Sealer-Divider-Dissector and Related Methods

Abstract

The surgical instrument includes a pair of jaws for manipulating tissue disposed therebetween, a housing, a hemostat-type gripping mechanism, an elongated shaft positioned between the housing and the pair of jaws and defining a longitudinal axis, and a pull tube disposed at least partially within the elongated shaft. The hemostat-type gripping mechanism includes a link system configured to move the jaws between an open position and an approximated position, the link system including a first shank having a distal end rotatably coupled to the housing at a first fixed pivot point and a proximal end coupled to the first finger grip, a second shank having a distal end rotatably coupled to the housing at a second fixed pivot point and a proximal end coupled to the second finger grip, and a slider link operatively coupled to the first shank and the second shank.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit under 35 U.S.C. § 119 to U.S. Provisional Patent Application No. 63 / 180782, filed April 28, 2021, the disclosure of which is incorporated herein by reference in its entirety.

[0002] The present invention relates to surgical instruments. More particularly, but not by way of limitation, embodiments of the present invention relate to surgical instruments for sealing tissue in surgical procedures. [Background technology]

[0003] Surgeons perform procedures, such as thyroidectomies, parathyroidectomies, and / or other resections, in small or confined spaces, such as the head / neck or other parts of the body. Small, confined areas within the body are packed with structures such as nerves, arteries, the thyroid gland, the esophagus, muscles, and / or other tight spaces that inhibit the surgeon's ability to maneuver during a surgical procedure (e.g., open, whole body, or laparoscopic).

[0004] Currently, available medical instruments are used in surgical procedures that may cause trauma to patients. For example, FIG. 1 shows a hemostat-type sealer-divider used in open surgical procedures. However, the hemostat-type sealer-divider of FIG. 1 is not suitable for laparoscopic procedures due to its large, scissor-like arms. Furthermore, hemostat-type sealer-dividers are difficult to use in certain open procedures, such as in tight internal body spaces, which further limit the surgeon's visibility. Furthermore, when using the instrument shown in FIG. 1, the maximum jaw opening is limited by the size of the surgeon's hand.

[0005] As a further example, surgeons may use sealer-dividers with pistol grips, such as those shown in FIG. 2. While sealer-dividers with pistol grips enable laparoscopic procedures, the pistol grips can cause instability, particularly when the surgeon opens and closes the end effector during a surgical procedure. For example, instability can occur when pistol-grip instruments are used in open procedures because they require greater hand / finger movement to reach the actuator, which can cause the surgeon to inadvertently touch nerves. Many pistol-grip instruments also include a ratchet mechanism that engages when the jaws are closed (to optimize pressure on the tissue during tissue sealing); after each seal, the surgeon must "click" the closed handle to release the ratchet mechanism, allowing the jaws to open, further contributing to instability during the surgical procedure. Such instability increases patient trauma, particularly when working in tight spaces (e.g., the head and neck).

[0006] Some patient injuries occur when surgical instruments inadvertently strike nerves and / or when electrical energy, such as that applied during tissue sealing procedures, spreads beyond the intended target tissue. To minimize patient injuries, it is desirable to minimize collateral burns and unnecessary contact with sensitive tissue during surgical procedures, but achieving this can be challenging when working in tight spaces such as the head and neck, especially with currently available equipment.

[0007] The embodiments described herein address these and / or other problems by providing a multi-function instrument that minimizes instrument instability during a surgical procedure, improves the surgeon's control, increases the surgeon's field of view at the distal end of the instrument, reduces instrument size while increasing jaw opening, and / or reduces the time required for the surgical procedure, any or all of which reduces trauma to the patient and improves surgical outcomes. Another advantage of the embodiments described herein is the ability to open the jaws of the instrument widely, which is advantageous during tissue dissection regardless of the surgeon's hand size. Summary of the Invention

[0008] In one embodiment, the surgical instrument comprises a distal portion having a pair of jaws configured to move between an open position and an approximated position to manipulate tissue disposed therebetween; a proximal portion having a housing and a hemostat-type gripping mechanism, the hemostat-type gripping mechanism including a first finger grip and a second finger grip; an elongated shaft positioned between the proximal and distal portions, the elongated shaft defining a longitudinal axis; and a pull tube at least partially disposed within the elongated shaft. The hemostat-type gripping mechanism of the surgical instrument includes a linkage system configured to move the pair of jaws between an open position and an approximated position, the linkage system including: a first shank having a distal end rotatably coupled to the housing at a first fixed pivot point and a proximal end coupled to the first finger grip, a second shank having a distal end rotatably coupled to the housing at a second fixed pivot point and a distal end coupled to the second finger clip, and a slider link operatively coupled to the first shank and the second shank. A pull tube of the surgical instrument has a proximal end coupled to the slider link and a distal end coupled to the pair of jaws, the pull tube configured to move between the first position and a second position proximal to the first position in response to manipulation of the first shank and / or the second shank, thereby moving the pair of jaws between the open position and the approximated position.

[0009] In some embodiments, the link system is a seven-bar link system comprising a first shank, a second shank, a housing, and a slider link. The link system further comprises a first lever link rotatably coupled to the first shank at a first floating pivot point and a slider link, respectively, a second lever link rotatably coupled to the second shank at a second floating pivot point and a slider link, and a slide track link fixed to or defined by the housing and configured to limit the slider link to longitudinal movement relative to the housing.

[0010] In some embodiments, the first and second shanks, the second lever link, and the first and second floating links are collectively configured to vary a mechanical advantage between an open position and an approximated position. In some embodiments, the mechanical advantage occurs when the first and second shanks move from the open position to the approximated position in a stroke, and the pair of jaws has a greater distance of travel in the first half of the stroke than in the second half of the stroke. Furthermore, the mechanical advantage occurs when the compressive force required to move the first and second grips closer together decreases as the pair of jaws approach the approximated position.

[0011] In some embodiments, the first and second floating pivot points are configured to move outward from a longitudinal axis defined by the elongate shaft when the pull tube is moved distally, and conversely, the first and second floating pivot points are configured to move inward from a longitudinal axis defined by the elongate shaft when the pull tube is moved proximally.

[0012] In these embodiments, the link system is configured to prevent locking of the pair of jaws in the approximated position. Optionally, the first and second floating pivot points are configured to lock the pair of jaws in the approximated position when the first shank and the first lever link form an angle of approximately 180 degrees therebetween.

[0013] In some embodiments, the slider link includes a spring housing that houses a load limiting spring configured to limit a tension force on the pull tube when the pair of jaws is in the approximated position and configured to disengage from the pull tube when the pair of jaws transitions from the approximated position to the open position.

[0014] The surgical instrument further includes an electrode actuator, a tissue sealing system having a first electrode disposed in a first jaw of the pair of jaws, and a second electrode disposed in a second jaw of the pair of jaws. The first and second electrodes are configured to seal tissue disposed between the pair of jaws in response to proximal movement of either one of the electrode actuators, the electrode actuators moving in response to a force applied to either one of the electrode actuators parallel to a longitudinal axis defined by the elongate shaft. The electrode actuator is disposed along and laterally offset from the longitudinal axis defined by the elongate shaft.

