Electrosurgical instrument and electrosurgical device

Abstract

Various embodiments provide an electrosurgical instrument for sealing and / or cutting tissue. The instrument comprises a transmission line used for transmitting microwave electromagnetic energy and / or radio frequency electromagnetic energy; a pair of jaws including a first jaw and a second jaw mounted at a distal end of the transmission line, where the first jaw and the second jaw are movable between an open position in which tissue can be inserted into a gap between the first jaw and the second jaw, and a closed position in which tissue can be inserted into the gap between the first jaw and the second jaw. In the closed position, the first jaw and the second jaw engage together to clamp tissue therebetween. The pair of jaws includes a first pair of electrodes including a first electrode and a second electrode, and a second pair of electrodes including a third electrode and a fourth electrode. The first pair of electrodes is configured to receive the microwave energy transmitted by the transmission line and transmit the received microwave energy to tissue located between the first clamping jaw and the second clamping jaw. The first electrode and the second electrode are spaced apart from each other such that a microwave sealing region is defined on inner surfaces of the pair of jaws between the first electrode and the second electrode. The second pair of electrodes is configured to receive radio frequency energy transmitted by the transmission line and work as an acting electrode and a returning electrode so as to transmit the radio frequency energy to tissue located between the first clamping jaw and the second clamping jaw. A radio frequency cutting area is defined on the inner surfaces of the pair of clamping jaws between the second electrode and the third electrode. The first pair of electrodes and the second pair of electrodes are arranged such that when the first jaw and the second jaw are in the closed position, the microwave sealing region is spaced apart from the radio frequency cutting region in a transverse direction orthogonal to a longitudinal axis of the pair of jaws.

Description

TECHNICAL FIELD

[0001] The present invention relates to an electrosurgical instrument for sealing and / or cutting tissue using the delivery of electromagnetic energy to the tissue. The instrument comprises a pair of jaws between which tissue can be clamped, the jaws comprising electrodes for delivering energy to the tissue. BACKGROUND

[0002] Electrosurgical instruments for delivering thermal energy to grasped biological tissue are known. For example, it is known to deliver microwave energy from a bipolar electrode arrangement in the jaws of a surgical forceps. The microwave energy can be used to seal blood vessels by thermal denaturation of the extracellular matrix proteins, such as collagen, within the vessel wall. The thermal energy can also cauterise the grasped tissue and promote coagulation.

[0003] It is also known to use radio frequency (RF) energy to cut tissue. Tissue cutting using RF energy operates on the principle that when an electric current passes through a tissue matrix, with the assistance of the ionic contents of the cells, the impedance to the flow of electrons throughout the tissue generates heat. When a pure sinusoidal wave is applied to the tissue matrix, sufficient heat is generated within the cells to vaporise the water content of the tissue. As a result, there is a large rise in the internal pressure of the cell beyond the control of the cell membrane, causing the cell to rupture. When this happens on a large scale, it is foreseen that the tissue is already cut.

[0004] Such electrosurgical instruments are typically applied to the end of minimally invasive laparoscopic surgical tools, but can equally be used in other clinical surgical fields such as gynaecological, endourological, gastrointestinal, ENT or endoscopic surgery. Depending on the environment of use, these devices can have different physical hooks, sizes, scales and complexities.

[0005] For example, a gastrointestinal instrument can nominally have a 3mm diameter, mounted at the end of a very long flexible shaft. In contrast, a laparoscopic instrument can be used at the end of a rigid or steerable steel shaft of industry standard nominal diameter 5mm or 10mm.

[0006] US 6,585,735 describes an endoscopic bipolar surgical forceps in which the jaws of the forceps are arranged to conduct bipolar energy through tissue held between them.

[0007] EP 2 233 098 describes a microwave surgical forceps for sealing tissue in which the sealing surfaces of the jaws comprise one or more microwave antennae for radiating microwave energy into tissue grasped between the jaws of the forceps.

[0008] WO 2015 / 097472 describes an electrosurgical forceps in which one or more pairs of non-resonant unbalanced lossy transmission line structures are arranged on the inner surfaces of a pair of jaws. SUMMARY

[0009] Most generally, the present application provides various types of electrosurgical instruments that are capable of fine tissue cutting and dissection of tissue.

[0010] In addition, the electrosurgical instruments can provide additional functionality, such as the use of a limited microwave field to seal biological tissue such as (blood) vessels, which can result in a well-defined sealing location with a lower thermal margin. In the presence of these additional functionalities, less device exchange during a procedure can be required.

[0011] The electrosurgical instruments disclosed herein can be used in any type of surgical procedure, but are expected to be particularly useful in non-invasive or minimally invasive procedures. For example, the electrosurgical instruments can be configured to be introduced to a treatment site through an instrument channel of a surgical scoping device such as a laparoscope or endoscope.

[0012] According to a first aspect of the present application, there is provided an electrosurgical instrument for sealing and / or cutting tissue, comprising: a transmission line for delivering microwave electromagnetic energy and / or radiofrequency electromagnetic energy; a pair of jaws comprising a first jaw and a second jaw mounted at a distal end of the transmission line, wherein the first jaw and the second jaw are movable between an open position in which tissue can be inserted into a gap between the first jaw and the second jaw, and a closed position in which the first jaw and the second jaw come together to clamp tissue therebetween; wherein the pair of jaws comprises: a first pair of electrodes comprising a first electrode and a second electrode; and a second pair of electrodes comprising a third electrode and a fourth electrode; wherein the first pair of electrodes is configured to receive microwave energy delivered by the transmission line and emit the received microwave energy into tissue located between the first jaw and the second jaw such that a microwave sealing region is defined on an inner surface of the pair of jaws between the first electrode and the second electrode; wherein the second pair of electrodes is configured to receive radiofrequency energy delivered by the transmission line and operate as an active electrode and a return electrode to deliver the radiofrequency energy to tissue located between the first jaw and the second jaw such that a radiofrequency cutting region is defined on an inner surface of the pair of jaws between the second electrode and the third electrode; and wherein the first pair of electrodes and the second pair of electrodes are arranged such that, when the first jaw and the second jaw are in the closed position, the microwave sealing region is spaced apart from the radiofrequency cutting region in a transverse direction orthogonal to a longitudinal axis of the pair of jaws.

[0013] The electrosurgical instrument of the present invention can be used to perform vessel sealing and vessel dissection. Vessel sealing can be performed by clamping a vessel between the pair of jaws to compress the vessel wall, and then applying microwave energy to the vessel through the first pair of electrodes. The application of microwave energy to the vessel can cause dielectric heating of the clamped tissue, which can cause tissue cell rupture / denaturation and form a collagen-based mixture in the vessel wall, effectively gluing the vessel wall together. Over time, post-operative cell repair and regeneration occurs to further strengthen the seal. Vessel dissection is the process of severing a continuous biological vessel to divide it into two pieces. It is typically performed after the vessel has been initially sealed, for example by microwave energy delivery as described above. With the electrosurgical instrument of the present invention, vessel dissection can be performed by delivering radiofrequency (RF) energy to the tissue clamped between the jaws through the second pair of electrodes. The delivery of RF energy to the tissue causes the vessel to be cut (excised) along the second pair of electrodes.

[0014] The inventors have found that the process of sealing tissue using microwave energy results in the tissue being charred and dried. However, if the tissue becomes too dry, it can become difficult to effectively cut the tissue using radiofrequency energy, as the tissue can not be conductive enough. Therefore, it can be difficult to cut tissue within a region that has been sealed using microwave energy. The electrosurgical instrument of the present invention solves this problem by providing dedicated pairs of electrodes for performing microwave sealing and RF cutting, with a lateral spacing provided between the two pairs of electrodes. In this way, RF cutting can be performed on a portion of tissue that is laterally spaced apart (e.g. adjacent) to a portion of tissue that has been sealed by microwave energy using the first pair of electrodes. The lateral spacing between the RF electrodes and the microwave electrodes can serve to ensure that the portion of tissue being RF cut is not completely dried, such that effective RF cutting can be performed. Furthermore, the lateral spacing between the RF electrodes and the microwave electrodes can avoid interference between the RF field and the microwave field, which can facilitate simultaneous delivery of microwave and RF energy.

[0015] The electrosurgical instrument of the present invention can therefore enable effective sealing and cutting of a vessel. Specifically, a vessel can be clamped between the jaws and sealed using microwave energy delivered through the first pair of electrodes. The vessel is then left clamped in the jaws and cut at a location adjacent to the seal using RF energy delivered through the second pair of electrodes. The provision of microwave sealing and radiofrequency cutting regions on the inner surface of the jaws enables a single instrument to be used to perform sealing and excision of tissue, without the need to move or reposition the instrument between the sealing procedure and the cutting procedure.

[0016] The transmission line can comprise any suitable energy delivery structure for delivering microwave electromagnetic energy and RF electromagnetic energy to the pair of jaws.

[0017] Microwave electromagnetic energy and RF electromagnetic energy can be delivered along a common signal pathway. For example, the transmission line can comprise a coaxial cable that provides a common signal pathway for delivery of both microwave energy and radio frequency energy. In such an arrangement, the transmission line can comprise a first filter (e.g. an inductive filter) for blocking microwave energy from reaching the second pair of electrodes, and a second filter (e.g. a capacitive filter) for blocking RF energy from reaching the first pair of electrodes.

[0018] In an alternative arrangement, radio frequency energy and microwave energy are delivered along separate pathways. In other words, the transmission line can comprise separate pathways for delivery of RF and microwave energy, respectively. For example, the transmission line can comprise a coaxial cable for delivery of microwave electromagnetic energy, and two or more wires for delivery of RF electromagnetic energy. In this case, the first filter and the second filter can be provided at a proximal end of the transmission line, e.g. in a handle.

[0019] The electrosurgical instrument can further comprise an instrument shaft through which the transmission line extends. The instrument shaft can be sized to fit within an instrument channel of a surgical scoping device. The surgical scoping device can be a laparoscope or an endoscope. Surgical scoping devices are typically provided with an insertion tube, which is a rigid or flexible (e.g. steerable) catheter that is introduced into a patient’s body during invasive surgery. The insertion tube can comprise the instrument channel and an optical channel (e.g. for passing light to illuminate a treatment site at a distal end of the insertion tube and / or to capture images of the treatment site). The instrument channel can have a diameter suitable for receiving an invasive surgical tool. The diameter of the instrument channel can be equal to or less than 13 mm, preferably equal to or less than 10 mm and more preferably (especially for flexible insertion tubes) equal to or less than 5 mm.

