Working mechanism for medical manipulator and cleaning method therefor

A working mechanism for a medical manipulator and a cleaning method therefor are provided. A working unit of a medical manipulator is equipped with a hollow connecting shaft, wires of a motive force transmitting member disposed in the connecting shaft, and a distal end working unit disposed on one end of the connecting shaft and which is moved by the wires. A cover covers at least a portion of the distal end working unit. A gap is provided between the cover and the connecting shaft, with oblong holes being disposed laterally on right and left sides of the cover. A cleaning agent is made to flow through the holes and the gap and/or a brush may be inserted through the holes and the gap for cleaning the distal end working unit.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a working mechanism for a medical manipulator and a cleaning method therefor, and in particular, concerns a medical manipulator working mechanism, which can be applied to the working unit of a manipulator equipped with a driving unit and a working unit that is attachable and detachable with respect to the driving unit. The present invention also concerns a cleaning method utilized on such a working mechanism.

2. Description of the Related Art

In laparoscopic surgery, a number of small holes are opened in a patient's abdomen or the like, and an endoscope, a forceps (or manipulator) or the like is inserted, and surgery is carried out while the surgeon observes an image from the endoscope on a monitor. In this type of laparoscopic surgery, owing to the fact that opening of the abdominal cavity is unnecessary, the burden on the patient is small, and the number of days required for the post-operative recovery and the number of days spent in the hospital can be significantly reduced. Therefore, laparoscopic surgical operations are expected to find an increased range of applications.

A manipulator system, for example, as disclosed in Japanese Laid-Open Patent Publication No. 2004-105451, comprises a manipulator main body, and a controller for controlling the main body. The manipulator main body comprises an operation command unit, which is operable by hand, and a working unit, which is detachable and exchangeable with respect to the operation command unit.

The working unit (tool) includes an elongate connecting shaft, and a distal end working unit (also referred to as an “end effector”) disposed at the end of the connecting shaft. One or more actuators (motors) are disposed in an operation command unit for driving the working unit by means of wires. The wires are wound around pulleys at a proximal end side. The controller drives the motors disposed in the operation command unit, and also drives the wires in an advancing/retracting manner via the pulleys.

The working unit is constructed so as to be detachable with respect to the operation command unit in order to enable cleaning to be carried out easily following completion of a surgical technique. Further, in laparoscopic surgery, various different types of working units are used depending on the surgery involved. A gripper, scissors, an electrical knife, an ultrasonic knife, a surgical drill or the like may be given as examples thereof. From the standpoint of being able to exchange these working units, a structure in which the working unit is detachable with respect to the operation command unit also is beneficial.

In the working unit, proximal end side pulleys thereof are constructed so as to engage with the rotational shafts of motors, which are disposed in the operation command unit.

By detaching and removing the working unit from the operation command unit, cleaning processing performed on the working unit becomes considerably easier. However, it would also be desirable for cleaning of the mechanisms, such as pulleys and gears or the like, which are disposed within the proximal end side, and in the distal end working unit (end effector) part of the working unit, to be conducted more easily.

The pulleys and gears are connected by wires within the working unit, whereby motive forces are transmitted thereby. It is desired to easily and reliably transmit motive forces through such pulleys, gears, and wires.

SUMMARY OF THE INVENTION

It is one of the objects of the present invention to provide a working mechanism for a medical manipulator, which is highly suitable and effective when applied to the manipulator and to provide a cleaning method for such a working mechanism.

According to one aspect of the present invention, a working mechanism for a medical manipulator includes a hollow shaft, a motive force transmitting member disposed in the shaft, a working unit disposed on one end of the shaft and equipped with a distal end working unit, which is moved by the motive force transmitting member, and a cover that covers at least a portion of the distal end working unit, wherein a gap is provided between the cover and the shaft, and holes are disposed laterally on sides of the cover.

Owing to the presence of the cover, foreign matter can be prevented from entering into the working unit. Also, a cleaning agent may be made to flow through the holes from sides of the cover, or a cleaning means may be inserted through the holes, thereby carrying out cleaning of the working unit.

