System for treating unwanted tissue

Abstract

The present technology can be used to selectively heat one or more diseased regions in the lung while limiting heating of healthy regions and surrounding tissue. This heating provides a therapeutic effect. Selective heating of diseased tissue can be achieved by exposing the lung to an electromagnetic field to cause dielectric or eddy current heating. The present technology is particularly useful for treating emphysema because the diseased regions of emphysema patients have reduced blood flow. The diseased regions will heat up quickly while healthy tissue will be cooled by blood flow. This is particularly effective for treating emphysema because the lung has a small mass and high blood flow. In one described embodiment, the frequency of the electromagnetic radiation is chosen to satisfy certain resonance conditions of the device. In another described embodiment, a coil is used to apply the electromagnetic radiation, the geometric parameters of the coil being chosen so that an electric field maximum is produced in the region to be heated. In another described embodiment, a pair of electromagnetic energy signal applicators are used to apply the electromagnetic radiation, the pair of electromagnetic energy signal applicators being positioned to surround the torso of the patient, one electromagnetic energy signal applicator being positioned cephalad relative to the treatment region and the other electromagnetic energy signal applicator being positioned caudal relative to the treatment region, and the pair of electromagnetic energy signal applicators being shaped to encircle or partially encircle the periphery of the torso.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Application No. 63 / 030,879, filed on May 27, 2020, entitled “SYSTEM FOR TREATING UNWANTED TISSUE,” which is hereby incorporated by reference for all purposes. In the United States of America, this application claims the benefit under 35 U.S.C. §119 of U.S. Application No. 63 / 030,879, filed on May 27, 2020, entitled “SYSTEM FOR TREATING UNWANTED TISSUE.” Technical Field

[0003] The present invention relates to medical devices and methods for treating unwanted tissue.The present invention has exemplary application in treating lung diseases such as chronic obstructive pulmonary disease (COPD), an example of which is emphysema. Background Art

[0004] There are a variety of medical conditions for which treatment may involve destroying or affecting undesirable tissue. Such treatment should ideally avoid harming normal tissue adjacent to the undesirable tissue. For example, some lung conditions may benefit from treatments that involve destroying or affecting diseased lung tissue. Some of these treatments involve heating the lung tissue. Background information about lung diseases can be found in medical textbooks, such as "Pulmonary Pathophysiology" by Dr. John B. West, ISBN 0-683-08934-X.

[0005] Emphysema is a disease that damages the alveoli (air sacs) in a patient's lungs.

[0006] Emphysema can cause the alveoli in a patient's lungs to rupture. This changes the distribution of air spaces in the lungs and reduces the surface area of ​​the lungs available for oxygen absorption. The lung damage caused by emphysema can trap stale air in the lungs and / or reduce the flow of fresh, oxygen-rich air into the lungs. In patients with emphysema, the diseased parts of the lungs are unable to effectively ventilate through the bronchi and trachea, thus preventing the lungs from fully deflation and inflation. The trapped air in the lungs prevents the diaphragm from moving up and down naturally. This condition leads to difficulty breathing and a decrease in overall health and quality of life.

[0007] Some prior art methods for heating diseased tissue in the lungs involve inserting an ablation device through the trachea and bronchi into the diseased area (e.g., see US 2016 / 0184013 by Brannan et al.). This approach has various disadvantages: it can only reach a small portion of the lung; it requires precise mapping of the diseased area; and the ablation device must be accurately guided to a precise location. Furthermore, during treatment, collateral damage is caused to tissue located along the device's path from the entry point to the treatment site.

[0008] Some prior references in the general field of the invention are:

[0009] a) US Patent 8,444,635 to Lichtenstein et al., which is incorporated herein by reference, discloses a system for exposing unwanted tissue to a scanned focused microwave beam.

[0010] b) US8019414 to Palti discloses combining chemotherapy treatment with low intensity, medium frequency alternating electric fields that are tuned for specific types of target cells.

[0011] c) US Pat. No. 4,269,199 to Armitage discloses a method for inducing local hyperthermia in the treatment of tumors by shortwave diathermy. The method comprises moving an induction coil over a part of the body containing the tumor so that the axis of the coil continuously intersects different parts of the tumor.

[0012] d) US4798215 to Turner discloses a combined hyperthermia treatment and non-invasive temperature measurement device.

[0013] e) US Pat. No. 5,010,897 to Leveen discloses a device for deep heating of cancer. This device utilizes two single-turn coaxial coils that rotate synchronously in parallel planes, with the central axis of each coil lying on the same line perpendicular to the planes of the coils. The combined magnetic field of the rotating coils continuously heats the tumor.

[0014] f) US5503150 to Evans discloses an apparatus and method for non-invasively localizing and heating a volume of tissue, including the ability to detect temperature changes in the volume of tissue.

[0015] g) US6181970 to Kasevich discloses a medical system and apparatus for providing thermal treatment of tissue and diagnostic imaging using microwave energy.

[0016] h) US8585645 to Barry et al. discloses the use of high temperature steam delivered through the lumen of a catheter to treat specific areas in a patient's lungs.

[0017] i) US2011 / 0054431 to Turnquist et al. discloses devices and methods for using emitted energy to non-invasively heat body tissue and fluids and non-invasively measure the resulting temperature changes in the target and surrounding fluids and tissues to detect and / or treat various physical conditions, such as, for example, vesicoureteral reflux.

[0018] j) WO 2017 / 201625 to Lichtenstein et al. describes methods and devices that can be used to treat emphysema by heating tissue using energy delivered through external electrodes or coils.

[0019] k) US8467858 to Vertikov et al. describes devices and techniques for thermal therapy based on optical imaging.

[0020] 1) Ruggera et al. CA1212424A describes a helical coil for a diathermy device that is driven at a frequency corresponding to an integer multiple of half the fundamental wavelength to achieve laterally uniform heating and enable the thermal focal volume to be offset along the coil axis from a normal center position on the axis produced by full-wave excitation.

[0021] It is generally desirable to have a system that can automatically heat tissue in a diseased area. It is generally desirable to have a system that can heat tissue in a diseased area without having to precisely locate the diseased area. In particular, there is a need for new, practical methods and devices for heating all diseased portions of the lung without overheating healthy portions of the lung or surrounding healthy tissue. Summary of the Invention

[0022] The present invention has many aspects. These aspects include, but are not limited to:

[0023] • Devices useful for selectively heating tissue within a patient.

[0024] Control systems for tissue heating devices;

[0025] A method for controlling a device for selectively heating tissue within a patient;

[0026] • A method for treating a patient, the method comprising selectively heating tissue within the patient.

[0027] Use of devices for the treatment of COPD and other lung diseases.

