electrosurgical instruments

Abstract

Various embodiments provide an electrosurgical instrument for applying radio frequency (RF) electromagnetic (EM) energy and / or microwave frequency EM energy to biological tissue. The electrosurgical instrument includes an instrument tip having a planar body made of a first dielectric material separating a first conductive element on a first surface from a second conductive element on a second surface, the second surface facing away from the first surface. The electrosurgical instrument also includes a coaxial feed cable including an inner conductor, an outer conductor coaxial with the inner conductor, and a dielectric material separating the inner and outer conductors, the coaxial feed cable for transmitting RF and / or microwave signals. The inner conductor is electrically connected to the first conductive element, and the outer conductor is electrically connected to the second conductive element, allowing the instrument tip to receive RF and / or microwave signals. An edge of the instrument tip has a notch defining a recess for internally engaging tissue.

Description

[Technical Field]

[0001] The present invention relates to electrosurgical instruments having an instrument tip that may be configured to deliver electromagnetic energy (e.g., radio frequency and / or microwave frequency energy) to living tissue to cut tissue and / or to achieve hemostasis (i.e., promote blood clotting). For example, the instrument may be sized for insertion through the instrument channel of a standard surgical endoscope. [Background technology]

[0002] Surgical resection is a procedure for removing a portion of an organ from the human or animal body. Such organs may be highly vascular. When tissue is cut (divided or transected), small blood vessels called arterioles are damaged or ruptured. Initial bleeding is followed by a clotting cascade, which converts blood into a clot in an attempt to plug the bleeding point. During surgery, it is desirable for the patient to lose as little blood as possible, and thus various devices have been developed in an attempt to produce a bleeding-free resection. Additionally, in the case of endoscopic surgery, bleeding is undesirable and must be managed appropriately, as blood flow can obstruct the surgeon's view, which can prolong the surgery and force the surgery to be terminated and an alternative method, such as open surgery, to be used instead.

[0003] Electrosurgical generators are common in hospital operating rooms and are often used in open and laparoscopic procedures, and increasingly with surgical scoping devices such as endoscopes. In endoscopic procedures, electrosurgical accessories are typically inserted through lumens inside the endoscope. Considering an equivalent access channel in laparoscopic surgery, such lumens have a relatively small internal diameter and are longer in length.

[0004] The use of microwave frequency energy for hemostasis (i.e., sealing ruptured blood vessels by promoting blood clotting) is known. Instruments are known that emit microwave energy from the edge of a planar transmission line to effect localized tissue ablation or coagulation.

[0005] Additionally, it is known to use radio frequency (RF) energy instead of sharp blades to cut biological tissue. Cutting methods using RF energy operate on the principle that when an electric current passes through the tissue matrix (assisted by the ionic content of cells and intracellular electrolytes), the impedance to electron flow across the tissue generates heat. In practice, an instrument is configured to apply an RF voltage across the tissue matrix sufficient to generate heat within the cells and evaporate tissue water. However, this desiccation can result in loss of direct physical contact between the tissue and the instrument, particularly adjacent to the RF emission area of ​​the instrument (where the current density of the current path through the tissue is highest). The applied voltage then manifests as a voltage drop across this small air gap, causing ionization within the air gap and generating a plasma. Plasma has a very high volume resistivity compared to tissue. Energy supplied to the instrument maintains the plasma, i.e., completing the electrical circuit between the instrument and the tissue. Volatile substances that enter the plasma can evaporate, hence the term tissue-dissociating plasma.

[0006] GB 2,523,246 describes an electrosurgical instrument for applying RF electromagnetic energy and / or microwave frequency EM energy to biological tissue. The instrument includes a shaft insertable through an instrument channel of a surgical scoping device. At the distal end of the shaft is an instrument tip including a planar transmission line formed from a sheet of a first dielectric material having first and second conductive layers on opposite surfaces thereof. The planar transmission line is connected to a coaxial cable carried by the shaft. The coaxial cable is configured to deliver either microwave energy or RF energy to the planar transmission line. The coaxial cable includes an inner conductor, an outer conductor coaxial with the inner conductor, and a second dielectric separating the outer conductor and the inner conductor. The inner and outer conductors extend beyond the second dielectric material at a connection interface, overlap opposite surfaces of the transmission line, and electrically contact the first and second conductive layers, respectively. The instrument further includes a protective hull structure having a convex lower surface smoothly contoured away from the planar transmission line. The lower surface includes a longitudinally extending recessed channel formed therein. A retractable needle is mounted within the device and operable to extend through the recessed channel and protrude from the distal end of the device, and can be used to inject fluid into the treatment zone before RF or microwave energy is applied.

[0007] The present invention has been devised in light of the above considerations. Summary of the Invention

[0008] The present invention provides a development of the concepts described in GB 2,523,246.

[0009] Most generally, the inventors have developed modified instrument tips shaped to improve positional control.

[0010] According to a first aspect of the present invention, there is provided an electrosurgical instrument for applying radio frequency (RF) electromagnetic (EM) energy and / or microwave frequency EM energy to biological tissue, the electrosurgical instrument comprising: an instrument tip having a planar body made from a first dielectric material separating a first conductive element on a first surface from a second conductive element on a second surface, the second surface facing away from the first surface; an instrument tip; an inner conductor; an outer conductor coaxial with the inner conductor; and a coaxial feed cable including a dielectric material separating the inner and outer conductors, the coaxial feed cable being for transmitting RF and / or microwave signals, the inner conductor being electrically connected to the first conductive element and the outer conductor being electrically connected to the second conductive element, allowing the instrument tip to receive the RF and / or microwave signals; and an edge of the instrument tip having a notch defining a recess for engaging tissue within the recess.

[0011] This configuration can advantageously provide improved control of the instrument tip and help reduce the risk of accidental puncture. Specifically, by engaging tissue within the recess, the notch can help increase the traction of the instrument tip within the tissue, thereby helping to prevent slippage of the instrument tip. The notch can be configured in various ways to provide different tissue engagement characteristics to suit different surgical applications and / or individual clinician preferences. Furthermore, the location of the notch on the edge of the instrument tip can serve as a visual indicator of insertion depth into biological tissue (e.g., lateral or axial insertion depth). This can help improve ease of use and make the clinician more familiar with using the instrument, especially when it is of a different (e.g., smaller) size than instruments the clinician has previously used.

