Method and apparatus for delivering tumor treating electric fields to a subject's body for near-surface tumors - Patents.com

Abstract

A method for determining a location of a transducer on a subject's body for applying a tumor treating electric field, the method comprising the steps of: determining a near-surface portion of a tumor in the subject's body, the near-surface portion of the tumor being located closer to a surface of the subject's body than other portions of the tumor, determining a near-tumor location on the subject's body, the near-tumor location on the subject's body being closer to the near-surface portion of the tumor than other portions of the subject's body, determining a perimeter of a transducer, the transducer comprising a plurality of electrode elements electrically coupled to one another, the plurality of electrode elements of the transducer being located within the perimeter, and identifying a portion of the perimeter of the transducer that will be substantially located at the near-tumor location on the subject's body.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to Taiwan Patent Application No. 111130490, filed August 12, 2022, U.S. Patent Application No. 17 / 886,371, filed August 11, 2022, U.S. Patent Application No. 17 / 698,457, filed March 18, 2022, U.S. Patent Application No. 63 / 232,329, filed August 12, 2021, and U.S. Patent Application No. 63 / 232,294, filed August 12, 2021, all of which are incorporated by reference herein. [Background technology]

[0002] Tumor treating electric fields (TT fields) are low intensity (e.g., 1-4 V / cm) alternating electric fields in the mid-frequency range (e.g., 50 kHz-1 MHz, e.g., 50-500 kHz, etc.) that may be used to treat tumors as described in U.S. Pat. No. 7,565,205. TT field therapy is an approved mononucleosis treatment for recurrent glioblastoma (GBM) and an approved combination therapy combined with chemotherapy for newly diagnosed GBM patients. TT fields may also be used to treat tumors in other parts of the subject's body (e.g., lung, ovary, pancreas, etc.). For example, TT field therapy is an approved combination therapy combined with chemotherapy for malignant pleural mesothelioma (MPM). TT fields are non-invasively induced in the region of interest by transducers (e.g., capacitively coupled electrode element arrays, etc.) that are placed directly on the patient's body (e.g., using the Novocure Optune™ system, etc.) and apply an AC voltage across the transducers. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] U.S. Patent No. 7,565,205 Summary of the Invention [Problem to be solved by the invention]

[0004] In the context of GBM, the conventional approach to positioning these transducers is to position a first pair of transducers over the front and back of the head, and a second pair of transducers over the right and left sides of the head. In the context of mesothelioma treatment, the conventional approach to positioning these transducers is to position a first pair of transducers over the front and back of the torso, and a second pair of transducers over the right and left sides of the torso. An AC voltage generator applies an AC voltage (e.g., 200 kHz in the context of GBM or 150 kHz in the context of mesothelioma) between the first pair of transducers for a first time interval (e.g., 1 second), which generates an electric field having field lines extending generally in the anterior-posterior direction. The AC voltage generator then applies an AC voltage at the same frequency between a second pair of transducers for a second time interval (e.g., 1 second), which generates an electric field having field lines extending generally in a side-to-side direction. The system then repeats this two-step sequence for the treatment period. [Brief description of the drawings]

[0005] [Figure 1] 1 is a flow chart showing an example of determining the position of a transducer on a subject's body for applying a TT field. [Diagram 2] 1 is a flow diagram showing an example for applying TT Fields to the body of a subject having a tumor. [Diagram 3] FIG. 13 shows an example of determining the position of a transducer on a subject's body based on the location of a tumor to apply a TT field. [Figure 4A] 1A and 1B are diagrams showing examples of transducer structures having multiple coupled electrode elements. [Figure 4B]1A and 1B are diagrams showing examples of transducer structures having multiple coupled electrode elements. [Figure 5A] FIG. 2 is a diagram showing an example of a transducer structure. [Figure 5B] FIG. 2 is a diagram showing an example of a transducer structure. [Figure 6A] FIG. 1 illustrates an example of mounting a transducer on a subject's body to deliver a tumor treating electric field. [Figure 6B] FIG. 1 illustrates an example of mounting a transducer on a subject's body to deliver a tumor treating electric field. [Figure 7A] 1A-1C show exemplary simulation results of electric field strength when the electric field is applied to a subject's head via transducers of various sizes. [Figure 7B] 1A-1C show exemplary simulation results of electric field strength when the electric field is applied to a subject's head via transducers of various sizes. [Figure 8A] 1A-1C show exemplary simulation results of power absorbed by tissue when an electric field is applied to a subject's head via transducers of various shapes. [Figure 8B] 1A-1C show exemplary simulation results of power absorbed by tissue when an electric field is applied to a subject's head via transducers of various shapes. [Figure 8C] 1A-1C show exemplary simulation results of power absorbed by tissue when an electric field is applied to a subject's head via transducers of various shapes. [Figure 9A] FIG. 13 shows example simulation results of electric field strength delivered to a tumor as a function of transducer length, comparing (a) transducer positioning such that the tumor is centered within the perimeter of the transducer array with (b) transducer positioning such that the tumor is at the edge of the perimeter of the transducer array. [Figure 9B]FIG. 13 shows example simulation results of electric field strength delivered to a tumor as a function of transducer length, comparing (a) transducer positioning such that the tumor is centered within the perimeter of the transducer array with (b) transducer positioning such that the tumor is at the edge of the perimeter of the transducer array. [Figure 9C] 1 shows example simulation results of electric field strength delivered to a tumor as a function of transducer length, comparing (a) transducer positioning such that the tumor is centered within the perimeter of the transducer array with (b) transducer positioning such that the tumor is at the edge of the perimeter of the transducer array, versus different distances to the surface of the subject's head, shown here at the closest distance to the surface of the subject's head. [Figure 9D] 1 shows example simulation results of the electric field strength delivered to a tumor as a function of transducer length (a) comparing transducer positioning such that the tumor is centered within the perimeter of the transducer array with (b) transducer positioning such that the tumor is at the edge of the perimeter of the transducer array, at different distances relative to the surface of the subject's head. [Figure 9E] 1 shows example simulation results of the electric field strength delivered to a tumor as a function of transducer length (a) comparing transducer positioning such that the tumor is centered within the perimeter of the transducer array with (b) transducer positioning such that the tumor is at the edge of the perimeter of the transducer array, at different distances relative to the surface of the subject's head. [Figure 9F]1 shows example simulation results of the electric field strength delivered to a tumor as a function of transducer length (a) comparing transducer positioning such that the tumor is centered within the perimeter of the transducer array with (b) transducer positioning such that the tumor is at the edge of the perimeter of the transducer array, at different distances relative to the surface of the subject's head. [Figure 10] FIG. 1 illustrates an example of an apparatus for generating a tumor segmentation with uncertainty estimation of a subject's body. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0006] Various embodiments will now be described in detail with reference to the accompanying drawings, in which like reference numerals refer to like elements and in which:

[0007] Providing an effective tumor treating electric field (TT Field) treatment to a subject requires precise placement of transducers on the subject's body to deliver high electric field strength to the target tumor. To determine the location of these transducers, one or more proximal tumor locations are determined on the subject's body that are closer to at least a portion of the tumor than other locations on the subject's body. Typically, the location of the transducers on the subject's body is then determined with a central or near-central portion of the transducer at a proximal tumor location or locations.

[0008] The inventors have realized that in a transducer comprising an array of electrode elements, the electrode elements located along the edges of the array may have a lower resistance to passing current than the electrode elements located near the middle of the array. This may generally result in a higher charge concentration at points on the edges (e.g., the periphery) of the array. Furthermore, electrode elements located at corners or similar sharp bends at the edges of the array will have a higher concentration than other electrode elements located along the edges of the array and at the center of the array. The tendency of a transducer to pass more current through electrode elements located along the edges of the array and specifically at the corners is referred to herein as the "edge effect."

[0009] By understanding this problem, the inventors have discovered an approach to apply TT Fields by placing the edge (e.g., periphery) of the transducer at a location on the subject's body near the tumor. By placing the periphery of the transducer at a location near the tumor, the edge effect of the transducer can be utilized, thus delivering a higher electric field strength to the target tumor site, thereby positively impacting the therapeutic effect of the TT Fields.