[0028] An exemplary and non-limiting application of the methods and devices described herein is the treatment of diseased lung tissue, such as lung tissue affected by emphysema or other forms of COPD. Some embodiments provide methods and / or devices particularly suitable for selectively heating lung tissue to treat COPD and / or other lung diseases.

[0029] One aspect of the present invention provides a device for treating emphysema or COPD, which treats emphysema or COPD by selectively heating diseased lung tissue of a patient to a therapeutic temperature sufficient to produce a therapeutic effect in the diseased lung tissue, the device comprising: at least one signal applicator, at least one signal applicator comprising an electrical conductor, the electrical conductor being sized to extend circumferentially around or nearly around the patient's torso; a power supply connected to deliver a radio frequency (RF) signal to the at least one applicator, the power supply comprising an impedance matching network, the impedance matching network being operable to match the output impedance of the power supply to the input impedance of the signal applicator; a controller operatively associated with the power supply and configured to control the power supply to apply the RF signal to the applicator; the applicator being operable to couple an electromagnetic energy signal into the patient's tissue when energized by the RF signal, such that the patient's tissue is heated by the electromagnetic energy signal and, due to the relatively low blood circulation to the diseased tissue, the diseased tissue is selectively heated to a higher temperature than healthy tissue.

[0030] In some embodiments, the power supply has a maximum RF signal output power of at least 500 W. In some embodiments, the RF signal generates a local axial electric or magnetic field in the patient's lungs. This local field can serve as the primary source of (dielectric) heating of the patient's tissue.

[0031] In some embodiments, the temperature monitor is operable to monitor the temperature at one or more locations within the patient's tissue, wherein the controller is connected to receive a temperature signal from the temperature monitor, the temperature signal being indicative of the temperature at the one or more locations, and the controller is configured to apply feedback control to the power supply to adjust the electromagnetic energy signal delivered to the patient based at least in part on the temperature signal.

[0032] In some embodiments, the temperature monitor is a non-invasive temperature monitor.

[0033] In some embodiments, a temperature monitor includes a magnetic resonance imaging (MRI) imaging system and a processor configured to process MRI signals provided by the MRI imaging system to determine a temperature corresponding to each of the one or more locations.

[0034] In some embodiments, the temperature monitor includes an ultrasound imaging (US) system and a processor configured to process ultrasound signals provided by the US imaging system to determine a temperature corresponding to each of the one or more locations.

[0035] In some embodiments, the controller is configured to control one or more parameters of the RF signal until the temperature at the location is at least equal to the treatment temperature.

[0036] In some embodiments, the controller includes a thermal model of at least a portion of the patient, the thermal model relating temperatures at one or more locations to a temperature at a location of interest, and the controller is configured to apply the thermal model using the temperature signal as an input and is configured to adjust the heating energy based at least in part on an output of the thermal model.

[0037] In some embodiments, the thermal model includes one or more of: electrical and thermal properties of different tissue types within the patient; the distribution of different tissue types within the patient; the geometry of one or more electromagnetic energy applicators; the expected electromagnetic field distribution generated; and the perfusion rate within the patient.

[0038] In some embodiments, at least one signal applicator comprises a coil.

[0039] In some embodiments, the coil includes in the range of 5 to 100 turns.

[0040] In some embodiments, the coil includes in the range of 10 to 60 turns.

[0041] In some embodiments, the turns of the coil are evenly spaced apart along the longitudinal axis of the coil.

[0042] In some embodiments, the turns of the coil are unevenly spaced along the longitudinal axis of the coil.

[0043] In some embodiments, the cross-section of the coil is not circular.

[0044] In some embodiments, the spacing between turns of the coil along the longitudinal axis of the coil is adjustable.

[0045] In some embodiments, the cross-section of the coil can be adjusted along the longitudinal axis of the coil.

[0046] In some embodiments, the coil has a length of at least 70 centimeters.

[0047] In some embodiments, the coil has a length of at least 1 meter.

[0048] In some embodiments, the coil has an inner diameter of at least 30 cm.

[0049] In some embodiments, the length of the coil is greater than or equal to the width of the coil.

[0050] In some embodiments, the length of the coil is greater than or equal to four times the width of the coil.

[0051] In some embodiments, the coil includes multiple layers of windings.

[0052] In some embodiments, the coil is configured to open like a clamshell to receive the patient.

[0053] In some embodiments, the apparatus includes a patient support configured to support a patient in a lying position, the patient support including a head support, wherein the head support is external to the coil.

[0054] In some embodiments, the RF signal has a frequency in the range of about 5 kHz to about 100 MHz.

[0055] In some embodiments, the RF signal has a frequency in the range of about 500 kHz to about 10 MHz.

[0056] In some embodiments, the controller is configured to set the frequency of the RF signal such that an electric field maximum of the electromagnetic energy signal is at a desired location relative to the at least one applicator.

[0057] In some embodiments, the controller is configured to set the frequency of the RF signal to generate a standing wave in the at least one applicator.

[0058] In some embodiments, the controller is configured to set the frequency of the RF signal to generate a standing wave in at least one applicator having an electric field maximum at a desired location (e.g., at or near the location of the volume of diseased tissue in the patient's lung).

[0059] In some embodiments, the controller is configured to set the frequency of the RF signal to be at or near a resonant frequency of the applicator and the patient.

[0060] In some embodiments, the controller is configured to set the frequency of the RF signal to be equal to or close to an integer multiple of the resonant frequency of the applicator when the patient is present.

[0061] In some embodiments, the RF signal has a power in a range of about 500 watts to about 5 kilowatts.

[0062] In some embodiments, the controller is configured to apply time domain modulation to the RF signal.

[0063] In some embodiments, the controller is configured to control the power supply to generate the RF signal as a pulse signal, and is configured to control the width of the pulses in the pulse signal.

[0064] In some embodiments, the one or more signal applicators include two signal applicators connected to a power source and operable to deliver electromagnetic energy signals into tissue of the patient.

[0065] In some embodiments, the two signal applicators include a first signal applicator positioned cephalad with respect to the volume to be treated and a second signal applicator positioned caudad with respect to the volume to be treated.

[0066] In some embodiments, each of the two signal applicators is shaped to surround or partially surround the periphery of the patient's torso.

[0067] In some embodiments, the signal applicator can be adjusted to conform to the contours of the patient being treated.

[0068] In some embodiments, the device includes a cooling device for cooling the patient.

[0069] In some embodiments, the cooling device includes a cooling fluid source arranged to bring the cooling fluid into thermal contact with the patient's skin area.

[0070] In some embodiments, the cooling device includes a patient support including channels connected to carry a cooling fluid, the channels being in thermal contact with a surface supporting the patient.

[0071] In some embodiments, the cooling device is configured to cool the chest and back of the patient.