[0012] As used herein, the term "edge" when referring to an instrument tip may refer to any region extending around the periphery of the instrument tip, including its distal and / or lateral region(s). Correspondingly, the notch may be located on any suitable edge for engaging tissue, for example, along the distal and / or lateral edge(s) of the instrument tip.

[0013] As used herein, the term "notch" may refer to a depression or cutout that forms a discontinuity (e.g., a corner, bend, turn, camber) in the surface at the edge (periphery) of the instrument tip, which defines a recess for engaging (e.g., hooking, catching, dragging) tissue. To engage tissue, the notch is preferably located in an exposed portion of the instrument tip that is located distal to the flexible shaft that connects the coaxial feed cable to the instrument tip.

[0014] A notch may be considered to include a rear wall and one or more side walls that define a recess. The rear wall and / or side walls may blend smoothly together (which may eliminate sharp corners between them and eliminate a clearly visible boundary between the rear wall and the side walls), or may be joined, for example, by a sharp bend or corner to clearly separate the respective walls. In this context, the term "rear wall" may refer to a surface of the notch that is located laterally medial to the surface of the edge adjacent to the notch, e.g., with the rear wall located closer to the central longitudinal axis of the instrument tip when the notch is at a lateral edge of the instrument tip, or with the rear wall being the proximal-most wall of the notch when the notch is at a distal edge of the instrument tip. The term "side wall" may refer to a surface that defines an end region of the notch.

[0015] The notch may be formed in any suitable element of the instrument tip for contacting tissue. Preferably, the notch may be formed in the planar body of the instrument tip. Optionally, the notch may also be formed in the first and / or second conductive elements, which may extend to the edge (e.g., distal edge) of the planar body. Preferably, the first and / or second conductive elements extend to the edge of the notch to treat tissue engaged within the recess of the notch. In some embodiments, the instrument tip may include a protective hull, which may include a notch formed in its edge. The protective hull may include a piece of dielectric material attached to cover the underside of the planar body. The protective hull may have a smoothly contoured convex underside facing away from the planar body.

[0016] As noted above, different notch configurations may be desired depending on the surgeon's preference and / or the procedure being performed. For example, optionally, at least one end of the notch forms a sharp corner at the edge of the instrument tip. As used herein, the term "sharp corner" refers to the junction between two surfaces of the instrument tip, which is angled to form a distinct boundary / point. This may be contrasted with two edges that have no clear boundary between them and are smoothed together. The two surfaces / walls that join to form the sharp corner may be flat and / or curved. For simplicity, a "sharp corner" may also be alternatively referred to as a "corner" herein. Advantageously, providing a notch that forms a sharp corner may be useful for using the notch to capture or hook a vessel. Furthermore, because the corner helps to precisely demarcate the end of the notch, this may help provide a clearer indication for measuring insertion depth (e.g., compared to a smooth contour).

[0017] Optionally, the notch may form twin corners, one on each end (lateral or axial) of the notch, which can provide the same benefits as above for grasping / hooking tissue, as well as an additional visual reference for measuring insertion depth (lateral or axial).

[0018] A sharp corner may form an acute, perpendicular, or obtuse angle (measured between two adjacent surfaces of the instrument tip in a direction through the instrument tip).

[0019] Obtuse angles are particularly useful in applications that benefit from relatively smooth insertion / retraction while still providing a distinct point for improving the perception of insertion depth, as compared to, for example, a smoothly contoured edge region. Additionally, obtuse angles may allow easier access to recesses, thereby facilitating easier cleaning, as compared to sharp or perpendicular corners.

[0020] Sharp angles can be particularly useful for hooking / catching individual tissue fibers and preventing the instrument tip from slipping when the instrument tip is pulled / pushed against the sharp corner. Conversely, if the instrument tip is pulled / pushed in the opposite direction, the sharp corner can facilitate smooth insertion / retraction of the instrument tip.

[0021] Optionally, the sharp corner may include a proximally facing barb. As used herein, the term "barb" has its general meaning relating to a protrusion angled away from a main (distal) point to make extraction more difficult. Thus, a barb refers to a sharp corner of the proximally facing (i.e., away from the distal) type. Optionally, the barb may also face in a lateral (left / right) direction so that it is oriented at an angle that is not parallel to the longitudinal axis of the instrument tip.

[0022] A barbed configuration can be particularly advantageous in allowing the instrument tip to be inserted smoothly (as the barbs point away from the distal end and therefore do not catch on fibers when moving distally), while also allowing the instrument tip to catch / pull on individual tissue fibers when pulled proximally.

[0023] The angles (e.g., barbs) may have blunt / smooth or sharp tips. A sharp tip may facilitate easier cutting of tissue / vessels.

[0024] Alternatively, the sharp corner may point distally, in which case it may be referred to as a "piercing element." Preferably, the piercing element may be located at the distal end of the instrument tip, which allows the piercing element to impinge on tissue and improve the distal cutting characteristics of the instrument tip, as further described below.

[0025] Alternatively, as discussed above, the pointed corners can be substantially perpendicular, rather than acute or obtuse. Substantially perpendicular corners can provide a useful balance between the sharp and obtuse configurations discussed above, aiding in hooking tissue without significantly impeding smooth proximal and distal insertion. Additionally, perpendicular corners can promote easier cleaning compared to sharp (e.g., barbed) corners.

[0026] Optionally, the distal end of the notch (e.g., only the distal end) forms a sharp corner, which may allow the distal end of the notch to be used for fine operations such as hooking / grabbing tissue near the distal end of the instrument tip.

[0027] In configurations where the notch is located at the distal edge (e.g., distal face) of the instrument tip and has pairs of side walls (left and right), each side wall may be considered to terminate at a respective "distal end point." Thus, in some embodiments, the notch may have pairs of distal end points, one or more of which may form respective sharp corners.

[0028] Alternatively, in configurations where the notch is located along a lateral edge of the instrument tip, the notch may have both a proximal end (near the proximal end of the instrument tip) and a distal end (near the distal end of the instrument tip), where the distal end may form a sharp corner. Alternatively, in some embodiments, the proximal end of the notch (e.g., only the proximal end) may form a sharp corner.

