JP3792587B2 - Surgical manipulator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a surgical manipulator, and is particularly suitable for a surgical manipulator corresponding to an MRI (magnetic resonance imager) environment.
[0002]
[Prior art]
As described in Japanese Patent Application Laid-Open No. 2000-254876, a surgical manipulator corresponding to a conventional MRI environment has a low space occupancy rate in the work environment of the manipulator, and transmits a driving force to the end effector of the manipulator from a distance An arm mechanism and an end effector to enable sterilization of the manipulator, reduce noise to the medical device, and to enable the surgical manipulator to be usable even in an MRI environment A manipulator having a position / posture transmission mechanism for transmitting to the manipulator between the arm mechanism and an end effector, wherein the position / posture transmission mechanism is fixed to a link mechanism and a second link fixed to the end effector. Link machine capable of 6-DOF position and orientation transmission with other links In connecting, lever - there is that the parallel link type pose transmission mechanism.
[0003]
[Problems to be solved by the invention]
However, the above-described parallel link mechanism in the prior art has a problem that the movable range of the position / posture in working coordinates is narrow. In other words, safety and workability are in a trade-off relationship when working with a surgical manipulator in a limited confined space such as the inside of an MRI. However, there is a problem that it is difficult to cope with such a surgical operation with the above-described conventional mechanism.
[0004]
Furthermore, in order to realize a surgical manipulator that operates with little MRI magnetic field and electromagnetic waves and operates safely, it is preferable that the material of at least the portion that goes into the imaging region and is not magnetic is an insulator. For this reason, although not described in the above-described prior art, it is conceivable that the material of the link member that enters the inside of the MRI is, for example, engineering plastic or engineering ceramic, but the link member is insufficient due to insufficient strength and rigidity. There is a possibility that it will bend in the middle or vibrate with a large amplitude during operation, which causes a problem that it is difficult to accurately control the position and orientation of the tip.
[0005]
In addition, if the base part of the surgical manipulator moves due to an accident such as a collision with staff or other equipment or devices, or an earthquake, the surgical manipulator with a long link member will move within a large range. There is a problem that it may be
[0006]
In addition, the necessary and sufficient movable ranges for various subjects / cases / procedures are different from each other. However, with conventional general surgical manipulators, this is limited in terms of control, and mechanical operation limitations are limited. Since this is not done, there is a problem that it is difficult to essentially prevent movement outside the operating range. For example, if there is a risk that the operation manipulator will move unnecessarily large when working in a small range, if the mechanism is configured to operate only in a small range, It could not be applied to work that requires a larger operating range. Therefore, it has been difficult to use the same surgical manipulator for various subjects, cases, and procedures while ensuring safety.
[0007]
An object of the present invention is to provide a surgical manipulator capable of achieving both workability and safety in the MRI.
[0008]
Other objects and advantages of the present invention will become apparent from the following description.
[0009]
[Means for Solving the Problems]
To achieve the above object, the surgical manipulator of the present invention controls the posture by being arranged at the MRI imaging region side tip of the arm unit provided to extend from the outside of the MRI to the imaging region. A posture control mechanism unit that is disposed outside the MRI of the arm unit, and a posture control mechanism drive unit that drives the posture control mechanism unit via a transmission mechanism, and is disposed outside the MRI of the arm unit. In addition, a position control drive mechanism that controls and drives the position of the arm portion outside the MRI, a drive coupling portion that couples the arm portion and the position control drive mechanism, and a fulcrum of the arm portion An intermediate support part for supporting the intermediate part; An intermediate support fixing member for fixing the intermediate support portion to the outside, The intermediate support part supports an intermediate part of the arm part located in the MRI space. The fixing position of the intermediate support part and the intermediate support fixing member can be changed at a plurality of positions in the longitudinal direction of the arm part. There is.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[0011]
The overall configuration of the surgical manipulator of this embodiment will be described with reference to FIG. FIG. 1 is a block diagram of a surgical manipulator showing an embodiment of the present invention.
[0012]
In FIG. 1, 1 is a posture control mechanism drive unit composed of a tip joint drive unit, 2 is a position control drive mechanism unit composed of an arm root drive unit, and 3 is a drive coupling unit composed of an arm root support unit, 4 is an arm part, 5 is an intermediate support part, 6 is a posture control mechanism part composed of a tip joint part, 7 is an intermediate support fixing member, 8 is a driving part fixing base, 9 is an open type MRI, and 9a is an MRI 9 part. An upper magnet, 9b is a lower magnet of the MRI 9, 11 is a patient lying base, 12 is a patient, and 13 is an intermediate support attachment.
[0013]
The surgical manipulator in the present embodiment includes an attitude control mechanism drive unit 4, a position control drive mechanism unit 2, a drive coupling unit 3, an arm unit 1, an intermediate support unit 5, and an attitude control mechanism unit 6. In addition, the MRI 9 in the present embodiment includes an upper magnet 9a, a lower magnet 9b, and a patient lying base 11. Then, the patient lying table 11 is translated after laying the patient outside the MRI, the patient is guided between the upper magnet 9a and the lower magnet 9b of the MRI 9, and the affected area to be operated is roughly positioned to the imaging center.
