Electrosurgical resection tool

Abstract

This invention relates to an electrosurgical resection tool for cutting, coagulating, and ablating biological tissue. The electrosurgical resection tool has an instrument tip including a first jaw and a second jaw; wherein the second jaw is movable relative to the first jaw between a closed position and an open position. The first jaw includes a first pair of electrodes electrically isolated from each other, the first pair of electrodes including an inner electrode and an outer electrode, and the second jaw includes a single electrode. The first pair of electrodes is operable as an active electrode and a return electrode for delivering RF EM energy, and the single electrode is operable as an active electrode when the inner electrode of the first jaw is operable as a return electrode, or the single electrode is operable as a return electrode when the inner electrode of the first jaw is operable as an active electrode. The instrument tip is also operable as a microwave field emission structure for emitting microwave EM energy.

Description

Technical Field

[0001] This invention relates to an electrosurgical resection tool for cutting, coagulating, and ablating biological tissue. Specifically, this invention relates to an electrosurgical resection tool capable of delivering radio frequency (RF) energy and / or microwave frequency energy for cutting biological tissue, hemostasis (i.e., closing ruptured blood vessels by promoting blood coagulation), and tissue ablation. Background Technology

[0002] Surgical resection is the removal of parts of an organ from a human or animal. Organs can be highly vascularized. When tissue is cut (i.e., sliced ​​or transversely), small blood vessels may be damaged or ruptured. First comes bleeding, followed by a cascade of coagulation, where the blood forms a clot to try and stop the bleeding. During surgery, it is desirable for the patient to lose as little blood as possible; therefore, various devices have been developed to attempt bleeding-free cuts. For endoscopic surgery, bleeding is undesirable because the flow of blood can obscure the surgeon's vision, and the inability to easily manage the bleeding is also problematic.

[0003] Instead of sharp blades, it is known that RF energy can be used to cut biological tissue. The method of cutting using RF energy operates on the principle that when an electric current passes through the tissue matrix (with the aid of ionic cellular contents), the resistance to electron flow throughout the tissue generates heat. When a pure sine wave is applied to the tissue matrix, sufficient heat is generated within the cells to evaporate the tissue's water. This causes a significant increase in internal cellular pressure, which the cell membrane cannot control, leading to cell rupture. When this occurs over a large area, the tissue can be seen to be transversely cut. This procedure works well in lean tissue but is less efficient in adipose tissue because there is less ionic content to facilitate electron passage. This means that much more energy is required to evaporate the cellular contents, as the latent heat of fat evaporation is much greater than that of water evaporation.

[0004] RF coagulation operates by applying a less efficient waveform to the tissue, thereby heating the cellular contents to approximately 65°C instead of evaporating them. This drying process dries the tissue and denatures proteins in the blood vessel walls. This denaturation stimulates the coagulation cascade, thus enhancing blood clotting. Simultaneously, collagen in the walls denatures, changing from rod-shaped molecules to coiled molecules, leading to vasoconstriction and a reduction in size, providing anchoring points for the clot and creating a smaller area of ​​blockage. However, RF coagulation is less efficient in the presence of fatty tissue due to a weakened electrical effect. Therefore, it can be difficult to close sites of fatty hemorrhage. Such tissue does not have clean, white edges but instead presents a blackened, burned appearance.

[0005] Tissue ablation using microwave electromagnetic (EM) energy is based on the fact that biological tissues are primarily composed of water. The water content of human soft tissues typically ranges between 70% and 80%. Water molecules possess a permanent electric dipole moment, meaning there is a charge imbalance throughout the molecule. When a time-varying electric field is applied, this charge imbalance causes the molecules to rotate in response to the forces generated by the applied field, aligning their electric dipole moments with the polarity of the applied field. At microwave frequencies, rapid molecular oscillations lead to frictional heating, dissipating the field energy as heat. This is known as dielectric heating. Microwave ablation therapy utilizes this principle, in which water molecules in the target tissue are rapidly heated by the application of a localized electromagnetic field at microwave frequencies, leading to tissue coagulation and cell death. Summary of the Invention

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

[0007] This invention represents a development of the electrosurgical resection tool concept discussed in GB2567480. The electrosurgical resection tool of this invention includes a pair of jaws, wherein the first jaw includes a pair of electrodes, and the second jaw includes a single electrode (i.e., only one electrode is present on the second jaw). This allows the electrosurgical resection tool to operate according to three complementary modes: (i) RF-based sliding cutting when the jaws are closed, (ii) scissor cutting of tissue held between the jaws using a combination of RF energy and applied pressure, and (iii) coagulation or vascular closure of tissue held between the jaws using a combination of microwave energy and applied pressure. The inventors have discovered that by providing three electrodes on the resection tool as described herein, the tool's ability to cut and coagulate tissue using EM energy can be improved. Specifically, this electrode arrangement allows multiple RF fields to be established across the jaws, resulting in smoother, more uniform cuts. Similarly, by enabling the emission of a more uniform microwave field, this electrode configuration results in more effective tissue coagulation and ablation using microwave energy.

[0008] According to the present invention, an electrosurgical resection tool is provided, comprising: an energy delivery structure for carrying radio frequency (RF) electromagnetic (EM) energy and microwave EM energy, the energy delivery structure including a coaxial transmission line having an inner conductor separated from an outer conductor by a dielectric material; an instrument end mounted at a distal end of the energy delivery structure, wherein the instrument end includes a first jaw and a second jaw; wherein the second jaw is movable relative to the first jaw between a closed position and an open position, in the closed position the first jaw and the second jaw are positioned side by side with each other, and in the open position the second jaw is spaced apart from the first jaw to receive biological tissue; wherein the first jaw includes a first pair of electrodes electrically isolated from each other; wherein the second jaw includes a single electrode (i.e., only one electrode is present on the second jaw); wherein the first pair of electrodes is coupled to the energy delivery structure such that the first pair of electrodes is operable as an active electrode and a return electrode for delivering RF EM energy carried by the energy delivery structure; wherein the single electrode is coupled to the energy delivery structure for delivering RF EM energy carried by the energy delivery structure. The EM energy allows a single electrode to operate as an active electrode when the inner electrode of the first jaw is operable as a return electrode, or vice versa; and the device end is operable as a microwave field emission structure for emitting microwave EM energy carried by the energy delivery structure. For the avoidance of doubt, with respect to "single electrode," it should be understood that the second jaw comprises only one electrode, and no other electrodes for delivering RF energy and / or microwave energy are provided on the second jaw.

[0009] The energy delivery structure can be positioned within the lumen of the shaft (or outer sheath) such that the instrument tip protrudes from the distal end of the shaft. This shaft can be any suitable shaft through which a coaxial transmission line can be inserted. The shaft can be flexible, for example, adaptable to bending or other deflections to reach the treatment site. A flexible shaft allows the device to be used in surgical endoscopic devices such as endoscopes. In other examples, the shaft can be rigid, for example, for use in open surgery or with a laparoscopy.

[0010] Coaxial transmission lines can be adapted to transmit both RF EM energy and microwave EM energy. Alternatively, the energy delivery structure may include different paths for RF EM energy and microwave EM energy. For example, microwave EM energy can be delivered via a coaxial transmission line, while RF EM energy can be delivered via twisted-pair cables, etc. The coaxial transmission line may be in the form of a flexible coaxial cable.

