Electrode assembly having a perforated anisotropic layer and system and method for applying a tumor treatment field therewith - Patents.com

Abstract

The device includes at least one electrode element, an anisotropic material layer, a first conductive adhesive layer disposed between a skin-facing surface of the at least one electrode element and an outer-facing surface of the anisotropic material layer, and a skin contact layer. The skin contact layer includes a biocompatible conductive adhesive and is disposed on the skin-facing side of the anisotropic material layer. The first conductive adhesive layer facilitates electrical contact between the skin-facing surface of the at least one electrode element and the outer-facing surface of the anisotropic material layer. A plurality of openings extend through the anisotropic material layer.

Description

[Technical field]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims priority to and the benefit of the filing date of U.S. Provisional Application No. 63 / 325,948, filed March 31, 2022, which is incorporated herein by reference in its entirety. [Background technology]

[0002] Tumor Treating Field (TT Field) Therapy is a proven approach to treat tumors using alternating electric fields with frequencies between 50 kHz and 1 MHz (e.g., 100-500 kHz). The alternating electric field is induced by an electrode assembly (e.g., an array of capacitively coupled electrodes, also called a transducer array) placed on opposite sides of a target location in a subject's body. When an alternating voltage is applied between the opposing electrode assemblies, an alternating current flows through the electrode assemblies into the subject's body. And higher currents are strongly correlated with higher therapeutic efficacy.

[0003] One potential issue with transducer arrays is the patient's comfort level. The skin area under the electrodes can generate heat, and some patients can also sweat, both of which can cause at least some discomfort to the patient. Additionally, sweat under the array can compromise the contact seal of the electrode elements, which may result in higher currents being required to overcome unnecessary current losses. Therefore, a transducer array that is less susceptible to heat and moisture collection and retention against the skin is desirable. Summary of the Invention [Means for solving the problem]

[0004] In various aspects, the present disclosure relates to a device having at least one electrode element, an anisotropic material layer, a first conductive adhesive layer, and a skin contact layer. The at least one electrode element has a skin-facing surface. The anisotropic material layer has a skin-facing surface and an opposite outer-facing surface. The first conductive adhesive layer is disposed between the skin-facing surface of the at least one electrode element and the outer-facing surface of the anisotropic material layer. The skin contact layer includes a biocompatible conductive adhesive and is disposed on the skin-facing side of the anisotropic material layer. The first conductive adhesive layer is configured to facilitate electrical contact between the skin-facing surface of the at least one electrode element and the outer-facing surface of the anisotropic material layer. A plurality of openings extend through the anisotropic material layer from the skin-facing surface to the outer-facing surface.

[0005] In another aspect, the disclosure relates to a method including forming a plurality of openings extending through an anisotropic material layer of a device, the device including a first conductive adhesive layer, a skin contact layer including a biocompatible conductive adhesive, and the anisotropic material layer, the anisotropic material being disposed between the first conductive adhesive layer and the skin contact layer. [Brief description of the drawings]

[0006] [Figure 1A] 1 is a schematic top view of an exemplary device having electrode elements as disclosed herein. [Figure 1B] 1B is a cross-sectional view of the device of FIG. 1A taken along line 1B-1B'. [Figure 2A] 1 is an enlarged cross-sectional view of an exemplary device having an opening extending through an anisotropic layer, a conductive adhesive layer, and / or a skin contact layer as disclosed herein. [Figure 2B] FIG. 2 is an enlarged cross-sectional view of another exemplary device having an opening extending through the anisotropic layer, the conductive adhesive layer, and / or the skin contact layer as disclosed herein. [Diagram 3] 1 is a cross-sectional view of an exemplary device having a dielectric element coupled to a respective electrode element as disclosed herein. [Figure 4]1 is a cross-sectional view of an exemplary device disclosed herein having an absorbent or wicking material covering the exterior-facing surface of the device. [Figure 5A] 1 is a schematic top view of an exemplary anisotropic layer having a plurality of openings as disclosed herein; [Figure 5B] FIG. 2 is a schematic top view of another example of an anisotropic layer having a plurality of openings, as disclosed herein. [Figure 6] FIG. 1 is a block diagram illustrating an exemplary system for delivering a TT field to a target area of ​​a patient using a device as disclosed herein. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] Various embodiments will now be described in detail with reference to the accompanying drawings, in which like reference numerals represent like elements.

[0008] This application describes devices (eg, example treatment assemblies) that can be used, for example, to deliver a TT field to the body of a subject to treat one or more cancers or tumors located in the body of a subject.

[0009] The present invention may be more readily understood by reference to the following detailed description, examples, drawings, claims, and accompanying text, but it is to be understood that the invention is not limited to the particular apparatus, devices, systems, and / or methods disclosed, unless expressly stated, as such may, of course, vary.

[0010] Headings are provided for convenience only and should not be construed as limiting the invention in any way. An embodiment shown under any heading or in any portion of this disclosure may be combined with an embodiment shown under the same or any other heading or portion of this disclosure.

[0011] Any combination of the elements described herein in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or clearly contradicted by context.

[0012] As used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

[0013] 1A-2B, a device 10 is disclosed that includes at least one electrode element 20 having a skin-facing surface 22. The device 10 may further include an anisotropic material layer 30 having a skin-facing surface 32 and an opposite, outer-facing surface 34. A first layer of conductive adhesive or conductive gel / hydrogel 40 may be disposed between the skin-facing surface 22 of the at least one electrode element 20 and the outer-facing surface 34 of the anisotropic material layer 30. The device 10 may include a skin contact layer 50 that includes a biocompatible conductive adhesive or conductive gel / hydrogel. The skin contact layer 50 may be disposed on the skin-facing side 36 of the anisotropic material layer 30.