[0072] In some embodiments, the cooling device is configured to cool the patient's groin.

[0073] In some embodiments, the cooling device comprises a source of cold air.

[0074] In some embodiments, the device is used in the treatment of emphysema or COPD.

[0075] One aspect of the present invention provides a method for treating emphysema or COPD by selectively heating diseased lung tissue of a patient to a therapeutic temperature sufficient to produce a therapeutic effect in the diseased lung tissue, the method comprising: providing at least one signal applicator, the at least one signal applicator comprising an electrical conductor extending circumferentially around or nearly around the patient's torso; delivering a radio frequency (RF) signal to the at least one applicator and allowing the RF signal to be absorbed in both healthier tissue and diseased tissue of the patient's lungs, thereby heating the tissue of the patient's lungs, whereby the heating raises the diseased tissue to a temperature exceeding a therapeutic threshold temperature while maintaining the temperature of the healthier tissue below a safe threshold temperature lower than the therapeutic threshold temperature by virtue of blood circulation through the healthier tissue; maintaining the temperature of the diseased tissue above the therapeutic threshold temperature for a cumulative time sufficient to provide a therapeutic effect.

[0076] In some embodiments, the RF signal has an output power of at least 500 Watts.

[0077] In some embodiments, the therapeutic effect is ablation of diseased tissue.

[0078] In some embodiments, the therapeutic effect is necrosis of diseased tissue.

[0079] In some embodiments, the therapeutic effect is the induction of inflammation in diseased tissue.

[0080] In some embodiments, the RF signal creates a localized, axially extending alternating electric or magnetic field in the patient's lungs.

[0081] In some embodiments, at least one applicator comprises a coil, and the patient's lung is within the coil.

[0082] In some embodiments, the RF signal generates an alternating magnetic field that extends substantially parallel to the superior-inferior direction of the patient.

[0083] In some embodiments, the method includes providing a strength of the alternating magnetic field that is substantially uniform within the coil.

[0084] In some embodiments, at least one applicator includes a pair of conductive members spaced apart along the patient's torso.

[0085] In some embodiments, the RF signal creates a localized alternating electric field that extends in an axial direction substantially parallel to the superior-inferior direction of the patient.

[0086] In some embodiments, the method includes monitoring the temperature of tissue within the patient and controlling the RF signal based on the monitored temperature. For example, controlling the RF signal can include setting the frequency of the RF signal and setting one or more of the amplitude or power of the RF signal. In some embodiments, the method includes setting the frequency of the RF signal to generate an electromagnetic standing wave within the patient (e.g., within the patient's lungs).

[0087] Other aspects and example implementations are shown in the accompanying drawings and / or described in the following description.

[0088] The present invention has aspects expressed as methods and aspects expressed as apparatuses. Where an apparatus is described herein, all described features of the apparatus and uses of such an apparatus are intended to also describe the corresponding method, and where a method is described herein, the disclosure of such a method is intended to also provide an apparatus configured to implement such a method.

[0089] It is emphasized that the invention relates to all combinations of features mentioned above, even if these are recited in different claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0090] The accompanying drawings illustrate non-limiting example embodiments of the invention.

[0091] Figure 1 An apparatus according to an example embodiment is shown.

[0092] Figure 1A is a schematic graph illustrating differential heating of diseased and healthy tissue.

[0093] Figure 1B is a block diagram illustrating an example control system for the apparatus described herein.

[0094] Figure 1C is a schematic cross section of a coil illustrating one way to adjust the cross-sectional shape of the coil.

[0095] Figure 2 is a side elevation view of an apparatus including a multi-layer coil according to an example embodiment.

[0096] Figure 3 is a side elevational view of another example device including a pair of spaced-apart applicators that extend circumferentially or partially circumferentially around a patient. DETAILED DESCRIPTION

[0097] Throughout the following description, specific details are set forth in order to provide a more thorough understanding of the present invention. However, the present invention can be practiced without these details. In other cases, well-known elements are not shown or described in detail to avoid unnecessarily obscuring the present invention. Therefore, the description and drawings should be regarded as illustrative rather than restrictive.

[0098] Figure 1 An apparatus 10 according to an example embodiment is shown. A patient P has a volume V of tissue that it is desired to treat by heating. The volume V may, for example, comprise alveoli in the lungs L of a patient affected by emphysema.

[0099] Volume V may have relatively low blood circulation compared to healthier tissue in other parts of the lung L, such that delivering energy of a given power density to tissue in volume V (i.e., delivering energy to tissue in volume V at a given rate, which may be measured, for example, in watts per unit volume in volume V, which may be measured, for example, in cm2) may increase the temperature of the tissue in volume V compared to the temperature increase that would occur if the same power density of energy were delivered to healthier tissue in other parts of the lung L. 3 The higher temperature increase in volume V can be due, at least in large part, to reduced blood circulation in volume V compared to blood circulation in healthier tissue. The circulating blood acts as a coolant, removing energy from the healthier tissue at a higher rate than it is removed from volume V. This effect can be used to heat the tissue in volume V to a temperature high enough to achieve a desired result (e.g., destruction of the tissue in volume V such as tissue ablation, tissue necrosis, or initiation of inflammation in the tissue in volume V), while the temperature in the surrounding healthier tissue can remain below a safe threshold temperature so that the surrounding healthier tissue is not harmed.

[0100] For example, if each volume of tissue in the portion of the lung L that includes one or more volumes V of diseased tissue can be made to consume the same amount of power per unit volume, the power level can be selected so that the one or more volumes of diseased tissue within the lung L with poor blood circulation will be heated to a temperature that is at least at a therapeutic temperature threshold, while the temperature of the volume of healthier tissue within the lung L with better blood circulation remains below a safe temperature threshold.

[0101] Figure 1A is a schematic diagram illustrating the above principle. Initially, the temperature T in the volume V of the diseased tissue V The temperature T in the volume of healthy tissue H Equal to body temperature T B At time t=0, energy with a selected power density is applied to volume V and to the volume of healthy tissue. This causes the temperature TV and T H When this happens, the temperature T V Tends to be higher than temperature T H , which is due to poor blood circulation in the volume V. The power density of the applied energy and the time over which the applied energy is delivered to the patient P are selected so that the temperature of healthy tissue does not exceed the safety threshold temperature T1, while the temperature in the volume V reaches at least the therapeutic temperature threshold T2.

[0102] The device 10 delivers energy to tissue within the patient's body by means of a signal applicator, which in the device 10 has the form of a coil 20 extending around a portion of the patient's P body that includes the diseased tissue to be heated.

