Interface joint for interconnecting an electrosurgical generator and an electrosurgical instrument

Abstract

To provide an interface joint for interconnecting an electrosurgical generator and an electrosurgical instrument.SOLUTION: An interface joint 120 comprises: a housing 122 having an inlet for receiving electromagnetic energy from the electrosurgical generator, and an outlet; a slidable trigger 135 on the housing, the slidable trigger being attached to a push rod 130 that extends out of the housing through the outlet; and a single cable assembly for connecting the outlet to the electrosurgical instrument, the single cable assembly comprising a flexible sleeve 154 that conveys the push rod and a coaxial cable 142 that is connected to the inlet. The interface joint 120 may include a reinforcement element coupled to a first portion of the push rod so as to reinforce the first portion.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to an interface joint for interconnecting an electrosurgical generator and an electrosurgical instrument. The electrosurgical instrument can be for delivering electromagnetic energy (e.g., radio frequency and / or microwave energy) to living tissue to cut tissue and / or to stop bleeding (i.e., to promote blood coagulation).

Background Art

[0002] Surgical resection is a means of removing a part of an organ from within the human body or an animal. Such organs can be highly vascular. When tissue is cut (divided or severed), small blood vessels called arterioles are damaged or ruptured. Following initial bleeding, a coagulation cascade occurs and the blood changes to a blood clot to seal the bleeding point. During surgery, it is desirable to minimize the blood lost by the patient, and various devices have been developed to provide bloodless cutting. In the case of endoscopic surgery, bleeding is also undesirable as the blood flow obscures the operator's view, which can prolong the surgery and necessitate ending the surgery and potentially using an alternative method, such as open surgery, and thus it is necessary to address it in an appropriate way.

[0003] Electrosurgical generators are widespread in hospital operating rooms and are often used in open and laparoscopic surgeries, and are increasingly being used with surgical scoping devices, such as endoscopes. In endoscopic surgery, electrosurgical accessories are typically inserted through the lumen within the endoscope. Compared to the equivalent access channels for laparoscopic surgery, such lumens are relatively narrow in diameter and long in length.

[0004] Instead of a sharp blade, it is known to use radio frequency (RF) energy to cut biological tissue. The method of cutting using RF energy operates using the principle that when an electric current passes through the tissue matrix (assisted by the ionic content of the cells and the extracellular electrolytes), the impedance to the flow of electrons across the tissue generates heat. In practice, the instrument is arranged to apply an RF voltage across the entire tissue matrix sufficient to generate heat within the cells to vaporize the water content of the tissue. However, as a result of this increased drying, there is a possibility of losing direct physical contact between the tissue and the instrument, particularly adjacent to the RF emission region of the instrument (which has the highest current density of the current path through the tissue). The applied voltage appears as a voltage drop across this small void, which causes ionization within the void and the generation of plasma. Plasma has a very high volume resistivity compared to tissue. The energy supplied to the instrument sustains the plasma, i.e., completes the electrical circuit between the instrument and the tissue. Volatile substances entering the plasma can be vaporized, and thus the perception is of plasma cutting through the tissue.

[0005] GB2523246 describes an electrosurgical instrument for applying RF electromagnetic energy and / or microwave frequency EM energy to biological tissue. The instrument includes a shaft that can be inserted through the instrument channel of a surgical scoping device. At the distal end of the shaft is an instrument tip that includes 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 arranged to supply either microwave 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 material separating the outer conductor from the inner conductor, and the inner and outer conductors extend beyond the second dielectric at the connection interface and overlap the opposite surfaces of the transmission line and are in electrical contact with the first and second conductive layers, respectively. The instrument It further includes a protective outer shell with a smooth - contoured convex lower surface facing away from the planar transmission line. The lower surface includes a longitudinally extending recessed channel formed therein. A retractable needle is attachable within the instrument and is operable to extend through the recessed channel so as to protrude from the distal end of the instrument. The needle can be used to inject fluid into the treatment zone before RF or microwave energy is applied.

[0006] GB2523246 also describes an interface joint for integrating all of (i) fluid supply, (ii) needle movement mechanism, and (iii) energy supply (e.g., a cable for supplying RF and / or microwave energy) into a single - cable assembly. The cable assembly can be sized to fit through the instrument channel of a conventional endoscope. More specifically, the interface joint is a housing made of an electrically insulating material, having a first inlet for receiving radio - frequency (RF) electromagnetic (EM) energy and / or microwave - frequency EM energy from an electrosurgical generator, a second inlet for receiving fluid, and an outlet; and a single - cable assembly for connecting the outlet to an electrosurgical instrument, the single - cable assembly including a flexible sleeve that defines a fluid flow path fluidly connected to the second inlet and carries a coaxial cable connected to the first inlet. Also, the interface joint can include a slidable trigger on the housing, and the slidable trigger is attached to a push - rod that extends out of the housing through the outlet.

SUMMARY OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] Most generally, the present invention provides a development of the interface - joint concept discussed in GB2523246. The development can include reinforcement of the push - rod. In this way, the damage of the push - rod and the resulting possibility of malfunction can be reduced.

[0008] Furthermore, the flexible sleeve can include an inner tube that surrounds the push rod and is free to slide relative to the push rod. Development can include limiting the maximum slide distance of the inner tube over the push rod. In this way, damage to the inner tube and the resulting possibility of malfunction can be reduced.

Means for Solving the Problem

[0009] One aspect of the present invention provides an interface joint for interconnecting an electrosurgical generator and an electrosurgical instrument, the interface joint having a housing having an inlet for receiving electromagnetic energy from the electrosurgical generator and an outlet, and a slidable trigger on the housing, the slidable trigger being attached to a push rod extending out of the housing through the outlet, and a single cable assembly for connecting the outlet to the electrosurgical instrument, the single cable assembly including a flexible sleeve carrying the push rod and a coaxial cable connected to the inlet.

[0010] The interface joint can also include a second inlet for receiving fluid. Also, the flexible sleeve can define a fluid flow path that is in fluid communication with the second inlet. Thus, the aforementioned inlet for receiving electromagnetic energy can be referred to as the "first" inlet.

[0011] The electromagnetic energy can include radio frequency (RF) energy and / or microwave frequency energy. The electrosurgical generator can be any device capable of delivering RF EM energy or microwave frequency EM energy for the treatment of biological tissue and can be. For example, the generator described in WO2012 / 076844 can be used.