[0029] Optionally, both ends of the notch may form respective sharp corners on the edge of the instrument tip. The sharp corners on each end may have similar / complementary configurations or different configurations depending on the desired application and surgeon preference.

[0030] Optionally, at least one end of the notch may be smoothly contoured into an edge of the instrument tip (e.g., at one or both end regions of the notch). As used herein, the term "smoothly contoured" may refer to a curved region at the edge of the instrument tip, where the curvature of the edge changes at the turning point to smoothly define the end region of the notch without forming a sharp corner.

[0031] A smooth contour may be particularly advantageous for providing smooth insertion / retraction, and the increased surface area of ​​the notch increases traction / friction, thereby helping to prevent the instrument tip from slipping against the tissue. Additionally, a smooth contour may further facilitate ease of cleaning compared to sharp (e.g., sharp, barbed) edges.

[0032] It should be noted that a notch may be referred to herein as having first and / or second "ends." For example, these may be first and second axial ends (e.g., distal and proximal ends) or first and second lateral ends (e.g., left and right ends, each of which may be located at the distal end of the instrument tip). In a notch having sharp corners at both ends, the ends appear abrupt and distinct. However, in embodiments in which the notch is smoothly contoured at one or both ends into the edge of the instrument tip, the end(s) may be relatively less abrupt / distinct. Thus, references to a "first end" or a "second end" may interchangeably refer to the first end region and the second end region.

[0033] Optionally, both ends of the notch may be smoothly contoured to merge into the edges of the instrument tip.

[0034] Optionally, the proximal end of the notch (e.g., only the proximal end) may enter the edge of the instrument tip to provide a smooth contour. This may help provide smooth insertion and retraction. Optionally, the distal end of the notch may form a sharp corner (e.g., a barb, a blunt corner, or a straight corner), as described above. Providing a smooth contour in combination with a sharp corner may help promote smooth insertion / retraction (via the smooth contour) and may also provide the benefit of improved grasping at the distal end and improved measurement of insertion depth (via the sharp corner).

[0035] Optionally, the notch can be located at the distal end of the instrument tip and can face distally from the instrument tip. By providing a distally facing notch, the instrument tip can have better performance / traction when delivering energy end-on to a vessel / tissue. The notch can be shaped in various ways to provide desired characteristics to the vessel / tissue. For example, the notch can form a pair of sharp corners that define a recess for engaging (receiving) tissue therebetween, with each corner facing away from the distal end of the instrument tip to abut against the tissue. This can be particularly useful for grasping individual fibers / vessels at the distal end of the instrument within the cavity defined by the notch. A distally facing notch is also sometimes referred to as a "fishmouth" type notch.

[0036] Optionally, one or both sharp corners may be configured as piercing elements defining a distally facing acute angle, as described above. Optionally, the piercing element(s) may also be oriented inward toward the central axis of the instrument tip. This may help to hold / grasp the vessel within the recess.

[0037] The notches can be configured in various ways to define different types of recesses. For example, optionally, the notches can define smoothly contoured concave recesses (cavities) for grasping vessels / fibers. Alternatively, the notches can each include one or more corners / bends to define two or more walls (e.g., planar walls). For example, the notches can define triangular recesses formed by pairs of angled walls. Alternatively, the notches can include three walls, which can provide a substantially rectangular or trapezoidal recess. The shape of the recess can be selected based on the characteristics of the vessel and the desired interaction with the tissue.

[0038] Optionally, the notch may define a hook-shaped recess for capturing / hooking / hooking tissue within the recess. In such an embodiment, the hook may terminate in a barb as described above.

[0039] As noted above, the notches may optionally be located on the lateral edges of the instrument tip, which may be particularly advantageous for providing depth perception and / or for applications where side-on (rather than end-on) cutting / coagulation is desired.

[0040] Optionally, the notch may be an elongated notch (e.g., a single elongated notch) disposed along a lateral edge of the instrument tip. The term "elongated" may refer to a notch that is long (length extending from the proximal end to the distal end) rather than deep (e.g., measured as the lateral depth of the recess into the instrument tip, perpendicular to the edge of the instrument tip). Advantageously, an elongated notch may be less likely to become clogged with biological material compared to a short notch, thereby facilitating easier cleaning.

[0041] As used herein, the term "lateral depth" may refer to the depth of the notch measured to the edge of the instrument (e.g., perpendicular to the axial direction). Conversely, the term "axial depth" or "insertion depth" may refer to the depth measured along the length of the instrument tip, i.e., axially.

[0042] The length of the elongated notch (from the first end to the second end) may provide an indication of insertion depth. For example, the elongated notch may have a length of about 1 mm. Optionally, the elongated notch may form a corner on the edge of the planar body, which may further facilitate this visual indication. The corner may be configured in any suitable manner, as described above.

[0043] In an alternative embodiment, the elongated notch may be smoothly contoured into the side of the instrument tip.

[0044] Optionally, the notch has a lateral depth (measured to the instrument tip) of less than 30%, optionally less than 20%, and optionally less than 15% of the maximum width of the instrument tip. The depth of the notch can be varied to provide smoother insertion and easier cleaning (e.g., by providing a shallower notch that is 15% or less of the maximum width of the instrument tip), or to provide improved gripping / traction (e.g., by providing a deeper notch that is more than 15% of the maximum width of the instrument tip).

[0045] Optionally, the instrument tip has two or more notches. Each notch may be configured in any suitable manner, as discussed herein. The notches may have the same / similar or different configurations (e.g., both elongated notches, or one short notch and one long notch). Optionally, two or more notches may be axially spaced apart. The axial spacing of the multiple notches may help provide an indication of insertion depth. One or more of the notches may be "short" notches, e.g., having a depth substantially equal to its width. Optionally, to improve ease of cleaning and reduce the chance of clogging, the short notch(es) may be smoothly contoured into the edge of the instrument tip (short notches are particularly susceptible, e.g., compared to elongated notches). Optionally, two or more notches may be located along the same ("first") side of the instrument tip and axially spaced apart, which may further help measure insertion depth.