[0014] The first layer of conductive adhesive or conductive gel / hydrogel 40 may be configured to facilitate electrical contact between the skin-facing surface 22 of at least one electrode element 20 and the outer-facing surface 34 of the anisotropic material layer 30. A plurality of openings 35 (e.g., perforations) may extend through the anisotropic material layer 30 from the skin-facing surface 32 to the outer-facing surface 34. In this manner, moisture may be transferred through the anisotropic material. Additionally, the openings 35 (e.g., perforations) may provide ventilation, thereby allowing heat dissipation. Thus, the openings 35 may provide cooling and sweat dissipation. In addition to improving patient comfort, evaporation of sweat from the outer-facing surface 34 of the anisotropic material 30 may help avoid problems with sweat under the electrodes. In some embodiments, the plurality of openings (e.g., perforations) may extend only through the anisotropic material layer.

[0015] 2A, in some embodiments, the device 10 may further include a second plurality of openings 45 extending through the first layer of the conductive adhesive or conductive gel / hydrogel 40 and / or a third plurality of openings 55 extending through the skin contact layer 50. An opening of the second plurality of openings 45, or an opening of the third plurality of openings 55, or both, may be coaxially aligned with a respective opening of the plurality of openings 35 of the anisotropic material layer 30. Thus, the plurality of openings may extend only through the anisotropic layer or may extend through multiple layers of the electrode assembly. And, if an opening extends through more than one layer, the opening may or may not be coaxially aligned with one or more of the plurality of openings of the other layers. In some embodiments, the plurality of openings may extend through all layers except the circuit board layer (e.g., optionally a printed circuit board (PCB) layer). All layers of the electrode assembly can be constructed in one operation and multiple openings can be punched in all layers, or all layers except the printed circuit board (PCB) layer can be constructed in one operation to form a pre-structure, multiple openings can be punched in all layers of the pre-structure, and a printed circuit board (PCB) layer (without openings) can be added to form the electrode assembly.

[0016] The cross-sectional area of ​​the openings is not particularly limited. Conveniently, the openings may be of the size of a needle or pinprick, but may also be significantly smaller or larger. In a particular electrode assembly configuration, the openings may all be approximately the same size (cross-sectional area) or may vary in size. Furthermore, the dimensions of the cross-sectional area of ​​the openings may be of regular shape (e.g., approximately circular) or irregular shape (e.g., irregular slit shape).

[0017] 1B, 2B, 3, and 4, device 10 may include electrical connections 70. For example, in some embodiments, device 10 may include a circuit board 72 (e.g., optionally a printed circuit board (PCB)). In some embodiments, at least one electrode 20 may be coupled to circuit board 72. In further embodiments, at least one electrode 20 may be a component of circuit board 72. In yet another embodiment, electrical connections 70 may include wires 75, as shown in FIG.

[0018] With reference to FIG. 2B, the circuit board 72 may have a perimeter 74. The perimeter may have a perimeter shape. The perimeter shape may overlay the anisotropic material layer 30. In some embodiments, as shown in FIG. 2B, all of the plurality of openings 35 through the anisotropic material layer 30 may be located outside of the perimeter shape. Thus, in some embodiments, with further reference to FIG. 5B, the anisotropic material layer 30 may include an interior region 38 without openings. In some embodiments, the interior region 38 without openings may be partially or entirely surrounded by an area having openings 35. In some embodiments, with reference to FIG. 2A, at least one opening of the plurality of openings 35 through the anisotropic material layer 30 may be disposed within the perimeter shape overlaying the anisotropic material layer 30. In some embodiments, as shown in FIG. 2B, at least one electrode 20 (optionally all of the electrodes) may be disposed within the perimeter 74 of the circuit board 72.

[0019] 3, in some optional embodiments, the device 10 may include at least one dielectric element 90. Each dielectric element 90 may be coupled to a respective electrode element of the at least one electrode element 20. In further embodiments, the dielectric element 90 may be omitted, as shown in FIG. 1B.

[0020] In some optional embodiments, as shown in Figure 4, the device 10 may include an absorbent or wicking material 80 covering at least a portion of (optionally the entire) the outer-facing surface 15 of the device. Optionally, the absorbent or wicking material 80 may include a woven material or a superabsorbent material. For example, the superabsorbent material may include cross-linked polyacrylic acid and / or copolymers thereof.

[0021] In various embodiments, the cover 100 may extend over the device 10. For example, in some embodiments, the cover 100 and the patient's skin may cooperate to enclose the device 10. For example, the cover 100 may be a breathable overlay dressing or plaster.

[0022] In some embodiments, the first layer of conductive adhesive or conductive gel / hydrogel 40 may include a dielectric material and conductive particles dispersed within the dielectric material. In some embodiments, at least a portion of the conductive particles may define a conductive path through the thickness of the first layer of conductive adhesive or conductive gel / hydrogel 40.

[0023] In some optional embodiments, the anisotropic material layer 30 may include graphite. In various embodiments, the anisotropic material layer 30 may include pyrolytic graphite, graphitized polymer, or graphite foil made from compressed high purity exfoliated mineral graphite.