[0012] An electrosurgical instrument can be any device that is prepared to use RF EM energy or microwave frequency EM energy for the treatment of biological tissue during use. The electrosurgical instrument can use RF EM energy and / or microwave frequency EM energy for any or all of excision, coagulation, and ablation. For example, the instrument can be an excision device as disclosed herein, but alternatively can be any of a pair of microwave forceps, a snare that emits microwave energy and / or couples RF energy, and an argon beam coagulator.

[0013] The interface joint may include a reinforcing element (or structure) coupled to the first portion of the push rod to reinforce the first portion. The first portion can be disposed partially or completely inside the housing. Further, the first portion may be partially (i) inside the outlet, (ii) inside the single cable assembly, or (iii) inside both. For example, when a slidable trigger is actuated to fully retract the push rod, the reinforcing element can be disposed only inside the housing, rather than, for example, inside the outlet or the single cable assembly (or flexible sleeve). Additionally or alternatively, when a slidable trigger is actuated to fully extend the push rod, the reinforcing element may be disposed inside the housing and the outlet, and optionally the single cable assembly (and flexible sleeve). In this way, the push rod can be strengthened and supported while disposed in the free space of the housing. Next, the operation of the slidable trigger when extending or retracting the push rod improves reliability because the push rod is less likely to bend or otherwise be damaged. As a result, the operation of the slidable trigger when operating the push rod becomes more consistent, thereby facilitating user control. For example, the reinforcing element is a support tube surrounding the first portion. The support tube may be made of stainless steel. Also, the support tube can be fixed to the first portion to prevent relative movement between the support tube and the first portion. In one embodiment, the support tube is fixed to the first portion by mechanical crimping and / or an adhesive (e.g., an ultraviolet adhesive). Additionally or alternatively, the support tube may be laser welded to the first portion.

[0014] The flexible sleeve includes an inner tube that surrounds a second portion of the push rod, and the inner tube is free to slide relative to the push rod. The second portion can be the distal side of the reinforcing element. The second portion can be partially or fully disposed within the single cable assembly. Further, the second portion can be partially (i) inside the housing, (ii) inside the outlet, or (iii) inside both. For example, when a slidable trigger is actuated to fully extend the push rod, the inner tube can be disposed only within the single cable assembly (and the flexible sleeve), rather than, for example, inside the outlet or the housing. Additionally or alternatively, when a slidable trigger is actuated to fully retract the push rod, the inner tube can be disposed inside the single cable assembly, the outlet, and optionally the housing. The inner tube can be a single lumen tube that can define a single channel for a plurality of different uses. For example, the single lumen tube can carry the push rod. Also, if the interface joint includes a second inlet for receiving fluid, the single lumen tube can carry a fluid supply conduit for providing a fluid flow path between the instrument and the interface joint. Additionally or alternatively, the single lumen tube can have an open portion for providing a fluid flow path between the instrument and the interface joint, i.e., a separate fluid conduit is not required. Thus, the fluid flow path can overflow the internal cavity and the push rod can be immersed in the fluid. Accordingly, the function of the single lumen tube can be to provide lubricity to the push rod. However, in another embodiment, the inner tube can be a multi-lumen tube or a single lumen tube having extruded separator elements that define a plurality of channels (e.g., two, three, or more). For example, separate lumens / channels can carry one or more of the fluid flow path and the push rod.

[0015] The interface joint may include a slide limiting mechanism coupled to the push rod and configured to limit the maximum slide distance of the inner tube on the push rod. In this way, the movement of the inner tube is restricted to avoid damage to the tube or other components. However, since the slide limiting mechanism allows a certain amount of movement of the inner tube, the inner tube can move (in a restricted manner) relative to the push rod, thus reducing damage (e.g., due to friction) to the inner tube. The slide limiting mechanism can include a first stopper element (or structure) fixed to the outer surface of the push rod on the distal side of the inner tube, and the first stopper element is configured (e.g., dimensioned and / or shaped) to prevent the inner tube from sliding past the first stopper element. Further, the slide limiting mechanism can include a second stopper element (or structure) fixed to the outer surface of the push rod on the proximal side of the inner tube, and the second stopper element is configured (e.g., dimensioned and / or shaped) to prevent the inner tube from sliding past the second stopper element. Thus, the first and second stopper elements limit the sliding movement of the inner tube. For example, the first and second stopper elements may be spaced apart on the push rod such that the maximum slide distance of the inner tube on the push rod is limited to between 4 mm and 10 mm, preferably 5 mm. The second stopper element may be spaced apart from the distal end of the push rod by, for example, between 3 mm and 7 mm, preferably 5 mm. The first stopper element may include a mass, granule, bead, or ball of adhesive (e.g., UV adhesive). The first and second stopper elements can surround only all or a part of the circumference of the push rod. The second stopper element may be provided by a support tube (e.g., the distal end of the support tube).

[0016] The housing may be made of an electrically insulating material. The housing can provide a double-insulation barrier for the operator, i.e., the housing can include an outer casing (first-level insulation) that encloses a branching passage (second-level insulation) in which various inputs are integrated into a single cable assembly. The branching passage can define a fluid flow path between a second inlet (if present) and an outlet, and can provide a watertight volume having a first port adjacent to a first inlet for receiving a coaxial cable. In this embodiment, the outer casing can lead to UV encapsulation.

[0017] In use, the interface joint can be a location where fluid for treatment with the instrument is introduced. The operator of the interface joint can control the introduction of fluid via a syringe or other fluid introduction mechanism attached to the second inlet (if present). The interface joint can also include a fluid delivery deployment mechanism that acts to direct or control fluid delivery with the electrosurgical instrument. For example, as described above, the interface joint can include a slidable trigger on the housing, and the slidable trigger is attached to a push rod that extends out of the housing through an outlet. The push rod can extend through a flexible shaft to the electrosurgical instrument, where it can control a fluid delivery structure. For example, the electrosurgical instrument can include a retractable needle that can be switched to make or break fluid connection with a fluid flow path within the flexible shaft by sliding the push rod back and forth.

[0018] In this arrangement, the branching passage can include a second port adjacent to the slidable trigger for receiving the push rod.

