WO2016100667A2

WO2016100667A2 - Surgical device

Info

Publication number: WO2016100667A2
Application number: PCT/US2015/066381
Authority: WO
Inventors: Ryan C. Abbott
Original assignee: Maquet Cardiovascular Llc
Priority date: 2014-12-17
Filing date: 2015-12-17
Publication date: 2016-06-23
Also published as: WO2016100667A3

Abstract

In accordance with one aspect of the disclosure, a surgical device includes: a handle portion including a movable handle; an elongated tubular portion extending distally from the handle portion; a first jaw having a first engagement surface; a second jaw having a second engagement surface, wherein at least the first jaw moves between open and closed configurations, wherein the jaws are arranged to receive tissue therebetween when open and to exert force on tissue when in the closed configuration; and a drive assembly operates to drive at least the first jaw to transition the jaws between the open and closed configurations, wherein the drive assembly actuates by the movable handle that has an initial position and at least first and second preset positions, wherein in the first preset position the jaws exert a first clamping force and in the second preset position the jaws exert a second clamping force that is greater than the first clamping force. In accordance with another aspect of the disclosure, a surgical device for treatment of parenchyma includes: a handle portion including a movable handle; an elongated tubular portion extending distally from the handle portion, the elongated tubular portion having a transverse cross-sectional dimension at least at a distal region not exceeding 12 millimeters; a first jaw at a distal portion of the device having a first engagement surface; a second jaw at the distal portion of the device having a second engagement surface, wherein at least the first jaw is movable to transition the jaws between an open and closed configurations, wherein the jaws are arranged to receive parenchyma therebetween when open and to exert force on the tissue via the first and second engagement surfaces when in the closed configuration without causing blunt dissection of the parenchyma, wherein the first and second jaws in the closed configuration have a transverse cross-sectional dimension not exceeding 12 millimeters.

Description

SURGICAL DEVICE

[0000] This application claims priority to, and the benefit of, the following United States Provisional Applications: United States Provisional Application No. 62/092,985, filed December 17, 2014; and U.S. Provisional Application No. 62/092,992, filed December 17, 2014. The entire disclosures of the above applications are incorporated herein by reference.

BACKGROUND

[0001] Surgical devices are known in the health care industry for assisting medical professionals in the performance of a myriad of medical procedures. One type of device includes an end effector assembly at one end of a shaft that is controllable by a user holding or operating the device via a handle positioned at an opposite proximal end of the shaft. End effector assemblies may include jaws, staplers, bipolar sealers, monopolar sealers, and other components. There is an ever-present desire in the medical industry for new and alternate surgical devices, particularly those that enable procedures to be performed more effectively, efficiently, or under a wider array of scenarios and conditions. Certain devices are limited to a small range of tissue thicknesses. It would be beneficial to provide surgical devices with applications to a broad range of tissue thicknesses.

SUMMARY

[0002] The devices and methods of the present disclosure overcome the disadvantages and deficiencies of the prior art.

[0003] In accordance with a first aspect of the present disclosure, a surgical device is provided comprising a handle portion including a movable handle, an elongated tubular portion extending distally from the handle portion; a first jaw having a first engagement surface, and a second jaw having a second engagement surface. At least the first jaw is movable to transition the first jaw and the second jaw between an open configuration and a closed configuration, wherein the first jaw and the second jaw are arranged to receive tissue therebetween when in the open configuration and to exert force on the tissue via the first engagement surface and the second engagement surface when in the closed configuration. A drive assembly is operable to drive at least the first jaw to transition the first and second jaws between the open configuration and the closed configuration, the drive assembly actuable by the movable handle, the movable handle having an initial position and at least first and second preset positions, wherein in the first preset position, the jaws exert a first clamping force on tissue and in the second preset position the jaws exert a second clamping force on tissue, the second clamping force being greater than the first clamping force.

[0004] In some embodiments, in accordance with the first aspect, the drive assembly includes a follower and a non-linear groove, the follower engageable with the groove. Preferably, the follower and groove are positioned in the handle portion. In some embodiments, the groove has a variable depth.

[0005] In some embodiments, in accordance with the first aspect, the groove has a first stop corresponding to the first preset position of the movable handle. The groove can also have a second stop corresponding to the second preset position of the movable handle. In some embodiments, the groove has a substantially Z-shaped portion.

[0006] The device can further include a force transfer member operatively connected to at least the first jaw, wherein the movable handle includes an abutment surface engageable with a collar, the collar moving the force transfer member. The force transfer member can extend through the tubular portion and can be operably connected to at least the first jaw and to the movable handle. Preferably, movement of the movable handle retracts the force transfer member to transition the jaws to the closed configuration.

[0007] In some embodiments, in accordance with the first aspect, the interaction of the groove and follower is as follows: (a) movement of the movable handle from its initial position causes the follower to encounter a first ramp and follow the groove into a first stop, wherein a depth of the groove increases at the first stop to prevent the follower from backtracking through the groove, the follower being biased inwardly into the groove; (b) after the first stop, the follower engages a second ramp resulting in the follower positioning in a second stop, the second stop corresponding to the first preset position, wherein a depth of the groove increases at the second stop to prevent the follower from backtracking through the groove; and (c) upon further actuation of the movable handle, the follower travels in the groove to a third stop, the depth of the groove increasing at the third stop, wherein after the third stop the follower engages a third ramp resulting in the follower positioning in a fourth stop, the fourth stop corresponding to the second preset position.

[0008] In some embodiments, in accordance with the first aspect, the surgical device includes an electrode disposed on the first and/or second jaw. The first and second electrodes can in some embodiments extend in a substantially U-shape configuration spaced inwardly from a peripheral edge of the respective first and second jaws and a non-conductive material can be positioned within the U-shape of the second electrode. In some embodiments, the first and second jaws each have a metal portion, an outer insulator material positioned over the metal portion and an inner insulator positioned between the metal portion and the electrode. In some embodiments, a spacer can be provided extending from the first jaw to maintain a minimum distance between the first and second engagement surfaces.

[0009] In some embodiments, in accordance with the first aspect, the first jaw is movable toward the second jaw; in other embodiments, both the first and second jaws are movable toward each other by the drive assembly.

[0010] In some embodiments, in accordance with the first aspect, the first jaw includes an arm and a float portion having a first electrode, the float portion rotatably connected to the first arm to enable the electrode to float with respect to the arm.

[0011] The device can further include a cutting blade movable to sever tissue clamped between the first and second jaws, the cutting blade movable independently of jaw closure. A blade actuating member is preferably operably connected to a trigger at the handle portion and to the blade, the blade actuating member extending in the elongated portion.

[0012] The device can further include an articulation member for moving the jaws between a first position substantially aligned with a longitudinal axis of the tubular portion and a second position at an angle to the longitudinal axis, the articulation member extending in the elongated portion. In some embodiments, the jaws can be articulatable to an angle of up to about 60 degrees to the longitudinal axis. [0013] In some embodiments, in accordance with the first aspect, the drive assembly includes a cam with a non-linear groove disposed in the handle portion to vary the forces exerted by the jaws on tissue.

[0014] In some embodiments, in accordance with the first aspect, a cam follower including an arm and a pin is engageable with the groove, wherein the arm is movable in a direction transverse to a longitudinal axis of the device and is restricted from movement in a direction aligned with the longitudinal axis and the groove moves in proximal and distal directions. In some embodiments, in the initial position of the movable handle, the pin is at a proximal region of the groove.

[0015] In accordance with a second aspect of the present disclosure, a surgical device is provided comprising a handle portion including a movable handle, an elongated tubular portion extending distally from the handle portion, a first jaw having a first engagement surface and a second jaw having a second engagement surface. At least the first jaw is movable to transition the first jaw and the second jaw between an open configuration and a closed configuration, wherein the first jaw and the second jaw are arranged to receive tissue therebetween when in the open configuration and to exert force on the tissue via the first engagement surface and the second engagement surface when in the closed configuration. A drive assembly is operable to drive at least the first jaw to transition the first and second jaws between the open configuration and the closed configuration, the drive assembly actuable by the movable handle, and the drive assembly including a cam with a non-linear groove and a pin engageable with the groove. The groove and pin are positioned within the handle portion, and movement of the movable handle causes relative movement of the pin and groove.

[0016] In some embodiments, in accordance with the second aspect, the groove has a substantially Z-shaped portion. In some embodiments, the pin is movable in a direction transverse to a longitudinal axis and the cam is movable in a proximal and distal direction. The groove can have a stop wherein the pin is engageable with the stop to provide a first preset position of the movable handle. The groove can have an additional stop wherein the pin is engageable with the additional stop to provide a second preset position of the movable handle. In some embodiments, the groove causes a variation of clamping forces applied by the first and second jaws to tissue. In some embodiments, the groove has a first portion and second portion having a greater depth than the first portion.

[0017] Preferably, in the first preset position, the jaws exert a first clamping force on tissue and in the second preset position the jaws exert a second clamping force on tissue. In some embodiments, the second clamping force is greater than the first clamping force.

[0018] In accordance with a third aspect of the present disclosure, a surgical device is provided comprising a handle portion, an elongated tubular portion extending from the tubular portion, a pair of jaws at a distal end of the elongated tubular portion, a window of light transmitting material disposed at the handle portion, the window having a viewing surface extending at least partially along a first plane, a light source at the handle portion operatively arranged with the window for transmitting light through the material of the window along an axis extending substantially parallel to a first plane, and a reflection surface arranged in the window along a second plane transverse to the first plane, the reflection surface configured at a first angle with respect to the axis to reflect the light toward the viewing surface at an angle either greater or less than a critical angle to enable the light to escape the viewing surface.

[0019] In some embodiments, in accordance with the third aspect, the device further comprises a controller operatively coupled to the light source for controlling the light in response to a condition of the device. In some embodiments, the light can be controlled to provide a different pattern of light depending on a condition of the device. In some embodiments, the window includes an insignia, and the insignia has a series of grooves forming the reflection surface. In some embodiments, the first plane is transverse to a longitudinal axis of the tubular portion. The surface can be treated with a reflective coating. The surface can have a roughened surface to scatter reflected light across a wide range of angles.

[0020] The condition can be one or more of the following: the application of electrosurgical energy to tissue clamped between the jaws, an error detected by the device, and/or a change in status of the device.

[0021] In accordance with a fourth aspect of the present disclosure, a surgical device for treatment of parenchyma is provided comprising a handle portion including a movable handle, an elongated tubular portion extending distally from the handle portion and having at least at a distal region a transverse cross-sectional dimension not exceeding 12 millimeters, a first jaw at a distal portion of the device having a first engagement surface, and a second jaw at the distal portion of the device having a second engagement surface. At least the first jaw is movable to transition the first jaw and the second jaw between an open configuration and a closed configuration, wherein the first jaw and the second jaw are arranged to receive parenchyma therebetween when in the open configuration and to exert force on the tissue via the first engagement surface and the second engagement surface when in the closed configuration without causing blunt dissection of the parenchyma. The first and second jaws in the closed configuration have a transverse cross-sectional dimension not exceeding 12 millimeters.

[0022] In some embodiments, in accordance with the fourth aspect, the surgical device further comprises a drive assembly operable to drive at least the first jaw to transition the first and second jaws between the open configuration and the closed configuration, the drive assembly actuable by the movable handle.

[0023] The movable handle can in some embodiments, in accordance with the fourth aspect, have an initial position and at least first and second preset positions, wherein in the first preset position, the jaws exert a first clamping force on tissue and in the second preset position the jaws exert a second different clamping force on tissue. In some embodiments, the second clamping force is greater than the first clamping force.

[0024] In other embodiments, in accordance with the fourth aspect, the drive assembly moves at least the first jaw so that the first jaw and the second jaw variably exert the force on the tissue as a function of a distance between the first engagement surface and the second engagement surface according to a force curve, wherein the force curve is shaped so that the force exerted on the tissue is greater than a threshold force when the distance between the first engagement surface and the second engagement surface is less than a threshold distance and the force exerted on the tissue is less than the threshold force when the distance between the first engagement surface and the second engagement surface is greater than the threshold distance. In some embodiments, the force curve is non-linear, and the force curve can have a progressive slope when the first and second jaws are at a first range of distances and the force curve can substantially plateau when the first and second jaws are at a second range of distances. [0025] In some embodiments, in accordance with the fourth aspect, the drive assembly moves at least the first jaw so that the first jaw and the second jaw variably exert the force on the tissue as a function of a distance between the first engagement surface and the second engagement surface such that forces applied to the tissue by the jaws progressively increase when the first and second engagement surfaces are spaced any of a first set of distances from each other and the forces applied to tissue substantially plateaus when the first and second engagement surfaces are spaced any of a second set of distances from each other, the first set of distances being greater than the second set of distances. The first set of distances can in some embodiments have a percentage force change several times greater than a percentage force change over the second set of distances.

[0026] In some embodiments, in accordance with the fourth aspect, the drive assembly is operable so the first jaw and the second jaw variably exert the force on the tissue as a function of a distance between the first engagement surface and the second engagement surface according to a force curve, wherein the force curve is shaped so that the force exerted on the tissue when the first engagement surface and second engagement surface are spaced a first range of distances changes a first percentage and the force exerted on the tissue when the first engagement surface and the second engagement surface are spaced a second range of distance changes a second percentage, the second percentage being less than the first percentage. In some embodiments, the forces exerted on tissue during the first range of distances progressively increase and the forces exerted on tissue during the second range of distances vary slightly.

[0027] In some embodiments, in accordance with the fourth aspect, the drive assembly includes a non-linear track in the handle portion and a follower engageable with the track, the track having first and second stops.

