Optimization of composite electrodes

Abstract

[0003] An apparatus and method for imposing an electric field through a target region within a patient's body are described. The apparatus includes a sensor array having a plurality of temperature sensors, wherein a first plurality of temperature sensors of the sensor array are connected to a first conductor and a second plurality of temperature sensors are connected to a second conductor. A circuit is configured to provide a known amount of electricity via the first conductor and the second conductor to a third temperature sensor, the third temperature sensor being within the first plurality of temperature sensors and the second plurality of temperature sensors.

Description

[Technical Field]

[0001] Cross-Reference to Related Applications / Incorporation-by-Reference Statement This patent application claims priority to the provisional application identified by U.S. Serial No. 63 / 128,265, filed December 21, 2020, the entire contents of which are incorporated herein by reference.

[0002] STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT Not applicable. [Background technology]

[0003] Tumor Treating Fields (TTFields or TTFs) are low-intensity (e.g., 1-3 V / cm) alternating electric fields in the mid-frequency range (50 kHz to 1 MHz) that target solid tumors by disrupting mitosis. This non-invasive treatment targets solid tumors and is described, for example, in U.S. Patent Nos. 7,016,725, 7,089,054, 7,333,852, 7,565,205, 8,244,345, 8,715,203, 8,764,675, 10,188,851, and 10,441,776. TTFields are typically delivered via two pairs of transducer arrays that generate perpendicular fields within the tumor being treated, with the transducer arrays comprising each pair positioned on opposite sides of the body part being treated. More specifically, for the OPTUNE® system, one pair of electrodes of the transducer array is placed on the left and right (LR) sides of the tumor, and the other pair of electrodes is placed on the anterior-posterior (AP) side of the tumor. TTFields are approved for the treatment of glioblastoma multiforme (GBM) and can be delivered, for example, via the OPTUNE® system (Novocure Limited, St. Helier, Jersey), which includes a transducer array placed on the patient's shaved head.

[0004] Each transducer array used for TTFields delivery in the OPTUNE® device comprises a set of non-conductive ceramic disc electrodes that are coupled to a patient's skin (such as, but not limited to, a patient's shaved head for the treatment of GBM) via a layer of conductive medical gel. To form the ceramic disc electrodes, a conductive layer is formed on the top surface of the non-conductive ceramic material. The bottom surface of the non-conductive ceramic material is bonded to the conductive medical gel. The non-conductive ceramic material is a safety feature to ensure that direct current signals are prevented from being unintentionally transmitted to the patient. By inserting a non-conductive ceramic material between the conductive layer and the conductive medical gel, prior art systems have believed that this ensures that the patient remains protected. The purpose of the medical gel is to conform to the contours of the body and provide good electrical contact between the array and the skin, thus bridging the gel interface and reducing interference. The device is intended to be worn continuously by the patient for 2-4 days, then removed for hygienic care and re-shaving (if necessary), after which a new set of arrays is reapplied. Thus, the medical gel remains in substantially continuous contact with an area of ​​a patient's skin for 2-4 days at a time, with only a short period of time during which the area of ​​skin is uncovered and exposed to the environment before further application of medical gel is made.

[0005] One approach to applying TTFields in different directions is to apply the fields between a first set of electrodes for a period of time, then apply the fields between a second set of electrodes for a period of time, and then repeat the cycle for an extended duration (e.g., over several days or weeks).

[0006] To generate TTFields, an electrical current is applied to each electrode of the transducer array. Application of the electrical current over a period of time can cause each electrode to warm up and eventually heat up, which can be uncomfortable or painful for the patient. Therefore, the amplitude of the alternating current delivered through the transducer array can be controlled so that the skin temperature (measured at the skin beneath the transducer array) does not exceed a safety threshold (e.g., 41 degrees Celsius). Temperature measurements at the patient's skin are obtained using temperature sensors (e.g., thermistors) positioned under some of the disks of the transducer array. For example, each array can include eight thermistors, one thermistor positioned under each disk in the array.

[0007] The thermistors in each array are connected via long wires to an electronic device called a "cable box," where the temperatures from all the thermistors (e.g., 4 arrays x 8 thermistors per array) are measured and analog-to-digital converted to digital values ​​for each thermistor. These measurements are then transmitted from the cable box to the field generator via additional wires that facilitate bidirectional digital serial communication between the cable box and the field generator. A controller within the field generator uses the temperature measurements to control the current to be delivered through each pair of arrays to maintain a temperature at the patient's skin below, for example, 41 degrees Celsius. The current itself is delivered to each array via additional wires (i.e., one wire for each array) that run from the field generator through the cable box to the arrays. However, attaching the temperature sensors and transducer arrays to the patient is cumbersome due to the amount of wires. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] U.S. Patent No. 7,016,725 [Patent Document 2] U.S. Patent No. 7,089,054 [Patent Document 3] U.S. Patent No. 7,333,852 [Patent Document 4] U.S. Patent No. 7,565,205 [Patent Document 5] U.S. Patent No. 8,244,345 [Patent Document 6] U.S. Patent No. 8,715,203 [Patent Document 7] U.S. Patent No. 8,764,675 [Patent Document 8] U.S. Patent No. 10,188,851 [Patent Document 9] U.S. Patent No. 10,441,776 Summary of the Invention [Means for solving the problem]

[0009] In some embodiments, a device for imposing an electric field through a target region within a patient's body is described. The device may include at least one transducer array, a sensor array, a circuit, and a controller. The at least one transducer array has a plurality of electrode elements configured for placement on the patient's body, the electrode elements configured to provide TTFields via an alternating current waveform. The sensor array has a plurality of temperature sensors disposed in proximity to the plurality of electrode elements, with a first plurality of temperature sensors connected to a first conductor and a second plurality of temperature sensors connected to a second conductor. The circuit is configured to provide a known amount of electricity via the first conductor and the second conductor to a third temperature sensor, the third temperature sensor being within the first plurality of first temperature sensors and the second plurality of second temperature sensors, and the circuit is configured to obtain a first electrical reading corresponding to a first temperature reading of the third temperature sensor. The controller adjusts the alternating current waveform based on the first temperature reading. [Brief explanation of the drawings]