[0024] The arrangement of the plurality of openings 35 may be regular or irregular. For example, referring to FIG. 5, in some optional embodiments, the plurality of openings 35 through the anisotropic material layer 30 may be arranged in rows 37 and columns 39. In other embodiments, the plurality of openings may be arranged in a completely random manner. Adjacent openings of the plurality of openings 35 may have regular or different spacings. The number of openings and the size of the openings may be selected based on the desired properties. For example, more openings and larger openings may improve breathability, but too many openings or too large an area defined by the openings may reduce the electrical conductivity properties of the anisotropic material layer. In exemplary embodiments, the size of the openings (e.g., perforations) may have a cross-sectional dimension (e.g., diameter) of about 0.1 mm to about 0.2 mm, e.g., about 0.2 mm to about 2 mm.

[0025] Optionally, the device 10 may include multiple electrode elements 20. In other embodiments, the device 10 may have only a single electrode 20.

[0026] Methods of using the device 10 disclosed herein may include an electric field using at least one electrode element 20 of the device. FIG. 6 shows an exemplary system 200 for applying an electric field using the device 10 disclosed herein. Multiple devices 10 (e.g., two devices as shown) may be positioned with a target area between them. A voltage or current generator 210 may be in communication with at least one electrode 20 of each device 10. The voltage or current generator 210 may be configured to generate an electric field through the target area.

[0027] The method may include placing a first device 10 at a first location on or within the subject's body. For example, the device 10 may be placed on the skin on the right side of the subject's head facing a target area (e.g., a tumor in the brain).

[0028] The second device 10 may be placed at a second location on or within the patient's body. For example, the second device 10 may be placed on the subject's skin on the left side of the patient's head facing the target area.

[0029] An AC voltage may be applied between the devices 10. This may be done by applying an AC voltage between (i) a first electrode element placed in electrical contact with the anisotropic material layer 30 of the first device 10, and (ii) a second electrode element placed in electrical contact with the anisotropic material 30 of the second device 10.

[0030] In some embodiments, the frequency of the AC voltage is between 50 kHz and 1 MHz, or between 100 kHz and 500 kHz. In some aspects, the AC voltage generator may be controlled by a controller. The controller may use the temperature measurements to control the amplitude of the current supplied through the device 10 to maintain the temperature below a safety threshold (e.g., 41° C.). This may be accomplished, for example, by measuring a first temperature of the first electrode element, measuring a second temperature of the second electrode element, and controlling application of the AC voltage based on the first and second temperatures, as described below.

[0031] More specifically, a temperature sensor (e.g., a thermostat) may be disposed in thermal contact with a respective electrode element in each device 10. The temperature sensors may measure respective first and second temperatures (e.g., at the first and second electrode elements in the first and second devices 10, respectively), and the controller may control the output of the AC voltage generator based on these temperatures.

[0032] The method of manufacturing the device disclosed herein can form a plurality of openings 35 extending through the anisotropic material layer 30 of the device 10, the device comprising a first layer of conductive adhesive or conductive gel / hydrogel 40, a skin contact layer 50 comprised of a biocompatible conductive adhesive or conductive gel / hydrogel, and an anisotropic material layer, the anisotropic material being disposed between the first layer of conductive adhesive or conductive gel / hydrogel 40 and the skin contact layer 50.

[0033] In some optional embodiments, a second plurality of openings 45 may be formed extending through the first layer of conductive adhesive or conductive gel / hydrogel 40, and a third plurality of openings 55 may be formed extending through the skin contact layer 50. An opening of the second plurality of openings 45 and an opening of the third plurality of openings 55 may be coaxially aligned with a respective opening of the plurality of openings 35 extending through the anisotropic material layer 30. In exemplary embodiments, the plurality of openings 35, 45, and 55 may be integrally formed; that is, the openings may be formed through an assembly including the anisotropic material layer 30, the first layer of conductive adhesive or conductive gel / hydrogel 40, and the skin contact layer 50.

[0034] In some embodiments, the device 10 can include a circuit board 72 coupled to the first conductive adhesive layer, the circuit board having a perimeter. The first conductive adhesive layer 40 can be disposed between the circuit board 72 and the anisotropic material layer 30. In some embodiments, the plurality of openings 35 in the anisotropic material layer 30 can be formed only outside the perimeter of the circuit board 72.

[0035] In a further embodiment, after the plurality of openings 35 are formed in the anisotropic material layer 30, a circuit board 72 may be bonded to the first conductive adhesive layer 40.

[0036] In some embodiments, the plurality of openings 35 may be formed by a roller having protrusions (e.g., needles) configured to provide such openings / perforations. In further embodiments, the plurality of openings 35 may be formed by a press having protrusions configured to provide such openings or by a stamping machine.

[0037] Optionally, portions of the anisotropic material layer 30 may be removed to form a plurality of openings 35 in the anisotropic material layer 30. For example, the anisotropic material layer 30 may be punched to form a plurality of openings 35. In a further embodiment, the anisotropic material layer 30 may be punched to form the openings 35.

[0038] In one example, the moisture vapor transmission rate (MVTR) was measured for four different material samples, each with a different number of openings through the anisotropic material layer. Each material sample (layered structure) includes a skin contact layer containing a carbon-filled pressure-sensitive adhesive, an anisotropic material layer containing pyrolytic graphite, and a first conductive adhesive layer containing a carbon-filled pressure-sensitive adhesive. In this example, 15 milliliters of distilled water are placed in a plastic Petri dish (D=5.5 cm) and tightly sealed with the tested device. The Petri dish is then placed on a heating plate at room temperature (37° C.). After 24 hours, the weight of water vapor that has permeated the layered structure is measured by differential gravimetry. Table 1 shows the effect of openings on the MVTR.

[0039] [Table 1]

[0040] Thus, the openings 35 (eg, perforations) in the anisotropic material layer allow moisture to escape from beneath the layered structure.

