Patent Description:
Various types of surgical instruments used to endoscopically treat tissue are known in the art, and are commonly used, for example, for closure of tissue or organs in transection, resection, anastomoses, for occlusion of organs in thoracic and abdominal procedures, and for electrosurgically fusing or sealing tissue.

One example of such a surgical instrument is a surgical stapling instrument. Typically, surgical stapling instruments include an end effector having an anvil assembly and a cartridge assembly for supporting an array of surgical staples, an approximation mechanism for approximating the cartridge and anvil assemblies, a rotation assembly for rotating the cartridge and anvil assemblies about an axis, and a firing mechanism for ej ecting the surgical staples from the cartridge assembly.

During laparoscopic or endoscopic surgical procedures, access to a surgical site is achieved through a small incision or through a narrow cannula inserted through a small entrance wound in a patient. Because of limited area available to access the surgical site, many endoscopic instruments include mechanisms for articulating the end effector of the instrument in relation to a body portion of the instrument to improve access to tissue to be treated.

It would be beneficial to provide an improved surgical instrument having an articulation assembly that would enable the end effector to articulate about <NUM>° to further improve access to target tissue.

<CIT> shows a surgical instrument for use in operating tissue, which has an articulation section that is coupled with a shaft and includes an articulation control assembly having a motor and a drive shaft with two threaded portions threaded in opposite directions relative to each other.

Certain embodiments are defined by the dependent claims.

The present disclosure relates to a surgical instrument including a handle assembly, an elongated portion, an end effector, and an articulation assembly. The elongated portion extends distally from the handle assembly and defines a first longitudinal axis. The end effector is disposed adjacent a distal end of the elongated portion and defines a second longitudinal axis. The articulation assembly is disposed in mechanical cooperation with the end effector and is configured to cause the end effector to move between a first position where the second longitudinal axis is aligned with the first longitudinal axis and a second position where the second longitudinal axis is disposed at an angle to the first longitudinal axis. The articulation assembly includes a dual threaded rod, a first nut, a second nut, a first articulation rod, and a second articulation rod. The dual threaded rod includes a body, a first thread encircling at least a portion of the body in a first direction, and a second thread encircling at least a portion of the body in a second direction. The first direction is opposite the second direction. The first nut is mechanically engaged with the first thread such that rotation of the dual threaded rod in a first direction relative to the elongated portion causes the first nut to move distally relative to the dual threaded rod. The second nut is mechanically engaged with the second thread such that rotation of the dual threaded rod in the first direction relative to the elongated portion causes the second nut to move proximally relative to the dual threaded rod. The first articulation rod is coupled to the first nut and to the end effector, and the second articulation rod is coupled to the second nut and to the end effector.

In disclosed aspects, the surgical instrument may include an actuation mechanism disposed in mechanical cooperation with the handle assembly and with the articulation assembly. The surgical instrument may also include a driver disposed in mechanical cooperation with the articulation assembly and in mechanical cooperation with the actuation mechanism. The driver may be rotatable about the longitudinal axis relative to the elongated portion. In aspects, the driver may be disposed in mechanical cooperation with the dual threaded rod, and the driver may be rotationally fixed with respect to the dual threaded rod.

In aspects, the first nut may be translatable proximally and translatable distally relative to the elongated portion, and the second nut may be translatable proximally and translatable distally relative to the elongated portion.

In further aspects, the first articulation rod may be longitudinally fixed to the first nut, and the second articulation rod may be longitudinally fixed to the second nut.

In disclosed aspects, rotation of the dual threaded rod in the first direction about the longitudinal axis relative to the elongated portion may cause the first articulation rod to move distally relative to the elongated portion and may cause the second articulation rod to move proximally relative to the elongated portion. In aspects, rotation of the dual threaded rod in a second direction about the longitudinal axis relative to the elongated portion may cause the first articulation rod to move proximally relative to the elongated portion and may cause the second articulation rod to move distally relative to the elongated portion.

In yet other aspects, the first nut and the second nut may be rotationally fixed relative to the elongated portion.

In disclosed aspects, the articulation assembly may further include a proximal stop disposed on the dual threaded rod proximally of the first nut, a distal stop disposed on the dual threaded rod distally of the second nut, and a middle stop disposed on the dual threaded rod distally of the first nut and proximally of the second nut.

