Medical manipulator

A medical manipulator wherein a first section provided with a driven coupling is detachably attached to a second section provided with a driving coupling that includes a drive source and is driven by the drive source. The driving coupling and the driven coupling are fitted to each other to transmit the drive force from the drive source to a tip-end operation part. In at least one coupling among the driving coupling and the driven coupling, tooth ends on the side where the fitting of the driving coupling and the driven coupling begins when the first section and the second section are connected become thinner towards the axial-direction end surface.

FIELD OF THE INVENTION

The present invention relates to a medical manipulator equipped with a drive source.

BACKGROUND OF THE INVENTION

In an endoscopic surgical operation (also referred to as “laparoscopic surgery”), one or a plurality of holes are punctured in the abdomen or the like of a patient, trocars (cylindrical instruments) are inserted through the holes, and a laparoscope (camera) and a plurality of forceps are inserted into the body cavity via the respective trocars. Grippers for gripping biological tissue, scissors, or blades of an electrosurgical scalpel are mounted to the distal end of the forceps as an end effector.

If the laparoscope and the forceps are inserted into the body cavity, an operator operates the forceps while viewing a state of the inner portion of the abdominal cavity, which is shown on a monitor that is connected to the laparoscope. Since the surgical procedure does not require a laparotomy, the burden on the patient is reduced, which reduces the number of days for postoperative recovery and leaving the hospital. For this reason, the fields that such an operative method can be applied to are expected to expand.

Other than typical forceps that are not provided with joints at distal end portions thereof, as forceps that are inserted through a trocar, forceps referred to as a medical manipulator have been developed that are provided with joints at distal end portions and which can carry out a rolling operation or a tilting operation of an end effector (for example, refer to Japanese Patent No. 4391762). In accordance with such a medical manipulator, a high degree of operational freedom is facilitated in the body cavity, manual procedures are made easy, and thus there are a large number of medical cases to which the medical manipulator may be applied.

Further, with the aim of improving operability and facilitating manipulation, a medical manipulator has been proposed that carries out a portion or all of the operations of a distal end working unit by a drive source (motor) (see, for example, Japanese Laid-Open Patent Publication No. 2008-104854). With this type of medical manipulator, a motor serving as a drive source is mounted in a handle on which an operating button is provided. An operating member (a portion corresponding to a forceps) including a shaft and the distal end working unit is capable of being attached and detached with respect to the handle. Multiple types of implements, such as a needle driver, an electrosurgical scalpel, and the like may be used as operating members, and various different types of such operating members are selectively attachable and detachable to and from the handle.

SUMMARY OF THE INVENTION

Incidentally, in the case that a portion on which the distal end working unit is disposed and a portion on which the drive source is disposed are capable of attachment and detachment to and from each other, as in the above-described medical manipulator, for transmitting a driving force from the drive source to the distal end working unit, it can be considered to adopt a configuration in which, accompanying connection of the two portions, the drive coupling and the driven coupling are fitted together mutually, wherein one of the couplings is a male coupling and the other of the couplings is a female coupling. However, when the drive coupling and the driven coupling contact one another, in the event that the teeth thereof are overlapped, it becomes difficult for the drive coupling and the driven coupling to be fitted together, and there is a concern that connection of the two portions cannot be performed smoothly.

The present invention has been devised while taking into consideration the aforementioned problems, and has the object of providing a medical manipulator, in which a portion on which the distal end working unit is disposed and a portion on which the drive source is disposed are capable of attachment and detachment to and from each other, and connection of the two portions can be performed smoothly.

For achieving the aforementioned object, the medical manipulator includes a handle, a shaft that is extended from the handle, a distal end working unit capable of operating with respect to the shaft, and a drive source for operating the distal end working unit. A first portion, which includes the distal end working unit and the shaft and on which a driven coupling is disposed, and a second portion, which includes the drive source and on which a drive coupling that is driven by the drive source is disposed, are capable of being attached and detached. In a state in which the first portion and the second portion are connected, the drive coupling and the driven coupling are fitted together, and a driving force of the drive source is transmitted to the distal end working unit. Further, on at least one of the drive coupling and the driven coupling, a tooth-end portion, on a side that initiates fitting between the drive coupling and the driven coupling when the first portion and the second portion are connected, becomes narrower toward an end surface thereof in an axial direction.

According to the above configuration, at a time of contact between the driven coupling and the drive coupling, even if the phases of the teeth thereof overlap, accompanying relative rotation between the driven coupling and the drive coupling, both of the couplings are fitted together along the tooth surfaces of the tooth-end portions, which become narrower toward the end surfaces in the axial direction. Consequently, fitting between the drive coupling and the driven coupling is carried out reliably and easily, and the connection of the first portion and the second portion can be performed smoothly.

In this case, the first portion may comprise a manipulator main body including a handle, and the second portion may comprise a drive unit that is capable of attachment and detachment with respect to the handle. In accordance with this configuration, in a medical manipulator, in which a common drive unit can be mounted and used with respect to handles having different functions and shapes, the drive unit can easily and reliably be attached to the handle.

The tooth-end portion may be disposed on the drive coupling. According to this configuration, as to the drive coupling and the driven coupling, the tooth-end portions, which become narrower toward end surfaces thereof in the axial direction, are provided on the drive coupling. Thus, with respect to any handles having different functions and shapes, fitting between the drive coupling and the driven coupling can easily and reliably be carried out upon attachment of the drive unit.

As to the drive coupling and the driven coupling, in the coupling on which the tooth-end portion is disposed, a curve of a tooth shape thereof may form an involute curve. By this configuration, since the tooth-end portions become thinner continuously in the axial direction from the tooth shape, which is formed by an involute curve, fitting between the drive coupling and the driven coupling can be carried out more smoothly.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, a preferred embodiment of a medical manipulator according to the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1is a perspective view with partial omission of a medical manipulator10A (hereinafter referred to in abbreviated form as a “manipulator10A”) according to an embodiment of the present invention. The manipulator10A is a medical device that grasps a needle, a thread, or a part of the living body or touches the living body using a gripper12(end effector) provided at the distal end thereof, and carries out a predetermined treatment.

The manipulator10A comprises a handle14on which a plurality of input operating members are provided, a shaft16that extends from the handle14, a distal end working unit18disposed on a distal end of the shaft16including a gripper12, and a drive unit22in which a motor20(drive source) is provided for driving the distal end working unit18, and which is capable of attachment and detachment to and from the handle14. A manipulator main body11A is made up from the handle14, the shaft16, and the distal end working unit18.

In the foregoing manner, with the manipulator10A according to the present embodiment, the manipulator main body11A (first portion) and the drive unit22(second portion) can be attached and detached to and from each other. In a state in which the drive unit22is mounted on the handle14(hereinafter referred to as an “attached state”), when the motor20is driven, the driving force of the motor20is transmitted to the distal end working unit18.

The manipulator10A shown inFIG. 1is constituted as a needle driver that is capable of grasping a medical needle (a curved needle or the like) with the gripper12disposed on the distal end thereof. The gripper12is a portion that carries out a surgical treatment, and in the illustrated example, the gripper12includes first and second gripper members12a,12b, and is configured to carry out opening and closing operations on the basis of a predetermined opening and closing operation axis Og. In the illustrated example, although concerning the gripper12, a case has been described in which the first gripper member12ais constituted as a fixed member and the second gripper member12bis constituted as a movable member, both of the gripper members12a,12bmay be constituted as movable members.

The posture of the distal end working unit18including the gripper12can be changed at a plurality of degrees of freedom with respect to the shaft16. In the present embodiment, the distal end working unit18can carry out a “tilting operation” (swinging operation) in which the distal end working unit18is operated to tilt in left and right (transverse or lateral) directions with respect to an axis of the shaft16about a tilt axis Oy, and a “rolling operation” in which the distal end working unit18is rotated about the axial line (roll axis Or) in the longitudinal direction of the distal end working unit18. The tilt axis Oy is not limited to being set in the vertical direction, and the tilt axis Oy may be set in a different direction that intersects the axis of the shaft16.

The shaft16is an oblong small diameter tubular member that connects the handle14and the distal end working unit18. InFIG. 1, a portion of the shaft16is omitted from illustration, and the shaft is rendered shorter than it actually is. A plurality of members configured to make up a power transmission mechanism are inserted through and arranged in a hollow portion of the shaft16. Such a power transmission mechanism transmits, from the handle14to the distal end working unit18, power that is necessary for carrying out the opening and closing operation of the gripper12, and the rolling operation and the tilting operation of the distal end working unit18. A structure may be provided in which one or a plurality of joints are provided at an intermediate location in the longitudinal direction of the shaft16to enable the tilting operation by the joints. Further, a structure may be provided in which the rolling operation is enabled at the proximal end of the shaft16, or at an intermediate location in the longitudinal direction of the shaft16.

