Patent Description:
Endoscopic surgical instruments are often preferred over traditional open surgical devices because a smaller incision. tends to reduce the post-operative recovery time and complications. Consequently, significant development has gone into a range of endoscopic surgical instruments that are suitable for precise placement of a distal end effector at a desired surgical site through a cannula of a trocar. These distal end effectors engage the tissue in a number of ways to achieve a diagnostic or therapeutic effect (e.g., endocutter, grasper, cutter, staplers, clip applier, access device, drug/gene therapy delivery device, and energy device using ultrasound, RF, laser, etc.).

Positioning the end effector is constrained by the trocar. Generally, these endoscopic surgical instruments include a long shaft between the end effector and a handle portion manipulated by the clinician. This long shaft enables insertion to a desired depth and rotation about the longitudinal axis of the shaft, thereby positioning the end effector to a degree. With judicious placement of the trocar and use of graspers, for instance, through another trocar, often this amount of positioning is sufficient. Surgical stapling and severing instruments, such as described in <CIT>, are an example of an endoscopic surgical instrument that successfully positions an end effector by insertion and rotation.

One stapler manufactured by United States Surgical Corporation and described in <CIT> and <CIT> have an end effector that pivotally moves along a single plane in steps dependent upon activation of a lever that correspondingly moves along a single plane in similar steps. See <FIG> and <FIG> therein. Surgical Corp. stapler, however, is limited by the predetermined angles that it can achieve and by the limited side to side pivoting (-<NUM> degrees to +<NUM> degrees) that requires two hands for operation.

Depending upon the nature of the operation, it may be desirable to further adjust the positioning of the end effector of an endoscopic surgical instrument rather than being limited to insertion and rotation. In particular, it is often desirable to orient the end effector at an axis transverse to the longitudinal axis of the shaft of the instrument. The transverse movement of the end effector relative to the instrument shaft is conventionally referred to as "articulation". This articulated positioning permits the clinician to more easily engage tissue in some instances. In addition, articulated positioning advantageously allows an endoscope to be positioned behind the end effector without being blocked by the instrument shaft.

While the aforementioned non-articulating stapling and severing instruments have great utility and may be successfully employed in many surgical procedures, it is desirable to enhance their operation with the ability to articulate the end effector, thereby giving greater clinical flexibility in their use. Articulating surgical instruments generally use one or more firing bars that move longitudinally within the instrument shaft and through the articulation joint to fire the staples from the cartridge and to cut the tissue between the innermost staple lines. One common problem with these surgical instruments is control of the firing bar through the articulation joint. At the articulation joint, the end effector is longitudinally spaced away from the shaft so that the edges of the shaft and end effector do not collide during articulation. This gap must be filled with support material or structure to prevent the firing bar from buckling out of the joint when the single or multiple firing bars is subjected to longitudinal firing loads. What is needed is a support structure that guides and supports the single or multiple firing bars through the articulation joint and bends or curves as the end effector is articulated. <CIT> discloses a medical device comprising a control handle having a stapling actuator, an articulation joint actuator having an unactuated state and an actuated state and a body through which the stapling actuator and the articulation joint actuator traverse. <CIT> describes a flexible articulation joint that is formed from an elastomeric or plastic material that bends at the flexible joint or "flex neck". The firing bars are supported and guided through a hollow tube within the flex neck. The flex neck is a portion of the jaw closure mechanism and moves longitudinally relative to the end effector, shaft, and firing bars when the jaws are closed on tissue. The firing bars then move longitudinally within the flex neck as the staples are fired and tissue is cut.

<CIT> (owned by Richard-Allan Medical Industries, Inc. ) describes an articulation joint that pivots around a pin, rather than bends around a flex joint. In this instrument, firing bars are supported between a pair of spaced support plates connected at one end to the shaft and at another end to the end effector. At least one of those connections is a slidable connection. The support plates extend through the articulation joint adjacent to the flexible drive member in the plane of articulation such that the support plates bend through the gap in the plane of articulation and the flexible firing bar bends against the support when the tip is articulated in one direction from its aligned position. <CIT> from U. Surgical teaches the use of support plates that are fixedly attached to the shaft and slidably attached to the end effector.

Although these known support plates guide a firing bar through an articulation joint, it is believed that performance may be enhanced. For instance, it is often desirable for the firing bar to be rapidly accelerated during firing to ensure sufficient momentum for severing tissue effectively. Rigidly attached support plates may tend to dislodge in response, allowing the firing bar to blow out from the articulation joint. As a further example, it is desirable for the instrument to operate in the same manner whether articulated or not. Increased friction when articulated would be inconvenient and distracting to the clinician if required to exert a varying amount of firing force.

Document <CIT> discloses a surgical instrument and method for applying fasteners to bodily tissue. The instrument includes a handle assembly, a jaw portion, and an optional stent portion.

The instrument can be configured and dimensioned to be insertable through a cannula, and is useful for joining tubular organs. A plurality of fasteners, e.g. staples, is disposed in each of two jaws.

Consequently, a significant need exists for an improved articulation mechanism for a surgical instrument mechanism that provides enhanced support to a firing bar through the articulation joint.

It is accordingly an object of the invention to provide a medical device that overcomes the herein afore-mentioned disadvantages of the heretofore-known devices of this general type and that provides an articulating surgical end effector.

According to the present invention, this object is achieved by a medical device according to claim <NUM>. The dependent claims define further embodiments of the invention.

The construction and method of operating the inventive devices, however, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.

Advantages of embodiments of the present invention will be apparent from the following detailed description of the preferred embodiments thereof, which description should be considered in conjunction with the accompanying drawings in which:.

Aspects of the invention are disclosed in the following description and related drawings directed to specific embodiments of the invention. Alternate embodiments may be devised without departing from the scope of the invention. Additionally, well-known elements of exemplary embodiments of the invention will not be described in detail or will be omitted so as not to obscure the relevant details of the invention.

Before the present invention is disclosed and described, it is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. It must be noted that, as used in the specification and the appended claims, the singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise.

While the specification concludes with claims defining the features of the invention that are regarded as novel, it is believed that the invention will be better understood from a consideration of the following description in conjunction with the drawing figures, in which like reference numerals are carried forward. The figures of the drawings are not drawn to scale.

Referring now to the figures of the drawings in detail and first, particularly to <FIG> thereof, there is shown a first exemplary embodiment of a stapling and cutting end effector <NUM> The major parts of the end effector <NUM> include a clevis <NUM>, an anvil <NUM>, a cartridge holder <NUM> for receiving a staple cartridge <NUM>, an adapter sleeve <NUM>, and a lateral translation or articulation device <NUM>. <FIG> illustrates the removability of the staple cartridge <NUM> from the cartridge holder <NUM>.

Connecting the anvil <NUM> to the cartridge holder <NUM> and the staple cartridge <NUM> is a staple-actuating and tissue-cutting slide <NUM>. This slide <NUM> operative engages both the anvil <NUM> and the cartridge holder <NUM> to keep the two parts <NUM>, <NUM> in proper alignment so that the actuated staples inside the cartridge <NUM> hit their respective stapler anvils within the anvil <NUM> and secure the staples around tissue disposed between the anvil <NUM> and the cartridge <NUM>. The distal facing surface of the slide <NUM> contains a blade <NUM> for cutting the tissue disposed in the jaws <NUM>, <NUM> as the tissue is being stapled together. Proximal movement of the slide is shown, diagrammatically, in <FIG>. So that the slide <NUM> can be seen in <FIG> and <FIG>, the anvil <NUM> is uncoupled from the top end of the slide <NUM>. In operation, however, the slide <NUM> must be coupled to the anvil <NUM> as shown in <FIG> and, especially, in <FIG>.

