Patent Application
20060289600
The present invention relates in general to surgical stapler instruments that are capable of applying lines of staples to tissue while cutting the tissue between those staple lines and, more particularly, to improvements relating to stapler instruments and improvements in processes for forming various components of such stapler instruments.
Surgical instruments for minimally invasive surgery are increasingly relied upon to reduce the hospital stay and recovery time for various surgical procedures. Many of these surgical instruments include mechanisms that actuate an end effector via an elongate shaft that performs a surgical step that entails two opposing surfaces being brought into opposition to each other. For instance, pivotally opposed jaws are used in graspers. Pivotally attached scissor blades are incorporated into cutting devices. Providing an actuating control down the elongate shaft with sufficient strength is complicated by a design goal of minimum cross sectional area so as to pass through a small cannula of a trocar. In addition, the elongate shaft often has a plurality of control functions (e.g., rotation, articulation, etc.) Further, it is desirable to have reduced design complexity so as to provide an economical device.
As an illustration of a particularly challenging surgical instrument, surgical staplers have been used in the prior art to simultaneously make a longitudinal incision in tissue and apply lines of staples on opposing sides of the incision. Such instruments commonly include a pair of cooperating jaw members that, if the instrument is intended for endoscopic or laparoscopic applications, are capable of passing through a cannula passageway. One of the jaw members receives a staple cartridge having at least two laterally spaced rows of staples. The other jaw member defines an anvil having staple-forming pockets aligned with the rows of staples in the cartridge. The instrument includes a plurality of reciprocating wedges which, when driven distally, pass through openings in the staple cartridge and engage drivers supporting the staples to effect the firing of the staples toward the anvil.
An example of a surgical stapler suitable for endoscopic applications, described in U.S. Pat. No. 5,465,895, advantageously provides distinct closing and firing actions. Thereby, a clinician is able to close the jaw members upon tissue to position the tissue prior to firing. Once the clinician has determined that the jaw members are properly gripping tissue, the clinician can then fire the surgical stapler, thereby severing and stapling the tissue. The simultaneous severing and stapling avoids complications that may arise when performing such actions sequentially with different surgical tools that respectively only sever or staple.
These minimally invasive surgical instruments have been widely used and have proven to be a significant advance over traditional open surgical techniques. It would be desirable to incorporate yet additional features and capabilities.
The invention overcomes the above-noted and other deficiencies of the prior art by including a surgical instrument that is suitable for minimally invasive surgical procedures which has a handle that positions an end effector through a surgical opening via an elongate shaft. The end effector has a pair of pivoting members opposingly contacting tissue. A fluid actuated closure mechanism responds to a closure action by a fluid actuator attached to the handle by bi-directionally transferring fluid across a fluid conduit to a fluid reservoir positioned to urge the pair of pivoting members closed. Thereby, the integration of fluid conduits within an elongate shaft allows for shafts of a desirable small cross section which are able to perform an important surgical operation.
In one aspect of the invention, a surgical instrument has an end effector that is actuated by a fluid actuator to open and close upon tissue. Once closed, a firing bar that is received for reciprocating a longitudinal firing motion in an elongate shaft transfers a longitudinal firing motion from a handle to actuate a staple cartridge and to sever the clamped tissue in the end effector.
In yet another aspect of the invention, a surgical instrument includes a handle that produces closure actuation that transfers fluid through a fluid conduit in an elongate shaft to a fluid actuator positioned in a lever cavity to position a lever. The lever of a first tissue contacting member extends proximally into the lever cavity from a pivotal connection with a second tissue contacting member. Fluid transfer advantageously effects pivotal movement of the pair of tissue contacting members.
These and other objects and advantages of the present invention shall be made apparent from the accompanying drawings and the description thereof.
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention, and, together with the general description of the invention given above, and the detailed description of the embodiments given below, serve to explain the principles of the present invention.