[0010] [Figure 1]FIG. 1 is a block diagram of an exemplary system for measuring the temperature of a transducer array applying TTFields to a patient's body in accordance with the present disclosure. [Figure 2] FIG. 2 is a schematic diagram of an exemplary hub for use in the system shown in FIG. 1 according to the present disclosure. [Figure 3] FIG. 2 is a schematic diagram of an exemplary distal circuit for use in the system shown in FIG. 1 according to the present disclosure. [Figure 4A] 2 is a schematic diagram of an exemplary embodiment of a sensor array for use in the system shown in FIG. 1 in accordance with the present disclosure. [Figure 4B] 2 is a schematic diagram of an exemplary embodiment of a sensor array for use in the system shown in FIG. 1 in accordance with the present disclosure. [Figure 4C] 2 is a schematic diagram of an exemplary embodiment of a sensor array for use in the system shown in FIG. 1 in accordance with the present disclosure. [Figure 5] 2 is a schematic diagram of another exemplary embodiment of a sensor array for use in the system shown in FIG. 1 in accordance with the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0011] Before describing in detail at least one embodiment of the inventive concept in exemplary language and results, it should be understood that the inventive concept is not limited in its application to the details of construction and the arrangement of components set forth in the following description. The language used herein is intended to be accorded the broadest possible scope and meaning, and the embodiments are intended to be illustrative and not exhaustive.

[0012] Unless otherwise required by context, singular terms shall include pluralities and plural terms shall include the singular.

[0013] All patents, published patent applications, and non-patent publications referenced in any portion of this application are expressly incorporated herein by reference in their entirety to the same extent as if each individual patent or publication was specifically and individually indicated to be incorporated by reference. As utilized in accordance with the present disclosure, the following terms, unless otherwise indicated, shall be understood to have the following meanings:

[0014] When used in conjunction with the term "comprising" in the claims and / or specification, the use of the terms "a" or "an" may mean "one," but is also consistent with the meanings of "one or more," "at least one," and "one or more." Thus, the terms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to a "compound" may refer to one or more compounds. The term "plurality" refers to "two or more."

[0015] Use of the term "at least one" will be understood to include not only one, but any quantity of two or more. Additionally, use of the term "at least one of X, Y, and Z" will be understood to include X alone, Y alone, and Z alone, as well as any combination of X, Y, and Z. Use of ordinal terminology (i.e., "first," "second," "third," "fourth," etc.) is solely for the purpose of distinguishing between two or more items and is not intended to imply, for example, any sequence or order or importance of one item relative to another item, or any ordering of additional items.

[0016] The use of the word "or" in the claims is used to mean an inclusive "and / or" unless explicitly stated to refer to only alternatives or unless the alternatives are mutually exclusive. For example, a condition "A or B" is satisfied by any of the following: A is true (or exists) and B is false (or does not exist), A is false (or does not exist) and B is true (or exists), and both A and B are true (or exist).

[0017] As used herein, any reference to "one embodiment," "embodiment," "some embodiments," "one example," "for example," or "one example" means that a particular element, feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment.

[0018] Throughout this application, the term "about" is used to indicate that a value includes the inherent variation of apparatus / device error, the method used to determine the value, or the variation that exists among study subjects.

[0019] As used in this specification and claims, the words "comprising" (and any variations of comprising, such as "comprises" and "comprises"), "having" (and any variations of having, such as "have" and "have"), "including" (and any variations of including, such as "include" and "includes"), or "containing" (and any variations of containing, such as "contains" and "containing") are inclusive or open-ended and do not exclude additional, unrecited elements or method steps.

[0020] As used herein, the term "or combinations thereof" refers to all permutations and combinations of the items listed before the term. For example, "A, B, C, or combinations thereof" is intended to include at least one of A, B, C, AB, AC, BC, or ABC, and also BA, CA, CB, CBA, BCA, ACB, BAC, or CAB, if the order is useful in the particular context.

[0021] As used herein, the term "substantially" means that the subsequently described event or circumstance occurs entirely, or that the subsequently described event or circumstance occurs to a significant extent or degree. For example, when referring to a particular event or circumstance, the term "substantially" means that the subsequently described event or circumstance occurs with at least an 80% probability, or at least an 85% probability, or at least a 90% probability, or at least a 95% probability. For example, the term "substantially adjacent" means that two items are 100% adjacent to each other, or that two items are very close to each other but not 100% adjacent to each other, or that a portion of one of two items is very close to the other item but not 100% adjacent to the other item.

[0022] As used herein, the term "patient" includes human and veterinary subjects. "Mammal" for purposes of treatment refers to any animal classified as a mammal, including (but not limited to) humans, domestic or farm animals, non-human primates, and any other animal with mammary tissue.

[0023] As used herein, a circuit may be analog and / or digital components, or one or more appropriately programmed processors (e.g., microprocessors) and associated hardware and software, or hardwired logic. Also, a "component" may perform one or more functions. The term "component" may include hardware such as a processor (e.g., microprocessor), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or a combination of hardware and software. As used herein, the term "processor" refers to a single processor or multiple processors functioning independently or jointly to collectively perform a task.

[0024] As discussed above, attaching temperature sensors and transducer arrays to a patient is cumbersome due to the amount of wires. Accordingly, the present inventors have recognized a need for new and improved array assemblies that reduce the number of wires, which may increase patient comfort and reduce costs. It is to such assemblies, as well as methods of making and using the same, that the present disclosure is directed.

