Electrode assembly comprising plurality of thermally connected but electrically isolated graphite flakes for applying tumor treatment field (TT field)

Abstract

An alternating electric field (e.g., a TT field) may be applied to a subject's body using electrode assemblies, each of the electrode assemblies including a plurality of graphite flakes (or another sheet of conductive anisotropic material) that are adjacent to each other but not in contact. One or more electrode elements are arranged in electrical contact with each of the graphite sheets. Strips of electrically insulating thermally conductive material are disposed between the graphite flakes, and the strips are disposed in thermal contact with adjacent graphite flakes. These graphite flakes facilitate passive propagation of heat within the range of any given flake. And these strips of material allow passive propagation of heat to continue to extend beyond the range of any given sheet without affecting electrical isolation between sheets.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Application No. 63 / 357,111, filed on June 30, 2022, the entire contents of which are incorporated herein by reference. Background Art

[0003] Tumor Treating Field (TT Field) therapy is a proven tumor treatment method that uses an alternating electric field with a frequency, for example, between 50kHz and 1MHz (more commonly 100KHz to 500KHz). The alternating electric field is induced by electrode assemblies (e.g., an array of capacitively coupled electrodes, also called a transducer array) placed on opposite sides of the subject's body. When an AC voltage is applied between the opposing electrode assemblies, an AC current is coupled through the electrode assemblies and into the subject's body. And higher currents are closely associated with higher therapeutic efficacy.

[0004] Figure 1A is a schematic diagram of a prior art electrode assembly 40 that includes nine prior art electrode elements labeled X1 through X9. Figure 1B is along Figure 1A Schematic diagram of a cross-section of electrode elements X1 to X3 of an electrode assembly 40 cut by dotted lines.

[0005] like Figure 1B As shown, the electrode element X1 (as an example) includes a metal layer (shown with diagonal shading) and a ceramic (dielectric) layer. A corresponding conductive hydrogel layer is provided between each ceramic layer and the subject's skin to ensure good electrical contact between the electrode element and the body. An AC voltage from an AC voltage generator (not shown) is applied to the metal layer of the electrode element in the opposing electrode assembly to generate a TT field in the subject's body.

[0006] During use, the hydrogel and skin under the electrode elements heat up, and safety considerations require that the skin temperature remain below a safety threshold (e.g., 41° C.). Because most of the heat occurs directly under the electrode elements X1 to X9, the prior art electrode assembly has hot spots directly under the electrode elements and cooler areas between the electrode elements. And these hot spots limit the amount of current that can be delivered through the prior art electrode assembly. Summary of the invention

[0007] One aspect of the present application relates to a first electrode assembly, which includes: a first sheet of conductive anisotropic material having a front side and a front surface and a rear side and a rear surface; and one or more first electrode elements, each of which is arranged to be in electrical contact with the first sheet. The first electrode assembly also includes: a second sheet of conductive anisotropic material having a front side and a front surface and a rear side and a rear surface; and one or more second electrode elements, each of which is arranged to be in electrical contact with the second sheet. The second sheet is adjacent to the first sheet but does not contact the first sheet. The first electrode assembly also includes a first electrically insulating thermally conductive material strip, which is arranged between the first sheet and the second sheet. The first material strip is arranged to be in thermal contact with both the first sheet and the second sheet.

[0008] In some embodiments of the first electrode assembly, the first material strip comprises coated graphite. In some embodiments of the first electrode assembly, the width of the first material strip is less than 2 mm. In some embodiments of the first electrode assembly, the first sheet and the second sheet each comprise synthetic graphite, pyrolytic graphite, a graphitized polymer film, or a graphite foil made from compressed high-purity exfoliated mineral graphite.

[0009] Some embodiments of the first electrode assembly further include: a first skin-compatible conductive material layer disposed on the front side of the first sheet; and a second skin-compatible conductive material layer disposed on the front side of the second sheet.

[0010] In some embodiments of the first electrode assembly, there are at least two first electrode elements and at least two second electrode elements. Each of the first electrode elements includes a corresponding first metal layer and a corresponding first dielectric layer, the corresponding first dielectric layer is arranged on the corresponding first metal layer, and each of the first dielectric layers is arranged to be in electrical contact with the first sheet and located behind the first sheet. Each of the second electrode elements includes a corresponding second metal layer and a corresponding second dielectric layer, the corresponding second dielectric layer is arranged on the corresponding second metal layer, and each of the second dielectric layers is arranged to be in electrical contact with the second sheet and located behind the second sheet.

[0011] Optionally, in the embodiment of the preceding paragraph, each of the first dielectric layers and each of the second dielectric layers comprises a polymer layer having a dielectric constant of at least 10. Optionally, in the embodiment of the preceding paragraph, the electrical contact between each of the first dielectric layers and the first sheet is achieved using a first conductive gel or conductive adhesive layer, and the electrical contact between each of the second dielectric layers and the second sheet is achieved using a second conductive gel or conductive adhesive layer.

[0012] In some embodiments of the first electrode assembly, there are at least two first electrode elements and at least two second electrode elements. Each of the first electrode elements includes a corresponding first metal layer, which is arranged to be in electrical contact with the first sheet, and each of the second electrode elements includes a corresponding second metal layer, which is arranged to be in electrical contact with the second sheet.

[0013] In some embodiments of the first electrode assembly, there are at least two first electrode elements and at least two second electrode elements, and the electrode assembly also includes: a plurality of first metal conductors, each of which is arranged to be electrically contacted with only one corresponding first electrode element in the first electrode elements; and a plurality of second metal conductors, each of which is arranged to be electrically contacted with only one corresponding second electrode element in the second electrode elements.

[0014] In some embodiments of the first electrode assembly, there are at least two first electrode elements and at least two second electrode elements, and the electrode assembly also includes: at least one first metal conductor, which is arranged to electrically connect all the first electrode elements in the first electrode element; and at least one second metal conductor, which is arranged to electrically connect all the second electrode elements in the second electrode element.

[0015] Some embodiments of the first electrode assembly further include a support having an adhesive backing having a shape and size suitable for holding the electrode assembly in close proximity to a human body, wherein the front side of the first sheet and the front side of the second sheet face toward the human body.

[0016] Some embodiments of the first electrode assembly also include a coil through which energy from the primary conductor power source is shunted and stored locally on a capacitor for reuse in powering a controller or circuit, or for generating digital data related to temperature measurements.

[0017] In some embodiments of the first electrode assembly, there are at least two first electrode elements and at least two second electrode elements, and the electrode assembly further includes: a third sheet of electrically conductive anisotropic material having a front side and a front surface and a rear side and a rear surface; a plurality of third electrode elements, each of the third electrode elements being arranged to be in electrical contact with the third sheet; and a second strip of electrically insulating thermally conductive material, the second strip of electrically insulating thermally conductive material being arranged between the second sheet and the third sheet. The third sheet is adjacent to the second sheet but does not contact the second sheet and does not contact the first sheet, and the second strip of material is arranged to be in thermal contact with both the second sheet and the third sheet.

[0018] Optionally, the embodiments of the preceding paragraph may further include: a plurality of first metal conductors, each of which is arranged to be in electrical contact with only one corresponding first electrode element among the first electrode elements; a plurality of second metal conductors, each of which is arranged to be in electrical contact with only one corresponding second electrode element among the second electrode elements; and a plurality of third metal conductors, each of which is arranged to be in electrical contact with only one corresponding third electrode element among the third electrode elements.