Turning to the Drawings, wherein like numerals denote like components throughout the several views,
With particular reference to
Left and right fluid actuator bladders (lift bags) 24, 26 are supported within an aft portion 28 of a staple channel 30. The anvil 12 includes a pair of inwardly directed lateral pivot pins 32, 34 that pivotally engage outwardly open lateral pivot recesses 36, 38 formed in the staple channel 30 distal to the aft portion 28. The anvil 12 includes a proximally directed lever tray 40 that projects into the aft portion 28 of the staple channel 30 overtop and in contact with the fluid actuator bladders (lift bags) 24, 26 such that filling the fluid actuator bladders 24, 26 causes a distal clamping section 41 of the anvil 12 to pivot like a teeter-totter toward a staple cartridge 42 held in an distal portion 44 of the staple channel 30. Evacuation and collapse of the fluid actuator bladders 24, 26, or some other resilient feature of the end effector 14, causes the anvil 12 to open. Left and right fluid conduits 46, 48 communicate respectively with the left and right fluid actuator bladders 24, 26 to bi-directionally transfer fluid for actuation.
It will be appreciated that the terms “proximal” and “distal” are used herein with reference to a clinician gripping a handle of an instrument. Thus, the staple applying assembly 20 is distal with respect to the more proximal handle 22. It will be further appreciated that, for convenience and clarity, spatial terms such as “vertical” and “horizontal” are used herein with respect to the drawings. However, surgical instruments are used in many orientations and positions, and these terms are not intended to be limiting and absolute.
The elongate shaft 18 includes a frame 50 (
Medical substance dispensing is integrated into the elongate shaft 18 by including a laterally offset cylindrical cavity 90 formed in the frame 50 that communicates along its longitudinal length to the outside via a rectangular aperture 92 that is slightly shorter than an electroactive polymer (EAP) syringe 100 that is inserted through the aperture 92 into the cylindrical cavity 90. A proximal portion of the cylindrical cavity 90 contains a longitudinally aligned compression spring 102 that urges a distal dispensing cone 104 of the EAP syringe 100 distally into sealing contact with the frame 50 and allows translation for insertion and removal of the EAP syringe 100. An electrical conductor 106 passes through the frame 50 and is attached to the compression spring 102, which is also formed of an electrically conductive metal. An aft portion of the EAP syringe is conductive and contacts the spring 102 to form a cathode to an EAP actuator 110 held in a proximal portion of the EAP syringe 100. It will be appreciated that another conductor, perhaps traveling with the conductor 106, also electrically communicates to the EAP actuator 110 to serve as the anode.
When activated, the EAP actuator 110 longitudinally expands, serving as a plunger to dispel a medical substance 112 in a distal portion of the EAP syringe 100 through the distal dispensing cone 104. Insofar as the EAP actuator 110 laterally contracts to compensate for its longitudinal expansion, a plunger seal 114 maintains a transverse seal within the EAP syringe 100. A vent (not shown), such as around conductor 106 allows air to refill the EAP syringe 100 as the medical substance 112 is dispensed. The vent may rely upon the surface tension of the medical substance 112 to prevent leaking. Alternatively, a one-way valve may be used for the same purpose. As described below, the medical substance 112 is conducted by the frame 50 to a lateral fluid groove 120 that is formed in the firing bar 62 and the E-beam 64 to direct the medical substance to a cutting surface 122 of the E-beam 64. The frame slot 58 is sized to seal the lateral fluid groove 120. The portion of the lateral fluid groove 120 that is positioned under the spring clip 76 is sealed by a firing bar guide 124. In the illustrative version, an outer sheath 82 encompasses the frame 50 and proximally projecting lever tray 40 of the anvil 12. A top distal opening 131 allows closing of the anvil 12.
An outer rectangular aperture 132 of the outer sheath 130 is sized and longitudinally positioned to correspond to the rectangular aperture 92 formed in the frame 50. In some applications, the outer sheath 130 may be rotated to selectively align the rectangular aperture 92 with the outer rectangular aperture 132 for insertion or removal of the EAP syringe 100. It should be appreciated that in some applications the EAP syringe 100 may be integrally assembled into an elongate shaft that does not allow for selecting a desired medical substance. For instance, a disposable implement portion with an integral staple cartridge and medical dispensing reservoir may be selected by the clinician as a unit. It is believed that allowing insertion at the time of use, though, has certain advantages including clinical flexibility in selecting a medical substance (e.g., anesthetics, adhesives, antibiotics, cauterizing compound, etc.) and extending the shelf life/simplifying storage and packaging of the implement portion 16.
