Minimally invasive microwave ablation device

Abstract

An electrosurgical device (10) is provided that is operable to deliver microwave energy within a controlled range of angles to cause ablation of target tissue. The device (10) includes a blocking or reflective material, such as a cylindrical member (34) laterally spaced from an antenna (20) operable to transmit microwave energy. The reflective material creates areas within and / or around the device where sensors (51), such as thermocouple wires, can be placed to monitor conditions associated with the device or the patient's body.

Description

[0001] Related Applications

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 62 / 852,671, filed on May 24, 2019, which is incorporated herein by reference in its entirety.

[0003] STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[0004] This invention was made with government support under Grant No. 1819177 from the National Science Foundation (NSF). The government has certain rights in this invention. Technical Field

[0005] The present invention generally relates to electrosurgical devices operable to deliver microwave energy of sufficient intensity to cause targeted ablation of tissue located in a human or animal body. The electrosurgical devices are capable of delivering microwave energy within a controlled range of angles using blocking and / or reflecting materials located within the device. Background Art

[0006] Microwave ablation (MWA) is a thermal therapy modality that is increasingly being used for minimally invasive treatment of tumors and benign diseases. Other energy sources used for thermal ablation include radiofrequency current, lasers, catheter-based ultrasound applicators, and cryoablation. These procedures can be performed minimally invasively (usually under ultrasound guidance or computed tomography guidance), laparoscopically, or openly. MWA has clinical applications in the treatment of liver, kidney, lung, and bone tumors, as well as in the treatment of cardiac arrhythmias, ablation of benign prostatic tissue for hyperplasia (BPH), ablation of the endometrium for menorrhagia, ablation of the esophageal wall for Barrett's esophagus and gastroesophageal reflux disease (GERD), nerve ablation for back pain, and renal nerve ablation for chronic hypertension.

[0007] During an ablation procedure, an antenna is inserted into or placed near the target tissue and radiates electromagnetic power at microwave frequencies; most currently available devices operate in the frequency bands centered around 915 megahertz (MHz) and 2.45 gigahertz (GHz) approved for industrial, scientific, and medical (ISM) use. The electromagnetic power radiated from the antenna is deposited in the electromagnetically lossy tissue, resulting in heating via dielectric hysteresis. Although thermal damage following ablation is a complex function of the time-temperature history during heating, temperatures exceeding 60°C result in near-instantaneous cell death due to coagulative necrosis. Cells heated above 42°C may suffer irreversible but non-lethal thermal damage. The fundamental principle of successful ablation is to create an ablation zone that adequately covers the entire target while providing a safety margin for adjacent tissue.

[0008] In the past, microwave ablation devices were configured to be inserted into the center of the target tissue, and the ablation zone grew radially outward. When ablating targets close to critical structures, care needs to be taken to ensure complete thermal coverage of the target volume while preventing thermal damage to non-target tissue. These devices are based on a coaxial antenna design and have a roughly axisymmetric radiation pattern. Typically, there is no control over the energy deposition pattern over an angular range. Spatial control of the energy deposition pattern is limited to controlling heating along the length of the antenna, for example through the use of sleeve / choke elements and / or active cooling.

[0009] Recently, directional microwave applicators such as those described in U.S. Patent Nos. 7,410,485 and 8,235,981 and U.S. Patent Application Publication No. 2017 / 0265940 provide the ability to control the energy deposition pattern along a range of angles by using reflectors and / or window structures formed in the tubular outer wall of the applicator. Since these devices are constructed for percutaneous use, device diameter and stiffness are important considerations. It is highly desirable that the device have as small a diameter as possible to allow minimal invasiveness of insertion into the patient's body. In addition, since the tissue through which the device must be inserted may be thick and fibrous, the device must have sufficient stiffness and internal strength to avoid deflection along its insertion path so that it can predictably reach the target tissue.

[0010] It has been found that in certain prior art designs, achieving a sufficiently small device diameter while maintaining sufficient device rigidity can be difficult.Therefore, there is a need in the art for an improved directional microwave applicator that achieves these goals. Summary of the invention

[0011] According to one embodiment of the present invention, there is provided a device for delivering electromagnetic energy to a target tissue in a human or animal body. The device comprises an elongated body comprising a proximal end, a distal end and at least one lumen interconnecting the proximal end and the distal end. An antenna is located in the at least one lumen and is configured to emit electromagnetic energy from the lumen sufficiently strong to cause tissue ablation. The device also comprises at least one elongated cylindrical member located in the same or different lumen as the antenna. The at least one elongated cylindrical member is disposed laterally from the antenna. Preferably, the at least one elongated cylindrical member comprises a distal end segment fixed to the distal end of the elongated body.

[0012] According to another embodiment of the present invention, a device for delivering electromagnetic energy to a target tissue in a human or animal body is provided. The device includes an elongated body including a proximal end, a distal end, and an inner cavity interconnecting the proximal end and the distal end. The antenna is located in the inner cavity and is configured to emit electromagnetic energy strong enough from the inner cavity to cause tissue ablation. The device also includes a plurality of elongated cylindrical members, which are preferably conductive, located in the inner cavity and arranged laterally from the antenna. The plurality of elongated cylindrical members are configured to reflect a portion of the electromagnetic energy emitted from the antenna and shield the posterior tissue from the electromagnetic energy.

[0013] According to another embodiment of the present invention, there is provided a device for delivering electromagnetic energy to a target tissue in a human or animal body, the device comprising an elongated body formed of a synthetic resin material, an antenna and at least one conductive member. The elongated body comprises a proximal end, a distal end and at least two cavities interconnected with the proximal end and the distal end. The antenna is located in one of the at least two cavities and is configured to emit sufficiently strong electromagnetic power from the cavity to cause tissue ablation. At least one reflective member is located in another of the at least two cavities and is spaced apart from the antenna and is disposed laterally from the antenna.

[0014] According to another embodiment of the present invention, there is provided a device for delivering electromagnetic energy to a target tissue in a human or animal body, the device comprising an elongated body having a proximal end and a distal end, an antenna, at least one elongated cylindrical member, and a rigid spacer at the distal end of the elongated body, wherein the distal portion of the antenna is received in the spacer. The elongated body comprises at least one lumen interconnecting the proximal end and the distal end. The antenna is located in at least one lumen and is configured to emit electromagnetic power strong enough from the lumen to cause tissue ablation. At least one elongated cylindrical member is located in the same or different lumen as the antenna and is disposed laterally from the antenna.

[0015] According to yet another embodiment of the present invention, a method for ablating tissue in a body is provided. The method comprises inserting a device for delivering electromagnetic energy to a target tissue as described herein into a body containing tissue to be ablated. The device antenna is positioned adjacent to the tissue to be ablated, the tissue to be ablated being substantially located on one side of the antenna. The device is activated so that the antenna emits electromagnetic radiation strong enough to cause tissue ablation.

[0016] According to yet another embodiment of the present invention, a method of ablating tissue within a body organ is provided, wherein a directional microwave ablation device is inserted into a body containing tissue to be ablated. The device includes an antenna that causes electromagnetic energy to be emitted from the device that is sufficiently strong to cause tissue ablation. The device is in direct contact with the organ, but does not penetrate the organ. The device is then activated to cause the antenna to emit electromagnetic radiation that is sufficiently strong to cause tissue ablation within the organ.