[0019] Both the first port and the second port may each include a sealing plug that defines a watertight passage for a coaxial cable and a push rod. The sealing plug can be formed from an elastically deformable material, such as silicone rubber, whereby the coaxial cable and the push rod are encapsulated by the material as they pass through the material. Sealing the first and second ports in this manner means that the only path for fluid from the interface joint is through the outlet along the fluid flow path of the flexible sleeve.

[0020] The branched passage can have any suitable configuration. In one embodiment, it is formed from a pair of Y-shaped conduits connected to each other to define a first length that aligns with the outlet, a second length that extends at an oblique angle to the first length from a side of the first length, and a third length that extends from a side of the second length. One or both of the Y-shaped conduits are made of polycarbonate or acrylonitrile butadiene styrene (ABS). The first length can have a push rod extending therethrough and can terminate at its proximal end at the sealing plug. The second length can have a coaxial cable extending therethrough and can terminate at its proximal end at the sealing plug. The third length can terminate at a second port for receiving fluid. In this arrangement, the housing can take the shape of a pistol. However, in another embodiment, the branched passage can have a more compact configuration in which the different lengths of the passage run substantially parallel to each other. In this arrangement, the housing can be an elongated capsule sized to fit in an operator's hand.

[0021] When the housing has a pistol-like shape, this shape may have an upper barrel portion and a lower adjacent portion extending away from the proximal end of the upper barrel portion. For example, the upper barrel portion has a length between 115 mm and 125 mm, preferably 120 mm, when measured from the distal end of the housing (i.e., the proximal end of the outlet) to the proximal end of the upper barrel portion. Also, the lower adjacent portion has a length between 100 mm and 110 mm, preferably 105 mm, when measured from the distal end of the housing (i.e., the proximal end of the outlet) to the proximal end of the lower adjacent portion.

[0022] Also, the housing (e.g., the upper barrel portion) can include a slot on its outer surface, and a slidable trigger is slidably fixed to the housing (e.g., the upper barrel portion) such that it is slidable within the slot. The slidable trigger has an integral button portion on the outside of the housing and an integral elongated portion on the inside of the housing, and the button portion is shorter in length (i.e., shorter) than the elongated portion. In one embodiment, the slot is disposed toward the proximal end of the upper barrel portion, and the button portion is disposed toward the proximal end of the elongated portion. In this way, the button can be disposed toward the proximal end of the upper barrel portion so that the slidable trigger is more easily accessible to the user and thereby more controllable by the user. For example, the slot has a length between 54 mm and 58 mm, preferably between 56.2 mm, and a width between 1.0 mm and 1.6 mm, preferably between 1.3 mm. In another embodiment, the slot has a length between 25 mm and 31 mm, preferably 28 mm, and a width between 1.1 mm and 1.8 mm, preferably 1.4 mm. Disposing the slot and the button portion toward the proximal end makes the button portion more easily accessible to the user, facilitating control, i.e., the user does not have to reach as far to move the button portion along the full length of the slot. Also, in this configuration, the slide distance of the button can be maximized to maximize the distance the pull rod can move. Next, this additional slide distance allows the slidable trigger to compensate for the difference between the linear and curved positions of the push rod. and provide additional force to overcome friction when the needle ferrule is in a tight configuration.

[0023] The interface joint can be particularly suitable for gathering a plurality of inputs into a single cable assembly before being inserted through the instrument channel of the endoscope. To achieve this, the cable assembly can have an outer diameter of 9 mm or less, for example 2.8 mm or less, in the case of a flexible video colonoscope.

[0024] To facilitate the operation of the instrument at the distal end of the instrument channel of the endoscope, the flexible sleeve can comprise a longitudinal braid therein to assist in the transmission of torque, i.e., to transmit the torsional movement at the proximal end of the cable assembly to the distal end of the cable assembly, where the torsional movement can cause the two-way rotation of the instrument since the instrument is attached to the cable assembly. The flexible sleeve can include an inner tube and an outer tube, which are joined together or otherwise attached with a metallized braided tube therebetween. The inner tube or the outer tube can be made of a polymer such as a thermoplastic elastomer such as polyether block amide or PEBA (e.g., PEBAX (trademark)). Also, the braided tube can include two or more (e.g., three) radially spaced layers of wrap-mounted braided wires. Each layer or each wrap can consist of a plurality of wires, e.g., six wires. In one embodiment, each wire can have a substantially flat cross-section. Further, adjacent layers of the braided wires can have opposite winding directions. The pitch of the braid can be variable along the length of the cable assembly. For example, it may be useful to widen the pitch in a certain region, e.g., the distal portion of the cable where flexibility is important. To prevent the metallized braid from interfering with the RF field or microwave field of the instrument, a distal portion of the flexible sleeve without a braid can be provided. The distal portion can be manufactured separately and attached (e.g., joined or welded) to the braided portion. The distal portion is called a "soft tip" and can facilitate the operation of the device by forming a more flexible portion that can move with the endoscope during use. The distal portion can also function to couple the tip of the instrument to the flexible sleeve.

[0025] The housing can be attached to the outlet and further include a strain relief element surrounding the flexible sleeve. The function of the strain relief element is to limit the movement of the sleeve at this location and prevent excessive bending that could damage the internal components.

[0026] The distal end of the push rod can be connected to the proximal end of a needle ferrule to which a needle is clamped at its distal end. The ferrule can be hollow and have one or more openings in its outer wall, whereby its interior is in fluid communication with a fluid flow path passing through a flexible sleeve. The distal end of the ferrule may be open such that a needle attached to the distal end is in fluid communication with the fluid flow path. The proximal end of the ferrule can be sealed by the push rod.

[0027] The interface joint can include a coaxial cable attached to a first inlet via an interface connection, the interface connection being configured to allow relative rotation of the interface joint with respect to the coaxial cable.

[0028] As used herein, radio frequency (RF) can mean a stable fixed frequency in the range of 10 kHz to 300 MHz, and microwave frequency can mean a stable fixed frequency in the range of 300 MHz to 100 GHz. The RF energy should have a frequency high enough to prevent the energy from causing nerve stimulation and low enough to prevent the energy from causing tissue branching or unnecessary thermal margins or damage to tissue structures. Preferred spot frequencies for RF energy include any one or more of 100 kHz, 250 kHz, 400 kHz, 500 kHz, 1 MHz, 5 MHz. Preferred spot frequencies for microwave energy include 915 MHz, 2.45 GHz, 5.8 GHz, 14.5 GHz, 24 GHz.