In the illustrative version, an elongate stack of many disk-shaped EAP layers are aligned longitudinally and configured to expand along this longitudinal axis. Electroactive polymers (EAPs) are a set of conductive doped polymers that change shape when electrical voltage is applied. In essence, the conductive polymer is paired to some form of ionic fluid or gel and electrodes. Flow of the ions from the fluid/gel into or out of the conductive polymer is induced by the voltage potential applied and this flow induces the shape change of the polymer. The voltage potential ranges from 1V to 4 kV, depending on the polymer and ionic fluid used. Some of the EAPs contract when voltage is applied and some expand. The EAPs may be paired to mechanical means such as springs or flexible plates to change the effect that is caused when the voltage is applied.
There are two basic types of EAPs and multiple configurations of each type. The two basic types are a fiber bundle and a laminate version. The fiber bundle consists of fibers around 30-50 microns. These fibers may be woven into a bundle much like textiles and are often called EAP yarn because of this. This type of EAP contracts when voltage is applied. The electrodes are usually made up of a central wire core and a conductive outer sheath that also serves to contain the ionic fluid that surrounds the fiber bundles. An example of a commercially available fiber EAP material, manufactured by Santa Fe Science and Technology and sold as PANION™ fiber, is described in U.S. Pat. No. 6,667,825, which is hereby incorporated by reference in its entirety.
The other type is a laminate structure, which consists of a layer of EAP polymer, a layer of ionic gel and two flexible plates that are attached to either side of the laminate. When a voltage is applied, the square laminate plate expands in one direction and contracts in the perpendicular direction. An example of a commercially available laminate (plate) EAP material is manufactured by Artificial Muscle Inc, a division of SRI Laboratories. Plate EAP material is manufactured by EAMEX of Japan and is referred to as thin film EAP.
It should be noted that EAPs do not change volume when energized; they merely expand or contract in one direction while doing the opposite in the transverse direction. The laminate version may be used in its basic form by containing one side against a rigid structure and using the other much like a piston. The laminate version may also be adhered to either side of a flexible plate. When one side of the flexible plate EAP is energized, it expands, flexing the plate in the opposite direction. This allows the plate to be flexed in either direction, depending on which side is energized.
An EAP actuator usually consists of numerous layers or fibers bundled together to work in cooperation. The mechanical configuration of the EAP determines the EAP actuator and its capabilities for motion. The EAP may be formed into long stands and wrapped around a single central electrode. A flexible exterior outer sleeve will form the other electrode for the actuator as well as contain the ionic fluid necessary for the function of the device. In this configuration when the electrical field is applied to the electrodes, the strands of EAP shorten. This configuration of EAP actuator is called a fiber EAP actuator. Likewise, the laminate configuration may be placed in numerous layers on either side of a flexible plate or merely in layers on itself to increase its capabilities. Typical fiber structures have an effective strain of 2-4% where the typical laminate version achieves 20-30%, utilizing much higher voltages.
For instance, a laminate EAP composite may be formed from a positive plate electrode layer attached to an EAP layer, which in turn is attached to an ionic cell layer, which in turn is attached to a negative plate electrode layer. A plurality of laminate EAP composites may be affixed in a stack by adhesive layers there between to form an EAP plate actuator. It should be appreciated that opposing EAP actuators may be formed that can selectively bend in either direction.
A contracting EAP fiber actuator may include a longitudinal platinum cathode wire that passes through an insulative polymer proximal end cap through an elongate cylindrical cavity formed within a plastic cylinder wall that is conductively doped to serve as a positive anode. A distal end of the platinum cathode wire is embedded into an insulative polymer distal end cap. A plurality of contracting polymer fibers are arranged parallel with and surrounding the cathode wire and have their ends embedded into respective end caps. The plastic cylinder wall is peripherally attached around respective end caps to enclose the cylindrical cavity to seal in ionic fluid or gel that fills the space between contracting polymer fibers and cathode wire. When a voltage is applied across the plastic cylinder wall (anode) and cathode wire, ionic fluid enters the contracting polymer fibers, causing their outer diameter to swell with a corresponding contraction in length, thereby drawing the end caps toward one another.
Additional description of applications of EAP actuators in a surgical instrument are described in commonly-owned U.S. patent application Ser. No. 11/082,495 filed on 17 Mar. 2005, and entitled “SURGICAL INSTRUMENT INCORPORATING AN ELECTRICALLY ACTUATED ARTICULATION MECHANISM”, the disclosure of which is hereby incorporated by reference in its entirety.