[0019] In some embodiments of the first electrode assembly, there are at least two first electrode elements and at least two second electrode elements, and the electrode assembly further comprises: a third sheet of conductive anisotropic material having a front surface and a rear surface; a plurality of third electrode elements, each of the third electrode elements being arranged to be in electrical contact with the third sheet; a second strip of electrically insulating thermally conductive material, the second strip of electrically insulating thermally conductive material being arranged between the second sheet and the third sheet; a first layer of skin-compatible conductive material, the first layer of skin-compatible conductive material being arranged on the front side of the first sheet; a second layer of skin-compatible conductive material, the second layer of skin-compatible conductive material being arranged on the front side of the second sheet; and a third layer of skin-compatible conductive material, the third layer of skin-compatible conductive material being arranged on the front side of the third sheet. The third sheet is adjacent to the second sheet but does not contact the second sheet and does not contact the first sheet, and the second strip of material is arranged to be in thermal contact with both the second sheet and the third sheet. In these embodiments, the first strip of material and the second strip of material each comprise coated graphite.

[0020] Another aspect of the present application relates to a second electrode assembly, the second electrode assembly comprising: a first sheet of electrically conductive anisotropic material; at least one first electrode element, the first electrode element being arranged to be in electrical contact with the first sheet; a second sheet of electrically conductive anisotropic material, the second sheet of electrically conductive anisotropic material being adjacent to but not in contact with the first sheet; at least one second electrode element, the second electrode element being arranged to be in electrical contact with the second sheet; and a strip of electrically insulating thermally conductive material, the strip of electrically insulating thermally conductive material being arranged between the first sheet and the second sheet. The strip of material is arranged to be in thermal contact with both the first sheet and the second sheet.

[0021] In some embodiments of the second electrode assembly, the strip of material comprises coated graphite. In some embodiments of the second electrode assembly, the width of the strip of material is less than 2 mm. In some embodiments of the second electrode assembly, the first sheet and the second sheet each comprise synthetic graphite, pyrolytic graphite, a graphitized polymer film, or a graphite foil made from compressed high-purity exfoliated mineral graphite.

[0022] Another aspect of the present application relates to a first method for planning treatment of a target area in a subject using an alternating electric field. The first method includes positioning a first group of N electrode elements on a first side of the target area on or in the subject's body. Each of the N electrode elements is arranged to be in electrical contact with a corresponding sheet of conductive anisotropic material, and N is at least 4. The first method also includes positioning a second group of M electrode elements on a second side of the target area on or in the subject's body. Each of the M electrode elements is arranged to be in electrical contact with a corresponding sheet of conductive anisotropic material, and M is at least 4. The second side is opposite to the first side. The first method also includes: sequentially measuring the corresponding impedance or conductance between each of the N electrode elements in the first group and each of the M electrode elements in the second group during a first time window; calculating a first impedance or conductance at each of at least 27 voxels corresponding to the positions between the first group of N electrode elements and the second group of M electrode elements based on the impedance or conductance measurement values; and generating a plan for treating the target area by an alternating electric field based on the first impedance or conductance of the voxel.

[0023] In some examples of the first method, a plurality of strips of electrically insulating thermally conductive material are disposed between adjacent sheets of the electrically conductive anisotropic material, and each of the strips is disposed in thermal contact with the adjacent sheets. In some examples of the first method, each of the sheets of the electrically conductive anisotropic material comprises synthetic graphite, pyrolytic graphite, a graphitized polymer film, or a graphite foil made from compressed high-purity exfoliated mineral graphite. In some examples of the first method, the plan comprises generating a recommendation to move at least one set of electrode elements to a different location on or in the subject's body.

[0024] Some examples of the first method further include, after the step of generating the plan, applying an alternating voltage between the plurality of the electrode elements in the first group and the plurality of the electrode elements in the second group to induce an electric field in the target area. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1A is a schematic diagram of an electrode assembly in the prior art.

[0026] Figure 1B yes Figure 1A Cross-sectional view of a prior art electrode assembly.

[0027] Figure 2A is a plan view of an electrode assembly for applying a TT field to a subject's body.

[0028] Figure 2B yes Figure 2A Cross-sectional view of an electrode assembly.

[0029] Figure 3 is a schematic diagram of a heat map of an electrode assembly used in a specific anatomical situation.

[0030] Figure 4A and Figure 4B are plan and cross-sectional views of an exemplary electrode assembly.

[0031] Figure 5 Depicted with Figure 4A / Figure 4B A set of suitable electrical connections for the electrode elements of an embodiment.

[0032] Figure 6 Shown with Figure 4A / Figure 4B An alternative set of suitable electrical connections for the electrode elements in the embodiments.

[0033] Fig. 7A and Figure 7B are plan and cross-sectional views of another exemplary electrode assembly.

[0034] Figure 8 Another electrode assembly is depicted in which the number of graphite sheets matches the number of electrode elements.

[0035] Various embodiments are described in detail below with reference to the drawings, wherein like reference numerals refer to like elements. DETAILED DESCRIPTION

[0036] The present application describes exemplary electrode assemblies that can be used, for example, to deliver an alternating electric field to a subject's body. The alternating electric field can be a tumor treatment field (TT field) for treating one or more cancers or tumors located in the subject's body, and most of the examples below assume this background. However, the electrode assemblies described herein can also be used to deliver other electrical signals, including alternating electric fields applied for purposes other than treating tumors. For example, the electrode assemblies described herein can be used to apply an alternating electric field to increase the permeability of the blood-brain barrier (e.g., as described in U.S. Patent No. 10,967,167), or to increase the permeability of cell membranes (e.g., as described in U.S. Patent No. 11,103,698).

[0037] When the TT field is applied to the subject's body, the temperature of the subject's body can increase in response to the increase in the induced electric field strength. Regulations limit the amount of current that can be driven by the electrode assembly to an amount that keeps the temperature measured at the location on the subject's body below a temperature threshold. As practiced in the art, the temperature at the location of the electrode assembly on the subject's body is controlled below the temperature threshold by reducing the operating current driven by the electrode assembly, thereby reducing the strength of the resulting TT field. This in turn becomes the primary limitation on the TT field strength that can be used to treat tumors.

[0038] On an electrode assembly that includes multiple electrode elements, portions of the electrode assembly that are directly below an electrode element may become hotter than portions of the electrode assembly that are located between the electrode elements. In addition, on an electrode assembly that includes multiple electrode elements, higher currents flow through electrode elements located along the edge of the array compared to electrode elements located toward the middle of the array. In addition, electrode elements located at corners or similar sharp bends in the edge of the array will have higher currents than other electrode elements along the edge of the array and near the center of the array. The tendency of the electrode assembly to drive higher currents through electrode elements along the edge of the array, particularly at the corners, is referred to herein as the "edge effect."

[0039] The uneven distribution of current through the electrode assembly due to the distribution of electrode elements or edge effects may result in the creation of higher temperature areas (or "hot spots"), for example, at the corners or edges of the electrode assembly. These hot spots are where the threshold temperature is first reached, thus controlling the requirement to reduce the current. Therefore, the creation of hot spots limits the maximum operating current that can be driven by the electrode assembly, as well as the strength of the resulting TT field.

[0040] The present application describes various methods for reducing or minimizing uneven current distribution in an electrode assembly, ultimately allowing the use of higher operating currents without exceeding a threshold temperature. Electrode assemblies operated at increased currents can induce stronger TT fields in a subject, ultimately leading to better patient outcomes. The electrode assemblies disclosed herein allow current and heat to be more evenly distributed across an array, thereby minimizing or eliminating hot spots.

[0041] Combined with the following Figure 2A / Figure 2B Figure 4 to Figure 8 The described method reduces or minimizes hot spots on an electrode assembly using sheets of conductive anisotropic material (e.g., pyrolytic graphite sheets) that are incorporated into the electrode assembly to passively carry heat away from the hot spots, as described below. When a given AC voltage is applied to the electrode assembly, this lowers the temperature of the hot spots and raises the temperature of the cooler areas (as described above). Figure 1A / Figure 1B As compared to prior art configurations). Thus, the current can be increased (and thus the therapeutic effect) without exceeding a safe temperature threshold at any point on the subject's skin.

