Patent Description:
The present disclosure relates generally to surgical instruments. In particular, the disclosure relates to shaft-based surgical instruments such as electrosurgical forceps.

Instruments such as electrosurgical forceps are commonly used in open and endoscopic surgical procedures to coagulate, cauterize and/or seal tissue. Such forceps typically include a pair of jaw members that can be controlled by a surgeon to grasp targeted tissue, such as, e.g., a blood vessel. The jaw members may be approximated to apply a mechanical clamping force to the tissue, and are associated with at least one electrode to permit the delivery of electrosurgical energy to the tissue. The combination of the mechanical clamping force and the electrosurgical energy has been demonstrated to join adjacent layers of tissue captured between the jaw members to form a tissue seal.

A bipolar electrosurgical forceps typically includes electrodes disposed on the opposed jaw members. The electrodes are charged to opposite electrical potentials such that an electrosurgical current may be selectively transferred through tissue grasped between the electrodes. The electrosurgical forceps is typically equipped with a mechanism that allows a clinician to manually rotate the jaw members without having to rotate the entire instrument. Documents <CIT>, <CIT> and <CIT> disclose instruments of the prior art.

Claim <NUM> defines the invention and dependent claims disclose embodiments. No surgical methods are claimed. The techniques of this disclosure generally relate to a gear system incorporated into a surgical instrument (e.g., a shaft-based electrosurgical forceps) that reduces the amount of rotation of an actuator needed to rotate an end effector a selected amount. As such, a clinician may rotate the end effector a selected amount by rotating the actuator to a lesser degree than the selected amount. The gear system may include planetary gears, worm gears, bevel gears, helical gears, or other suitable gear mechanisms. In aspects, a selective gear ratio mechanism (e.g., a clutch) may be provided to allow a clinician to select different actuation input to output rotation ratios. A ratchet-type rotation wheel or lever may be implemented to allow ratcheting motion to rotate the end effector. In other aspects, a motor-driven system may be provided for smoother and easier function. In aspects, one actuator may be actuated to rotate the end effector clockwise, and another actuator may be actuated to rotate the end effector counter-clockwise; alternatively, single-direction rotation may be provided, e.g., in <NUM> degree, <NUM> degree, or other suitable increments.

In one aspect of the present disclosure, provided is a surgical instrument including a handle assembly and a shaft portion. The handle assembly includes a handle housing, an actuator rotatably coupled to the handle housing, and a main gear operably coupled to the actuator. The shaft portion has a proximal end portion rotatably supported by the handle assembly, and a distal end portion configured to support an end effector. The shaft portion is configured to rotate relative to the handle assembly about a longitudinal axis defined by the shaft portion. The shaft portion is non-rotatably coupled to the main gear and is configured to rotate with the main gear in response to a rotation of the actuator at a rate greater than a rate of rotation of the actuator.

In aspects, the handle assembly may further include a ring gear rotationally fixed to the handle housing, and a plurality of planet gears rotationally supported on the actuator and in meshing engagement with the ring gear. The main gear may be a sun gear in meshing engagement with the planet gears such that the rotation of the actuator rotates the planet gears relative to the ring gear to rotate the sun gear.

In aspects, the sun gear may be fixed to the proximal end portion of the shaft portion.

In aspects, the actuator may be configured to slide relative to the sun gear between a first position and a second position. In the first position, the actuator is engaged to the planet gears. In the second position, the actuator is engaged directly to the main gear.

In aspects, the actuator may be a rotation wheel that protrudes outwardly from the handle housing.

In aspects, the rotation wheel may define a plane that is parallel with the longitudinal axis of the shaft portion.

In aspects, the rotation wheel may be configured to rotate about a rotation axis that is perpendicular to the longitudinal axis of the shaft portion.

In aspects, the rotation wheel may have a first annular array of teeth in meshing engagement with the main gear.

In aspects, the rotation wheel may have an upper surface, and the first annular array of teeth may extend upwardly relative to the upper surface.

In aspects, the first annular array of teeth may be disposed at a radial distance from the rotation axis of the rotation wheel that is at least double a diameter of the main gear.

In aspects, a gear ratio between the rotation wheel and the main gear may be from <NUM>:<NUM> to <NUM>:<NUM>.

In aspects, the rotation wheel may have a second annular array of teeth disposed at a different radial distance from the rotation axis than the first annular array of teeth.

In aspects, the main gear may be configured for selective engagement with the first or second annular array of teeth to adjust a gear ratio between the rotation wheel and the main gear.

In aspects, the actuator may be a lever arm.

