Investigation of physical properties of an object

Patent metadata

Field	Value
Publication number	US-9164033-B2
Application number	US-200913122791-A
Country	US
Kind code	B2
Filing date	Oct 12, 2009
Priority date	Oct 13, 2008
Publication date	Oct 20, 2015
Grant date	Oct 20, 2015

Abstract

An imaging system for an object such as human or animal tissue uses scattering of an illuminating electromagnetic wave by acoustic vibrations to generate a scattered electromagnetic wave including Doppler components shifted from the frequency of the illuminating electromagnetic wave by frequencies of the acoustic vibration and multiples thereof. An acoustic transducer apparatus applies acoustic vibrations localized in two or three dimensions in a plurality of regions. A transmitter simultaneously illuminates the object with an illuminating electromagnetic wave that has a frequency in the range from 100 MHz to 100 GHz, the vibration direction of the acoustic vibration having a component parallel to the propagation direction of the illuminating electromagnetic wave. A receiver receives the scattered electromagnetic wave. A signal processing apparatus derives characteristics of the Doppler components, and stores image data representing the derived characteristic.

First claim

The invention claimed is:

1. A method comprising:
applying to an object acoustic vibration localized in two or three dimensions in a plurality of regions in the object simultaneously but with different frequencies in each region;
simultaneously illuminating the object with an illuminating electromagnetic wave that has a frequency in a range extending down from 30 THz, the vibration direction of the acoustic vibration having a component parallel to the propagation direction of the illuminating electromagnetic wave so that the acoustic vibration of the object in each of the plurality of regions generates a scattered electromagnetic wave including Doppler components shifted from the frequency of the illuminating electromagnetic wave by frequencies of the acoustic vibration and multiples thereof;
receiving the scattered electromagnetic wave generated in each of the plurality of regions,
deriving from the received, scattered electromagnetic wave data representing at least one characteristic of the Doppler components in respect of each region; and
storing the derived data in respect of each region as image data representing an image.

2. The method according to claim 1 , wherein the object is human or animal tissue.

3. The method according to claim 1 , wherein said range of the frequency of the illuminating electromagnetic wave extends down from 100 GHz.

4. The method according to claim 1 , wherein said range of the frequency of the illuminating electromagnetic wave extends down to 100 MHz.

5. The method according to claim 1 , wherein the acoustic vibration has a frequency in the range from 10 MHz to 1 GHz.

6. The method according to claim 1 , wherein the vibration direction of the acoustic vibration and the propagation direction of the illuminating electromagnetic wave are parallel.

7. The method according to claim 1 , wherein the scattered electromagnetic wave is received along a line parallel or antiparallel to the propagation direction of the illuminating electromagnetic wave.

8. The method according to claim 1 , wherein at least one characteristic of the Doppler components includes at least one of an amplitude or a phase of one or more of the Doppler components.

9. The method according to claim 1 , wherein the step of deriving at least one characteristic of the Doppler components comprises frequency-modulation demodulating the Doppler components from the component of the scattered electromagnetic wave of the same frequency as the illuminating electromagnetic wave.

10. The method according to claim 1 , wherein the acoustic vibration applied to the object is localized in three dimensions in the plurality of regions in the object, being applied as pulses of different frequencies each localized in space in a first and second dimension in different regions and localized in a third dimension in different regions at different times as it propagates.

11. The method according to claim 1 , wherein the acoustic vibration applied to the object is localized in three dimensions in the plurality of regions in the object, being applied as a plurality of simultaneous propagating beams of different frequencies localized in space in a first and second dimension in different regions and localized in a third dimension in different regions at different times as the beams propagate.

12. The method according to claim 1 , wherein the electromagnetic wave has a radio frequency.

13. The method according to claim 1 , wherein the step of applying to the object acoustic vibration localized in two or three dimensions in a plurality of regions in the object simultaneously but with different frequencies in each region further comprises scanning the plurality of regions across the object.

14. A system comprising:
an acoustic transducer apparatus including a drive circuit driving an array of transducers arranged to apply to an object acoustic vibration localized in two or three dimensions in a plurality of regions in the object simultaneously but with different frequencies in each region;
a transmitter arrangement including a transmitter antenna and a radio frequency source arranged to illuminate the object with an illuminating electromagnetic wave having a frequency in a range extending down from 30 THz simultaneously with the application of acoustic vibration, the vibration direction of the acoustic vibration having a component parallel to the propagation direction of the illuminating electromagnetic wave so that the acoustic vibration of the object in each of the plurality of regions generates a scattered electromagnetic wave including Doppler components shifted from the frequency of the illuminating electromagnetic wave by frequencies of the acoustic vibration and multiples thereof;
a receiver arrangement including a receiver antenna arranged to receive the scattered electromagnetic wave generated in each of the plurality of regions;
a signal processing apparatus arranged to derive, from the received scattered electromagnetic wave generated in respect of each region, data representing at least one characteristic of the Doppler components in respect of each region and arranged to store the derived data in respect of each region as image data representing and image.

15. The system according to claim 14 , wherein said range of the frequency of the illuminating electromagnetic wave extends down from 100 GHz.

16. The system according to claim 14 , wherein said range of the frequency of the illuminating electromagnetic wave extends down to 100 MHz.

17. The system according to claim 14 , wherein the acoustic vibration has a frequency in the range from 10 MHz to 1 GHz.

18. The system according to claim 14 , wherein the array of transducer and the transmitter antenna are positioned relative to each other such that the vibration direction of the acoustic vibration and the propagation direction of the illuminating electromagnetic wave are parallel.

19. The system according to claim 14 , wherein the receiver arrangement is arranged to receive the scattered electromagnetic wave along a line parallel or antiparallel to the propagation directions of the illuminating electromagnetic wave.

20. The system according to claim 14 , wherein at least one characteristic of the Doppler components includes at least one of the amplitude and phase of one or more of the Doppler components.

21. A system according to claim 14 , wherein the signal processing apparatus includes a frequency-modulation demodulator arranged to demodulate the Doppler components from the component of the scattered electromagnetic wave of the same frequency as the illuminating electromagnetic wave.

22. The system according to claim 14 , wherein the drive circuit and array of transducers are arranged to apply the acoustic vibration localized in three dimensions in the plurality of regions in the object, being arranged to apply the acoustic vibration as pulses of different frequencies each localized in space in first and second dimensions in different regions and localized in a third dimension in different regions at different times as the acoustic vibration propagates.

23. The system according to claim 14 , wherein the drive circuit and array of transducers are arranged to apply the acoustic vibration localized in three dimensions in the plurality of regions in the object, the acoustic transducer apparatus being arranged to apply the acoustic vibration as a plurality of propagating beams of different frequencies localized in space in first and second

Assignees

• Edwards David John
• Stevens Christopher John
• Isis Innovation

Inventors

• Edwards David John
• Stevens Christopher John

Classifications

• G01S15/899

  Combination of imaging systems with ancillary equipment · CPC title

• A61B8/488

  involving Doppler signals · CPC title

• G01N21/4795 Primary

  spatially resolved investigating of object in scattering medium (in vivo A61B) · CPC title

• A61B8/08

  Clinical applications (A61B8/02, A61B8/04, A61B8/06 take precedence) · CPC title

• A61B8/0825

  for diagnosis of the breast, e.g. mammography · CPC title