Imaging using gated elements

Patent metadata

Field	Value
Publication number	US-10716488-B2
Application number	US-201415108052-A
Country	US
Kind code	B2
Filing date	Dec 29, 2014
Priority date	Dec 30, 2013
Publication date	Jul 21, 2020
Grant date	Jul 21, 2020

Abstract

Exemplary methods and systems may image an object of interest using one or more waveguide assemblies including gated elements. The gated elements may be configurable in a transmission state, a reception state, or a passive state. The exemplary methods and systems may deliver electromagnetic energy (e.g., microwave energy) to an object of interest using a gated element of a waveguide assembly configured in a transmission state and sample scattered field using a gated element of another waveguide assembly configured in the reception state while the remainder of gated elements are configured in the passive state.

First claim

What is claimed is:

1. A method of imaging an object using microwave imaging, wherein the method comprises:
providing a plurality of waveguide assemblies positioned about an object, wherein each waveguide assembly of the plurality of waveguide assemblies comprises:
a waveguide structure configured to deliver and sample electromagnetic energy, and
one or more gated elements, wherein each gated element of the one or more gated elements defines an aperture extending into the waveguide structure, wherein each gated element of the one or more gated elements is configurable in at least a transmission state, a reception state, and a passive state, wherein each gated element of the one or more gated elements is configured to allow electromagnetic energy to radiate from the waveguide structure through the aperture when in the transmission state, to allow electromagnetic energy to be received through the aperture into the waveguide structure when in the reception state, and to neither allow electromagnetic energy to radiate from the waveguide structure through the aperture nor allow electromagnetic energy to pass through the aperture into the waveguide structure when in the passive state;

delivering electromagnetic energy using at least one waveguide assembly of the plurality of waveguide assemblies to irradiate the object resulting in scattered electromagnetic energy;
sampling the scattered electromagnetic energy using at least one waveguide assembly of the plurality of waveguide assemblies; and
reconstructing an image of the object based on the sampled scattered electromagnetic energy.

2. The method of claim 1 , wherein, to sample the scattered electromagnetic energy using at least one waveguide assembly of the plurality of waveguide assemblies, a modulation signal is applied to an individual gated element of the one or more gated elements to configure the individual gated element into the reception state.

3. The method of claim 2 , wherein the modulation signal has a lower frequency than the electromagnetic energy delivered using at least one waveguide assembly of the plurality of waveguide assemblies.

4. The method of claim 1 , wherein sampling the scattered electromagnetic energy using at least one waveguide assembly of the plurality of waveguide assemblies comprises sampling the scattered electromagnetic energy using each gated element individually of the one or more gated elements of each waveguide assembly of the plurality of waveguide assemblies until each gated element of the one or more gated elements of the plurality of waveguide assemblies has been individually used to sample the scattered electromagnetic energy, wherein, to sample the scattered electromagnetic energy using each gated element individually, a selected gated element is configured in the reception state, the remaining gated elements of the one or more gated elements of the plurality of waveguide assemblies are configured in the passive state, and the waveguide assembly comprising the selected gated element samples the scattered electromagnetic energy.

5. The method of claim 1 , wherein delivering electromagnetic energy using at least one waveguide assembly of the plurality of waveguide assemblies comprises delivering the electromagnetic energy using each gated element individually of the one or more gated elements of each waveguide assembly of the plurality of waveguide assemblies until each gated element of the one or more gated elements of the plurality of waveguide assemblies has been individually used to deliver the electromagnetic energy, wherein, to deliver the electromagnetic energy using each gated element individually, a selected gated element is configured in the transmission state, the remaining gated elements of the one or more gated elements of the plurality of waveguide assemblies are configured in the passive state, and the waveguide assembly comprising the selected gated element delivers the electromagnetic energy to radiate from the selected gated element.

6. The method of claim 1 , wherein the plurality of waveguide assemblies are in a fixed position relative to the object.

7. The method of claim 1 , wherein the plurality of waveguide assemblies are positioned around a perimeter of the object to form at least a portion of an imaging chamber.

8. The method of claim 1 , wherein the reconstructed image is a quantitative image.

9. The method of claim 1 , wherein each waveguide assembly comprises two or more gated elements.

10. The method of claim 1 , wherein each waveguide assembly is configured to provide a standing wave within the waveguide structure when electromagnetic energy is being delivered therefrom.

11. The method of claim 1 , wherein the waveguide structure defines an enclosed volume for confining electromagnetic energy therein.

12. The method of claim 1 , wherein each gated element of the one or more gated elements comprises a switchable segment configurable between a conducting configuration and a non-conducting configuration, wherein the switchable segment is configured in the conducting configuration when the gated element is in the passive state, and wherein the switchable segment is configured in the non-conducting configuration when the gated element is the transmission state.

13. The method of claim 1 , wherein the aperture of each gated element defines a length that is half the wavelength of the electromagnetic energy delivered by the plurality of waveguide assemblies.

14. The method of claim 1 , wherein the aperture of each gated element defines a slot, wherein the slot defines a width and a length perpendicular to the width, and wherein the length is greater than the width.

15. The method of claim 1 , wherein the one or more gated elements comprise:
at least one gated element to collect electromagnetic energy of a first selected polarization when in the reception state; and
at least one gated element to collect electromagnetic energy of a second selected polarization when in the reception state, wherein the first selected polarization is different than the second selected polarization.

16. A system for use in imaging an object using microwave imaging, wherein the system comprises:
a plurality of waveguide assemblies positioned about an object, wherein each waveguide assembly of the plurality of waveguide assemblies comprises:
a waveguide structure configured to deliver and sample electromagnetic energy, and
one or more gated elements, wherein each gated element of the one or more gated elements defines an aperture extending into the waveguide structure, wherein each gated element of the one or more gated elements is configurable in at least a transmission state, a reception state, and a passive state, wherein each gated element of the one or more gated elements is configured to allow electromagnetic energy to radiate from the waveguide structure through the aperture when in the transmission state, to allow electromagnetic energy to be received through the aperture into the waveguide structure when in the reception state, and to neither allow electromagnetic energy to radiate from the waveguide structure through the aperture nor allow electromagnetic energy to pass through the aperture into the waveguide structure when in the passive state; and

processing apparatus coupled to the plurality of waveguide assemblies, wherein the processing apparatus is configured to:
deliver electromagnetic energy using at least one waveguide assembly of the plurality of waveguide assemblies to irradiate the object resulting in scattered electromagnetic energy;
sample the scattered electromagnetic energy using at le

Assignees

• Univ Manitoba
• The Univ Of Manitoba

Inventors

• Ostadrahimi Majid
• Lovetri Joe

Classifications

• A61B5/0507 Primary

  using microwaves or terahertz waves · CPC title

• A61B2562/0228

  Microwave sensors · CPC title

• G01N22/00

  Investigating or analysing materials by the use of microwaves or radio waves, i.e. electromagnetic waves with a wavelength of one millimetre or more (G01N3/00 - G01N17/00, G01N24/00 take precedence) · CPC title

• G01S13/89

  for mapping or imaging · CPC title