[0017] According to yet another embodiment of the present invention, a method of ablating a tumor in vivo is provided, wherein a directional microwave ablation device is inserted into the tumor to be ablated. The device includes an antenna that causes electromagnetic energy to be emitted from the device sufficiently strong to cause tissue ablation. The device is activated so that the antenna emits electromagnetic radiation that is sufficiently strong to cause ablation of a portion of the tumor. The device is then rotated within the tumor without being removed from the tumor, and then another portion of the tumor is ablated with the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic partial cross-sectional view of an embodiment of a directional ablation device according to the present invention;

[0019] Figure 2 yes Figure 1 A partial cross-sectional view of an ablation device of , depicting an exemplary ablation pattern that can be achieved with the device;

[0020] Figure 3 yes Figure 1 A partially cut-away stereoscopic view of the device taken from a proximal perspective;

[0021] Figure 4 yes Figure 1 A partially cut-away stereoscopic view of the device taken from a distal perspective;

[0022] Figure 5 It is along Figure 2 A cross-sectional view of the device taken along line 5-5;

[0023] Figure 6a It is along Figure 2 A cross-sectional view of the device taken along line 6-6 of FIG. 1 and further depicting an exemplary ablation pattern;

[0024] Figure 6b It is along Figure 2 A cross-sectional view of an alternative device configuration taken along line 6-6;

[0025] Figure 6c It is along Figure 2 A cross-sectional view of yet another alternative device configuration taken along line 6-6 of ;

[0026] Figure 7 is a cross-sectional view of an alternative embodiment of the present invention, showing a cylindrical member and an exemplary ablation pattern produced thereby;

[0027] Figure 8 is a cross-sectional view of an alternative embodiment of the present invention, showing three cylindrical members and an exemplary ablation pattern produced thereby;

[0028] Fig. 9is a cross-sectional view of an alternative embodiment of the present invention, showing four cylindrical members and an exemplary ablation pattern produced thereby;

[0029] Fig.10 is a cross-sectional view of a multi-lumen device of an alternative embodiment of the present invention, and an exemplary ablation pattern produced thereby;

[0030] Fig.11 is a cross-sectional view of a multi-cavity device including a planar reflector element;

[0031] Fig.12 is a cross-sectional view of a multi-cavity device including a narrow curved reflector element with a concave surface facing an antenna;

[0032] Fig.13 is a cross-sectional view of a multi-cavity device including a wide curved reflector element with a concave surface facing the antenna;

[0033] Fig.14 is a cross-sectional view of a multi-lumen device including a curved reflector element wherein a convex surface faces an antenna;

[0034] Fig.15 is a partial cross-sectional view of an alternative embodiment of an ablation device formed with concentric tubular members;

[0035] Fig.16 yes Fig.11 A cutaway perspective view of a device;

[0036] Fig.17 It is along Fig.11 A cross-sectional view of the device taken along line 13-13;

[0037] Fig.18 is a schematic diagram of a device equipped with a swivel connector attachment according to the present invention;

[0038] Fig.19 is another schematic diagram of a device equipped with a swivel connector attachment according to the present invention;

[0039] Fig. 20 is a schematic diagram of a device according to the present invention equipped with a formable cable capable of supporting the weight of the device;

[0040] Fig.21 is a schematic diagram of an "outside-in" ablation protocol using two devices according to the present invention;

[0041] Fig. 22 is a schematic diagram of an "outside-in" ablation protocol using three devices according to the present invention;

[0042] Fig.23 is a schematic diagram of a "regional scanning" ablation scheme using a device according to the present invention;

[0043] Fig.24 is a schematic diagram of an ablation protocol using a device according to the present invention, wherein a tumor located in an organ is ablated without the device entering the organ;

[0044] Fig.25 is a cross-sectional view of a directional ablation device equipped with a trocar tip configured to transmit RF energy to surrounding tissue for cutting, cauterizing, or sensing, wherein one of the cylindrical members is used to deliver the electromagnetic energy;

[0045] Fig.26 is a cross-sectional view of a directional ablation device equipped with a trocar tip configured to transmit RF energy to surrounding tissue for cutting, cauterizing, or sensing, wherein the electromagnetic energy is delivered using a connecting wire carried by one of the cylindrical members;

[0046] Fig. 27 is a cross-sectional view of a directional ablation device equipped with a return electrode including a circumferential band positioned around the exterior of the device body and electrically connected to another cylindrical member;

[0047] Fig.28 is a cross-sectional view of a directional ablation device equipped with a return electrode including an electrode pad positioned on the exterior of the device body and electrically connected to another cylindrical member;

[0048] Fig.29 is a cross-sectional view of a directional ablation device equipped with a lumen extending through a distal end of the device to allow for fluid or drug delivery conveyed within one of the cylindrical members;

[0049] Fig.30 is a cutaway perspective view of a directional ablation device equipped with a spacer in which a distal end portion of a cylindrical member and an antenna are received and secured; and

[0050] Fig.31 yes Fig.30 Cross-sectional view of a directional ablation device.

[0051] Although the drawings do not necessarily provide exact dimensions or tolerances for the components or structures shown, the drawings are drawn to scale with respect to the relationships between components of the structures shown in the drawings. DETAILED DESCRIPTION

[0052] Controlling microwave radiation along an angular range can be achieved using blocking / reflecting materials. Many metals such as copper, steel, titanium, and metal alloys such as Nitinol have very high electrical conductivity, which makes them very good electrical conductors. The electromagnetic field inside a good conductor drops to 0 volts per meter (V / m) within a short distance (i.e., several "skin depths") past its surface. Electromagnetic waves incident on a good conductor induce surface currents, which in turn produce radiation. If the conductor is placed at an appropriate distance from the incident radiation source and has a favorable geometry, the reflected electromagnetic waves will interfere with the main radiation source, resulting in radiation in a preferred direction. This effect limits the electromagnetic power radiated in the target direction or in the region.

[0053] As an alternative, antenna directivity can be created by layering different materials to create strongly reflecting boundaries. When an electromagnetic wave is incident on a material boundary, the proportion of power that is transmitted or reflected and the direction of propagation of the resulting wave depend directly on the ratio of the dielectric constant of the material to the angle of incidence of the wave on the material boundary. For example, transitioning from a relatively high dielectric constant material such as water to a much lower dielectric constant material such as air or plastic causes most of the incident power to be reflected and causes more power to be radiated to the desired area.

[0054] As previously mentioned, in minimally invasive medical devices, it may be desirable to constrain the size of the applicator, particularly the diameter. Therefore, it may be challenging to directly apply the above concepts to their theoretically optimal settings. Instead, embodiments of the present invention modify and combine these concepts to achieve directionality in minimally invasive electromagnetic radiation (e.g., microwave) ablation applicators.