<FIG> illustrates the end effector <NUM> with the adapter sleeve <NUM> removed to make visible various features of the translation therein.

A first of two primary parts of the lateral translation device <NUM> are apparent in <FIG>. A proximal part <NUM> includes a proximal sprocket <NUM>, an intermediate castellated connector <NUM>, and a distal rod <NUM>. In the exemplary embodiment, the intermediate castellated connector <NUM> has four distally projecting teeth <NUM>, clearly shown in <FIG>.

Also visible in <FIG> is a pull cable adapter <NUM>. The pull cable adapter <NUM> is connected to a pull cable <NUM> (dashed lines) at a proximal side and to the cartridge holder <NUM> at a distal side thereof. The pull cable adapter <NUM>, therefore, is used to pull or push the cartridge holder <NUM> with respect to the anvil <NUM> and, thereby, pivot the anvil <NUM> from an open position to a closed position, or vice-versa, dependent upon movement of the cartridge holder <NUM>. The proximal end of the anvil <NUM> has a cam follower <NUM> on either side thereof. The proximal end of the cartridge holder <NUM> defines two cam surfaces <NUM> on either side thereof and aligned to receive a respective one of the cam followers <NUM>. Accordingly, movement of the cartridge holder in a distal or proximal direction results in a corresponding opening or closing pivoting movement of the anvil <NUM>.

<FIG> shows the lateral articulating movement of the stapler <NUM>, <NUM> with respect to the clevis <NUM>.

In <FIG>, all parts, including the adapter sleeve <NUM> and the clevis <NUM> are shown in wire frame, thereby, revealing features therein. The clevis <NUM> contains four lumens, two of which are shown in <FIG> and all four are shown in <FIG> and <FIG>. A first <NUM> of the lumens is formed to contain a non-illustrated shaft for controlling distal and proximal movement of an end effector lateral movement locking pin <NUM>, which pin <NUM> is first shown in <FIG> and <FIG>. The two lateral lumens <NUM> are shaped to receive the pull-wire that moves the pull cable adapter <NUM> proximally (distal movement of the pull cable adapter <NUM> is caused by a spring). The other of the two lumens <NUM> is extra and can receive any number of possible additional instrumentation. The drive cable lumen <NUM> is the last of the four lumens and is shaped to receive the flexible drive cable that turns the drive screw <NUM> (see <FIG>), which controls movement of the slide <NUM>.

At the distal end of the drive cable lumen <NUM>, the clevis <NUM> defines an oblong cavity <NUM> for receiving therein the lateral movement locking pin <NUM>. <FIG>, in particular, show an exemplary shape of this cavity <NUM>. Because the lateral movement locking pin <NUM> is oblong in circumferential shape, the pin <NUM> does not rotate away from an aligned position with the teeth of the sprocket <NUM>.

Also visible under the top side of the clevis <NUM> in <FIG> are two centering springs <NUM>. These springs <NUM> are also shown in <FIG> and, in particular, <FIG>. To prevent undesired interaction between the springs <NUM>, a dividing plate <NUM> is sandwiched between the springs <NUM>. <FIG> illustrates the two springs <NUM> with the dividing plate <NUM> therebetween.

The features underneath the transparent sleeve <NUM> are better explained with respect to <FIG>. The sleeve <NUM> defines two exterior structures and two internal bores. The first exterior structure is a proximal cylinder <NUM>. The proximal cylinder <NUM> defines castellations <NUM> at a proximal end thereof. These castellations <NUM> match and interact with the intermediate castellated connector <NUM> of the proximal part <NUM>. The proximal cylinder <NUM> also defines a first bore <NUM> that is shaped to receive the distal rod <NUM> of the proximal part <NUM>. There is a cylindrical, tubular radial clearance between the rod <NUM> and the interior surface of the first bore <NUM> and a longitudinal clearance between the proximal end of the cable adapter <NUM> and the proximal inside surface of the first bore <NUM>. This tubular-shaped clearance can receive a first tubular biasing device (e.g., a coil spring), which is not illustrated for clarity. The first biasing device is positioned to apply a proximally directed force on the proximal-most end of the adapter sleeve <NUM>. In such a configuration, the force applied by the first biasing device presses the distal castellations <NUM> towards and against the proximal castellations <NUM>.

The second exterior structure of the sleeve <NUM> is a distal cylinder <NUM>. The distal cylinder <NUM> defines a second bore <NUM> that is shaped to receive therein the pull cable adapter <NUM>. The pull cable adapter <NUM> also defines an interior bore <NUM> that is shaped to receive the distal rod <NUM> of the proximal part <NUM>. For clarity in the figures, the rod <NUM> is shown extending entirely into the interior bore <NUM> only by the dashed lines in <FIG>. In operation, the rod <NUM> extends entirely into the interior bore <NUM>. The interior bore <NUM> is coaxial and, in an exemplary embodiment, has the same interior diameter of the first bore <NUM>. Accordingly, there exists a cylindrical, tubular radial clearance between the rod <NUM> and the interior surface of the interior bore <NUM> and a longitudinal clearance between the distal surface of the cable adapter <NUM> and the inside distal surface of the interior bore <NUM>. This is because it is also shaped to house a second tubular biasing device (e.g., a coiled spring), also not illustrated for clarity. The second biasing device is provided to impart a distally directed biasing force against the pull cable adapter <NUM>. Such a force keeps the jaws <NUM>, <NUM> in an open position. Accordingly, the jaws <NUM>, <NUM> have an at-rest open position.

Without providing an intermediate part, the two non-illustrated biasing devices connect and, therefore, form a single spring. However, it is desirable to not have the two biasing devices interact because separation of the castellated parts causes an unwanted force to be applied to the cartridge holder <NUM> and movement of the cartridge holder <NUM> may loosen the connection of the castellated parts. Accordingly, a non-illustrated washer is disposed between the two biasing devices in the cylindrical cavity <NUM> defined by the proximal end surface of the pull cable adapter <NUM> and the distal end surface of the second bore <NUM>. <FIG> particularly illustrates the proximal side for holding this washer, which is shaped to only receive the distal rod <NUM> therethrough. Accordingly, because the washer is trapped between the pull cable adapter <NUM> and the sleeve <NUM>, the two springs are decoupled and provide their respective biasing forces independent of one another.

The underside view of <FIG> and <FIG> illustrate the drive shaft <NUM> of the slide <NUM> and the proximal idler bushing <NUM> that holds the drive shaft <NUM> in place within the cartridge holder <NUM>. At the position of the idler bushing <NUM>, the drive shaft <NUM> does not have threads. However, distal to the idler bushing <NUM>, the drive shaft <NUM> has threads (which are not illustrated) extending towards the distal end of the drive shaft <NUM>. <FIG> and <FIG> do not show the thrust bearing <NUM> on the opposite end of the drive shaft <NUM>, but <FIG> clearly illustrates this bearing <NUM>. Also illustrated in <FIG>, <FIG>, and <FIG> is the bottom of the slide <NUM> in the form of a drive nut <NUM>. In an exemplary embodiment, this drive nut <NUM> is a part that is separate from the blade <NUM> of the slide <NUM> but is fixedly connected at the bottom of the blade <NUM>. The illustrated shape of the drive nut <NUM> has a dumbbell-shaped cross-section to relieve some of the forces exerted upon the threads. In <FIG>, the drive nut <NUM> is in a proximal position where the anvil <NUM> is in an opened position. <FIG> and <FIG>, in contrast, show the drive nut <NUM> in intermediate positions where the anvil <NUM> is in a partially closed position.

<FIG> is especially useful in illustrating the shape and configuration of the slide <NUM>, including the blade <NUM> and the drive nut <NUM>.