[0103] The coil 20 is driven by a power source 25 to generate an electromagnetic field that delivers energy to the tissue of the patient P. In the device 10, the power source 25 has output terminals 26A and 26B that are connected to apply signals to corresponding terminals of the coil 20 through signal conductors 27A and 27B. In some embodiments, the power source 25 is connected to the coil 20 at the ends of the coil 20 (e.g., at terminals 28A and 28B). In some embodiments, the power source 25 is connected to the coil 20 at terminals located away from the ends of the coil 20 (e.g., at terminals 28C and 28D).

[0104] Controller 24 controls power source 25 to deliver energy to tissue of patient P to produce a desired therapeutic outcome. In some embodiments, controller 24 is coupled to receive feedback from temperature monitor 23 that monitors the temperature at one or more points 23A in and / or near volume V.

[0105] The controller 24 may be configured to adjust the signals delivered to the coil 20 to produce a desired temperature distribution in the tissue of the patient P. For example, it may be desirable to heat a volume of diseased tissue to a temperature of at least a therapeutic temperature threshold T2 for a desired period of time while maintaining the temperature of healthier tissue below a safety temperature threshold T1.

[0106] The controller 24 may include a feedback controller having one or more inputs. The one or more inputs may include a temperature measurement of the tissue of the patient P. The apparatus 10 includes a temperature monitor 23 that obtains the temperature measurement. The temperature measurement may be performed using one or more temperature sensors of any suitable type.

[0107] The coil 20 has a plurality of windings 20A. In typical, non-limiting embodiments, the number of windings is in the range of 5 to 100. In some embodiments, the coil 20 has a number of windings 20A in the range of 10 to 60. The coil 20 need not have an integer number of windings.

[0108] The winding 20A may include, for example, a conductive wire, a conductive tube, a conductive bar, etc. The winding 20A may have a cross-section such as a circle, an ellipse, or other shapes. The cross-section may vary along the length of the coil 20. In some embodiments, the winding 20A has a tubular configuration.

[0109] The coil 20 is arranged to receive at least a portion of the body of the patient P including the volume V. For example, in the case where the volume V is located in the lungs, the coil 20 may be sized to receive the torso of the patient P such that the volume V is located within the coil 20. Figure 1 In the case where the patient P is an adult and the coil 20 receives the torso of the patient P, the coil 20 may then have a diameter D20 of, for example, approximately 30 cm to 90 cm (a diameter near the high end of this range, or even higher, may be required for some larger patients). The winding 20A may be tightly wound around the patient P, or may be sized such that there is a gap between the winding 20A and the patient P. When the patient P is a child or other person of small stature, the coil 20 may have a smaller diameter but be large enough to extend around the torso of the patient P.

[0110] Figure 1B is a block diagram illustrating a control system that can be used in the device 10 described herein or other devices. In this example, the power supply 25 includes a signal generator 25A that delivers an output signal 22-1 to an amplifier 25B. The signal generator 25A is operable to generate a signal that is amplified by the amplifier 25B to produce an amplified signal 22-2. The amplified signal 22-2 is applied to drive the coil 20.

[0111] The amplified signal 22-2 can, for example, include a sinusoidal signal having a frequency in the range of approximately 5 kHz to approximately 100 MHz. In some embodiments, the signal 22-2 has a frequency in the range of approximately 500 kHz to approximately 10 MHz. In some embodiments, the amplified signal 22-2 has a power in the range of approximately 500 watts to 5 kilowatts.

[0112] exist Figure 1BIn an embodiment, power supply 25 includes an impedance matching network 25C. Impedance matching network 25C is connected between the output of amplifier 25B and coil 20 and can be adjusted to provide optimal power delivery to patient P. As known to those skilled in the art of RF systems, a matching network comprises a combination of circuit elements, such as capacitors, resistors, and / or inductors, which can be connected in various topologies to match the output impedance of amplifier 25B to the input impedance of the system including coil 20 and patient P. The input impedance of coil 20 and patient P depends on the characteristics of coil 20 and patient P, as well as the characteristics of the channel that delivers the RF energy of signal 22-2 to coil 20. Matching network 25C can be adjusted to maximize power delivery to patient P and minimize power reflected back to amplifier 25B.

[0113] exist Figure 1B In the illustrated embodiment, a reflection detector 25D is provided to measure RF power reflected from the coil 20 and the patient P. The reflection detector 25D may, for example, include a circulator configured to direct the RF power reflected from the coil 20 to an output port, where any suitable type of RF power meter is provided to measure the reflected power. The matching network 25C may be tuned to minimize the reflected power detected by the reflection detector 25D for a particular patient P and coil 20.

[0114] Signal 22-2 causes an alternating current to flow in winding 20A of coil 20. This current induces an alternating magnetic field within coil 20. The alternating magnetic field results in an alternating electric field, which induces eddy currents in the conductive material (e.g., tissue of patient P) located within coil 20. The combination of coil 20 and the signal provided by power supply 25 can be selected so that the electric field maximum is in a plane perpendicular to the axis of coil 20 and is located at a desired location (e.g., at the location of treatment volume V).

[0115] In the illustrated embodiment, the coil 20 has a solenoid form, and the magnetic field generated within the coil 20 by the flow of current in the winding 20A is generally oriented parallel to the longitudinal axis of the coil 20. In the illustrated embodiment, the coil 20 is oriented so that the magnetic field lines extend in an up / down direction (i.e., parallel to the longitudinal centerline of the patient's body). Advantageously, the magnetic field strength is generally uniform in a cross-section through the coil 20 taken perpendicular to the longitudinal axis of the coil 20.

[0116] Figure 1BThe outputs and inputs of an example controller 24 are shown. Some embodiments may include all of these outputs and inputs. Other embodiments may lack some of these inputs and outputs. The same hardware may optionally provide two or more or all of the different inputs and / or outputs of the controller 24. The control signals and / or data signals may include analog or digital signals in any suitable format.

[0117] The controller 24 obtains patient data 30 as input 30-1. The patient data 30 may include one or more of the following:

[0118] • prescribed characteristics of the amplifier output signal 22 - 2 , such as one or more of the following: the power or power density to be delivered to a particular patient P, the frequency or spectrum of the signal 22 - 2 , etc.;

[0119] A prescribed sequence of power delivery to a specific patient P;

[0120] Treatment temperature and / or temperature threshold;

[0121] • the location of one or more volumes V containing the diseased tissue to be treated;

[0122] Physical characteristics of a specific patient P (e.g., height, weight, body fat percentage, waist circumference, pulmonary circulation measurements, lung volumes, pre-treatment imaging data (e.g., from MRI, CT scans, etc.), from which the size and / or tissue characteristics of the patient P can be determined); etc.

[0123] The input 30 - 1 may, for example, receive input from one or more of a graphical user interface, discrete controls, a wired or wireless data interface, a data store, a data server, or the like.

