SYSTEM AND METHOD FOR EXCITATION GENERATION IN SOFT-FIELD TOMOGRAPHY

• US 20130013239A1
• Filed: 07/08/2011
• Published: 01/10/2013
• Est. Priority Date: 07/08/2011
• Status: Abandoned Application

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Ross, Alexander Seth, Mahalingam, Sakethraman, Meethal, Manoj Kumar Koyithitta, Tiwari, Arvind, Panicker, Somakumar Ramachandra
• Application Number:
  US13/179,179
• Publication Number:
  US 20130013239A1
• Time in Patent Office: Days
• US Class Current: 702/66
• CPC Class Codes: A61B 5/0073 by tomography, i.e. reconstruction of 3D images from 2D projections A61B5/0066 takes precedence
• CPC Class Codes: A61B 5/0075 by spectroscopy, i.e. measuring spectra, e.g. Raman spectroscopy, infrared absorption spectroscopy A61B5/0071 takes precedence
• CPC Class Codes: A61B 5/0507 using microwaves or terahertz waves
• CPC Class Codes: A61B 5/0522 Magnetic induction tomography
• CPC Class Codes: A61B 5/0536 Impedance imaging, e.g. by tomography
• CPC Class Codes: A61B 5/7228 Signal modulation applied to the input signal sent to patient or subject; demodulation to recover the physiological signal modulation H03C
• CPC Class Codes: A61B 8/13 Tomography A61B8/10, A61B8/12 take precedence; tomography for radiation diagnosis A61B6/02

Abstract

A system and method for excitation generation in soft-field tomography are provided. One method includes applying a plurality of phase modulated (or phase and amplitude modulated) excitations to a plurality of transducers of a data acquisition system positioned proximate a surface of an object and measuring a response to the applied phase modulated (or phase and amplitude modulated) excitations at the plurality of transducers. The method also includes determining a property of the object based on the measured responses.

Claims

1. A method for acquiring soft-field data, the method comprising:

applying a plurality of phase modulated excitations to a plurality of transducers of a soft-field data acquisition system positioned proximate a surface of an object;

measuring a response to the applied phase modulated excitations at the plurality of transducers; and

determining a property of the object based on the measured responses.

2. The method of claim 1, wherein the plurality of excitations are n-phase modulated excitations and further comprising applying the n-phase modulated excitations to at least a subset of the plurality of transducers.

3. The method of claim 2, further comprising applying the n-phase modulated excitations to at least another subset of the plurality of transducers until excitations have been applied to all of the plurality of transducers.

4. The method of claim 3, further comprising applying the n-phase modulated excitations during a excitation sequence, wherein the excitation sequence is based on an application for the soft-field tomography system, which is optimized using at least one of signal-to-noise ratio, resolution, detection capability, instrumentation complexity or acquisition speed.

5. The method of claim 3, further comprising applying n-phase modulated excitations over multiple excitation sequences over time at different temporal frequencies.

6. The method of claim 1, further comprising applying n-phase modulated excitations to subsets of the plurality of transducers using one or more of a sinusoidal waveform, a multisine waveform or a composite waveform.

7. The method of claim 1, further comprising amplitude modulating the excitations applied to the plurality of transducers.

8. The method of claim 1, wherein a phase of the phase modulated excitation applied to the plurality of transducers is different for each of the plurality of transducers.

9. The method of claim 1, further comprising performing a temporal frequency scan of the object to determine one or more properties at the different frequencies to reconstruct the spatial distribution of a plurality of materials within the object.

10. The method of claim 1, wherein the phase modulated excitations comprise one or more of electrical signals, optical signals, magnetic signals, thermal signals, radio-frequency signals or microwave signals distributed in space symmetrically or asymmetrically in space and time.

11. The method of claim 1, wherein the spatial property distribution is a distribution as determined in one of Electrical Impedance Spectroscopy (EIS), Electrical Impedance Tomography (EIT), Diffuse Optical Tomography (DOT), Near InfraRed Spectroscopy (NIRS), thermography, elastography or microwave tomography.

12. The method of claim 1, wherein the spatial property distribution comprises a distribution of one or more of electric conductivity, electric permittivity, magnetic permeability, optical absorbance, optical scattering, optical reflectivity, elasticity, or thermal conductivity.

13. The method of claim 1, wherein determining the property of the object comprises determining a spatially distributed property of the object.