[0010] The present invention will be more readily understood by reference to the following detailed description, examples, drawings, and claims, as well as their foregoing and following descriptions, but it should be understood that the invention is not limited to the specific apparatus, devices, systems, and / or methods disclosed herein, unless expressly stated to the contrary, and as such may, of course, vary.

[0011] Headings are provided for convenience only and should not be construed as limiting the invention in any way. Embodiments described under any heading or anywhere in this disclosure may be combined with embodiments described under the same or any other heading or elsewhere in this disclosure.

[0012] Unless otherwise indicated herein or clearly contradicted by context, any combination of the elements described herein in all possible variations is encompassed by the invention.

[0013] Some or all of the embodiments disclosed herein may relate to placing transducers on the body to treat tumors located within the body. Some or all of the embodiments disclosed herein may relate to placing transducers on the head to treat tumors located in the head, such as in the brain. Some or all of the embodiments disclosed herein may relate to placing transducers on the torso or other parts of the body to treat tumors located in the torso or other parts of the body.

[0014] 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.

[0015] 1 is a flow diagram showing an example method 100 for determining the position of a transducer on a subject's body for applying a TT field. In this example, the electric field is applied between a pair of transducers. However, it should be noted that the method 100 also applies to two electric fields when applied between two pairs of transducers. Each pair of transducers corresponds to a channel for generating a TT field in the subject's body.

[0016] Certain steps of the method 100 are described as being computer-implemented, which may be any device having one or more processors and memory accessible by the one or more processors, the memory storing instructions that, when executed by the one or more processors, cause the computer to perform the relevant steps of the method 100.

[0017] Referring to FIG. 1, in step S102, the method 100 includes determining a near-surface portion of a tumor in the subject's body that is located closest to the subject's body surface. The determination of the near-surface portion of the tumor is based on, for example, the location of the tumor in the subject's body, the size and shape of the tumor, and the type of tumor. In one example, the near-surface portion of the tumor is determined by image data. The image data may include one or more images of a portion of the subject's body. The image data may include, for example, one or more X-ray images, magnetic resonance images (MRI), computed tomography (CT) images, ultrasound images, or any images of the subject's body that provide an internal visualization of the subject's body. Each image may include an external shape of the portion of the subject's body and an area corresponding to the tumor in the subject's body. In one embodiment, one or more near-surface portions of the tumor may be determined. In one example, the one or more near-surface portions of the tumor may be classified based on a distance to the surface of the subject's body.

[0018] In step S104, method 100 includes determining a location on the subject's body near the tumor that is closer to a portion of the tumor near the surface than other portions of the subject's body. In one example, determining the location on the subject's body near the tumor is based on image data, such as one or more X-ray images, MRI images, CT images, ultrasound images, or any image of the subject's body that provides an internal visualization of the subject's body. Each image may include an external shape of a portion of the subject's body and an area within the subject's body that corresponds to the tumor.

[0019] In some embodiments, the tumor is located near the surface of the subject's body. In one embodiment, for example, the near surface portion of the tumor is located 80 mm or less from the location on the subject's body near the tumor. As another example, the near surface portion of the tumor is located 66 mm or less from the location on the subject's body near the tumor. In other embodiments, the near surface portion of the tumor is located 100 mm or less, 90 mm or less, 80 mm or less, 70 mm or less, 66 mm or less, 60 mm or less, 50 mm or less, 40 mm or less, 30 mm or less, or even less than 20 mm from the location on the subject's body near the tumor. In other embodiments, for example, when a line segment is drawn that intersects with the near surface portion of the tumor, the line segment has a first endpoint and a second endpoint on both sides of the subject's body, the first endpoint intersects with the location on the subject's body near the tumor, and the distance between the first endpoint and the near surface portion of the tumor is 50% or less of the distance between the second endpoint and the near surface portion of the tumor. As another example, the distance between the first endpoint and the near-surface portion of the tumor is 25% or less than the distance between the second endpoint and the near-surface portion of the tumor, hi other embodiments, the distance between the first endpoint and the near-surface portion of the tumor is 50% or less, 40% or less, 30% or less, 25% or less, 20% or less, or even less than 10% of the distance between the second endpoint and the near-surface portion of the tumor.

[0020] In one example, the location of the tumor is within the head of the subject's body. In this example, the location near the tumor is on the surface of the subject's head. For example, the location near the tumor may be located on the skull. In another example, the location of the tumor is within the subject's torso. In this example, the location near the tumor is on the surface of the subject's torso. For example, the location near the tumor is on the subject's chest, back, or abdomen. Figures 6A-6B show examples of transducers for use with the head and torso, which are discussed further below.

[0021] In step S106, the method includes determining an outer perimeter of a first transducer of a first pair of transducers to be placed on the subject's body to apply the TT field. In one example, the first transducer comprises a plurality of electrode elements electrically coupled to each other, the plurality of electrode elements of the first transducer being located within the outer perimeter. In one example, the outer perimeter of the first transducer is substantially square, rectangular, regular polygonal, irregular polygonal, circular, elliptical, near-elliptical, oval, or oval. In this embodiment, the substantially square, rectangular, regular polygonal, or irregular polygonal perimeter includes a substantially square, rectangular, regular polygonal, or irregular polygonal shape with rounded vertices. In one example, the surface area of ​​the first transducer is 5000 mm 2 In another example, the surface area of ​​the first transducer is 6500 mm 2 In another embodiment, the surface area of ​​the first transducer is 1000 mm 2 More than 2000mm 2 More than 3000mm 2 More than 4000mm 2 More than 5000mm 2 More than 6000mm 2 Above 6500mm 2 More than 7000mm 2 More than 8000mm 2 More than 9000mm 2 More than 10000mm 2 More than 15000mm 2 More than 20000mm 2 More than 25000mm 2 More than 50,000 mm 2 or more, or 75,000 mm 2 That is all. In general, the surface area of ​​the first transducer is 75,000 mm 2 (750cm 2 ), but the maximum surface area is determined by the size of the human (or animal) to be treated. For example, the surface area of ​​the first transducer is 1000 to 75000 mm 2 Or 2000 to 60000 mm2 Or 4000 to 50000 mm 2 Or 4000 to 25000 mm 2 may be also possible.

[0022] In one embodiment, the periphery of the first transducer is an edge of the first transducer. In another embodiment, the periphery of the first transducer is a convex periphery of the first transducer. In one example, the convex periphery surrounds all of the electrode elements of the first transducer. In another example, the convex periphery contacts at least three of the electrode elements.

[0023] In one example, the portion of the periphery of the first transducer that will be placed substantially at a location on the subject's body near the tumor contacts at least one of the electrode elements of the first transducer. In other embodiments, the portion of the periphery of the first transducer that will be placed substantially at a location on the subject's body near the tumor contacts at least two or at least three of the electrode elements of the first transducer. In another example, the portion of the periphery of the first transducer that will be placed substantially at a location on the subject's body near the tumor is no more than 20% of the circumference. As another example, the portion of the periphery of the first transducer that will be placed substantially at a location on the subject's body near the tumor is no more than 10% of the circumference, or even less than 5%.

[0024] In one embodiment, the first transducer is configured to be positioned on the subject's body with a surface of the first transducer facing the subject's body. In one example, when viewed perpendicularly to the surface of the first transducer, a number of the electrode elements of the first transducer are peripheral electrode elements that define an outer periphery of the first transducer, and these peripheral electrode elements substantially surround any other electrode elements of the first transducer. In another example, when viewed perpendicularly to the surface of the first transducer, a portion of the tumor near the surface is substantially located within the outer periphery of the first transducer.

[0025] In one embodiment, the electrode elements of the first transducer are capacitively coupled. In another embodiment, the electrode elements of the first transducer are not capacitively coupled. In one embodiment, the electrode elements of the first transducer comprise ceramic disks. In one example, each ceramic disk has a diameter of about 2 cm and a maximum thickness of about 1 mm. In another embodiment, the electrode elements of the first transducer are non-disk shaped ceramic elements. In another embodiment, the electrode elements of the first transducer are non-ceramic dielectric materials. Examples of non-ceramic dielectric materials include polymer films. Examples of these embodiments are shown in Figures 4A-4B and 5A-5B and are discussed further below.

