Patent Description:
Treatment of certain diseases requires the destruction of malignant tissue growths, for example, tumors. Electromagnetic radiation can be used to heat and destroy tumor cells. Treatment may involve inserting ablation probes into tissue where cancerous tumors have been identified. Once the probes are positioned, electromagnetic energy is passed through the probes into surrounding tissue.

In the treatment of diseases such as cancer, certain types of tumor cells have been found to denature at elevated temperatures that are slightly lower than temperatures normally injurious to healthy cells. Known treatment methods, such as hyperthermia therapy, heat diseased cells to temperature at which irreversible cell destruction occurs. These methods involve applying electromagnetic radiation to heat or ablate tissue.

Electrosurgical devices utilizing electromagnetic radiation have been developed for a variety of uses and applications. Typically, devices for use in ablation procedures include a power generation source, for example, a microwave or radio frequency (RF) electrosurgical generator that functions as an energy source, and a microwave ablation instrument (e.g., a microwave ablation probe having an antenna assembly) for directing energy to the target tissue. The generator and microwave ablation instrument are typically operatively coupled by a cable assembly having a plurality of conductors for transmitting energy from the generator to the instrument, and for communicating control, feedback and identification signals between the instrument and the generator.

A common mechanism used to monitor the temperature of a probe during tissue ablation application is a temperature sensor, such as a thermocouple. Generally, thermocouples consist of two dissimilar metal wires, joined at one end, that are selected to correlate with a targeted temperature range. Thermocouples measure a voltage change between the wires to be used to precisely calculate the temperature of the probe. In this context, document <CIT> is referred to.

Because of the small temperature difference between the temperature required for denaturing malignant cells and the temperature normally injurious to healthy cells, a known heating pattern and precise temperature monitoring are needed. For example, precise temperature control may lead to more predictable temperature distribution during tumor cell eradication, while minimizing damage to surrounding healthy cells.

According to an embodiment of the present disclosure, a microwave ablation device includes a cable assembly, a feedline, and a transmission line. The cable assembly is configured to connect to an energy source. The feedline is in electrical communication with the cable assembly and includes a first temperature sensor and a second temperature sensor. The first temperature sensor is disposed at a first axial location of the feedline and is configured to sense a temperature at the first axial location. The first temperature sensor extends along a length of the feedline. The second temperature sensor is disposed at a second axial location along the length of the feedline and configured to sense a temperature at the second axial location. The first temperature sensor is disposed proximal to the second temperature sensor. The transmission line extends from the first temperature sensor and is disposed parallel and in contact with an outer conductor of the feedline. The microwave ablation device includes a balun disposed on the outer conductor of the feedline, wherein the first temperature sensor is disposed proximate to the balun.

In embodiments, the microwave ablation device may further include an antenna assembly. The antenna assembly is electrically connected to the feedline and positioned distal to the balun. The antenna assembly may include a proximal radiating section, a distal radiating section, and a feedgap. The proximal radiating section may be disposed proximate to the balun. The distal radiating section may be disposed distal to the proximal radiating section. The feedgap may be disposed between the proximal radiating section and the distal radiating section.

In embodiments, the first temperature sensor may be disposed distal to the balun and proximal to the feedgap.

In embodiments, the feedline may further include an inner conductor, an outer conductor extending coaxially with the inner conductor, and a dielectric material disposed between the inner conductor and the outer conductor.

In embodiments, the first temperature sensor may be disposed over the outer conductor.

In embodiments, the feedline may further include a plurality of second temperature sensors. Each of the second temperature sensors may be disposed at a different axial location along the length of the feedline and configured to sense a temperature at each of the different axial locations. The first temperature sensor may be located proximal to the plurality of second temperature sensors. The plurality of second temperature sensors may be arranged in an array.