Returning to
As an alternative, a closure trigger (not shown) or other actuator may be included that bi-directionally transfers fluid to the fluid actuator bladders 24, 26. In the above-referenced patent application Ser. No. 11/061,908, a number of such fluid actuators for articulation of a pivoting shaft are described that may be adapted for closing the anvil 12. To take full advantage of the differential fluid transfer described for several of these versions, it should be appreciated that an opposing lift bag (not shown) may be placed above the lever tray 40 of the anvil 12 to assert an opening force as the left and right fluid actuator bladders (lift bags) 24, 26 collapse.
To avoid undesirable firing situations, sensing may be advantageously incorporated into the control circuitry. For instance, a pressure transducer and/or position sensing may be positioned to monitor the fluid transfer and/or anvil position. For instance, the proximity of the anvil to the 12 to the staple channel 30 may be sensed and firing locked out if not closed. Monitoring may detect a fluid pressure exceeding a threshold indicating that anvil 12 commanded closed with something preventing this closing (e.g., excessive tissue in the end effector 14). Similarly, a fluid pressure below a lower threshold with anvil 12 commanded open may indicate an inability for the anvil 12 to open (e.g., abutting tissue). Colored light emitting diodes (LEDs) (not shown) on the handle 22 may give an indication to the surgeon by color, flashing, etc. These indications may include POWER ON, Self-Test GOOD, Self-Test BAD, BATTERY LOW, ANVIL OPEN, ANVIL CLOSED, ANVIL BLOCKED OPEN, ANVIL BLOCK CLOSED. An indication that would warrant precluding firing may be used to disable firing.
With particular reference to
An anti-backup mechanism 170 of the firing rod 152 may be advantageously included for a handle 22 that includes a multiple stroke firing trigger 150 and a retraction biased firing mechanism coupled to the firing rod 152 (not shown). In particular, an anti-backup locking plate 172 has the firing rod 152 pass through a closely fitting through hole (not shown) that binds when a retracting firing rod 152 tips the lock plate 172 backward as shown with the bottom of the locking plate held in position within the frame 50. An anti-backup cam sleeve 174 is positioned distal to the anti-backup locking plate 172 and urged into contact by a more distal compression spring 176 through which the firing rod 152 passes and that is compressed within the frame 50. It should be appreciated that mechanisms in the handle 22 may manually release the anti-backup mechanism 170 for retraction of the firing rod 152.
In
In
In
It should be appreciated that one or more sensor in the surgical stapling and severing instrument 10 may sense a firing condition (e.g., movement of firing bar or mechanism coupled to the firing bar, position of the firing trigger, a separate user control to dispense, etc.) and activate dispensing control circuitry to effect dispensing.
In
In
A fluid actuator bladders (lift bag) 424 is supported within a staple channel 430 beneath a proximally directed lever 440 that projects such that filling the fluid actuator bladder 424, 26 causes the anvil 412 to pivot like a teeter-totter toward a staple cartridge 442 held in an distal portion 44 of the staple channel 30. Evacuation and collapse of the fluid actuator bladder 424 is assisted by a resilient pressure transducer 425 positioned above the anvil lever 440 in opposition to the fluid actuator bladder 424, urging fluid to flow proximally through a fluid conduit 446.
Control circuitry 450 is powered when enabled by an ON/OFF switch 452 to electrically connect batteries 454 that are physically accessed via a battery cap 456 that closes a battery compartment 457 in a pistol grip 458 of the handle 422. A controller (e.g., microcontroller, programmed logic array, analog control circuit, etc.) 460 receives electrical signals from switches that are actuated by a user or from sensors that indicate a state of the instrument 410. For instance, a thumb button pressure sensor 462 contacting a thumb button 464 senses a closure command. This closure command signal may be a discrete open/close signal or a more continuous value indicating intermediate degrees of closure. Alternatively, the controller 460 may sense a first depression of the thumb button 464 to close and sense a second depression of the thumb button 464 to then open.