[0055] Now turn to Figure 1-5 as well as Figure 6a-6c, shows an embodiment of a device 10 for delivering electromagnetic energy, especially microwave energy, to a target tissue in a human or animal body. The device includes an elongated body 12, which includes a proximal end 14, a distal end 16 and at least one lumen 18 interconnecting the proximal end and the distal end. The elongated body 12 can be formed of any suitable material for percutaneous use in a human or animal body. However, in a preferred embodiment, the elongated body is composed of a lossless or low-loss dielectric material, such as a synthetic resin material (e.g., an elastic material or a plastic material, such as polyimide, PTFE, fiberglass, and polyetherketone (PEEK) tubing), a dielectric material, or a ceramic material. Although it is also within the scope of the present invention that the elongated body 12 is formed of a conductive material such as a metal (e.g., stainless steel), the use of an elastic material or a plastic material reduces the adhesion of the ablated tissue to the device 10 during use, thereby facilitating easier insertion and removal of the device into and from the patient's body. In an alternative configuration, the elongated body 12 can be formed of a connecting section of plastic, fiberglass, metal, or other material to achieve the desired durability or rigidity. Preferably, the overall outer diameter of the device is 0.083 inches (14 gauge), but the concepts described herein are applicable to devices as small as 0.053 inches (17 gauge). It should be understood that the device 10 can have any diameter suitable for a given application, including outer diameters greater than 14 gauge or less than 17 gauge.

[0056] The device 10 also includes an antenna 20, which is located within the lumen 18 and is configured to emit electromagnetic energy strong enough from the lumen to cause tissue ablation. The antenna 20 generally forms a terminal of a transmission line 22, which is configured to transmit electromagnetic signals from a signal generator. Preferably, the transmission line 22 is a coaxial cable, which includes an inner conductor 24 and an outer conductor 26 and a dielectric material 28 disposed therebetween, but other two-wire assemblies may also be used. In some embodiments, the inner conductor 24 includes, for example, copper, silver, gold, silver-plated copper welds, or any combination thereof, and the outer conductor 26 includes a conductive metal, such as copper or steel. The coaxial cable may be composed of a solid (semi-rigid) or braided center conductor and an outer conductor. In the case of a flexible device 10, the outer conductor 26 may be a braided metal (e.g., copper) shield. Preferably, the conductor is made of a non-magnetic material, which may facilitate the use of the device 10 in an MRI machine. In other cases, alternative materials such as stainless steel may be used, which may impart increased rigidity to the device 10, thereby enhancing percutaneous usability. It is also within the scope of the present invention that more than one antenna 20 and transmission line 22 be used with the device 10. For example, the device 10 may include two antennas 20, each extending from its own transmission line 22.

[0057] The dielectric material 28 may include, for example, polytetrafluoroethylene, air, polyethylene, alumina, nylon, and combinations thereof. The proximal end 30 of the transmission line 22 includes an SMA connector 23 or other structure (e.g., N-type and BNC connectors) suitable for connecting the transmission line to a signal generator. The distal end 32 of the transmission line 22 includes a portion of the line in which the outer conductor 26 and the dielectric material 28 have been removed to expose a small length (preferably less than 1 mm) of the dielectric material and a length (preferably about 5 to about 10 mm) of the inner conductor 24 to form the antenna 20. Preferably, the center conductor 26 is bent and offset near the exposed dielectric material 28 to position the antenna 20 away from the one or more elongated cylindrical elements, described in more detail below, and closer to the outer wall structure of the elongated body 12, and to achieve better impedance matching between the antenna 20 and the transmission line 22. In some embodiments, the antenna 20 includes a monopole antenna; however, other types of antenna configurations, such as dipole antennas, slot antennas, and helical antennas, may also be used without departing from the scope of the present invention. Additionally, the exposed antenna 20 may be constructed with an alternative antenna bend or without a bend. The monopole antenna may be coated or covered in a dielectric material. In certain embodiments, the outer conductor 26 and dielectric material 28 may be removed flush with each other to leave no exposed dielectric material.

[0058] The device 10 also includes at least one elongated cylindrical member 34 located within the lumen 18 (the same lumen as the antenna). As shown, the device 10 preferably includes at least two elongated cylindrical members 34, 36. The elongated cylindrical members 34, 36 are generally disposed laterally from the antenna 20, wherein the antenna 20 is located entirely outside of the cylindrical members, rather than being located within, concentric with, or at least partially carried through one of the cylindrical members. Figure 7-9 , alternative embodiments of the device 10 are shown in which one, three, or more than four elongated cylindrical members are disposed laterally from the coaxial transmission line 22. It is also within the scope of the present invention to use other numbers of elongated cylindrical members in the construction of the device 10 than those shown in the figures. Different configurations can be used to modify the angular radiation pattern, improve mechanical performance and device rigidity, balance cooling fluid inflow and outflow areas, or provide conduits for fluid delivery and auxiliary instruments. For example, Figure 7 Depicted is a single elongated cylindrical member 34 disposed to one side of the transmission line 22 and antenna 20. This configuration tends to produce a wider ablation pattern, as shown by the various dashed lines, which represent zones of different radiation intensities. Figure 8 A configuration is depicted in which three elongated cylindrical members are disposed laterally from the transmission line 22. Specifically, the cylindrical members have different diameters, with the diameter of member 38 being smaller than the diameter of member 40. This configuration tends to produce a ratio Figure 6a-6c and Figure 7Narrower ablation pattern shown. Fig. 9 Yet another configuration is depicted in which four elongated cylindrical members are disposed laterally from the transmission line 22. As shown, the device includes two small diameter members 38 positioned outside two larger diameter members 40. This configuration provides a Figure 6a-6c and Figure 8 "Narrow ablation pattern" means that the electromagnetic energy emitted from antenna 20 is primarily directed toward the tissue closest to antenna 20. Figure 6a-6c and Figure 7-9 It can be seen that the greater the extent to which the slender cylindrical member is radially positioned around the transmission line 22, the more energy is directed in the anterior direction (i.e., toward the antenna side of the device) and the less energy is delivered to the lateral and posterior tissues (i.e., to one side and the opposite side of the antenna).

[0059] The elongated cylindrical member can be any cylindrical configuration, such as a circular, rectangular, triangular, elliptical cylinder, and is preferably formed of at least a portion of a conductive material, such as stainless steel, silver, copper, gold and other metals and alloys, especially the distal portion. Alternatively, the cylindrical member may include a non-metallic material, the distal portion of which carries one or more conductive elements, such as a metal pad or strip sprayed or electroplated thereon near the antenna. In other embodiments, the elongated cylindrical member is made of any material with a high electrical conductivity (σ> ~104S / m). The use of conductive materials for cylindrical members produces a reflective / shielding effect, which creates an area within the device 10 or within the cylindrical member itself that is shielded from the electromagnetic power emitted by the antenna 20. As described below, this shielding effect creates an opportunity for the device 10 to carry optional accessories that enhance the practicality of the device 10.

[0060] In certain embodiments, the elongated cylindrical member 34 may comprise a solid metal wire. However, in a preferred embodiment, the elongated cylindrical member 34 may comprise a hollow tube. In those embodiments comprising a plurality of elongated cylindrical members 38, 40, a combination of wire and tube may be used if desired.

