A multi-degree-of-freedom forceps includes a insertion portion that has a first bending portion and a second bending portion connected to each other at both ends via an operating member; a treatment portion that is attached to the first bending portion and is used for tissue treatment; and an operating portion that is attached to the second bending portion to bend the second bending portion to thereby bend the first bending portion. The operating portion has a handle body capable of being swung relative to the insertion portion with the second bending portion as an operation center. The handle body has a grip portion that is gripped by a user in use. The grip portion is provided around the operation center or closer to the insertion portion side than the operation center.

TECHNICAL FIELD

The present invention relates to a multi-degree-of-freedom forceps capable of bending a distal end side of an insertion portion provided with a treatment portion.

BACKGROUND ART

In the related art, in laparoscopic surgery or the like, forceps are used in order to perform various procedures within a body cavity. As one of such forceps, there is known a multi-degree-of-freedom (hereinafter, refer to DOF) forceps that enables bending of a distal end side of a long insertion portion inserted into a body cavity in order to increase the degree of freedom of operations of a treatment portion used to perform a procedure, within a body cavity.

For example, PCT International Publication No. WO2009/088430 discloses a multi-DOF forceps including bending portions at both ends of a long and rigid insertion portion. The two bending portions have a well-known structure in which bending pieces or joint rings are arranged side by side in an axis direction and are connected to each other by an operating member, such as a wire. A treatment portion is connected to one of end portions of the insertion portion and an operating portion is connected to the other. If a user operates a handle or the like of the operating portion to bend the bending portion (second bending portion) closer to the operating portion in a desired direction, the operating member connected to the second bending portion advances and retreats in the axis direction. As a result, the bending portion (first bending portion) distant from the operating portion can be bent in a direction opposite to the second bending portion so as to direct the treatment portion to an intended direction.

When the multi-DOF forceps is used, the insertion portion is inserted into a body cavity from an access port, such as a trocar attached to a patient so as to pass through a body wall, a tissue, or the like. The user moves the treatment portion at the distal end of the insertion portion to a desired position to perform a procedure, using generally three operations including the above-described bending operation, the advance/retreat operation of the insertion portion relative to the access port, and an swinging operation (pivot operation) of the insertion portion having the access port as an operation center.

SUMMARY OF THE INVENTION

A first aspect of the present invention includes a insertion portion which is longitudinal, extends along a longitudinal axis and has a joint portion at a proximal end portion; an operating portion which has a handle body that is coupled to the joint portion so as to be rotatable in a direction intersecting the longitudinal axis of the insertion portion and that is provided so as to be capable of swinging and operating relative to the insertion portion; a bending portion which is provided at a distal end portion of the insertion portion so as to be bendable according to the swinging operation of the handle body relative to the insertion portion; a bending locking mechanism which enables fixation of the rotation of the insertion portion in the direction intersecting the longitudinal axis of the insertion portion relative to the handle body, and release of the fixation; an access port which has a pivot portion that supports the insertion portion so as to be movable along the longitudinal axis and supports the insertion portion so as to be pivotally operable and that is mountable on a body wall; a pivot locking mechanism which enables fixation of the pivot operation of the insertion portion relative to the pivot portion and the movement of the insertion portion in the direction along the longitudinal axis, and release of the fixation; and a switching operating portion which performs switching between a state where the fixation by the bending locking mechanism is released and the fixation by the pivot locking mechanism is performed, and a state where the fixation by the bending locking mechanism is performed and the fixation by the pivot locking mechanism is released.

According to a second aspect of the present invention, in the first aspect, the switching operating portion may further perform switching to a state where the fixation by the bending locking mechanism is released and the fixation by the pivot locking mechanism is released.

According to a third aspect of the present invention, in the first aspect, a distal end portion of a locking member of the bending locking mechanism may be provided so as to be movable from a position apart from the joint portion to a position where the distal end portion of the locking member is locked to the joint portion, and as the distal end portion of the locking member is locked to the joint portion, the locking member may fix the handle body to the insertion portion in the direction intersecting the longitudinal axis of the insertion portion.

According to a fourth aspect of the present invention, in the first aspect, a movable member of the pivot locking mechanism may be provided so as to be movable from a position apart from the pivot portion to a position where the pivot portion is pressed, and as the movable member presses the pivot portion, the fixation by the pivot locking mechanism may be performed.

According to a fifth aspect of the present invention, in the first aspect, the multi-degree-of-freedom forceps may further include a treatment portion that is attached to the bending portion and is used for tissue treatment, the operating portion may have a rotating knob that is provided apart from the longitudinal axis of the insertion portion and rotates the treatment portion relative to the insertion portion, and the rotating knob may be connected to the treatment portion via a shaft having flexibility.

According to a sixth aspect of the present invention, in the first aspect, the operating portion may be attached to the joint portion so as to be capable of swinging relative to the insertion portion with the second bending portion as an operation center, the joint portion may have a spherical first member, and a spherical second member that is attached so as to be rotatable around a first rotation axis of the first member, and the handle body may be attached so as to be rotatable around a second rotation axis of the second member orthogonal to the first rotation axis.

According to a seventh aspect of the present invention, in the sixth aspect, an outer periphery of the first member may be formed with a first engaging protrusion, an outer periphery of the second member may be formed with a second engaging protrusion, the first member and the second member may be arranged so that a first plane including the first engaging protrusion and a second plane including the second engaging protrusion intersect each other, and the bending direction of the bending portion may be regulated so that the bending portion bends along the first plane and the second plane.

According to a eighth aspect of the present invention, in the first aspect, the operating portion may be attached to the insertion portion via a biaxial gimbal structure.

According to a ninth aspect of the present invention, in the first aspect, the switching state of the switching operating portion is maintained even if a user removes user's hand from the switching operating portion.

According to a tenth aspect of the present invention, in the first aspect, the pivot portion includes a first tubular portion and a second tubular portion that are fittable to each other and a spherical portion that has a through hole and is arranged in a lumen of the first tubular portion and the second tubular portion so as to be held by the first tubular portion and the second tubular portion.

According to an eleventh aspect of the present invention, in the first aspect, a radial cross-section of the insertion portion is a non-circular and is impossible to rotate relative to the access port attached to a patient.