[0124] Depending on the nature of the patient data 30 and the capabilities of the controller 24, the controller 24 may directly receive the specified characteristics of the signal 22-2 or derive the characteristics of the signal 22-2 based on information about the patient P (e.g., one or more of the types of information described above). Also depending on the nature of the patient data 30 and the capabilities of the controller 24, the controller 24 may: receive and apply specific parameters in the patient data 30 for controlling the power source 25; apply built-in control parameters; or derive the control parameters by processing the patient data 30.

[0125] The controller 24 may receive an input signal 31 at an input 31-1 indicating one or both of the RF power reflected from the coil 20 and the RF power delivered to the coil 20. The controller 24 may output a signal 33 at an output 33-1 connected to the matching network 25C. The controller 24 may be configured to adjust the matching network 25C via the signal 33 to minimize the reflected RF power from the coil 20 / patient P. This adjustment may be performed once prior to treatment and / or automatically on a continuous or periodic basis.

[0126] If signal 31 includes the measured power level of signal 22 - 2 , controller 24 may use the measured power level of signal 22 - 2 as feedback for controlling signal 22 - 2 .

[0127] Controller 24 may receive signal 32 at input 32-1 from temperature monitor 23. Based on signal 32, controller 24 may be configured to control the power of signal 22-2, control the modulation of signal 22-2, and / or stop therapy if the measured temperature crosses a high temperature threshold.

[0128] Figure 1B Output 34-1 is shown that delivers control signal 34 to control signal generator 25 A. Signal 34 may, for example, control one or more of the frequency of signal 22-1, the spectrum of signal 22-1, the pulse of signal 22-1, and the amplitude of signal 22-1.

[0129] Figure 1B An output 35-1 is shown that delivers a control signal 35 used to control amplifier 25B. Control signal 35 may, for example, control the gain of amplifier 25B.

[0130] Controller 24 may adjust the power delivered to the tissue of patient P (e.g., via signals 34 and / or 35) in response to the temperature measurement (e.g., in signal 32). For example, controller 24 may control power supply 25 to perform one or more of the following:

[0131] Adjusting the power level of signal 22 - 2 ; for example, to match the cooling effect of the perfusion in healthy tissue so that the healthy tissue does not overheat while the diseased tissue is heated to the desired temperature;

[0132] Performing time-domain modulation of the signal 22 - 2 to, for example, allow intermittent power delivery, which enables perfusion in healthy areas to cool tissue below a desired temperature while allowing diseased tissue to remain at a desired temperature;

[0133] • Adjust the frequency of the signal 22 - 1 to be at a resonant frequency, for example, as described below.

[0134] In some embodiments, the controller 24 includes a thermal model of at least a portion of the patient being treated. The thermal model relates the temperature at one or more locations within the patient being treated, P, for which temperature measurements are available, to the temperature at one or more locations of interest for which temperature measurements may not be available. The controller 24 can be configured to apply the thermal model using the measured temperature as an input to the thermal model and to adjust the signal 22-2 based at least in part on the output of the thermal model.

[0135] The thermal model may, for example, include one or more of the following: electrical and thermal properties of different tissue types in the treated patient P; the distribution of different tissue types in the treated patient P; the geometry of the coil 20 and the expected field distribution generated; and the perfusion rate in the treated patient P.

[0136] In some embodiments, the controller 24 is configured to deliver power to the patient P during energization intervals separated by periods of no RF power being delivered to the patient P or periods of reduced RF power being delivered to the patient P. For example, the controller 24 can cause the signal 22 - 2 to be applied during energization intervals having a length ranging from a few seconds to a few minutes, separated by pauses ranging from a few seconds to a few minutes. The controller 24 can be configured to control the duration of the energization intervals and / or the pauses.

[0137] In some embodiments, the controller 24 can be configured to terminate treatment when completion criteria are met (e.g., a certain number of power-on intervals are completed, the diseased tissue of patient P reaches a certain temperature, the diseased tissue of patient P reaches a certain temperature function - e.g., the time that the temperature exceeds a threshold, etc.).

[0138] In some embodiments, the frequency of signal 22-1 (and 22-2) is selected to generate a standing wave in coil 20. The choice of frequency generally depends on the characteristics of coil 20 (e.g., geometry, number of windings W) and the impedance of patient P. In some embodiments, the standing wave has a single electric field maximum. Coil 20 can be positioned relative to patient P so that the electric field maximum is located at or near the diseased tissue to be treated within patient P.

[0139] In some embodiments, the frequency of signal 22-2 is adjusted to be at or nearly at the resonant frequency of coil 20 (including patient P). In some embodiments, the frequency of the signal is adjusted to be at or nearly at an integer multiple of the resonant frequency of coil 20 including patient P. The choice of frequency generally depends on the characteristics of the coil (e.g., geometry, number of windings 20A) and the impedance of patient P. The frequency can be pre-calculated using these parameters (e.g., by controller 24 or in a calculation external to controller 24) and fine-tuned later by measuring the electric field in coil 20 using an electric field meter.

[0140] The power of signal 22 - 2 applied to drive coil 20 (e.g., by controlling the gain of amplifier 25B and / or adjusting the amplitude of signal 22 - 1 ) can be selected to deliver a prescribed amount of heating to the tissue of patient P. The power of signal 22 - 2 applied to coil 20 can be selected, for example, based on factors such as one or more of the following:

[0141] The weight of patient P;

[0142] An estimate of the weight of a portion of the patient P (e.g., the lungs of the patient P);

[0143] Patient P's height and / or waist circumference;

[0144] RF absorption by the tissue of the patient P within the coil 20 (this depends primarily on the percentage of fat in the patient P);

[0145] • RF coupling between the coil 20 and the tissue of the patient P (which depends on the frequency of the signal and the size and geometry of the coil 20); and

[0146] • Measurement of the pulmonary circulation of patient P.

[0147] In some embodiments, the temperature monitor 23 is of a type operable to perform non-invasive temperature sensing. For example, tissue temperature may be measured by processing ultrasound signals or magnetic resonance imaging (MRI) signals.

[0148] In some embodiments, temperature measurements are performed using a non-contact temperature sensing system (e.g., processing MRI data). In some such embodiments, coil 20 is located inside the MRI system. Controller 24 can be configured to interrupt delivery of signal 22-2 to coil 20 to allow temperature measurements to be taken.

[0149] In some embodiments, temperature measurements are performed using an invasive temperature sensor placed within the patient P (eg, via a needle or catheter).

[0150] In some embodiments, the devices described herein are combined with an imaging system (eg, an ultrasound imaging system or an MRI system) that can be used for temperature monitoring and / or for imaging the patient P.