[0026] The power density of the TT field can be used to indicate the TT field dose delivered to the tumor. The power density of the applied TT field can be converted, for example, to watts / volume. In one example, the power density of the applied TT field can be converted, for example, to mW / cm. 3 The power density of a TT field applied between a first transducer and a second transducer can be calculated by the following equation: P=1 / 2σE 2 equation 1 where P is the power density of the applied TT field, σ is the tissue conductivity, and E is the electric field magnitude of the applied TT field.

[0027] As discussed above, in a transducer having an array of electrode elements, electrode elements located along the edges of the array may carry a higher amount of current than electrode elements located near the center of the array (e.g., edge effect). Thus, according to Equation 1, the power density along the edges of the transducer may be higher than the central portion of the transducer. In one embodiment, the power density at the outer periphery of the transducer may be 100% to 300% of the power density at the central portion of the transducer. For example, the power density at the outer periphery of the transducer may be within a range in which the lower limit is 100%, 110%, 120%, 130%, 140%, 150%, 160%, 170%, 180%, 190%, or 200% of the power density at the center of the transducer and the upper limit is 150%, 160%, 170%, 180%, 190%, 200%, 210%, 220%, 230%, 240%, 250%, 260%, 270%, 280%, 290%, or 300% of the power density at the center of the transducer, for example, within a range of 120 to 280% or 150% to 250% of the power density at the center of the transducer.

[0028] Thus, if the tumor is located near the surface of the subject's body, i.e., close to the first transducer, a higher electric field output can be delivered to the tumor by placing the edge (rather than the center) of the first transducer at a location on the subject's body near the tumor, since the power density at the edge is higher than the power density at the center of the transducer. If the tumor is located far from the surface of the subject's body, i.e., far from the first transducer, a higher electric field output can be delivered to the tumor by placing the center or near-center portion of the first transducer at a location on the subject's body near the tumor, rather than the edge, since the cumulative electric field output of the edge and center portions of the transducer can be delivered to the tumor. Examples of these embodiments are shown in Figures 9A-9F and are discussed further below.

[0029] In step S108, the method 100 includes identifying a plurality of portions of the periphery of the first transducer or a plurality of orientations of the first transducer that will be positioned substantially on the subject's body at a location near the tumor. As an example, if the periphery of the first transducer is substantially square, rectangular, regular polygonal, or irregular polygonal, the plurality of portions of the periphery may comprise one or more corners (e.g., sharp or rounded vertices) and one or more edges of the substantially square, rectangular, regular polygonal, or irregular polygonal. As an example, if the periphery of the first transducer is substantially circular, elliptical, approximately elliptical, oval, or oval, the plurality of portions of the periphery may consist of arcs or perimeters of a substantially circular, elliptical, approximately elliptical, oval, or oval.

[0030] In step S110, the method includes selecting at least one of the multiple portions of the periphery or at least one of the multiple orientations of the first transducer. In one example, the selection of at least one of the multiple portions of the periphery of the first transducer is based on the shape of the periphery, the distribution of the electrode elements on the periphery, and / or the size and shape of the tumor. As an example, when the periphery of the first transducer is substantially square, rectangular, regular polygonal, or irregular polygonal, at least one of the one or more corners (e.g., acute angles or rounded vertices) may be selected. As an example, when the periphery of the first transducer is substantially circular, elliptical, near-elliptical, oval, or oval, at least one or more of the arcs or perimeter portions may be selected. As another example, the selected at least one portion of the periphery contacts at least one of the electrode elements of the first transducer. In other embodiments, the selected at least one portion of the periphery contacts at least two or at least three of the electrode elements of the first transducer.

[0031] In one embodiment, the periphery of the first transducer is an edge of the first transducer. In this example, the method may include identifying and outputting a segment of the edge (e.g., periphery) of the first transducer. When viewed perpendicular to the face of the first transducer that will be positioned on the subject's body, this segment of the edge substantially overlaps a location near the surface of the tumor. In one example, this segment of the edge is located closer to the location near the surface of the tumor than the center of gravity of the first transducer.

[0032] In another embodiment, the outer periphery of the first transducer is a convex periphery of the first transducer. In this example, the method 100 may include identifying and outputting a near-tumor portion of the convex periphery of the first transducer to be placed on the subject's body that is located closer to a location near the surface of the tumor than other portions of the first transducer.

[0033] In step S112, method 100 includes outputting at least one of the multiple portions of the perimeter or at least one of the multiple orientations of the first transducer selected in step S110 to be substantially located at a location on the subject's body near the tumor. In one embodiment, at least one of the multiple portions of the perimeter or at least one of the multiple orientations of the first transducer is output at an output device.

[0034] 2 is a flow diagram illustrating an example method 200 for applying TT fields to the body of a tumor-bearing subject. In this example, two electric fields are applied alternately between two pairs of transducers.

[0035] Referring to FIG. 2, in step S202, the method 200 includes arranging a first pair of transducers and a second pair of transducers on the subject's body. In one example, the first pair of transducers includes a first transducer and a second transducer, and the second pair of transducers includes a first transducer and a second transducer. Each transducer of the first pair of transducers and the second pair of transducers may be a transducer having an electrode element array. In one example, a location for arranging at least one of the transducers of the first pair of transducers and the second pair of transducers is determined by the method 100.

[0036] In one example, the first and second transducers of the first pair of transducers are capacitively coupled and the first and second transducers of the second pair of transducers are capacitively coupled, in another example, the first and second transducers of the first pair of transducers are not capacitively coupled and the first and second transducers of the second pair of transducers are not capacitively coupled.

[0037] In one example, the first pair of transducers and the second pair of transducers are positioned on the head of the subject's body. In another example, the first transducer of each of the first pair of transducers and the second pair of transducers is positioned on the head of the subject's body, and the second transducer of each of the first pair of transducers and the second pair of transducers is positioned on the neck of the subject's body. In another example, the first pair of transducers and the second pair of transducers are positioned on the torso of the subject's body. In another example, the first transducer of each of the first pair of transducers and the second pair of transducers is positioned on the torso of the subject's body, and the second transducer of each of the first pair of transducers and the second pair of transducers is positioned below the torso of the subject's body.

[0038] In step S202, the method 200 includes alternately generating a first tumor treatment electric field (TT field) between a first pair of transducers and a second tumor treatment electric field (TT field) between a second pair of transducers. The first TT field is generated by applying a first AC voltage generated by a first AC generator between the first pair of transducers for a first time interval, for example having a low intensity (e.g., 1-4 V / cm) and a medium frequency range (e.g., 125-250 kHz or in some examples, 50-500 kHz). In one example, the frequency of the first TT field is 150 kHz. The first AC voltage is applied to the first pair of transducers for a first time interval (e.g., 1 second). After the first time interval, generation of the first TT field is terminated. A second TT field is then generated by applying a second AC voltage generated by a second AC generator between the second pair of transducers for a second time interval, for example having a low intensity (e.g., 1-4 V / cm) and a mid-frequency range (e.g., 125-250 kHz or in some examples, 50-500 kHz). In one example, the frequency of the second TT field is 150 kHz. The second AC voltage is applied to the second pair of transducers for a second time interval (e.g., 1 second). The second time interval and the first time interval may be the same or different. After the second time interval, generation of the second TT field ceases. The method then repeats the process of alternating between generating the first TT field between the first pair of transducers for the first time interval and generating the second TT field between the second pair of transducers for the second time interval.

[0039] FIG. 3 shows an example of determining the location of a transducer on a subject's body based on the location of a tumor to which a TT field is applied.

[0040] In the example shown in FIG. 3, a tumor 301 is located within a subject's body 300. In this example, the tumor 301 is located within the subject's head. A near-surface portion 302 of the tumor 301 is determined. In one example, the near-surface portion 302 of the tumor 301 is located closer to the surface of the subject's body than other portions of the tumor 301. A near-tumor location 304 on the subject's head is determined based on the near-surface portion 302. In one example, the near-tumor location 304 is located closer to the near-surface portion 302 of the tumor 301 than other portions of the subject's body. A line segment 303 intersects the near-surface portion 302 and the near-tumor location 304. In one example, the line segment 303 has a first endpoint and a second endpoint on either side of the subject's body. In this example, the first endpoint is the near-tumor location 304 and the second endpoint 305 is located on the opposite side of the subject's head.