[0011] The first and second jaws are mounted at the distal end of the energy transfer structure, such that the first and second jaws are movable relative to each other between an open and a closed position. Various types of relative movement between the jaws can be used. Relative movement between the first and second jaws may include rotational movement and / or translational movement. At least one of the first and second jaws may be movably mounted relative to the distal end of the energy transfer structure to achieve relative movement between the first and second jaws. In some cases, only one of the first and second jaws may be movably mounted relative to the distal end of the energy transfer structure, while in other cases, both the first and second jaws may be movably mounted relative to the distal end of the energy transfer structure.

[0012] As an example, the first jaw and the second jaw may be pivotable relative to each other, for example, making the opening angle between the first jaw and the second jaw adjustable. This example may be similar to a scissor closure. The first jaw and / or the second jaw may be pivotally mounted at the distal end of the energy transfer structure.

[0013] In another example, once tissue is clamped between the first and second jaws, it may be advantageous for the gap between the first and second jaws to be uniform, for example, to ensure that the supplied energy is uniform along the length of the jaws. In this example, the first and second jaws may be configured to remain parallel as they move relative to each other. For example, the first and second jaws may be parallel when the jaws are in the open position, and may remain parallel as the first and second jaws slide past each other to reach the closed position.

[0014] The first jaw may include a first blade element, and the second jaw may include a second blade element. Then, when the jaws are in the closed position, the first blade element may be placed side by side with the second blade element, and when the jaws are in the open position, a gap for receiving biological tissue may exist between the first blade element and the second blade element.

[0015] The first and second blade elements can be configured to cut tissue disposed in the gap between the first and second jaws when the first and second jaws move from an open position to a closed position. Therefore, each of the first and second blade elements may include a cutting (e.g., sharp) edge arranged for cutting tissue. The cutting interface may be defined between the first and second jaws, corresponding to the area of ​​tissue cut between the jaws when the jaws are closed.

[0016] The first and second blade elements can be arranged to slide past each other as the first and second jaws move between an open and a closed position, for example, to achieve mechanical cutting of tissue by applying a shearing force. Therefore, the cutting achieved by the first and second blade elements can be similar to a scissor-type cutting mechanism.

[0017] The first and / or second blade elements may include one or more serrations (e.g., teeth). The serrations facilitate clamping and cutting of tissue located in the gap between the jaws.

[0018] Electrosurgical resection tools may include actuators for controlling the movement of a second jaw relative to a first jaw. The actuator may include any suitable type of actuator for controlling relative movement between the jaws. As an example, the actuator may include a control rod extending along an energy transmission structure (e.g., inside a shaft) and movable along its length to control the position of one or both of the jaws. The control rod may have attachment features that engage with one or both of the first and second jaws, whereby longitudinal movement of the control rod results in movement of the second jaw relative to the first jaw. The attachment features may be hooks or any suitable engagement for transmitting thrust and pull forces to one or both of the jaws.

[0019] A first pair of electrodes is disposed on a first jaw. The first electrode in the first pair acts as an active electrode for RF EM energy, and the second electrode in the first pair acts as a return electrode for RF EM energy. In this way, RF EM energy carried by the energy delivery structure can be delivered to the tissue via the first pair of electrodes. The first pair of electrodes can establish a first RF cutting field using the RF EM energy from the energy delivery structure to cut the target tissue. The first pair of electrodes can be exposed on the surface of the first jaw, allowing them to contact the target tissue to deliver RF EM energy into it.

[0020] A single electrode is disposed on the second jaw and can function as either an active electrode or a return electrode for RF EM energy. Specifically, the single electrode can operate as an active electrode when the inner electrode of the first jaw is operable as a return electrode, or vice versa. In this way, the single electrode can cooperate with the first pair of electrodes on the first jaw to establish a second RF cutting field using RF EM energy from the energy delivery structure to cut the target tissue. The single electrode on the second jaw can be exposed on the surface of the second jaw, allowing it to contact the target tissue to deliver RF EM energy into it.

[0021] Therefore, when RF EM energy is delivered by the energy delivery 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 a single electrode on the second jaw and the first pair of electrodes. Thus, RF cutting can occur at the first jaw and also between the two jaws. This allows for RF cutting across larger tissue regions and enables more uniform RF cutting.

[0022] Furthermore, three electrodes define a microwave field emission structure for emitting (or radiating) microwave EM energy from the energy delivery structure. Therefore, microwave EM energy carried by the energy delivery structure can be radiated from the electrodes into the target tissue to coagulate and / or ablate it. The specific shape of the emitted microwave field will depend on the arrangement of the electrodes in the jaws. For example, electrodes in two jaws can together form a microwave field emission structure, such that a common microwave field is emitted across both jaws. Using paired electrodes to radiate microwave EM energy can improve the uniformity and symmetry of the microwave field emitted across the jaws, which can enhance the effectiveness of treating tissues with microwave EM energy.

[0023] In some embodiments, the first jaw may include a first planar dielectric element having an inner surface facing the second jaw and an outer surface facing away from the second jaw, and a first pair of electrodes may include an inner electrode and an outer electrode respectively disposed on the inner and outer surfaces of the first planar dielectric element; and the second jaw may include a second planar dielectric element having an inner surface facing the first jaw and an outer surface facing away from the first jaw. A single electrode may include an inner electrode disposed on the inner surface of the second planar dielectric element, or an outer electrode disposed on the outer surface of the second planar dielectric element. Thus, when the jaws are closed, the electrodes can be substantially aligned with each other in the lateral direction. This enables effective treatment of large areas of target tissue when the jaws are closed.

[0024] The first planar dielectric element and the second planar dielectric element may be substantially parallel to each other; for example, the plane defined by the inner surface of the first planar dielectric element may be substantially parallel to the plane defined by the inner surface of the second planar dielectric element. The first planar dielectric element and the second planar dielectric element may each be aligned parallel to a plane in which the first jaw and the second jaw can move relative to each other.

[0025] Each of the first and second planar dielectric elements may be formed from a sheet of dielectric (i.e., insulating) material, such as ceramic (e.g., alumina). In this document, the reference to a “planar” element may refer to a flat sheet of material with a thickness significantly smaller than its width and length. Each planar dielectric element may have a length dimension aligned longitudinally, a thickness dimension aligned laterally, and a width dimension orthogonal to both the length and thickness dimensions. The plane of the planar dielectric element is the plane containing the length and width dimensions, 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 arranged on opposite sides of the planar dielectric element relative to its width.

[0026] Using planar dielectric elements in each jaw on which electrodes are arranged greatly facilitates the fabrication of the instrument tip. This is because, for example, electrodes can be readily formed on the inner and / or outer surfaces of the planar dielectric element by depositing conductive material onto the surface and / or by attaching a conductive element to the surface. In contrast, in prior art excision tools, the jaws are typically made of conductive material coated with an insulating material, and the electrodes are defined by areas of the jaw where the insulating material has been etched away. Defining the electrodes by etching away the insulating material can be a lengthy, tedious, and time-consuming process. Furthermore, the inventors have found that tissue can adhere to the insulating material, making the instrument tip difficult to clean. Therefore, using planar dielectric elements in the jaws facilitates the fabrication of the instrument tip and prevents tissue adhesion to the instrument tip.

[0027] In some cases, the first planar dielectric element may define the first blade element. For example, the first planar dielectric element may include a cutting edge configured to contact and cut tissue located between the jaws when the jaws are closed. Then, a first pair of inner electrodes may be formed at or near the cutting edge of the first planar dielectric element.