According to a twelfth aspect of the present invention, in the tenth aspect, a radial cross-section of the insertion portion is a non-circular and is impossible to rotate relative to the spherical portion, and if a force equal to or more than a predetermined value is applied, the insertion portion rotates relative to the first tubular portion and the second tubular portion together with the spherical portion.

According to a thirteenth aspect of the present invention, in the tenth aspect, the insertion portion may be inserted through the access port attached to a patient and introduced into a body cavity of the patient, the pivot locking mechanism may be configured to include the spherical portion, and a rail member attached to the insertion portion, and the spherical portion may have a bearing that reduces the advance or retreat resistance of the insertion portion inserted through the through hole.

According to a fourteenth aspect of the present invention, in the tenth aspect, the pivot portion may have an airtight portion that is provided in the lumen of at least one of the first tubular portion and the second tubular portion and maintains an airtight state of an inner cavity of the access port.

According to a fifteenth aspect of the present invention, in the tenth aspect, the pivot portion may be detachable relative to the access port.

According to a sixteenth aspect of the present invention, in the tenth aspect, the access port may have an airtight portion that maintains an airtight state of a lumen of the access port when the pivot portion is not attached.

According to a seventeenth aspect of the present invention, in the first aspect, the multi-degree-of-freedom forceps may further include a treatment portion which is attached to the bending portion and is used for tissue treatment, the treatment portion may have a pair of forceps pieces that are opened and closed, the operating portion may have a second operating portion that is connected to the pair of forceps pieces and opens and closes the forceps pieces, and the second operating portion may be rotatably attached to the handle body.

According to a eighteenth aspect of the present invention, in the first aspect, the multi-degree-of-freedom forceps may further include a treatment portion which is attached to the bending portion and is used for tissue treatment, the operating portion may have a rotating knob that rotates the treatment portion relative to the insertion portion, and the rotating knob may be connected to the treatment portion at a position closer to a distal end side than a proximal end portion of the insertion portion.

PREFERRED EMBODIMENTS

Basic Structure

FIG. 1is a view showing the overall configuration of a multi-DOF forceps1of the present embodiment. The multi-DOF forceps1includes a long rigid insertion portion10, an operating portion50provided on the proximal end side of the insertion portion10, a first bending portion (bending portion)11, a bending locking mechanism150, an access port100, a pivot locking mechanism160, and a locking lever (switching operating portion)81. The detailed configuration of them will be described below.

Additionally, the multi-DOF forceps1may include a treatment portion30that is attached to the first bending portion11and is used for tissue treatment.

The basic structure regarding the bending operation of the insertion portion10is the same as that described in the above PCT International Publication No. WO2009/088430, and includes the first bending portion11on the distal end side and a second bending portion12on the proximal end side, which are connected to each other by four operating members (refer toFIG. 5A). The insertion portion10includes an outermost outer pipe13and a plurality of pipes that are inserted through and coaxially arranged in the outer pipe13. One of the plurality of pipes is a rotation operating pipe (to be described below) connected to the treatment portion30, and extends to the inside of the operating portion50through the inside of the outer pipe13. Additionally, the insertion portion10is bent at a curved portion14that is curved so as to be easily operated even if a plurality of multi-DOF forceps are inserted through one access port (to be described below). The curved angle and number of curved portions can be appropriately set in consideration of the operation aspects of the multi-DOF forceps.

The treatment portion30has a well-known structure including a pair of openable and closable forceps pieces31and32. As shown inFIGS. 1 and 2, an operating member33connected to the forceps pieces31and32is advanced and retreated by operating an opening and closing lever91provided at the operating portion50. This enables the pair of forceps pieces31and32to be opened and closed. The operating member33extends in the longitudinal direction of the insertion portion10.

As shown inFIG. 2, the operating portion50includes a first operating portion60for operating the second bending portion12and a second operating portion90for performing the opening and closing operation of the treatment portion30.

FIG. 4is a perspective view showing the operating portion50. The first operating portion60includes a swivel joint portion (joint portion)61fixed to the insertion portion10, and a handle portion70attached to the swivel joint portion61.

FIG. 5Ais a cross-sectional view of the first operating portion60. As shown inFIGS. 4 and 5A, the swivel joint portion61has a first member62fixed to the distal end side of the second bending portion12, and a second member63that has a second rotation axis O2and is attached so as to cover a portion of the first member62. Additionally, the second member63is attached so as to be rotatable around a first rotation axis O1of the first member62. The proximal end side of the first member62has a semispherical shape having a space therein. An outer peripheral surface of the first member62is formed with a circular-arc engaging protrusion (first engaging protrusion)62A passing above a plane (the same plane as the cross-section ofFIG. 5A) passing through the central axis of the insertion portion10. The engaging protrusion62A is formed in the shape of a sawtooth in which a plurality of ridges and valleys are alternately arranged in an extending direction. The second member63has an inner surface and an outer surface on a substantially spherical surface, and the inner surface thereof is formed with an engaging groove63A with dimensions corresponding to the engaging protrusion62A. The first member62and the second member63are assembled so that the engaging protrusion62A is located within the engaging groove63A. Therefore, the first member62and the second member63are engaged with each other so as to be relatively rotatable in the extending direction of the engaging protrusion62A, with the center of the swivel joint portion61as a rotation center.

A regulating portion may be formed that regulates the operation direction of the handle body71(to be described below) relative to the insertion portion10in the same direction as the bending direction of the first bending portion11as the engaging groove63A and the engaging protrusion62A are engaged with each other. Additionally, the first bending portion11is provided at a distal end portion of the insertion portion10so as to be bendable according to the swinging operation of the handle body71relative to the insertion portion10. In this case, an operator can grasp the bending direction intuitively. The engaging groove63A and the engaging protrusion62A may not be formed in the shape of a sawtooth, and the engaging groove63A and the engaging protrusion62A only have to be engaged with each other and regulate the operation direction. Additionally, an outer peripheral surface of the first member62may be formed with the engaging groove, and an inner surface of the second member63may be formed with the engaging protrusion.

Additionally, the insertion portion10extends along the longitudinal axis and has the swivel joint portion (joint portion)61at a proximal end portion thereof. The operating portion50has the handle body71that is coupled to the swivel joint portion61so as to be rotatable in a direction intersecting the longitudinal axis of the insertion portion10and is provided so as to be capable of swinging and operating relative to the insertion portion10.

