Electrosurgical Cutting Instruments

Abstract

Various embodiments provide an electrosurgical cutting instrument including an energy transfer structure for delivering high frequency electromagnetic energy and / or microwave electromagnetic energy, and an instrument tip attached to a distal end of the energy transfer structure, the instrument tip including a first jaw and a second jaw. The first jaw includes a first pair of electrodes electrically insulated from one another. The first pair of electrodes is coupled to the energy transfer structure. The first jaw and the second jaw are movable relative to one another between a closed position in which the first jaw and the second jaw are positioned alongside one another, and an open position in which the second jaw is separated from the first jaw by a gap for receiving biological tissue. The first jaw extends distally beyond the second jaw in the closed position. The first jaw includes a distal end surface, and the first pair of electrodes are exposed at the distal end surface.

Description

[Technical field]

[0001] The present invention relates to electrosurgical cutting instruments and electrosurgical instruments for cutting, coagulating and ablating biological tissue. In particular, the present invention relates to electrosurgical cutting instruments and electrosurgical instruments capable of delivering radio frequency (RF) energy and / or microwave frequency energy for cutting, hemostasis (i.e., sealing broken blood vessels by promoting clotting of blood) and tissue / or ablation of biological tissue. [Background technology]

[0002] Surgical resection is a means of removing parts of an organ from within the human or animal body. Organs may be highly vascular. When tissue is cut (i.e., divided or transected), small blood vessels become damaged or rupture. An initial hemorrhage is followed by a clotting cascade in which the blood is converted into a clot in an attempt to plug the bleeding point. During surgery, it is desirable for the patient to lose as little blood as possible, and therefore various devices have been developed in an attempt to achieve a hemorrhage-free cut. In the case of endoscopic procedures, bleeding may occur and is also undesirable if not properly addressed, as the blood flow may obscure the surgeon's view.

[0003] Instead of sharp blades, it is known to use RF energy to cut biological tissue. The method of cutting using RF energy works using the principle that when an electric current is passed through the tissue matrix (aided by the ionic content of the cells), the impedance to the flow of electrons across the tissue generates heat. When a pure sine wave is applied to the tissue matrix, enough heat is generated within the cells to vaporize the water in the tissue. Thus, the internal pressure of the cell increases enormously and cannot be controlled by the cell membrane, resulting in the cell bursting. When this occurs over a large area, it can be seen that the tissue has been cut. The above procedure works well in lean tissue, but is less efficient in fatty tissue, as it has less ionic content to aid the passage of electrons. This means that the energy required to vaporize the contents of a cell is much greater, as the latent heat of vaporization of fat is much greater than that of water.

[0004] RF coagulation works by applying a low-efficiency waveform to tissue, which instead of vaporizing it heats the cellular contents to about 65°C, dehydrating the tissue and denaturing proteins in the vessel walls. This denaturation acts as a stimulus to the coagulation cascade, thus promoting clotting. At the same time, collagen in the walls denatures from rod-like to coiled molecules, causing the vessel to shrink and reduce in size, providing an anchor point for the clot and reducing the area of ​​blockage. However, the presence of fatty tissue reduces the efficiency of RF coagulation, as it reduces the electrical effect. Thus, fatty hemorrhages can be very difficult to plug. Instead of a clean white edge, the tissue takes on a burnt, black appearance.

[0005] Tissue ablation using microwave electromagnetic (EM) energy is based on the fact that biological tissue is composed primarily of water. Human soft organ tissues typically have a water content of 70%-80%. Water molecules have a permanent electric dipole moment, meaning that there is an imbalance of charge throughout the molecule. This charge imbalance causes the molecules to move in response to forces generated by the application of a time-varying electric field as the molecules rotate to align their electric dipole moment with the polarity of the applied electric field. At microwave frequencies, rapid molecular vibrations cause frictional heating, resulting in dissipation of field energy in the form of heat. This is known as dielectric heating. This principle is utilized in microwave ablation therapy, where application of a localized electromagnetic field at microwave frequencies rapidly heats water molecules in the target tissue, resulting in tissue coagulation and cell death. Summary of the Invention [Problem to be solved by the invention]

[0006] Most generally, the present invention provides an electrosurgical ablation instrument (or electrosurgical ablation device) having an energy delivery structure that provides multiple modes of operation to facilitate the cutting and sealing of biological tissue using radio frequency (RF) electromagnetic energy and / or microwave EM energy. In particular, the present invention relates to a combined actuation and energy delivery mechanism that is compact enough to allow the instrument to be inserted through an instrument channel of a surgical scoping device such as an endoscope, gastroscope, or bronchoscope. The device can also be used in laparoscopic and open surgery, i.e., opening the abdominal cavity to perform bloodless resection of liver lobes. [Means for solving the problem]

[0007] The present invention represents an expansion of the concept of an electrosurgical cutting instrument discussed in GB2567480. The electrosurgical cutting instrument of the present invention comprises a pair of jaws, a first jaw comprising a first pair of electrodes and a second jaw optionally comprising a single electrode (i.e. only one electrode is present in the second jaw) or a second pair of electrodes (i.e. two electrodes are present in the second jaw). This allows the electrosurgical cutting instrument to operate according to three complementary modes: (i) RF-based sliding cutting when the jaws are closed, (ii) scissor-type cutting performed on tissue grasped between the jaws using a combination of RF energy and applied pressure, and (iii) coagulation or vessel sealing action performed on tissue grasped between the jaws using a combination of microwave energy and applied pressure. The inventors have discovered that by providing the cutting instrument with two, three or four electrodes as described herein, the ability of the instrument to cut and coagulate tissue using EM energy can be improved. In particular, such electrode placement may allow multiple RF fields to be established throughout the jaws, resulting in smoother, more uniform cutting. Similarly, such electrode configurations may result in more effective coagulation and ablation of tissue using microwave energy by allowing a more uniform microwave field to be emitted. For the avoidance of doubt, it should be understood that "single electrode" means that the second jaw comprises only one electrode and that no other electrodes are provided on the second jaw for delivering RF and / or microwave energy.

[0008] An electrosurgical cutting instrument is provided that includes an energy transfer structure for delivering high frequency electromagnetic energy and / or microwave electromagnetic energy, an instrument tip (or instrument tip or tip of a scope device) attached to a distal end of the energy transfer structure, the instrument tip comprising a first jaw and a second jaw, the first jaw comprising a first pair of electrodes electrically insulated from one another, the first pair of electrodes being coupled to the energy transfer structure, the first jaw and the second jaw being movable relative to one another between a closed position in which the first jaw and the second jaw are positioned alongside one another and an open position in which the second jaw is separated from the first jaw by a gap for receiving biological tissue, the first jaw extending distally beyond the second jaw in the closed position, the first jaw including a distal end surface, the first pair of electrodes being exposed at the distal end surface.

[0009] An electrosurgical cutting instrument can be considered an electrosurgical instrument (such as an electrosurgical cutting instrument) and / or an electrosurgical (scope) device (with cutting function). An electrosurgical cutting instrument can be configured to (uniformly) emit microwave radiation for sealing (blood) vessels. An electrosurgical cutting instrument further provides a cutting or ablation function at the distal end face when a first pair of electrodes is exposed at the distal end face. This allows current to flow between the pair of electrodes at the distal end face. An electrosurgical cutting instrument provides cutting not only between the jaws, but also at the distal end face. When the first jaw extends beyond the second jaw in the closed position, the distal end face is the most distal surface of the electrosurgical cutting instrument. That is, when the electrosurgical cutting instrument is moved or pushed distally, the distal end face is the first to contact tissue (in the closed position). An electrosurgical cutting instrument has a small outer diameter, so that the distal end face also has a small area. The outer diameter of the electrosurgical cutting instrument is smaller than the cavity of the scope device or endoscope through which the electrosurgical cutting instrument may be moved, allowing for precision cutting at the distal end face, particularly when the electrosurgical cutting instrument is capable of cutting its way to a problem site, for example, to gain access to the cavity.

[0010] The energy transfer structure may comprise a coaxial transmission line having an inner conductor separated from an outer conductor by a dielectric material. A first pair of electrodes may be coupled to the energy transfer structure such that the first pair of electrodes are operable as active and return electrodes for delivering radio frequency electromagnetic energy transferred by the energy transfer structure. Optionally, the instrument tip is operable as a microwave field emitting structure for emitting microwave electromagnetic energy carried by the energy transfer structure.

[0011] The energy transmission structure may be disposed within the lumen of the shaft (or outer sheath) such that the instrument tip protrudes from the distal end of the shaft. The shaft may be any suitable shaft into which a coaxial transmission line may be inserted. The shaft may be flexible, e.g., suitable for bending or other maneuvering to reach the treatment site. A flexible shaft may allow the device to be used with a surgical scoping device, such as an endoscope. In other examples, the shaft may be rigid, e.g., for use in open surgery or laparoscopy.

[0012] The coaxial transmission line may be adapted to transmit both RF and microwave EM energy. Alternatively, the energy transmission structure may comprise different routes for the RF and microwave EM energy. For example, microwave EM energy may be delivered via a coaxial transmission line, while RF EM energy may be delivered via a twisted pair wire, etc. The coaxial transmission line may be in the form of a flexible coaxial cable.

[0013] The first and second jaws are attached to the distal end of the energy transfer structure such that they are movable relative to one another between an open position and a closed position. Various types of relative motion between the jaws can be used. The relative motion between the first and second jaws can include rotational and / or translational motion. At least one of the first and second jaws can be movably attached to the distal end of the energy transfer structure to allow for relative motion between the first and second jaws. In some cases, only one of the first and second jaws can be movably attached to the distal end of the energy transfer structure, while in other cases, both the first and second jaws can be movably attached to the distal end of the energy transfer structure.

[0014] As an example, the first and second jaws may be pivotable relative to one another, such as to allow for adjustment of the angular spread between the first and second jaws. An example of this may resemble a scissor-type closure. The first and / or second jaws may be pivotally attached to a distal end of the energy transfer structure.

[0015] In another example, it may be beneficial for the gap between the first and second jaws to be uniform when tissue is grasped therebetween, for example to ensure that the energy delivered is uniform along the entire length of the jaws. In this example, the first and second jaws may be configured to remain parallel as they move relative to one another. For example, the first and second jaws may be parallel when the jaws are in an open position, and the first and second jaws may remain parallel as they slide past one another to a closed position.

[0016] The first and second jaws can be moved between an open position and a closed position. The open position is where the first and second jaws are furthest from one another. The closed position is where the first and second jaws are closest to one another or overlap one another. There are multiple intermediate positions between the open and closed positions. The first and second jaws can be positioned continuously between the open and closed positions or there are multiple distinct intermediate positions between the open and closed positions.

[0017] The first jaw may comprise a first blade element and / or the second jaw may comprise a second blade element, such that when the jaws are in a closed position, the first blade element can be positioned alongside the second blade element, and when the jaws are in an open position, a gap can exist between the first and second blade elements to receive biological tissue.

[0018] The first and second blade elements can be configured to cut tissue disposed in a gap between the first and second jaws when the first and second jaws move from the open position to the closed position. Thus, the first and second blade elements can each include a cutting (e.g., sharp) blade arranged to cut tissue. A cutting interface can be defined between the first and second jaws corresponding to an area where tissue between the jaws is cut when the jaws are closed.