[0029] Embodiments embodying the present invention are described in detail below with reference to the accompanying drawings.

Brief Description of the Drawings

[0030]

Figure 1

Figure 2

Figure 3

Figure 4A

Figure 4B

Figure 5A

Figure 5B

Figure 6

Figure 7A

Figure 7B

Figure 8

Figure 9

Figure 10A

Figure 10B

Figure 10C

DETAILED DESCRIPTION OF THE INVENTION

[0031] Various aspects of the present invention are presented below in the context of an electrosurgical system that provides an electrosurgical invasive instrument for use in endoscopic surgery for the removal of polyps and malignancies through the controlled delivery of both microwave and RF energy. However, it should be understood that the aspects of the invention presented herein need not be limited to this particular application. They may be equally applicable in embodiments where only RF energy is required, or in embodiments where only RF energy and fluid delivery are required.

[0032] FIG. 1 is a schematic diagram of a complete electrosurgical system 100 that can selectively supply any or all of RF energy, microwave energy, and a fluid, such as saline or hyaluronic acid, to the distal end of an invasive electrosurgical instrument. System 100 includes a generator 102 for controllably supplying electromagnetic (EM) energy. In this embodiment, the EM energy includes RF EM energy and / or microwave frequency EM energy. A suitable generator for this purpose is described in WO2012 / 076844, which is incorporated herein by reference.

[0033] Generator 102 is connected to interface joint 106 by interface cable 104. Interface joint 106 is also connected to receive a fluid supply 107 from a fluid delivery device 108, such as a syringe. Interface joint 106 houses a needle movement mechanism operable by sliding trigger 110. The function of interface joint 106 is to couple inputs from generator 102, fluid delivery device 108, and the needle movement mechanism to a single flexible shaft 112, which extends from the distal end of interface joint 106. It should be understood that shaft 112 may form part of interface joint 106. The internal configuration of interface joint 106 is discussed in more detail below.

[0034] The flexible shaft 112 is insertable through the entire length of the instrument (working) channel of the surgical scoping device 114. The torque transmission unit 116 is attached to the proximal length of the shaft 112 between the interface joint 106 and the surgical scoping device 114. The torque transmission unit 116 engages with the shaft and can rotate the shaft within the instrument channel of the surgical scoping device 114.

[0035] The flexible shaft 112 passes through the instrument channel of the surgical scoping device 114 and has an electrosurgical instrument tip 118 shaped to protrude (e.g., inside the patient) at the distal end of the endoscope's tube. The instrument tip includes an active tip for delivering RF EM energy and / or microwave EM energy to biological tissue and a retractable subcutaneous injection needle for delivering fluid. These combined techniques provide a unique solution for cutting and destroying unwanted tissue and the ability to seal blood vessels around the target area. By using the retractable subcutaneous injection needle, the surgeon can inject saline and / or hyaluronic acid with added marker dye between tissue layers to inflate and mark the location of the lesion being treated. The injection of liquid in this way lifts and separates the tissue layers, facilitates resection of both the plane passing around the lesion and through the submucosal layer, and reduces the risk of intestinal wall perforation and unnecessary thermal damage to the muscular layer.

[0036] As discussed in more detail below, the instrument tip 118 further includes a protective outer shell disposed under the active tip to assist in supporting a tissue planning type of resection operation, protecting against inadvertent perforation, and again helping to ensure the viability of the remaining tissue, which in turn facilitates rapid healing and postoperative recovery.

[0037] The structure of the instrument tip discussed below can be specifically designed for use with a conventional steerable flexible endoscope having a working channel with an inner diameter of at least 3.3 mm and a channel length between 60 cm and 170 cm. Thus, most of the relatively small diameter (less than 3 mm) instruments are housed within the lumen of a flexible endoscope channel, which is much larger and is typically a polymer-insulated device having an outer diameter of usually 11 mm to 13 mm. In practice, only 15 mm to 25 mm of the distal assembly protrudes from the distal end of the endoscope channel so as not to obstruct the view or adversely affect the focusing of the camera. The protruding portion of the distal assembly is the only part of the instrument that comes into direct contact with the patient.

[0038] Normally, at the proximal end of the endoscope working channel, which is held from 50 cm to 80 cm from the patient, the flexible shaft 112 exits the working channel port and extends an additional 30 cm to 100 cm to the interface joint 106. During use, the interface joint 106 is typically held by an assistant wearing gloves throughout the procedure. The interface joint 106 is designed and manufactured from a polymer material in such a way as to provide primary and secondary electrical insulation with an extended creep distance and clearance distance. The interface cable 104 is connected to the generator 102 using a QMA type coaxial interface designed to allow continuous rotation in a clockwise or counterclockwise direction. Thereby, the interface joint 106 can rotate with the torque transmission unit 116 under the control of the user. The assistant supports the interface joint 106 throughout the procedure to assist the user with rotation of the sympathetic instrument, control of the needle, and injection of fluids.

[0039] Figures 2 and 3 show the structure of the interface joint 120, which is an embodiment of the present invention. The interface joint includes a housing or a rigid plastic shell 122 that encloses several internal components. In Figures 2 and 3, half of the shell 122 is removed to show the inside of the joint. The shell 122 is in the shape of a pistol, that is, it has an upper barrel portion 121 and a lower adjacent portion 123 that extends obliquely away from the proximal end of the upper barrel portion. The upper barrel portion 121 includes a needle movement mechanism, while the lower adjacent portion 123 includes connections for fluid and energy supply. In one embodiment, the upper barrel portion has a length of about 120 mm and the lower adjacent portion has a length of about 105 mm.

[0040] The core of the interface joint 120 is a pair of Y-shaped conduits 124, 126, which are fitted together to define a branched passage. The Y-shaped conduits can be made of polycarbonate or other suitable rigid plastics (e.g., ABS) and are shown in more detail in Figures 4A and 4B.