[0028] In some embodiments, in accordance with the fourth aspect, a first electrode is disposed on the first jaw and a second electrode is disposed on the second jaw. The first and second electrodes can extend in a substantially U-shape configuration spaced inwardly from a peripheral edge of the respective first and second jaws and a non-conductive material can be positioned within the U-shape of the second electrode. [0029] In some embodiments, in accordance with the fourth aspect, a first slot is in the first jaw and a second slot is in the second jaw, the first slot having a region angled with respect to the longitudinal axis of the first jaw, and a drive pin is movable within the first slot to rotate the first jaw toward the second jaw, wherein the first slot sets the force exerted by the first and second jaws on tissue.

[0030] In some embodiments, in accordance with the fourth aspect, the drive assembly sets the force exerted by the first and second jaws on tissue in response to thickness of tissue.

[0031] In some embodiments, in accordance with the fourth aspect, the second jaw is stationary while the first jaw is movable toward the second jaw; in other embodiments, both the first and second jaws are movable toward each other by the drive assembly.

[0032] In some embodiments, t in accordance with the fourth aspect, he first and second jaws each have a length over 30 millimeters.

[0033] The first and second jaws can each have a metal portion, an outer insulator material positioned over the metal portion and an inner insulator positioned between the metal portion and the electrode.

[0034] The first jaw can include an arm and a float portion having a first electrode, the float portion rotatably connected to the first arm to enable the electrode to float with respect to the arm. A spacer can be provided extending from the first jaw to maintain a minimum distance between the first and second engagement surfaces.

[0035] A cutting blade can be provided movable to sever tissue clamped between the first and second jaws, the cutting blade movable independently of jaw closure.

[0036] In accordance with a fifth aspect of the present disclosure, a minimally invasive surgical device is provided comprising a handle portion including a movable handle, an elongated tubular portion extending distally from the handle portion, a first jaw having a first engagement surface and a first electrode and a length exceeding 30 millimeters, and a second jaw having a second engagement surface and a length exceeding 30 millimeters. At least the first jaw is movable to transition the first jaw and the second jaw between an open configuration and a closed configuration, wherein the first jaw and the second jaw are arranged to receive tissue therebetween when in the open configuration and to exert force on the tissue via the first engagement surface and the second engagement surface when in the closed configuration. The first and second jaws in the closed configuration have a transverse cross-sectional dimension not exceeding 12 millimeters.

[0037] In some embodiments, in accordance with the fifth aspect, the device further comprises a drive assembly including a force transfer member operably connected to the movable handle and to at least the first jaw for moving at least the first jaw to the closed configuration, wherein the force transfer member extends in the elongated tubular portion and the force transfer member moves at least the first jaw to the closed position.

[0038] The device can further include a blade actuating member operably connected to a trigger at the handle portion and to a blade, the blade actuating member extending in the elongated tubular portion. The device can also include an articulation member for moving the jaws between a first position substantially aligned with a longitudinal axis of the elongated tubular portion and a second position at an angle to the longitudinal axis, the articulation member extending in the elongated portion. The jaws can in some embodiments be articulatable to an angle of up to about 60 degrees to the longitudinal axis.

[0039] In some embodiments, in accordance with the fifth aspect, the second jaw has a second electrode, and the first and second jaws each have a metal portion, an outer insulator material positioned over the metal portion and an inner insulator positioned between the metal portion and the electrode.

[0040] In some embodiments, in accordance with the fifth aspect, the drive assembly includes a non-linear slot in the first jaw to vary the forces exerted by the jaws on tissue. In other embodiments, the drive assembly includes a non-linear slot in the handle portion to vary the forces exerted by the jaws on tissue.

[0041] In accordance with a sixth aspect of the present disclosure, a method of minimally invasively sealing parenchyma is provided comprising the steps of: (a) providing a surgical device having an elongate portion and first and second jaws at a distal portion and a first electrode carried by the first jaw; (b) inserting the first and second jaws through a trocar cannula having a diameter not exceeding 12 millimeters; (c) positioning parenchyma between the first and second jaws when the jaws are in the open configuration; (d) transitioning the first and second jaws to a closed configuration to clamp the parenchyma; (e) applying energy to the first electrode to seal the parenchyma; and (f) sealing the parenchyma with the electrode.

[0042] In some embodiments, in accordance with the sixth aspect, the jaws exert a variable force on the parenchyma as a function of a distance of the jaws and the step of transitioning the jaws to clamp the parenchyma clamps the parenchyma without blunt dissection of the parenchyma.

[0043] In some embodiments, in accordance with the sixth aspect, the second jaw carries a second electrode and the method includes applying energy to the second electrode carried by the second jaw.

[0044] In some embodiments, in accordance with the sixth aspect, the force exerted by the first and second jaws on the parenchyma is varying dependent on the gap between the first and second jaws, the force increasing a first percentage upon initial clamping and subsequently varying a second percentage upon further clamping of the jaws, the second percentage being substantially less than the first percentage.

[0045] In accordance with the sixth aspect, the method can further include the step of actuating a jaw actuator to move a force transfer member within the elongated tubular portion to transition the first and second jaws to the closed position. In some embodiments, the step of actuating the jaw actuator to move the force transfer member moves a pin within a non-linear slot in the first jaw, the slot configured to control the force exerted by the jaws. In other embodiments, the step of actuating the jaw actuator to move the force transfer member moves a pin within a non-linear slot in the handle portion, the slot configured to control the force exerted by the jaws and having first and second preset positions to provide first and second clamping positions of the jaws.

[0046] In accordance with the sixth aspect, the method can further include the step of advancing a blade to sever tissue clamped by the first and second jaws, the blade actuated by a blade actuator movably positioned in the elongated portion. Preferably, the step of advancing the blade is independent of movement of the force transfer member for closing the jaws. In some embodiments, the step of advancing the blade is independent of movement of the force transfer member and the step of advancing the blade cannot be performed if the first and second jaws are not in the closed configuration.

[0047] In some embodiments, in accordance with the sixth aspect, the step of actuating the jaw actuator moves the first jaw toward the second jaw, the second jaw remaining stationary; in other embodiments, the step of actuating the jaw actuator moves both the first and second jaws toward each other.

[0048] The device can further include an indicator to indicate the advancement of the blade.

[0049] In some embodiments, in accordance with the sixth aspect, the step of applying energy to the first electrode cannot be performed unless the first and second jaws are in the closed configuration.

[0050] In some embodiments, in accordance with the sixth aspect, the gap between the jaws in the closed configuration varies along a width of the jaws so the gap is greater at a distance further from a center of the jaw than closer to the center of the jaw.

[0051] In some embodiments, in accordance with the sixth aspect, the step of actuating a jaw actuator so the force transfer member engageable with at least the first jaw transitions at least the first jaw toward the second jaw so the first and second jaws (1) apply a first range of forces to tissue as the jaws transition through a first range of distances, the distances defined between the first and second engagement surfaces; and (2) subsequently apply a second smaller range of forces to tissue as the jaws transition through a second range of distances less than the first range of distances. In some embodiments, the first range of forces progressively increases and the second range of forces varies slightly.

BRIEF DESCRIPTION OF THE DRAWINGS [0052] The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike:

[0053] Figure 1 is a perspective view of a surgical device in accordance with one embodiment having an end effector assembly including a set of jaws shown in an open position and a trigger for a blade shown in an initial position;

[0054] Figure 2 is a perspective view of the handle portion of the surgical device of Figure 1 with a portion of the handle housing removed to illustrate internal components;

[0055] Figure 3 is a cross-sectional view of the surgical device of Figure 1;

[0056] Figure 4 is a perspective view of the surgical device of Figure 1 with the jaws in a closed position and the blade trigger in the initial position;

[0057] Figure 5 is a perspective view of the handle housing of the surgical device of Figure 4 with a portion of the handle housing removed and corresponding to the position of Figure 4;

[0058] Figure 6 is a cross-sectional view of the handle portion of the surgical device of Figure 1 corresponding to the position of Figure 4;

[0059] Figure 7 is a perspective view of the surgical device of Figure 1 with the jaws in a closed configuration and the blade trigger in an actuated position;

[0060] Figure 8 is a perspective view of the handle housing of the surgical device of Figure 1 with a portion of the handle housing removed corresponding to the position of Figure 7;

[0061] Figure 9 is a cross-sectional view of the surgical device of Figure 1 corresponding to the position of Figure 7;

[0062] Figure 10A is a close up perspective view of the jaws of Figure 1 shown in an open position;

[0063] Figure 10B is a cross-sectional view of the jaws of Figure 1 shown in the open position; [0064] Figure IOC is a cross-sectional view of the jaws of Figure 1 shown in the closed position;

[0065] Figure 10D is bottom perspective view of the upper jaw of Figure 1 shown in the open position;

[0066] Figure 11 is a perspective view of the circle area of Figure 7 showing jaws in the closed configuration; and

[0067] Figure 12 is a cross-sectional view of the circle area of Figure 3 showing the jaws in the open position;

[0068] Figure 13 is a cross-sectional view of the circled area of Figure 9 showing the jaws in the closed position;

[0069] Figure 14 is a transverse cross-sectional view of the jaws taken generally along the line 14-14 in Figure 13;

[0070] Figure 15 is a cross-sectional view schematically illustrating a set of jaws clamping a representative hollow or layered tissue structure;

[0071] Figure 16 is a cross-sectional view schematically illustrating a set of jaws initially clamping a representative bulk tissue structure;

[0072] Figure 17 is a cross-sectional view of the jaws of Figure 16 after a clamping pressure of the jaws on the bulk tissue structure has been increased;

[0073] Figure 18 is a plot schematically illustrating a force curve for controlling the operation of jaws of a surgical device according to one embodiment;

[0074] Figure 19 is an enlarged view of the area generally circled in Figure 2;

[0075] Figure 20A is an enlarged view of the area of Figure 19 with the blade trigger in the actuated position;

[0076] Figure 20B is an enlarged bottom perspective view of the area of Figure 19 with the blade trigger in the actuated position. [0077] Figure 21 is a perspective view of a feedback mechanism for indicating actuation of the trigger of the surgical device of Figure 1 ;

[0078] Figure 22 is a cross-sectional view of a shaft of the surgical device taken generally along line 22-22 in Figure 13;

[0079] Figure 23 is a perspective view of a surgical device according to an alternate embodiment of the present disclosure illustrating the proximal portion of the surgical device;

[0080] Figures 24A and 24B are cross-sectional views of the window of the surgical device of Figure 23;

[0081] Figure 25 is a side view of another alternate embodiment of the surgical device, the jaws shown in the open position and the trigger shown in the initial position;

[0082] Figure 26 is a cross-sectional view of the device of Figure 25;

[0083] Figure 27 is a perspective view of the handle portion of the device of Figure 25 with a portion of the handle housing removed;

[0084] Figures 28A and 28B are enlarged side perspective views of the lock mechanism of the surgical device of Figure 25; and

[0085] Figure 28C is an enlarged side perspective view of the lock mechanism of Figure 28A showing the pin at an intermediate portion of the lock mechanism.

DETAILED DESCRIPTION

[0086] A detailed description of one or more embodiments of the disclosed device and method are presented herein by way of exemplification and not limitation with reference to the Figures.

[0087] Referring now to the Figures, a surgical device 10 according to one embodiment is described with respect to Figures 1-22B. The surgical device 10 includes a body or housing 12 having a handle portion or handle assembly 14. The handle assembly 14 is intended to be held, gripped, grasped, operated, manipulated, etc., by a user, e.g., a medical professional, during use of the device 10. A shaft or elongated tubular portion 16 extends distally from the housing 12 along a longitudinal axis 17 and terminates at an end effector assembly 18. The terms distal and proximal as used herein are generally with reference to a user of the surgical device 10, with proximal denoting closer to the user and distal denoting further from the user, and it is accordingly to be appreciated that the housing 12 is said to be located at a proximal end of the shaft 16, while the end effector assembly 18 is located at a distal end of the shaft 16. Likewise, movement toward the end effector assembly 18, e.g., along the axis 17, is considered to be in the distal direction, while oppositely directed movement is considered to be in the proximal direction.

[0088] In one embodiment, the device 10 is used as a resection instrument, e.g., for sealing and/or cutting blood vessels, parenchyma, and/or other tissue. To this end, the end effector assembly 18 can include any desired tools or components, e.g., a pair of jaws clampable together to grip tissue therebetween, a blade or knife for cutting tissue, one or more electrodes for providing thermal energy to the tissue suitable for sealing the tissue, a stapler, etc., examples of which are described in more detail below. The terms seal, weld, bond, cauterize, fuse, etc. are generally interchangeable as used herein and refer to the sealing, welding, bonding, or fusing of tissue together, such as to prevent the flow of fluid through the seal or weld. For example, the application of heat can be used to coagulate compounds in the tissue, denature collagen and other proteins, etc. Proteins such as collagen are then entangled and re-crosslink to bond previously separate portions of the tissue together. Cutting or severing refers to the separation, e.g., mechanical separation, of portions of the tissue, e.g., by a blade, knife, or other cutting implement. By first sealing the tissue, e.g., via the application of heat from one or more electrodes, the seal will prevent fluids, e.g., blood through vessels, air through lung parenchyma, etc., from undesirably escaping from the tissue when the tissue is cut.

[0089] In the illustrated embodiment, the end effector assembly 18 of the surgical device 10 positioned at the distal portion of device includes a set or pair of jaws identified individually as a jaw 20a and a jaw 20b, and which may be collectively referred to herein as "the jaws 20". In the illustrated embodiment, the jaw 20a is movable with respect to the shaft 16, while the jaw 20b is fixed with respect thereto. It is to be appreciated that in non-illustrated embodiments the jaw 20b can be movable and the jaw 20a fixed, or both of the jaws 20 can be movable toward and away from each other for movement between open and closed configurations (positions). Regardless of which of the jaws 20 is/are movable, relative motion between the jaws 20 is capable in order to transition the jaws 20 between an open configuration (e.g., as illustrated in Figures 1, 3, 10, 12) and a closed configuration (e.g., as illustrated in Figures 4, 7, 9, 11, 13).