In accordance with another aspect of the disclosure, a surgical instrument is provided that includes a handle assembly and a shaft portion. The handle assembly includes a handle housing, a rotation wheel rotationally supported in the handle housing, a ring gear rotationally fixed to the handle housing, a plurality of planet gears rotationally supported on the rotation wheel and in meshing engagement with the ring gear, and a sun gear in meshing engagement the planet gears such that a rotation of the rotation wheel in a first direction rotates the plurality of planet gears relative to the ring gear to rotate the sun gear. The shaft portion may have a proximal end portion rotatably supported by the handle assembly, and a distal end portion configured to support an end effector. The shaft portion is configured to rotate relative to the handle assembly about a longitudinal axis defined by the shaft portion. The shaft portion is non-rotatably coupled to the sun gear such that the shaft portion is configured to rotate in the first direction with the sun gear in response to a rotation of the rotation wheel in the first direction.

In aspects, the rotation wheel may be configured to slide relative to the sun gear between a first position and a second position. In the first position, the rotation wheel is engaged to the planet gears. In the second position, the rotation wheel is engaged directly to the sun gear.

In aspects, a gear ratio between the rotation wheel and the sun gear may be from <NUM>:<NUM> to <NUM>:<NUM>.

As is traditional, the term "distal" refers herein to an end of the electrosurgical instrument or component thereof that is farther from an operator, and the term "proximal" refers herein to the end of the electrosurgical forceps or component thereof that is closer to the operator.

Objects and features of the present disclosure will become apparent to those of ordinary skill in the art when descriptions of various embodiments thereof are read with reference to the accompanying drawings, of which:.

Referring initially to <FIG>, a surgical instrument, such as, for example, an electrosurgical forceps <NUM> is provided and generally includes a handle assembly <NUM> that supports various actuators thereon for remotely controlling an end effector <NUM> through a shaft portion <NUM>. Although this configuration is typically associated with instruments for use in laparoscopic or endoscopic surgical procedures, various aspects of the present disclosure may be practiced with traditional open instruments and in connection with endoluminal procedures as well. The handle assembly <NUM> includes a handle housing <NUM> constructed of a left housing half and a right housing half. The housing halves may be constructed of sturdy plastic, and may be joined to one another by adhesives, ultrasonic welding, mechanical fastening, or other suitable assembly methods. The shaft portion <NUM> has a proximal end portion 116a rotatably supported in the handle housing <NUM>, and a distal end portion 116b configured to support the end effector <NUM>.

To mechanically control the end effector <NUM>, the housing <NUM> supports a stationary handle <NUM>, a movable handle <NUM>, a trigger <NUM>, and an actuator, such as, for example, a rotation knob or wheel <NUM> (<FIG>). The present disclosure also contemplates robotic implementations wherein the handle housing mounts on a robotic arm and the manual actuators are replaced with robotic inputs. Thus, terms like handle, lever, etc. that are typically associated with manual grasping and/or manipulation are utilized herein to also cover robotic, powered, or other non-manual implementations. The movable handle <NUM> is operable to move the end effector <NUM> between an open configuration wherein upper and lower jaw members <NUM>, <NUM> are disposed in spaced relation to one another, and a closed or clamping configuration wherein the jaw members <NUM>, <NUM> are closer together, e.g., for grasping tissue. Approximation of the movable handle <NUM> with the stationary handle <NUM> moves the end effector <NUM> to the closed configuration and separation of the movable handle <NUM> from the stationary handle <NUM> moves the end effector <NUM> to the open configuration. The trigger <NUM> is operable to extend and retract a knife blade (not explicitly shown) through the end effector <NUM> when the end effector <NUM> is in the closed configuration. The rotation wheel <NUM> (<FIG>) rotates the shaft portion <NUM> and the end effector <NUM> about a longitudinal axis "X" defined by the shaft portion <NUM>, as will be described in further detail.

To electrically control the end effector <NUM>, the stationary handle <NUM> supports a depressible button <NUM> thereon, which is operable by the user to initiate and terminate the delivery of electrosurgical energy to the end effector <NUM>. The depressible button <NUM> is mechanically coupled to a switch (not shown) disposed within the stationary handle <NUM> and is engageable by a button activation post <NUM> extending from a proximal side of the moveable handle <NUM> upon proximal movement of the moveable handle <NUM> to an actuated or proximal position. The switch is in electrical communication with an electrosurgical generator (not explicitly shown) via suitable electrical wiring extending from the housing <NUM> through a cable extending between the housing <NUM> and the electrosurgical generator. The cable may include a connector (not shown) thereon such that the forceps <NUM> may be selectively coupled electrically to the generator. Further details about the end effector <NUM> may be found, for example, in <CIT>, entitled "ENDOSCOPIC VESSEL SEALER AND DIVIDER FOR LARGE TISSUE STRUCTURES".