The horizontal cross-section along approximately the longitudinal axis of the end effector in <FIG> and <FIG> is particularly useful in viewing the bores around the distal rod <NUM>. Again, for clarity, the rod <NUM> is not shown extending all the way to the distal surface of the bore <NUM> in the pull cable adapter <NUM>. even though it does extend all the way to this surface. Around the proximal end of the rod <NUM> is the first bore <NUM> in the adapter sleeve <NUM>. Just distal of the first bore <NUM> is the cavity <NUM> for receiving the washer therein and, just distal of the cavity <NUM>, is the interior bore <NUM> of the pull cable adapter <NUM> for receiving the second biasing device.

The vertical cross-section along approximately the longitudinal axis of the end effector in <FIG> is particularly useful in viewing the connection between the drive nut <NUM> and the drive shaft <NUM>. Again, for clarity, the rod <NUM> is not shown extending all the way to the proximal surface of the bore <NUM> in the pull cable adapter <NUM>.

The vertical cross-section along approximately the longitudinal axis of the end effector in <FIG> is particularly useful in viewing the connection between the slide <NUM> and both the anvil <NUM> and the cartridge holder <NUM>. Two upper wings <NUM> are disposed in a groove inside the anvil <NUM> and two lower wings <NUM> form an upper holding surface of the I-shape formed by the lower wings <NUM> and the drive nut <NUM>.

<FIG> are illustrations. of the entire longitudinal extent of the stapling device with the distal end effector <NUM> and a first exemplary embodiment of the actuating handle <NUM>. As shown in <FIG>, the jaws <NUM>, <NUM> are at rest in an open position.

The thumb trigger is connected to the proximal end of the pull cable that ends at the pull cable adapter <NUM>. Thus, when the thumb trigger <NUM> is actuated (see <FIG>), the cartridge holder <NUM> is pulled in a proximal direction. Due to the shape of the cam surfaces <NUM>, the cam followers <NUM> are caused to move and, thereby, pivot the anvil <NUM> approximately into its stapling position. As set forth above, it is not the thumb trigger <NUM> that insures correct parallel orientation of the anvil <NUM> with respect to the cartridge holder <NUM> and, thereby, the staple cartridge <NUM>. Rather, it is the slide <NUM> that insures the proper parallel orientation.

<FIG> illustrate how the end effector <NUM> is passively articulated in a lateral direction. When the index finger trigger <NUM> is depressed, the lateral movement locking pin <NUM> is moved rearward to disengage from the sprocket <NUM>. If no force is applied to the end effector <NUM>, then, due to the two centering springs <NUM>, the end effector <NUM> remains in the axial aligned orientation shown in <FIG>. However, when an external force is applied to the end effector <NUM> (as shown in <FIG>), the laterally free end effector <NUM> can be moved about the axis of the sprocket <NUM> into any position, e.g., an approximately <NUM> degree left position shown in <FIG>, or into any other orientation. See, e.g., <FIG>. When the index finger trigger <NUM> is released, the lateral movement is prevented by returning the distal end of the locking pin <NUM> in between two teeth of the sprocket <NUM>. Thus, as shown for example in <FIG> and <FIG>, the end effector can be locked into a significant number of laterally articulated positions. It is noted that the staple cartridge <NUM> is not illustrated in <FIG> for clarity.

<FIG> illustrate the axial rotational control of the end effector. Such axial control is provided by the two respective castellated features <NUM>, <NUM> of the adapter sleeve <NUM> and the lateral translation device <NUM>, respectively. In <FIG>, the castellations are engaged and the anvil is in the <NUM> degree position with respect to the handle. To disengage the castellations, a force sufficient to overcome the first biasing device is exerted on the end effector <NUM> and the castellation features <NUM>, <NUM> separate. Then, the end effector <NUM> can be rotated clockwise or counter-clockwise. <FIG> shows, for example, the anvil <NUM> rotated counter-clockwise into an approximately <NUM> o'clock position.

<FIG> can be used to illustrate the operation of the motorized stapling function of the stapling device In <FIG>, the slide <NUM> is in a proximal position. A reversible motor is housed inside the handle. A three-way switch is connected to the motor. When in a middle position, for example, the motor is off. When in a proximal position, the motor is turned on and will rotate the drive shaft <NUM> so that the slide <NUM> moves in a proximal direction. In contrast, when the switch is in a distal position, the motor is turned on and will rotate the drive shaft <NUM> so that the slide <NUM> moves in a distal direction. Of course, the switch can be merely a two-way switch without an off position.

<FIG> and <FIG> illustrate a second exemplary embodiment of the stapling and cutting system <NUM> according to the invention. This system <NUM> is different than the first embodiment in that the motorized stapling assembly is entirely contained in the end effector <NUM>. Therefore, the handle <NUM> only needs to have two actuating devices. The first actuating device <NUM> is a ball joint releasing lever and the second actuating device is the stapling/cutting motor on/off button <NUM>.

The end effector <NUM> is connected to the distal end of the actuation shaft <NUM> of the handle <NUM> at a ball-joint connector <NUM>. The end effector <NUM> has, at its distal-most end, a ball joint <NUM>. The ball joint <NUM> has two opposing cup-shaped clamps <NUM>, <NUM>. The interior surfaces of the clamps <NUM>, <NUM> are shaped to correspond to the outer shape of the ball joint <NUM>. The clamps <NUM>, <NUM> translate towards or away from one another based upon an actuation of the lever <NUM>.

The clamps <NUM>, <NUM> are biased towards one another in a closed position such that, when the ball joint <NUM> is disposed therein, the two clamps <NUM>, <NUM> tightly grip the ball joint <NUM>. Actuation of the lever <NUM> causes the clamps <NUM>, <NUM> to separate and, thereby, allow the ball joint <NUM> to rotate freely in between the two clamps <NUM>, <NUM>. Thus, when the lever <NUM> is actuated, the end effector <NUM> is "free" to move based upon pressure against structures in the environment, such as tissue near a stapling/cutting site. The lever <NUM> can be pushed down sufficiently far to allow the ball joint <NUM> to move entirely out of the clamps <NUM>, <NUM>. Therefore, if a first end effector <NUM> is clamped at a first site and a second end effector <NUM> is desired to clasp and cut a second site, the first end effector <NUM> can be left clamped at the first site, the shaft <NUM> can be removed from the body and loaded with a second end effector <NUM>, and the second end effector <NUM> can be guided to the second site.

The second actuating device <NUM> is needed when the user desires to effect the stapling and cutting with the end effector <NUM>. When the end effector <NUM> is at the desired position for stapling/cutting, the actuator <NUM> (e.g., button) is depressed. This actuation, preferably, completes (or interrupts) a circuit that connects power to the motor inside the end effector <NUM>, thereby causing the slide <NUM> to move distally and effect the stapling and cutting functions of the jaws.

<FIG> illustrates the complete freedom for orienting the end effector <NUM> in any position with respect to the ball joint <NUM>. In <FIG>, the end effector <NUM> is shown in a right lateral orientation of approximately <NUM> degrees and with an anvil orientation of approximately <NUM> degrees.

<FIG> and <FIG> illustrate a variation of the second embodiment of the end effector shown in <FIG> and <FIG>. In particular, the handle <NUM> is the same as in <FIG> and <FIG>. However, the end effector <NUM> is different. Specifically, the end effector <NUM> has a proximal ball joint <NUM> similar to the ball joint <NUM> in <FIG> and <FIG>, but also has a second, distal ball joint <NUM>, having a shape virtually identical to the proximal ball joint <NUM>. Therefore, when the lever <NUM> is pressed down to release the ball joint <NUM>, <NUM>, the end effector <NUM> can be allowed to rest within the body and the opposite end can be grasped between the clamps <NUM>, <NUM>. In such an orientation, shown in <FIG>, the stapling/cutting can be actuated when the jaw opening is facing the user.

