Concatenated Scalograms

• US 20090326831A1
• Filed: 05/07/2009
• Published: 12/31/2009
• Est. Priority Date: 06/30/2008
• Status: Abandoned Application

• Current Assignee: Nellcor Puritan Bennett Ireland
• Original Assignee: Nellcor Puritan Bennett Ireland
• Inventors: Addison, Paul Stanley, Watson, James, McGonigle, Scott
• Application Number:
  US12/437,317
• Publication Number:
  US 20090326831A1
• Time in Patent Office: Days
• US Class Current: 702/19
• CPC Class Codes: A61B 5/14551 for measuring blood gases
• CPC Class Codes: A61B 5/7207 of noise induced by motion artifacts
• CPC Class Codes: A61B 5/7225 Details of analog processing, e.g. isolation amplifier, gain or sensitivity adjustment, filtering, baseline or drift compensation A61B5/30, A61B5/316 take precedence; transformers for specific applications H01F38/00; amplifiers H03F
• CPC Class Codes: A61B 5/7239 using differentiation including higher order derivatives
• CPC Class Codes: A61B 5/726 using Wavelet transforms

Abstract

Embodiments may include systems and methods capable of processing an original signal by selecting and mirroring portions of the signal to create new signals. Any suitable number of new signals may be created from the original signal and scalograms may be derived at least in part from the new signals. Regions of the scalograms may be selected based on a characteristic of the original signal. The selected regions may be concatenated, and a sum along amplitudes across time may be applied to the concatenated regions. Desired information, such as respiration information within the original signal, may be determined from the sum along amplitudes across time.

Claims

1. A signal processing method comprising:

receiving data indicative of an original signal at a sensor;

generating scalograms from the original signal;

selecting regions of the generated scalograms based at least in part on at least one characteristic of the generated scalograms;

concatenating the selected regions to form a concatenated scalogram;

applying a sum along amplitudes across time to at least a portion of the concatenated scalogram to form a sum along amplitudes function; and

determining a desired parameter based at least in part on the sum along amplitudes function.

2. The method of claim 1, wherein generating scalograms comprises generating a plurality of up scalograms and a plurality of down scalograms by:

selecting a first portion of the original signal;

mirroring the first portion of the original signal about a first vertical axis to create a mirrored first portion;

selecting a subsequent second portion of the original signal;

mirroring the second portion of the original signal about a second vertical axis to create a mirrored second portion;

combining the mirrored first portion and the mirrored second portion to create a new signal;

transforming the new signal using a wavelet transform; and

generating a scalogram based at least in part on the transformed signal.

3. The method of claim 1, wherein generating scalograms comprises generating a plurality of interpolated scalograms by:

selecting a portion of the original signal;

generating samples of the selected portion of the original signal using at least one characteristic of the original signal;

interpolating between the samples to create an interpolated signal;

transforming the interpolated signal using a wavelet transform; and

generating a scalogram based at least in part on the transformed signal.

4. The method of claim 3, wherein the at least one characteristic comprises an amplitude of at least one of an up stroke and a down stroke of a pulse in the original signal.

5. The method of claim 2, wherein the selected regions comprise at least one region of the up scalograms and at least one region of the down scalograms.

6. The method of claim 1, wherein the at least one characteristic comprises a peak in the original signal.

7. The method of claim 1, further comprising selecting at least one ridge in at least one of the generated scalograms, wherein the at least one characteristic comprises consistency in at least one of the scale and amplitude of at least one ridge.

8. The method of claim 1, wherein concatenating the selected regions further comprise normalizing at least one of the scale and amplitude of the selected regions.

9. The method of claim 1, wherein applying a sum along amplitudes across time further comprises summing the median amplitude for each scale increment in the concatenated scalogram.

10. The method of claim 1, wherein applying a sum along amplitudes across time further comprises:

identifying at least one outlier in the concatenated scalogram; and

applying a sum along amplitudes across time to regions of the concatenated scalogram that do not contain the at least one outlier.

11. The method of claim 1, wherein determining the desired parameter further comprises:

selecting a peak of the sum along amplitudes function; and

analyzing the peak to obtain respiration information.

12. The method of claim 1, wherein determining the desired parameter further comprises:

identifying a point of maximum curvature of the sum along amplitudes function; and

analyzing the point to obtain respiration information.

16. The system of claim 3, wherein the at least one characteristic comprises an amplitude of at least one of an up stroke and a down stroke of a pulse in the original signal.

13. A system for processing a signal, the system comprising:

a sensor for receiving data indicative of an original signal;

a processor coupled to the sensor, wherein the processor is configured to;

generate scalograms from the original signal;

select regions of the generated scalograms based at least in part on at least one characteristic of the generated scalograms;

concatenate the selected regions to form a concatenated scalogram;

apply a sum along amplitudes across time to at least a portion of the concatenated scalogram to form a sum along amplitudes function;

determine a desired parameter based at least in part on the sum along amplitudes function; and

an output coupled to the processor, wherein the output is configured to display at least one of the concatenated scalogram, the sum along amplitudes function, and the determined parameter.

14. The system of claim 13, wherein the processor is further configured to:

select a first portion of the original signal;

mirror the first portion of the original signal about a first vertical axis to create a mirrored first portion;

select a subsequent second portion of the original signal;

mirror the second portion of the original signal about a second vertical axis to create a mirrored second portion;

combine the mirrored first portion and the mirrored second portion to create a new signal;

transform the new signal using a wavelet transform; and

generate a scalogram based at least in part on the transformed signal.

15. The system of claim 13, wherein the processor is further configured to:

select a portion of the original signal;

generate samples of the selected portion of the original signal using at least one characteristic of the original signal;

interpolate between the samples to create an interpolated signal;

transform the interpolated signal using a wavelet transform; and

generate a scalogram based at least in part on the transformed signal.

17. The system of claim 13, wherein the selected regions comprise at least one region of the up scalograms and at least one region of the down scalograms.

18. The system of claim 13, wherein the at least one characteristic comprises a peak in the original signal.

19. The system of claim 13, wherein the processor is further configured to select at least one ridge in at least one of the generated scalograms, wherein the at least one characteristic comprises consistency in at least one of the scale.

20. The system of claim 13, wherein the processor is further configured to normalize at least one of the scale and amplitude of the selected regions.

21. The system of claim 13, wherein the processor is further configured to sum the median amplitude for each scale increment in the concatenated scalogram.

22. The system of claim 13, wherein the processor is further configured to:

identify at least one outlier in the concatenated scalogram; and

apply a sum along amplitudes across time to regions of the concatenated scalogram that do not contain the at least one outlier.

23. The system of claim 13, wherein the processor is further configured to:

select a peak of the sum along amplitudes function; and

analyze the peak to obtain respiration information.

24. The system of claim 13, wherein the processor is further configured to:

identify a point of maximum curvature of the sum along amplitudes function; and

analyze the point to obtain respiration information.