Electrosurgical instrument

Abstract

The present invention relates to electrosurgical instruments. An electrosurgical instrument, particularly a scissors-type vessel sealer, includes two overmolded jaws formed of a structural polymer, the two overmolded jaws being held in place by a pivot pin. The molded structural polymer replaces many of the metal components that such an assembly would otherwise require. Additionally, it is possible to position a reinforcement member within the jaws of the instrument to provide support. The use of the molded structural polymer not only simplifies the assembly of the instrument but also enables the following additional functions: molded pivot holes, flanges providing lateral support, and flexible lever arms that are intended to provide the force required to clamp and seal blood vessels.

Description

Technical Field

[0001] Embodiments of the invention described herein relate to an electrosurgical device, and more particularly to a scissor-type vessel sealer. Background Art

[0002] Electrosurgical instruments offer advantages over traditional surgical instruments in that they can be used for coagulation and tissue sealing purposes. Electrosurgical forceps are used to clamp tissue or blood vessels before cutting and / or sealing the tissue by delivering a coagulating RF signal to one or more electrodes located at the distal end of the instrument. Current market vessel sealers have a lot of assembly complexity both in terms of the number of components and the materials used to assemble a pair of jaws. Specifically, scissor-type vessel sealers on the market use a combination of materials and components to form the jaw and lever arm assemblies. These assemblies involve many expensive metal parts, require various manufacturing and joining techniques, and insulation from the electrodes. Due to the use of many components, these assemblies are typically very costly. Summary of the Invention

[0003] Embodiments of the present invention provide an electrosurgical instrument, and more particularly a scissor-type vessel sealer, comprising two overmolded jaws formed of a structural polymer, the two overmolded jaws being held in place by a pivot pin. The molded structural polymer replaces many of the metal parts that would otherwise be required for such an assembly. The use of the molded structural polymer not only simplifies the assembly of the instrument, but also enables the following additional functions: molded pivot holes, flanges for providing lateral support, and flexible lever arms that are designed to provide the force needed to clamp and seal blood vessels. No metal reinforcement parts are required inside the lever arms. In some embodiments of the present invention, metal reinforcements are added to support the jaws. The metal reinforcements can be partially or fully encapsulated within an overmold formed of the structural polymer. Metal reinforcements that support the jaws are advantageous because they significantly reduce the bending of the jaws under load.

[0004] Accordingly, in a first aspect, there is provided an electrosurgical instrument comprising: a first component including a distal first jaw member, a first central portion, and a proximal first arm, the first component being formed from a first single-piece polymeric material; and a second component including a distal second jaw member and a second central portion, the second component being formed from a second single-piece polymeric material, wherein the central portion is connected to a proximal second arm. The first and second components are pivotally connected such that at least one of the first and second arms is movable relative to the other arm between an open position in which the arms are spaced apart from each other and a closed position in which the arms are close together, and the first and second jaw members are movable between a first state and a second state in response to relative movement of at least one of the arms. The first component and / or the second component includes one or more reinforcement members positioned to respectively support the first and / or second jaw members, the one or more reinforcement members being arranged to provide support for the first and / or second components.

[0005] The above aspect is advantageous because the use of polymer overmolding replaces many metal components that would otherwise be required for such an assembly. Metal components are expensive, require various manufacturing and joining techniques, and need to be insulated from the electrodes. The use of metal components results in high assembly costs due to the use of many parts. In some embodiments, there is no exposed metal within the instrument other than the pivot pin and the electrodes. The use of polymeric materials greatly reduces the complexity of the instrument, reduces the number of parts, and greatly simplifies assembly. Although the use of polymeric materials is advantageous for the reasons stated above, one or more jaws of the instrument would benefit from additional reinforcement to reduce bending of the jaws under load. The addition of reinforcement members in the instrument provides support for the jaws.

[0006] In some embodiments, one or more reinforcement members project into the first central portion and / or the second central portion as cantilevers. This is advantageous because it not only provides support for the jaws but also provides support for the central portions.

[0007] In some embodiments, one or more reinforcement members are partially or fully encapsulated by the first single-piece polymeric material and / or the second single-piece polymeric material. In the case where the reinforcement members are fully encapsulated by the first single-piece polymeric material and / or the second single-piece polymeric material, there is no exposed metal within the instrument other than the pivot pin and the electrodes.