[0151] When the apparatus 10 is used to treat diseased tissue in the lungs of a patient P, the coil 20 preferably has a length sufficient to at least contain the lungs L of the patient P within the coil 20. It is generally desirable to shield the head of the patient P from RF radiation and / or from the exterior of the coil 20.

[0152] Figure 1 A non-limiting example embodiment is depicted in which the length L20 of the coil 20 approximates the height of the patient P. Figure 1 , the windings of the coil 20 extend around the body of the patient P, and the volume V includes the lungs L. Other configurations are also possible. For example, the coil 20 can have a shorter length so that the coil 20 receives the torso of the patient P within the coil 20. The length L20 can be selected based on the characteristics of the patient P.

[0153] The cross section of the coil 20 may be circular, but this is not mandatory. In some embodiments, the coil 20 is flat. For example, the coil 20 may have an oval or elliptical cross section.

[0154] In some embodiments, the cross-sectional shape of coil 20 is adjustable. For example, the material of coil 20 may be elastically deformable, such that coil 20 can be deformed into a configuration that expands the bore of coil 20 and reduces the height of coil 20. This can be achieved, for example, by stretching coil 20. Figure 1C Stretching of the coil 20 by separating the non-conductive strips 29 is schematically shown.

[0155] In some embodiments, the cross-sectional shape of the coil 20 can be independently adjusted along the longitudinal axis of the coil 20. Such adjustment can be performed based on the patient's characteristics. Adjustment of the cross-sectional shape of the coil 20 can be achieved by making the turns of the coil 20 from a flexible conductive material (e.g., a flexible wire, a flexible strip) and deforming the coil 20 to assume the desired shape by shifting the turns of the coil 20.

[0156] In some embodiments, the geometry of the coil 20 varies along the length of the coil 20. For example, the turns of the coil 20 can be made closer together (with a smaller spacing PD between adjacent turns). For example, to achieve optimal results, it may be beneficial to wrap the coil 20 more tightly (smaller PD) around certain areas. In some embodiments, the ends of the coil 20 are wound more tightly than the middle portion between the ends of the coil 20.

[0157] The windings 20A are spaced apart along a length L20. The windings 20A may be evenly or unevenly spaced apart from one another (ie, the pitch PD may be even or uneven).

[0158] In some embodiments, the spacing between windings 20A along the longitudinal axis of coil 20 is adjustable. In such embodiments, the spacing between windings 20A can be adjusted based on the patient's characteristics. This can be achieved, for example, by using flexible elements such as coaxial network cables or other flexible wires as the windings of coil 20 and supporting the windings on an adjustable frame made of a material that does not absorb radio frequency (RF) radiation.

[0159] In some embodiments, the diameter of coil 20 varies along the length of coil 20 .

[0160] In some embodiments, the coil 20 has, for example, Figure 2 Multilayer winding shown.

[0161] The techniques described herein may vary. For example, instead of a single coil 20, the apparatus described herein may include two or more applicators that cooperate to deliver energy to the tissue of the patient P. For example, Figure 3 An example device 40 is shown, which is the same as device 10, except that device 40 includes two spaced-apart applicators A1 and A2. Each of applicators A1 and A2 is configured to surround or partially surround the periphery of the torso of patient P. Applicators A1 and A2 can be annular. Applicators A1 and A2 can have, for example, a circular cross-section, an elliptical cross-section, or an oblong cross-section.

[0162] In some embodiments, applicators Al and A2 extend completely (360 degrees) around the torso of patient P. In some embodiments, one or both of applicators Al and / or A2 extend through an angle of at least 180 degrees, or at least 230 degrees, or at least 250 degrees, or at least 270 degrees, or at least 300 degrees, or at least 330 degrees within the plane of the applicator relative to a point centered laterally and vertically within the applicator. In some embodiments, applicators Al and A2 extend nearly circumferentially around patient P. In this disclosure, "nearly around" as applied to an applicator means that the applicator extends through an angle in the range of 180 to 360 degrees within the plane of the applicator relative to a point centered laterally and vertically within the applicator.

[0163] For example, applicators A1 and A2 may be made from a thin conductive sheet (such as copper foil) formed to extend around the body of the patient P.

[0164] When the output signal 22 - 2 of the power supply 25 is delivered to the applicators A1 and A2 , the varying electric field between the applicators A1 and A2 causes energy to be delivered to and dissipated in the tissue of the patient P.

[0165] In apparatus 40, one or both of applicators A1 and A2 overlap with a volume V in which tissue to be treated resides. In another example embodiment, applicators A1 and A2 are symmetrically positioned relative to the volume V comprising the tissue to be treated. For example, applicator A1 can be positioned cranially relative to treatment volume V, while applicator A2 can be positioned caudally relative to treatment volume V.

[0166] In another example embodiment, applicators A1 and / or A2 are configured to form an unclosed portion of a loop. The applicators can be connected to terminals of a power source 25. For example, one of the applicators can be grounded, while the other applicator can be connected to a terminal of the power source 25 that carries a signal 22-1 (e.g., a varying voltage signal).

[0167] The technology described herein can be further varied. For example, the apparatus 10 and the apparatus 40 can be positioned vertically rather than horizontally, so that the patient P stands or sits within the coil 20 or within the applicators A1 and A2. This eliminates the need for a table for the patient P to lie on and may have additional advantages.

[0168] Other variations of the disclosed technology are possible. For example, the coil 20 and / or the applicators A1, A2 can be configured to open like a clamshell to receive the patient P. The windings of the applicators A1, A2 or the coil 20 can be separated along the opening line of the clamshell and can make electrical contact when the clamshell is closed.

[0169] In some embodiments, the coil 20 is wrapped around the patient P while the patient P is lying on a table, sitting, or standing.

[0170] In some embodiments, shielding is provided to shield certain parts of the patient from RF radiation. Shielding can be provided, for example, by a shield made of a mesh of conductive material, a grid of conductive material, or a continuous sheet of conductive material. The shield can optionally be transparent to allow observation of the shielded portion.

[0171] In some embodiments, the entire device, including the patient P, is contained within a shielding structure, such as a Faraday cage or any other enclosure made of conductive material. Such a structure can prevent radio frequency radiation from the device from interfering with other systems. The shielding structure can be continuous or made of wire mesh. In some embodiments, suitable RF shielding is embedded in or supported on the walls of the room where the device is located.

[0172] Some embodiments include devices for locally cooling the skin of the patient P (e.g., by flowing air, water, or other fluid in direct contact with the skin, or by flowing air, water, or other fluid via a bladder placed in contact with the area to be cooled). Such cooling can help protect the skin and surface tissues of the patient P from overheating, improve the comfort of the patient P, and / or help remove heat from the blood of the patient P.