The handle portion70has the handle body71gripped by a user, and a receiving member72provided inside the handle body71. The basic shape of the handle body71is a substantially hollow truncated conical shape whose cylindrical appearance expands gradually toward the distal end side, and a grip portion71A is provided on the distal end side of the handle body71. The grip portion71A is provided around the oscillation center of the second bending portion12along the length direction of the handle portion70(so as to surround the operation center of the second bending portion12). In the present embodiment, the grip portion71A is arranged so as to wrap around the swivel joint portion61. Additionally, the handle body71is attached so as to be rotatable around the second rotation axis O2of the second member63orthogonal to the first rotation axis O1. Additionally, the grip portion71A has a pair of grip surfaces, and the shape of the handle body71is not limited to the hollow truncated conical shape but only has to have a structure where the swivel joint portion61is arranged between a pair of grip surfaces which are gripped by the operator.

The receiving member72has a basic shape including an inner surface on a substantially spherical surface, and is attached so that the second member63of the swivel joint portion61is covered from the outside. The receiving member72is fixed to the handle body71, and the proximal end side of the receiving member72is fixed to a proximal end portion12A of the second bending portion12.

FIG. 5Bis a perspective view of the swivel joint portion61. As shown inFIG. 5B, an outer surface of the second member63is formed with the same engaging protrusion (second engaging protrusion)63B as the first member62, and an inner surface of the receiving member72is formed with an engaging groove72A with dimensions corresponding to the engaging protrusion63B. Since the second member63and the receiving member72are assembled so that the engaging protrusion63B is located within the engaging groove72A, the second member63and the receiving member72are relativity rotatable in an extending direction of the engaging protrusion63B, with the center of the swivel joint portion61as a rotation center.

As shown inFIGS. 5A and 5B, a plane (a first plane including the engaging protrusion62A on which a projection of a first claw member155is hooked) P1defined by the engaging protrusion62A of the first member62, and a plane (second plane where oscillation is regulated by the fitting between the engaging groove72A and the engaging protrusion63B) P2defined by the engaging protrusion63B of the second member63are orthogonal to each other on a central axis OC of the second bending portion12in a state where the second bending portion12is made linear. By such assembling, the handle portion70is able to swing relative to the swivel joint portion61, with the center of the swivel joint portion61as an operation center. If the handle body71of the handle portion70is swung, the receiving member72swings relative to the swivel joint portion61, the proximal end portion12A of the second bending portion12moves along with the receiving member72, and the second bending portion12bends. As a result, as shown inFIG. 3, the operation direction of the handle body71relative to the insertion portion10is regulated in the same direction as the bending direction of the first bending portion11, and the first bending portion11bends according to the operation direction of the handle body71. In this case, the first claw member155, the engaging protrusion62A, the engaging groove72A, and the engaging protrusion63B function as a regulating portion.

As shown inFIG. 4, the second operating portion90has the opening and closing lever91attached so as to be rotatable around an axis AX2relative to the handle portion70. Since the operating member33connected to the forceps pieces31and32of the treatment portion30protrudes from the proximal end side of the first operating portion60and is connected to the opening and closing lever91, the opening and closing lever91is operated, so that the operating member33can be advanced and retreated in the axis direction thereof and the pair of forceps pieces31and32can be opened and closed. Since the opening and closing lever91includes a ratchet92, the opening angle of the forceps pieces31and32can be fixed to a desired degree by fixing the operation state of the opening and closing lever91. Since the opening and closing lever91is rotatably attached to the handle portion70and the operating member33is arranged substantially coaxially with the axis O of the insertion portion10, the second operating portion90is rotatable relative to the first operating portion60, with an axis AX1as a rotation center. Therefore, the positional relationship between the opening and closing lever91and each operation part of the first operating portion60to be described below can be freely adjusted.

Access Port and Pivot Portion

The multi-DOF forceps1is inserted through the access port attached to a patient and introduced into a body cavity. Additionally, since the multi-DOF forceps1is inserted through the access port in a state where pivot portions are attached to the insertion portion10, the structure of the access port and the pivot portions will be described here.

An access port100has pivot portions110that supports the insertion portion10so as to be movable along the longitudinal axis and support the insertion portion10so as to be pivotally operable and that is mountable on a body wall.

FIG. 6is a front view of the access port100to which the pivot portions110are attached, andFIG. 7is a cross-sectional view, in the axis direction of the access port100, of the access port100to which the pivot portions110are attached. The access port100is installed in a hole formed in the body wall by incision or the like, or natural openings, such as the anus, and includes a tubular main body101, and a port portion102to which the pivot portions are attached.

The port portion102is disk-shaped and is attached to one end portion side of a main body101. The port portion102is formed with a total of three holes of one port103for an endoscope and two ports104for forceps. A pair of fixing members105for mounting a pivot portion110are arranged around each port104for forceps so as to face each other across the central axis of the port for forceps. As shown inFIG. 7, an airtight membrane (airtight portion)106made of rubber or the like with a slit is attached between the port portion102and the main body101, and has a structure where airtightness at the port portion102side is maintained even in a state where there is not anything inserted through each port of the port portion102. Instead of providing the airtight portion so as to be pinched between the port portion102and the main body101, as schematically shown inFIG. 8A, airtight membranes106may be individually attached to respective ports, such as the ports104for forceps. Additionally, when the airtight portion is attached to each port, a valve107may be used instead of the airtight membrane as shown inFIG. 8B. As the valve107, for example, a valve provided in a general trocar can be used.

As shown inFIG. 9, a guide groove108to which a pin (to be described below) of the pivot portion110is locked is provided in each fixing member105so as to open toward the port104for forceps.

FIG. 10is a perspective view of the pivot portion110, andFIG. 11is a schematic view showing the basic structure of the pivot portion110. As shown inFIGS. 10 and 11, the pivot portion110includes a first cylindrical tubular portion111and a second cylindrical tubular portion112, and a spherical portion113arranged at inner cavities of the first tubular portion111and the second tubular portion112.

The spherical portion113is provided with a through hole113A. The insertion portion10of the multi-DOF forceps1is inserted through the pivot portion110by passing through the through hole113A. As the spherical portion113through which the insertion portion10is inserted slides so as to rotate relative to the first tubular portion111and the second tubular portion112, the insertion portion10is capable of oscillating relative to the first tubular portion111and the second tubular portion112or the access port100, with a central portion of the spherical portion113as an operation center, thereby performing a pivot operation.