[0041] Figures 4A and 4B show a Y-shaped conduit 250 in which a branched passage is formed. Each Y-shaped conduit has a main linear channel between a first inlet 252 and an outlet 254, and a second channel is at an oblique angle to the main linear channel. The second channel has a second inlet 256 and joins the main linear channel along about half of its length. Each of the first inlet 252 and the second inlet 256 has a rotary luer lock fitting 258.

[0042] Returning to FIGS. 2 and 3, the first length 128 of the branch passage is attached to and along the upper barrel portion 121 of the shell 122. The first length 128 receives, at its proximal end, a push rod 130 for controlling the deployment of the retractable needle. The push rod 130 has a bent proximal end 132 which is attached, for example by heat staking, to a slidable trigger 135. The slidable trigger 135 includes an integral elongated portion 134 disposed inside the shell 122 and an integral button portion 136 disposed outside the shell 122. The push rod 130 can be fixed to the proximal end of the elongated portion 134. The button portion can be shorter in length than the elongated portion 134 such that most of the structure of the slidable trigger 135 is disposed within the shell 122.

[0043] Considering the slidable trigger 135 in more detail, the upper barrel portion 121 includes a slot 137 on its outer surface, and the slidable trigger 135 is slidably fixed to the upper barrel portion 121 so as to be slidable within the slot 137. For example, the slidable trigger 135 can be formed with side grooves that each receive a different side end of the slot 137 such that the slidable trigger 135 can slide along the side surface of the slot 137. In one embodiment, the slot has a length of about 56.2 mm and a width of about 1.3 mm. The button portion 136 projects from the shell 122 of the interface joint 120, such that the user's thumb can move the button portion 136 back and forth, thereby causing the needle to slide in and out of the distal assembly via the sliding movement of the push rod 130 and the needle ferrule, as described in more detail below. In one embodiment, the slot 137 is disposed toward the proximal end of the upper barrel portion 121, and the button portion 136 is disposed toward the proximal end of the elongated portion 134. Disposing the slot 137 and the button portion 136 toward the proximal end makes control easier because the button portion 136 is more readily accessible to the user during use. That is, this configuration is more comfortable for the human hand to hold than, for example, holding the distal end of the shell 122, so the user is likely to hold the interface joint toward its proximal end. Also By holding the proximal end of the shell 122, it is possible to maximize the slide distance of the button portion 136 and thus maximize the distance that the pull rod 130 can move in and out (i.e., its maximum slide travel distance). The additional slide distance enables the slidable trigger 135 to compensate for the difference between the linear and curved positions of the push rod 130 and provides additional force to overcome friction when the needle ferrule is in a tight configuration. Further, the additional slide distance can conveniently enable the needle to be extended at the position of a curved endoscope. Such advantages may be available by generally increasing the interface joint, but this increases the bulk of the device and thus makes handling and control less easy. Therefore, arranging the slot and button portion as described above enables the same advantages without the need to increase the overall bulk of the interface joint.

[0044] The proximal end of the first length 128 is sealed by a silicone plug 138, which is shown in more detail by FIGS. 5A and 5B. FIGS. 5A and 5B are a perspective view and a cross-sectional view, respectively, of the plug 138 sealing the proximal end of the first length of the branch passage. The plug includes a rotary luer lock fitting 246 and, for example, an integral sealing diaphragm 248 made of elastic deformable rubber.

[0045] Returning to FIGS. 2 and 3, the second length 140 of the branch passage is attached to the lower adjacent portion 123 and is in a state along it, that is, at an oblique angle with respect to the first length 128. The second length 140 carries the coaxial cable 142 from the proximal QMA type connector 144 to the proximal end of the first length 128, where the coaxial cable 142 contacts the push rod 130 and exits the interface joint 120 through the distal outlet 146. The QMA type connector 144 is connected to the interface cable from the generator. The coaxial cable 142 can be a Sucoform 047 coaxial cable coated with a 30 μm layer of parylene C. The coaxial cable 142 can pass through the silicone sealing plug 148 at the proximal end of the second length 140.

[0046] The third length 150 of the branch passage exits from the second length 140 and provides an outward fluid receiving port 152. The fluid receiving port 152 can be a threaded luer lock fitting for sealing engagement with a suitable syringe or the like. The sealing plug 148 and the stopper 138 seal the branch passage so that water-tight, and thus the fluid introduced into the fluid receiving port 152 can only exit through the distal outlet 146 from the interface joint 120.

[0047] The distal outlet 146 of the interface joint receives the proximal portion of the flexible shaft 154 that is guided through it into the instrument channel of the endoscope. The flexible shaft carries fluid, the push rod 130, and the coaxial cable 142, as discussed below. The proximal end of the flexible shaft 154 is directly coupled to the branch passage, and as a result, there is some overlap along the upper barrel portion 121. This coupled joint fits like a stretched glove and is masked by a cover 156 (e.g., silicone rubber) that is coupled in place. The cover 156 functions as a strain relief element and also as the end of the flexible bend restrictor of the shaft.

[0048] The primary user of the interface joint 120 can be an assistant to the endoscopist. During use, the operator typically provides the distal tip of the instrument to the endoscopist for insertion into the working channel of the flexible endoscope, makes an electrical connection between the interface joint 120 and the interface cable (connected to the generator), and then supports the interface joint 120 itself throughout the procedure. During the surgery, the operator can inject inflation / marker fluid as needed via a 5 to 20 mL syringe attached to the fluid receiving port 152 and operate the needle slider 134 according to the endoscopist's instructions. inject and can operate the needle slider 134 according to the endoscopist's instructions.

[0049] The flexible shaft 154 includes a coaxial cable 142, a push rod 130, and an outer cannula tube containing fluid. The specific internal structure of the flexible shaft will be described below with reference to FIG. 8. The distal assembly is fixed to the outer cannula tube in such a way that rotation applied to the tube will be passed on to the distal assembly. Therefore, a torque transmission unit (e.g., 116 in FIG. 1) is attached to the flexible shaft to facilitate its rotation in order to enable rotatable operation of the distal assembly.

[0050] The slidable trigger 135 can have free relative movement as in the embodiments shown in FIGS. 2 and 3. However, in some other embodiments, a latching mechanism (not shown) can be provided to lock the slidable trigger 135 in the fully retracted needle position. Alternatively, the slidable trigger 135 can have a spring-like action that biases the mechanism into the retracted state. Using the spring-loaded option, the user (assistant) needs to hold the slider forward against the spring while injecting fluid.