[0041] When a TT field is applied to a subject's body, the temperature of the subject's body may increase in proportion to the induced electric field. Regulations limit the amount of current that can be passed through the transducer array to an amount that keeps the temperature measured at each site on the subject's body below a temperature threshold. As practiced in the art, the temperature at the location of the transducer array on the subject's body is controlled below the temperature threshold by reducing the operating current driven by the transducer array and reducing the strength of the resulting TT field. This places a priority limit on the TT field strength that can be used to treat tumors.

[0042] Uneven distribution of current through the transducer array due to electrode element distribution or edge effects can cause high temperature zones (or "hot spots") at the corners and edges of the transducer array. These hot spots are the first to reach a threshold temperature, thus controlling the requirement to reduce the current. The creation of hot spots therefore limits the maximum operating current that can be driven by the transducer array and the resulting TT field strength.

[0043] The inventors have recognized that there is a need for a transducer array that reduces or minimizes uneven distribution of current, thereby allowing for the application of higher operating currents. Transducer arrays that operate at increased currents can induce stronger TT fields within the subject's body, ultimately improving patient outcomes. The devices (e.g., electrode assemblies) disclosed herein allow current and heat to be spread evenly over the array, thereby minimizing or eliminating hot spots.

[0044] Advantageously, in addition to facilitating the removal of sweat and moisture from beneath the electrodes, the breathability of the device 10 via the multiple openings 35 may further reduce body temperature. Thus, the disclosed device may increase the applicable potential TT field strength.

[0045] The embodiments described herein incorporate a sheet of material (also referred to herein as anisotropic material layer 30) having anisotropic thermal and / or electrical properties into the electrode assembly. If the sheet of material has anisotropic thermal properties (e.g., greater in-plane thermal conductivity than 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., greater in-plane electrical conductivity than perpendicular to the plane, or conversely, lower in-plane resistance than perpendicular to the plane), the sheet spreads current more evenly over a larger surface area. In either case, this results in a lower temperature in hot spots and an increased temperature in cold regions when a given AC voltage is applied to the electrode assembly (compared to the prior art configurations described above). Thus, the current can be increased (and thereby the therapeutic effect increased) without exceeding a safe temperature threshold at any point on the subject's skin.

[0046] In some embodiments, the anisotropic material is anisotropic with respect to electrical conductivity properties. In some embodiments, the anisotropic material is anisotropic with respect to thermal conductivity properties. In some embodiments, the anisotropic material is anisotropic with respect to both electrical conductivity and thermal conductivity properties.

[0047] Anisotropic thermal properties include directional thermal properties. Specifically, the 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 surface is at least two times higher than the first thermal conductivity. In some preferred embodiments, the thermal conductivity in the parallel direction (within the plane of the sheet) 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 may be more than 1.5 times, 2 times, 3 times, 5 times, 10 times, 20 times, 100 times, 200 times, or 1,000 times higher than the first resistance.

[0048] Anisotropic electrical properties include directional electrical properties. Specifically, the sheet has a first resistance in a direction perpendicular to its surface, and a resistance in a direction parallel to the surface of the sheet is less than the first resistance. In some preferred embodiments, the resistance in the parallel direction is less than half 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 may be less than 75%, 50%, 40%, 30%, 20%, 10%, 5%, 1%, 0.5%, or 0.1% of the first resistance.

[0049] In some embodiments (eg, when the sheet of anisotropic material is a sheet of pyrolytic graphite), the sheet of anisotropic material has both anisotropic electrical properties and anisotropic thermal properties.

[0050] In some embodiments (e.g., when the sheet of anisotropic material is a sheet of pyrolytic graphite), the sheet of anisotropic material is non-metallic. These embodiments are particularly advantageous in situations where it is desirable to prevent the migration of ions into the subject's body. In particular, the use of a metallic sheet may allow ions to enter the subject's body. In situations where this is undesirable, embodiments using a non-metallic sheet of anisotropic material are preferred.

[0051] FIG 1A is a schematic diagram of an embodiment of an electrode assembly 10 including electrode elements used to apply a TT field to a subject's body. In FIG 1A, only two electrode elements 20 are shown, however, additional electrode elements may be included in the device 10. In alternative embodiments, the device 10 includes only a single electrode element 20. Notably, FIG 1A generally illustrates the device 10, which may have different configurations (e.g., as described below in connection with FIG 1B-FIG 4).

[0052] FIG. 1B is a cross-sectional view of an electrode assembly 10 including an electrode element 20 taken along dashed line 1B-1B' of FIG. 1A.

[0053] In the embodiment of FIG. 1B, the device 10 includes an anisotropic material layer 30. The anisotropic material layer 30 has a first thermal conductivity in a direction perpendicular to the front surface. The thermal conductivity of the anisotropic material layer 30 in a direction parallel to the front surface is more than two times higher than the first thermal conductivity. In some embodiments, the thermal conductivity of the anisotropic material layer 30 in a direction parallel to the front surface is more than ten times higher than the first thermal conductivity. The anisotropic material layer 30 in the embodiment of FIG. 1B may be anisotropic in other respects as well. More specifically, the anisotropic material layer 30 has a first resistance in a direction perpendicular to the front surface, and the resistance of the sheet in a direction parallel to the front surface may be less than half of the first resistance. In some embodiments, the resistance of the sheet in a direction parallel to the front surface is less than 10% of the first resistance.