The first tubular portion111and the second tubular portion112are integrally connected by screw fitting. By changing the screwing length of the first tubular portion111and the second tubular portion112, the contact pressure between the inner surfaces of the first tubular portion111and the second tubular portion112and the outer surface of the spherical portion113can be adjusted to a constant range, and an operation feeling (weight) of the pivot operation can be adjusted to a desired state. For example, by setting a force required for the pivot operation to be greater than a force required for the oscillation of the handle body71, the pivot operation can be kept from occurring inadvertently when bending the first bending portion11. Additionally, since an optimal operation feeling of the pivot operation varies according to the specific configuration of the treatment portion30, pivot portions whose weight is adjusted for each treatment portion may be prepared and separately used.

As shown inFIG. 10, a pair of pins111A that are engaged with the guide grooves108of the access port100protrude from the outer peripheral surface of the first tubular portion111. As shown inFIGS. 9 and 10, if the first tubular portion111is pressed against the port portion102and is rotated around an axis so that the pins111A do not interfere with the fixing members105, the pair of pins111A enter the guide grooves108, and the pivot portions110are mounted on the ports104for forceps. The width of a portion of each guide groove108that extends in the circumferential direction of the port104for forceps and is located ahead in the entering direction of the pin111A is large. As the pin111A enters the portion of the wide portion108A, unintended falling of the pivot portion110is prevented. The pivot portion110removable from the access port100by rotating in a direction opposite to a direction when being mounted, and is attachable to and detachable from the access port100.

As shown inFIG. 11, the airtight membrane106is attached to the proximal end side of the second tubular portion112located on the proximal end side when the pivot portion110is attached to the access port100, similar to the access port. This maintains the airtight state of the access port even in a state where the insertion portion10is not inserted through the pivot portion110. Instead of the airtight membrane106, the valve107may be used as shown inFIG. 12, and this point is also the same as that of the access port. Additionally, the airtight membrane106only has to be provided in at least one of the first tubular portion111and the second tubular portion112.

Since the detailed structure of the spherical portion113relates to the pivot locking mechanism that locks the pivot operation, this will be described below.

Locking Mechanism of Bending Operation and Pivot Operation and Switching Mechanism of Locked State

Next, the mechanism of locking a bending operation and a pivot operation and the mechanism of switching locked states of these operations, which is one of the features of the multi-DOF forceps1, will be described.

FIGS. 13A to 13Care views describing the operation of a multi-DOF forceps of the related art. In a multi-DOF forceps400of the related art, if a second bending portion402is bent as shown inFIG. 13Bby applying a force to an operating portion420from a state shown inFIG. 13Ain order to bend a first bending portion401, the pivot operation of an insertion portion410may occur with a fulcrum430, such as the access port, as an operation center as shown inFIG. 13C, along with the bending operation of the second bending portion402. This causes movement of the treatment portion403to an unintended position during a procedure.

One of the causes is that, since the operating portion420gripped by the user is located closer to the proximal end side than an intermediate portion (hereinafter simply referred to as “operation center”) of the second bending portion402that is a substantial operation center of the second bending portion402, a force for bending the second bending portion402acts also as a moment that pivotally operates the insertion portion410.

Additionally, even when the user does not apply a force to the operating portion intentionally, the first bending portion may bend along with the advance or retreat operation or pivot operation of the insertion portion.FIG. 14is a schematic view describing this case, and shows a position where the user applies an operation force as a force point P, the operation center as X, and the access port as a fulcrum S. InFIG. 14, if the distance between the fulcrum S and the operation center X changes or the fulcrum S moves relative to the operation center X while keeping the distance from the operation center X constant, a torque around the operation center X is generated according to the distance L between the force point P and the operation center X. In the operation of the multi-DOF forceps, the operation of advancing and retreating the insertion portion relative to the pivot portion is the operation of changing the distance between the fulcrum S and the operation center X, and the pivot operation is the operation of moving the fulcrum S relative to the operation center X while keeping the distance from the operation center X constant. Accordingly, along with these operations, the above-described torque is generated and an unintended operation of the first bending portion is generated.

In the multi-DOF forceps1of the present embodiment, as shown inFIG. 15, the user grips the handle body71of the handle portion70and operates a dial75(to be described below) and the opening and closing lever91with arbitrary fingers. At this time, a hand or fingers of the user Us who grips a grip portion71A of the handle body71are arranged so as to wrap around the swivel joint portion61that is also the operation center of the handle portion70including the operation center X. In such a gripped state, the distance between the force point P and the operation center X becomes significantly shorter than the multi-DOF forceps of the related art. As a result, the above-described moment generated when a force is applied to the handle portion70so as to bend the second bending portion12becomes significantly small, and the above-described torque also becomes small. Accordingly, since the grip portion71A is arranged around the operation center X, the user can easily separate the bending operation of the first bending portion11from the pivot operation of the insertion portion to operate the multi-DOF forceps, without advanced skill.

Here, in order to completely eliminate the above-described torque, it is required to make the distance between the fulcrum S and the operation center X zero, but this is not practical in terms of the configuration of the multi-DOF forceps. Thus, the bending locking mechanism and the pivot locking mechanism that lock the bending operation and the pivot operation are provided in the multi-DOF forceps1in order to more reliably separate the pivot operation from the advance or retreat operation of the insertion portion and bending operation.

The bending locking mechanism150enables fixation of the rotation of the insertion portion10in the direction intersecting the longitudinal axis of the insertion portion10relative to the handle body71, and release of this fixation.

The pivot locking mechanism160enables fixation of the pivot operation of the insertion portion10relative to the pivot portion110to be described below and the movement of the insertion portion in the direction along the longitudinal axis, and release of this fixation.

Bending Locking Mechanism

FIGS. 16 and 17are views showing the operating portion50excluding the handle body71.FIG. 18is a cross-sectional view of the first operating portion60, and shows a state different fromFIG. 5A. The bending locking mechanism150includes a movable body151and a pair of locking members152that are arranged within the handle body71.