[0051] Figures 6, 7A, and 7B show details of an exemplary distal assembly 214 that includes an active tip that can be used with an interface joint, according to one embodiment. Figure 6 shows an exploded view of the components that form the distal assembly 214. The distal assembly 214 is attached to the distal end of the outer cannula tube 216 of the flexible shaft 154 discussed above. To provide a torque transfer function, most of the outer cannula tube 216 is formed of a braided tube that includes, for example, braided wire (such as stainless steel) lap-mounted between a radially inner polymer layer and a radially outer polymer layer. The inner polymer layer or the outer polymer layer can be made of a thermoplastic elastomer such as polyether block amide or PEBA (such as PEBAX (trademark)). Also, the braided tube can include two or more (such as three) radially spaced layers of lap-mounted braided wire. Each wrap or each layer can be composed of a plurality of wires, such as six wires. Also, the wires can have a flat cross-section. Further, adjacent layers of the braided wire can have opposite winding directions. For example, the braided tube can have five layers, and the radially innermost layer is wound in a counterclockwise winding direction, and each subsequent layer can be wound in the next winding direction, that is, clockwise, counterclockwise, clockwise, and counterclockwise. However, to avoid the braided material interfering with the delivery of RF and / or microwave frequency EM energy to the distal assembly, the distal portion 218 of the outer cannula tube 216 is made purely from a polymer layer, that is, without an internal braid.

[0052] The distal portion 218 of the outer cannula layer 216 conforms to the corresponding proximal portion 220 of the protective outer shell 222. The protective outer shell 222 is formed from polyether ether ketone (PEEK) or any other suitable engineering plastic and has a number of functions, namely - attachment to the flexible shaft of the distal assembly, - providing a protective bottom surface for the active tip, - providing a protective housing for the needle - Positioning of the active tip relative to the coaxial cable; Execute.

[0053] The distal assembly 214 includes an active tip 224, which is a planar piece of dielectric material (e.g., alumina) with a conductive layer (e.g., gold) on its upper and lower surfaces. The distal end of the active tip 224 is curved. The conductive layer is carried by a flexible shaft 216. 2. The coaxial cable 142 is electrically connected to the inner and outer conductors of the coaxial cable 142 that is fed through the active tip 224. At the distal end of the coaxial cable 142, its outer sheath is removed to expose a length of the outer conductor 226. The inner conductor 228 of the coaxial cable extends beyond the distal end of the outer conductor 226. The coaxial cable 142 and the active tip 224 are attached to one another such that the protruding portion of the inner conductor 228 is on the first conductive layer of the active tip, while the outer conductor 226 is electrically connected to the second conductive layer by the conductive adapter element 230. The first conductive layer is separated from the outer conductor 226 and the second conductive layer is separated from the inner conductor 228.

[0054] 7A and 7B, the active tip 224 and the coaxial cable 142 are bonded to each other and to the outer shell 222 by applying an epoxy adhesive to the portion of the inner conductor 228 that protrudes from the outer conductor. This epoxy adhesive also serves to form an end plug for the outer cannula tube, which is a fluid-tight seal, meaning that the only exit for fluids conducted at the interface joint is through the needle.

[0055] The outer shell 222 includes a recess for holding, for example, a needle guide tube 232 made of polyimide. During use, the distal assembly 214 is in close contact with the patient. The needle 234 extends beyond the distal end of the active tip 224 and can be retracted into a position inside the guide tube 232 via control of a slider mechanism on the interface joint. In its extended position, the needle is used by the endoscopist to inject fluid for the purpose of locally expanding and marking tissue. The conductive layer on the active tip 224 forms a bipolar electrode for delivering RF and / or microwave frequency energy.

[0056] The needle guide 232 extends rearwardly inside and proximal to the distal assembly, providing an expanded creep clearance to ensure that RF / microwave activation occurs only throughout the distal tip region of the active tip 224.

[0057] Similarly, it can be seen that the conductive layer 236 is hidden behind the distal tip region of the active tip 224. This is done on both the top and bottom surfaces to increase the tracking / creep distance at the proximal end of the active tip, further ensuring that RF / microwave energy is concentrated at the distal end of the tip and the intended active elements.

[0058] FIG. 8 shows a typical cross-section of a flexible shaft 154 that can form part of an interface joint according to one embodiment. As described above, the flexible shaft can connect the distal assembly 214 to other parts of the interface joint. The flexible shaft 154 is 2.3 m or 1.75 m and can operate, for example, at the overall length of an instrument that connects the interface joint to the distal assembly. During use, most of the length of this shaft is within the working channel of the flexible endoscope. The flexible shaft 154 includes a fluid-tight cannula 237 and an outer cannula tube 216 (i.e., the braided tube described above) that forms an electrical barrier between the user / patient, and a coaxial Sucoform cable 142 that is itself further insulated. The outer cannula tube 216 also houses an inner tube 238 that provides a low-friction path for the push rod 130 and stability / support to the structure while ensuring that the fluid path is always maintained along the entire length of the cannula. In one embodiment, the inner tube 238 is a single-lumen PTFE tube. In the embodiment of FIG. 8, the push rod is immersed in the fluid contained within the inner tube 238.

[0059] Throughout the length of the flexible shaft 154, the coaxial cable 142 (e.g., Sucofolm047 cable) forms a braid and double insulation that forms the flexible protective instrument shaft. One lumen of the composite structure with the beveled outer cannula tube 216 is formed. To manage the potential thermal risks posed during use, activation control can be imposed on the use of microwave energy by the generator. For example, in the first application stage, activation is limited to 20 seconds (continuous output), and thereafter, the average power incidence at the proximal end of the distal assembly can be limited to 4W. This control can be imposed independently of the endoscopist, for example, via the generator software. When this control is properly implemented, a temperature of 40°C was observed after 20 seconds of continuous activation on the polymer surface of the instrument shaft immediately distal to the interface joint. After 20 seconds, further continuous microwave activation by the endoscopist is automatically interrupted by the generator software, and subsequently the temperature decreases. The maximum activation ability of 20 seconds can be prevented until 240 seconds (12 × 20 seconds) have elapsed.