[0020] The transmission line can be flexible to facilitate insertion into the instrument channel of the scoping device. Likewise, the instrument shaft can also be flexible. Furthermore, the transmission line can be arranged within an inner lumen of the shaft. The instrument shaft can cover and / or shield the transmission line. The transmission line can extend from a distal end to a proximal end of the electrosurgical instrument. In particular, the transmission line can electrically connect the first pair of electrodes and the second pair of electrodes to an electrosurgical generator arranged to generate microwave and / or RF energy.

[0021] The first jaw and / or the second jaw can be movable relative to the distal end of the transmission line. The first jaw and / or the second jaw can be attached to the distal end of the transmission line and / or a distal end of the instrument shaft by a joint (or hinge). The joint can comprise a pivot axis about which the first jaw and / or the second jaw can rotate. The first jaw and / or the second jaw can be actuated by one or more actuation rods or control wires connected to the first jaw and / or the second jaw, respectively. The one or more actuation rods or control wires can extend within the instrument shaft to a proximal end of the electrosurgical instrument. The one or more actuation rods can be connected to a handle with which the first jaw and / or the second jaw can be actuated, e.g. opened and / or closed. The electrosurgical instrument can comprise an actuation mechanism that converts a reciprocating motion of the actuation rod or control wire into a rotational motion of the first jaw and / or the second jaw.

[0022] For example, both jaws can be movable, e.g. rotatable about a (common) pivot axis. In another embodiment, one of the jaws is fixed to the shaft, while the other jaw is movable relative to the one jaw.

[0023] In the open position, the first jaw and the second jaw are (maximally) spaced apart such that a free space (gap) exists between the inner surfaces of the two jaws. In this way, tissue can be inserted between the jaws in the open position. Typically, the first jaw and the second jaw are moved towards tissue such that in the open position of the first jaw and the second jaw, tissue is pushed into the space between the inner surfaces of the jaws.

[0024] By moving the first jaw and / or the second jaw from the open position to the closed position, tissue between the first surface and the second surface can be grasped and / or pinched between the first jaw and the second jaw. In this way, in the closed position, tissue can be fixed between the inner surfaces of the first jaw and the second jaw.

[0025] The inner surface of the first jaw and the inner surface of the second jaw correspond to the faces (surfaces) of the first jaw and the second jaw, respectively, that face each other in the open and / or closed position. In the closed position, the inner surfaces of the two jaws can extend parallel to each other. In the closed position, the inner surfaces of the two jaws can be in contact with each other.

[0026] The pair of jaws can be pivotable relative to each other about a hinge axis that extends transverse to a longitudinal axis of the transmission line (which can be the same as the longitudinal axis of the pair of jaws). In one example, the pair of jaws comprises a stationary jaw that is fixed relative to the instrument shaft and a movable jaw that is pivotably mounted relative to the stationary jaw to open and close the gap between the opposing inner surfaces. In another example, for example in a symmetrical forceps-type or scissors-type arrangement, the jaws are each arranged to pivot relative to the instrument shaft.

[0027] In another example, the pair of jaws are arranged to move relative to each other in a manner that maintains the inner surfaces of the jaws in an aligned (e.g. parallel) orientation. Such a configuration can be desirable to maintain a uniform pressure on the grasped tissue along the length of the jaws. One example of such a closure mechanism is disclosed in WO 2015 / 097472.

[0028] The first jaw and / or the second jaw can have a Maryland configuration. This can comprise the first jaw and the second jaw not being straight but being curved / curvilinear, for example forming an arc or an S-shape in side view.

[0029] The first pair of electrodes is configured to receive microwave energy from the transmission line and emit (radiate) the received microwave energy. For example, where the transmission line comprises a coaxial cable, the first electrode can be connected to the inner conductor of the coaxial cable and the second electrode can be connected to the outer conductor of the coaxial cable. The first pair of electrodes can form a dipole antenna for radiating microwave energy into the target tissue.

[0030] The first pair of electrodes can be located in the first jaw or the second jaw. In other words, both the first electrode and the second electrode can be located on the same jaw.

[0031] The first pair of electrodes is arranged such that microwave energy is emitted from the inner surfaces of the pair of jaws, such that microwave energy is emitted into tissue in contact with the inner surfaces. In this way, a microwave sealing region is defined on the inner surfaces of the jaws between the first electrode and the second electrode, such that tissue in contact with the microwave sealing region will receive microwave energy emitted by the first pair of electrodes, for example such that the tissue can be sealed. Depending on which jaw the first pair of electrodes is located on, the inner surface on which the microwave sealing region is defined can be on the first jaw or the second jaw.

[0032] The first pair of electrodes can be exposed at the inner surface of one of the jaws. In this way, the microwave sealing region can correspond to the region of the inner surface that is located between the exposed portions of the first and second electrodes. Alternatively, the first pair of electrodes can be partially or fully covered. For example, the first pair of electrodes can be partially or fully covered by an electrically insulating material. In this case, the microwave sealing region can correspond to the region of the inner surface that is arranged between the first and second electrodes.

[0033] The second pair of electrodes is configured to receive RF energy from the transmission line and to deliver the RF energy to tissue located between the jaws. For example, the third electrode can be connected to the transmission line to act as a working electrode, and the fourth electrode can be connected to the transmission line to act as a return electrode for the RF energy (or vice versa).

[0034] The second pair of electrodes can be located in the first jaw or the second jaw. In other words, both the third electrode and the fourth electrode can be located on the same jaw.

[0035] The second pair of electrodes can be exposed on the inner surface of one of the jaws to enable delivery of RF energy to tissue in contact with the inner surface of the jaw. Consistent with the discussion above, delivery of RF energy to tissue by the second pair of electrodes can result in cutting of tissue along the second pair of electrodes. Thus, an RF cutting region is defined on the inner surface of the jaw between the third and fourth electrodes. Depending on which jaw the second pair of electrodes is located on, the inner surface on which the RF cutting region is defined can be on the first jaw or the second jaw.

[0036] The first pair of electrodes and the second pair of electrodes are separate (different) from each other, i.e. there is no sharing of electrodes between the first pair of electrodes and the second pair of electrodes. This serves to avoid any overlap between the microwave sealing region and the RF cutting region.

[0037] The first pair of electrodes and the second pair of electrodes are arranged in the jaw such that they are spaced apart from each other in the lateral direction. Thus, when the jaw is in the closed position, the second pair of electrodes can be offset from the first pair of electrodes in the lateral direction. As a result, the microwave sealing region is spaced (offset) from the RF cutting region in the lateral direction. In other words, the first pair of electrodes is arranged such that the microwave sealing region (between the first electrode and the second electrode) and the RF cutting region (between the third electrode and the fourth electrode) do not overlap (or cover) each other when the jaw is in the closed position. Consistent with the discussion above, the lateral offset between the microwave sealing region and the RF cutting region can ensure that tissue sealing and cutting are performed at adjacent locations on a piece of tissue clamped between the jaws, thereby facilitating RF cutting of the tissue after microwave sealing.

[0038] Here, the longitudinal axis of the pair of jaws can correspond to a central axis of the pair of jaws, the central axis extending from a proximal end of the pair of jaws (i.e., the end of the jaws positioned towards the distal end of the transmission line) towards the distal end of the pair of jaws. The longitudinal axis of the pair of jaws can correspond to a longitudinal axis of the transmission line. The lateral direction is perpendicular to the longitudinal axis, e.g., the lateral direction corresponds to a width direction of the jaws. The lateral direction can be substantially parallel to an inner surface of one or both of the jaws.

[0039] In some embodiments, the first pair of electrodes and the second pair of electrodes can be on the same jaw, e.g., on the first jaw. In this case, the first pair of electrodes can be spaced apart from the second pair of electrodes in the lateral direction by a dielectric material in the first jaw. Thus, both the microwave sealing region and the RF cutting region can be located on the inner surface of the first jaw, with the microwave sealing region and the RF cutting region being spatially separated from each other (i.e., they do not overlap).

[0040] Alternatively, the first pair of electrodes and the second pair of electrodes can be on different jaws, e.g., the first pair of electrodes can be on the first jaw and the second pair of electrodes can be on the second jaw. Thus, the microwave sealing region can be on the inner surface of the first jaw and the RF cutting region can be on the inner surface of the second jaw. As mentioned above, the microwave sealing region and the RF cutting region are then arranged such that they do not overlap each other when the jaws are in the closed position. In other words, a projection of the RF cutting region on the first jaw along a direction orthogonal to the inner surface of the first jaw does not overlap the microwave sealing region when the jaws are in the closed position.

[0041] The first pair of electrodes and the second pair of electrodes can extend along a longitudinal direction of the jaw, e.g. along a direction substantially parallel to the longitudinal axis. Thus, the microwave sealing region can comprise an elongated region on the inner surface of the jaw, e.g. to form a correspondingly shaped tissue seal. Likewise, the RF cutting region can comprise an elongated region on the inner surface of the jaw, e.g. to form a correspondingly shaped cut in the tissue.

[0042] The RF cutting region can be substantially centered with respect to the longitudinal axis. In other words, the third electrode and the fourth electrode can be substantially evenly spaced around the longitudinal axis in the transverse direction. In this way, the RF cutting region can be centered with respect to the width of the pair of jaws. This can result in the RF cut being directed towards the middle of the jaw, which can facilitate accurate cutting of the tissue.

[0043] The first pair of electrodes can be shaped to define a first microwave sealing region and a second microwave sealing region, and the first microwave sealing region and the second microwave sealing region can be arranged on either side of the second pair of electrodes when the first jaw and the second jaw are in the closed position. In other words, the microwave sealing region discussed above can comprise a first microwave sealing region and a second microwave sealing region. In this way, when microwave energy is delivered to the first pair of electrodes, tissue seals can be formed at the microwave sealing regions on either side of the second pair of electrodes. RF cutting can then be performed with the second pair of electrodes at a location between the two seals. This arrangement can facilitate vessel sealing and cutting, as sealing the vessel on either side of the RF cutting region can serve to ensure that the two ends of the vessel are sealed when the vessel is cut in half. The first microwave sealing region and the second microwave sealing region can be positioned towards the outer sides of the jaw, while the RF cutting region can be arranged towards the middle of the jaw.