[0025] Turning now to the inventive concept, certain non-limiting embodiments thereof are described, including an apparatus for imposing an electric field through a target region within a patient's body. The apparatus may include at least one transducer array, a sensor array, circuitry, and a controller. The at least one transducer array has a plurality of electrode elements configured for placement on the patient's body, the electrode elements configured to provide TTFields via an alternating current waveform. The sensor array has a plurality of temperature sensors disposed in proximity to the plurality of electrode elements, with a first plurality of temperature sensors of the sensor array connected to a first conductor and a second plurality of temperature sensors connected to a second conductor. The circuitry is configured to provide a known amount of electricity via the first conductor and the second conductor to a third temperature sensor, the third temperature sensor being within the first plurality of first temperature sensors and the second plurality of second temperature sensors, and the circuitry is configured to obtain a first electrical reading corresponding to a first temperature reading of the third temperature sensor. The controller adjusts the alternating current waveform based on the first temperature reading.

[0026] Referring now to the drawings, and particularly to FIGS. 1 and 2, there is shown a block diagram of an exemplary embodiment of a system 10 having one or more circuits 12. The circuits 12 are described herein, by way of example, as one or more distal circuits 12 positioned in close proximity to one or more transducer arrays 14 to obtain one or more temperature readings from one or more temperature sensors 16. Each of the transducer arrays 14 includes one or more electrode elements 18. Alternative structures for the transducer array 14 may also be used, including, for example, transducer arrays using non-disk-shaped ceramic elements and / or transducer arrays using non-ceramic dielectric materials disposed on multiple flat conductors. Examples of the latter include polymer films disposed on pads on a printed circuit board or on flat metal strips. Transducer arrays using electrode elements that are not capacitively coupled may also be used. In this situation, each element of the transducer array may be implemented using an area of ​​conductive material configured for placement against a person's body, without an insulating dielectric layer disposed between the conductive element and the body. Examples of conductive materials include, but are not limited to, conductive films, conductive fabrics, and / or conductive foams. Other alternative structures for mounting the transducer array may also be used, so long as they (a) allow for the delivery of TTFields to the human body and (b) utilize the improved connector designs described herein positioned in the locations specified herein. Optionally, in any of the embodiments described herein, a layer of hydrogel may be positioned between the transducer array and the human body.

[0027] One or more temperature sensors 16 are positioned to detect the temperature at the electrode elements 18. In some embodiments, the temperature sensors 16 may be thermistors, thermocouples, resistance temperature detectors (RTDs), integrated circuit temperature sensors such as the Analog Devices AD590 and Texas Instruments LM135, and / or combinations thereof.

[0028] Each distal circuit 12 interfaces with one or more temperature sensors 16 incorporated into a respective transducer array 14 to obtain a temperature reading from each of the one or more temperature sensors 16. The distal circuit 12 may then convert the temperature readings (e.g., from analog to digital), forward the temperature readings, and / or transmit the temperature readings to the hub 20. The hub 20 may then forward the temperature readings and / or transmit the temperature readings to the field generator 22 (e.g., via a serial communication link). In some embodiments, the field generator 22 may determine an adjustment to the current to the transducer array 14 based on the temperature readings.

[0029] In some embodiments, the conductors 30 may extend distally beyond the distal circuitry 12 into the transducer array 14. Each temperature sensor 16 may be connected to at least two conductors 30 such that selective activation of the at least two conductors 30 may activate the temperature sensor 16 to obtain one or more temperature readings (e.g., time-based selective activation).

[0030] Additionally, wiring extending from the distal circuitry 12 may include, but is not limited to, one or more conductors for a common ground for one or more temperature sensors, one or more conductors for the TTFields signal (i.e., AC current for the electrode elements), etc. In some embodiments, the distal circuitry 12 may be implemented using a single-chip microcontroller or programmable system on chip (PSoC) with an integrated analog front end and multiplexer. Part numbers suitable for this purpose include CY8C4124LQI-443, manufactured by Cypress Semiconductor Corp., having principal offices in San Jose, California.

[0031] As one skilled in the art will appreciate, some embodiments may include one or more microcontrollers with integrated and / or separate analog front ends and / or multiplexers. For example, the analog front ends and multiplexers may obtain temperature readings from one or more temperature sensors 16. Those temperature readings may then be digitized and / or transmitted (e.g., via a serial data link) to the hub 20. In some embodiments, each distal circuit 12 may also include one or more through conductors 34 (see FIG. 3 ). The one or more through conductors 34 may be configured to route one or more TTFields signals generated in the field generators 22 to the transducer array 14.

[0032] In some embodiments, each distal circuit 12 may be connected to the hub 20 via one or more cables 36. Conductors 34 in each cable 36 may run between the distal circuit 12 and the hub 20. For example, in FIG. 3, four conductors 34 run between each distal circuit 12 and the hub 20, including one conductor 34 for power (Vcc), one conductor 34 for ground (GND), one conductor for serial data communication (DATA), and one conductor for the TTF signal.

[0033] In general, the hub 20 may receive one or more temperature readings from each of the distal circuits 12 and may transmit one or more temperature readings to the field generator 22. Any of a wide variety of architectures may be used to receive and transmit one or more temperature readings. For example, FIG. 2 shows a controller 40 configured to send a signal to a digital multiplexer (DIGITAL MUX) 42 instructing the digital multiplexer 42 to select one of the distal circuits 12 so that the hub 20 may receive digital data from the distal circuits 12 (e.g., a first distal circuit 12).

[0034] The controller 40 receives one or more temperature readings from selected inputs of the distal circuits 12 and transmits the one or more temperature readings to the field generator 22 via the transceiver 44. The controller 40 may then update the control signal to the digital multiplexer 42 so that the digital multiplexer 42 selects another distal circuit 12 (e.g., the second distal circuit 12). The controller 40 then receives one or more temperature readings from the input of the second distal circuit 12 and transmits the one or more temperature readings to the field generator 22. A corresponding sequence may then be executed to obtain appropriate temperature readings (e.g., nine temperature readings) from each of the distal circuits 12. In some embodiments, the entire sequence, or portions of the sequence, of obtaining each of the one or more temperature readings from each of the distal circuits 12 may be repeated periodically (e.g., every 1 / 100th of a second, every second, every 10 seconds, every 30 seconds, etc.) to update the one or more temperature readings provided to the field generator 22.