[0019] The first and second blade elements may be arranged to slide past one another as the first and second jaws move between the open and closed positions, for example, to effect mechanical cutting of tissue through application of a shear force, and thus, the cuts effected by the first and second blade elements may resemble a scissor-type cutting mechanism.

[0020] In the closed position, both the first jaw and the second jaw are oriented parallel to the distal direction. In other words, in the closed position, the first jaw is disposed parallel to the second jaw. In the open position, one of the first jaw and the second jaw, optionally the stationary or non-moving jaw, remains disposed parallel to the distal direction. The distal direction may be parallel to the longitudinal direction of the electrosurgical cutting instrument. In the closed position, the first jaw may be distally longer than the second jaw, and the first jaw protrudes distally from the second jaw.

[0021] The first and / or second blade elements may include one or more serrated portions (e.g., teeth), which can facilitate grasping and cutting tissue located in the gap between the jaws.

[0022] The electrosurgical cutting instrument may include an actuator for controlling the movement of the second jaw relative to the first jaw. The actuator may include any suitable type of actuator for controlling the relative movement between the jaws. By way of example, the actuator may include a control rod extending along the energy transmission structure (e.g., inside the shaft) and movable along its entire length to control the position of one or both of the jaws. The control rod may have an attachment mechanism that engages one or both of the first and second jaws, such that longitudinal movement of the control rod causes movement of the second jaw relative to the first jaw. The attachment mechanism may be a hook or any suitable engagement for transmitting push and pull forces to one or both of the jaws.

[0023] A first pair of electrodes is disposed on the first jaw, with a first electrode in the first pair functioning as an active electrode of RF EM energy and a second electrode in the first pair functioning as a return electrode of RF EM energy. In this manner, RF EM energy carried by the energy transfer structure can be delivered to tissue via the first pair of electrodes. The first pair of electrodes can establish a first RF cutting field with the RF EM energy from the energy transfer structure to cut the target tissue. The first pair of electrodes can be exposed on a surface of the first jaw, such that they can contact the target tissue to deliver RF EM energy to the target tissue. In particular, the first pair of electrodes can contact the target tissue to deliver RF EM energy to the target tissue at the distal end face.

[0024] A single electrode or a second pair of electrodes may be disposed in the second jaw and function as an active electrode and / or a return electrode for RF EM energy. In particular, the single electrode may be operable as an active electrode when the inner electrode of the first jaw is operable as a return electrode, or may be operable as a return electrode when the inner electrode of the first jaw is operable as an active electrode. In this manner, the single electrode may cooperate with the first pair of electrodes of the first jaw to establish a second RF cutting field with RF EM energy from the energy transfer structure to cut the target tissue. The single electrode of the second jaw may be exposed on a surface of the second jaw so as to contact the target tissue and deliver RF EM energy to the target tissue.

[0025] Thus, when RF EM energy is transmitted by the energy transmission structure, a first RF cutting field is established by the first pair of electrodes and a second RF cutting field is established between the jaws by one of a single electrode or the second pair of electrodes of the second jaw and the first pair of electrodes. Thus, RF cutting can occur at the first jaw as well as between the two jaws. This may allow RF cutting to be performed over a larger area of ​​tissue and may allow more uniform RF cutting to be performed.

[0026] Additionally, the three electrodes function to define a microwave field emitting structure for emitting (or radiating) microwave EM energy from the energy transfer structure. As such, microwave EM energy carried by the energy transfer structure may be radiated from the electrodes into the target tissue to coagulate and / or ablate the target tissue. The particular shape of the emitted microwave field(s) depends on the arrangement of the electrodes in the jaws. For example, the electrodes in both jaws may together form a microwave field emitting structure such that a common microwave field is emitted across both jaws. Using paired electrodes to radiate microwave EM energy may improve the uniformity and symmetry of the emitted microwave field across the jaws, improving the effectiveness of treating tissue with microwave EM energy.

[0027] In an optional embodiment, the first jaw comprises a first planar dielectric element having an inner surface facing the second jaw and an outer surface facing away from the second jaw, and the first pair of electrodes comprises an inner electrode and an outer electrode, the inner electrode disposed on the inner surface of the first planar dielectric element and the outer electrode disposed on the outer surface of the first planar dielectric element. The second jaw may comprise a second planar dielectric element having an inner surface facing the first jaw in the closed position and an outer surface facing away from the first jaw in the closed position. The second jaw may comprise an inner electrode disposed on the inner surface of the second planar dielectric element and / or an outer electrode disposed on the outer surface of the second planar dielectric element.

[0028] This allows the electrodes to be substantially aligned laterally relative to one another when the jaws are closed. This can allow for effective treatment of target tissue over a large area when the jaws are closed. Furthermore, because the first jaw is longer than the second jaw, this configuration allows for the first pair of electrodes to be used to cut / ablate tissue at the distal end surface.

[0029] The first and second planar dielectric elements may be substantially parallel to one another, e.g., a plane defined by an inner surface of the first planar dielectric element may be substantially parallel to a plane defined by an inner surface of the second planar dielectric element. The first and second planar dielectric elements may each be aligned parallel to a plane in which the first and second jaws are movable relative to one another.

[0030] Each of the first and second planar dielectric elements may be formed by a piece of dielectric (i.e. insulating) material, such as ceramic (e.g. alumina). Reference herein to a "planar" element may mean a flat piece of material having a thickness that is substantially less than its width and length. Each planar dielectric element may have a length dimension aligned vertically, a thickness dimension aligned horizontally, and a width dimension orthogonal to both the length dimension and the thickness dimension. The plane of the planar dielectric element is the plane in which the length and width dimensions lie, i.e., the plane orthogonal to the width dimension. The inner and outer surfaces of each planar dielectric element may be parallel to the plane of the planar dielectric element, i.e., they may be orthogonal to the width dimension. The inner and outer surfaces of each planar dielectric element may be disposed on opposite sides of the planar dielectric element with respect to its width.

[0031] The distal end surface can be a surface of the first jaw that is seen when looking longitudinally at the first jaw.

[0032] The use of a planar dielectric element in each jaw on which the electrodes are disposed may greatly facilitate the manufacture of the instrument tip, since the electrodes may be easily formed on its inner and / or outer surfaces, for example, by depositing a conductive material on the surface and / or by attaching a conductive element to the surface. In contrast, in prior art cutting instruments, the jaws are typically made of a conductive material coated with an insulating material, and the electrodes are defined by areas of the jaw where the insulating material is etched away. Etching the insulating material to define the electrodes may be a tedious and time-consuming process. Furthermore, it has been found that tissue may adhere to the insulating material, making cleaning of the instrument tip difficult. Thus, the use of planar dielectric elements in the jaws may not only facilitate the manufacture of the instrument tip, but may also avoid tissue from adhering to the instrument tip.

[0033] In some cases, the first planar dielectric element can define a first blade element. For example, the first planar dielectric element can include a cutting edge configured to contact tissue located between the jaws and cut the tissue when the jaws are closed. The inner electrode of the first pair of electrodes can then be formed at or near the cutting edge of the first planar dielectric element.

[0034] Similarly, the second planar dielectric element may define a second blade element, e.g., the second planar dielectric element may include a cutting edge configured to contact and cut tissue located between the jaws. In turn, if the single electrode is the inner electrode or the inner electrode of the second pair of electrodes, the inner electrode of the second pair may be formed at or near the cutting edge of the second planar dielectric element.

[0035] Where the first planar dielectric element defines a first blade element and the second planar dielectric element defines a second blade element, an inner surface of the first planar dielectric element can be arranged to slide across an inner surface of the second planar dielectric element as the jaws move between the open and closed positions.

[0036] In optional embodiments, the inner electrode of the first pair of electrodes in the first jaw may include a first conductive layer formed on an inner surface of the first planar dielectric element, the outer electrode of the first jaw includes a second conductive layer formed on an outer surface of the first planar dielectric element, the inner electrode of the second jaw includes a first conductive layer formed on an inner surface of the second planar dielectric element, and / or the outer electrode of the second jaw includes a second conductive layer formed on an outer surface of the second planar dielectric element.

[0037] Thus, each inner electrode may be formed by a respective layer of conductive material on the immediate inner surface of the respective planar dielectric element, and / or each outer electrode may be formed by a respective layer of conductive material on the immediate outer surface of the respective planar dielectric element. For example, the layer of conductive material may be deposited using any suitable deposition technique, or the layer of conductive material may be otherwise attached (e.g., via an adhesive) to the inner and / or outer surface. The conductive layer of each inner electrode may be formed of any suitable conductive material, such as gold. A single electrode of the second jaw may be formed on the inner or outer surface of the second planar dielectric element, such that the single electrode is the inner or outer electrode.

[0038] The first conductive layer of the first and / or second jaw may extend longitudinally, i.e., along all or a portion of the length of the first and / or second planar dielectric elements. Similarly, the second conductive layer of the first and / or second jaw may extend longitudinally, i.e., along all or a portion of the length of the first and / or second planar dielectric elements.

[0039] Preferably, the first jaw may include a third planar dielectric element having an inner surface facing toward the second jaw, the third planar dielectric element being disposed on the inner surface of the inner electrode of the first jaw. Additionally or alternatively, the second jaw may include a fourth planar dielectric element having an inner surface facing toward the first jaw, the fourth planar dielectric element being disposed on the inner surface of the single electrode of the second jaw. For example, the third and / or fourth planar dielectric elements may be applied as a dielectric coating that provides an insulating barrier between the inner electrodes. For example, the coating may be a ceramic (e.g., alumina) coating, a diamond-like coating, an enamel coating, or a silicon-based paint coating. This coating may be further coated with Parylene N to seal the insulating coating (e.g., coated with a layer 2-10 micrometers deep) that penetrates the pores and makes the insulator waterproof. Alternatively, the dielectric coating may be a thermoplastic polymer, such as a polyether or ketone (PEEK). The dielectric coating can ensure that the inner electrode is exposed substantially only at the top surface of the blade element, thereby ensuring that the EM energy is concentrated in the desired area. The provision of a third and / or fourth dielectric element in this manner can ensure that the risk of electrical breakdown or discharge between the two inner electrodes is minimized, such that the energy is preferentially directed to the tissue. Such an arrangement can also improve symmetry between the jaws, which in turn can improve the symmetry of the RF and microwave energy emitted by the instrument tip.

[0040] Additionally, in some cases, the outer electrode of the first and / or second pair of electrodes may include a third conductive layer formed on the outer surface of the first planar dielectric element. The third conductive layer may be formed in a manner similar to the first and second conductive layers described above. Of course, in some instances, the single electrode of the second jaw may be formed in a similar manner.

[0041] Therefore, no patterning and etching of insulating layers of any of the jaws may be required to form the electrodes, which may greatly facilitate manufacture of the instrument tip.

[0042] The first pair of electrodes may be flush with the front surface of the first planar dielectric element such that the first pair of electrodes contacts tissue when tissue is in contact with the front surface of the first planar dielectric element. Similarly, the inner and / or outer electrodes of the second pair of electrodes may be flush with the front surface of the second planar dielectric element such that the inner and / or outer electrodes of the second pair of electrodes contact tissue when tissue is in contact with the front surface of the second planar dielectric element.