With reference to <FIG>, the handle assembly <NUM> further includes a gear assembly <NUM> supported in the handle housing <NUM> and configured to transmit rotational motion originating in the rotation wheel <NUM> to the shaft portion <NUM> and the attached end effector <NUM>. The gear assembly <NUM> may be a planetary gear assembly including a ring gear <NUM>, a plurality of planet gears <NUM>, and an elongated main gear or sun gear <NUM>. The ring gear <NUM> is rotationally fixed to the handle housing <NUM> and defines a plurality of gear teeth <NUM> extending inwardly. The planet gears <NUM> are rotationally supported on the rotation wheel <NUM> and in meshing engagement with the ring gear <NUM> and the sun gear <NUM>. In aspects, the gear assembly <NUM> may include four planet gears. In other aspects, the gear assembly <NUM> may include more or less than four planet gears. The sun gear <NUM> extends centrally through the ring gear <NUM> and is in meshing engagement with each of the planet gears <NUM> such that a rotation of the rotation wheel <NUM> rotates the planet gears <NUM> relative to the ring gear <NUM> to rotate the sun gear <NUM>.

As best shown in <FIG>, the rotation wheel <NUM> functions as a planet carrier and includes an annular body portion <NUM> that protrudes outwardly through slots defined within the handle housing <NUM> on either side thereof and a plurality of pegs <NUM> protruding longitudinally from the annular body portion <NUM>. The pegs <NUM> are configured for receipt in the corresponding planet gears <NUM> and permit rotation of the planet gears <NUM> thereabout. The annular body portion <NUM> of the rotation wheel <NUM> defines a channel <NUM> therethrough configured for receipt of the sun gear <NUM>.

The gear ratio between the rotation wheel <NUM> and the sun gear <NUM> may range from about <NUM>:<NUM> to about <NUM>:<NUM>. As such, for every degree of rotation inputted by the rotation wheel <NUM>, there is a greater degree of rotation output by the sun gear <NUM> and, in turn, the shaft portion <NUM> and the attached end effector <NUM>. The sun gear <NUM> may have from about <NUM> teeth to about <NUM> teeth, and in some aspects <NUM> teeth; each of the four planet gears <NUM> may have between about <NUM> teeth to about <NUM> teeth, and in some aspects <NUM> teeth; and the ring gear <NUM> may have from about <NUM> teeth to about <NUM> teeth, and in some aspects <NUM> teeth.

With continued reference to <FIG> and <FIG>, the proximal end portion 116a of the shaft portion <NUM> has the sun gear <NUM> non-rotatably fixed thereto such that the shaft portion <NUM> is configured to rotate with the sun gear <NUM> in response to a rotation of the rotation wheel <NUM>. For example, the sun gear <NUM> may have a detent (not explicitly shown) protruding inwardly therefrom that is received in a corresponding recess (not explicitly shown) defined in the proximal end portion 116a of the shaft portion <NUM> to non-rotatably couple the sun gear <NUM> to the shaft portion <NUM>. In aspects, the sun gear <NUM> may be fixed to the shaft portion <NUM> via other suitable fastening engagements, such as, for example, monolithic formation, adhesive, fasteners, or the like.

In aspects, the channel <NUM> defined in the rotation wheel <NUM> may allow for translational movement of the rotation wheel <NUM> relative to and along the sun gear <NUM>. The rotation wheel <NUM> may have a plurality of teeth (not explicitly shown) protruding into the channel <NUM> of the annular body portion <NUM>. The teeth are configured for meshing engagement with gear teeth <NUM> of the sun gear <NUM> when the rotation wheel <NUM> is moved to a proximal position. More specifically, the rotation wheel <NUM> may be configured as a clutch that slides relative to and along the sun gear <NUM> between a distal or first position, in which the pegs <NUM> of the rotation wheel <NUM> are received in the planet gears <NUM> to indirectly couple the rotation wheel <NUM> to the sun gear <NUM>, and the proximal or second position, in which the pegs <NUM> of the rotation wheel <NUM> are withdrawn from the planet gears <NUM> and the teeth of the rotation wheel <NUM> directly engage with the gear teeth <NUM> of the sun gear <NUM>. In this aspect, a clinician may selectively move the rotation wheel <NUM> between the first and second positions to adjust the gear ratio between the rotation wheel <NUM> and the shaft portion <NUM>. In such aspects, plural gear assemblies <NUM> may be provided, each having a different gear ratio and being selectively engagable with rotation wheel <NUM>. In aspects, a pin (not shown) may be provided that may be used to selectively lock the rotation wheel <NUM> to the sun gear <NUM> such that the sun gear <NUM> is configured to rotate with the rotation wheel <NUM> in a <NUM>:<NUM> gear ratio.