According to another aspect of the present invention, in the cleaning method, when cleaning of the working mechanism is carried out, an end of the shaft is inserted together with the cover into one end of a tube, the tube and the shaft are sealed by a sealing means, a cleaning agent sucking and discharging means is disposed on another end of the tube, and another end of the shaft is immersed into the cleaning agent. Thus, by activating the sucking and discharging means, sucking and discharging of the cleaning agent is carried out repeatedly from the other end of the shaft.

Owing thereto, the cleaning agent can be sucked and discharged through the hollow space inside the shaft, the cleaning agent is not blocked by the pulleys, gears, and the like of the distal end working unit, and cleaning can be performed easily and effectively by causing the cleaning agent to flow through the gap and the holes.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Descriptions of an embodiment of a working mechanism for a medical manipulator and a cleaning method therefor, utilizing the medical manipulator according to the present invention, shall be described below with reference toFIGS. 1 through 9.

The medical manipulator10grips a portion of a living body or a curved needle or the like by a distal end working unit12to carry out predetermined processing, and ordinarily is referred to as a gripping forceps or a needle driver (needle holder) or the like.

As shown inFIGS. 1 and 2, the manipulator10includes an operation command unit (driving unit)14at a proximal end portion thereof, which is gripped and operated by hand, and a working unit (medical manipulator working mechanism)16that is attachable and detachable with respect to the operation command unit14.

It shall be assumed in the following descriptions that, as shown inFIG. 1, the transverse direction is defined as an X direction, the vertical direction as a Y direction, and the longitudinal directions of the connecting shaft48as a Z direction. Further, among the X directions, the rightward direction is defined as an X1 direction, and the leftward direction as an X2 direction, among the Y directions, the upward direction is defined as a Y1 direction, and the downward direction as a Y2 direction, and among the Z directions, the forward direction is defined as a Z1 direction, and the rearward direction as a Z2 direction. Moreover, unless otherwise noted, these directions represent directions of the manipulator10when it is in a neutral posture (the posture of the state shown inFIG. 3). The definitions of the above directions are for illustrative purposes only, and the manipulator10can be used in any of various orientations (for example, the manipulator may be used upside down).

The working unit16includes a distal end working unit12, a connector (retaining chamber)15that is connected to an actuator block30of the operation command unit14, and a hollow connecting shaft48of a given length dimension connected between the distal end working unit12and the connector15. The working unit16is capable of being detached and separated from the operation command unit14by means of a predetermined operation in the actuator block30, wherein cleaning, disinfecting or sterilizing, maintenance and the like can be carried out thereon.

The distal end working unit12and the connecting shaft48are narrow in diameter, and can be inserted into a body cavity22through a trocar20in the form of a hollow cylinder mounted in an abdominal region or the like of the patient. By operations of the operation command unit14, various techniques can be performed to cut, grip, remove, suture, or ligate (tie-knot) an affected part of the patient's body within the body cavity22.

The operation command unit14includes a grip handle26, which is gripped by hand, a bridge28extending from an upper portion of the grip handle26, and the actuator block30, which is connected to a distal (frontal) end of the bridge28.

As understood clearly fromFIG. 1, a lower surface of the connector15abuts against an upper surface of the actuator block30with substantially no gaps therebetween, whereas the rear surface (surface facing the Z2 direction) of the connector15abuts against a front surface (surface facing the Z1 direction) of the bridge28with substantially no gaps therebetween. The lower surface of the connector15and the upper surface of the actuator block30lie in the XZ plane, and the rear surface of the connector15and the front surface of the bridge28lie in the XY plane. The left and right side surfaces of the connector15and the left and right side surfaces of the bridge28and the actuator block30make up a continuous YZ plane respectively, whereas the upper surface of the connector15and the upper surface of the bridge28respectively and continuously form a smooth curved surface. Owing thereto, the connector15is formed integrally and compactly with respect to the operation command unit14, and moreover, since unnecessary irregularities in shape hardly exist at the region where the connector15and the operation command unit14are interconnected, operability is excellent.

The grip handle26includes a trigger lever32, which is operable by a finger of the user, a first command lever34, and a second command lever36. The trigger lever32is disposed in a position where it can easily be pulled by the index finger.

