System for Ventricular Arrhythmia Detection and Characterization

• US 20120179382A1
• Filed: 09/19/2011
• Published: 07/12/2012
• Est. Priority Date: 01/06/2011
• Status: Active Grant

• Current Assignee: PixArt Imaging Incorporated
• Original Assignee: Siemens Medical Solutions USA Incorporated (Siemens AG)
• Inventors: Zhang, Hongxuan
• Granted Patent: US 9,706,952 B2
• Time in Patent Office: Days
• US Class Current: 702/19
• CPC Class Codes: A61B 5/021 Measuring pressure in heart or blood vessels A61B5/0205 takes precedence
• CPC Class Codes: A61B 5/02416 using photoplethysmograph signals, e.g. generated by infrared radiation A61B5/14552 takes precedence
• CPC Class Codes: A61B 5/14551 for measuring blood gases
• CPC Class Codes: A61B 5/361 Detecting fibrillation
• CPC Class Codes: A61B 5/363 Detecting tachycardia or bradycardia
• CPC Class Codes: A61B 5/7203 for noise prevention, reduction or removal
• CPC Class Codes: A61B 5/7207 of noise induced by motion artifacts
• 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 5/746 Alarms related to a physiological condition, e.g. details of setting alarm thresholds or avoiding false alarms alarms per se G08B
• CPC Class Codes: G16H 50/20 for computer-aided diagnosis, e.g. based on medical expert systems

Abstract

A system for heart performance characterization and abnormality detection detects peaks and at least one of, a valley and a baseline comprising a substantially zero voltage level, of received signal data representing oxygen content of blood in a patient vessel over multiple heart beat cycles. The signal processor determines signal parameters including at least one of, (a) a signal amplitude magnitude between a maximum peak and minimum valley, of the received signal data, (b) a signal amplitude magnitude between a maximum peak and a baseline, of the received signal data and (c) a signal amplitude magnitude between a second highest maximum peak and minimum valley, of the received signal data. The system compares a determined signal parameter or value derived from the determined signal parameter, with a threshold value and generates an alert message associated with the threshold, in response to the comparison.

Claims

1. A system for heart performance characterization and abnormality detection, comprising:

an interface for receiving signal data representing oxygen content of blood in a patient vessel over a plurality of heart beat cycles;

a signal processor for detecting peaks and at least one of,

a valley and

a baseline comprising a substantially zero voltage level, of the received signal data and determining signal parameters including at least one of

(a) a signal amplitude magnitude between a maximum peak and minimum valley, of the received signal data,

(b) a signal amplitude magnitude between a maximum peak and a baseline, of the received signal data and

(c) a signal amplitude magnitude between a second highest maximum peak and minimum valley, of the received signal data; and

a comparator for comparing a determined signal parameter or value derived from the determined signal parameter with a threshold value to Provide a comparison indicator; and

a patient monitor for in response to said comparison indicator, generating an alert message associated with the threshold.

2. A system according to claim 1, wherein

said signal data is digitally sampled data and

said signal data representing oxygen content of blood comprises SPO2 signal data indicating Saturation of Hemoglobin with Oxygen as measured by pulse Oximetry.

3. A system according to claim 1, wherein

said signal processor detects peaks of a waveform within the received signal data using a peak detector and detects a valley as a negative peak in the signal data using a peak detector and

said signal processor detects a baseline of the signal by filtering out a static (DC) voltage signal component from the received signal data and by determining a substantially zero voltage level of the resultant filtered received signal data.

4. A system according to claim 3, wherein

said signal processor detects peaks or valleys of a waveform within the received signal data by using a peak or valley in segmenting the received signal data into windows where a peak or valley is expected and identifying the peak or valley within a window.

5. A system according to claim 4, wherein

said signal processor segments the received signal data by synchronizing a detection window with respect to a detected peak or valley.

6. A system according to claim 1, wherein

said signal processor determines signal parameters including at least one of,

(i) a signal amplitude magnitude between a second highest maximum peak and a baseline, of the received signal data,

(ii) a signal amplitude magnitude between a minimum valley and a baseline, of the received signal data and

(iii) a signal amplitude magnitude between a maximum peak and a second highest maximum peak, of the received signal data.

7. A system according to claim 1, wherein

said received signal data comprises at least one of ECG, IECG, dP/dt and hemodynamic signal data.

8. A system according to claim 1, wherein

said signal processor detects peaks in response to synchronization using at least one of an ECG, IECG, dP/dt and hemodynamic signal.

9. A system according to claim 1, wherein

said signal processor includes a timing detector for detecting time duration between a detected peak and a detected valley in the received signal data.

10. A system according to claim 9, wherein

said timing detector detects time duration between

(i) a maximum peak to a minimum valley, of the received signal data;

and

(ii) a minimum valley to a maximum peak, of the received signal data.

11. A system according to claim 1, wherein

said signal processor includes a timing detector for detecting time duration between a detected peak of a heart activity signal of the patient and a detected peak of the received signal data of the patient.

12. A system according to claim 1, wherein

said signal processor includes a timing detector for detecting time duration between a detected peak of a blood pressure representative signal of the patient and a detected peak of the received signal data of the patient.

13. A system according to claim 1, wherein

said signal processor determines a ratio of the determined signal parameters.

14. A system according to claim 1, wherein

said threshold value is derived from received signal data for said patient.

15. A system according to claim 1, wherein

said threshold value is derived from received signal data for a population of patients.

16. A system according to claim 15, wherein

said population of patients has similar demographic characteristics including at least two of, (a) age, (b) weight, (c) gender and (d) height, to those of said patient.

17. A system according to claim 1, wherein

said signal processor dynamically adjusts said threshold value in response to a determined sensitivity of arrhythmia detection.

18. A system according to claim 1, wherein

said signal processor calculates a standard deviation of a determined parameter over a plurality of heart cycles and

said patient monitor, in response to a comparison indicator indicating a calculated standard deviation value exceeds a predetermined threshold value, generates an alert message.

19. A system according to claim 1, including

a repository of mapping information, associating ranges of a determined parameter with corresponding medical conditions and

said comparator compares the determined parameter with said ranges to provide a comparison indicator identifying a medical condition and

said patient monitor generates an alert message identifying said medical condition.

20. A system according to claim 19, wherein

said predetermined mapping information associates ranges of determined parameters with particular patient demographic characteristics and with corresponding medical conditions and said system uses patient demographic data including at least one of, age weight, gender and height in comparing a determined parameter with said ranges and generating an alert message indicating a potential medical condition.

21. A method for heart performance characterization and abnormality detection, comprising the activities of:

receiving signal data representing oxygen content of blood in a patient vessel over a plurality of heart beat cycles;

detecting peaks and at least one of,

a valley and

a baseline comprising a substantially zero voltage level, of the received signal data and determining signal parameters including at least one of,

(a) a signal amplitude magnitude between a maximum peak and minimum valley, of the received signal data,

(b) a signal amplitude magnitude between a maximum peak and a baseline, of the received signal data and

(c) a signal amplitude magnitude between a second highest maximum peak and minimum valley, of the received signal data; and

in response to comparing a determined signal parameter or value derived from the determined signal parameter with a threshold value, generating an alert message associated with the threshold.