[0015] In some embodiments, the link system is configured to vary the mechanical advantage between the open position and the approximated position. In some embodiments, the mechanical advantage occurs when the first and second shanks of the link system move from the open position to the approximated position during a stroke, with the pair of jaws having a greater distance traveled in the first half of the stroke than in the second half of the stroke. In this embodiment, the mechanical advantage decreases throughout the stroke. In some embodiments, the mechanical advantage occurs when the compressive force required to move the first and second finger grips decreases as the pair of jaws approaches the approximated position.

[0016] In another embodiment, a surgical instrument configured to process tissue is disclosed. The surgical instrument includes a handle operably coupled to an end effector by a linkage system and an elongated shaft, the handle including a first shank and a second shank, and the end effector including opposing jaws selectively movable between an open position and an approximated position when the handle is actuated. The linkage system is configured such that a stroke of the handle moves the opposing jaws to the approximated position to engage tissue disposed therebetween by moving the first shank and the second shank toward each other, and the mechanical advantage varies during the stroke, such that the opposing jaws have a greater distance of travel in a first half of the stroke than in a second half of the stroke.

[0017] In some embodiments, the link system is configured such that moving the first and second shanks rotates the first shank about a first fixed pivot of the link system and rotates the second shank about a second fixed pivot of the link system.

[0018] Optionally, the first and second fixed pivots are laterally offset from a longitudinal axis defined by the elongate shaft.

[0019] In some embodiments, the surgical instrument further comprises one or more electrode actuators, each having a contact surface for a user's finger, at least one of the electrode actuators disposed along and laterally offset from a longitudinal axis defined by the elongate shaft, the contact surface of the at least one actuator being radially offset from the longitudinal axis a first distance, and the fixed pivot point being radially offset from the longitudinal axis a second distance greater than the first distance.

[0020] In some embodiments, the surgical instrument further comprises a protrusion coupled to the slider link, at least a portion of the protrusion being slidably disposed within the guide member, the protrusion and the guide member configured to prevent rotation of the slider link.

[0021] In yet another embodiment, a method of operating a surgical instrument for processing tissue is disclosed. The surgical instrument used by the method includes a handle operably coupled to an end effector by a linkage system and an elongated shaft, the handle including a first shank and a second shank, and the end effector including opposing jaws selectively movable between an open position and an approximated position using the handle. The method includes moving the opposing jaws to the approximated position to engage tissue disposed therebetween by moving the first and second shanks toward each other, varying a mechanical advantage as the opposing jaws move toward the approximated position. Moving the first and second shanks includes rotating the first shank about a first fixed pivot and rotating the second shank about a second fixed pivot. The first and second fixed pivots are laterally offset from a longitudinal axis defined by the elongated shaft.

[0022] In some embodiments of the method of operating a surgical instrument, the instrument further includes a load limit spring, the method further includes engaging the load limit spring when the pair of jaws is in the approximated position and disengaging the load limit spring when the pair of jaws approaches the open position, and the method further includes moving the pair of jaws between the open position and the approximated position without locking the pair of jaws in the approximated position.

[0023] In another embodiment, a method of operating an instrument having a hemostat-type gripping mechanism mechanically coupled to a pair of jaws for opening and closing the pair of jaws is disclosed. The pair of jaws includes electrodes electrically coupled to an actuator disposed on a proximal portion of the instrument and configured to selectively activate the electrodes. The method includes activating the electrodes by applying a compressive force to the actuator parallel to a longitudinal axis of the instrument. In an embodiment in which the actuator has an outer surface radially offset from the longitudinal axis by a predetermined distance, the method further includes rotating the first shank and the second shank about respective pivot points, the pivot points being radially offset from the longitudinal axis by a first distance, and the outer surface of the actuator being radially offset from the longitudinal axis by a second distance, the second distance being greater than the first distance. [Brief explanation of the drawings]

[0024] The drawings illustrate the design and utility of the embodiments, and like elements are given common reference numerals. The drawings are not necessarily to scale. To better understand how the above and other advantages and objects are achieved, a more particular description of the embodiments, as illustrated in the accompanying drawings, is presented below. These drawings are merely exemplary embodiments and should not be construed as limiting the scope of the claims.

[0025] [Figure 1] FIG. 1 is a perspective view of a typical device (prior art). [Figure 2] FIG. 2 is a perspective view of another typical device (prior art). [Figure 3] FIG. 3 is a perspective view of a sealer-divider-dissector in accordance with an embodiment of the present invention. [Figure 4] FIG. 4 is a first side view of the device of FIG. [Figure 5] FIG. 5 is a second side view of the device of FIG. [Figure 6] FIG. 6 is a perspective view of some components of the device of FIG. [Figure 7]FIG. 7 is a first side cross-sectional view of some of the components of FIG. 3, overlaid with a schematic diagram of the link components of FIG. [Figure 8] FIG. 8 is a first side schematic view of the link component of FIG. 6. [Figure 9] FIG. 9 is a first side view of the device of FIG. 3 with some components removed for clarity. [Figure 10] FIG. 10 is a second side view of the device of FIG. 3 with some components removed for clarity. [Figure 11] FIG. 11 is a perspective exploded view of the device of FIG. 3 with some components removed for clarity. [Figure 12] FIG. 12 is a first side view of some components of the device of FIG. 3, with some features removed for clarity. [Figure 13] FIG. 13 is a perspective view of the distal end of the instrument of FIG. 3 grasping tissue. [Figure 14] FIG. 14 is a side view of the distal end of the instrument of FIG. 3 grasping tissue, with some components removed for clarity. [Figure 15A] FIG. 15A outlines the differences between the devices of FIGS. [Figure 15B] FIG. 15B outlines the differences between the devices of FIGS. [Figure 15C] FIG. 15C outlines the differences between the devices of FIGS. [Figure 15D] FIG. 15D outlines the differences between the devices of FIGS. [Figure 15E] FIG. 15E outlines the differences between the devices of FIGS. [Figure 16] FIG. 16 is a flow chart of an exemplary method of use of the device of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0026] For the following defined terms, these definitions shall apply unless a different definition is given in the claims or elsewhere in this specification.

[0027] All numerical values ​​herein are assumed to be modified by "about," whether or not expressly indicated. "About" generally refers to a range of numbers that one of ordinary skill in the art would consider equivalent to the recited value (i.e., having the same function or result). In many instances, "about" can include numbers rounded to the nearest significant figure.

[0028] The recitation of numerical ranges by endpoints includes all numbers within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5).

[0029] As used in this specification and claims, the singular includes the plural unless the context clearly indicates otherwise. As used in this specification and claims, "or" is used in its sense including "and / or" unless the context clearly indicates otherwise.