The handle14is a portion that is gripped by an operator during use of the medical manipulator10A, and by input operating members (in the present embodiment, a later described tilt wheel26, a rolling switch28, and a lever30) being touched and operated by a finger, drives the distal end working unit18that is connected to the distal end of the shaft16.

The handle14comprises a body portion24that is connected to a proximal end of the shaft16, the tilt wheel26constituting a tilt operating unit that is provided on the body portion24, the rolling switch28(input operating member) constituting a rolling operating unit that is provided on the body portion24, and the lever30constituting an opening and closing operating unit that is provided on the body portion24.

The body portion24makes up a part that is gripped by a user when the manipulator10is used. In the present embodiment, the body portion24is constituted in the form of a stick that extends over a certain length in the axial direction of the shaft16. The body portion24includes a casing32made up from a left cover32aand a right cover32b, with frames, drive components (pulleys, gears, wires, etc.) or the like being arranged in the interior of the casing32. For insertion and installation of the drive unit22in the interior of the casing32from the rear side, a rearwardly open installation hole33(see alsoFIG. 4) is formed.

The tilt wheel26for carrying out a tilting operation of the distal end working unit18is disposed near the center in the longitudinal direction of the body portion24, and is rotatable about the vertically oriented axis of the handle14. The tilt wheel26is constituted as a manual operating member, such that the tilt wheel26partially protrudes from openings27provided on left and right sides of the casing32.

When the tilt wheel26is operated by being rotated, the operating force applied thereto is transmitted mechanically to the distal end working unit18through a tilting operation power transmission system, which is disposed internally in the handle14and the shaft16, whereupon the distal end working unit18is tilted about an axis (tilt axis Oy) in a non-parallel direction with respect to the axis of the shaft16. More specifically, when the tilt wheel26is rotated clockwise as viewed in plan, the distal end working unit18is tilted in a rightward direction about the handle14, whereas when the tilt wheel26is rotated counterclockwise as viewed in plan, the distal end working unit18is tilted in a leftward direction about the handle14.

With the manipulator10A of the illustrated example, the rolling switch28for carrying out a rolling operation of the distal end working unit18is disposed on an upper portion in the vicinity of the distal end of the body portion24. In the present embodiment, the rolling switch28is constituted as an electrical manipulating portion, which supplies an operating command to the motor20through a controller36. Because the rolling switch28is an electrical switch, the rolling switch28is not limited to the location shown inFIG. 1, but can be arranged in a different location of the handle14.

In a state in which the drive unit22is mounted in the handle14, and the power source of the controller36is turned on, when the rolling switch28is operated and moved, the operating state (position) of the rolling switch28is detected by the controller36, the motor20is driven under the controlling action of the controller36, and by the driving force of the motor20being transmitted to the distal end working unit18, the distal end working unit18is rotated about the longitudinal axis (roll axis Or) of the distal end working unit18.

FIG. 2is a cross-sectional view showing a switch structure including the rolling switch28, which is a transverse cross-sectional view taken along line II-II ofFIG. 1. InFIG. 2, portions apart from the switch structure of the handle14are omitted from illustration. In the present illustrated example, on a switch pedestal40having an arcuate slide surface40a, the rolling switch28is arranged swingably in a lateral direction. In another structural example, the rolling switch28may be supported through a rotating shaft on a switch support member, and thereby arranged in a swingable manner.

A movable-side contact member42is disposed on the rolling switch28, and on the side of the switch pedestal40, first and second fixed-side contact members44,46are disposed facing the movable-side contact member42. The rolling switch28is biased by a non-illustrated spring elastically toward a neutral position in the transverse direction, and in a state in which the rolling switch28is not pressed in the transverse direction, the rolling switch28maintains the neutral position (the position shown inFIG. 2) under an elastic action thereof.

When the rolling switch28is positioned in the neutral position, the movable-side contact member42remains out of contact with respect to either one of the first and second fixed-side contact members44,46, and the rolling operation of the distal end working unit18is not performed.

When the rolling switch28is operated to move the switch pedestal40in a leftward direction, a first contact point42aof the movable-side contact member42comes into contact with a contact point44aof the first fixed-side contact member44, whereupon the operating state of the rolling switch28is detected by the controller36, and under a drive control of the motor20by the controller36, the distal end working unit18is rotated to the left.

When the rolling switch28is operated to move the switch pedestal40in a rightward direction, a second contact point42bof the movable-side contact member42comes into contact with a contact point46aof the second fixed-side contact member46, whereupon the operating state of the rolling switch28is detected by the controller36, and under a drive control of the motor20by the controller36, the distal end working unit18is rotated to the right.

A lever30for performing an opening and closing operation of the gripper12is disposed on a lower part of the body portion24, and is swingably mounted upward and downward about the distal end side thereof which serves as a support point. According to the present embodiment, the lever30is constructed as a manual operating member, in which an opening and closing operation of the gripper12is carried out by mechanically transmitting to the gripper12of the distal end working unit18an operating force applied with respect to the lever30. More specifically, a structure is provided in which the gripper12is opened when the lever30is opened, and the gripper12is closed when the lever30is closed.

As shown inFIG. 1, the drive unit22of the manipulator10A is used in a condition of being connected to the controller36through a cable54. The controller36controls the supply of power and driving or the like of the motor20, and receives electrical power from an external power source. In a state in which the drive unit22is mounted on the handle14, when the rolling switch28is operated, the controller36controls driving of the motor20in response to operation thereof. The rotation of the motor20may be detected, and the motor20may be feedback controlled through the controller36.

The form of use can be one in which, concerning the manipulator10A that is constructed in the foregoing manner, the manipulator main body11A can be discarded after being used a predetermined number of times, whereas the drive unit22can be used repeatedly many times by changing the manipulator main body11A that is connected to the drive unit22.

FIG. 3is a perspective view of the drive unit22.FIG. 4is a vertical cross-sectional view with partial omission of a proximal end side of the medical manipulator10A. The drive unit22includes a housing48, the motor20(drive source) disposed inside the housing48, and a drive coupling50(drive member) that is fixed to an output shaft21of the motor20. The cable54including a plurality of power lines52and signal lines53is connected to the proximal end side of the drive unit22. Inside the housing48, the power lines52are connected to the motor20, and the signal lines53are connected to a plurality of unit-side terminal members84, to be discussed later.

As shown inFIG. 1, a guide mechanism55, which guides movement of the drive unit22relative to the handle14when the drive unit22is attached and detached with respect to the handle14, is connected to the manipulator10A.FIG. 5is a transverse cross-sectional view taken along line V-V ofFIG. 4. As shown inFIGS. 4 and 5, the guide mechanism55includes guide rails56disposed on the handle14, and guide receiving members58disposed on the drive unit22and which are capable of sliding along the guide rails56.

More specifically, as shown inFIG. 5, the guide rails56project out respectively from left and right inner surfaces of the casing32, and extend along a longitudinal direction of the handle14. The guide receiving members58are disposed as groove-like shapes on left and right outer side surfaces of the housing48of the drive unit22, and extend longitudinally along the drive unit22. As shown inFIG. 3, distal ends of the guide receiving members58are open at a distal end of the housing48.

In the present embodiment, the motor20is housed hermetically in the interior of the housing48. More specifically, as shown inFIG. 4, a ring-shaped first seal member60is arranged on a distal end inner circumferential portion of the housing48, and an inner circumferential portion of the first seal member60is placed in slidable contact hermetically with an outer circumferential portion of the output shaft21of the motor20. At a proximal end part of the housing48, a ring-shaped lid member62is screw-engaged and fixed, and a hollow cable connecting member64is screw-engaged and fixed in the lid member62. A washer66is gripped between the cable connecting member64and the lid member62, and a ring-shaped second seal member68is interposed between the washer66and the housing48. The cable connecting member64is constituted from a plurality of components. A liquidtight and airtight seal is formed between the cable54and the cable connecting member64.

In this manner, by the first seal member60that is provided on the distal end side of the housing48, a hermetic seal is maintained between the motor20and the housing48, and by the second seal member68that is provided on the proximal end side of the housing48, the proximal end side of the housing48is hermetically sealed and closed. Further, the housing48and the motor20are fixed together mutually by a screw47(seeFIG. 4). Between the screw47and a hole48bof the housing48through which the screw47is inserted, an adhesive is filled in an airtight manner. Furthermore, between a plurality of later-described unit-side terminal members84and insertion holes94into which the unit-side terminal members84are inserted, an adhesive is filled in an airtight manner. By the above constitution, a hermetically sealed condition, i.e., airtightness, is secured in the interior of the housing48.