[0061] The elongated cylindrical members 34, 36 are preferably fixed to each other, such as by welding, brazing or adhesive, to form a cohesive unit having enhanced rigidity compared to a single member. In certain embodiments, the outer conductor 26 of the transmission line 22 may also be fixed to the elongated cylindrical members 34, 36, such as by brazing or welding, thereby fusing the cylindrical member and the transmission line together to increase rigidity. In addition, fusing the cylindrical member and the transmission line together limits surface currents along the outer surfaces of the transmission line and the cylindrical member, which may otherwise contribute to the retention or reverse travel of electromagnetic waves. Fixing the members 34, 36 and the transmission line 22 together also provides improved or easier manufacture and assembly of the device 10, because the assembly can be slid into the elongated body 12 as a single unit. In a preferred embodiment, the cylindrical members 34, 36 and the transmission line 22 form a triangular arrangement in cross section. However, it will be understood that many other configurations are also possible.

[0062] In certain embodiments, the cylindrical members 34, 36, particularly the distal segments thereof, are anchored in a plug 42 located toward the distal end 16. As described below, in other embodiments, a non-metallic spacer associated with the distal end of the device may be used in place of the plug 42. Preferably, the plug 42 comprises a non-conductive epoxy material that is located at the distal-most end of the device 10, approximately 1-5 mm beyond the distal end of the antenna 20. This allows the cylindrical members 34, 36 to provide axial rigidity through the device 10 by securing them to the proximal end 14 and the distal end 16.

[0063] In those embodiments where the elongated cylindrical members 34, 36 include tubes, one or more tubes may be used to provide an inflow or outflow path for circulating a cooling fluid within the device 10 to dissipate heat generated during operation. A small notch 44 is cut in each tube slightly proximal away from the distal plug 42 to provide a path for the circulating cooling fluid to enter or leave the tube. Note that multiple notches or holes spaced around the periphery of each tube may also be provided instead of a single notch. The notches may be configured to face the same or different directions within the lumen 18. For example, the notches in the cylindrical members 34, 36 may all face the front of the device, may all face away from the front of the device, or one notch may face the front of the device and one notch away from the front of the device to balance the flow of cooling fluid through the device. Alternatively, the tube may be configured to terminate before being inserted into the distal plug 42, wherein the flow path for the cooling fluid is provided through the open end of the tube. The distal portions of the cylindrical members 34, 36 may be cut, shaped, or otherwise modified to form a variety of alternative shapes. For example, the circular cross-section of the cylindrical members 34, 36 may be cut in half and removed from the length of the distal end of the cylindrical member, resulting in a concave / convex structure near the antenna as a means of changing performance characteristics or promoting smaller diameter design variations. Alternatively, the cylindrical member may be flattened or curved along a portion of the distal end. Thus, the cylindrical members do not need to have a constant cross-sectional profile along their entire length. The distal end of the device 10 may terminate in a trocar tip 46 or other type of tip for easier insertion into tissue.

[0064] As previously mentioned, water is the preferred cooling fluid for circulation within the apparatus 10. Figure 1-5 , the gap 48 in the inner cavity 18 between the elongated body 12 and the assembly including the elongated cylindrical members 34, 36 and the transmission line 22 forms part of the outflow / inflow path for the circulating water (see directional arrows). In this embodiment, the antenna 20 is unsupported at its distal end and is surrounded by the circulating water. The high relative dielectric constant of the surrounding water facilitates proper antenna impedance matching. In an alternative construction, the distal and / or proximal ends of the antenna 20 may be fixed in place by epoxy or some other material. This may allow for improved manufacturability or performance consistency. Since water also has considerable conductivity, an alternative construction may use a low-loss material with a high dielectric constant, such as the ceramic materials alumina and TiO 2 Fill some or all of the gap 48 between the antenna 20 and the cylindrical members 34, 36. The cylindrical member may be slotted at a location proximal to the antenna 20 (in some embodiments, approximately 2 mm from the base of the antenna 20) to allow for reflow in a design variation where the entire space within the elongated body 12 is filled with a low loss material to surround the antenna element and the cylindrical members 34, 36. Such a material may include TiO 2The low-loss material may also be molded into or otherwise used to completely encapsulate the antenna 20 and cylindrical member, wherein the low-loss material also forms a portion of the outer surface of the applicator for a certain length near the distal end 46 of the device 10. Including a low-loss material near the antenna 20 will limit microwave absorption losses inside the device 20, thereby allowing more microwave energy to reach the outside of the device 10 and produce a larger ablation zone in the target tissue. In addition, because microwave losses within the device 20 increase the internal temperature of the device, including an alternative low-loss material can enable the applicator to operate at higher power levels. A practical example of such a construction is a small diameter TiO2 film located between the antenna 20 and the cylindrical members 34, 36. 2 Cylinder 47 to displace the lost water in this area. See e.g. Figure 2 and 6a Note that cylinder 47 is optional and need not be present in every embodiment of the present invention. If a dielectric other than water is used around antenna 20, it should have a large dielectric constant similar to that of water (e.g., TiO 2 ), and alternative cooling fluids may be used, including brine, fluorescent agents, liquid chlorodifluoromethane, nitrous oxide, nitrogen, carbon dioxide, and air. Figure 6b Another variation of this concept is depicted, where the antenna 20 is at least partially embedded in the TiO 2 The cylindrical element 49 is filled with TiO 2 A cylindrical element 49 surrounds. Figure 6c A further variation of this concept is shown in which voids 48 and a portion of space 50 are filled with TiO along the length of antenna 20. 2 Material 58. Note that in this embodiment, circulation of the cooling fluid may need to occur entirely within the cylindrical members 34, 36, at least in the region of the antenna 20.

[0065] Because the cylindrical members 34, 36 are conductive, they are very effective in shielding the interior and exterior areas of the device 10 from the electromagnetic power emitted by the antenna 20. These shielded areas can be used to place at least one sensor configured to detect operating conditions of the device 10 or conditions associated with the body in which the target tissue is located. In one embodiment, the space 50 between the elongated body 12 and the cylindrical members 34, 36 opposite the transmission line 22 can be used as a shielded location for adding at least one sensor 51. See Figure 6a-6c The sensor 53 may also be adhered to that portion of the outer surface of the elongated body 12 that is shielded by the cylindrical members 34 , 36 .

[0066] In one embodiment, at least one sensor is a temperature sensor, and preferably a thermocouple. When placed in the space 50, the thermocouple temperature sensor 51 can be used to monitor the internal temperature of the device 10 as a safety or feedback mechanism. When adhered to the shielded outer surface of the elongated body 12, the temperature sensor 53 or an additional sensor can be used as a real-time safety system to warn the user of accidental heating in an undesirable tissue area. The sensor 55 (e.g., a thermocouple) can also be included in the lumen 52 of the metal tube 34, 36, which is well shielded from the electromagnetic power emitted from the antenna 20. When the thermocouple sensor 55 is used in this manner, the end of the (one or more) thermocouples can be anchored in the same distal plug 42 as the cylindrical member 34, 36, and is configured to measure the real-time temperature at any point around the periphery of the device 10. Electromagnetic shielding is important for thermocouple wires because they are also metal, and any microwave radiation reaching them will cause heating and lead to erroneous readings.

[0067] In further embodiments, one or more of the metal tubes 34, 36 may be used as a conductor to transmit radiofrequency energy to the end of the conductive device. This may be used for radiofrequency ablation, cutting or cauterization.