[0030] Various embodiments will now be described with reference to the drawings. The drawings are not necessarily to scale, and the relative scale of selected elements may be exaggerated for clarity, with elements of similar structure or function being designated by like reference numerals throughout the drawings. Additionally, the drawings are intended only to facilitate the description of the embodiments and are not intended to be exhaustive or to limit the scope of the invention, which is defined solely by the claims and their equivalents. Furthermore, an illustrated embodiment does not necessarily include all of the presented features or advantages. Features or advantages discussed in connection with a particular embodiment are not necessarily limited to that embodiment and may be implemented in any other embodiment, even if not otherwise illustrated.

[0031] Those skilled in the art will appreciate that "tissue cutting," as used herein, refers to the procedure of separating tissue by piercing the tissue with the jaws closed or brought together and then opening or moving the jaws of the instrument apart, whereas "tissue dividing," as used herein, refers to the procedure of cutting tissue clamped between the jaws of the instrument.

[0032] 3-5 are a perspective view, a first side view, and a second side view, respectively, of a sealer-divider-dissector instrument 100 in accordance with an embodiment of the present invention. The instrument 100 comprises a proximal portion 102, a distal portion 104, and a body portion 103 disposed therebetween. The proximal portion 102 allows a user (e.g., a surgeon, clinician) to grasp, manipulate, and operate the instrument 100 with one hand. The proximal portion 102 comprises an actuator, such as a handle. The distal portion 104 is configured to grasp, hold, and / or manipulate tissue. The distal portion 104 is further configured to seal, divide, and / or cut tissue when the instrument 100 is actuated, as described further below. The body portion 103 comprises an elongate shaft 118 configured to transmit actuation (e.g., translation and / or rotation) of the proximal portion 102 of the instrument 100 by the surgeon to the distal portion 104 of the instrument 100. The elongate shaft 118 and / or the distal portion 104 may be rotatable relative to the proximal portion 102 of the instrument 100 .

[0033] The distal portion 104 of the instrument 100 includes an end effector 105 having a pair of jaws (i.e., a first jaw 114 and a second jaw 116). The jaws 114 and 116 are configured to move between an open position (FIGS. 3-5) and an approximated position (FIGS. 13 and 14). The approximated position is defined as a position in which the jaws 114 and 116 are closed to grasp, hold, and / or restrain tissue disposed therebetween. Those skilled in the art will appreciate that the approximated position is determined by tissue thickness, which may change during surgical procedures such as tissue sealing and dissection. One or both surfaces of the jaws 114 and 116 (e.g., the first electrode 136 and the second electrode 138) may include one or more non-conductive stop elements 115 (FIG. 14) that prevent direct contact between the surfaces of the jaws 114 and 116, in a manner understood by those skilled in the art, to avoid electrical shorting.

[0034] Proximal portion 102 of instrument 100 includes a housing 160 and a hemostat-style gripping mechanism, handle, or actuator 162. Housing 160 and / or hemostat-style gripping mechanism / actuator 162 may be formed from one or more components. A hemostat-style gripping mechanism is defined as a mechanism configured to be grasped by a user similar to the hemostat instrument of FIG. 1 (i.e., as opposed to the pistol-grip instrument of FIG. 2).

[0035] 3, electrical wire(s) 320 extend from a power source 350, such as a radio frequency generator, through the housing 160 to the end effector 105. The electrical wire(s) 320 are configured to deliver energy to the end effector 105. In another embodiment, the electrical wire(s) 320 can extend from the actuator 162 to the end effector 105. In some embodiments, the connection of the instrument 100 to the power source 350 is wireless (not shown). The delivered energy can be radio frequency (RF) energy or energy suitable for sealing, dividing, and cutting tissue.

[0036] As shown in Figures 3-5, the proximal portion 102 of the instrument 100 further includes a first shank 112 and a second shank 108, and a linkage system 120 (Figures 7 and 8) for actuating the jaws 114 and 116 to an open and / or approximated (closed) position. The first shank 112 is coupled to a first finger grip 110, and the second shank 108 is coupled to a second finger clip 106. Although the finger grips 110 and 106 are shown as rings in the figures, one skilled in the art will appreciate that the finger grips 110 and 106 can include any suitable configuration that provides a secure grip on the instrument 100, such as concave / corrugated surfaces, indentations, and / or depressions on one or both shanks 112 or 108.

[0037] The proximal portion 102 of the instrument 100 further includes a finger wheel 128 coupled to the elongated shaft 118. The finger wheel 128 is configured to rotate the elongated shaft 118 and / or the jaws 114, 116 relative to the proximal portion 102 of the instrument 100 (e.g., housing 160) in response to actuation of the finger wheel 128. In some embodiments, the proximal portion 102 of the instrument includes a power actuator 132 and a knife actuator 146 on one side (FIGS. 3 and 4) and an electrode actuator 134 and a knife actuator 148 on the other side (FIG. 5). The electrodes and knife actuators are described in more detail below.

[0038] Figure 6 is a perspective view of instrument 100 with some features removed for clarity. Specifically, Figure 6 shows hemostat-style gripping mechanism 162 on proximal portion 102 of instrument 100 coupled to elongated shaft 118 of body portion 103, and end effector 105 on distal portion 104. Hemostat-style gripping mechanism 162 includes and / or is coupled to linkage system 120 for moving pair of jaws 114, 116 between an open position and an approximated position.

[0039] 7 and 8 show details of link system 120 of instrument 100. In particular, FIG. 8 is a schematic diagram of link system 120. The schematic diagram of FIG. 8 is superimposed on instrument 100 shown in FIG. 7. As shown in FIGS. 6-8, link system 120 includes first shank 112 and second shank 108. Each shank 112 and 108 has a respective distal end 113 and 109. The distal ends 113 and 109 of shanks 112 and 108 are rotatably coupled to housing 160 (FIG. 7). Finger grip 106 is disposed at or near proximal end 117 of shank 108, and finger grip 110 is disposed at or near proximal end 111 of shank 112 (FIG. 6). Link system 120 further includes first lever link 124 and second lever link 122. The first lever link 124 is rotatably coupled to the first shank 112 and the cartridge spring housing 156, while the second lever link 122 is rotatably coupled to the second shank 108 and the cartridge spring housing 156. The cartridge spring housing 156 is limited in longitudinal movement relative to a housing 160. The cartridge spring housing 156 includes a load-limiting spring 158. Rotational movement of the shanks 112, 108 about their respective distal ends 113, 109 is configured to be transmitted to the cartridge spring housing 156 and the tubular member 126, which in turn rotates the jaws 114, 116. In some embodiments, the tubular member 126 is a hollow pull tube or rod. The link system 120 can be operatively coupled to a jaw link system 300 ( FIG. 13 ) or the jaws 114, 116. The linkage system 120 is configured to move the jaws 114, 116 in response to manipulation of the shanks 112, 108.