In aspects, when the end effector is in the second position, the second longitudinal axis may be disposed at about <NUM>° relative to the first longitudinal axis.

The present disclosure also relates to an articulation assembly for use with a surgical device including a dual threaded rod, a proximal nut, a distal nut, a first articulation rod, and a second articulation rod. The dual threaded rod includes a body, a first thread encircling at least a portion of the body in a first direction, and a second thread encircling at least a portion of the body in a second direction. The first direction is opposite the second direction. The proximal nut at least partially encircles the body of the dual threaded rod and engages with the first thread of the dual threaded rod. The distal nut at least partially encircles the body of the dual threaded rod and engages with the second thread of the dual threaded rod. The first articulation rod is coupled to the proximal nut and is disposed on a first lateral side of the dual threaded rod. The second articulation rod is coupled to the distal nut and is disposed on a second lateral side of the dual threaded rod. Rotation of the dual threaded rod in a first direction relative to the proximal nut causes the proximal nut and the first articulation rod to move distally relative to the dual threaded rod, and causes the distal nut and the second articulation rod to move proximally relative to the dual threaded rod.

In disclosed aspects, rotation of the dual threaded rod in a second direction relative to the proximal nut may cause the proximal nut and the first articulation rod to move proximally relative to the dual threaded rod, and may cause the distal nut and the second articulation rod to move distally relative to the dual threaded rod.

In aspects, the articulation assembly may also include a proximal stop disposed on the dual threaded rod proximally of the proximal nut, a distal stop disposed on the dual threaded rod distally of the distal nut, and a middle stop disposed on the dual threaded rod distally of the proximal nut and proximally of the distal nut.

The present disclosure also relates to a method of articulating an end effector of a surgical instrument. The method includes rotating a dual threaded rod, translating a first nut proximally, translating a second nut distally, translating a first articulation rod proximally, and translating a second articulation rod distally. Translating the first nut proximally and translating the second nut distally occur simultaneously.

In disclosed aspects, translating the first articulation rod proximally and translating the second articulation rod distally may occur simultaneously. In aspects, translating the first nut proximally and translating the first articulation rod proximally may occur simultaneously.

In yet other aspects, the dual threaded rod may define a first longitudinal axis, the end effector may define a second longitudinal axis, and the method may further include moving the end effector from a first position wherein the first longitudinal axis is aligned with the second longitudinal axis, to a second position where the second longitudinal axis is disposed at about <NUM>° relative to the first longitudinal axis.

Various aspects of the present disclosure are illustrated herein with reference to the accompanying drawings, wherein:.

Aspects of the presently disclosed surgical instrument will now be described in detail with reference to the drawings wherein like numerals designate identical or corresponding elements in each of the several views. As is common in the art, the term "proximal" refers to that part or component closer to the user or operator, i.e. surgeon or physician, while the term "distal" refers to that part or component farther away from the user.

A surgical instrument of the present disclosure is indicated as reference numeral <NUM> in <FIG>. Generally, the surgical instrument <NUM> includes a handle assembly <NUM>, an elongated portion <NUM> extending distally from handle assembly <NUM> and defining a longitudinal axis "A-A," a loading unit <NUM> disposed adjacent a distal end of elongated portion <NUM>, and an articulation assembly <NUM> (<FIG> and <FIG>). While <FIG> illustrates surgical instrument <NUM> including a handle assembly <NUM> having a trigger <NUM>, various types of handles can be used such as, for example, a pivotable handle, powered, motor-driven, hydraulic, ratcheting, etc. As used herein, "handle assembly" encompasses all types of handle assemblies. Additionally, a robotic surgical system may be used in connection with the aspects of the present disclosure.

The loading unit <NUM> may be releasably attachable to the elongated portion <NUM> of the surgical instrument <NUM>, e.g., to allow the surgical instrument <NUM> to have greater versatility. This arrangement allows the clinician to select a particular loading unit <NUM> for a given procedure. As used herein, "loading unit" encompasses both single use loading units ("SULU") and disposable loading units ("DLU"). Additionally or alternatively, the surgical instrument <NUM> may have a cartridge that is removable and replaceable in the reusable jaws of the surgical instrument.