[0028] Similarly, the second planar dielectric element may define the second blade element; for example, the second planar dielectric element may include a cutting edge configured to contact and cut tissue located between the jaws. Then, in the case where the single electrode is an inner electrode, a second pair of inner electrodes may be formed at or near the cutting edge of the second planar dielectric element.

[0029] When a first planar dielectric element defines a first blade element and a second planar dielectric element defines a second blade element, the inner surface of the first planar dielectric element may be arranged to slide over the inner surface of the second planar dielectric element when the jaws move between an open position and a closed position.

[0030] The inner electrodes of the first pair of electrodes on the first jaw may include a first conductive layer formed on the inner surface of the first planar dielectric element; and the individual electrode of the second jaw may include a second conductive layer formed on the inner surface of the second planar dielectric element. Therefore, each inner electrode may be formed directly on the inner surface of the respective planar dielectric element by a corresponding conductive material layer. For example, the conductive material layer may be deposited using any suitable deposition technique, or the conductive material layer may be otherwise mounted to the inner surface (e.g., via an adhesive). The conductive layer for each inner electrode may be formed of any suitable conductive material (e.g., gold). It is also conceivable that the individual electrode of the second jaw may alternatively be formed on the outer surface of the second planar dielectric element, such that the individual electrode is an outer electrode. For example, as described below, the outer electrode of the second jaw may be formed in substantially the same manner as the outer electrode of the first jaw.

[0031] The first conductive layer may extend in the longitudinal direction, that is, the first conductive layer may extend along all or part of the length of the first planar dielectric element. Similarly, the second conductive layer may extend in the longitudinal direction, that is, the second conductive layer may extend along all or part of the length of the second planar dielectric element.

[0032] Preferably, the first jaw may include a third planar dielectric element having an inner surface facing the second jaw, disposed on the inner surface of the inner electrode of the first jaw. Alternatively, the second jaw may include a fourth planar dielectric element having an inner surface facing the first jaw, disposed on the inner surface of a single electrode of the second jaw. For example, the third and / or fourth planar dielectric elements may be applied as a dielectric coating providing an insulating barrier between the inner electrodes. For example, the coating may be a ceramic (e.g., alumina) coating, a diamond-like carbon coating, an enamel coating, or a silicon-based coating. This coating may be further coated with a parylene N insulating coating (e.g., a layer between 2 and 10 micrometers deep) to seal penetrating pores and waterproof the insulator. Alternatively, the dielectric coating may be a thermoplastic polymer, such as polyetheretherketone (PEEK). The dielectric coating ensures that the inner electrode is essentially exposed only at the upper surface of the blade element, which ensures that EM energy is focused on the desired area. By providing a third and / or fourth dielectric element in this manner, minimal risk of electrical breakdown or discharge is ensured between the two inner electrodes, allowing energy to be preferentially directed into the tissue. This arrangement also improves the symmetry between the jaws, which in turn improves the symmetry of the RF and microwave energy emitted from the instrument tip.

[0033] Furthermore, in some cases, the outer electrode of the first 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 mentioned above. Of course, in some examples, the single electrode of the second jaw may be formed in a similar manner.

[0034] Therefore, in order to form electrodes, it is not necessary to pattern and etch the insulating layer on any jaw, which greatly facilitates the fabrication of instrument ends.

[0035] The first jaw may further include a first conductive housing attached to the outer surface of the first planar dielectric element and arranged to form at least a portion of the outer electrode of the first pair of electrodes. Thus, the outer electrode may include a conductive housing mounted on the outer surface of the corresponding planar dielectric element. The first conductive housing may define the outer surface of the first jaw. In some embodiments, the second jaw may similarly include a second conductive housing attached to the outer surface of the second planar dielectric element and arranged to form at least a portion of a single electrode of the second jaw. The conductive housing, or each conductive housing, can therefore serve the dual purpose of defining the outer electrode and protecting the planar dielectric element to which it is mounted. The conductive housing, or each conductive housing, may be formed from a sheet of conductive material attached to the outer surface of the corresponding planar dielectric element (e.g., via adhesive and / or mechanical fastening). Any suitable conductive material may be used for the conductive housing, such as stainless steel.

[0036] The surface area of ​​the conductive housing or each conductive housing may be larger than the surface area of ​​the inner electrode of the first pair of electrodes. For example, the conductive housing 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 electrode may be formed as a relatively thin conductive layer on the inner surface of the first planar dielectric element. Therefore, the conductive housing or each conductive housing can be used to increase the surface area of ​​the outer electrode relative to the inner electrode.

[0037] The inventors have discovered that when performing RF cutting of tissue using a pair of spaced-apart electrodes of different sizes, the tissue tends to be cut near the smaller of the two electrodes. Therefore, using a conductive housing with a larger surface area compared to the inner electrode ensures that RF cutting of the tissue occurs near the inner electrode. This allows for well-defined cutting of tissue located between jaws using RF EM energy. Specifically, this can be used to ensure that the cut generated by RF EM energy is located at or near the cutting interface between the blade elements.

[0038] Advantageously, the outer electrode of the first jaw and the individual electrodes of the second jaw can be electrically coupled to each other. This can help provide symmetry in the RF EM field and / or microwave EM field emitted by the end, particularly with respect to the inner electrode of the first jaw and the region symmetry between the first and second jaws. For example, the outer electrode of the first jaw and the individual electrodes of the second jaw can both be coupled to a common conductor in the power transfer structure, such that the outer electrode and the individual electrode are electrically coupled via the power transfer structure.

[0039] The device end may also include a base structure that connects the external electrode of the first jaw and a single electrode of the second jaw to a distal end of the power delivery structure. For example, the base structure may include a first base portion and a second base portion, the first base portion rigidly connecting the external electrode of the first jaw to the distal end of the power delivery structure, and the second jaw pivotally connected to the second base portion such that the second jaw can pivot relative to the second base portion.

[0040] The base structure can be any suitable structure for supporting the jaws at the end of the energy delivery structure. The base structure may, for example, include an arm, one end of which is fixed to the distal end of the energy delivery structure, and the other end of which is connected to a first jaw and a second jaw. This base structure can be used to reinforce the distal end of the energy delivery structure (which can typically be flexible) and facilitate the transmission of longitudinal forces to the instrument tip. The base structure may include a rigid material (e.g., a metal, such as stainless steel).

[0041] The first jaw and / or the second jaw can be movably connected to the base structure to allow 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.

[0042] In some cases, the first base portion may be part of the first conductive housing, i.e., the first conductive housing may form part of the base structure. For example, the first base portion may be a portion of the first conductive housing extending between the first jaw and the distal end of the energy transfer structure. This can be used to ensure a rigid connection between the first jaw and the distal end of the energy transfer structure, and to facilitate an electrical connection between the outer electrodes of the first pair and the energy transfer structure.

[0043] The base structure may include a conductive material (e.g., made of a conductive material) that electrically connects the first conductive housing to a first of the inner and outer conductors at the distal end of the coaxial transmission line. In this way, the first conductive housing can be directly connected to the conductors 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 housing to a first of the inner and outer conductors.

[0044] Alternatively, the base structure may include a conductive material (e.g., made of a conductive material) that electrically connects a single electrode of the second jaw to a first of the inner and outer conductors at the distal end of the coaxial transmission line. In this way, the inner electrode of the second jaw can be directly connected to the 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 of the inner and outer conductors.

[0045] In the case where the individual electrodes of the first conductive housing and the second jaw are electrically coupled to each other, the base structure may include a conductive material (e.g., made of a conductive material) that connects each of the first and second conductive housings to the first of the inner and outer conductors at the distal end of the coaxial transmission line. Therefore, the inner electrodes of the first conductive housing and the second jaw can be electrically coupled via the base structure.