[0041] In one example, the distance between the near-surface portion 302 and the near-tumor location 304 is 80 mm or less. In another example, the distance between the near-surface portion 302 and the near-tumor location 304 is 66 mm or less. In another example, the distance between the near-surface portion 302 and the near-tumor location 304 is 80 mm or less, 70 mm or less, 66 mm or less, 60 mm or less, 55 mm or less, 50 mm or less, 45 mm or less, 40 mm or less, or 35 mm or less, or even 30 mm or less, such as between 30-80 mm, 35-80 mm, or 40-80 mm. In another example, the distance between the near-tumor location 304 and the near-surface portion 302 is 50% or less of the distance between the second endpoint 305 and the near-surface portion 302. In another example, the distance between the near-tumor location 304 and the near-surface portion 302 is 25% or less of the distance between the second endpoint 305 and the near-surface portion 302. In other embodiments, the distance between the near-tumor location 304 and the near-surface portion 302 is 50% or less, 40% or less, 30% or less, 25% or less, 20% or less, 10% or less, or even 5% or less of the distance between the second endpoint 305 and the near-surface portion 302. For example, the distance between the near-tumor location 304 and the near-surface portion 302 may be between 5%-50% or 5%-30% of the distance between the second endpoint 305 and the near-surface portion 302.

[0042] In one embodiment, the location of the first transducer of the first pair of transducers on the subject's body is determined based on the location 304 near the tumor. In one example, the first transducer is positioned with a portion of the periphery of the first transducer located substantially at the location 304 near the tumor. In one embodiment, the location near the tumor located on the surface of the subject's body is located at a distance from the periphery of the first transducer that is less than 10% or even less than 5%, such as between 0% and 5%, of the distance from the periphery of the transducer to the center of gravity of the transducer when viewed perpendicular to the plane of the first transducer. In another embodiment, the location near the tumor located on the surface of the subject's body is located at a distance from the periphery of the first transducer that is less than 50%, less than 30%, less than 25%, less than 20%, less than 15%, less than 10%, or less than 5% of the distance from the periphery of the transducer to the center of gravity of the transducer when viewed perpendicular to the plane of the first transducer. In another embodiment, the location on the subject's body near the tumor, when viewed perpendicular to the plane of the first transducer, is located at a distance from the periphery of the first transducer that is between 0%-50%, or 5%-50%, or 0%-30%, or even 5%-30% of the distance from the periphery of the transducer to the center of gravity of the transducer. In another embodiment, the location of the second transducer of the first pair of transducers on the subject's body is determined based on the second end point 305. In one example, the second transducer is positioned with a central portion of the second transducer substantially located at the second end point 305. One example of the first and second transducers is a transducer array, each transducer array comprising a plurality of electrically coupled electrode elements.

[0043] 4A and 4B are examples of transducer structures. For example, as shown in FIG. 4A, the transducer 400A has a substrate 401A and a plurality of electrode elements 402A. The substrate 401A is configured for mounting the transducer to the body of a subject. Suitable materials for the substrate 401A include or are conductive materials, which may include, for example, fabric, foam, and flexible plastic. In one example, the substrate 401A is or is a conductive medical gel, which may typically have a thickness of about 0.5 mm or more, or may be injected / absorbed into the substrate material (e.g., fabric, foam, flexible plastic, etc.). In another example, the substrate 401A is or is a conductive adhesive, which may have a thickness of about 20 μm or more, or may be injected / absorbed into the substrate material (e.g., fabric, foam, flexible plastic, etc.). In a more specific example, the substrate 401A is a conductive hydrogel layer having a minimum thickness of 0.5 mm. In one example, the transducer 400A is configured to be positioned on the subject's body with the transducer face 403A facing against the subject's body.

[0044] A plurality of capacitively coupled electrode elements 402A are positioned on the substrate 401A, each capacitively coupled electrode element having a conductive plate with a dielectric layer disposed thereon facing the substrate. Optionally, one or more sensors may be positioned below each electrode element in a manner similar to conventional configurations used in Novocure Optune® systems. In one example, the one or more sensors are temperature sensors (e.g., thermistors).

[0045] 4B shows another example of the structure of the transducer 400B. In this example, the transducer 400B comprises a plurality of electrode elements 401B. The plurality of electrode elements 401B are electrically and mechanically connected to each other without using a substrate. In one example, the plurality of electrode elements 401B are connected to each other via conductive wires 402B.

[0046] 5A and 5B show example transducer structures having multiple electrically coupled electrode elements as viewed perpendicular to the face of the transducer facing the subject's body.

[0047] In the example shown in Figure 5A, the transducer 500A has a substrate 501A and a number of electrode elements 502A (e.g., 502-1A to 502-8A and 506A). The substrate 501A is configured for mounting the transducer to the body of a subject. Suitable materials for the substrate 501A include, for example, fabric, foam, and flexible plastic, as discussed above.

[0048] A plurality of capacitively coupled electrode elements 502A (e.g., 502-1A through 502-8A, and 506A) are positioned on a substrate 501A, with each capacitively coupled electrode element 502A having a conductive plate with a dielectric layer disposed on the substrate. Optionally, one or more sensors may be positioned below each electrode element in a manner similar to conventional configurations used in Novocure Optune® systems. In one example, the one or more sensors are temperature sensors (e.g., thermistors).

[0049] In some embodiments, multiple of the electrode elements 502-1A-502-8A of the transducer 500A define a perimeter of the transducer. In one example, the perimeter 504A of the transducer 500A is determined by a centroid 503A of the peripheral electrode elements. In this example, the centroids of the peripheral electrode elements 502-1A-502-8A define the perimeter 504A. In this example, the perimeter 504A is rectangular.

[0050] In another example, the perimeter 505A of the transducer 500A is determined by a shape that surrounds and contacts several of the perimeter electrode elements. In this example, the outermost edges of the peripheral electrode elements 502-1A to 502-8A define the perimeter 505A.

[0051] In one example, peripheral electrode elements 502-1A to 502-8A surround other electrode elements (eg, electrode element 506A located at the center of transducer 500A).

[0052] In one embodiment, when the periphery of transducer 500A is placed at a location substantially near the tumor on the subject's body, at least one of peripheral electrode elements 502-1A through 502-8A is placed at a location substantially near the tumor.

[0053] FIG. 5B illustrates an example of a transducer 500B having non-ceramic electrically coupled electrode elements 502-B (e.g., 502-1B to 502-8B). In this example, the transducer 500B has a substrate 501B and a number of non-ceramic electrode elements 502-B (e.g., 502-1B to 502-8B). In one embodiment, the non-ceramic electrode elements include a flexible dielectric material. Examples of flexible dielectric materials include a dielectric polymer or a dielectric copolymer. In some embodiments, the non-ceramic electrode elements 502-1B to 502-8B have a non-circular shape. In this example, the electrode elements 502-1B to 502-8B have a substantially triangular or wedge shape. In another embodiment, the transducer 500B does not include a substrate. In this example, the non-ceramic electrode elements 502-1B to 502-8B are attached directly to the subject's body.

[0054] In some embodiments, multiple of the electrode elements 502-1B-502-8B define a perimeter of the transducer 500B. In the example shown in Figure 5B, the perimeter 503B of the transducer 500B has an elliptical shape. In this example, the outermost edges of the peripheral electrode elements 502-1B-502-8B define the perimeter 503B.

[0055] Additionally, transducers using arrays of electrode elements that are not capacitively coupled may be used. In this situation, transducers 500A and 500B may be implemented using a region of conductive material configured to be placed against the subject's body, where no insulating dielectric layer is disposed between the conductive elements and the body.

[0056] 6A and 6B show an example of mounting a transducer on a subject relative to the body to deliver a tumor treating electric field.

[0057] In the example shown in FIG. 6A, transducers 601A, 602A, 603A, and 604A are attached to the subject's head to apply a TT field to the subject's head. In one embodiment, two electric fields are applied alternately between two pairs of transducers. Each pair of transducers corresponds to a channel for generating a TT field in the subject's body. With respect to the pair of transducers, transducers 601A and 603A may constitute a first pair of transducers, and transducers 602A and 604A may constitute a second pair of transducers.