It is also noted that placement of an end effector <NUM>, <NUM> at a surgical site sometimes requires the access to the surgical site to be rather small in comparison to the opened jaws of the end effector <NUM>, <NUM>. With the ability to reverse the end effector <NUM>, some difficult-to-reach sites may be accessed that are not reachable with the single ball joint end effector <NUM>.

<FIG> and <FIG> show the clamps <NUM>, <NUM> at the distal-most end of the actuating shaft <NUM> of the surgical stapling and cutting device <NUM>, <NUM> of <FIG> holding a ball-joint <NUM>, <NUM>, <NUM> of the end effector <NUM>, <NUM> of <FIG>. These figures illustrate that the lever <NUM> is connected to a push rod <NUM> having at its distal end a plunger <NUM>. This plunger <NUM> has a cup-shaped surface <NUM> at its distal-most end with a shape corresponding to the outer shape of the ball joint <NUM>, <NUM>, <NUM>. Thus, when the plunger <NUM> is in its distal-most position in contact with the ball joint <NUM>, <NUM>, <NUM>, the ball is captured and does not move or rotate. In contrast, when the plunger <NUM> is moved proximally as shown in <FIG>, the ball of the ball joint <NUM>, <NUM>, <NUM> is free to rotate between the clamps <NUM>, <NUM>.

The endostapler illustrated in <FIG> <NUM><NUM> add various different alternative and/or additional features to the endostapler illustrated in <FIG>.

In all of <FIG>, the top jaw or anvil <NUM> is only shown in <FIG> and <FIG> for the sake of clarity. Further, the anvil <NUM> is described above in detail with regard to <FIG> and, therefore, any repetitive description is avoided hereinafter.

The exemplary handle shown in <FIG> is manufactured by Ethicon Endo-Surgery, Inc. , and can be found, for example, on Ethicon's linear cutter model ECHELON <NUM> Endopath Stapler. Description of this handle is, therefore, believed to be redundant as parts and functional descriptions of this handle are published in the art.

As set forth above, the distal end of the endostapler of the present invention is configured to house a standard staple cartridge <NUM>. This cartridge <NUM>, too, is described in prior publications and does not need to be repeated here.

<FIG> illustrates portions of an alternative embodiment of the endostapler <NUM> of the present invention. It is noted that two distal actuation levers on the handle <NUM> of the endostapler <NUM> are hidden from view in <FIG> for the sake of clarity.

The distal end of the handle <NUM> includes a bell-shaped actuator <NUM>, which provides two degrees of control for the articulating portions of the endostapler <NUM>. First, the bell actuator <NUM> freely rotates about the central axis of the endostapler <NUM> on distal end of the handle <NUM>. Because the bell actuator <NUM> is rotationally fixedly connected to the outer tube <NUM>, when the bell actuator <NUM> is rotated clockwise or counterclockwise, the entire distal end of the endostapler <NUM> rotates correspondingly. Second, the bell actuator <NUM> can be displaced over a given distance in a proximal direction on the distal end of the handle <NUM>. As will be described below in further detail, proximal displacement of the bell actuator <NUM> causes a corresponding movement of the articulation lock release slide <NUM>, <NUM> to allow the distal end effector <NUM> to articulate at the translation device <NUM>, <NUM>. A non-illustrated bias device (i.e., a compression spring) located, for example, in the distal portion of the bell actuator <NUM> is used to bias the bell actuator <NUM> and the articulation lock release slide <NUM> in a distal direction so that the articulation lock release slide <NUM>, <NUM> remains in the actuated or locked position while the bell actuator <NUM> is in an un-actuated state. See, i.e., <FIG> and <FIG>. This bias device is housed inside the bell actuator <NUM> but is not shown in <FIG> for clarity. Also not shown is a snap ring that fits into a groove <NUM> around the inner tube <NUM>. The bias device is delimited on the proximal side of the rod pullblock <NUM> (see <FIG>) and the distal side of the snap ring. In such a configuration, when the bell actuator <NUM> is pulled proximally, the actuator <NUM> forces the rod pullblock <NUM> proximally to, thereby, move the articulation lock release slide <NUM>, <NUM> into an unlocked position. A keyhole on the interior surface of the bell actuator <NUM> form-lockingly surrounds the rod pullblock <NUM> so that rotation of bell actuator <NUM> about the longitudinal axis of the inner tube <NUM> forces the rod pullblock <NUM> into a corresponding rotation. A form-locking or form-fitting connection is one that connects two elements together due to the shape of the elements themselves, as opposed to a force-locking connection, which locks the elements together by force external to the elements. As such, the inner tube and the entire distal assemblies of the device <NUM> rotates as well. In an alternative configuration, the longitudinal movement of the bell actuator <NUM> can function similar to a standard ball point pen by a first actuation placing the slide <NUM>, <NUM> in an unlocked state and a second actuation placing the slide <NUM>, <NUM> in a locked state.

With the bell actuator <NUM> of the present invention, a physician is able to operate every function of the endostapler <NUM> with one hand.

<FIG> illustrates the proximal end of the endostapler <NUM> without the handle <NUM>. Coaxially disposed inside the bell actuator <NUM> is a pushrod <NUM> that will be used to move the cutting blade <NUM> when the stapler is in the firing orientation.

<FIG> is an illustration of the parts at the proximal end of endostapler <NUM> that axially fixedly and rotationally freely connect the distal assembly to the bell actuator <NUM>. More specifically, an inner tube <NUM> (to be disposed inside the outer tube <NUM>) has a proximal extension <NUM> defining an inner tube coupling chamber <NUM>. A clam-shell bushing <NUM> has a length substantially equal to the extension <NUM> of the inner tube <NUM> and a bushing coupling chamber <NUM> corresponding to the coupling chamber <NUM> of the proximal extension <NUM>. A rotational couple <NUM> has a distal T-shaped rotation link <NUM> having an outer shape corresponding to both of the coupling chambers <NUM> and <NUM> so that, when the link <NUM> is disposed between the extension <NUM> and the bushing <NUM>, the link <NUM> is free to rotate therein. This couple <NUM> is fixed inside the handle <NUM> through a proximal port <NUM> on a proximal end of the couple <NUM>.

When placed together, the inner tube <NUM> is axially held with respect to the couple <NUM> but is rotationally independent of the couple <NUM>. Because the three coupling parts <NUM>, <NUM>, <NUM> are sized to fit inside the outer tube <NUM>, when the parts are placed inside the outer tube <NUM>, the outer tube <NUM> becomes a form-locking connection that prevents any separation of the inner tube <NUM> and the bushing <NUM> (so long as the outer tube <NUM> sufficiently covers this area). Thus, when the bell actuator <NUM> is rotated about the longitudinal axis of the inner tube <NUM>, the inner and outer tubes <NUM>, <NUM> are able to rotate about the coaxial axis of the tubes <NUM>, <NUM> but remain longitudinally stable with respect to the couple <NUM>, which is longitudinally fixed inside the handle <NUM>.

<FIG> illustrates the proximal end of the endostapler <NUM> without the handle <NUM>, the bell actuator <NUM>, and the outer tube <NUM>. As can be seen, the inner tube <NUM> is hollow and receives therethrough the pushrod <NUM>, which will be described in further detail below. Also shown in these figures are the clevis <NUM> and the drum sleeve <NUM>, which, together, form the articulating connection or joint <NUM> of the endostapler <NUM>.

