Systems and methods for monitoring heart rate and blood pressure correlation

• US 8,932,219 B2
• Filed: 06/20/2012
• Issued: 01/13/2015
• Est. Priority Date: 03/05/2009
• Status: Active Grant

• Current Assignee: Nellcor Puritan Bennett Ireland
• Original Assignee: Nellcor Puritan Bennett Ireland
• Inventors: Addison, Paul Stanley, Watson, James, Sethi, Rakesh
• Primary Examiner(s): Gedeon, Brian T
• Application Number:
  US13/528,755
• Publication Number:
  US 20120259235A1
• Time in Patent Office: 937 Days
• Field of Search: None
• US Class Current: 600/301
• 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 5/7264 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: G16H 40/63 for local operation
• CPC Class Codes: G16H 50/20 for computer-aided diagnosis, e.g. based on medical expert systems

Abstract

Systems and methods are provided for monitoring a correlation between heart rate and blood pressure in a patient. When a characteristic of the correlation exceeds a threshold, a patient status indicator signal is sent to a monitoring device. In some embodiments, the patient status indicator signal indicates a particular medical condition or alerts a care provider to a change in status. In some embodiments, the heart rate signal is used to improve a blood pressure estimate generated by a different signal. In some embodiments, the heart rate, blood pressure and correlation signals are used in a predictive mathematical model to estimate patient status or outcome.

Claims

1. A method for monitoring patient status with a processor, the method comprising:

receiving an electronic signal indicative of a patient'"'"'s heart rate;

receiving an electronic signal indicative of a patient'"'"'s blood pressure;

calculating a correlation of the electronic signal indicative of a patient'"'"'s heart rate and the electronic signal indicative of a patient'"'"'s blood pressure;

determining whether the correlation is positive or negative;

comparing a characteristic of the correlation to a threshold in response to determining that the correlation is positive;

generating a patient status indicator signal based on the comparison; and

indicating, with an output device, a patient status based on the generated patient status indicator signal.

2. The method of claim 1, wherein the characteristic of the correlation comprises a change in heart rate relative to a change in blood pressure.

3. The method of claim 1, wherein the characteristic of the correlation comprises a rate of change in heart rate relative to a rate of change in blood pressure.

4. The method of claim 1, wherein indicating the patient status comprises at least one of displaying the correlation characteristic on a screen, displaying a message associated with the patient status indicator signal, displaying a color associated with the patient status indicator signal, displaying a graphic associated with the patient status indicator signal, and producing a sound associated with the patient status indicator signal.

5. The method of claim 1, further comprising calculating a current blood pressure based at least in part on the received electronic signal indicative of the patient'"'"'s heart rate.

6. The method of claim 1, further comprising predicting at least one of a patient outcome and current status using a computational model based at least in part on the electronic signal indicative of a patient'"'"'s heart rate and the electronic signal indicative of a patient'"'"'s blood pressure.

7. The method of claim 1, wherein the characteristic of the correlation is selected from the group consisting of a maximum value, a minimum value, an average value, a median value, a mode value, a rate of change, a second derivative, an amplitude of a signal landmark, a timing of a signal landmark, a similarity of the correlation over an interval to a pre-defined pattern, a function of the one or more correlations, a frequency content, and any combination thereof.

8. The method of claim 1, further comprising:

calculating more than one correlation of the electronic signal indicative of the patient'"'"'s heart rate and the electronic signal indicative of the patient'"'"'s blood pressure;

comparing each of more than one characteristic of the more than one correlation to a respective corresponding threshold;

generating the patient status indicator signal based on the comparisons; and

combining the comparisons using at least one of algebraic operations and logical operations, wherein generating the patient status indicator signal is further based on the combined comparisons.

9. A system for monitoring patient status with a processor, the system comprising:

a processor capable of receiving at least one input signal, the processor configured to;

receive an electronic signal indicative of a patient'"'"'s heart rate;

receive an electronic signal indicative of a patient'"'"'s blood pressure;

calculate a correlation of the electronic signal indicative of a patient'"'"'s heart rate and the electronic signal indicative of a patient'"'"'s blood pressure;

determine whether the correlation is positive or negative;

compare a characteristic of the correlation to a threshold in response to determining that the correlation is positive;

generate a patient status indicator signal based on the comparison; and

an output device communicably coupled to the processor configured to indicate a patient status based on the generated patient status indicator signal.

10. The system of claim 9, wherein the characteristic of the correlation comprises a change in heart rate relative to a change in blood pressure.

11. The system of claim 9, wherein the characteristic of the correlation comprises a rate of change in heart rate relative to a rate of change in blood pressure.

12. The system of claim 9, wherein the output device is further configured to perform at least one of displaying the correlation characteristic on a screen, displaying a message associated with the patient status indicator signal, displaying a color associated with the patient status indicator signal, displaying a graphic associated with the patient status indicator signal, and producing a sound associated with the patient status indicator signal.

13. The system of claim 9, wherein the processor is further configured to calculate a current blood pressure based at least in part on the received electronic signal indicative of the patient'"'"'s heart rate.

14. The system of claim 9, wherein the processor is further configured to predict at least one of a patient outcome and current status using a computational model based at least in part on the electronic signal indicative of a patient'"'"'s heart rate and the electronic signal indicative of a patient'"'"'s blood pressure.

15. The system of claim 9, wherein the characteristic of the correlation is selected from the group consisting of a maximum value, a minimum value, an average value, a median value, a mode value, a rate of change, a second derivative, an amplitude of a signal landmark, a timing of a signal landmark, a similarity of the correlation over an interval to a pre-defined pattern, a function of the one or more correlations, a frequency content, and any combination thereof.

16. The system of claim 9, wherein the processor is further configured to:

calculate more than one correlation of the electronic signal indicative of the patient'"'"'s heart rate and the electronic signal indicative of the patient'"'"'s blood pressure;

compare each of more than one characteristic of the more than one correlation to a respective corresponding threshold;

generate the patient status indicator signal based on the comparisons; and

combine the comparisons using at least one of algebraic operations and logical operations; and

generate the patient status indicator signal based on the combined comparisons.

17. A system for monitoring patient status, the system comprising:

non-transitory computer readable medium storing computer executable instructions for;

receiving an electronic signal indicative of a patient'"'"'s heart rate;

receiving an electronic signal indicative of a patient'"'"'s blood pressure;

calculating a correlation of the electronic signal indicative of a patient'"'"'s heart rate and the electronic signal indicative of a patient'"'"'s blood pressure;

determining whether the correlation is positive or negative;

comparing a characteristic of the correlation to a threshold in response to determining that the correlation is positive; and

generating a patient status indicator signal based on the comparison; and

an output device configured to indicate a patient status based on the generated patient status indicator signal.

18. The system of claim 17, wherein the characteristic of the correlation comprises a change in heart rate relative to a change in blood pressure.

19. The system of claim 17, wherein the characteristic of the correlation comprises a rate of change in heart rate relative to a rate of change in blood pressure.