Electrosurgical sealer and divider

Abstract

To provide an electrosurgical instrument that reliably cuts and seals tissue.SOLUTION: The electrosurgical instrument includes: a movable tissue cutting mechanism; and a pair of opposing jaws that are shaped and configured to move between a closed position for clamping and sealing tissue held therebetween and an open position. The first jaw comprises an exposed tissue sealing surface which has a primary sealing surface and at least one protrusion extending from the primary sealing surface for concentrating a sealing current through the at least one protrusion. The second jaw comprises an exposed tissue sealing surface which has a primary sealing surface and at least one recess in the primary sealing surface for concentrating a sealing current through the at least one recess. The protrusion and the recess oppose each other when the pair of opposing jaws are in the closed position. Each one of the pair of opposing jaws comprises an elongated slot for receiving a portion of the cutting mechanism. A related method is also disclosed.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. patent application Ser. No. 15 / 487,856, entitled "Electrosurgical Sealer and Divider," filed April 14, 2017. This U.S. patent application claims priority to U.S. provisional patent application Ser. No. 62 / 323,030, entitled "Electrosurgical Sealer and Divider," filed April 15, 2016. The entire disclosures of the patent applications cited herein are incorporated by reference for all appropriate purposes.

[0002] The present invention relates to medical devices, and in particular, although not intended to be limiting, embodiments of the present invention relate to electrosurgical instruments for cutting and sealing tissue. [Background technology]

[0003] Many electrosurgical devices for cutting and sealing tissue are known in the art.

[0004] For example, currently available devices include the LigaSure (Ligasure is a trademarked brand of Medtronic) product line, which includes a combination sealer and divider. This tool includes a pair of jaws with a substantially planar interface. That is, as shown in FIG. 1, the end effectors have respective sealing surfaces that are substantially flat or in a horizontal plane and a substantially linear cutting path. The LigaSure tool also includes a non-conductive travel stop to prevent the tool from completely closing. LigaSure tools are known to apply a cyclic force of 180 watts to 300 watts of sealing power to the tissue to seal it, which facilitates tacking the tissue between the end effectors during use.

[0005] Known devices, such as the LigaSure tool, also have electrode surfaces with large tissue sealing surfaces. Known devices include those described in U.S. Patent Nos. 5,629,999, 5,729,965, 5,733,925, and 5,823,232. However, there remains a need for devices that provide the ability to reliably cut and seal tissue without compromising non-target tissue and / or other new and innovative features.

[0006] [Prior art documents] [Patent Documents] [Patent Document 1] Special Publication No. 2011-504794 [Patent Document 2] Special Publication No. 2004-524122 [Patent Document 3] International Publication No. 2015 / 81042 Summary of the Invention

[0007] An exemplary electrosurgical instrument includes a movable tissue cutting mechanism and a pair of opposing jaws having a first jaw and a second jaw. The pair of opposing jaws are shaped and configured to move between a closed position and an open position to clamp and seal tissue held therebetween. The first jaw has an exposed tissue sealing surface. The exposed tissue sealing surface has a primary sealing surface and at least one protrusion extending from the primary sealing surface to concentrate a sealing current therethrough. The second jaw has an exposed tissue sealing surface having a primary sealing surface and at least one recess in the primary sealing surface to concentrate a sealing current therethrough. The at least one protrusion and the at least one recess oppose each other when the pair of opposing jaws is in the closed position. Each of the pair of opposing jaws has an elongated slot that receives a portion of a cutting mechanism, the cutting mechanism configured to move between a proximal position and a distal position to cut tissue held therebetween.

[0008] An exemplary method of making an electrosurgical instrument includes providing a movable tissue cutting mechanism and providing a pair of jaws having a first jaw and a second jaw. Each jaw has an elongated slot that receives the movable tissue cutting mechanism. The first jaw has an exposed tissue sealing surface having a major sealing surface and at least one protrusion extending from the major sealing surface, the protrusion concentrating a sealing current through the at least one protrusion. The second jaw has an exposed tissue sealing surface having a major sealing surface and at least one recess in the major sealing surface, the recess concentrating a sealing current through the at least one recess. The exemplary method further includes molding the pair of opposing jaws such that the at least one protrusion and the at least one recess oppose each other when the pair of opposing jaws are in a closed position. The exemplary method further includes coupling the pair of jaws such that the pair of jaws are movable between a closed position and an open position for clamping tissue therebetween. [Brief explanation of the drawings]

[0009] Various objects and advantages of the present invention, as well as a more complete understanding thereof, will become apparent and will be more readily appreciated by reference to the following detailed description and appended claims in conjunction with the accompanying drawings, in which like or similar elements are designated by the same reference numerals throughout the several views, in which: [Figure 1] 1 is a perspective view of a prior art device; [Figure 2] FIG. 2 is a side view of a distal portion of a surgical instrument. [Figure 3] FIG. 3 is a cross-sectional view of the device of FIG. 2. [Figure 4] FIG. 3 is another cross-sectional view of the device of FIG. 2; [Figure 5] FIG. 3 is an end view of the device of FIG. 2. [Figure 6] FIG. 3 is a perspective view of the lower jaw and other features of the device of FIG. 2; [Figure 7] FIG. 3 is a perspective view of the upper jaw and other features of the device of FIG. 2. [Figure 8] FIG. 3 is a bottom perspective view of the device of FIG. 2 in an open configuration. [Figure 9] FIG. 3 is a bottom perspective view of the device of FIG. 2 in a closed configuration. [Figure 9A] FIG. 10 is a bottom perspective view of the device of FIG. 9 with modified features. [Figure 10] FIG. 3 is a side view of the device of FIG. 2 in a closed position. [Figure 11] FIG. 3 is a schematic diagram showing details of the apparatus of FIG. 2. [Figure 12] FIG. 1 is a perspective, partially transparent view of an exemplary device. [Figure 13A] FIG. 1 is a top partial perspective view of an exemplary device. [Figure 13B] FIG. 1 is a cross-sectional side view of an exemplary device. [Figure 14] FIG. 1 is a perspective view of an overmold suitable for an exemplary device. [Figure 15] 1 is a flowchart of an exemplary method. [Figure 16] FIG. 1 is a side view of an exemplary instrument. [Figure 17] FIG. 17 is a distal end view of the device of FIG. 16. [Figure 18] FIG. 17 is a cross-sectional end view of the device of FIG. 16. [Figure 19] FIG. 17 is a cross-sectional end view of the device of FIG. 16. [Figure 20] FIG. 1 is a perspective view of an exemplary instrument. [Figure 21] FIG. 1 is an exploded perspective view of the jaws of an exemplary instrument. [Figure 22] FIG. 22 is a perspective view of the jaw portion of FIG. 21 . [Figure 23] FIG. 1 is a perspective view of the jaws of an exemplary instrument. [Figure 24] FIG. 24 is a side view of the jaw of FIG. 23; [Figure 25] 1 is a perspective view of an exemplary surgical instrument. [Figure 25A] FIG. 26 is a perspective view of a detail of the device of FIG. 25; [Figure 26] FIG. 26 is another perspective view of the device of FIG. 25. [Figure 27] 1 is a flowchart of an exemplary method. [Figure 28] Table 1 is a table of test results using an exemplary device. DETAILED DESCRIPTION OF THE INVENTION

[0010] As previously alluded to in the background of this specification and as shown in FIG. 1, known prior art devices such as the LigaSure include sophisticated tissue sealing and cutting devices. Such high-power devices, and similar high-power devices such as those described in U.S. Patent No. 6,033,399 to Gines, apply 100 watts or more of power to the tissue to create a seal. The LigaSure tool is known to apply 180 watts or more to the tissue to create a seal. Such high-power applications result in a phenomenon known as lateral thermal spread, which is the spread of energy, heat, and charring to nearby and unintended tissue. This means that high-power devices do not qualify for certain regulatory safety evaluations.