The actuator block30houses therein three motors40,42,44(actuators) corresponding to respective mechanisms providing three degrees of freedom, which are incorporated in the distal end working unit12. The motors40,42,44are arrayed in parallel in the longitudinal direction of the connecting shaft48. The motors40,42,44are small in size and narrow in diameter, thereby allowing the actuator block30to have a compact flat shape. The actuator block30is disposed downwardly of the end of the operation command unit14in the Z1 direction. The motors40,42,44are energized to rotate drive shafts thereof under the control of a controller (control unit)45, based on operations of the operation command unit14.

The connector15is covered by a resin cover37, and houses and retains rotatably therein driven pulleys (driven rotating bodies)50a,50b,50c, which engage with drive axes of the motors40,42,44. Wires (linear bodies)52,54,56are wound respectively around pulleys50a,50b,50c, extending to the distal end working unit12through a hollow space48a(seeFIG. 3) of the connecting shaft48. The wires52,54,56can be formed of the same type of materials having the same diameter, respectively.

The wires52,54,56serve to transmit motive forces to a compound mechanism102and the end effector104through a wire coupling100(seeFIG. 3) at the end of the connecting shaft48.

Further, between the cover160and the connecting shaft48, a gap51is provided through which a gear134, and another gear138, etc., are exposed. The gap51communicates with the hollow space48aof the connecting shaft48.

A pair of tongue-members58, which project at the distal end of the connecting shaft48, are disposed so as to face one another toward the central axis of the connecting shaft48. The hollow space48aof the connecting shaft48communicates with the space formed between the pair of tongue-members58. Two pairs of respective shaft holes60a,60aand60b,60bare disposed in confronting positions in the pair of tongue-members58. The distal ends of the tongue-members58are formed with arcuate shapes, respectively. Further, confronting inside surfaces of the tongue-members58are formed as parallel flat surfaces.

The two shaft holes60a,60aand the two shaft holes60b,60bare disposed so as to sandwich the central axis therebetween. The shaft holes60aand60bare disposed in parallel along the Z direction, with the shaft holes60bbeing positioned more closely to the distal end side than the shaft holes60a.

As shown inFIG. 3, the distal end working unit12incorporates therein mechanisms providing three degrees of freedom. These mechanisms include a mechanism having a first degree of freedom for rotating an end portion that is positioned ahead of a first rotational axis Oy (pivot axis) extending along the Y-axis direction, in yawing directions about the first rotational axis Oy, a mechanism having a second degree of freedom for rotating the end portion in rolling directions about a second rotational axis Or, and a mechanism having a third degree of freedom for opening and closing the end effector104about a third rotational axis Og.

The end effector104makes up a portion for performing actual work during an operation. The first rotational axis Oy and the second rotational axis Or serve to change the posture of the end effector104to facilitate working. In general, the mechanism having the third degree of freedom for opening and closing the end effector104is referred to as a gripper. The mechanism having the first degree of freedom for rotating in yawing directions is referred to as a yaw axis, whereas the mechanism having the second degree of freedom for rotating in rolling directions is referred to as a roll axis.

The distal end working unit12is made up of and includes the wire coupling100, the compound mechanism102, and the end effector104.

With reference toFIGS. 3,4,5and6, detailed explanations shall now be made concerning the wire coupling100, the compound mechanism102, and the end effector104.

The wire coupling100is disposed between the pair of tongue-members58, and serves to convert reciprocating motions of the respective wires52,54,56into rotary motions, which are then transmitted to the compound mechanism102. The wire coupling100includes a shaft110inserted through the shaft holes60a,60a, another shaft112(perpendicular shaft) inserted through the shaft holes60b,60b, and a gear body114, which is axially and rotatably supported about the shaft110. The shafts110and112are fixed by press fitting or welding, for example, with respect to the shaft holes60a,60b. The shaft112is positioned on the first rotational axis Oy.

The gear body114comprises a tubular body116and a gear118disposed concentrically on an upper portion of the tubular body116. The gear118comprises a spur gear greater in diameter than the tubular body116. Unless otherwise specified, the gears referred to herein comprise spur gears. The gear body114has a height, which is substantially equal to the distance H, and is rotatably disposed between the pair of tongue-members58. The gear118has a thickness D1 sufficiently thinner than the height H, so that the height (H−D1) of the tubular body116takes up a substantial portion of the height H between the tongue-members58. The gear118has a low annular rib118adisposed on an upper surface thereof around the hole through which the shaft110is inserted. The annular rib118aprevents the upper surface of the gear118from contacting the upper tongue-member58, thereby reducing sliding resistance therebetween.

