JP5500889B2 - 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 expected that the pipe portion has a curved shape, and it is desired that the posture changing operation can be surely performed even in such a case.

  Note that some medical actuators that do not have an elongated pipe part can change the position of the part where the tool is provided relative to the hand-held part (for example, Patent Document 4), but the position of the tool can be changed remotely. Nothing has been proposed to make it happen.

The purpose of this inventions is the attitude of a tool provided at the distal end of the elongated pipe part can be changed by remote control, yet remote operation is allowed to reliably position change even when the spindle guide section of the pipe portion is curved A mold actuator is provided.

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, inserted retractably flexible attitude altering member to the tip member is posture changes into the guide hole by tip is advanced and retracted in contact with said tip member, wherein the posture control member A forward / backward movement is performed by a posture changing drive source.

  According to this structure, cutting of a bone etc. is performed by rotation of the tool provided in the tip member. In this case, when the posture operation member is moved forward and backward by the posture change drive source, the tip of the posture operation member acts on the tip member, so that the posture can be changed to the tip of the spindle guide portion via the tip member connecting portion. The position of the tip member attached to is changed. The posture changing drive source is provided at a position away from the tip member, and the posture change of the tip member is performed by remote control. 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. In addition, since the posture operation member is flexible, the posture changing operation is reliably performed even when the spindle guide portion is curved.

In the present invention, the tool rotation drive source and / or the posture changing drive source may be provided in a drive unit housing to which a base end of the spindle guide unit is coupled.
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.

The tool rotation drive source and the attitude change drive source may be provided outside the drive unit housing to which the base end of the spindle guide unit is coupled.
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 providing either or both of the tool rotation drive source and the attitude change drive source outside the drive unit housing to which the base end of the spindle guide unit is coupled, the tool rotation drive source and the attitude change It is preferable that the driving force of the driving source provided outside the driving unit housing among the driving source for transmission 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.

In this invention, the flexible posture operation member may be composed of a plurality of force transmission members arranged in a line. The force transmission member can be, for example, a ball or a columnar body.
If the posture operation member is composed of a plurality of force transmission members arranged in a line in the guide hole, each force transmission member can be made flexible as a whole while being rigid.

  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, the tip member connecting portion is a spherical or cylindrical guide surface in which the guide portion on the spindle guide portion side and the guided portion on the tip member side have a center of curvature located on the center line of the spindle. In the case of contact with each other, it is preferable that the center of the connection portion between the spindle and the rotation shaft is at the same position as the center of curvature of the guide surface.
If the center of the connection point between the spindle and the rotating shaft is at the same position as the center of curvature of the guide surface, the tip member can be changed in posture smoothly because no force is applied to the rotating shaft by changing the posture of the tip member. .

In the present invention, an operation amount detector for detecting an operation amount of the attitude changing drive source may be provided, and an attitude detection means for detecting the attitude of the tip member from a detection value of the operation amount detector may be provided.
According to this configuration, appropriate tip member posture control can be performed based on the detection result of the posture detection means.

When the posture changing drive source is an electric actuator, it is preferable to provide load detecting means for measuring the power supplied to the electric actuator and detecting the load acting on the tip member.
According to this configuration, by controlling the feed amount of the entire remote-operated actuator and the posture change of the tip member based on the detection result of the load detection means, the load on the tip member can be maintained appropriately while maintaining the load on the bone. Cutting can be performed.

In the present invention, the posture changing drive source may be a linear actuator. In this case, a force transmission mechanism including a lever mechanism that increases the output of the linear actuator and transmits the output to the posture operation member may be provided.
When the boost transmission mechanism is provided, it is possible to apply a large force to the posture operation member even with a linear actuator with a small output, and thus it is possible to reduce the size of the linear actuator.