[0046] Optionally, two or more notches may be located on opposing lateral edges of the instrument tip. Thus, both sides of the instrument tip can be used to provide tissue cutting / hooking. Optionally, the notches may be axially aligned, thereby providing similar functionality on both sides of the device and facilitating ease of use. Optionally, the two or more notches together form an elongated, thin-walled section of the instrument tip, the width of which may be less than 50%, optionally less than 40%, optionally less than 30%, and optionally less than 20% of the maximum width of the instrument tip. The term "elongated" refers to a section that is longer in length (in the axial direction) than in width (in the lateral direction). The thin-walled section may provide several advantages, as described below.

[0047] In some embodiments, the elongated thin-walled section terminates in a rounded end. The rounded end may form the end of the instrument tip. In such embodiments, the instrument tip may also be referred to as having a "pen tip" configuration. In these embodiments, the thin-walled section may advantageously allow for precise and fine cutting and may be easily cleaned because the instrument tip terminates in an elongated thin-walled section and a rounded end rather than including a further enlargement distal to the elongated thin-walled section.

[0048] In alternative embodiments, the elongated thinned section can terminate in an enlarged section, which may define a sharp corner (e.g., a barb). In such embodiments, the thinned section may advantageously increase the amount of tissue that can be captured within the notch proximal to the sharp corner. In embodiments in which the sharp corner is configured as a barb, the instrument tip may be referred to as having a "barbed tip."

[0049] Optionally, the instrument tip may be substantially symmetrical along its central axis, and thus may have the same notch configuration on both sides, which may facilitate ease of use.

[0050] Optionally, the instrument tip may have a different notch configuration on a first side of the instrument tip than on a second side of the instrument tip, which may allow the device to perform different functions depending on the orientation, such as, for example, interfacing with different types of vessels, providing varying degrees of hooking, providing different types of cutting, and / or helping to reduce slippage.

[0051] For example, the notches may be axially spaced along opposite sides of the instrument tip, e.g., in a staggered configuration, which may allow different types of cuts to be performed along a first side of the instrument tip compared to a second side, depending on the orientation of the device.

[0052] Alternatively, for example, the instrument tip may have one or more notches on its first side and no notches on its second side, which may facilitate smooth insertion on the second side while providing the desired functionality (e.g., catch, hook, insertion depth measurement, etc.) via the notches on the first side.

[0053] Optionally, the instrument tip includes only a single notch. For example, this may be a single notch (which may be symmetrical) located at the distal end of the instrument tip. Such a configuration may be referred to as a fishmouth notch for head-on engagement of tissue. Alternatively, the single notch may be located along only a single side of the instrument tip, resulting in one-sided grasping of tissue.

[0054] As described above, the notches can serve to provide axial and / or lateral insertion depth indicators. Alternatively, or in combination, optionally, the first conductive element can be patterned to provide axial and / or lateral depth indicators. For example, the first conductive element can be provided on only a portion of the planar body, such that the first conductive element varies in (lateral) width along its (axial) length. In this manner, the region of varying width of the first conductive element can be used as an indicator of the axial (end-on) insertion depth of the instrument tip into the biological tissue. Correspondingly, the lateral variations of the first conductive element can provide an indicator of the lateral (side-on) insertion depth into the biological tissue. Alternatively, or in combination, the first conductive element can be etched (e.g., laser etched) to include scales to indicate the axial and / or lateral insertion depth of the instrument tip into the tissue.

[0055] The present invention includes any combination of the described aspects and preferred features except where such a combination is expressly impermissible or explicitly avoided.

[0056] Illustrative embodiments illustrating the principles of the present invention will now be described with reference to the accompanying drawings, in which like numerals refer to like elements and in which: FIG. [Brief explanation of the drawings]

[0057] [Figure 1] 1 is a schematic diagram of a complete electrosurgical system to which the present invention can be applied; [Figure 2] FIG. 12 is a perspective view of an embodiment of an instrument tip having twin elongated notches. [Figure 3] FIG. 12 is a perspective view of an embodiment of an instrument tip having multiple short notches. [Figure 4] 1A-C are top views showing modified elongated notches according to an embodiment of the present invention. [Figure 5] 1A-B are top views showing a modified short notch according to an embodiment of the invention. [Figure 6]1A-C are top views showing modified shapes of notches for hooking tissue according to embodiments of the present invention. [Figure 7] 8A-8B are top views of an alternative embodiment of the instrument tip having a notch forming a thinned section. [Figure 8] 1A-E are top views showing an alternative instrument tip having a different notch configuration on a first side compared to a second side, according to an embodiment of the invention. [Figure 9] 1A-D are top views of an embodiment of the instrument tip having a distally facing notch. [Figure 10] 1A-C are top views of an embodiment of the instrument tip having a relatively shallow notch. [Figure 11] 10A-10C are top views showing various embodiments of instrument tips having different notch configurations in the planar body and / or first conductive element. [Figure 12] FIG. 10 is a top view showing an embodiment of the instrument tip connected to a flexible shaft. [Figure 13] FIG. 1 is a perspective view of an embodiment of an instrument tip connected to a flexible shaft, the flexible shaft being transparent to show the connection between the instrument tip and a coaxial cable within the interior of the flexible shaft. [Figure 14] FIG. 14 is a perspective view of the instrument tip and flexible shaft of FIG. 13, the flexible shaft being opaque and showing the exterior surface of the shaft. DETAILED DESCRIPTION OF THE INVENTION

[0058] Aspects and embodiments of the present invention will now be described with reference to the accompanying drawings. Further aspects and embodiments will be apparent to those skilled in the art. All documents mentioned in this text are incorporated herein by reference.

[0059] 1 is a schematic diagram of a complete electrosurgical system 100 capable of selectively delivering any or all of RF energy, microwave energy, and fluid, such as saline or hyaluronic acid, to the distal end of an invasive electrosurgical instrument. System 100 includes a generator 102 for controllably delivering electromagnetic (EM) energy. In this embodiment, the EM energy includes RFEM energy and / or microwave frequency EM energy. Suitable generators for this purpose are described in WO 2012 / 076844, which is incorporated herein by reference.