The compound mechanism102is a mechanism that serves both to open and close the end effector104, as well as to, in combination therewith, cause a change in the posture of the end effector104.

The compound mechanism102comprises a gear body126, a main axis member128, and a gear body130, which are rotatably supported on the shaft112, and are arranged successively from the Y1 direction toward the Y2 direction.

The gear body126comprises a tubular body132and a gear134disposed concentrically on an upper portion of the tubular body132. The gear134meshes with the gear118and has the same thickness as the gear118. The gear134has a greater number of gear teeth than the gear118and can transmit rotation of the gear118at a reduced speed (while increasing torque). Naturally, depending on design conditions, rotation may also be transmitted at the same speed or at a higher speed. The gear134has a low annular rib134adisposed on the upper surface thereof around the hole through which the shaft112is inserted. The annular rib134aprevents the upper surface of the gear134from contacting the upper tongue-member58, thereby reducing sliding resistance therebetween.

The gear body130is essentially identical in shape to the gear body126, but is in an upside-down orientation with respect to the gear body126. The gear body130comprises a tubular body136and a gear138disposed concentrically on a lower portion of the tubular body136. The tubular body136is substantially identical in diameter and shape to the tubular body132. The gear138has a number of teeth, which may be somewhat smaller than that of the teeth of the gear134. A wire securing mechanism120, which is similar to the wire securing mechanism120of the tubular body116, is disposed on a side surface of the tubular body136that faces the Z2 direction, such that the wire54is fastened to the tubular body136thereby.

The main axis member128has a tubular body140through which the shaft112is inserted, an annular seat142facing the Z1 direction, and a support bar144extending from the center of the annular seat142in the Z1 direction. The support bar144is aligned axially with the second rotational axis Or. The support bar144has an externally threaded distal end portion.

The annular seat142is disposed at a position spaced slightly from the outside surface of the tubular body140through two upper and lower protective plates171, and a hole146through which the wire52can be inserted is disposed between the tubular body140and the annular seat142. On a side surface in the Z2 direction of the tubular body140, a wire securing mechanism120, which is the same as that of the tubular body116, is provided, to which the wire52is fixed.

The protective plate171has a roughly 90° circular arc shape in the Z2 direction, expands in the Z1 direction, and is substantially in the shape of a chevron when viewed in plan.

As shown inFIG. 5, when viewed in plan, the maximum width of the protective plate171is wider than the gear118, the gear134, and the gear138. Further, the teeth of the face gear168and the face gear170are inserted into a recess171aprovided in the end surface facing the Z1 direction. Accordingly, the gear teeth do not come into contact with a suture (thread) or the like that is used for performing a ligation (tie-knot) operation, and sutures are not drawn therein, so that entanglement or interference with the gear teeth can be prevented.

It is not essential that the protective plate171, which acts as a member for preventing entanglement or interference of threads, etc., be constructed integrally with the main axis member128. For example, the protective plate171may be disposed separately from the main axis member128and underneath the main axis member128(in the Y2 direction).

In this manner, as a result of the protective plate171being disposed so as to cover at least a portion of the face gears168and170, entanglement of sutures (threads) or the like in the face gears168and170can be prevented. In particular, the protective plate171has a shape that becomes narrower toward the rearward direction, and thus the protective plate171does not hinder movement in the yaw axis direction, and sutures or the like are not unnecessarily drawn into the face gears168and170, or the gear134, such that entanglement and interference therewith can more reliably be prevented.

The main axis member128is rotated in yawing directions about the first rotational axis Oy accompanying reciprocating movement of the wire52, whereby the support bar144can make swinging movements in the XZ plane.

The tubular body140, the gear body126, and the gear body130are stacked together along the shaft112, forming an axis thereof, and have a stacked height which is essentially equal to the height H, and thus are disposed with substantially no gaps between the pair of tongue-members58.