[0046] The base structure may define a cavity in which the inner electrode of the first jaw is electrically connected at the distal end of the coaxial transmission line to a second of the inner and outer conductors. In this way, the base structure can be used to protect the electrical connection between the inner electrode of the first jaw and the second of the inner and outer conductors. The conductive material of the base structure may also be used to provide electromagnetic shielding for the electrical connection within the cavity. The cavity may be a space or void defined within the base structure.

[0047] The cavity may contain a dielectric material. This ensures that the electrical connections within the cavity are electrically insulated to prevent breakdown between the internal electrical connections and the surrounding base structure. The dielectric material can be any suitable type. As an example, an electro-encapsulating material can be used as the dielectric material in the cavity, such as thermosetting plastics, silicone, epoxy, or resin.

[0048] The base structure may include openings formed in the sidewalls of the base structure for injecting dielectric material into the cavity. For example, the openings may be holes or orifices formed in the sidewalls of the base structure. This allows dielectric material to be injected into the cavity after the device tip has been assembled to the distal end of the power delivery structure. This facilitates the assembly of the device tip.

[0049] In some embodiments, both the outer electrode of the first jaw and a single electrode of the second jaw are electrically connected to the first of the inner and outer conductors, and the inner electrode of the first jaw is electrically connected to the second of the inner and outer conductors. This electrode configuration allows a first RF cutting field to be established between a pair of electrodes on the first jaw, and a second RF cutting field to be established between the inner conductors of the first and second jaws. The two RF fields can be substantially symmetrical about the cutting interface between the blade elements, which can produce a highly uniform cut on the tissue held between the jaws. Additionally, with this electrode configuration, a substantially symmetrical microwave field can be emitted across the jaws, thereby achieving microwave ablation and / or coagulation of the tissue around the jaws.

[0050] Advantageously, the first pair of electrodes and the single electrode can operate together as a microwave field emission structure for emitting microwave EM energy carried by the energy transfer structure. That is, all three electrodes can cooperate to emit microwave EM energy.

[0051] The size of the instrument tip can be configured to fit within the instrument channel of a surgical endoscope. Therefore, in another aspect, the present invention provides an electrosurgical device comprising: an electrosurgical generator for supplying radio frequency (RF) electromagnetic (EM) energy and microwave EM energy; a surgical endoscope having an instrument cord for insertion into a patient, the instrument cord having an instrument channel extending therethrough; and an electrosurgical resection tool as described above, the electrosurgical resection tool being inserted through the instrument channel of the surgical endoscope.

[0052] The device may include a handheld component for controlling an electrosurgical resection tool. The handheld component may be mounted on the proximal end of the shaft, for example, external to a surgical endoscopic device.

[0053] The term "surgical viewing device" may be used herein to refer to any surgical device equipped with an insertion tube, which is a rigid or flexible (e.g., manipulable) catheter introduced into the patient during invasive surgery. The insertion tube may include an instrument channel and an optical channel (e.g., for transmitting light to illuminate the treatment site at the distal end of the insertion tube and / or to capture an image of the treatment site). The instrument channel may have a diameter suitable for receiving invasive surgical instruments. The diameter of the instrument channel may be 5 mm or less.

[0054] In this document, the term "inner" refers to something radially closer to the center (e.g., axis) of the instrument channel and / or coaxial transmission line. The term "outer" refers to something radially farther from the center (axis) of the instrument channel and / or coaxial transmission line.

[0055] Unless the context otherwise indicates otherwise, the term “conductive” is used in this document to refer to electrical conductivity.

[0056] In this document, the terms "proximal" and "distal" refer to the ends of the elongated tool. In use, the proximal end is closer to the generator used to provide RF and / or microwave energy, while the distal end is further away from the generator.

[0057] In this specification, "microwave" can be used broadly to indicate a frequency range of 400 MHz to 100 GHz, but is preferably 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 indicate a frequency range at least three orders of magnitude lower, for example, up to 300 MHz, preferably 10 kHz to 1 MHz, and most preferably 400 kHz.

[0058] This invention includes combinations of the described aspects and preferred features, unless such combinations are explicitly not permitted or explicitly avoided. Attached Figure Description

[0059] The embodiments and experiments illustrating the principles of the invention will now be discussed with reference to the accompanying drawings, in which:

[0060] Figure 1 This is a schematic diagram of an electrosurgical system as an embodiment of the present invention;

[0061] Figure 2 This is a perspective view of an electrosurgical resection tool according to an embodiment of the present invention;

[0062] Figure 3 yes Figure 2 A perspective view of an electrosurgical resection tool;

[0063] Figure 4 It is a description Figure 2 A schematic diagram of a portion of an electrosurgical resection tool;

[0064] Figure 5 It is a description Figure 2 A schematic diagram of the electrosurgical resection tool before assembly;

[0065] Figure 6 yes Figure 2 A schematic diagram of the electrosurgical resection tool before it is fully assembled;

[0066] Figure 7A This is a perspective view of the contents of an instrument shaft that can be used with an electrosurgical resection instrument as an embodiment of the present invention;

[0067] Figure 7B yes Figure 7A The cross-section of the instrument shaft shown;

[0068] Figure 8 This is a schematic diagram showing the instrument tip of an electrosurgical resection tool according to an embodiment of the present invention; and

[0069] Figure 9 This is a schematic diagram showing the instrument tip of an electrosurgical resection tool according to another embodiment of the present invention. Detailed Implementation

[0070] Aspects and embodiments of the invention will now be discussed with reference to the accompanying drawings. Further aspects and embodiments will be apparent to those skilled in the art. All documents mentioned herein are incorporated by reference.

[0071] Figure 1 This is a schematic diagram of a complete electrosurgical system 100 as an embodiment of the present invention. System 100 is arranged to treat (e.g., cut or close) biological tissue using radio frequency (RF) or microwave electromagnetic (EM) energy from the instrument tip. System 100 includes a generator 102 for controllably supplying RF EM energy and microwave EM energy. A suitable generator for this purpose is described in WO 2012 / 076844, which is incorporated herein by reference. Generator 102 is connected to a handpiece 106 via 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), but this is not necessary. If desired, the handpiece 106 may house an instrument actuation mechanism operated by an actuator 109, such as a thumb-operated slider or plunger. For example, as discussed herein, the instrument actuation mechanism may be used to operate the opening and closing of the jaws of a cutting instrument. Other mechanisms may also be included in the handpiece. For example, a needle movement mechanism (operable by a suitable trigger on the handpiece) may be provided for deploying a needle at the end of the instrument. 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.

[0072] The flexible shaft 112 is insertable along its entire length through the instrument (working) channel of the surgical endoscope 114. The flexible shaft 112 has an instrument tip 118 shaped to extend through the instrument channel of the surgical endoscope 114 and protrude at the distal end of the endoscope's insertion tube (e.g., inside a patient). The instrument tip 118 includes a pair of jaws with blade elements for clamping and cutting biological tissue and an energy delivery structure arranged to deliver RF EM or microwave EM energy transmitted from the generator 102. Optionally, the instrument tip 118 may also include a retractable hypodermic needle for delivering fluid from the fluid delivery device 108. The handheld component 106 includes an actuation mechanism for opening and closing the jaws of the instrument tip 118. The handheld component 106 may also include a rotation mechanism for rotating the instrument tip 118 relative to the instrument channel of the surgical endoscope 114.