The operation and release of the bending locking mechanism150are performed by the locking lever (switching operating portion)81attached to the first operating portion60. That is, the locking lever81performs switching between a state where the fixation by the bending locking mechanism150is released and the fixation by the pivot locking mechanism160is performed, and a state where the fixation by the bending locking mechanism150is performed and the fixation by the pivot locking mechanism160is released. The locking lever81may perform switching to a state where the fixation by the bending locking mechanism150is released and the fixation by the pivot locking mechanism160is released.

The locking lever81and the movable body151are connected by a link82. As shown inFIG. 16, the movable body151moves to the proximal end side if the locking lever81is distal endped to the proximal end side, and the movable body151moves to the distal end side if the locking lever is pulled up to the distal end side.

As shown inFIG. 16, the locking lever81is arranged between the pair of locking members152, and as shown inFIG. 18, respective intermediate portions of the pair of locking members152are fixed to the first operating portion60by a pivot shaft153. Accordingly, each locking member152is rotatable around the pivot shaft153. The first claw member155and the second claw member156that engage the swivel joint portion61are provided at a distal end portion152A of each locking member152so as to protrude toward the swivel joint portion61. A proximal end portion152B of each locking member152is located closer to the proximal end side than the movable body151. Additionally, a torsion spring154is attached to each pivot shaft153. The pair of locking members152are biased by the torsion springs154so that the distance between the distal end portions152A becomes larger than the distance between the proximal end portions152B.

The locking member152may be provided so that the distal end portion of the locking member152of the bending locking mechanism150is movable from a position apart from the swivel joint portion61to a position where the locking member is locked to the swivel joint portion61. Additionally, as the distal end portion of the locking member152is locked to the swivel joint portion61, the locking member152may fix the handle body71to the insertion portion10in the direction intersecting the longitudinal axis of the insertion portion10.

The operation of the bending locking mechanism150will be described.

If the locking lever81is distal endped toward the proximal end side, the movable body151moves to the proximal end side, and as shown inFIG. 5A, enters between two proximal end portions152B of the pair of locking members152. Therefore, the two proximal end portions152B are moved by the pair of locking members152so that the distance between the proximal end portions152B increases. Each locking member152rotates around the pivot shaft153, and the distal end portion152A approaches the swivel joint portion61. The first claw member155provided at the distal end portion152A bites the engaging protrusion62A of the first member62exposed in a portion from between the first claw member and the second member63in the swivel joint portion61, and is locked so that the first member62cannot rotate relative to the handle body71. On the other hand, the second claw member156bites a sawtooth-shaped locking protrusion63C provided parallel to the engaging protrusion63B on the outer surface of the second member63, and is locked so that the second member63cannot rotate relative to the handle body71. Therefore, the swivel joint portion61is completely locked to the handle portion70, and the bending operation is fixed so that the state of the first bending portion11and the second bending portion12do not change.

Whether the first claw member155and the second claw member156approach any of ridges and valleys of the sawtooth shape of the engaging protrusion62A and the locking protrusion63C varies depending on the bending state of the second bending portion12or the like. As shown inFIG. 5A, a plate spring157is oscillatably arranged in connection regions between the locking members152, and the first claw member155and the second claw member156, and the elastic force of the plate spring157acts so as to suppress position changes in the respective claw members155and156caused by an approaching part. As a result, irrespective of the bending state of the second bending portion12, eventually, the respective claw members155and156reliably bite the swivel joint portion61and the bending operation is locked.

The operating state of the bending locking mechanism150is maintained by a spring83that is connected to the locking lever81to bias the locking lever81to the proximal end side, and a frictional force generated between the movable body151, which has entered between the proximal end portions152B, and the proximal end portions152B even if the user removes user's hand from the locking lever81. Additionally, the distal end portion152A of each locking member152is exposed onto the outer surface of the handle body from a cutout provided in the handle body71. Accordingly, as the user presses the distal end portions152A to engage the respective claw members155and156with the swivel joint portion61even in a state where the locking lever81is pulled up, it is possible to temporarily lock the bending operation.

If the user pulls up the locking lever81, the movable body151separates from the proximal end portions152B of the locking members152, and is brought into non-contact with the proximal end portions152B. Therefore, the distal end portions152A of the pair of locking members152separate from the swivel joint portion61by the biasing forces of the torsion springs154, and the swivel joint portion61is rotatable relative to the handle portion70.

Pivot Locking Mechanism

FIG. 19is an enlarged perspective view showing the pivot locking mechanism160. The pivot locking mechanism160is configured by a plurality of rail members161provided along the longitudinal direction of the insertion portion10, and the spherical portion113of the pivot portion110.

FIG. 20is a cross-sectional view of the spherical portion113in a cross-section orthogonal to the through hole113A. The spherical portion113includes a first region121, a second region122, and a third region123that are divided at every central angle of 120 degrees around a central axis X1of the through hole113A. Each of the regions121,122, and123has a relatively large base member131and a relatively small movable member132, and a bearing133is attached to each movable member132. The rotation plane of each bearing133passes through the central axis X1and is parallel to the central axis X1. A rotating shaft134of each bearing133is formed from a coil, and has flexibility such that the rotating shaft flexes to a certain degree in the longitudinal direction.

Additionally, the movable members132of the pivot locking mechanism160may be provided so as to be movable from a position apart from the pivot portion110to a position where the pivot portion110is pressed. Additionally, the fixation by the pivot locking mechanism160may be performed by the movable members132pressing the pivot portion110.

Three rail members161are attached so as to be parallel to the axis of the insertion portion10and 120 degrees apart in the circumferential direction.FIG. 21is a cross-sectional view in a cross-section of the pivot locking mechanism160parallel to the axis of the insertion portion. As shown inFIG. 21, a plurality of legs162that protrude toward the insertion portion10are provided at intervals in each rail member161. The dimension of each leg162in the longitudinal direction of the rail member161becomes gradually shorter when approaching a projection end, and an inclination surface162A is formed on the distal end side of each leg162.

Each leg162enters the insertion portion10through a hole13A formed in an outer pipe13of the insertion portion10. A locking pipe163for making each rail member161approach and separate from the outer peripheral surface of the outer pipe13is inserted into the outer pipe13. The outer surface of the locking pipe163is formed with a sliding hole163A corresponding to each leg162. Each leg162enters an inner cavity of the locking pipe163through the hole13A of the outer pipe13and the sliding hole163A of the locking pipe163. A portion of the outer peripheral surface of the locking pipe163is formed so as to become gradually thin toward the distal end side of the sliding hole163A. An inclination surface163B is formed on the distal end side of the sliding hole163A.