In this invention, the outline of the spindle guide portion may be an outline 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 configuration, when a plurality of rolling bearings that rotatably support the rotating shaft in the spindle guide portion are provided, the outer diameter surfaces of the plurality of rolling bearings are supported by the plurality of reinforcing shafts and the guide pipe. can do.
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 case of providing a bearing that rotatably supports the rotating shaft in the spindle guide portion, a cooling unit that cools the bearing with a coolant that passes through the inside of the outer pipe may be provided.
Rotating members such as a spindle and a rotating shaft that rotate the tool generate heat due to rotational friction. Along with this, the bearing is heated. If a cooling means is provided, a bearing and the said heat_generation | fever location can be cooled with a cooling fluid. If the coolant is allowed to pass through the outer pipe, there is no need to provide a separate coolant supply pipe, and the spindle guide portion can be simplified and reduced in diameter.
Furthermore, the effect of lubricating the bearing with the coolant is also obtained. If the coolant is also used for the lubrication of the bearing, it is not necessary to use grease or the like generally used for the bearing, and it is not necessary to provide a separate lubricating device.

The cooling liquid passing through the interior of the outer Guo, or by cooling liquid supplied from the outside may be provided with a cooling means for cooling the tool.
At the time of processing, the tool and the work piece generate heat. If the cooling means is provided, the tool and the workpiece can be cooled by the coolant.

The coolant is preferably water or physiological saline.
When the cooling liquid is water or physiological saline, the cooling liquid does not adversely affect the living body when the tip member is inserted into the living body for processing.

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.

  The remote control type actuator according to the present invention is for medical use, for example, and is suitable for a case where all or a part of the tip member is inserted into a patient's body at the time of treatment. Specifically, the tool is suitable for a tool that cuts bone. More specifically, it is suitable for the one used for cutting the medullary cavity of bone in artificial joint replacement surgery.

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 includes a rotation shaft that transmits the rotation of the tool rotation drive source to the spindle, a plurality of rolling bearings that rotatably support the rotation shaft in the spindle guide portion, and an inner diameter that penetrates both ends. a guide pipe hole serves as a guide hole having the inside of the outer shell of the spindle guide part, said part of the outer surface of the plurality of rolling bearings Gaidopa Supported by flop, inserted retractably flexible attitude altering member to the tip member is posture changes into the guide hole by tip is advanced and retracted in contact with said tip member, wherein the posture control member Because the posture change drive source is used to move forward and backward, the posture of the tool provided at the tip of the elongated spindle guide can be remotely controlled, and the posture can be changed reliably even when the spindle guide is curved. Be made.

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 tip member and a spindle guide portion of the remote operation type actuator, (B) is a sectional view taken along the line IIB-IIB, and (C) is a diagram showing a connection structure between the tip member and a rotating shaft. (A) is the figure which combined and displayed the control system in the front view of the tool rotation drive mechanism and attitude | position change drive mechanism of the remote operation type | mold actuator, (B) is the IIIB-IIIB sectional drawing. 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 concerning different embodiment of this invention, (B) is the VB-VB 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 VIB-VIB 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 VIIB-VIIB sectional drawing. FIG. 8 is a cutaway side view of a tool rotation drive mechanism and a posture change drive mechanism of the remote operation type actuator shown in FIGS. 6 and 7. 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 rotary shaft 22 via a rolling bearing 29 at the distal end inner peripheral portion thereof. The pipe end portion 25a may be a separate member from the outer pipe 25 and may be joined by welding or the like.

  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 a plurality of force transmission members are provided in the guide hole 30a which is the inner diameter hole of the guide pipe 30. The posture operation member 31 composed of the ball 31a and the columnar pins 31b at both ends is inserted in such a manner as to freely advance and retract. The balls 31a and the columnar pins 31b are arranged in a line along the length direction of the guide holes 30a and are arranged without gaps. The distal end of the columnar pin 31 b on the distal end member 2 side is spherical and is in contact with the proximal end surface of the distal end member housing 11. The tip of the columnar pin 31b on the drive unit housing 4a side is also spherical, and is in contact with the side surface of the lever 43b (FIG. 3) described later.

  For example, compression is provided 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 made of a coil spring 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.

  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 linear actuator, and the movement of the output rod 42 a that moves in the left-right direction in FIG. 3A is transmitted to the posture operating member 31 through the force transmission mechanism 43. The boost transmission mechanism 43 has a lever 43b that is rotatable around a support shaft 43a. The force of the output rod 42a acts on an action point P1 of the lever 43b that is long from the support shaft 43a. The force is applied to the posture operation member 31 at the force point P <b> 2 having a short distance, and the output of the posture changing drive source 42 is increased and transmitted to the posture operation member 31. If the boost transmission mechanism 43 is provided, a large force can be applied to the posture operation member 31 even with a linear actuator having a small output, and thus the linear actuator can be downsized. The rotating shaft 22 penetrates the opening 44 formed in the lever 43b. Instead of providing the posture changing drive source 42 and the like, the posture of the tip member 2 may be remotely operated manually.