Also provided in accordance with the present disclosure is a feedline including an inner conductor, an outer conductor, a dielectric material, a first temperature sensor, a second temperature sensor, and a balun. The outer conductor is disposed coaxially with the inner conductor, wherein the dielectric material is disposed between the inner conductor and outer conductor. The first temperature sensor is disposed at a first axial location of the outer conductor and extends along a length of the outer conductor. The first temperature sensor is configured to sense a temperature at the first axial location. The second temperature sensor is disposed at a second axial location along the length of the outer conductor. The second temperature sensor is configured to sense a temperature at the second axial location. The first temperature sensor is disposed proximal to the second temperature sensor. A balun is disposed on the outer conductor, wherein the first temperature sensor is disposed proximate to the balun.

In embodiments, the feedline may further include a plurality of second temperature sensors with each being disposed at different axial locations along the length of the outer conductor and configured to sense a temperature at each of the different axial locations. The first temperature sensor may be positioned proximal to the plurality of second temperature sensors. The plurality of the second temperature sensors may be arranged in an array.

In another aspect of the present disclosure, a method of manufacturing a feedline is provided. A feedline is formed by coating a conductive wire with a dielectric material, placing a conductive material over the dielectric material, positioning a balun on the conductive material, positioning a first temperature sensor over the conductive material, wherein the first temperature sensor is disposed proximate to the balun, and positioning one or more second temperature sensors over the conductive material, wherein the first temperature sensor is proximal to the one or more second temperature sensors.

Some methods may further include positioning a second temperature sensor over the conductive material. The first temperature sensor may be proximal to the second temperature sensor.

Some methods may further include positioning a plurality of second temperature sensors over the conductive material. The first temperature sensor may be proximal to the plurality of second temperature sensors.

Objects and features of the present disclosure will become apparent to those of ordinary skill in the art when descriptions of various embodiments thereof are read with reference to the accompanying drawings, of which:.

The present disclosure is directed to a microwave ablation device including a probe assembly with a temperature sensor and methods of manufacturing the probe assembly. In particular, the present disclosure provides a microwave ablation probe which includes a temperature sensor positioned upon and extending coaxially with the feedline. In this way, the temperature sensor may be placed more accurately within the probe to thereby provide more reliable temperature readings. As a result, the probe assembly may be more precisely controlled during an ablation procedure.

Hereinafter, embodiments of the microwave ablation device of the present disclosure are described with reference to the accompanying drawings. Like reference numerals may refer to similar or identical elements throughout the description of the figures. As shown in the drawings and as used in this description, and as is traditional when referring to relative positioning on an object, the term "proximal" refers to the portion of the apparatus or component thereof, closer to a clinician and the term "distal" refers to the portion of the apparatus, or component thereof, farther from the clinician.

With reference to <FIG> and <FIG>, various views of a microwave ablation system are provided. The microwave ablation system includes a microwave ablation device <NUM> and a generator <NUM>. Device <NUM> generally includes a probe assembly <NUM>, a cable assembly <NUM>, a connector assembly <NUM>, and a handle assembly <NUM>. The probe assembly <NUM> is operably coupled by the cable assembly <NUM> to the connector assembly <NUM>.

The connector assembly <NUM> is a cable connector suitable to operably connect the microwave ablation device <NUM> to the microwave generator <NUM>. The connector may house a memory (e.g., an EEPROM) (not separately shown in <FIG>) storing a variety of information regarding the cable assembly <NUM> and the microwave ablation device <NUM>. For example, the memory may include identification information that can be used by the microwave generator <NUM> to ensure that only properly identified microwave ablation devices are connected thereto. In addition, the memory may store operating parameters of the microwave ablation device <NUM> (for example, time, power, and dosage limits), cable compensation parameters of the cable assembly <NUM>, and information regarding the usage of the microwave ablation device <NUM> or the cable assembly <NUM>. Still further, the connector assembly <NUM> may include sensor electronics (not separately shown in <FIG>) related to radiometry and temperature sensing as described below.

The cable assembly <NUM> may include a tubular member <NUM>, which defines a lumen <NUM> through which a transmission line <NUM> and an electrical wire <NUM> pass. The transmission line <NUM> may be any suitable, flexible transmission line, and particularly a coaxial cable including an inner conductor, and an outer conductor coaxially surrounding a dielectric material. The electrical wire <NUM> may be any suitable electrical wire.

