Method and Apparatus for Distinguishing Between Clinically Significant Changes and Artifacts in Patient Physiological Information

• US 20080208012A1
• Filed: 05/31/2006
• Published: 08/28/2008
• Est. Priority Date: 06/09/2005
• Status: Active Grant

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips N.V.
• Inventors: Ali, Walid S. I.
• Granted Patent: US 8,070,677 B2
• Time in Patent Office: Days
• US Class Current: 600/301
• CPC Class Codes: G06F 2218/18 by plotting the signal segments against each other, e.g. analysing scattergrams
• CPC Class Codes: G16H 40/63 for local operation

Abstract

A patient physiological information monitoring system includes a plurality of patient monitoring devices (6) and a physiological information analyzer (2). The plurality of patient monitoring devices (6) monitor physiological information from a patient and generate corresponding physiological signals. The physiological information analyzer (2) processes the monitored physiological information and determines whether a physiological change is a clinically significant event or an artifact. The physiological information analyzer includes at least one receiver (4) that receives the physiological signals from the patient monitoring devices; a signal correlator (10) that generates morphograms from pairs of the received physiological signals; a signature generator (12) that applies a wavelet decomposition to each morphogram to compute a signature for each morphogram; and a decision component (14) that compares the morphogram signatures within and across sampling intervals and determines if a physiological change is a clinically significant change or an artifact.

Claims

1. A patient physiological information monitoring system, comprising:

a plurality of patient monitoring devices that monitor physiological information from a patient and generate corresponding physiological signals; and

a physiological information analyzer that processes the monitored physiological information and determines whether a physiological change is a clinically significant event or an artifact, the physiological information analyzer including;

at least one receiver that receives the physiological signals from the patient monitoring devices;

a signal correlator that generates morphograms from pairs of the received physiological signals;

a signature generator that applies a wavelet decomposition to each morphogram to compute a signature for each morphogram; and

a decision component that compares the morphogram signatures within and across sampling intervals and determines if a physiological change is a clinically significant change or an artifact.

2. The patient physiological information monitoring system as set forth in claim 1, wherein the decision component determines the physiological change is an artifact if the shape perturbation is only in a subset of signatures with at least one common signal.

3. The patient physiological information monitoring system as set forth in claim 1, wherein the decision component determines an alarm is valid if a shape perturbation is present in the signatures with signals related to the physiological change.

4. The patient physiological information monitoring system as set forth in claim 1, further including a display component that visually presents at least some of the signatures for observation by a clinical staff.

5. The patient physiological information monitoring system as set forth in claim 1, wherein the analyzer discards signatures that include artifact and stores signatures that include clinically significant physiological changes in a storage component (8).

6. The patient physiological information monitoring system as set forth in claim 1, wherein the wavelet is a Symlet wavelet.

7. The patient physiological information monitoring system as set forth in claim 1, wherein the signature of a morphogram is represented by one or more coefficients that fully describe morphogram shape variability.

8. The patient physiological information monitoring system as set forth in claim 7, wherein the one or more coefficients include a horizontal detail, a vertical detail, and a diagonal detail that includes both a horizontal component and vertical component.

9. The patient physiological information monitoring system as set forth in claim 1, wherein the wavelet decomposition includes one or more levels of decomposition.

10. The patient physiological information monitoring system as set forth in claim 1, wherein the sampling intervals occur at a sampling rate that is less than or equal to an alarm latency period of the corresponding patient monitor device, the alarm latency period corresponds to a time over which an alarm condition exits in order to trigger an alarm with a high degree of correctness.

11. The patient physiological information monitoring system as set forth in claim 1, wherein the physiological information includes at least one or more ECG signals and an arterial blood pressure (ABP) signal.

12. The patient physiological information monitoring system as set forth in claim 1, wherein the physiological information analyzer sounds an alarm and/or prematurely invokes a monitoring device to alarm when it determines a clinically significant physiological change has occurred.

13. The patient physiological information monitoring system as set forth in claim 1, the physiological information analyzer prevents or turns off a patient monitoring device alarm when the analyzer determines a monitored physiological change is an artifact.

15. The method as set forth in claim 1, wherein the wavelet is a Symlet wavelet.

16. The method as set forth in claim 1, wherein each signature is a unique descriptor represented as coefficients that describe morphogram shape variability.

17. The method as set forth in claim 15, further including using the result of the determination to invoke or override a patient monitoring device related alarm, the patient monitoring device alarm being invoked when the perturbation is determined to be due to a clinically significant physiological.

18. The method as set forth in claim 15, further including displaying at least the signatures for observation by clinical staff.

14. A method for determining whether a physiological change captured by a patient monitoring device is a clinically significant change or an artifact, comprising:

receiving physiological signals indicative of physiological information monitored from patient;

generating a morphogram for pairs of the physiological signals as the physiological information for each sampling interval is received;

applying a wavelet decomposition on each morphogram to generate a signature for each morphogram; and

comparing the signatures within and across sampling intervals; and

determining whether signatures perturbations are a result of clinically significant changes or artifacts.

19. A computer programmed to perform the method of claim 14.

20. A method of patient monitoring, comprising:

generating morphograms from related patient monitoring signals;

decomposing the morphograms via a wavelet decomposition to generate signatures;

comparing changes in the signatures relative to each other or over time; and

based on the signature comparisons, determining whether a clinically significant event or an artifact has occurred.