ADAPTIVE SELECTION OF DIGITAL ECG FILTER

• US 20170156618A1
• Filed: 02/16/2017
• Published: 06/08/2017
• Est. Priority Date: 03/14/2013
• Status: Active Grant

• Current Assignee: Vital Connect, Inc.
• Original Assignee: Vital Connect, Inc.
• Inventors: NARASIMHAN, Ravi, FERDOSI, Nima, NAZARI, Nersi
• Granted Patent: US 11,051,745 B2
• Time in Patent Office: Days
• CPC Class Codes: A61B 2562/028 Microscale sensors, e.g. electromechanical sensors [MEMS]
• CPC Class Codes: A61B 5/0006 ECG or EEG signals
• CPC Class Codes: A61B 5/0022 Monitoring a patient using a global network, e.g. telephone networks, internet
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61B 5/0245 by using sensing means generating electric signals, i.e. ECG signals
• CPC Class Codes: A61B 5/316 Modalities, i.e. specific diagnostic methods
• CPC Class Codes: A61B 5/349 Detecting specific parameters of the electrocardiograph cycle
• CPC Class Codes: A61B 5/352 Detecting R peaks, e.g. for synchronising diagnostic apparatus; Estimating R-R interval
• CPC Class Codes: A61B 5/364 Detecting abnormal ECG interval, e.g. extrasystoles, ectopic heartbeats
• CPC Class Codes: A61B 5/7203 for noise prevention, reduction or removal
• CPC Class Codes: A61B 5/721 using a separate sensor to detect motion or using motion information derived from signals other than the physiological signal to be measured
• CPC Class Codes: G16H 40/63 for local operation
• CPC Class Codes: G16Z 99/00 Subject matter not provided for in other main groups of this subclass

Abstract

A method and system for filtering a detected ECG signal are disclosed. In a first aspect, the method comprises filtering the detected ECG signal using a plurality of digital filters. The method includes adaptively selecting one of the plurality of digital filters to maintain a minimum signal-to-noise ratio (SNR). In a second aspect, the system comprises a wireless sensor device coupled to a user via at least one electrode, wherein the wireless sensor device includes a processor and a memory device coupled to the processor, wherein the memory device stores an application which, when executed by the processor, causes the processor to carry out the steps of the method.

Claims

1. A system to filter a detected ECG signal, comprising:

a wireless sensor device communicatively coupled to a user via at least one electrode, wherein the wireless sensor device includes a processor; and

a memory device communicatively coupled to the processor, wherein the memory device stores an application which, in response to being executed by the processor, causes the wireless sensor device to;

filter a detected ECG signal using a plurality of digital filters; and

adaptively select one of the plurality of digital filters to maintain a minimum signal-to-noise ratio (SNR).

2. The system of claim 1, wherein the plurality of digital filters includes a plurality of parallel digital band-pass filters having varying high-pass cutoff frequencies.

3. The system of claim 1, wherein the application, in response to further execution by the processor, causes the wireless sensor device to:

utilize an output of the adaptively selected digital filter to calculate an R wave to R wave (RR) interval of the detected ECG signal.

4. The system of claim 1, wherein the application, in response to further execution by the processor, causes the wireless sensor device to:

calculate a Quality Metric for each of the plurality of digital filters, wherein the Quality Metric is utilized to adaptively select one of the plurality of digital filters.

5. The system of claim 4, wherein the calculating occurs on one of the plurality of digital filters at a time to conserve power consumption.

6. The system of claim 4, wherein the application, in response to further execution by the processor, causes the wireless sensor device to:

calculate a statistical quality indicator of the Quality Metric; and

calculate a mid-beat SNR quality indicator of the Quality Metric.

7. The system of claim 6, wherein the application, in response to further execution by the processor, causes the wireless sensor device to:

combine the statistical quality indicator and the mid-beat SNR quality indicator via a weighted linear combination to calculate the Quality Metric.

8. The system of claim 4, wherein the application, in response to further execution by the processor, causes the wireless sensor device to:

calculate an activity level using a microelectromechanical systems (MEMS) device embedded within a wireless sensor device to measure noise of the detected ECG signal.

9. The system of claim 4, wherein the application, in response to further execution by the processor, causes the wireless sensor device to:

maintain a minimum Quality Metric to prevent erratic switching between the plurality of digital filters.

10. The system of claim 4, wherein the application, in response to further execution by the processor, causes the wireless sensor device to:

provide notifications of ECG signal quality and recommended actions based upon the calculated Quality Metric and the calculated activity level.

11. A wireless sensor device, comprising:

at least one electrode, removably attached to a user, that detects an electrocardiogram (ECG) signal of the user; and

a memory device storing executable instructions that, in response to execution, causes a processor of the wireless sensor device to perform operations including;

filtering the detected ECG signal using a plurality of digital filters; and

adaptively select one of the plurality of digital filters to maintain a minimum signal-to-noise ratio (SNR).

12. The wireless sensor device of claim 11, wherein the plurality of digital filters includes a plurality of parallel digital band-pass filters having varying high-pass cutoff frequencies.

13. The wireless sensor device of claim 11, wherein the executable instructions, in response to further execution by the processor, causes the processor to:

utilize an output of the adaptively selected digital filter to calculate an R wave to R wave (RR) interval of the detected ECG signal.

14. The wireless sensor device of claim 11, wherein the executable instructions, in response to further execution by the processor, causes the processor to:

calculate a Quality Metric for each of the plurality of digital filters, wherein the Quality Metric is utilized to adaptively select one of the plurality of digital filters.

15. The wireless sensor device of claim 14, wherein the calculating occurs on one of the plurality of digital filters at a time to conserve power consumption.

16. The wireless sensor device of claim 14, wherein the executable instructions, in response to further execution by the processor, causes the processor to:

calculate a statistical quality indicator of the Quality Metric; and

calculate a mid-beat SNR quality indicator of the Quality Metric.

17. The wireless sensor device of claim 16, wherein the executable instructions, in response to further execution by the processor, causes the processor to:

combine the statistical quality indicator and the mid-beat SNR quality indicator via a weighted linear combination to calculate the Quality Metric.

18. The wireless sensor device of claim 14, wherein the executable instructions, in response to further execution by the processor, causes the processor to:

calculate an activity level using a microelectromechanical systems (MEMS) device embedded within a wireless sensor device to measure noise of the detected ECG signal.

19. The wireless sensor device of claim 14, wherein the executable instructions, in response to further execution by the processor, causes the processor to:

maintain a minimum Quality Metric to prevent erratic switching between the plurality of digital filters.

20. The wireless sensor device of claim 14, wherein the executable instructions, in response to further execution by the processor, causes the processor to:

provide notifications of ECG signal quality and recommended actions based upon the calculated Quality Metric and the calculated activity level.