[0090] As noted above, in one embodiment the end effector assembly 18 is arranged to seal a section of tissue. In the illustrated embodiment, the end effector assembly 18, shown best in Figures 10-14, includes an electrode 22a disposed with the jaw 20a and an electrode 22b disposed with the jaw 20b (collectively and/or generally, "the electrodes 22"). By providing the electrodes 22 with opposing polarities, radiofrequency (RF) energy can be communicated through the tissue clamped between the electrodes 22 by the jaws 20. As shown in Figure 10A, electrode 22b positioned on jaw 22b extends in a U-shape adjacent to, but spaced inwardly of a periphery of the jaw 20b. An insulating material or non-conductive base 80 is positioned within the "u" of electrode 22a, extending in the center of the jaw 20a along a longitudinal axis of jaw 20a. Similarly, electrode 22a of jaw 20a extends in a U-shape adjacent to, but spaced inwardly of a periphery of the jaw 20b. The RF energy will heat the tissue in order to create a seal or weld as described above. In one embodiment, the electrodes 22 are heating elements, e.g., resistance heaters, which generate heat via the resistance of current flowing therethrough as opposed to communicating RF energy through the tissue. In the illustrated embodiment, a single electrode is provided with the jaws 20 but in alternate embodiments multiple electrodes spaced apart can be provided in each jaw. In order to prevent the sticking of heated tissue to the outer surfaces of electrodes 22, the electrodes 22 and/or other outer surfaces of the jaws 20 can be coated with polytetrafluoroethylene (PTFE) or another "non-stick" material.

[0091] The handle assembly 14 is arranged to actuate, activate, or otherwise control operation of the end effector assembly 18, e.g., to move the jaws 20 between their open and close configurations (positions). To this end, the handle assembly 14 includes a fixed handle member 24 and a movable handle member 26. The jaws 20 are transitionable into the aforementioned open and closed configurations by respectively moving the movable handle member 26 relative to the fixed handle member 24 between an initial, default, or first position (e.g., as shown in Figures 1-3) and an actuated, activated, or second position (e.g., as shown in Figures 4-6). For example, a user can grip the surgical device 10 by placing a thumb of one hand around the fixed handle member 24 and other fingers of that hand around the movable handle member 26. The jaws 20 can then be transitioned by squeezing the thumb and fingers together to move the movable handle member 26 proximally between its initial or first and actuated or second positions. The user's index finger can be used for other and/or additional purposes described below, e.g., actuating a trigger to deploy a blade of the end effector assembly 18, activating a switch to power the electrodes 22, etc.

[0092] The movable handle member 26 of the handle assembly 14 in the illustrated embodiment includes a lever 28. The lever 28 is secured to the housing 12 at a pin or pivot 30 in order to enable rotational movement of the movable handle member 26 relative to the fixed handle member 24. A torsion spring 32 or other biasing element can be included for biasing the movable handle member 26 distally towards its initial position, thereby maintaining the movable handle member 26 in or toward its initial position when the movable handle member 26 is not being actuated.

[0093] The movable handle member 26 is coupled to the end effector assembly 18 via a drive assembly 34 in order to transition the jaws 20 between their respective open and closed configurations in response to the movable handle member 26 moving between its initial and actuated positions. The drive assembly 34 includes a follower member 36 movably mounted on the shaft 16 that is displaceable along the shaft 16 due to movement of the movable handle member 26. Movement of the follower member 36 results in compression of a spring 38 or other biasing element against a collar 40. As shown, spring 38 is positioned proximal of follower 36 and distal of collar 40. The collar 40 is also movably mounted on the shaft 16, but can move independent of the lever 28 and the follower member 36. Movement of the collar 40 relative to the shaft 16 is limited by a pin 42, fixed to the collar 40, located in an axially extending slot 44 formed in the shaft 16. The pin 42 is also secured to the proximal end of a force transfer member 46 that extends (Figure 3) through the shaft 16 to the end effector assembly 18. Thus, collar 42 is operatively connected to the jaws 20. In this way, the force applied, e.g., by a user, to the movable handle member 26 is received by the drive assembly 34 and ultimately transferred to the end effector assembly 18 via the force transfer member 46.

[0094] The drive assembly 34 additionally includes a jaw drive pin 48 secured to the distal end of the force transfer member 46. In order to effect movement of the jaw 20a relative to the jaw 20b, the drive pin 48 as shown in Figure 10-14 rides simultaneously in a slot 50 directed axially with respect to the axis 17 of the shaft 16 and a variable slot 52 that is curved, bent, angled, or otherwise misaligned or variable in angle with respect to the axis 17. Accordingly, the slot 52 may be referred to as the variable slot 52. The slot 50 is formed in the fixed jaw 20b, or in the movement for the fixed jaw 20a, which restricts the drive pin 48 to only axial movement with respect to the fixed jaw 20b, while the variable slot 52 is formed in the movable jaw 20a. As the movable jaw 20a is secured to the fixed jaw 20b at a pin or pivot 54, movement of the drive pin 48 along the axial slot 50 results in the movable jaw 20a rotating about the pivot 54 in order for the drive pin 48 to also travel along the variable slot 52. In this way, movement of the movable handle member 26 in the proximal direction (toward the fixed handle member 24) results in the force transfer member 46 moving proximally which moves the drive pin 48 proximally, which rotates the movable jaw 20a toward the fixed jaw 20b (to the closed configuration). Movement of the movable handle member 26 in the distal direction (away from the fixed handle member 24) results in the force transfer member 46 moving distally which moves the drive pin 48 distally, which rotates the movable jaw 20a away from the fixed jaw 20b (to the open configuration).

[0095] In the illustrated embodiment and as shown in Figures lOA-lOC, the variable slot is offset from a longitudinal axis of the jaw 20a. More particularly, the slot 52 has a varying curve configuration which controls the clamping forces on tissue. As shown, arcuate portion 52a of slot 52 has an increased radius of curvature as compared to portion 52 which can be linear or have a slight curvature. The effect of this slot geometry on clamping forces is described in more detail below in conjunction with the discussion of how the drive assembly 34 is structured to set desired forces exerted by the jaws on tissue.

[0096] When movable handle member 26 is pivoted proximally toward stationary handle member 24, lever 28 moves follower member 36 proximally which compresses spring 38 and moves collar 40 proximally to retract force transfer member 46 to move jaw 20a toward 20b. Release of movable member 26 causes the reverse motion, returning force transfer member 46 to its original distal position as spring 38 returns to its uncompressed position to open jaws 20. In the illustrated embodiment, the force transfer member 46 is formed by one or more drive ribbons, capable of transferring both compressive and tensile forces, although it is to be appreciated that any other structure capable of transferring force can be alternatively or additionally utilized, e.g., one or more rods, bars, wires, etc. Thus, the force transfer member 46 is moved in a proximal direction, i.e. pulled proximally, to effect jaw closure.

[0097] Representative sections of tissue are shown in Figures 15-17 being clamped by the jaws 20 and designated with the numerals 56a and 56b (collectively and/or generally, "the tissue 56")· In Figure 15, the tissue 56a schematically represents a blood vessel, a generally hollow structure having a lumen formed therethrough and/or some other multi-layered tissue structure. As illustrated, the clamping force exerted by the jaws 20 causes opposing wall portions of the tissue 56a, each having a wall thickness t, to contact together, creating a total cross- sectional thickness Tl of the tissue 56a clamped by the jaws 20 (with the thickness Tl equaling approximately twice that of the thickness t). By subjecting the tissue 56a to heat, e.g., via RF energy transferred between the electrodes 22, the opposing wall portions will denature, coagulate, etc., and become sealed or bonded together, e.g., in order to prevent blood from flowing through the sealed section of the tissue 56a.

[0098] The tissue 56b in Figures 16-17 is representative of a bulk of tissue, e.g., parenchyma, as opposed to the hollow structure represented by the tissue 56a. In some instances, particularly thick tissue may not be heated thoroughly therethrough, which may result in a poor or insufficient seal throughout the entire cross-section of the tissue 56b. Thus, in order to achieve a good seal with a relatively large bulk portion of tissue, in some situations, it may be desirable to perform several heating cycles with the electrodes 22. Figure 16 accordingly illustrates the tissue 56b being initially grabbed by the jaws 20 and only partially compressed therebetween. In this way, for example, the electrodes 22 can be powered a first time in order to heat the tissue 56b and begin sealing the cross-section of the tissue 56b clamped between the jaws 20. The denaturing, coagulating, re-crosslinking, etc., due to heating may result in a reduction of the cross-sectional thickness of the tissue 56b, as illustrated from a first thickness T2 shown in Figure 16 to a second thickness T3 shown in Figure 17. In some embodiments, the tissue 56b may be sufficiently sealed after one heating cycle, while in other embodiments it may be desired to power the electrodes 22 at least a second time in order to re -heat the now thinner cross- sectional portion of the tissue 56b and establish an improved seal.

[0099] It has been discovered by the inventors that certain tissue types, such as blood vessels and other relatively thin tissue structures (e.g., the thickness Tl of the representative tissue 56a, or the thickness T3 of the tissue 56b after undergoing a first heat cycle) may seal more favorably when subjected to relatively higher jaw forces. However, other tissue types, such as relatively thick sections of bulk or soft tissue, such as lung, liver, or other organ parenchyma (e.g., the thickness T2 of the representative tissue 56b before undergoing a first heat cycle), may undesirably blunt dissect at the same relatively high pressures that are desired to suitably seal blood vessels and other relatively thin tissue structures. Accordingly, the drive assembly 34, as discussed above, can be arranged to cause the jaws 20 to exert forces that are variable with respect to the cross-sectional thickness (e.g., the thickness Tl, T2, T3, etc.) of the tissue 56 being sealed. In lieu of directly measuring the cross-sectional thickness of the tissue, the jaws 20 can be arranged to exert different forces depending on the size of a gap 58 located between a tissue engagement or sealing surface 60a of the electrode 22a and a tissue engagement or sealing surface 60b of the electrode 22b (collectively and/or generally, "the surfaces 60"), as the distance of the gap 58 corresponds to the thickness of the tissue engaged between the surfaces 60.

[0100] In one embodiment, the drive assembly 34 is arranged to at least partially define the operating characteristics of the jaws 20 in response to actuation of the movable handle member 26. For example, as noted above, the drive assembly 34 can be arranged to set the force exerted by the jaws 20 on the tissue 56 in response to the thickness of the tissue 56. An exemplary force curve 62 that defines operation of the jaws 20 according to one embodiment is illustrated in Figure 18. Specifically, the force curve 62 shows the force exerted by the jaws 20 with respect to the distance of the gap 58.

[0101] From the force curve 62 of Figure 18, it can be seen that a relatively large force is exerted by the jaws 20 when the jaws 20 are relatively close together, but that the exerted force decreases rapidly at gap distances above a certain point. In furtherance of explanation, dashed lines 64 and 66 are included with the force curve 62 to depict a threshold force Fx and a threshold distance Tx. Also included are labels corresponding to gap distances equaling the thicknesses Tl, T2, and T3 of the tissues 56a and 56b (shown in Figures 15-17), as well as a set of forces Fl, F2, and F3, corresponding respectively thereto. It can be seen that the force exerted by the jaws 20 is relatively consistent and greater than the threshold force Fx for gap distances less than the threshold distance Tx. For example, it can be seen that the thicknesses Tl and T3 correspond to distances of the gap 58 that are less than the threshold distance Tx, and thus the corresponding forces Fl and F3 are both greater than the threshold force Fx. It is noted that although the distance T3 is substantially greater than the distance Tl, e.g., multiple times greater, the forces Fl and F3 remain substantially similar in value and greater than the threshold force Fx. Oppositely, the thickness T2 corresponds to a distance of the gap 58 that is greater than the threshold distance Tx, and thus the force F2 exerted by the jaws 20 is significantly less than the threshold force Fx. Advantageously, controlling operation of the jaws 20 according to the force curve 62 enables a variety of tissue structures of various cross-sectional thicknesses to be suitably sealed by the device 10 without deleterious effects such as blunt dissection of the tissue.

[0102] Stated another way, when the jaws 20 are initially closed and moved toward each other so the tissue engagement surfaces of the jaws are separated by a first set of distances, the force exerted on tissue progressively increases. This is represented in the slope of the line on the force curve of Figure 18. However, once the jaws 20 are brought to a certain point, i.e., the tissue engagement surfaces are moved to a predetermined distance apart, the force exerted on tissue essentially plateaus so that as the jaws 20 move closer together along a second set of distances between the tissue engagement surfaces, the forces do not continue to progressively increase at the same rate. This is illustrated in the more horizontal line of the force curve of Figure 18. It should be understood, that substantial plateau means that the forces no longer increase as they did during the first set of distances. This plateau could be linear so the forces do not change or slightly variable as in the line of Figure 18. In fact, the forces can even slightly decrease during the plateau portion. With this force curve, the percentage change in forces during the first set of distances is much greater than the percentage change in forces over the second set of distances. Note if the forces continued on an upward slope without plateauing such that the forces progressively increased as the tissue engagement surfaces got closer together, the forces applied to the tissue could increase to as much as 40 pounds which could dissect the tissue in certain applications.