As shown inFIG. 4, in a state in which the drive unit22is attached to the handle14, the drive coupling50(drive member), which is fixed to the output shaft21of the motor20, is fitted (enmeshed) with a driven coupling70disposed on the side of the handle14. By the drive coupling50and the driven coupling70, a power coupling69is constituted whereby, in a state in which the drive unit22is attached to the handle14, a rotary driving force of the motor20is transmitted to the side of the handle14.

In the present embodiment, a plurality of gear teeth51are provided, which are arrayed circumferentially on an inner circumferential portion of the drive coupling50, and a plurality of gear teeth71are provided, which are arrayed circumferentially on an outer circumferential portion of the driven coupling70. The drive coupling50and the driven coupling70are engaged together coaxially. The driven coupling70is fixed to a gear shaft72provided in the handle14. A rotational force, which is input from the drive coupling50to the driven coupling70, is transmitted to the gear shaft72, and further is transmitted to the distal end working unit18via another gear shaft73disposed in the handle14, a gear tube74that is enmeshed with the gear shaft73, and a torque-transmitting pipe75that is fixed coaxially with the gear tube74.

FIG. 6is a perspective view of the drive coupling50. Below, in relation to the drive coupling50and the constituent components thereof, an open side of the drive coupling50will be referred to as a distal end side or a distal end direction. In the present illustrated example, in the drive coupling50, the curve of the tooth shape forms an involute curve.

On the respective teeth51of the drive coupling50, tooth-end portions76(in the case of the illustrated example, distal end tooth portions in the direction of the axial line “a”), on a side that initiates fitting when the drive coupling50and the driven coupling70are connected, are shaped to taper into rectangular ribs toward the distal end side from the involute tooth shape. Stated otherwise, tooth surfaces76aon both sides of the respective tooth-end portions76are not parallel to the axial line “a” of the drive coupling50, but rather are tilted with respect to the axial line “a” so as to approach mutually in a circumferential direction in the direction of the distal end. Consequently, the widths of the respective tooth-end portions76become smaller (narrower) toward the distal end side (on the side of end surfaces76bthereof in the direction of the axial line “a”) of the drive coupling50.

Furthermore, on the tooth-end portions76of the respective teeth51, tapered portions78are provided, which are tilted so as to be displaced radially-outwardly toward the direction of the distal end of the drive coupling50.

In the present illustrated example, the drive coupling50is constituted as a female coupling, and the driven coupling70is constituted as a male coupling. However, in a modification of the present embodiment, the drive coupling50may be constituted as a male coupling, and the driven coupling70may be constituted as a female coupling. Further, in the illustrated example, the tooth-end portions76, which narrow toward the end surfaces76bin the axial direction, are disposed on the drive coupling50. However, in another modification of the present embodiment, similar tooth-end portions, which narrow toward the end surfaces (proximal end surfaces) in the axial direction, may be disposed on the driven coupling70.

As shown inFIG. 4, in the manipulator10A, there is further provided an electrical connection mechanism80that electrically connects the handle14and the drive unit22accompanying attachment of the drive unit22to the handle14. The electrical connection mechanism80includes handle-side terminal members82made up from a conductive material disposed on the handle14, and unit-side terminal members84made up from a conductive material disposed on the drive unit22. The handle-side terminal members82and the unit-side terminal members84preferably are constituted from a material that resists corrosion, for example, stainless steel, titanium, a titanium alloy, etc.

In the handle14, a unit holder86is provided that extends in forward and rearward directions of the handle14. On an upper surface of a proximal end side of the unit holder86, a plurality of the handle-side terminal members82is provided. As shown inFIGS. 7A and 7B, in the present illustrated example, five handle-side terminal members82ato82eare arranged at intervals in the widthwise direction (lateral direction) of the handle14.

Each of the handle-side terminal members82is fixed to the unit holder86by a fixing part87(screw) at a distal end side thereof, and elastically deformable elastic pieces88, which are folded back upwardly and around toward the distal end, are provided on proximal end sides of the handle-side terminal members82. The elastic pieces88include portions that are convexly shaped upwardly, and the convexly shaped apex portions88athereof come into contact with the unit-side terminal members84. The elastic pieces88, instead of being disposed on the handle-side terminal members82, may be disposed on the unit-side terminal members84. The handle-side terminal members82of the present illustrated example are constituted integrally by spring elements for pressing the terminals, and electrically conductive elements. However, a structure can be adopted in which the spring elements and the electrically conductive elements are two separate members. In this case, for example, the handle-side terminal members82may be constituted from conductive terminal main bodies, which are arranged displaceably, and springs for pressing the main bodies. The springs need not be metallic, but may be made from carbon or resin. Further, the shape of the springs is not particularly limited. Plate springs, helical springs, or the like may be used.

As shown inFIG. 7A, among the five handle-side terminal members82ato82e, the centrally disposed handle-side terminal member82cis arranged at a lowest position, the handle-side terminal members82b,82ddisposed adjacent to both sides of the handle-side terminal member82care arranged at positions higher than the central handle-side terminal member82c, and the outermost disposed handle-side terminal members82a,82eare arranged at positions higher than the handle-side terminal members82b,82dthat lie inwardly adjacent thereto.

As will be discussed later, the two handle-side terminal members82b,82dfunction as detection terminals for detecting attachment and detachment of the drive unit22. As shown inFIG. 7B, among the five handle-side terminal members82ato82e, the two handle-side terminal members82b,82dthat function as detection terminals are arranged at positions shifted more frontward (toward the distal end side) than the remaining handle-side terminal members82a,82c,82e.

The central handle-side terminal member82cand the two handle-side terminal members82a,82don outer sides thereof are capable of conducting electricity, through respective lead wires90connected thereto, to the movable-side contact member42of the rolling switch28, and first and second fixed-side contact members44,46shown inFIG. 2. More specifically, when the movable-side contact member42and the first fixed-side contact member44are in contact, electricity is conducted between the central handle-side terminal member82cand the left handle-side terminal member82a. Further, when the movable-side contact member42and the second fixed-side contact member46are in contact, electricity is conducted between the central handle-side terminal member82cand the right handle-side terminal member82e.

In a state in which the drive unit22is mounted on the handle14, when the rolling switch28is positioned in a neutral position, because the central handle-side terminal member82cis not electrically connected to either one of the left and right handle-side terminal members82a,82e, the controller36performs a control to place the motor20in a stopped condition.

When the rolling switch28is operated to move in a leftward direction, electricity is conducted between the central handle-side terminal member82cand the left handle-side terminal member82a. Such a condition is detected by the controller36, whereupon the controller36controls driving of the motor20, and in the distal end working unit18, a left-handed rolling operation is carried out.

When the rolling switch28is operated to move in a rightward direction, electricity is conducted between the central handle-side terminal member82cand the right handle-side terminal member82e. Such a condition is detected by the controller36, whereupon the controller36controls driving of the motor20, and in the distal end working unit18, a right-handed rolling operation is carried out.

In this manner, the handle-side terminal members82function as switch terminals (operation terminals) for detecting the operating state of the rolling switch28.

The other two handle-side terminal members82b,82dare electrically connected via a short-circuiting member92. The handle-side terminal members82b,82dfunction as detection terminals for detecting whether or not the drive unit22has been attached with respect to the handle14.

In the present illustrated example, among the five handle-side terminal members82ato82e, the switch terminal and the detection terminal are arranged alternately one by one. However, the manner of arrangement thereof is not limited, and the switch terminal and the detection terminal may be arranged in any manner.

Next, the unit-side terminal members84will be described.FIG. 8is a perspective view of the drive unit22, which is shown partially by phantom lines.FIG. 9is a perspective view as seen obliquely from below the drive unit22. In the present embodiment, five unit-side terminal members84ato84eare disposed mutually in parallel and with intervals therebetween in the circumferential direction of the motor20. The respective unit-side terminal members84are shaped in the form of elongate narrow pins, with the longitudinal directions thereof being arranged along the longitudinal direction of the drive unit22. The respective unit-side terminal members84may be plate-shaped.

Proximal end sides of the respective unit-side terminal members84are retained by spacers96that are fixed to the housing48.