[0014]
The arm unit 1 is provided so as to extend from the outside of the MRI 9 to the imaging region. The posture control mechanism unit 6 is provided on the MRI imaging region side of the arm unit 1 so as to control the posture. The posture control mechanism drive unit 4 is disposed outside the MRI of the arm unit 1 and is provided so as to drive the posture control mechanism unit 6 via a transmission mechanism. The position control drive mechanism unit 2 is arranged on the MRI outside side of the arm unit 1 and is provided so as to control and drive the position on the MRI outside side. The drive coupling unit 3 is provided so as to couple the arm unit 1 and the position control drive mechanism unit 2. The intermediate support part 5 is provided so as to support the intermediate part of the arm part 1 as a fulcrum of the arm part 1 and to support the intermediate part of the arm part located in the MRI imaging region. The attitude control mechanism drive unit 4 and the position control drive mechanism unit 2 are configured by independent drive mechanisms.
[0015]
The intermediate support portion 5 has its fixing plate 51 fixed to the intermediate support fixing member 7 via the intermediate support mounting portion 13. The intermediate support fixing member 7 is fixed to the upper magnet 9a. The fixing portion 7 is provided with a plurality of portions for fixing the intermediate support portion 5 in the longitudinal direction of the arm portion 1. By changing the position of the fixing portion and fixing the intermediate support portion 5, an approximate movable range at the distal end portion of the arm portion 1 can be defined in relation to the installation position of the drive portion fixing base 8. . Therefore, the safety can be further improved by changing the fixing position of the intermediate support portion 5 so as to set an appropriate movable range in accordance with the type of surgery.
[0016]
Since the surgical manipulator is placed in the magnetic field of the MRI 9, its constituent materials and parts are selected so as not to interfere with the imaging of the MRI apparatus.
[0017]
That is, as the mechanical material of the surgical manipulator, polyether ether ketone, FRP, various machinable ceramics / engineering ceramics (excluding those mixed with conductive material fibers such as alumina or CFRP) are used. . In particular, the bearing is a ceramic bearing, and the screws and bolts are made of polyetheretherketone. In addition, about the base part comparatively far from a magnetic field, aluminum alloy and brass are used partially.
[0018]
In addition, an actuator is provided in a joint part of a surgical manipulator, and a force necessary for a therapeutic operation is generated by these. These actuators are so-called piezoelectric actuators utilizing an electrostrictive effect in ceramics such as PZT and applications thereof. An ultrasonic motor is used. Non-magnetic materials such as ceramic bearings and brass / aluminum alloys are also used as the structural material for ultrasonic motors. The displacement of each joint is guided by an optical fiber, and light modulated or transmitted by the encoder board (for example, the number of rectangular waves according to the rotation of the encoder board) or transmitted or reflected light is again transmitted by the optical fiber. It guides out of the magnetic field of an MRI apparatus, converts it there into an electrical signal, and then uses it to detect the position of each joint.
[0019]
Next, details of each element constituting the surgical manipulator will be sequentially described.
[0020]
First, the position control drive mechanism 2 will be described with reference to FIG. FIG. 2 is a perspective view of the position control drive mechanism in the surgical manipulator of FIG.
[0021]
In FIG. 2, 21 is an X-axis direction base plate, 22a to 22c are X, Y, and Z axis direction actuators, 23a to 23c are X, Y, and Z axis direction driving ball screws, and 24a to 24c are X, Y, and Z axes. Direction linear guides, 25a to 25c are X, Y and Z axis direction linear encoders, 26 is an X axis direction moving plate, 27 is a Y axis direction moving plate, 28 is a Z axis direction fixed plate, 29 is a Z axis direction moving plate, Reference numeral 29a denotes a drive coupling portion mounting hole. The X, Y, and Z-axis direction linear guides 24a to 24c are composed of two guides arranged in parallel. The X-axis direction moving plate 26 also serves as a Y-axis direction base plate. The Y-axis direction moving plate 27 also serves as a Z-axis direction base plate.
[0022]
The X-axis direction base plate 21 is fixed to the drive unit fixing base 8. The base plate 21 is connected to the X-axis direction moving plate 26 through a linear guide 24a. The X-axis direction linear guide 24 a is configured such that an X-axis direction rail fixed to the X-axis direction base plate 21 and an X-axis direction rail fixed to the X-axis direction moving plate 26 are slidably coupled. It is configured and two of them are provided in parallel. The operation of the X-axis direction moving plate 26 is restricted in one direction (X-axis direction) by the X-axis direction linear guide 24a. The X-axis direction actuator 22a fixed to the X-axis direction base plate 21 generates a rotational driving force to rotate the X-axis direction driving ball screw 23a. Since the X-axis direction driving ball screw 23 a is screwed to the X-axis direction moving plate 26, the rotational force of the X-axis direction driving ball screw 23 a is converted into a linear propulsive force with respect to the X-axis direction moving plate 26. As a result, the X-axis direction moving plate 26 is moved in the X-axis direction.