[0042] Figure 2A is a schematic diagram of an electrode assembly 50 including an embodiment of an electrode element for applying a TT field to a subject's body, Figure 2B is along Figure 2A A cross-sectional view of the same electrode assembly 50 is shown cut along the dashed line in FIG. Figure 2A In FIG. 5 , only four electrode elements, labeled E1 to E4, are shown, but additional electrode elements may be included in electrode assembly 50. In an alternative embodiment, electrode assembly 50 includes only one electrode element.

[0043] The electrode assembly 50 includes a conductive anisotropic material sheet (e.g., a graphite sheet) 70 having a front side and a front surface ( Figure 2B Examples of suitable forms of graphite include synthetic graphite, such as pyrolytic graphite (including but not limited to pyrolytic graphite flakes (PGS), available from Panasonic Industry, Kadoma City, Osaka Prefecture, Japan), another form of graphite includes but is not limited to graphite foil made from compressed high purity exfoliated mineral graphite (including but not limited to 2010A flexible graphite, available from Mineral Seal Corp., Tucson, Arizona, USA) or a graphitized polymer film, such as a graphitized polyimide film (including but not limited to products of Kaneka Corp., Mooka, Tochigi, Japan). Note that in the examples described herein and in the accompanying drawings, the conductive anisotropic material sheet is described and depicted as a graphite sheet. However, in alternative embodiments, a conductive anisotropic material other than graphite may be used instead of graphite.

[0044] Exemplary embodiments disclosed herein incorporate sheets of material having anisotropic thermal and / or anisotropic electrical properties (also referred to herein as sheets of conductive anisotropic material) into an electrode assembly. If the sheet of material has anisotropic thermal properties (e.g., thermal conductivity in a plane is greater than thermal conductivity perpendicular to the plane), the sheet spreads heat more evenly over a larger surface area. If the sheet of material has anisotropic electrical properties (e.g., conductivity in a plane is greater than conductivity perpendicular to the plane; or conversely, resistance in a plane is less than resistance perpendicular to the plane), the sheet spreads current more evenly over a larger surface area. In each case, when a given AC voltage is applied to the device, this lowers the temperature of the hot spot and raises the temperature of the cooler area. Thus, the current can be increased (thereby enhancing the therapeutic effect) without exceeding a safe temperature threshold at any point on the subject's skin.

[0045] In some embodiments, the anisotropic material is anisotropic in electrical conductivity properties. In some embodiments, the anisotropic material is anisotropic in thermal conductivity properties. In some embodiments, the anisotropic material is anisotropic in both electrical and thermal conductivity properties.

[0046] Anisotropic thermal properties include directional thermal properties. Specifically, the anisotropic material sheet has a first thermal conductivity in a direction perpendicular to its front surface. And the thermal conductivity of the sheet in a direction parallel to the front surface is more than twice higher than the first thermal conductivity. In some preferred embodiments, the thermal conductivity in the parallel direction is more than ten times higher than the first thermal conductivity. For example, the thermal conductivity of the sheet in a direction parallel to the front surface can be 1.5 times, 2 times, 3 times, 5 times, 10 times, 20 times, 100 times, 200 times or even 1,000 times higher than the first thermal conductivity.

[0047] Anisotropic electrical properties include directional electrical properties. Specifically, the anisotropic material sheet has a first resistance in a direction perpendicular to its front surface. And the resistance of the sheet in a direction parallel to the front surface is less than the first resistance. In some preferred embodiments, the resistance in the parallel direction is less than half of the first resistance or less than 10% of the first resistance. For example, the resistance of the sheet 70 in a direction parallel to the front surface can be less than: 75%, 50%, 40%, 30%, 20%, 10%, 5%, 1%, 0.5% or even less than 0.1% of the first resistance.

[0048] In some embodiments (eg, when the anisotropic material sheet is a pyrolytic graphite sheet), the anisotropic material sheet has both anisotropic electrical properties and anisotropic thermal properties. Preferably, the anisotropic material is a non-metallic material.

[0049] The electrode assembly 50 also includes a front biocompatible conductive material layer 60 disposed on the front side (e.g., on the front surface) of the graphite sheet 70. The front material layer 60 is configured to ensure good electrical contact between the device and the body. In some embodiments, the front material layer 60 covers the entire front surface of the graphite sheet 70. The size of the front material layer 60 can be the same as or larger than the size of the graphite sheet 70. In some embodiments, the front conductive material layer 60 includes a hydrogel. In these embodiments, the thickness of the hydrogel can be between 50 μm and 2000 μm, such as 100 μm to 1000 μm, or even 300 μm to 500 μm. In some embodiments, the front conductive material layer 60 is a non-hydrogel biocompatible conductive adhesive. In some embodiments, the front conductive material layer 60 is a non-hydrogel biocompatible conductive adhesive, such as FLX068983-, a development product of FLEXcon in Spencer, Massachusetts, USA. OMNI-WAVE TM TT 200BLACKH-502150POLYH-9

[0050] 44PP-8, or other such OMNI-WAVE products from FLEXcon; or manufactured and sold by Adhesives Research, Inc., Glen Rock, Pennsylvania, USA 8006 Conductive adhesive composition. The non-aqueous gel conductive adhesive may include an anhydrous polymer having adhesive properties in which a conductive filler (e.g., carbon particles, powders, fibers, flakes, or nanotubes) is arranged. The adhesive polymer may be, for example, an acrylic polymer or a silicone polymer or a combination thereof, which may be provided as an acrylic or silicone carbon-filled tape (e.g., a transfer tape). The adhesive may additionally include one or more conductive polymers (e.g., polyaniline (PANI), or poly(3,4-ethylenedioxythiophene) (PEDOT), or other polymers known in the art). If present, the conductive filler in the front conductive material layer 60 should be non-metallic. In these embodiments, the thickness of the biocompatible conductive adhesive may be between 10 μm and 2,000 μm, such as 20 μm to 1000 μm, or even 30 μm to 400 μm.

[0051] The electrode assembly 50 also includes electrode elements E1 to E4 located behind the graphite sheet 70. Each electrode element E1 to E4 has a front surface arranged to be in electrical contact with the rear surface of the graphite sheet 70. Each electrode element E1 to E4 includes: a dielectric material layer 310 having a front surface and a back surface; and a metal layer 320 arranged on the back surface of the dielectric material layer 310. The front surface of the dielectric material layer 310 is the front surface of the electrode elements E1 to E4. The dielectric material 310 in these embodiments can be, for example, a flat ceramic material sheet (such as a ceramic sheet) having a high dielectric constant. Figure 2A / Figure 2B ), or a polymer layer having a dielectric constant of at least 10.

[0052] In some embodiments, dielectric material layer 310 may have a dielectric constant in the range of 10 to 50,000. In some embodiments, dielectric material layer 310 includes a high dielectric polymer material such as poly(vinylidene fluoride-trifluoroethylene-chlorotrifluoroethylene) and / or poly(vinylidene fluoride-trifluoroethylene-1-chlorofluoroethylene). These two polymers are abbreviated herein as "poly(VDF-TrFE-CTFE)" and "poly(VDF-TrFE-CFE)", respectively. These embodiments are particularly advantageous because the dielectric constants of these materials are about 40. In some embodiments, the polymer layer may be poly(vinylidene fluoride-trifluoroethylene-chlorotrifluoroethylene-chlorofluoroethylene) or "poly(VDF-TrFE-CTFE-CFE)".