[0060] In practice, perfusion at the tip is a concern, and since there is a possibility of damage to the entire thickness of the intestinal wall, it may not be necessary to activate the coagulation function for longer than 10 seconds.

[0061] Figures 9, 10A, 10B, and 10C show the transition path from the push rod 130 to the needle 234. For clarity, it should be understood that Figures 9, 10A, 10B, and 10C do not show many of the above components such as the flexible tube 154, the coaxial cable 142, the shell 122, or the outlet 146. Nevertheless, these components are present, and they are only not shown in the schematic diagrams of Figures 9, 10A, 10B, and 10C for clarity. Also, as described above with reference to Figures 2 and 3, it should be understood that the proximal end of the push rod 130 is fixed to the slidable trigger 135.

[0062] Considering FIGS. 9, 10A, 10B and 10C, the needle ferrule 240 is connected to the push rod 130 at its proximal end and to the needle 234 at its distal end. A set of holes 242 on the outer surface of the needle ferrule 240 allows fluid from the flexible shaft to enter for delivery out of the needle 234. As shown in FIG. 10A, the distal end of the push rod 130 is fixed (e.g., by welding) to the proximal end of the ferrule 240. The stopper element 244 is fixed to the outer surface of the push rod 130 towards the distal end of the push rod. In one embodiment, the stopper element 244 is disposed at a distance of between about 2 mm and 6 mm from the distal end (and the needle ferrule 240). The aforementioned inner tube 238 surrounds a portion of the push rod 130 that is proximal to the stopper element 244. The support tube 248 surrounds another portion of the push rod 130 that is proximal to the inner tube 238. Further, a portion of the push rod 130 may protrude beyond the proximal end of the support tube 248. Alternatively, although not shown, the proximal ends of the push rod 130 and the support tube 248 can terminate at the same point, i.e., neither can protrude beyond the other.

[0063] Support tube 248 provides a reinforcing element that couples to push rod 130 to reinforce a portion of the push rod that is located inside shell 122. Support tube 248 is disposed within shell 122 of the interface joint when push rod 130 is fully retracted, but when push rod 130 is fully extended, the distal end of support tube 248 can project into outlet 146 and flexible shaft 154. Support tube 248 can be manufactured from stainless steel. Also, support tube 248 can be fixed to push rod 130 to prevent relative movement between support tube 248 and the portion of push rod 130 that support tube 248 surrounds. For example, support tube 248 can be fixed to push rod 130 via one or both of mechanical crimping or an adhesive (e.g., a UV adhesive). For example, mechanical crimping can be applied first and then sealed with an adhesive. Also, laser welding can be used to join push rod 130 and support tube 248. This can be done.

[0064] The function of the reinforcing element is to strengthen the portion of push rod 130 that is located within the free space or cavity of shell 122. Since this portion is located in free space, it is susceptible to the effects of bending and flexing, which can in turn affect the retraction and extension of needle 234. For example, when a user slides slidable trigger 135, the sliding force can cause a portion of push rod 130 within shell 122 to bend radially, in addition to or instead of sliding axially. As a result of this bending, and considering the amount of slide applied to the trigger, the movement of the needle at the end can be less than expected or desired. Since the operation of the needle is associated with delicate surgical procedures, the effects of bending can be problematic for long surgical procedures. Thus, the introduction of the reinforcing element strengthens the push rod to reduce the likelihood of the push rod bending. Next, the operation of the interface joint and the broader electrosurgical system is improved.

[0065] In some other embodiments, it should be understood that the reinforcing element can take a form different from that of the support tube 248. For example, in another embodiment, the reinforcing element can be an elongated structure that is parallel to and fixed to a portion of the push rod 130 disposed inside the shell 122. The elongated structure can be solid or partially hollow. The elongated structure can have a circular or rectangular cross-section. The elongated structure can be parallel to the push rod 130 but not coaxial and can be fixed to the push rod 130 by one or more mechanical fixtures. The reinforcing element in this form operates in the same manner as the aforementioned support tube in that the elongated structure provides additional strength to the push rod 130, thereby avoiding bending of the push rod 130 within the shell 122.

[0066] Returning to the embodiments of FIGS. 9, 10A, 10B, and 10C, the inner tube 238 surrounds a portion of the push rod 130 that is outside of the shell 122 and the outlet 146. Also, the inner tube 238 surrounds a portion of the push rod 130 that is distal to the support tube 248. In one embodiment, when the push rod 130 is fully extended, the inner tube 238 can be disposed outside of the outlet 146 and the shell 122 within the flexible sleeve 154. However, the proximal end of the inner tube 238 can protrude into the outlet 146 and the shell 122 when the push rod 130 is fully retracted. The inner tube 238 can have one or more lumens or channels. However, in the illustrated embodiment, the inner tube 238 is a single lumen tube. The inner tube 238 can be made of polytetrafluoroethylene (PTFE). The inner tube 238 transports the push rod 130 and slides freely relative to the push rod 130. That is, the inner diameter of the inner tube 238 is larger than the outer diameter of the push rod 130, as can be clearly seen in FIGS. 8 and 10B. However, the interface joint also includes a slide limiting mechanism that limits the amount by which the inner tube 238 can slide on the push rod 130. In one embodiment, the slide limiting mechanism includes a stopper element 244 that is fixed to the outer surface of the push rod 130 distally of the inner tube 238. The stopper element 244 is configured to prevent the inner tube from sliding beyond the first stopper element. For example, the stopper element 244 can be sized and / or shaped to prevent the inner tube 238 from sliding thereon. The stopper element 244 can be a small mass, granule, bead, or ball of adhesive (e.g., UV adhesive). Thus, the stopper element 244 can surround only a portion of the circumference of the push rod 130. Alternatively, the stopper element 244 can be a small tubular portion that surrounds the circumference of the push rod 130. Also, the slide limiting mechanism is at the proximal side of the inner tube 238 on the push rod 130 It includes another stopper element fixed to the outside. Similar to the previous one, this other stopper element is configured to prevent the inner tube 238 from slipping through and sliding over it. In this embodiment, the other stopper element is provided by the distal end of the support tube 248. As described above, the support tube 248 is fixed to the push rod 130, and thus restricts the sliding of the inner tube in the proximal direction. However, it should be understood that in some other embodiments, a dedicated second stopper element may be included between the proximal end of the inner tube 238 and the distal end of the support tube 248. For example, the second stopper element may be something like the stopper element 244.