[0040] As shown in FIGS. 6-8 , link system 120 comprises a seven-bar linkage system configured to translate rotational movement of shanks 112, 108 into longitudinal movement of pull tube 126. To facilitate disclosure of link system 120, the links will be described in the order shown in FIG. 8 from right to left (rather than numerical order). Link system 120 comprises base link 1 fixedly coupled to or defined by housing 160. Base link 1 may be a feature 161 within or affixed to housing 160. Base link 1 comprises a first fixed pivot point 410 and a second fixed pivot point 420, each of which is fixed to the housing (i.e., no rotation or translation of the pivot point). Link system 120 further comprises link 2 and link 7. Link 2 may be first shank 112, and link 7 may be second shank 108. Link system 120 includes link 3 and link 6. Link 3 may be a first lever link 124, and link 6 may be a second lever link 122. First lever link 124 is rotatably coupled to first shank 112 at a first floating pivot point 430, and second lever link 122 is rotatably coupled to second shank 108 at a second floating pivot point 440. Floating pivot points 430, 440 are configured to allow movement of links 3 and 6 relative to their respective connecting links 2 and 7, as shown by the arrows in FIG. 8 , in response to movement of shanks 112 and 108 by a user. Thus, first floating pivot point 430 and second floating pivot point 440 are configured to move outward from the longitudinal axis of instrument 100 when pull tube 126 is moved distally, and further configured to move inward from the longitudinal axis of instrument 100 when pull tube 126 is moved proximally.

[0041] Link system 120 further includes a slider link 5 coupled to links 3 and 6. Slider link 5 may be a cartridge spring housing 156. Cartridge spring housing 156 is coupled to first lever link 124 and second lever link 122 via respective pivot points 450 and 460. Cartridge spring housing 156 is configured to translate, as shown by the arrows in FIG. 8, in response to movement of lever links 124, 122. Link system 120 includes a slide track link 4. Slide track link 4 is a feature within or fixedly attached to housing 160. Slide track link 4 may include one or more flange surfaces 171, 173 (FIGS. 6-8 and 11-12) configured to allow longitudinal movement of slider link 5 or cartridge spring housing 156 relative to housing 160.

[0042] Optionally, cartridge spring housing 156 can include a protrusion (not shown), at least a portion of which can be configured to slidably engage or be slidably disposed within guide member 480. Guide member 480 includes a complementary groove, track, or other suitable guide mechanism (not shown) configured to receive and slidably engage the protrusion of cartridge spring housing 156. Guide member 480 and the protrusion are configured to guide movement of cartridge spring housing 156, thereby restricting the movement to two degrees of freedom (i.e., allowing translation along the x-axis and preventing rotation of cartridge spring housing 156 relative to housing 160 of instrument 100). As shown in FIG. 7 and in the schematic diagram of link system 120 in FIG. 8, guide member 480 is slidably coupled to cartridge spring housing 156 and is shown opposite slide track link 4. The guide member 480 may be positioned laterally to the cartridge spring housing 156 and / or rotated clockwise in the XZ plane (FIG. 4) of the instrument 100 so that the guide member 480 is positioned below the cartridge spring housing 156 or in another suitable location that limits the movement of the cartridge spring housing to translation along the x-axis.

[0043] It should be appreciated that the length of the links can be varied to change the leverage of the link system 120 and increase the mechanical advantage of the instrument 100. The link system 120 is configured to provide controlled movement of the jaws 114, 116.

[0044] To actuate linkage system 120, a user can move shanks 112, 108 toward one another (e.g., to a closed or approximated position) and move cartridge spring housing 156 proximally (e.g., within and / or proximally relative to housing 160). Additionally, a user can move shanks 112, 108 away from one another (e.g., to an open position) and move cartridge spring housing 156 distally (e.g., within and / or distally relative to housing 160). Cartridge spring housing 156 is coupled to pull tube 126 such that proximal movement of cartridge spring housing 156 causes proximal translation of pull tube 126, which places jaws 114, 116 in an approximated position (e.g., closed) ( FIGS. 7 and 10 ). Conversely, distal movement of cartridge spring housing 156 translates pull tube 126 distally, which opens jaws 114, 116. Thus, moving the shanks 112, 108 away from each other (open position) opens the jaws 114, 116. As shown in Figure 6, the pull tube 126 includes a proximal end 126a coupled to the cartridge spring housing 156 and a distal end 126b coupled to the jaws 114, 116.

[0045] In some embodiments, the link system 120 is configured to provide optimal mechanical advantage at the end of the closing stroke, such as when the shanks 112, 108 are moved toward one another (e.g., toward the housing 160). For example, the mechanical advantage of the instrument 100 occurs when the first and second shanks 112, 108 of the link system 120 move from an open position to an approximated position during the stroke, with the pair of jaws 114, 116 having a greater travel in the first half of the stroke than in the second half of the stroke. The jaws 114, 116 are considered to be in an approximated position when they grasp, hold, and / or place tissue 200 ( FIG. 13 ). The approximated position is determined by the thickness of the tissue 200 between the jaws 114, 116. Because the pull tube 126 is prevented from further proximal movement when the jaws 114, 116 are in the approximated position, further approximation of the shanks 112, 108 causes the cartridge spring housing 156 to engage the load limit spring 158 in a manner known to those skilled in the art. As the tissue 200 between the jaws 114, 116 dehydrates, dries, or melts, the tissue 200 tends to become thinner, which redefines the approximated position of the jaws 114, 116 and allows the pull tube 126 and cartridge spring housing 156 to move proximally in the process. In some embodiments, the load limit spring 158 can be configured to limit the pulling force on the pull tube 126 to about 40 pounds (18.14 kilograms of force) or less, or about 35 pounds (15.88 kilograms of force) or less, or about 30 pounds (13.6 kilograms of force) or less.

[0046] Those skilled in the art will appreciate that at least a portion of the pull tube 126 can be positioned within the elongated shaft 118 (FIGS. 9 and 10). The pull tube 126 can be operatively coupled to the link system 120 and / or the cartridge spring housing 156. The pull tube 126 is configured to slide or move relative to the elongated shaft 118 between a first position and a second position. The first position of the pull tube 126 is responsive to movement of the shanks 112 and / or 108 (e.g., an approximated or closed position), and the second position of the pull tube 126 is responsive to movement of the shanks 112 and / or 108 (e.g., an open position). Movement of the pull tube 126 engages a jaw link system 300 (FIG. 13) of the end effector 105 at the distal portion 104 of the instrument 100, causing the pair of jaws 114, 116 to move between the open and approximated positions. Jaw link system 300 includes links 302 and 304, similar to jaw link systems for actuating jaws 114, 116 known to those skilled in the art. Bringing shanks 112, 108 together brings jaws 114, 116 together. Releasing shanks 112, 108 opens jaws 114, 116. Thus, both jaws 114, 116 move in response to movement of shanks 112, 108 as shown in the embodiment disclosed herein. In another embodiment, one of the jaws (112 or 108) moves relative to the other jaw (not shown).