[0058] In the example shown in FIG. 6B, transducers 601B, 602B, 603B, and 604B are attached to the subject's body to apply a TT field to the subject's torso. In one embodiment, two electric fields are applied alternately between two pairs of transducers. Each pair of transducers corresponds to a channel for generating a TT field in the subject's body. In the example shown in FIG. 6B, transducer 601B is attached to the subject's right front chest, transducer 602B is attached to the subject's right front thigh, transducer 603B is attached to the subject's left back chest, and transducer 604B is attached to the subject's left back thigh. With respect to the pair of transducers, transducers 601B and 604B may constitute a first pair of transducers, and transducers 602B and 603B may constitute a second pair of transducers.

[0059] 7A and 7B show example simulation results of electric field strength when the electric field is applied to a subject's head through transducers of various sizes. In the example shown in FIG. 7A and 7B, the transducer is a conductive flexible sheet. Furthermore, the same TT field with the same frequency and voltage is used to obtain the simulation results shown in FIG. 7A and 7B.

[0060] FIG. 7A includes a lateral image of a three-dimensional model of a subject's head and a horizontal slice through the three-dimensional model of the head showing the electric field strength distribution across the three-dimensional model. In this example, an 80×52 mm 2 A rectangular shaped transducer with a size of 4,160 mm is simulated to deliver the TT field to the subject's head. In this example, the surface area of ​​the rectangular transducer is 4,160 mm. 2 As shown in the horizontal slice of the head in Figure 7A, the electric field strength near the surface of the head is about 3.5 V / cm (orange / red), and this field strength is substantially uniformly distributed along the length of the transducer. Therefore, the simulation results in Figure 7A do not show edge effects.

[0061] FIG. 7B includes a lateral image of a three-dimensional model of the subject's head and a horizontal slice through the three-dimensional model of the head showing the electric field strength distribution across the three-dimensional model. In this example, a 140×91 mm 2 A rectangular shaped transducer having a size of 12,740 mm is simulated to deliver a TT field to the subject's head. In this example, the surface area of ​​the rectangular transducer is 12,740 mm. 2 As shown in the horizontal slice of the head in Figure 7B, the electric field strength near the surface of the head at the edges of the transducer is about 3.5 V / cm (orange / red), and the electric field strength near the surface of the head between the two edges of the transducer is about 2 V / cm (yellow / green). Thus, the simulation results in Figure 7B show edge effects.

[0062] 8A-8C show exemplary simulation results of power absorbed by tissue below a transducer array when an electric field is applied to a subject's head through transducers of various shapes. In the examples shown in FIGS. 8A-8C, the transducer is a conductive flexible sheet. Furthermore, the same TT field with the same frequency and voltage is used to obtain the simulation results shown in FIGS. 8A-8C. FIGS. 8A-8C show various examples of edge effects.

[0063] In the example shown in Fig. 8A, an elliptical transducer is placed on the subject's head to deliver a TT field. As shown in Fig. 8A, the power delivered to the subject's head by the outer periphery of the elliptical transducer is about 70 W / kg (yellow), and the power delivered by the center of the elliptical transducer is nearly zero (black / dark blue). Furthermore, the power delivered by the portion of the elliptical transducer located between the center and the outer periphery is about 12 W / kg (blue).

[0064] In the example shown in Fig. 8B, a circular transducer is placed on the subject's head to deliver a TT field. As shown in Fig. 8B, the power delivered to the subject's body by the outer periphery of the circular transducer is about 50 W / kg (orange / yellow), and the power delivered by the center of the elliptical transducer is nearly zero (black / dark blue). Furthermore, the power delivered by the part of the circular transducer located between the center and the outer periphery is about 12 W / kg (blue).

[0065] In the example shown in Fig. 8C, a rectangular transducer is placed on the subject's head to deliver a TT field. As shown in Fig. 8C, the power delivered to the subject's body by the corners of the periphery of the rectangular transducer is about 70 W / kg (yellow), and the power delivered by the edges of the periphery is about 42 W / kg (red). Furthermore, the power delivered by the center of the rectangular transducer is almost zero (black / dark blue), and the power delivered by the part of the rectangular transducer located between the center and the periphery is about 12 W / kg (blue).

[0066] Comparing the examples shown in Figures 8A-8C, the power of the elliptical transducer (Figure 8A) is most evenly distributed around the circumference of the transducer. Furthermore, the power of the rectangular transducer (Figure 8C) is most unevenly distributed around the circumference of the transducer. Furthermore, the power of the circular transducer (Figure 8B) is less evenly distributed around the circumference of the transducer than the elliptical transducer and more evenly distributed than the rectangular transducer. Furthermore, the size of the center of the elliptical transducer, where the power is near zero, is smallest, the size of the center of the rectangular transducer is largest, and the size of the center of the circular transducer is between the size of the elliptical transducer and the rectangular transducer.

[0067] 9A-9F show example simulation results of the electric field strength delivered to a tumor as a function of the length of a rectangular transducer. In each example, (a) the transducer is positioned so that the tumor is centered within the perimeter of the transducer array, compared to (b) the transducer is positioned so that the tumor is at the edge of the perimeter of the transducer array. Each of FIGS. 9C-9F shows the relationship for different distances to the surface of the subject's head, with FIG. 9C showing the closest distance to the surface of the subject's head. As shown (9C), the edge effect of the transducer can result in higher electric field strength for tumors near the surface.

[0068] FIG. 9A is a side view image of a three-dimensional model of a subject's head with a rectangular transducer positioned on the subject's head to deliver a TT field. In this example, the width of the rectangular transducer 903 is 65 mm. The length L of the rectangular transducer 903 varies between 80 mm and 130 mm (see the x-axis of the graphs in FIG. 9C-FIG. 9F). The image includes two tumor locations 901A and 902A, each having four depth locations (these locations are successively 10 mm further from the surface) as shown in FIG. 9B.

[0069] Figure 9B is a top view of the three-dimensional model of the subject's body of Figure 9A showing eight tumor locations with four distances relative to the surface of the subject's head. Tumor location 901A (Figure 9A, right side of transducer) includes locations 901-1B, 901-2B, 901-3B, and 901-4B (Figure 9B, right side locations). Tumor location 902A (Figure 9A, center of transducer) includes locations 902-1B, 902-2B, 902-3B, and 902-4B (Figure 9B, left side locations). In the example shown in FIG. 9B, tumor locations 901-1B and 902-1B are located closest to the surface of the subject's head (distance of 901-1B to the surface = 4 cm), tumor locations 901-4B and 902-4B are located farthest from the surface of the subject's head (distance of 901-4B to the surface = 7 cm), and tumor locations 901-2B, 902-2B (distance of 901-2B to the surface = 5 cm) and tumor locations 901-3B, 902-3B (distance of 901-3B to the surface = 6 cm) are located between tumor locations 901-1B and 902-1B and tumor locations 901-4B and 902-4B. The transducer is positioned on the lower side of FIG. 9B such that positions 902-1B, 902-2B, 902-3B, and 902-4B in FIG. 9B are aligned behind the center of the transducer (as shown in FIG. 9A), and positions 901-1B, 901-2B, 901-3B, and 901-4B in FIG. 9B are aligned behind the right edge of the transducer (as shown in FIG. 9A).

[0070] 9A and 9B, for tumor locations 901-1B through 901-4B, the simulation results are the electric field strength delivered to the tumor by a portion of the outer periphery of the transducer (corresponding to tumor location 901A in FIG. 9A). Similarly, for tumor locations 902-1B through 902-4B, the simulation results are the electric field strength delivered to the tumor by a central portion of the transducer (corresponding to tumor location 902A in FIG. 9A).

[0071] FIG. 9C is a graph of the electric field strength delivered to tumor locations 901-1B and 902-1B as a function of the transducer length. In FIG. 9C, graph 901C is the electric field strength delivered to tumor location 901-1B, i.e., the electric field strength delivered by a portion of the outer periphery of the transducer placed at a location on the subject's body near the tumor. And graph 902C is the electric field strength delivered to tumor location 902-1B, i.e., the electric field strength delivered by a central portion of the transducer placed at a location on the subject's body near the tumor. When the transducer length is 100 mm or less, the electric field strengths of the outer and central portions of the transducer are approximately the same. When the transducer length is more than 100 mm, the electric field strength of the central portion of the transducer remains approximately the same, while the electric field strength of the outer periphery increases significantly. Therefore, if the tumor is located at a distance from the surface of the subject's body that is less than or equal to the distance of position 1B relative to the surface of the subject's body, a higher electric field output can be delivered to the tumor by placing a portion of the periphery of the transducer at a location on the subject's head near the tumor.

