METHOD FOR IMPROVED OXYGEN SATURATION ESTIMATION IN THE PRESENCE OF NOISE

• US 20140371554A1
• Filed: 08/28/2014
• Published: 12/18/2014
• Est. Priority Date: 06/30/2008
• Status: Abandoned Application

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Covidien LP (Medtronic Plc)
• Inventors: Bake, Clark R. Jr.
• Application Number:
  US14/472,038
• Publication Number:
  US 20140371554A1
• Time in Patent Office: Days
• US Class Current: 600/323
• CPC Class Codes: A61B 5/14551 for measuring blood gases
• CPC Class Codes: A61B 5/7203 for noise prevention, reduction or removal
• CPC Class Codes: A61B 5/7264 Classification of physiological signals or data, e.g. using neural networks, statistical classifiers, expert systems or fuzzy systems neural networks per se G06N3/00; expert systems per se G06N5/00
• CPC Class Codes: A61B 5/7282 Event detection, e.g. detecting unique waveforms indicative of a medical condition A61B5/4094, A61B5/4818, A61B5/349, A61B5/0823 take precedence
• CPC Class Codes: A61B 5/7405 using sound
• CPC Class Codes: A61B 5/742 using visual displays A61B5/339 takes precedence
• CPC Class Codes: A61B 5/7455 characterised by tactile indication, e.g. vibration or electrical stimulation
• CPC Class Codes: G16H 50/20 for computer-aided diagnosis, e.g. based on medical expert systems

Abstract

The present disclosure relates, according to some embodiments, to devices, systems, and methods for estimating a physiological parameter in the presence of noise. For example, the disclosure relates, in some embodiments, to devices, systems, and methods for assessing (e.g., estimating, measuring, calculating) oxygen saturation (SpO2). Methods of assessing SpO2 may include assessing a noise metric associated with motion artifact. In some embodiments, a percentage (e.g., an empirically determined percentage) of a noise metric may be simply added to the SpO2 estimate to produce a corrected SpO2 estimate. An oximetry algorithm may include, according to some embodiments, combining multiple internal SpO2 estimates and associated noise and/or signal quality metrics (e.g., using a radial basis neural network) to produce a modified (e.g., corrected) SpO2 estimate (e.g., rather than merely selecting the estimate from a finite number of candidates). A modified SpO2 estimate may include little or no movement-based error.

Claims

1. A device for estimating oxygen saturation in the presence of noise, the device comprising:

a processor in communication with a neural network, wherein the processor is configured to receive oximetry data, process the oximetry data to produce at least one oxygen saturation estimate, communicate the at least one oxygen saturation estimate to the neural network, and receive a modified oxygen saturation estimate from the neural network comprising less noise bias than the at least one oxygen saturation estimate, wherein the neural network is configured to define the modified oxygen saturation estimate based at least in part on combining the at least one oxygen saturation estimate with corresponding signal quality metrics; and

a display in communication with the processor, wherein the display is configured to display a representation of the modified oxygen saturation estimate.

2. The device of claim 1, wherein the neural network comprises a radial basis neural network.

3. The device of claim 2, wherein the radial basis neural network comprises a single-hidden-layer network.

4. The device of claim 3, wherein the single-hidden-layer network has a plurality of nodes, and each node of the plurality of nodes includes one or more associated weights and a single bias.

5. The device of claim 4, wherein the single bias of at least one node of the plurality of nodes is in the range of about 5% oxygen saturation to about 10% oxygen saturation.

6. The device of claim 4, wherein the single bias of at least one node in the plurality of nodes is in the range of about 1% oxygen saturation to about 5% oxygen saturation.

7. The device of claim 1, wherein the neural network is configured to define the modified oxygen saturation estimate based at least in part on combining the at least one oxygen saturation estimate with one or more additional oxygen saturation estimates.

8. The device of claim 7, wherein the modified oxygen saturation estimate has a value that is not between the values of the at least one oxygen saturation estimate and the one or more additional oxygen saturation estimates.

9. The device of claim 1, wherein the processor is configured to compare the modified oxygen saturation estimate with a hypoxia oxygen saturation threshold and to initiate an alarm if the modified oxygen saturation estimate is less than or equal to the hypoxia oxygen saturation threshold.

10. The device of claim 9, wherein the alarm comprises one or more of a visible alert, an audible alert, a tactile alert, or any combination thereof

11. A method for estimating oxygen saturation in the presence of noise, the method comprising:

generating at least one oxygen saturation estimate using the processor;

communicating the at least one oxygen saturation estimate to a neural network using the processor;

receiving, at the processor, a modified oxygen saturation estimate from the neural network comprising less noise bias than the at least one oxygen saturation estimate, wherein the neural network defines the modified oxygen saturation estimate based at least in part on combining the at least one oxygen saturation estimate with corresponding signal quality metrics; and

presenting, via the processor, a representation of the modified oxygen saturation estimate on a display that is in communication with the processor.

12. The method of claim 11, wherein the neural network comprises a radial basis neural network.

13. The method of the claim 12, wherein the radial basis neural network comprises a single-hidden-layer network.

14. The method of claim 13, wherein the single-hidden-layer network has a plurality of nodes, and each node of the plurality of nodes includes one or more associated weights and a single bias.

15. The method of claim 11, wherein the neural network defines the modified oxygen saturation estimate based at least in part on combining the at least one oxygen saturation estimate with one or more additional oxygen saturation estimates.

16. The method of claim 15, wherein the modified oxygen saturation estimate has a value that is not between the values of the at least one oxygen saturation estimate and the one or more additional oxygen saturation estimates.

17. The method of claim 11, comprising comparing the modified oxygen saturation estimate with a hypoxia oxygen saturation threshold using the processor and initiating an alarm, via the processor, if the modified oxygen saturation estimate is less than or equal to the hypoxia oxygen saturation threshold.

18. The method of claim 11, comprising receiving oximetry data from a pulse oximeter at the processor and generating the at least one oxygen saturation estimate based on the received oximetry data, using the processor.

19. A system for estimating oxygen saturation in the presence of noise, the system comprising:

a processor in communication with a radial basis neural network, wherein the processor is configured to process oximetry data to produce at least one oxygen saturation estimate, the radial basis neural network is configured to receive the at least one oxygen saturation estimate from the processor and to modify the at least one oxygen saturation estimate based on corresponding signal quality metrics indicative of an accuracy of the at least one oxygen saturation estimate to define a modified oxygen saturation estimate having less noise bias than the at least one oxygen saturation, and the processor is configured to provide an output indicative of the modified oxygen saturation estimate.

20. The system of claim 19, wherein the processor is configured to compare the modified oxygen saturation estimate with a hypoxia oxygen saturation threshold and to initiate an alarm if the modified oxygen saturation estimate is less than or equal to the hypoxia oxygen saturation threshold.