[0011] To meet the need for devices that qualify for such regulatory safety evaluations, applicants have generally determined that low-power devices having specific parameters can be utilized to reliably and safely seal tissue. Such teachings are disclosed in commonly owned U.S. Patent No. 9,265,561 to Kennedy et al. (the '561 patent), which discloses a system and method for sealing tissue with low power. The entire contents of the '561 patent are incorporated herein by reference in their entirety as if fully set forth herein.

[0012] In a related patent, commonly owned U.S. Patent No. 9,039,694 to Ross et al. (the '694 patent) discloses a system and method for powering an electrosurgical instrument. The entire contents of the '694 patent are incorporated herein by reference in their entirety as if fully set forth herein.

[0013] The teachings of the following U.S. patents are incorporated herein by reference for any appropriate purposes: U.S. Patent No. 5,876,401 to Schulze, U.S. Patent No. 6,174,309 to Wrublewski, U.S. Patent No. 6,458,128 to Schulze, U.S. Patent No. 6,682,528 to Frazier, U.S. Patent No. 7,083,618 to Couture, U.S. Patent No. 7,101,373 to Dycus, U.S. Patent No. 7,156,846 to Dycus, U.S. Patent No. 7,101,371 to Dycus, U.S. Patent No. 7,255,697 to Dycus, Dumbauld U.S. Patent No. 7,722,607, Dycus U.S. Patent No. 8,540,711, Dycus U.S. Patent No. 7,131,971, Latterell U.S. Patent No. 7,204,835, Treat U.S. Patent No. 7,211,080, Dycus U.S. Patent No. 7,473,253, Odom U.S. Patent No. 7,491,202, Dycus U.S. Patent No. 7,857,812, Dycus U.S. Patent No. 8,241,284, Bucciag U.S. Patent No. 8,246,618 to Bucciaglia, U.S. Patent No. 8,361,072 to Dumbauld, U.S. Patent No. 8,469,956 to McKenna, U.S. Patent No. 8,523,898 to Bucciaglia, U.S. Patent No. 8,579,894 to Falkenstein, U.S. Patent No. 8,968,311 to Allen, U.S. Patent No. 9,011,437 to Woodruff, U.S. Patent No. 9,028,495 to Mueller, U.S. Patent No. 9,113, No. 901, U.S. Patent No. 5,800,440 to Wales, U.S. Patent No. 5,462,546 to Rydell, U.S. Patent No. 5,445,638 to Rydell, U.S. Patent No. 5,697,949 to Giurtino, U.S. Patent No. 5,797,938 to Parashak, U.S. Patent No. 6,334,860 to Dorn, U.S. Patent No. 6,458,130 to Frazier, U.S. Patent No. 6,113,598 to Baker, and U.S. Patent No. 6,033,399 to Gines.

[0014] The teachings of the following US patents are incorporated herein by reference for any appropriate purposes: U.S. Patent Application Publication No. 2014 / 0031819A1 to Dycus, U.S. Patent Application Publication No. 2015 / 0250531A1 to Dycus, U.S. Patent Application Publication No. 2015 / 0133930 to Allen, U.S. Patent Application Publication No. 2013 / 0131651 to Strobl, U.S. Patent Application Publication No. 2014 / 0257285 to Moua, U.S. Patent Application Publication No. 2007 / 0173813 to Odom, U.S. Patent Application Publication No. 2009 / 0076506 to Baker, U.S. Patent Application Publication No. 2005 / 0010212 to McClurken, U.S. Patent Application Publication No. 2007 / 0173804 to Wham, and U.S. Patent Application Publication No. 2007 / 0156140 to Baily.

[0015] The teachings of Eggers, European Patent Application Publication No. EP 0 986 990 A1, are incorporated herein by reference for any appropriate purposes.

[0016] Applicant has developed a device that can safely seal and cut tissue that not only functions reliably at low power outputs, but also occupies a significantly smaller area of ​​affected tissue, meaning that Applicant's device is not prone to stray burns to tissue near the surgical site, thereby providing a tool that qualifies for certain regulatory safety assessments.

[0017] Turning now to FIG. 2, FIG. 2 illustrates an apparatus 100 for a surgical instrument for cutting and sealing tissue. The apparatus 100, which may be referred to as an end effector, includes an upper jaw 102, a lower jaw 104, a cutting mechanism 106 (see FIG. 8), a linkage 108 that enables operation of the jaws 102, 104, and an electrosurgical control mechanism 110. In some embodiments, the apparatus 100 may be configured to apply bipolar power to tissue clamped between the jaws 102, 104 and may be referred to as a bipolar apparatus 100. Note that for ease of reference, a proximal portion of the apparatus 100 is shown on the left side of FIG. 2 and a distal portion of the apparatus 100 is shown on the right side of FIG. 2.

[0018] The jaws 102, 104 may be curved to the right or left of the X-Y plane formed by the longitudinal axis X and the vertical axis Y to aid in grasping, dissecting, manipulating, and / or retracting tissue. That is, the longitudinal axis X may be formed by a straight line, while the sealing axis W may be curved in two or three dimensions. In the embodiment shown in Figure 2, the sealing axis W is curved in two dimensions. See also Figure 6.

[0019] In some embodiments, the jaws 102, 104 are configured to selectively apply surgical power to seal tissue at various power levels in much the same manner as shown or described in the '561 patent. The jaws 102, 104 may be constructed from other design options, including materials, such as those disclosed in the '561 and / or '694 patents. In the illustrated embodiment, the overmold 160 is shown as transparent, and one skilled in the art will understand that the overmold 160 may include several features for aesthetic purposes and / or electrical isolation.

[0020] In some embodiments, as shown in FIG. 9 , one or both of the jaws 102, 104 includes a non-conductive travel stop 112 at or near the distal portion 126, 130 of at least one of the jaws 102, 104 and a jaw interlock mechanism 136 in a proximal region to prevent the jaws 102, 104 from over-rotating (see FIGS. 2 , 8 , and 9 ). In some embodiments, the jaw interlock mechanism 136 may include a protrusion 138 on the first jaw 102 configured to abut a flange, ridge, or other surface 140 of the second jaw 104. The jaw interlock mechanism 136, in combination with the non-conductive protrusion 112, may prevent the jaws 102, 104 from over-clamping around the tissue therebetween. In some embodiments, as shown most clearly in FIG. 10 , the jaws 102, 104 may be configured to maintain a gap G of about 0.007 inches (about 0.178 mm) to about 0.002 inches (about 0.051 mm) between the major sealing surfaces 142, 143 of the jaws 102, 104 when in a closed position without tissue clamped therebetween. In some embodiments, the jaws 102, 104 may have a tip bias. That is, a distal portion of the jaws 102, 104, such as the travel stop(s) 112, may be configured to contact or otherwise stop movement toward closure when the proximal portion has a gap G of at least 0.005 inches (about 0.127 mm) and / or when the distal portion of the gap G is smaller than the proximal portion of the gap G. A portion of one or both of the jaws 102, 104 between the protrusion(s) 112 and the jaw interlocking mechanism 136 may flex during clamping. Thus, one skilled in the art will appreciate that the gap G is determined prior to applying full clamping force to the tissue, but rather the gap G is calculated or defined at the time of initial contact. In some embodiments, additional travel stops 112 may be provided in different areas to further ensure that the jaws 102, 104 do not touch or short out.