The respective unit-side terminal members84are fixed to the housing48in a state of penetrating through the insertion holes94(seeFIG. 4) that are disposed in the housing48. As shown inFIG. 4, distal end sides of the respective unit-side terminal members84project out from the insertion holes94, and protrude from the housing48on the lower surface side of the housing48.

In a state in which the drive unit22is mounted on the handle14, the central unit-side terminal member84cand the outermost unit-side terminal members84a,84eare in contact with the central handle-side terminal member82cand the outermost handle-side terminal members82a,82e(switch terminals) provided on the handle14, whereas the remaining two unit-side terminal members84b,84dare in contact with the two handle-side terminal members82b,82d(detection terminals) provided on the handle14.

On a lower portion of the housing48, at intervals in the widthwise direction of the housing48, a plurality of (four) partition walls98are provided that extend in the longitudinal direction of the housing48and project downwardly therefrom. Distal end side portions of the unit-side terminal members84are arranged with respective gaps between the partition walls98.

Further, on a lower portion of the housing48, at a position in front of the respective unit-side terminal members84, a plurality of downwardly projecting protrusions100are provided so as to face the distal ends of the unit-side terminal members84. The protrusions100include tapered lower surfaces100athat are tilted so as to be displaced downwardly toward the rear.

As shown inFIG. 1, in the manipulator10A, there is further provided a lock mechanism102that restricts the drive unit22so as not to become detached from the handle14, in a state in which the drive unit22has been attached to the handle14. In the present embodiment, the lock mechanism102includes engagement members104disposed on the handle14, and a lever device106disposed on the drive unit22.

Accompanying attachment of the drive unit22to the handle14, portions of the lever device106engage with the engagement members104, whereby the drive unit22is prevented from becoming detached and separating away from the handle14. On the other hand, by releasing the engagement between the engagement members104and the lever device106, the drive unit22is capable being detached from the handle14. More specifically, the lock mechanism102is constituted in the manner described below.

As shown inFIG. 7A, the engagement members104in the lock mechanism102are disposed on both left and right sides of a proximal end portion of the unit holder86. In the present illustrated example, elongate grooves105are formed on both left and right sides of the proximal end portion of the unit holder86, and portions on proximal end sides of the grooves105function as the engagement members104.

As shown inFIG. 10, the lever device106in the lock mechanism102includes lever members108, distal end parts of which are connected swingably with respect to the housing48, and being bent in crank-like shapes at intermediate regions in the longitudinal direction thereof, operating tabs110fixed to proximal end outer sides of the lever members108, and a biasing member112that biases the lever members108elastically downward.

The lever members108and the operating tabs110are disposed in a pair to the left and right of the drive unit22. The left and right lever members108are capable of swinging with respect to the housing48independently of one another. On each of the lever members108, downwardly projecting engagement pawls109are disposed more on the distal end side than the portions thereof that are bent in crank-like shapes.

The drive unit22is inserted from a proximal end side of the handle14, and when advanced up to a predetermined position, proximal end surfaces109aof the engagement pawls109become hooked over the engagement members104(seeFIG. 7A) provided on the handle14. As a result, a locked state is brought about in which movement of the drive unit22in the proximal end direction relative to the handle14is prevented. Further, tapered lower surfaces109b, which are displaced upwardly toward the distal end direction of the lever members108, are provided on the engagement pawls109.

The operating tabs110project out to the left and right from the proximal end of the lever members108, and protrude through openings49provided on both left and right side lower portions of the housing48. Consequently, a user can directly touch and operate the operating tabs110that protrude from the openings49. The biasing member112in the present illustrated example includes a pair of springs113, which bias the left and right lever members108in a downwardly pressed manner.

As shown inFIG. 9, a lower cover114is fixed to a proximal end lower portion of the housing48. Proximal end portions of the lever members108are biased elastically by the biasing member112, and in a state of being pressed against the lower cover114, are arranged between the housing48and the lower cover114. The biasing member112is fixed to the lower cover114.

In a state in which the drive unit22is mounted on the handle14, when the operating tabs110are pressed upwardly, the lever members108are rotated upwardly in opposition to the elastic force of the biasing member112, whereupon the engagement between the engagement pawls109and the engagement members104is released. Consequently, by releasing locking by the lock mechanism102, the drive unit22is capable of being displaced in the proximal end direction relative to the handle14.

Instead of the vertically swingably disposed lever members108, according to a modified example, lever members constructed in the form of plate springs, which are elastically deformable in lateral (left and right) directions, may be disposed on both left and right sides, or on either the left or right side of the drive unit22. In this case, engagement pawls (portions corresponding to the engagement pawls109), which are capable of engaging with engagement members (portions corresponding to the engagement members104) disposed on the handle14, are provided on outer surfaces of the lever members according to the modified example.

A return spring member115is fixed to the lower cover114. The return spring member115in the present illustrated example includes two elastic members116that are separated in the lateral direction, and in a state in which the drive unit22is attached to the handle14, the elastic members116are pressed by pressing members118(seeFIG. 7A) disposed on the proximal end of the unit holder86, and thus are subjected to elastic compressive deformation. Accordingly, the occurrence of play or chattering between the handle14and the drive unit22can be prevented. If locking by the lock mechanism102is released to enable displacement of the drive unit22relative to the handle14, accompanying the shapes of the elastic members116being resiliently restored, the drive unit22is moved in the proximal end direction by a slight amount with respect to the handle14. A chattering prevention mechanism to prevent chattering between the pressing members118and the elastic members116may be provided at a location other than that shown in the present illustrated example.

As shown inFIG. 9, a positioning pin120that projects in the proximal direction is disposed on a proximal end side lower portion (specifically, the lower cover114) of the housing48. In a state in which the drive unit22is mounted on the handle14, the positioning pin120is inserted into a positioning hole122(seeFIG. 7A) disposed on the proximal end of the unit holder86.

The positioning pin120may be disposed not on the housing48, but on another portion (for example, on the lower cover114) of the drive unit22. The positioning hole122may be disposed not on the unit holder86, but on another portion of the handle14, for example, on the casing32. Further, differing from the present illustrated example, the positioning hole122may be disposed on the side of the drive unit22, and the positioning pin120may be disposed on the side of the handle14.

In the manipulator10A according to the present embodiment, only the rolling operation of the distal end working unit18is effected by an electrical drive provided through the motor20, whereas the tilting operation and the opening/closing operation of the distal end working unit18are effected by a manual drive. However, in a modification of the manipulator10A, a structure may be provided in which not only the rolling operation, but also one or both of the tilting operation and the opening/closing operation are effected by an electrical drive.

Next, operations of the manipulator10A, which is constructed in the foregoing manner, will be described.

During use of the manipulator10A, the drive unit22is attached to the handle14. As shown inFIG. 11, when the drive unit22starts to be inserted from the proximal end side of the handle14, the guide rails56disposed on the handle14are inserted into the guide receiving members58(see alsoFIG. 3) disposed on the drive unit22. Consequently, under a guiding action by the guide rails56and the guide receiving members58, the drive unit22can be inserted smoothly into the handle14.

In addition, upon further advancement of the drive unit22, as shown inFIG. 12, the drive coupling50approaches toward the driven coupling70, and the elastic pieces88of the handle-side terminal members82ato82ebegin to enter into a groove48a(see alsoFIG. 9) that is formed on a lower portion of the housing48.

As shown inFIG. 13, upon further advancement of the drive unit22, the distal end of the drive coupling50and the proximal end of the driven coupling70come into contact, whereupon fitting of the drive coupling50with the driven coupling70is started. In this case, since the tooth-end portions76of the teeth51of the drive coupling50are formed to become smaller in width toward the open side (seeFIG. 6), at the time of contact between the drive coupling50and the driven coupling70, although the phases of the teeth51,71overlap, while the driven coupling70undergoes rotation, the drive coupling50is inserted along the tooth surfaces76aof the tooth-end portions76, which become narrower toward the end surfaces76bin the axial direction. Consequently, fitting between the drive coupling50and the driven coupling70can be carried out reliably and easily. Further, since the tapered portions78, which are tilted so as to be displaced in a radial outward direction toward the distal end side, are provided on the distal ends of the teeth51of the drive coupling50, fitting of the drive coupling50and the driven coupling70can be performed more smoothly.

Further, as shown inFIG. 13, at a point in time that fitting between the drive coupling50and the driven coupling70is started, the elastic pieces88of the handle-side terminal members82are pressed and resiliently deformed downwardly by the protrusions100provided on the lower portion of the housing48, and a condition is brought about in which contact with the unit-side terminal members84is prevented. Since the tapered lower surfaces100a(seeFIG. 9) are provided on the protrusions100, the elastic pieces88of the handle-side terminal members82are easily deformed elastically accompanying movement of the drive unit22. Consequently, there is no impediment to insertion of the drive unit22.