The compound mechanism102further includes a drive base150, a gear ring152, a gear-attached pin154, fastening nuts156,158, and a cover160. The fastening nut156has a plurality of radial fine holes156adefined therein for insertion of a narrow rotary tool. At least one of the fine holes156ais exposed in a radial direction (seeFIG. 3). The fastening nut158has parallel surfaces158a, which are engageable by a rotary tool such as a wrench or the like.

The drive base150includes a tubular body164rotatably fitted over a proximal end portion of the support bar144, a pair of support arms166projecting in the Z1 direction from both left and right ends of the tubular body164, and a face gear168disposed on a surface of the tubular body164that faces the Z2 direction. Each of the support arms166serves to support the end effector104, and has respective holes166adefined therein, which are aligned in the X direction. After the tubular body164has been inserted onto the proximal end portion of the support bar144, the fastening nut156is threaded over the externally threaded distal end portion of the support bar144, whereby the drive base150is rotatably supported on the support bar144for rotation in rolling directions centrally about the support bar144(i.e., about the second rotational axis Or).

The face gear168is held in mesh with the gear138. Consequently, the drive base150is rotatable about the second rotational axis Or, in response to rotation of the tubular body136.

The gear ring152is in the form of a thin tubular body including a face gear170on a surface thereof facing the Z2 direction, and another face gear172on a surface thereof facing the Z1 direction. The gear ring152is fitted over the tubular body164of the drive base150for sliding rotation with respect to the outer circumferential surface of the tubular body164. The gear ring152is fitted over the tubular body164such that the face gear170is slightly displaced off the face gear168of the drive base150in the Z1 direction, until being held in mesh with the gear134. The face gear170meshes with the gear134, such that the gear ring152is rotatable about the second rotational axis Or accompanying rotation of the gear body126.

The gear-attached pin154includes a gear174, which meshes with the face gear172, and a pin176extending in the X1 direction from the center of the gear174. The pin176has an externally threaded distal end portion. The pin176passes through the two holes166a, such that the threaded distal end portion projects from one of the support arms166, and the fastening nut158is threaded thereover. Owing thereto, the gear-attached pin154, with the gear174meshing with the face gear172, is rotatably supported with respect to the support arms166. Further, the pin176is cut in a D-shaped cross section, for engagement with a portion of the end effector104.

The cover160serves to protect the respective components of the compound mechanism102and the end effector104, covering the gear ring152and the gear174, etc. The cover160includes a tubular portion180extending in the Z2 direction, a pair of ears182that project in the Z1 direction from respective left and right end portions of the tubular portion180, and slit-shaped holes183provided respectively in the ears182. The ears182are shaped such that circumferential wall portions of the tubular portion180extend in the Z1 direction in gradually tapering conical shapes. The cover160has a lower portion fastened to a portion of the end effector104by a cover-fastening pin162. The cover160has a diameter, which is equal to or smaller than the diameter of the connecting shaft48when viewed in front elevation. Holes183are provided over an area from the tubular portion180to the ears182.

As made clear fromFIG. 3, the compound mechanism102and the end effector104are formed with an elongated shape in the axial direction. The holes183are oblong holes in the lengthwise direction of the compound mechanism102and the end effector104. Both ends of the holes183are formed in semicircular shapes.

The cover160may be in the form of a hollow cylindrical or conical-shaped cover for covering the compound mechanism102and the end effector104, almost in their entirety, to such an extent that operations of the compound mechanism102and the end effector104will not be hampered. Further, the cover160may also be fastened using the pin196.

By means of such a cover160, foreign matter (body tissues, medical agents, sutures, etc.) can be prevented from entering inside the compound mechanism102and the end effector104making up the working unit.

Next, the end effector104comprises a first end effector member190, a second end effector member192, a link194, and the pin196. The pin196is aligned axially with the third rotational axis Og.

The first end effector member190includes a pair of laterally spaced side walls200facing each other and having respective holes200adefined in distal end portions of the side walls200and respective holes200bdefined in rear end portions of the side walls200, a first gripper202projecting in the Z1 direction from lower distal end portions of the side walls200, and a cover mount204disposed on rear lower end portions of the side walls200. The holes200ahave diameters such that the pin196can be press-fitted therein. The first gripper202narrows in width slightly along the Z1 direction and is formed with an arcuate distal end portion. The first gripper202has a number of small closely spaced conical upper projections disposed over the entire surface thereof substantially without gaps and facing in the Y1 direction.