It is noted at this point that the lower jaw/staple cartridge holder <NUM> is longitudinally fixed with respect to the handle <NUM>. This fixation contrasts with the upper anvil <NUM>, which can be pivoted and be moved somewhat longitudinally when sliding through the keyhole shaped cam surfaces <NUM> to close and/or open the jaws (described in further detail below/above with respect to cam surfaces <NUM>).

To form the longitudinally fixed connection of the staple cartridge holder <NUM> and the handle <NUM>, the inner tube <NUM> must be connected to the staple cartridge holder <NUM>. But, at the same time, the staple cartridge holder <NUM> must be able to articulate with respect to the longitudinal extent of the inner tube <NUM>. Thus, an axially fixed but laterally articulating connection must exist between the two parts <NUM>, <NUM>.

To provide such a connection, the present invention includes at least one pullband <NUM>, shown, for example, in <FIG>. In an exemplary configuration, multiple pullbands <NUM> are provided, one next to the other. Three or four bands form two possible configurations. With two pullbands <NUM> as opposed to one, the longitudinal strength remains approximately the same but the force needed to laterally bend the pullbands <NUM> is reduced. The same is true for three or four pullbands <NUM>. <FIG> illustrates the proximal end of the pullband <NUM>, which is longitudinally pinned to the distal end of the inner tube <NUM> with a proximal pullband pin <NUM>. To provide a strong connection between the pullband <NUM> and the inner tube <NUM>, a proximal guide block <NUM>, for example, made of brass, is disposed between the distal end of the inner tube <NUM> and the pullband <NUM>.

The pullband <NUM> spans the entire extent of the articulation joint <NUM>, as shown in <FIG>, and is connected, as shown in <FIG>, to a distal guide block <NUM>. The distal guide block <NUM> (also, e.g., made of brass) has at least one projection that fits into at least one recess on the proximal end of the staple cartridge holder <NUM>. Later figures illustrate the measures by which the distal guide block <NUM> is connected to the staple cartridge holder <NUM> so that, finally, the staple cartridge holder <NUM> is axially fixedly connected to the handle <NUM> while being able to articulate with respect to the inner tube <NUM>. As shown in <FIG>, a distal pullband pin <NUM> axially locks the distal end of the pullband <NUM> to the distal guide block <NUM>.

A first embodiment of jaw <NUM>, <NUM> movement is described in the text above. There, the staple cartridge <NUM> moves axially and the anvil <NUM> is relatively stationary. In the configuration of the endostapler <NUM> shown in <FIG> et seq. , movement is operationally opposite.

Noting that the staple cartridge holder <NUM> is longitudinally fixed with respect to the handle <NUM>, there still must be an assembly that permits closure of the two jaws <NUM>, <NUM>; <NUM>, <NUM>. Closure is, therefore, accomplished by movement of the upper jaw/anvil <NUM> as set forth in the following text.

A first of the two levers of the handle <NUM> (e.g., a proximal handle) is operatively connected to the outer tube <NUM> to move the outer tube <NUM> distally when the first lever is compressed/actuated. Because the clevis <NUM>, the articulation joint <NUM>, and the drum sleeve <NUM> are axially fixedly connected to the outer tube <NUM> (and because the outer tube <NUM> can slide longitudinally along the inner tube <NUM>), an actuation of the first lever moves the drum sleeve <NUM> distally.

<FIG> illustrates the anvil <NUM> in an open state. As can be seen therein, a gap <NUM> exists between the distal end of the drum sleeve <NUM> and a proximal shelf at the bottom of the staple cartridge holder <NUM>. In such an orientation, the drum sleeve <NUM>, the clevis <NUM>, and the outer tube <NUM> are proximally disposed at a distance from the shelf.

<FIG> illustrates the anvil <NUM> in a closed state. As can be seen therein, no gap <NUM> exists between the distal end of the drum sleeve <NUM> and the proximal shelf of the staple cartridge holder <NUM>. In such an orientation, the drum sleeve <NUM>, the clevis <NUM>, and the outer tube <NUM> are in a position where the drum sleeve <NUM> contacts the shelf.

In contrast to the axially fixed position of the staple cartridge holder <NUM> with respect to the handle <NUM>, and similar to the movement of the drum sleeve <NUM>, the knife <NUM>, <NUM> must translate with respect to the handle <NUM> along the longitudinal axis. <FIG>, <FIG>, and <FIG> illustrate the axially displaceable connection of the knife <NUM> to the knife-moving features of the handle <NUM>.

With regard to <FIG>, a pushrod <NUM> extends from the handle <NUM> and is connected to a second non-illustrated lever (e.g., a distal lever) of the handle <NUM>. The distal end of the pushrod <NUM> is connected to at least one flexible knife blade <NUM> through a pushrod pin <NUM>. The distal end of the knife blade <NUM> is connected to the proximal side of the cutting blade <NUM> such that the cutting blade <NUM> moves distally or proximally to follow corresponding movement of the pushrod <NUM>. It is noted that the knife blade <NUM> has a proximal, upwardly extending flange <NUM> that houses a bore for receiving the pushrod pin <NUM>. This off-axis connection between the pushrod <NUM> and the knife blade <NUM> causes the distal end of the knife blade <NUM> to be forced downwardly when pushed in the distal direction and, therefore, to stay in position inside a pushrod-blade support <NUM> shown, for example, in <FIG> and <FIG>.

The knife blade <NUM> is flexible enough to bend in any way that the articulation joint <NUM> bends. Therefore, the knife blade <NUM> is also flexible enough to possibly kink if it was not supported. The present invention, therefore, provides a pushrod-blade support <NUM>, which is shown in <FIG> and <FIG>. Therein, the proximal end of the pushrod-blade support <NUM> clearly reveals the rectangular blade channel <NUM> for supporting slidably the rectangular knife blade <NUM>. Also shown therein is a curved pushrod channel <NUM> for supporting slidably the curved (e.g., cylindrical) exterior of the pushrod <NUM>. Thus, the pushrod-blade support <NUM> supports the pushrod <NUM> at locations where the pushrod <NUM> is inside the support <NUM> and also supports the knife blade <NUM> where the knife blade <NUM> is inside the support <NUM>.

<FIG> shows the connection of the support <NUM> and its relation to the proximal guide block <NUM>.

Like the pullbands <NUM>, more than one knife blade <NUM> can be next to one another. In such a configuration, the multiple blades <NUM> have the same longitudinal stiffness but provide greater flexibility when there is a bend in the articulation joint <NUM>.

Revealed in <FIG> is the articulation lock release slide <NUM> that locks the articulation of the jaws <NUM>, <NUM>.

<FIG> illustrate a vertical cross-section of the tube portion distal of the handle <NUM> along planes that are orthogonal to the longitudinal axis of the endostapler <NUM>.

<FIG> shows the cross-section of the connection junction of the knife blade <NUM> and the pushrod pin <NUM>. The pushrod pin <NUM> passes through the entirety of two adjacent blades <NUM> and the pushrod <NUM> but does not extend outside the pushrod's outer surface. This figure also illustrates the relationship of the inner and outer tubes <NUM>, <NUM> and the pushrod-blade support <NUM>. Also apparent in this figure is an unlock pullrod <NUM> used for unlocking the lock release slide <NUM>. The longitudinal extent of the unlock pullrod <NUM> is first shown in <FIG> and is also shown in <FIG>, <FIG>, <FIG>, and <FIG> and <FIG>. Most particularly, with exterior parts hidden, <FIG> shows how the pullrod <NUM> connects the bell actuator <NUM> to the articulation lock release slide <NUM>. With the distal end of the pullrod <NUM> passed through and wrapped around the distal end of the articulation lock release slide <NUM> as shown in <FIG>, the unlock pullrod <NUM> establishes a longitudinally fixed connection between the bell actuator <NUM> and the articulation lock release slide <NUM>. As such, when the bell actuator <NUM> is moved proximally, the articulation lock release slide <NUM> moves in a corresponding proximal direction to separate the distal teeth <NUM> of the articulation lock release slide <NUM> and the spokes <NUM> of the sprocket <NUM>. See, in particular, <FIG> and <FIG>. It is noted that the wrapped connection between the pullrod <NUM> and the articulation lock release slide <NUM> is only an exemplary embodiment. Other form-locking or force-locking connections are possible as well.