The locking pipe163and the locking lever81of the operating portion50are connected by an operating member84(refer toFIG. 17), such as a wire. If the locking lever81is distal endped to the proximal end side, the operating member84is pushed out and the locking pipe163moves (advances) to the distal end side, and if the locking lever81is pulled up, the operating member84is towed and the locking pipe163moves (retreats) to the proximal end side.

The operation of the pivot locking mechanism160will be described.

In a state where the locking lever81is distal endped to the proximal end side, as shown inFIGS. 20 and 21, the insertion portion10and the spherical portion113only come into contact with each other with the bearings133and the rail members161. In this state, the insertion portion10can be easily and pivotally operated, and the advance-retreat resistance of the insertion portion10is reduced by the rotation of the bearings133, and the insertion portion10can be smoothly advanced and retreated relative to the spherical portion113.

If the locking lever81is pulled up, the locking pipe163retreats gradually and eventually the inclination surface163B of the locking pipe163and the inclination surfaces162A of the legs162of the rail members161come into contact with each other. Moreover, if the locking pipe163retreats, the rail members161are gradually pushed up by the locking pipe163, and the rail members161begin to separate from the outer peripheral surface of the outer pipe13.

The rail members161separating from the outer pipe13first press the bearings133of the respective regions121,122, and123. As shown inFIG. 22, each bearing133is pushed up to the rail member161while flexing the rotating shaft134. After the rotating shaft134is flexed by a certain amount, the movable members132are pushed up together with the bearings133. As a result, each movable member132protrudes from the base member131, the contact pressure between the first and second tubular portions111and112and the spherical portion113of the pivot portion110increases at the portion of the movable member132, and a force required for the pivot operation increases. Even in this state, the advance-retreat operation of the insertion portion10can be performed with a comparatively small force by the bearings133.

Moreover, if the locking lever81is pulled up, the bearings133and the movable members132are pushed up, and as shown inFIG. 23, the rail members161and the base members131come into contact with each other. After that, all of the respective regions121,122and the123are pushed up so as to separate from the outer peripheral surface of the outer pipe13along with the retreat of the locking pipe163. If the locking lever81is completely pulled up, the legs162of the rail members161ride on the inclination surface163B of the locking pipe163, and projection ends of the legs162and the outer peripheral surface of the locking pipe163come into contact with each other. Therefore, as shown inFIG. 24, each region of the spherical portion113separates from the outer peripheral surface of the outermost pipe13. In this state, the contact pressure with the first tubular portion111and the second tubular portion112is increased in the overall outer peripheral surface of the spherical portion113, and as a result, the pivot operation of the insertion portion10is completely locked. Moreover, since the bearings133also no longer function substantially, the advance or retreat operation of the insertion portion10is also locked. Since the position of the locking pipe163is maintained by frictional forces generated between the locking pipe and the legs162, there is no case in which the insertion portion advances naturally if the locking lever81is not operated. Accordingly, even if the user removes use's hand from the locking lever81, the operating state of the pivot locking mechanism160is maintained.

As described above, the locking lever81is connected to both the bending locking mechanism150and the pivot locking mechanism160. If the locking lever81is completely distal endped to the proximal end side, only the bending operation is locked and the pivot operation and advance or retreat operation of the insertion portion10are enabled, and if the locking lever81is completely pulled up, the pivot operation and the advance or retreat operation are locked, and only the bending operation is enabled. In addition, when the locking lever81is midway between both states, the weight of the pivot operation varies. Additionally, since all the operations can be performed, three types of states can be produced by the operation of the locking lever81.

Accordingly, the locked state of the bending operation and the locked state of the pivot operation can be suitably switching simply by operating the locking lever81. As a result, the user can reliably separate these operations without skill or the like, and can operate the treatment portion30of the distal end of the insertion portion10as intended.

Additionally, since the locked state of the bending operation and the locked state of the pivot operation are suitably maintained even if the user removes user's hand from the locking lever, the user does not need to continue operating the locking lever and operation is kept from becoming complicated.

Moreover, since the rail members161are attached to the insertion portion10, a radial cross-section of the whole insertion portion10is formed into a non-circular shape having a projection in which a portion of a circular shape protrudes. For this reason, the insertion portion10and the spherical portion113are not rotatable relative to each other, and the insertion portion10can be prevented from rotating around the axis unintentionally while repeating the bending operation in a procedure. Moreover, if a force with a magnitude equal to or greater than a predetermined value is applied, the spherical portion113and the insertion portion10can be integrally rotated relative to the first tubular portion111and the second tubular portion112. Therefore, an operation can be made such that the insertion portion10is rotated in a state where a tissue or the like is gripped by the treatment portion30.

Operation in Use

FIG. 25is a view showing an example of a state where the multi-DOF forceps1is used. The user mounts the pivot portion110on the access port100installed in the patient, and inserts the insertion portion10of the multi-DOF forceps1through the pivot portion. Moreover, an endoscope140as observation means is inserted into the port103for an endoscope.FIG. 25shows a state where two multi-DOF forceps1are inserted into one access port100. Although the multi-DOF forceps1are inserted through the pivot portions110mounted on adjacent ports for forceps, respectively, respective operating portions50thereof can be arranged apart from each other because the insertion portions10have the curved portions14. Therefore, the respective operating portions50can be easily operated. The user grips the operating portion50after the second operating portion90of the operating portions50is rotated relative to the first operating portion60if required and is brought into a desired positional relationship. A predetermined procedure is performed by appropriately combining the operation of the first operating portion60and the second operating portion90and the pivot operation and advance-retreat operation of the insertion portion10while observing the treatment portion30and its periphery of each multi-DOF forceps1, with the endoscope140. When the opening and closing direction of the treatment portion30is adjusted, the dial75provided on the distal end side of the handle body71is rotated. As shown inFIG. 16, the dial75is connected to the gear77arranged on the proximal end side of the swivel joint portion via a flexible shaft76having flexibility. Since the gear77is connected to a rotation operating pipe (not shown) connected to the treatment portion30, the dial75can be rotated so as to rotate the treatment portion30to adjust the opening and closing direction of a pair of forceps pieces. The locking lever81is appropriately operated when the bending operation, the pivot operation, or the like is locked or the locked state is switched.