[0021] 9A shows the device of FIG. 9 with variations of jaw interlocking mechanism 136, protrusions 138, and flanges, ridges, or other surfaces 140. Those skilled in the art will recognize that such features will function substantially as shown in FIG.

[0022] In some embodiments, the device is configured to maintain a gap G between major sealing surfaces 142, 143 of between about 0.2 millimeters and about 0.05 millimeters. In some embodiments, gap G is between about 0.16 millimeters and about 0.20 millimeters at the proximal portion. In some embodiments, gap G is between about 0.05 millimeters and about 0.07 millimeters at the distal portion. In some embodiments, gap G is at least 0.07 millimeters. In some embodiments, gap G decreases continuously from the proximal portion to the distal portion.

[0023] In some embodiments, the device is configured to maintain a gap G between major sealing surfaces 142, 143 of between about 0.25 millimeters and about 0.03 millimeters. In some embodiments, gap G is between about 0.16 and about 0.25 millimeters at the proximal portion. In some embodiments, gap G is between about 0.03 millimeters and about 0.07 millimeters at the distal portion.

[0024] 3 and 4, in some embodiments, when one or both of the jaws 102, 104 are in the closed position as shown in Figures 3 and 4, the channels 114, 116 and the jaws 102, 104 form a travel path 118 through which the tissue cutting mechanism 106 or knife can travel to cut tissue after being sealed. The (at least one) channel 114, 116 or the (at least one) elongated slot may be non-linear such that the knife or cutting mechanism travels a non-linear path to cut tissue.

[0025] As shown in FIG. 6 , in some embodiments, the first jaw 102 may have a first sealing surface 120. A major sealing surface 142 of this sealing surface has a generally convex shape. In some embodiments, a portion of the first jaw 102 may have the first sealing surface 120 having a first curvature R1 about a sealing axis W. In some embodiments, the sealing axis W is defined by the path of travel 118 of the cutting mechanism 106. That is, the first curvature R1 may be relative to the path of travel 118. In some embodiments, the first curvature R1 is constant from the proximal portion 124 of the first jaw 102 to the distal portion 126 of the first jaw 102. In some embodiments, the first curvature R1 is larger at the proximal portion 124 of the first jaw 102 than at the distal portion 126 of the first jaw 102. In some embodiments, the first curvature R1 is defined by a circle with a radius R1. In some embodiments, the first curvature R1 is defined by an elliptical function.

[0026] In this regard, as shown in FIG. 7 , the second jaw 104 may have a second sealing surface 122, the major sealing surface 143 of which has a generally concave shape or is otherwise shaped and configured to receive the first jaw 102. In some embodiments, a portion of the second jaw 104 may have the second sealing surface 122 having a second curvature R2 centered about the sealing axis W and / or the path of travel 118 of the cutting mechanism. The second curvature R2 is greater than the first curvature R1. In some embodiments, the second curvature R2 is constant from the proximal portion 128 of the second jaw 104 to the distal portion 130 of the second jaw 104. In some embodiments, the second curvature R2 is greater at the proximal portion 128 of the second jaw 104 than at the distal portion 130 of the second jaw 104. In some embodiments, the second curvature R2 is defined by a circle of radius R2. In some embodiments, the second curvature R2 is defined by an elliptical function.

[0027] Returning to FIG. 6 , either the first jaw 102 and / or the second jaw 104 may have a current concentrator surface 132, 134. Such a surface may be one or more conductive protrusions 132 and / or recesses 134 shaped and configured to direct electrosurgical energy toward specific areas of the sealing surfaces 122, 124. In some embodiments, the total power applied to the jaws 102, 104 may be substantially that described in the '561 and / or '694 patents. The conductive protrusions 132 may be of various shapes and sizes, as shown, and may have one or more curved surfaces with one or more radii of curvature, elliptical functions, or other non-linear functions.

[0028] As shown in FIG. 11 , in some embodiments, the height H of the (at least one) protrusion 132 from the major sealing surface 120 is between about 0.001 inches and about 0.0025 inches (about 0.0254 millimeters and about 0.0635 millimeters). The height H is selected to be sufficient to induce an energy concentration without creating a faint or weakened spot of electrical potential within the tissue sealed using the device 100. In some embodiments, the height H is between about 0.015 millimeters and about 0.080 millimeters. In some embodiments, the height H is between about 0.03 millimeters and about 0.6 millimeters. One skilled in the art will appreciate that the height H and / or depth D should be configured to prevent the jaws 102, 104 from contacting each other and / or to prevent the induction of a spark between the jaws. In some embodiments, a gap G of at least about 0.002 inches, i.e., at least about 0.051 millimeters, is maintained between the jaws 102, 104.

[0029] In some embodiments, the height H of the first protrusion exceeds the height H of the second protrusion. In some embodiments, the height H of the protrusion at the proximal region of the jaws 102, 104 exceeds the height H of the protrusion near the distal region of the jaws 102, 104. In some embodiments, the protrusion 132 near the proximal region of the jaws 102, 104 may have a circular portion with a smaller radius of curvature than the circular portion of the protrusion 132 near the distal region of the jaws 102, 104. In some embodiments, the protrusion 132 near the proximal region may be configured to induce a greater current concentration than the protrusion 132 near the distal region.

[0030] 11 , the gap G between the (at least one) protrusion 132 and the second jaw or recess 134 may be maintained constant. That is, in some embodiments, the protrusion 132 of the first jaw 102, 104 corresponds with the recess 134 of the second jaw 102, 104 to maintain the gap G. In some embodiments, the gap G is approximately 0.002 inches (approximately 0.051 millimeters) between the primary sealing surface 142, 143 and the current concentrator (protrusion / recess 132, 134). In some embodiments, a relief is provided between the protrusion 132 or recess 134 and the primary sealing surface 142, 143 to prevent spark induction at sharp corners.

[0031] In some embodiments, one of the jaws 102, 104 has a single protrusion 132. In some embodiments, two protrusions 132 are provided on each of the jaws 102, 104.

[0032] Returning again to FIG. 7 , one or both of the first jaw 102 or the second jaw 104 may have a more conductive recess 134 shaped and configured to direct electrosurgical energy toward specific regions of the sealing surfaces 122, 124. The conductive recess 134 may be of various shapes and sizes, as shown, and may have one or more curved surfaces with one or more radii of curvature. The conductive recess 134 may correspond to opposing ones of the conductive protrusions 132, or some or all of the conductive protrusions 132 may be housed within the conductive recess 134. In some embodiments, all of the conductive protrusions 132 are on one of the first or second jaw 102, 104 and all of the conductive recess 134 are on the other of the first or second jaw 102, 104. In some embodiments, some of the conductive protrusions 132 are on one of the jaws 102, 104 and some of the conductive protrusions 132 are on the other of the jaws 102, 104. Each of the conductive recesses 134 may be uniformly distributed and positioned. The conductive recesses 134 may be of various shapes and sizes as shown, and may have one or more curved surfaces with one or more radii of curvature, elliptical functions, or other non-linear functions.

[0033] The conductive recess 134 may have a depth corresponding to the height H of the (at least one) protrusion 132, further ensuring that the energy concentration is induced without creating weak or weakened spots of electrical potential in the tissue sealed with the device 100.