  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.

  The posture changing drive mechanism 4c is provided with a wattmeter 47 that detects the amount of power supplied to the posture changing drive source 42, which is an electric actuator. The detected value of the supplied wattmeter 47 is output to the load detecting means 48. 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 detected values in 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, the posture operation member 31 includes a plurality of balls 31a and columnar pins 31b, and has a flexible property as a whole. Therefore, even when the spindle guide portion 3 is curved, 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.

  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. 4 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 locations such as the tool 1, the workpiece, the spindle 13, the rotary shaft 22, and the bearings 26 and 29 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.

  FIG. 5 shows a different embodiment. This remote control type actuator is provided with two guide pipes 30 at circumferential positions in the outer pipe 25 that are 180 degrees in phase with each other, and in the guide hole 30a that is the inner diameter hole of the guide pipe 30, the same attitude as described above. The operating member 31 is inserted so as to freely advance and retract. 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. 5 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 in which 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. 5A. 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. 6 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 (42U, 42L, 42R) (FIG. 8) for individually moving the three posture operation members 31 (31U, 31L, 31R) forward and backward. The attitude of the tip member 2 is changed by driving these three attitude changing drive sources 42 in conjunction with each other.
For example, when the upper one posture operation member 31U in FIG. 6 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 pushed, 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.

  FIG. 7 shows a further different embodiment. In this remote operation type actuator, the force transmission member of the posture operation member 31 is a columnar body 31c such as a cylinder. The plurality of columnar bodies 31c and the columnar pins 31b at both ends are arranged without gaps along the length direction of the guide hole 30a. In this embodiment, the posture operation member 31 is provided at three circumferential positions at a phase of 120 degrees, but the posture operation member 31 is at two circumferential positions at a phase of 180 degrees. The present invention can also be applied to a configuration in which the posture operation member 31 provided at one place in the circumferential direction and the corresponding elastic member 32 for restoration are combined.

  Even when the force transmission member is the columnar body 31c, the posture operating member 31 is advanced and retracted by driving the posture changing drive source 42 as in the case of the ball 31a, and acts on the tip member 2. Effect. Even if the force transmission member is the columnar body 31c, 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. Moreover, even when the spindle guide portion 3 is flexible and curved, the posture changing operation of the tip member 2 is reliably performed. When the force transmission member is the columnar body 31c, there is an advantage that the rigidity of the spindle guide portion 3 can be increased as compared with the case of the ball 31a. You may comprise the attitude | position operation member 31 using both the columnar body 31c and the ball | bowl 31a.

  When the posture operation member 31 is provided in three places in the circumferential direction as shown in FIGS. 6 and 7, the posture change drive mechanism 4c can be configured as shown in FIG. 8, for example. That is, three posture change drive sources 42 (42U, 42L, 42R) for individually moving the posture operation members 31 (31U, 31L, 31R) forward and backward are arranged in parallel on the left and right sides, and each posture change drive source is provided. A lever 43b (43bU, 43bL, 43bR) corresponding to 42 is provided so as to be rotatable around a common support shaft 43a, and each lever 43b has a long distance from the support shaft 43a at an action point P1 (P1U, P1L, P1R). The force of the output rod 42a (42aU, 42aL, 42aR) of each posture changing drive source 42 is applied, and a force is applied to the posture operating member 31 at a force point P2 (P2U, P2L, P2R) having a short distance from the support shaft 43a. As a configuration. Thereby, the output of each posture change drive source 42 can be increased and transmitted to the corresponding posture operation member 31. The rotary shaft 22 passes through an opening 44 formed in the lever 43bU for the upper posture operation member 31U.