By the above operation, the user can operate the position of the distal end portion of the insertion portion10and the treatment portion30in each multi-DOF forceps1so as to reliably reflect a user's intention, and suitably perform various procedures on a patient.

Modified Example of Bending Locking Mechanism

A modified Example of the bending locking mechanism will be described. In this modified Example, the locking of the bending operation and the locking of the pivot operation are switched by making a locking button exposed to the outer surface of the handle body slide.

FIG. 26is an external view of an operating portion200of this modified Example. In the first operating portion210, a pair of locking buttons (switching operating portions)201are provided in an exposed manner on the outer surface of the handle body71instead of the locking lever, and are capable of sliding parallel to the axis direction of the handle body71.

FIGS. 27 and 28are views of a first operating portion210excluding the handle body71.FIGS. 29 and 30are views showing the first operating portion210further excluding a slider202formed with the locking buttons201.

A pair of locking members that come into contact with a swivel joint portion203and lock a bending operation are arranged so as to face each other across the swivel joint portion203, substantially similar to the first embodiment. One first locking member211is connected to a first interlocking member221arranged on another second locking member212side. Similarly, the second locking member212is connected to a second interlocking member222arranged on the first locking member211side. The first locking member211and the second interlocking member222are rotatably supported by a pivot shaft213A, and the second locking member212and the first interlocking member221are rotatably supported by a pivot shaft2138. Therefore, the first locking member211and the first interlocking member221rotate in the same direction in an interlocking manner, and the second locking member212and the second interlocking member222rotate in the same direction in an interlocking manner.

As shown inFIGS. 29 and 30, the first interlocking member221and the second interlocking member222intersect each other closer to the proximal end side than the pair of locking members211and212, and extend to the first locking member211side and the second locking member212side, respectively. Proximal end portions221A and222A of the respective interlocking members221and222are connected to a link portion232that advances and retreats an advancing-retreating member231in the axis direction of the operating portion200. A flexible shaft233connected to the locking pipe163is connected to the advancing-retreating member231. If the advancing-retreating member231advances and retreats, the locking pipe163is advanced and retreated via the flexible shaft233. The structure of the pivot locking mechanism is the same as that of the first embodiment.

Proximal end portions of the pair of locking members211and222are provided with projections214that come into contact with the slider202to rotate the locking members. As shown inFIGS. 27 and 28, the slider202is provided with a first contact portion204that comes into contact with the outside of a projection214and a second contact portion205that comes into contact with the inside of the projection214. Only the projection214of the second locking member212is seen inFIGS. 27 and 28. Although not shown, the same projection214is also provided on the first locking member211on the back side (the side behind a sheet plane inFIGS. 27 and 28). The slider202is also formed with corresponding first and second contact portions204and205.

The operation of the operating portion200of this modified Example will be described.FIGS. 27 and 29show a state where the locking buttons201have been operated and the slider202has advanced. If the slider202advances, the first contact portions204and the outer side of the projections214of the pair of locking members211and212come into contact, and the pair of locking members rotate so that the proximal end portions thereof approach each other. As a result, distal end portions of the locking members move so as to separate from each other and are separated from the swivel joint portion203, and are brought into a state where the bending operation is possible. At this time, the first interlocking member221and the second interlocking member222also rotate in interlocking with the pair of locking members211and212. As a result, the proximal end portion221A of the first interlocking member221and the proximal end portion222A of the second interlocking member222move so as to approach each other, and make the link portion232linear. As a result, the advancing-retreating member231retreats, the locking pipe163retreats, and the pivot locking mechanism160operates. The locked state of the pivot operation is maintained by frictional forces generated between the projections214and the first contact portions204.

FIGS. 28 and 30show the state where the slider202has retreated. If the slider202retreats, the second contact portions205and the inside of the projections214of the pair of locking members211and212come into contact with each other, and the pair of locking members rotate so that the proximal end portions thereof separate from each other. As a result, the distal end portions of the locking members move so as to approach each other and come into contact with the swivel joint portion203to thereby lock the bending operation by pressing. At this time, the first and second interlocking members221and222are also rotated in interlocking with the pair of locking members211and212, and the proximal end portions221A and222A of the first and second interlocking members move so as to separate from each other, and bend the link portion232. As a result, the advancing-retreating member231advances and is brought into a state where the pivot operation is possible. The locked state of the bending operation is maintained by frictional forces generated between the projections214and the second contact portions205.

Even in the above configuration, the user can suitably switch the locked state of the bending operation and the locked state of the pivot operation by operating the locking buttons201to advance and retreat the slider202.

Second Embodiment

A second embodiment of the present invention will be described with reference toFIGS. 31 to 36. A multi-DOF forceps301of the present embodiment is different from the multi-DOF forceps1of the first embodiment in several respects including the first operating portion. In the following description, the same components as those already described will be designated by the same reference numerals, and duplicate description will be omitted.

FIG. 31is an overall view of the multi-DOF forceps301. A first operating portion310includes a joint portion320instead of the swivel joint portion61, and a handle body311is different in shape from the handle body71of the first embodiment. Additionally, in the present embodiment, the handle body311is provided closer to the insertion portion10side than the operation center of the second bending portion12.

FIG. 32is an enlarged view of the first operating portion310. The handle body311includes a cylindrical proximal end portion312to which the joint portion320is attached, and a grip portion313that extends to the treatment portion30side from the proximal end portion312. The grip portion313has a shape in which a portion of the peripheral wall of a substantially hollow truncated conical shape is removed, and is provided with two holes of a knob hole315for exposing a rotating knob314used for the rotational operation of the insertion portion10of the treatment portion30and a finger hooking hole316. As shown inFIG. 32, the rotating knob314is provided apart from the axis O of the insertion portion10. Additionally, as shown inFIG. 31, the rotating knob314is connected to the treatment portion30via a shaft (flexible shaft317to be described below) having flexibility.

Although an opening and closing lever91A is slightly different in shape from the opening and closing lever91of the first embodiment, the operating methods or functions thereof are the same as those of the opening and closing lever91.