[0073] The instrument tip 118 can be configured to have a maximum outer diameter suitable for passage through the working channel. Typically, the diameter of the working channel in a surgical endoscopic 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, or 3.8 mm. The maximum diameter of the flexible shaft 112 can be less than this value, for example, 2.65 mm. The length of the flexible shaft 112 can be equal to or greater than 1.2 m, for example, 2 m or more. In other examples, the instrument tip 118 can be mounted at the distal end of the flexible shaft after the flexible shaft 112 has been 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 the distal end before its proximal connection is made. In these arrangements, the distal end assembly 118 can be allowed to have a size larger than the working channel of the surgical endoscopic device 114. The system described above is one way of introducing an instrument into a patient's body. Other techniques are possible. For example, catheters can also be used to insert the instrument.

[0074] Although the examples in this article are presented in the context of surgical endoscopic devices, it should be understood that electrosurgical resection instruments can be embodied in devices suitable for open surgery or used in conjunction with laparoscopy.

[0075] Figures 2 to 6 The instrument tip 200 of an electrosurgical resection tool, as an embodiment of the present invention, is shown. The instrument tip 200 may, for example, correspond to the above-described... Figure 1 The device end 118 is under discussion. Figure 2 A first schematic perspective view of the instrument tip 200 is shown, depicting a first side of the instrument tip 200, and... Figure 3 A second schematic perspective view of the instrument tip 200 is shown, depicting a second side of the instrument tip 200. Figures 4 to 6 The structure of the instrument end 200 is shown.

[0076] The device end 200 is mounted at the distal end of an energy transmission structure, which is in the form of a coaxial cable 202 (e.g., ...). Figures 4 to 6 (As shown). Coaxial cable 202 extends through flexible shaft 204, which may correspond to flexible shaft 112 discussed above. Specifically, flexible shaft 204 defines a lumen through which coaxial cable 202 extends, and instrument tip 200 protrudes from the distal end of flexible shaft 204. Coaxial cable 202 is arranged to transmit RF EM energy and microwave EM energy from an electrosurgical generator (e.g., generator 102 mentioned above) to instrument tip 200.

[0077] The instrument end 200 has a first jaw 206 and a second jaw 208 that are movable relative to each other between an open position and a closed position. Specifically, in the example shown, the first jaw 206 is stationary, i.e., it is fixed relative to the distal end of the coaxial cable 202, while the second jaw 208 is pivotally mounted to the first jaw 208. An actuator in the form of a control line (or bar) 210 is connected to the second jaw 208 (see example...). Figure 3 and Figure 6 The control line 210 is disposed within the lumen of the flexible shaft 204 and is longitudinally slidable within the lumen to move the second jaw 208. The proximal end of the control line 210 may be connected to a handpiece (e.g., handpiece 106) operable to control the movement of the second jaw 208 via the control line 210. Figure 2 and Figure 3 Jaws 206, 208 are depicted in the open position, wherein a gap for receiving tissue is defined between jaws 206, 208.

[0078] 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 a cutting edge arranged to contact tissue located in the gap between the jaws and to cut the tissue when the jaws are moved to a closed position. Specifically, the second blade element 214 is arranged to slide past the first blade element 212 as the second jaw 208 moves toward the closed position, such that a shearing force is applied to the tissue located in the gap between the jaws 206 and 208. Thus, by pivoting the second jaw 208 toward the closed position, tissue located in the gap between the jaws can be cut.

[0079] The first blade element 212 is defined by a first planar dielectric element 216 in the first jaw 206, and the second blade element 214 is defined by a second planar dielectric element 218 in the second jaw 208. Specifically, the first planar dielectric element 216 includes an inner surface 220 facing the second planar dielectric element 218, and when the second jaw 208 pivots relative to the first jaw 206, the inner surface 222 of the second planar dielectric element 218 slides over this inner surface, resulting in a shearing motion between the two planar dielectric elements. Each of the first and second planar dielectric elements may be made of ceramic (e.g., alumina) or other suitable electrically insulating material. Each of the first and second planar dielectric elements defines a plane parallel to the plane through which the second jaw 208 pivots relative to the first jaw 206. The second planar dielectric element 218 includes a pair of protrusions (or teeth) 223 that act as serrations of the second blade element 214. Therefore, the protrusion 223 can be used to clamp tissue located in the gap between the jaws to facilitate holding and / or cutting the tissue. The first planar dielectric element 216 may include similar protrusions (not shown) to act as serrations of the first blade element 212.

[0080] The instrument tip 200 includes three electrodes for delivering energy to tissue, one jaw including a pair of electrodes and the other jaw including a single electrode. In the illustrated embodiment, 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. Thus, the first planar dielectric element 216 serves to electrically isolate the inner electrode 224 and the outer electrode 226 of the first jaw 206 from each other. The second jaw 208 includes an outer electrode 228 formed on the outer surface of the second planar dielectric element 218. Of course, in some embodiments, a single electrode may be formed on the inner surface 222 of the second jaw 208, wherein the first jaw 206 may advantageously include a dielectric coating or a third planar dielectric element formed on the inner electrode 224 and the inner surface 220 of the first planar 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 dielectric planar element or coating material may be arranged such that the inner electrode 224 is exposed along the top surface of the first jaw 206 to ensure that RF energy and / or microwave energy can be emitted from the inner electrode, as described below. Figure 5 Therefore, the coating or third planar dielectric element is used to electrically isolate the inner electrode 224 of the first jaw 206 and the inner electrode 228 of the second jaw 208 from each other. However, in the case where the single electrode is the outer electrode 228, the second planar dielectric element 218 is used to ensure that there is no electrical connection with the inner electrode 224 of the first jaw.

[0081] The inner electrode 224 of the first jaw 206 is formed of a layer or film of conductive material (e.g., gold) deposited on the inner surface 220 of the first planar dielectric element 216. The inner electrode 224 covers a portion of the inner surface 220 and extends along the cutting edge of the first blade element 212 (i.e., the first planar dielectric element 216). The outer electrode 226 of the first jaw 206 is 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 conductive shell is a single sheet of conductive material covering the entire outer surface of the first planar dielectric element 216, and its thickness is similar to that of the first planar dielectric element 216. The outer surface of the first conductive shell serves as the outer surface of the first jaw 206. The outer surface of the first conductive shell may be circular, giving the first jaw 206 a smooth outer surface. The conductive shell may include protrusions shaped to engage with grooves formed in the first dielectric element 216 to prevent slippage between the two portions and to ensure that the two portions are correctly oriented relative to each other.

[0082] A single electrode of the second jaw 208 can be formed in a manner similar to the inner electrode 224 or outer electrode 226 of the first jaw 206. For example, a single inner electrode of the second jaw 208 can be formed from a layer or film of a conductive material (e.g., gold) deposited on the inner surface 222 of the second planar dielectric element 218. Thus, the inner electrode covers a portion of the inner surface 222 and extends along the cutting edge of the second blade element 214 (i.e., the second planar dielectric element 218) such that when the jaws are closed, the inner electrode is located at the cutting interface between the first and second blade elements. In this embodiment, the outer surface of the second jaw 208 is formed by the outer surface of the second planar dielectric element 218, which can be circular, giving the second jaw 208 a smooth outer surface. Alternatively, a single electrode of the second jaw 208 is an outer electrode 228, which is in the form of a second conductive shell attached (e.g., glued) to the outer surface of the second planar dielectric element 218, and its thickness is similar to the thickness of the second planar dielectric element 218. There are no other electrodes on the second jaw 208, so the second jaw 208 can be considered as a single-electrode jaw.