  In each of the above embodiments, the spindle guide portion 3 has a linear shape. However, in the remote control type actuator of the present invention, the posture operation member 31 is flexible, and the posture of the tip member 2 is maintained even when the spindle guide portion 3 is curved. Since the changing operation is performed reliably, the spindle guide portion 3 may be curved in the initial state 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. The posture operation member 31 may be composed of a plurality of columnar bodies curved in accordance with the curved shape of the guide pipe 30 in addition to the plurality of balls. In that case, it is preferable that the curved columnar body has a short length and a shape in which corners are dropped by chamfering or the like.

  FIGS. 10-13 shows embodiment from which the structure of the drive mechanism for a tool rotation and the drive mechanism for attitude | position change differs. In the 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. 13, the tool rotation drive source 41 and the attitude change drive source 42 are provided in a drive source housing 60 different from the drive unit housing 4a.

  In the tool rotation drive mechanism 61 of this embodiment, the rotation of the output shaft 41a of the tool rotation drive source 41 provided in the drive source housing 60 is driven by the inner wire 64 (FIG. 12) of the tool rotation cable 62. It transmits to the base end of the rotating shaft 22 in 4a. The tool rotation cable 62 has a structure shown in FIG. 12, for example. That is, a flexible inner wire 64 is rotatably supported by a plurality of rolling bearings 66 at the center of the flexible outer tube 63. Both ends of the inner wire 64 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 66, spring elements 67A and 67B for generating a preload on the rolling bearings 66 are provided. The spring elements 67A and 67B are, for example, compression coil springs. There are an inner ring spring element 67A for generating a preload on the inner ring of the rolling bearing 66 and an outer ring spring element 67B for generating a preload on the outer ring, which are arranged alternately. Thus, the inner wire 64 can be rotated at a high speed by applying a preload to the rolling bearing 66 by the spring elements 67A and 67B. A commercially available flexible shaft may be used.

  Further, the posture changing drive mechanism 71 of this embodiment moves the operation of the posture changing drive source 42 provided in the drive source housing 60 to the drive mechanism portion 73 in the drive unit housing 4a via the posture changing cable 72. introduce. The drive mechanism unit 73 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 rod 42a of the posture change drive source 42 in the posture change drive mechanism 4c. Further, an advancing / retreating member 75 is provided that advances and retreats with respect to the drive unit housing 4a in a state where the tip is in contact with the lever 43b. The advance / retreat member 75 is moved forward and backward with respect to the drive unit housing 4a by converting a rotational motion into a straight motion by a screw mechanism 75a such as a ball screw. In this case, the posture changing drive source 42 is a rotary actuator, and the rotation of the posture changing drive source 42 is transmitted to the advance / retreat member 75 by the inner wire 74 (FIG. 13) of the posture changing cable 72.

  The posture changing cable 72 has the same structure as the tool rotating cable 62, and has the structure shown in FIG. 13, 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 42a and the advance / retreat member 75 of the attitude changing drive source 42, 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.

  As shown in FIG. 10, the controller 5 that controls the tool rotation drive source 41 and the posture 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.

  The medical remote control actuator has been described above, but the present invention can be applied to remote control actuators for other purposes. For example, in the case of machining, drilling of a curved hole or cutting of a deep part inside the groove is possible.

DESCRIPTION OF SYMBOLS 1 ... Tool 2 ... Tip member 3 ... Spindle guide part 4a ... Drive part housing 5 ... Controller 11a ... Guided part 13 ... Spindle 15 ... Tip member connection part 21a ... Guide part 22 ... Rotating shaft 25 ... Outer pipe 26, 29 ... Rolling bearings 27A, 27B ... Spring element 30 ... Guide pipe 30a ... Guide hole 31 ... Posture operation member 31a ... Ball (force transmission member)
31c ... Columnar body (force transmission member)
32 ... Restoring elastic member 34 ... Reinforcement shaft 41 ... Tool rotation drive source 42 ... Posture change drive source 43 ... Boosting transmission mechanism 45 ... Operation amount detector 46 ... Posture detection means 47 ... Supply wattmeter 48 ... Load detection means 50 ... cooling means F1, F2 ... guide surface

Claims (25)

