System and method for monitoring autoregulation

• US 10,383,579 B2
• Filed: 10/13/2015
• Issued: 08/20/2019
• Est. Priority Date: 10/16/2014
• Status: Active Grant

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Covidien LP (Medtronic Plc)
• Inventors: Addison, Paul S., Watson, James N.
• Primary Examiner(s): Winakur, Eric F
• Application Number:
  US14/881,455
• Publication Number:
  US 20160106372A1
• Time in Patent Office: 1,407 Days
• CPC Class Codes: A61B 5/0205 Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition
• CPC Class Codes: A61B 5/021 Measuring pressure in heart or blood vessels A61B5/0205 takes precedence
• CPC Class Codes: A61B 5/14553 specially adapted for cerebral tissue
• CPC Class Codes: A61B 5/7221 Determining signal validity, reliability or quality A61B5/7207 and A61B5/7217 take precedence
• CPC Class Codes: A61B 5/7246 using correlation, e.g. template matching or determination of similarity

Abstract

A method for monitoring autoregulation includes, using a processor, receiving a blood pressure signal and an oxygen saturation signal from a patient. The method also includes determining a linear correlation between the blood pressure signal and the oxygen saturation signal and determining a significance value associated with the linear correlation. The method further includes providing a signal indicative of the patient'"'"'s autoregulation status to an output device based on the linear correlation and the significance value.

Claims

1. A method for monitoring autoregulation, the method comprising:

receiving, by one or more processors, a blood pressure signal indicative of a blood pressure of a patient and an oxygen saturation signal indicative of blood oxygen saturation of the patient;

determining, by the one or more processors, a linear correlation between the blood pressure signal and the oxygen saturation signal;

determining, by the one or more processors, a significance value associated with the linear correlation, wherein the significance value comprises a p-value; and

providing, by the one or more processors, a signal indicative of the patient'"'"'s autoregulation status to an output device based on the linear correlation and the significance value.

2. The method of claim 1, comprising:

determining, by the one or more processors, the significance value is below a predetermined threshold; and

providing, by the one or more processors, a cerebral oximetry index value to the output device only while the significance value is below the predetermined threshold.

3. The method of claim 1, comprising:

determining, by the one or more processors, the significance value is above a predetermined threshold; and

providing, by the one or more processors, a prior reliable cerebral oximetry index value to the output device in response to determining the significance value is above the predetermined threshold.

4. The method of claim 1, comprising:

determining, by the one or more processors, the significance value is above a predetermined threshold; and

averaging, by the one or more processors, a current cerebral oximetry index value with a prior reliable cerebral oximetry index value to generate an average cerebral oximetry index value in response to determining the significance value is above the predetermined threshold.

5. The method of claim 4, comprising providing the average cerebral oximetry index value to the output device.

6. The method of claim 1, wherein receiving the oxygen saturation signal comprises receiving the oxygen saturation signal from a regional saturation sensor comprising at least one emitter and a plurality of detectors.

7. The method of claim 1, comprising receiving a signal quality metric related to the blood pressure signal, the oxygen saturation signal, or both.

8. The method of claim 7, comprising:

comparing, by the one or more processors, the signal quality metric to a signal quality metric threshold; and

determining, by the one or more processors, the linear correlation between the blood pressure signal and the oxygen saturation signal only while the signal quality metric is above the signal quality metric threshold.

9. A monitor for monitoring autoregulation, the monitor comprising:

an output device; and

one or more processors configured to;

receive a blood pressure signal indicative of a blood pressure of a patient and an oxygen saturation signal indicative of blood oxygen saturation of the patient;

determine a linear correlation between the blood pressure signal and the oxygen saturation signal;

determine a significance value associated with the linear correlation, wherein the significance value comprises a p-value; and

provide a signal indicative of the patient'"'"'s autoregulation status to the output device based on the linear correlation and the significance value.

10. The monitor of claim 9, wherein the one or more processors are configured to:

determine the significance value is below a predetermined threshold; and

provide a cerebral oximetry index value to the output device only while the significance value is below the predetermined threshold.

11. The monitor of claim 9, wherein the one or more processors are configured to:

determine the significance value is above a predetermined threshold; and

provide a prior reliable cerebral oximetry index value to the output device in response to determining the significance value is above the predetermined threshold.

12. The monitor of claim 9, wherein the one or more processors are configured to:

determine the significance value is above a predetermined threshold;

average a current cerebral oximetry index value with a prior reliable cerebral oximetry index value to generate an average cerebral oximetry index value in response to determining the significance value is above the predetermined threshold; and

provide the average cerebral oximetry index value to the output device.

13. The monitor of claim 9, wherein the one or more processors are configured to receive the oxygen saturation signal from a regional saturation sensor comprising at least one emitter and plurality of detectors.

14. The monitor of claim 9, wherein the one or more processors are configured to receive a signal quality metric related to the blood pressure signal, the oxygen saturation signal, or both.

15. The monitor of claim 14, wherein the one or more processors are configured to:

compare the signal quality metric to a signal quality metric threshold; and

determine the linear correlation between the blood pressure signal and the oxygen saturation signal only while the signal quality metric is above a signal quality metric threshold.

16. A system for monitoring autoregulation, the system comprising:

an oxygen saturation sensor configured to obtain an oxygen saturation signal indicative of blood oxygen saturation of a patient;

a controller comprising one or more processors configured to;

receive the oxygen saturation signal and a blood pressure signal indicative of a blood pressure of the patient;

determine a linear correlation between the blood pressure signal and the oxygen saturation signal;

determine a significance value associated with the linear correlation, wherein the significance value comprises a p-value; and

provide a signal indicative of the patient'"'"'s autoregulation status to an output device based on the linear correlation and the significance value.

17. The system of claim 16, wherein the oxygen saturation sensor is configured to generate the oxygen saturation signal and the blood pressure signal.

18. The system of claim 16, comprising the output device, wherein the one or more processors are configured to cause the output device to display a cerebral index value indicative of the patient'"'"'s autoregulation status, an indication of a cerebral index value reliability, an indication of the patient'"'"'s autoregulation status, or any combination thereof.

19. The system of claim 18, wherein the one or more processors are configured to provide an alarm signal to the output device, and the output device is configured to provide a visual or audible alarm based on the alarm signal.

20. The system of claim 16, wherein the one or more processors are configured to:

determine the significance value is above a predetermined threshold; and

block transmission of the signal indicative of the patient'"'"'s autoregulation status to the output device in response to determining the significance value is above the predetermined threshold.