As shown inFIG. 14, upon further advancement of the drive unit22, among the handle-side terminal members82ato82e, the three handle-side terminal members82a,82c,82ethat constitute switch terminals come into contact with the three unit-side terminal members84a,84c,84ethat correspond therewith. At this time, the remaining two handle-side terminal members82b,82dthat constitute detection terminals do not yet come into contact with the unit-side terminal members84b,84d.

In addition, as shown inFIG. 15, upon further advancement of the drive unit22, the two handle-side terminal members82b,82dthat constitute detection terminals come into contact with the unit-side terminal members84b,84d. In this manner, in the manipulator10A, when the drive unit22is moved to mount the drive unit22with respect to the handle14, after the handle-side terminal members82a,82c,82ethat constitute the switch terminals have contacted the unit-side terminal members84a,84c,84ecorresponding thereto, the handle-side terminal members82b,82dthat constitute the detection terminals are placed in contact with the remaining unit-side terminal members84b,84d. Thereafter, the positioning pin120that is provided on the lower portion of the drive unit22(lower portion of the housing48) starts to be fitted into the positioning hole122provided on the proximal end of the unit holder86.

On the other hand, while the handle-side terminal members82and the unit-side terminal members84come into contact, and as shown inFIG. 16A, the engagement pawls109of the lever members108ride up onto the engagement members104. In addition, at a position in which the drive unit22has advanced slightly from the position (seeFIG. 15) in which the handle-side terminal members82b,82dand the unit-side terminal members84b,84dbegin to contact one another, as shown inFIG. 16B, the engagement pawls109drop off from the engagement members104, and under the biasing action from the biasing member112(seeFIG. 10), the lever members108are restored to their original positions. As a result, a condition (locked state) is brought about in which movement of the drive unit22in the proximal end direction relative to the handle14is prevented.

Moreover, at the position at which the drive unit22has been advanced slightly from the position where the engagement pawls109drop off from the engagement members104, as shown inFIG. 4, by the distal end of the housing48of the drive unit22abutting against a portion of the handle14(in the illustrated example, a frame124that rotatably supports the gear shaft72to which the driven coupling70is fixed), the drive unit22is stopped. As a result, a state (attached state) is brought about in which the drive unit22is attached appropriately with respect to the handle14. In the attached state, not only the guide rails56and the guide receiving members58are fitted together, but since positioning is also effected by fitting the positioning pin120into the positioning hole122, a secure positional relationship between the handle14and the drive unit22is stably maintained.

In the attached state of the drive unit22, when the rolling switch28is operated, the operating state of the rolling switch28is detected in the controller36through the handle-side terminal members82a,82c,82e(seeFIGS. 7A and 7B) and the unit-side terminal members84a,84c,84e(seeFIG. 8) that make up the electrical connection mechanism80, and the controller36controls driving of the motor20. The driving force of the motor20is transmitted to the handle14through the power coupling69that is made up from the drive coupling50and the driven coupling70, and motive power is further transmitted to the distal end working unit18through the power transmission system in the interior of the handle14, whereupon the distal end working unit18performs a predetermined operation (in the present example, a rolling operation).

To remove the drive unit22from the handle14, the operation tabs110provided in the drive unit22(seeFIG. 1) may be operated and pulled up with the fingers. Upon doing so, together with the lever members108being displaced upwardly in opposition to the elastic force of the biasing member112, the engagement between the engagement pawls109and the engagement members104is released, and the drive unit22can be moved in the proximal end direction with respect to the handle14. At this time, due to the resilient force of the elastic members116(seeFIG. 10) in the return spring member115, the drive unit22moves slightly in the proximal end direction, and therefore, it is easy to pull out the drive unit22.

The drive unit22, which is constructed as described above, can be mounted and used not only with the manipulator main body11A, which is constituted as a needle driver, but also with a manipulator main body11B, which is constituted as an electrosurgical scalpel, as shown inFIG. 17. In this case, by combining together the manipulator main body11B and the drive unit22, an electrosurgical scalpel type medical manipulator10B (hereinafter referred to in an abbreviated form as a “manipulator10B”), which is driven by the motor20, is constructed.

The manipulator main body11B comprises a handle126on which a plurality of input operating members are provided, a shaft128that extends from the handle126, and a distal end working unit132disposed on a distal end of the shaft128and including a gripper130(end effector). The manipulator main body11A shown inFIG. 1is of an overall stick-like (rod-like) shape suitable for use as a needle driver. In contrast thereto, with the manipulator main body11B shown inFIG. 17, a grip127that projects downwardly on a lower part of the handle126is provided, and the handle126is in the shape of a pistol as a whole, having a shape that is suitable for use as an electrosurgical scalpel. Further, such a pistol type handle shape also is suitable for use with scissors, a grasping implement, and a peeling implement, etc.

The gripper130is capable of making opening and closing movements, and serves as a portion for gripping biological tissue, and cauterizing the biological tissue by conduction of current through the tissue. The gripper130of the present illustrated example includes a first gripper member130aand a second gripper member130b, which are capable of swinging or pivoting in mutually opposite directions about an opening and closing operation axis Og. The manipulator main body11B may be constructed as a bipolar type of electrical scalpel in which the first gripper member130aand the second gripper member130bare electrically energized at different polarities, or a monopolar type of electrical scalpel in which either one of the first gripper member130aor the second gripper member130bis electrically energized.

The opening and closing operation of the gripper130is carried out by mechanically transmitting the operation of a lever134, which is provided on the handle126, to the distal end working unit132through a non-illustrated opening/closing drive transmission system. More specifically, in the present illustrated example, the lever134is constructed as a manual operating member, and opening and closing operations of the gripper130are performed not by a motor drive, but by a manual drive on the basis of an operating force from the operator.

The lever134is disposed for displacement in forward and rearward directions with respect to the grip127, such that when the lever134is pressed out forwardly relative to the grip127, the gripper130opens, and when the lever134is drawn in rearwardly relative to the grip127, the gripper130is closed. A structure may also be adopted in which the opening/closing operation of the gripper130is performed by a motor drive.

In the manipulator10B in accordance with the combination of the manipulator main body11B and the drive unit22, a power supplying connector136is connected to the handle126, whereby the manipulator10B can be used as an electrosurgical scalpel. The power supplying connector136is connected to a non-illustrated high frequency power supply device through an energizing cable138, and by the high frequency power supply device, a high frequency voltage is applied in order to electrically energize the gripper130.

The distal end working unit132is capable of being tilted laterally (yaw operation) by a bending portion140disposed on a distal end of the shaft128. The bending portion140has a plurality of joint members142, which are coupled rotatably within a predetermined angular range to one another. Although in a state in which the joint members142are aligned coaxially, the bending portion140exhibits a linear shape, when the adjacent joint members142themselves are mutually tilted, the bending portion140exhibits a curved shape as a whole.

The tilting operation of the distal end working unit132is carried out by the controller36controlling driving of the motor20based on an operation made with respect to a tilting switch144provided on the handle126, and by mechanically transmitting the driving force of the motor20to the distal end working unit132through the handle126and the shaft128. More specifically, in the present illustrated example, the tilting switch144is constructed as an electrical operating member, and the tilting operation of the distal end working unit132is performed by a motor drive.

The distal end working unit132, at a portion thereof located more toward the distal end side than the bending portion140, is capable of executing a rolling operation about the roll axis Or. The rolling operation is carried out by mechanically transmitting a rotating operation made with respect to a rotating knob146(input operating member), which is provided on the handle126, to the distal end working unit132through a non-illustrated rolling drive transmission system. More specifically, in the present illustrated example, the rotating knob146is constructed as a manual operating member, and the rolling operation of the distal end working unit132is performed not by a motor drive, but by a manual drive on the basis of an operating force from the operator. A structure may also be adopted in which the rolling operation of the distal end working unit132is performed by a motor drive.

On an upper end side of the handle126, a mounting hole126ais provided, which opens rearwardly. The drive unit22is inserted into the mounting hole126a, and thus can be mounted with respect to the handle126. More specifically, the drive unit22is capable of being attached to and detached from the proximal end side of the handle126. In a state in which the drive unit22is mounted in the handle126, so that operating tabs110, which are disposed on the drive unit22, can be touched and operated by the user, the operating tabs110protrude through openings127bprovided on side surfaces on left and right sides of the handle126.