[0044] The first microwave sealing region can be arranged such that it is spaced (offset) from the RF cutting region in the transverse direction on a first side, while the second microwave sealing region is spaced (offset) from the RF cutting region in the transverse direction on a second side. In this way, the RF cutting region can be located between the first microwave sealing region and the second microwave sealing region when the jaw is in the closed position.

[0045] The first microwave sealing region can be defined between a first portion of the first electrode and the second electrode that is laterally spaced from the second pair of electrodes on a first side, and the second microwave sealing region can be defined between a second portion of the first electrode and the second electrode that is laterally spaced from the second pair of electrodes on a second side.

[0046] In the case where both the first pair of electrodes and the second pair of electrodes are located on the first jaw, an RF cut region can be located on the inner surface of the first jaw between the first microwave seal region and the second microwave seal region. The RF cut region can be separated from the first and second seal regions by a dielectric material in the first jaw.

[0047] The first microwave seal region and the second microwave seal region can be substantially evenly spaced around the RF cut region in the lateral direction (when the jaws are in the closed position). In other words, a first distance between the RF cut region and the first microwave seal region and a second distance between the RF cut region and the second microwave seal region can be equal. In this way, microwave seals can be formed evenly (e.g. symmetrically) on either side of the RF cut region. This can serve to ensure that there is sufficient spacing between the RF cut region and the microwave seal regions to facilitate RF cutting, as well as accurate sealing and cutting of tissue. The first microwave seal region and the second microwave seal region can likewise be substantially evenly spaced around the longitudinal axis in the lateral direction when the RF cut region is substantially centred with respect to the longitudinal axis.

[0048] The first electrode can comprise a first side portion and a second side portion spaced by a first gap in the lateral direction, and wherein the first side portion and the second side portion of the first electrode are located on either side of the second pair of electrodes when the first jaw and the second jaw are in the closed position. The first portion of the first electrode can thus serve to define the first microwave seal region, while the second portion of the first electrode can serve to define the second microwave seal region. The first side portion and the second side portion of the first electrode can be electrically connected together, for example they can both be connected to the inner conductor of the coaxial cable. The width of the first gap can be greater than the width of the RF cut region (in the lateral direction). This can ensure that the first microwave seal region and the second microwave seal region are laterally spaced from the RF cut region.

[0049] In the case where the first microwave seal region and the second microwave seal region are substantially evenly spaced around the RF cut region in the lateral direction, the first side portion and the second side portion of the first electrode can be substantially evenly spaced around the longitudinal axis in the lateral direction.

[0050] In the case where the first pair of electrodes and the second pair of electrodes are in the first jaw, the first side portion and the second side portion of the first electrode can define a first channel therebetween, with the second pair of electrodes located in the first channel. In other words, the first side portion and the second side portion of the first electrode can define side walls of the first channel in which the second pair of electrodes is located. The second pair of electrodes can be isolated and spaced apart from the first side portion and the second side portion by a dielectric material in the first channel.

[0051] The first electrode can further comprise a first connecting portion connecting the first side portion and the second side portion of the first electrode across the first gap. In this way, the first connecting portion can provide a structural and electrical connection between the first side portion and the second side portion, which can improve the performance of the first electrode. The first connecting portion can extend along the length of the first side portion and the second side portion of the first electrode. Thus, for example, the length of the first electrode can have a U-shaped cross-section. The first connecting portion can define a bottom wall of the first channel mentioned above.

[0052] The second electrode can comprise a first side portion and a second side portion spaced apart by a second gap in the lateral direction, and wherein the first electrode is located within the second gap. In this way, a first microwave sealing region can be defined between the first side portion of the first electrode and the second electrode, and a second microwave sealing region can be defined between the second side portion of the first electrode and the second electrode. The first side portion and the second side portion of the second electrode can be electrically connected together, for example they can both be connected to the outer conductor of the coaxial cable. The second gap can be greater than the width of the first electrode, such that the first electrode (including its spaced apart first and second portions) can accommodate the second gap. Thus, the first electrode can be located between the side portions of the second electrode, while the second pair of electrodes can be located between the side portions of the first electrode. This arrangement can be used to provide local microwave sealing regions around the outside of the RF cutting region.

[0053] The first side portion and the second side portion of the second electrode can define a second channel therebetween, with the first electrode located in the second channel. In other words, the first side portion and the second side portion of the second electrode can define side walls of the second channel in which the first electrode is located. The first electrode can be isolated and spaced apart from the first side portion and the second side portion of the second electrode by a dielectric material in the second channel.

[0054] The second electrode can further comprise a second connecting portion connecting the first side portion and the second side portion of the second electrode across the second gap. In this way, the second connecting portion can provide a structural and electrical connection between the first side portion and the second side portion of the second electrode, which can improve the performance of the second electrode. The second connecting portion can extend along the length of the first side portion and the second side portion of the second electrode. Thus, for example, the length of the second electrode can have a U-shaped cross-section. The second connecting portion can define the bottom wall of the second channel mentioned above. In this way, the second electrode can partially surround the first electrode. This can serve to ensure that microwave energy is only emitted at the inner surface of the jaw, i.e. the second electrode can act as a shield preventing microwave energy from being emitted out of the inner surface of the jaw.

[0055] The second electrode can be formed by the electrically conductive outer housing of one of the jaws. For example, in the case that the first pair of electrodes is in the first jaw, the second electrode can be formed by the electrically conductive outer housing of the first jaw.

[0056] In the case that the first microwave sealing region and the second microwave sealing region are substantially uniformly spaced around the radio frequency cutting region in the transverse direction, the first side portion and the second side portion of the second electrode can be substantially uniformly spaced around the longitudinal axis in the transverse direction. In particular, the first and second sides of both the first and second electrodes can be substantially uniformly spaced around the RF cutting region to provide first and second microwave sealing regions that are uniformly spaced around the RF cutting region.

[0057] In the case that the first jaw comprises the first pair of electrodes and the second pair of electrodes, the first pair of electrodes can be spaced apart from the second pair of electrodes by a dielectric material in the first jaw. Thus, a dielectric material can be provided between the first pair of electrodes and the second pair of electrodes to isolate the two pairs of electrodes from one another. The dielectric material can comprise any suitable electrically insulating (isolating) material. A portion of the dielectric material can be exposed at the inner surface of the first jaw between the first pair of electrodes and the second pair of electrodes (e.g. between the first electrode and the second pair of electrodes). The first electrode and the second electrode can be separated by a dielectric material, which can be the same as or different from the dielectric material separating the first pair of electrodes and the second pair of electrodes. Likewise, the third electrode and the fourth electrode can be separated by a dielectric material, which can be the same as or different from the dielectric material separating the first pair of electrodes and the second pair of electrodes.

[0058] The second jaw can include a third pair of electrodes, including a fifth electrode and a sixth electrode. The third pair of electrodes can be configured to receive microwave energy delivered by the transmission line and emit the received microwave energy into tissue located between the first jaw and the second jaw, such that a microwave sealing region is defined on an inner surface of the second jaw between the fifth electrode and the sixth electrode. The third pair of electrodes can be arranged such that the microwave sealing region on the inner surface of the second jaw is spaced apart from the radio frequency cutting region in the transverse direction when the first jaw and the second jaw are in the closed position. In this manner, a microwave sealing region can be provided on the inner surface of the first jaw (between the first electrode and the second electrode) and on the inner surface of the second jaw (between the fifth electrode and the sixth electrode). Thus, when a piece of tissue is clamped between the jaws, microwave energy can be applied to both sides of the piece of tissue, which can facilitate sealing of the tissue across its entire thickness. Consistent with the discussion above, because the microwave sealing region on the second jaw is laterally offset from the RF cutting region, the portion of the tissue being RF cut can not be completely dried by the microwave sealing.

[0059] The third pair of electrodes can be connected to the transmission line in a similar manner as the first pair of electrodes discussed above, e.g., the fifth electrode can be connected to the inner conductor of the coaxial cable and the sixth electrode can be connected to the outer conductor of the coaxial cable (or vice versa).

[0060] The third pair of electrodes can be arranged such that the microwave sealing region on the inner surface of the second jaw covers (i.e., is aligned with) the microwave sealing region on the inner surface of the first jaw when the jaws are in the closed position. In this manner, the sealing regions on the first jaw and the second jaw can cooperate to seal a piece of tissue from opposite sides, which can enhance the quality of the seal.

[0061] The third pair of electrodes can have a structure that is a mirror image of the structure of the first pair of electrodes (e.g. when the jaws are in the closed position). In other words, the layout of the third pair of electrodes in the second jaw can be a mirror image of the first pair of electrodes in the first jaw. This can serve to ensure that the microwave seal performed on tissue clamped between the jaws is symmetrical, to provide a clear local seal. Accordingly, any features discussed above in relation to the first pair of electrodes apply equally to the third pair of electrodes. For example, the third pair of electrodes can be shaped to define a third microwave seal region and a fourth microwave seal region, which are arranged either side of the RF cut region when the jaws are in the closed position. The fifth electrode can have a first side portion and a second side portion, and optionally a connecting portion. Likewise, the sixth electrode can have a first side portion and a second side portion (with the fifth electrode located therebetween), and optionally a connecting portion. The sixth electrode can be formed from the electrically conductive outer housing of the second jaw.

[0062] The minimum lateral spacing between the microwave seal region and the RF cut region can be at least 0.1 mm. The inventors have found that such a spacing can be sufficient to ensure that tissue in contact with the RF cut region is not completely desiccated by microwave energy applied to the tissue at the microwave seal region when tissue is clamped between the jaws, such that RF cutting can be performed effectively using the second pair of electrodes.

[0063] Increasing the lateral spacing between the microwave seal region and the RF cut region can reduce desiccation of tissue in the RF cut region due to the application of microwave energy at the microwave seal region, thereby improving the quality of the RF cut. Accordingly, in some cases the minimum lateral spacing between the microwave seal region and the RF cut region can be at least 0.3 mm, or at least 0.4 mm, or at least 0.5 mm.

[0064] The minimum lateral spacing between the first electrode and the second electrode can be, for example, at least 0.1 mm. In some cases, the minimum lateral spacing between the first electrode and the second electrode in the lateral direction can be between 0.1 mm and 3 mm. The lateral spacing between the first electrode and the second electrode can correspond to the width of the microwave seal region.