[0043] The first jaw may further comprise a first cover, which may be a first conductive shell. The first cover may be attached to an outer surface of the first planar dielectric element. The outer or second conductive layer of the first pair of electrodes may be disposed between the first cover and the first planar dielectric element. The first cover may be disposed to be in electrical contact with the second conductive layer, thus forming at least a portion of the outer electrode of the first pair of electrodes. Thus, the outer electrode may comprise a conductive shell (first cover) attached to the outer surface of the corresponding planar dielectric element. The first cover or the first conductive shell may define the outer surface of the first jaw.

[0044] In some embodiments, the second jaw may also include a second cover, which may be a second conductive shell. The second cover is attached to an outer surface of the second planar dielectric element. An outer or second conductive layer of the second pair of electrodes may be disposed between the second cover and the second planar dielectric element. The second cover may be disposed to be in electrical contact with the outer or second conductive layer, thus forming at least a portion of the outer electrode of the second jaw.

[0045] Thus, the first and / or second covers may serve the dual purpose of defining a portion of the outer electrode and protecting the planar dielectric element to which it is attached. The first and / or second covers may be formed from a piece of conductive material that is attached (e.g., by adhesive and / or mechanical fastening) to the outer surface of the corresponding planar dielectric element. Any suitable conductive material may be used for the conductive shell, such as stainless steel.

[0046] The surface area of ​​the first and / or second covers may be greater than the surface area of ​​the inner (first) and / or outer (second) conductive layers of the first and second pairs of electrodes. For example, the first and / or second covers may be formed from a relatively thick block of conductive material covering all or most of the outer surface of the planar dielectric element, while the inner (first) and / or outer (second) conductive layers may be formed as relatively thin and / or narrow conductive layers on the inner and / or outer surfaces of the first and / or second planar dielectric elements. Thus, the first and / or second covers may serve to increase the surface area of ​​the outer electrodes compared to the inner electrodes.

[0047] The inventors have found that when RF cutting of tissue is performed using a pair of spaced apart electrodes having different sizes, the tissue tends to be cut near the smaller of the two electrodes. Thus, using a conductive shell (first and / or second cover) with a large surface area compared to the inner electrode can ensure that RF cutting of tissue occurs near the inner electrode. This can allow for a well-defined cut to be made in the tissue located between the jaws using RF EM energy. In particular, this can serve to ensure that the cut made by the RF EM energy is located at or near the cutting interface between the blade elements.

[0048] Advantageously, the outer electrode of the first jaw and the outer electrode of the second jaw (which can also be a single electrode of the second jaw) can be electrically coupled to each other. This can help to provide symmetry of the RF and / or microwave EM field emitted by the tip, particularly with respect to the inner electrode of the first jaw and the region between the first and second jaws. For example, the outer electrode of the first jaw and the outer electrode of the second jaw can both be coupled to a common conductor of the energy transfer structure such that they are electrically coupled via the energy transfer structure. Furthermore, the inner electrode of the first jaw and the inner electrode of the second jaw can both be coupled to a common conductor of the energy transfer structure such that they are electrically coupled via the energy transfer structure.

[0049] The instrument tip may further comprise a base structure connecting the outer electrode of the first jaw and the outer electrode of the second jaw to a distal end of the energy transfer structure. For example, the base structure may include a first base portion that rigidly connects the outer electrode of the first jaw to the distal end of the energy transfer structure and a second base portion to which the second jaw is pivotally connected such that the second jaw is pivotable relative to the second base portion.

[0050] The base structure may be any suitable structure for supporting the jaws at the end of the energy transfer structure. The base structure may, for example, comprise an arm fixed at one end to the distal end of the energy transfer structure and connected at the other end to the first and second jaws. Such a base structure may help reinforce the distal end of the energy transfer structure (which may typically be flexible) and facilitate the transfer of longitudinal forces to the instrument tip. The base structure may comprise a rigid material (e.g., a metal such as stainless steel).

[0051] The first jaw and / or the second jaw can be movably connected to the base structure to enable relative movement between the first jaw and the second jaw. For example, the first jaw and / or the second jaw can be pivotally connected to the base structure.

[0052] In some cases, the first base portion may be part of the first cover, i.e., the first cover may form part of the base structure. For example, the first base portion may be part of the first cover that extends between the first jaw and the distal end of the energy transfer structure. This may help to ensure a robust connection between the first jaw and the distal end of the energy transfer structure, as well as to facilitate an electrical connection between the outer electrode in the first pair and the energy transfer structure.

[0053] The base structure may include (e.g., be made of) a conductive material that electrically connects the first cover to a first one of the inner and outer conductors of the distal end of the coaxial transmission line. In this manner, the first cover may be directly connected to the conductor of the coaxial transmission line via the base structure. For example, the first base portion may include a conductive material that electrically connects the first conductive shell to a first one of the inner and outer conductors.

[0054] Additionally or alternatively, the base structure may include (e.g., be made of) a conductive material that electrically connects the inner or outer electrode of the second jaw to a first one of the inner and outer conductors of the distal end of the coaxial transmission line. In this manner, the inner electrode of the second jaw may be directly connected to a conductor of the coaxial transmission line via the base structure. For example, the second base portion may include a conductive material that electrically connects the inner electrode of the second jaw to a first one of the inner and outer conductors.

[0055] When the first cover and the outer electrode of the second jaw are electrically coupled to one another, the base structure may include (e.g., be made of) a conductive material that connects each of the first and second covers to a first one of the inner and outer conductors of the distal end of the coaxial transmission line. Thus, the first conductive shell and the inner electrode of the second jaw may be electrically coupled via the base structure.

[0056] The base structure may define a cavity in which the inner electrode of the first and / or second jaw is electrically connected to the second of the inner and outer conductors of the distal end of the coaxial transmission line. In this manner, the base structure may serve to protect the electrical connection between the inner electrode of the first and / or second jaw and the second of the inner and outer conductors. The conductive material of the base structure may also serve to provide an electromagnetic shield for the electrical connection inside the cavity. The cavity may be a space or void defined within the base structure.

[0057] The cavity may include a dielectric material. This can ensure that the electrical connections in the cavity are electrically insulated, so as to avoid dielectric breakdown between the electrical connections inside the cavity and the surrounding base structure. The dielectric material may be any suitable type of dielectric material. As an example, an electrical potting material such as a thermosetting plastic, silicone, epoxy or resin may be used as the dielectric material in the cavity.

[0058] The base structure may include an opening formed in a sidewall of the base structure for injecting a dielectric material into the cavity. For example, the opening may be a hole or an aperture formed in the sidewall of the base structure. This may allow the dielectric material to be injected into the cavity after assembling the instrument tip with the distal end of the energy transfer structure. This may facilitate assembly of the instrument tip.

[0059] In some embodiments, the outer electrode of the first jaw and the outer electrode of the second jaw are both electrically connected to a first one of the inner and outer conductors, and the inner electrode of the first jaw is electrically connected to a second one of the inner and outer conductors. Such an electrode configuration may allow a first RF cutting field to be established between the pair of electrodes of the first jaw and a second RF cutting field to be established between the inner conductor of the first jaw and the inner conductor of the second jaw. The two RF fields may be substantially symmetrical about the cutting interface between the blade elements, which may result in a highly uniform cut of tissue held between the jaws. Furthermore, such an electrode configuration may allow a substantially symmetrical microwave field to be emitted throughout the jaws, enabling microwave ablation and / or coagulation of tissue surrounding the jaws.

[0060] Advantageously, the first pair of electrodes and the single electrode may be operable together as a microwave field emitting structure for emitting microwave EM energy carried by the energy transfer structure, i.e. all three electrodes may cooperate to emit microwave EM energy.

[0061] In any embodiment, the first jaw includes first teeth that project toward the second jaw (in the open position), the first teeth forming part of the distal end face.

[0062] The first tooth may protrude from the front face of the first jaw or the cutting edge of the first jaw. The front face of the first jaw faces the second jaw in the open position. The first tooth may define the distal end of the cutting edge of the first jaw. In the absence of the first tooth, the cutting edge of the first jaw may extend to the distal end face. The first tooth may be disposed between the distal end face and the cutting edge. In particular, the side of the first tooth may define a portion of the distal end face. Thus, when viewed along the longitudinal direction at the distal end face of the first jaw, the side of the first tooth is visible. The first tooth may be an integral part of the first dielectric planar element. In other words, the first tooth defines a portion of the first jaw.

[0063] Optionally, the first teeth are arranged side by side with the distal end face of the second jaw in the closed position of the electrosurgical cutting instrument. This means that the distal end of the first jaw protrudes distally from the distal end of the second jaw (in the closed position). The first jaw is longer than the second jaw (in the closed position) by the width of the first teeth. In the closed position, the second jaw is arranged at least partially side by side with the second jaw, e.g., the cutting edge of the first jaw overlaps with the cutting edge of the second jaw in the closed position when viewed from the side. However, the second jaw does not overlap with the first teeth in the closed position due to the shorter longitudinal extension of the second jaw compared to the first jaw.

[0064] In optional embodiments, the first jaw includes a front surface facing the second jaw and a back surface facing away from the second jaw, and optionally, the first pair of electrodes extend to the front surface at the distal end surface and / or the first pair of electrodes are spaced apart from the back surface at the distal end surface.

[0065] The front surface of the first jaw may be the side of the first jaw defined by the cutting edge. For example, the first planar dielectric element includes a front surface, an inner surface, an outer surface, and a rear surface. The front surface of the first planar dielectric element faces towards the second jaw. The front surface of the first planar dielectric element provides a substantial portion of the front surface, and the first pair of electrodes may also contribute to the front surface. The first teeth may define a portion of the front side. Similarly, the rear surface of the first jaw may be provided in part by the rear surface of the first planar dielectric element. The first cover may also contribute to the rear surface of the first jaw.

[0066] The first pair of electrodes, particularly the inner and outer conductive layers, extend along the cutting edge as a narrow layer. Thus, the first pair of electrodes, particularly the inner and outer conductive layers, do not cover the complete inner and outer surfaces of the first planar dielectric element, respectively. However, the first pair of electrodes, particularly the inner and outer conductive layers, can cover the complete area of ​​the first tooth and extend to the distal end surface. The first pair of electrodes, particularly the inner and outer conductive layers, extend along the distal end surface from the front surface to the rear surface, with a gap between the first pair of electrodes, particularly the inner and outer conductive layers, and the rear surface. This means that the first pair of electrodes, particularly the inner and outer conductive layers, are not exposed to the rear surface. This allows electrosurgical cutting to occur only at the distal end surface, but not at the rear surface of the first jaw, when the electrosurgical cutting instrument is in the closed position.

[0067] The first pair of electrodes, particularly the inner and outer conductive layers, are large in the area of ​​the first tooth (including the distal end face) compared to the area along the cutting edge. The inner conductive layer and / or the outer conductive layer of the first jaw may (completely) cover the first tooth on the inner and / or outer surface. Alternatively, the outer conductive layer of the first jaw does not cover the second tooth on the outer surface.

[0068] In optional embodiments, the movable jaw of the first jaw and the second jaw includes at least one second tooth protruding toward the stationary jaw of the first jaw and the second jaw includes at least one second tooth protruding toward the first jaw, optionally the second tooth includes a front surface facing the distal end face and a rear surface facing away from the distal end face, and further optionally, in the closed position the front and / or rear surface are inclined toward the distal end face.

[0069] The stationary jaw may be the first jaw and the movable jaw may be the second jaw. However, the stationary jaw may be the first jaw and the movable jaw may be the second jaw. It is also possible for both the first jaw and the second jaw to be movable. Movable is defined as each jaw being movable relative to the base structure or the energy transfer structure.