[0053] In some embodiments, dielectric material layer 310 comprises a terpolymer comprising polymerized units of monomers such as VDF, TrFE, CFE, and / or CTFE in any suitable molar ratio. Suitable terpolymers include, for example, those having 30 to 80 mol% VDF, 5 to 60 mol% TrFE, wherein CFE and / or CTFE constitute the remainder of the mol% of the terpolymer.

[0054] The electrode assembly 50 also includes a conductive material layer 380 located between the front face of the electrode elements E1 to E4 (i.e., the front face of the dielectric material layer 310) and the rear surface of the graphite sheet 70. These conductive material layers 380 facilitate electrical contact between the front faces of the electrode elements E1 to E4 and the rear surface of the graphite sheet 70. In some embodiments, the conductive material layer 380 is a hydrogel layer. However, in alternative embodiments, different conductive materials (e.g., conductive grease, conductive adhesive, conductive tape, conductive composite, etc.) can be used. In some embodiments, the conductive material layer 380 can be a non-hydrogel conductive adhesive, such as described above. In an alternative embodiment (not shown), instead of positioning a separate conductive material layer 380 between the front face of each individual electrode element E1 to E4 and the rear surface of the graphite sheet 70, a single large conductive material layer can be positioned between all of the electrode elements E1 to E4 and the rear surface of the graphite sheet 70.

[0055] The metal layers 320 of all electrode elements (i.e., E1 to E4 in the illustrated embodiment) can be wired together (e.g., using wires, traces on a flex circuit, etc.) to leads 90. Leads 90 provide AC voltage from an AC voltage generator (not shown) to the electrode elements to generate a TT field when the electrode assembly 50 is secured to a subject's body for treatment.

[0056] Optionally, the device may include a coil, and energy from the primary conductor power source may be shunted through the coil and stored locally on a capacitor for reuse in powering a controller (e.g., which may control a duty cycle), or in powering a circuit (such as for a switch), or for use in generating digital data related to temperature measurements.

[0057] Optionally, the electrode assembly 50 includes a flexible self-adhesive backing 55 configured to support the graphite sheet 70, the electrode elements E1 to E4, and the front conductive material layer 60 so that the front conductive material layer 60 can be placed against the skin of the subject.

[0058] As mentioned above, Figure 2Ais a schematic plan view of an electrode assembly 50 including electrode elements E1 to E4. When an AC voltage is applied to the electrode elements E1 to E4, the current and heat will be spread through the graphite sheet 70, which minimizes or eliminates hot spots. Because both the current and heat in this embodiment are spread over a larger area, hot spots are eliminated (or at least minimized). This means that for a given applied AC voltage, Figure 2A / Figure 2B The hottest point under the electrode assembly in the embodiment will have a lower temperature than the hottest point under the electrode assembly in the prior art example of FIG. 1. Therefore, the current can be increased (relative to the prior art current) without exceeding the safe temperature threshold at any point under the electrode assembly. This increase in current will help enhance the efficacy of TT field therapy.

[0059] Combination of the above Figure 2A / Figure 2B The described embodiments make a very significant contribution to reducing the temperature of the hottest point on any given electrode assembly by using a single graphite sheet to passively transfer heat from the hottest point on the electrode assembly to a cooler point on the electrode assembly. This passive heat transfer advantageously allows the electrode assembly to carry higher currents without exceeding a safe temperature threshold at any point on the electrode assembly.

[0060] However, in some anatomical situations, combined with Figure 2A / Figure 2B The passive heat distribution techniques described may not be able to remove enough heat from the hottest points on the electrode assembly. When this occurs, the hottest points on the electrode assembly still limit the amount of current that can be delivered through any given electrode assembly (because any further increase in current will cause these hottest points to exceed the safe temperature threshold).

[0061] An example of such an anatomical situation is when the TT field is applied between a 9-element electrode assembly located at the front / top of the subject's head (referred to herein as the anterior array) and a second 9-element electrode assembly located at the back of the subject's head (referred to herein as the posterior array). In this anatomical situation, if the same signal is applied to Figure 1A / Figure 1B If all nine electrode elements in the array are present, the last three elements in the front array and the top three elements in the rear array will usually be significantly hotter than the rest of the elements in these arrays, e.g. Figure 3 More specifically, in Figure 3 In this example, the operating temperature of the three rearmost elements of the front array is approximately 37.5°C, while the operating temperature of the other six elements is approximately 36.25°C. Figure 2A / Figure 2BThe passive heat distribution techniques described may not be able to remove enough heat from the hottest spots on the electrode assembly.

[0062] One possible method to equalize the temperature of the electrode elements on the electrode assembly is to redesign the electrode assembly so that each individual electrode element can be independently activated using independent wires (e.g., for an electrode assembly including nine electrode elements, nine wires are used). This method is referred to herein as the "independent element method."

[0063] Another possible way to equalize the temperature of the electrode elements is to connect the electrode elements in groups so that each group can be activated independently of the other groups. Figure 3 The electrode elements in the depicted nine-element electrode assembly are connected, with the three elements on the left side of the page connected to one wire, the three elements in the middle connected to a second wire, and the three elements on the right side of the page connected to a third wire. This method is referred to herein as the "grouped element method."

[0064] In both the independent component method and the grouped component method, the Figure 3 The temperature of the hottest electrode element is reduced by reducing the duty cycle of the signal of the hottest electrode element. More specifically, if Figure 3 The depicted heat map represents the resulting temperature when all electrode elements are driven using the same signal, then the temperature of the three electrode elements on the left side of the page can be reduced by reducing the duty cycle of the three signals driving the three electrode elements using the independent element method. Similarly, when the grouped element method is implemented, the temperature of the three electrode elements on the left side can be reduced by reducing the duty cycle of the single signal driving the three electrode elements.

[0065] In the independent element approach, reducing the duty cycle of the signal applied to a given electrode element in order to reduce the temperature of that electrode element will only work if the individual electrode elements remain electrically isolated from each other, because it is not possible to apply a signal to one electrode element without applying the same signal to another electrode element if a conductive path exists between the two.

[0066] Similarly, in the grouped element approach, reducing the duty cycle of the signal applied to a given group of electrode elements in order to reduce the temperature of the electrode elements within that group will only work if electrical isolation is maintained between the groups of electrode elements, because if there is a conductive path between one group of electrode elements (e.g., the three electrode elements on the left) and another group of electrode elements (e.g., the three electrode elements on the right), it is not possible to apply a signal to the first group of electrode elements without applying the same signal to the second group of electrode elements.

[0067] Since electrical isolation between electrode elements (or groups of electrode elements) is a prerequisite for using duty-cycle-based techniques to reduce the temperature of any given electrode element (or group of electrode elements), the duty-cycle-based techniques described in this section cannot be used in conjunction with the above-mentioned Figure 2A / Figure 2B In combination with an embodiment, this embodiment relies on a single sheet of conductive anisotropic material (e.g., graphite sheet 70) to dissipate heat away from the hottest electrode elements. This is because Figure 2A / Figure 2B Each of the electrode elements E1 to E4 in FIG. 3 is electrically connected to the same graphite sheet 70 via a corresponding conductive material layer 380. Graphite has a very high electrical conductivity, so Figure 2A / Figure 2B The graphite sheet 70 in the embodiment destroys the electrical isolation between the individual electrode elements (or groups of electrode elements). Also, since electrical isolation must be maintained for duty cycle-based techniques to work properly, these techniques are not compatible with Figure 2A / Figure 2B The embodiments are not compatible.