[0034] In some embodiments, the depth is between about 0.015 millimeters and about 0.080 millimeters. In some embodiments, the depth is between about 0.03 millimeters and about 0.06 millimeters. In some embodiments, the depth of the first recess 134 is greater than the depth of the second recess 134. In some embodiments, the depth of the recess at the proximal region of the jaws 102, 104 is greater than the depth of the recess near the distal region of the jaws 102, 104. In some embodiments, the recess 134 near the proximal region of the jaws 102, 104 may have a circular portion with a smaller radius of curvature than the circular portion of the recess 134 near the distal region of the jaws 102, 104. In some embodiments, the recess 134 near the proximal region may be configured to induce a greater current concentration than the recess 134 near the distal region.

[0035] One or more conductive protrusions 132 and, optionally, conductive recesses 134 are provided to induce an energy concentration at the protrusions 132 and recesses 134, which may be referred to as an energy concentrator or current concentrator. That is, the conductive protrusions 132 do not necessarily have corresponding recesses 134. By inducing this energy concentration, Applicant has provided an improved method of sealing tissue. Specifically, the current concentration at each protrusion / recess 132, 134 interface is configured to induce an initial flow of energy between the jaws 102, 104 before the energy flows across the respective surfaces 120, 122. This in turn reduces the overall power requirements for the system 100 while still providing the ability to seal relatively large tissue portions at power levels and current concentrations, including low power, such as 40 watts or less, as described in the '561 patent. In some embodiments, the device 100 is configured to provide 50 watts or less of power. In some embodiments, the device 100 is configured to provide 40 watts or less of power. In some embodiments, the device 100 is configured to provide 35 watts or less of power. In some embodiments, device 100 is configured to provide power of 20 watts or less. In some embodiments, device 100 is configured to provide current of 3 amps or less. In some embodiments, device 100 is configured to provide current of 2.5 amps or less. The current concentrator or energy concentrator may be shaped to concentrate the current without inducing sparks.

[0036] In some embodiments, the device 100 is shaped to pass through a cannula having an inner diameter of 6 millimeters or less.

[0037] Additionally, the protrusions / recesses 132, 134 and / or curved sealing surfaces 120, 122 reduce or eliminate the chance of tissue sticking to the jaws 102, 104 after sealing is complete, without using dissimilar materials for the jaws 102, 104. That is, the jaws 102, 104, including the protrusions 132 and recesses 134, may be made of surgical stainless steel without any non-stick coating. For example, the protrusions 132 and / or recesses 134 may be shaped and / or positioned to begin to exert a focused distancing effect on relatively targeted areas of tissue when the jaws 102, 104 are open, thereby enhancing separation. In some cases, the protrusions 132 and / or recesses 134 may be shaped and / or positioned to apply a greater separation force to targeted regions of tissue than to non-targeted regions of tissue (e.g., tissue further away from the protrusions 132 and / or recesses 134, such as tissue between the major sealing surfaces 142, 143). In some embodiments, the gap between one or more conductive protrusions 132 and one or more recesses 134 is less than the gap G between the major sealing surfaces 142, 143 of the jaws 102, 104.

[0038] In some embodiments, the (at least one) jaw 102, 104 may have a sealing surface 120, 122 with a sealing surface area of ​​24 square millimeters or less. In some embodiments, the (at least one) jaw 102, 104 may have a sealing surface 120, 122 with a sealing surface area of ​​10 square millimeters or less.

[0039] 6 and 7 , the device 100 may include a curved travel path 118 through which the cutting mechanism may pass, such as after applying a seal to tissue clamped between the jaws 102, 104. Those skilled in the art will appreciate that in some embodiments, the cutting mechanism 106 may be flexible (e.g., a bending knife) to flow down the travel path 118, and / or the width of the channels 114, 116 may be appropriately wide enough for the cutting mechanism 106 to pass through without bending. The channels 114, 116 may be curved in some embodiments, as shown. In some embodiments, the channels 114, 116 and the cutting path 118 may be substantially straight. In some embodiments, the cutting mechanism 106 is flexible. In some embodiments, the cutting mechanism 106 is relatively rigid.

[0040] In some embodiments, the cutting path 118 defines a length of stroke S (of the cutting mechanism 106), as shown, for example, in FIG. 14 . The length of stroke S may extend through the entire sealing portion of the jaws 102, 104. That is, the cutting path 118 may be shaped and positioned to cut the entire tissue held between the jaws 102, 104 with a single stroke of the cutting mechanism 106. In some embodiments, the length of stroke S may only extend partially through the sealing portion of the jaws 102, 104.

[0041] In some embodiments, the channels 114, 116 and / or cutting path 118 may generally include one or more stop mechanisms (not shown) to allow a user to adjust the length of the stroke S relative to the jaws 102, 104. In some embodiments, the channels 114, 116 and / or cutting path 118 may generally include one or more tactile feedback mechanisms (not shown) to provide tactile feedback to the user. The tactile feedback mechanism may provide the user with the ability to fire the cutting mechanism 106 less than the full length of the stroke S or less than the full length of the tissue sealed in a first stroke, optionally open the jaws 102, 104, optionally confirm that the tissue is properly sealed, and then, after reclosing the jaws 102, 104, optionally fire the cutting mechanism 106 a second stroke that is a greater distance than the first stroke. In some embodiments, the tactile feedback mechanism provides the user with a sense of application of three or more stroke lengths. The tactile feedback mechanism may comprise one or more ridges, depressions, detents and / or any other tactile feedback means, whether now known or yet to be developed, suitable for indicating the general position of the cutting mechanism 106 relative to the jaws 102, 104.

[0042] 6 and 7 , a coated conductive medium, which may be a wire 152 terminating in the first jaw 102, and a coated conductive medium, which may be a wire 154 terminating in the second jaw 104, provide an energy path through the jaws 102, 104. The wires 152, 154 may be soldered or welded to the jaws 102, 104. In some embodiments, the wires 152, 154 may be coupled to the jaws 102, 104 by insulation displacement contact or insulation piercing contact in a manner known to those skilled in the art. In some embodiments, an overmold 160 may be provided around the wires 152, 154 and other features of the device 100.

[0043] 8 and 9, a cutting mechanism 106 having a distal knife portion and a proximal rod portion may be configured to travel within a split rod 156. While the cutting mechanism 106 itself may function substantially as known in the industry, those skilled in the art will recognize that positioning the cutting mechanism 106 within the split rod 156 may reduce the footprint of the device 100.

[0044] As previously described herein, in some embodiments, a relatively small sealing / cutting device 100 may be provided. For example, in some embodiments, device 100 may have an overall envelope of less than 3.0 millimeters and / or may be configured to fit within a 3.5 millimeter cannula. In some embodiments, device 100 may have an envelope of less than 5.0 millimeters and / or may be configured to fit within a 5.5 millimeter cannula. In some embodiments, device 100 may be configured to fit within a 7.5 millimeter cannula. In some embodiments, device 100 may be configured to fit within a 10.5 millimeter cannula.

[0045] Those skilled in the art will recognize that a smaller device 100, as described herein, must still provide the same clamping force as a larger device, resulting in significant force concentrations at the interface between, for example, the jaws 102, 104 and the links 162, 164 that control the jaws 102, 104. For this reason, in some embodiments, the jaws 102, 104 include a plurality of bushings 144, 146, 148, 150 (see FIGS. 6 and 7 ) made of a non-conductive, incompressible, or low-compressibility material. In some embodiments, the jaws 102, 104 include non-conductive or ceramic bushings 144, 146, 148, 150 for interfacing with the linkage 108, which includes the links 162, 164 and the split shaft 166. In some embodiments, bushings 144, 146, 148, 150 isolate actuators such as links 162, 164 from the conductive jaws 102, 104.