[0023]
The linear movement amount of the X-axis direction moving plate 26 is detected by the X-axis direction linear encoder 25a and sent to a built-in control system (not shown). The control system drives the actuator 22a to move the X-axis direction moving plate 26 to the target position based on the detected movement amount. Regarding the input of the target position, for example, the operator operates the multi-joint multi-degree-of-freedom mechanism, detects and processes the movement, and sets the target value, or uses a general computer input / output interface. Can be considered. Also, depending on the situation, the control computer may generate a target position based on the measurement data of the MRI 9 and other diagnostic apparatuses and the spatial position and orientation measurement apparatus using light, and may operate according to the target position.
[0024]
The Y-axis direction moving plate 27 is connected to the X-axis direction moving plate 26 via a Y-axis direction linear guide 24b. The Y-axis direction linear guide 24b is configured such that a rail extending in the Y-axis direction fixed to the X-axis direction moving plate 26 and a rail extending in the Y-axis direction fixed to the Y-axis direction moving plate 27 are slidably coupled. It is configured and two of them are provided in parallel. Thus, the operation of the Y-axis direction moving plate 27 is restricted in one direction (Y-axis direction). The Y-axis direction actuator 22b fixed to the X-axis direction moving plate 26 generates a rotational driving force to rotate the Y-axis direction driving ball screw 23b. Since the Y-axis direction driving ball screw 23 b is screwed to the Y-axis direction moving plate 27, the rotational force of the Y-direction driving ball screw 23 b is converted into a linear propulsive force with respect to the Y-axis direction moving plate 27. As a result, the Y-axis direction moving plate 27 is moved in the Y-axis direction.
[0025]
The linear movement amount of the Y-axis direction moving plate 27 is detected by the Y-axis direction linear encoder 25b and sent to the control system. Based on the detected movement amount, the control system drives the actuator 22b to move the Y-axis direction moving plate 27 to the target position. The control system for driving the actuator 22b may be the same as or different from the control system for the X-axis direction actuator 22a.
[0026]
The Z-axis direction fixed plate 28 and the Z-axis direction moving plate 29 are connected via a Z-axis direction linear guide 24c. The movement of the Z-axis direction moving plate 29 is restricted only in one vertical direction. The Z-axis direction fixed plate 28 is fixed to the Y-axis direction moving plate 27 and is erected vertically on the upper surface of the Y-axis direction moving plate 27. The Z-axis linear guide 24c is configured by a slidably coupled rail extending in the Z-axis direction fixed to the Z-axis direction fixed plate 28 and a rail extending in the Z-axis direction fixed to the Z-axis direction moving plate 29. At the same time, these two are formed in parallel. Thereby, the operation of the Z-axis direction moving plate 29 is restricted in one direction (Z-axis direction). The Z-axis direction actuator 22c fixed to the Y-axis direction moving plate 27 generates a rotational driving force to rotate the Z-axis direction driving ball screw 23c. Since the Z-axis direction driving ball screw 23 c is screwed to the Z-axis direction moving plate 29, the rotational force of the Z-axis direction driving ball screw 23 c is converted into a linear propulsive force with respect to the Z-axis direction moving plate 29. As a result, the Z-axis direction moving plate 29 is moved in the Z-axis direction.
[0027]
The linear movement amount of the Z-axis direction moving plate 29 is detected by the Z-axis direction linear encoder 25c and sent to the control system. The control system drives the Z-axis direction actuator 22c so as to move the Z-axis direction moving plate 29 to the target position based on the detected movement amount. The control system for driving the Z-axis direction actuator 22c may be the same as or different from the control system for the X-axis direction actuator 22a and the Y-axis direction actuator 22b.
[0028]
Two attachment holes 29 a for attaching the drive coupling portion 3 are formed in the upper part of the Z-axis direction moving plate 29. A screw or a protrusion is inserted into the mounting hole 29a from the drive coupling portion 3 to restrain relative movement between the Z-axis direction moving plate 29 and the drive coupling portion 3.
[0029]
Each plate 21, 26, 27, 28, 29 is made of either a non-magnetic metal duralumin made of a high strength grade material or an engineering plastic such as a polyether ether ketone high strength grade. I have to. However, in the case where the position control drive mechanism unit 2 is disposed far from the imaging center of the MRI 9 and in the vicinity of the boundary of the magnetic field strength called the so-called 5 gauss line, it has been described above in consideration of trade-offs with workability and price. The grade may be lowered.
[0030]
Each of the actuators 22a to 22c is an ultrasonic motor that does not generate electromagnetic force. The casings of the actuators 22a to 22c are made nonmagnetic by using materials such as duralumin for the shaft, brass for the shaft, and ceramic for the bearing. In addition, beryllium copper is used for each of the ball screws 23a to 23c in consideration of strength and low magnetism (magnetic susceptibility).
[0031]
The linear guides 24a to 24c include rails and blocks made of beryllium copper, screws made of titanium or brass, balls made of ceramic, and end plates made of resin. Titanium and brass are low magnetic susceptibility materials like beryllium copper, and other materials are non-magnetic and insulators.