[0065] The minimum lateral spacing between the third electrode and the fourth electrode can be, for example, at least 0.1 mm. In some cases, the minimum lateral spacing between the third electrode and the fourth electrode in the lateral direction can be between 0.1 mm and 3 mm. The lateral spacing between the third electrode and the fourth electrode can correspond to the width of the RF cut region.

[0066] The second pair of electrodes may protrude from the inner surface of the first jaw of the first and second jaws. In other words, the second pair of electrodes may include portions that extend from the inner surfaces of the jaws. In this way, when tissue is clamped between the jaws, the protruding second pair of electrodes can be pressed into the tissue, which can be used to enhance the quality of RF cutting performed using the second pair of electrodes. This can also improve the uniformity of the RF incision by ensuring that the tissue is in close contact with the second pair of electrodes along the length of the second pair of electrodes. When the second pair of electrodes is in the first (second) jaw, the electrodes may protrude from the inner surface of the first (second) jaw.

[0067] The second jaw of the first and second jaws may include a recess for accommodating the protruding portion of the second pair of electrodes when the first jaw and the second jaw are in the closed position. This may help to position the jaws closer to the closed position when tissue is located between the jaws. Additionally, when tissue is located between the jaws, a portion of the tissue may be securely held in the recess by the protruding second pair of electrodes, which may help to provide a well-defined localized incision along the tissue held in the recess. The recess may be formed in the inner surface of the jaws and shaped to accommodate the protruding portion of the second pair of electrodes. For example, the recess may be in the form of a channel or groove in the inner surface of the jaws. Where the second pair of electrodes is in the first jaw, the recess may be in the second jaw (or vice versa).

[0068] The ends of the third electrode and the fourth electrode can be exposed at the distal end of the first jaw of the first jaw and the second jaw. In this way, the ends of the third electrode and the fourth electrode exposed at the distal end can serve as active electrodes and return electrodes for RF cutting. This can allow fine cutting at the distal end of the electrosurgical instrument, for example, to cut a hole in tissue located in front of the instrument so that the instrument can be further advanced into and / or through the tissue, for example, as part of a tunneling procedure. In addition, the third electrode and the fourth electrode exposed at the distal end can be used to cut fine or small pieces of tissue clamped or grasped between the jaws. Thus, tissue can be "nibbled away". As an example, with the second pair of electrodes in the first jaw, the ends of the third electrode and the fourth electrode can be exposed at the distal end (e.g., the distal end face) of the first jaw.

[0069] The ends of the third and fourth electrodes may be exposed on a distal end surface (surface) of the jaw, wherein the distal end surface faces in a distal (forward) direction, i.e., away from the transmission line. In this manner, the exposed ends of the third and fourth electrodes may be used to deliver RF energy to tissue located in front of the jaw.

[0070] A second one of the first and second jaws can comprise an overhang arranged to cover the exposed end portions of the third and fourth electrodes when the first and second jaws are in the closed position. This can enable tissue to be clamped or grasped between the distal end of the jaw and the overhang. In this way, RF energy applied to the second pair of electrodes can be utilized to cut a small portion of tissue clamped between the distal end and the overhang of the jaw. This can enable fine cutting of tissue on a relatively small area at the distal end of the jaw, for example compared to a larger RF cutting area located on an inner surface of the jaw.

[0071] A slot can be defined between the third and fourth electrodes, and the instrument can further comprise a blade movable along the slot to cut tissue located between the first and second jaws. In this way, the instrument can enable mechanical cutting with a blade in addition to RF cutting. Since the slot is defined between the third and fourth electrodes, the blade can be movable along the RF cutting area. In this way, the blade can complement the RF cutting by facilitating the separation (cutting) of tissue along the RF cutting area. The blade can be electrically isolated from the third and fourth electrodes. Alternatively, the blade can be electrically connected to one of the third and fourth electrodes, for example such that the blade can act as an active electrode to deliver RF energy to tissue in the RF cutting area.

[0072] The electrosurgical instrument can comprise any suitable mechanism for moving the blade along the slot. For example, the instrument can comprise a control wire or actuation rod for actuating the blade. The control wire or actuation rod can extend within the instrument shaft and be connected to a handle.

[0073] The second pair of electrodes can be supported in one of the jaws by an isolating portion comprising a resiliently deformable material, such that the second pair of electrodes can be movable in the jaw upon application of pressure to the second pair of electrodes. The second pair of electrodes can be considered to float in the isolating portion. In other words, the second pair of electrodes can be individually attached to the jaw by the isolating portion. For example, there can be no structural portion supporting the second pair of electrodes in the jaw other than the isolating portion. As an example, the isolating portion can support the second pair of electrodes relative to a rigid outer housing of the jaw in which the second pair of electrodes is located. The rigid outer housing can for example correspond to the electrically conductive outer housing of the jaw mentioned above.

[0074] A flexible electrical connection, such as a flexible electrical wire, can provide an electrical connection between the second pair of electrodes and the transmission line. Thus, the pair of electrodes can be able to move relative to other components of the jaw. For example, where the first pair of electrodes and the second pair of electrodes are in the first jaw, the second pair of electrodes can be able to move relative to the first pair of electrodes. Movement of the second pair of electrodes is associated with deformation, such as compression or stretching, of the elastically deformable material in the isolation portion. For example, if pressure is applied to the second pair of electrodes (i.e., the third electrode and / or the fourth electrode) such that the second pair of electrodes is pressed into the isolation portion (e.g., when tissue is grasped between the first jaw and the second jaw), the isolation portion can be compressed and the second pair of electrodes can move away from the opposing jaw and / or relative to the first pair of electrodes.

[0075] The ability of the second pair of electrodes to move in response to compression can result in uniform pressure on the tissue along the RF cut region and avoid pinch points. This can be particularly relevant if the second pair of electrodes protrude from the inner surface of the jaw such that the pressure between the second pair of electrodes and the opposing jaw can be higher than other regions of the inner surface of the jaw. Additionally, compression of the isolation portion provides a force to further compress the tissue between the second pair of electrodes and the opposing jaw, which can be helpful for RF cutting.

[0076] The elastically deformable material can include any electrically insulating material that is elastically deformable in response to application of pressure to the second pair of electrodes. The elastically deformable material can have a higher flexibility (i.e., be more easily deformable) than the second pair of electrodes or the structure in which the second pair of electrodes is formed. The elastically deformable material can also have a higher flexibility than the rigid outer housing of the jaw.

[0077] Where the first pair of electrodes and the second pair of electrodes are in the first jaw, the isolation portion can correspond to the dielectric material mentioned above. In other words, the first pair of electrodes and the second pair of electrodes can be spaced apart by the isolation portion. The elastically deformable material can thus allow some relative motion between the second pair of electrodes and the first pair of electrodes. A portion of the elastically deformable material between the first pair of electrodes and the second pair of electrodes can define a portion of the inner surface of the first jaw.

[0078] In some cases, the first electrode can also be supported in the isolation portion. Thus, both the first electrode and the second pair of electrodes can be supported in the isolation portion.

[0079] The elastically deformable material can comprise silicone. Advantageously, silicone is a non-stick material, such that when silicone is used, tissue and other biological matter can not stick to the isolation portion. This can avoid tissue sticking to the inner surface of the jaw. Silicone is also a good thermal insulator, which can help to reduce the build-up of latent heat in the instrument during electrosurgical procedures.

[0080] The isolation portion can interlock with one or more features on the second pair of electrodes. This can be used to ensure that the second pair of electrodes remain fixed in the isolation portion. In this way, the second pair of electrodes can be securely held in the isolation portion even when the isolation portion is deformed under compression. Such interlocking features can be particularly beneficial in the case of silicone due to its non-stick properties.

[0081] Any suitable interlocking feature can be used which provides a mechanical connection (interlock) between the isolation portion (elastically deformable material) and the second pair of electrodes to hold the second pair of electrodes. As an example, the third and fourth electrodes can each comprise one or more through-holes into which the isolation portion protrudes, i.e. the one or more through-holes can be filled with the elastically deformable material.

[0082] In some embodiments, the second pair of electrodes can comprise electrically conductive tracks which are partially embedded in the elastically deformable material. In this way, the second pair of electrodes can be supported in the elastically deformable material. The electrically conductive tracks can be elongate elements of electrically conductive material which extend along the longitudinal direction of the jaw. The electrically conductive tracks can have a rigidity which is greater than the elastically deformable material. In this way, when pressure is applied to the second pair of electrodes, the elastically deformable material can deform preferentially to the electrically conductive tracks.

[0083] In other embodiments, the electrosurgical instrument can further comprise an electrode support made of electrically isolating material, wherein the third and fourth electrodes each comprise a respective strip of electrically conductive material on the support, and wherein the electrode support is partially embedded in the elastically deformable material. Thus, the second pair of electrodes can be provided on an electrode support which itself is supported in the elastically deformable material. The strips of electrically conductive material forming the third and fourth electrodes can be on a portion of the electrode support which protrudes from the elastically deformable material. The electrode support can be made of a material which has a rigidity which is greater than the elastically deformable material, such that when pressure is applied to the electrode support, the elastically deformable material can deform preferentially to the electrode support. As an example, the electrode support can be made of a ceramic material, such as alumina.

[0084] The electrode support can comprise a support base plate and support ribs arranged on the support base plate to form a T-shape in a cross-sectional view of the jaw, wherein the third and fourth electrodes each comprise a strip of electrically conductive material arranged on opposite sides of the support ribs.

[0085] According to a second aspect of the application, there is provided an electrosurgical apparatus for sealing and cutting tissue, comprising: a generator unit for generating radio frequency and / or microwave electromagnetic energy; and an electrosurgical instrument according to the first aspect of the application; wherein the transmission line is configured to deliver the microwave energy to the first pair of electrodes and the radio frequency energy to the second pair of electrodes. Any of the features described above in relation to the first aspect of the application can be shared with the second aspect of the application.

[0086] The generator unit can be configured to generate electromagnetic energy at a single fixed frequency or a plurality of single fixed frequencies. Alternatively or additionally, the generator unit can be tunable to generate electromagnetic energy at various frequencies, for example within a continuous range of frequencies between a minimum frequency and a maximum frequency. The generator unit can be connected to a power source which provides energy for generating radio frequency electromagnetic energy and / or microwave electromagnetic energy.

[0087] The generator unit is electrically and / or electronically (directly or indirectly) connected to the transmission line.