[0068] Figure 4A and Figure 4B 2 is a plan view and a cross-sectional view of the mechanical layout of an embodiment of an electrode assembly, which advantageously allows the use of duty cycle-based techniques to reduce the temperature of certain electrode elements, thereby coexisting with passive heat dissipation techniques based on conductive anisotropic material sheets (e.g., graphite sheets). The embodiment has multiple conductive anisotropic material sheets (e.g., graphite sheets 20), each of which has a front surface and a rear surface. (As used herein, the front surface faces the subject's body and the rear surface faces away from the subject's body.) Note that although Figure 4A Three graphite sheets 20 are depicted, but the number of graphite sheets may vary, for example, from 2 to 20. Examples of suitable forms of graphite for making graphite sheets 20 include some types of synthetic graphite, including pyrolytic graphite, graphitized polymer films, and graphite foil made from compressed, high-purity exfoliated mineral graphite. It is also noted that while Figure 4A A graphite sheet 20 is depicted as being oriented vertically, but the graphite sheet 20 may also be oriented horizontally. Note that in the examples described herein and in the accompanying drawings, the conductive anisotropic material sheet is described and depicted as a graphite sheet. However, in alternative embodiments, a conductive anisotropic material other than graphite may be used in place of graphite.

[0069] A plurality of electrode elements are arranged to be in electrical contact with each of the graphite sheets 20. In the illustrated embodiment, each of the first electrode elements (E1 to E3) is arranged to be in electrical contact with the first graphite sheet 20 (ie, Figure 4AEach of the second electrode elements (E4 to E6) is arranged to be electrically contacted with the second graphite sheet 20 (ie, Figure 4A and each of the third electrode elements (E7 to E9) is arranged to be in electrical contact with the third graphite sheet 20 (ie, Figure 4A Note that although Figure 4A Three electrode elements are depicted as being arranged in contact with each of the graphite sheets 20, but the number of electrode elements associated with each graphite sheet may vary, for example, a number of 1 to 10. Of course, when the number of electrode elements associated with each graphite sheet is 1, only one electrode element (rather than a plurality of electrode elements) will be arranged in electrical contact with each of the graphite sheets 20.

[0070] The second graphite sheet 20 is adjacent to the first graphite sheet 20 but does not contact the first graphite sheet. When more than two graphite sheets 20 are included, the graphite sheets should be placed adjacent to each other without contacting each other. Figure 4A In the embodiment, the third graphite sheet is adjacent to the second graphite sheet 20 , but does not contact the second graphite sheet 20 or the first graphite sheet 20 .

[0071] A first electrically insulating thermally conductive material strip 25 is disposed between the first graphite sheet 20 and the second graphite sheet 20, and the first material strip is disposed in thermal contact with both the first graphite sheet 20 and the second graphite sheet 20. When more than two graphite sheets 20 are included, additional electrically insulating thermally conductive material strips should be disposed between the graphite sheets. Figure 4A / Figure 4B In an embodiment, a second electrically insulating thermally conductive material strip 25 is arranged between the second graphite sheet 20 and the third graphite sheet 20, and the second material strip 25 is arranged in thermal contact with both the second graphite sheet and the third graphite sheet.

[0072] The purpose of these electrically insulating thermally conductive material strips 25 is to diffuse heat from the hottest graphite sheet 20 to the adjacent graphite sheets, thereby reducing the temperature of the hottest spot on the entire electrode assembly. Figure 2A / Figure 2B Unlike the situation in FIG. 2 (where no electrode elements are electrically isolated from each other), the strips of material 25 are electrically insulating, thereby providing electrical isolation between adjacent graphene sheets 20. Figure 4A The electrode elements E1 to E9 in the / 4B embodiment are not all electrically connected to the same graphite sheet 70. Therefore, current cannot flow from one graphite sheet 20 to another, which means that different signals can be applied to different groups of electrode elements.

[0073] In some preferred embodiments, each of the material strips 25 comprises coated graphite. The coating may be (but not necessarily is) a tape, such as an acrylic tape, a polyester (polyethylene terephthalate, PET) tape, a high-resistance polyetheretherketone (PEEK) tape, a polyimide tape, etc. However, in alternative embodiments, the material strips 25 may be made of other materials, including but not limited to hexagonal boron nitride, a coated (as described above) isolation metal sheet, a thermally conductive metal oxide, or diamond. In some preferred embodiments, each of the material strips 25 has a width of less than 2 mm. However, in alternative embodiments, the material strips 25 may be wider (e.g., 2 mm to 5 mm in width).

[0074] Figure 4A / Figure 4B Embodiments further include a skin-compatible conductive material layer 15 disposed on the front side of each of the graphite sheets. Figure 4A / Figure 4B In the embodiment shown, a layer of skin-compatible conductive material 15 is disposed on the front surface of each of the graphite sheets 20. Examples of suitable skin-compatible conductive materials include hydrogels, conductive greases, and conductive carbon-filled acrylic adhesives, such as the OMNI-WAVE adhesive composition manufactured and sold by FLEXCON (Spencer, Massachusetts, USA), and the OMNI-WAVE adhesive composition manufactured and sold by Adhesives Research, Inc. (Glen Rock, Pennsylvania, USA). 8006 conductive adhesive composition. During use, the front side of the conductive material 15 will be in contact with the user's skin. Although the skin-compatible conductive material 15 can contact or partially overlap the electrically insulating material strips 25, care should be taken to ensure that the skin-compatible conductive material 15 does not extend beyond the electrically insulating material strips 25 to the extent that the electrically insulating function of these material strips 25 is impaired.

[0075] In some embodiments (including Figure 4A / Figure 4B In the embodiments shown in the drawings, the electrode elements E1 to E9 are capacitive coupling electrode elements. In these embodiments, each of these electrode elements has a corresponding metal layer that receives an AC signal and a corresponding dielectric layer arranged on the corresponding metal layer. The dielectric layer of each of the electrode elements E1 to E9 is arranged to be in electrical contact with and behind the corresponding graphite sheet 20. For example, in Figure 4A / Figure 4BIn the illustrated embodiment, each of the electrode elements E1 to E3 has a dielectric layer that is arranged to be in electrical contact with and behind the first graphite sheet 20 (i.e., the sheet on the left); each of the electrode elements E4 to E6 has a dielectric layer that is in electrical contact with and behind the second graphite sheet 20 (i.e., the middle sheet); and each of the electrode elements E7 to E9 has a dielectric layer that is arranged to be in electrical contact with and behind the third graphite sheet 20 (i.e., the sheet on the right).

[0076] The dielectric layer in these embodiments can be, for example, a flat sheet of ceramic material with a high dielectric constant, or a polymer layer with a dielectric constant of at least 10, or a combination of the above. Figure 2A / Figure 2B In these embodiments, the electrical contact between the dielectric layer of each of the electrode elements E1 to E9 and the corresponding graphite sheet 20 is achieved using a conductive adhesive layer. However, in alternative embodiments, the electrical contact between the dielectric layer of each of the electrode elements E1 to E9 and the corresponding graphite sheet 20 can be achieved using another method (e.g., a conductive gel layer, such as a hydrogel), for example, using the above-mentioned combination of Figure 2A / Figure 2B Any of the methods described may be implemented.

[0077] Figure 4A / Figure 4B Embodiments also include a support 30 with an adhesive backing. The support may be made of, for example, fabric or foam material (e.g., similar to a conventional self-adhesive bandage). The shape and size of the support 30 is suitable for holding the electrode assembly against the human body, with the graphite sheet facing the human body.

[0078] Figure 4A / Figure 4B The electrical connection with the electrode elements E1 to E9 in the embodiments can be achieved using a variety of methods, including the above-mentioned independent element method and grouped element method.

