Systems and methods for evaluating a physiological condition using a wavelet transform and identifying a band within a generated scalogram

• US 8,358,213 B2
• Filed: 07/06/2009
• Issued: 01/22/2013
• Est. Priority Date: 07/15/2008
• Status: Active Grant

• Current Assignee: Nellcor Puritan Bennett Ireland
• Original Assignee: Covidien LP (Medtronic Plc)
• Inventors: Watson, James Nicholas, Addison, Paul Stanley, McKenna, Edward M., Ochs, James P.
• Primary Examiner(s): HOFSASS, JEFFERY A
• Application Number:
  US12/497,824
• Publication Number:
  US 20100013642A1
• Time in Patent Office: 1,296 Days
• Field of Search: 340/539.12, 340/573.1, 702/1, 702/19, 600/500
• US Class Current: 340/573.1
• 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 5/726 using Wavelet transforms
• CPC Class Codes: G06F 2218/06 by applying a scale-space analysis, e.g. using wavelet analysis
• CPC Class Codes: G16H 40/67 for remote operation
• CPC Class Codes: G16Z 99/00 Subject matter not provided for in other main groups of this subclass

Abstract

A method and system are provided for evaluating in patient monitoring whether a signal is sensed optimally by receiving a signal, transforming the signal using a wavelet transform, generating a scalogram based at least in part on the transformed signal, identifying a pulse band in the scalogram, identifying a characteristic of the pulse band, determining, based on the characteristic of the pulse band, whether the signal is sensed optimally; and triggering an event. The characteristics of the pulse band and scalogram may be used to provide an indication of monitoring conditions.

Claims

1. A method comprising:

using a processor for;

receiving a signal;

transforming the signal using a wavelet transform;

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

identifying a band in the scalogram;

identifying a characteristic of the band;

determining, based at least in part on the characteristic of the band, whether the signal is sensed generally optimally; and

triggering an event.

2. The method of claim 1 wherein identifying a characteristic of the band comprises obtaining an incremental slice of the pulse band.

3. The method of claim 1 wherein the characteristic of the band comprises a height of the band, a width of the band, an amplitude of the band, a strength of the band, and/or a shape of the band, and/or combinations thereof.

4. The method of claim 1 further comprising using a processor for comparing the characteristic to a threshold value.

5. The method of claim 4 wherein the event is triggered if the characteristic does not correspond to the threshold value.

6. The method of claim 1 wherein the event comprises sending a control signal to a light associated with the signal, an alert, and/or moving a sensor, and/or combinations thereof.

7. The method of claim 6 wherein the alert comprises an indication of use of increased light intensity, an indication of use of decreased light intensity, an indication to move the sensor, an indication to move the sensor closer to an artery, an indication to move the sensor away from an artery, an indication that the sensor is not optimally located, an indication to examine a patient, and/or an indication of use of a second sensor.

8. The method of claim 5 further comprising:

using a processor for;

generating at least a second scalogram based at least in part on the signal; and

comparing the scalogram, the second scalogram, and/or the threshold value.

9. The method of claim 1 further comprising using a processor for identifying a feature of a marker region in the scalogram.

10. The method of claim 9 wherein the feature of the marker region comprises a characteristic feature positioned at one or more scales above or below the band.

11. A system comprising:

a signal generator for generating a signal;

a processor coupled to the signal generator, wherein the processor is capable of receiving the signal, transforming the signal using a wavelet transform, generating a scalogram based at least in part on the transformed signal, identifying a pulse band in the scalogram, identifying a characteristic of the pulse band;

determining, based at least in part on the characteristic of the pulse band, whether the signal is sensed generally optimally; and

triggering an event; and

a display for viewing information based at least in part on the signal.

12. The system of claim 11 wherein the signal generator comprises a pulse oximeter coupled to a sensor.

13. The system of claim 11 wherein the characteristic of the pulse band comprises one of the group of:

a height of the pulse band, a width of the pulse band, an amplitude of the pulse band, a strength of the pulse band, and a shape of pulse band.

14. The system of claim 11 wherein the processor is capable of comparing the characteristic to a threshold value.

15. The system of claim 14 wherein the processor triggers the event if the characteristic does not correspond to the threshold value.

16. The system of claim 15 wherein the event comprises sending a control signal to a light associated with the signal, an alert, and/or moving a sensor.

17. The system of claim 16 wherein the alert comprises an indication of use of increased light intensity, an indication of use of decreased light intensity, an indication to move the sensor, an indication to move the sensor closer to an artery, an indication to move the sensor away from an artery, an indication that the sensor is not optimally located, an indication to examine a patient, and/or an indication of use of a second sensor.

18. The system of claim 17 wherein the processor is capable of:

generating at least a second scalogram based at least in part on the signal; and

comparing at least two of;

the scalogram, the second scalogram, and the threshold value.

19. The system of claim 11 wherein the processor is capable of identifying a feature of a marker region in the scalogram.

20. The system of claim 19 wherein the feature of the marker region comprises at least one characteristic feature positioned at one or more scales above or below the pulse band.