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US-12622748-B2 - Apparatus for application of evanescent waves to biological tissues

US12622748B2US 12622748 B2US12622748 B2US 12622748B2US-12622748-B2

Abstract

There are many devices that are used to deliver electromagnetic energy to biological tissues. However, physical properties of current techniques limit the strength and efficacy of the applied field. This invention introduces a new apparatus for the application of evanescent waves into biological tissue. The apparatus is planar, conformal, and electrically insulated and is comprised of two or more conductive regions spatially separated by a non-conductive gap insulated by low-dielectric constant, non-conductive material. The apparatus is powered by one or more RF voltage sources that can be applied to individual or several conductive regions to create voltage differentials that generate evanescent waves. The apparatus can be used for treating cancer tumors, deep brain stimulation, and other therapeutic purposes.

Inventors

  • Timothy J. Brockett
  • Mehran Matloubian
  • Gregg A. Hollingsworth

Assignees

  • EVANESC THERAPEUTICS, INC.

Dates

Publication Date
20260512
Application Date
20230306

Claims (20)

  1. 1 . An apparatus for an application of a plurality of evanescent waves to at least one biological tissue comprising; an RF voltage source generating an RF signal having a frequency of 100 kHz to 500 kHz at an output, the RF voltage source with the ability to shift phase from 0 to 360 degrees; an electrically conducting wire(s) or RF cable(s) coupled to the output of the RF voltage source; a pair of planar conductive regions configured at a voltage differential within a local region in a vicinity of a spatial volume and the configuration of the pair of planar conductive regions being spatially separated by a non-conductive gap that generates the plurality of evanescent waves within the spatial volume and the configuration reduces a formation of one or more travelling waves within the spatial volume such that a ratio of evanescent waves to travelling waves is more than ten to one and less than ten thousand to one, each of the pair of planar conductive regions comprising an overlying insulating material of a low dielectric constant material, the low dielectric material having a dielectric constant ranging from 1 to 10; and an electric field distribution caused from the configuration of the planar conductive regions and characterizing the spatial volume, such that the spatial volume that is spatially positioned within a vicinity of a biological tissue provides a higher strength electric field than a region outside of the spatial volume such that the higher strength electric field ranges from 10 times to 105 times of a lower strength electric field in the region outside of the spatial volume.
  2. 2 . The apparatus of claim 1 wherein the pair of planar conductive regions is configured as an evanescent wave generator.
  3. 3 . The apparatus of claim 1 wherein the pair of planar conductive regions is configured to deliver RF energy to the biological tissue via a plurality of reactive fields, a plurality of near field radiative waves, or a plurality of attenuating traveling waves, or any combination thereof.
  4. 4 . The apparatus in claim 1 wherein the pair of planar conductive regions comprises a copper, an aluminum, a conductive thread, and/or a conductive ink.
  5. 5 . The apparatus in claim 1 wherein the insulating material comprises a plastic, a polyimide, a cotton, a nylon, a polyester, a polypropylene, a silk, a cellulose material, and/or a silicone.
  6. 6 . The apparatus in claim 1 wherein the configuration of the pair of planar conductive regions is conformal to the biological tissue.
  7. 7 . The apparatus in claim 1 wherein the insulating material primarily allows a tangential component of the electric field distribution to be incident upon the biological tissue and blocks a normal component of the electric field distribution from being incident upon the biological tissue.
  8. 8 . The apparatus in claim 1 wherein the apparatus can be used for treating cancer tumors, deep brain stimulation, drug sensitizing, blood-brain barrier suppression, and/or other therapeutic purposes.
  9. 9 . The apparatus in claim 1 wherein the RF voltage source has a frequency range from 100 kHz to 300 kHz.
  10. 10 . The apparatus in claim 1 wherein more than one RF frequency is provided simultaneously or sequentially.
  11. 11 . The apparatus in claim 1 wherein the output of the RF voltage source is differential, amplitude modulated, or frequency modulated, or pulse-width modulated.
  12. 12 . The apparatus in claim 1 further comprising an impedance matching network coupled between the RF voltage source and the pair of planar conductive regions to couple the RF energy efficiently to the biological tissue.
  13. 13 . The apparatus in claim 1 wherein the biological tissue is a solid tumor cancer.
  14. 14 . The apparatus in claim 1 wherein the plurality of evanescent waves are applied with other cancer treatments including radiation therapy, chemotherapy, immunotherapy, and surgery.
  15. 15 . The apparatus of claim 1 wherein the configuration of the pair of planar conductive regions are adjacent within a plane or are vertically stacked, or a first conductive region is placed within an angle of a second conductive region.
  16. 16 . An apparatus for an application of a plurality of evanescent waves to at least one biological tissue comprising; a plurality of RF voltage sources each of which is generating an RF signal having a frequency of 50 kHz to 50 MHz at an output; each of the plurality of RF voltage sources with the ability to shift phase from 0 to 360 degrees; an electrically conducting wire(s) or RF cable(s) coupled to the output of each of the plurality of RF voltage sources; a plurality of planar conductive regions configured at a voltage differential within a local region in a vicinity of a spatial volume and the configuration of the plurality of planar conductive regions being spatially separated by a non-conductive gap that generates the plurality of evanescent waves within the spatial volume and the configuration reduces a formation of one or more travelling waves within the spatial volume such that a ratio of evanescent waves to travelling waves is more than ten to one and less than ten thousand to one, each of the plurality of planar conductive regions comprising an overlying insulating material of a low dielectric constant material, the low dielectric material having a dielectric constant ranging from 1 to 10; and an electric field distribution caused from the configuration of the plurality of planar conductive regions and characterizing the spatial volume, such that the spatial volume that is spatially positioned within a vicinity of a biological tissue provides a higher strength electric field than a region outside of the spatial volume such that the higher strength electric field ranges from 10 times to 105 times of a lower strength electric field in the region outside of the spatial volume.
  17. 17 . The apparatus of claim 16 wherein the planar conductive regions delivers RF energy to the biological tissue via a plurality of reactive fields, a plurality of near field radiative waves, or a plurality of attenuating traveling waves, or any combination thereof.
  18. 18 . The apparatus in claim 16 wherein the planar conductive regions comprises a copper, an aluminum, a conductive thread, or a conductive ink.
  19. 19 . The apparatus in claim 16 wherein the insulating material comprises a plastic, a polyimide, a cotton, a nylon, a polyester, a polypropylene, a silk, a cellulose material, and/or a silicone.
  20. 20 . The apparatus in claim 16 wherein the arrangement of the planar conductive regions and the insulating material are conformal to the biological tissue.