Although omitted from illustration inFIG. 17, guide rails56(seeFIG. 5) are provided on the handle126, which are similar to those of the handle14in the manipulator main body11A. Consequently, under a guiding action of a guide mechanism55made up from the guide rails56and the guide receiving members58, the drive unit22can move smoothly relative to the handle126, and the drive unit22can be mounted easily and reliably at an accurate positional relationship with respect to the handle126.

Although omitted from illustration inFIG. 17, a driven coupling70(seeFIG. 4) is provided in the handle126, which is similar to that of the handle14in the manipulator main body11A. Consequently, in a state in which the drive unit22is mounted with respect to the handle126, by engagement of the drive coupling50and the driven coupling70, a driving force of the motor20can be transmitted reliably to the handle126.

Although omitted from illustration inFIG. 17, a plurality of handle-side terminal members82(seeFIG. 4) are provided in the handle126, which are similar to those of the handle14in the manipulator main body11A. Consequently, in a state in which the drive unit22is mounted with respect to the handle126, by the plural handle-side terminal members82being placed in contact with the plural unit-side terminal members84, an operating state of the tilting switch144can be detected reliably by the controller36, and the controller36can appropriately control driving of the motor20.

On the handle126, similar to the handle14shown inFIG. 1and the like, engagement members104are provided that are capable of engaging with engagement pawls109of the lever members108disposed on the drive unit22. Accordingly, together with attachment of the drive unit22with respect to the handle126, a condition (locked state) is brought about in which movement of the drive unit22in the proximal end direction relative to the handle126is prevented.

In this manner, the drive unit22can be attached and detached with respect to the manipulator main bodies11A,11B (forceps portions) having different functions and shapes, and in the attached state, transmission of a driving force of the motor20to the handles14,126, electrical connections between the handles14,126and the drive unit22, and preventing the drive unit22from moving with respect to the handles14,126can reliably be achieved.

The form of the manipulator main bodies11A,11B, which enable attachment and detachment of the drive unit22, is not limited to the two forms (needle driver, electrosurgical scalpel) described above, and forms having other different functions and shapes, for example, scissors, a grasping forceps, or the like, may be provided. In addition, a suction device, a cleaning device, an energy device, etc., may be provided.

As described above, with the medical manipulators10A,10B according to the present embodiment, by providing the guide mechanism55(seeFIG. 5), which is made up from the guide rails56and the guide receiving members58, the drive unit22can be attached smoothly and easily at an appropriate positional relationship with respect to the handles14,126. Further, by providing the power coupling69(seeFIG. 4), which is made up from the drive coupling50and the driven coupling70, in a state in which the drive unit22is attached with respect to the handles14,126, based on the driving force of the motor20, the distal end working unit18can be operated reliably. Furthermore, by providing the electrical connection mechanism80(seeFIG. 4) made up from the handle-side terminal members82and the unit-side terminal members84, the rolling switch28operating condition can be detected in the controller36, and driving of the motor20can appropriately be controlled.

Consequently, by being equipped with the guide mechanism55, the power coupling69, and the electrical connection mechanism80in the foregoing manner, the drive unit22can be mounted easily and reliably with respect to handles14,126having different shapes and functions, and together therewith, based on an operation of an input operating member (rolling switch28, tilting switch144) disposed on the handles14,126, the motor20can be driven, and the distal end working unit18can be operated by the driving force thereof.

In the case of the present embodiment, a movement direction of the drive unit22when the drive unit22is attached and detached with respect to the handles14,126may be a lengthwise direction of the drive unit22and a longitudinal (forward/rearward) direction of the handles14,126. According to such a configuration, in a state in which the drive unit22is attached to the handles14,126, the medical manipulators10A,10B can be constructed in a compact manner, without the drive unit22projecting out significantly from the handles14,126.

In the present embodiment, the drive unit22is capable of attachment and detachment from a side that is opposite to the side on which the shafts16,128are provided in the handles14,126. In accordance with this configuration, since the shafts16,128do not become an obstruction during attachment and detachment of the drive unit22, the operation of attaching and detaching the drive unit22is facilitated.

In the case of the present embodiment, the guide mechanism55includes the guide rails56disposed on the handles14,126, and the guide receiving members58disposed on the drive unit22. According to this configuration, when the drive unit22is attached to the handles14,126, since the guide receiving members58provided on the drive unit22slide along the guide rails56provided on the handles14,126, the attachment operation of the drive unit22can be carried out smoothly and easily. Further, upon attachment thereof, the drive unit22can be guided appropriately to an exact mounting position.

In the present embodiment, in a state in which the drive unit22is mounted with respect to the handles14,126, because the drive coupling50is fitted coaxially with the driven coupling70, the driving force from the motor20can be transmitted efficiently to the driven coupling70from the drive coupling50.

In the present embodiment, at the time of contact between the drive coupling50and the driven coupling70, although the phases of the teeth51,71overlap, accompanying relative rotation between the drive coupling50and the driven coupling70, both of the couplings50,70are fitted together along the tooth surfaces76a(seeFIG. 6) of the tooth-end portions76, which become narrower toward the end surfaces76bin the axial direction. Consequently, fitting between the drive coupling50and the driven coupling70can be carried out reliably and easily.

In the case of the present embodiment, as to the drive coupling50and the driven coupling70, the tooth-end portions76, which become narrower toward the end surfaces76bthereof in the axial direction, are provided on the drive coupling50. Thus, with respect to either one of the handles14,126having different functions and shapes, fitting between the drive coupling50and the driven coupling70can easily and reliably be carried out upon attachment of the drive unit22.

In the case of the present embodiment, in the drive coupling50in which the tooth-end portions76are provided, a curve of the tooth shape is formed as an involute curve. By this configuration, since the tooth-end portions76become thinner continuously in the axial direction from the tooth shape, which is formed by an involute curve, fitting between the drive coupling50and the driven coupling70can be carried out more smoothly.

In the case of the present embodiment, accompanying relative movement of the drive unit22with respect to the handles14,126when the drive unit22is attached and detached with respect to the handles14,126, the unit-side terminal members84slide while in abutment with the handle-side terminal members82. In accordance with such a configuration, upon attachment and detachment of the drive unit22with respect to the handles14,126, the handle-side terminal members82and the unit-side terminal members84rub against each other, and at the portions subjected to such mutual rubbing, an effect (refreshing effect) by which the electrical contact point is activated can be obtained. Consequently, for example, with respect to the drive unit22or the manipulator main bodies11A,11B, even if corrosion in the handle-side terminal members82or the unit-side terminal members84occurs by performing a sterilization treatment (autoclave sterilization, etc.) using high-pressure steam, or even if foreign matter is deposited thereon or adhered thereto, the electrical connection can suitably be assured as a result of the refreshing effect upon attachment and detachment of the drive unit22.

In the case of the present embodiment, the handle-side terminal members82include the elastic pieces88(refer toFIG. 7A) that are capable of being deformed elastically, and in the attached state, the handle-side terminal members82and the unit-side terminal members84come into contact at portions of the elastic pieces88. In accordance with this configuration, since the handle-side terminal members82and the unit-side terminal members84are held together in intimate contact in a pressed condition by the elastic force of the elastic pieces88, conduction between both members is further improved. Together therewith, upon attachment of the drive unit22, due to the handle-side terminal members82and the unit-side terminal members84rubbing against one another mutually, it is easy for the refreshing effect to be more effectively exhibited.

In the present embodiment, in a state in which the drive unit22is attached to the handles14,126, the handle-side terminal members82b,82dthat constitute detection terminals come into contact with the unit-side terminal members84b,84d, which are disposed on the drive unit22so as to correspond to the handle-side terminal members82b,82d. According to such a configuration, whether or not the drive unit22has been attached with respect to the handles14,126can be detected easily.

In the present embodiment, since the motor20is housed in an airtight manner inside the housing48(refer toFIG. 4), even in the case that the drive unit22is subjected to sterilization under a high pressure steam atmosphere (for example, autoclave sterilization), the motor20remains protected within the housing48. More specifically, since the drive unit22includes a structure that can withstand corrosion by the steam in the sterilization treatment under a high-pressure steam atmosphere, damage to the motor20due to the sterilization process can be prevented, and durability can be enhanced.

With the medical manipulators10A,10B described above, a configuration is provided in which the operating state of the rolling switch28or the tilting switch144is detected in the controller36through the electrical connection mechanism80. In a modification of the medical manipulators10A,10B, movement of the rolling switch28or the tilting switch144may be transmitted to the drive unit22through a link mechanism.