[0035] In some embodiments, the controller 40, the digital multiplexer 42, and / or the transceiver 44 may be integrated into a single chip. In some embodiments, the controller 40 and the digital multiplexer 42 may be integrated into a circuit comprising a single chip, and a separate transceiver 44 is used. For example, the controller 40 and the digital multiplexer 42 may be implemented using a Cypress CY8C4244LQI-443 manufactured by Cypress Semiconductor Corp., having principal offices in San Jose, California, and the transceiver 44 may be implemented using a Linear Technology LTC2856CMS8-2#PBF manufactured by Linear Technology Corp., having principal offices in Milpitas, California. The controller 40 and / or the digital multiplexer 42 may be implemented as a processor executing software to perform the functions described herein.

[0036] Hub 20 may communicate with field generator 22 using any conventional communication technique (e.g., RS485). In some embodiments, hub 20 may include one or more feedthrough conductors configured to pass one or more TTFields signals directly from field generator 22 to each of transducer arrays 14. In some embodiments, hub 20 may communicate with field generator 22 via an eight-conductor spiral cable 50, optionally connecting via connector 21 (FIG. 1). For example, hub 20 may communicate with field generator 22 via eight-conductor spiral cable 25, where four wires (e.g., P1, P2, N1, N2) may provide the TTFields signal from each transducer array 14, one wire may provide ground (GND), one wire may provide voltage (Vcc) to distal circuitry 12, and two wires may provide communication (RS485A and RS485B). It should be understood that the use of the eight-conductor spiral cable 50 is configured to be backward compatible with previous versions of TTFields delivery systems within the art, as will be understood by those skilled in the art.

[0037] Communication wires may be configured to carry data communication (i.e., for temperature data) between distal circuitry 12, hub 20, and field generator 22. In some embodiments, one wire may be configured to carry communication in each direction. In some embodiments, the total number of wires between hub 20 and field generator 22 may be reduced by replacing multiple data communication wires with a single data wire that implements bidirectional communication (using a conventional single-wire communication protocol).

[0038] FIG. 3 is a schematic diagram of an exemplary distal circuit 12 for interfacing a hub 20 with one or more transducer arrays 14. Each transducer array 14 may include one or more electrode elements 18 and one or more temperature sensors 16 (e.g., 16a-i in FIG. 3 ) positioned to sense the temperature of the one or more electrode elements 18. The one or more temperature sensors 16 may include, but are not limited to, thermistors, thermocouples, RTDs, integrated circuit temperature sensors such as the Analog Devices AD590 and Texas Instruments LM135, and / or combinations thereof. Any temperature sensor 16 known in the art may be used if configured to provide accurate and / or precise temperature readings in accordance with the present disclosure. In some embodiments, the one or more temperature sensors 16 may be thermistors.

[0039] The distal circuit 12 may include a first multiplexer (MUX1) 60a and a second multiplexer (MUX2) 60b. Generally, the first multiplexer 60a drives a known amount of electricity (e.g., current) to one or more temperature sensors 16, and the second multiplexer 60b electrically connects the one or more temperature sensors 16 to a reference point (e.g., GND).

[0040] The first multiplexer 60a includes an output 62a and one or more selectable inputs 64a. Each of the one or more selectable inputs 64a may be connected to two or more temperature sensors 16. Similarly, the second multiplexer 60b includes an output 62b and one or more selectable inputs 64b. Each of the one or more selectable inputs 64b may be connected to two or more temperature sensors 16. To that end, each temperature sensor 16 may be connected to at least two conductors 30. At least one terminal 64c may be a common ground. In some embodiments, the output 62a of the first multiplexer 60a may be provided to an input 66 of an amplifier 68 (e.g., an amplifier having a high input impedance, such as an operational amplifier configured as a voltage follower). An output 70 of the amplifier 68 may be provided to an input 72 of an analog-to-digital converter (ADC) 74. An output 76 of the analog-to-digital converter is provided to an input 78 of a controller 80. Controller 80 may include circuitry including, but not limited to, a processor that executes computer-executable instructions, eg, software, to perform the functions described herein.

[0041] In some embodiments, controller 80 may be configured to coordinate the operation of one or more of the components within dashed line 82. Controller 80 may be configured to send one or more commands to first multiplexer 60a and second multiplexer 60b to select two or more conductors 30 in communication with one of temperature sensors 16 to obtain a temperature reading from the temperature sensors 16. In some embodiments, first multiplexer 60a and second multiplexer 60b are configured to provide an open circuit for unselected conductors 30 such that only a particular one of temperature sensors 16 is read at any particular moment.

[0042] In some embodiments, a temperature reading may be obtained by routing a known amount of electricity, e.g., current, to the temperature sensor 16 (e.g., a thermistor) through at least two conductors 30 and measuring an electrical reading, e.g., voltage, that appears across the temperature sensor 16. For example, the programmable current source 84 may be configured to generate a known current (e.g., 150 μA) through the at least two conductors 30. The first multiplexer 60 a may be bidirectional so that the known current may be routed to the temperature sensor 16 through the conductor 30 selected by the first multiplexer 60 a.

[0043] 3 and 4A, temperature readings obtained from the temperature sensors 16 in the sensor array 90a may be obtained using selective activation of at least two conductors 30. For example, the first plurality of temperature sensors 16a, 16d, and 16g of the sensor array 90a are connected to the first conductor 30a. For example, the second plurality of temperature sensors 16a, 16b, and 16c of the sensor array 90a are connected to the second conductor 30d. The controller 80 sends one or more commands to the first multiplexer 60a and the second multiplexer 60b to select the at least two conductors 30a and 30d that communicate with the third temperature sensor 16a in the sensor array 90a, and configures the current source 84 to generate a known current through the two conductors 30a and 30d. In this example, the third temperature sensor 16a is among the plurality of first temperature sensors (16a, 16d, and 16g) and also among the plurality of second temperature sensors (16a, 16b, and 16c).