The distal end portions of each of the side walls200are arcuate in shape, whereas both outer side surfaces of the rear end portions thereof have respective recesses200cdefined therein in which the support arms166are fitted. A hole190a(seeFIG. 5) is defined between the first gripper202and the cover mount204for preventing interference with respect to the rear end portion of the second end effector member192. The cover mount204has a hole defined therein into which the cover-fastening pin162is press-fitted.

The second end effector member192comprises a base210, a second gripper212extending in the Z1 direction from a distal end of the base210, a pair of ears214extending in the Z2 direction from both left and right rear end portions of the base210, and a shaft support sleeve216disposed on a lower surface at the distal end of the base210. The shaft support sleeve216has a hole216adefined therein, which has an inside diameter large enough to enable the pin196to be inserted therein. When the pin196is inserted into the shaft support sleeve216and is press-fitted, for example, in the hole200a, the second end effector member192is made swingable centrally about the third rotational axis Og. The second gripper212is identical in shape to the first gripper202, but is arranged in an upside-down orientation with respect to the first gripper202. When the second end effector member192is rotated about the third rotational axis Og, the second gripper212is brought into abutment against the first gripper202, so that a curved needle or the like can be gripped therebetween. The ears214have oblong holes214adefined respectively therein.

The link194has a hole220defined in an end thereof and a pair of engaging fingers222disposed on the other end, which project laterally away from each other. The engaging fingers222slidably engage in the respective oblong holes214a. The hole220is cut in a D-shaped cross section for receiving the pin176snugly therein, and thus, the hole220serves to position the pin176and prevent the pin176from rotating about its own axis. When the pin176is inserted in the holes166a, as well as in the holes200band220, the fastening nut158is threaded over the distal end portion of the pin176, and the link194is made swingable about the pin176.

Further, the wire52is wound for 1.5 turns around the tubular body140, the wire54is wound 1.5 turns around the tubular body136, and the wire56is wound 2.5 turns (900°) around the tubular body116. As made clear fromFIG. 5, the diameter of the tubular body140is set to a value equal to or greater than the sum of the diameter of the tubular body116and the diameters of the two wires56. As viewed in plan, the wires52,54are disposed slightly outwardly of the wire56. Therefore, each of these wires is easily prevented from interfering with each other.

More specifically, the wire56is disposed inwardly of the wire52, and the wire56does not interfere with the wire52. Accordingly, without concern to the position of the wire52, the wire56can be wound around the tubular body116over a region116athereof, which is about two-thirds of the overall height of the tubular body116(seeFIG. 6). The region116ais wide enough to allow the wire56to be wound 2.5 turns (or even more, e.g., 3.5 turns (1260°)) therearound, so that the gear body114can be rotated to make 2.5 revolutions (or more). Further, since the rotation amount of the gear body114is large, the gear ratio between the gear118and the gear134can be set largely, thereby enabling an increase in the rotational torque of the gear body126.

Next, with reference toFIGS. 7 and 8, a description shall be given concerning a method for cleaning the working unit16.

As shown inFIG. 7, after the working unit16is detached from the operation command unit14, the distal end of the connecting shaft48along with the cover160is inserted into one end of a tube320, and the tube320and connecting shaft48are sealed in a fluid-tight manner by a band (sealing means)340. The tube320is appropriately larger in diameter than the connecting shaft48and the cover160.

The sealing means is not limited to a band340, and any means that provides a suitable fluid-tight seal may be used. Also, the seal need not strictly prohibit leakage of the cleaning agent. So long as the cleaning agent can flow through the connecting shaft48and the tube320, a small amount of leakage can be tolerated.

Next, as shown inFIG. 8, the other end of the tube320is connected to a syringe (sucking and discharging means)342, and an end of the connecting shaft48, i.e., the connector15, is immersed in the cleaning agent (which may be a water or an enzyme cleaning agent, for example), which is provided in a moderately-large vat343. Initially, it is preferable to operate the piston344of the syringe342until the syringe342becomes filled with the cleaning agent. Preferably, the syringe342is chosen to have a sufficiently large capacity, which is greater than the total interior volume of the connecting shaft48and the tube320.