[0054] In some embodiments, the anisotropic material layers 30 are sheets of pyrolytic graphite. The thermal conductivity of these sheets in a direction parallel to the front surface of the pyrolytic graphite sheet (i.e., in the ab-plane) is typically more than 50 times higher than the thermal conductivity of these sheets in a direction perpendicular to the front surface of the pyrolytic graphite sheet (i.e., in the c-direction). Additionally, the electrical resistivity of these sheets in a direction parallel to the front surface of the pyrolytic graphite sheet (i.e., in the ab-plane) is typically less than 2% of the electrical resistivity of these sheets in a direction perpendicular to the front surface of the pyrolytic graphite sheet (i.e., in the c-direction).

[0055] In other embodiments, the anisotropic material layer 30 is a graphitized polymer film, such as graphitized polyimide. In other embodiments, the anisotropic material layer 30 is a graphite foil made from compressed high purity exfoliated mineral graphite. In other embodiments, the anisotropic material may be pyrolytic carbon. Other embodiments may utilize sheets of other conductive materials with anisotropic properties. In some embodiments (e.g., when the sheet of anisotropic material is a sheet of pyrolytic graphite), the anisotropic material layer 30 is non-metallic.

[0056] The electrode assembly 10 of FIG. 1B further includes a skin contact layer 50 of a biocompatible conductive material disposed on the skin-facing surface of the anisotropic material layer 30. The skin contact layer 50 is configured to ensure good electrical contact between the device and the body. In some embodiments, the skin contact layer 50 can cover the entire front surface of the anisotropic material layer 30. The skin contact layer 50 can be the same size as or larger than the anisotropic material layer 30. In some embodiments, the skin contact layer 50 includes a hydrogel. In these embodiments, the hydrogel can have a thickness between 50 μm and 2000 μm. In other embodiments, the skin contact layer 50 includes a conductive adhesive composite as further disclosed herein.

[0057] In the embodiment shown in FIGS. 3 and 4, a dielectric material 90 (eg, ceramic) may be disposed against the skin-facing surface 22 of each electrode element 20.

[0058] In some embodiments, the anisotropic material layer 30 has a center of gravity, and the center of gravity of the skin-facing surface 22 of at least one electrode element 20 may be located less than 3 cm away from the center of gravity of the anisotropic material layer 30. In some embodiments, the anisotropic material layer 30 has a center of gravity and a dimension (e.g., length or width) parallel to the rear surface of the anisotropic material layer 30, and a center of gravity of a first front surface of the electrode element. FIG. 20 is located less than 10% of a dimension away from the center of gravity of the anisotropic material layer 30.

[0059] The electrode elements 20 may include metal. The electrode elements 20 may be wired together into a lead (e.g., using wires, traces on a flex circuit, etc.). Wires 75 (FIG. 3) may supply an AC voltage from a voltage / current generator 210 (FIG. 6) to the electrode elements to generate a TT field when the device 10 is secured to the subject's body for treatment.

[0060] In some embodiments where the at least one electrode is a plurality of electrodes, the area of ​​the anisotropic material layer 30 is greater (e.g., at least 10 times greater) than the combined area of ​​the plurality of electrode elements 20. When an AC voltage is applied to the electrode elements 20, heat spreads throughout the anisotropic material layer 30, minimizing or eliminating hot spots.

[0061] [Device having a layer containing a conductive adhesive composite] Optionally, the conductive adhesive layer 40 and / or the skin contact layer 50 may be or include a hydrogel. It is further contemplated that the conductive adhesive layer 40 and / or the skin contact layer 50 may be or include a conductive adhesive composite (described further below) rather than a hydrogel.

[0062] In exemplary aspects, the conductive adhesive composite may include a dielectric material and conductive particles dispersed within the dielectric material. In some aspects, at least a portion of the conductive particles define a conductive path through the thickness of the conductive adhesive composite. In some aspects, it is believed that the conductive particles may be aligned in response to application of an electric field such that the conductive particles undergo electrophoresis. In some aspects, the dielectric material is a polymer adhesive. Optionally, in these aspects, the polymer adhesive may be an acrylic adhesive. In some aspects, the conductive particles may include carbon. Optionally, in these aspects, the conductive particles may include graphite powder. Additionally or alternatively, the conductive particles may include carbon flakes. Additionally or alternatively, the conductive particles may include carbon granules. Additionally or alternatively, the conductive particles may include carbon nanotubes. Additionally or alternatively, the conductive particles may include carbon black powder. In further aspects, the conductive adhesive composite further includes a polar material (e.g., a polar salt). The polar salt may be a quaternary ammonium salt, such as a tetraalkylammonium salt. Exemplary conductive adhesive composites and methods of making such conductive adhesive composites are disclosed in U.S. Patent Nos. 8,673,184 and 9,947,432, which are incorporated herein by reference for all purposes. In an exemplary embodiment, the conductive adhesive composite can be a dry carbon / salt adhesive, such as the OMNI-WAVE adhesive composition manufactured and sold by FLEXCON (Spencer, Massachusetts, USA) or the ARcare® 8006 conductive adhesive composition manufactured and sold by Adhesives Research, Inc. (Glen Rock, Pennsylvania, USA).

[0063] In an exemplary embodiment, the skin contact layer 50 does not include a hydrogel.

[0064] In a further exemplary embodiment, the skin-contacting layer 50 does not include a latex rubber polymer.

[0065] In a further exemplary embodiment, the skin contact layer of the electrode assembly does not include silver or silver chloride.

[0066] In yet another embodiment, the conductive adhesive composite layer has a thickness ranging from about 30 μm to about 2000 μm, such as from 30 μm to about 70 μm. Optionally, the conductive adhesive composite can have a thickness ranging from about 45 μm to about 55 μm.