[0008] In some embodiments, one or more reinforcement members are formed from metal. For example, stainless steel, titanium.

[0009] In some embodiments, one or more reinforcement members include one or more metal inserts.

[0010] In some embodiments, at least the first arm is formed by the shape and thickness of a polymeric material such that it bends when a certain force is exceeded, whereby in use the jaw members provide a clamping force to clamp a blood vessel held between the first and second jaw members, and the bending of at least the first arm when a certain force is exceeded prevents an excessive clamping force from being applied to the blood vessel.

[0011] A further advantage of using a polymeric material is that it provides the additional functionality of molding pivot holes and flexible lever arms with integral finger rings. The flexibility of the lever arms can be specifically adjusted to provide the correct clamping force for clamping and sealing the blood vessel. The correct clamping force is achieved by the lever arms becoming flexible when a certain force is exceeded. Thus, if the user applies a large force that would normally be above the predetermined acceptable range for clamping and / or sealing the blood vessel, the lever arms bend. This bending of the lever arms causes the excess force to be dissipated and the remaining force to be transmitted to the jaws, such that the correct clamping / sealing force is applied to the blood vessel / tissue. No metal reinforcement components are required within the lever arms. The adjustment of the flexibility of the lever arms is achieved by designing the thickness of the material forming the arms to give the desired flexibility, as the thicker the material, the lower the flexibility and the greater the force transmitted to the jaw members before the arms bend. The width and height thickness dimensions can be adjusted to give the desired flexibility response.

[0012] In some embodiments, the flexibility of the first arm is selected such that the clamping force is within a predetermined range.

[0013] In some embodiments, at least one of the first and second jaw members includes a conductive sealing surface for transmitting RF energy through the tissue held therebetween, wherein at least one of the first and second arms includes a radio frequency (RF) electrical connection capable of connecting the conductive sealing surface to an RF energy source.

[0014] In some embodiments, at least one of the first and second arms includes a finger ring.

[0015] In some embodiments, the first and second components are plugged together such that the second component is inserted through an opening in the first central portion of the first component. This is advantageous as it allows for quick and easy assembly of the instrument, thereby reducing the assembly cost.

[0016] In some embodiments, the opening is defined by a first flange and a second flange, and the second central portion of the second component is held within the opening of the first central portion of the first component and is supported by the first and second flanges. The flanges are an advantageous result of using a polymeric material and they provide lateral support and guide the opening and closing of the device.

[0017] In some embodiments, the first component and the second component are pivotally connected using a pivot pin.

[0018] In some embodiments, the pivot pin passes through a first pivot hole in the first flange, a second pivot hole in the second central portion, and a third pivot hole in the second flange.

[0019] In some embodiments, the instrument further includes an activation button that is operable to deliver radiofrequency (RF) energy to at least one of the first jaw member and the second jaw member. Having an activation button on the instrument is advantageous as it allows the user to directly and easily access the button, thereby enabling the user to freely activate and deactivate the coagulation function.

[0020] In some embodiments, the first jaw member and the second jaw member include a pair of bipolar forceps.

[0021] In some embodiments, the first single-piece polymer material and the second single-piece polymer material are formed by a structural polymer overmolding having more than 50% glass fiber reinforcement to provide sufficient strength and stiffness while also allowing flexibility for dissipating excessive forces. In one embodiment, a polymer material called PARA IXEF can be used. PARA IXEF is a favorable choice of structural polymer as it provides a combination of strength and aesthetics. PARA IXEF typically contains about 50 - 60% glass fiber reinforcement, thereby providing strength and stiffness. PARA IXEF has high resistance to mechanical stress, high stiffness, and can be used for complex shapes.

[0022] A second aspect provides an electrosurgical system that includes an RF electrosurgical generator and the electrosurgical instrument as described above.