[0046] In some embodiments, a pin 168 passes through a pair of distal bushings 146, 150 on the jaws 102, 104, an elongated slot in the cutting mechanism 106, and the split shaft 166 to rotatably mount the jaws 102, 104 to the shaft 166. In some embodiments, a protrusion on a pair of links 162, 164 engages a pair of proximal bushings 144, 148 on the jaws 102, 104 to help translate the opening and closing motion of the split rod 156 into a rotational motion of the jaws 102, 104.

[0047] Returning now to FIG. 11 , which shows a schematic cross-section of first jaw 102, in some embodiments, device 100 may be configured to apply a shear force F to tissue when jaws 102, 104 move away from one another after sealing tissue therebetween. In some embodiments, conductive protrusions 132 and / or conductive recesses 134 on surfaces 120, 122 may be positioned such that protrusions 132 and / or recesses 134 apply shear force F to tissue when jaws 102, 104 move from a clamping or closed position toward a non-clamping or open position. Those skilled in the art will appreciate that if protrusions 132 and / or recesses 134 are substantially circular or elliptical in nature, shear force F may be transverse, longitudinal, and / or perpendicular to path of travel 118, thereby generating a focused shear force F that initiates separation of tissue from jaws 102, 104. Those skilled in the art will appreciate that once separation is initiated, separation of other portions of tissue may be further facilitated. By providing a relatively smooth transition between the protrusion 132 or recess 134 and the primary sealing surfaces 142, 143, undesirable transitions in energy concentration may be avoided.

[0048] 12, 13A, and 13B show various views of an exemplary instrument 100, and more particularly, how the jaws 102, 104 and cutting mechanism 106 or knife / knife pulling rod, along with the pulling rod 163 and outer housing or tube 180 for the jaws, may be operated.

[0049] FIG. 14 shows one embodiment of how the coated wires 152, 154 may be secured to the jaws 102, 104, for example, by providing an overmold 160 that surrounds the distal or exposed conductive portions of the wires 152, 154 and the proximal portions of the jaws 102, 104.

[0050] 15 , a method 1500 for sealing and cutting tissue will now be disclosed in further detail. Method 1500 includes the step 1502 of providing an electrosurgical cutter / sealer having a sealing surface with at least one feature configured to induce an energy concentration on the sealing surface. Method 1500 also includes the step 1504 of applying electrosurgical power to the tissue to be sealed. Applying electrosurgical power 1504 may include distributing power unevenly throughout the tissue clamped between the pair of jaws and / or clamping the tissue between the jaws in an apical biased manner. Method 1500 may include the step 1506 of cutting the tissue clamped between the jaws. Cutting 1506 may include causing a cutting mechanism to travel a non-linear path through the tissue. The method 1500 also includes a step 1508 of separating the electrosurgical device from the tissue clamped therebetween, the separating step 1508 including pulling the pair of jaws away from each other in a manner that applies vertical and / or lateral shear forces to the tissue clamped therebetween.

[0051] Method 1500 may be accomplished using apparatus such as those previously described with reference to FIGS.

[0052] 16-19, energy concentrators and / or travel stops need not be provided. That is, in some embodiments, some or substantially all of the curved sealing surfaces 120, 122 may be suitably curved to reduce or eliminate the chance of tissue adhering to the jaws 102, 104 after sealing is completed without the use of dissimilar materials and the presence of energy concentrators in the jaws 102, 104. Other features of the exemplary device shown in FIGS. 16-19 may be substantially as otherwise described herein with reference to the device.

[0053] 20 , in some embodiments, all, a portion, or most of the first and second sealing surfaces 120, 122 may be flat. In some embodiments, a substantial portion of one or both of the jaws 102, 104 may have a coating. For example, a substantial portion of one or both of the jaws 102, 104 may be overmolded with a coating 170, 182. The coating may be made of a substantially non-conductive material. The coatings 170, 182 may be applied by overmolding, plasma spraying, detonation spraying, wire arc spraying, thermal spraying, flame spraying, high velocity oxygen-fuel spraying, high velocity air-fuel spraying, warm spraying, or cold spraying.

[0054] In some embodiments, a travel stop 174 is provided at or near the proximal region of one or both of the jaws 102, 104 to limit over-compression in much the same manner as travel stop 112 described previously herein. In some embodiments, travel stop 174 at the proximal region of the jaws may be formed from a coating 182. Travel stop 174 may be a flange at the proximal region of jaw 102, 104. One skilled in the art will appreciate that while FIG. 20 shows stops 112, 174 positioned on the second jaw 104, one or both of travel stops 112, 174 may be positioned on the first jaw 102. One skilled in the art will appreciate that one or both travel stops 112, 174 may provide the necessary protection from over-compression.

[0055] 21 and 22 show exploded and assembled views, respectively, of an exemplary first jaw 102 suitable for use with the device 100. The jaw 102 may have a conductive core member 176 partially covered by a non-conductive coating 170. The conductive core member 176 may have a sealing surface 120. In some embodiments, the sealing surface 120 may be flat, as shown in FIGS. 21 and 22, or the sealing surface 120 may be curved and / or include conductive recesses and / or protrusions, as described previously herein. The jaw 102 or core member 176 may include a plurality of recesses 178, 184 positioned in a proximal region of the core member 176. The recesses 178, 184 may be passageways. The recesses 178, 184 may be shaped to receive the bushings 144, 146 and may be positioned to control rotation of the jaw 102. As shown in Figures 21, 23, 6 and 7, the jaws 102, 104 may include a plurality of recesses 178, 184, 186, 188 shaped and positioned to allow rotation of the jaws 102, 104 relative to the control rod or cannula, substantially as described hereinabove. The coating 170 may position a conductive wire 152 to maintain contact with the core member 176 for conducting energy to the sealing surface 120. Although not shown in Figures 21 and 22, a proximal travel stop 174 may also be provided, as shown in Figure 20.

[0056] As shown in FIGS. 23 and 24 , the second jaw 104 may be coated with a coating 182. The coating 182 may be applied and positioned in substantially the same manner as described above with reference to the first jaw 102. The second jaw 104 or the first jaw 102 may have a travel stop 112 at a distal region of the jaw 102, 104, and the travel stop 112 may have a height of up to about 0.003 inches or up to about 0.08 millimeters. In some embodiments, the proximal portion of the (at least one) jaw 102, 104 may have a coating 170, 182 that is up to about 0.004 inches thick or up to about 0.1 millimeter thick in an area near the (at least one) recess 178, 184, 186, 188. The recess itself may be free of the coating 170, 182. Although the second jaw 104 is shown with a distal travel stop 112 and no proximal travel stop, one skilled in the art will recognize that a proximal travel stop 174 may also be provided, as shown in FIG. 20.

[0057] As described with reference to the previously cited figures, the device shown in FIGS. 20-24 may be configured to maintain a gap between the primary sealing surfaces 120, 122.

[0058] 25 and 26 , the exemplary instrument 100 may include a first jaw 102 and a second jaw 104. A coating 170, 182 on the first and / or second jaws may be provided and shaped to expose the concave sealing surfaces 120, 122. The concave sealing surfaces 120, 122 may be quite narrow. For example, in some embodiments, the distance D from the channel 114 or elongated slot may be up to 0.5 millimeters. In some embodiments, the distance D may be greater than 0.2 millimeters. In some embodiments, the distance may be 0.6 millimeters or less. In some embodiments, the distance may be 0.8 millimeters or less. In some embodiments, the distance D may be 1 millimeter or less. In some embodiments, the distance D may be between 0.2 millimeters and 0.7 millimeters.