[0103] Figure 18 illustrates an example of the threshold force and distance values In one embodiment, the threshold force Fx can be about 90% to about 95% of a maximum force 68 that is exertable by the jaws 20. In one embodiment by way of example, the threshold distance Tx can be the range of about 2.0 mm to about 3.5 mm and in a further embodiment can be in the range of about 2.5mm to about 3.0 mm. In other embodiments, the threshold distance Tx can be as low as about 1mm (thereby corresponding to typical vessel geometry, which is generally less than 1mm in total thickness as noted above), or as large as about 7mm (corresponding to larger vessels or other tissue bundles that would benefit from higher clamping forces). It should be appreciated that these are provided by way of example as other values distances are also contemplated. In one embodiment, the threshold force can be in the range of about 17 pounds to about 20 pounds, and in a further embodiment can be in the range of about 18 pounds to about 19 pounds, although it is to be appreciated that the force exerted by the jaws 20 can be modified to greater or lesser values in order to accommodate different types of tissue, different dimensions and/or geometries for the jaws 20, etc. Thus, in the example represented by the force curve of Figure 18, as the tissue engagement surfaces of the jaw 20 decrease from a distance apart of about 5mm to about 2.75 mm, the force exerted on the tissue increases from about 14 pounds to about 18.5 pounds. When the distance between the tissue engagement surfaces of the jaw 20 continues to decrease from about 2.75mm towards a minimal or no gap, the force exerted on tissue is only slight variable between about 18.5 to 19 pounds. It should be appreciated, that the numeric values shown in Figure 18 and described herein are provided by way of example for ease of understanding and applicable to only some embodiments, it being understood in alternate embodiments, the gap (distance) between the tissue engagement surfaces and the resulting forces applied by the jaws will have different values, although the forces would still follow a force curve of more rapidly increasing and then leveling off as described above.

[0104] In one embodiment, the curvature or angulation of the variable slot 52 is set in order to control the force exerted on the jaw 20a by the drive pin 48 at different points along the length of travel along the variable slot 52 of jaw 20a. The changing angle or curvature of the variable slot 52 results in the force transferred to the jaw 20a via the drive pin 48 to change with respect to the position of the drive pin 48 along the variable slot 52. For example, a relatively more axially orientated section of the variable slot 52 may have a slope, curvature, or angle with respect to the axis 17 that results in a relatively smaller degree of rotation of the jaw 20a, and thus, a relatively lower force exerted by the jaws 20, per unit length of movement of the force transfer member 46, with the slope, angle, or curvature of the variable slot 52 becoming steeper or resulting in greater forces to be transferred to the jaw 20a per unit length of movement of the pin 48 within the variable slot 52 as the jaws 20 become increasing closed. In this way, the force curve (e.g., the force curve 62) can be set to include a generally plateaued or constant range of forces in one gap distance range (e.g., the forces corresponding to gap distances below the threshold distance Tx in the force curve 62, which are all above the threshold force Fx), but with a significant change in force outside of that range (e.g., as seen in the relatively steep or sudden drop off in force for gap distances greater than the threshold distance Tx).

[0105] In addition to or in lieu of the using the geometry of the variable slot 52 to control the force, the properties of other components of the drive assembly 34 can be set to achieve the desired jaw force curve (e.g., the force curve 62), such as the properties of the spring or biasing element 38, e.g., spring constant, length, pre-load, etc. For example, the force exerted by the spring or biasing element 38 on the jaw 20a via the force transfer member 46 changes due to elongation and compression of the spring 38 as the follower member 36 (due to actuation of the movable handle member 26) moves toward and away from the collar 40. The jaws 20 of the end effector assembly 18 can be arranged to accommodate a number of different tissue arrangements in order to create high quality seals with the surgical device 10 under a variety of conditions. For example, in the illustrated embodiment, the jaw 20a is formed by an actuation arm 70 and a float portion 72. The actuation arm 70 includes the variable slot 52 and is pinned to the fixed jaw 20b at the pivot 54 as described above. The float portion 72 is connected rotatably to the actuation arm 70 at a pin or pivot 74 and includes the electrode 22a thereon in order to enable the electrode 22a to float with respect arm 70, i.e., rotate to some degree relative to the arm 70. The float portion 72 thereby enables, for example, the electrode 22a of the jaw 20a to more readily accommodate or conform to tissues of different and/or inconsistent thicknesses, shapes, or sizes, maintain parallelism with the electrode 22b, etc. Advantageously, this enables sufficiently high and/or consistent forces to be exerted on tissue clamped between the jaws 20, even if the tissue is of various cross- sectional shapes or thicknesses, which can promote better sealing.

[0106] It has also been found by the current inventors that the size of the gap 58 between the tissue engagement surfaces 60 of the electrodes 22 can be determinative of the quality of the seal created when communicating RF energy through each unique section of the tissue 56. For example, different tissue types (e.g., vessels as opposed to parenchyma) or different sections of the same tissue type (e.g., varying between different patients or even different locations within the same patient) can benefit from different distances for the gap 58 even when the same device and generator are used. To this end, in one embodiment, one or both of the electrodes 22 can be tapered, contoured, shaped, or otherwise arranged such that the gap 58 is variable across the width of the jaws 20. In other words, the electrodes 22 can be non-complementarily formed such that the distance defining the gap 58 changes with respect to the width of the jaws 20.

[0107] For example, the end effector assembly 18 is shown in cross- sectional across the width of the jaws 20 in Figure 14. By across the width, it is generally meant that the cross- section of Figure 14 is formed in a plane that is generally perpendicular to the proximal-distal direction, e.g., as represented by the line 14-14 in Figure 13. In this embodiment, the electrode gap 58 is defined by multiple distances that vary with the width of the electrodes 22. Specifically in the embodiment of Figure 14, the electrode 22b is shaped such that the engagement surface 60b is formed by a first inner surface portion 75 (closer to the center) and an outer second surface portion 76 (further from the center). The first surface portion 75 results in the electrode gap 58 being defined by a distance Dl between the engagement surface 60b of the electrode 22b and an engagement surface 60a of the electrode 22a, while the second surface portion 76 tapers or slopes away (radially outward) from the surface portion 75 so that the electrode gap 58 is defined by distances greater than Dl. Stated another way, the electrode 22b tapers laterally (in opposing directions from an intermediate portion of the electrode) so that the distance from electrode 22b to electrode 22a progressively increases toward the outer edge. The changing distance between the electrodes affects the force and energy applied to the clamped tissue, with a greater force toward the center of the clamped tissue. Thus, the taper causes the gap to increase away from the center line. Note that the taper region can be a flat angled surface or a curved surface, either one resulting in a changed distance between the electrodes. Additionally, although Figure 14 shows the tapered electrode on the stationary jaw 20b, it is also contemplated that the taper can be formed on the electrode of the movable jaw 20a either in addition to or instead of taper on the electrode of the stationary jaw 20b. As can be appreciated, the shape of the surface portion 76 results in the electrode gap 58 variably spanning a range of distances. By defining the electrode gap 58 to include multiple or a range of distances, the likelihood is increased the electrode gap 58 will include a distance at which the device 10 will suitably seal tissue, e.g., the tissue 56, regardless of the patient, tissue type, etc. The electrode 22a is illustrated with the engagement surface 60a being consistently substantially flat or proud (e.g., in a plane parallel to the axis 17 when the jaws 20 are fully closed), although it is noted that the electrode 22a can alternatively or additionally be contoured, tapered, shaped, or profiled to create the aforementioned variable distances for the gap 58. Additionally, the contours shown are according to just one example, and it is understood that the electrodes 22 can take other non- complementary shapes that result in a variable size for the electrode gap 58.

[0108] A tip of the electrode 22b can be tapered in a distal direction, designated by region 29b in Figures 9, 10A and 13. A tip of the electrode 22a can also be tapered in a distal direction.

[0109] In addition to variability of the electrode (engagement surface) gap, a minimum size for the electrode gap 58 can be set by inclusion of one or more conductive protrusions 78 (see e.g., Figs. 10A, 10B, 12, and 14) extending between the electrodes 22. That is, even if the jaws 20 are fully closed, the protrusions 78 will support the jaws 20 against each other in order to maintain a minimum spacing between the electrodes 22. In the illustrated embodiment, the protrusions 78 extend from the electrode 22a toward the electrode 22b and contact the non- conductive base such as a ceramic insulator in jaw 20a, disposed oppositely therefrom. It should be understood that the conductive protrusions 78 can alternatively or additionally be formed extending from the electrode 22b toward the electrode 22a in which case electrode 22a would have an insulating material in receiving contact with the protrusions. In the illustrated embodiment, the protrusions 78 are integrally formed with the electrode 22a. The protrusions 78 can have any desired shape and/or size, and any number of the protrusions 78 can be included to properly support the jaws 20 when the jaws 20 are brought together. In the illustrated embodiment by way of example three sets of protrusions can be provided: one at a distal region of electrode 22a, one at an intermediate region of electrode 22a, and one at a proximal region of the electrode 22a. As shown, the protrusions 78 are slightly off center of the central longitudinal axis of the jaw 20a to accommodate a pair of protrusions side by side. Other numbers and locations of protrusions are also contemplated.

[0110] The protrusions 78 are arranged to prevent contact between the electrodes 22, as contact can result in malfunction of the device 10, e.g., an electrical short, charring or severing of the tissue clamped between the jaws 20, poor welds, etc. The protrusions 78 are offset from or misaligned with respect to the engagement surfaces 60 of the electrodes 22 such that when the jaws 20 are brought to the closed configuration the protrusions 78 engage against the non- conductive base 80, which is also offset from the surfaces 60. That is, for example, in the illustrated embodiment the surfaces 60 extend continuously distally to proximally, with the protrusions 78 and the non-conductive base 80 being offset in a direction transverse to the distal- proximal direction. More specifically, with respect to the illustrated embodiment, the electrodes 22 are generally U-shaped, with the protrusions 78 and the non-conductive base 80 offset to the inside of the 'LP. It is to be understood that in alternate embodiments, the offset can be to the outside of the U- shape or in some other direction with respect to other shapes for the electrodes 22. Additionally, the non-conductive base 80 is illustrated having a U-shape, but can be arranged in other embodiments as discrete structures aligned with each of the protrusions 78, strips aligned with each row of the protrusions 78, etc. As illustrated, the non-conductive base 80 can be flush with and/or slightly recessed from the engagement surface 60b of the electrode 22b, e.g., in order to reduce contact of the base 80 with tissue, e.g., the tissue 56, in order to control loading on the tissue, reduce sticking, etc.

[0111] The surgical device 10 includes a power switch 82 disposed within the housing 12. The power switch 82 is electrically coupled to the electrodes 22 via electrical conductors 83, e.g., electrical cables or wiring. The power switch 82 is arranged to be triggered by the user of the device 10, e.g., by pressing a button 84 (see e.g., Fig. 3). By triggering the power switch 82 via mechanical activation of the button 84, power can be selectively supplied from a generator 85 to the electrodes 22. The generator 85 can include or be in communication with a computer device or other control unit to control or set the power delivered by the generator 85, e.g., in response to parameters such as impedance, temperature, time, etc., sensed or measured by sensors in communication with the electrodes 22. For clarity of the other components, portions of the electrical conductors 83 are not shown in each drawing, but it is to be understood that the conductors 83 extend from the generator 85 to the power switch 82 and from the power switch 82 through the shaft 16 to each of the electrodes 22. It is to be appreciated that the generator 85 can be arranged to supply different levels of power to the electrodes 22, e.g., depending on input sensed or measured by the device 10 or input by a user of the device. For example, in one embodiment, the device 10 can be arranged such that pressing the button 84 multiple times cycles through a number of different power options for the generator 85. In one embodiment, the device 10 can include multiple buttons, or a single button having multiple settings, with the multiple buttons and/or settings corresponding to different power levels or modes of operation for the generator 85.

[0112] The electrodes 22 are not intended to be powered prior to clamped engagement of tissue by the jaws 20. In order to prevent premature activation of the electrodes 22, the movable handle member 26 includes a cover 86 that selectively impedes access to the power switch 82. Namely, the cover 86 forms a cavity 88 into which the button 84 is recessed or hidden when the movable handle member 26 is in its initial position, e.g., as illustrated in Figure 1. As shown, in the position of Figure 1 the trigger 120 also blocks access to the button 84 recessed within the cover. When the jaws 20 are closed by moving the movable handle member 26 to its actuated position, e.g., as shown in Figure 4, ready access to the button 84 is enabled. In other words, moving the movable handle member 26 to its actuated position in order to transition the jaws 20 to their closed configuration results in the cover 86 moving relative to the button 84 to a position at which the button 84 extends at least partially out from the cavity 88 for access by the user. In this way, a user is effectively prevented from accessing the button 84 and activating the electrodes 22 via the button 84 of the power switch 82 until after the jaws 20 have been closed. [0113] As noted above, the torsion spring 32 assists in maintaining the jaws 20 in their open configuration by biasing the movable handle member 26 toward its initial position when the movable handle member 26 is not being actuated. Similarly, the surgical device 10 can include a jaw lock mechanism 90, best seen in Figures 3 and 6, arranged to maintain the jaws 20 in the closed configuration even after a user releases pressure on the movable handle member 26. In the illustrated embodiment, the jaw lock mechanism 90 includes a cam 92 and a cam follower 94. The cam 92 includes a slot or groove 96 through which the cam follower 94 traverses as the movable handle member 26 is actuated toward the fixed handle member 24. The cam follower 94 is secured at the end of a cantilevered element 98 that is arranged to enable the cam follower 94 at the free end of the cantilevered element 98 to follow the groove 96 and then to be springingly or resiliency urged back to a default position by the element 98. In the illustrated embodiment, the cam 92 is formed in the movable handle member 26, and the cam follower 94 is secured to the fixed handle member 24, although it is to be appreciated that these components can be arranged oppositely (e.g., the cam follower 94 with the movable handle member 26) or between other pairs of components that experience relative movement with respect to the movable handle member 26.