[0088] The generator unit can be configured to simultaneously generate microwave electromagnetic energy at a first frequency and radio frequency electromagnetic energy at a second frequency. This can enable simultaneous tissue sealing with microwave energy and RF cutting.

[0089] For example, the generator unit can comprise a generator configured to simultaneously generate electromagnetic energy at two different (fixed) frequencies. Alternatively, the generator unit can comprise a first generator for generating electromagnetic energy at a first frequency and a second generator for generating electromagnetic energy at a second frequency. The output of the first generator and the output of the second generator can be combined using a multiplexer.

[0090] The multiplexer can be a diplexer and can combine inputs from various sources into one output. For example, the multiplexer (or diplexer) is used to combine the outputs of the first and second generators into a single output which is connected or coupled to the transmission line.

[0091] In an alternative embodiment, a first coaxial cable is connected to the generator unit to receive the first frequency and a second coaxial cable is connected to the generator unit to receive the second frequency. Again, the generator unit can comprise a first generator for generating electromagnetic energy of the first frequency and a second generator for generating electromagnetic energy of the second frequency. The first coaxial cable is connected to the first generator and the second coaxial cable is connected to the second generator.

[0092] The generator unit can be configured to alternately generate microwave electromagnetic energy of the first frequency and RF electromagnetic energy of the second frequency. For example, the generator unit can comprise a first generator for generating electromagnetic energy of the first frequency and a second generator for generating electromagnetic energy of the second frequency. The output of the first generator and the output of the second generator can be combined using a multiplexer as described above.

[0093] The generator unit can be configured to switch between the generation of microwave energy and RF energy. This switching capability can be used to first seal tissue using microwave energy and then cut tissue using RF energy. Alternatively, the switching between the output of microwave energy and RF energy can be performed repeatedly and rapidly, thereby providing almost simultaneous cutting and sealing.

[0094] In this document, the terms "proximal" and "distal" refer to the end of the electrosurgical instrument, the jaws, the shaft and / or the coaxial transmission line that is further away and closer to the treatment site, respectively. Thus, in use, the proximal end is closer to the generator unit for providing RF and / or microwave energy, while the distal end is closer to the treatment site, i.e. the patient.

[0095] Unless the context dictates otherwise, the term "electrically conductive" is used herein to mean electrically conductive. The term "isolated" or "insulated" as used herein can mean electrically isolated or insulated.

[0096] The term "longitudinal" as used hereinafter refers to the direction along the axis of the (coaxial) transmission line of the instrument channel. In the context of the pair of jaws, the term "longitudinal" refers to the direction connecting the proximal end of the jaw to the distal end of the jaw. In case the jaw is curved, the longitudinal "axis" can be considered as a line extending from the proximal end to the distal end of the jaw and the line is centered with respect to the width of the jaw.

[0097] The term "transverse" refers to the direction perpendicular to the longitudinal direction. In the context of the jaw, the transverse direction can extend along the width direction of the jaw.

[0098] The term "inner" can mean closer to the center (e.g. axis) of the instrument channel in the radial direction. The term "outer" can mean further away from the center (axis) of the instrument channel in the radial direction.

[0099] The term "electrosurgery" relates to the use of instruments, devices or tools used during surgery and utilising radio frequency (RF) electromagnetic (EM) energy and / or microwave electromagnetic energy.

[0100] In this context, radio frequency electromagnetic energy can mean a steady, fixed frequency in the range of 10 kHz to 300 MHz, preferably in the range of 100 kHz to 5 MHz and more preferably in the range of 360 kHz to 440 kHz. Microwave electromagnetic energy can mean electromagnetic energy with a steady, fixed frequency in the range of 300 MHz to 100 GHz. The radio frequency electromagnetic energy should have a frequency high enough to prevent the energy from causing nerve stimulation. In use, the amplitude of the radio frequency electromagnetic energy and the duration of application of the energy can be selected to prevent the energy from causing tissue whitening or unwanted thermal margins or damage to tissue structures. Preferred point frequencies of the radio frequency electromagnetic energy include any one or more of: 100 kHz, 250 kHz, 400 kHz, 500 kHz, 1 MHz or 5 MHz. Preferred point frequencies of the microwave electromagnetic energy include 915 MHz, 2.45 GHz, 5.8 GHz, 14.5 GHz, 24 GHz. 2.45 GHz and / or 5.8 GHz can be preferred. BRIEF DESCRIPTION OF DRAWINGS

[0101] Embodiments of the application are described in detail below with reference to the attached drawing figures, wherein:

[0102] Figure 1 A schematic view of an embodiment of an electrosurgical device is shown;

[0103] Figure 2a A schematic perspective view of a pair of jaws of an electrosurgical instrument according to an embodiment of the application is shown;

[0104] Figure 2b A schematic partial cross-sectional view of a jaw of Figure 2a is shown;

[0105] Figure 2c A schematic cross-sectional view of a jaw of Figure 2a is shown;

[0106] Figure 2d A schematic perspective view of a portion of a first jaw of a jaw of Figure 2a is shown;

[0107] Figure 2e A schematic cross-sectional view of a pair of jaws of an electrosurgical instrument according to an embodiment of the application is shown;

[0108] Figure 3a A schematic perspective view of a pair of jaws of an electrosurgical instrument according to another embodiment of the application is shown; and

[0109] Figure 3b schematic partial cross-sectional view of a jaw of the Figure 3a DETAILED DESCRIPTION

[0110] The present invention relates to electrosurgical instruments and apparatus capable of delivering microwave energy to seal tissue (e.g. blood vessels) and / or cut tissue. The electrosurgical instruments and apparatus can be used in open surgery, but are particularly suitable for use in surgery where the treatment site is difficult to access. For example, the electrosurgical instruments of the present invention can be adapted to fit within the instrument channel of a surgical scoping device (i.e. laparoscope, endoscope, etc.). Figure 1 A schematic view of an electrosurgical apparatus 10 in which the electrosurgical instruments of the present invention are used is shown.

[0111] Figure 1 is a schematic view of an electrosurgical apparatus 10 that is an embodiment of the present invention. The electrosurgical apparatus 10 is arranged to treat biological tissue using radiofrequency (RF) and / or microwave electromagnetic (EM) energy delivered from an electrosurgical instrument 12. The electromagnetic energy emitted by the electrosurgical instrument 12 into a treatment zone can be used to coagulate, cut and / or ablate tissue in the treatment zone.

[0112] The electrosurgical apparatus 10 also comprises a generator unit 14 that is capable of controllably providing radiofrequency and / or microwave electromagnetic energy to the electrosurgical instrument 12. The generator unit 14 can comprise a first generator 16 and a second generator 17. Suitable generators for this purpose are described in WO 2012 / 076844, which is incorporated herein by reference. The generator unit 14 can be arranged to monitor a reflected signal received back from the electrosurgical instrument 12 in order to determine an appropriate power level for delivery. For example, the generator unit 14 can be arranged to calculate an impedance seen at the electrosurgical instrument 12 in order to determine an optimal delivery power level.

[0113] The electrosurgical apparatus 10 also comprises a surgical scoping device 18, such as a bronchoscope, endoscope, gastroscope, laparoscope, etc. The scoping device 18 can comprise a handpiece 20 and a flexible shaft 22. The handpiece 20 can comprise means for guiding the flexible shaft 22 through a body cavity. For example, the handpiece 20 can comprise means for moving a distal end of the flexible shaft 22 to change the direction of the distal end of the flexible shaft 22. This facilitates steering the flexible shaft 22 through the body cavity. The flexible shaft 22 can comprise a working channel through which an elongate structure can be moved and thus positioned at a treatment zone within the body cavity.

[0114] ​The first generator 16 and the second generator 17 are each configured to produce electromagnetic energy at a fixed frequency. However, the generator unit 14 is not limited to this configuration; the first generator 16 and / or the second generator 17 can be configured to produce AC electromagnetic energy in a continuous range between a minimum frequency and a maximum frequency. An interface (not shown in the figures) can be used to select the frequency of the electromagnetic energy to be produced by the first generator 16 and / or the second generator 17.

[0115] The generator unit 14 can comprise a combiner 26 configured to temporarily switch between outputting the output of the first generator 16 or the output of the second generator 17. The combiner 26 can also be configured to combine the output of the first generator 16 and the output of the second generator 17. In this case, the combiner 26 acts as a multiplexer or a diplexer.

[0116] The generator unit 14 is therefore able to produce and control the electrical power delivered to the electrosurgical instrument 12, for example through a transmission line 28 that extends from the generator unit 14 through the surgical scoping device 18 and the instrument channel to the distal tip of the instrument channel. The generator unit 14 can have a user interface for selecting and / or controlling the electrical power delivered to the electrosurgical instrument 12, for example controlling the first generator 16 and / or the second generator 17 and / or the combiner 26. The generator unit 14 can have a display for showing the selected energy delivery mode. In some examples, the generator unit 14 can allow the energy delivery mode to be selected based on the size of the blood vessel to be sealed. Alternatively or additionally, the energy delivery will be adjusted based on the tissue state.

[0117] The electrosurgical instrument 12 comprises a transmission line 28, an instrument shaft (not shown in the figures), a joint 32, a first jaw 34 and a second jaw 36. Examples of the first and second jaws 32, 34 will be discussed in more detail below. The transmission line 28 can comprise a coaxial cable that connects the generator unit 14 to the first jaw 34 and / or the second jaw 34 to transmit radiofrequency and / or microwave energy to the jaws, as discussed in more detail below.

[0118] Between the open position and the closed position, the first jaw 34 and the second jaw 36 are movable relative to each other. The first jaw 34 and the second jaw 36 are operably coupled to the joint 32 in a manner that enables the jaws to open and close, with the joint 32 being mounted at the distal end of the instrument shaft. The first jaw 34 and / or the second jaw 36 can be pivotally mounted relative to the joint 32. The joint 32 can be arranged to ensure that the jaws remain laterally aligned as they move together. In some embodiments, the pair of jaws 34, 36 can include a stationary jaw that is fixed relative to the instrument shaft or joint, while the other jaw is pivotable or rotatable. The joint 32 can include a pivot axle (not shown) that defines a pivot axis. The first jaw 34 and / or the second jaw 36 are pivotable about the pivot axis or pivot axle. For example, the pivot axle can be fixed to the joint 32, and the first jaw 34 and the second jaw 36 are rotatable about the pivot axle. Any other suitable mechanism that enables relative motion between the jaws can be used.