Next, by reciprocally moving the piston344, the cleaning agent is repeatedly sucked and discharged from the first cleaning hole314and/or the second cleaning hole316of the connector15. The cleaning agent is drawn in from the first cleaning hole314and the second cleaning hole316and passes into the hollow space48aof the connecting shaft48, reaching the distal end working unit12. During times of ordinary usage, the first cleaning hole314and the second cleaning hole316are blocked.

Incidentally, as clearly understood fromFIG. 5, in the distal end working unit12, the drive base150and the gear ring152are disposed therein, and the interior of the cover160is blocked almost entirely thereby, so that at first glance, a fluid passage does not appear to be formed thereby.

Notwithstanding, in the working unit16, because the gap51is disposed between the cover160and the connecting shaft48, and furthermore, owing to the holes183that are provided on both sides of the cover160, as shown by the arrow G inFIG. 7, fluid flows through the gap51and the holes183, so that a fluid passage is secured. The cleaning agent, which has passed through the gap51and the holes183, flows through the tube320and is sucked inside the syringe342. In the case of discharging the fluid, the fluid flows in reverse and passes from the syringe342, through the tube320, the holes183, the gap51, and the connecting shaft48, whereupon the cleaning agent is discharged into the vat343. The discharged cleaning agent is diluted with the remaining cleaning agent in the vat343, so that when sucked again in the next cycle, a cleaning agent having adequate purity can be drawn in.

In accordance with such a cleaning method, by continual reciprocating movements of the piston344in the syringe342, the cleaning agent is sucked and discharged through the hollow space48aof the connecting shaft48, and without blockage of the flow passage midway by mechanical components, the cleaning agent flows through the gap51and the holes183, whereby cleaning can easily be performed. Further, the connecting shaft48and the distal end working unit12can be cleaned easily and highly effectively at the same time.

As a cleaning method for the distal end working unit12, the tube320may be arranged such that the tube320covering the cover160only, wherein the cleaning agent is made to flow through the tube320from the other end thereof. Consequently, the cleaning agent is made to flow sideways from the holes183of the cover160, producing multiple flows of the cleaning agent inside the cover160, whereby the end effector104and the compound mechanism102can be cleaned effectively. Further, a cleaning means such as a brush or the like may be used for cleaning inside of the cover160.

Because holes183are disposed on both left and right sides of the cover160, cleaning on the left and right sides of the end effector104can also be carried out. Since the holes183are formed with semicircular shapes at the end portions thereof, it is unlikely that sutures (threads) and the like, which are used for suturing during surgery, will become caught thereon and drawn into the interior of the end effector104.

A cleaning means, such as a brush, a high-pressure water flow means, or means for supplying compressed air or the like may be inserted from the holes183, whereby cleaning is carried out thereby.

Further, even when a structure is provided for operating the piston344automatically so as to be reciprocally moved over a long period of time, only the cleaning agent provided in the vat343is utilized, so that a large amount of cleaning agent is not consumed inadvertently. The used cleaning agent is collected into the vat343without scattering or spillage of the cleaning agent, so that no special anti-scattering means or collecting means is required, and disposal processing of the cleaning agent can be easily performed. The fluid suction and discharge means is not limited to the syringe342. For example, an automatically driven cylinder or the like may be used in place of the syringe342.

With the above-mentioned compound mechanism102, through rotation of the gear body130, rotation is transmitted from the gear138to the face gear168, whereby the drive base150, and the end effector104coupled to the drive base150, can be rotated about the second rotational axis Or. Further, by rotation of the gear body114, rotation is transmitted from the gear118to the pin176through the gear134, the face gear170, the face gear172and the gear174, thereby enabling the gear-attached pin154to be rotated.

As described above, with the distal end working unit12, in the manipulator10according to the present embodiment, as a result of providing the cover160, foreign matter can be prevented from entering into the distal end working unit12. In addition, a cleaning agent can be injected from the holes183formed in side surfaces of the cover160, whereby cleaning of the distal end working unit12can be carried out.