[0079] Figure 5 When each of the electrode elements E1 to E9 includes a metal layer and a dielectric layer (eg Figure 4A / Figure 4B ), a set of suitable electrical connections for the electrode elements E1 to E9 for implementing the independent element method. The bold dots in the lower right quadrant of each electrode element E1 to E9 represent the electrical contact between the dielectric layer of each of the electrode elements E1 to E9 and the corresponding graphite sheet 20. Figure 5 In the embodiment, the above combination is used Figure 4A / Figure 4BAny form of graphite described, or non-graphite conductive anisotropic materials may be used. A single metal conductor (e.g., one or more wires and / or conductive traces) extends from the metal layer of each of the electrode elements E1 to E9 to the corresponding pins of the connector 35. And these metal conductors transmit the AC signal applied to the connector 35 to the metal layer of each of the electrode elements E1 to E9, respectively. Therefore, each individual electrode element can be independently activated using an independent wire. However, it should be noted that this independence is affected within the scope of any individual graphite sheet in the graphite sheet 20 because each graphite sheet 20 is conductive.

[0080] When using Figure 5 The wiring configuration depicted can be achieved by reducing the amount of current applied to the three electrode elements on the left (i.e., Figures 4 and Figure 5 The duty cycle of the signal of the electrode elements E1 to E3 in the Figure 3 The problem situation depicted (where the three electrode elements on the left are hotter than the remaining electrode elements) is solved, thereby reducing the temperature of these three electrode elements. It is worth noting that because each of the graphite sheets 20 is thermally conductive, each graphite sheet will also passively dissipate heat away from the hottest electrode element within any given sheet. Furthermore, because the material strips 25 are thermally conductive, the passive propagation of heat is not limited to the confines of any given single graphite sheet. Instead, whichever graphite sheet 20 is the hottest can dissipate some of the heat into adjacent graphite sheets via the thermally conductive material strips 25. Therefore, the FIG. 4 / Figure 5 Embodiments advantageously combine duty cycle based compatibility techniques for reducing temperature and passive heat dissipation techniques for reducing temperature.

[0081] As described above, because each graphene sheet 20 is conductive, the independence of all electrode elements within any given graphene sheet 20 is affected. Figure 6 As depicted, by connecting all electrode elements on any given graphene sheet 20 in parallel, the same as above can be obtained. Figure 5 Results are very similar to those described.

[0082] Figure 6 When each of the electrode elements E1 to E9 includes a metal layer and a dielectric layer (eg Figure 4A / Figure 4B ), a set of alternative suitable electrical connections for the electrode elements E1 to E9 for implementing the grouped element method. The bold dots in the lower right quadrant of each electrode element E1 to E9 represent electrical contacts between the dielectric layer of each of the electrode elements E1 to E9 and the corresponding graphite sheet 20. Figure 6 In the embodiment, the above combination is used Figure 4A / Figure 4BAny form of graphite described, or non-graphite conductive anisotropic materials may be used. One group of metal conductors (e.g., wires or conductive traces) extends from the metal layers of all three electrode elements E1 to E3 to one pin of connector 35. Another group of metal conductors extends from the metal layers of all three electrode elements E4 to E6 to another pin of connector 35. Yet another group of metal conductors extends from the metal layers of all three electrode elements E7 to E9 to yet another pin of connector 35. Each group of metal conductors transmits the AC signal applied to connector 35 to the metal layers of each group of electrode elements (i.e., E1 to E3, E4 to E6, or E7 to E9, respectively). Therefore, each group of electrode elements can be activated independently of other groups using independent wires.

[0083] therefore Figure 6 The depicted wiring configuration improves the performance by reducing the duty cycle of the signal applied to the three electrode elements. Figure 3 Another approach to the problem situation depicted, where the three elements on the left are hotter than the remaining electrode elements. Again, because each of the graphite sheets 20 is thermally conductive, each will also passively dissipate heat away from the hottest electrode element within any given sheet. Whichever graphite sheet 20 is the hottest can also dissipate some of the heat into adjacent graphite sheets via the strips of thermally conductive material 25. Thus, FIG. 4 / Figure 6 Embodiments also advantageously combine duty cycle based techniques for reducing temperature and passive heat dissipation techniques for reducing temperature.

[0084] Another method of electrically connecting the electrode elements E1 to E9 is to distribute the electrode elements E1 to E9 on different graphite sheets (for example, as described above in conjunction with Figure 6 ), but all electrode elements E1 to E9 are connected in parallel. When this approach is adopted, only a single electrical connection to the connector is required to energize all nine elements.

[0085] The above text combines Figure 4 to Figure 6 The described embodiment assumes that each of the electrode elements E1 to E9 is a capacitive coupling electrode element, which includes a metal layer behind a dielectric layer. However, the scope of the present application is not limited to capacitive coupling electrode elements. Instead, non-capacitive coupling electrode elements may be used.

[0086] Fig. 7A and Figure 7B2 is a plan view and a cross-sectional view of the mechanical layout of another embodiment of an electrode assembly, which advantageously allows the use of a duty cycle-based technique to reduce the temperature of certain electrode elements, thereby coexisting with a passive heat dissipation technique based on a conductive anisotropic material sheet (e.g., a graphite sheet). This embodiment also has a plurality of conductive anisotropic material sheets (e.g., graphite sheets 20), each of which has a front surface and a rear surface. Note that although Fig. 7A Three graphene sheets 20 are depicted, but the number of graphene sheets may vary, for example, from 2 to 20. Fig. 7A / Figure 7B In the embodiment, the above combination is used Figure 4A / Figure 4B Graphite in the form described, or other graphite conductive anisotropic materials may be used in place of graphite.

[0087] The plurality of electrode elements E1 to E9 are arranged to be in electrical contact with each of the graphite sheets 20. For example, in the illustrated embodiment, each of the first electrode elements (E1 to E3) is arranged to be in electrical contact with the first graphite sheet 20 (i.e., Fig. 7A Each of the second electrode elements (E4 to E6) is arranged to be electrically contacted with the second graphite sheet 20 (ie, Fig. 7A and each of the third electrode elements (E7 to E9) is arranged to be in electrical contact with the third graphite sheet 20 (ie, Fig. 7A Note that although Fig. 7A Three electrode elements are depicted as being arranged in contact with each of the graphite sheets 20, but the number of electrode elements associated with each graphite sheet may vary, for example, a number of 1 to 10. Of course, when the number of electrode elements associated with each graphite sheet is 1, only one electrode element (rather than a plurality of electrode elements) will be arranged in electrical contact with each of the graphite sheets 20.

[0088] The second graphite sheet 20 is adjacent to the first graphite sheet 20 but does not contact the first graphite sheet. When more than two graphite sheets 20 are included, the graphite sheets should be placed adjacent to each other without contacting each other, as described above in conjunction with Figure 4A / Figure 4B The embodiments described.

[0089] One or more electrically insulating thermally conductive material strips 25 are arranged between the graphite sheets 20, as described above in conjunction with Figure 4A / Figure 4B The purpose of these electrically insulating thermally conductive material strips 25 is to diffuse heat from the hottest graphite sheet 20 to the adjacent graphite sheets, thereby reducing the temperature of the hottest spot on the entire electrode assembly. Figure 2A / Figure 2B Unlike the situation in FIG. 2 (where no electrode elements are electrically isolated from each other), the strips of material 25 are electrically insulating, thereby providing electrical isolation between adjacent graphene sheets 20. Fig. 7A The electrode elements E1 to E9 in the / 7B embodiment are not all electrically connected to the same graphite sheet 70. Therefore, current cannot flow from one graphite sheet 20 to another, which means that different signals can be applied to different groups of electrode elements.