In an embodiment, usage monitoring may enable limiting re-use of the microwave ablation device <NUM> beyond a certain number of energizations or a single use of the device and/or the sensed temperatures may be analyzed. In this regard, a temperature monitoring system <NUM> (<FIG>) may be included as part of the microwave generator <NUM>. In another example, the temperature monitoring system <NUM> may be separate from the microwave generator <NUM> and may be configured to provide audible or visual feedback to the clinician during use of the microwave ablation device <NUM>. The temperature monitoring system <NUM> may be utilized with the probe assembly <NUM> to observe/monitor tissue temperatures in or adjacent an ablation zone.

Referring now to <FIG>, the temperature monitoring system <NUM> can be, for example, a radiometry system, a thermocouple based system or any other tissue temperature monitoring system known in the art. In the embodiment illustrated in <FIG>, the temperature monitoring system <NUM> is configured as a computing device including a memory <NUM>, a processor <NUM>, display <NUM>, a network interface <NUM>, an input device <NUM>, and/or an output module <NUM>. The temperature monitoring system <NUM> is configured to provide tissue temperature and ablation zone information to the microwave generator <NUM>.

The memory <NUM> includes any non-transitory computer-readable storage media for storing data and/or software that is executable by the processor <NUM> and which controls the operation of the microwave ablation device <NUM>. In an embodiment, the memory <NUM> stores data <NUM> related to ablation zone configurations, previously gathered through empirical testing, as one or more data look-up tables. Alternatively or in addition to the one or more solid-state storage devices, the memory <NUM> may include one or more mass storage devices connected to the processor <NUM> through a mass storage controller (not shown) and a communications bus (not shown). Although the description of computer-readable media contained herein refers to a solid-state storage, it should be appreciated by those skilled in the art that computer-readable storage media can be any available media that can be accessed by the processor <NUM>. That is, computer readable storage media includes non-transitory, volatile and non-volatile, removable and non-removable media implemented in any method or technology for storage of information such as computer-readable instructions, data structures, program modules or other data. For example, computer-readable storage media includes RAM, ROM, EPROM, EEPROM, flash memory or other solid state memory technology, CD-ROM, DVD, Blu-Ray or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can be accessed by the microwave ablation device <NUM>.

The memory <NUM> may store an application <NUM>. The application <NUM> may, when executed by the processor <NUM>, cause the processor <NUM> to correlate the tissue temperature and ablation zone data gathered by temperature sensors (for example, a first temperature sensor <NUM> and/or a second temperature sensor(s) <NUM> in the probe assembly <NUM>) with the data <NUM> stored in the memory <NUM>. In another embodiment, the application <NUM>, when executed by the processor <NUM>, may cause the temperature monitoring system <NUM> to calculate a proposed course of treatment, a power setting, and the duration or number of serial energy applications that will achieve a desired ablation zone effective for treating the target tissue. For example, the clinician may enter the size of the target tissue into the temperature monitoring system <NUM>, and the system <NUM> provides instruction for the treatment of the target tissue. In another embodiment, the application <NUM>, when executed by the processor <NUM>, causes the system <NUM> to access the data look-up tables stored in the memory <NUM>, and to compare the tissue temperatures and/or ablation zone temperatures sensed by the first temperature sensor <NUM> (<FIG>) and/or the second temperature sensor(s) <NUM> (<FIG>) with the stored ablation zone configuration. Command signals may be sent automatically to adjust the microwave energy output to the microwave ablation device <NUM>. In another embodiment, a manual adjustment protocol may be utilized to control the microwave energy output to the microwave ablation device <NUM>, for example, to cause an indicator to provide an output (for example, visual, audio and/or tactile indications) to the clinician when a particular tissue temperature and/or ablation zone temperature is matched to a corresponding ablation zone configuration.