[0114] In operation, movement of the movable handle member 26 toward the fixed handle member 24 results in the cam follower 94 encountering a first angled surface or ramp 100. The ramp 100 causes the cam follower 94 to move along the groove 96 in the generally downward direction with respect to the orientation of the device 10 in Figures 3 and 6. Continued actuation of the movable handle member 26 causes engagement of the cam follower 94 with a first stop 102 in the groove 96, preventing further movement of the movable handle member 26 toward the fixed handle member 24. Releasing the movable handle member 26 when the cam follower 94 is at the first stop 102 results in the torsion spring 32 or other biasing element urging the movable handle member 26 back away from the fixed handle member 24, while the cantilever element 98 urges the cam follower 94 in the generally upward direction with respect to the orientation of the device 10 in Figures 3 and 6, causing the cam follower 94 to engage and "climb" a second angled surface 104 until engaging with a second stop 106. When in the second stop 106, the torsion spring 32 or other biasing element holds the movable handle member 26 in its second, or actuated, position, as shown in Figure 6, which corresponds to the closed configuration of the jaws 20. Re-actuating the movable handle 24 causes the cam follower 94 to travel along the groove 96 until engagement with a third stop 108, preventing further actuation of the movable handle member 26. Releasing the movable handle member 26 when the cam follower 94 is at the third stop results in the torsion spring 32 or other biasing element again moving the movable handle member 26 away from the fixed handle member 24, thereby enabling the cam follower 94 to exit from the groove 96. This resets the jaw lock mechanism 90 such that it can re-lock the movable handle member 26 during each subsequent actuation thereof.

[0115] In addition to sealing tissue with the end effector assembly 18, as described above, the end effector assembly 18 may also be arranged to cut, sever, or dissect portions of tissue, e.g., the tissue 56. For this reason, the end effector assembly 18 optionally includes a blade, knife, or cutting implement 110, which can be best seen in the cross-sectional view of Figures 12 and 13. The cutting blade 110 is located at the distal end of a force transfer member 112, e.g., a drive ribbon, bar, rod, etc., that extends through the shaft 16. The proximal end of the force transfer member 112 is secured to a drive collar 114 (Figures 2 and 3) via a pin or fastener 116. Note the force transfer member 112 for the blade 110 is positioned radially spaced from the force transfer member 46 for jaw 20a, both extending within the shaft 16 and both radially spaced from a central longitudinal axis of the shaft 16. Movement of the pin 116 is delimited by the positioning of the pin 116 within an axially extending slot 118 formed in the shaft 16. A trigger 120, secured rotatably to the housing at a pivot 122, and in the illustrated embodiment positioned above (as viewed in the orientation of Figure 2) the movable handle 26 is operably coupled to the blade 110 such that actuation of the trigger 120, e.g., by a finger of a user of the surgical device 10, results in deployment of the blade 110 in order to cut tissue, e.g., the tissue 56. The trigger 120 is shown in a first or initial position in Figures 1-6, corresponding to the retracted position of the blade 110 shown in Figure 12 (the jaws 20 closed with the blade still retracted in the configuration of Figures 4-6), and in a second or actuated position in Figures 7-9, corresponding to the deployed position of the blade 110 shown in Figure 13. Thus, pulling the trigger 120 to move the blade 110 is actuable separately (independently) from jaw actuation. [0116] The drive collar 114 is connected to the trigger 120 via an arm 124, extending from the trigger 120 opposite to the pivot 122, and a linkage 126 extending between the arm 124 and the collar 114. In this way, actuation of the trigger 120 rotates the arm 124 clockwise, which moves the collar 114 in the distal direction via the linkage 126. The connection of the collar 114 to the force transfer member 112 via the pin 116 causes the collar 114 to also move force transfer member 112, and thus the blade 110, in the distal direction. A cutting plane 127 is included in Figures 15 and 17 to illustrate one location and orientation for the blade 110 as it cuts through the tissue 56a and/or 56b due to actuation of the blade 110 via the trigger 120. A spring 128 or other biasing element can be included, e.g., between the housing 12 and the arm 124, in order to urge the trigger 120 and the blade 110 back toward the initial position when not actuated.

[0117] As discussed above, cover 86 prevents premature activation of the electrodes 22 before the jaws 20 are transitioned to the closed configuration. A blade lock mechanism 130 can also be included to prevent actuation of the blade 110 until the jaws 20 are closed. In the illustrated embodiment, the blade lock mechanism 130 includes one or more lock or blocking arms 132 extending toward the trigger 120 from the lever 28 of the movable handle member 26. When the movable handle member 26 is in the initial position, e.g., as shown in Figures 2 and 19, the lock (blocking) arms 132 engage with and support a locking feature or projection 134 projecting eccentrically from the trigger 120 in order to prevent rotation of the trigger 120 about the pivot 122 due to interference of the feature 134 with the lock arms 132. As shown in Figures 20B the engagement (or abutment) member 134 in the initial position rests on ledge 132a of arms 132. When the movable handle member 26 is moved to the actuated position, as shown in Figures 5, 8, and 20, and the jaws 20 are thus transitioned to their closed configuration, the lock arms 132 are moved proximally away from the trigger 120, removing blocking of the projection 134, which enables the trigger 120 to rotate about the pivot 122.

[0118] Additionally, as can be seen in Figure 19 and 20A, the lock arms 132 extend distally beyond the feature 134 when the movable handle member 26 is in its initial position such that the lock arms 132 advantageously remain engaged with the feature 134 over a degree of movement of the movable handle member 26 toward the actuated position from the initial position. This ensures that the trigger 120 and blade 110 are not free for movement if the movable handle member is moved only partially proximally to partially close the jaws, but only free for movement when movable handle member 26 has moved a sufficient distance to close the jaws.

[0119] It is also to be appreciated that the lock arms 132 and the feature 134 are arranged such that forces exerted on the trigger 120 (e.g., by a user purposely or inadvertently before the blade 110 is unlocked) are transferred to the arms 132 via the feature 134 in a direction substantially perpendicular to the direction of movement/actuation of the lever 28. Since the forces are perpendicularly directed with respect to the direction of actuation of the movable handle member 26, such forces will not readily cause actuation of the movable handle 24. In other words, the device 10 is arranged such that prematurely pulling the trigger 120 will not result in actuation of the movable handle member 26. This is due to the fact that engagement member 134 is positioned atop (as viewed in the orientation of Figures 19 and 20A) locking arms 132. Since the trigger 120 moves in a pivoting motion, if a user attempts to pull back on the trigger 120 it will only apply a downward force on the lock arm 132 and not a proximal force so that the lock arms 132 will not be moved proximally out of the way of the trigger 120.

[0120] It is additionally noted that the lock arms 132 are arranged to return the blade 110 to the retracted position when the movable handle member 26 is moved back to the initial position from the actuated position. That is, movement of the lock arms 132 toward the initial (distal) position from the actuated (proximal) position will cause the arms 132 to encounter the feature 134 and force rotation of the trigger 120, via engagement with the arms 132, back to its initial position and thereby retract the blade 110 as force transfer member 112 is pulled proximally via linkage 126 and collar 114.

[0121] The trigger 120 may also be equipped with a feedback mechanism 135 for indicating to the user when the blade 110 becomes fully deployed, i.e., reaches the position shown in Figure 13. In the illustrated embodiment, the feedback mechanism 135, shown in Figure 21, includes a resilient prong 136 secured to the housing 12 in a cantilevered manner and extending toward the arm 124 of the trigger 120. As the blade 110 approaches its fully deployed position, the trigger 120 reaches an intermediate position at which the arm 124 contacts the prong 136, as illustrated in Figure 21. Thus, prong 136 and arm 124 are initially spaced a distance corresponding to the distance trigger 120 and this arm 124 move to advance the blade 110 close to its fully deployed position The arm 124 may include a surface or feature 138 arranged to engage against the prong 136. Once contacted, continued actuation of the trigger 120 will cause the prong 136 to flex or buckle against the surface 138. This flexing or buckling may also increase the resistance felt by the user when further pulling the trigger 120. Further actuation of the trigger 120 toward the actuated position (e.g., toward the position of Figure 7) will result in the prong 136 disengaging or releasing from the arm 124. This disengagement or release is communicable to the user as a "pop" or "ping" in the trigger 120 as the buckled prong 136 suddenly and resiliency deflects off to the side of the arm 124. The change in resistance, sound, and/or the vibrations experienced by the user due to the prong 136 suddenly disengaging from the arm 124 indicates to the user that the blade 110 has reached its fully deployed position.

[0122] According to the illustrated embodiment, the surgical device 10 includes an articulation assembly 140 that is arranged to cause rotation of the shaft 16 about the axis 17 and/or rotation of the end effector assembly 18 about an axis oriented transversely with respect to the axis 17, e.g., about an axis 142 formed through a pin or pivot 144. The articulation assembly 140 includes a body 146 fixed to the shaft 16, e.g., via one or more keys (not shown) inserted into openings 148 of the shaft 16. In this way, rotation of the shaft 16 about the axis 17 is enabled by rotating the housing or body 146 of the articulation assembly 140 about the axis 17. Rotation of the shaft 16 likewise causes rotation of jaws 20. The body 146 in the illustrated embodiment includes a plurality of fins 150 (Figure 1), which are arranged to enable a user to securely grip the body 146 and rotate the body 146 in order to rotate the shaft 16 about the axis 17.

[0123] In the illustrated embodiment, the pivot 144 that enables rotation of the end effector assembly 18 about the axis 142 (Figure 12) is formed at the distal end of the shaft 16 where the shaft 16 is secured to the end effector assembly 18. It is to be appreciated that such a pivot can be included at any desired location along the length of the shaft 16, that the shaft 16 can be segmented including multiple pivots along the length of the shaft, etc. Articulation of the end effector assembly 18 is achievable by rotating a rotatable driver 152 of the articulation assembly 140. More specifically, one or more force transfer members 154 (see e.g., Figures 8 and 10A), two in the illustrated embodiment, extend from the rotatable driver 152 through the shaft 16, and connect to the end effector assembly 18. A single one of the force transfer members 154 can be included if arranged as a drive ribbon, rod, bar, etc., or other member capable of transferring both compressive and tensile forces.

[0124] The rotatable driver 152 is rotatable about an axis 156 (Figure 6) that is arranged in parallel with the axis 142 and perpendicularly with respect to the axis 17. The force transfer members 154 are eccentrically secured to the rotatable driver 152, which results in the force transfer members 154 translating axially with respect to the shaft 16 during rotation of the rotatable driver 152. Axial movement of the force transfer members 154 exerts compressive and/or tensile forces on one or both sides of the end effector assembly 18 (i.e., pushes and/or pulls) to cause the end effector assembly 18 to rotate (pivot) at the pivot 144 about the axis 142. A knob 158 is fixed to the rotatable driver 152 in order to enable a user to rotate the rotatable driver 152, and therefore articulate the end effector assembly 18, with the knob 158. The knob 158 in the illustrated embodiment is arranged substantially resembling one of the fins 150 so that the knob 158 can additionally be gripped by a user when causing rotation of the shaft 16 about the axis 17 with the body 146.

[0125] As discussed above, the force transfer members 46 and 112 for the jaws 20 and the blade 110, respectively, are formed as ribbons in the illustrated embodiment. The use of ribbons, or other thin bars, facilitates articulation of the end effector assembly 18 about the axis 142, as the ribbons can readily bend in the articulation directions while maintaining the ability to transfer compressive and tensile forces longitudinally therethrough (e.g., as opposed to wires or cables that can only transfer tensile forces). The ribbons are moved in a proximal, pulling direction to close the jaws rather than a pushing motion to facilitate bending around a corner as jaw closure through a pushing motion could cause the pushing member to buckle. Thus, articulation of the device can be effected to greater than 45 degrees and in some embodiments up to 60 degrees with respect to the longitudinal axis of shaft (elongated tubular portion) 16. To help support the force transfer members 46 and 112, and/or prevent buckling thereof, one or more guide blocks 160 can be included. The guide blocks 160 can include smoothly rounded surfaces that are arranged to receive the force transfer member 46 and/or force transfer member 112 when the end effector assembly 18 is articulated and be made from materials having low coefficients of friction, such as PTFE, with respect to the material of the force transfer members 46 and 112.

[0126] In one embodiment, the articulation assembly 140 is provided with preset discrete positions that correspond to varying degrees of rotation of the end effector assembly 18 about the axis 142. For example, in the illustrated embodiment, the rotatable driver 152 is provided with a plurality of detents 162 about its circumference. A ball 164 or other member as shown in Figure 3 formed for reception within and/or engagement with the detents 162 is biased, e.g., via a spring or other biasing element, into the detents 162. Rotation of the rotatable driver 152 results in the ball 164 being forced out of one of the detents 162 for reception in an adjacent one of the detents 162. The ball 164 and detents 162 accordingly resist disengagement in order to assist in maintaining the rotatable driver 152 in a selected position, which maintains the end effector assembly 18 at a selected angle (about the axis 142) with respect to the longitudinal axis of the shaft 16 until forced into a new position, e.g., by a user rotating the rotatable driver 152 via the knob 158.

[0127] Figure 22 illustrates a cross-section of the shaft 16. As discussed above, the force transfer members 46, 112, and 154 all extend through the shaft 16. The conductors 83 also extend through the shaft 16 in order to electrically couple the generator 85 and the power switch 82 to the electrodes 22. For example, two conductors designated with the numerals 83a and 83b are illustrated in Figure 22, with the conductor 83a providing power to the electrode 22a, and the conductor 83b providing power to the electrode 22b. In order to guide and support the force transfer members 46, 112, and 154, and the conductors 83a and 83b, and to prevent undesired or unintentional interaction between these components, the passage or lumen formed through the shaft can include a guide 166. In the illustrated embodiment, the guide 166 includes a jaw channel 168 in which the force transfer member 46 is positioned, a blade channel 170 in which the force transfer member 112 is positioned, a pair of articulation channels 172 in which the force transfer members 154 are positioned, and a pair of conductor channels 174 in which the conductors 83a and 83b are positioned. It is to be appreciated that other configurations are possible, e.g., the conductor channels 174 could be combined to hold both of the conductors 83a and 83b, or both of the conductors 83a and 83b combined in a single conductor that extends through the shaft 16 and splits as necessary at the distal end of the shaft 16, or only one of the articulation channels 172 would be needed in embodiments having only one force transfer member 154, etc.