[0072] FIG. 9D is a graph of the electric field strength delivered to tumor locations 901-2B and 902-2B as a function of transducer length. In FIG. 9D, graph 901D is the electric field strength delivered to tumor location 901-2B, i.e., the electric field strength delivered by a portion of the outer periphery of the transducer placed at a location on the subject's body near the tumor. And graph 902D is the electric field strength delivered to tumor location 902-2B, i.e., the electric field strength delivered by a central portion of the transducer placed at a location on the subject's body near the tumor. In the example shown in FIG. 9D, the electric field strengths of the outer and central portions of the transducer are nearly identical. (Note that the y-axis scale of FIG. 9D is different from the y-axis scale of FIG. 9C.) Furthermore, as the transducer length increases, the electric field strength of the former portion of the outer periphery increases, except when the transducer length is between 100 and 120 mm. Furthermore, as the length of the transducer increases, the electric field strength at the center of the transducer increases, so that if a tumor is located at a distance from the surface of the subject's body similar to the distance of location 2B from the surface of the subject's body, placing a portion of the periphery of the transducer at a location on the subject's head near the tumor or placing the center of the transducer at a location on the subject's head near the tumor may result in a similar electric field output to the tumor.

[0073] FIG. 9E is a graph of the electric field strength delivered to tumor locations 901-3B and 902-3B as a function of transducer length. In FIG. 9E, graph 901E is the electric field strength delivered to tumor location 901-3B, i.e., the electric field strength delivered by a portion of the periphery of the transducer placed at a location on the subject's body near the tumor. And graph 902E is the electric field strength delivered to tumor location 902-3B, i.e., the electric field strength delivered by a central portion of the transducer placed at a location on the subject's body near the tumor. In the example shown in FIG. 9E, the electric field strengths at the periphery and central portions of the transducer are approximately the same. (Note that the y-axis scales of FIG. 9D, FIG. 9E, and FIG. 9F are different from the y-axis scale of FIG. 9C.) Furthermore, as the length of the transducer increases, the electric field strength at the former portion of the periphery of the transducer and the electric field strength at the central portion of the transducer increase. Therefore, if a tumor is located at a distance from the surface of the subject's body similar to the distance of location 3B from the surface of the subject's body, the electric field output delivered to the tumor may be similar whether a portion of the periphery of the transducer is placed at a location on the subject's head near the tumor, or a central portion of the transducer is placed at a location on the subject's head near the tumor.

[0074] FIG. 9F is a graph of the electric field strength delivered to tumor locations 901-4B and 902-4B as a function of the transducer length. In FIG. 9F, graph 901F is the electric field strength delivered to tumor location 901-4B, i.e., the electric field strength delivered by a portion of the periphery of the transducer placed at a location on the subject's body near the tumor. And graph 902F is the electric field strength delivered to tumor location 902-4B, i.e., the electric field strength delivered by a central portion of the transducer placed at a location on the subject's body near the tumor. In the example shown in FIG. 9F, the electric field strength at the portion of the periphery of the transducer is lower than the electric field strength at the central portion of the transducer. Furthermore, as the transducer length increases, the electric field strength at the central portion of the transducer increases, while the electric field strength at the former portion of the periphery of the transducer decreases. Therefore, if the tumor is located at a distance from the surface of the subject's body that is greater than or equal to the distance of position 4B relative to the surface of the subject's body, a higher electric field output can be delivered to the tumor by placing the central portion of the transducer at a location on the subject's head near the tumor.

[0075] When considering Figures 9C-9F together, note that the y-axis scale is slightly different in Figure 9C. Whereas in Figures 9D-9F the field strength data is generally between 1.5-2.5 V / cm, curve 901C in Figure 9C shows a significant field strength of >6 V / cm for the edge-positioned transducer. That is, by far the most significant effect is seen for the edge-positioned transducer applying the field to the tumor at location 901-1B, which is the closest location to the body surface. However, this effect is only evident when the transducer length is 110 mm or greater. Figures 7A and 7B illustrate this effect qualitatively. Figure 7A shows that shorter length transducers (L<110 mm) do not produce an edge effect, i.e., the charge is evenly distributed along the length of the transducer and there is no shorter path for the current to travel than through the center of the head. On the other hand, Figure 7B shows the case of a longer length transducer (L>110mm) which does not produce edge effects: a higher charge concentration is located at the edges of the transducer, and furthermore there is a shorter path for the current to flow from one transducer to the other (from one edge to the other) than through the center of the head. Thus, with a longer transducer there is a higher electric field strength at the edges of the transducer than with a shorter transducer.

[0076] 10 illustrates an example of an apparatus 1000 for implementing the methods discussed herein. In this example, the apparatus 1000 includes one or more processors 1002, one or more output devices 1006, a memory 1003, and one or more user input devices 1005.

[0077] The one or more processors 1002 may comprise a general purpose processor, an integrated circuit, a server, other programmable logic devices, or any combination thereof. The processor may be a conventional processor, a microprocessor, a controller, a microcontroller, or a state machine. The one or more processors may be one, two, or more processors of the same or different types. Additionally, the one or more processors may be computers, computing devices, user devices, and the like.

[0078] The memory 1003 is accessible by the one or more processors 1002 via link 1004 to allow the one or more processors 1002 to read and write information from and to the memory 1003. In one example, one or more user inputs collected by one or more user input devices 1005 are processed by the one or more processors 1002 and stored in the memory 1003. The memory may be integral to the processor or may be separate from the processor. Examples of the memory 1003 include RAM, flash, ROM, EPROM, EEPROM, registers, disk storage, or any other form of storage media. The memory 1003 may store instructions that, when executed by the one or more processors 1002, facilitate the implementation of one or more embodiments of the present invention or instructions that facilitate the implementation of one or more embodiments of the present invention by the one or more processors 1002. The memory 1003 may be a non-transitory computer-readable medium that stores instructions that, when executed by a computer, prompt the computer to perform one or more of the example methods discussed herein.

[0079] In one example, based on one or more inputs 1001, the one or more processors select at least one of a plurality of portions of the perimeter and / or a plurality of orientations of the transducer to deliver a tumor treating electric field to the subject's body. The one or more inputs 1001 may include image data and / or user input. The one or more user inputs 1001 may be received via one or more input devices 1005. The selected at least one of the plurality of portions of the perimeter and / or the plurality of orientations may be output at one or more output devices 1006 of the apparatus 1000.

[0080] Example Embodiments The present invention includes other exemplary embodiments, such as the following.

[0081] Exemplary embodiment 1. A computer-implemented method for determining a location of a transducer on a subject's body to apply a tumor-treating electric field, the method including the steps of: determining a near-surface portion of a tumor in the subject's body, the near-surface portion of the tumor being closer to the surface of the subject's body than other portions of the tumor; determining a near-tumor location on the subject's body, the near-tumor location on the subject's body being closer to the near-surface portion of the tumor than other portions of the subject's body; determining an outer perimeter of a first transducer of a pair of transducers to be placed on the subject's body to apply the tumor-treating electric field, the first transducer comprising a plurality of electrode elements electrically coupled to each other, the plurality of electrode elements of the first transducer being located within the outer perimeter; and identifying a portion of the outer perimeter of the first transducer to be placed substantially at the near-tumor location on the subject's body.

[0082] Exemplary embodiment 2. The method of exemplary embodiment 1, wherein the near-surface portion of the tumor is located 80 mm or less from a near-tumor location on the subject's body.

[0083] Exemplary embodiment 3. The method of exemplary embodiment 2, wherein the near-surface portion of the tumor is located 66 mm or less from a near-tumor location on the subject's body.

[0084] Exemplary embodiment 4. The method of exemplary embodiment 2, further comprising the steps of determining a central portion of the first transducer centrally located within the outer periphery of the first transducer, and determining the power density at the aforementioned portion of the outer periphery of the first transducer and the power density at the central portion of the first transducer when applying a tumor treating electric field to the subject's body, wherein the power density at the aforementioned portion of the outer periphery of the first transducer is 100% to 300% of the power density at the central portion of the first transducer.