In another embodiment, the application <NUM> may, when executed by the processor <NUM>, cause the display <NUM> to present the user interface <NUM>. The network interface <NUM> may be configured to connect to a network such as a local area network (LAN) consisting of a wired network and/or a wireless network, a wide area network (WAN), a wireless mobile network, a Bluetooth network, and/or the internet. The input device <NUM> may be any device by means of which a user may interact with the microwave ablation device <NUM>, such as, for example, a mouse, keyboard, foot pedal, touch screen, and/or voice interface. The output module <NUM> may include any connectivity port or bus, such as, for example, parallel ports, serial ports, universal serial busses (USB), or any other similar connectivity port known to those skilled in the art.

With reference to <FIG>, the probe assembly <NUM> includes an outer tubular member <NUM>, an inner tubular member <NUM>, a feedline <NUM>, an antenna assembly <NUM>, a temperature sensor <NUM> (<FIG>), and a distal tip <NUM>. The outer tubular member <NUM> and the inner tubular member <NUM> may be formed of any suitable non-electrically-conductive material, such as, for example, polymeric or ceramic material. In an embodiment, the inner tubular member <NUM> is coaxially disposed around the feedline <NUM> and defines a first lumen <NUM> therebetween, and the outer tubular member <NUM> is coaxially disposed around the inner tubular member <NUM> and defines a second lumen <NUM> therebetween. In an embodiment, the distal tip <NUM> may be a trocar.

Turning now to <FIG>, in an embodiment of a portion of the probe assembly <NUM>, an antenna assembly <NUM> is included having a first radiating portion (for example, distal radiating section <NUM>) and a second radiating portion (for example, proximal radiating section <NUM>). The antenna assembly <NUM> includes the proximal radiating section <NUM> having a length "L1," the distal radiating section <NUM> including an electrically-conductive element <NUM> having a length "L2," and a feedgap <NUM> disposed therebetween. In an embodiment, the proximal radiating section <NUM> may have the length "L1" in a range of from about <NUM> inches (<NUM>) to about <NUM> inches (<NUM>). The electrically-conductive element <NUM> may be formed of any suitable electrically-conductive material, for example, metal such as stainless steel, aluminum, titanium, copper, or the like. In an embodiment, the electrically-conductive element <NUM> may have the length "L2" in a range from about <NUM> inches (<NUM>) to about <NUM> inches (<NUM>). In an embodiment, the electrically-conductive element <NUM> has a stepped configuration, such that the outer diameter of a distal portion <NUM> thereof is less than the outer diameter of a proximal portion <NUM> thereof. The antenna assembly <NUM> is operably coupled by the feedline <NUM>, which is described in more detail below, to a transition assembly <NUM> shown in <FIG>. The transition assembly <NUM> is adapted to transmit microwave energy, from the cable assembly <NUM> to the feedline <NUM>.

The feedline <NUM> may be a coaxial cable or any other type of suitable transmission line. In an embodiment, as shown in <FIG>, the feedline <NUM> includes an inner conductor <NUM>, an outer conductor <NUM> extending coaxially with to be disposed around the inner conductor <NUM>, and a dielectric material <NUM> disposed therebetween. Additionally, the feedline <NUM> includes a first temperature sensor <NUM> disposed on the coaxial cable <NUM>. The inner conductor <NUM> and the outer conductor <NUM> may be formed from any suitable electrically-conductive material. In an embodiment, the inner conductor <NUM> is formed from a first electrically-conductive material (for example, stainless steel) and the outer conductor <NUM> is formed from a second electrically-conductive material (for example, copper). Electrically-conductive materials used to form the feedline <NUM> may be plated with other materials, for example, other conductive materials, such as gold or silver, to improve their properties, for example, to improve conductivity, decrease energy loss, etc. The dielectric material <NUM> may be formed from any suitable dielectric material, for example, polyethylene, polyethylene terephthalate, polyimide or polytetrafluoroethylene (PTFE).