[0128] In an alternate embodiment illustrated in Figures 23, 24A and 24B, a window is provided in the handle assembly for transmitting light therethrough. Such window is shown and described with the device of Figure 23, it being understood that the window could also be used with any of the other surgical devices disclosed herein.

[0129] More particularly, Figures 23-24B illustrate surgical device 175. The device 175 is identical to device 10 of Figure 1, e.g., includes the shaft 16 connected at a distal end to the end effector assembly 18 having jaws 20, the trigger 120 for actuating a blade of the end effector assembly 18, the movable handle member 26 for closing the jaws, 20, etc. For this reason, some components of the device 175 similar to those of the device 10 are accordingly referenced with like-numerals. Also, for brevity, a discussion of the components which are identical to the components of Figure 1 are not further discussed, it being understood that these components and their function with respect to device 10 are fully applicable to device 175 of Figure 23. It is to be appreciated that the device 175 has components from the device 10 that are not illustrated or labeled in Figures 23-24B, e.g., the drive assembly 34, the blade 110, the articulation assembly 140, etc.

[0130] A primary difference of the device 175 is that instead of the housing 12 of the device 10, the device 175 has a housing 176 that includes a window 178. The window 178 is made of a material that is at least partially transparent or otherwise capable of transmitting light therethrough. For example, in one embodiment, a user viewing the device 175 can see through the window 178 to the internal components of the device 175 (e.g., such as the drive assembly 34). The window 178 is provided with a light source 180, which in one embodiment takes the form of a light emitting diode (LED), although other sources of light are possible. The light source 180 produces light that is transmitted through the material of the window 178 in a direction substantially parallel to a front or exterior surface 182 and a corresponding back or interior surface 184, as indicated by an arrow 186. Since the light is traveling in this direction parallel to the surfaces 182 and 184, and not, for example, reflecting toward the user, the user's view through the window 178 is substantially unaffected by this light.

[0131] In one embodiment, the window 178 includes an insignia 188 comprising one or more images, letters, words, or characters, which is intended to be illuminated by the light source 180. The insignia 188 can take many forms, and, for example, be indicative of a manufacturer, a company name, a product name, a trademark or service mark, etc. In the illustrated embodiment, the insignia 188 contains a plurality of letters spelling the word "MAQUET" (the name of the original assignee for the applications directed to the current invention).

[0132] Figures 24A and 24B show a cross-section of the window 178 taken through a portion of the 'M' of the insignia 188. In order to reflect the light from the light source 180 toward the users of the device 175, and thus make the insignia 188 viewable by users of the device 175, the insignia 188 is formed by grooves, slots, slits, impressions, etc., having one or more angled surfaces 190. By angled it is meant that the surfaces 190 are at an angle generally transverse or nonparallel relative to the direction 186 of the light transmitted by the light source 180. The material of the window 178 can be selected such that light naturally reflects off of the surface 190, e.g., due to the total internal reflection of light striking the surface 190 at angles larger than a critical angle of the material. In one embodiment, the surfaces 190 can be optionally treated with a reflective coating to facilitate reflection. In one embodiment the surfaces 190 can optionally be made rough or textured in order to scatter reflected light across a range of angles, e.g., as indicated in Figure 24B by a plurality of arrows 192, thereby increasing visibility of the insignia 188 by users. The reflection off of the surfaces 190 causes the insignia 188 to appear to glow, while the remainder of the window 178 remains generally transparent.

[0133] In one embodiment, the light source 180 is coupled to a logic or control unit 194 arranged for controlling when the light source 180 is turned on and off, the intensity, brightness, or color of the light transmitted by the light source 180, etc. In this way, for example, changing the output of the light source 180 can be used to indicate information e.g., a condition of the device, to a user of the device 175, namely, via the change in illumination of the insignia 188. For example, in one embodiment, the light source 180 illuminates the insignia 188 with a blue light when the device 175 is functioning properly and with a red light when the device 175 detects or experiences an error, e.g., via the control unit 194 or a sensor coupled thereto. In one embodiment, the light source 180 pulses on and off, such that the insignia 188 flashes, in order to convey a status of the device 175, e.g., the device 175 is ready for use, the device 175 has detected an error, the jaws 20 are electrified and sealing tissue, or other conditions of the device, with a steady light or different pattern of flashing indicating some other status or the end of one of the aforementioned statuses. Those of ordinary skill in the art will appreciate a myriad of errors or status that can be detected and/or communicated to a user by changing the manner in which the insignia 188 is illuminated. Advantageously, the prominence and positioning of the insignia 188 enables a user to easily see the change in status indicated thereby, even when the user is concentrating on the performance of a medical procedure.

[0134] Figures 25-27, 28A, 28B and 28C depict a surgical device 200 according to an alternate embodiment disclosed herein. Those of ordinary skill in the art will recognize similarities in the structure and operation of several components of the device 200 with respect to those of the device 10. For example, the device 200 includes a shaft 202 (e.g., generally resembling the shaft 16) connected between a handle housing or handle portion 204 (e.g., generally resembling the housing 12) at its proximal end and an end effector assembly 205 (e.g., generally resembling the assembly 18) at its distal end. The end effector assembly 205 can include any desired components, e.g., a set of jaws 206 (e.g., generally resembling the jaws 20) for clamping tissue, electrodes (e.g., resembling the electrodes 22) for applying energy to the tissue clamped between the jaws 206, a cutting blade (e.g., resembling the blade 110) for severing tissue clamped between the jaws 206, etc. The housing 204 includes a handle assembly 208 (e.g., generally resembling the handle assembly 14) having a movable handle member 210 (e.g., generally resembling the movable handle member 26) that is movable in order to cause actuation of the end effector assembly 205 via a drive assembly 212. The movable handle member 210 is intended to be actuated from a first or initial position, e.g., as shown in Figures 25-27, to a fully actuated position (not illustrated, but the handle position resembles the position of Figure 4 for the device 10) at which the movable handle member 210 is positioned closer to a fixed handle member 214 of the handle assembly 208. Similar to the operation of the jaws 20, the jaws 206 are in an open configuration when the movable handle member 210 is in its initial position and a closed configuration when the movable handle member 210 is in its actuated position. A spring 216, engageable with the movable handle member 210, can be included within housing portion 204 to urge the movable handle member 210 toward its initial position when not being actuated by a user or otherwise held in its actuated position. Pivoting of handle member 210 toward stationary handle 214 compresses the spring 216.

[0104] The drive assembly 212 includes a follower 218 that is slidably mounted on the shaft 202 and in mechanical communication (operatively connected) with the movable handle member 210 via a cross pin 219 extending through the follower 218 and movable handle member 210. A force transfer member 220 extends through the shaft 202 and has a pin 221 which slides within slot 223 as the force transfer member 220 is moved between proximal and distal positions by movable handle member 210. Force transfer member 220 is connected at its distal end via one or more pins 222 to a component of the end effector assembly 205, e.g., at least one of the jaws to cause actuation (opening and closing) of the jaws 206 in the manner described above with respect to device 10. As described above, either one or both of the jaws can be movable to transition the jaws between open and closed positions. Movement of the force transfer member 220 in a proximal direction in response to movement of handle 210 proximally, transitions the jaws 206 to the closed position. Unlike the device 10 (that indirectly transfers force from the movable handle member 26 to the end effector assembly 18 via the spring 38 or other biasing element), force from the movable handle member 210 is transferred directly to the force transfer member 220 via the follower 218 without being modulated or controlled by a spring or other biasing element. More particularly, a curved engagement or abutment surface 227 is formed at a proximal end of movable handle member 210. Engagement surface 227 contacts proximal collar or lip 229a of follower 218. Consequently, when the movable handle member 210 is pivoted proximally (clockwise), engagement surface 227, which is in engagement with collar 229a, forces follower 218 proximally to move the force transfer member 220 proximally to close the jaws. Note an engagement surface 227 is formed on both proximal edges of the handle 210. Similarly, a curved engagement or abutment surface is provided on the distal edges of movable handle 210 which contacts distal collar or lip 229b of follower 218 to move the force transfer member 220 back to its distal position.

[0105] The device 200 includes a multi-stage lock mechanism 224 that is arranged to enable different preset forces to be exerted on the end effector assembly 205. These different preset forces exerted on components of the end effector assembly 205 provide multiple corresponding preset clamping forces that are exertable by the jaws 206 on tissue clamped between the jaws 206. More specifically, the mechanism 224 is arranged to maintain the movable handle member 210 in multiple preset actuated positions, with each position corresponding to a different force transferred to the end effector assembly 205 and exertable by the jaws 206. Thus, a multi-stage clamping, which in some embodiments can apply variable clamping forces, is provided. The movable handle member 210 is movable between an initial position and at least a first preset actuation position and a second preset actuation position. For example, the movable handle member 210 can exert a first preset force on the end effector assembly 205, corresponding to a first clamping force on tissue, via the drive assembly 212 when in the first preset actuation position, and a second force on the end effector assembly 205, corresponding to a second clamping force on tissue, when in the second preset actuation position. It is to be understood that the mechanism 224 can include any number of steps, stages, or preset positions for enabling the transfer of any corresponding number of different preset forces on the end effector assembly 205 via the drive assembly 212. Such multi-stage clamping and locking enables wider use of the device as due to its variable clamping, it can for example be used on a wider range of tissues, such as on parenchyma, without dissecting the tissue, as described below.

[0106] In the illustrated embodiment, the mechanism 224 includes a cam 225 with a groove or track 226 that is traversed by a cam follower 228 formed by arm 228a and pin attached to the arm. These components may be referred to singularly as they act in unison, but it is to be understood that the device 200 includes a pair of opposing copies of the cam 225 and the cam follower 228, e.g. for stability, with one copy disposed on each opposite side of the movable handle member 210. During actuation of the movable handle 210, the cam follower 228 is initially in the position of Figures 27 and 28A. The cam follower 228 is arranged to enable relative movement between the movable handle member 210 (and thus the cam 225) and the cam follower 228. In this way, actuation of the movable handle 210 from its initial position causes the cam follower 228 to encounter a ramp or shoulder 230 and follow the groove 226 into a first stop 232. As shown, groove (slot) 226 has a first angled portion transitioning into a substantially Z-shaped groove portion 226a and then exiting in an upper curved groove or track portion 226b (as viewed in the orientation of Figure 28B). The depth of the groove 226 varies to direct and retain the position. As discussed below, lower groove (track) portion 226c has an increased depth which directs the cam follower 228 down into the lower groove.

[0107] Note the arm 228a, which is pivotably attached (and therefore attached pin 228b), can move only in a vertical direction (as viewed in the orientation of Figure 26-28). That is, movement is restricted to a direction transverse to a longitudinal axis of the device, or stated another way, transverse to a direction of movement of the force transfer member 220. The track (groove) 226 moves from its initial distal position (Figure 27) in a proximal direction upon actuation of the movable handle 210. Thus, in the initial position of movable handle 210 with the jaws in the open position of Figure 26, cam follower 228 is at the proximal-most portion of groove 226 (Figures 27 and 28).

[0108] The depth of the groove 226 increases at the stop 232, which forms a shoulder or ramp 234. The cam follower 228 is biased inwardly, e.g., by a spring 236 or other biasing element, thus urging the cam follower 228 to drop deeper into the groove 226 along lower groove portion 228a when the cam follower 228 is moved to the first stop 232. In this way, when actuation forces on the movable handle member 210 are relieved, the movable handle member 210 is naturally moved back toward its initial position, e.g., via the spring 216 or another biasing element. The inward urging of the cam follower 228, e.g., via the spring 236, causes interference between the cam follower 228 and the ramp 234 (Figure 28c), which results in the cam follower 228 climbing the ramp 234 toward a second stop 238 of the substantially Z- shaped portion 226a instead of backtracking through the groove 226.

[0109] The second stop 238 corresponds to the aforementioned first preset actuation position for the movable handle member 210. The movable handle member 210 will be held in the first actuation position due to the cam follower 238 being urged toward the second stop 238 by the spring 236 or other biasing element. When in the first actuation position, the drive assembly 212 can be arranged to exert a first (e.g., relatively smaller) force on the end effector assembly 205, e.g., which results in a first preset clamping force to be exerted by the jaws 206. The depth of the groove 226 can again increase at the second stop 238 to prevent the cam follower 238 from backtracking through the groove 226.

[0110] Re-actuating the movable handle member 210 in the proximal direction causes the cam follower 228 to continue along the groove 226 to a third stop 240 of the substantially Z- shaped portion 226a. Similar to the first and second stops 232 and 238, the depth of the groove 226 again increases at the third stop 240, creating a ramp or shoulder 242. The inward urging of the cam follower 228, e.g., via the spring 236, causes interference between the cam follower 228 and the ramp 242, which results in the cam follower 228 climbing the ramp 242 into a fourth stop 244 instead of backtracking through the groove 226. The fourth stop 244 corresponds to the aforementioned second preset actuation position for the movable handle member 210. When in the second actuation position, the drive assembly 212 can be arranged to exert a second (e.g., relatively larger) force on the end effector assembly 205, e.g., which results in a second clamping force to be exerted by the jaws 206, e.g., relatively larger than the first clamping force.