[0059] Although shown as flat surfaces, those skilled in the art should understand that the sealing surfaces 120, 122 of the instrument shown in FIG. 25 may include curvatures R1, R2, protrusions 132 and / or recesses 134 (and primary sealing surfaces) as previously described herein with reference to the previously cited figures. The instrument 100 shown in FIG. 25 may also include distal travel stop 112 and / or proximal travel stop 176 as previously described herein. Other features may be substantially as previously described herein. Of particular note, applicant has determined that, contrary to conventional thinking in the industry, instruments such as tissue sealers with very narrow or thin tissue contact margins provide very high burst strengths to tissue sealed by such instruments. Furthermore, because the sealing surface area is so small, the device may be held at very low power, such as 50 watts or less, 40 watts or less, or 35 watts or less, or 3 amps or less, or 2 amps or less, and still achieve a strong seal without damaging the surrounding tissue. In some embodiments, a current of 1.5 amps to 3.0 amps may be provided at a power level of 50 watts.

[0060] Turning now to FIG. 27 , a method 2700 of making an electrosurgical instrument is described. The method 2700 may include the step 2702 of providing a movable tissue cutting mechanism. The method 2700 may include the step 2704 of providing a pair of jaws. At least one jaw of the pair of jaws has a conductive core member, each jaw having an elongated slot for receiving a portion of the movable tissue cutting mechanism, the cutting mechanism configured to move between a proximal position and a distal position to cut tissue clamped between the pair of opposing jaws. The method 2700 may include the step 2706 of coating at least one jaw with a non-conductive coating such that the non-conductive coating exposes a portion of the core member to form a recessed sealing surface area against the non-conductive coating. The method 2700 may include the step 2708 of coupling the pair of jaws such that the pair of jaws are movable between a closed position and an open position opposing each other to clamp tissue therebetween.

[0061] In some embodiments, the coating step 2706 includes at least one of overmolding, plasma spraying, detonation spraying, wire arc spraying, thermal spraying, flame spraying, high velocity oxygen-fuel spraying, high velocity air-fuel spraying, warm spray, or cold spraying.

[0062] The following is a non-exhaustive list of exemplary embodiments, from which one skilled in the art can readily recognize that many features of the device 100 shown in the figures can be added or deleted, and that features shown in the first figure are suitable for use in the device shown in the second figure, even though not so illustrated.

[0063] Example

[0064] Referring now to Table 1, an electrosurgical instrument according to embodiments described herein was tested with five different seals. The jaws of the instrument had a sealing surface of approximately 57 square millimeters, and a coating on a portion of each jaw provided a concave sealing surface recessed relative to the coating. The sealing surface was recessed by at least 0.101 millimeters on each jaw, and a stop provided a gap of approximately 0.127 millimeters between the jaws during sealing. The device was set to nominal power settings of 50 watts maximum power, 100 volts maximum voltage, and 2.5 amps maximum current. The device was also set to stop applying power when the impedance to the energy passing through the tissue reached 250 ohms.

[0065] This equipment was used to apply the five types of encapsulation listed in Table 1.

[0066] After sealing, each seal was cut and inspected and determined to be of excellent quality. Specifically, the seals were found to be clear and had intact edges (the transition from sealed to unsealed tissue), indicating a strong seal. No burnt or other damage was observed adjacent to the seal, indicating minimal heat spread.

[0067] For comparison, another device was tested having a jaw sealing surface area of ​​approximately 113 square millimeters and the same power settings as above (50 watts, 100 volts, 2.5 amps, and a shutoff at 250 ohms). All other factors being equal, the 113 square millimeter jaws were inoperable to seal a vessel across the entire surface of the jaws. The inoperability of the 113 square millimeter jaws at the same power settings demonstrates that smaller sealing surface areas provide increased functionality at lower power settings.

[0068] More specifically, devices providing a current density of about 0.0345 amps per square millimeter (2.00 amps per 58 square millimeters or less) have been found to provide a reliable seal. In some embodiments, the device is configured to provide a current density of about 0.025 amps per square millimeter or greater. In some embodiments, the device is configured to provide a current density of about 0.030 amps per square millimeter or greater. In some embodiments, the device is configured to provide a current density of about 0.030 amps per square millimeter or greater and a power of 50 watts or less. Those skilled in the art will recognize that a pair of jaws 102, 104 that is not completely filled with tissue will have even higher concentrations. In some embodiments, the current concentrators 132, 134 described herein may provide a high concentration of current effective to initiate a sealing action. That is, the current concentrators 132, 134 may be configured to achieve a current concentration of at least 0.025 amperes per square millimeter in areas proximate the current concentrators 132, 134, but not necessarily throughout the tissue clamped between the jaws 102, 104, even if other areas of the tissue clamped between the jaws 102, 104 do not have this concentration.

[0069] The following is a non-exhaustive list of embodiments described herein.

[0070] Embodiment 1. An electrosurgical instrument comprising a movable tissue cutting mechanism and a pair of opposing jaws having a first jaw and a second jaw, the pair of opposing jaws configured to move between a closed position and an open position to clamp and seal tissue therebetween. At least one jaw comprises a conductive core member and a non-conductive coating. The non-conductive coating covers a portion of the core member and exposes a portion of the core member to form a recessed sealing surface area relative to the non-conductive coating. Each jaw includes an elongated slot for receiving a portion of a cutting mechanism, the cutting mechanism configured to move between a proximal position and a distal position to cut tissue clamped between the pair of opposing jaws.

[0071] Embodiment 2. The instrument of embodiment 1, wherein the non-conductive coating is formed on the core member of the at least one jaw by at least one of overmolding, plasma spray coating, detonation spray coating, wire arc spray coating, thermal spray coating, flame spray coating, high velocity oxygen-fuel spray coating, high velocity air-fuel coating, warm spray coating, or cold spray coating.

[0072] Embodiment 3. The apparatus of embodiment 1 or 2, wherein the sealing surface area of ​​at least one jaw extends a distance of 0.8 millimeters or less from the elongated slot.

[0073] Embodiment 4. The device of any one of embodiments 1-3, wherein the sealing surface region extends a distance between 0.2 millimeters and 0.7 millimeters from the elongated slot.

[0074] Embodiment 5. The device of any one of embodiments 1-4, wherein the sealing surface area of ​​at least one jaw extends no more than 0.6 millimeters from the elongated slot.

[0075] Embodiment 6. The instrument of any one of embodiments 1-5, wherein the coating is configured to maintain a gap between the surface areas of the pair of jaws in the closed position, the gap being 0.05 millimeters or greater.

[0076] Embodiment 7. The device of embodiment 6, wherein the gap is 0.18 millimeters or less.

[0077] Embodiment 8. The device of embodiment 7, wherein the gap is at least 0.07 millimeters.

[0078] Embodiment 9. The apparatus of any one of embodiments 1-8, wherein the non-conductive coating is formed on the core member by at least one of overmolding, plasma spray coating, detonation spray coating, wire arc spray coating, thermal spray coating, flame spray coating, high velocity oxygen-fuel spray coating, high velocity air-fuel coating, warm spray coating, or cold spray coating.

[0079] Embodiment 10. The apparatus of embodiment 9, wherein the device is further configured to deliver up to 50 watts of power and up to 3 amps of current to tissue clamped between the jaws.

[0080] Embodiment 11. The instrument of any one of embodiments 1-10, wherein the pair of jaws is further shaped to fit through a cannula having an inner diameter of 6 millimeters or less when both jaws are in the closed position.