[0083] Three electrodes are electrically connected to the distal end of coaxial cable 202, enabling the electrodes to deliver RF EM energy and microwave EM energy transmitted via coaxial cable 202. The manner in which the electrodes are connected to coaxial cable 202 will be discussed in more detail below.

[0084] Now for reference Figures 4 to 6The construction of the instrument tip 200 is discussed, and these figures depict the various assembly stages of the instrument tip 200. 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. A first jaw 206 and a second jaw 208 are mounted 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 rigidly connects the first jaw 206 to the distal end of the coaxial cable 202. The first base portion 244 includes an arm extending between the distal end of the coaxial cable 202 and a first conductive housing (which forms the outer electrode 226 of the first jaw 206). In the illustrated example, the first conductive housing and the first base portion 244 are integrally formed as a single piece of conductive material. However, in other examples, the first conductive housing and the first base portion may be formed as separate parts connected together. 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. The length of the outer sheath 240 of the coaxial cable 202 is removed near the distal end of the coaxial cable, exposing the outer conductor 236. Therefore, the outer conductor 236 is 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 can be secured within the channel in the first mounting portion 246 using a suitable conductive epoxy resin. Thus, the first conductive housing (and therefore the outer electrode 226 of the first jaw 206) is electrically connected to the outer conductor 236 via the first base portion 244.

[0085] The base structure 242 also includes 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 a 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 a first mounting portion 246 on the first base portion 244, such that the first base portion 244 and the second base portion 248 are in electrical contact. The first mounting portion 246 and the second mounting portion 250 have complementary shapes of mating surfaces that engage with each other when the base portions are secured together. Figure 6As shown, the first base portion 244 and the second base portion 248 are secured together by a conductive ring 252, which surrounds the first mounting portion 246 and the second mounting portion 250 to hold the first mounting portion and the second mounting portion together. Adhesive can be injected into the conductive ring 252 to secure the conductive ring 252 in place on the first mounting portion and the second mounting portion. In addition to holding the base structure 242 together, the conductive ring 252 also acts as a microwave shield, preventing microwave energy from being radiated before reaching the electrodes in the jaws.

[0086] The second base portion 248 includes an arm extending longitudinally from the second mounting portion 250, to which the second jaw 208 is pivotally mounted. In the illustrated example, the second jaw 208 is pivotally mounted to the second base portion 240 via a rivet 254. A single electrode is electrically contacted with the second base portion 248 via the rivet 254 (which is made of a conductive material). Thus, the single electrode on 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. Therefore, both the outer electrode 226 of the first jaw 206 and the single electrode of the second jaw are electrically connected to the outer conductor 236 via the base structure 242.

[0087] The second base portion 248 may include a passage (not shown) through which the control line 210 extends to connect to the second jaw 208. The second conductive housing may include an attachment portion 251 to which the distal end of the control line 210 is attached. The second conductive housing may also be provided with a limiting pin 253 (e.g., Figure 5 As shown, the limiting pin is used to limit the movement of the second jaw 208 relative to the first jaw 206 between the open and closed positions. This allows for more precise control of the position of the second jaw 208.

[0088] The inner electrode 224 of the first jaw 206 is electrically connected to the inner conductor 234 of the coaxial cable 202. For example... Figure 4 As shown, the first planar dielectric element 216 includes a connection portion 256 extending 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 the inner conductor is located on the connection portion 256 of the first planar dielectric element 216. A wire 258 extends longitudinally along the connection portion 256 of the first planar dielectric element to electrically connect the inner electrode 224 to the distal end of the inner conductor 234. The wire 258 may be part of the inner electrode 224 extending along the connection portion 256; for example, the wire 258 and the inner electrode 224 may be deposited together on the inner surface 220 of the first planar dielectric element 216.

[0089] A dielectric block 264 is mounted between the second base portion 248 and the first planar dielectric element 216 to prevent electrical breakdown between the wire 258 and the conductive second base portion 248. For example, the dielectric block 264 may be made of a ceramic material (such as alumina). The dielectric block 264 can be fixed in place using an adhesive. Furthermore, the base structure 242 is shaped to form a cavity between the first base portion 244 and the second base portion 248, in which the inner conductor 234 is electrically connected to the wire 258 (and therefore electrically connected to the inner electrode 224). This cavity may be filled with a dielectric material, such as a potting compound, to reduce the risk of electrical breakdown between the distal end of the inner conductor 234 and the base structure 242. Filling the cavity with dielectric material can also be used to reinforce the instrument tip 200 and hold the first and second base portions together. The second base portion 248 may include an injection port through which the dielectric material can be injected into the cavity.

[0090] exist Figure 4 In the diagram, for clarity, the first jaw 206 is shown with the inner electrode 224 exposed. However, in some embodiments, to ensure that there is no electrical connection between the inner electrode 224 and a single inner electrode of the second jaw 208 when the jaws are closed, a dielectric coating 225 is applied to the inner surfaces of the first jaw 206 and the inner electrode 224. The dielectric coating material 225 may be arranged such that the inner electrode 224 is exposed along the top surface of the first jaw 206 to ensure that RF energy and / or microwave energy can be emitted from this inner electrode, such as... Figure 5 As shown.

[0091] To assemble the instrument tip 200, the first base portion 244 and the first jaw 208 can be assembled first and connected to the distal end of the coaxial cable 202, as follows: Figure 4 As shown. Figure 5 As shown, the second jaw 208 is connected to the second base portion 248 via a rivet 254. Then, the dielectric block 264 can be placed on the inner surface 220 of the first planar dielectric element 216 (e.g., Figure 5 (As shown), the second base portion 248 is then mounted on the first base portion 244. Dielectric potting material can then be injected into the cavity between the first base portion 244 and the second base portion 248. The conductive ring 252 can then slide on the coaxial cable 202 and onto the first mounting portion 246 and the second mounting portion 250 to hold the first base portion 244 and the second base portion 248 together. As described above, the conductive ring 252 can be fixed to the first mounting portion 246 and the second mounting portion 250 using adhesive. The control line 210 can then pass through the passage in the second base portion 248 and connect to the attachment portion on the second jaw 208 (e.g., ...). Figure 6(As shown). Finally, the flexible shaft 204 can be pulled onto the coaxial cable 202 and, for example, secured to the conductive ring 252 using adhesive.

[0092] Reference Figures 2 to 6 In the described embodiment, only one jaw is movable. However, in other embodiments, both jaws can be movably mounted 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 different electrical connections to the electrodes can be used in different embodiments. For example, in some embodiments, the inner electrode 224 of the first jaw 206 can be connected to the outer conductor 236, while a single electrode of the second jaw 208 and the outer electrode 226 of the first jaw 206 can be connected to the inner conductor. Reference below... Figure 8 and Figure 9 Various electrode configurations are discussed.

[0093] Figure 7A This is a cross-sectional perspective view of the instrument shaft 612 as it travels toward the instrument end. The instrument shaft 612 includes an outer sleeve 648 that defines a lumen for conveying the coaxial cable 626 and the control rod 636. In this example, the coaxial cable 626 and the control rod 636 are held within a longitudinally extending insert 650. The insert 650 is an extrusion, for example, formed of a deformable polymer such as PEEK or other plastics with similar mechanical properties. Figure 7B As shown more clearly, the insert 650 is a cylindrical element having a series of sub-lumens 664 cut out around its outer surface. The sub-lumens 664 penetrate the outer surface of the insert 650 to define a plurality of discrete legs 662 around its circumference. The size of the sub-lumens 664 can be configured to transmit components such as coaxial cable 626 or control rod 636, or can be used for the purpose of allowing fluid to flow along the lumen of sleeve 648.