[0111] Again re-actuating the movable handle member 210 in the proximal direction causes the cam follower 228 to be moved to a fifth stop 246. The groove 226 at the fifth stop 246 again increases in depth to create a ramp or shoulder 248. Accordingly, releasing the movable handle member 210 when the cam follower 228 is at the fifth stop 246 causes the cam follower 228, urged by the spring 236, to climb the ramp 248 and follow the upper portion 226b of groove 226 back to the initial position for the cam follower 228 (e.g., as shown in Figure 28). In this way, the movable handle member 210 can be cycled between an initial or non-actuated position and multiple preset actuation positions (e.g., the first and second preset positions corresponding to when the cam follower 228 is located at the stops 238 and 244, respectively, of the groove (slot) 226), with the multiple preset actuation positions in turn corresponding to different tissue clamping forces for the jaws 206. Note the groove (track) can be configured to provide additional stops to provide additional pre-set actuation positions, and thus additional clamping positions and clamping forces.

[0112] As noted above, certain tissues, such as lung parenchyma, may tend to blunt dissect when subjected to relatively high clamping forces. Accordingly, in one embodiment, the multi-stage mechanism 224 enables the first preset clamping force exerted by the jaws 206 to be lower than a blunt dissection threshold force for the tissue. After reaching the first preset actuation position, electrodes (e.g., the electrodes 22) disposed with the jaws 206 can then be powered or activated a first time to thermally treat the tissue to begin creating a weld or seal. If the tissue is particularly thick, a first powering of the electrodes may not create a seal through the full cross-section of the tissue. However, this first powering of the electrodes will strengthen the tissue, e.g., so that it does not blunt dissect at higher clamping pressures, which enables the movable handle member 210 to be moved to the second preset actuation position in order to exert a second relatively larger clamping force with the jaws 206. The electrodes can then be powered or activated a second time, with the jaws 206 exerting the relatively higher clamping force, in order to improve the seal across the entire cross-section of the tissue. It is to be appreciated that this method of operating the device 200 generally parallels the embodiment for operating the device 10 discussed above with respect to sealing the tissue 56b of Figures 16-17.

[0113] The surgical device 200 as well as the other devices described herein are advantageously structured and dimensioned for minimally invasive surgery. It is further dimensioned in certain embodiments so that it can be inserted through a 12mm trocar. As can be appreciated, it is advantageous to minimize the size of the access port, e.g., trocar cannula, to reduce patient trauma and speed up recovery time. Depending on the surgical applications, the trocar can for example be inserted through the rib cage to access lung tissue, through the abdomen for laparoscopic surgery, etc. However, minimizing the transverse dimension of the surgical device can be difficult to achieve due to the various components which are contained within the tubular portion, e.g., for jaw actuation, blade actuation, articulation, energy supply, etc. Additionally, the structural integrity of the jaw needs to be maintained in order to apply the desired jaw closure and clamping forces on tissue. Such objective becomes more difficult as the length of the jaws increase. Therefore, the objective is to balance the above while minimizing the transverse dimension. This is achieved in the devices disclosed herein. For example, in the surgical devices 100 and 200, the elongated tubular portion inserted through the trocar and the jaws 206 in their closed position have an overall transverse cross-sectional dimension less than or equal to about 12mm so they can fit through a 12 mm trocar. If the "12 mm" trocar has an opening slightly exceeding 12 mm, the jaws could have a transverse cross-sectional dimension slightly exceeding 12 mm as long as dimensioned smaller than the opening. Additionally, the jaws for some surgical applications can have a length of over 30mm, and in some embodiments can have a length between about 30mm and about 40mm, and in some embodiments can have a length of about 37mm. Providing this relatively long jaw length does not sacrifice jaw strength. This is achieved in part by the configuration of the jaws as shown in Figure 14 where each jaw has an outer plastic insulator 21a positioned over the metal jaw and an inner insulator 21c between the electrode and the metal jaw 21b. Additionally, the use of ribbons and proximal movement of the jaw closure member to effect movement of the drive pin in the jaw cam slot minimizes the size of the components within the tubular portion 202. Consequently, the surgical device 200, as well as the other devices disclosed herein have a dimension to not exceed 12 millimeters, or not substantially exceeding 12 millimeters if the "12 mm" trocar has an opening slightly exceeding 12 millimeters, so they can be inserted through a 12 millimeter trocar for certain surgical procedures, including for example, tissue welding of parenchyma.

[0114] The surgical device 200 includes a power switch 250 that is electrically coupled between a supply of power (e.g., the generator 85 or other generator), and electrical components of the surgical device 200 (e.g., electrodes disposed with the jaws 206 of the end effector assembly 205). Electrical communication can be achieved by suitable conductors, cables, or wiring, e.g., as taught with respect to the conductors 83, but which are not illustrated for clarity of the other components of the device 200. A button 252 is included with the power switch 250 and arranged to enable activation of the power switch 250 via mechanical interaction with the button 252, e.g., by a user pressing the button 252. [0115] A toggle switch 254 can also be included in electrical communication with the power switch 250, a generator, electrodes or other electrical components of the device 200. For example, the toggle switch can be set to one of a plurality of positions, each position corresponding to a different operating characteristic for the device 200. In one embodiment, the toggle switch 254 can be toggled between a low power setting and a high power setting for electrodes disposed with the end effector assembly 205, as different tissue types may respond favorably to different electrode power levels or modes of operation for a generator.

[0116] The device 200 also includes an articulation assembly 256. The articulation assembly 256 generally resembles the articulation assembly 140 discussed above with respect to the device 10. For example, the articulation assembly 256 includes a pair of force transfer members 258 extending between a rotatable driver 260 and the end effector assembly 205 in order to cause rotation of the end effector assembly 205 about a pin or pivot 262. The articulation assembly 256 includes a knob 264 secured to the rotatable driver 260 to enable rotation of the rotatable driver 260 via the knob 264, and a body 266 secured to the shaft 202 to enable rotation of the shaft 202 via the body 266. Rotation of the shaft 202 about its axis is also enabled by rotation of a wheel 268 fixedly secured to the shaft 202. The wheel 268 extends at least partially out from the housing 204 to enable a user to rotate the wheel 268, e.g., by use of a thumb of the user's hand that is gripped about the fixed handle member 214.

[0117] A trigger 270 generally resembling the trigger 120, e.g., for deploying and retracting a blade disposed with the end effector assembly 205, can also be included in the device 200. The trigger 270 is connected by a set of linkages 272 to a collar 274 that is connected to a force transfer member 276 that extends through the shaft 202. The force transfer member 276 can actuate a blade 278 or other component, e.g., as taught with respect to the force transfer member 112 for the blade 110. As shown in Figures 25-27, the trigger 270 is disposed directly adjacent to and/or resting against the movable handle member 210 when the movable handle member 210 is in its initial position. This proximity between the trigger 270 and the movable handle member 210 physically prevents the trigger 270 from actuating, e.g., in order to deploy a blade of the end effector assembly 205, until the movable handle member 210 is first moved to its actuated position, e.g., in order to close the jaws 206 of the end effector assembly 205. This ensures the jaws are closed prior to advancement of the blade.

[0118] While the invention has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the claims. Also, in the drawings and the description, there have been disclosed exemplary embodiments of the invention and, although specific terms may have been employed, they are unless otherwise stated used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention therefore not being so limited. Moreover, the use of the terms first, second, etc. do not denote any order or importance, but rather the terms first, second, etc. are used to distinguish one element from another. Furthermore, the use of the terms a, an, etc. do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item.

Claims

IN THE CLAIMS

1. A surgical device comprising:

a handle portion including a movable handle;

an elongated tubular portion extending distally from the handle portion;

a first jaw having a first engagement surface;

a second jaw having a second engagement surface, wherein at least the first jaw is movable to transition the first jaw and the second jaw between an open configuration and a closed configuration, wherein the first jaw and the second jaw are arranged to receive tissue therebetween when in the open configuration and to exert force on the tissue via the first engagement surface and the second engagement surface when in the closed configuration; and a drive assembly operable to drive at least the first jaw to transition the first and second jaws between the open configuration and the closed configuration, wherein the drive assembly is actuable by the movable handle, and the movable handle has an initial position and at least first and second preset positions, wherein in the first preset position the jaws exert a first clamping force on tissue and in the second preset position the jaws exert a second clamping force on tissue, wherein the second clamping force is greater than the first clamping force.

2. The surgical device according to claim 1, wherein the drive assembly includes a follower and cam comprising a non-linear groove, wherein the follower is engageable with the groove.

3. The surgical device according to claim 2, wherein the follower and the groove are positioned in the handle portion.

4. The surgical device according to claim 3, further comprising a force transfer member operatively connected to at least the first jaw, wherein the movable handle includes an abutment surface engageable with a collar to move the force transfer member.

5. The surgical device according to claim 2, wherein the groove has a variable depth.

6. The surgical device according to claim 2, further comprising a first stop in the groove, wherein the first stop provides the first preset position of the movable handle.

7. The surgical device according to claim 6, further comprising a second stop in the groove, wherein the second stop provides the second present position of the movable handle.

8. The surgical device according to claim 2, wherein the groove has a substantially Z- shaped portion.

9. The surgical device according to claim 1, wherein the drive assembly includes a force transfer member extending through the tubular portion and operably connected to at least the first jaw and operably connected to the movable handle.

10. The surgical device according to claim 9, wherein movement of the movable handle retracts the force transfer member to transition the jaws to the closed configuration.

11. The surgical device according to claim 1, wherein the drive assembly includes a nonlinear groove in the handle portion, a drive pin engageable with the groove, and the groove has first and second stops.

12. The surgical device according to claim 3, wherein movement of the movable handle from the initial position causes the follower to encounter a first ramp and follow the groove into a first stop.

13. The surgical device according to claim 12, wherein a depth of the groove increases at the first stop to prevent the follower from backtracking through the groove, wherein the follower is biased inwardly toward the groove.

14. The surgical device according to claim 13, wherein after engaging the first stop the follower engages a second ramp resulting in the follower positioning in a second stop, wherein the second stop corresponds to the first preset position.

15. The surgical device according to claim 14, wherein a depth of the groove increases at the second stop to prevent the follower from backtracking through the groove, and upon further actuation of the movable handle the follower travels in the groove to a third stop, wherein the depth of the groove increases at the third stop.

16. The surgical device according to claim 15, wherein after engaging the third stop the follower engages a third ramp resulting in the follower positioning in a fourth stop, wherein the fourth stop corresponds to the second preset position.

17. The surgical device according to claim 1, further comprising a first electrode disposed on the first jaw.

18. The surgical device according to claim 17, further comprising a second electrode disposed on the second jaw.

19. The surgical device according to claim 18, wherein the first and second electrodes extend in a substantially U-shape configuration spaced inwardly from a peripheral edge of the respective first and second jaws and a non-conductive material is positioned within the U-shape of the second electrode.

20. The surgical device according to claim 18, wherein the first and second jaws each have a metal portion, an outer insulator material positioned over the metal portion and an inner insulator positioned between the metal portion and an electrode portion.

21. The surgical device according to claim 1, wherein the second jaw is stationary while the first jaw is movable toward the second jaw.

22. The surgical device according to claim 1, wherein both the first and second jaws are movable toward each other by the drive assembly.

23. The surgical device according to claim 1, wherein the first jaw includes an arm and a float portion having a first electrode, wherein the float portion is rotatably connected to the arm to enable the electrode to float with respect to the arm.

24. The surgical device according to claim 18, further comprising a spacer extending from the first jaw to maintain a minimum distance between a first engagement surface of the first jaw and a second engagement surface of the second jaw.

25. The surgical device according to claim 1, further comprising a cutting blade movable to sever tissue clamped between the first and second jaws, wherein the cutting blade is movable independently of jaw closure.

26. The surgical device according to claim 25, further comprising a blade actuating member operably connected to a trigger at the handle portion and to the blade, wherein the blade actuating member extends in the elongated tubular portion.

27. The surgical device according to claim 1, further comprising an articulation member for moving the jaws between a first position substantially aligned with a longitudinal axis of the elongated tubular portion and a second position at an angle to the longitudinal axis, wherein the articulation member extends in the elongated tubular portion.

28. The surgical device according to claim 27, wherein the jaws are moveable to an angle of up to about 60 degrees to the longitudinal axis.

29. The surgical device according to claim 1, wherein the drive assembly includes a cam with a non-linear groove that is disposed in the handle portion to vary the forces exerted by the jaws on tissue.

30. The surgical device according to claim 29, further comprising a cam follower including an arm and a pin engageable with the groove, wherein the arm is movable in a direction transverse to a longitudinal axis of the device and is restricted from movement in a direction along the longitudinal axis.

31. The surgical device according to claim 29, wherein the groove moves in proximal and distal directions.

32. The surgical device according to claim 30, wherein the groove moves in proximal and distal directions.

33. The surgical device according to claim 30, wherein in the initial position of the movable handle, the pin is at a proximal region of the groove.

34. A surgical device comprising:

a handle portion including a movable handle;

an elongated tubular portion extending distally from the handle portion;

a first jaw having a first engagement surface;

a second jaw having a second engagement surface, wherein at least the first jaw is movable to transition the first jaw and the second jaw between an open configuration and a closed configuration, wherein the first jaw and the second jaw are arranged to receive tissue therebetween when in the open configuration and to exert force on the tissue via the first engagement surface and the second engagement surface when in the closed configuration; and a drive assembly operable to drive at least the first jaw to transition the first and second jaws between the open configuration and the closed configuration, wherein the drive assembly is actuable by the movable handle, and the drive assembly includes a cam with a nonlinear groove and a pin engageable with the groove, wherein the groove and pin are positioned within the handle portion, and movement of the movable handle causes relative movement of the arm and groove.