FIG. 33is a cross-sectional view of the first operating portion310. A mechanism for rotating the treatment portion30includes substantially the same structure as the first embodiment. The flexible shaft (shaft)317connected to the rotating knob314provided instead of the dial is connected to a gear318that rotates the rotation operating pipe at the rear portion of the handle body311. The rotating knob314is partially exposed through the knob hole315, and the user can rotate the rotating knob314to adjust the opening and closing direction of the treatment portion30in a state where the user has gripped the grip portion313.

FIG. 34is an exploded view of the joint portion320. The proximal end side of the insertion portion10is inserted into an outer tube321, and a proximal end portion of the outer tube321is provided with a pair of facing fixed walls322. The fixed walls322are fitted into a hole312A formed in the proximal end portion312of the handle body311and are fixed to the handle body311. The second bending portion12is inserted through a through hole323A of a rotary body323, and the rotary body323is arranged so as to substantially coincide with the center of the second bending portion12in the longitudinal direction. The basic shape of the rotary body323is a substantially rectangular parallelepiped, and as shown inFIG. 34, and the rotary body is arranged within a hole312A so as to be located between the pair of fixed walls322in a state with the long sides thereof being parallel to the fixed walls322. The rotary body323is supported so as to be rotatable relative to the handle body311on two axes of a first axis Xa parallel to the long sides and a second axis Xb parallel to short sides and orthogonal to the first axis Xa, by four cantilevered shafts that are not shown. A pair of cantilevered shafts that rotatably support the rotary body323on the second axis Xb are attached to the rotary body323through the pair of fixed walls322.

From the above structure, the joint portion320has a so-called biaxial gimbal structure, and the handle body311can be swung around the first axis Xa and the second axis Xb with an intersection point between the first axis Xa and the second axis Xb as the operation center X. However, since the outer tube321is assembled so as not to be rotatable relative to the handle body311, relative rotation of the handle body311and the joint portion320around the axis of the insertion portion10can be regulated.

Although the multi-DOF forceps301does not include the pivot locking mechanism or the bending locking mechanism and the mechanism that switches locked states, as shown inFIG. 35, a rotation-regulating member331is attached to an intermediate part of the insertion portion10located within the access port in use, and the cross-sectional shape of the outer peripheral surface thereof is a non-circular oval shape. Since an insertion hole332A of the access port332has the same shape as the appearance of the rotation-regulating member331, the access port332and the insertion portion10basically do not rotate relatively. Therefore, the insertion portion10is kept from rotating around the axis relative to the access port332while repeating the bending operation. On the other hand, since the cross-section of the insertion portion10is circular, if a constant force is made to act on the insertion portion10, it is also possible to rotate the insertion portion10relative to the rotation-regulating member331.

The cross-sectional shape of the outer peripheral surface of the rotation-regulating member331may be other shapes, such as a polygonal shape when the cross-sectional shape is noncircular. Additionally, the shape of the insertion hole of the spherical portion of the pivot portion110in the first embodiment instead of the access port332may be made to correspond to the rotation-regulating member, and the insertion portion10may be inserted through the pivot portion110.

When the multi-DOF forceps301of the present embodiment is used, as shown inFIG. 36, the user applies user's wrist Wr to the proximal end portion312of the handle body311and grips the grip portion313so as to wrap around the grip portion. Then, an operation is made in a state where a thumb Th is applied to the finger hooking hole316and a middle finger F2is hooked to the opening and closing lever91A. During the bending operation for bending the first bending portion11, a hand that has gripped the grip portion313is moved in a desired direction to perform the swinging operation of the handle body311, and when the pivot operation is performed, a distal end is fixed from the wrist Wr and the whole arm is moved.

According to the multi-DOF forceps301of the present embodiment, the second bending portion12is located at the proximal end portion312of the handle body311, and the grip portion313is located closer to the distal end side than the second bending portion12. Therefore, the handle body311is gripped in a state where the operation center X of the handle body in the bending operation and the position of the wrist Wr are made to substantially coincide with each other in the direction of the axis of the first operating portion310. The wrist is a part where a joint that connects a hand and an arm is located, and hardly moves even if the hand is moved in any way. Accordingly, even if the hand grips the handle body311and is moved, a moment that makes the insertion portion10produce the pivot operation is hardly generated. Therefore, by performing operation as described above, a procedure can be performed while the bending operation from the pivot operation is suitably separated without advanced skill.

Although the respective embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications can be added to the respective constituent elements, omissions can be made from the constituent elements, and the constituent elements of the respective embodiments can be combined, without departing from the spirit of the present invention.

For example, although the multi-DOF forceps including the bending locking mechanism and the pivot locking mechanism has been described in the above-described first embodiment, a configuration including only one of the mechanisms instead of this may be used. In this case, although the ease of operation deteriorates slightly, the bending operation and the pivot operation can be separated and operated by locking one operation to carefully perform the other operation.

Additionally, the part that operates the bending locking mechanism and the part that operates the pivot locking mechanism may not be the same but may be separably provided, respectively. Even in this case, although operability decreases slightly as compared with the respective embodiments, the bending operation and the pivot operation can be separably operated.

Moreover, the rotating knob that rotates the treatment portion may be directly attached to the insertion portion without interposing the flexible shaft. In this case, the grip portion can be arranged at an operable position while being gripped by exposing a portion of the rotation operating pipe at a position closer to the distal end side than the proximal end of the insertion portion and connecting the rotating knob to the exposed part.

Moreover, a configuration may be formed where the grip portion may be formed from an elastically deformable material, and the user may apply a force to the grip portion to elastically deform the grip portion so as to bring the grip portion into close contact with the swivel joint portion. If the user elastically deforms the grip portion in this way, it is possible to increase the frictional force between the grip portion and the swivel joint and to temporarily apply locking to the bending operation.

According to the above multi-DOF forceps, since the grip portion is arranged around the operation center, the user can easily and separably operate the bending operation of the first bending portion and the pivot operation of the insertion portion, without requiring advanced skill.

All the constituent elements described in the above respective embodiments and modified Examples can be carried out by appropriate combinations or omissions within the scope of the technical idea of the present invention. Moreover, although the preferred examples of the present invention have been described above, the present invention is not limited to these examples. Additions, omissions, substitutions, and other modifications can be made without departing from the spirit of the present invention. The present invention is not to be considered as being limited by the foregoing description, and is limited only by the scope of the appended claims.