In this case, an electrical switch, for example, a tact switch or the like, is disposed in the drive unit22. An airtight and liquidtight condition with the exterior is secured by covering the electrical switch with a cover body made of silicone rubber, for example. When the rolling switch28or the tilting switch144is operated, through the link mechanism, movement due to the operation thereof is converted into a movement for pressing the electrical switch provided in the drive unit22. According to such a configuration, it is possible to eliminate the presence of an electrical switch on the handle14.

In the above-described drive unit22, instead of the drive coupling50, a drive coupling150(drive member) may be adopted according to the modification shown inFIGS. 18A to 19.FIG. 18Ais a perspective view of the drive coupling150.FIG. 18Bis a cross-sectional view taken along line XVIIIB-XVIIIB ofFIG. 18A.FIG. 19is an exploded perspective view of the drive coupling150.

The drive coupling150includes a coupling base member152, a coupling main body portion154, and a retaining member156. The coupling base member152is fixed to the output shaft21of the motor20, and is driven rotatably by the motor20. Engagement recesses158are disposed on a distal end surface (a surface on a side opposite to the side on which the output shaft21is fixed) of the coupling base member152. In the coupling base member152of the illustrated example, two engagement recesses158are provided. The two engagement recesses158are disposed on opposite sides from each other about an axial center of the coupling base member152. The respective engagement recesses158of the illustrated example extend in radial directions of the coupling base member152. One engagement recess158may be provided, or three or more of such engagement recesses158may be provided at intervals in the circumferential direction.

The coupling main body portion154is a member that receives a rotational force from the coupling base member152and rotates together with the coupling base member152. In the present illustrated example, the coupling main body portion154is of a hollow bottomed cylindrical shape. On an inner circumferential part of the coupling main body portion154(an inner circumferential part of a cylindrical portion155of the coupling main body portion154), a plurality of circumferentially arrayed teeth159are provided. The coupling main body portion154and the driven coupling70are capable of being fitted together in a state in which the teeth159of the coupling main body portion154and the teeth71of the driven coupling70(seeFIG. 4) are enmeshed. Further, the respective teeth159of the coupling main body portion154, in the same manner as the respective teeth51in the drive coupling50shown inFIG. 6, may have tooth-end portions that narrow in width toward the distal end direction, or may not have such tooth-end portions (the width thereof may be constant).

Engagement protrusions160, which project toward the coupling base member152, are provided on the proximal end of the coupling main body portion154. More specifically, in the illustrated example, a flange162that projects radially-outwardly is disposed on the proximal end of the coupling main body portion154, and the engagement protrusions160are disposed on a rear surface of the flange162.

With the coupling main body portion154of the illustrated example, two of such engagement protrusions160are provided. The engagement protrusions160extend along the diametrical direction of the coupling main body portion154. The two engagement protrusions160are disposed on opposite sides from each other about an axial center of the coupling main body portion154. One engagement protrusion160may be provided, or three or more of such engagement protrusions160may be provided at intervals in the circumferential direction.

The engagement protrusions160provided on the coupling main body portion154are smaller than the engagement recesses158provided on the coupling base member152. A slight gap (amount of play) exists between the engagement protrusions160and the engagement recesses158. Therefore, the coupling main body portion154, on an inner surface thereof perpendicular to the axial direction of the drive coupling150, is capable of relative displacement with respect to the coupling base member152. Stated otherwise, the coupling main body portion154is capable of relative displacement with respect to the coupling base member152, in a direction perpendicular to the axial direction of the drive coupling150.

The retaining member156is fixed to the coupling base member152. Although the retaining member156may be fixed by a fixing part164(screw) with respect to the coupling base member152, the retaining member156may be fixed to the coupling base member152by another joining means (e.g., an adhesive or the like). The retaining member156retains the coupling main body portion154while permitting relative displacement of the coupling main body portion154with respect to the coupling base member152.

The retaining member156of the present illustrated example is constituted in the form of a hollow cylinder, and an inwardly projecting member166, which projects inwardly, is disposed on the distal end thereof. The inwardly projecting member166may extend once around (360°) in the circumferential direction as in the illustrated example, or may be disposed partially therearound in the circumferential direction. The flange162that is provided on the coupling main body portion154is arranged on an inner side of the retaining member156. The inner diameter of the inwardly projecting member166is smaller than the outer diameter of the flange162provided on the coupling main body portion154. Consequently, through engagement between the inwardly projecting member166and the flange162, pulling out of the coupling main body portion154from the retaining member156is prevented.

The inner diameter of the inwardly projecting member166is greater than the outer diameter of the cylindrical portion155of the coupling main body portion154. A slight gap (amount of play) exists between the inside edge of the inwardly projecting member166and the outer circumferential surface of the cylindrical portion155. Therefore, the coupling main body portion154is capable of being displaced, only by the portion of the gap, with respect to the coupling base member152.

In accordance with the drive coupling150that is configured in the above-described manner, the coupling main body portion154can be displaced relative to the coupling base member152. Therefore, when the drive coupling150and the driven coupling70are engaged, axial matching of the coupling main body portion154and the driven coupling70can be performed automatically. More specifically, the coupling main body portion154can be displaced so as to follow the driven coupling70, whereby the coupling main body portion154can automatically be aligned (centered) therewith. Consequently, resistance accompanying power transmission from the drive coupling150to the driven coupling70can be reduced.

Further, by providing the drive coupling150with the retaining member156, without inhibiting the alignment function of the coupling main body portion154, the coupling base member152and the coupling main body portion154can be coupled together to enable power transmission therebetween.

Instead of the above configuration, the engagement recesses158may be disposed on the coupling main body portion154, and the engagement protrusions160may be disposed on the coupling base member152.

The structural configuration of the drive coupling150may be applied to the driven coupling70shown inFIG. 4. In this case, the modification of the driven coupling70includes respective elements corresponding to the coupling base member152, the coupling main body portion154, and the retaining member156on the drive coupling150. According to such a modification of the driven coupling70as well, when fitted to the drive coupling50or the drive coupling150, an automatic centering function can be exhibited.

In the medical manipulators10A,10B described above, instead of the electrical connection mechanism80(seeFIG. 4), an electrical connection mechanism of a different structure that offers the same functions or operations may be adopted. Accordingly, for example, an electrical connection mechanism168according to a first modification shown inFIGS. 20A and 20B, or an electrical connection mechanism180according to a second modification shown inFIGS. 21A and 21Bmay be adopted.FIGS. 20A to 21Bschematically illustrate respective constituent elements.

As shown inFIGS. 20A and 20B, the electrical connection mechanism168according to the first modification includes handle-side terminal members170provided on the handle14, and unit-side terminal members174provided on the drive unit22. Plural handle-side terminal members170are provided, having functions corresponding to those of the handle-side terminal members82shown inFIGS. 7A and 7B. The respective handle-side terminal members170are constituted from a pair of terminal pieces172. The terminal pieces172are made from an electrically conductive material, and are constituted from elastically deformable plate-like members, which are bent in the illustrated shapes.

Plural unit-side terminal members174are provided, having functions corresponding to those of the unit-side terminal members84shown inFIGS. 8, 9, and the like. The respective unit-side terminal members174include contact members176, which can be inserted between the pair of terminal pieces172.

As shown inFIG. 20B, in a state in which the drive unit22is attached with respect to the handle14, the contact members176of the unit-side terminal members174are inserted between the pairs of terminal pieces172in the handle-side terminal members170.

When the drive unit22is attached and detached with respect to the handle14, accompanying relative movement of the drive unit22with respect to the handle14, the unit-side terminal members174slide while in abutment with the handle-side terminal members170. The pairs of terminal pieces172are deformed elastically in directions away from each other accompanying insertion of the contact members176.

Consequently, in accordance with the configuration of the electrical connection mechanism168according to the first modification, upon attachment and detachment of the drive unit22with respect to the handle14, the handle-side terminal members170and the unit-side terminal members174rub against each other. In addition, at the portions subjected to such mutual rubbing, an effect (refreshing effect) by which the electrical contact point is activated can be obtained.

The configurations of the handle-side terminal members170and the unit-side terminal members174shown inFIGS. 20A and 20Bmay be switched with each other. More specifically, the modification of the handle-side terminal members170may be constructed in the same shape as the unit-side terminal members174, and the modification of the unit-side terminal members174may be constructed in the same shape as the handle-side terminal members170.

As shown inFIGS. 21A and 21B, the electrical connection mechanism180according to the second modification includes handle-side terminal members182provided on the handle14, and unit-side terminal members186provided on the drive unit22.