[0023] A third aspect provides a method of assembling an electrosurgical instrument, the method comprising the steps of: forming a first component from a first single-piece polymeric material, the first component including a first jaw member at a distal end, a first central portion, and a first arm at a proximal end; forming a second component from a second single-piece polymeric material, the second component including a second jaw member at a distal end and a second central portion; connecting the second central portion to a proximal second arm; and pivotally connecting the first component and the second component together such that at least one of the first arm and the second arm is movable relative to the other arm between an open position where the arms are spaced apart from each other and a closed position where the arms are close together, and the first jaw member and the second jaw member are movable between a first state and a second state in response to relative movement of at least one of the arms. Wherein, the first component and / or the second component includes one or more strengthening members, the one or more strengthening members being positioned to respectively support the first jaw member and / or the second jaw member, and the one or more strengthening members being arranged to provide support for the first component and / or the second component.

[0024] This simple assembly method is advantageous because it greatly reduces the assembly cost while still providing support for the jaws such that the jaws do not bend under load.

[0025] In some embodiments, the step of pivotally connecting the first component and the second component includes: inserting the second component through an opening in the first central portion of the first component; closing the first jaw member and the second jaw member such that a first pivot hole in a first flange, a second pivot hole in the second central portion, and a third pivot hole in a second flange are aligned; and inserting a pivot pin through the first pivot hole, the second pivot hole, and the third pivot hole such that the first component and the second component are pivotally connected. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Embodiments of the present invention will now be further described only by way of example and with reference to the accompanying drawings, in which like reference numerals refer to like parts, and in which:

[0027] Figure 1 is a side view of an electrosurgical instrument according to an embodiment of the present invention;

[0028] Figure 2 shows three perspective views of an electrosurgical instrument according to an embodiment of the present invention, the perspective views showing how the components of the instrument are assembled together;

[0029] Figure 3 shows an isolated view of a first component of the electrosurgical instrument;

[0030] Figure 4 shows the distal end of the first component in more detail;

[0031] Figure 5Side view of the first component of an electrosurgical instrument;

[0032] Figure 6 Top view of the first component of an electrosurgical instrument;

[0033] Figure 7 Representation of an electrosurgical system including a generator and an instrument according to an embodiment of the present invention;

[0034] Figure 8 Side view of the second component of an electrosurgical instrument;

[0035] Figure 9 Perspective view of the second component of an electrosurgical instrument; and

[0036] Figure 10 Perspective view of the second component of an electrosurgical instrument. Detailed Description

[0037] Referring to the accompanying drawings, Figure 1 there is shown an electrosurgical instrument 100 according to a first example of the present invention. The instrument 100 includes a first component 100a and a second component 100b. The first component 100a is formed of a single piece of polymeric material. Similarly, the second component 100b is also formed of a single piece of polymeric material. The first component 100a includes a first jaw member 102, a first central portion 111, and a first arm 106. The second component 100b includes a second jaw member 103 and a second central portion 113. The second component 100b may be connected to a second arm 105.

[0038] The instrument 100 includes a distal actuator 101 that includes a first jaw member 102 and a second jaw member 103, thereby defining a pair of opposing jaws. At least one of the jaw members 102, 103 is movable relative to the other between a first open position in which the jaw members 102, 103 are disposed in a spaced-apart relationship relative to each other and a second closed position in which the jaw members 102, 103 cooperate to grasp tissue therebetween. The jaw members 102, 103 are capable of being connected to a power source such that the jaws 102, 103 can conduct energy through tissue held therebetween to effect tissue sealing or coagulation. To achieve this, the jaw members 102, 103 may include one or more electrodes ( Figure 1 not shown in ) that are disposed on the inner opposing surfaces of the jaw members 102, 103 or as the inner opposing surfaces of the jaw members 102, 103 and have connections in use to receive an electrosurgical radio frequency (RF) signal to seal or coagulate tissue.

[0039] The jaw members 102, 103 may further be provided with slots or other openings in their inner opposing surfaces through which mechanical cutting blades (not shown), etc., may protrude when activated by the user. The jaw members 102, 103 may be curved (as Figure 4 best shown therein) such that the moving elements of the instrument 100 are always in view. This is important for a vessel sealing device used to operate on a body area that may obstruct the user's view of the device during use.