[0047] 9-12 are detailed exploded perspective views of instrument 100 in accordance with an embodiment of the present invention. End effector 105 of instrument 100 includes a cutting mechanism or knife 152 slidably disposed between jaws 114, 116. In some embodiments, at least a portion of knife 152 is disposed within and translatable relative to elongate shaft 118. Knife 152 is translatable between a first position (e.g., a distal or proximally retracted position away from the jaws, as shown in FIGS. 9-10 and 14 ) and a second position (e.g., a distally activated position between the jaws, not shown). Knife 152 moves to the second position in response to a user's actuation of either knife actuator 146, 148. Knife actuators 146, 148 are configured to move knife 152 distally to the second position in response to proximal movement of knife actuators 146, 148. The second position (e.g., the active distal position) of the knife 152 is configured to cut, incise, and / or separate tissue 200 grasped, held, and / or restrained between the jaws 114, 116. The instrument 100 may further include a biasing mechanism, such as a knife spring 154, for biasing the knife 152 toward the first position (e.g., in a retracted or proximal direction). The knife tube 150 may be coupled to or formed integrally with the knife 152. The knife tube allows the knife 152 to be moved by the knife actuators 146, 148. The knife tube 150 is configured to allow the knife 152 to be moved regardless of the rotation and / or orientation of the proximal end 102 of the instrument 100 relative to the housing 160, or vice versa.

[0048] In some embodiments, the pair of jaws 114, 116 are configured to incise tissue disposed between the pair of jaws in response to opening movement of the first shank 112 and the second shank 108 (not shown).

[0049] The end effector 105 of the instrument 100 includes a first electrode 136 disposed in the first jaw 114 and a second electrode 138 disposed in the second jaw 116 (FIGS. 6 and 9-11). The instrument 100 further includes a first electrode actuator 132 (FIGS. 4 and 12) and a second electrode actuator 134 (FIG. 5). The first and second electrodes 136, 138 are configured to deliver sealing energy to tissue 200 grasped, held, and / or restrained between the jaws 114, 116 (FIG. 13) in response to movement (e.g., proximally) of either of the electrode actuators 132, 134. The electrode actuators 132, 134 can be or include a switch 130 (FIG. 12) for electrically activating the electrodes 136, 138. Those skilled in the art will appreciate that electrical leads 320 connect the electrodes 136, 138 to a power source 350, such as a generator (FIG. 3). The generator is described in commonly owned U.S. Patent No. 10,342,599, issued July 9, 2019, which is incorporated by reference in its entirety. Those skilled in the art will recognize that the sealing system can further include features disclosed in commonly owned U.S. Patent No. 9,144,455, issued September 29, 2015, which is incorporated by reference in its entirety. The teachings of commonly owned U.S. Patent No. 10,765,471, issued September 8, 2020, are also incorporated by reference in their entirety.

[0050] The sealing system can be configured as a low-power sealing system having a maximum power of 60 watts and 2.5 amps to seal tissue placed, grasped, held and / or restrained between the jaws 114, 116, and can be configured to seal tissue in one second or less.

[0051] In some embodiments, the knife actuators 146, 148 are positioned proximal to the electrode actuators 132, 134 to improve instrument stability due to the position of the user's hands during patient treatment. In some embodiments, the knife actuators 146, 148 are coupled to the knife trigger yoke 144 and / or the knife tube 150 to move the knife 152 (FIG. 9).

[0052] In some embodiments, the electrode actuators 132, 134 are positioned along and laterally offset from an axis defined by the elongated shaft 118 (e.g., the X-axis in FIG. 4 ). Positioning the electrode actuators 132, 134 in a plane intersecting this axis minimizes movement of the distal portion 104 of the instrument 100 during a surgical procedure, improving instrument stability. For example, as shown in the coordinate system illustrated in FIG. 4 , the electrode actuator 132 is configured to move parallel to the longitudinal X-axis defined by the elongated shaft 118, increasing the stability of the instrument 100 during use. Positioning the electrode actuators 132, 134 adjacent to the X-axis of the instrument 100 ( FIG. 4 ) is achieved by using the seven-bar linkage system 120 ( FIGS. 6-8 ) described above. The linkage system 120 is configured to provide adequate room or space in the center of the housing 160, such as for positioning the electrode actuators 132, 134 ( FIG. 12 ). In prior art devices, the electrode actuators are actuated by applying pressure substantially offset from the X-axis of the device and / or perpendicular to the device shaft, resulting in undesirable movement of the distal end of the device when the electrodes are actuated by the user. Undesirable movement (e.g., wiggling) of the distal end of prior art devices near fragile body parts (e.g., thin aortic walls, intestinal tract, etc.) can cause unintended obstructions, tears, and damage to these sensitive areas. Therefore, link system 120 allows for favorable placement of electrode actuators 132, 134 in device 100, providing relatively greater stability (e.g., jaw stability) of device 100 during use when electrode actuators 132, 134 are actuated by the user. Furthermore, the location of electrode actuators 132, 134 (e.g., symmetrically positioned about the X-axis of device 100) is ergonomically suitable for right-handed and left-handed users.

[0053] In the disclosed embodiment, the instrument 100 does not have a jaw closure lock. Those skilled in the art will appreciate that a jaw closure lock may include a ratchet or other type of aperture that maintains the jaws in a closed or approximated position after the user closes and releases the handles. Often, to unlock the jaw closure lock, the user must perform a separate operation of the instrument, such as "clicking" the handles to unlock the jaw closure lock. The omission of the jaw closure lock in the disclosed embodiment reduces the amount of unintended movement of the instrument 100 during a procedure. The omission of the jaw closure lock in this design also allows for rapid and repeated cutting, grasping, sealing, and dividing of tissue without changing tools and / or inducing unintended movement of the instrument 100 and / or tissue.

[0054] In another embodiment, link system 120 can be configured to include a jaw-closed lock in an approximated position. For example, when pivot points 410, 430, and 450 are collinear with one another, pivot points 420, 440, and 460 are collinear with one another (not shown). Thus, instrument 100 (e.g., first and second floating links 430 and 440) can be configured to lock the jaws closed and / or in an approximated position when first shank 112 and first lever link 124 form an angle of approximately 180 degrees therebetween.

[0055] In the disclosed embodiment, the link system 120 (in combination with the increasing force of the load-limiting spring 158 as the jaws 114, 116 approach their approximated position) is configured to reduce the user's force required to hold the shanks 112, 108 (and thus the jaws 114, 116) in the approximated position. That is, the force experienced by the gripping mechanism 162 decreases at the end of the approximation movement, eliminating the need for a jaw closure lock, improving user control and feedback and reducing user fatigue (by reducing the force required to hold the jaws closed during tissue sealing). The link system 120 is configured to reduce the pushback experienced by the user's hand when the jaws 114, 116 are in the approximated position compared to the pushback experienced by the user's hand just prior to reaching the approximated position. This reduction in pushback experienced by the user's hand is made possible by the seven-bar design of the link system 120, as described above. The seven-bar linkage system 120 is configured to provide a mechanical advantage when the device 100 reaches the approximated position, so that the compressive force applied by the user to the finger clips 106, 110 is less than the force required to reach the approximated position, minimizing fatigue on the user's hand when in the approximated position.