[0060] The generator 102 is connected to an interface joint 106 by an interface cable 104. The interface joint 106 is also connected to receive a supply of pressurized fluid from a fluid delivery device 108 via a fluid supply cable 107. The function of the interface joint 106 is to combine inputs from the generator 102 and the fluid delivery device 108 to a single flexible shaft 112 that extends from the distal end of the interface joint 106. It will be appreciated that the shaft 112 may form part of the interface joint 106.

[0061] The flexible shaft 112 is insertable through the entire length of the instrument (working) channel of the surgical scoping device 114. A torque transfer unit 116 may be attached to the proximal length of the shaft 112 between the interface joint 106 and the surgical scoping device 114. The torque transfer unit 116 engages the shaft such that the shaft can rotate within the instrument channel of the surgical scoping device 114. The configuration of the torque transfer unit 116 is described in more detail below.

[0062] The flexible shaft 112 passes through an instrument channel of a surgical scoping device 114 (e.g., an endoscope) and has an electrosurgical instrument tip 118 shaped to protrude (e.g., into a patient's body) at the distal end of the instrument channel. The instrument tip includes an active tip for delivering RFEM energy and / or microwave EM energy into biological tissue and an opening for delivering pressurized fluid (e.g., saline, gelofusine, and / or hyaluronic acid with a marker dye). These combined technologies provide a unique solution for cutting and destroying unwanted tissue and the ability to seal blood vessels around the target area. By applying pressure to the fluid, the surgeon can inject the fluid between tissue layers to dilate and mark the location of the lesion to be treated. Injecting the fluid in this manner lifts and separates the tissue layers, facilitating both resection around the lesion and flattening the submucosa, reducing the risk of puncturing the bowel wall or unnecessary thermal damage to the muscle layer.

[0063] The instrument tip 118 further includes a protective hull positioned below the active tip to assist in tissue-planarizing cutting actions, which also protects against inadvertent puncture and helps ensure viability of remaining tissue, thereby promoting faster healing and post-operative recovery.

[0064] The structure of the instrument tip 118 may be specifically designed for use with conventional steerable flexible endoscopes having working channels with inner diameters of at least 2 mm and working lengths of 60 cm to 170 cm. Thus, most relatively small diameter instruments are housed primarily within the much larger, polymeric isolator, i.e., the lumen, of the flexible endoscope channel. In practice, only 5 mm to 25 mm of the distal assembly protrudes beyond the distal end of the endoscope channel so as not to obstruct the field of view or adversely affect camera focusing. The protruding portion of the distal assembly is the only portion of the instrument that comes into direct contact with the patient.

[0065] At the proximal end of the endoscope's working channel, which is typically held 50 cm to 80 cm away from the patient, the flexible shaft 112 exits the working channel port and extends another 30 cm to 100 cm to the interface joint 106. In use, the interface joint 106 is typically held by a gloved assistant throughout the procedure. The interface cable 104 connects to the generator 102 using a QMA-type coaxial interface designed to allow continuous clockwise or counterclockwise rotation. This allows the interface joint 106 to rotate with the torque transfer unit 116 under the user's control. The assistant holds the interface joint 106 throughout the procedure to sympathetically assist the user with instrument rotation and fluid injection.

[0066] FIG. 2 is a perspective view of an embodiment of an instrument tip 218 that may be used as instrument tip 118 in the system of FIG.

[0067] The instrument tip 218 includes a planar body 220 made of a dielectric material that separates a first conductive element 222 on a first (upper) surface of the planar body from a second conductive element (not shown) on a second (lower) surface of the planar body. A vertical edge 221 extends around the periphery of the planar body between the upper and lower surfaces.

[0068] A proximal portion 224 of the instrument tip 218 may be connected to a flexible shaft (e.g., flexible shaft 112 of FIG. 1 ), which may carry a coaxial feed cable for transmitting RF and / or microwave energy to the first and second conductive elements. The instrument tip 218 includes a pair of lateral steps 226, one on each lateral edge of the planar body 220. The steps 226 are configured to increase the lateral width of the planar body 220 from the proximal portion 224 to the distal portion 228 and are sized to accommodate the distal end of the flexible shaft, such that the flexible shaft can form a substantially flush connection within the proximal portion 224 and against the steps 226 with the exposed (distal) portion 228 of the instrument tip.

[0069] The exposed distal portion 228 of the instrument tip generally tapers inward, providing a decrease in diameter from the lateral step 226 to the rounded distal end 230. A notch 232 is formed on each lateral edge of the exposed portion along a portion of the edge 221 that is axially between the respective step 226 and the rounded tip 230.

[0070] In this embodiment, the notches 232 have corresponding (identical and opposing) configurations such that the instrument tip is symmetrical across its central axis. Specifically, each notch 232 defines a recess formed by a proximal wall, a distal wall, and a rear wall extending between the proximal and distal walls. Together, the walls have a smoothed contour, forming a smoothly concave recess. Each notch 232 forms a respective proximal pointed corner 234 at the edge 221 of the instrument tip and a respective distal pointed corner 236 at the edge 221 of the instrument tip. Each of these corners contributes to providing a visual indication of insertion depth during use. For example, each distal pointed corner 236 may be located 1 mm from the distal end 230, and each proximal pointed corner 234 may be located 2 mm from the distal end 230. These may serve as markers for the clinician to gauge axial insertion depth into biological tissue.

[0071] The first conductive element 222 can also be configured to provide an insertion depth marker. For example, as shown in FIG. 2, the first conductive element 222 can be patterned to form an edge 238 that extends laterally across the planar body and perpendicular to its central axis. This edge can be located, for example, about 4.3 mm from the distal end 230.

[0072] 2, each notch 232 is elongated, being axially longer than it is lateral wide. Additionally, each of the sharp corners 234 and 236 forms a substantially perpendicular angle within the edge 221 of the instrument tip. Each of these features can help to capture the vessel and facilitate cleaning.

[0073] 3 is a perspective view of an alternative instrument tip 240 according to another embodiment of the present invention. Instrument tip 240 is generally similar to instrument tip 218, and like reference numerals refer to like elements unless otherwise noted.