[0173] In some embodiments, cooling is provided to an area of ​​the patient P where there is significant blood circulation close to the skin, such as the groin area. Figure 2 A fan 33 is shown arranged to deliver a flow of cooling air to the patient P. In some embodiments, the patient P is supported on a cooling support (e.g., a table or pad including channels carrying cooling gas or fluid, or a grid through which cooling gas can be delivered to remove heat from the patient's P skin).

[0174] The signals described herein may be delivered from their source to their destination in any suitable manner. For example, control signals may be carried by electrical conductors, optical conductors, wireless communication techniques, etc. Power signals, such as the output signal 22-2 of the power supply 25, may be delivered to the destination via suitable electrical conductors such as coaxial cables, wires, waveguides, inductive or capacitive coupling, free space transmission, etc.

[0175] The controller 24 may be implemented using any suitable technology including specially designed hardware, configurable hardware, a programmable data processor (configured by providing software (which may optionally include "firmware") that can be executed on the data processor), a special-purpose computer or data processor (specifically programmed, configured, or constructed to perform one or more steps of the method as described in detail herein), and / or a combination of two or more of these. Examples of specially designed hardware are logic circuits, application specific integrated circuits ("ASICs"), large-scale integrated circuits ("LSIs"), very large-scale integrated circuits ("VLSIs"), and the like. Examples of configurable hardware are one or more programmable logic devices such as programmable array logic ("PALs"), programmable logic arrays ("PLAs"), field programmable gate arrays ("FPGAs"), and configurable neural networks such as convolutional neural networks ("CNNs"). Examples of programmable data processors are microprocessors, digital signal processors ("DSPs"), embedded processors, graphics processors, mathematical coprocessors, general-purpose computers, server computers, cloud computers, mainframe computers, computer workstations, and the like. For example, one or more data processors in the controller 24 may implement the method as described herein by executing software instructions in a program memory accessible to the processors.

[0176] Explanation of terms

[0177] Throughout the specification and claims, unless the context clearly requires otherwise:

[0178] "Include", "comprising", etc. should be interpreted in an inclusive sense rather than an exclusive or exhaustive sense; that is, in the sense of "including but not limited to";

[0179] "Connected," "coupled," or any variation thereof, means any connection or coupling between two or more elements, whether direct or indirect; the coupling or connection between elements may be physical, logical, or a combination thereof;

[0180] "Herein," "above," "hereunder," and words of similar meaning, when used to describe this specification, shall refer to this specification as a whole and not to any particular part of this specification;

[0181] · “or” when referring to a list of two or more items encompasses all of the following interpretations of the word: any of the items in the list, all of the items in the list, and any combination of the items in the list;

[0182] The singular forms "a", "an" and "the" also include any appropriate plural forms.

[0183] As used in this specification and any appended claims (if any), directional words such as "vertical," "lateral," "horizontal," "upward," "downward," "forward," "backward," "inward," "outward," "left," "right," "front," "backward," "top," "bottom," "below," "above," "below," and the like depend on the specific orientation of the device being described and illustrated. The subject matter described herein can assume a variety of alternative orientations. Accordingly, these directional terms are not strictly defined and should not be interpreted narrowly.

[0184] Some aspects of the present invention can also be provided in the form of a program product. The program product may include any non-transient medium carrying a set of computer-readable instructions, which, when executed by a data processor, causes the data processor to perform the method of the present invention. For example, a program product can store computer-executable instructions, which, when executed by one or more processors, cause the execution of one or more control methods performed by the controller 24. The program product according to the present invention can be in any various forms. The program product may include, for example, a non-transient medium, such as a magnetic data storage medium including a floppy disk, a hard drive, an optical data storage medium including a CD ROM, a DVD, an electronic data storage medium including a ROM, a flash RAM, an EPROM, a hard-wired or pre-programmed chip (e.g., an EEPROM semiconductor chip), a nanotechnology memory, etc. The computer-readable signal on the program product may optionally be compressed or encrypted.

[0185] Where reference is made above to a component (e.g., a coil, applicator, amplifier, matching network, power supply, controller, station, assembly, device, circuit, etc.), unless otherwise indicated, reference to that component (including reference to "means") should be interpreted to include any component that performs the function of the described component (i.e., is functionally equivalent) as an equivalent to that component, including components that are not structurally equivalent to the disclosed structure that perform the function in the illustrated exemplary embodiments of the invention.

[0186] For purposes of illustration, specific examples of systems, methods, and apparatus have been described herein. These are merely examples. The techniques provided herein can be applied to systems other than the example systems described above. In the practice of the present invention, many changes, modifications, additions, omissions, and substitutions are possible. The present invention includes variations of the described embodiments that are obvious to those skilled in the art, including variations obtained by: replacing features, elements, and / or actions with equivalent features, elements, and / or actions; mixing and matching features, elements, and / or actions from different embodiments; combining features, elements, and / or actions from the embodiments described herein with features, elements, and / or actions of other technologies; and / or omitting to combine features, elements, and / or actions from the described embodiments.

[0187] For example, although different methods are presented as being performed in a given sequence, alternative examples may be performed in a different sequence or a routine with steps may be performed in a different order or a system with blocks may be employed. Steps, actions, processes, or blocks may be deleted, moved, added, subdivided, combined, and / or modified to provide alternatives or sub-combinations. The described processes or blocks may be implemented in a variety of ways. Furthermore, although processes or blocks are sometimes shown as being performed serially, certain processes or blocks may be performed in parallel or at different times.

[0188] Various features are described herein as being present in "some embodiments". Such features are not mandatory and may not be present in all embodiments. Embodiments of the invention may include zero, any one, or any combination of two or more such features. Even if such features are shown in different figures and / or described in different parts or paragraphs, all possible combinations of such features are still contemplated by the present disclosure. This is only to the extent that some of such features are incompatible with other of such features, i.e., it is impossible for a person of ordinary skill in the art to construct a practical embodiment that combines such incompatible features. Therefore, a description that "some embodiments" have feature A and "some embodiments" have feature B should be interpreted as an explicit indication that the inventor also envisions embodiments that combine features A and B (unless the description states otherwise or features A and B are not compatible at all).

[0189] It is therefore intended that the appended claims and the introduced claims be interpreted to include all such modifications, permutations, additions, omissions, and sub-combinations as can reasonably be inferred. The scope of the claims should not be limited by the preferred embodiment set forth in the examples, but should be given the broadest interpretation consistent with the description as a whole.