[0067] In yet another embodiment, the conductive adhesive composite is water-free.

[0068] In exemplary embodiments, the conductive particles of the conductive adhesive composite include groups of conductive particles. In these embodiments, the conductive particles of the groups of bonded conductive particles may be aligned to define respective conductive paths through the thickness of the electrical conductor in the adhesive composite electrode assembly.

[0069] In further exemplary embodiments, as disclosed above, the device may include at least one electrode element having a skin-facing surface, an anisotropic material layer having a skin-facing surface and an opposite outer-facing surface, and a skin contact layer comprising a conductive adhesive composite or a conductive gel / hydrogel. In these embodiments, the at least one electrode element may be electrically coupled to (and optionally electrically contact) the outer-facing surface of the anisotropic material layer, and the skin contact layer may be disposed on the skin-facing surface of the anisotropic material layer.

[0070] Optionally, in exemplary embodiments, the skin contact layer may be removably connected to the anisotropic material layer. In these embodiments, it is contemplated that the skin contact layer may be selectively detached from the anisotropic material and replaced with a new skin contact layer (e.g., when a maximum / threshold period of use is approached or reached).

[0071] In an exemplary embodiment, the sheet of anisotropic material is a sheet of synthetic graphite.

[0072] In an exemplary embodiment, the sheet of anisotropic material is a sheet of pyrolytic graphite or a sheet of a graphitized polymer, such as a graphitized polyimide.

[0073] In an exemplary embodiment, the sheet of anisotropic material is a graphite foil made from compressed high purity exfoliated mineral graphite.

[0074] In an exemplary embodiment, the sheet of anisotropic material is non-metallic.

[0075] In an exemplary embodiment, a sheet of anisotropic material has a first thermal conductivity in a direction perpendicular to the plane of the sheet, and the thermal conductivity of the sheet in a direction parallel to the plane of the sheet is at least two times greater than the first thermal conductivity.

[0076] In exemplary embodiments, the sheet of anisotropic material has a first resistance in a direction perpendicular to the plane of the sheet, and the resistance of the sheet in a direction parallel to the plane of the sheet is less than half of the first resistance. Optionally, in exemplary embodiments, the device may further include a release liner covering the skin contact layer. In these embodiments, it is contemplated that the device may be provided with a release liner to ensure that the skin contact layer does not adhere to undesirable surfaces or locations prior to use. Immediately prior to use, the release liner may be removed and the skin contact layer may be placed in contact with the patient's skin.

[0077] In exemplary embodiments, it is contemplated that by using a conductive adhesive composite as the skin contact layer as disclosed herein, additional backing and / or cover layers (e.g., an adhesive backing layer or overlay dressing, etc.) may be omitted. In these embodiments, the conductive adhesive composite may provide sufficient adhesion to the skin such that additional layers are not required to maintain the desired position of the electrode assembly on the subject's body, thereby reducing ease of use and overall cost of manufacture and use.

[0078] In a further aspect, by avoiding the use of hydrogels in the electrode assembly, it is believed that the electrode assembly including the conductive adhesive composite as disclosed herein does not require moisture-proof packaging, thereby making packaging costs much more affordable. Furthermore, it is believed that the conductive adhesive composite of the disclosed electrode assembly can avoid the signal fluctuation problem of hydrogels, thereby providing consistent material properties (e.g., tackiness) and reliable performance during the delivery of TT fields. Furthermore, it is believed that the disclosed conductive adhesive composite has a much longer shelf life than hydrogels, thereby reducing the frequency with which the electrode assembly (or the skin-contacting layer of the electrode assembly) must be replaced.

[0079] It is further contemplated that embodiments including sheets of anisotropic material further help to avoid or reduce overheating of the electrodes and associated skin discomfort by dissipating both electrical current and heat laterally (in the plane) rather than concentrating them directly through the layer (perpendicular to the plane of the skin contact layer).

[0080] [Illustrative Embodiments] In view of the described products, systems, and methods and variations thereof, certain more detailed embodiments of the present invention are set forth below. However, these specifically recited embodiments should not be construed as having a limiting effect on any different claims that incorporate different or more general teachings set forth herein, or as being limited in any way other than in the inherent meaning of the language in which "certain" embodiments are literally used.

[0081] Aspect 1: An apparatus comprising: at least one electrode element having a skin-facing surface; a layer of anisotropic material having a skin-facing surface and an opposite exterior-facing surface; a first conductive adhesive layer disposed between a skin-facing surface of the at least one electrode element and an outer-facing surface of the anisotropic material layer; a skin contact layer comprising a biocompatible conductive adhesive, the skin contact layer being disposed on a skin-facing side of the anisotropic material layer; the first conductive adhesive layer is configured to facilitate electrical contact between a skin-facing surface of the at least one electrode element and an outer-facing surface of the anisotropic material layer; The device, wherein a plurality of openings extend through the anisotropic material layer from the skin-facing surface to the exterior-facing surface.

[0082] Aspect 2: The device of aspect 1, further comprising a second plurality of openings extending through the first conductive adhesive layer and a third plurality of openings extending through the skin contact layer, wherein an opening of the second plurality of openings and an opening of the third plurality of openings are coaxially aligned with a respective opening of the plurality of openings in the anisotropic material layer.

[0083] Example 3: The apparatus of example 1 or example 2, further comprising a circuit board, wherein the at least one electrode is coupled to or is a component of the circuit board.

[0084] Aspect 4: An apparatus as described in aspect 3, wherein the circuit board has an outer periphery having an outer periphery shape, the outer periphery shape being capable of being superimposed on the anisotropic material layer, and all of the multiple openings through the anisotropic material layer being positioned outside the outer periphery shape.