[0074] Instrument tip 240 differs from instrument tip 218 in the configuration of its notches. Whereas instrument tip 218 includes a single elongated notch 232 on each of its lateral edges, instrument tip 240 includes multiple (e.g., two) shorter notches 242 and 244 on each of its lateral edges. Each lateral edge of instrument tip 240 includes a respective proximal notch 242 and a distal notch 244. Each of the notches defines a respective concave recess that terminates in a respective distal and proximal pointed corner.

[0075] Each short notch can be substantially as long (axially) as it is deep (laterally). Thus, it can have a higher curvature than the elongated notch 232 of FIG. 2. This higher curvature can aid in the perception of insertion depth by facilitating that the midpoint of each notch can be easily measured. Additionally, each proximal notch 242 is separated from its respective distal notch 244 by an intermediate edge portion 246, which can also provide an additional indication of depth perception. The intermediate edge portion 246 can be substantially planar, thereby not gripping or snagging tissue.

[0076] By providing multiple notches along each lateral edge, separated by respective edge portions, instrument tip 240 may contribute to providing a more precise scale of depth insertion perception compared to the single elongated notch 242 of FIG. 1 . For example, the distal corner of each distal notch 244 may be located approximately 1 mm from rounded end 230, the center point of each intermediate edge portion 246 may be located approximately 1.5 mm from the rounded end, and the proximal corner of each proximal notch 242 may be located approximately 2 mm from the rounded end. Different reference depths may be useful for different surgical applications. For example, a 1 mm guide may be useful for applications within the lower gastrointestinal tract, while a 2 mm guide may be useful for applications within the stomach.

[0077] 4A-10C show top views of instrument tips 248A-V having various notch configurations. For simplicity, FIGS. 4A-10C do not show the complete configuration of each instrument tip, including the conductive elements, but instead outline the general shape of the instrument tip. However, it will be understood that the shapes shown may be provided by one or more of the planar body, the conductive element(s), and / or a protective hull (if present) on the underside of the planar body. Furthermore, each of these instrument tips 248A-V can be used as a modification to the instrument tip 218 of FIGS. 2 and 3.

[0078] Figures 4A-4C show instrument tips 248A-C, each having an elongated notch. The instrument tips 248A-C of Figures 4A-4C differ from one another primarily by the elongated notch and the angle formed within the elongated notch.

[0079] For example, Figure 4A shows a top view of an instrument tip 248A having a similar shape to that shown in Figure 2, with like reference numerals indicating like elements unless otherwise stated. In contrast to the instrument tip of Figure 2, the instrument tip 248A of Figure 4A omits the lateral step 226. However, like the instrument tip 218 of Figure 2, the instrument tip 248A has a pair of elongated notches 232A along opposite sides. Each elongated notch 232A terminates in a respective proximal pointed corner 234A and distal pointed corner 236A. Each proximal pointed corner 234A forms an obtuse angle between two adjacent surfaces of the instrument tip, i.e., between a proximal end wall 250A of the notch 232A and a proximal edge portion 252A of the instrument tip (e.g., a planar body) adjacent the notch 232A. Similarly, each distal sharp corner 236A forms an obtuse angle between the distal end wall 254A of the notch and the distal edge (also referred to as the distal edge portion) 256A of the planar instrument tip (e.g., planar body) adjacent the notch 232A. Each notch 232A includes a substantially planar rear wall 258A located laterally inward of the end walls 254A and 250A, providing a smooth contour to the respective end walls 254A and 250A. This configuration helps to reduce clogging and provide a notch that is easily cleaned.

[0080] In contrast, Figure 4B shows a configuration with a pair of opposing elongated notches 232B, each having a distal pointed corner 254B that forms a substantially perpendicular angle between the distal end wall 254B of the notch 232B and the distal edge 256B of the instrument tip 248B. This can further improve traction and help trap tissue within the notch recess. Furthermore, within each notch 232B, the rear wall 258B and end wall 250B meet to form a pointed corner rather than forming a smoothly contoured recess as shown in Figure 4A. As in Figure 4A, each proximal pointed corner 234B in Figure 4B still forms an obtuse angle at the edge of the instrument tip, which promotes smooth insertion into tissue distally.

[0081] 4C shows a configuration with a pair of opposing elongated notches 232C, each having a distal pointed corner 236C that forms an acute angle between the distal end wall 254C of the notch and the distal edge portion 256C of the planar body. Each acute corner 236C faces proximally, thereby functioning as a barb that may help anchor the instrument tip in a specific location by resisting proximal movement / misalignment relative to the biological tissue. Each acute corner 236C contributes to forming / overhanging a hook-shaped recess in the distal end wall 254C of the notch 232C, which further contributes to hooking onto individual tissue fibers or blood vessels. The hook-shaped recesses of the notches are smoothly contoured and their lateral depths are tapered so that the proximal end of the notch is shallower than the distal end of the notch. Thus, each notch 232C terminates at its proximal end in a proximal sharp corner 234C that is more obtuse than the proximal sharp corners 234A-B shown in Figures 4A-4B, thereby further facilitating smooth distal insertion into tissue.

[0082] Figures 5A and 5B show instrument tips 248D-E, each having multiple short notches. Instrument tip 248D of Figure 5A is similar to that shown in Figure 3, with like reference numbers indicating like elements. However, instrument tip 248D of Figure 5A has been modified to omit lateral step 226 shown in Figure 3. Instrument tip 248D includes multiple (e.g., two) short notches 242D, 244D on each side, with each notch terminating in a pair of sharp corners.

[0083] 5B shows a further modified instrument tip 248E whereby notches 242E and 244E are smoothly contoured to the lateral edges of the instrument tip (e.g., a planar body) rather than forming sharp corners at the edges of the instrument tip (e.g., a planar body). As a result, each intermediate edge portion 246E is similarly smoothly contoured and forms a curve between the respective notches 242E and 244E.

[0084] 6A-6C show embodiment instrument tips 248F-H, which may be particularly useful for hooking and pulling individual fibers, respectively. Fig. 6A shows instrument tip 248F having a pair of opposing elongated notches 232F, each terminating in a barb 236F that projects from the distal end of the recess, thereby forming a hook. Instrument tip 248F is similar to instrument tip 248C, except that notches 232F form a deeper hook-like recess, which allows for better hooking and helps further prevent the device from slipping.