[0081] Embodiment 12. The instrument of any one of embodiments 1-11, further comprising a linkage for controlling relative rotation of the pair of jaws, the linkage having a first pair of non-conductive bushings of the first jaw, a second pair of non-conductive bushings of the second jaw, a pin extending through a first one of the bushings of each jaw and rotatable relative to the split rod, and a link coupled to a second one of the bushings of each jaw.

[0082] Embodiment 13. The device of embodiment 12, wherein a non-conductive bushing separates the links and pins from the core member.

[0083] Embodiment 14. The instrument of any one of embodiments 1-13, wherein the sealing surface area of ​​at least one jaw is less than 24 square millimeters, and the sealing surface area extends no more than 0.8 millimeters from the elongated slot.

[0084] Embodiment 15. The device of any one of Embodiments 1-14, wherein at least one of the jaws has a sealing surface area of ​​less than 10 square millimeters, or the sealing surface area extends no more than 0.6 millimeters from the elongated slot.

[0085] Embodiment 16. The instrument of any one of embodiments 1-15, wherein the instrument is further configured to apply 50 watts or less of power to tissue clamped between the opposing jaws, and wherein the instrument is further configured to apply 3 amps or less of current to tissue clamped between the opposing jaws.

[0086] Embodiment 17. The instrument of any one of embodiments 1-16, wherein at least one jaw has a proximal end with a pair of non-conductive bushings and a distal end, and the coating is configured to maintain a gap between the sealing surfaces of the pair of jaws, the proximal portion of the gap being larger than the distal portion of the gap.

[0087] Embodiment 18. The device of embodiment 17, wherein the coating extends from the proximal region to the distal region.

[0088] Embodiment 19. The device of any one of embodiments 1-18, wherein the concave sealing surface of at least one jaw includes a major sealing surface, and the major sealing surface is a curved surface.

[0089] Embodiment 20. The instrument of embodiment 19, wherein the concave sealing surface further comprises at least one of a protrusion or a recess for concentrating the flow of electrical current from at least one jaw through tissue clamped between the pair of jaws.

[0090] Embodiment 21. The instrument of any one of embodiments 1-20, wherein the concave sealing surface of at least one jaw includes a major sealing surface, and the major sealing surface is a flat surface.

[0091] Embodiment 22. The instrument of embodiment 21, wherein the concave sealing surface of at least one jaw further includes at least one of a protrusion or a recess for concentrating the flow of electrical current from the at least one jaw through tissue clamped between the pair of jaws.

[0092] Embodiment 23. The instrument of any one of embodiments 1-22, wherein the concave sealing surface of at least one jaw includes a primary sealing surface and at least one of a protrusion or a recess for concentrating the flow of electrical current from the at least one jaw through tissue clamped between the pair of jaws.

[0093] Embodiment 24. The apparatus of any one of embodiments 1-23, wherein the concave sealing surface of at least one jaw comprises a protrusion, and the other jaw of the opposing pair comprises a recess opposite the protrusion, the protrusion and the recess configured to concentrate the flow of current through the protrusion and the recess.

[0094] Embodiment 25. The device of any one of embodiments 1 to 24, wherein at least a portion of the elongated slot is non-linear.

[0095] Embodiment 26. A method of making an electrosurgical instrument, comprising: providing a movable tissue cutting mechanism; providing a pair of jaws, at least one of the pair of jaws having an electrically conductive core member, each jaw having an elongated slot that receives a portion of the movable tissue cutting mechanism, the cutting mechanism configured to move between a proximal position and a distal position for cutting tissue clamped between the pair of opposing jaws; coating at least one jaw with a non-conductive coating such that the non-conductive coating exposes a portion of the core member to form a recessed sealing surface area against the non-conductive coating; and coupling the pair of jaws such that the jaws oppose each other and are movable between a closed position for clamping tissue therebetween and an open position.

[0096] Embodiment 27. The method of embodiment 26, wherein the coating comprises at least one of overmolding, plasma spraying, detonation spraying, wire arc spraying, thermal spraying, flame spraying, high velocity oxygen-fuel spraying, high velocity air-fuel spraying, warm spraying, or cold spraying.

[0097] Embodiment 28. An electrosurgical instrument comprising: a movable tissue cutting mechanism; and a pair of opposing jaws having a first jaw and a second jaw, the pair of opposing jaws shaped and configured to move between a closed position for clamping tissue therebetween and an open position, the first jaw comprising an exposed tissue sealing surface having a primary sealing surface and at least one protrusion extending from the primary sealing surface for concentrating a sealing current through the at least one protrusion, the second jaw comprising an exposed tissue sealing surface having the primary sealing surface and at least one recess in the primary sealing surface for concentrating the sealing current through the at least one recess, the at least one protrusion and the at least one recess facing each other when the pair of opposing jaws are in the closed position, and each of the pair of opposing jaws comprising an elongated slot for receiving a portion of a cutting mechanism, the cutting mechanism configured to move between a proximal position and a distal position to cut tissue clamped between the pair of opposing jaws.

[0098] Embodiment 29. At least one of the first jaw or the second jaw has a conductive core member and a non-conductive coating, the non-conductive coating covering a portion of the conductive core member and exposing the tissue sealing surface such that the tissue sealing surface is recessed relative to the non-conductive coating; 29. The apparatus of embodiment 28, wherein the non-conductive coating is formed on the core member of at least one jaw by at least one of overmolding, plasma spray coating, detonation spray coating, wire arc spray coating, thermal spray coating, flame spray coating, high velocity oxygen fuel spray coating, high velocity air fuel coating, warm spray coating, or cold spray coating.

[0099] Embodiment 30. The instrument of embodiment 28 or 29, wherein at least one of the first jaw or the second jaw comprises at least one of a non-conductive distal travel stop positioned distal to the elongated slot and configured to maintain a gap between the major sealing surfaces of the first and second jaws in the closed position, or a non-conductive proximal travel stop positioned proximal to the exposed tissue sealing surface and configured to maintain a gap between the major sealing surfaces of the first and second jaws in the closed position, wherein the gap is between 0.05 millimeters and 0.18 millimeters.

[0100] Embodiment 31. The instrument of any one of Examples 28-30, wherein the instrument is configured to maintain a gap between the at least one protrusion and the at least one recess when the jaws are in the closed position, the gap being between 0.05 millimeters and 0.18 millimeters.

[0101] Embodiment 32. The instrument of any one of Examples 28-31, wherein the device is further configured to deliver up to 50 watts of power to tissue clamped between the jaws.

[0102] Embodiment 33. The instrument of any one of embodiments 28-32, wherein the instrument is further shaped to fit through a cannula having an inner diameter of 6 millimeters or less when the jaws are in the closed position.

[0103] Embodiment 34. The instrument of any one of embodiments 28-33, further comprising a linkage for controlling relative rotation of the pair of jaws, the linkage including a first pair of non-conductive bushings of the first jaw, a second pair of non-conductive bushings of the second jaw, a pin extending through a first bushing of each of the jaws to enable rotation relative to the split rod, and a link coupled to a second bushing of each of the jaws.

[0104] Embodiment 35. The device of embodiment 34, wherein a non-conductive bushing separates the link and pin from the core member of the pair of jaws.

[0105] Embodiment 36. The instrument of any one of embodiments 28-35, wherein the exposed tissue sealing surface of at least one of the first or second jaws has a surface area of ​​24 square millimeters or less.

[0106] Embodiment 37. The instrument of embodiment 36, wherein the exposed tissue sealing surface of at least one of the first jaw or the second jaw has a surface area of ​​10 square millimeters or less.