[0090] Fig. 7A / Figure 7B The embodiment further includes a skin-compatible conductive material layer 15, which is disposed on the front side of each of the graphite sheets (e.g., as shown in the figure, on the front surface of each of the graphite sheets), as described above in conjunction with Figure 4A / Figure 4B The embodiments described.

[0091] It is worth noting that Figure 4A / Figure 4B In a different embodiment, each electrode element E1 to E9 comprises a metal layer behind a dielectric layer, which in turn is arranged in electrical contact with the corresponding graphene sheet. Fig. 7A / Figure 7B The electrode elements E1 to E9 in the embodiment do not include a dielectric layer. Fig. 7A / Figure 7B The electrode elements E1 to E9 in the embodiment have a metal layer arranged to be in electrical contact with the corresponding graphite sheet 20 without an intermediate dielectric layer. Fig. 7A / Figure 7B In the illustrated embodiment, each of the electrode elements E1 to E3 has a metal layer that is arranged to be in electrical contact with and behind the first graphite sheet 20 (i.e., the sheet on the left); each of the electrode elements E4 to E6 has a metal layer that is in electrical contact with and behind the second graphite sheet 20 (i.e., the middle sheet); and each of the electrode elements E7 to E9 has a metal layer that is arranged to be in electrical contact with and behind the third graphite sheet 20 (i.e., the sheet on the right).

[0092] In the illustrated embodiment, the electrical contact between the metal layer of each of the electrode elements E1 to E9 and the corresponding graphite sheet 20 is achieved using a conductive adhesive layer. However, in alternative embodiments, the electrical contact between the metal layer of each of the electrode elements E1 to E9 and the corresponding graphite sheet 20 may be achieved using another method (e.g., a conductive gel layer such as a hydrogel).

[0093] Fig. 7A / Figure 7BThe embodiment also includes a support member 30 having a structure similar to that of the above combination. Figure 4A / Figure 4B The embodiment described herein has an adhesive backing for support member 30 .

[0094] Fig. 7A / Figure 7B In the embodiment, the electrical connection with the electrode elements E1 to E9 can be achieved by various methods, including independent element method and group element method, and is used to perform the above combination. Figure 5 to Figure 6 The described electrical connection method can be used for Fig. 7A / Figure 7B embodiment (except that the electrical connection to the graphite sheet is to the metal layer of each electrode element E1 to E9 rather than the dielectric layer).

[0095] In the embodiments depicted in Figures 4 to 7, multiple electrode elements are arranged to be in electrical contact with each graphene sheet. However, in alternative embodiments, the number of conductive anisotropic material sheets (e.g., graphene sheets) may be increased to match the number of electrode elements, in which case only one electrode element is arranged to be in electrical contact with any given conductive anisotropic material sheet (e.g., graphene sheet), such as Figure 8 In yet other embodiments (not shown), multiple electrode elements are arranged to be in electrical contact with some of the conductive anisotropic material sheets, and only one electrode element is arranged to be in electrical contact with each of the remaining conductive anisotropic material sheets. Figure 4A / Figure 4B Graphite in the form described, or other graphite conductive anisotropic materials may be used in place of graphite.

[0096] Figure 8 The embodiments and alternatives described in the preceding paragraphs may be implemented using capacitively coupled electrode elements or using non-capacitively coupled electrode elements. When the electrode elements are capacitively coupled, an electrical connection between any given electrode element E1 to E9 and the corresponding graphite sheet 20 will be made between the dielectric layers of the electrode elements E1 to E9 and the corresponding graphite sheet 20 (e.g., as described above in conjunction with Figure 4A / Figure 4B Alternatively, when the electrode elements are not capacitively coupled, electrical connections between any given electrode element E1 to E9 and the corresponding graphite sheet 20 are made between the metal layers of the electrode elements E1 to E9 and the corresponding graphite sheet 20 (e.g., as described above in connection with Fig. 7A / Figure 7B described).

[0097] In this Figure 8 In the embodiment, electrically insulating thermally conductive material strips 25 are arranged between the graphite sheets 20. The structure and shape of these material strips 25 can be combined as described above. Figure 4A / Figure 4B As described above, these strips 25 are arranged in thermal contact with any adjacent graphite sheets 20. The purpose of these electrically insulating thermally conductive strips 25 is to diffuse heat from the hottest graphite sheet 20 to the adjacent graphite sheets, thereby reducing the temperature of the hottest spot on the entire electrode assembly. It is worth noting that these strips 25 are electrically insulating, thereby providing electrical isolation between adjacent graphite sheets 20. Therefore, the Figure 8 The electrode elements E1 to E9 in the embodiment are all electrically isolated from each other. Accordingly, current cannot flow from one graphite sheet 20 to another graphite sheet 20, which means that different signals can be applied to each electrode element. As described above, a similar method as described above in conjunction with Figure 4A / Figure 4B and Fig. 7A / Figure 7B The adhesive backing of the support member 30 described in the embodiment allows the electrode assembly to be closely attached to the human body.

[0098] When the electrode assembly is Figure 8 When the electrode assemblies are constructed as depicted, and multiple electrode assemblies are located on opposite sides of the target area, the electrode assemblies can be used to perform impedance tomography of the target area in an apparatus designed to perform electrical impedance tomography (EIT) and treat disease using TT field therapy with array temperature control. Performing EIT using a transducer array is described in U.S. patent application serial number 17 / 710,041 (filed on March 31, 2022), which is hereby incorporated by reference into the present disclosure.

[0099] For example, if each electrode assembly includes N electrode elements (where N is at least 4), this can be achieved by using appropriate switching circuits and impedance measurement circuits to sequentially measure the impedance between each of the N electrode elements on one side of the target area and each of the N electrode elements on the other side of the target area, thereby generating a total of N 2 impedance measurements. These impedance measurements are then input into a back-propagation algorithm to generate an impedance map of the space between the electrode assemblies. This impedance map, or a series of such maps acquired over a period of time, can then be used to develop a treatment plan, modify a previously developed treatment plan, or monitor the progression (growth) or regression (shrinkage) of one or more cancers, tumors, or metastases during long-term TT field therapy and change the positioning of the transducer array accordingly.

[0100] In some embodiments, only a subset of the electrode elements that have been placed on the subject's body is used in the impedance measurement. For example, if a pair of 5x 5 arrays of electrode elements are placed on opposite sides of a target area on the subject's body, the impedance between the N=16 electrode elements on one side of the target area and the M=21 electrode elements on the other side of the target area can be measured in sequence using a switching circuit and an impedance measurement circuit, thereby generating a total of N×M (i.e., 336) impedance measurements. These impedance measurements are then input into a back-propagation algorithm to generate an impedance map of the space between the N electrode elements and the M electrode elements.

[0101] After the treatment plan is generated, an alternating voltage is applied between most (or at least a plurality) of electrode elements on one side of the target area and most (or at least a plurality) of electrode elements on the other side of the target area, which will induce an alternating electric field in the target area.

[0102] In the above text, in conjunction with Figures 4 to Figure 8 In the described embodiments, all conductive anisotropic material sheets 20 (e.g., graphite sheets) in any given embodiment are of substantially the same size, and each conductive anisotropic material sheet 20 is associated with the same number of electrode elements (e.g., three electrode elements in FIGS. 4 to 7 , or Figure 8 In some embodiments, the conductive anisotropic material sheet 20 may be in contact with one electrode element (one electrode element in the case of a conductive anisotropic material sheet). However, in alternative embodiments (not shown), the size of the conductive anisotropic material sheet 20 may be different within a single electrode assembly, and / or the number of electrode elements in contact with any given conductive anisotropic material sheet 20 may vary. For example, some conductive anisotropic material sheets 20 may only be in contact with one electrode element, while other conductive anisotropic material sheets 20 may be in contact with two or more electrode elements. In another example, some conductive anisotropic material sheets 20 may be in contact with two electrode elements, while other conductive anisotropic material sheets 20 may be in contact with three or more electrode elements.