35. The surgical device according to claim 34, wherein the groove has a substantially Z- shaped portion.

36. The surgical device according to claim 34, wherein the pin is movable in a direction transverse to a longitudinal axis of the device and the cam is movable in a proximal and distal direction.

37. The surgical device according to claim 34, wherein the groove has a stop, and the pin is engageable with the stop to provide a first preset position of the movable handle.

38. The surgical device according to claim 37, wherein the groove has an additional stop, and the pin is engageable with the additional stop to provide a second preset position of the movable handle.

39. The surgical device according to claim 34, wherein the groove causes a variation of clamping forces that provide the force exerted by the first and second jaws to tissue.

40. The surgical device of claim 38, wherein in the first preset position the jaws exert a first clamping force on the tissue, and in the second preset position the jaws exert a substantially different second clamping force on tissue.

41. The surgical device according to claim 40, wherein the second clamping force is greater than the first clamping force.

42. The surgical device of claim 34, wherein the groove has a first portion and a second portion having a greater depth than the first portion.

43. A surgical device comprising:

a handle portion;

an elongated tubular portion extending from the handle portion;

a pair of jaws at a distal end of the elongated tubular portion;

a window of light transmitting material disposed at the handle portion, wherein the window has a viewing surface extending at least partially along a first plane;

a light source at the handle portion operatively arranged with the window so as to transmit light through the material of the window along an axis extending substantially parallel to a first plane; and

a reflection surface arranged in the window along a second plane transverse to the first plane, wherein the reflection surface is configured at a first angle with respect to the axis to reflect the light toward the viewing surface at an angle of incidence less than a critical angle to enable the light to escape the viewing surface.

44. The surgical device according to claim 43, further comprising a controller operatively coupled to the light source for controlling the light in response to a condition of the device.

45. The surgical device according to claim 44, wherein the light can be controlled to provide a different pattern of light depending on a condition of the device.

46. The surgical device according to claim 43, wherein the window includes an insignia, and the insignia has a series of grooves forming the reflection surface.

47. The surgical device according to claim 43, wherein the first plane is transverse to a longitudinal axis of the tubular portion.

48. The surgical device according to claim 43, wherein the surface is treated with a reflective coating,

49. The surgical device according to claim 43, wherein the surface has a roughened surface to scatter reflected light across a wide range of angles.

50. The surgical device according to claim 44, wherein the condition of the device is the application of electrosurgical energy to tissue clamped between the jaws.

51. The surgical device according to claim 44, wherein the condition of the device is an error detected by the device.

52. The surgical device according to claim 44, wherein the condition of the device is a change in status of the device.

53. The surgical device according to claim 43, wherein the reflection surface is configured at the first angle with respect to the axis to reflect the light toward the viewing surface at an angle of either greater or less than the critical angle to enable the light to escape the viewing surface.

54. A surgical device for treatment of parenchyma comprising:

a handle portion including a movable handle;

an elongated tubular portion extending distally from the handle portion, the elongated tubular portion having a transverse cross-sectional dimension at least at a distal region not exceeding 12 millimeters;

a first jaw at a distal portion of the device having a first engagement surface; a second jaw at the distal portion of the device having a second engagement surface, wherein at least the first jaw is movable to transition the first jaw and the second jaw between an open configuration and a closed configuration, wherein the first jaw and the second jaw are arranged to receive parenchyma therebetween when in the open configuration and to exert force on the tissue via the first engagement surface and the second engagement surface when in the closed configuration without causing blunt dissection of the parenchyma, wherein the first and second jaws in the closed configuration have a transverse cross-sectional dimension not exceeding 12 millimeters.

55. The surgical device according to claim 54, further comprising a drive assembly operable to drive at least the first jaw to transition the first and second jaws between the open configuration and the closed configuration, wherein the drive assembly is actuable by the movable handle, and the movable handle has an initial position and at least first and second preset positions, wherein in the first preset position the jaws exert a first clamping force on tissue, and in the second preset position the jaws exert a substantially different second clamping force on tissue.

56. The surgical device according to claim 55, wherein the second clamping force is greater than the first clamping force.

57. The surgical device according to claim 54, further comprising a drive assembly operable to drive at least the first jaw to transition the first and second jaws to the closed configuration, wherein the drive assembly moves at least the first jaw so that the first jaw and the second jaw variably exert the force on tissue as a function of a distance between the first engagement surface and the second engagement surface according to a force curve, wherein the force curve is shaped so that the force exerted on tissue is greater than a threshold force when the distance between the first engagement surface and the second engagement surface is less than a threshold distance and the force exerted on tissue is less than the threshold force when the distance between the first engagement surface and the second engagement surface is greater than the threshold distance.

58. The surgical device according to claim 57, where the force curve is non-linear.

59. The surgical device according to claim 57, wherein the force curve has a progressive slope when the first and second jaws are at a first range of distances and the force curve substantially plateaus when the first and second jaws are at a second range of distances.

60. The surgical device according to claim 55, wherein the drive assembly includes a nonlinear track in the handle portion, and a follower engageable with the track, wherein the track has first and second stops.

61. The surgical device according to claim 60, wherein the track is movable in proximal and distal directions.

62. The surgical device according to claim 54, further comprising a first electrode disposed on the first jaw and a second electrode disposed on the second jaw.

63. The surgical device according to claim 62, wherein the first and second electrodes extend in a substantially U-shape configuration spaced inwardly from a peripheral edge of the respective first and second jaws and a non-conductive material is positioned within the U-shape of the second electrode.

64. The surgical device according to claim 54, further comprising a first slot in the first jaw and a second slot in the second jaw, wherein the first jaw has a longitudinal axis, and the first slot has a region angled with respect to the longitudinal axis of the first jaw, and a drive pin is movable within the first slot to rotate the first jaw toward the second jaw, wherein the first slot sets the force exerted by the first and second jaws on tissue.

65. The surgical device according to claim 54, wherein the drive assembly sets the force exerted by the first and second jaws on tissue in response to thickness of tissue.

66. The surgical device according to claim 54, wherein the second jaw is stationary while the first jaw is movable toward the second jaw.

67. The surgical device according to claim 54, wherein both the first and second jaws are movable toward each other by the drive assembly.

68. The surgical device according to claim 54, wherein the first and second jaws each have a length over 30 millimeters.

69. The surgical device according to claim 62, wherein the first and second jaws each have a metal portion, an outer insulator material positioned over the metal portion and an inner insulator positioned between the metal portion and an electrode portion.

70. The surgical device according to claim 54, wherein a drive assembly moves at least the first jaw so that the first jaw and the second jaw variably exert the force on tissue as a function of a distance between the first engagement surface and the second engagement surface such that forces applied to tissue by the jaws progressively increase when the first and second engagement surfaces are spaced any of a first set of distances from each other and the forces applied to tissue substantially plateaus when the first and second engagement surfaces are spaced any of a second set of distances from each other, wherein the first set of distances are greater than the second set of distances.

71. The surgical device according to claim 70, wherein the first set of distances has a percentage force change several times greater than a percentage force change over the second set of distances.

72. The surgical device according to claim 54, wherein the first jaw includes an arm and a float portion having a first electrode, wherein the float portion is rotatably connected to the first arm to enable the electrode to float with respect to the arm.

73. The surgical device according to claim 62, further comprising a spacer extending from the first jaw to maintain a minimum distance between the first and second engagement surfaces.

74. The surgical device according to claim 54, further comprising a drive assembly operable to drive at least the first jaw to transition the first and second jaws to the closed configuration, wherein the drive assembly is operable so the first jaw and the second jaw variably exert the force on tissue as a function of a distance between the first engagement surface and the second engagement surface according to a force curve, wherein the force curve is shaped so that the force exerted on the tissue when the first engagement surface and second engagement surfaces are spaced a first range of distances changes a first percentage and the force exerted on the tissue when the first engagement surface and the second engagement surfaces are spaced a second range of distance changes a second percentage, wherein the second percentage is less than the first percentage.

75. The surgical device according to claim 74, wherein the forces exerted on tissue during the first range of distances progressively increases and the forces exerted on tissue during the second range of distances varies slightly.

76. The surgical device according to claim 54, further comprising a cutting blade movable to sever tissue clamped between the first and second jaws, wherein the cutting blade is movable independently of jaw closure.

77. A minimally invasive surgical device comprising:

a handle portion including a movable handle;

an elongated tubular portion extending distally from the handle portion; a first jaw having a first engagement surface and a first electrode, and the first jaw has a length exceeding 30 millimeters; and

a second jaw having a second engagement surface, and the second jaw has a length exceeding 30 millimeters, wherein at least the first jaw is movable to transition the first jaw and the second jaw between an open configuration and a closed configuration, wherein the first jaw and the second jaw are arranged to receive tissue therebetween when in the open configuration and to exert force on the tissue via the first engagement surface and the second engagement surface when in the closed configuration, and wherein the first and second jaws in the closed configuration have a transverse cross-sectional dimension not exceeding 12 millimeters.

78. The surgical device according to claim 77, further comprising a drive assembly including a force transfer member operably connected to the movable handle and to at least the first jaw for moving at least the first jaw to the closed configuration, wherein the force transfer member extends in the elongated tubular portion, wherein retraction of the force transfer member moves at least the first jaw to the closed position.

79. The surgical device according to claim 77, further comprising a blade actuating member operably connected to a trigger at the handle portion and to a blade, wherein the blade actuating member extends in the elongated tubular portion.

80. The surgical device of claim 77, further comprising an articulation member that moves the jaws between a first position substantially aligned with a longitudinal axis of the elongated tubular portion and a second position at an angle to the longitudinal axis, wherein the articulation member extends in the elongated tubular portion.

81. The surgical device of claim 80, wherein the jaws are moveable to an angle of up to about 60 degrees to the longitudinal axis.

82. The surgical device according to claim 80, further comprising a blade actuating member operably connected to a trigger at the handle portion and to a blade, wherein the blade actuating member extends in the elongated tubular portion.

83. The surgical device according to claim 77, wherein the second jaw has a second electrode, and the first and second jaws each have a metal portion, an outer insulator material positioned over the metal portion and an inner insulator positioned between the metal portion and an electrode portion.

84. The surgical device according to claim 78, wherein the drive assembly includes a nonlinear slot in the first jaw to vary the forces exerted by the jaws on tissue.

85. The surgical device according to claim 78, wherein the drive assembly includes a nonlinear slot in the handle portion to vary the forces exerted by the jaws on tissue.

86. A method of minimally invasively sealing parenchyma comprising the steps of:

preparing a surgical device for minimally invasive surgical use, wherein the surgical device has an elongate portion and first and second jaws at a distal portion and a first electrode carried by the first jaw;

inserting the first and second jaws through a trocar cannula having a diameter not exceeding 12 millimeters;

positioning parenchyma between the first and second jaws when the jaws are in the open configuration;

transitioning the first and second jaws to a closed configuration to clamp the parenchyma; applying energy to the first electrode to seal the parenchyma; and

sealing the parenchyma with energy from the first electrode.

87. The method according to claim 86, wherein the jaws exert a variable force on the parenchyma as a function of a distance of the jaws and the step of transitioning the jaws to clamp the parenchyma includes clamping the parenchyma without blunt dissection of the parenchyma.

88. The method according to claim 87, wherein the second jaw carries a second electrode and the method further includes the step of applying energy to the second electrode carried by the second jaw.

89. The method according to claim 86, wherein the force exerted by the first and second jaws on the parenchyma is varying dependent on a gap between the first and second jaws, wherein the force increases a first percentage upon initial clamping and subsequently varies a second percentage upon further clamping of the jaws, wherein the second percentage is substantially less than the first percentage.

90. The method according to claim 86, wherein the step of transitioning the first and second jaws to the closed configuration comprises the step of actuating a jaw actuator to move a force transfer member within the elongated tubular portion to transition the first and second jaws to the closed configuration.

91. The method according to claim 90, wherein the step of actuating the jaw actuator to move the force transfer member moves a pin within a non-linear slot in the first jaw, wherein the slot is configured to control the force exerted by the jaws.

92. The method according to claim 90, wherein the step of actuating the jaw actuator to move the force transfer member moves a pin within a non-linear slot in the handle portion, wherein the slot is configured to control the force exerted by the jaws and has first and second preset positions to provide first and second clamping positions of the jaws.

93. The method according to claim 90, further comprising the step of advancing a blade to sever tissue clamped by the first and second jaws, wherein the blade is actuated by a blade actuator movably positioned in the elongated tubular portion.

94. The method according to claim 93, wherein the step of advancing the blade is

independent of movement of the force transfer member.

95. The method according to claim 90, wherein the step of actuating the jaw actuator moves the first jaw toward the second jaw, and the second jaw remains stationary.

96. The method according to claim 90, wherein the step of actuating the jaw actuator moves both the first and second jaws toward each other.

97. The method according to claim 94, wherein the step of advancing the blade cannot be performed when the first and second jaws are not in the closed configuration.

98. The method according to claim 93, further comprising the step of providing an indicator to indicate the advancement of the blade.

99. The method according to claim 86, wherein the step of applying energy to the first electrode cannot be performed unless the first and second jaws are in the closed configuration.

100. The method according to claim 86, wherein a gap between the jaws in the closed configuration varies along a width of the jaws so the gap is greater at a distance further from a center of the jaw than closer to the center of the jaw.

101. The method according to claim 86, further comprising the step of actuating a jaw actuator so a force transfer member engageable with at least the first jaw transitions at least the first jaw toward the second jaw so the first and second jaws apply a first range of forces to tissue as the jaws transition through a first range of distances, wherein the distances are defined between first and second engagement surfaces of the respective first and second jaws; and subsequently applying a smaller second range of forces to tissue as the jaws transition through a second range of distances less than the first range of distances.

102. The method according to claim 101, wherein the first range of forces progressively increases and the second range of forces varies slightly.