14. A soft-field data acquisition system comprising:

a plurality of transducers configured for positioning proximate a surface of an object;

one or more excitation drivers coupled to the plurality of transducers and configured to generate excitation signals for the plurality of transducers, wherein the excitation signals comprise phase modulated excitations;

one or more response detectors coupled to the plurality of transducers and configured to measure a response of the object at the plurality of transducers to the excitation applied by the plurality of transducers based on the excitation signals; and

a soft-field reconstruction module configured to reconstruct a property distribution based on the excitation signals and the measured response.

15. The sat-field data acquisition system of claim 14, wherein the one or more excitation drivers are configured to generate n-phase modulated excitations and apply the n-phase modulated excitations to at least a subset of the plurality of transducers.

16. The soft-field data acquisition system of claim 15, wherein the one or more excitation drivers are configured to generate the n-phase modulated excitations and apply the n-phase modulated excitations to at least another subset of the plurality of transducers until excitations have been applied to all of the plurality of transducers.

17. The soft-field data acquisition system of claim 16, wherein the one or more excitation drivers are configured to apply the n-phase modulated excitations during an excitation sequence, wherein the excitation sequence is based on an application that is optimized using at least one of signal-to-noise ratio, resolution, detection capability, instrumentation complexity or acquisition speed.

18. The soft-field data acquisition system of claim 16, wherein the one or more excitation drivers are configured to apply n-phase modulated excitations over multiple excitation sequences over time at different temporal frequencies.

19. The soft-field data acquisition system of claim 14, wherein the one or more excitation drivers are configured to apply n-phase modulated excitations to subsets of the plurality of transducers using one or more of a sinusoidal waveform, a multisine waveform or a composite waveform.

20. The soft-field data acquisition system of claim 14, wherein the property distribution is a distribution as determined in one or more of Electrical Impedance Spectroscopy (EIS), Electrical Impedance Tomography (EIT), Diffuse Optical Tomography (DOT), Near InfraRed Spectroscopy (NIRS), thermography, elastography or microwave tomography.

21. The soft-field data acquisition system of claim 14, wherein the property distribution comprises a distribution of one or more of electric conductivity, electric permittivity, magnetic permeability, optical absorbance, optical scattering, optical reflectivity, elasticity, or thermal conductivity.

22. The soft-field data acquisition system of claim 14, wherein the one or more excitation drivers are configured to generate n-phase and amplitude modulated excitations and apply the n-phase and amplitude modulated excitations to at least a subset of the plurality of transducers.

23. A computer readable storage medium for acquiring soft-field data and reconstructing a property distribution of an object using a processor, the computer readable storage medium including instructions to command the processor to:

apply a plurality of phase modulated excitations to a plurality of transducers of a soft-field tomography system positioned proximate a surface of an object;

measure a response to the applied phase modulated excitations at the plurality of transducers; and

determine a property of the object based on the measured response.

24. The computer readable storage medium of claim 23, wherein the plurality of excitations are n-phase modulated excitations, and the instructions command the processor to further apply the n-phase synchronized excitations to at least a subset of the plurality of transducers.

25. The computer readable storage medium of claim 24, wherein the instructions command the processor to further apply the n-phase modulated excitations to at least another subset of the plurality of transducers until excitations have been applied to all of the plurality of transducers.

26. The computer readable storage medium of claim 25, wherein the instructions command the processor to further apply the n-phase modulated excitations during an excitation sequence, wherein the excitation sequence is based on an application for the soft-field tomography system, which is optimized using at least one signal-to-noise ratio, resolution, detection capability, instrumentation complexity or acquisition speed.

27. The computer readable storage medium of claim 23, wherein the instructions command the processor to further apply n-phase modulated excitations over multiple excitation sequences over time at different temporal frequencies.

28. The computer readable storage medium of claim 23, wherein the instructions command the processor to further apply n-phase modulated excitations to subsets of the plurality of transducers using one or more of a sinusoidal waveform, a multisine waveform or a composite waveform.

29. The computer readable storage medium of claim 23, wherein the instructions command the processor to further generate n-phase and amplitude modulated excitations and apply the n-phase and amplitude modulated excitations to at least a subset of the plurality of transducers.

30. The computer readable storage medium of claim 23, wherein the instructions command the processor to further determine a spatially distributed property of the object based on the measured response.