member 3 ... Spindle guide part 4a ... Drive part housing 5 ... Controller 13 ... Spindle 15 ... Tip member connection part 22 ... Rotating shaft 25 ... Outer pipe 26, 29 ... Rolling bearing 27A, 27B ... Spring element 30 ... guide pipe 30a ... guide hole 31 ... posture operation member 31a ... posture operation wire 31d ... force transmission member 32 ... restoring elastic member 34 ... reinforcing shaft 36 ... screw mechanism 36a ... male screw portion 36b ... female screw portion 41 ... drive for tool rotation Source 42 ... Posture changing drive source 43 ... Deceleration rotation transmission mechanism 83 ... Drive mechanism section

Claims (15)

An elongated spindle guide portion, a tip member attached to the tip of the spindle guide portion via a tip member connecting portion so that the posture can be freely changed, a tool rotatably provided on the tip member, and a tool for rotating the tool A tool rotation drive source; and a posture change drive source for operating the posture of the tip member;
The tip member rotatably supports a spindle that holds the tool, the spindle guide portion includes a rotation shaft that transmits the rotation of the tool rotation drive source to the spindle, and the rotation shaft in the spindle guide portion. A plurality of rolling bearings that support the outer periphery of the spindle guide portion and guide pipes having inner diameter holes penetrating at both ends as guide holes, and the outer diameter surfaces of the plurality of rolling bearings. A posture operation member that changes a posture of the tip member by advancing and retreating with a part of the guide pipe supported by the guide pipe and having the tip directly or indirectly in contact with the tip member is inserted into the guide hole so as to freely advance and retract. Providing a drive mechanism unit that transmits the operation of the posture changing drive source to the posture operation member;
The drive mechanism has a screw mechanism including a male screw formed at a base end of the posture operation member, and a female screw fixed to a drive housing that houses the drive mechanism and screwed into the male screw. The drive housing is coupled to a proximal end of the spindle guide portion, and the attitude changing drive source is a rotary actuator, and the screw mechanism is rotated by rotating the proximal end of the attitude operating member with the rotary actuator. A remote operation type actuator characterized in that the posture operation member is advanced and retracted by the action of.   The remote operation type actuator according to claim 1, wherein both or one of the tool rotation drive source and the posture change drive source is provided in the drive unit housing.   The remote operation type actuator according to claim 1, wherein the tool rotation drive source and the posture change drive source are provided outside the drive unit housing.   2. The tool rotation drive source and the posture change drive source according to claim 1, wherein either or both of the tool rotation drive source and the posture change drive source are provided outside the drive unit housing, A remote operation type actuator that transmits a driving force of a driving source provided outside the housing to the rotating shaft or the posture operation member by a flexible cable.   5. The remote operation type actuator according to claim 1, wherein the posture operation member is configured to change a posture of the tip member by operating to a side of pressing the tip member. 6.   5. The remote operation type actuator according to claim 1, wherein the posture operation member is configured to change the posture of the tip member by operating to the side of pulling the tip member. 6.   The restoring elasticity according to any one of claims 1 to 6, wherein the guide hole and the posture operation member inserted into the guide hole are provided in only one place, and the tip member is biased toward a predetermined posture. A remote operation type actuator provided with a member, wherein the posture operation member changes the posture of the tip member against an urging force of the elastic member for restoration.   7. The posture change member according to claim 1, wherein the guide hole and the posture operation member inserted into the guide hole are provided at two locations, and the posture change drive source is individually provided for each posture operation member. A remote-operated actuator that is provided on the front end and changes and maintains the posture of the tip member by balancing the acting forces of the two posture operation members on the tip member. 7. The posture operation according to claim 1, wherein the tip member connecting portion supports the tip member so as to be tiltable in an arbitrary direction, and is inserted into the guide hole and the guide hole. Members are provided at three or more positions around the tilt center of the tip member, the posture changing drive source is provided individually for each posture operation member, and the three or more posture operation members to the tip member are provided. A remote control type actuator that changes and maintains the posture of the tip member according to a balance of acting forces.   10. The remote operation type actuator according to claim 1, further comprising a reduction rotation transmission mechanism that decelerates the rotation of the rotary actuator and transmits the rotation to the base end of the posture operation member. 11. The remote control type actuator according to claim 1, wherein the outer shell is an outer pipe .   In Claim 11, the said rotating shaft is arrange | positioned in the center in the said outer pipe, and several reinforcement shafts and the said guide pipe are arranged in the circumferential direction between this rotating shaft and the internal diameter surface of an outer pipe. Remote controlled actuator. 12. The remote control type actuator according to claim 11, wherein outer diameter surfaces of the plurality of rolling bearings are supported by the plurality of reinforcing shafts and the guide pipe. Any one smell of claims 11 to 13 Te, between adjacent meet the rolling bearings, remote controlled actuator having a spring element which gives preload to these rolling bearings.   15. The remote control type actuator according to claim 1, wherein the spindle guide portion has a curved portion.

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