Claims

1. A device for treating emphysema or chronic obstructive pulmonary disease (COPD), wherein the device treats emphysema or COPD by selectively heating diseased lung tissue of a patient to a therapeutic temperature sufficient to produce a therapeutic effect in the diseased lung tissue, the device comprising: at least one signal applicator comprising an electrical conductor sized to extend circumferentially around or nearly around the patient's torso; a power supply connected to deliver a radio frequency (RF) signal to the at least one applicator, the power supply including an impedance matching network operable to match an output impedance of the power supply to an input impedance of the signal applicator; a controller operatively associated with the power supply and configured to control the power supply to apply the RF signal to the applicator; wherein the controller is configured to set the frequency of the RF signal to be at or near an integer multiple of a resonant frequency of the applicator when the patient is present to create a local alternating electric field extending in an axial direction substantially parallel to an inferior-superior direction of the patient; The applicator, when energized by the RF signal, is operable to couple an electromagnetic energy signal into the patient's tissue such that the patient's tissue is heated by the electromagnetic energy signal and, due to relatively low blood circulation to the diseased tissue compared to blood circulation to healthy tissue, the diseased tissue is selectively heated to a higher temperature than the healthy tissue.

2. The apparatus of claim 1 , comprising a temperature monitor operable to monitor the temperature at one or more locations within the patient's tissue, wherein The controller is connected to receive a temperature signal from the temperature monitor, the temperature signal being indicative of the temperature at the one or more locations, and the controller is configured to apply feedback control to the power supply to adjust the electromagnetic energy signal delivered to the patient based at least in part on the temperature signal.

3. The device according to claim 2, wherein The temperature monitor is a non-invasive temperature monitor.

4. The device according to claim 2, wherein The temperature monitor includes a magnetic resonance imaging (MRI) imaging system and a processor configured to process MRI signals provided by the MRI imaging system to determine a temperature corresponding to each of the one or more locations.

5. The device according to claim 2, wherein The temperature monitor includes an ultrasound imaging system and a processor configured to process ultrasound signals provided by the ultrasound imaging system to determine a temperature corresponding to each of the one or more locations.

6. The device according to any one of claims 2 to 5, wherein: The controller is configured to control one or more parameters of the RF signal until the temperature at the location is at least equal to the treatment temperature.

7. The device according to any one of claims 2 to 6, wherein: The controller includes a thermal model of at least a portion of the patient, the thermal model relating temperatures at the one or more locations to a temperature at a location of interest, and The controller is configured to apply the thermal model using the temperature signal as an input and to adjust heating energy based at least in part on an output of the thermal model.

8. The device according to claim 7, wherein The thermal model includes one or more of the following: electrical and thermal properties of different tissue types in the patient; the distribution of different tissue types in the patient; the geometry of one or more electromagnetic energy applicators; the expected electromagnetic field distribution generated; and the perfusion rate in the patient.

9. The device according to any one of claims 1 to 8, wherein The at least one signal applicator includes a coil.

10. The device according to claim 9, wherein The coil comprises in the range of 5 to 100 turns.

11. The device according to claim 9, wherein The coil comprises in the range of 10 to 60 turns.

12. The device according to any one of claims 9 to 11, wherein The turns of the coil are evenly spaced apart along a longitudinal axis of the coil.

13. The device according to any one of claims 9 to 12, wherein: The turns of the coil are unevenly spaced along a longitudinal axis of the coil.

14. The device according to any one of claims 9 to 13, wherein The cross section of the coil is not circular.

15. The device according to any one of claims 9 to 14, wherein The spacing between the turns of the coil along the longitudinal axis of the coil is adjustable.

16. The device according to any one of claims 9 to 15, wherein The cross section of the coil can be adjusted along the longitudinal axis of the coil.

17. The device according to any one of claims 9 to 16, wherein The coil has a length of at least 70 centimeters.

18. The device according to any one of claims 9 to 16, wherein The coil has a length of at least 1 meter.

19. The device according to any one of claims 9 to 16, wherein The coil has an internal diameter of at least 30 cm.

20. The device according to any one of claims 9 to 19, wherein The length of the coil is greater than or equal to the width of the coil.

21. The device according to any one of claims 9 to 19, wherein The length of the coil is greater than or equal to four times the width of the coil.

22. The device according to any one of claims 9 to 21, wherein The coil includes multiple layers of windings.

23. The device according to any one of claims 9 to 22, wherein The coil is configured to open like a clamshell to receive the patient.

24. Apparatus according to any one of claims 9 to 23, comprising a patient support configured to support the patient in a lying position, the patient support comprising a head support, wherein The head support is external to the coil.

25. The device according to any one of claims 1 to 24, wherein The RF signal has a frequency in the range of 5 kHz to 100 MHz.

26. The device according to any one of claims 1 to 24, wherein The RF signal has a frequency in the range of 500 kHz to 10 MHz.

27. The device according to any one of claims 1 to 26, wherein The controller is configured to set the frequency of the RF signal such that an electric field maximum of the electromagnetic energy signal is at a desired location relative to the at least one applicator.

28. The device according to any one of claims 1 to 27, wherein The controller is configured to set the frequency of the RF signal to generate a standing wave in the at least one applicator.

29. The device according to any one of claims 1 to 28, wherein The controller is configured to set the frequency of the RF signal to generate a standing wave in the at least one applicator, the standing wave having an electric field maximum at a desired location.

30. The device according to any one of claims 1 to 29, wherein The RF signal has a power of at least 500 watts.

31. The device according to any one of claims 1 to 30, wherein The controller is configured to apply time domain modulation to the RF signal.

32. The device according to any one of claims 1 to 31, wherein The controller is configured to control the power supply to generate the RF signal as a pulse signal, and is configured to control a width of a pulse in the pulse signal.

33. The device according to any one of claims 1 to 32, wherein The at least one signal applicator includes two signal applicators connected to the power source and operable to deliver the electromagnetic energy signal into tissue of the patient.

34. The apparatus of claim 28, comprising two signal applicators, the two signal applicators comprising a first signal applicator positioned cranially relative to the volume to be treated and a second signal applicator positioned caudally relative to the volume to be treated.

35. The apparatus of claim 34, wherein: Each of the two signal applicators is shaped to surround or partially surround the periphery of the patient's torso.

36. The apparatus according to claim 34 or 35, wherein The signal applicator can be adjusted to conform to the contours of the patient being treated.

37. The apparatus of any one of claims 1 to 36, comprising cooling means for cooling the patient.

38. The apparatus according to claim 37, wherein The cooling device includes a cooling fluid source arranged to bring cooling fluid into thermal contact with the patient's skin area.

39. The apparatus according to claim 38, wherein The cooling device includes a patient support including channels connected to carry the cooling fluid, the channels being in thermal contact with a surface supporting the patient.

40. The device according to any one of claims 37 to 39, wherein The cooling device is configured to cool the chest and back of the patient.

41. The device according to any one of claims 37 to 40, wherein The cooling device is configured to cool the patient's groin.

42. The apparatus according to any one of claims 37 to 40, wherein The cooling device includes a source of cold air.

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