Examples of loading units for use with a surgical stapling instrument are disclosed in commonly-owned <CIT>, the entire contents of which are hereby referenced herein. Further details of an endoscopic surgical stapling instrument are described in detail in commonly-owned <CIT>, the entire contents of which are hereby referenced herein.

With reference to <FIG>, the loading unit <NUM> of the present disclosure is shown. The loading unit <NUM> includes a proximal body portion <NUM>, and a tool assembly or end effector <NUM> defining an axis "B-B" and including a pair of jaw members (i.e., an anvil assembly <NUM> and a cartridge assembly <NUM>). In aspects, the proximal body portion <NUM> may be configured to removably attach to the elongated portion <NUM> of surgical instrument <NUM>.

In the surgical instrument <NUM> in accordance with disclosed aspects, actuation of the trigger <NUM> (and/or at least one additional actuation mechanism) causes movement of at least one jaw member towards the other jaw member, distal movement of a firing rod to deploy fasteners from the cartridge assembly <NUM>, and/or distal movement of a knife to sever tissue.

Additionally, actuation of an articulation lever or controls 114a, 114b (<FIG>; collectively "articulation control <NUM>") engages the articulation assembly <NUM> and causes the end effector <NUM> to move from a first position (<FIG>) where the axis "B-B" defined by the end effector <NUM> is aligned with the longitudinal axis "A-A," to a second position (<FIG>) where the axis "B-B" is disposed at an angle (e.g. up to about <NUM>°) relative to the longitudinal axis "A-A.

With reference to <FIG> and <FIG>, the articulation assembly <NUM> includes a driver <NUM>, a dual threaded rod <NUM>, a proximal stop <NUM>, a middle stop <NUM>, a distal stop <NUM>, a proximal nut <NUM>, a distal nut <NUM>, a first articulation rod <NUM>, and a second articulation rod <NUM>. Additionally, and with particular reference to <FIG>, the surgical instrument <NUM> includes a pivot assembly <NUM>, which interconnects the articulation assembly <NUM> with the anvil assembly <NUM> and the cartridge assembly <NUM>. The pivot assembly <NUM> includes a first pivotlink <NUM> pinned to the first articulation rod <NUM> by a first pin <NUM>, and pinned to a proximal end of the anvil assembly <NUM> and the cartridge assembly <NUM> by a second pin <NUM>. The pivot assembly <NUM> also includes a second pivot link <NUM> pinned to the second articulation rod <NUM> by a third pin <NUM>, and pinned to a proximal end of the anvil assembly <NUM> and the cartridge assembly <NUM> by a fourth pin <NUM>.

With particular reference to <FIG> and <FIG>, further details of the articulation assembly <NUM> of the surgical instrument <NUM> are shown. The driver <NUM> is rotatable about the longitudinal axis "A-A" in response to actuation of the articulation control <NUM> (<FIG>). The dual threaded rod <NUM> is disposed adjacent a distal end of the driver <NUM> and is rotationally fixed relative to the driver <NUM>. The dual threaded rod <NUM> includes a body <NUM>, a first thread or series of threads <NUM> (e.g., right-hand threads) encircling the body <NUM> in a first direction (e.g., clockwise) and a second thread series of threads <NUM> (e.g., left-hand threads) encircling the body <NUM> in a second, opposite direction (e.g., counter-clockwise).

With continued reference to <FIG> and <FIG>, the proximal stop <NUM> is encircles a proximal portion of the dual threaded rod <NUM> and is rotationally and longitudinally fixed relative to the dual threaded rod <NUM>. The distal stop <NUM> is encircles a distal portion of the dual threaded rod <NUM> and is rotationally and longitudinally fixed relative to the dual threaded rod <NUM>. The middle stop <NUM> encircles a mid-portion of the dual threaded rod <NUM> and is positioned between the proximal stop <NUM> and the distal stop <NUM>.