[0085] 6B shows a modified instrument tip 248G having a pair of opposing, relatively short notches 260G located at (e.g., only at) the distal-most end of the instrument tip 248G, e.g., in the distal quarter of the exposed portion of the instrument tip 248G. In contrast, instrument tips 248A-F had notches located along their central regions (e.g., within the central two-quarters along the length of the exposed portion of the instrument tip). Thus, instrument tip 248G is particularly useful for fine retraction and retraction near the end of the instrument tip 248G.

[0086] 6C shows a modified instrument tip 248H having multiple pairs (e.g., three pairs) of opposing notches formed along most of the lateral edges of the instrument tip. Each notch includes a barbed distal corner 236H, 236H', and 236H''. The barbed corners vary in sharpness, with the most distal barbed corner 236H being the sharpest and the most proximal barbed corner 236H'' being the most obtuse.

[0087] 7A-7B show modified instrument tips 248I-248J that may be particularly advantageous for fine work. Instrument tip 248I includes paired notches 262I and 264I that together form elongated, thinned section 266I of the instrument tip. Thinned section 266I has a lateral width that is approximately 30% of the maximum lateral width of instrument tip 248I. Elongated, thinned section 266I terminates in rounded ends, forming a "pen tip" configuration at the distal end of instrument tip 248I for precisely controlled cutting.

[0088] Instrument tip 248J similarly has paired notches 262J and 264J that form elongated, thinned section 266J. However, elongated, thinned section 266J terminates in enlarged sections 268J that define paired sharp corners that form respective barbs at the distal ends of notches 262J and 264J. Thinned section 266J maximizes the size of the hooks formed by notches 262J and 264J, thereby increasing the amount of tissue that can be captured within the notches.

[0089] 8A-8E show modified instrument tips 248K-O having different notch configurations on a first side compared to a second side. Specifically, instrument tips 248K-O are single-sided instrument tips each having a notch on only its first side. This allows for different types of cuts to be performed depending on the orientation of the device. Additionally, this also allows for larger notches, which can increase the amount of tissue that can be captured, as can be seen, for example, in FIGS. 8B and 8D.

[0090] 9A-9D show modified instrument tips 248P-S that are particularly suited for end-on delivery of energy to vessels / tissue. Each instrument tip 248P-S has a single "fishmouth" notch 270P-S located at the distal end of the respective instrument tip 248P-S and facing distally from the respective instrument tip 248P-S. Each fishmouth notch forms a pair of sharp corners that define a recess for engaging tissue therebetween. Each corner faces distally, away from the distal end of the instrument tip, and abuts against tissue during use. Each notch 270P-S has a different internal shape to provide varying contact with tissue. For example, notch 270P forms a substantially trapezoidal recess, notch 270Q forms a triangular recess, and notches 270R and 270S each form a rounded (elliptical) recess of different depths.

[0091] 10A-10C show modified instrument tips 248T-V with relatively shallow, symmetrical notches that improve traction compared to instrument tips without any notches without adding excessive friction. The notches each have a lateral depth that is less than 30% of the maximum width of the respective instrument tip 248T-V.

[0092] Figure 11 shows various instrument tips 272A-E having shapes similar to those described above, but showing details of the planar body and first conductive element. For example, instrument tip 272A has a planar body 248A that has a pen-tip notch configuration similar to that shown in Figure 7A, and conductive element 222A does not include any notches formed therein. In contrast, instrument tips 272B-E each have notches formed in both their planar body and first conductive element.

[0093] Figure 12 shows yet another instrument tip 272F, which is connected to flexible shaft 112. Instrument tip 272F includes a pair of opposing notches, each having a pointed distal end and a smoothly contoured proximal end. This allows the distal edges of the notches to better engage tissue while also ensuring that the proximal ends of the notches do not impede insertion of the instrument tip. Flexible shaft 112 is substantially flush with the exposed portion of instrument tip 272F because it rests on a pair of lateral steps formed in the planar body of instrument tip 272F, similar to those described above in connection with Figures 2 and 3.

[0094] Figures 13 and 14 show a modified instrument tip 274 connected to flexible shaft 112, for use in the system of Figure 1, for example. Instrument tip 274 is similar to instrument tip 218 of Figure 2 in that both have pairs of opposing elongated notches.

[0095] Similar to FIG. 2 , instrument tip 274 comprises an active tip including a planar body 220 separating first conductive element 222 from second conductive element 222. A pair of elongated notches 232 are formed in opposing side edges of the active tip. In FIGS. 13 and 14 , instrument tip 274 further includes a protective hull 276 disposed below the active tip. Protective hull 276 includes a strip of dielectric material, which may have a smoothly contoured, convex underside facing away from planar body 220. Optionally, protective hull 276 may include a channel (e.g., a tubular channel or needle) 278 for conveying fluid into the processing zone. As shown in FIGS. 13 and 14 , notches 232 may be formed in opposing side edges of protective hull 276 and in the active tip.

[0096] 13 and 14 further differs from the instrument tip 218 of Figure 2 in that the first conductive element 222 of the instrument tip 274 has a different pattern that covers a different (e.g., a larger) percentage of the planar body 220 compared to the first conductive element 222 of the instrument tip 218. The second conductive element may have a similar pattern as the first conductive element 222 in each embodiment.

[0097] 13 and 14 further illustrate the connection between the flexible shaft 112 and the instrument tip 274. In FIG. 13, the shaft 112 is transparent for purposes of illustration to show the electrical connection with the instrument tip 274. Specifically, the flexible shaft 112 comprises a coaxial cable 280 for transmitting RF and / or microwave frequency EM signals to the instrument tip 274. The coaxial cable 280 comprises an inner conductor 282, an outer conductor 284 coaxial with the inner conductor 282, and a dielectric material 286 separating the inner and outer conductors. The inner conductor 282 is electrically connected to the first conductive element 222, and the outer conductor 284 is electrically connected to the second conductive element, allowing the instrument tip to receive the EM signals.

[0098] Alternatively, it will be understood that any variant of the instrument tip described herein may be connected to the coaxial feed cable in a corresponding manner. The features disclosed in the foregoing description, or in the following claims, or in the accompanying drawings, are expressed in their specific form, or in terms of means for performing a disclosed function, or methods or processes for obtaining a disclosed result, and such features can be utilized individually or in any combination, as appropriate, to realize the invention in various forms thereof.