A tube320that is appropriately large in diameter is used to cover the connecting shaft48and the cover160, and by causing reciprocal movement of the piston344in the syringe342, the cleaning agent is sucked in and discharged through the hollow space48aof the connecting shaft. Without blockage of the fluid passage by mechanical components, the cleaning agent flows through the gap51and the holes183, so that cleaning can be carried out easily and effectively.

The cover160is connected to the motive force transmitting member (wires) and is moved together with movements of the distal end working unit12. For example, when yaw-axis movements of the distal end working unit12take place, the cover160also is moved around the yaw-axis with respect to the connecting shaft48.

Due to the existence of the gap51between the connecting shaft48and the cover160, the exposed region of the yaw axis joint becomes widened by movement of the yaw axis, whereby the effectiveness of cleaning can be enhanced.

Holes183are provided not only on the tubular portion180, but also over an area from the tubular portion180to the ears182, i.e., formed as an elongate slit in the Z direction. Accordingly, the cover160has strength higher than a cover in which holes having the same size are provided only on the tubular portion180. Further, flow of the cleaning agent through the holes183in the Z1 or Z2 direction is prevented from being blocked, and thus, cleaning efficiency is improved.

Further, from the fact that the cover160is connected to the motive force transmitting member, the distal end working unit12, which is connected to the motive force transmitting member, can be covered efficiently, and compared to a situation in which the cover160is attached to the connecting shaft48and covers the distal end working unit12, a more compact cover shape results, which does not cause an obstruction to operation of the manipulator.

When holes183are disposed in the cover160, apart from the aforementioned cleaning method using flowing water, a method in which the flowing water flows effectively by a washer-disinfector apparatus, or a method in which a cavitation effect is developed in detail by means of an ultrasonic cleaning apparatus, can be utilized.

Further, in processes involving plasma sterilization or EOG (ethylene oxide gas) sterilization as well, contact with the sterilizing environment increases, so that more effective processing can be carried out.

The holes183are disposed substantially centrally on left and right side surfaces of the cover160. At this location, the possibility of direct contact with living tissue inside the body cavity is minimized. Therefore, it is unlikely that foreign substances from living body tissue will enter the driving section that moves relatively, including the gears, the links, and the like disposed inside the cover160.

The working unit16has been described as being connected to an operation command unit14, which is operated manually. However, as shown inFIG. 9, the working unit16may also be applied to a surgical robot system700.

The surgical robot system700includes a multi-articulated robot arm702together with a console704. The working unit16is connected to an end of the robot arm702. The same mechanism as that of the aforementioned actuator block30is provided at the end of the robot arm702, thereby enabling connection and driving of the working unit16. In this case, the manipulator10is made up from the robot arm702and the working unit16. The robot arm702may comprise means therein for causing movements of the working unit16, and is not limited to a stationary system, but for example, may also be an autonomous mobile system. For the console704, a table type structure or a control panel structure may be adopted.

When the robot arm702includes six or more independent joints (rotational or slide axes), the position and orientation of the working unit16can be set arbitrarily in an appropriate manner. An end actuator block30may be constructed integrally with an end portion708of the robot arm702.

The robot arm702is moved under operations of the console704, and may be configured to move automatically according to a given program, or to move correspondingly to movements of a joystick706disposed on the console704, or by a combination of such operations. The console704includes the functions of the aforementioned controller45.

Two joysticks706and a monitor710are provided on the console704, serving as an operation command section for mechanisms among those of the aforementioned operation command unit14excluding the actuator block30. Although not shown by the present illustration, two robot arms702may be provided, which are operated separately by two joysticks706. The two joysticks706are disposed at positions where they can be easily operated by both hands. The monitor710displays information of images or the like produced by an endoscope.

The joysticks706are capable of being moved up and down, left and right, and of making twisting or torsional movements, as well as tilting movements, wherein the robot arm702can be moved responsive to the movements of the joysticks706. Further, by the trigger lever32, the first command lever34, and the second command lever36which are provided on the grip handle26, the same operations as with the operation command unit14are possible. The joysticks706may also comprise a master arm. The communication means between the robot arm702and the console704may consist of wired or wireless communications, communication over a network, or any combination of the same.

The working mechanism for a medical manipulator and the cleaning method according to the present invention are not limited to the aforementioned embodiments. It should be understood that various other configurations may be adopted without deviating from the scope of the invention as set forth in the appended claims.