[0070] The second tooth or teeth protrude from a cutting edge of the respective jaw, such as the second jaw. The second teeth may be an integral part of the respective planar dielectric element, such as the second planar dielectric element. The inner conductive layer and / or the outer conductive layer of the second jaw may (completely) cover the second teeth on the inner surface and / or the outer surface. Alternatively, the outer conductive layer of the second jaw does not cover the second teeth on the outer surface. One of the second teeth may form part of a distal end face of the second jaw. In particular, all references and descriptions regarding the arrangement of the first teeth apply equally to the second teeth.

[0071] The second tooth includes an inner surface (which may be an integral part of the inner surface of the second planar dielectric element), an outer surface (which may be an integral part of the outer surface of the second planar dielectric element), a front surface, and / or a rear surface. The front surface of the second tooth may be an integral part of a distal end surface for one of the second teeth disposed at a distal end of the second jaw. The front and rear surfaces are opposing surfaces of the second tooth. The front and rear surfaces may be spaced apart from one another in a longitudinal direction of the second jaw.

[0072] The front and / or rear faces are inclined with respect to the longitudinal direction of the second jaw and the longitudinal direction of the instrument tip in the closed position, i.e. when the longitudinal direction of the second jaw is parallel to the longitudinal direction of the instrument tip or the first jaw. The inclination angle may be 10°-89°, preferably 60°-85°, more preferably 75°-85°. This means that the second teeth are slightly inclined towards the distal end of the instrument tip. This allows the front face of the second teeth (the face bounded by the inner, outer, front and rear faces of the second teeth) to contact the tissue first before one of the inner, outer, front or rear faces contacts the tissue while the second jaw moves from the open to the closed position.

[0073] In an optional embodiment, the electrosurgical cutting instrument further comprises a control wire for actuating a movable jaw of the first jaw and a movable jaw of the second jaw, optionally the movable jaw includes an opening through which the control wire extends for engagement with the movable jaw, and further optionally, the ends of the control wire are rounded. Additionally or alternatively, the control wire is bent.

[0074] The control wire may be an example of the actuator mentioned above. The control wire is coupled to the movable jaw such that a pulling or pushing movement of the control wire results in a movement of the movable jaw, for example, from a closed position to an open position or vice versa. The control wire may be coupled to the movable jaw by an opening. A portion of the control wire extends through the opening. The opening may be a through hole of the second jaw. The opening may be disposed in the second cover. The opening may have an extension direction perpendicular to the longitudinal direction in which the control wire extends through the shaft. Thus, the control wire may include a bend. Preferably, the control wire includes only a single bend from the extension direction of the shaft to the direction of the opening. This may be a 90° bend. Alternatively, the control wire includes two bends (e.g., a corner or angular portion). The first bend connects the extension direction of the control wire in the shaft to the extension direction of the control wire in the opening. The second bend is located between the end of the control wire and the opening. The first bend and / or the second bend may be a 90° bend. The end of the control wire may extend in a plane parallel to the extension of the control wire in the shaft. In particular, the first bend and the second bend are S-shaped in side view. The second bend may prevent the end of the wire from being pulled through the opening. Thus, the second bend may act as an abutment.

[0075] The inner diameter of the opening may be larger than the outer diameter of the control wire. Thus, the control wire can move relative to the opening in the absence of a rounded end or second bend in the control wire. The rounded end reduces the risk of the end of the control wire connecting or adhering to tissue or other parts of the electrosurgical cutting instrument.

[0076] In an optional embodiment, the rounded end of the control wire has a diameter larger than the inner diameter of the opening.

[0077] The control wire may be rounded by welding, particularly laser welding, resulting in a rounded end having a diameter larger than the diameter of the control wire and the inner diameter of the opening. The control wire is rounded after being inserted into the opening. This results in fixation of the control wire in the opening between the rounded end and the bend in the control wire.

[0078] In an optional embodiment, the movable jaw includes a chamfer adjacent the opening, and optionally the rounded end of the control wire is at least partially disposed within the chamfer.

[0079] The chamfer may have a funnel shape and be in fluid communication with the opening. The chamfer may constitute a gradual extension from the diameter of the opening from the inner diameter to the opening to an increased diameter at the surface of the second cover. The rounded end of the control wire may be partially received in the chamfer, so that only a small portion of the rounded end protrudes from the second cover. This further reduces the risk of the control wire accidentally engaging tissue or other portions of the electrosurgical cutting instrument.

[0080] In an optional embodiment, the planar dielectric element of the stationary jaw of the first and second jaws extends to a distal end of the energy transfer structure, and optionally the instrument tip further comprises a connecting element connecting an inner conductor of the energy transfer structure to an inner electrode of the first pair of electrodes, and / or a dielectric block disposed between the movable jaw of the first and second jaws and the distal end of the energy transfer structure. The connecting element is optionally sandwiched between the planar dielectric element of the stationary jaw and the dielectric block, and optionally the dielectric block is attached to the planar dielectric element of the stationary jaw using an adhesive, preferably comprising an adhesive component and particles soaked in the adhesive component.

[0081] The planar dielectric element of the stationary jaw, optionally the first jaw, may include a portion defining the first jaw and a portion defining the connecting portion. Thus, the first planar dielectric element of the first jaw and the connecting portion may be considered as part of an integral component. The portion defining the first jaw may have a longitudinal length corresponding to the first pair of electrodes, while the connecting portion is the portion of the (first) planar dielectric element that extends towards the energy transfer structure.

[0082] The connecting element may extend into the connecting portion of the planar dielectric element, while the inner and / or outer conductive layer is disposed in the portion of the (first) planar dielectric element that defines the first jaw. The connecting element may be an integral component with the inner conductive layer and may therefore be manufactured from the same material as the inner conductive layer. The connecting element may be electrically connected to the inner conductor of the energy transfer structure.

[0083] The dielectric block is made of a dielectric material, such as a ceramic including alumina, and may be made of the same dielectric material as the first and / or second planar dielectric elements. The dielectric block is disposed longitudinally between the movable (second) jaw and the energy transfer structure. The dielectric block provides a barrier between the movable jaw and the energy transfer structure. The dielectric block may have a height corresponding to a height of the movable jaw. The first planar dielectric element and the dielectric block sandwich a connecting element therebetween. The first planar dielectric element and the dielectric block may be surrounded by a sleeve or a conductive ring.

[0084] The dielectric block may be adhered to the first planar dielectric element using, for example, an adhesive used by dentists to attach crowns to teeth. The adhesive may be G-CEM Bond, 3M™ RelyX™ Ultimate, or 3M™ RelyX™ Ultimate 2. The adhesive may include an adhesive component that provides the adhesive properties of the adhesive. The adhesive component may be (UV) light curable. The adhesive component may include a monomer that provides the adhesive properties by polymerization of the monomer. The adhesive component may include a diurethane methacrylate.

[0085] The adhesive may include one or more fillers, such as ytterbium (III) fluoride. Particles made of dielectric, polymeric, and / or ceramic materials are immersed in the adhesive component. The particles have an average diameter in the micromillimeter range and / or in the nanometer range, for example from 50 nm or 100 nm to 50 μm to 100 μm. The particles may include glass powder. The surface of the (glass powder) particles may be modified. The particles impart the mechanical and electrical properties of the adhesive. For example, the particles are less sensitive to plasmas (such as sparks) generated near the electrodes compared to the adhesive component. Thus, the particles reduce the modification of the adhesive and result in a more stable adhesion of the dielectric block to the first planar dielectric element.

[0086] In an optional embodiment, a cavity is provided between the dielectric block and the distal end of the energy transfer structure, and optionally the cavity is filled with an adhesive.

[0087] The cavity may be the cavity described above. Adhesive is an example of a dielectric material that may be used instead of a potting material and may fill the cavity. The adhesive helps to (initially) attach the first base part, the second base part, and the dielectric block to each other. The first base part, the second base part, and the dielectric block may be permanently fixed to each other by a sleeve or conductive ring that is pressed onto the first base part and the second base part and thus surrounds the first base part and the second base part.

[0088] The instrument tip can be sized to fit inside the instrument channel of the surgical scoping device. Thus, in another aspect, there is provided an electrosurgical generator that provides radio frequency (RF) electromagnetic (EM) energy and microwave EM energy, a surgical scoping device having an instrument cord for insertion into a patient's body, the surgical scoping device having an instrument channel through which the instrument cord extends, and an electrosurgical instrument, as described above, that includes an electrosurgical cutting instrument that is inserted through the instrument channel of the surgical scoping device.

[0089] The instrument may include a handpiece for controlling the electrosurgical cutting tool, which may be attached to the proximal end of the shaft, for example, on the exterior of a surgical scoping device.

[0090] As used herein, the term "surgical scope device" may refer to any surgical device that includes an insertion tube, which is a rigid or flexible (e.g., steerable) conduit that is introduced into a patient's body during an invasive procedure. The insertion tube may include an instrument channel and an optical channel (e.g., for transmitting light to illuminate and / or capture images of a treatment site at the distal end of the insertion tube). The instrument channel may have a diameter suitable for receiving an invasive surgical instrument. The diameter of the instrument channel may be 5 mm or less.

[0091] As used herein, the term "inner" means radially closer to the center (e.g., axis) of the equipment channel and / or coaxial transmission line, and the term "outer" means radially farther from the center (axis) of the equipment channel and / or coaxial transmission line.

[0092] The term "conductive" is used herein to mean electrically conducting, unless the context indicates otherwise.

[0093] As used herein, the terms "proximal" and "distal" refer to the ends of an elongate instrument. In use, the proximal end is closer to a generator for supplying RF and / or microwave energy, while the distal end is further from the generator.

[0094] As used herein, "microwave" may be used broadly to refer to a frequency range of 400 MHz to 100 GHz, but preferably refers to a range of 1 GHz to 60 GHz. Specific frequencies considered are 915 MHz, 2.45 GHz, 3.3 GHz, 5.8 GHz, 10 GHz, 14.5 GHz, and 24 GHz. In contrast, this specification uses "radio frequency" or "RF" to refer to a frequency range at least three orders of magnitude lower, e.g., up to 300 MHz, preferably 10 kHz to 1 MHz, and most preferably 400 kHz.

[0095] The present invention includes embodiments and combinations of the preferred features described except where such combinations are clearly unacceptable or clearly avoided.