[0103] The headings are provided for convenience only and should not be construed as limiting the invention in any way. The embodiments shown under any heading or in any section of the disclosure may be combined with embodiments shown under the same or any other heading or other section of the disclosure.

[0104] Although the present invention has been disclosed with reference to certain embodiments, various modifications, changes and variations of the described embodiments are possible without departing from the field and scope of the invention as defined in the appended claims. Therefore, it is intended that the present invention is not limited to the described embodiments, but has the full scope defined by the language of the appended claims and their equivalents.

Claims

1. An electrode assembly, comprising: a first sheet of conductive anisotropic material having a front side and surface and a back side and surface; one or more first electrode elements, each of the first electrode elements being arranged in electrical contact with the first sheet; a second sheet of conductive anisotropic material having a front side and surface and a back side and surface, wherein the second sheet is adjacent to but not in contact with the first sheet; one or more second electrode elements, each of the second electrode elements being arranged in electrical contact with the second sheet; and A first strip of electrically insulating thermally conductive material is disposed between the first sheet and the second sheet, wherein the first strip of material is disposed in thermal contact with both the first sheet and the second sheet. 2 . The electrode assembly of claim 1 , wherein the first material strip comprises coated graphite. The electrode assembly of claim 1 , wherein the width of the first material strip is less than 2 mm.

4. The electrode assembly of claim 1, wherein the first sheet comprises synthetic graphite, pyrolytic graphite, a graphitized polymer film, or a graphite foil made from compressed high-purity exfoliated mineral graphite, and wherein the second sheet comprises synthetic graphite, pyrolytic graphite, a graphitized polymer film, or a graphite foil made from compressed high-purity exfoliated mineral graphite.

5. The electrode assembly according to claim 1, further comprising: a first layer of skin-compatible conductive material, the first layer of skin-compatible conductive material being arranged on the front side of the first sheet; and A second skin-compatible conductive material layer is disposed on the front side of the second sheet.

6. The electrode assembly of claim 1, wherein there are at least two first electrode elements, wherein each of the first electrode elements comprises a respective first metal layer and a respective first dielectric layer, the respective first dielectric layer being arranged on the respective first metal layer, and wherein each of the first dielectric layers is arranged in electrical contact with the first sheet and behind the first sheet, and There are at least two second electrode elements, wherein each of the second electrode elements comprises a corresponding second metal layer and a corresponding second dielectric layer, the corresponding second dielectric layer is arranged on the corresponding second metal layer, and wherein each of the second dielectric layers is arranged to be in electrical contact with the second sheet and is located behind the second sheet. 7 . The electrode assembly of claim 6 , wherein each of the first dielectric layers and each of the second dielectric layers comprises a polymer layer having a dielectric constant of at least 10.

8. The electrode assembly according to claim 6, wherein the electrical contact between each of the first dielectric layers and the first sheet is achieved using a first conductive gel or conductive adhesive layer, and The electrical contact between each of the second dielectric layers and the second sheet is achieved using a second conductive gel or conductive adhesive layer.

9. The electrode assembly of claim 1, wherein there are at least two first electrode elements, and wherein each of the first electrode elements comprises a respective first metal layer, the respective first metal layer being arranged in electrical contact with the first sheet, and There are at least two second electrode elements, and wherein each of the second electrode elements comprises a respective second metal layer arranged in electrical contact with the second sheet.

10. The electrode assembly of claim 1, wherein there are at least two first electrode elements and at least two second electrode elements, and wherein the electrode assembly further comprises: a plurality of first metal conductors, each of the first metal conductors being arranged to be in electrical contact with only a corresponding one of the first electrode elements; as well as A plurality of second metal conductors, each of the second metal conductors being arranged to be in electrical contact with only a corresponding one of the second electrode elements.

11. The electrode assembly of claim 1 , wherein there are at least two first electrode elements and at least two second electrode elements, and wherein the electrode assembly further comprises: at least one first metal conductor arranged to electrically connect all of the first electrode elements; as well as At least one second metal conductor, the second metal conductor being arranged to electrically connect all of the second electrode elements.

12. The electrode assembly of claim 1 further comprising a coil, wherein energy from a primary conductor power source is shunted through the coil and stored locally on a capacitor for reuse in powering a controller or circuit, or for generating digital data associated with temperature measurements.

13. The electrode assembly of claim 1, wherein there are at least two first electrode elements and at least two second electrode elements, and wherein the electrode assembly further comprises: a third sheet of conductive anisotropic material having a front side and surface and a back side and surface, wherein the third sheet is adjacent to but not in contact with the second sheet and is not in contact with the first sheet; a plurality of third electrode elements, each of the third electrode elements being arranged in electrical contact with the third sheet; and A second strip of electrically insulating and thermally conductive material is disposed between the second sheet and the third sheet, wherein the second strip of material is disposed in thermal contact with both the second sheet and the third sheet.

14. The electrode assembly according to claim 13, further comprising: a plurality of first metal conductors, each of the first metal conductors being arranged to be in electrical contact with only a corresponding one of the first electrode elements; a plurality of second metallic conductors, each of the second metallic conductors being arranged to be in electrical contact with only a corresponding one of the second electrode elements; as well as A plurality of third metal conductors, each of the third metal conductors being arranged to be in electrical contact with only a corresponding one of the third electrode elements.

15. The electrode assembly according to claim 13, further comprising: a first layer of skin-compatible conductive material, the first layer of skin-compatible conductive material being arranged on the front side of the first sheet; a second layer of skin-compatible conductive material, the second layer of skin-compatible conductive material being disposed on the front side of the second sheet; and a third skin-compatible conductive material layer, the third skin-compatible conductive material layer being arranged on the front side of the third sheet, wherein the first strip of material comprises coated graphite, and Wherein the second material strip comprises coated graphite.

16. A method for planning treatment of a target area in a subject using an alternating electric field, the method comprising: positioning a first set of N electrode elements on a first side of the target area on or in the subject, wherein each electrode element of the N electrode elements is arranged to be in electrical contact with a respective sheet of conductive anisotropic material, and wherein N is at least 4; positioning a second set of M electrode elements on a second side of the target area on or in the subject's body, wherein each of the M electrode elements is arranged to be in electrical contact with a respective sheet of conductive anisotropic material, and wherein M is at least 4 and wherein the second side is opposite the first side; sequentially measuring the corresponding impedance or conductance between each of the N electrode elements in the first group and each of the M electrode elements in the second group during a first time window; calculating a first impedance or conductance at each of at least 27 voxels corresponding to locations between the first set of N electrode elements and the second set of M electrode elements based on the impedance or conductance measurements; as well as Based on the first impedance or conductance of the voxel, a plan is generated for treating the target area with an alternating electric field.

17. The method of claim 16, wherein a plurality of strips of electrically insulating thermally conductive material are arranged between adjacent sheets of the electrically conductive anisotropic material, and wherein each of the strips is arranged in thermal contact with the adjacent sheet.

18. The method of claim 17, wherein each of the sheets of the conductive anisotropic material sheet comprises synthetic graphite, pyrolytic graphite, a graphitized polymer film, or a graphite foil made from compressed high-purity exfoliated mineral graphite.

19. The method of claim 17, further comprising, after the step of generating the plan, applying an alternating voltage between a plurality of the electrode elements in the first group and a plurality of the electrode elements in the second group to induce an electric field in the target area.

20. The method of claim 17, wherein the planning comprises generating a recommendation to move at least one set of electrode elements to a different location on or in the subject's body.

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