[0067] The function of the slide limiting mechanism (e.g., the stopper element 244 and the distal end of the support tube 248) is to limit the maximum slide distance of the inner tube 238 on the push rod 130. For example, the maximum slide distance can be restricted between 4 mm and 10 mm. That is, when the inner tube 238 has a length of 2000 mm, the two stopper elements of the slide limiting mechanism can be fixed to the push rod 130 at a separation distance between 2004 mm and 2010 mm. In this way, the inner tube 238 can slide between 4 mm and 10 mm. Therefore, the inner tube 238 can slide on the push rod 130 in a constrained manner. The advantage of the constrained slide compared to the unconstrained slide is that the inner tube 238 is less likely to buckle, get caught, or tear at the needle ferrule 240, and is less likely to cause problems with the performance of the needle. Also, since the inner tube 238 can move with the push rod 130, the inner tube 238 does not float much on the push rod 130, thereby reducing the wear due to friction along the push rod 130 (i.e., improving the friction performance). In addition, since the possibility of damage to the inner tube 238 is reduced, the possibility of damage to other parts of the system as a result of the damaged inner tube 238 is also reduced.

[0068] Various embodiments of the present invention may be particularly suitable in gastrointestinal (GI) surgeries related to the lower and upper digestive tracts, for example, for removing intestinal polyps, i.e., for endoscopic mucosal resection or endoscopic submucosal dissection. The present invention may also be suitable for other surgeries, such as those suitable for general surgery or laparoscopic surgery. The present invention can be used in ear, nose, and throat surgeries and liver resections. The present invention can also be used to address surgeries related to the pancreas, for example, to excise or remove tumors or abnormalities adjacent to the portal vein or pancreatic duct.

[0069] In the foregoing description, or in the following claims, or in their specific forms, or with respect to the means for performing the disclosed functions or the methods or processes for obtaining the disclosed results, in the accompanying drawings appropriately represented, the disclosed features can be utilized separately or in any combination of such features to implement the present invention in its various forms.

[0070] The present invention has been described in conjunction with the above exemplary embodiments, but many equivalent modifications and variations will be apparent to those skilled in the art when the present disclosure is provided. Accordingly, the above exemplary embodiments of the present invention are considered to be illustrative and not restrictive. Various changes to the described embodiments can be made without departing from the spirit and scope of the present invention.

[0071] To avoid misunderstanding, the theoretical explanations provided herein are for the purpose of improving the reader's understanding. The inventors do not wish to be bound by any of these theoretical explanations.

[0072] The section headings used herein are for organizational purposes only and should not be construed as limiting the subject matter being described.

[0073] Throughout this specification, including the claims which follow, unless the context requires otherwise, the words "have", "comprise", and "include", and variations such as "having", "comprises", "comprising", and "including", are to be understood to mean including the stated integer or step or group of integers or steps but not excluding other integers or steps or group of integers or steps.

[0074] 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 one particular value and / or to another 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" associated with a numerical value is optional and means, for example, + / -10%.

[0075] As used herein, the terms "preferred" and "preferably" refer to embodiments of the invention that may provide certain advantages in some circumstances. However, it should be understood that other embodiments may also be preferred, in the same or different circumstances. Accordingly, the recitation of one or more preferred embodiments does not mean or imply that other embodiments are not useful, nor is it intended to exclude other embodiments from the scope of this disclosure or the scope of the claims.

Claims

1. An interface joint for interconnecting an electrosurgical generator and an electrosurgical instrument, a housing, an inlet for receiving electromagnetic energy from the electrosurgical generator, an outlet, the housing having the same, a slidable trigger on the housing, attached to a push rod extending out of the housing through the outlet, the slidable trigger, a single cable assembly for connecting the outlet to the electrosurgical instrument, including a flexible sleeve carrying the push rod and a coaxial cable connected to the inlet, the flexible sleeve including an inner tube surrounding a portion of the push rod, the inner tube being free to slide relative to the push rod, the single cable assembly, a slide limiting mechanism coupled to the push rod and configured to limit a maximum slide distance of the inner tube on the push rod, the interface joint including the same.

2. The interface joint according to claim 1, wherein the inner tube is a single lumen tube.

3. The interface joint according to claim 1 or 2, wherein the slide limiting mechanism includes a first stopper element fixed to an outer surface of the push rod on a distal side of the inner tube, the first stopper element being configured to prevent the inner tube from sliding past the first stopper element.

4. The interface joint according to claim 3, wherein the slide limiting mechanism includes a second stopper element fixed to the outer surface of the push rod on a proximal side of the inner tube, the second stopper element being configured to prevent the inner tube from sliding past the second stopper element.

5. The interface joint according to claim 4, wherein the second stopper element is spaced from a distal end of the push rod.

6. The interface joint according to claim 4 or 5, wherein the first stopper element and the second stopper element are arranged relative to each other such that the maximum slide distance of the inner tube on the push rod is between 4 mm and 10 mm.

7. The housing has a pistol-like shape having an upper barrel portion and a lower adjacent portion extending away from the proximal end of the upper barrel portion. The upper barrel portion includes a slot on its outer surface, and the slidable trigger is slidably fixed to the upper barrel portion so as to be slidable within the slot. The slidable trigger has an integral button portion outside the housing and an integral elongated portion inside the housing, and the button portion is shorter in length than the elongated portion. The slot is disposed toward the proximal end of the upper barrel portion, and the button portion is disposed toward the proximal end of the elongated portion. The interface joint according to any one of claims 1 to 6.

8. The interface joint according to claim 7, wherein the upper barrel portion has a length between 115 mm and 125 mm, and the lower adjacent portion has a length between 100 mm and 110 mm.

9. The interface joint according to claim 7 or 8, wherein the slot has a length between 54 mm and 58 mm and a width between 1.0 mm and 1.6 mm.

10. The interface joint according to any one of claims 1 to 9, wherein the flexible sleeve includes a braided tube lap-mounted between a radially inner polymer layer and a radially outer polymer layer, and the braided tube includes two or more radially spaced layers of lap-mounted braided wires.

11. The interface joint according to claim 10, wherein adjacent layers of the lap-mounted braided wires have opposite lapping directions.

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