[0068] Figure 25-27 Further embodiments of the device 10 are depicted, which may be configured for RF cutting or cauterization, or for sensing conditions associated with tissue contacted by the device 10, such as tissue impedance. Fig.25 and 26 , two embodiments of the device 10 are shown, wherein the device 10 is equipped with a conductive trocar tip 46. Fig.25 In the embodiment of FIG. 1 , electromagnetic energy is delivered to the distal end 46 via the conductive cylindrical member 34. As can be seen, the cylindrical member 34 extends through the plug 42 and is electrically coupled to the distal end 46 at the interface 122. Fig.26 The embodiments of the present invention are similarly configured, however, the electromagnetic energy is delivered to the tip 46 via the connecting wire 124, which is shown as being carried by the cylindrical member 34, but this is not always the case. In these embodiments, the tip 46 can be used to cut or cauterize tissue using RF energy, or the tip 46 can be configured to transmit an electrical signal via the cylindrical member 34 or the connecting wire 124, which is indicative of a condition associated with the surrounding tissue, such as tissue impedance.

[0069] Since tip 46 acts as the first electrode of the cutting, cauterizing or sensing system, a second electrode must be provided as a return path for the signal. Fig. 27 and 28 Two alternative embodiments for placing and connecting the second electrode are depicted. Fig. 27The embodiment includes an external electrode strip 124 located on the outer surface of the elongated body 12. The strip 124 is electrically connected to the cylindrical member 36 through a connector 128. Fig.28 The embodiment includes an electrode pad 126 positioned on the outer surface of the elongated body 12 and electrically connected to the cylinder 36 via a connector 130. As a further alternative, the return electrode need not be part of the device 10 at all, but may be in the form of an external ground pad (not shown) adhered to the patient's skin.

[0070] In an alternative embodiment, one or more metal tubes 34, 36 may extend all the way through the distal plug 42 and / or the tip 46 and serve as a conduit for delivering fluids / drugs to the patient's body. Fig.29 4. As can be seen, tube 34 includes a distal beveled edge that is flush with the outer surface of tip 46 and connects the lumen of tube 34 to the exterior of device 10. Various modifications to this embodiment are readily contemplated without departing from the overall scope of the present invention. For example, tip 46 may be formed with a lumen that communicates with the lumen of tube 34, but tube 34 does not extend into or all the way through the lumen of the tip.

[0071] In other embodiments, one or more metal tubes 34, 36 may extend beyond the distal plug 42 and be electrically connected to a sensor (not shown) mounted on the applicator surface to monitor target tissue impedance or other electrical characteristics. However, as described above, the device tip 46 may also be configured to operate as a sensor or electrical contact without adding additional external sensors to the device.

[0072] Fig.30 and 31 An alternative embodiment of a directional ablation device 134 according to the present invention is depicted. As with certain other embodiments described herein, the device 134 includes an elongated body 136 defining an inner cavity 138 into which a transmission line 140, an antenna 142, and cylindrical members 144, 146 are received. The distal end of the device 134 terminates in a trocar tip 148 fixed to the distal end of the body 136. Each cylindrical member 144, 146 includes a plurality of apertures 150 that communicate the interior of each cylindrical member with the inner cavity 138.

[0073] The distal end 152 of each cylindrical member 144, 146 is disposed within a spacer 154 secured to the tip 148. In a preferred embodiment, the spacer 154 is non-conductive (e.g., formed of a rigid plastic or other insulating material) so as to electrically isolate the cylindrical members 144, 146 from the tip 148, but this need not always be the case. In the illustrated embodiment, the spacer includes a protrusion 156 that is received within a bore 158 formed in the tip 148. Thus, the spacer 154 provides a rigid connection between the distal end 152 of the cylindrical member and the rigid tip 148. In an alternative embodiment, the spacer 154 and the tip 148 may be integral (i.e., formed of a single piece, particularly if the tip 148 may be formed of a rigid, non-conductive material) and need not include separate components. However, from a manufacturing perspective, it may be advantageous to use separate but connectable components.

[0074] In addition, in one or more embodiments, the distal end 160 of the antenna 142 can also be received in the spacer 154, which supports the distal end 160 and maintains the position of the antenna 142 relative to the cylindrical members 144, 146 to ensure proper antenna impedance matching. It should be noted that the cylindrical members 144, 146 and / or the antenna 142 can be frictionally fixed to the spacer 154, or fixed to the spacer with an adhesive, such as epoxy.

[0075] Go to Fig.10 , another embodiment of this 54 for providing electromagnetic energy to target tissue is shown. Device 54 includes an elongated body 56 formed of a synthetic resin material. Device 54 includes a proximal end, a distal end, and two inner chambers 62, 64 that interconnect the proximal end and the distal end. As shown, device 54 also includes a third inner chamber 66, but this is not always the case. In addition, device 54 includes any number of inner chambers, such as two, three, four, five or six, which is also within the scope of the present invention. The various inner chambers formed in the elongated body 56 are separated by a wall structure extending between the proximal end and the distal end. For example, inner chamber 62 is separated from inner chamber 64 by wall 65. Preferably, the shape of wall 65 is an arch with a concave-convex structure, but wall 65 has any suitable structure and is also within the scope of the present invention. Similarly, inner chamber 64 is separated from inner chamber 66 by wall 67, which is preferably flat but can be of any suitable structure.

[0076] In certain embodiments, the multi-lumen elongate body 56 comprises a synthetic resin material, such as PEEK, that can be extruded into a desired configuration, although elongate body 56 formed from any material that is electromagnetically transparent at microwave frequencies is within the scope of the present invention.

[0077] Lumen 62 is preferably set against one side of the outer wall of elongated body 56 and has a height large enough to accommodate coaxial transmission line 69. Preferably, lumen 62 is sized to hold transmission line 69 snugly between the outer wall of elongated body 56 and wall 65. Antenna 68 is located within lumen 62 and is configured to emit electromagnetic energy strong enough from the lumen to cause tissue ablation. Antenna 68 can be constructed similarly to antenna 20 discussed above.

[0078] The device 54 includes at least one conductive member (also referred to herein as a "reflective member") located within the lumen 64 (i.e., a lumen different from that in which the antenna 68 is located) that is operable to at least partially reflect microwave energy and / or shield at least a portion of the device and / or the patient's tissue from microwave energy. The at least one reflective member can include any of several configurations. For example, Fig.10 As shown, the at least one reflective member may include a cylindrical member 70, which may be a wire or tube as described above. Preferably, the at least one reflective member frictionally engages the partition wall 65 and at least one other wall surface defining the inner cavity 66 (e.g., the elongated body outer wall and / or the wall 67), in which the at least one reflective member is received.

[0079] However, if Figure 11-14 As shown, the reflective member may include a planar reflector 72 or a concave-convex reflector (collectively 74). Preferably, the reflective member is metallic and extends between the proximal and distal ends of the elongated body 56, but it is within the scope of the invention for at least one reflective member to be positioned primarily toward the distal portion of the device 54 of the antenna 68.