[0107] Embodiment 38. The instrument of any one of embodiments 28-37, wherein the instrument is further configured to apply a power of no more than 50 watts and a current of no more than 3 amps to tissue clamped between the pair of opposing jaws.

[0108] Embodiment 39. The instrument of any one of embodiments 28-38, wherein at least one of the first or second jaws has a conductive core member having a proximal end and a distal end, the proximal end of the core member having a pair of recesses, and a pair of non-conductive bushings positioned in the pair of recesses.

[0109] Embodiment 40. The device of any one of embodiments 28 to 39, wherein the primary sealing surfaces of the first and second jaws are curved.

[0110] Embodiment 41. The device of embodiment 40, wherein a first one of the major sealing surfaces is concave and a second one of the major sealing surfaces is convex.

[0111] Embodiment 42. The instrument of embodiment 41, wherein a first one of the major sealing surfaces is concave and a second one of the major sealing surfaces is convex, whereby the major sealing surfaces are shaped to facilitate disengagement of tissue sealed therebetween upon movement from the closed position to the open position.

[0112] Embodiment 43. The device of any one of embodiments 28 to 42, wherein at least a portion of the elongated slot is non-linear.

[0113] Embodiment 44. A method of making an electrosurgical instrument, comprising: providing a movable tissue cutting mechanism; providing a pair of jaws having a first jaw and a second jaw, each jaw having an elongated slot for receiving the movable tissue cutting mechanism, the first jaw having an exposed tissue sealing surface having a major sealing surface and at least one protrusion extending from the major sealing surface for concentrating a sealing current through the at least one protrusion, and the second jaw having an exposed tissue sealing surface having the major sealing surface and at least one recess in the sealing surface for concentrating the sealing current through the at least one recess; shaping the pair of jaws so that the at least one protrusion and the at least one recess oppose each other when the pair of opposing jaws is in a closed position; and coupling the pair of jaws so that the pair of jaws are movable between a closed position and an open position for clamping tissue therebetween.

[0114] Embodiment 45. The method of embodiment 44, further comprising forming one of the major sealing surfaces with a concave curve and forming the other of the major sealing surfaces with a convex curve.

[0115] Embodiment 46. Any one of embodiments 1 to 46, wherein the device is a vessel sealing / cutting device.

[0116] Embodiment 47. Any one of embodiments 1-46, wherein each jaw has a jaw sealing surface, the jaw sealing surface having a surface area between 23 square millimeters and 58 square millimeters, the device is configured to apply 50 watts or less of power at 3 amps or less and 100 volts or less to tissue clamped between the jaws, the tissue being a vessel greater than 5 millimeters wide and up to 15 millimeters wide, and the device is configured to seal the tissue clamped between the jaws within 5 seconds.

[0117] Embodiment 48. The device of embodiment 47, wherein the device is configured to seal tissue clamped between the jaws within 4 seconds.

[0118] Embodiment 49. The device of embodiment 47 or 48, wherein the device is configured to deliver 3 amps or less to tissue clamped between the jaws.

[0119] Embodiment 50. The device or method of any one of embodiments 1-49, wherein the device is configured to apply a current density of at least 0.025 amperes per square millimeter across at least a portion of tissue clamped between the jaws.

[0120] Each of the various elements disclosed herein can be achieved in a variety of ways. The present disclosure should be understood to encompass each such variation, whether it be a variation of any apparatus embodiment, method, or process embodiment, or merely a variation of such an embodiment. In particular, it should be understood that each element term may be expressed by equivalent apparatus or method terms even if the function or result is the same. Such equivalent terms, broader terms, or more general terms should be considered to be encompassed in the description of each element or operation. Such terms can be substituted as necessary where desired to clarify the implicitly broad scope to which this invention is entitled.

[0121] As an example, it should be understood that any action can be expressed as a means for performing that action or as an element that causes that action. Similarly, each disclosed physical element should be understood to encompass a disclosure of the action that the physical element facilitates. With regard to this last aspect, a disclosure of a "fastener" (whether explicitly contemplated or not) should be understood to encompass a disclosure of the act of "fastening," and conversely, if there were only a disclosure of the act of "fastening," such disclosure should be understood to encompass a disclosure of a "fastening mechanism." Such variations and alternative terms should be understood to be expressly included in the description.

[0122] Furthermore, the claims shall be construed such that a claim reciting "at least one of A, B, or C" shall be read as a device requiring only "A." The claim shall be read as a device requiring only "B." The claim shall be read as a device requiring only "C." Similarly, the claim shall be read as a device requiring "A+B," etc. The claim shall be read as a device requiring "A+B+C."

[0123] The claims shall also be construed such that any relational language (e.g., orthogonal, straight, parallel, flat, etc.) is understood to include a recitation of "within reasonable manufacturing tolerances at the time of manufacture of the device or at the time of the invention, whichever is greater."

[0124] In conclusion, the present invention provides, among other things, systems and methods for electrosurgical procedures. Those skilled in the art will readily recognize that many variations and substitutions may be made in the invention, its use, and its configuration to achieve substantially the same results as those achieved by the embodiments described herein. Therefore, it is not intended to limit the invention to the exemplary forms disclosed. Many variations, modifications, and alternative arrangements are within the scope and spirit of the disclosed invention, as expressed in the claims.

Claims

1. 1. An electrosurgical instrument comprising: a pair of opposing jaws having a first jaw and a second jaw, the pair of opposing jaws shaped and configured to move between a closed position to clamp and seal tissue therebetween and an open position, the first and second jaws each including a sealing surface configured to conduct a sealing current through tissue clamped therebetween; a cutting mechanism configured to move between a proximal position and a distal position to cut tissue sandwiched between the pair of opposing jaws; each of the first and second jaws includes an elongated slot that aligns with the jaws to form an elongated channel when the jaws are in a closed position, and through which the cutting mechanism moves as the cutting mechanism moves from the proximal position to the distal position; for each jaw, each longitudinal edge of said slot is no more than 0.8 millimeters from each elongated outer edge of said sealing surface; the sealing surface is configured to provide a current density of at least 0.025 amps per square millimeter at a power of 50 watts or less; a link mechanism configured to move the pair of opposing jaws; the first jaw and the second jaw are rotatably connected to each other via a pin; the first jaw and the second jaw each include a first non-conductive bushing and a second non-conductive bushing; the first non-conductive bushing of the first jaw and the second jaw is disposed around the pin; The second non-conductive bushing electrically isolates the linkage from the pair of opposing jaws.

2. The electrosurgical instrument according to claim 1, wherein each longitudinal edge of the slot is 0.2 to 0.7 millimeters from each elongated outer edge of the sealing surface.

3. The electrosurgical instrument according to claim 1 , wherein a longitudinal edge of each of the slots is within 0.5 millimeters of an elongated outer edge of each of the sealing surfaces.

4. The electrosurgical instrument according to claim 1 , wherein a longitudinal edge of each of the slots is within 0.2 millimeters of an outer elongated edge of each of the sealing surfaces.

5. The electrosurgical instrument of claim 1 , wherein the current density is at least 0.03 amperes per square millimeter at a power of 50 watts or less.

6. The electrosurgical instrument according to claim 1 , wherein each of the elongated slots has a first radius of curvature at a proximal portion of the first jaw and a second radius of curvature at a distal portion of the first jaw.

7. The electrosurgical instrument according to claim 1 , wherein the first jaw has a radius of curvature defined by an elliptical function.

8. An electrosurgical instrument as described in claim 1, comprising a first conductive wire fixed to the first jaw portion at a first position near the pin, and a second conductive wire fixed to the second jaw portion at a second position near the pin.

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