[0119] A control wire or actuation rod extending in the instrument shaft between the handle 20 and the joint 32 can be used to control the opening and closing of the jaws. The joint 32 can include a conversion mechanism that converts the longitudinal, reciprocating motion of the control wire or actuation rod into rotational motion of the first jaw 34 and / or the second jaw 36 to effect opening and closing of the jaws.

[0120] In use, the first jaw 34 and the second jaw 36 are intended for grasping biological tissue, in particular a blood vessel, therebetween. The first jaw 34 and the second jaw 36 are arranged to exert pressure on biological tissue between the opposing inner surfaces of the jaws 34, 36 and to deliver energy, preferably microwave and / or radiofrequency electromagnetic energy, from the transmission line 28 into the tissue.

[0121] Figure 2a 、 Figure 2b 、 Figure 2c and Figure 2d Fig. 1 illustrates a first example of a jaw 34, 36 according to an embodiment of the present application. Figure 2a Fig. 2 shows a perspective view of the jaw 34, 36, while Figure 2b Fig. 3 shows a partial cross-sectional view of the jaw 34, 36. Figure 2c A schematic cross-sectional view of the jaw 34, 36 is shown in Fig. 1. The first jaw 34 comprises a first inner surface 202 and the second jaw 36 comprises a second inner surface 204, which are the exposed surfaces of the jaws that face each other. By closing the jaws, the first inner surface 202 and the second inner surface 204 can be brought into contact with each other. In this way, the first inner surface 202 and the second inner surface 204 can be regarded as pressure pads or pressure zones that can exert pressure on tissue located between the first jaw 34 and the second jaw 36.

[0122] The first jaw 34 (shown in the figures as the lower jaw) includes a first pair of electrodes for delivering microwave energy received from the transmission line 28, and a second pair of electrodes for delivering RF energy received from the transmission line 28. The first pair of electrodes includes a first electrode 206 and a second electrode 208, while the second pair of electrodes includes a third electrode 210 and a fourth electrode 212. The first pair of electrodes is connected to the transmission line 28 to receive microwave energy from the generator unit 14 delivered by the transmission line 28, while the second pair of electrodes is connected to the transmission line 28 to receive RF energy from the generator unit 14 delivered by the transmission line 28. In some embodiments, the transmission line 28 can include a first filter (e.g., an inductive filter) for blocking microwave energy from reaching the second pair of electrodes, and a second filter (e.g., a capacitive filter) for blocking RF energy from reaching the first pair of electrodes.

[0123] The third electrode 210 and the fourth electrode 212 are in the form of a pair of electrically conductive tracks that are uniformly spaced about a longitudinal axis 214 of the jaw and extend parallel to the longitudinal axis 214. The longitudinal axis 214 of the jaw extends in a direction that is orthogonal to the plane of the cross-sectional view of Figure 2c and extends from a proximal end of the jaw 34, 36 toward a distal end of the jaw 34, 36. The third electrode 210 and the fourth electrode 212 are substantially uniformly spaced about the longitudinal axis such that the second pair of electrodes is centered with respect to a width of the first jaw 34. An RF cutting region 216 is defined on the first inner surface 202 between the third electrode 210 and the fourth electrode 212. In particular, when RF energy is delivered to the second pair of electrodes through the transmission line 28, tissue in contact with the RF cutting region 216 on the first jaw 34 can be cut.

[0124] The first electrode 206 defines a first channel in which the third electrode 210 and the fourth electrode 212 are located. In more detail, the first electrode 206 has a first side portion 218a and a second side portion 218b that are located on either side of the second pair of electrodes and define side walls of the first channel. The first electrode 206 also includes a first connecting portion 218c that connects the first side portion 218a and the second side portion 218b and forms a bottom wall of the first channel. Thus, as shown in Figure 2c the first electrode 206 can have a U-shaped cross-section that extends about a portion of the second pair of electrodes. The first side portion 218a and the second side portion 218b of the first electrode 206 are substantially uniformly spaced about the longitudinal axis 214 of the jaw. In this way, the spacing between the first side portion 218a and the third electrode 210 can be the same as the spacing between the second side portion 218b and the fourth electrode 210.

[0125] The second electrode 208 is formed by an electrically conductive outer shell of the first jaw 34. The electrically conductive outer shell can be formed of a rigid electrically conductive material, such as a metal or metal alloy. The second electrode 208 defines a second channel in which the first electrode 206 is located. In particular, the second electrode 208 has a first side portion 220a and a second side portion 220b that are located on either side of the first electrode 206 and define side walls of the second channel. The second electrode 208 also includes a second connecting portion 220c that connects the first and second side portions 220a, 220b and forms a bottom wall of the second channel. Thus, as shown in Figure 2c the first and second side portions 218a, 220a of the first and second electrodes 206, 208 can be substantially uniformly spaced about the longitudinal axis 214. In this way, the spacing between the first and second side portions 218a, 220a of the first and second electrodes 206, 208 can be the same as the spacing between the second side portions 218b, 220b of the first and second electrodes 206, 208.

[0126] Thus, the second electrode 208 can be formed on the outside of the first jaw 34 and define a second channel in which the first electrode 206 is located, the first electrode 206 itself defining a first channel in which the second pair of electrodes is located. A microwave sealing region is defined on the first inner surface 202 between the first and second electrodes 206, 208. In particular, a first microwave sealing region 222 is defined on the first inner surface 202 between the first side portions 218a, 220a of the first and second electrodes 206, 208, while a second microwave sealing region 224 is defined on the first inner surface 202 between the second side portions 218b, 220b of the first and second electrodes 206, 208. Thus, the first and second microwave sealing portions 222, 224 are arranged on either side of the RF cutting region 216 and are substantially uniformly spaced about the longitudinal axis 214. The first and second electrodes 206, 208 are arranged to radiate microwave energy received from the generator unit 14 into tissue that is in contact with the first and second microwave sealing regions 222, 224 on the first inner surface 202.

[0127] For example, in Figure 2cAs can be seen, the side portions 218a, 218b of the first electrodes 206 are spaced apart from the second pair of electrodes in a transverse direction orthogonal to the longitudinal axis 214. Thus, the first and second microwave sealing regions 222, 224 are laterally spaced (offset) from the RF cutting region 216, such that there is no overlap between the RF cutting region 216 and the microwave sealing regions 222, 224 on the first inner surface 202. Thus, when a piece of tissue is clamped between the jaws 34, 36, microwave energy and RF energy can be applied to different portions of the tissue. This can avoid the portion of the tissue in contact with the RF cutting region being completely desiccated by the microwave energy delivered to the tissue at the microwave sealing regions 222, 224. The transverse direction can be parallel to the inner surfaces 202, 204 of the jaws 34, 36, and in the plane of the first and second electrodes 206, 208. Figure 2c The transverse direction is indicated by arrow 215.

[0128] A minimum distance between the RF cutting region 216 and the microwave sealing regions 222, 224 can be provided to ensure that the tissue at the RF cutting region 216 is not excessively desiccated by the microwave energy applied at the microwave sealing regions 222, 224. For example, the minimum distance between the RF cutting region 216 and the microwave sealing regions 222, 224 can be at least 0.1 mm, as this is sufficient to avoid the tissue in the RF cutting region 216 being excessively desiccated. In some cases, the minimum distance between the RF cutting region 216 and the microwave sealing regions 222, 224 can be at least 0.3 mm, 0.4 mm, or 0.5 mm. The minimum distance between the RF cutting region 216 and the microwave sealing regions in the transverse direction 215 is indicated in Figure 2c The minimum distance (spacing) between the RF cutting region 216 and the microwave cutting regions 222, 224 in the transverse direction 215 can be seen to correspond to the spacing between the first side portion 218a of the first electrode on one side and the third electrode 210, and to the spacing between the second side portion 218b of the first electrode on the other side and the fourth electrode 212.

[0129] The spacing between the third electrode 210 and the fourth electrode 212 in the lateral direction 215 can be at least 0.1 mm, and in some cases at least 0.3 mm. The spacing between the third electrode 210 and the fourth electrode 212 can define the width of the RF cutting region 216. The spacing between the first electrode 206 and the second electrode 208 in the lateral direction 215 can be at least 0.1 mm, and in some cases at least 0.3 mm. In particular, the spacing between the first side portions 218a, 220a of the first and second electrodes can be at least 0.1 mm (or 0.3 mm), and the spacing between the second side portions 218b, 220b of the first and second electrodes can be at least 0.1 mm (or 0.3 mm). Thus, the first microwave sealing region 222 and the second microwave sealing region 224 can have a width of at least 0.1 mm (or 0.3 mm). Each of the jaws 34, 36 can have a width (along the lateral direction 215) of between about 1.5 mm and 8 mm. As an example, the width of the jaws 34, 36 can be 3.45 mm.

[0130] The second pair of electrodes and the first electrode 206 are supported in the first jaw by a dielectric material. In more detail, the second pair of electrodes is supported in a first channel defined by the first electrode 206 by a first isolating portion 226 formed of a dielectric material. Thus, the second pair of electrodes is held in the first channel and is spaced apart (isolated) from the first electrode 206 by the first isolating portion 226. Portions of the first isolating portion 226 are exposed between the first electrode 206 and the second pair of electrodes to form portions of the first inner surface 202 of the first jaw 34. The first isolating portion 226 fills the first channel defined by the first electrode and partially surrounds the second pair of electrodes such that the third electrode 210 and the fourth electrode 212 are partially embedded in the first isolating portion 226. In this way, portions of the third electrode 210 and the fourth electrode 212 protrude from the first isolating portion 226 and thus protrude (extend) from the first inner surface 202. The first isolating portion 226 also fills the gap between the third electrode 210 and the fourth electrode 212 in order to isolate the third electrode 210 and the fourth electrode 212 from each other.

[0131] The dielectric material of first isolating portion 226 can be any suitable dielectric (insulating) material. In some embodiments, the dielectric material can be an elastically deformable dielectric material, such as silicone. This can enable the second pair of electrodes to move relative to first electrode 206 and / or other portions of first jaw 34 in response to the application of pressure to the second pair of electrodes. Specifically, the second pair of electrodes can be supported in the first channel defined by first electrode 206 solely by the elastically deformable dielectric material. Thus, when jaws 34, 36 are pressed together in a closed position, this can result in the application of pressure to the second pair of electrodes, thereby causing elastic deformation of the first isolating portion, thereby enabling the second pair of electrodes to move away from second jaw 36. The second pair of electrodes (i.e., third electrode 210 and fourth electrode 212) can have a higher stiffness than the elastically deformable dielectric material of first isolating portion 226, such that when pressure is applied to the second pair of electrodes, first isolating portion 226 can deform in preference to the second pair of electrodes.