[0096] BRIEF DESCRIPTION OF THE DRAWINGS Embodiments and experiments illustrating the principles of the present invention will now be discussed with reference to the accompanying figures. [Brief description of the drawings]

[0097] [Figure 1] 1 is a schematic diagram of an electrosurgical system according to an embodiment of the present invention. [Diagram 2] 1 is a perspective view of an electrosurgical cutting instrument in an open position in accordance with an embodiment of the present invention; [Diagram 3] 3 is another perspective view of the electrosurgical cutting instrument of FIG. 2 in an intermediate position and including an actuation wire. [Figure 4] 3 is a perspective view of the electrosurgical cutting instrument of FIG. 2 in a closed position. [Diagram 5] 3 is another perspective view of the electrosurgical cutting instrument of FIG. 2 in a closed position. [Figure 6] 3 is another perspective view of the electrosurgical cutting instrument of FIG. 2 in a closed position. [Figure 7] 3 is a front view of the distal end face of the electrosurgical cutting instrument of FIG. 2 in a closed position. [Figure 8] 3 is another perspective view of the electrosurgical cutting instrument of FIG. 2 in an intermediate position. [Figure 9] 3 is a further perspective view of the electrosurgical cutting instrument of FIG. 2 in an intermediate position. [Figure 10] 3 is an exploded view of the electrosurgical cutting instrument of FIG. 2 in an intermediate position. [Figure 11] 10 is a perspective view of the electrosurgical cutting instrument of FIG. 9, with the conductive ring visible. [Figure 12] FIG. 1 is a perspective view showing portions of an electrosurgical cutting instrument prior to assembly. [Figure 13] 13 is an exploded perspective view showing the portions of the electrosurgical cutting instrument of FIG. 12 prior to assembly. [Figure 14] 13 is an exploded perspective view showing portions of the electrosurgical cutting instrument of FIG. 12 prior to full assembly. [Figure 15] FIG. 1 is a perspective view of the contents of an instrument shaft that can be used with an electrosurgical instrument according to an embodiment of the present invention. [Figure 16] FIG. 17 is a cross-sectional view of the instrument shaft shown in FIG. 16. [Figure 17] 1 is a schematic diagram illustrating an instrument tip of an electrosurgical cutting instrument according to an embodiment of the present invention. [Figure 18] 11 is a schematic diagram illustrating an instrument tip of an electrosurgical cutting instrument according to a further embodiment of the present invention. [Figure 19] 11 is a schematic diagram illustrating an instrument tip of an electrosurgical cutting instrument according to a further embodiment of the present invention. [Figure 20] 11 is a schematic diagram illustrating an instrument tip of an electrosurgical cutting instrument according to a further embodiment of the present invention. [Figure 21] 11 is a schematic diagram illustrating an instrument tip of an electrosurgical cutting instrument according to a further embodiment of the present invention. [Figure 22] 1 is a perspective view of an instrument tip of an electrosurgical cutting instrument according to an embodiment of the present invention in a closed position. [Figure 23] 23 is another perspective view of the electrosurgical cutting instrument of FIG. 22 in an intermediate position. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0098] Aspects and embodiments of the present invention will now be described with reference to the accompanying drawings. Further aspects and embodiments will be apparent to those skilled in the art. All documents mentioned in this text are incorporated herein by reference.

[0099] FIG. 1 is a schematic diagram of an electrosurgical system 100 according to an embodiment of the present invention. The system 100 is configured to treat (e.g., cut or seal) biological tissue using radio frequency (RF) or microwave electromagnetic (EM) energy from an instrument tip 118. The system 100 includes a generator 102 for controllably supplying RF and microwave EM energy. A suitable generator for this purpose is described in WO2012 / 076844, which is incorporated herein by reference. The generator 102 is connected to a handpiece 106 by an interface cable 104. The handpiece 106 may also be connected to receive a fluid supply 107 from a fluid delivery device 108, such as a syringe, although this is not required. If necessary, the handpiece 106 may house an instrument actuation mechanism operable by an actuator 109, such as a thumb-operated slider or plunger. For example, the instrument actuation mechanism may be used to operate the jaws of a resection instrument opening and closing, as discussed herein. The handpiece may also include other mechanisms. For example, a needle movement mechanism (operable by an appropriate trigger on the handpiece) may be provided for deploying a needle at the instrument tip 118. The function of the handpiece 106 is to combine inputs from the generator 102, the fluid delivery device 108, and the instrument actuation mechanism, along with any other inputs that may be required, into a single flexible shaft 112 that extends from the distal end of the handpiece 106.

[0100] The flexible shaft 112 is insertable through the entire length of the instrument (working) channel of the surgical scoping device 114. The flexible shaft 112 has an instrument tip 118 shaped to pass through the instrument channel of the surgical scoping device 114 and protrude (e.g., into the patient's body) at the distal end of the insertion tube of the endoscope. The instrument tip 118 includes a pair of jaws having blade elements for grasping and cutting biological tissue, and an energy delivery structure configured to deliver RF or microwave EM energy transmitted from the generator 102. Optionally, the instrument tip 118 may also include a retractable hypodermic needle for delivering fluid delivered from the fluid delivery device 108. The handpiece 106 includes an actuation mechanism for opening and closing the jaws of the instrument tip 118. The handpiece 106 may also include a rotation mechanism for rotating the instrument tip 118 relative to the instrument channel of the surgical scoping device 114.

[0101] The structure of the instrument tip 118 can be arranged to have a maximum outer diameter suitable for passing through the working channel. Typically, the diameter of the working channel of a surgical scoping device, such as an endoscope, is less than 4.0 mm, for example, any one of 2.8 mm, 3.2 mm, 3.7 mm, and 3.8 mm. The flexible shaft 112 may have a smaller maximum diameter, for example, 2.65 mm. The length of the flexible shaft 112 can be 1.2 m or more, for example, 2 m or more. In other examples, the instrument tip 118 can be attached to the distal end of the flexible shaft 112 after the shaft is inserted through the working channel (and before the instrument cord is introduced into the patient). Alternatively, the flexible shaft 112 can be inserted into the working channel from its distal end before making its proximal connection. In these configurations, the distal tip assembly 118 can be allowed to have a larger dimension than the working channel of the surgical scoping device 114. The above system is one way of introducing an instrument into the patient's body. Other techniques are possible. For example, the device may be inserted using a catheter.

[0102] Although the examples herein are illustrated in the context of a surgical scope apparatus, it should be understood that the electrosurgical cutting instrument may be embodied in an apparatus suitable for use in open surgery or with a laparoscope.

[0103] Figures 2-11 show an instrument tip 200 of an electrosurgical cutting instrument according to an embodiment of the present invention. Instrument tip 200 may correspond to, for example, instrument tip 118 described above in connection with Figure 1. Figure 2 shows a first schematic view of a first side of instrument tip 200, and Figures 8 and 9 show schematic views of a second side of instrument tip 200. Figures 12-14 show the structure of another embodiment of instrument tip 200, which is presented to illustrate certain features of instrument tip 200 of Figures 2-11.

[0104] The instrument tip 200 is attached to the distal end of an energy transfer structure in the form of a coaxial cable 202 (shown in FIGS. 12-14). The coaxial cable 202 extends through a flexible shaft 204, which may correspond to the flexible shaft 112 described above. In particular, the flexible shaft 204 defines a lumen through which the coaxial cable 202 extends, with the instrument tip 200 protruding from the distal end of the flexible shaft 204. The coaxial cable 202 is positioned to transfer RF and microwave EM energy from an electrosurgical generator (e.g., the generator 102 described above) to the instrument tip 200.

[0105] The instrument tip 200 has a first jaw 206 and a second jaw 208 that are movable relative to one another between an open position and a closed position. Specifically, in the illustrated example, the first jaw 206 is stationary, i.e., fixed relative to the distal end of the coaxial cable 202, while the second jaw 208 is pivotally attached to the first jaw 208. The first jaw 206 may be considered a stationary or fixed jaw, and the second jaw 208 may be considered a movable jaw. However, the invention is not so limited. The second jaw 208 may be a stationary jaw, and the first jaw 206 may be a movable jaw.

[0106] An actuator in the form of a control wire or (or rod) 210 is connected to the second jaw 208 to control the movement of the second jaw 208 relative to the first jaw 206 (see, e.g., FIGS. 3 and 14). The control wire 210 is disposed within a lumen of the flexible shaft 204 and is longitudinally slidable within the lumen to move the second jaw 208. A proximal end of the control wire 210 may be connected to a handpiece (e.g., handpiece 106) operable to control the movement of the second jaw 208 via the control wire 210. FIG. 2 illustrates the jaws 206, 208 in an open position, with a gap defined therebetween that can receive tissue. FIGS. 4-7 depict the jaws 206, 208 in a closed position, with no gap between the jaws 206, 208 and with the jaws 206, 208 extending parallel to one another. Figures 3 and 8 to 11 show intermediate positions which are positions between the (fully) open and closed positions.

[0107] The first jaw 206 includes a first blade element 212, and the second jaw 208 includes a second blade element 214. Each blade element may include an edge arranged to contact tissue located in the gap between the jaws and cut the tissue when the jaws are moved to the closed position. Specifically, the second blade element 214 is arranged to slide across the first blade element 212 as the second jaw 208 moves toward the closed position, such that a shear force is applied to the tissue located in the gap between the jaws 206, 208. Thus, tissue located in the gap between the jaws can be cut by pivoting the second jaw 208 toward the closed position.

[0108] The first blade element 212 is defined by a first planar dielectric element 216 of the first jaw 206, and the second blade element 214 is defined by a second planar dielectric element 218 of the second jaw 208. In particular, the first planar dielectric element 216 includes an inner surface 220 that faces the second planar dielectric element 218 in the closed position, over which an inner surface 222 of the second planar dielectric element 218 slides when the second jaw 208 pivots relative to the first jaw 206, such that a shear motion occurs between the two planar dielectric elements. Each of the first and second planar dielectric elements 216, 218 may be made of a ceramic (e.g., alumina) or other suitable electrically insulating material. Each of the first and second planar dielectric elements 216, 218 defines a plane parallel to the plane in which the second jaw 208 pivots relative to the first jaw 206.

[0109] The second planar dielectric element 218 includes a pair of protrusions (or second teeth) 223 that function as the serrated portion of the second blade element 214. The second teeth 223 can thus function to grip tissue located in the gap between the jaws to facilitate holding and / or cutting of the tissue. The first planar dielectric element 216 may include similar protrusions (not shown) that function as the serrated portion of the first blade element 212. The second teeth 223 have a front surface 223a and a rear surface 223b. The rear surface 223b faces the flexible shaft 204 in the closed position. The front surface 223a is an opposite site compared to the rear surface 223b and faces outward from the flexible shaft 204 in the closed position. In other words, the front surface 223a faces towards the distal end surface 227 of the instrument tip 200, while the rear surface 223b faces outward from the distal end surface 227. In the closed position, the front surface 223a and / or the rear surface 223b are inclined relative to the extension direction of the instrument tip 200. The front surface 223a and / or the rear surface 223b define an angle of less than 90° with the extension direction of the instrument tip 200. The second teeth 223 face forward when facing flat tissue for better tissue engagement. The surface of the second teeth 223 facing the first jaw 206 and disposed between the front surface 223a and the rear surface 223b contacts the tissue first compared to the front surface 223a.

[0110] In one embodiment, the instrument tip 200 includes two electrodes for delivering energy to tissue, with one of the jaws 206, 208 including a pair of electrodes and the other jaw 206, 208 including no electrodes. In another embodiment, the instrument tip 200 includes three electrodes for delivering energy to tissue, with one jaw 206, 208 including a pair of electrodes and the other jaw 206, 208 including a single electrode.

[0111] In a further embodiment shown, the first jaw 206 includes an inner electrode 224 formed on the inner surface 220 of the first planar dielectric element 216 and an outer electrode 226 disposed on the outer surface of the first planar dielectric element 216. The first planar dielectric element 216 thus functions to electrically insulate the inner electrode 224 from the outer electrode 226 of the first jaw 206 from each other. The inner electrode 224 and / or the outer electrode 226 may include a conductive layer deposited on the first planar dielectric element 216. The outer electrode 226 may also include a first cover 229 made from a conductive material such as a metal (e.g., steel) or from a non-conductive material. The first cover 229 covers the outer electrode 226 and / or the conductive layer of the first planar dielectric element 216. Optionally, the first cover 229 covers the entire first planar dielectric element 216.