[0032]
The linear encoders 25a to 25c guide the incident light through the optical fiber from the point where the magnetic field and high frequency of the MRI 9 do not affect, and return the transmitted or reflected light to the point again through the optical fiber, using a phototransistor or the like. An encoder signal is generated by a photoelectric conversion circuit. In this embodiment, the linear encoders 25a to 25c are illustrated. However, a rotating optical fiber encoder that detects the rotation of a motor or a ball screw is used, or a medium that does not interfere with a magnetic field or high frequency generated by the MRI 9, such as light, infrared rays, and sound waves. Position measurement may be performed using a position measurement device that uses the.
[0033]
Next, the drive coupling part 3 is demonstrated based on FIG. FIG. 3 is a perspective view of a drive coupling portion in the surgical manipulator of FIG.
[0034]
In FIG. 3, 31 is a fixed plate, 32 is a vertical rotating frame, 33 is a vertical rotating shaft, 34 is a vertical rotating shaft stop, 35 is a front and rear rotating shaft, 36 is a front and rear rotating block, 37 is a sliding material for arm twist rotation, Reference numeral 38 denotes an arm twist rotation driving gear, 39 an arm twist rotation amount detection encoder, and 30 an arm twist rotation actuator.
[0035]
The fixed plate 31 is fixed to the Z-axis direction moving plate 29 using an attachment hole 29a (see FIG. 2). The vertical rotation frame 32 is fitted at the bottom to a vertical rotation shaft 33 protruding upward from the fixed plate 31 and freely rotates about the vertical rotation shaft 33 as a rotation center. There is no actuator that directly drives the vertical rotation shaft 33. The front / rear rotation block 36 is fitted with front / rear rotation shafts 35 projecting inwardly from both side surfaces of the frame 32, and freely rotates about the front / rear rotation shaft 35. The arm twist rotating sliding member 37 is installed so as to form a through hole in the central portion of the front / rear rotating block 36, and the arm portion 1 is passed through the hole. Since the outer wall of the arm portion 1 and the inner wall of the arm twist rotation sliding member 37 slide smoothly, the arm can be easily twisted and rotated.
[0036]
The above-mentioned rotation axes in the three directions of vertical, front-back, and twisting are configured to intersect at one point, thereby forming a gimbal structure. As a result, the vertical / front / rear free rotation is generated by driving the X, Y, and Z axes and constraining the middle of the arm portion 1 with a similar gimbal structure. However, the torsional rotation is driven by the actuator 30 without interfering with them.
[0037]
An arm twist rotation actuator 30 and an arm twist rotation amount detection encoder 39 are attached to the upper part of the front / rear rotation block 36. The output of the actuator 30 is transmitted via the arm twisting rotation driving gear 38. The rotation amount of the arm is detected by the encoder 39.
[0038]
A high-strength engineering plastic such as polyether ether ketone is used as the material of each element of the drive coupling portion 3. In particular, since the arm twist rotating sliding member 37 has a sliding portion, a material having a high sliding grade (high sliding resistance) is selected. Since the drive coupling portion 3 is far from the imaging center, it is possible to partially use a non-magnetic metal, but it is more preferable to use engineering plastic or engineering ceramic. As the actuator 30, an ultrasonic motor adapted to be non-magnetic is used in the same manner as the actuators 22 a to 22 c described above. An optical fiber light guide type encoder 39 is used to prevent interference of the MRI 9 magnetic field and noise due to the excitation high frequency and interference with the RF signal.
[0039]
Next, the attitude control mechanism driving unit 4 will be described with reference to FIG. FIG. 4 is an explanatory diagram of a posture control mechanism driving unit in the surgical manipulator of FIG. 4A is a plan view and FIG. 4B is a side view.
[0040]
In FIG. 4, 41 is a composite cylinder, 42a to 42d are actuators for rotating the composite cylinder 41, 43 is a power transmission wire, 44 is a displacement transmission wire to the encoder, 45 is a displacement transmission pulley, and 46 is a composite cylinder 41. , 47a to 47b are tension pulleys of the power transmission wire 43, 48 is a composite cylindrical rotating slide, and 49 is a housing. The composite cylinder 41 serves as both a driving cylinder and a displacement transmitting cylinder.
[0041]
Two of these are configured in a box shape, and the attitude control mechanism 6 is controlled and driven by transmitting the power of two systems to the tip by the wire 43.
[0042]
The composite cylinder 41 has a shape in which cylinders having different diameters are stacked, and is rotated by pressing the outer periphery of the lowermost cylinder with a plurality of actuators 42a to 42d. The actuators 42a to 42d have a projecting contact portion, and this contact portion draws an ellipse in the long side plane. When these contact portions are brought into contact with the composite cylinder 41, these contact portions are in phase and push the outer peripheral portion of the composite cylinder 41 in the circumferential direction, and the composite cylinder 41 rotates. The middle cylinder serves as a power transmission pulley. A power transmission wire 43 is wound around the middle cylinder, and the wire 43 passes through the inside of the arm portion 1 to the posture control mechanism portion 6 in a state where tension for preventing slackening is applied by tension pulleys 47a to 47b. Has reached. A displacement transmission wire 44 to the encoder 46 is wound around the uppermost cylinder of the composite cylinder 41. The wire 44 is also wound around a displacement transmission pulley 45, and the pulley 45 rotates the encoder 46 so as to detect the rotational displacement of the composite cylinder 41. For smooth rotation between the housing 49 and the composite cylinder 41, a composite cylinder rotating slide 48 is sandwiched. A bearing made of a non-magnetic material (for example, ceramic) may be used instead of the sliding body 48.