[0085] Exemplary embodiment 5. The method of exemplary embodiment 1, wherein for a line segment having a first endpoint and a second endpoint on both sides of the subject's body and intersecting with a near-surface portion of the tumor, the first endpoint intersects with a location on the subject's body near the tumor, and the distance between the first endpoint and the near-surface portion of the tumor is less than or equal to 50% of the distance between the second endpoint and the near-surface portion of the tumor.

[0086] Exemplary embodiment 6. The method of exemplary embodiment 5, wherein the distance between the first endpoint and the near-surface portion of the tumor is less than or equal to 25% of the distance between the second endpoint and the near-surface portion of the tumor.

[0087] Exemplary embodiment 7. The surface area of ​​the first transducer is 5000 mm 2 The method according to example embodiment 1 is as described above.

[0088] Exemplary embodiment 8. The surface area of ​​the first transducer is 6500 mm 2 The method according to example embodiment 1 is as described above.

[0089] Exemplary embodiment 9. The method of exemplary embodiment 1, wherein a first transducer is configured to be positioned on the subject's body with a side of the first transducer facing the subject's body, and a near-surface portion of the tumor is located substantially within the periphery of the first transducer when viewed perpendicular to the side of the first transducer.

[0090] Exemplary embodiment 10. The method of exemplary embodiment 1, wherein a location near the tumor on the subject's body is located substantially within the periphery of the first transducer and at a distance from the periphery that is less than 10% of the distance from the periphery to the center of gravity of the transducer.

[0091] Exemplary embodiment 11. The method of exemplary embodiment 1, wherein a location near the tumor on the subject's body is located substantially within the periphery of the first transducer and is located at a distance from the periphery that is between 0% and 50% of the distance from the periphery to the center of gravity of the transducer.

[0092] Exemplary embodiment 12. The method of exemplary embodiment 1, wherein a first transducer is configured to be positioned on a subject's body with a side of the first transducer facing the subject's body, and wherein, when viewed perpendicularly to the side of the first transducer, multiple of the electrode elements of the first transducer are peripheral electrode elements that define an outer periphery of the first transducer, and these peripheral electrode elements substantially surround any other electrode elements of the first transducer.

[0093] Exemplary embodiment 13. The method of exemplary embodiment 1, wherein at least one of the electrode elements of the first transducer contacts the aforementioned portion of the outer periphery of the first transducer that will be positioned substantially at a location on the subject's body near the tumor.

[0094] Exemplary embodiment 14. The method of exemplary embodiment 1, wherein the portion of the circumference of the first transducer that will be substantially positioned at a location on the subject's body near the tumor is no more than 20% of the circumference.

[0095] Exemplary embodiment 15. The method of exemplary embodiment 14, wherein the portion of the circumference of the first transducer that will be substantially positioned at a location on the subject's body near the tumor is less than 10% of the circumference.

[0096] Exemplary embodiment 16. The method of exemplary embodiment 1, wherein the perimeter of the first transducer is substantially square, rectangular, regular polygonal, irregular polygonal, circular, elliptical, near-elliptical, oval, or oval.

[0097] Exemplary embodiment 17. The method of exemplary embodiment 1, further comprising the steps of identifying a plurality of portions of a circumference of the first transducer to be positioned substantially at a location on the subject's body near the tumor, selecting at least one of the plurality of portions of the circumference of the first transducer, and outputting the selected at least one of the plurality of portions of the circumference of the first transducer to determine a location of the transducer on the subject's body for applying a tumor treating electric field.

[0098] Exemplary embodiment 18. The method of exemplary embodiment 1, further comprising the steps of identifying a plurality of orientations of the first transducer on the subject's body to substantially position the aforementioned portion of the periphery of the first transducer at a location on the subject's body near the tumor, selecting at least one of the plurality of orientations of the first transducer, and outputting the selected at least one of the plurality of orientations of the first transducer to determine a position of the transducer on the subject's body for applying a tumor treating electric field.

[0099] Exemplary embodiment 19. The method of exemplary embodiment 1, wherein the electrode elements are capacitively coupled to each other.

[0100] Exemplary embodiment 20. The method of exemplary embodiment 1, wherein the electrode elements are not capacitively coupled to each other.

[0101] Exemplary embodiment 21. The method of exemplary embodiment 1, wherein the electrode element comprises a polymer film.

[0102] Exemplary embodiment 22. The method of exemplary embodiment 1, wherein the electrode element comprises a ceramic disc.

[0103] Exemplary embodiment 23 The method of exemplary embodiment 1, wherein the tumor is located within the subject's head.

[0104] Exemplary embodiment 24 The method of exemplary embodiment 1, wherein the tumor is located within the torso of the subject.

[0105] Exemplary embodiment 25. A computer-implemented method for determining a location of a transducer on a subject's body to apply a tumor-treating electric field, the method comprising the steps of: determining an edge of a first transducer of a pair of transducers to be placed on the subject's body to apply the tumor-treating electric field, the first transducer comprising an array of electrode elements electrically coupled to each other; determining a location near the surface of a tumor in the subject's body and a location on the surface of the subject's body that is closest to the tumor; and identifying a segment of the edge of the first transducer that substantially overlaps the location near the surface of the tumor when viewed perpendicularly to a face of the first transducer to be positioned on the subject's body, the segment of the edge being closer to the location near the tumor on the surface of the subject's body than the center of gravity of the first transducer.

[0106] Exemplary embodiment 26. The method of exemplary embodiment 25, wherein when viewed perpendicular to the aforementioned face of the first transducer, a location near the tumor on the surface of the subject's body is located at a distance from the edge of the transducer that is less than 10% of the distance from the edge of the transducer to the center of gravity of the transducer.

[0107] Exemplary embodiment 27. The method of exemplary embodiment 25, wherein when viewed perpendicular to the aforementioned face of the first transducer, a location near the tumor on the surface of the subject's body is located at a distance from the edge of the transducer that is within a range of 0% to 50% of the distance from the edge of the transducer to the center of gravity of the transducer.

[0108] Exemplary embodiment 28. The method of exemplary embodiment 25, wherein a plurality of the electrode elements are peripheral electrode elements that define edges of the first transducer when viewed perpendicular to the aforementioned face of the first transducer, and these peripheral electrode elements substantially surround any other electrode elements of the first transducer.

[0109] Exemplary embodiment 29. Apparatus for determining transducer position on a subject's body for applying a tumor treating electric field. The apparatus comprises one or more processors and a memory accessible by the one or more processors, the memory storing instructions which, when executed by the one or more processors, prompt the apparatus to determine a convex perimeter of a first transducer of a pair of transducers to be placed on the subject's body to apply a tumor treating electric field, the first transducer having an array of electrode elements electrically coupled to each other, the convex perimeter surrounding all of the electrode elements of the first transducer, the convex perimeter contacting at least three of the electrode elements, and when executed by the one or more processors, determine a near-surface location of a tumor within the subject's body, the near-surface location of the tumor being located closer to the surface of the subject's body than other locations of the tumor, and when executed by the one or more processors, identify a near-tumor portion of the convex perimeter of the first transducer to be placed on the subject's body that is located closer to the near-surface location of the tumor than other locations of the first transducer.

[0110] Exemplary embodiment 30. A method of applying a tumor treating electric field to a body of a subject having a tumor, the method including the steps of positioning a first pair of transducers on the body of the subject and a second pair of transducers on the body of the subject, and alternatingly applying a first electric field between the first pair of transducers and a second electric field between the second pair of transducers. A first transducer of a first pair of transducers is configured to be positioned on the subject's body with a side of the first transducer facing the subject's body, the first transducer has a plurality of electrode elements electrically coupled to each other, when viewed perpendicular to the side of the first transducer, a plurality of the electrode elements of the first transducer are peripheral electrode elements that define a convex-shaped periphery of the first transducer, the peripheral electrode elements substantially surround any other electrode elements of the first transducer, the tumor has a near-surface portion of the tumor that is located closer to a near-tumor location on the surface of the subject's body than other portions of the tumor, and the near-tumor portion of the convex-shaped periphery of the first transducer is located closer to the near-surface portion of the tumor than other portions of the first transducer.