[0112] The second jaw 208 includes an outer electrode 228 formed on an outer surface of the second planar dielectric element 218, and an inner electrode 230 disposed on an inner surface of the second planar dielectric element 218. Thus, the second planar dielectric element 218 functions to electrically insulate the inner electrode 230 from the outer electrode 228 of the first jaw 208 from each other. The inner electrode 230 and / or the outer electrode 228 may include a conductive layer deposited on the second planar dielectric element 218. The outer electrode 228 may also include a second cover 231 made from a conductive material such as a metal (e.g., steel) or from a non-conductive material. The second cover 231 covers the outer electrode 228 and / or the conductive layer of the second planar dielectric element 218. Optionally, the second cover 231 covers the entire second planar dielectric element 218. The inner electrode 224 of the first planar dielectric element 216 contacts the inner electrode 230 of the second planar dielectric element 218 in the open and / or closed positions.

[0113] Of course, in some embodiments, the single electrode may be formed on the inner surface 222 of the second jaw 208, and the first jaw 206 may advantageously include a dielectric coating or third planar dielectric element formed on the inner electrode 224 and inner surface 220 of the first planar dielectric element 216 to ensure that there is no electrical connection between the inner electrode 224 and the single electrode of the second jaw when the jaws are closed. However, the third planar dielectric element or coating material may be positioned to ensure that the inner electrode 224 is exposed along the top surface of the first jaw 206 and RF and / or microwave energy may be emitted therefrom, as described below with respect to Figures 21 and 22. This coating, or third planar dielectric element, serves to electrically insulate the inner electrode 224 of the first jaw 206 and the inner electrode 228 of the second jaw 208 from one another. However, when the single electrode is the outer electrode 228, the second planar dielectric element 218 serves to ensure that there is no electrical connection with the inner electrode 224 of the first jaw.

[0114] The inner electrode 224 of the first jaw 206 and / or the inner electrode 230 of the second jaw 208 may comprise a layer or film of a conductive material (e.g., gold) deposited on the inner surface 220 of the first planar dielectric element 216 and the inner surface 222 of the second planar dielectric element 216, respectively. The inner electrode 224 and / or the inner electrode 230 cover a portion of the inner surface 220 and the inner surface 222, respectively, and extend along the cutting edges of the first blade element 212 (i.e., of the first planar dielectric element 216) and the second blade element 214 (i.e., of the second planar dielectric element 218), respectively.

[0115] The outer electrode 226 of the first jaw 206 and / or the outer electrode 228 of the second jaw 208 may include a layer or film of a conductive material (e.g., gold) deposited on an outer surface of the first planar dielectric element 216 and an outer surface of the second planar dielectric element 216, respectively. The conductive layer of the outer electrode 226 of the first jaw 206 may be sandwiched between the first planar dielectric element 216 and a first cover 229. The conductive layer of the outer electrode 228 of the second jaw 208 may be sandwiched between the second planar dielectric element 218 and a second cover 231.

[0116] Either the first jaw 206 or the second jaw 208, which includes the first pair of electrodes, is longer than the other jaw 206, 208 in the closed position. In the embodiment shown in Figures 2-11, the first jaw 206 is longer than the second jaw 208 in the closed position. Thus, the first jaw 206 extends beyond the second jaw 208 in the closed position. The distal end face 227 of the first jaw 206 is the most distal surface of the instrument tip 200. The inner electrode 224 and the outer electrode 226 of the first jaw 206, and in particular the conductive layer thereof, extend along the distal end face 227. For example, the inner electrode 224 and the outer electrode 226 are flush with the distal end face such that when the distal end face contacts tissue, the inner electrode 224 and the outer electrode 226 also contact tissue.

[0117] The longer of the first and second jaws 206, 208 includes a first tooth 232 that protrudes towards the shorter of the first and second jaws 206, 208. In the embodiment shown in Figures 2-11, the first tooth 232 is disposed on the first jaw 206. Optionally, the first jaw 206 is longer than the second jaw 208 by the width of the first tooth 232 in the direction of the first jaw 206. Thus, in the closed position, the first tooth 232 is not covered by the second jaw 208. The first tooth 232 may be an integral part of the first planar dielectric element 216.

[0118] The first jaw 206 can include a front surface facing the second jaw 208 and a back surface facing away from the second jaw 208. The cutting edge can be an edge of the front surface. The front surface and / or the back surface can be provided by the inner electrode 220, the first planar dielectric element 216, the outer electrode 222, and / or the first cover 231.

[0119] The inner electrode 224 and the outer electrode 226, particularly the conductive layer thereof, extend along the distal end surface 227 to a front surface of the first tooth 232. The front surface of the first tooth 232 may be a surface facing the second jaw 208 and adjacent to the first distal end surface 227. The first tooth 232 may define a distal end of the cutting edge of the first blade element 212. The inner electrode 224, particularly the conductive layer thereof, may cover the entire area of ​​the inner surface 220 of the first planar dielectric element 216 corresponding to the first tooth 232. The outer electrode 226, particularly the conductive layer thereof, may cover the entire area of ​​the outer surface 222 of the first planar dielectric element 216 corresponding to the first tooth 232.

[0120] The inner electrode 224 and the outer electrode 226, particularly their conductive layers, extend along the distal end surface 227 toward the rear surface of the first jaw 206, but terminate spaced apart from the rear surface. The inner electrode 224 and the outer electrode 226, particularly their conductive layers, do not contact or are not flush with the rear surface. There is a gap between the conductive layers of the inner electrode 224 / outer electrode 226 and the rear surface. Thus, tissue contacting the rear surface does not contact the conductive layers of the inner electrode 224 and the outer electrode 226.

[0121] The first cover 229 may be in the form of a first conductive shell attached (e.g., glued) to the outer surface of the first planar dielectric element 216. The first cover 229 is a piece of conductive material that covers the entire outer surface of the first planar dielectric element 216 and has a thickness similar to that of the first planar dielectric element 216. The outer surface of the first cover 229 serves as the outer surface of the first jaw 206. The outer surface of the first cover 229 may be rounded so that the first jaw 206 has a smooth outer surface. The first cover 229 may include protrusions formed to engage grooves formed in the first dielectric element 216 to avoid slippage between the two parts and ensure that the parts are accurately oriented relative to one another.

[0122] The inner and / or outer electrodes 228, 230 of the second jaw 208 may be formed in a manner similar to the inner electrode 224 and / or outer electrode 226 of the first jaw 206. For example, the inner and outer electrodes 228, 230 of the second jaw 208 may include a layer or film of a conductive material (e.g., gold) deposited on the inner and outer surfaces, respectively, of the second planar dielectric element 218. This causes the conductive layer of the inner electrode 230 to cover a portion of the inner surface 222 and extend along the cutting edge of the second blade element 214 (i.e., the second planar dielectric element 218) such that it is at the cutting interface between the first blade element and the second blade when the jaws are closed. In such an embodiment, the outer surface of the second jaw 208 is formed by the outer surface of the second planar dielectric element 218, which may be rounded such that the second jaw 208 has a smooth outer surface. The conductive layer of the outer electrode 228 may be covered with a second cover 231 in the form of a second conductive shell that is (for example) adhesively attached to the outer surface of the second planar dielectric element 218 and has a thickness similar to that of the second planar dielectric element 218.

[0123] The four electrodes 224, 226, 228, 230 are electrically connected to the distal end of the coaxial cable 202 such that the electrodes are capable of delivering the RF and microwave EM energy carried by the coaxial cable 202. The manner in which the electrodes are connected to the coaxial cable 202 is discussed in more detail below.

[0124] 10 and 12, the instrument tip 200 includes a connecting element 258 and a dielectric block 264. The connecting element 258 may be a wire, extending longitudinally along the connecting portion 256 of the first planar dielectric element 216 and electrically connecting the inner electrode 224 to the distal end of the inner conductor 234. The connecting element 258 may be a portion of the inner electrode 224 that extends along the connecting portion 256, for example, the connecting element 258 and the inner electrode 224 may be deposited together on the inner surface 220 of the first planar dielectric element 216. The inner electrode 230 of the second jaw 208 may be in electrical sliding contact with the connecting element 258, i.e., the inner electrode 230 of the second jaw 208 slides over the connecting element 258 as the second jaw 208 moves between the first position and the second position.

[0125] The dielectric block 264 is attached between the second base portion 248 and the first planar dielectric element 216 (particularly the connecting portion 256) to avoid electrical breakdown between the connecting element 258 and the conductive second base portion 248. For example, the dielectric block 264 can be made of a ceramic material such as alumina. The connecting element 258 is sandwiched between the dielectric block 264 and the connecting portion 256. The dielectric block 264 can be fixed in place using an adhesive that can include an adhesive component and particles soaked in the adhesive component. The particles can be made of a dielectric or ceramic material such as alumina or glass. The particles reduce modification of the adhesive by the plasma generated by the electrodes 224, 226, 228, 230.

[0126] A cavity 235 is formed between the first base portion 244 and the second base portion 248 (described below) and is shaped such that the inner conductor 234 is electrically connected therein to the connecting element 258 (and thus the inner electrodes 224, 230). The cavity 235 may be filled with a dielectric material, such as a potting material, or an adhesive as previously described, to reduce the risk of electrical breakdown between the distal end of the inner conductor 234 and the base structure 242. Filling the cavity 235 with a dielectric material or adhesive may also help reinforce the instrument tip 200 and hold the first and second base portions 244, 248 together. The second base portion 248 may include an injection port through which a dielectric material or adhesive may be injected into the cavity 235. The particles in the adhesive provide similar dielectric properties to the dielectric material.

[0127] The structure of the instrument tip 200 will now be discussed with reference to Figures 12-14, which show various stages of assembly of the instrument tip 200.

[0128] The coaxial cable 202 includes an inner conductor 234 and an outer conductor 236 separated by a dielectric material 238. Additionally, the coaxial cable 202 includes an outer sheath 240 made of an insulating material. The first jaw 206 and the second jaw 208 are attached to the distal end of the coaxial cable 202 via a base structure 242. The base structure 242 includes a first base portion 244 made of a conductive material that securely connects the first jaw 206 to the distal end of the coaxial cable 202. The first base portion 244 includes an arm that extends between the distal end of the coaxial cable 202 and the first cover 229. In the illustrated example, the first cover 229 and the first base portion 244 are integrally formed as a single piece of conductive material. However, in other examples, they may be formed as separate parts connected to each other. The first base portion 244 includes a first mounting portion 246 that includes a channel in which the distal end of the coaxial cable 202 is received. A length of the outer sheath 240 of the coaxial cable 202 is removed near the distal end of the coaxial cable, thereby exposing the outer conductor 236. The outer conductor 236 is thus in electrical contact with the first base portion 244 within the channel in the first mounting portion 246. The distal end of the coaxial cable 202 may be secured to the channel of the first mounting portion 246 using a suitable conductive epoxy. As a result, the first cover 229 (and thus the outer electrodes 226, 228 of the first and second jaws 206, 208) are electrically connected to the outer conductor 236 via the first base portion 244.