The controller 460 responds to the closure signal by activating an electrical fluid control, which in the illustrative version is an EAP syringe actuator 470 containing an EAP stack actuator 472 that translates a plunger 474 within a cylinder 476 to dispense fluid through the fluid conduit 446. The cylinder 476 may be advantageously sized to produce a desired fluid flow rate at a desired fluid pressure to effect closure without excessive pressure if too much tissue is grasped.
The pressure of the fluid may be advantageously sensed by a fluid pressure transducer 478 attached to the cylinder 476 and/or by sensing movement of the anvil 412 from the resilient pressure transducer 425. Alternatively or in addition, fluid volume transferred may be advantageously sensed, such as by Hall effect transducers 480, 482 attached to the cylinder 476 to sense a target incorporated into the plunger 474. The controller 460 may provide indications to the surgeon via an alphanumeric display (not shown) or via a plurality of LEDs, such as a POWER LED 490, an ANVIL POSITION LED 492, and FAULT LED 494. The controller 460 may also sense firing, such as a trigger sensor 496, and in response thereto command the EAP medical substance dispenser 100 to dispense.
In use, as depicted in
While the present invention has been illustrated by description of several embodiments and while the illustrative embodiments have been described in considerable detail, it is not the intention of the applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications may readily appear to those skilled in the art.
For example, while a non-articulating shaft is described herein for clarity, it should be appreciated that fluid actuated end effector and/or medical substance dispensing may be incorporated into an articulating shaft. In particular, flexible fluid conduits may be incorporated that pass through an articulation joint of a shaft. Alternatively, passages may be formed in a flex-neck type articulation joint to transfer fluid there through.
As another example, while both medical substance dispensing and fluid actuated anvil closing are illustrated herein, applications consistent with aspects of the invention may include either of these features. Further, for applications in which an adhesive and/or cauterizing medical substance is dispensed, it should be appreciated that features such as staples may be omitted.
As another example, while a staple applying assembly 20 is illustrated herein, it should be appreciated that other end effectors (graspers, cutting devices, etc.) may benefit from either or both of fluid controlled closing and medical substance dispensing.
As yet another example, a receptacle for the EAP syringe may be formed in the handle rather than in the elongate shaft.
While an electroactive polymer plunger has various advantages, it should be appreciated that other types of electrically actuated devices may be employed to dispense a medical substance through the elongate shaft to the end effector.
As yet an additional example, a symmetric arrangement for a second EAP syringe may be formed in the elongate channel so that two medical substances may be simultaneously dispensed during firing.
As yet a further example, while a staple applying apparatus provides an illustrative embodiment, it should be appreciated that other endoscopic instruments may benefit from the ability to dispense a liquid at or near a distal end thereof. Examples of instruments that may benefit include, but are not limited to, an ablation device, a grasper, a cauterizing tool, an anastomotic ring introduction device, a surgical stapler, a linear stapler, etc. As such, those instruments that do not employ a firing bar that serves herein as a convenient fluid passage to a cutting surface may instead incorporate ducting or fluid conduits to an appropriate location.
While an electroactive polymer plunger has various advantages, it should be appreciated that other types of electrically actuated devices may be employed to dispense a medical substance through the elongate shaft to the end effector.
As yet an additional example, a fluid actuator bladder that is constrained within a recess of the elongate shaft may be substituted with a cylinder and piston ram.
It should be appreciated that in some applications consistent with the invention, both pivoting members of an end effector pivot with respect to a distal end of the end effector in a scissor-like arrangement. Thus, a fluid actuator bladder may be positioned to assert a force to separate or to draw together respective levers proximally projecting from a pivoting connection of these pivoting members to effect closure (e.g., grasping, cutting) or opening.
As an alternative, it should be appreciated that a fluid actuator bladder may be positioned distal to the pivotal engagement between opposing jaws to urge the jaws open.
As another example, although a handle 22 for direct manipulation by a surgeon is depicted for clarity, a robotically positioned instrument consistent with aspects of the invention may advantageously take advantage of the electrical control and sensing with fluid transfer actuation as described herein.
This application claims the benefit of U.S. patent application Ser. No. 11/061,908 entitled “SURGICAL INSTRUMENT INCORPORATING A FLUID TRANSFER CONTROLLED ARTICULATION MECHANISM” to Kenneth Wales and Chad Boudreaux, filed on 18 Feb. 2005, the disclosure of which is hereby incorporated by reference in its entirety.