[0040] In this example, the end effector 101 is actuated using a handle generally designated 104, where the handle includes a second arm 105 extending from the proximal end of the second jaw member 103 and a first arm 106 extending from the proximal end of the first jaw member 102, and the two arms 105, 106 are movable relative to each other. The proximal end of the handle 104 may include means for actuating each of the arms 105, 106, such as finger rings 110, 112, etc. The distal ends of the two arms 105, 106 are pivotally connected together by a central or main pivot 108. Thus, when the arms 105, 106 move relative to each other between a first open position and a second closed position where the arms 105, 106 are disposed in a spaced-apart relationship relative to each other, this movement causes corresponding opening and closing of the jaw members 102, 103.

[0041] The electrosurgical instrument 100 may include a power line 114 for supplying RF energy to the end effector 101. The power line 114 may be connected to either the first arm 105 or the second arm 106. The electrosurgical instrument 100 may further include a mechanical cutting blade (not shown) coupled to a blade actuator, such as a blade trigger (not shown). The cutting blade may be disposed within one of the arms 105, 106 such that actuation of the blade trigger causes the cutting blade to translate along the corresponding arm 105, 106 and between the two jaw members 102, 103 to cut any tissue grasped therebetween.

[0042] The electrosurgical instrument 100 may further be provided with a switching mechanism. The switching mechanism may include an activation button 117 located on the handle 104 for activating an RF signal to coagulate tissue. Additionally or alternatively, the switching mechanism may include a foot switch (not shown).

[0043] In operation, the arms 105, 106 are manipulated by a user to move the jaw members 102, 103, thereby selectively opening and closing the jaw members 102, 103. The jaw members 102, 103 and the arms 105, 106 are movable through a plurality of positions, preferably at least three positions. In a first position, the jaw members 102, 103 and the arms 105, 106 are open such that the distal ends of the first jaw member 102 and the second jaw member 103 are spaced apart and the proximal ends of the first arm 105 and the second arm 106 are spaced apart. In a second position, the jaw members 102, 103 and the arms 105, 106 are closed such that the first jaw member 102 and the second jaw member 103 are close to each other and the first arm 105 and the second arm 106 are close to each other. In a third position, the jaw members 102, 103 remain closed as in the second position while the arms 105, 106 are clamped shut. In the third position, associated circuitry or contacts may be connected to connect the appropriate electrodes of the jaws to associated connection points of an electrosurgical generator to supply RF energy to fuse tissue grasped between the jaws 102, 103.

[0044] Figure 2 Three perspective views (labeled A, B, and C) of an electrosurgical instrument 100 according to an embodiment of the present invention are shown, which show how a first component 100a and a second component 100b are assembled together. This will be described in more detail below.

[0045] The first component 100a is shown separately in Figures 3 to 6 . The first jaw 102 has an exposed electrode 116 (best shown in Figure 4 ) for directing RF energy to fuse tissue grasped between the jaws 102, 103. The first component 100a includes a molded material, called a first central portion 111, adjacent to the jaw member 102. The first central portion 111 includes a flange 109 to provide lateral support and to guide the opening and closing of the instrument 100. The first component 100a also includes a flexible lever arm (described above as the "first arm") 106 having a bend 118, a finger ring 110, and an activation button 117. The first component 100a is formed from a single piece of polymer, i.e., the first jaw 102, the first central portion 111, the flange 109, the lever arm 106, the finger ring 110, and the activation button 117 are all formed from a single piece of polymer.

[0046] The second jaw 103 may also have an exposed electrode 116 for directing RF energy to fuse tissue grasped between the jaws 102, 103. The second component 100b includes a molded material called the second central portion 113 adjacent to the jaw member 103. The second component 100b is formed from a single piece of polymer, i.e., the second jaw 103 and the second central portion 113 are formed from a single piece of polymer. The second central portion 113 may then be connected to the second arm 105, as Figure 1 described above.

[0047] In some embodiments of the present invention, one or more strengthening members may be added to the structure of the instrument 100 to provide additional support. The strengthening members may include metal inserts. The strengthening members may be positioned to support one or both of the jaws 102, 103 and may project into the central portions 113, 115 in a cantilevered manner. In Figures 8 to 10 an example of the use of a strengthening member within the second component 100b is shown, and the strengthening members described with respect to Figures 8 to 10 may alternatively or additionally be applied to the first component 100a.