[0043]
The material of the housing 49 is preferably an engineering plastic, but it is non-magnetic (generally considered to have a low magnetic susceptibility) metal such as duralumin in consideration of trade-offs such as the distance from the imaging center and strength / workability. May be used. Engineering plastic is used for the composite cylinder 41, the displacement transmission pulley 45, and the tension pulleys 47a to 47b. The actuator is a ceramic structure housed in a duralumin casing. Other screws such as titanium, brass, or engineering plastic are also used.
[0044]
Next, the intermediate support part 5 is demonstrated based on FIG. FIG. 5 is a perspective view of an intermediate support member in the surgical manipulator of FIG.
[0045]
In FIG. 5, 51 is a fixed plate, 52 is a vertical rotating frame, 53 is a front / rear rotating block, 54 is a hollow cylindrical sliding member, 55 is a front / rear rotating shaft, and 56 is a vertical rotating shaft.
[0046]
The intermediate support portion 5 has the same configuration as that of the drive coupling portion 3, but has an upside-down direction, does not have a drive system for arm twist rotation drive, and an arm portion on the inner wall of the hollow cylindrical sliding member 54. There is a difference in that there is a twisting rotation of 1 and a linear movement of the arm portion 1 in the cylindrical axis direction and sliding in two directions. The details of the configuration example common to the drive coupling portion 3 and the intermediate support portion 5 will be described later.
[0047]
Next, the arm part 1 will be described with reference to FIG. FIG. 6 is a perspective view of an arm portion in the surgical manipulator of FIG.
[0048]
In FIG. 6, 14 is an arm structural member, 15 is a retaining member from the drive coupling portion 3, 16 is a receiving side gear of an arm twisting rotation driving gear 38 attached to the drive coupling portion 3, and 17 is a spacer. The arm structure material 14 includes a plurality of arm structure materials 14A and 14B. The stopper 15, the receiving side gear 16 and the spacer 17 are provided on the arm structure material 14 </ b> A side.
[0049]
For the arm structure material 14, the retaining member 15, and the spacer 17, an engineering plastic such as polyether ether ketone or a material such as FRP is used. A non-magnetic metal such as duralumin is used for the receiving gear 16 because of tradeoffs such as strength and workability. The arm structure member 14 is formed in a cylindrical shape, and the inside thereof is hollow or has at least a space through which the drive transmission wire 43 to the attitude control mechanism unit 6 passes. Further, a reinforcing structure may be provided inside to increase the strength.
[0050]
Next, the attitude control mechanism unit 6 will be described with reference to FIG. FIG. 7 is an explanatory diagram of a posture control mechanism unit in the surgical manipulator of FIG. 7A is a plan view and FIG. 7B is a side view.
[0051]
In FIG. 7, 61 is a swing part frame, 62 is a surgical instrument guide cylinder, 63a to 63b are shaft stops, 64a to 64b are shaft support parts, 65a to 65b are power transmission pulleys, and 66a to 66b are input shaft umbrellas. Tooth gears, 67a to 67b, power transmission wires, and 68, an output shaft bevel gear.
[0052]
The power transmission pulleys 65 a to 65 b are driven by the power transmission wire 43. The pulleys 65a to 65b are supported by shaft support portions 64a to 64b so as to rotate integrally with the input shaft bevel gears 66a to 66b. The input shaft bevel gears 66a to 66b and the output shaft bevel gear 68 constitute a differential mechanism, and the operation is performed according to the direction and ratio of the drive amount given from the power transmission wire 43 to the input shaft bevel gears 66a to 66b. The tool guide cylinder 62 is swung and twisted. For example, when each wire 43 is pulled so that the rotation of the input shaft bevel gears 66a to 66b is in the same direction and the same angular amount with respect to the common rotation shaft, the surgical instrument guide cylinder 62 is swung without twisting, If only the rotation direction is reversed, twisting motion occurs in the surgical instrument guide cylinder 62 without shaking the head. Note that the swing axis of the head swing and the surgical instrument guide are arranged so as to intersect the rotational axis of the arm twist at one point.
[0053]
By combining these swinging / twisting rotations and the twisting rotation of the arm 1 itself, it is possible to control the degree of freedom of posture 3 at the tip of the arm. In addition, an operation of swinging the head in a cross about a certain direction can be easily realized by swinging and twisting the arm. By combining this with the position control operation with 3 degrees of freedom of the distal end generated by the position control drive mechanism unit 2, the necessary operation in the percutaneous operation for inserting and operating the surgical instrument to be equipped at the distal end through the trocar, In other words, the so-called pivot motion (with the portion that intersects the skin and the surface at the time of insertion being fixed, performing a multi-degree-of-freedom operation at the tip thereof. There is no risk of spreading the skin and the surface of the insertion portion, (Essential movement in endoscopic surgery or the like) can be easily realized.
