SYSTEMS AND METHODS FOR MONITORING HEART RATE AND BLOOD PRESSURE CORRELATION

• US 20100228102A1
• Filed: 03/05/2009
• Published: 09/09/2010
• 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
• Granted Patent: US 8,216,136 B2
• Time in Patent Office: Days
• 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 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 two received signals;

determining whether a characteristic of the correlation exceeds a threshold;

generating a patient status indicator signal in response to determining whether the characteristic of the correlation exceeds a threshold; and

indicating, with an output device, a patient status in response to receiving the 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 determining whether the characteristic of the correlation exceeds a threshold comprises determining when the correlation is positive and when the correlation is negative.

5. The method of claim 1 wherein indicating a 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.

6. The method of claim 1, wherein generating a patient status indicator signal comprises querying a lookup table to retrieve a value for a patient status, wherein the lookup table is stored in an electronic memory device communicably coupled to the processor.

7. The method of claim 1 further comprising calculating a current blood pressure based at least in part on the received electronic signal indicative of a patients heart rate.

8. 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 two received signals.

9. A system for monitoring a patient'"'"'s status comprising:

at least one memory device;

a display device, capable of indicating a patient status in response to receiving a patient status indicator signal;

a processor, communicably coupled to the at least one memory device and the display device and capable of receiving at least one input signal, the processor configured to;

calculate a heart rate waveform based on at least an input signal indicative of a patient'"'"'s heart rate;

calculate a blood pressure waveform based at least an input signal indicative of a patients blood pressure;

store a patient status indicator value in one of the at least one memory device;

calculate a correlation of the two calculated waveforms;

for each of at least one patient condition;

identifying a characteristic, associated with the condition, of the correlation;

determining whether the correlation characteristic exceeds a threshold associated with the condition, wherein the threshold is stored in one of the at least one memory device;

when the correlation characteristic exceeds the threshold, updating the stored patient status indicator value to represent the condition;

generate a patient status indicator signal based on at least the stored patient status indicator value.

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 determining whether the characteristic of the correlation exceeds a threshold comprises determining when the correlation is positive and when the correlation is negative.

13. The system of claim 9 wherein indicating a patient status in response to receiving a patient status indicator signal with the display device 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.

14. The system of claim 9, wherein generating a patient status indicator signal comprises querying a lookup table to retrieve a value for a patient status, wherein the lookup table is stored in an electronic memory device communicably coupled to the processor.

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

16. 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 signals.

17. Computer-readable medium for use in monitoring patient status, the computer-readable medium having computer program instructions recorded thereon 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 two received signals;

determining whether a characteristic of the correlation exceeds a threshold;

generating a patient status indicator signal in response to determining whether the characteristic of the correlation exceeds a threshold; and

directing an output device to indicate a patient status in response to receiving the patient status indicator signal.

18. The computer-readable medium of claim 17 wherein the characteristic of the correlation comprises a change in heart rate relative to a change in blood pressure.

19. The computer-readable medium of claim 17 wherein determining whether the characteristic of the correlation exceeds a threshold comprises determining when the correlation is positive and when the correlation is negative.

20. The computer-readable medium of claim 17 wherein generating a patient status indicator signal comprises querying a lookup table, stored in an electronic memory device, to retrieve a value for a patient status.