[0048] Figures 8 to 10 The second component 100b incorporating the strengthening member 800 is shown. The second component 100b is as described above and additionally incorporates the strengthening member 800. The strengthening member 800 may be a metal insert. The strengthening member 800 is positioned within the jaw 103 and may project into the second central portion 113 in a cantilevered manner. The strengthening member may be held in place by inserting one or more fastening means 802 into one or more holes 902 ( Figure 9 shown). The fastening means may be pins or threaded fasteners. The strengthening member 800 provides additional support to the jaw and the entire second component 100b. The strengthening member 800 advantageously significantly reduces any bending of the jaw 103 under load. Any strengthening member 800 may be positioned prior to overmolding of the polymer or, alternatively, inserted in place after the polymer has been molded. The overmolded portion of the polymer partially or fully encapsulates the internal structure (including any strengthening member 800) and electronic components (e.g., internal wiring 114). The electrode surface 116 is exposed.

[0049] In some embodiments, both jaws 102, 103 include one or more strengthening members 800 for additional support.

[0050] In Figures 8 to 10 the internal wiring 114 is shown as being surrounded by the polymer overmolding and the strengthening member 800. However, in other examples, the internal wiring 114 may not be surrounded by the strengthening member 800. As Figure 1 and Figure 7As shown, the internal wiring 114 is an extension of the power line 114 and connects the electrode 116 to an electrosurgical generator to allow an RF signal to be fed to the end effector of the instrument 100 and also allows a control signal to be received to command the electrosurgical generator to output an RF coagulation signal to the instrument 100, as described in more detail later.

[0051] Embodiments of the present invention allow for a simple assembly method that requires the use of a pivot pin 108 to hold together two overmolded parts (a first part 100a and a second part 100b) to form a pair of functional jaws.

[0052] As Figure 2 shown in view A, the first part 100a and the second part 100b are inserted together such that the second part 100b is inserted through an opening 115 in the first central portion 111 of the first part 100a. In practice, the second central portion 113 of the second part 100b will be inserted upward through the opening 115 in the first part 100a because the curved jaws 103 will prevent the second part 100b from being inserted downward through the opening 115 at the first jaw end. The opening 115 is defined by a first flange and a second flange 109. The second central portion 113 is held in the opening 115 and is supported by the flange 109. As Figure 2 shown in view B, once assembled, the jaws 102, 103 come together, which aligns the three polymer pivot holes 107 (one in each flange 109 of the first part 100a and one in the second part 100b). The pivot pin 108 passes through the three pivot holes 107 to hold the assembly together, as Figure 2 shown in view C. The pivot pin 108 can be a press-fit pivot pin 10 or a riveted pivot pin 108.

[0053] Except for the pivot pin 108 and the electrodes 116 on the two jaws 102, 103, there may be no exposed metal within the assembly. This is advantageous because exposed metal would require insulation from the electrodes 116. The polymer used for the first part 100a and the second part 100b of the assembly is PARA IXEF, which serves as a metal substitute in this case. The use of the polymer greatly reduces the complexity of the product, reduces the number of parts, and greatly simplifies the assembly. As described above, one or more strengthening members 800 can be used to strengthen one or both of the jaws 102, 103. Such a member 800 can be a metal insert and can be fully or partially encapsulated by a polymer overmolding.

[0054] A method of assembling the instrument 100 will now be described. The method includes forming a first component 100a from a first single-piece polymeric material and forming a second component 100b from a second single-piece polymeric material. In some embodiments of the present invention, one or more reinforcement members 800 may be positioned relative to internal components (e.g., internal wiring 114, electrodes 116) before forming the first component and / or the second component from the polymeric material. The first component 100a and / or the second component 100b may then be formed by overmolding the polymer, encapsulating any reinforcement members 800 and internal components. The second component 100b may be connected to the second arm 105. The first component 100a and the second component 100b are then pivotally connected together. The components 100a, 100b may be pivotally connected by inserting the second component 100b through an opening 115 in a first central portion 111 of the first component 100a and closing the first jaw member 102 and the second jaw member 103 so as to align a first pivot hole in a first flange, a second pivot hole in a second central portion, and a third pivot hole in a second flange, and passing a pivot pin through the first pivot hole, the second pivot hole, and the third pivot hole such that the first component 100a and the second component 100b are pivotally connected.