[0132] The first electrode 206 is supported in the second channel defined by the second electrode 208 by a second isolating portion 228 formed of a dielectric material. Thus, the first electrode 206 is held in the second channel and spaced (isolated) from the second electrode 208 by the second isolating portion 228. Portions of the second isolating portion 228 are exposed between the first electrode 206 and the second electrode 208 to form portions of the first inner surface 202 of the first jaw 34. Specifically, the exposed portions of the second isolating portion 208 may correspond to the first microwave sealing area 222 and the second microwave sealing area 224 discussed above. The second isolating portion 228 fills the second channel defined by the second electrode 208 and partially surrounds the first electrode 206. Figure 2c As shown, first electrode 206 is encapsulated between first isolating portion 226 and second isolating portion 228, such that first electrode 206 is partially or completely embedded in the dielectric material in first jaw 34. In some cases, the surface of first electrode 206 on first side portion 218a and second side portion 218b thereof can be exposed at first inner surface 202 of first jaw 34. Alternatively, first electrode 206 can be completely embedded in the dielectric material forming first isolating portion 226 and second isolating portion 228, such that none of its surfaces are exposed. The dielectric material of first isolating portion 226 can be the same as the dielectric material of second isolating portion 228. In some cases, first isolating portion 226 can be connected to second isolating portion 228.

[0133] Like the first isolation portion 226, the second isolation portion 228 can be formed from an elastically deformable dielectric material, such as silicone or the like. This can enable the first electrode 206 to move within the second channel in response to pressure being applied to the first inner surface 202 of the first jaw 34. In particular, the first electrode 206 can be supported in the second channel only by the elastically deformable dielectric material of the second isolation portion 228. The first electrode 206 can be of higher stiffness compared to the elastically deformable dielectric material of the second isolation portion 228, such that the second isolation portion 228 can deform preferentially to the first electrode 206 when pressure is applied to the first inner surface 202.

[0134] Flexible electrical connections, for example in the form of flexible electrical wires, can be provided to connect the transmission line 28 to the first electrode 206 and the second pair of electrodes to allow the electrodes to move within the jaw 34. For example, the joint 32 can comprise a set of flexible electrical wires that electrically connect the transmission line 28 to the first electrode 206 and the second pair of electrodes.

[0135] The first isolation portion 226 can interlock with one or more features in the second pair of electrodes. This can ensure that the second pair of electrodes are securely held in the first isolation portion 226, which can be particularly beneficial where the first isolation portion 226 is formed from a non-stick material, such as silicone. Figure 2d A perspective view of the first jaw 34 is shown, in which the first isolation portion 226 and the second isolation portion 228 are omitted for illustrative purposes. As can be seen, the third electrode 210 and the fourth electrode 212 comprise a set of through-holes 230. The dielectric material of the first isolation portion 226 fills the through-holes 230 in the first electrode 210 and the second electrode 212 to mechanically interlock the first isolation portion 226 with the third electrode 210 and the fourth electrode 212.

[0136] Similarly, the first isolation portion 226 and / or the second isolation portion 228 can interlock with one or more features on the first electrode 206, which can ensure that the first electrode 206 is securely held within the first jaw 34. For example, as shown in Figure 6, the first isolation portion 226 can comprise a set of through-holes 232 that are aligned with a set of through-holes 234 in the first electrode 206. The dielectric material of the first isolation portion 226 fills the through-holes 232 and 234 to mechanically interlock the first isolation portion 226 with the first electrode 206. Figure 2dAs shown, the first electrode 206 includes a through-hole 232 formed in its first side portion 218a and second side portion 218b. The dielectric material of the first isolation portion 226 and / or the second isolation portion 228 can extend into the through-hole 232 to provide mechanical interlocking with the first electrode 206. Preferably, the first isolation portion 226 and the second isolation portion 228 can be connected to each other by the through-hole 232, such that the isolation portions 226, 228 form a continuous matrix into which the first electrode 206 and the second pair of electrodes are at least partially embedded. Where the first isolation portion 226 and the second isolation portion 228 are connected to each other, the isolation portions can be formed by pouring the dielectric material (in a fluid state) into the channel of the first electrode 206 and the second pair of electrodes 208 while the first electrode 206 and the second pair of electrodes are held in place to fill the gap between the electrodes. In addition, the second electrode 208 (formed by the electrically conductive outer housing of the first jaw 34) can include one or more features that interlock with the second isolation portion 228 to securely hold the second isolation portion 228 in the second channel defined by the second electrode 208. For example, the second electrode 208 can include a series of holes 234 (e.g., through-holes) into which the second isolation portion 228 extends to provide mechanical interlocking with the second electrode 208.

[0137] As Figure 2b and Figure 2cAs shown, the second jaw 36 can include a third pair of electrodes including a fifth electrode 236 and a sixth electrode 238. The third pair of electrodes is configured to receive microwave energy delivered by the transmission line 28 and radiate the microwave energy into tissue located between the jaws 34, 36, for example, to coagulate or seal the tissue. The third pair of electrodes is structured similarly to the first pair of electrodes (including the first electrode 206 and the second electrode 208) in the first jaw 34 described above. In particular, the third pair of electrodes is arranged to mirror the first pair of electrodes, for example, about a plane parallel to the inner surfaces of the jaws 34, 36. Thus, the third pair of electrodes defines a first microwave sealing region 240 on the inner surface 204 of the second jaw 36 between a first side portion of the fourth electrode 236 and the fifth electrode 238, and a second microwave sealing region 242 on the inner surface 204 of the second jaw 36 between the fourth electrode 236 and a second side portion of the fifth electrode 238. The microwave sealing regions 240, 242 on the second jaw 34 are arranged such that, when the jaws 34, 36 are in the closed position, the microwave sealing regions are spaced apart from the RF cutting region 216 in the transverse direction 215. Thus, the microwave sealing regions 240, 242 on the second jaw 36 do not overlap the RF sealing region 216 in the transverse direction 215. The first and second microwave sealing regions 240, 242 on the second jaw 36 are arranged opposite the first and second microwave sealing regions 222, 224, respectively, on the first jaw 34. In this way, when a piece of tissue is held between the jaws 34, 36, microwave sealing can be performed at corresponding locations on opposite sides of the piece of tissue, which can facilitate sealing the entire thickness of the piece of tissue.

[0138] The structure of the fifth electrode 236 is similar to that of the first electrode 206 described above, with the fifth electrode 236 being arranged to mirror the first electrode 206. Thus, the fifth electrode 236 includes side portions and a connecting portion that define the walls of the channel. Similarly, the structure of the sixth electrode 238 is similar to that of the second electrode 208 described above, with the sixth electrode 238 being arranged to mirror the second electrode 208. Thus, the sixth electrode 238 is formed by the conductive outer shell of the second jaw 36 and includes side portions and a connecting portion that define the walls of the channel within which the fifth electrode 236 is located. The channels within the fifth and sixth electrodes 236, 238 can be filled with a dielectric material, such as the same dielectric material used in the first jaw 34, such as an elastically deformable dielectric material. Thus, the fifth electrode 236 can be supported within the second jaw 36 by the dielectric material in which it is at least partially embedded. The fifth electrode 236 and the sixth electrode 238 may include one or more features (e.g., holes or through-holes) that interlock with the dielectric material to provide a mechanical connection between the electrodes and the dielectric material in the second jaw 36. The inner surface 204 of the second jaw 36 may also include a recess 244 that is arranged to receive at least a portion of the protruding second pair of electrodes when the jaws 34, 36 are in the closed position. The recess 244 may correspond to a channel formed in the dielectric material of the second jaw 36.

[0139] like Figure 2a As shown, the ends of the third electrode 210 and the fourth electrode 212 are exposed at the distal end of the first jaw 34. Specifically, the ends of the third electrode 210 and the fourth electrode 212 are exposed on the distal end surface 246 of the first jaw 34, with the distal end surface 246 facing in the distal (forward) direction. In this manner, the exposed ends of the third electrode 210 and the fourth electrode 212 can act as a pair of RF electrodes on the distal end surface 246 for cutting tissue located in front of the jaws. This can enable the use of RF energy delivered to the second pair of electrodes to cut tissue located in front of the jaws 34, 36, which can, for example, enable the jaws 34, 36 to be inserted into (tunnel through) the target tissue. In some embodiments, the second jaw 36 can also include an overhang (not shown) that is arranged to cover the exposed ends of the third electrode 210 and the fourth electrode 212 when the jaws are in the closed position. For example, the overhang can extend from the distal end of the second jaw 36 in a direction toward the first jaw 34, such that when the jaws are in the closed position, the overhang is disposed in front of the ends of the third electrode 210 and the fourth electrode 212. This can enable tissue to be clamped between the overhang on the second jaw 36 and the distal end surface 246 of the first jaw 34, thereby facilitating the use of the ends of the third electrode 210 and the fourth electrode 212 to cut the tissue.

[0140] Figure 2eShows the above Figures 2a to 2d Schematic cross-sectional view of a variation of the embodiment described. Figure 2e As shown, in some embodiments, the first jaw 34 may further include a blade 402 for cutting tissue located between the jaws 34, 36. Specifically, a slot 404 may be defined between the third electrode 210 and the fourth electrode 212, and the blade 402 may be movable along the slot 404. For example, a dielectric carrier (element) may be located between the third electrode 210 and the fourth electrode 212, the dielectric carrier defining the slot 404 along which the blade 402 may move. Thus, the blade may be movable along the length of the RF cutting zone 216, thereby providing an additional means for cutting tissue located within the RF cutting zone. The slot 404 may extend along all or part of the length of the first jaw 34, enabling the blade 402 to move (in the longitudinal direction) along all or part of the length of the first jaw 34. For example, the slot 404 may extend from the proximal end to the distal end of the first jaw 34. The second jaw 36 may further include a second slot 406, which is configured to receive the blade 402 when the jaws 34, 36 are in the closed position. The slot 406 can extend along the length of the second jaw 36. The instrument 12 can include a control wire or actuator rod for actuating the blade 402 (i.e., for moving the blade 402 along the slot 404). The control wire or actuator rod can extend within the instrument shaft and be connected to the handle 20, which can be operable to control the movement of the blade 402 along the slot 404. The blade 402 can be electrically isolated from the third electrode 210 and the fourth electrode 212 in the slot. Alternatively, the blade 402 can be electrically connected to one of the third electrode 210 and the fourth electrode 212 to enable the blade 402 to act as an action or return electrode for RF energy.