[0044] A known current from a current source 84 is configured to flow through the first multiplexer 60a and to the third temperature sensor 16a via the two conductors 30a and 30b connected to the third temperature sensor 16a, resulting in a voltage across the third temperature sensor 16a that appears at the output 62a of the first multiplexer 60a. In some embodiments, the known current from the current source 84 is configured to flow through the first multiplexer 60a and to the third temperature sensor 16a via the two conductors 30a and 30b connected to the third temperature sensor 16a, resulting in a voltage across the third temperature sensor 16a and the output 62a of the first multiplexer 60a. An input 66 of an amplifier 68 receives the voltage across the third temperature sensor 16a, and the amplifier 68 amplifies the voltage and then provides the amplified voltage to an input 72 of an analog-to-digital converter 74. The controller 80 instructs the analog-to-digital converter 74 to digitize the resulting voltage. The controller 80 obtains the digitized resultant voltage reading from the analog-to-digital converter 74, temporarily stores the digitized resultant voltage reading (corresponding to the third temperature sensor 16a) in a buffer, and uses the digitized resultant voltage reading to determine a temperature reading based on the digitized resultant voltage reading. The digitized resultant voltage reading may be referred to herein as a first electrical reading. This procedure may be repeated sequentially for each of the temperature sensors 16 having conductors 30 (i.e., 30a-f) in the sensor array 90a. For example, to obtain a reading from temperature sensor 16b, the controller 80 sends one or more commands to the first multiplexer 60a and the second multiplexer 60b to select at least two conductors 30b and 30d that both communicate with temperature sensor 16b, and configures the current source 84 to generate a known current in the at least two conductors 30b and 30d.A known current from a current source 84 is configured to flow through the first multiplexer 60a, via conductor 30b to temperature sensor 16b, and via conductor 30d to the second multiplexer 60b, resulting in a voltage across temperature sensor 16b that appears at output 62a of the first multiplexer 60a. An input 66 of an amplifier 68 receives the voltage across temperature sensor 16b, which amplifies the voltage and then provides the amplified voltage to an input 72 of an analog-to-digital converter 74. A controller 80 directs the analog-to-digital converter 74 to digitize the resulting voltage. The controller 80 obtains a digitized resultant voltage reading from the analog-to-digital converter 74 and temporarily stores the digitized resultant voltage reading (corresponding to the third temperature sensor 16a) in a buffer, where the digitized resultant voltage reading is used to determine a temperature reading based on the digitized resultant voltage reading. The digitized resultant voltage reading from temperature sensor 16b may be referred to herein as a second electrical reading. Similarly, to obtain a reading from temperature sensor 16h, controller 80 sends one or more commands to first multiplexer 60a and second multiplexer 60b to select at least two conductors 30b and 30f in communication with temperature sensor 16h and configures current source 84 to generate a known current. The known current from current source 84 is configured to flow through first multiplexer 60a, via conductor 30b to temperature sensor 16h, and via conductor 30f to second multiplexer 60b, resulting in a voltage across temperature sensor 16h that appears at output 62a of multiplexer 60a. Controller 80 may pass the first and / or second temperature readings to controller 40 in hub 20, which may communicate with field generator 22 to adjust the AC waveform based on the first and / or second temperature readings.

[0045] It should be understood that additional conductors 30 may be used to increase the number of temperature sensors 16 in the sensor array 90. For example, FIG. 4B shows another exemplary embodiment of a sensor array 90b having thirteen temperature sensors 16a-16m connected to conductors 30a-30h. Selective activation of at least two predetermined conductors 30 can result in a voltage appearing across at least one temperature sensor 16 connected to at least two conductors 30, resulting in a temperature reading as described herein. FIG. 4C shows another exemplary embodiment of a sensor array 90c having twenty temperature sensors 16a-16t connected to conductors 30a-30i. Selective activation of at least two conductors 30 can result in a voltage appearing across the temperature sensors 16 connected to at least two conductors 30, resulting in a temperature reading as described herein.

[0046] FIG. 5 shows another exemplary embodiment of a sensor array 90d that includes a reduced number of conductors 30 (30a-d) relative to the embodiment of FIGS. 4A-4C , but includes multiple electronic switches 92 (92a-h), such as diodes, configured to provide selective activation of one temperature sensor 16 (FIG. 5 shows 16a-h) when two or more temperature sensors 16 are connected to the two conductors 30. In one embodiment, selection of a temperature sensor 16 can be achieved by providing a voltage of a particular polarity across the two conductors 30. Generally, a particular temperature sensor 16 can be activated by providing a positive or negative polarity to a combination of conductors 30. For example, two temperature sensors 16g and 16h are circuit-connected to two conductors 30b and 30d and two electronic switches 92g and 92h. Electronic switch 92g is in series with temperature sensor 16g, and electronic switch 92h is in series with temperature sensor 16h. Electronic switch 92g is configured to conduct based on negative polarity, and electronic switch 92h is configured to conduct based on positive polarity. By applying a positive polarity across conductors 30b and 30d, temperature sensor 16h is activated (and temperature sensor 16g is not activated), and a temperature reading can be provided. By applying a negative polarity across the same conductors 30b and 30d, temperature sensor 16g is activated (and temperature sensor 16h is not activated), and a temperature reading can be provided.