[0056] To improve user feedback, such as to indicate that the jaws 114, 116 are in an approximated position, audible and / or tactile feedback can be provided, such as a click board 174 (FIG. 12). The click board 174 is configured to produce an audible click to indicate that the jaws 114, 116 are in an approximated position or closed.

[0057] It should be appreciated that the approximated position of the jaws 114, 116 can be variable. For example, when tissue 200 is placed, grasped, held, and / or restrained between the jaws 114, 116, the tissue 200 prevents the jaws 114, 116 from contacting each other, but the jaws 114, 116 are placed in an approximated or closed position (FIGS. 13 and 14). Further examples are when a) no tissue 200 is placed between the jaws 114, 116, or b) very thin tissue 200 is placed between the jaws 114, 116 and the jaws 114, 116 are placed in a closed or approximated position (not shown). The jaws 114, 116 include one or more non-conductive stop members 115 that prevent direct contact between the faces of the jaws 114, 116, avoiding short-outs in a manner known to those skilled in the art, but the jaws 114, 116 are placed in a closed or approximated position as shown in FIG. 14.

[0058] In some embodiments, the instrument 100 can be configured to apply pressure to tissue grasped, held, and / or restrained between the jaws 114, 116 when the jaws 114, 116 are in the approximated position. In some embodiments, the pressure is between about 100 pounds per square inch (about 689 kilopascals) and about 120 pounds per square inch (about 827 kilopascals). In some embodiments, the pressure is between about 50 pounds per square inch (about 345 kilopascals) and about 180 pounds per square inch (about 1241 kilopascals).

[0059] 15A-15E are schematic diagrams of jaw movement between currently available prior art instruments and the instrument 100 according to an embodiment of the present invention. FIG. 15A is a schematic diagram of the handle opening angle θ of the prior art hemostat-type sealer-divider of FIG. 1. For the instrument of FIG. 1, the jaw opening angle θ' is the same as or substantially the same as the handle opening angle θ. To open the jaws widely, such as to incise tissue, the user must spread the handles very wide, resulting in a distance T between the handles. The 1:1 relationship in opening angles (θ:θ') presents a challenge for users with small hands. Furthermore, visibility is obstructed when working in tight spaces with the instrument of FIG. 1. FIGS. 15B-15C are schematic diagrams of the opening jaw angle of a prior art sealer-divider with a pistol grip (FIG. 2). A user of the instrument of FIG. 2 has more freedom to open the jaws to wider angles (e.g., angle α or angle β) compared to angle θ' of the instrument of FIG. 1. Jaw angles α and β are achieved with smaller pistol grip movements (angles a and b, respectively) of the instrument in Figure 2. However, pistol grips cause instability, especially when used in open surgical procedures. Sealer-dividers with pistol grips typically require a jaw closure lock, which further destabilizes the instrument when unlocked.

[0060] FIG. 15D is a schematic diagram of the open jaws of an instrument 100 in accordance with an embodiment of the present invention. The instrument 100 addresses the aforementioned problems of prior art instruments. As shown in FIG. 15D, the jaws of the schematic instrument 100 open to a wide angle α, comparable to the angle α of a pistol-grip instrument (FIG. 15D), but the distance A between the handles is much smaller than the distance T of a hemostat-type instrument (FIG. 15A). In other words, the distance A between the handles of the instrument 100 is significantly smaller than the distance T between the handles of a hemostat-type instrument when the jaw opening angle α of the instrument 100 is equal to the jaw opening angle θ of the hemostat-type instrument. Thus, the instrument 100 disclosed herein provides greater stability than a hemostat-type instrument, better visibility, and greater jaw opening than a pistol-grip instrument. FIG. 15E is a comparison between the handle distance or distal grip angle and the respective jaw opening angles of FIGS. 15A-15D.

[0061] 16 illustrates a method 1100 of using a sealer-divider-dissector in accordance with an embodiment of the present invention. The instrument 100 is configured for use in the manner, operations, and / or steps described by the method 1100. The method 1100 can include engaging 1104 a first finger grip with the thumb of a user's first hand. The method 1100 can include engaging 1106 a second finger grip with a middle finger, ring finger, or pinky finger of the user's first hand.

[0062] Optionally, method 1100 can include manipulating 1108 the first shank and the second shank. Manipulating 1108 can include using a user's thumb to manipulate the first shank and at least one of the user's middle finger, ring finger, or little finger of the same hand to manipulate the second shank to move the pair of jaws between an open position and a closed or approximated position. Manipulating 1108 the first and second shanks can include using the user's thumb and at least one of the user's ring finger or little finger of a first hand to apply an opening motion to the first shank and the second shank to move the pair of jaws toward the open position, and using the user's thumb and at least one of the user's ring finger or little finger of the first hand to apply a approximation motion to the first shank and the second shank to move the pair of jaws toward the approximated position.

[0063] Optionally, the method 1100 can include using at least one of the index finger, middle finger, or ring finger of the user's first hand to move 1110 (e.g., proximally) the electrode actuator to activate the first and second electrodes.

[0064] Optionally, the method 1100 can include using at least one of the index finger or middle finger of the user's first hand to move 1112 the knife actuator (e.g., proximally) to move the knife distally.

[0065] Further, the method 1100 may include using the middle finger of the user's first hand to move the electrode actuator parallel to (e.g., proximally) the axis defined by the elongate shaft 118 and using the index finger of the user's first hand to move (e.g., proximally) the knife actuator.

[0066] Additionally, the method 1100 can include disengaging a load limiting spring when the pair of jaws approaches an open position and engaging the load limiting spring when the pair of jaws is in a closed or approximated position.

[0067] Additionally, the method 1100 can include moving the pair of jaws between the open position and the closed or approximated position multiple times without engaging the jaw closure lock.