[0141] Figure 3a and Figure 3b A second example of jaws 34 , 36 according to another embodiment of the present invention is shown. Figure 3a A perspective view of the jaws 34, 36 is shown, and Figure 3b A partial cross-sectional view of the jaws 34 , 36 is shown. Figure 3a and Figure 3b The jaws 34, 36 have similar structures and are similar to those described above. Figures 2a to 2d The grippers described above operate in a similar manner. Figures 2a to 2d Features of the gripper Figure 3a and Figure 3b The characteristics of the gripper in Figures 2a to 2d The same reference numerals are used to designate the same figures in the drawings and will not be described again.

[0142] and Figures 2a to 2dThe illustrated embodiment, in which the second pair of electrodes is formed as a pair of electrically conductive tracks floating in the first insulating portion 226, is compared to the embodiment of Figure 3a and Figure 3b In the illustrated embodiment, the second pair of electrodes is provided on an electrode support 302 made of a rigid dielectric material. The electrode support 302 can for example be made of a ceramic material such as aluminum oxide. The electrode support 302 comprises a support base plate 304 and support ribs 306 provided on the support base plate, such that the electrode support is T-shaped in a cross-sectional view of the first jaw 34. The third electrode 210 and the fourth electrode 212 each comprise a strip made of an electrically conductive material and arranged on opposite sides of the support ribs 306. In particular, the third electrode 210 and the fourth electrode 212 are formed on portions of the support ribs 306 that protrude from the inner surface 202 of the first jaw 34. Note that the fourth electrode 212 is not visible in Figure 3a and Figure 3b as it is located on a side of the support ribs 306 that is not visible in the perspective view of the figure.

[0143] The support base plate 304 and / or the support ribs 306 can each have an elongated shape and can be made of a plate or strip of a non-conductive material such as a ceramic. The support base plate 304 can for example be (permanently) attached to the support ribs 302 by adhesion. Alternatively, the support base plate and the support ribs are an integral part.

[0144] The electrode support 302 is centered within the first channel defined by the first electrode 206 and is mostly buried or covered by the first insulating portion 226, only portions of the support ribs 306 being exposed or protruding from the first insulating portion 226 at the first inner surface 202. The support base plate 304 can be provided for interlocking the electrode support 304 with the first insulating portion 226. For example, the support base plate 304 protrudes from the support ribs 306 on one or both sides, such that the width of the support base plate 304 is greater than the thickness of the support ribs 306, where width and thickness are measured in the transverse direction 215 of the jaw. The support base plate 304 can extend perpendicular to the support ribs 306. The support base plate 304 can be attached to the support ribs 306 at an end of the support ribs 306 opposite the end of the support ribs 306 that is exposed at the first inner surface 202. The support base plate 304 can be fully embedded in the first insulating portion 226.

[0145] In case an elastically deformable dielectric material such as silicone is used for the first insulating portion 226, the stiffness of the dielectric material of the electrode support 302 can be greater than the elastically deformable dielectric material. In this way, the first insulating portion 226 can deform preferentially to the electrode support 302 when pressure is applied to the electrode support 302, thereby enabling the electrode support (and thus the second pair of electrodes) to move within the first jaw 34 in response to the pressure application.

[0146] Figure 3a and Figure 3b Embodiments of the above can be adapted to include a blade (not shown) to provide an additional means of cutting tissue between the jaws 34, 36. As an example, a slot can be defined within the support rib 306 of the electrode support 302 that extends along the longitudinal direction between the third and fourth electrodes 210, 212. Accordingly, a blade can be positioned in the slot and be movable along the slot to cut tissue held between the jaws 34, 36. In particular, since the slot is positioned between the third and fourth electrodes 210, 212, the blade can be used to cut tissue along the length of the RF cutting region. In a similar manner to the above example, the blade can be moved along the slot using a control wire or actuation rod connected to the handle 20.

Claims

1. An electrosurgical instrument for sealing and / or cutting tissue, comprising: a transmission line for transmitting microwave electromagnetic energy and / or radio frequency electromagnetic energy; a pair of jaws comprising a first jaw and a second jaw mounted at a distal end of the transmission line, wherein the first jaw and the second jaw are movable between an open position in which tissue can be inserted into a gap between the first jaw and the second jaw, and a closed position in which the first jaw and the second jaw are brought together to clamp tissue therebetween; wherein the pair of jaws includes a first pair of electrodes including a first electrode and a second electrode, and a second pair of electrodes including a third electrode and a fourth electrode; wherein the first pair of electrodes is configured to receive microwave energy conveyed by the transmission line and to transmit the received microwave energy into tissue located between the first jaw and the second jaw such that a microwave seal region is defined on an inner surface of the pair of jaws between the first electrode and the second electrode; wherein the second pair of electrodes is configured to receive radiofrequency energy delivered by the transmission line and operate as active electrodes and return electrodes to deliver the radiofrequency energy to tissue located between the first jaw and the second jaw, such that a radiofrequency cutting zone is defined on inner surfaces of the pair of jaws between the second electrode and the third electrode; and The first and second pairs of electrodes are arranged such that when the first and second jaws are in the closed position, the microwave sealing region is spaced apart from the RF cutting region in a transverse direction orthogonal to a longitudinal axis of the pair of jaws.

2. An electrosurgical instrument as claimed in claim 1, wherein the radio frequency cutting zone is substantially centered relative to the longitudinal axis.

3. An electrosurgical instrument as described in claim 1 or 2, wherein the first pair of electrodes is shaped to define a first microwave sealing area and a second microwave sealing area, and wherein when the first jaw and the second jaw are in the closed position, the first microwave sealing area and the second microwave sealing area are arranged on either side of the second pair of electrodes.

4. The electrosurgical instrument of claim 3, wherein the first microwave sealing region and the second microwave sealing region are substantially evenly spaced around the RF cutting region in the transverse direction.

5. An electrosurgical instrument as described in claim 3 or 4, wherein the first electrode includes a first side portion and a second side portion separated by a first gap in the lateral direction, and wherein when the first jaw and the second jaw are in the closed position, the first side portion and the second side portion of the first electrode are located on either side of the second pair of electrodes. 6 . The electrosurgical instrument of claim 5 , wherein the first electrode further comprises a first connecting portion connecting the first side portion and the second side portion of the first electrode across the first gap.

7. The electrosurgical instrument of any one of claims 5 to 6, wherein the second electrode comprises a first side portion and a second side portion separated by a second gap in the lateral direction, and wherein the first electrode is located within the second gap. 8 . The electrosurgical instrument of claim 7 , wherein the second electrode further comprises a second connecting portion connecting the first side portion and the second side portion of the second electrode across the second gap.

9. An electrosurgical instrument as claimed in claim 7 or 8 when dependent on claim 4, wherein the first and second side portions of the second electrode are substantially evenly spaced about the longitudinal axis in the transverse direction.

10. An electrosurgical instrument as claimed in any preceding claim, wherein the first jaw comprises the first pair of electrodes and the second pair of electrodes, and wherein the first pair of electrodes is separated from the second pair of electrodes by a dielectric material in the first jaw.

11. An electrosurgical instrument as claimed in claim 10, wherein: The second clamping jaw includes a third pair of electrodes, and the third pair of electrodes includes a fifth electrode and a sixth electrode; the third pair of electrodes being configured to receive microwave energy conveyed by the transmission line and to transmit the received microwave energy into tissue located between the first jaw and the second jaw such that a microwave seal region is defined on an inner surface of the second jaw between the fifth electrode and the sixth electrode; and The third pair of electrodes is arranged such that when the first and second jaws are in the closed position, the microwave sealing area on the inner surface of the second jaw is spaced apart from the radio frequency cutting area in the lateral direction.

12. An electrosurgical instrument as claimed in any preceding claim, wherein the minimum spacing between the microwave sealing region and the radio frequency cutting region in the transverse direction is at least 0.1 mm.

13. An electrosurgical instrument as claimed in any preceding claim, wherein the second pair of electrodes protrude from an inner surface of a first jaw of the first jaw and the second jaw.

14. The electrosurgical instrument of claim 13, wherein a second of said first and second jaws comprises a recess for receiving a protruding portion of said second pair of electrodes when said jaws and said second jaw are in said closed position.

15. An electrosurgical instrument as claimed in any preceding claim, wherein ends of the third electrode and the fourth electrode are exposed at a distal end of a first jaw of the first jaw and the second jaw.

16. The electrosurgical instrument of claim 15, wherein a second jaw of the first jaw and the second jaw comprises an overhanging portion arranged to cover the exposed ends of the third electrode and the fourth electrode when the first jaw and the second jaw are in the closed position.

17. An electrosurgical instrument as claimed in any preceding claim, wherein a slot is defined between the third electrode and the fourth electrode, and the instrument further comprises a blade movable along the slot to cut tissue located between the first jaw and the second jaw.

18. An electrosurgical instrument as claimed in any preceding claim, wherein the second pair of electrodes is supported in one of the jaws by an insulating portion comprising a resiliently deformable material such that the second pair of electrodes can move in the jaws when pressure is applied to the second pair of electrodes.

19. An electrosurgical instrument as defined in claim 18, wherein the elastically deformable material comprises silicone.

20. An electrosurgical instrument as claimed in claim 18 or 19, wherein the isolation portion interlocks with one or more features on the second pair of electrodes.

21. An electrosurgical instrument as claimed in any one of claims 18 to 20, wherein the second pair of electrodes comprises conductive tracks partially embedded in the resiliently deformable material.

22. An electrosurgical instrument as claimed in any one of claims 18 to 20, further comprising an electrode support made of an electrically insulating material, wherein the third electrode and the fourth electrode each comprise a respective strip of electrically conductive material on the support, and wherein the electrode support is partially embedded in the elastically deformable material.

23. An electrosurgical device for sealing and cutting tissue, comprising: a generator unit for generating radio frequency and / or microwave electromagnetic energy; as well as An electrosurgical instrument according to any preceding claim; wherein the transmission line is configured to deliver the microwave energy to the first pair of electrodes and deliver the radiofrequency energy to the second pair of electrodes.

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