[0047] Referring to FIG. 3 , in some embodiments, a conventional voltage divider approach may be used to interface with one or more temperature sensors 16. In some embodiments, to increase the accuracy and / or precision of temperature readings obtained from one or more temperature sensors 16, additional readings may be obtained and used for self-calibration. For example, in FIG. 3 , at least one input 64c of first multiplexer 60a is connected to ground, and at least one input 64d of first multiplexer 60a is connected to precision resistor 100. Controller 80 may temporarily store digitized readings from precision resistor 100 and ground input 64c in a buffer and / or any memory configured to store data. These additional readings may ultimately be used to calibrate readings obtained from one or more temperature sensors 16. In some embodiments, such calibration may be performed via controller 80. In some embodiments, calibration may occur prior to transmission of digital data corresponding to the temperature readings. In some embodiments, the calibration may be performed in a downstream processor (e.g., controller 40 in hub 20) such that digital data corresponding to precision resistor 100 (and optionally ground input 64) may be transmitted to the downstream processor in addition to any uncalibrated temperature readings obtained from one or more temperature sensors 16.

[0048] In some embodiments, calibration using precision resistor 100 may compare the actual voltage measured across precision resistor 100 to an expected voltage based on Ohm's Law, the known value of precision resistor 100, and the expected value of the current generated by current source 84. The deviation between the actual measured voltage and the expected voltage may be used to determine (e.g., use as a multiplier) subsequent measurements from one or more temperature sensors 16.

[0049] In some embodiments, the controller 80 in the distal circuit 12 may be configured to communicate with the hub 20 via a universal asynchronous receiver-transmitter (UART) 102 and transmit temperature readings obtained from the one or more temperature sensors 16 to the hub 20. In some embodiments, the controller 80 may be a processor programmed to operate autonomously and configured to automatically collect temperature readings from each of the one or more temperature sensors 16, store the results in a buffer as described above, and then transmit the contents of the buffer (i.e., the readings from each of the temperature sensors 16, and optionally additional readings as described herein) to the hub 20.

[0050] In some embodiments, controller 80 may be a processor programmed to operate as a slave to a master controller located in hub 20. For example, controller 80 may begin in a quiescent state where controller 80 solely monitors for incoming commands from the master controller arriving via UART 102. Examples of commands that may arrive from the master controller may include, but are not limited to, a "collect sample" command, a "send data" command, etc. When controller 80 recognizes that a "collect sample" command has arrived, controller 80 may be configured to initiate the methods described herein to obtain one or more temperature readings from one or more temperature sensors 16 and store the results in a buffer and / or any memory configured to store data. In another example, controller 80 may recognize a "send data" command and execute a method to transmit previously collected temperature readings from a buffer and / or memory to hub 20 via UART 102.

[0051] In some embodiments, temperature readings may be synchronized. For example, the controller 40 in the hub 20 may send a "collect sample" command simultaneously or in rapid succession to one or more controllers 80 in the distal circuit 12 so that temperature readings obtained from each of the transducer arrays 14 may be obtained simultaneously or near simultaneously. In some embodiments, temperature readings may be collected by the hub 20 in one or more batches for each controller 80.

[0052] Most systems using TTFields to treat tumors periodically (e.g., every second) switch the direction of the field applied to the tumor. To minimize noise in the temperature measurements, a short time gap can be introduced during which the field is not applied in either direction, and temperature measurements can be taken during the time gap. In some embodiments, a controller 40 located in the hub 20 can synchronize the timing of “collect sample” commands to all controllers 80 so that each of the distal circuits 12 can acquire a temperature reading during the time gap. Temperature readings acquired simultaneously from each transducer array 14 can minimize the duration of the time gap. For example, if the system 10 requires 100 microseconds to acquire a single measurement, acquiring 36 measurements in a sequence (i.e., four distal circuits times nine temperature sensors 16 in each distal circuit 12, etc.) can take 3.6 milliseconds. In contrast, if each of the four distal circuits 12 operates in parallel, each distal circuit 12 can acquire 9 samples in 900 microseconds, such that 36 samples can be acquired in 900 microseconds. It should be noted that the "send data" command may be less sensitive to noise and therefore less time-critical, such that the "send data" command can be executed while the field remains on.

[0053] In some embodiments, some or all of the following components may be implemented by a single integrated circuit: first multiplexer 60a, second multiplexer 60b, amplifier 68, analog-to-digital converter 74, controller 80, UART 102, and current source 84. An example of a single integrated circuit containing all of these functional blocks is the Cypress CY8C4124LQI-443T Programmable System-on-Chip (PSoC) manufactured by Cypress Semiconductor Corp., with principal offices in San Jose, California.

[0054] Embodiments illustrated under any heading or in any portion of this disclosure may be combined with embodiments illustrated under the same or any other heading or other portion of this disclosure. 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.

[0055] The present invention includes other exemplary embodiments as follows.

[0056] Exemplary Embodiment 1. A device for imposing an electric field through a target region within a patient's body, the device comprising: at least one transducer array having a plurality of electrode elements configured for placement on a patient's body, the electrode elements configured to provide TTFields via an alternating current waveform; a sensor array having a plurality of temperature sensors disposed within proximity of a plurality of electrode elements, wherein a first plurality of temperature sensors of the sensor array are connected to a first conductor and a second plurality of temperature sensors are connected to a second conductor; a circuit configured to provide a known amount of electricity via a first conductor and a second conductor to a third temperature sensor, the third temperature sensor being within a first plurality of first temperature sensors and a second plurality of second temperature sensors, the circuit configured to obtain a first electrical reading corresponding to a first temperature reading of the third temperature sensor; a controller that adjusts the AC waveform based on the first temperature reading; An apparatus comprising:

[0057] Exemplary embodiment 2. A circuit comprising: a current source providing a known amount of electricity; a first multiplexer having an input and an output, the first multiplexer being connected to a current source; a second multiplexer having an input and an output, the second multiplexer connected to the reference point; a controller configured to send at least one command to the first multiplexer to select the first conductor and to send at least one command to the second multiplexer to select the second conductor; 10. The apparatus of Exemplary Embodiment 1, further comprising:

[0058] Exemplary Embodiment 3. The apparatus of Exemplary Embodiment 2, wherein the controller is configured to communicate with the current source and instruct the current source to generate a known amount of electricity in the first conductor and the second conductor.