The proximal nut <NUM> encircles a portion of the dual threaded rod <NUM> and is positioned between the proximal stop <NUM> and the middle stop <NUM>. More particularly, the proximal nut <NUM> defines an aperture <NUM>, and the wall defining the aperture <NUM> includes threads <NUM> (e.g., right-hand threads; <FIG>). The threads <NUM> of the proximal nut <NUM> are configured to engage or mesh with the first series of threads <NUM> of the threaded rod <NUM> such that rotation of the dual threaded rod <NUM> in a first direction (e.g., in the general direction of arrow "C" in <FIG>) causes the proximal nut <NUM> to move in a first longitudinal direction (e.g., in the general direction of arrow "D" in <FIG> -- distally), and rotation of the dual threaded rod <NUM> in a second direction (e.g., in the general direction of arrow "E" in <FIG>) causes the proximal nut <NUM> to move in a second longitudinal direction (e.g., in the general direction of arrow "P" in <FIG> -- proximally).

The distal nut <NUM> encircles a portion of the dual threaded rod <NUM> and is positioned between the distal stop <NUM> and the middle stop <NUM>. More particularly, the distal nut <NUM> defines an aperture <NUM>, and the wall defining the aperture <NUM> includes threads <NUM> (e.g., left-hand threads; <FIG>). The threads <NUM> of the distal nut <NUM> are configured to engage or mesh with the second series of threads <NUM> of the threaded rod <NUM> such that rotation of the dual threaded rod <NUM> in the first direction (e.g., in the general direction of arrow "C" in <FIG>) causes the distal nut <NUM> to move in the second longitudinal direction (e.g., in the general direction of arrow "P" in <FIG> -- proximally), and rotation of the dual threaded rod <NUM> in the second direction (e.g., in the general direction of arrow "E" in <FIG>) causes the distal nut <NUM> to move in the longitudinal direction (e.g., in the general direction of arrow "D" in <FIG>distally).

That is, rotation of the dual threaded rod <NUM> in the first direction (e.g., in the general direction of arrow "C" in <FIG>) causes the proximal nut <NUM> to move distally and simultaneously causes the distal nut <NUM> to move proximally. Rotation of the dual threaded rod <NUM> in the second direction (e.g., in the general direction of arrow "E" in <FIG>) causes the proximal nut <NUM> to move proximally and simultaneously causes the distal nut <NUM> to move distally. Moreover, rotation of the dual threaded rod <NUM> causes the proximal nut <NUM> and the distal nut <NUM> to move in opposite directions from each other.

Referring now to <FIG>, <FIG>, and <FIG>, the proximal stop <NUM> is positioned with respect to the dual threaded rod <NUM> such that the proximal stop <NUM> limits the amount of proximal movement of the proximal nut <NUM> relative to the dual threaded rod <NUM>. The middle stop <NUM> is positioned with respect to the dual threaded rod <NUM> such that the middle stop <NUM> limits the amount of distal movement of the proximal nut <NUM> relative to the dual threaded rod <NUM>, and limits the amount of proximal movement of the distal nut <NUM> relative to the dual threaded rod <NUM>. The distal stop <NUM> is positioned with respect to the dual threaded rod <NUM> such that the distal stop <NUM> limits the amount of distal movement of the distal nut <NUM> relative to the dual threaded rod <NUM>.

With reference to <FIG>, a radial cross-section of a portion of the articulation assembly <NUM> and the elongated portion <NUM> is shown. The elongated portion <NUM> includes an outer wall <NUM> and an inner body <NUM>. The inner body <NUM> defines an opening <NUM> dimensioned to accommodate the proximal nut <NUM>, the distal nut <NUM> (not shown in <FIG>), the first articulation rod <NUM>, and the second articulation rod <NUM> (not shown in <FIG>). The shape of the opening <NUM> of the elongated portion <NUM> ensures that the proximal nut <NUM>, the distal nut <NUM>, the first articulation rod <NUM>, and the second articulation rod <NUM> are fixed from rotation about the longitudinal axis "A-A" (<FIG>) relative to the elongated portion <NUM>. Accordingly, rotation of the dual threaded rod <NUM> relative to the elongated portion <NUM> results longitudinal translation (and no rotation) of the proximal nut <NUM>, the distal nut <NUM>, the first articulation rod <NUM>, and the second articulation rod <NUM> relative to the elongated portion <NUM>.