[0080] Figure 12-14 Embodiments include concave and convex reflectors 74a-c. Fig.12 The embodiment uses a narrow reflector 74a, while Fig.13 The embodiment of uses a wider reflector 74b with a larger radius of curvature. Fig.12 and 13 In the embodiment of FIG. 5 , the reflectors 74a, b are oriented concavely in facing relationship with the antenna 68, thereby effectively creating a parabolic reflector that tends to focus the microwave energy toward the front of the device. Fig.14 In the embodiment of FIG. 7 , reflector 74c is oriented with its convex surface facing antenna 68. In this embodiment, the angle of microwave energy dispersion and the resulting ablation shape may be slightly different than that experienced by reflectors 74a, b.

[0081] As with device 10, device 54 is configured to allow a cooling fluid (e.g., water) to circulate therethrough. For example, the cooling fluid may be introduced into the device via lumen 64. The cooling fluid may flow through the lumen itself, or it may flow through one or more cylindrical members 70 located within lumen 64. Toward distal end 60, wall 65 may be removed by a small section (e.g., 0.5-10 mm) to allow a return path for the cooling fluid through lumen 62. Wall 65 also provides a high to low dielectric constant (water to plastic) material interface, which may result in some microwave energy being reflected to the desired region for tissue ablation.

[0082] like Fig.10 As shown, the device 54 includes at least two reflective members, here cylindrical members 70, which are closely mounted between the outer wall of the elongated body 56 and the walls 65, 67. As with the device 10, at least one reflective member of the device 54 can be fixed in a plug for sealing the distal end of the device. The plug can be constructed similarly to the plug 42 described above and can provide the device 54 with increased strength and rigidity.

[0083] Lumen 66 is comprised of an area defined by the outer wall of elongated body 56 and wall 67. In certain embodiments, lumen 66 can be filled with air to provide a water, plastic, air interface reflective boundary to enhance the directionality of the applicator. Additionally, device 54 can be constructed such that lumen 66 is shielded from microwave radiation by at least one reflective member, thereby allowing routing of at least one sensor configured to detect an operating condition of the device or a condition associated with the body in which the target tissue is located. In certain embodiments, at least one sensor 71 comprises a thermocouple routed in lumen 66. See, e.g., Fig.11 In other embodiments, the temperature sensor 73 may be positioned on the back (shielded) side of the device 54. This temperature sensor may be used as a real-time safety system to alert the user of unexpected heating in undesired areas. Additional sensors (not shown) may be used to monitor the temperature inside the device as a safety or feedback mechanism. If one or more of the reflective members include tubes 70, additional sets of thermocouple wires 77 may be passed through these tubes as described above.

[0084] In other embodiments, lumen 66 can be used as an additional closed flow channel for cooling fluid to enhance indirect cooling in the posterior region. Lumen 66 can also be opened at the distal end to allow open system cooling flow to the posterior region. If device 54 is rotated 180 degrees before or after ablation therapy, the open flow from lumen 66 can also be used to deliver drugs to the posterior region or the anterior region.

[0085] In an alternative configuration, one or more elongated cylindrical members 70 may extend all the way through the distal stopper and the device tip for use in delivering fluid / drug to the patient's body.

[0086] In further embodiments, one or more of the elongated cylindrical members 70 can be used as a conductor to transmit radiofrequency energy to the distal end of the conductive device. This can be used for radiofrequency ablation, cutting or cauterization.

[0087] In further embodiments, one or more of the elongated cylindrical members 70 may extend beyond the distal plug and be electrically connected to a sensor (not shown) mounted on the applicator surface to monitor target tissue impedance or other electrical characteristics.

[0088] Figure 15-17 Another embodiment of a device 80 for providing electromagnetic energy to a target tissue is depicted. The device 80 is configured such that an elongated body 82 includes an outer tubular member 84 having a proximal end 86 and a distal end 88. The elongated body 82 also includes an inner tubular member 90 having a proximal end 92 and a distal end 94. The proximal end 92 of the inner tubular member 90 is received by the distal end 88 of the outer tubular member 84. Thus, the outer diameter of the inner tubular member 90 is approximately the same as or slightly smaller than the inner diameter of the outer tubular member 84. Preferably, the tubular members 84, 90 are metallic and may include the same materials used for the cylindrical members 34-40 described above. However, it is also within the scope of the present invention for the tubular members 84, 90 to be formed of microwave transparent materials such as those described above for the elongated body 12.

[0089] The inner tubular member 90 includes a window section 96 formed therein that is configured to allow transmission of electromagnetic power emitted from the antenna 98. In a preferred embodiment, the window section 96 is formed by removing a portion of the inner tubular member 90 corresponding to the desired size of the window section (preferably 10-15 mm in length). The device 80 also includes an electromagnetically transparent sleeve 100 that is positioned around at least a portion of the inner tubular member 90 in a covering relationship with the window section 96. Thus, the sleeve 100 seals the window section 96 and prevents the inner cavity 102 from being directly connected to the outside of the device 80. The sleeve 100 can be made of any number of non-metallic materials, such as polyimide, PEEK or ceramic. Preferably, the diameter of the sleeve 100 is close to the diameter of the outer tubular member 84. The inner tubular member 90 can then act as a reflector that directs the electromagnetic power emitted by the antenna 98 to the window section 96 in a forward direction.

[0090] Other components and features of device 80 may be constructed similarly to those of device 10. However, it is also within the scope of the present invention to construct device 80 using a concentric tube design, whereby the antenna extends from a transmission line that passes through an inner lumen of the tube through which a cooling fluid may circulate. U.S. Patent Application Publication No. 2017 / 0265940 shows an exemplary concentric flow tube design, the entire contents of which are incorporated herein by reference.

[0091] Several circumferential attachments may be used with the device described herein to improve its functionality. The circumferential attachments described herein may be used alone or in combination with each other depending on the application requirements. Fig.18 and 19 The device 10 is schematically shown, wherein the device includes a swivel connector 104 coupled to the proximal end 14 of the elongated body 12 and to the base portion 106 of the device. The base portion 106 is configured to receive a microwave transmission line 107 and cooling fluid flow lines 108, 110 from an electromagnetic power source and / or pump (collectively referred to as 112) for circulating a cooling fluid within the device. The swivel connector 104 allows the base portion 106 to rotate axially freely relative to the elongated body 12. Therefore, once the distal end 16 of the device 10 is positioned within the patient, the effects of rotational torque due to the weight of the transmission line 107 and the cooling fluid flow lines 108, 110, which may cause the position / target of the device 10 to drift during use, can be avoided. Therefore, the risk of thermal damage to unintended areas within the patient is reduced.

[0092] Fig. 20 Another circumferential attachment that can be used with the device of the present invention is schematically shown. Specifically, a shapeable transmission cable 114 can be used to interconnect an electromagnetic power source and / or a pump 112. The shapeable cable 114 is a semi-rigid coaxial cable that is configured to be manually shaped into a desired shape and maintain the shape while supporting the weight of the device 10. In certain embodiments, the shapeable cable 114 can be used as a support for the device 10, thereby keeping the device in place during an ablation procedure or moving a patient into or out of a CT for imaging. As shown, the shapeable cable 114 is operably connected to a base portion 106 that is coupled to the proximal end 14 of the elongated body 12. The shapeable transmission cable 114 is operably connected to the source 112. The shapeable transmission cable 114 is configured to freely support the weight of the elongated body 12 and the base 106 without additional assistance.