<FIG> shows the connection through the pullband <NUM> and inner tube <NUM> pin joint. As set forth above, the proximal pullband pin <NUM> passes entirely through the blades <NUM>, the proximal guide block <NUM>, and the inner tube <NUM> but not through the outer tube <NUM>.

<FIG> shows the area immediately proximal of the proximal end of the articulation lock release slide <NUM>. In this exemplary embodiment, two pullbands <NUM> are disposed above two blades <NUM>. To provide support to at least one of the pullbands <NUM> and the blades <NUM>, a pair of hammocks <NUM> is placed along sides of the articulating portions of the pullbands <NUM> and blades <NUM>. Each of the hammocks <NUM> has a U-shape (along a longitudinal cross-section) so that the proximal arm of each hammock <NUM> bends around the proximal surface of the clevis <NUM> and the distal arm of each hammock <NUM> bends around a catching surface within the drum sleeve <NUM>, as shown in <FIG>, for example.

Inside the clevis <NUM> are disposed two spring rods <NUM> about which are respective spring rod collars <NUM>, the function of which is to bias laterally the entire assembly distal of the articulation joint <NUM> towards and along the longitudinal axis. The spring rods and collars <NUM>, <NUM> will be described in further detail below.

<FIG> illustrates the open area in the center of the articulation lock release slide <NUM> that receives the bend portion of the pullrod <NUM> (not illustrated in this figure). Also shown are the cavities <NUM> in which the non-illustrated bias springs of the spring rods <NUM> rest. This cross-sectional area also includes portions of the two pullbands <NUM> disposed above the two knife blades <NUM>.

<FIG> illustrates the open area in which the distal end of spring rods <NUM> acts against cam surfaces <NUM>. It is noted that the cam surfaces <NUM> are arcuate in shape so that contact between the spring rods <NUM> and the cam surfaces <NUM> always act in an axial direction normal to the surface at the distal-most end of the spring rods <NUM>. See, for example, <FIG>. In such a configuration, the force that is applied by the spring rods <NUM> against the cam surfaces <NUM> to bias the distal articulating assembly (e.g., anvil <NUM>, staple cartridge holder <NUM>, drum sleeve <NUM>) towards the longitudinal axis of the inner and outer tubes <NUM>, <NUM> is always at the same radius about the articulation axis of the articulating staple cartridge holder <NUM>. One advantage of such a configuration lies in the fact that the spring rods <NUM> are not forced laterally in any way, in which case, the distal-most end of the spring rods <NUM> could catch and lock on the cam surface <NUM>.

<FIG> illustrates, in cross-section, the area within the endostapler articulation joint <NUM>. Again, this area includes portions of the two pullbands <NUM>, of the two blades <NUM>, and of the two hammocks <NUM>. Upper and lower axle pucks <NUM> are inserted in orifices <NUM> above and below on surfaces of the drum sleeve <NUM>. Connection of the clevis <NUM> to the drum sleeve <NUM> at the articulation joint <NUM> is symmetrical on the top and bottom. The pucks <NUM> are inserted into the orifices <NUM> in the top and bottom of the proximal end of the drum sleeve <NUM>. In this orientation, the assembly is inserted into the distal end of the clevis <NUM> to align screw holes <NUM> with center threaded bores <NUM> of the pucks <NUM>. When aligned, screws <NUM> are threaded respectively into the pucks <NUM> to axially secure the drum sleeve <NUM> into the clevis <NUM> while allowing the drum sleeve <NUM> to articulate about the axis defined by the longitudinal axis of the two screws <NUM>.

<FIG> illustrates the area of the distal pullband pin joint. In this area, the distal ends of the pullbands <NUM> are secured by the distal pullband pin <NUM> disposed inside the bore of the distal guide block <NUM>. The distal guide block <NUM> is disposed in the staple cartridge holder <NUM> and secured thereto as set forth above.

<FIG> illustrates the area just proximal of the cutting blade <NUM> and the fixed connection of the two knife blades <NUM> inside a proximal orifice of the cutting blade <NUM>. This view also clearly shows the cam surfaces <NUM> that allow the anvil <NUM> to pivot and translate with respect to the staple cartridge holder <NUM>.

<FIG> shows a longitudinal cross-section through the spring rods <NUM>. Visible in this view is the entire longitudinal extent of the hammocks <NUM>. The distal sections of the hammocks <NUM> articulate about a vertical axis near the distal end of the hammocks <NUM>. In <FIG>, there exists a substantial gap between the spring rods <NUM> and the hammocks <NUM>. If the hammocks <NUM> were not present, there exists the possibility that the thin knife blades <NUM> could bend and warp or kink into these gaps. By placing the hammocks <NUM> therebetween, any possibility of impermissible bending of the knife blades <NUM> is prevented. <FIG> is provided to show the extreme bending extent of the hammocks <NUM> and the blades <NUM> therebetween in a test bed made for such a purpose. It is noted that the upper hammock <NUM> is not utilized in an upward bend with respect to <FIG> because it tracks the inside surface of the curve at the critical bending area. In contrast, the lower hammock <NUM> is utilized to substantially prevent the knife blades <NUM> therebetween (two in this exemplary embodiment) from impermissibly bending into the gap of the test bed. Because each hammock <NUM> is held rigidly at either end and is made out of a substantially non-elastic material (e.g., of stainless steel), it forms a sling or "hammock" that supports the bent knife blade(s) <NUM> therebetween.

<FIG> illustrates a cross-section through the articulation lock release slide <NUM> and clearly shows the distal connection bend of the unlock pullrod <NUM> inside the slide <NUM>. In such a configuration, proximal displacement of the unlock pullrod <NUM> causes a corresponding proximal displacement of the slide <NUM> to unlock the teeth <NUM> of the slide <NUM> from between the corresponding teeth <NUM> on the proximal side of the drum sleeve <NUM>. A distal bias is imparted upon the articulation lock release slide <NUM> by a non-illustrated bias device that resides in a hollow <NUM> and presses against the distal end of the hollow <NUM> and a block <NUM> that is fixed with respect to the clevis <NUM>.

<FIG> shows the connection between the unlock pullrod <NUM> and the handle <NUM>. A rod pullblock <NUM> has a longitudinal bore <NUM> for receiving therein the pullrod <NUM>. The rod pullblock <NUM> also has transverse bores <NUM> for receiving non-illustrated set screws therein for securing the pullrod <NUM> inside the rod pullblock <NUM>. An interior portion of the bell actuator <NUM> is shaped to engage the rod pullblock <NUM> (for example, in a form-fitting connection such as a keyhole) and displace the rod pullblock <NUM> proximally when the bell actuator <NUM> is moved proximally.

<FIG> is an exploded perspective view of the distal parts of the endostapler as viewed from the distal end thereof.

It is noted that the clevis <NUM> in <FIG> is a one-piece part. Alternatively, the clevis <NUM> can be molded in two halves. In such a case, the pucks <NUM> can be eliminated and, instead, form parts of each of the two clevis halves, thereby eliminating the need for the screws <NUM> because the outer tube <NUM> will hold the two halves together when attached to the proximal end of the clevis <NUM>. Such a configuration is illustrated in the endostapler embodiment of <FIG> et seq.