[0085] Aspect 5: The device of aspect 3, wherein the circuit board has an outer periphery, and at least one of the at least one electrodes is located within the outer periphery of the circuit board.

[0086] Example 6: The device of Example 2, wherein all of the plurality of openings extend through all layers of the device except for the circuit board.

[0087] Embodiment 7: The device of any one of the preceding embodiments, further comprising an absorbent or wicking material covering at least a portion of an exterior-facing surface of the device.

[0088] Embodiment 8: The device of embodiment 7, wherein the absorbent or wicking material comprises a woven material or a superabsorbent material.

[0089] Embodiment 9: The device of embodiment 8, wherein the superabsorbent material comprises crosslinked polyacrylic acid and / or copolymers thereof.

[0090] Example 10: An apparatus described in any one of the preceding examples, further comprising at least one dielectric element, each dielectric element of the at least one dielectric element being coupled to a respective electrode element of the at least one electrode element.

[0091]

[0036] Embodiment 11. The device of any one of the preceding embodiments, wherein the first conductive adhesive layer comprises: A dielectric material; and conductive particles dispersed within the dielectric material, in one embodiment, at least a portion of the conductive particles define a conductive path through a thickness of the first conductive adhesive layer.

[0092] Example 12: The apparatus of any one of Examples 1-3, wherein the anisotropic material comprises graphite.

[0093] Example 13: The apparatus of any one of Examples 1-5, wherein the anisotropic material comprises a graphite foil made from pyrolytic graphite, graphitized polymer, or compressed high-purity exfoliated mineral graphite.

[0094] Aspect 14: A method comprising: 20. A method comprising applying an electric field using at least one electrode element of an apparatus according to any one of the preceding aspects.

[0095] Aspect 15: A method comprising: forming a plurality of openings extending through an anisotropic material layer of the device, the device comprising: A first conductive adhesive layer; a skin contact layer comprising a biocompatible conductive adhesive; the anisotropic material layer, the anisotropic material being disposed between the first conductive adhesive layer and the skin contact layer.

[0096] Aspect 16: A method according to aspect 15, further comprising forming a second plurality of openings extending through the first conductive adhesive layer and a third plurality of openings extending through the skin contact layer, wherein an opening of the second plurality of openings and an opening of the third plurality of openings are coaxially aligned with a respective opening of a plurality of openings extending through the anisotropic material layer.

[0097] Aspect 17: A method according to aspect 15, wherein the apparatus includes a circuit board bonded to the first conductive adhesive layer, the circuit board having an outer periphery, the first conductive adhesive layer being disposed between the circuit board and the first conductive adhesive layer, and the step of forming the multiple openings in the anisotropic material layer includes forming the multiple openings only outside the periphery of the circuit board.

[0098] Example 18: The method of example 15, further comprising the step of bonding a circuit board to the first conductive adhesive layer after forming the plurality of openings in the anisotropic material layer.

[0099] Aspect 19: A method according to any one of aspects 15 to 18, wherein the step of forming the plurality of openings in the anisotropic material layer includes a step of forming the plurality of openings using a roller having protrusions configured to provide the openings.

[0100] Aspect 20: The method according to any one of Aspects 17-19, wherein forming the plurality of openings in the anisotropic material layer comprises removing portions of the anisotropic material layer to form the plurality of openings.

[0101] Example 21: The method of any one of Examples 15-20, wherein the anisotropic material layer comprises pyrolytic graphite made from compressed high-purity exfoliated mineral graphite, a graphitized polymer, or a graphite foil.

[0102] Aspect 22: An apparatus, comprising: at least one electrode element having a skin-facing surface; a layer of anisotropic material having a skin-facing surface and an opposite exterior-facing surface; a first layer of conductive adhesive or conductive gel / hydrogel disposed between a skin-facing surface of the at least one electrode element and an outer-facing surface of the anisotropic material layer; a skin contact layer comprising a biocompatible conductive adhesive or conductive gel / hydrogel, the skin contact layer being disposed on a skin-facing side of the anisotropic material layer; the first layer of conductive adhesive or conductive gel / hydrogel is configured to facilitate electrical contact between a skin-facing surface of the at least one electrode element and an outer-facing surface of the anisotropic material layer; The device, wherein a plurality of openings extend through the anisotropic material layer from the skin-facing surface to the exterior-facing surface.

[0103] Aspect 23: The device described in Aspect 22, further comprising the step of forming a second plurality of openings extending through the first conductive adhesive layer and a third plurality of openings extending through the skin contact layer, wherein the openings of the second plurality of openings and the openings of the third plurality of openings are coaxially aligned with respective openings of the plurality of openings extending through the anisotropic material layer.

[0104] Example 24: The device described in any one of Examples 22-23, wherein the anisotropic material layer comprises a graphite foil made from pyrolytic graphite, graphitized polymer, or compressed high-purity exfoliated mineral graphite.

[0105] Aspect 25: A method comprising: A method comprising the step of applying an electric field using at least one electrode element of an apparatus according to any one of aspects 22-24.

[0106] Aspect 26: A method comprising: forming a plurality of openings extending through an anisotropic material layer of the device, the device comprising: a first layer of conductive adhesive or conductive gel / hydrogel; a skin contact layer comprising a biocompatible conductive adhesive or conductive gel / hydrogel; a layer of anisotropic material, the anisotropic material being disposed between the first layer of conductive adhesive or conductive gel / hydrogel and the skin contact layer.