[0099] While the present invention has been described in conjunction with the above exemplary embodiments, many equivalent modifications and variations will become apparent to those skilled in the art given this disclosure. Accordingly, the exemplary embodiments of the present invention set forth above are considered to be illustrative and not limiting. Various changes can be made to the described embodiments without departing from the spirit and scope of the invention.

[0100] For the avoidance of doubt, the theoretical explanations provided herein are provided for the purpose of enhancing the understanding of the reader, and the inventors do not wish to be bound by any of these theoretical explanations.

[0101] Any section headings used herein are for organizational purposes only and should not be construed as limiting the subject matter described.

[0102] Throughout this specification, including the claims that follow, unless the context clearly indicates otherwise, the words "comprise" and "include" and variations thereof (such as "comprises," "comprising," and "including") are understood to mean the inclusion of a stated integer or step or group of integers or steps, but not the exclusion of other integers or steps or groups of integers or steps.

[0103] It should be noted that, as used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Ranges may be expressed herein as from "about" one particular value and / or to "about" another particular value. When such a range is expressed, another embodiment includes from the one particular value and / or to the other particular value. Similarly, when values ​​are expressed as approximations, by use of the antecedent "about," it will be understood that the particular value forms another embodiment. The term "about" with respect to numerical values ​​is arbitrary and means, for example, + / - 10%. [Explanation of symbols]

[0104] 100 Electrosurgical System 102 Generator 104 Interface cable 106 Interface Joint 108 Fluid Delivery Device electrosurgical instruments 112 Flexible shaft 280 coaxial cable 282 Inner conductor 284 Outer conductor 286 Dielectric Materials 118, 218, 240, 248A~V, 272A~F, 274 Instrument tip 220, 248 Planar bodies 222 first conductive element 238 Edge 276 Protective Hull 278 channels 224 Proximal 226 Side Step 228 Distal 230 distal end 232 Long and narrow notch 234 Proximal sharp corner 236 Distal sharp corner 250 proximal end wall 254 Distal end wall 258 Back wall 242 Proximal Notch 244 Distal Notch 246 Middle edge part 252 Proximal marginal portion 256 Distal margin 266 Long, thin-walled section 262, 264 Pair of notches 268 Enlarged section 270 Fishmouth Notch 107 Fluid supply cable 114 Surgical Scoping Device 116 Torque transmission unit

Claims

1. 1. An electrosurgical instrument for applying radio frequency (RF) electromagnetic (EM) energy and / or microwave frequency EM energy to biological tissue, said electrosurgical instrument comprising: an instrument tip comprising a planar body made from a first dielectric material separating first conductive elements on a first surface from second conductive elements on a second surface, the second surface facing away from the first surface; a coaxial feeder cable including an inner conductor, an outer conductor coaxial with the inner conductor, and a dielectric material separating the inner conductor and the outer conductor, the coaxial feeder cable being for transmitting RF and / or microwave signals; the inner conductor is electrically connected to the first conductive element and the outer conductor is electrically connected to the second conductive element, allowing the instrument tip to receive the RF signals and / or the microwave signals; The electrosurgical instrument wherein the edge of the instrument tip has a notch defining a recess for engaging tissue therein.

2. The electrosurgical instrument of claim 1 , wherein at least one end of the notch forms a sharp corner at the edge of the instrument tip.

3. The electrosurgical instrument of claim 2 , wherein the sharp corner forms an obtuse angle between two adjacent surfaces of the instrument tip.

4. The electrosurgical instrument of claim 2 , wherein the sharp corner forms an acute angle between two adjacent surfaces of the instrument tip.

5. The electrosurgical instrument of claim 4 , wherein the sharp corner comprises a proximally facing barb.

6. An electrosurgical instrument according to claim 2 , wherein a distal end of the notch forms the sharp corner.

7. Electrosurgical instrument according to any preceding claim, wherein at least one end of the notch smoothly merges with the edge of the instrument tip.

8. An electrosurgical instrument according to claim 7 , wherein the proximal end of the notch smoothly merges with the edge of the instrument tip.

9. 10. An electrosurgical instrument according to any preceding claim, wherein the notch is located at the distal end of the instrument tip and faces distally away from the instrument tip.

10. 10. The electrosurgical instrument of claim 9, wherein the notch forms a pair of sharp corners defining the recess for engaging tissue therebetween, each corner facing away from the distal end of the instrument tip to abut the tissue.

11. An electrosurgical instrument according to any one of claims 1 to 8, wherein the notch is located on a lateral edge of the instrument tip.

12. The electrosurgical instrument of claim 11 , wherein the notch is an elongated notch located along the lateral edge.

13. 13. An electrosurgical instrument according to claim 11 or 12, wherein the notch has a lateral depth of less than 30%, optionally less than 20%, optionally less than 15% of the maximum width of the instrument tip.

14. 10. An electrosurgical instrument according to any preceding claim, comprising two or more notches.

15. The electrosurgical instrument of claim 14 , wherein the two or more notches are axially spaced apart.

16. 16. An electrosurgical instrument according to claim 14 or 15, wherein the two or more notches are located on opposite lateral edges of the instrument tip.

17. 17. The electrosurgical instrument of claim 16, wherein the two or more notches together form an elongated thinned portion of the instrument tip, the width of the thinned portion being less than 50%, optionally less than 40%, optionally less than 30%, optionally less than 20% of the maximum width of the instrument tip.

18. The electrosurgical instrument of claim 17 , wherein the elongated thinned section terminates in a rounded end.

19. The electrosurgical instrument of claim 17 , wherein the elongated thinned portion terminates in an enlarged portion to define a sharp corner.

20. 10. An electrosurgical instrument according to any preceding claim, wherein the instrument tip is substantially symmetrical about a central axis.

21. 20. An electrosurgical instrument according to any preceding claim, wherein the instrument tip has a different notch configuration on a first side of the instrument tip than on a second side of the instrument tip.

22. Electrosurgical instrument according to any preceding claim, wherein the first conductive element is patterned to provide axial and / or lateral depth indication.

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