<FIG> shows some internal parts of this fourth embodiment of the end effector. The anvil <NUM> is disposed opposite the staple cartridge holder <NUM> and a closure ring <NUM> surrounds the proximal end of the staple cartridge holder <NUM>. The inner and outer tubes <NUM>, <NUM> are removed so that the articulation lock release slide <NUM>, the pushrod <NUM>, and the pushrod-blade support <NUM> can be seen clearly. A screen door <NUM> is mounted around the pushrod <NUM> and inside the inner and outer tubes <NUM>, <NUM> and the bell actuator <NUM>. The handle <NUM> and bell actuator <NUM> are removed for clarity. The screen door <NUM> restricts movement of the pushrod <NUM> to only one directiondistal -- because the knife/cutting blade <NUM> only moves in the distal direction.

The two-part clevis is best illustrated in the views of <FIG> and <FIG>. These figures show various internal features of the end effector of <FIG> with the outer tube <NUM> removed. In the exploded view of <FIG>, connection of the pullband(s) <NUM> to the staple cartridge holder <NUM> is apparent. A non-illustrated pin (see also <FIG>) passes through a first proximal flange of the holder <NUM>, a first spacer <NUM>, a distal flange of the pullband <NUM>, a second spacer <NUM>, and a second opposing proximal flange of the holder <NUM>, respectively. The closure ring <NUM>, as shown in <FIG>, holds the pin therein to provide the longitudinal connection of these components.

Various features of the knife/cutting blade <NUM> are also revealed in <FIG>. The blade <NUM> has a proximal recess <NUM> for connecting a distal end of the knife blade <NUM> thereto. In the exemplary embodiment, the recess <NUM> and distal end form a keyhole-shaped lock. The upper half of the blade <NUM> has two opposing guide wings <NUM> having an exterior shape that fits into a corresponding groove inside the bottom surface of the upper anvil <NUM>. The lower half of the blade <NUM> also has two opposing guide wings <NUM>. The holder <NUM> has a groove inside the top surface thereof for receiving the lower wings <NUM> therein. These two pairs of wings <NUM>, <NUM> ensure that the anvil <NUM> and the holder <NUM> are at a fixed parallel position when the blade <NUM> is traversing therealong in the cutting and stapling process. Also disposed on the lower half of the blade <NUM> is a proximally extending flange <NUM>. A plate spring <NUM> is attached to the staple cartridge holder <NUM> by rivets <NUM>. The plate spring <NUM> and other features of the blade <NUM> will be described in greater detail below.

<FIG> and <FIG> also show various portions of the two-part clevis <NUM>, <NUM>. As can be seen in <FIG> and <FIG>, the interior surface of the upper clevis half <NUM> defines two cavities <NUM> that each house a respective spring rod <NUM> and the non-illustrated bias device for that spring rod <NUM>. In the exemplary embodiment shown, the upper clevis half <NUM> defines the entire cavity <NUM> for the spring rods <NUM> and the lower clevis half <NUM> defines the bottom cavity portion <NUM> for accommodating only the bias device. The clevis halves <NUM>, <NUM> also define articulation ports <NUM>, <NUM> for receiving therein articulation bosses <NUM>, <NUM> on each of the two dogbone clevis parts <NUM>, <NUM>.

<FIG> and <FIG> illustrate the longitudinal connectivity of the features within the outer tube <NUM>. The pushrod-blade support <NUM> is disposed inside a lower channel of the inner tube <NUM>. This pushrod-blade support <NUM> also has a distal extension <NUM> with a narrow proximal neck <NUM> and a relatively wider distal head <NUM>. With a corresponding recess <NUM> in the bottom of the lower clevis half <NUM>, the distal extension <NUM> can be longitudinally fixed to the clevis half <NUM> and, therefore, the remainder of the clevis.

The outer tube <NUM> and the lower clevis half <NUM> are removed in <FIG> to illustrate the configuration of the spring rods <NUM> inside the spring rod cavities <NUM>. Again, the spring rod bias devices (e.g., coil springs) are not shown in the cavities <NUM> for clarity. With various parts removed, the articulating extent of the pullbands <NUM> is clearly shown in <FIG>. The supporting surfaces for the pullbands <NUM> inside the upper clevis half <NUM> are visible at the cross-section plane of <FIG>. The upper dogbone clevis <NUM> has two opposing supporting surfaces <NUM> each at a similar acute angle with respect to the centerline of the un-articulated pullbands <NUM>. Likewise, the upper clevis half <NUM> has two opposing supporting surfaces <NUM> each at an acute angle with respect to the centerline of the un-articulated pullbands <NUM>.

The opposite viewing direction towards the interior of the lower clevis half <NUM> is illustrated in <FIG> and <FIG>. The articulation section for the knife blades <NUM> is illustrated along with the supporting surfaces <NUM> for the dogbone <NUM> inside the lower. dogbone clevis <NUM> and the supporting surfaces <NUM> for the dogbone <NUM> inside the lower clevis half <NUM>. Also visible in this orientation are guiding and supporting surfaces for the dogbone guide <NUM>. In <FIG>, it is seen that the lower dogbone clevis has a kidney-shaped distal dogbone depression <NUM> and the lower clevis half <NUM> has a kidney-shaped proximal dogbone depression <NUM>. These depressions <NUM>, <NUM> and surfaces <NUM>, <NUM> are also illustrated in <FIG> and will be described in detail below. A further feature visible in <FIG>, <FIG>, and <FIG> is the interior passage of the dogbone guide <NUM> having left and right surfaces <NUM> and will be describe in further detail below.

The distal end of the dogbone guide <NUM> is shown in the vertical cross-section of <FIG>. The distal dogbone depression <NUM> houses the distal end of the dogbone guide <NUM> and, when unarticulated, the dogbone guide <NUM> does not touch the supporting surfaces <NUM> of the lower dogbone clevis <NUM>.

The proximal housing for the distal end of the dogbone guide <NUM> is illustrated in <FIG>. To better reveal the features of the proximal dogbone depression <NUM>, the dogbone guide <NUM> is removed from these figures.

Both of the depressions <NUM>, <NUM> with the lower extending portions of the dogbone guide <NUM> disposed therein are shown in horizontal, longitudinally transverse cross-section of <FIG>. Also shown therein are the lower features of the pushrod-blade support <NUM>, the cutting blade <NUM>, and the staple sled <NUM> (which is a part of the removable staple cartridge <NUM>). These features are enlarged in <FIG> and <FIG>.

<FIG>, <FIG>, and <FIG> illustrate the knife blade <NUM> lock-out feature. In other words, the safety that prevents the knife blade <NUM> from advancing when there is no staple cartridge <NUM> or a previously fired staple cartridge <NUM> in the staple cartridge holder <NUM>. For ease of understanding, the only part of the staple cartridge <NUM> shown in these figures is the staple sled <NUM>.