[0129] The base structure 242 further comprises a second base portion 248 that pivotally mounts the second jaw 208 to the distal end of the coaxial cable 202. The second base portion 248 is made of an electrically conductive material, which may be the same material as the first base portion 244 (e.g., stainless steel). The second base portion 248 includes a second mounting portion 250 that is secured to the first mounting portion 246 of the first base portion 244 such that the first and second base portions 244 and 248 are in electrical contact. The first and second mounting portions 246 and 250 have complementary shaped engagement surfaces that engage with each other when the base portions are secured to each other. As shown in FIG. 14, the first and second base portions 244 and 248 are secured together via a conductive ring 252 that fits around the first and second mounting portions 246, 250 to hold them together. An adhesive (such as those described above) can be injected inside the conductive ring 252 to secure the conductive ring 252 in place over the first and second mounting portions. In addition to holding the base structure 242 together, the conductive ring 252 can act as a microwave shield to prevent microwave energy from radiating before it reaches the electrodes of the jaws.

[0130] The second base portion 248 extends longitudinally from the second mounting portion 250 and includes an arm to which the second jaw 208 is pivotally attached. In the illustrated example, the second jaw 208 is pivotally attached to the second base portion 240 via a rivet 254. The outer electrode 228, and in particular the second cover 231, is in electrical contact with the second base portion 248 via the rivet 254 (made of a conductive material). Thus, the outer electrode 228 of the second jaw 208 is electrically connected to the outer conductor 236 of the coaxial cable 202 via a conductive path formed by the rivet 254, the second base portion 248, the mounting portion 246, and the first base portion 244. Thus, both the outer electrode 226 of the first jaw 206 and the outer electrode 228 of the second jaw 208 are electrically connected to the outer conductor 236 via the base structure 242.

[0131] The second base portion 248 may include a passageway (not shown) through which the control wire 210 extends to connect to the second jaw 208. The second cover 231 may include an opening 251a through which the distal end of the control wire 210 extends. The second cover shell 231 may also be provided with a limit pin 253 (shown in FIG. 13 ) that functions to limit the movement of the second jaw 208 between the open and closed positions relative to the first jaw 206. This may allow for more precise control of the position of the second jaw 208.

[0132] The opening 251a may be a through hole having an inner diameter and has a chamfered portion 251b (see FIG. 4). The chamfered portion 251b is adjacent to and in fluid communication with the opening 251a. The chamfered portion 251b is funnel-shaped. The control wire 210 has a rounded distal end (see FIGS. 3-14, which disclose different embodiments). The distal end of the control wire 210 may be rounded by laser welding. The rounded distal end of the control wire 210 has an outer diameter larger than the inner diameter of the opening 251a. This attaches the distal end of the control wire 210 to the opening 251a. A portion of the rounded distal end of the control wire 210 is received in the chamfered portion 251b such that only a portion of the rounded distal end of the control wire 210 protrudes from the chamfered portion 251b. This, along with the rounded distal end, reduces the risk of the distal end of the control wire 210 getting caught in tissue.

[0133] The inner electrode 224 of the first jaw 206 and the inner electrode 230 of the first jaw 208 are electrically connected to an inner conductor 234 of the coaxial cable 202. As shown in Figures 10 and 12, the first planar dielectric element 216 includes a connection portion 256 that extends between the first blade element 212 and the distal end of the coaxial cable 202. The distal end of the inner conductor 234 protrudes beyond the distal end of the coaxial cable 202 such that it rests on the connection portion 256 of the first planar dielectric element 216.

[0134] 10 and 12, for clarity, the first jaw 206 is shown with the inner electrode 224 exposed. However, in some embodiments, a dielectric coating 225 is applied to the inside surface of the first jaw 206 and the inner electrode 224 to ensure that there is no electrical connection between the inner electrode 224 of the first jaw and the inner electrode 230 of the second jaw 208 when the jaws 206, 208 are closed. The dielectric coating material 225 may be positioned to ensure that the inner electrode 224 is exposed along the top surface of the first jaw 206 from which RF and / or microwave energy may be emitted, as shown in FIG.

[0135] To assemble the instrument tip 200, the first base portion 244 and the first jaw 208 can be first assembled and connected to the distal end of the coaxial cable 202, as shown in FIG. 12. The second jaw 208 is connected to the second base portion 248 via a rivet 254, as shown in FIG. 13. Next, a dielectric block 264 can be glued to the inner surface 220 of the first planar dielectric element 216 (as shown in FIG. 13), after which the second base portion 248 is attached to the first base portion 244. A dielectric potting material or adhesive can then be injected into the cavity 235 between the first base portion 244 and the second base portion 248. The cavity 235 can be empty of material. The conductive ring 252 can then be slid over the coaxial cable 202 and over the first and second mounting portions 246, 250 to hold the first and second base portions 244, 248 together. As described above, an adhesive may be used to secure the conductive ring 252 onto the first and second mounting portions 246, 250. The control wire 210 may then be threaded through the opening 251a in the cover 231 and secured to the opening 251a in the second jaw 208 (as shown in FIGS. 3 and 14). To this end, the distal end of the control wire 210 may be rounded. Finally, the flexible shaft 204 may be pulled over the coaxial cable 202 and secured to the conductive ring 252, for example, using an adhesive.

[0136] In the embodiment described with reference to Figures 2-14, only one of the jaws is movable. However, in other embodiments, both jaws may be movably attached to the distal end of the coaxial cable 202, for example to provide scissor-like opening and closing of the jaws. It should also be noted that in different embodiments, different electrical connections to the electrodes may be used. For example, in some embodiments, the inner electrode 224 of the first jaw 206 and the inner electrode 230 of the second jaw 208 may be connected to the outer conductor 236, while the outer electrode 228 of the second jaw 208 and the outer electrode 226 of the first jaw 206 may be connected to the inner conductor. Various electrode configurations are described below with reference to Figures 17-21.

[0137] FIG. 15 is a cutaway perspective view of the instrument shaft 612 as it moves toward the instrument tip. The instrument shaft 612 includes an outer sleeve 648 that defines a lumen for carrying the coaxial cable 626 and the control rod 636. In this example, the coaxial cable 626 and the control rod 636 are held in a longitudinally extending insert 650. The insert 650 is an extrusion formed from a deformable polymer such as PEEK or other plastic with similar mechanical properties. As shown more clearly in FIG. 16, the insert 650 is a cylindrical element having a series of sublumens 664 cut around its outer surface. The sublumens 664 break through the outer surface of the insert 650 to define a plurality of separate legs 662 therearound. The sublumens 664 may be sized to carry components such as the coaxial cable 626 or the control rod 636, or may be present for the purpose of allowing fluid to flow along the lumen of the sleeve 648.

[0138] It may be beneficial for the insert not to include any enclosed sublumens, as fully enclosed sublumens may be prone to residual deformation when stored in a bent state, which may result in jerky movement during use.

[0139] The insert 650 may include a sublumen for receiving the coaxial cable 626. In this example, the coaxial cable 626 includes an inner conductor 658 separated from an outer conductor 654 by a dielectric material 656. The outer conductor 654 may in turn have a protective covering or sheath 652 formed, for example, from PTFE or other suitable low friction material, to allow relative longitudinal movement between the insert and the coaxial cable as the shaft undergoes flexion of the shaft.

[0140] Another sublumen may be positioned to receive a standard PFTE tube 660 through which the control rod 636 extends. In an alternative embodiment, the control rod 636 may be provided with a low friction (e.g., PFTE) coating prior to use, such that a separate PFTE tube is not required.

[0141] The insert is positioned such that when installed along with the coaxial cable 626 and control rod 636, it fills the lumen of the sleeve 648, i.e., fits snugly within it. This means that the insert functions to limit relative movement between the coaxial cable, control rod, and sleeve while the shaft 612 is being bent and rotated. Additionally, by filling the sleeve 648, the insert helps prevent the sleeve from collapsing and losing rotation if it is over-rotated. The insert is preferably made from a material that exhibits a rigidity that resists such movement.

[0142] The presence of the insert can further prevent “lost” control rod travel caused by deformation of the instrument shaft 612 .

[0143] The extruded insert described above provides a cam-like foot that catches on the inside of the sleeve and prevents the control rod from wrapping around the axis of the sleeve, thereby reducing the lost travel discussed above.

[0144] 17-21 are schematic diagrams illustrating possible electrode configurations in electrosurgical cutting instruments according to embodiments of the present invention.

[0145] FIG. 17 shows a schematic cross-sectional view of a portion of an instrument tip 900 of an electrosurgical cutting instrument having a first jaw 902 and a second jaw 904. The first and second jaws 902, 904 are movable (e.g., pivotable) relative to one another, and each jaw includes a respective blade element for cutting tissue located between the jaws. In a preferred embodiment of the invention, the first jaw 902 may be a stationary jaw and the second jaw 904 may be a movable jaw, as described above with respect to FIG. 2. The first jaw 902 includes an inner electrode 906 and an outer electrode 908, which are separated by a dielectric material element 910. The inner electrode 906 is electrically connected to an inner conductor of a coaxial cable of the electrosurgical cutting instrument, while the outer electrode 908 is electrically connected to an outer conductor of the coaxial cable. The second jaw 904 includes a single electrode 914, which is also electrically connected to the outer conductor of the coaxial cable. The single electrode 914 may be formed as either an inner or outer electrode and may be provided in a manner similar to the inner or outer electrodes of the first jaw, i.e., attached to the dielectric material element 910. In the schematic diagrams shown in Figures 17-19, the single electrode 914 is considered to be the inner electrode of the second jaw 904, but it should be understood that the connections and description of the emission field are substantially the same whether the single electrode is an inner or outer electrode. The "+" and "-" symbols in Figures 17-19 indicate whether each electrode is connected to the inner or outer conductor of a coaxial cable, with "+" indicating that the electrode is connected to the inner conductor and "-" indicating that the electrode is connected to the outer conductor.

[0146] To prevent electrical connection between the inner electrode 906 of the first jaw 902 and the inner electrode 914 of the second jaw 904, the first jaw 902 comprises a second dielectric material element 912 disposed on the inner surface of the inner electrode 906. The second dielectric material element 912 may be made of the same dielectric material as the first dielectric material element 910, and may be in the form of, for example, a planar dielectric element attached to the first jaw 902. Additionally or alternatively, a piece of dielectric material may be provided on the second jaw 904 to cover the inner surface of the inner electrode 914 and to be located between the inner electrode 906 and the inner electrode 912. It may be preferable to cover each of the inner electrodes with a dielectric material to ensure that the risk of electrical breakdown between the two inner electrodes is minimized. This may also improve the symmetry between the jaws, which in turn may improve the symmetry of the RF and microwave energy emitted by the instrument tip.

[0147] In the electrode configuration shown in Figures 18 and 19, two RF cutting fields may be generated when RF EM energy is transmitted to the electrodes via the coaxial cable. A first RF cutting field may be established between an inner electrode 906 and an outer electrode 908, both of the first jaw 902, with the inner electrode 906 acting as an active electrode and the outer electrode 908 acting as a first return electrode for the RF EM energy. A second RF cutting field may be established between the inner electrode 906 of the first jaw 902 and a single inner electrode 914 of the second jaw 904, with the inner electrode 906 of the first jaw 902 acting as an active electrode and the inner electrode 914 of the second jaw 904 acting as a second return electrode for the RF EM energy (or vice versa - see Figure 19). As a result, the RF cutting field may be substantially symmetrical about the inner electrode 906 of the first jaw 902, which may enable uniform RF cutting of tissue.