[0093] As described above, the electromagnetic power supply 112 is used to generate the desired microwave power and transmit it to the device 10. The electromagnetic power supply 112 may include a microwave signal generator, and optionally include a DC power supply, a power amplifier, and a power monitor. In certain embodiments, the frequency generated by the signal generator is similar to the frequency associated with the frequency commonly used to heat water. In particularly preferred embodiments, the frequency range generated is about 800MHz to 6GHz, about 900MHz to about 5GHz, or about 1GHz to about 3GHz, or about 915MHz or about 2.45GHz.

[0094] The operation of the device 10 and its various peripheral accessories can be monitored and controlled by a microprocessor such as a personal computer or handheld device. Alternatively, the operation of the device 10 and its peripheral accessories can be monitored and controlled by a user interface and control system integrated with the electromagnetic power supply 112.

[0095] The device described herein can be used for ablating tissue in a human or animal body, such as a variety of applications of tumors, nerves or other tissues. Typically, the device is inserted into the body containing the tissue to be ablated. Specifically, when the device 10 is equipped with a trocar tip 46 to form an opening in the skin, the insertion of the device can be performed percutaneously. The device can also be used for open surgery or inserted laparoscopically, such as through an incision and / or through a trocar previously inserted into the patient's body. In addition, in some embodiments, if the antenna is incorporated into the distal end of the flexible cable assembly, the device can be used endoscopically or directly in a body cavity (intracavity), such as in a vein or artery (intravascular), or under bronchoscope. Once in the patient's body, the device 10, specifically the device antenna 20, is positioned adjacent to the tissue to be ablated, such as into an organ where a tumor is located. In a preferred embodiment, the antenna 20 is positioned so that the tissue to be ablated is substantially located on one side of the antenna, rather than being centrally positioned in the tissue. Then, the device 10 is activated so that the antenna emits electromagnetic radiation strong enough to cause tissue ablation, preferably microwave radiation.

[0096] The directional nature of the device 10 provides angular control of the ablation pattern, thereby enabling several applications that conventional non-directional devices are not suitable for performing. Conventional non-directional devices must generally be inserted into the center of the target tissue because the ablation energy will radiate outward in a substantially symmetrical pattern. However, this can cause problems when the tissue to be ablated is irregular in shape or the center of the tissue is not easily accessible to the device. Therefore, a directional device according to an embodiment of the present invention enables alternative ablation schemes.

[0097] For example, Fig.21 and 22 An "outside-in" approach is depicted that may be used for thermal ablation of target tissue. In this approach, one or more devices 10, preferably two or three devices, may be inserted into a patient's body 116 and positioned adjacent to, but not penetrating, a target tissue such as a tumor 118. Devices 10 are activated so that antennas 20 emit ablative microwave radiation into tissue 118 in a particular directional pattern (indicated by dashed lines), achieving ablation from the outer edges of the tissue inward toward the center of the tissue. The devices may be powered on simultaneously for operation (i.e., all devices continuously radiate microwave radiation during an ablation procedure), or power may be cycled between the devices. For example, consider Fig.21In the dual device approach shown in , one device 10 may be powered for a period of time (e.g., 5 seconds) while the other device is not powered. Next, power to the first device will be cut off and power to the second device will be provided for a similar or different period of time as the situation requires. Power will then be alternated between the devices throughout the ablation procedure. Further, depending on the geometry of the target tissue, device position, and antenna orientation, the power provided to each device and the duration of each ablation step need not be equal. Thus, excessive ablation of tissue adjacent to the target tissue can be limited and reverse heating from the device can be minimized.

[0098] Another ablation protocol that can be performed is the “sector scanning” approach, e.g. Fig.23 As shown. In this treatment technique, a percutaneously placed omnidirectional ablation applicator cannot reach the central axis of the target, or the target has an asymmetric shape. According to this embodiment of the invention, a directional microwave applicator 10, such as those described herein, is inserted into an off-axis target 118, which is used to apply one power level to a portion of the tumor using one power / time setting in one direction, and then rotated (preferably without removing the device from the target) to apply different power levels with different time / power settings to different portions of the tumor in one or more other directions. The scheme is depicted by the asymmetric ablation pattern shown in dotted lines. The scheme allows for complete ablation of symmetrical tumors that cannot be accessed along the central axis or other tumors that do not have a symmetrical shape. The method can also be used for selective re-treatment procedures within the same target area that has shown viability after initial ablation.

[0099] Fig.24 Yet another ablation scheme according to an embodiment of the present invention is shown, which scheme may be referred to as surface ablation. In this scheme, the device 10 is inserted into the patient's body 116. The portion of the elongated body 12 containing the antenna 20 is positioned adjacent to an organ 120 such as the liver or pancreas. Note that in this embodiment, the device 10 is positioned to be in direct contact with the organ 120, preferably with the help of CT or ultrasound guidance, but does not penetrate or extend into the interior thereof. This method is particularly useful when the tumor 118 to be ablated is located near the outer surface of the organ 120 or extends inwardly from the outer surface of the organ 120. The ablation pattern (dashed line) generated by the antenna 20 can be configured to ablate substantially the entire target tissue while causing minimal thermal damage to surrounding healthy tissue. In addition, further trauma to the organ 120 is avoided because the device 10 is not inserted into the organ.

[0100] Certain embodiments of the present invention may be used to perform cutting or cauterization of tissue located within the body, particularly by delivering radiofrequency energy from the device tip 46 as described above. This may help minimize bleeding that may occur during placement or removal of the applicator, which may obscure CT or ultrasound image guidance. Additionally, as described above, certain devices according to the present invention may be used to sense electrical properties of tissue located within the body, such as tissue impedance, which may be used for treatment planning or determining treatment endpoints.

[0101] It should be understood that the above description is intended to illustrate the preferred features and concepts of the present invention and should not be considered as limiting its scope. In addition, any of the above-mentioned individual features and concepts may be modified or combined with any other individual features and concepts discussed herein to form alternative embodiments of the present invention.

Claims

1. A device for delivering electromagnetic energy to a target tissue in a human or animal body, comprising: an elongated body comprising a proximal end, a distal end, and at least one lumen interconnecting the proximal end and the distal end; an antenna positioned within the at least one lumen and configured to emit electromagnetic energy from the lumen sufficiently intense to cause tissue ablation; as well as at least one elongated cylindrical member, the at least one elongated cylindrical member being located within the same or a different lumen as the antenna, the at least one elongated cylindrical member being disposed laterally from the antenna, the at least one elongated cylindrical member comprising a distal end segment secured to the elongated body, wherein the at least one elongated cylindrical member is configured to reflect a portion of the electromagnetic energy emitted from the antenna to provide a directional pattern for delivering the electromagnetic energy to the target tissue, and Wherein, the at least one elongated cylindrical member comprises at least one tube, and the device is configured to circulate a cooling fluid through the at least one tube and into the at least one inner cavity.

2. The device according to claim 1, characterized in that The device comprises at least two elongated cylindrical members.

3. The device according to claim 2, characterized in that The at least two elongated cylindrical members are fixed together.

4. The device according to claim 2, characterized in that The at least two elongated cylindrical members have different diameters.