[0055] The use of the polymer enables the electrodes 116 and any reinforcement members 800 to be overmolded to form the jaws 102, 103 and also extends the molding function to include the following additional functions:

[0056] (i) Molding the pivot holes 107.

[0057] (ii) Flanges 109 which provide lateral support and guide the opening and closing of the instrument 100.

[0058] (iii) A flexible lever arm 106 with an integral finger ring 110 which is designed to provide the forces required to clamp and seal a blood vessel.

[0059] The flexible integral lever arm 106 is part of the first component 100a and is thus part of the same polymeric overmold. There are no metal reinforcement components within the lever arm 106. The flexible lever arm is described as the first arm 106 although in practice it could be the second arm 105, or both.

[0060] Figure 5Shows a first component 100a and a flexible lever arm 106. The flexibility of the lever arm 106 can be specially adjusted to provide the correct clamping force for clamping and sealing blood vessels. The correct clamping force can be considered to include a predetermined acceptable range. The correct clamping force is achieved by the lever arm 106 being flexible when a certain force is exceeded. Thus, if the user applies a large force that would normally be above the predetermined acceptable range for clamping and / or sealing a blood vessel, the lever arm 106 bends. This bending of the lever arm 106 causes excessive force to be dissipated, and the remaining force is transmitted to the jaws 102, 103, so that the correct clamping / sealing force is applied to the blood vessel / tissue. The more flexible the lever arm 106, the smaller the force transmitted to clamp the blood vessel.

[0061] Figure 6 Is a top view of the first component 100a. The width of the lever arm 106 is specially selected to provide the correct lateral stiffness for the lever arm. The wider the lever arm 106, the stiffer the lever arm 106.

[0062] As an illustrative working example, the distance of the handles 110, 112 from the pivot 108 can be approximately three times the clamping / sealing position between the jaws 102, 103. This means that the force at the clamping / sealing position is approximately three times the force applied at the handles. The correct clamping / sealing pressure may be about 1.5 MPa. For a 2 cm 2 clamping / sealing area of the jaws, the required clamping / sealing force is 300 N. Therefore, the force applied at the handles 110, 112 should be about 100 N.

[0063] A typical grip strength of a person may be about 30 - 40 kg (about 300 - 400 N). Generally, surgeons do not use all of their grip strength as the force applied to the instrument handles. However, the lever arm 106 is designed to be flexible when a certain force (e.g., 100 N) is exceeded. Thus, if a surgeon applies a force greater than 100 N, if all of this force is transmitted, it would result in a clamping / sealing force greater than 300 N, and the lever arm 106 bends, thus dissipating excessive force.

[0064] The polymer PARA IXEF from which the instrument can be made has a flexural strength of approximately 200 MP. The flexural strength is equal to the stress in the material just before it breaks in a bending test. If the maximum required force is 100 N, the cross-sectional area of the lever arm 106 must be significantly greater than 0.5 mm 2 because at 0.5 mm 2 the lever arm 106 would break under a 100 N force. A suitable cross-sectional area can be 30 - 50 mm 2 .

[0065] This example makes many simplified assumptions, just for illustrative purposes.

[0066] In embodiments where one or both of the jaws 102, 103 include one or more reinforcement members 800, the applied force can be better transmitted to the jaws 102, 103 because the reinforcement members 800 significantly reduce the bending of the jaws 102, 103 under the load of the applied force.

[0067] Now referring Figure 7 , the instrument 100 is designed to be connected, in use, to an electrosurgical generator 200 having a controllable RF source (not shown) therein, which RF source generates an RF coagulation signal in use, and the RF coagulation signal coagulates or seals the tissue when applied to the tissue through the electrodes of the end effector of the instrument 100. The electrosurgical generator 200 includes control input switches 204 and 202 to respectively allow the generator to be turned on and off and to allow control of the power of the RF coagulation signal fed to the instrument 100. In these respects, the electrosurgical generator 200 is conventional.