Referring to <FIG>, <FIG>, <FIG>, and <FIG>, the proximal nut <NUM> is mechanically coupled to the first articulation rod <NUM>, and the distal nut <NUM> is mechanically coupled to the second articulation rod <NUM>. More particularly, with particular reference to <FIG>, the first articulation rod <NUM> is affixed to a first lateral side <NUM> of the proximal nut <NUM>, and the second articulation rod <NUM> is affixed to a second lateral side <NUM> of the distal nut <NUM>. The first lateral side <NUM> of the proximal nut <NUM> and the second lateral side <NUM> of the distal nut <NUM> are on opposite sides of the longitudinal axis "A-A. " Accordingly, longitudinal movement of the proximal nut <NUM> causes a corresponding longitudinal movement of the first articulation rod <NUM> on a first side of the longitudinal axis "A-A," and longitudinal movement of the distal nut <NUM> causes a corresponding longitudinal movement of the second articulation rod <NUM> on a second side of the longitudinal axis "A-A.

Moreover, rotation of the dual threaded rod <NUM> in the first direction (e.g., in the general direction of arrow "C" in <FIG>) causes the proximal nut <NUM> and the first articulation rod <NUM> to move distally, and simultaneously causes the distal nut <NUM> and the second articulation rod <NUM> to move proximally. Rotation of the dual threaded rod <NUM> in the second direction (e.g., in the general direction of arrow "E" in <FIG>) causes the proximal nut <NUM> and the first articulation rod <NUM> to move proximally, and simultaneously causes the distal nut <NUM> and the second articulation rod <NUM> to move distally.

Referring now to <FIG>, <FIG>, and <FIG>, engagement between the articulation assembly <NUM> and the pivot assembly <NUM> is shown. As noted above, the first articulation rod <NUM> is pivotably coupled to the first pivot link <NUM> by a first pin <NUM>, and the second articulation rod <NUM> is pivotably coupled to the second pivot link <NUM> by a third pin <NUM>. The first pivot link <NUM> is pivotably coupled to the proximal end of the anvil assembly <NUM> and the cartridge assembly <NUM> by a second pin <NUM>, and the second pivot link <NUM> is pivotably coupled to the anvil assembly <NUM> and the cartridge assembly <NUM> by a fourth pin <NUM>. Accordingly, when the first articulation rod <NUM> is moved proximally and when the second articulation rod <NUM> is moved distally (which, as discussed above, occur simultaneously), the end effector <NUM> is moved or articulated in the general direction of arrow "R" (<FIG>). Likewise, when the first articulation rod <NUM> is moved distally and when the second articulation rod <NUM> is moved proximally (which, as discussed above, occur simultaneously), the end effector <NUM> is moved or articulated in the general direction of arrow "L" (<FIG>).

Thus, the end effector <NUM> is being simultaneously pushed and pulled in opposite directions. More particularly, when one lateral side of the end effector <NUM> is being pushed, the opposite lateral side of the end effector <NUM> is being pulled, and vice versa. Therefore, a mechanical advantage exists versus an articulation assembly including a single articulation rod, for instance, which is only able to push or pull the end effector, instead of being able to push and pull the end effector.

Claim 1:
An articulation assembly (<NUM>) for use with a surgical device (<NUM>), the articulation assembly comprising:
a dual threaded rod (<NUM>) including a body (<NUM>), a first thread (<NUM>) encircling at least a portion of the body in a first direction, and a second thread (<NUM>) encircling at least a portion of the body in a second direction,
wherein the first direction is opposite the second direction;
a proximal nut (<NUM>) at least partially encircling the body of the dual threaded rod (<NUM>) and engaged with the first thread (<NUM>) of the dual threaded rod;
a distal nut (<NUM>) at least partially encircling the body of the dual threaded rod (<NUM>) and engaged with the second thread (<NUM>) of the dual threaded rod;
a first articulation rod (<NUM>) coupled to the proximal nut (<NUM>) and disposed on a first lateral side of the dual threaded rod (<NUM>); and
a second articulation rod (<NUM>) coupled to the distal nut (<NUM>) and disposed on a second lateral side of the dual threaded rod (<NUM>),
wherein rotation of the dual threaded rod (<NUM>) in a first direction relative to the proximal nut (<NUM>) causes the proximal nut and the first articulation rod (<NUM>) to move distally relative to the dual threaded rod, and causes the distal nut (<NUM>) and the second articulation rod (<NUM>) to move proximally relative to the dual threaded rod;
characterised in the surgical device is a surgical stapling device; and
in that at least a portion of the first thread is overlapping at least a portion of the second thread.