[0111] Exemplary embodiment 31. The method of exemplary embodiment 30, wherein the first transducer is positioned such that a location near the tumor on the surface of the subject's body is located substantially within the periphery of the first transducer and at a distance from the periphery that is less than 10% of the distance from the periphery to the center of gravity of the transducer.

[0112] Exemplary embodiment 32. The method of exemplary embodiment 30, wherein the first transducer is positioned such that a location near the tumor on the surface of the subject's body is located substantially within the periphery of the first transducer and at a distance from the periphery that is within a range of 0% to 50% of the distance from the periphery to the center of gravity of the transducer.

[0113] Although the present invention has been disclosed with reference to particular embodiments, numerous modifications, variations, and alterations to the described embodiments are possible without departing from the scope of the invention as defined in the appended claims. Accordingly, the present invention is not limited to the described embodiments, but is intended to have the full scope defined by the language of the appended claims and equivalents thereof. [Explanation of symbols]

[0114] 300 body 301 Tumor 302 Near the surface of tumor 301 303 Line Segments 304 Location near the tumor 305 Second End Point 400A transducer 400B Transducer 401A Board 402A Electrode element 401B Electrode element 402B Conductive Wire 403A Transducer Face 500A transducer 500B Transducer 501A Board 501B Board 502A Electrode element 502-1A~502-8A Electrode elements, peripheral electrode elements 502-B Electrode Element, Non-Ceramic Electrode Element 502-1B~502-8B Electrode elements, non-ceramic electrode elements, peripheral electrode elements 503A Center of gravity of outer peripheral electrode element 503B Outer periphery of transducer 500B 504A Outer periphery of transducer 500A 505A Outer periphery of transducer 500A 506A Electrode element 601A Transducer 601B Transducer 602A Transducer 602B Transducer 603A Transducer 603B Transducer 604A Transducer 604B Transducer 901A Tumor location 901-1B Tumor location 901-2B Tumor location 901-3B Tumor location 901-4B Tumor location 902A Tumor location 902-1B Tumor location 902-2B Tumor location 902-3B Tumor location 902-4B Tumor location 903 Rectangular Transducer 1000 devices 1001 User Input 1002 Processor 1003 Memory 1004 Link 1005 User Input Devices 1006 Output Device

Claims

1. A computer-implemented method for determining the position of a transducer on a subject's body for applying a tumor treatment electric field, comprising: determining a portion near the surface of a tumor within the subject's body, wherein the portion near the surface of the tumor is located closer to the surface of the subject's body than other portions of the tumor; determining a position near the tumor on the subject's body, wherein the position near the tumor on the subject's body is located closer to the portion near the surface of the tumor than other positions on the subject's body; for a first transducer of a pair of transducers to be disposed on the subject's body for applying a tumor treatment electric field, determining an outer peripheral portion of the first transducer, wherein the first transducer comprises a plurality of electrode elements electrically coupled to each other, and the plurality of electrode elements of the first transducer are located within the outer peripheral portion; identifying a portion of the outer peripheral portion of the first transducer that will be substantially disposed at the position near the tumor on the subject's body; and a computer-implemented method.

2. The method according to claim 1, wherein the portion near the surface of the tumor is located at a position 80 mm or less from the position near the tumor on the subject's body.

3. determining a central portion of the first transducer located at the center within the outer peripheral portion of the first transducer; determining the power density at the portion of the outer peripheral portion of the first transducer and the power density at the central portion of the first transducer when applying a tumor treatment electric field to the subject's body; and further comprising: The method according to claim 2, wherein the power density at the portion of the outer peripheral portion of the first transducer is 100% to 300% of the power density at the central portion of the first transducer.

4. Having a first end point and a second end point on both sides of the body of the subject, with respect to a line segment that intersects a portion near the surface of the tumor, the first end point intersects a position near the tumor on the body of the subject, and the distance between the first end point and the portion near the surface of the tumor is 50% or less of the distance between the second end point and the portion near the surface of the tumor, the method according to claim 1.

5. The first transducer is configured to be positioned on the body of the subject in a state where a surface of the first transducer faces the body of the subject. When viewed from a direction perpendicular to the surface of the first transducer, the portion near the surface of the tumor is substantially located within the outer peripheral portion of the first transducer, the method according to claim 1.

6. The position near the tumor on the body of the subject is substantially located within the outer peripheral portion of the first transducer and is located at a distance from the outer peripheral portion that is 0% to 50% of the distance from the outer peripheral portion of the transducer to the center of gravity, the method according to claim 1.

7. The first transducer is configured to be positioned on the body of the subject in a state where a surface of the first transducer faces the body of the subject. When viewed from a direction perpendicular to the surface of the first transducer, a plurality of the electrode elements of the first transducer are peripheral electrode elements that define the outer peripheral portion of the first transducer, and the peripheral electrode elements substantially surround any other electrode element of the first transducer, the method according to claim 1.

8. At least one of the electrode elements of the first transducer contacts a portion of the outer peripheral portion of the first transducer that will be substantially disposed at a position near the tumor on the body of the subject, the method according to claim 1.

9. The portion of the outer peripheral portion of the first transducer that will be substantially disposed at a position near the tumor on the body of the subject is 20% or less of the outer peripheral portion, the method according to claim 1.

10. Identifying a plurality of portions of the outer peripheral portion of the first transducer that will be substantially disposed at a position near the tumor on the body of the subject. Selecting at least one of the plurality of portions of the outer peripheral portion of the first transducer; Outputting the selected at least one of the plurality of portions of the outer peripheral portion of the first transducer to determine the position of the transducer on the body of the subject for applying a tumor treatment electric field; The method according to claim 1, further comprising:

11. Identifying a plurality of orientations of the first transducer on the body of the subject to substantially dispose the portion of the outer peripheral portion of the first transducer at a position near the tumor on the body of the subject; Selecting at least one of the plurality of orientations of the first transducer; Outputting the selected at least one of the plurality of orientations of the first transducer to determine the position of the transducer on the body of the subject for applying a tumor treatment electric field; The method according to claim 1, further comprising:

12. A computer-implemented method for determining the position of a transducer on a subject's body for applying a tumor treatment electric field, Determining an edge of a first transducer of a pair of transducers to be placed on the body of the subject for applying a tumor treatment electric field, the first transducer comprising an array of electrode elements electrically coupled to each other; Determining a position near the surface of a tumor in the subject's body and a position closest to the tumor on the surface of the subject's body; Identifying a segment of the edge of the first transducer that substantially overlaps the position near the surface of the tumor when viewed from a direction perpendicular to a surface of the first transducer to be positioned on the body of the subject, the segment of the edge being closer to the position near the tumor on the surface of the subject's body than the center of gravity of the first transducer; A computer-implemented method comprising:

13. The method according to claim 12, wherein when viewed from the vertical direction with respect to the surface of the first transducer, the position near the tumor on the surface of the subject's body is located at a distance from the edge of the transducer that is 0% to 50% of the distance from the edge of the transducer to the center of gravity of the transducer.

14. A method of applying a tumor treatment electric field to the body of a subject having a tumor, comprising: placing a first pair of transducers on the body of the subject and a second pair of transducers on the body of the subject; alternately applying a first electric field between the first pair of transducers and a second electric field between the second pair of transducers; wherein the first transducer of the first pair of transducers is configured to be positioned on the body of the subject with a surface of the first transducer facing the body of the subject; the first transducer has a plurality of electrode elements electrically coupled to each other; when viewed from a direction perpendicular to the surface of the first transducer, a plurality of the electrode elements of the first transducer are peripheral electrode elements that define a convex-shaped periphery of the first transducer, and the peripheral electrode elements substantially surround any other electrode element of the first transducer; the tumor has a portion near the surface of the tumor that is closer to a position near the tumor on the surface of the subject's body than other portions of the tumor; a method, wherein a portion of the convex-shaped periphery of the first transducer near the tumor is located closer to the portion near the surface of the tumor than other portions of the first transducer.

15. The method according to claim 14, wherein the first transducer is positioned such that the position near the tumor on the surface of the subject's body is substantially located within the outer periphery of the first transducer and at a distance from the outer periphery of the transducer that is 0% to 50% of the distance from the outer periphery to the center of gravity of the transducer.

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