[0068] The instrument 100 is connected to the generator 200 in use by a control and power cord 114, and the control and power cord 114 includes separate wires to allow the RF signal to be fed to the end effector of the instrument 100 through the internal wiring 114 and also to allow receipt of control signals to command the electrosurgical generator to output an RF coagulation signal to the instrument 100. The control signal can be initiated by an activation button 117 on the instrument 100 or by a foot switch (not shown). In use, the surgeon activates the generator by the on-off switch 204 and uses the button 202 to select the intensity of the coagulation or sealing signal generated by the internal RF source. During a surgical procedure using the instrument, when the end effector needs to seal or coagulate an RF signal, the surgeon controls the generator to generate such a signal by pressing the activation button on the instrument (or by using the foot switch), and the generated RF signal is then transmitted through the wire 114 to the end effector. That is, pressing the activation button in use causes an RF coagulation or sealing signal to be provided to the appropriate electrodes included within the end effector.

[0069] The jaw members 102, 103 may each have an electrode 116 or a conductive pad. In this case, the conductive pads of the first jaw member 102 and the second jaw member 103 are electrically coupled to the electrosurgical generator 200 via wires 114 and connectors to provide RF energy to the tissue clamped between the conductive pads. The conductive pads are arranged with opposite polarities. The wires and associated connectors may extend from the activation button 117 through the second arm 105 and / or the first arm 106 to the first jaw member 102 and the second jaw member 103 and to the respective connectors of the first electrode and the second electrode. The activation button 117 may complete the circuit when actuated by electrically coupling at least two leads together. Thus, a circuit path is then established from the electrosurgical generator 200 to the actuator to provide RF energy to the instrument 100.

[0070] Various modifications may be made to the above-described embodiments, either by adding, deleting, or substituting features to provide further embodiments, and any and all embodiments are intended to be covered by the appended claims.

Claims

1. An electrosurgical instrument, the electrosurgical instrument comprises: A first component, the first component includes a distal first jaw member, a first central portion, and a proximal first arm, and the first component is formed of a first single-piece polymeric material; and A second component, the second component includes a distal second jaw member and a second central portion, and the second component is formed of a second single-piece polymeric material, wherein the second central portion is connected to a proximal second arm; wherein the first component and the second component are pivotally connected such that at least one of the first arm and the second arm can move relative to the other arm between an open position where the first arm and the second arm are spaced apart from each other and a closed position where the first arm and the second arm are close together, the first jaw member and the second jaw member can move between a first state and a second state in response to the relative movement of at least one arm, and wherein the first component and / or the second component includes one or more strengthening members, the one or more strengthening members are positioned to respectively support the first jaw member and / or the second jaw member, and the one or more strengthening members are arranged to provide support for the first component and / or the second component, wherein the one or more strengthening members project into the first central portion and / or the second central portion in a cantilever shape.

2. The electrosurgical instrument according to claim 1, wherein, the one or more strengthening members are partially or completely encapsulated by the first single-piece polymeric material and / or the second single-piece polymeric material.

3. The electrosurgical instrument according to claim 1, wherein, the one or more strengthening members are formed of metal.

4. The electrosurgical instrument according to claim 3, wherein, the one or more strengthening members include one or more metal inserts.

5. The electrosurgical instrument according to claim 1, wherein, the shape and thickness of the polymeric material forming at least the first arm are such that the first arm bends when a certain force is exceeded, whereby in use the first jaw member and the second jaw member provide a clamping force to clamp a blood vessel held between the first jaw member and the second jaw member, and the bending of at least the first arm when a certain force is exceeded prevents an excessive clamping force from being applied to the blood vessel.

6. The electrosurgical instrument according to claim 5, wherein, the flexibility of the first arm is selected such that the clamping force is within a predetermined range.

7. The electrosurgical instrument according to claim 1, wherein, at least one of the first jaw member and the second jaw member includes a conductive sealing surface for transmitting RF energy through tissue held between the first jaw member and the second jaw member, and at least one of the first arm and the second arm includes a radio RF electrical connector capable of connecting the conductive sealing surface to an RF energy source.

8. The electrosurgical instrument according to claim 1, wherein, at least one of the first arm and the second arm includes a finger ring.

