Systems and methods for use and measurement of non-thermal effects of microwave radiation

Patent metadata

Field	Value
Publication number	US-11382188-B2
Application number	US-201816487625-A
Country	US
Kind code	B2
Filing date	Feb 21, 2018
Priority date	Feb 21, 2017
Publication date	Jul 5, 2022
Grant date	Jul 5, 2022

Abstract

Microwave systems and new applications of microwave in medical, chemical and materials manufacturing and processing, food and health industries as well as in analytical chemistry instrumentation for in situ study of microwave effects are provided. In the case of medical applications, the microwave based damage is conducted in a way to diminish ablating or damaging the collateral tissue and to increase the probability of procedure achievement.

First claim

What is claimed is:

1. A method of controlling the temperature of a target material while subjecting the material to microwave irradiation, comprising:
measuring the temperature of the target and its surroundings;
applying a variable length microwave pulse to the target;
and means of transporting the microwave radiation that allows microwave field at the target in which the microwave has either its maximum electric field intensity over the area of the target with least magnetic field intensity over the same area or its maximum magnetic field intensity over the area of the target with least electric field intensity over the area;
actively cooling the target; and
adjusting the variable length microwave pulse, pulse sequence, pulse shapes, and using phase encoding and the active cooling of the target and its surrounding dependent on the measured temperature to achieve a desired temperature.

2. The method of claim 1 , wherein actively cooling the target consists of at least one of circulating a coolant near the target, circulating a coolant around a chamber containing the target, circulating a coolant through the target, cooling a chamber housing the target, cooling the target using a laser cooling technique, and moving the target through the variable length radiation pulse.

3. The method of claim 1 , wherein a source of the microwave pulses is at least one of one of a magnetron, klystron, traveling-wave tube, gyrotron, a field-effect transistor, tunnel diode, and a Gunn diode.

4. The method of claim 1 , wherein the coolant is selected from the group consisting of but not limited to liquid carbon dioxide, expanding gaseous carbon dioxide, nitrogen, argon, helium, ethylene glycol, salt solutions, ionic liquids, deep eutectic solvents, solid carbon dioxide, cooled vapor carbon dioxide, silicone oils, compounds containing hydroxyl group, and mixtures of fluids that go through endothermic phase transitions at different temperatures.

5. The method of claim 1 , wherein the target is a food.

6. The method of claim 5 , wherein the food is selected from the group consisting of but not limited to fruit juice, milk, tomato sauce, salad sauce, broth, solid food, raw food, meats, seafood, and vegetables, and wherein the radiation pulse is sufficient to reduce microbial contamination without cooking the food.

7. The method of claim 6 , wherein the food is cooled using a non-toxic coolant and the electric field and magnetic field effects of the microwave are enhanced using a nontoxic salt, ionic liquid, or magnetic material.

8. The method of claim 1 , wherein the microwave radiation is delivered through an array of microwave needle antennas or at least one antenna.

9. The method of claim 1 , wherein the target is a biological tissue.

10. The method of claim 9 , further comprising simultaneously irradiating the target with a high energy ion, an ionizing photon, or an ionizing or magnetic particle beam and means of a transport system to transfer antimicrobial electric field or magnetic field effect enhancer materials or radiosensitizers or antimicrobial material for shielding such fields or effects.

11. The method of claim 10 , wherein irradiating the target with an ion, an ionizing photon, or ionizing or magnetic particle beam occurs between pulses of the microwave.

12. The methods of claim 11 , wherein the microwave pulses are generated by at least one monopole microwave antenna or by an array of microwave needle antennas.

13. The method of claim 9 , wherein the microwave pulse is delivered laparoscopically, and means for using a microwave absorbing shield and incorporating interlock safety systems are provided.

14. The method of claim 9 , further comprising applying a microwave waveguide directly on the outer layer of the target tissue or skin to deliver the variable length microwave pulse sequence, providing the means of a microwave absorbing shield, incorporated interlock safety systems, and providing the means to transfer antimicrobial electric field or magnetic field effect enhancer materials or radiosensitizers or antimicrobial material for shielding such fields or effects.

15. A non-thermal microwave device, comprising:
a variable pulse width microwave source operable to provide a variable width microwave pulse, with added possibility of setting the pulse sequence, pulse shapes, and phase encoding, to a target;
a microwave transport system that allows microwave field at the target in which the microwave has either its maximum electric field intensity over the area of the target with least magnetic field intensity over the same area or its maximum magnetic field intensity over the area of the target with least electric field intensity over the area;
a temperature monitoring probe operable to measure the temperature of a target and its surrounding;
a transport system for flow of additional material to the target or its surroundings;
a cooling system operable to control the temperature of the target; and
an electronic control circuit operable to adjust pulses properties and the cooling system to maintain a temperature measured by the temperature monitoring probes, the flow of additional materials, and the safety systems such as interlocks.

16. The non-thermal microwave device of claim 15 , wherein the microwave source comprises an array of microwave antenna or at least one monopole microwave antenna.

17. The non-thermal microwave device of claim 15 , further comprising an imaging device operable to image the target, in which the imaging species has the means to enhance microwave effects locally on target and therefore act as a microwave focusing lens.

18. The non-thermal microwave device of claim 15 , wherein the target is selected for transformation from the group (in any state of the material) consisting of a chemical reactant, a biological sample, a food, a polymer, a semi-conductor, a surface, a photo catalyst, a solar panel and an industrial waste.

19. The non-thermal microwave device of claim 15 , wherein the target is an alloy, ceramic or the precursors of an alloy or ceramic.

20. A pulsed microwave tool comprising:
one or a set of temperature probes for real-time, and in situ or indirect measurements of a temperature of a target and its surrounding;
a cooling system for cooling the target and its surrounding;
a microwave generator operable to generate a variable pulse width microwave with appropriate variable pulse timings and sequences in response to the temperature of the target and its surrounding;
a microwave wave guide, antenna or a set of microwave antennas in the middle of the tool;
a cylindrical cooling jacket at the top with inlet and outlet to circulate cooling liquid in order to control the temperature of the target and cool down material adjacent the target; and
means for transport of ionizing irradiation and probe lights.

21. A method of measuring the effects of microwave radiation on a target that could provide the feedback to control microwave pulses applied for different applications such as but not limited to radiation therapy, surface modification of material, in situ, comprising:
measuring the temperature of the target;
applying a variable length microwave pulse to the target;
actively cooling the target;
adjusting the variable length microwave pulse, pulse sequence, pulse shapes, and using phase encoding and the active cooling of the target dependent on the measured temperature to achieve a desired temperature profile; and when the temperature and temperature profile of

Assignees

• Univ Guelph

Inventors

• Ghandi Khashayar
• Afaghi Pooya

Classifications

• A23B2/08

  using microwaves or dielectric heating · CPC title

• B01J2219/123

  Vessels in the form of a cup · CPC title

• B01J2219/1209

  Features relating to the reactor or vessel · CPC title

• B01J19/126

  Microwaves · CPC title

• A61N5/02 Primary

  using microwaves · CPC title