[0094] It may be advantageous for the insert not to include any closed sub-lumens. If stored in a bent state, fully closed sub-lumens may easily remain deformed. Such deformation may lead to vibration during use.

[0095] The insert 650 may include a sub-cavity for receiving the coaxial cable 626. In this example, the coaxial cable 626 includes an inner conductor 658 separated from the outer conductor 654 by a dielectric material 656. The outer conductor 654 may further have a protective cap or sheath 652, for example, formed of PTFE or other suitable low-friction material, to allow relative longitudinal movement between the insert and the coaxial cable as the shaft flexes.

[0096] Another sub-lumen can be arranged to receive a standard PFTE tube 660, through which a control rod 636 extends (this could be...). Figure 3(guide wire tube 252). In an alternative embodiment, the control rod 636 may be coated with a low-friction (e.g., PFTE) coating before use, so that a separate PFTE tube is not required.

[0097] When installed with coaxial cable 626 and control rod 636, the insert is arranged to fill the cavity of sleeve 648, i.e., to fit tightly within the cavity. This means the insert is used to limit relative movement between the coaxial cable, control rod, and sleeve during bending and rotation of shaft 612. Furthermore, by filling sleeve 648, the insert helps prevent the sleeve from collapsing and losing rotation during excessive rotation. The insert is preferably made of a material that exhibits rigidity to resist such movement.

[0098] The presence of the insert also prevents “loss” of travel of the control rod caused by deformation of the instrument shaft 612.

[0099] The extrusion insert discussed above provides a cam-shaped support that engages with the inside of the sleeve and prevents the control rod from winding around the sleeve's axis. This reduces the stroke loss discussed above.

[0100] Figure 8 and Figure 9 This is a schematic diagram illustrating possible electrode configurations in an electrosurgical resection tool according to an embodiment of the present invention.

[0101] Figure 8 A schematic cross-sectional view of a portion of the instrument tip 900 of an electrosurgical resection tool, having a first jaw 902 and a second jaw 904. The first and second jaws are movable relative to each other (e.g., pivotable), and each jaw includes a corresponding 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. Figure 2 The first jaw 902 includes an inner electrode 906 and an outer electrode 908 separated by a dielectric material element 910. The inner electrode 906 is electrically connected to the inner conductor of the coaxial cable of the electrosurgical resection tool, while the outer electrode 908 is electrically connected to the 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 an inner electrode or an outer electrode and may be provided in a manner similar to the inner or outer electrode of the first jaw. Figure 8 and Figure 9 In the schematic diagram shown, the single electrode 914 is considered to be the inner electrode of the second clamp 904, but it should be understood that the description of the connection and the emission field is essentially the same regardless of whether the single electrode is the inner electrode or the outer electrode. Figures 8 to 9The "+" and "-" symbols indicate which of the inner and outer conductors of the coaxial cable each electrode is connected to, with "+" indicating that the electrode is connected to the inner conductor and "-" indicating that the electrode is connected to the outer conductor.

[0102] 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 includes a second dielectric material element 912 positioned 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, for example, in the form of a planar dielectric element mounted on the first jaw 902. Alternatively, a sheet of dielectric material may be provided on the second jaw 904 such that it covers the inner surface of the inner electrode 914 and is located between the inner electrodes 906 and 912. Covering each of the inner electrodes with dielectric material may be preferred to ensure that the risk of electrical breakdown between the two inner electrodes is minimized. This also improves the symmetry between the jaws, which in turn improves the symmetry of the RF and microwave energy emitted from the instrument tip.

[0103] use Figure 8 The electrode configuration shown generates two RF cutting fields when RF EM energy is delivered to the electrodes via a coaxial cable. A first RF cutting field can be established between the inner electrode 906 and the outer electrode 908 of the first jaw 902, where the inner electrode 906 acts as the active electrode for the RF EM energy, and the outer electrode 908 acts as the first return electrode. A second RF cutting field can be established between the inner electrode 906 of the first jaw 902 and a single inner electrode 914 of the second jaw 904, where the inner electrode 906 of the first jaw 902 acts as the active electrode for the RF EM energy, and the inner electrode 914 of the second jaw 904 acts as the second return electrode. Therefore, the RF cutting fields can be substantially symmetrical about the inner electrode 906 of the first jaw 902, which enables uniform RF cutting of the tissue.

[0104] When microwave EM energy is delivered to the electrodes in jaws 902 and 904 via a coaxial cable, a microwave field can be established around the jaws. Specifically, the electrodes together can serve 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 transmitter for emitting microwave energy. The outer electrode 908 and inner electrode 914 of the second jaw 904 act as grounding conductors for shaping the emitted microwave energy. This microwave field emitting structure results in the emission of a substantially symmetrical microwave field around the jaws.

[0105] Figure 9A schematic cross-sectional view of a portion of the instrument tip 1000 of an electrosurgical resection tool, having a first jaw 1002 and a second jaw 1004. The first and second jaws are movable relative to each other (e.g., pivotable), and each jaw includes a corresponding 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. Figure 2 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 outer conductor of the coaxial cable of the electrosurgical resection tool, while the outer electrode 1008 is electrically connected to the inner conductor of the coaxial cable. The second jaw 1004 includes a single inner electrode 1014, which is also electrically connected to the inner conductor of the coaxial cable.

[0106] To prevent electrical connection between the inner electrode 1006 of the first jaw 1002 and the inner electrode 1014 of the second jaw 1004, the first jaw 1002 includes a second dielectric material element 1012 positioned on the inner surface of the inner electrode 1006. The second dielectric material element 1012 may be made of the same dielectric material as the first dielectric material element 1010 and may be, for example, in the form of a planar dielectric element mounted on the first jaw 1002. Alternatively, a sheet of dielectric material may be provided on the second jaw 1004 such that it covers the inner surface of the inner electrode 1014 and is located between the inner electrodes 1006 and 1012. Covering each of the inner electrodes with dielectric material may be preferred to ensure that the risk of electrical breakdown between the two inner electrodes is minimized. This also improves the symmetry between the jaws, which in turn improves the symmetry of the RF and microwave energy emitted from the instrument tip.

[0107] use Figure 9 The electrode configuration shown generates two RF cutting fields when RF EM energy is transmitted to the electrodes via a coaxial cable. A first RF cutting field can be established between the inner electrode 1006 and the outer electrode 1008 of the first jaw 1002, where the outer electrode 1008 acts as a first active electrode for the RF EM energy, and the inner electrode 1006 acts as a return electrode. A second RF cutting field can be established between the inner electrode 1006 of the first jaw 1002 and the inner electrode 1014 of the second jaw 1004, where the inner electrode 1014 of the second jaw 1004 acts as a second active electrode for the RF EM energy, and the inner electrode 1006 of the first jaw 1002 acts as a return electrode. Therefore, the RF cutting fields can be substantially symmetrical about the inner electrode 1006 of the first jaw 1002, which enables uniform RF cutting of the tissue.

[0108] When microwave EM energy is delivered to the electrodes in jaws 1002 and 1004 via a coaxial cable, a microwave field can be established around the jaws. Specifically, the electrodes together can serve 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 serve as microwave transmitters for emitting microwave energy. The inner electrode 1006 of the first jaw 1002 serves as a grounding conductor for shaping the emitted microwave energy. This microwave field emitting structure results in the emission of a substantially symmetrical microwave field around the jaws.