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 flexible posture operating member that supports a part of the guide pipe and changes the posture of the tip member by advancing and retracting with the tip contacting the tip member is inserted into the guide hole so as to freely advance and retract. A remote operation type actuator, wherein a posture operation member is moved forward and backward by the posture change drive source.   2. 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 a drive unit housing to which a base end of the spindle guide unit is coupled.   2. The remote operation type actuator according to claim 1, wherein the tool rotation drive source and the posture change drive source are provided outside a drive unit housing to which a base end of the spindle guide unit is coupled.   2. The tool rotation drive source according to claim 1, wherein both or one of the tool rotation drive source and the posture change drive source is provided outside a drive unit housing to which a proximal end of the spindle guide unit is coupled. And a remotely operated actuator that transmits a driving force of a driving source provided outside the driving unit housing among the posture changing driving sources to the rotating shaft or the posture operating member by a flexible cable.   5. The remote operation type actuator according to claim 1, wherein the flexible posture operation member includes a plurality of force transmission members arranged in a line. 6.   6. The restoring elasticity according to claim 1, wherein the guide hole and the posture operation member inserted into the guide hole are provided at only one place, and the tip member is biased toward the predetermined posture side. 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.   6. The guide hole and the posture operation member inserted into the guide hole are provided at two locations according to claim 1, 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.   The posture according to any one of claims 1 to 5, 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. Operation members are provided at three or more positions around the tilt center of the tip member, and the posture changing drive source is provided individually for each posture operation member, to the tip member of the three or more posture operation members. A remote-operated actuator that changes and maintains the posture of the tip member by balancing the acting forces.   8. The tip member coupling portion according to claim 6, wherein the guide portion on the spindle guide portion side and the guided portion on the tip member side have a spherical shape in which the center of curvature is located on the center line of the spindle or A remote-operated actuator that is in contact with a cylindrical guide surface, and that the center of the connection point between the spindle and the rotation is at the same position as the center of curvature of the guide surface.   9. The tip member connecting portion according to claim 8, wherein the guide portion on the spindle guide portion side and the guided portion on the tip member side are in contact with a spherical guide surface whose center of curvature is located on the center line of the spindle. The remote control type actuator, wherein the center of the connecting portion between the spindle and the rotating shaft is at the same position as the center of curvature of the guide surface.   11. The operation amount detector for detecting an operation amount of the posture changing drive source is provided according to claim 1, and the posture of the tip member is detected from a detection value of the operation amount detector. Remote control type actuator provided with attitude detection means.   12. The load detection unit according to claim 1, wherein the posture changing drive source is an electric actuator, and a load acting on the tip member is detected by measuring power supplied to the electric actuator. Remote operation type actuator provided with   13. The remote control type actuator according to claim 1, wherein the posture changing drive source is a linear actuator.   14. The remote operation type actuator according to claim 13, further comprising a force transmission mechanism including a lever mechanism that increases an output of the linear actuator and transmits the output to the posture operation member. 15. The remote control type actuator according to claim 1 , wherein the outline of the spindle guide portion is an outline pipe .   16. The rotary shaft according to claim 15, wherein the rotary shaft is arranged at the center of the outer pipe, and a plurality of reinforcing shafts and the guide pipe are arranged in a circumferential direction between the rotary shaft and the inner diameter surface of the outer pipe. Remote controlled actuator. The remote operation type actuator according to claim 16, 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 claim 15 through claim 17 Te, between adjacent meet the rolling bearings, remote controlled actuator having a spring element which gives preload to these rolling bearings.   19. The remote control type actuator according to claim 17, further comprising a cooling unit that cools the bearing with a coolant that passes through the inside of the outer pipe. In any one of claims 1 to 19, the remote controlled actuator which cooling means is provided for cooling the tool by the cooling fluid, or coolant supplied from outside passes through the inside of the outer Guo.   21. The remotely operated actuator according to claim 19 or 20, wherein the cooling liquid is water or physiological saline.   The remote control type actuator according to any one of claims 1 to 21, wherein the spindle guide portion has a curved portion.   23. The medical remote-control actuator according to claim 1, wherein all or part of the distal end member is inserted into a patient's body during a treatment.   24. The medical remote-control actuator according to claim 1, wherein the tool is a tool for cutting bone.   25. The medical teleoperated actuator according to claim 24, which is used for shaving the medullary cavity of bone in artificial joint replacement surgery.

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