9. The electrosurgical instrument according to claim 1, wherein, the first component and the second component are inserted together such that the second component is inserted through an opening in the first central portion of the first component.

10. The electrosurgical instrument according to claim 9, wherein, the opening is defined by a first flange and a second flange, and the second central portion of the second component is held within the opening of the first central portion of the first component, and the second central portion is supported by the first flange and the second flange.

11. The electrosurgical instrument according to claim 1, wherein, the first component and the second component are pivotally connected using a pivot pin.

12. The electrosurgical instrument according to claim 1, wherein, the first component and the second component are inserted together such that the second component is inserted through an opening in the first central portion of the first component, the opening is defined by a first flange and a second flange, and the second central portion of the second component is held within the opening of the first central portion of the first component, and the second central portion is supported by the first flange and the second flange, and wherein a pivot pin passes through a first pivot hole in the first flange, a second pivot hole in the second central portion, and a third pivot hole in the second flange.

13. The electrosurgical instrument according to claim 1, the electrosurgical instrument further comprising an activation button that is operable to deliver a radiofrequency energy source, i.e., an RF energy source, to at least one of the first jaw member and the second jaw member.

14. The electrosurgical instrument according to claim 1, wherein, the first jaw member and the second jaw member include a pair of bipolar forceps.

15. The electrosurgical instrument according to claim 1, wherein, the first single-piece polymeric material and the second single-piece polymeric material are formed by a structural polymer overmolding having at least 50% glass fiber.

16. An electrosurgical system, the electrosurgical system comprising: an RF electrosurgical generator; and the electrosurgical instrument according to claim 1.

17. A method of assembling an electrosurgical instrument, the method comprising the steps of: forming a first component from a first single-piece polymeric material, the first component including a distal first jaw member, a first central portion, and a proximal first arm; forming a second component from a second single-piece polymeric material, the second component including a distal second jaw member and a second central portion; connecting the second central portion to a proximal second arm; and pivotally connecting the first component and the second component together such that at least one of the first arm and the second arm is movable relative to the other arm between an open position in which the first arm and the second arm are spaced apart from each other and a closed position in which the first arm and the second arm are close together, and the first jaw member and the second jaw member are movable between a first state and a second state in response to relative movement of at least one arm; Wherein, the first component and / or the second component includes one or more strengthening members, the one or more strengthening members being positioned to respectively support the first jaw member and / or the second jaw member, and the one or more strengthening members being arranged to provide support for the first component and / or the second component. Wherein, the one or more strengthening members project into the first central portion and / or the second central portion in a cantilevered manner.

18. The method according to claim 17, Wherein, The step of pivotally connecting the first component and the second component includes: Inserting the second component through an opening in the first central portion of the first component; Closing the first jaw member and the second jaw member such that a first pivot hole in the first flange, a second pivot hole in the second central portion, and a third pivot hole in the second flange are aligned; and Inserting a pivot pin through the first pivot hole, the second pivot hole, and the third pivot hole such that the first component and the second component are pivotally connected.

19. A clamp-type surgical instrument having a jaw-type end effector for clamping and treating tissue, corresponding upper and lower jaws of the jaw-type end effector being connected to respective arms extending to respective finger engagement rings that receive a user's fingers in use, the respective arms being connected by a pivotal connection to allow the user in use to pivotally open and close the jaw-type end effector by movement of the arms about the pivotal connection, the cross-sectional shape of the material forming at least one or two of the arms being such that the arms are flexible, the flexibility of one or two of the arms being adjusted to provide the correct clamping / sealing force for clamping and sealing blood vessels or tissue, the one or two arms being flexible when a certain predetermined force is exceeded, whereby if the user applies too much force beyond the predetermined acceptable range of force for clamping and / or sealing blood vessels or tissue, the one or two arms bend, causing any excessive force beyond the predetermined force to be dissipated and the remaining force to be transmitted to the upper and lower jaws such that the correct clamping / sealing force is applied to the blood vessels or tissue. Wherein, One or both of the upper jaw and the lower jaw are strengthened by one or more strengthening members that project into the central portion of the respective one or two arms in a cantilevered manner.

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