5. The device according to claim 2, characterized in that The at least two elongated cylindrical members have the same diameter.

6. The device according to claim 1, characterized in that At least a distal end of the at least one elongated cylindrical member includes one or more conductive elements.

7. The device according to claim 1, characterized in that The at least one elongated cylindrical member further comprises a wire.

8. The device according to claim 1, characterized in that The device also includes at least one sensor configured to detect an operating condition of the device or a condition associated with the body in which the target tissue is located, wherein the at least one tube includes a conductive pathway for the at least one sensor and / or provides shielding from microwave interference or heating of the at least one sensor.

9. The device according to claim 1, characterized in that The at least one tube is configured to provide a conduit for delivering fluids and / or drugs to the body where target tissue is located.

10. The device according to claim 1, characterized in that The device includes a thermocouple that is shielded from electromagnetic energy emitted from the antenna by the at least one elongated cylindrical member.

11. The device according to claim 1, characterized in that The antenna includes a coaxial transmission cable.

12. The device according to claim 11, characterized in that The coaxial transmission cable includes an outer conductor secured to one of the at least one elongated cylindrical members.

13. The device according to claim 1, characterized in that The elongated body includes a synthetic resin material.

14. The device according to claim 13, characterized in that The elongated body includes at least two lumens interconnecting the proximal end and the distal end, wherein adjacent lumens are separated by a wall structure extending between the proximal end and the distal end.

15. The device according to claim 1, characterized in that The elongated body includes an outer tubular member having a proximal end and a distal end, and an inner tubular member having a proximal end and a distal end, the proximal end of the inner tubular member being received through the distal end of the outer tubular member, the inner tubular member including a window section formed therein, the window section being configured to transmit electromagnetic energy emitted from the antenna, and there being an electromagnetically transparent sleeve positioned around at least a portion of the inner tubular member, the electromagnetically transparent sleeve being in covering relationship with the window section.

16. The device according to claim 1, characterized in that The device includes a swivel connector connected to the proximal end of the slender body and to the base portion of the device, the base portion of the device being operably connected to an electromagnetic energy source and / or a pump for circulating a cooling fluid within the device, the swivel connector allowing free axial rotation of the base portion relative to the slender body.

17. The device according to claim 1, characterized in that The device includes a base portion connected to the proximal end of the slender body, the base portion being operably connected to an electromagnetic energy source and / or a pump for circulating a cooling fluid within the device via a formable transmission cable, the formable transmission cable being configured to freely support the weight of the slender body and base portion without additional assistance.

18. A device for delivering electromagnetic energy to a target tissue in a human or animal body, comprising: an elongated body comprising a proximal end, a distal end, and a lumen interconnecting the proximal end and the distal end; an antenna positioned within the lumen and configured to emit electromagnetic energy from the lumen sufficiently intense to cause tissue ablation; as well as a plurality of elongated cylindrical members located within the inner cavity and disposed laterally from the antenna, the plurality of elongated cylindrical members being configured to reflect a portion of the electromagnetic energy emitted from the antenna and to shield a portion of the device from the electromagnetic energy, at least a portion of each of the plurality of elongated cylindrical members comprises an electrically conductive material, wherein the plurality of elongated cylindrical members are configured to reflect a portion of the electromagnetic energy emitted from the antenna, thereby providing a directional pattern for delivering the electromagnetic energy to the target tissue, and wherein the plurality of elongated cylindrical members include tubes, and the device is configured to circulate a cooling fluid through at least one of the tubes and into the inner cavity.

19. The device according to claim 18, characterized in that The elongated cylindrical member also includes a wire.

20. The device according to claim 18, characterized in that The device includes at least one sensor configured to detect an operating condition of the device or a condition associated with the body in which the target tissue is located, wherein at least one of the tubes includes a conductive pathway for the at least one sensor and / or provides shielding from microwave interference or heating of the at least one sensor.

21. The device according to claim 20, characterized in that The at least one sensor comprises a thermocouple.

22. The device according to claim 18, characterized in that The elongated cylindrical members are secured together to form a unitary structure.

23. The device according to claim 18, characterized in that The elongated body includes a material selected from the group consisting of a synthetic resin material, a dielectric material, a ceramic material, and a metal.

24. The device according to claim 18, characterized in that The antenna includes a coaxial transmission cable.

25. The device according to claim 24, characterized in that The coaxial transmission cable includes an outer conductor secured to at least one of the plurality of elongated cylindrical members.

26. A device for delivering electromagnetic energy to a target tissue in a human or animal body, comprising: an elongated body comprising a proximal end, a distal end, and at least one lumen interconnecting the proximal end and the distal end; an antenna positioned within the at least one lumen and configured to emit electromagnetic energy from the lumen sufficiently intense to cause tissue ablation; as well as at least one elongated cylindrical member located within the same or different internal cavity as the antenna, the at least one elongated cylindrical member being disposed laterally from the antenna, The elongated body distally comprises a rigid spacer at its distal end, the distal portion of the antenna being received in the spacer, wherein the at least one elongated cylindrical member is configured to reflect a portion of the electromagnetic energy emitted from the antenna to provide a directional pattern for delivering the electromagnetic energy to the target tissue, and Wherein, the at least one elongated cylindrical member comprises at least one tube, and the device is configured to circulate a cooling fluid through the at least one tube and into the at least one inner cavity.

27. A device for delivering electromagnetic energy to a target tissue in a human or animal body, comprising: an elongated body formed of a synthetic resin material, the elongated body comprising a proximal end, a distal end, and at least two lumens interconnecting the proximal end and the distal end; an antenna positioned within one of the at least two lumens and configured to emit electromagnetic energy from the lumen sufficiently intense to cause tissue ablation; as well as at least one conductive member located within another of the at least two cavities and spaced apart from and laterally disposed from the antenna, wherein the at least one conductive member is configured to reflect a portion of the electromagnetic energy emitted from the antenna to provide a directional pattern for delivering the electromagnetic energy to the target tissue, and Wherein, the at least one electrically conductive member comprises at least one tube, and the device is configured to circulate a cooling fluid through the at least one tube and into the inner cavity.

28. The device according to claim 27, characterized in that The elongated body includes three lumens interconnecting the proximal end and the distal end.

29. The device according to claim 27, characterized in that The inner cavity where the antenna is located is separated from the inner cavity where the conductive component is located by a concave-convex partition wall.

30. The device according to claim 29, characterized in that The at least one conductive member frictionally engages the arcuate dividing wall and at least another wall surface defining an interior cavity that receives the at least one conductive member.

31. The device according to claim 27, characterized in that The at least one conductive member includes a plurality of elongated cylindrical members.

32. The device according to claim 31, characterized in that The elongated cylindrical member also includes a wire.

33. The device according to claim 27, characterized in that The device includes at least one sensor configured to detect an operating condition of the device or a condition associated with the body in which the target tissue is located, wherein at least one of the tubes includes a conductive pathway for the at least one sensor and / or provides shielding from microwave interference or heating of the at least one sensor.

34. The device according to claim 27, characterized in that The device is configured to circulate a cooling fluid through at least two of the cavities.

35. The device according to claim 27, characterized in that The at least one conductive member comprises a planar or concave-convex reflector.

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