Description

CROSS-REFERENCES TO RELATED APPLICATIONS This application is a continuation in part and claims priority to U.S. Ser. No. 17/080,708 filed Oct. 26, 2020, and is a continuation in part and claims priority to U.S. Ser. No. 17/539,968 filed Dec. 1, 2021, which is a continuation of U.S. Ser. No. 16/183,427 filed Nov. 7, 2018 (now U.S. Pat. No. 11,213,349 B2), which claims priority to U.S. Provisional Patent Application No. 62/582,788, filed Nov. 7, 2017, each of which is commonly assigned is hereby incorporated by reference in its entirety. STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT NOT APPLICABLE REFERENCE TO A “SEQUENCE LISTING,” A TABLE, OR A COMPUTER PROGRAM LISTING APPENDIX SUBMITTED ON A COMPACT DISK NOT APPLICABLE BACKGROUND OF THE INVENTION Electromagnetic fields have shown to cause biological response in many types of tissues and its application is common in many therapeutic, medical, and scientific procedures. Applications of these fields are accomplished with many different devices such as electrodes, coils, capacitive plates, among others. Each of these devices are typically powered by a connected or wireless source, where voltage, current, and/or electromagnetic waves are produced then coupled to the device and subsequently the tissue. Common devices used to couple electromagnetic energy into tissues include electrodes, helical coils or spirals, capacitive plates, and antennas such as waveguides, horns, monopoles/dipoles, etc. Usually employed for diagnostics and monitoring, these devices are becoming more common in treatment of both acute and chronic diseases and conditions, such as solid tumor cancer treatment (U.S. Pat. Nos. 4,822,470 and 7,599,746 B2), depression and neurodegenerative conditions (U.S. Pat. Nos. 8,911,342 B2; and 9,433,797 B2), and other ailments. The most widely used devices are direct electrodes. Electrodes are conductive pads that, in conjunction with conductive gel, create a direct ohmic contact with the skin. They are typically connected to their electrical source by wires. When powered by a voltage source and a complete electric circuit is closed, electrical current passes directly through the tissues traveling from one electrode to the others, depending on the wiring configuration. Consequently, the voltage applied to the electrodes needs to be limited, as there is a risk of damaging the tissue due to high electrical currents or electrical disruption of biological processes such as in the heart or brain. Coil devices, including helical coils, spirals, and loops are often deployed in diagnostic tools such as MRIs, wireless charging systems for medical devices such as pacemakers, and some treatment/therapeutic devices such as seen in U.S. Pat. No. 10,046,172 B2. To operate these devices, a current is driven through the coil which produces a magnetic field that will penetrate any tissue within the coil. Any electrical response of the tissue by this field is induced within the tissue based on the electrical and magnetic properties of the tissue. Often, high current in the coil (and its resultant strong magnetic field) is required to observe a response in the tissue, requiring large coils, expensive magnetics, and powerful electrical sources. Capacitive plates operate like electrodes, however, in general they are placed directly across from one another with the tissue in between. In addition, capacitive plates are insulated from the skin by non-conductive material such as plastic, silicone, or ceramic. Capacitive plates are primarily used to create an electric field within the tissue, whose strength is determined by voltage differential applied to the plates, the distance between the capacitive plates, the dielectric properties of the insulating layer, and the dielectric properties of the tissue. In some designs of capacitive plates, it is possible to induce large amounts of electrical current, which can damage the tissue in a similar manner to the direct electrodes. As with the electrodes, this can limit the voltage level that can be applied to the plates, reducing the maximum strength of the electric field and likely reducing the efficacy of the treatment or measurement. Other devices to couple electromagnetic energy include waveguides (U.S. Pat. No. 6,813,515 B2), antennas, and coupled wires (U.S. Pat. No. 4,822,470). In typical waveguides and antennas, a resonant structure is used to propagate traveling electromagnetic waves to be incident on the tissue, where, depending on the tissue's dielectric properties, energy is absorbed. In this case, the waveguide and antennas are usually separated by a significant gap or insulator. In many cases of applying electromagnetic fields to biological tissue, it is imperative to be able to control the locality, strength, and direction/polarization of the fields. An example is in cancer tumor treatment (U.S. Pat. No. 7,805,201 B2), where a localized tumor must be illuminated with a certain s