The feedline <NUM> may have any suitable length defined between its proximal and distal ends. In accordance with an embodiment of the present disclosure, the feedline <NUM> is coupled at its proximal end to the transition assembly <NUM> (<FIG>) and coupled at its distal end to the antenna assembly <NUM> (<FIG>). The feedline <NUM> is disposed at least in part within the inner tubular member <NUM> (<FIG>). In an embodiment, the inner conductor <NUM> of the feedline <NUM> extends past the distal end of both the dielectric material <NUM> and the outer conductor <NUM> and into the proximal portion <NUM> of the antenna assembly <NUM>. An opening <NUM>, formed in the proximal portion <NUM> approximately at <NUM> degrees to the inner conductor <NUM> allows for solder, a set screw, or other securing mechanisms to physically secure the electrically conductive element <NUM> to the inner conductor <NUM> and therewith the feedline <NUM> of the microwave ablation device <NUM>.

In an embodiment, the outer conductor <NUM> may be braided, for example, including three or more strands intertwined. While the outer conductor <NUM> is described as a braid, the actual construction is not so limited and may include other formations of outer conductors of coaxial cables as would be understood by those of ordinary skilled in the art. The feedline <NUM> may incorporate one or more aspects of the ablation system described in <CIT> entitled "Microwave Ablation Catheter and Method of Utilizing the Same".

The probe assembly <NUM> may include a balun <NUM> disposed proximal to and spaced apart a suitable distance from the feedgap <NUM>. The balun <NUM> generally includes a balun short <NUM> and a balun insulator <NUM>, which both couple the balun <NUM> to the outer conductor <NUM> of the feedline <NUM>. The balun short <NUM> may be formed as a single structure and electrically coupled to the outer conductor <NUM> of the feedline <NUM> by a suitable manner of electrical connection, for example, soldering, welding or laser welding. Also, the balun short <NUM> may be formed by any suitable electrically-conductive materials, for example, copper, gold, silver or other conductive metals or metal alloys. In an embodiment, the balun short <NUM> has a generally ring-like or truncated tubular shape. In other embodiments, the balun <NUM> is devoid of a balun short. The size and shape of the balun short <NUM> may be varied from the configuration depicted in <FIG>. In an embodiment, the balun <NUM> may be a ¼ λ balun or a ¾ λ balun.

<FIG> and <FIG> further depict the balun insulator <NUM> extending coaxially with and disposed over the outer conductor <NUM> of the feedline <NUM>. The balun insulator <NUM> may be formed of any suitable insulative material, including, but not limited to, ceramics, water, mica, polyethylene, polyethylene terephthalate, polyimide, polytetrafluoroethylene (PTFE) (for example, Teflon®), glass, metal oxides or other suitable insulator, and may be formed in any suitable manner. In an embodiment, the balun insulator <NUM> may be a dielectric sleeve. The balun insulator <NUM> may be grown, deposited or formed by any other suitable technique. In an embodiment, the balun insulator <NUM> may be formed from a material with a dielectric constant (k) in the range of about <NUM> to about <NUM>.

A tubing member <NUM> including an inner layer of an electrically-conductive material <NUM> is illustrated. In an embodiment, the tubing member <NUM> may be a heat shrink tubing member, which has the capability of responding to heat and binding around an object. The heat shrink tubing member may be a thermoplastic. The electrically-conductive material <NUM> may be formed of any suitable electrically-conductive material, for example, metallic material. In an embodiment, the metallic material of electrically-conductive layer <NUM> is formed of a silver ink deposited or layered on an interior surface of the tubing member <NUM>. The tubing member <NUM> may have a length from about <NUM> inch (<NUM>) to about <NUM> inches (<NUM>) in length. However, the shape and size of the tubing member <NUM> and the balun insulator <NUM> may be varied from the configuration depicted in <FIG> and <FIG> without departing from the scope of the present disclosure. After the application of thermal energy to the tubing member <NUM>, the tubing member <NUM> shrinks causing the electrically-conductive material <NUM> to contact with the balun short <NUM> and a portion of the balun insulator <NUM>. For example, a portion of the balun insulator <NUM> may extend distally beyond the distal end of the tubing member <NUM> and the electrically-conductive layer <NUM>, to create a gap <NUM>. The gap <NUM> improves the microwave performance of the probe assembly <NUM> and can assist in achieving a desired ablation pattern. More specifically, the gap <NUM> ensures adequate coupling of microwave energy from the proximal radiating section <NUM> into the balun <NUM>, improving the performance of the balun <NUM> over a wide range of tissue dielectric conditions.