The plural handle-side terminal members182are provided, having functions corresponding to those of the handle-side terminal members82shown inFIGS. 7A, 7B, and the like. The respective handle-side terminal members182are constituted from an electrically conductive material. The respective handle-side terminal members182are capable of swinging forward and backward with respect to the handle14, and by way of biasing members184(torsion springs in the illustrated example), are biased elastically in an upright direction. The biasing members184may also be constituted from coil springs, plate springs, or other elastic bodies.

The plural unit-side terminal members186are provided, having functions corresponding to those of the unit-side terminal members84shown inFIGS. 8, 9, and the like. The respective unit-side terminal members186include contact members188, which are capable of pressing against the handle-side terminal members182.

As shown inFIG. 21B, in a state in which the drive unit22is attached with respect to the handle14, the contact members188of the unit-side terminal members186come into abutment with the handle-side terminal members182. At this time, the handle-side terminal members182are pressed by the contact members188of the unit-side terminal members186, and a condition is brought about in which the handle-side terminal members182are tilted forward by a predetermined angle in opposition to the biasing force (elastic force) of the biasing members184.

With the electrical connection mechanism180, when the drive unit22is attached and detached with respect to the handle14, accompanying relative movement of the drive unit22with respect to the handle14, the unit-side terminal members186slide while in abutment with the handle-side terminal members182. Consequently, in accordance with the configuration of the electrical connection mechanism180according to the second modification, upon attachment and detachment of the drive unit22with respect to the handle14, the handle-side terminal members182and the unit-side terminal members186rub against each other. In addition, at the portions subjected to such mutual rubbing, an effect (refreshing effect) by which the electrical contact point is activated can be obtained.

The configurations of the handle-side terminal members182and the unit-side terminal members186shown inFIGS. 21A and 21Bmay be switched with each other. More specifically, the modification of the handle-side terminal members182may be constructed in the same shape as the unit-side terminal members186, and the modification of the unit-side terminal members186may be constructed in the same shape as the handle-side terminal members182.

Instead of the above-described drive unit22, a drive unit190according to the modification shown inFIGS. 22A to 22Cmay be adopted. With the drive unit190, instead of the unit-side terminal members84(seeFIG. 8), unit-side terminal members192are disposed at intervals laterally on the distal end of the drive unit190. In this case, in the handle14in which the drive unit190is mounted, instead of the handle-side terminal members82(seeFIGS. 7A and 7B), non-illustrated handle-side terminal members are disposed at suitable positions on the handle14. The unit-side terminal members192may also be disposed at vertical as well as lateral intervals.

In the case of the drive unit190, both left and right side surfaces194and a bottom surface195function as guide surfaces when the drive unit190is attached to the handle14. Consequently, the guide receiving members58provided on the drive unit22(seeFIG. 3) are not provided on the drive unit190, and with the handle14, the guide rails56are unnecessary.

FIG. 22Bis a view as seen from below of the drive unit190. A lever device196, which is provided on the drive unit190, includes a pair of lever members198, which are capable of pivoting laterally in a housing191. The (pair of) two lever members198are biased elastically at all times outwardly by a biasing member200(a torsion spring in the illustrated example). Engagement pawls199are formed to project on outer side portions of the respective lever members198. Two biasing members200may be provided, and the pair of lever members198may be biased individually by the two biasing members200. Only one of the lever members198may be provided. The biasing members200may also be constituted from coil springs, plate springs, or other elastic bodies.

As shown inFIG. 22C, the (pair of) two lever members198may be partially overlapped vertically, and may be disposed so as to be swingable on the same axis. InFIG. 22C, the lever members198are biased outwardly by a single biasing member202. However, two biasing members202may be provided, and the lever members198may be biased outwardly individually by the two biasing members202. The biasing member202may also be constituted from a coil spring, a plate spring, or another elastic body.

Instead of a configuration in which attachment of the drive unit22to the handle14is detected by the handle-side terminal members82b,82d(FIG. 7A) and the unit-side terminal members84b,84d(FIG. 8) coming into contact, a detection mechanism204shown inFIGS. 23A and 23Bmay be adopted.

As shown inFIG. 23A, an engagement part206is fixed to an output shaft21of the motor20. On an outer circumferential portion of the engagement part206, one engagement projection207or a plurality of engagement projections207are disposed at predetermined intervals in the circumferential direction. The engagement projection or projections207engage with one or a plurality of engagement grooves210provided on an inner circumferential part of a proximal end side portion of a drive coupling208(drive member). The engagement grooves210extend in the axial direction of the drive coupling208. More specifically, the engagement part206and the drive coupling208are spline-fitted together. The drive coupling208includes plural teeth209, which are capable of meshing with the driven coupling70that is provided on the handle14. The respective teeth209, in the same manner as the respective teeth51in the drive coupling50shown inFIG. 6, may have tooth-end portions that narrow in width toward the distal end direction, or may not have such tooth-end portions (the width thereof may be constant).

The drive coupling208is capable of sliding with respect to the engagement part206. By an engagement action between the engagement projections207and the engagement grooves210, a rotary drive force is transmitted from the engagement part206to the drive coupling208. More specifically, accompanying rotation of the output shaft21of the motor20, the engagement part206and the drive coupling208are rotated together integrally. Instead of the engagement projections207on the engagement part206, engagement grooves may be provided, and instead of the engagement grooves210on the inner circumferential portion of the drive coupling208, engagement projections may be provided. With such a configuration as well, the drive coupling208and the engagement part206are spline-fitted together.

A biasing member212(a coil spring in the present illustrated example) is disposed between the engagement part206and the drive coupling208. The biasing member212of the illustrated example is arranged on an inner side of the drive coupling208. The biasing member212applies an elastic biasing force at all times to the drive coupling208in the distal end direction. In the drive coupling208, an engagement member214that engages with the engagement part206is disposed on a more proximal side than the engagement part206. The biasing member212may also be constituted from a coil spring, a plate spring, or another elastic body.

A short circuiting ring216made up from an electrically conductive material, e.g., a metal or the like, is disposed on a proximal end surface of the drive coupling208. The output shaft21is inserted through the interior of the drive coupling208via a hole216ain the short circuiting ring216.

A drive unit22A is capable of being attached and detached with respect to the handle14, and similar to the drive unit22shown inFIG. 1, etc., the drive unit22A is capable of being connected to the controller36through the cable54. In a housing48A of the drive unit22A, at a location corresponding to the short circuiting ring216, two contact members218made from a conductive material are provided. The two contact members218of the present illustrated example are constituted by balls218A. The balls218A are arranged in retaining holes221provided in ball retaining members220constituted from an insulating material (for example, a resin or the like). The balls218A are retained rollably by the ball retaining members220.

In the interior of the housing48A, two conductive members222made from an electrically conductive material, e.g., a metal or the like, abut respectively against the two balls218A. Lead wires224are connected respectively to the two conductive members222. The respective lead wires224are connected through the cable54(seeFIG. 1) to the controller36.

In the detection mechanism204, which is constructed as described above, in a state in which the drive unit22A is not attached to the handle14, as shown inFIG. 23A, the drive coupling208is retained in an advanced position by the elastic force of the biasing member212. Consequently, the short circuiting ring216and the two balls218A (contact members218) are not in contact, and in the controller36, attachment of the drive unit22A with respect to the handle14is not detected.

On the other hand, in a state in which the drive unit22A is attached to the handle14, as shown inFIG. 23B, the drive coupling208is pressed rearwardly by the driven coupling70. At this time, the drive coupling208is moved and retracted in opposition to the elastic force of the biasing member212, and the short circuiting ring216and the two balls218A are placed in contact. As a result, the two balls218A are electrically connected via the short circuiting ring216, and in the controller36, attachment of the drive unit22A with respect to the handle14is detected.

In the condition shown inFIG. 23B, together with the drive coupling208being driven rotatably by the motor20through the engagement part206, the short circuiting ring216also is rotated. At this time, although the short circuiting ring216and the two balls218A remain in contact, the balls218A, which are retained in the ball retaining members220, are capable of rolling in the retaining holes221together with rotation of the short circuiting ring216. Therefore, in a state in which the short circuiting ring216and the contact members218are in contact, a large increase in rolling resistance of the drive coupling208due to rotation of the drive coupling208can effectively be suppressed. Further, the contact members218are not limited to the balls218A. More specifically, the contact members218need not necessarily be members that are capable of rolling.

Although certain preferred embodiments of the present invention have been shown and described in detail above, it should be understood that various changes and modifications may be made to the embodiments without departing from the scope of the invention as set forth in the appended claims.