[0068] While specific embodiments have been shown and described, those skilled in the art should understand that no limitations on the invention are intended, and it will be apparent to those skilled in the art that various changes, substitutions, and modifications (e.g., different part sizes, combinations of parts) can be made without departing from the scope of the invention. The scope of the invention is defined by the following claims and their equivalents. The specification and drawings are therefore to be regarded as illustrative rather than restrictive. The various embodiments shown and described herein are intended to cover alternatives, modifications, and equivalents of the disclosed invention, which may be included within the scope of the claims. The present disclosure also includes the following aspects. [Aspect 1] A surgical instrument (100) comprising: a distal portion (104) having a pair of jaws (114, 116) configured to move between an open position and an approximated position to manipulate tissue (200) disposed therebetween; a proximal portion (102) having a housing (160) and a hemostat-type gripping mechanism (162), the hemostat-type gripping mechanism including a first finger grip (110) and a second finger grip (106); an elongated shaft (118) positioned between the proximal portion (102) and the distal portion (104), the elongated shaft (118) defining a longitudinal axis; a pull tube (126) at least partially disposed within the elongated shaft (118); Equipped with the hemostat-type gripping mechanism (162) comprises a link system (120) configured to move the pair of jaws (114, 116) between the open position and the approximated position, the link system (120) comprising: a first shank (112) having a distal end rotatably coupled to the housing (160) at a first fixed pivot point (410) and a proximal end coupled to the first finger grip (110); a second shank (108) having a distal end rotatably coupled to the housing (160) at a second fixed pivot point (420) and a proximal end coupled to the second finger grip (106); and slider links (5, 156) operatively coupled to the first shank (112) and the second shank (108); the pull tube (126) has a proximal end (126a) coupled to the slider link (5, 156) and a distal end (126b) coupled to the pair of jaws (114, 116), and the pull tube (126) is configured to move between a first position and a second position proximal to the first position in response to operation of the first shank (112) and / or the second shank (108), thereby moving the pair of jaws (114, 116) between the open position and the approximated position; Surgical equipment (100). [Aspect 2] The link system (120) is a seven-bar link system including a first shank (2, 112), a second shank (7, 108), a housing (160), and a slider link (5, 156), and the link system (120) further includes a first lever link (3, 124) rotatably coupled to the first shank (112) at each of a first floating pivot point (430) and the slider link (5, 156), and a second floating pivot point (440). and a second lever link (6, 122) rotatably coupled to the second shank (7, 108) at the slider link (5, 156); and a slide track link (4, 160, 171, 173) fixed to or defined by the housing (160) and configured to limit the slider link (5, 156) to longitudinal movement relative to the housing (160). Aspect 3 A surgical instrument (100) as described in aspect 2, wherein the first and second shanks (112, 108), the first and second lever links (124, 122), and the first and second floating links (430, 440) are collectively configured to vary mechanical advantage between the open position and the approximated position. Aspect 4 A surgical instrument (100) as described in aspect 3, wherein when the first and second shanks (112, 108) move from the open position to the approximated position during a stroke, the pair of jaws (114, 116) have a greater stroke distance in the first half of the stroke than in the second half of the stroke. Aspect 5 A surgical instrument (100) as described in aspect 3, wherein the compressive force required to move the first and second finger grips (110, 106) closer together decreases as the pair of jaws (114, 116) approach the approximated position. Aspect 6 A surgical instrument (100) according to any of aspects 2 to 5, wherein the first and second floating pivot points (430, 440) are configured to move outward from the longitudinal axis defined by the elongated shaft (118) when the pull tube (126) moves distally. Aspect 7 A surgical instrument (100) according to any of aspects 2 to 5, wherein the first and second floating pivot points (430 and 440) are configured to move inward from the longitudinal axis defined by the elongated shaft (118) when the pull tube (126) moves proximally. Aspect 8 A surgical instrument (100) according to any of aspects 2 to 6, wherein the first and second floating pivot points (430 and 440) are configured to lock the pair of jaws (114, 116) in the approximated position when the first shank (112) and the first lever link (124) form an angle of approximately 180 degrees therebetween. Aspect 9 A surgical instrument (100) according to any one of aspects 1 to 8, wherein the slider link (5) comprises a spring housing (156) that houses a load limiting spring (158), and the load limiting spring (158) is configured to limit the pulling force on the pull tube (126) when the pair of jaws (114, 116) are in the approximated position. Aspect 10 A surgical instrument (100) according to aspect 9, wherein the load limiting spring (158) is configured to disengage from the pull tube (126) when the pair of jaws (114, 116) move from the approximated position to the open position. Aspect 11 The surgical instrument (100) of any one of aspects 1-7 or 9-10, wherein the link system (120) is configured to prevent the pair of jaws (114, 116) from locking when in the approximated position. Aspect 12 A surgical instrument (100) according to any one of aspects 1 to 11, further comprising a tissue sealing system having an electrode actuator (132 or 134), a first electrode (136) disposed in a first jaw (114) of the pair of jaws, and a second electrode (138) disposed in a second jaw (116) of the pair of jaws (114, 116), wherein the first and second electrodes (136, 138) are configured to seal the tissue disposed between the pair of jaws (114, 116) in response to proximal movement of either one of the electrode actuators (132, 134), and the electrode actuator (132 or 134) moves in response to a force applied to either one of the electrode actuators (132 or 134) in a direction parallel to the longitudinal axis defined by the elongated shaft (118). Aspect 13 13. The surgical instrument of claim 12, wherein the electrode actuators are disposed along and laterally offset from the longitudinal axis defined by the elongated shaft. Aspect 14 The surgical instrument (100) of any of aspects 1-2 and 6-13, wherein the link system (120) is configured to vary the mechanical advantage between the open position and the approximated position. Aspect 15 A surgical instrument (100) as described in aspect 14, wherein when the first and second shanks (112, 108) of the link system (120) move from the open position to the approximated position during a stroke, the pair of jaws (114, 116) have a greater distance traveled in the first half of the stroke than in the second half of the stroke. Aspect 16 16. The surgical instrument of claim 15, wherein the mechanical advantage decreases throughout the stroke. Aspect 17 A surgical instrument (100) according to aspect 14, wherein the compressive force required to move the first and second finger grips (110, 106) decreases as the pair of jaws (114, 116) approach the approximated position. Aspect 18 A surgical instrument (100) configured to process tissue (200), said surgical instrument (100) comprising: a handle (162) operably coupled to an end effector (105) by a linkage system (120) and an elongated shaft (118), said handle (162) comprising a first shank (112) and a second shank (108), said end effector (105) comprising opposing jaws (114, 116) selectively movable between an open position and an approximated position when said handle (162) is actuated; Equipped with the linkage system (120) is configured such that a stroke of the handle (162) moves the first and second shanks (112, 108) closer together, thereby moving the opposing jaws (114, 116) to an approximated position to engage tissue (200) disposed therebetween, and a mechanical advantage is varied during the stroke, such that the opposing jaws (114, 116) have a greater travel distance in a first half of the stroke than in a second half of the stroke; Surgical equipment (100). Aspect 19 A surgical instrument (100) as described in aspect 18, wherein the link system (120) is configured such that movement of the first and second shanks (112, 108) causes the first shank (112) to rotate about a first fixed pivot (410) of the link system (120) and the second shank (108) to rotate about a second fixed pivot (420) of the link system (120). Aspect 20 Aspect 20. The surgical instrument (100) of aspect 19, wherein the first and second fixed pivots (410, 420) are offset laterally from a longitudinal axis defined by the elongated shaft (118). Aspect 21 A surgical instrument (100) as described in aspect 18, further comprising one or more electrode actuators (132, 134), each having a contact surface for a user's finger, at least one of the electrode actuators (132, 134) being positioned along the longitudinal axis defined by the elongated shaft (118) and offset laterally therefrom. Aspect 22 A surgical instrument (100) according to aspect 20 or 21, wherein the at least one contact surface of the actuator (132, 134) is radially offset from the longitudinal axis by a first distance, and the fixed pivot point (410, 420) is radially offset from the longitudinal axis by a second distance greater than the first distance. Aspect 23 The surgical instrument (100) of aspect 2 further comprises a protrusion coupled to the slider link (5, 156), at least a portion of the protrusion being slidably disposed within a guide member (480), and the protrusion and the guide member (480) being configured to prevent rotation of the slider link (5, 156). Aspect 24 A method of operating a surgical instrument (100) for treating tissue (200), the surgical instrument (100) comprising a handle (162) operably coupled to an end effector (105) by a linkage system (120) and an elongated shaft, the handle (162) comprising a first shank (112) and a second shank (108), the end effector (105) comprising opposing jaws (114, 116) selectively movable between an open position and an approximated position using the handle (162); The method further comprises: moving the first and second shanks (112, 108) toward each other, thereby moving the opposing jaws (114, 116) to an approximated position to engage tissue (200) disposed therebetween, and varying a mechanical advantage as the opposing jaws (114, 116) move toward the approximated position; method. Aspect 25 25. The method of claim 24, wherein moving the first shank (112) and the second shank (108) comprises rotating the first shank (112) around a first fixed pivot (410) and rotating the second shank (108) around a second fixed pivot (420). Aspect 26 26. The method of embodiment 25, wherein the first fixed pivot (410) and the second fixed pivot (420) are laterally offset from a longitudinal axis defined by the elongated shaft (118). Aspect 27 The surgical instrument (100) further comprises a load-limiting spring (158), and the method further comprises: engaging the load limiting spring (158) when the pair of jaws (114, 116) are in the approximated position; disengaging the load limiting spring (158) when the pair of jaws (114, 116) approach the open position; Including, 25. The method of embodiment 24. Aspect 28 25. The method of claim 24, further comprising moving the pair of jaws (114, 116) between the open position and the approximated position without locking the pair of jaws (114, 116) in the approximated position. Aspect 29 A method of operating an instrument (100) having a hemostat-type gripping mechanism (162) mechanically coupled to a pair of jaws (114, 116) for opening and closing the pair of jaws (114, 116), the pair of jaws (114, 116) including electrodes (136, 138) electrically coupled to an actuator (132 or 134) disposed in a proximal portion of the instrument (100) and configured to selectively activate the electrodes (136, 138); The method further comprises: actuating the electrodes (136, 138) by applying a compressive force to the actuator (132 or 134) in a direction parallel to the longitudinal axis of the instrument (100); A method comprising: Aspect 30 the actuator (132 or 134) has an outer surface that is radially offset from the longitudinal axis by a predetermined distance, and the method further comprises: rotating the first shank (2, 112) and the second shank (7, 108) about their respective pivot points (410, 420, 430, 440); the pivot point (410, 420, 430, 440) is radially offset from the longitudinal axis by a first distance, and the outer surface of the actuator (132 or 134) is radially offset from the longitudinal axis by a second distance, the second distance being greater than the first distance; 30. The method of embodiment 29.