[0059] Exemplary Embodiment 4. The apparatus of Exemplary Embodiment 2, wherein the first electrical reading is taken at an output of the first multiplexer.

[0060] Exemplary Embodiment 5. The apparatus of Exemplary Embodiment 4, wherein the circuitry further comprises an analog-to-digital converter configured to obtain the first electrical reading and to provide a digitized resultant reading corresponding to the first temperature reading of the third temperature sensor.

[0061] Exemplary Embodiment 6. The apparatus of Exemplary Embodiment 5, wherein the circuitry further comprises a buffer configured to store the digitized resultant reading of the third temperature sensor.

[0062] Exemplary Embodiment 7. The apparatus of Exemplary Embodiment 5, wherein the circuitry further comprises an amplifier configured to receive the first electrical reading and provide an amplified voltage to the analog-to-digital converter.

[0063] Exemplary Embodiment 8. The apparatus of any one of Exemplary Embodiments 1 to 7, wherein the known quantity of electricity is a known current, and the sensor array includes at least 12 temperature sensors, each temperature sensor connected to at least two conductors such that providing a known current to the at least two conductors connected to the temperature sensor provides a voltage across the temperature sensor.

[0064] Exemplary Embodiment 9. The apparatus of any one of Exemplary Embodiments 1 to 8, wherein the known quantity of electricity is a known current, and the sensor array includes at least 13 temperature sensors, each temperature sensor connected to two conductors such that providing a current to the two conductors connected to the temperature sensor provides a voltage across the temperature sensor.

[0065] Exemplary Embodiment 10. The apparatus of any one of Exemplary Embodiments 1 to 9, wherein the sensor array includes at least 24 temperature sensors, each temperature sensor connected to two conductors such that providing a known amount of electricity to the two conductors connected to the temperature sensor provides an electrical reading across the temperature sensor.

[0066] Exemplary Embodiment 11. The apparatus of any one of Exemplary Embodiments 1 to 10, wherein the sensor array includes a plurality of electronic switches configured to provide selective activation of the third temperature sensor.

[0067] Exemplary Embodiment 12. The apparatus of Exemplary Embodiment 11, wherein the first electronic switch is disposed in series with the third temperature sensor, and the first electronic switch is configured to conduct when a first predetermined polarity is disposed across the first electronic switch.

[0068] Exemplary Embodiment 13. The apparatus of Exemplary Embodiment 12, wherein a second electronic switch is disposed in series with the fourth temperature sensor such that a negative polarity across the first conductor results in a voltage across the fourth temperature sensor, and wherein the second electronic switch is configured to conduct when a second predetermined polarity is disposed across the second electronic switch.

[0069] Exemplary embodiment 14. A device for imposing an electric field through a target region within a patient's body, the device comprising: at least one transducer array having a plurality of electrode elements configured for placement on a patient's body, the electrode elements configured to provide TTFields via an alternating current waveform; a sensor array having a first temperature sensor and a second temperature sensor, the first temperature sensor of the sensor array being connected to the first conductor and the second conductor, and the second temperature sensor of the sensor array being connected to the first conductor and the third conductor; providing a first known amount of electricity via the first conductor and the second conductor for activation of the first temperature sensor, and providing a second known amount of electricity via the first conductor and the third conductor for activation of the second temperature sensor; obtaining a first electrical reading induced by a first known quantity of electricity and a second electrical reading induced by a second known quantity of electricity; determining a first temperature reading based on the first electrical reading and determining a second temperature reading based on the second electrical reading; With a controller configured as Equipped with The apparatus, wherein the AC waveform is adjusted based on the first temperature reading and the second temperature reading.

[0070] Exemplary Embodiment 15. The apparatus of Exemplary Embodiment 14, wherein the sensor array further comprises a first electronic switch in circuit with the first temperature sensor and a second electronic switch in circuit with the second temperature sensor.

[0071] Exemplary Embodiment 16. The apparatus of Exemplary Embodiment 15, wherein the controller is further configured to provide selective activation of the first electronic switch or the second electronic switch.

[0072] Exemplary Embodiment 17. The apparatus of Exemplary Embodiment 16, wherein the first electronic switch is disposed in series with the first temperature sensor.

[0073] Exemplary Embodiment 18. The apparatus of Exemplary Embodiment 16, wherein a second electronic switch is disposed in series with the second temperature sensor.

[0074] Exemplary Embodiment 19. Providing a first known quantity of electricity via a first conductor and a second conductor to activate a first temperature sensor of a sensor array, the sensor array being positioned proximate to a transducer array having a plurality of electrode elements configured for placement on a patient's body, the electrode elements being configured to provide TTFields via an alternating current waveform; obtaining a first temperature reading induced by activation of a first temperature sensor; providing a second known quantity of electricity via the first conductor and the third conductor to activate a second temperature sensor; obtaining a second temperature reading induced by activation of a second temperature sensor; adjusting the AC waveform based on at least one of the first temperature reading and the second temperature reading; A method comprising:

[0075] Exemplary Embodiment 20. The method of Exemplary Embodiment 19, wherein the step of adjusting the AC waveform is based on a second temperature reading.