The balun <NUM> is connected to the antenna assembly <NUM>. In operation, microwave energy having a wavelength lambda (λ) is transmitted through the antenna assembly <NUM> and radiated into the surrounding medium, for example, tissue. The length of the antenna for efficient radiation may be dependent on the effective wavelength, λeff, which is dependent upon the dielectric properties of the treated medium. The antenna assembly <NUM> through which microwave energy is transmitted at a wavelength λ may have differing effective wavelengths, λeff, depending upon the surrounding medium, e.g., liver tissue as opposed to breast tissue, lung tissue, kidney tissue, etc..

The first temperature sensor <NUM> is disposed on the feedline <NUM>. In particular, the first temperature sensor <NUM> is coupled to the outer conductor <NUM> and extends generally along a longitudinal axis of the feedline <NUM> and terminates under the balun <NUM> and is held in place under the balun <NUM> using potting material, such as, for example, a heat resistant epoxy. The first temperature sensor <NUM> is in contact and parallel with an outer surface of the outer conductor <NUM> of the feedline <NUM>. In an embodiment, the first temperature sensor <NUM> is a thermocouple and the transmission <NUM> is a thermocouple wire. In embodiments, the first temperature sensor <NUM> and the transmission <NUM> may be monolithically formed. The thermocouple wire <NUM> may be a two lead wire thermocouple wire, for example, and may be made up of an insulated (anodized) side-by-side Constantine wire and copper wire.

As illustrated in <FIG>, the first temperature sensor <NUM> may be disposed at a location along the length of the feedline <NUM> that is proximate to the axial location of the balun short <NUM>. The first temperature sensor <NUM> may be received or potted within a hole (not explicitly shown) defined in the balun short <NUM>. In one embodiment, the first temperature sensor <NUM> may be proximal to the axial location of the balun short <NUM> (<FIG>). In another embodiment, the first temperature sensor <NUM> may be distal to the axial location of the balun short <NUM> (not shown). In a further embodiment, the first temperature sensor <NUM> may be distal to the axial location of the balun insulator <NUM> (<FIG>). For example, in an embodiment illustrated in <FIG>, the first temperature sensor <NUM> is located between the balun insulator <NUM> and the feedgap <NUM>.

By disposing the first temperature sensor <NUM> closer to the balun short <NUM>, the temperature of the balun short <NUM> can be more accurately sensed to thereby permit the first temperature sensor <NUM> to act as a safety indicator. For instance, in response to the first temperature sensor <NUM> detecting a temperature that exceeds a pre-determined threshold temperature (for example, <NUM>), which can lead to unintended cell death in tissue, the system <NUM> may cause the generator <NUM> to shut down or provide an alarm as the sensed temperature approaches the pre-determined threshold temperature, thus preventing injury to the patient.

In accordance with another embodiment, the axial location of the first temperature sensor <NUM> along the feedline <NUM> may be at approximately <NUM> inch (<NUM>), <NUM> inch (<NUM>), <NUM> inches (<NUM>), and <NUM> inches (<NUM>) from the distal tip <NUM> of the microwave ablation device <NUM>. The distal end of the first temperature sensor <NUM> may be located a specified distance from the distal radiating section <NUM> that provides the most accurate temperature measurements.

With reference to <FIG>, an embodiment of the handle assembly <NUM> includes an inflow tube insert <NUM> received within a hub divider <NUM>. The inflow tube insert <NUM> includes a flange <NUM> formed on one end. The flange <NUM> forms a surface upon which fluid in an inflow chamber <NUM> acts, and when the inflow chamber <NUM> is pressurized, compresses the hub divider <NUM> forming a water tight seal. As a result of this seal between the flange <NUM> and the hub divider <NUM>, the circulated fluid is forced into the spacing between the inflow tube insert <NUM> and the feedline <NUM>. After flowing to the distal portion of the microwave ablation device <NUM>, the fluid is released into an outflow chamber <NUM>.