[0054]
Next, the details of the configuration example of the drive coupling unit 3 will be supplementarily described with reference to FIG. FIG. 8 is a detailed explanatory view of the drive coupling portion of FIG.
[0055]
8, 33a is a shaft portion of the vertical rotation shaft 33, 33b and 33c are sliding members of the vertical rotation shaft 33, 35a is a shaft portion of the front and rear rotation shaft 35, 35b is a spacer of the front and rear rotation shaft 35, and 35c is front and rear rotation. A sliding material 36 a of the shaft 35 represents a fitting hole of the front / rear rotation block 36.
[0056]
The shaft portion 33a of the vertical rotating shaft 33 is fitted into the lower portion of the fixed plate 31, passes through the fixed plate 31 and the vertical rotating frame 32 through the sliding members 33b to 33c, and is coupled by the shaft stopper 34. Accordingly, the vertical rotation frame 32 can freely rotate around the vertical axis with respect to the fixed plate 31.
[0057]
The sliding member 35 c of the front / rear rotating shaft 35 is fitted in the fitting hole 36 a of the front / rear rotating block 36. The shaft portion 35a of the front / rear rotating shaft 35 passes through the side surface portion of the vertical rotating frame 32 and the spacer 35b and reaches the sliding member 35c. Here, sliding between the shaft portion 35a and the sliding member 35c occurs, and the arm twist rotating sliding member 37 can freely rotate back and forth (in other words, tilting the arm portion 1 up and down).
[0058]
The detailed structure of the intermediate support part 5 is the same as the detailed structure of the drive coupling part 3 described above.
[0059]
The materials of the drive coupling portion 3 and the intermediate support portion 5 are as described above, and it is desirable to mainly use engineering plastics such as polyetheretherketone. As for the sliding portion, it is desirable to select one having a higher sliding resistance grade. In particular, since the intermediate support portion 5 is closer to the imaging center and disposed in the space of the MRI 9, it is better not to use metal as much as possible even if it is non-magnetic.
[0060]
Since the intermediate support portion 5 is fixed to the MRI 9 via the intermediate support fixing member 7, the space factor is good, but when it is difficult to fix to the MRI 9, it has a space coordinate system that is time-invariant. It may be fixed to what is considered. For example, as shown in FIG. 9, you may make it fix to the base 8 via the intermediate support fixing member 7A.
[0061]
Next, the operation of the surgical manipulator will be described with reference to FIG. FIG. 10 is a perspective view for explaining the operation of the surgical manipulator of FIG.
[0062]
In FIG. 10, 101 is an arrow indicating the X-axis drive direction, 102 is an arrow indicating the Y-axis drive direction, 103 is an arrow indicating the Z-axis drive direction, 104 is an arc with an arrow indicating the arm twist rotation drive direction, and 105 is a posture. An arc with an arrow indicating the swing drive direction of the control mechanism 6, 106 is an arc with an arrow indicating the twist drive direction of the attitude control mechanism 6, and 107 is caused by driving the X axis, the Y axis, or both. An arc with an arrow (dotted line) indicating the rotation direction of the vertical rotation frame 32, 108 is an arc with an arrow (dotted line) indicating the rotation direction of the front / rear rotation block 36 caused by driving the Z axis, and 109 is an X axis / Y An arc with an arrow (dotted line) indicating the direction of rotation of the vertical rotating frame 52 caused by driving the shaft or both, 110 is that the Z axis is driven Arcs with arrows indicating the rotation direction of the front / rear rotation block 53, 111 is an arm twist rotation shaft, 112 is a posture control mechanism section swing rotation shaft, 113 is a twist rotation shaft of the surgical instrument guide cylinder 62, and 114 is The rotation axis of the vertical rotation frame 32, 115 is the rotation axis of the vertical rotation block 36, 116 is the rotation axis of the vertical rotation frame 52, 117 is the rotation axis of the vertical rotation block 53, 118 is the X axis / Y axis / Z axis or all Arrows indicating the linear motion direction in the intermediate support portion 5 caused by driving the shaft are respectively represented.
[0063]
When the X, Y, and Z axes of the position control drive mechanism unit 2 cause linear motion in the operation directions 101, 102, and 103, the drive coupling unit 3 moves thereby, and the vertical rotary frame 32 and the front and rear rotary block 36 rotate. A rotational motion such as rotational directions 107 and 108 is generated about the axes 114 and 115. On the other hand, although the intermediate support portion 5 is fixed to the MRI 9, the vertical rotation frame 52 and the front / rear rotation block 53 rotate in the rotation directions 109 and 110 with the rotation shafts 116 and 117 as the central axes according to the driving force. At this time, since the arm center axis 111 is a straight line, the rotational displacement amounts in the rotational directions 107 and 109 are equal to the rotational displacement amounts in the rotational directions 108 and 110. Further, when the position control drive mechanism 2 is moved, the distance between the intersection of each rotation axis of the drive coupling portion 3 and the intersection of each rotation axis of the intermediate support portion 5 changes. That is, at that time, a linear motion 118 in the longitudinal direction of the arm portion 1 occurs in the intermediate support portion 5.