[0148] When microwave EM energy is delivered to the electrodes of the jaws 902, 904 via the coaxial cable, a microwave field may be established around the jaws. In particular, the electrodes may cooperate as a microwave field emitting structure (or antenna structure) for emitting microwave energy. The inner electrode 906 of the first jaw 902 acts as a microwave emitter for emitting microwave energy. The outer electrode 908 and the inner electrode 914 of the second jaw 904 act as ground conductors for shaping the emitted microwave energy. Such a microwave field emitting structure may result in a substantially symmetric microwave field being emitted around the jaws.

[0149] 20 and 21 show schematic cross-sectional views of a portion of an instrument tip 1000 of an electrosurgical cutting instrument having a first jaw 1002 and a second jaw 1004. The first and second jaws are movable (e.g., pivotable) relative to one another, and each jaw includes a respective blade element for cutting tissue located between the jaws. In a preferred embodiment of the invention, the first jaw 1002 may be a stationary jaw and the second jaw 1004 may be a movable jaw, as described above with respect to FIG.

[0150] In FIG. 20, the first jaw 1002 includes an inner electrode 1006 and an outer electrode 1008 separated by a dielectric material element 1010. The inner electrode 1006 is electrically connected to the inner conductor of a coaxial cable of the electrosurgical cutting instrument, while the outer electrode 1008 is electrically connected to the outer conductor of the coaxial cable. The second jaw 1004 includes an inner electrode 1012 and an outer electrode 1014 separated by a dielectric material element 1016. The inner electrode 1012 is electrically connected to the inner conductor of a coaxial cable of the electrosurgical cutting instrument, while the outer electrode 1016 is electrically connected to the outer conductor of the coaxial cable. The inner electrodes 1006 and 1012 can contact each other as described in connection with FIGS. 10 and 12.

[0151] 21, the inner electrode 1006 is electrically connected to the outer conductor of the coaxial cable of the electrosurgical cutting instrument, while the outer electrode 1008 is electrically connected to the outer conductor of the coaxial cable. The inner electrode 1012 of the second jaw 1004 is electrically connected to the inner conductor of the coaxial cable of the electrosurgical cutting instrument, while the outer electrode 1016 of the second jaw 1004 is electrically connected to the outer conductor of the coaxial cable. To prevent an electrical connection between the inner electrode 1006 of the first jaw 1002 and the inner electrode 1012 of the second jaw 1004, the second jaw 1004 includes a second dielectric material element 1018 disposed on an inner surface of the inner electrode 1012. The second dielectric material element 1012 may be made of the same dielectric material as the second dielectric material element 1016, and may be in the form of, for example, a planar dielectric element attached to the first jaw 1002. Additionally or alternatively, a strip of dielectric material may be provided on the first jaw 1002 to cover the inner surface of the inner electrode 1006 and to be located between the inner electrode 1006 and the inner electrode 1012. To ensure minimal risk of electrical breakdown between the two inner electrodes, it may be preferable to cover each of the inner electrodes with a dielectric material. This may also improve symmetry between the jaws, which in turn may improve symmetry of the RF and microwave energy emitted by the instrument tip.

[0152] In the electrode configuration shown in Figures 20 and 21, two RF cutting fields can be generated when RF EM energy is transmitted to the electrodes via the coaxial cable. A first RF cutting field can be established between the inner electrode 1006 and the outer electrode 1008, both of the first jaw 1002, with the outer electrode 1008 acting as a first active electrode and the inner electrode 1006 acting as a return electrode to the RF EM energy. In the embodiment of Figure 21, a second RF cutting field can be established between the inner electrode 1006 of the first jaw 1002 and the inner electrode 1012 of the second jaw 1004, with the inner electrode 1012 of the second jaw 1004 acting as a second active electrode and the inner electrode 1006 of the first jaw 1002 acting as a return electrode to the RF EM energy. As a result, the RF cutting field can be substantially symmetric about the inner electrode 1006 of the first jaw 1002, which can allow for uniform RF cutting of tissue.

[0153] When microwave EM energy is delivered to the electrodes of the jaws 1002, 1004 via the coaxial cable, a microwave field may be established around the jaws. In particular, the electrodes may cooperate as a microwave field emitting structure (or antenna structure) for emitting microwave energy. The inner electrode 1014 of the second jaw 1004 and the outer electrode 1008 of the first jaw 1002 act as a microwave emitter that emits microwave energy. The inner electrode 1006 of the first jaw 1002 acts as a ground conductor that shapes the emitted microwave energy. Such a microwave field emitting structure may result in a substantially symmetric microwave field being emitted around the jaws.

[0154] 22 and 23 illustrate further embodiments of an instrument tip 200 of an electrosurgical cutting instrument. The embodiment of Figs. 22 and 23 has the same features as the embodiment of Figs. 1-14, except for the following differences: The control wire 210 does not include a rounded distal end. Instead, the control wire 210 is bent above the opening 251a, i.e., between the end of the control wire 210 and the opening 251a. This bend can be considered a second bend. The first bend is the bend between the portion of the control wire 210 that extends at the opening 251a and the extension of the control wire 210 along the shaft 204. The first bend and / or the second bend can be a 90° bend. The bent control wire 210 can have an S-shape in side view. The end of the control wire 210 can be disposed against or above the second cover 231. The end of the control wire 210 does not have to be located on the side of the second cover 231 .

[0155] The features disclosed in the above description, or in the following claims, or in the accompanying drawings, and expressed in their specific form or in the form of means for performing a disclosed function, or methods or processes for obtaining a disclosed result, may be utilized separately, or in any combination of such features, as appropriate, to realize the invention in diverse forms thereof.

[0156] While the present invention has been described in conjunction with the above exemplary embodiments, many equivalent modifications and variations will be apparent to those skilled in the art given this disclosure. Accordingly, the above exemplary embodiments of the present invention are deemed to be illustrative and not limiting. Various changes to the described embodiments may be made without departing from the spirit and scope of the present invention.

[0157] For the avoidance of doubt, the theoretical explanations provided herein are provided for the purpose of enhancing the understanding of the reader, and the inventors do not wish to be bound by any of these theoretical explanations.

[0158] Any section headings used herein are for organizational purposes only and are not to be construed as limiting the subject matter described.

[0159] Throughout this specification, including the claims which follow, unless the context specifically requires, the words "comprise" and "include", as well as variations such as "comprises", "comprising" and "including", are understood to imply the inclusion of stated elements or steps, or groups of elements or steps, but not the exclusion of other elements or steps, or groups of elements or steps.

[0160] It should be noted that, as used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Ranges may be expressed herein as from "about" one particular value and / or to "about" another particular value. When such a range is expressed, another embodiment includes from the one particular value and / or to the other particular value. Similarly, when values ​​are expressed as approximations, by use of the antecedent "about," it will be understood that the particular value forms another embodiment. The term "about" in connection with numerical values ​​is arbitrary and means, for example, ±10%.

Claims

1. 1. An electrosurgical cutting instrument comprising: an energy transfer structure for carrying radio frequency electromagnetic energy and / or microwave electromagnetic energy; an instrument tip attached to a distal end of the energy transmission structure, the instrument tip including a first jaw and a second jaw; the first jaw includes a first pair of electrodes electrically isolated from one another; the first pair of electrodes is coupled to the energy transfer structure; the first jaw and the second jaw are movable relative to each other between a closed position in which the first jaw and the second jaw are positioned next to each other and an open position in which the second jaw is separated from the first jaw by a gap for receiving biological tissue; the first jaw extends distally beyond the second jaw in the closed position; the first jaw includes a distal end surface, the first pair of electrodes being exposed at the distal end surface; the distal end surface is positioned such that in the closed position, when the electrosurgical cutting instrument is moved distally, the distal end surface first contacts tissue; The electrosurgical cutting instrument, wherein the first jaw includes first teeth projecting toward the second jaw, the first teeth forming a portion of the distal end face.

2. the first jaw comprises a first planar dielectric element having an inner surface facing the second jaw in the closed position and an outer surface facing away from the second jaw in the closed position, the first pair of electrodes comprising an inner electrode and an outer electrode, the inner electrode disposed on the inner surface of the first planar dielectric element and the outer electrode disposed on the outer surface of the first planar dielectric element; and / or the second jaw comprises a second planar dielectric element having an inner surface facing the first jaw in the closed position and an outer surface facing away from the first jaw in the closed position; The second jaw comprises: an inner electrode disposed on the inner surface of the second planar dielectric element; and / or The electrosurgical cutting instrument of claim 1 , further comprising an outer electrode disposed on the outer surface of the second planar dielectric element.

3. the inner electrode of the first jaw includes a first conductive layer formed on the inner surface of the first planar dielectric element; and / or the outer electrode of the first jaw includes a second conductive layer formed on the outer surface of the first planar dielectric element; and / or the inner electrode of the second jaw includes a first conductive layer formed on the inner surface of the second planar dielectric element; and / or The electrosurgical cutting instrument of claim 2 , wherein the outer electrode of the second jaw includes a second conductive layer formed on the outer surface of the second planar dielectric element.

4. the first jaw includes a front surface facing the second jaw and a back surface facing away from the second jaw; the first pair of electrodes extending to the front surface at the distal end surface; The electrosurgical cutting instrument of claim 1 , wherein the first pair of electrodes is spaced from the rear surface of the distal end face.

5. the second jaw includes at least one second tooth projecting toward the first jaw; the second tooth includes a front surface facing the distal end surface and a rear surface facing outward from the distal end surface; The electrosurgical cutting instrument of claim 1 , wherein in the closed position, the front and / or rear faces are angled distally.

6. further comprising a control wire for actuating the movable jaws of the first jaw and the second jaw; the movable jaw includes an opening through which the control wire extends to engage the movable jaw; the ends of the control wires are rounded, and / or The electrosurgical cutting instrument of claim 1 , wherein the control wire is bent.

7. The electrosurgical cutting instrument of claim 6 , wherein the rounded end of the control wire has a diameter greater than an inner diameter of the opening.

8. the movable jaw includes a chamfer adjacent the opening; The electrosurgical cutting instrument of claim 7 , wherein the rounded end of the control wire is at least partially disposed within the chamfer.

9. the energy transfer structure comprises a coaxial transmission line having an inner conductor separated from an outer conductor by a dielectric material; the planar dielectric element of the stationary jaw of the first jaw and the second jaw extends to the distal end of the energy transfer structure; The instrument tip is a connecting element connecting the inner conductor of the energy transfer structure to the inner electrode of the first pair of electrodes; and a dielectric block disposed between a movable jaw of the first jaw and the second jaw and the distal end of the energy transfer structure; the connecting element is sandwiched between the planar dielectric element of the stationary jaw and the dielectric block; The electrosurgical cutting instrument of claim 2 , wherein the dielectric block is attached to the planar dielectric element of the stationary jaw using an adhesive comprising an adhesive component and particles impregnated in the adhesive component.

10. a cavity is provided between the dielectric block and the distal end of the energy transfer structure; The electrosurgical cutting instrument of claim 9 , wherein the cavity is filled with the adhesive.

11. 1. An electrosurgical instrument comprising: an electrosurgical generator for supplying radio frequency and microwave electromagnetic energy; a surgical scoping device having an instrument cord for insertion into a patient's body, the instrument cord having an instrument channel extending therethrough; and The electrosurgical instrument comprises an electrosurgical cutting instrument according to any one of claims 1 to 10 inserted through the instrument channel of the surgical scope apparatus.

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