System and Method For Signal Processing Using Fractal Dimension Analysis

• US 20090263034A1
• Filed: 04/21/2008
• Published: 10/22/2009
• Est. Priority Date: 04/21/2008
• Status: Active Grant

• Current Assignee: Brainscope SPV LLC
• Original Assignee: Brainscope Company Inc.
• Inventors: Causevic, Elvir
• Granted Patent: US 8,041,136 B2
• Time in Patent Office: Days
• US Class Current: 382/249
• CPC Class Codes: A61B 5/0002 Remote monitoring of patients using telemetry, e.g. transmission of vital signals via a communication network A61B5/07 takes precedence; transmission systems for measured values G08C; transmission H04B; transmission of digital information H04L; wireless communication networks H04W
• CPC Class Codes: A61B 5/316 Modalities, i.e. specific diagnostic methods
• CPC Class Codes: A61B 5/369 Electroencephalography [EEG] devices for psychotechnics A61B5/16
• CPC Class Codes: A61B 5/7253 characterised by using transforms
• CPC Class Codes: A61B 5/7257 using Fourier transforms
• CPC Class Codes: A61B 5/726 using Wavelet transforms

Abstract

A system and method of signal processing using linear or non-linear signal transformation and fractal dimension based analysis. Using a transform process (i.e. wavelet transform, Fourier transform, ICA transform, etc.), a signal is decomposed into a series of coefficients or components. Within this transform domain, fractal dimensions of the components are computed. The components with fractal dimensions higher than a pre-determined threshold are then selectively processed. A modified signal is reconstructed using inverse transform of the signal components.

Claims

1. A method for processing an acquired signal, comprising the steps of:

i. transforming the signal into a plurality of signal coefficients;

ii. computing fractal dimension of the coefficients;

iii. identifying unwanted coefficients based on their fractal dimension,

iv. automatically thresholding the identified unwanted coefficients;

v. reconstructing a modified signal using inverse transform.

2. The method as recited in claim 1, wherein the step of signal transformation is linear.

3. The method as recited in claim 1, wherein the step of signal transformation is non-linear.

4. The method as recited in claim 1, wherein the step of identifying unwanted components is performed automatically and requires no user intervention.

5. The method as recited in claim 1, wherein the step of automatic thresholding is performed on signal coefficients having a fractal dimension higher or lower than a threshold value.

6. The method as recited in claim 5, wherein the threshold value is predetermined.

7. The method as recited in claim 5, wherein the thresholding is a non-linear process.

8. The method as recited in claim 5, wherein the thresholding comprises removing or re-scaling the signal coefficients having a fractal dimension higher or lower than the threshold value.

9. The method of claim 8, wherein the step of reconstructing a modified signal is performed using inverse transform of intact coefficients and the re-scaled coefficients.

10. The method as recited in claim 1, further comprising the step of automatically forwarding the modified signal for further signal analysis.

16. The apparatus of claim 15, wherein the processor processes the signal according to the method recited in claim 1.

11. A system for signal processing, the system comprising:

means for signal transformation to deconstruct the signal into its coefficients;

means for computing the fractal dimension of the coefficients;

means for automatically thresholding the coefficients with fractal dimensions higher or lower than a predetermined threshold value; and

means for reconstructing a modified signal using inverse transform of intact and thresholded coefficients.

12. The system as recited in claim 11, wherein the means for signal transformation is linear.

13. The system as recited in claim 11, wherein the means for signal transformation is non-linear.

14. The system as recited in claim 11, wherein the thresholding comprises removing or re-scaling the coefficients with fractal dimensions higher or lower than the predetermined threshold value.

15. An apparatus for signal processing, comprising:

a signal acquisition module;

a handheld device module, wherein

a multichannel input/output interface is configured to receive signals from the signal acquisition module and subsequently digitize the signal;

a processor is configured to utilize one or more operating instructions to process the digitized signal using fractal dimension analysis in the signal transform domain;

a display module, wherein the results of the processed signal are displayed.

17. The apparatus of claim 15, wherein the signal acquisition module is connected to a subject'"'"'s body to receive biological signals.

18. The apparatus of claim 17, wherein the signal acquisition module communicates wirelessly with the handheld device module.

19. The apparatus of claim 15, wherein the display module is operatively connected to the processor to display a result of one or more operations performed by the processor;

and

wherein the display module can be integrated into the handheld device, or can be external to the handheld device.

20. The apparatus of claim 19, wherein the processor transmits the result wirelessly to the external display module.

21. The method of claim 19, wherein the handheld device module comprises a wireless power amplifier coupled to an antenna to transmit the result wirelessly to the external display module or to an external data storage unit.

22. The apparatus of claim 15, wherein the signal acquisition module and the handheld device module may be integrated into a single kit for field use or point-of-care applications.