[0107] Aspect 27: A method according to aspect 26, further comprising the step of forming a second plurality of openings extending through the first conductive adhesive layer and a third plurality of openings extending through the skin contact layer, wherein the openings of the second plurality of openings and the openings of the third plurality of openings are coaxially aligned with respective openings of the plurality of openings extending through the anisotropic material layer.

[0108] Example 28: The method of any one of Examples 25-27, wherein the anisotropic material layer comprises a graphite foil made from pyrolytic graphite, graphitized polymer, or compressed high-purity exfoliated mineral graphite.

[0109] Although the present invention has been disclosed with reference to particular embodiments, numerous modifications, variations, and changes to the described embodiments are possible without departing from the scope and spirit of the invention as defined in the appended claims. Accordingly, it is intended that the present invention not be limited to the described embodiments, but rather have the full scope defined by the language of the claims and their equivalents. [Explanation of symbols]

[0110] 10 Electrode Assembly 10 equipment 15 Surface 20 Electrode elements 22 Skin-facing surface of electrode element 20 30 Anisotropic material layer 32 skin-facing surface of anisotropic material layer 30 34 Outer facing surface of anisotropic material layer 30 35 Opening 36 skin-facing side of anisotropic material layer 30 37 rows 38 Internal area 39 columns 40 Conductive adhesive layer, 1st layer 45 Opening 50 Skin contact layer 55 Opening 70 Electrical Connection 72 Circuit Board 74 Circumference 75 Wire 80 Absorbent or wicking materials 90 Dielectric Elements 100 Cover 200 Systems 210 Current Generator

Claims

1. 1. An apparatus comprising: at least one electrode element having a skin-facing surface; a layer of anisotropic material having a skin-facing surface and an opposite exterior-facing surface; a first conductive adhesive layer disposed between a skin-facing surface of the at least one electrode element and an outer-facing surface of the anisotropic material layer; a skin contact layer comprising a biocompatible conductive adhesive, said skin contact layer being disposed on a skin-facing side of the anisotropic material layer; the first conductive adhesive layer is configured to facilitate electrical contact between a skin-facing surface of the at least one electrode element and an outer-facing surface of the anisotropic material layer; A plurality of openings extend through said anisotropic material layer from the skin-facing surface to the exterior-facing surface.

2. 2. The device of claim 1, further comprising a second plurality of openings extending through the first conductive adhesive layer and a third plurality of openings extending through the skin contact layer, wherein an opening of the second plurality of openings and an opening of the third plurality of openings are coaxially aligned with a respective opening of a plurality of openings in the anisotropic material layer.

3. The apparatus of claim 1 , further comprising a circuit board, the at least one electrode being coupled to or a component of the circuit board.

4. 4. The apparatus of claim 3, wherein the circuit board has a periphery having a periphery shape, the periphery shape being superimposable to the anisotropic material layer, and wherein all of the plurality of openings through the anisotropic material layer are disposed outside the periphery shape.

5. The device of claim 1 , further comprising an absorbent or wicking material covering at least a portion of an exterior-facing surface of the device.

6. The apparatus of claim 1 , further comprising at least one dielectric element, each of the at least one dielectric element being coupled to a respective electrode element of the at least one electrode element.

7. The first conductive adhesive layer is A dielectric material; and conductive particles dispersed within the dielectric material.

8. The apparatus of claim 1 , wherein the anisotropic material layer comprises graphite.

9. 10. The apparatus of claim 1, wherein the anisotropic material layer comprises a graphite foil made from pyrolytic graphite, graphitized polymer, or compressed high purity exfoliated mineral graphite.

10. 1. A method comprising: applying an electric field using at least one electrode element of a device, said device comprising: at least one electrode element having a skin-facing surface; a layer of anisotropic material having a skin-facing surface and an opposite exterior-facing surface; a first conductive adhesive layer disposed between a skin-facing surface of the at least one electrode element and an outer-facing surface of an anisotropic material layer; a skin contact layer comprising a biocompatible conductive adhesive, said skin contact layer being disposed on a skin-facing side of the anisotropic material layer; the first conductive adhesive layer is configured to facilitate electrical contact between a skin-facing surface of at least one electrode element and an outer-facing surface of the anisotropic material layer; A plurality of openings extend through the anisotropic material layer from the skin-facing surface to the exterior-facing surface.

11. 1. A method comprising: forming a plurality of openings extending through an anisotropic material layer of a device, the device comprising: A first conductive adhesive layer; a skin contact layer comprising a biocompatible conductive adhesive; an anisotropic material layer disposed between the first conductive adhesive layer and the skin contact layer.

12. 12. The method of claim 11, further comprising forming a second plurality of openings extending through the first conductive adhesive layer and a third plurality of openings extending through the skin contact layer, wherein an opening of the second plurality of openings and an opening of the third plurality of openings are coaxially aligned with a respective opening of a plurality of openings extending through the anisotropic material layer.

13. 12. The method of claim 11 , wherein the apparatus includes a circuit board coupled to the first conductive adhesive layer, the circuit board having a periphery, the first conductive adhesive layer being disposed between the circuit board and the first conductive adhesive layer, and the step of forming the plurality of openings in the anisotropic material layer includes forming a plurality of openings only outside a periphery of the circuit board.

14. The method of claim 11 , wherein forming the plurality of openings in the anisotropic material layer comprises forming the plurality of openings using a roller having protrusions configured to provide the openings.

15. The method of claim 11 , wherein the anisotropic material layer comprises a graphite foil made from pyrolytic graphite, graphitized polymer, or compressed high purity exfoliated mineral graphite.

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