Claims

1. 1. A surgical instrument comprising: a distal portion having a pair of jaws configured to move between an open position and an approximated position to manipulate tissue disposed therebetween; a proximal portion having a housing and a hemostat-type gripping mechanism, the hemostat-type gripping mechanism including a first finger grip and a second finger grip; an elongated shaft positioned between the proximal portion and the distal portion, the elongated shaft defining a longitudinal axis; a pull tube disposed at least partially within the elongated shaft; Equipped with the hemostat-type gripping mechanism includes a linkage system configured to move the pair of jaws between the open position and the approximated position, the linkage system including: a first shank having a distal end rotatably coupled to the housing at a first fixed pivot point and a proximal end coupled to the first finger grip; a second shank having a distal end rotatably coupled to the housing at a second fixed pivot point and a proximal end coupled to the second finger grip; and a slider link operatively coupled to the first shank and the second shank; the pull tube has a proximal end coupled to the slider link and a distal end coupled to the pair of jaws, the pull tube being configured to move between a first position and a second position proximal to the first position in response to manipulation of the first shank and / or the second shank, thereby moving the pair of jaws between the open position and the approximated position; The link system is a seven-bar link system including a first shank, a second shank, a housing, and a slider link, and the link system further includes: a first lever link rotatably coupled to the first shank at a first floating pivot point and to each of the slider links; a second lever link rotatably coupled to the second shank at a second floating pivot point and the slider link; a slide track link secured to or defined by the housing and configured to restrict the slider link to longitudinal movement relative to the housing; the first and second shanks, the first and second lever links, and the first and second floating pivot points are collectively configured to vary a mechanical advantage between the open position and the close position; a compressive force required to move the first and second finger grips closer together decreases as the pair of jaws approaches the approximated position; further comprising a protrusion coupled to the slider link, at least a portion of the protrusion being slidably disposed within a guide member, the guide member being fixed to the housing, the protrusion and the guide member being configured to prevent rotation of the slider link. Surgical equipment.

2. 2. The surgical instrument of claim 1, wherein as the first and second shanks move from the open position to the approximated position during a stroke, the pair of jaws have a greater distance traveled in a first half of the stroke than in a second half of the stroke.

3. The surgical instrument of claim 1 , wherein the first and second floating pivot points are configured to move outward from the longitudinal axis defined by the elongate shaft when the pull tube is moved distally.

4. The surgical instrument of claim 1 , wherein the first and second floating pivot points are configured to move inwardly from the longitudinal axis defined by the elongate shaft when the pull tube moves proximally.

5. 2. The surgical instrument of claim 1, wherein the first and second floating pivot points are configured to lock the pair of jaws in the approximated position when the first shank and the first lever link form an angle of approximately 180 degrees therebetween.

6. The surgical instrument of claim 1, wherein the slider link includes a spring housing that houses a load limiting spring, the load limiting spring configured to limit a pulling force on the pull tube when the pair of jaws are in the approximated position.

7. The surgical instrument of claim 6, wherein the load limiting spring is configured to disengage the pull tube when the pair of jaws transition from the approximated position to the open position.

8. The surgical instrument of claim 1 , wherein the linkage system is configured to prevent locking of the pair of jaws when in the approximated position.

9. 10. The surgical instrument of claim 1, further comprising a tissue sealing system having an electrode actuator, a first electrode disposed in a first of the pair of jaws, and a second electrode disposed in a second of the pair of jaws, the first and second electrodes configured to seal the tissue disposed between the pair of jaws in response to proximal movement of either of the electrode actuators, the electrode actuator moving in response to a force applied to either of the electrode actuators in a direction parallel to the longitudinal axis defined by the elongate shaft.

10. The surgical instrument of claim 9, wherein the electrode actuator is disposed along and laterally offset from the longitudinal axis defined by the elongate shaft.

11. The surgical instrument of claim 1 , wherein the link system is configured to vary the mechanical advantage between the open position and the approximated position.

12. 12. The surgical instrument of claim 11, wherein as the first and second shanks of the linkage system move from the open position to the approximated position during a stroke, the pair of jaws have a greater distance traveled in a first half of the stroke than in a second half of the stroke.

13. The surgical instrument of claim 12, wherein the mechanical advantage decreases throughout the stroke.

14. The surgical instrument of claim 11, wherein the compressive force required to move the first and second finger grips decreases as the pair of jaws approach the approximated position.

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