[0076] From the foregoing, it will be apparent that the inventive concepts disclosed and claimed herein are not only inherent in the present invention but are also well adapted to carry out the objects and attain the advantages set forth herein. While exemplary embodiments of the inventive concepts have been described for purposes of this disclosure, it will be understood that many modifications may be made which will readily suggest themselves to those skilled in the art and which are accomplished within the spirit of the inventive concepts disclosed and claimed herein. [Explanation of symbols]

[0077] 10 Systems 12 circuits 14 Transducer Array 16 Temperature Sensor 16a First temperature sensor, second temperature sensor, third temperature sensor 16a~16m temperature sensor 16a~16t Temperature sensor 16b Temperature sensor, second temperature sensor 16c Temperature sensor, second temperature sensor 16d First temperature sensor 16g First temperature sensor 16h temperature sensor 18 Electrode Elements 20 Hub 21 Connector 22 Field generator 25 8-conductor spiral cable 30 Conductors 30a first conductor, conductor 30a~30h conductor 30a~30i conductor 30d Second conductor, conductor 30f conductor 34 Through conductor 36 Cable 40 Controller 42 Digital Multiplexer (Digital MUX), Digital Multiplexer 44 Transceiver 50 8 conductor spiral cable 60a First Multiplexer (MUX1), First Multiplexer 60b Second Multiplexer (MUX2), Second Multiplexer 62a Output 62b output 64a input 64b input 64c terminal, input, ground input 64d input 66 inputs 68 Amplifier 70 Output 72 inputs 74 Analog-to-digital converter (ADC), analog-to-digital converter 80 Controller 82 dashed line 84 Programmable Current Source, Current Source 90a Sensor Array 92 Electronic Switch 92a~h Electronic Switch 100 precision resistors 102 Universal Asynchronous Receiver / Transmitter (UART), UART

Claims

1. 1. An apparatus for imposing an electric field through a target region within a patient's body, said apparatus comprising: at least one transducer array having a plurality of electrode elements configured for placement on the body of the patient, the electrode elements configured to provide TTFields via an alternating current waveform; a sensor array having a plurality of temperature sensors disposed within proximity of the plurality of electrode elements, wherein a first plurality of temperature sensors of the sensor array are connected to a first conductor and a second plurality of temperature sensors are connected to a second conductor; a circuit configured to provide a known amount of electricity via the first conductor and the second conductor to a third temperature sensor, the third temperature sensor being within the plurality of first temperature sensors and within the plurality of second temperature sensors, the circuit configured to obtain a first electrical reading corresponding to a first temperature reading of the third temperature sensor; a controller that adjusts the AC waveform based on the first temperature reading; Equipped with The circuit a current source providing the known amount of electricity; a first multiplexer having an input and an output, said first multiplexer being connected to said current source; a second multiplexer having an input and an output, said second multiplexer connected to a reference point; a controller configured to send at least one command to the first multiplexer to select the first conductor and to send at least one command to the second multiplexer to select the second conductor; The apparatus further comprises:

2. 2. The apparatus of claim 1, wherein the controller is configured to communicate with the current source and instruct the current source to generate the known amount of electricity in the first conductor and the second conductor.

3. The apparatus of claim 1 , wherein the first electrical reading is taken at the output of the first multiplexer.

4. 4. The apparatus of claim 3, wherein the circuitry further comprises an analog-to-digital converter configured to take the first electrical reading and provide a digitized resultant reading corresponding to the first temperature reading of the third temperature sensor.

5. 5. The apparatus of claim 4, wherein the circuitry further comprises a buffer configured to store the resulting digitized reading of the third temperature sensor.

6. 5. The apparatus of claim 4, wherein the circuitry further comprises an amplifier configured to receive the first electrical reading and provide an amplified voltage to the analog-to-digital converter.

7. 7. The apparatus of claim 1, wherein the known quantity of electricity is a known current, and the sensor array includes at least 12 temperature sensors, each temperature sensor connected to at least two conductors such that providing the known current to the at least two conductors connected to the temperature sensor provides a voltage across the temperature sensor.

8. 8. The apparatus of claim 1, wherein the known quantity of electricity is a known current, and the sensor array includes at least 13 temperature sensors, each temperature sensor connected to two conductors such that providing a current to the two conductors connected to the temperature sensor provides a voltage across the temperature sensor.

9. 8. The apparatus of claim 1, wherein the sensor array includes at least 24 temperature sensors, each temperature sensor connected to two conductors such that providing the known amount of electricity to the two conductors connected to the temperature sensor provides an electrical reading across the temperature sensor.

10. 8. The apparatus of claim 1, wherein the sensor array comprises a plurality of electronic switches configured to provide selective activation of each temperature sensor.

11. 11. The apparatus of claim 10, wherein a first electronic switch is disposed in series with the third temperature sensor, the first electronic switch being configured to conduct when a first predetermined polarity is disposed across the first electronic switch.

12. The sensor array further comprising a plurality of fifth temperature sensors connected to the first conductor, the plurality of fifth temperature sensors further comprising a fourth temperature sensor connected to the second conductor; 12. The apparatus of claim 11, wherein a second electronic switch is disposed in series with the fourth temperature sensor, the second electronic switch being configured to conduct when a second predetermined polarity opposite the first predetermined polarity is disposed across the second electronic switch.

13. An apparatus for imposing an electric field through a target region within a patient's body, said apparatus comprising: at least one transducer array having a plurality of electrode elements configured for placement on the body of the patient, the electrode elements configured to provide TTFields via an alternating current waveform; a sensor array having a plurality of temperature sensors disposed within proximity of the plurality of electrode elements, wherein a first plurality of temperature sensors of the sensor array are connected to a first conductor and a second plurality of temperature sensors are connected to a second conductor; a circuit configured to provide a known amount of electricity via the first conductor and the second conductor to a third temperature sensor, the third temperature sensor being within the plurality of first temperature sensors and within the plurality of second temperature sensors, the circuit configured to obtain a first electrical reading corresponding to a first temperature reading of the third temperature sensor; a controller that adjusts the AC waveform based on the first temperature reading; Equipped with the sensor array including a plurality of electronic switches configured to provide selective activation of each temperature sensor; a first electronic switch of the plurality of electronic switches disposed in series with the third temperature sensor, the first electronic switch configured to conduct when a first predetermined polarity is disposed across the first electronic switch; the sensor array further includes a plurality of fifth temperature sensors connected to the first conductor, the plurality of fifth temperature sensors further including a fourth temperature sensor connected to the second conductor; the apparatus, wherein a second electronic switch of the plurality of electronic switches is disposed in series with the fourth temperature sensor, the second electronic switch being configured to conduct when a second predetermined polarity opposite the first predetermined polarity is disposed across the second electronic switch.

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