The inflow tube insert <NUM> is disposed about a proximal end portion of the feedline <NUM>. The transmission <NUM> (e.g., the proximal portion of the first temperature sensor <NUM>) extends through a longitudinally-extending channel <NUM> defined through the inflow tube insert <NUM> and runs parallel with and along an outer surface of the outer conductor of the feedline <NUM>. The channel <NUM> of the inflow tube insert <NUM> has a diameter large enough to accommodate both the feedline <NUM> and the transmission <NUM> while providing a space between an inner annular surface thereof and the transmission <NUM>.

<FIG> depicts a further embodiment of the present disclosure in which more than one temperature sensor is included. Here, the device <NUM> includes a second temperature sensor <NUM>. The first temperature sensor <NUM> and the second temperature sensor <NUM> are disposed on the feedline <NUM> at different locations to sense the temperatures at different axial positions along the length of the feedline <NUM> simultaneously, for example, adjacent to the balun <NUM> and adjacent to the feedgap <NUM>.

<FIG> illustrates another embodiment including a plurality of temperature sensors. In this embodiment, the first temperature sensor <NUM> is disposed at an axial location proximate the proximal portion of the balun short <NUM>, the distal portion of the balun short <NUM> or the distal portion of the balun insulator <NUM>, while a plurality of second temperature sensors <NUM> may be disposed distal to the balun <NUM> and proximal to the feedgap <NUM>. According to an embodiment, the second temperature sensors <NUM> may be arranged in an array. For example, the plurality of the second temperature sensors <NUM> may be arranged at approximately <NUM> inch (<NUM>), <NUM> inch (<NUM>), <NUM> inches (<NUM>), and <NUM> inches (<NUM>) from the distal tip <NUM> of the microwave ablation device <NUM>. By using the second temperature sensors <NUM> and the first temperature sensor <NUM>, a thermographic profile of the tissue can be created for review and analysis during and after the procedure, a progression of the treatment may be monitored, and/or a terminal threshold of the treatment may be monitored to end the treatment. In an embodiment, the first temperature sensor <NUM> and the second temperature sensors <NUM> may detect rising temperatures of an ablation zone, which may be correlated with ablation growth in the surrounding tissue.

The feedline <NUM> may be manufactured using any one of numerous suitable processes. Generally, a conductive wire is provided to serve as the inner conductor <NUM>. The conductive wire may be drawn or extruded to thereby form the inner conductor <NUM>, which may serve as a core or center of the feedline <NUM>. The dielectric material <NUM> is used to coat and thereby encapsulate the inner conductor <NUM>, for example, by extrusion, at a secured position to form the dielectric material <NUM>. The outer conductor <NUM> is then formed over the dielectric material <NUM>. In an embodiment, a conductive material is placed around the dielectric material <NUM> to form the outer conductor <NUM>, for example, by inserting the dielectric material <NUM>, which may be shaped as a tube, or by wrapping the conductive material around the dielectric material <NUM>.

The temperature sensor <NUM> is positioned adjacent the outer conductor <NUM>. In an embodiment, a thermocouple forming a portion of the temperature sensor <NUM> is disposed at a desired position over a surface of the outer conductor <NUM>, and an associated transmission line <NUM>, which extends proximally from the thermocouple <NUM>, is disposed such that it runs along a length of the outer conductor <NUM> and extends past its proximal end. The proximal ends of the inner conductor <NUM>, the dielectric material <NUM>, and the outer conductor <NUM> are aligned, such that the transmission line <NUM> extends past all the proximal ends of the inner conductor <NUM>, the dielectric material <NUM>, and the outer conductor <NUM>.