In aspects, the gear ratio associated with gear assembly <NUM> may be selected such that a maximum rotation of rotation wheel <NUM> with a finger of the clinician without the need for repositioning the clinician's finger on rotation wheel <NUM> (e.g., wherein rotation wheel <NUM> is engaged with the clinician's finger at one end of the slot defined through handle housing <NUM> and is rotated to the opposite end of the slot defined through handle housing <NUM>) corresponds to a rotation of the shaft portion <NUM> and the attached end effector <NUM> of about <NUM> degrees or about <NUM> degrees.

<FIG> illustrate an electrosurgical forceps <NUM> similar to electrosurgical forceps <NUM> except that the rotation wheel <NUM> is replaced with a lever arm <NUM>. The lever arm <NUM> is configured to rotate a gear system (not explicitly shown), such as, for example, a worm drive, that rotates the shaft portion <NUM> at a greater rate of rotation than the lever arm <NUM>, or a gear system similar to gear assembly <NUM> (<FIG>). For example, a rotation of the lever arm <NUM> from a starting position (<FIG>) to a second position (<FIG>) of about <NUM> degrees effectuates a rotation of the shaft portion <NUM> and the attached end effector about <NUM> degrees or about <NUM> degrees. In aspects, a clutch (not shown) disengages lever arm <NUM> from the gear system at the second position of the lever arm <NUM> such that the lever arm <NUM> may be returned to the starting position, e.g., under a bias, without altering the rotational position of the shaft portion <NUM>. Upon returning to the starting position, the lever arm <NUM> is re-engaged with the gear system. A suitable push-push mechanism (including clutch and gearing system, suitably modified to provide a rotational output rather than a longitudinal output) suitable for this purpose is described in <CIT>, entitled "SURGICAL INSTRUMENT HAVING A BIPOLAR END EFFECTOR ASSEMBLY AND A DEPLOYABLE MONOPOLAR ASSEMBLY".

With reference to <FIG>, another electrosurgical forceps <NUM>, similar to electrosurgical forceps <NUM>, is illustrated, and includes a handle assembly <NUM>, a shaft portion <NUM>, and an end effector <NUM>. The handle assembly <NUM> includes a handle housing <NUM>, an actuator, such as, for example, a rotation wheel <NUM>, rotatably coupled to the handle housing <NUM>, and a main gear <NUM> (e.g., a pinion gear) operably coupled to the rotation wheel <NUM>. The shaft portion <NUM> has a proximal end portion 316a rotatably supported by the handle housing <NUM>, and a distal end portion 316b configured to support the end effector <NUM>. The main gear <NUM> is rotationally fixed about the proximal end portion 316a of the shaft portion <NUM> such that the shaft portion <NUM> rotates relative to the handle housing <NUM> about a longitudinal axis defined by the shaft portion <NUM> in response to a rotation of the main gear <NUM>.

The rotation wheel <NUM> protrudes outwardly from the handle housing <NUM> (e.g., through a slot defined therein on either side thereof) and lies on a plane that is parallel with the longitudinal axis of the shaft portion <NUM> such that the rotation wheel <NUM> is configured to rotate about a rotation axis that is perpendicular to the longitudinal axis of the shaft portion <NUM>. The rotation wheel <NUM> has an annular upper surface <NUM> and an annular outer peripheral surface <NUM> from which a first annular array of teeth <NUM> extend upwardly. The first array of teeth <NUM> may protrude from the outer peripheral surface <NUM> and are in meshing engagement with the main gear <NUM>.

The rotation wheel <NUM> has a larger diameter than the main gear <NUM> such that a full rotation of the rotation wheel <NUM> produces at least about two rotations of the main gear <NUM>. More specifically, the first annular array of teeth <NUM> are disposed at a radial distance from the rotation axis of the rotation wheel <NUM> that is at least twice the diameter of the main gear <NUM>. In some aspects, a gear ratio between the rotation wheel <NUM> and the main gear <NUM> is from about <NUM>:<NUM> to about <NUM>:<NUM>.