[0109] Features disclosed in the foregoing description or in the appended claims or drawings, expressed in a specific form or in view of the means for performing the disclosed functions or the methods or processes for obtaining the disclosed results, may, where appropriate, be used alone or in any combination of such features to implement the invention in various forms.

[0110] While the invention has been described in conjunction with the exemplary embodiments described above, many equivalent modifications and variations will be apparent to those skilled in the art upon this disclosure. Therefore, the exemplary embodiments of the invention set forth above are to be considered illustrative rather than restrictive. Various changes may be made to the described embodiments without departing from the spirit and scope of the invention.

[0111] To avoid any doubt, any theoretical explanations provided herein are intended to enhance the reader's understanding. The inventor does not wish to be bound by any of these theoretical explanations.

[0112] Any section headings used in this article are for organizational purposes only and should not be construed as limiting the subject matter described.

[0113] Throughout the entire specification, including the appended claims, unless the context otherwise requires, the words “comprising” and “including” and variations (such as “comprising,” “covering,” and “including”) shall be understood to imply the inclusion of the stated integer or step or group of integers or steps but not to exclude any other integer or step or group of integers or steps.

[0114] It must be noted that, unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “the” used in this specification and the appended claims include plural references. A range 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 one particular value and / or to another particular value. Similarly, when a value is expressed as an approximation using the antecedent “about,” it will be understood that the particular value forms another embodiment. The term “about” in relation to numerical values ​​is optional and means, for example, + / - 10%.

Claims

1. An electrosurgical resection tool comprising: an energy delivery structure for carrying radio frequency electromagnetic energy and microwave electromagnetic energy, the energy delivery structure comprising a coaxial transmission line having an inner conductor separated from an outer conductor by a dielectric material; an instrument tip mounted at a distal end of the energy delivery structure, wherein the instrument tip comprises a first jaw and a second jaw; wherein the second jaw is movable relative to the first jaw between a closed position in which the first and second jaws lie alongside each other and an open position in which the second jaw is spaced apart from the first jaw by a gap for receiving biological tissue; wherein the first jaw comprises a first pair of electrodes electrically isolated from each other, the first pair of electrodes comprising an inner electrode and an outer electrode; wherein the second jaw comprises a single electrode; wherein the first pair of electrodes are coupled to the energy delivery structure such that the first pair of electrodes are operable as active and return electrodes for delivering radio frequency electromagnetic energy carried by the energy delivery structure; wherein the single electrode is coupled to the energy delivery structure for delivering radio frequency electromagnetic energy carried by the energy delivery structure such that the single electrode is operable as an active electrode when the inner electrode of the first jaw is operable as a return electrode or the single electrode is operable as a return electrode when the inner electrode of the first jaw is operable as an active electrode; and wherein the instrument tip is operable as a microwave field launch structure for launching microwave electromagnetic energy carried by the energy delivery structure.

2. The electrosurgical resection tool of claim 1, wherein: 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, the inner electrode being arranged on the inner surface of the first planar dielectric element and the outer electrode being arranged on the outer surface of the first planar dielectric element; and the second jaw comprises a second planar dielectric element having an inner surface facing the first jaw and an outer surface facing away from the first jaw, and the single electrode comprises: an inner electrode arranged on the inner surface of the second planar dielectric element, or an outer electrode arranged on the outer surface of the second planar dielectric element.

3. The electrosurgical resection tool of claim 2, wherein: the inner electrode of the first jaw comprises a first conductive layer formed on the inner surface of the first planar dielectric element; and the single electrode of the second jaw comprises a second conductive layer formed on the inner surface of the second planar dielectric element.

4. The electrosurgical resection tool of claim 3, wherein: the first jaw comprises a third planar dielectric element having an inner surface facing the second jaw, the third planar dielectric element being arranged on an inner surface of the inner electrode of the first jaw. ​ ​ 5. The electrosurgical resection tool of claim 3 or claim 4, wherein: the second jaw includes a fourth planar dielectric element having an inner surface facing the first jaw, the fourth planar dielectric element being disposed on an inner surface of the single electrode of the second jaw.

6. The electrosurgical resection tool of claim 2, wherein: the first jaw further includes a first electrically conductive housing attached to the outer surface of the first planar dielectric element and arranged to form at least a portion of the outer electrode of the first pair of electrodes.

7. The electrosurgical resection tool of claim 2, wherein: the second jaw further includes a second electrically conductive housing attached to the outer surface of the second planar dielectric element and arranged to form at least a portion of the single electrode of the second jaw.

8. The electrosurgical resection tool of claim 2, wherein the outer electrode of the first jaw and the single electrode of the second jaw are electrically coupled to one another.

9. The electrosurgical resection tool of claim 8, wherein the instrument tip further includes a base structure connecting the outer electrode of the first jaw and the single electrode of the second jaw to the distal end of the energy delivery structure.

10. The electrosurgical resection tool of claim 9, wherein the base structure includes a first base portion rigidly connecting the outer electrode of the first jaw to the distal end of the energy delivery structure and a second base portion to which the second jaw is pivotably connected such that the second jaw can pivot relative to the second base portion.

11. The electrosurgical resection tool of claim 9, wherein the base structure includes an electrically conductive material electrically connecting the outer electrode of the first jaw and / or the single electrode of the second jaw to a first one of the inner conductor and the outer conductor at a distal end of the coaxial transmission line.

12. The electrosurgical resection tool of claim 11, wherein the base structure defines a cavity in which the inner electrode of the first jaw is electrically connected to a second one of the inner conductor and the outer conductor at the distal end of the coaxial transmission line.

13. The electrosurgical resection tool of claim 12, wherein the cavity contains a dielectric material.

14. The electrosurgical resection tool of claim 12, wherein the base structure includes an opening formed in a sidewall of the base structure for injecting a dielectric material into the cavity.

15. The electrosurgical resection tool of claim 2, wherein the outer electrode of the first jaw and the single electrode of the second jaw are both electrically connected to a first one of the inner conductor and the outer conductor, and the inner electrode of the first jaw is electrically connected to a second one of the inner conductor and the outer conductor.

16. The electrosurgical resection tool of claim 2, wherein the first pair of electrodes and the single electrode are operable together as a microwave field launch structure for launching microwave electromagnetic energy carried by the energy-carrying structure.

17. An electrosurgical apparatus comprising: an electrosurgical generator for supplying radio frequency electromagnetic energy and microwave electromagnetic energy; a surgical scoping device having an instrument string for insertion into a patient, the instrument string having an instrument channel extending therethrough; and an electrosurgical resection tool according to any preceding claim inserted through the instrument channel of the surgical scoping device.

18. The electrosurgical apparatus of claim 17, wherein the electrosurgical generator is operable to supply the radio frequency electromagnetic energy and the microwave electromagnetic energy to the electrosurgical resection tool via the surgical scoping device.

19. The electrosurgical apparatus of claim 18, wherein the electrosurgical generator is operable to supply the radio frequency electromagnetic energy and the microwave electromagnetic energy to the electrosurgical resection tool via the surgical scoping device and the instrument string.

20. The electrosurgical apparatus of claim 19, wherein the electrosurgical generator is operable to supply the radio frequency electromagnetic energy and the microwave electromagnetic energy to the electrosurgical resection tool via the surgical scoping device, the instrument string, and the instrument channel.

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