[0064]
As described above, when the X, Y, and Z axes of the position control drive mechanism 2 are driven, the position of the tip is changed by such a combination of the lever and the linear motion. The relationship between the linear displacement of the XYZ axes and the positional displacement of the tip is a simple geometric relationship and can be easily obtained. With such displacement, the twist angle with respect to the twist axis of the arm does not change. The same applies to the swinging and twisting of the posture control mechanism unit 6. Therefore, first, it is necessary to consider posture control of the tip twisting 105 around the arm twists 104 and 112 around the central axis 111 and the tip twisting 106 around the central shaft 111 by introducing the change in the tip posture associated with the position displacement. become.
[0065]
Since the mechanism is as described above, it is easy to realize the pivot motion as described above. The pivot motion does not necessarily require a degree of freedom for twisting the tip, but the presence of this allows the posture of the surgical tool to be controlled and a more complicated surgical operation to be realized.
[0066]
It goes without saying that all the elements constituting the surgical manipulator described above, or actuators for driving, wires, etc. that are not mentioned are all made of a non-magnetic material that is insensitive to a magnetic field. . As the structural material, non-magnetic metals such as duralumin (aluminum alloy) and titanium alloy, and engineering plastics are used. In the above example, the actuator is made of only a non-magnetic material and does not use the principle of electromagnetic drive. However, an ultrasonic motor is used, but a hydraulic / pneumatic actuator can be applied. In addition, it is desirable to use a polymer material with high toughness for the wire. The part of the surgical tool that is supposed to be attached to the tip is preferably made of engineering ceramic or machinable ceramic.
[0067]
The surgical manipulator configured as described above has the following advantages.
(1) The MRI external side of the arm portion 1 is driven by the position control drive mechanism portion 2 having a limited movable range, and an intermediate support portion 5 serving as a fulcrum of the arm portion 1 is provided in the space of the MRI 9 to provide an intermediate support portion. Since the operation range of 5 is limited, a dangerous malfunction such as the long arm portion 1 being swung can be mechanically prevented.
(2) Since the intermediate support portion 5 is provided in the portion of the arm portion 1 located in the space of the MRI 9, the bending at the MRI side tip of the arm portion 1 is reliably reduced, and safety as a surgical manipulator Reliability can be increased.
(3) Since the posture control mechanism unit 6 capable of controlling the posture is provided at the distal end of the arm unit 1 on the MRI imaging region side, the operation of the posture control mechanism unit 6 can be performed in a narrow space. Therefore, it is possible to cope with a special operation in a narrow MRI imaging region. Since a differential mechanism is used as the attitude control mechanism unit 6, it is possible to operate in a narrow space with a particularly compact structure.
(4) The posture control mechanism drive unit 4 which is a drive source of the posture control mechanism unit 6 is placed outside the MRI so that the driving force of the posture control mechanism drive unit 4 is transmitted to the posture control mechanism unit 6 by the wire 43. Therefore, the operation manipulator as a whole does not move much for driving the posture control mechanism 6 at the distal end of the arm 1, but a complex operation can be locally implemented at the distal end. Therefore, from this point, it is possible to cope with a special operation in a narrow MRI imaging region.
(5) Since a linear motion mechanism that linearly moves in the X-axis, Y-axis, and Z-axis directions is used to drive the position of the arm unit 1 outside the MRI, the movement of the surgical manipulator becomes intuitive and easy to understand. This facilitates the safety of surrounding workers.
(6) The speed of the attitude control mechanism unit 6 is mainly determined by the position driving speed and the position of the fulcrum, and the fixed position of the intermediate support unit 5 is made variable. The speed specification of the attitude control mechanism unit 6 can be made variable without changing the speed specification. For example, if the intermediate support portion 5 is brought to the posture control mechanism portion 6 side, the movable range of the posture control mechanism portion 6 becomes smaller and the maximum speed becomes smaller. This means that fine operation can be performed at a speed commensurate with the scale (that is, low speed in terms of spatial speed). Conversely, if the intermediate support portion 5 is brought to the opposite side of the posture control mechanism portion 6, the movable range of the posture control mechanism portion 6 is widened and the maximum speed is increased, and a large operation can be performed quickly. In other words, the ratio of the range of movement limited by the fulcrum of the arm unit 1 and the speed of movement from end to end can always be set to be the same. Has the effect of appearing the same speed.
(7) Since both the drive coupling part 3 and the intermediate support part 5 have the gimbal structure, the angle around the arm longitudinal direction is not changed when the XYZ axes of the position control drive mechanism part 2 are driven (does not interfere with the posture). You can Therefore, the attitude control mechanism 6 is not beaten by the position control drive mechanism 2.