In another embodiment in which multiple temperature sensors are included, thermocouples of each temperature sensor, for example, a first temperature sensor <NUM> and one or more second temperature sensors <NUM>, are disposed at a desired position, and transmission lines <NUM> corresponding to each are placed along a length of the outer conductor <NUM> to extend past a proximal end thereof. Dielectric material <NUM> surrounds the inner conductor <NUM>, for example, by extrusion. In another embodiment, the inner conductor <NUM> is coated with the dielectric material <NUM>. In either case, conductive material is disposed over the inner conductor <NUM> and dielectric material <NUM> to form the outer conductor <NUM>. The first temperature sensor <NUM>, the one or more second temperature sensor <NUM>, and the transmission line <NUM> are then secured to the outer conductor <NUM>. The temperature sensors <NUM>, <NUM> are positioned as desired.

Once manufactured, the feedline <NUM> and temperature sensor <NUM> may be further processed. For example, in an embodiment, the balun <NUM> is coupled to the outer conductor <NUM> by any suitable means at any desired location, such as proximate to the first temperature sensor <NUM>, between the first temperature sensor <NUM> and the second temperature sensor(s) <NUM>.

During operation, probe assembly <NUM> with the embedded temperature sensor <NUM> will monitor the temperature of components of the probe assembly <NUM> and propagate a signal that relays the measured temperature to the microwave ablation device <NUM>, which will regulate the temperature to prevent damage to components of the probe assembly <NUM>, and/or prevent harm to the clinician or patient.

Various embodiments of the present disclosure provide a probe assembly including an embedded temperature sensor, a balun, and a feedline. Embodiments may be suitable for utilization with hand-assisted, endoscopic, and laparoscopic surgical procedures such as Video Assisted Thoracic Surgery. Embodiments may be implemented using electromagnetic radiation at microwave frequencies, RF frequencies or at other frequencies. A microwave ablation device including the presently disclosed probe assembly is configured to operate at frequencies between about <NUM> and about <NUM>.

Various embodiments of the presently disclosed probe assembly including a temperature sensor, a balun, and a feedline are suitable for microwave or RF ablation and for use to pre-coagulate tissue for microwave or RF ablation-assisted surgical resection. Although various embodiments described hereinbelow are disclosed to perform microwave ablation and the complete destruction of target tissue, it is to be understood that embodiments for directing electromagnetic radiation may be used with other therapies in which the target tissue is partially destroyed or damaged, such as, for example, to prevent the conduction of electrical impulses within heart tissue. In addition, although the following description describes the use of a dipole microwave antenna, the teachings of the present disclosure may also apply to a monopole, helical or other suitable type of microwave antenna or RF electrode.

As it is used in this description, "ablation procedure" generally refers to any ablation procedure, such as, for example, microwave ablation, radiofrequency (RF) ablation, or microwave or RF ablation-assisted resection.

As it is used in this description, "length" may refer to electrical length or physical length. In general, electrical length is an expression of the length of a transmission medium in terms of the wavelength of a signal propagating within the medium. Electrical length is normally expressed in terms of wavelength, radians or degrees. For example, electrical length may be expressed as a multiple or sub-multiple of the wavelength of an electromagnetic wave or electrical signal propagating within a transmission medium. The wavelength may be expressed in radians or in artificial units of angular measure, such as degrees. The electrical length is in general different from the physical length. By the addition of an appropriate reactive element (capacitive or inductive), the electrical length may be made significantly shorter or longer than the physical length.

This description may use the phrases "in an embodiment," "in embodiments," "in some embodiments," or "in other embodiments," which may each refer to one or more of the same or different embodiments in accordance with the present disclosure.

Claim 1:
A feedline (<NUM>) comprising:
an inner conductor (<NUM>);
an outer conductor (<NUM>) disposed coaxially with the inner conductor;
a dielectric material (<NUM>) disposed between the inner conductor and outer conductor;
a first temperature sensor (<NUM>) disposed at a first axial location of the outer conductor, wherein the first temperature sensor extends along a length of the outer conductor and is configured to sense a temperature at the first axial location;
a second temperature sensor (<NUM>) disposed at a second axial location along the length of the outer conductor and configured to sense a temperature at the second axial location of the outer conductor, wherein the first temperature sensor is disposed proximal to the second temperature sensor; and
a balun (<NUM>) disposed on the outer conductor, wherein the first temperature sensor is disposed proximate to the balun.