The knife blade <NUM> should be allowed to move distally only when the staple sled <NUM> is present at the firing-ready position, i.e., when the sled <NUM> is in the position illustrated in <FIG>. If the sled <NUM> is not present in this position, this can mean one of two things, either there is no staple cartridge <NUM> in the holder <NUM> or the sled <NUM> has already been moved distally - in other words, a partial or full firing has already occurred with the loaded staple cartridge <NUM>. Thus, the blade <NUM> should not be allowed to move, or should be restricted in its movement. Accordingly, the sled <NUM> is provided with a lock-out contact surface <NUM> and the blade <NUM> is provided with a correspondingly shaped contact nose <NUM>. It is noted at this point that, the lower guide wings <NUM> do not rest against a floor <NUM> in the cartridge holder <NUM> until the blade <NUM> has moved distally past an edge <NUM>. With such a configuration, if the sled <NUM> is not present at the distal end of the blade <NUM> to prop up the nose <NUM>, then the lower guide wings <NUM> will follow the depression <NUM> just proximal of the edge <NUM> and, instead of advancing on the floor <NUM>, will hit the edge <NUM> and stop further forward movement of the blade <NUM>. To assist with such contact when the sled <NUM> is not present, the staple cartridge <NUM> has a plate spring <NUM> (attached thereto by rivets <NUM>). With the plate spring <NUM> flexed upward and pressing downward against the flange <NUM> (at least until the flange <NUM> is distal of the distal end of the plate spring <NUM>), a downwardly directed force is imparted against the blade <NUM> to press the wings <NUM> down into the depression <NUM>. Thus, as the blade <NUM> advances distally without the sled <NUM> being present, the wings <NUM> follow the lower curve of the depression <NUM> and are stopped from further distal movement when the distal edge of the wings <NUM> hit the edge <NUM>. <FIG>, for example, shows the distal edge <NUM> and two raised bosses <NUM> that extend the height of the edge <NUM> to insure that the wings <NUM> cannot be forced over the edge <NUM> when the sled <NUM> is not present.

<FIG> illustrates an exemplary movement of the dogbone <NUM> within the lower clevis half <NUM> and the lower dogbone clevis <NUM>. In the fully left articulated position of <FIG>, the distal bottom projection of the dogbone <NUM> is in a rotated position within the distal dogbone depression <NUM> and the proximal bottom projection is in a rotated position within the proximal dogbone depression <NUM>. Importantly, the left vertical surface of the dogbone <NUM> is almost fully supported on the left dogbone supporting surfaces <NUM>, <NUM>. The shapes of the depressions <NUM>, <NUM> and the bottom projections of the dogbone <NUM> are selected such that there is no elongation or compression of the dogbone <NUM> but, merely, a rocking left to right when articulation of the end effector occurs.

Three side-by-side knife blades <NUM> are diagrammatically illustrated in <FIG> within a left articulated position of the lower clevis halves <NUM>, <NUM>. When bent to the left, the knife blades <NUM> are pressed against the right interior surface <NUM> of the dogbone <NUM>. Accordingly, the interior surfaces <NUM> are shaped dependent upon the extent that the end effector will be articulated. Due to the limitations of drafting the features of the invention, the blades <NUM> are only shown in a diagrammatic, approximate curved orientation.

To better understand some features of the knife blades <NUM>, enlarged views of the proximal connection to the pushrod <NUM> and the pushrod-blade support <NUM> are shown in <FIG>. While a configuration having co-axially aligned knife blades <NUM> and the pushrod <NUM> is envisioned and possible, an offset connection shown, for example, in <FIG> and <FIG>, is used. As set forth above, the length of the knife blades <NUM> make it desirable for the knife blades <NUM> to be pressed down fully into the blade channel <NUM> within the pushrod-blade support <NUM>. <FIG> shows a first embodiment for an offset connection that biases the blades <NUM> into the channel <NUM>. <FIG> shows a second embodiment for this offset connection. In this second embodiment, the blades <NUM> are not fixedly connected to the pushrod <NUM> as in the first embodiment (connected by transverse pushrod pin <NUM>). Instead, the pushrod <NUM> is formed with a chamber <NUM> into which is inserted the proximal end of the blades <NUM>. By forming the chamber <NUM> in a shape that axially longitudinally holds the blades <NUM> (e.g., with a transverse offset), there is no need for a fixed connection. In this embodiment, the chamber <NUM> is approximately L-shaped in vertical cross-section to provide such a transverse offset, but it can be any number of different shapes.

The distal connection of the pullbands <NUM> is shown particularly well in <FIG>. It is noted that, in such a configuration, left or right articulation imparts a bend on each of the two, three, four, or more adjacent pullbands <NUM>. Because each pullband <NUM> has a fixed length, and because the pullbands <NUM> are stacked along side one another, articulation in a given direction bends each of the pullbands <NUM> differently, even if the difference is very slight. To compensate for such differences in bending, an alternative embodiment of the distal connection is provided and is shown in <FIG>. For clarity and simplicity, only a portion of the upper dogbone clevis <NUM> is shown diagrammatically in these figures.

This alternative embodiment replaces the spacers <NUM> in the first embodiment. Here, five pullbands <NUM> are disposed along side one another. The upper dogbone clevis <NUM> defines an interior bore <NUM> (e.g., a circular bore) into which is inserted a piston <NUM> having an exterior shape corresponding to the interior shape of the bore <NUM>. The bore <NUM> has a proximal window <NUM> through which the pullbands <NUM> project into the bore <NUM>. The window <NUM> has a width approximately equal (but just slightly larger than) the total width of the pullbands <NUM>.

The piston <NUM> has a transverse bore into which is threaded a proximal pullband pin <NUM> that functions as an axle when threaded through the piston <NUM> and through the distal pullband bore <NUM> of each of the pullbands <NUM>. The interior <NUM> of the piston <NUM> does not have a shape corresponding to the width of the stacked pullbands <NUM>. Instead, the interior opening for receiving the distal end of the pullbands <NUM> has a winged horizontally cross-sectional shape.

Claim 1:
A medical device, comprising:
a control handle (<NUM>, <NUM>) having:
a pushrod (<NUM>);
a rotatable bell-shaped actuator (<NUM>) in which said pushrod (<NUM>) is coaxially disposed, the bell-shaped actuator (<NUM>) having:
an unactuated state; and
an actuated state in which the bell-shaped actuator (<NUM>) is displaced over a given distance in a proximal direction on a distal end of the control handle (<NUM>, <NUM>); and
an outer tube (<NUM>) and an inner tube (<NUM>) through which said pushrod (<NUM>) is received, said outer tube (<NUM>) and inner tube (<NUM>) defining a longitudinal axis and being rotationally fixedly connected to the bell-shaped actuator (<NUM>);
a surgical stapling end effector (<NUM>) having:
a staple cartridge holder (<NUM>) for holding a stapler cartridge (<NUM>) having at least one staple;
an anvil (<NUM>) coupled to the staple cartridge holder (<NUM>);
a cutting blade (<NUM>); and
a flexible knife blade (<NUM>) operatively connected to said pushrod (<NUM>) to move the cutting blade (<NUM>);
a passive articulating joint (<NUM>) connecting said stapling end effector (<NUM>) to the outer tube (<NUM>) and the inner tube (<NUM>) of said control handle (<NUM>, <NUM>) and articulating about an articulation axis;
the passive articulating joint (<NUM>) coupling the staple cartridge holder (<NUM>) to the inner tube (<NUM>) by means of at least one pullband (<NUM>) and coupling the anvil (<NUM>) to the outer tuber (<NUM>);
the flexible knife blade (<NUM>) passing through said passive articulating joint (<NUM>) and flexing in a corresponding manner to an articulation of said passive articulating joint (<NUM>); and
said bell-shaped actuator (<NUM>):
when in said unactuated state, holding said passive articulating joint (<NUM>) and, thereby, said end effector (<NUM>), in a substantially fixed articulation position; and
when in said actuated state, releasing said passive articulating joint (<NUM>) into a freely articulating state to permit free articulation of said end effector (<NUM>) with respect to said control handle (<NUM>, <NUM>) dependent upon external forces acting upon said end effector (<NUM>); and
when rotated, causing rotation of the outer tube (<NUM>), the inner tube (<NUM>) and the end effector (<NUM>) with respect to the longitudinal axis.