(8) The movement magnification in the two directions perpendicular to the longitudinal direction can change the fulcrum position while keeping the movement magnification in the longitudinal direction of the arm constant by moving the intermediate support portion 5. In the assumed configuration, the surgical manipulator approaches from the side of the patient. Since the width of the patient's body is almost the same in every part, the operation magnification in this direction may be constant. On the other hand, as for the two directions perpendicular to this, first, there is the same direction as the body axis, and since the body extends in this direction, it is necessary to approach from the top to the bottom of the body with a certain technique. In some cases (for example, when a blood vessel is collected from a foot and used as a graft in the upper body surgery), the present invention can also be handled. In addition, the vertical direction can cope with the environment to be used, especially when the height and gap width of MRI are various.
[0068]
【The invention's effect】
As described above, according to the present invention, it is possible to provide a surgical manipulator that can achieve both workability and safety within the MRI.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a surgical manipulator showing an embodiment of the present invention.
2 is a perspective view of a position control drive mechanism unit in the surgical manipulator of FIG. 1. FIG.
FIG. 3 is a perspective view of a drive coupling portion in the surgical manipulator of FIG.
4 is an explanatory diagram of a posture control mechanism driving unit in the surgical manipulator of FIG. 1. FIG.
FIG. 5 is a perspective view of an intermediate support member in the surgical manipulator of FIG. 1;
6 is a perspective view of an arm portion in the surgical manipulator of FIG. 1. FIG.
7 is an explanatory diagram of a posture control mechanism unit in the surgical manipulator of FIG. 1. FIG.
FIG. 8 is a detailed explanatory diagram of the drive coupling portion of FIG. 3;
9 is a view showing a modified example of the fixing structure of the intermediate support portion in FIG.
10 is a perspective view for explaining the operation of the surgical manipulator of FIG. 1; FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Arm part, 2 ... Position control drive mechanism part, 3 ... Drive coupling part, 4 ... Attitude control mechanism drive part, 5 ... Intermediate support part, 6 ... Attitude control mechanism part, 7, 7A ... Intermediate support fixing member, 8 ... Driving unit fixing base, 9a... Upper magnet, 9b... Lower magnet, 11 .. patient lying base, 12... Patient, 13 .. intermediate support mounting portion, 14. , 17 ... Spacer, 21 ... X-axis direction base plate, 22a-22c ... X, Y, Z-axis direction actuator, 23a-23c ... X, Y, Z-axis direction ball screw, 24a-24c ... X, Y, Z Axis direction linear guide, 25a to 25c ... X, Y, Z axis direction linear encoder, 26 ... X axis direction moving plate, 27 ... Y axis direction moving plate, 28 ... Z axis direction fixed plate, 29 ... Z axis direction moving plate , 29a ... drive connection Part mounting hole, 31 ... fixed plate, 32 ... vertical rotating frame, 33 ... vertical rotating shaft, 33a, 33b ... spacer, sliding material, 34 ... vertical rotating shaft stopper, 35 ... front / rear rotating shaft, 35a ... shaft, 35b ... Spacer, 36 ... Front / rear rotation block, 36a ... Fitting hole, 37 ... Sliding material for arm twist rotation, 38 ... Arm twist rotation drive gear, 39 ... Arm twist rotation amount detection encoder, 30 ... Arm twist rotation Actuator, 41 ... Compound cylinder, 42a-42d ... Actuator, 43 ... Power transmission wire, 44 ... Displacement transmission wire, 45 ... Displacement transmission pulley, 46 ... Encoder, 47a-47b ... Tension pulley, 48 ... Compound cylinder rotation Sliding body for use 49... Housing, 51... Fixed plate 52. Vertical rotating frame 53. Front and rear rotating block 54. Hollow cylindrical sliding material 55 Front / rear rotating shaft, 56: Vertical rotating shaft, 61: Oscillating part frame, 62: Cylinder for operating tool guide, 63a-63b: Shaft stopper, 64a-64b: Shaft support, 65a-65b ... Power transmission pulley, 66a ~ 66b ... input shaft bevel gear, 68 ... output shaft bevel gear.

Claims (2)

An arm portion provided to extend from the outside of the MRI to the imaging region;
A posture control mechanism unit that is disposed at the MRI imaging region side tip of the arm unit and controls the posture;
An attitude control mechanism drive unit that is disposed on the MRI outside of the arm unit and drives the attitude control mechanism unit via a transmission mechanism;
A position control drive mechanism that is disposed outside the MRI of the arm and controls and drives the position of the arm outside the MRI;
A drive coupling unit coupling the arm unit and the position control drive mechanism unit;
An intermediate support part for supporting an intermediate part of the arm part as a fulcrum of the arm part;
An intermediate support fixing member for fixing the intermediate support part to the outside,
The intermediate support part supports an intermediate part of the arm part located in the MRI space,
The surgical manipulator characterized in that the fixing position between the intermediate support part and the intermediate support fixing member can be changed at a plurality of positions in the longitudinal direction of the arm part.   2. The surgical manipulator according to claim 1, wherein members located in an imaging region of the arm portion, the intermediate support portion, and the posture control mechanism portion are formed of a non-magnetic and insulating material. Surgical manipulator.

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