In aspects, the rotation wheel <NUM> may have a second annular array of teeth <NUM> disposed radially inward of the first array of teeth <NUM>. The main gear <NUM> may be configured for selective engagement with the first or second array of teeth <NUM>, <NUM> to adjust a gear ratio between the rotation wheel <NUM> and the main gear <NUM>. Since the second array of teeth <NUM> are radially closer to a rotation axis of the rotation wheel <NUM> than is the first array of teeth <NUM>, when the main gear <NUM> is engaged to the second array of teeth <NUM>, a rotation of the rotation wheel <NUM> rotates the main gear <NUM> to a lesser extent than the same amount of rotation of the rotation wheel <NUM> when the first array of teeth <NUM> of the rotation wheel <NUM> is engaged to the main gear <NUM>. It is contemplated that the rotation wheel <NUM> may be slid relative to the main gear <NUM> to selectively engage the first or second array of teeth <NUM>, <NUM> to the main gear <NUM>. Similarly as above, the gear ratio may be selected such that a maximum single-finger rotation of the rotation wheel <NUM> provides a rotation of the shaft portion <NUM> of about <NUM> degrees or about <NUM> degrees.

With reference to <FIG>, another electrosurgical forceps <NUM>, similar to electrosurgical forceps <NUM>, is illustrated, and includes a handle assembly <NUM>, a shaft portion <NUM>, and an end effector <NUM>. The handle assembly <NUM> includes a handle housing <NUM>, an actuator, such as, for example, a rotation wheel <NUM>, rotatably coupled to the handle housing <NUM>, and a gear assembly <NUM> operably coupled to the rotation wheel <NUM>. The shaft portion <NUM> has a proximal end portion 416a operably coupled to the gear assembly <NUM>, and a distal end portion 416b configured to support the end effector <NUM>.

The gear assembly <NUM> is housed within a bracket or housing <NUM> that is fixed to the handle housing <NUM>. The gear assembly <NUM> is operably coupled between the rotation wheel <NUM> and the proximal end portion 416a of the shaft portion <NUM> such that a rotation of the rotation wheel <NUM> cases a rotation of the shaft portion <NUM>. The gear assembly <NUM> includes a proximal shaft <NUM>, a transmission wheel <NUM>, and a distal gear <NUM>. The proximal shaft <NUM> is non-rotatably coupled to the rotation wheel <NUM> such that the proximal shaft <NUM> rotates with and by the rotation wheel <NUM>. The proximal shaft <NUM> has a proximal gear <NUM>, such as, for example, a crown gear, fixed thereabout. In aspects, the proximal shaft <NUM> may have any suitable type of gear fixed thereabout.

The transmission wheel <NUM> is rotationally supported in the housing <NUM> and includes a lower surface defining a first set of teeth <NUM> arranged in an annular row, and a second set of teeth <NUM> arranged in an annular row. The first set of teeth <NUM> are disposed concentrically within the second set of teeth <NUM>. The first set of teeth <NUM> are in meshing engagement with the proximal gear <NUM> of the proximal shaft <NUM> such that the transmission wheel <NUM> rotates in response to a rotation of the proximal shaft <NUM>. The distal gear <NUM>, which is fixed to the proximal end portion 416a of the shaft portion <NUM>, may be a crown gear, and is in meshing engagement with the second set of teeth <NUM> of the transmission wheel <NUM>. Since the second set of teeth <NUM> has a larger diameter than the first set of teeth <NUM>, the transmission wheel <NUM> increases the gear ratio between the proximal gear <NUM> and the distal gear <NUM> from about <NUM>:<NUM> to about <NUM>:<NUM>. It is contemplated that the distal gear <NUM> may be fixed to the proximal end portion 416a of the shaft portion <NUM> via any suitable fastening engagement, such as, for example, a clip, adhesive, or the like.

Claim 1:
A surgical instrument, comprising:
a handle assembly including:
a handle housing (<NUM>);
a rotation wheel (<NUM>) rotationally supported in the handle housing;
a ring gear (<NUM>) rotationally fixed to the handle housing;
a plurality of planet gears (<NUM>) rotationally supported on the rotation wheel and in meshing engagement with the ring gear; and
a sun gear (<NUM>) in meshing engagement with the plurality of planet gears such that a rotation of the rotation wheel in a first direction rotates the plurality of planet gears relative to the ring gear to rotate the sun gear; and
a shaft portion (<NUM>) having a proximal end portion rotatably supported by the handle assembly, and a distal end portion configured to support an end effector (<NUM>), the shaft portion configured to rotate relative to the handle assembly about a longitudinal axis defined by the shaft portion, the shaft portion being non-rotatably coupled to the sun gear such that the shaft portion is configured to rotate in the first direction with the sun gear in response to a rotation of the rotation wheel.