ECG SENSING APPARATUSES, SYSTEMS AND METHODS

• US 20140364756A1
• Filed: 08/25/2014
• Published: 12/11/2014
• Est. Priority Date: 11/03/2009
• Status: Active Grant

• Current Assignee: VivaQuant LLC
• Original Assignee: VivaQuant LLC
• Inventors: BROCKWAY, BRIAN, BROCKWAY, MARINA
• Granted Patent: US 9,492,096 B2
• Time in Patent Office: Days
• US Class Current: 600/513
• CPC Class Codes: A61B 5/0006 ECG or EEG signals
• CPC Class Codes: A61B 5/0245 by using sensing means generating electric signals, i.e. ECG signals
• CPC Class Codes: A61B 5/259 using conductive adhesive means, e.g. gels
• CPC Class Codes: A61B 5/28 for electrocardiography [ECG]
• CPC Class Codes: A61B 5/316 Modalities, i.e. specific diagnostic methods
• CPC Class Codes: A61B 5/33 specially adapted for cooperation with other devices
• 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 5/7253 characterised by using transforms
• CPC Class Codes: A61B 7/00 Instruments for auscultation
• CPC Class Codes: G06F 17/14 Fourier, Walsh or analogous domain transformations , e.g. Laplace, Hilbert, Karhunen-Loeve, transforms for correlation function computation G06F17/156; spectrum analysers G01R23/16
• CPC Class Codes: G06F 2218/04 Denoising
• CPC Class Codes: G06F 2218/10 by analysing the shape of a waveform, e.g. extracting parameters relating to peaks
• CPC Class Codes: G16H 50/30 for calculating health indices; for individual health risk assessment

Abstract

Aspects of the present disclosure are directed to processing ECG signals from a subject. As may be implemented in accordance with one or more embodiments, respective electrodes sense ECG signals from a subject, and the ECG signals are digitized and processed, such as to remove noise, detect a QRS complex, evaluate quality, detect arrhythmia and/or to store the signals. In response to an input from the subject, one or more of the ECG signals is recorded along with sound from the user, such as to concurrently record the user'"'"'s voice for describing conditions in connection with the recording of the ECG signals. This approach can be carried out in an enclosed housing, operated adjacent the subject'"'"'s thorax. The processed digitized ECG signals and the audio signals are then communicated for receipt by an external device.

Claims

1. An apparatus comprising:

first and second electrodes configured and arranged to sense ECG signals from a subject;

a digitizing circuit configured and arranged to receive and digitize the ECG signals sensed by the electrodes;

an audio circuit configured and arranged to capture sounds from the subject and to convert the sound into electrical audio signals;

a processing circuit configured and arranged with the electrodes and digitizing circuit to digitize the ECG signals and to process each digitized ECG signal by at least one of;

removing noise from the digitized ECG signal, storing the digitized ECG signal in a memory circuit, detecting a QRS complex in the digitized ECG signal, evaluating quality of the digitized ECG signal, and detecting arrhythmia in the digitized ECG signal;

an input circuit configured and arranged to receive an input from the subject, the processing circuit and audio circuit being respectively configured and arranged with the input circuit to initiate recording of at least one of the ECG signals and the sound in response to the input; and

a communication circuit configured and arranged to communicate the processed digitized ECG signals and the audio signals for receipt by an external device.

2. The apparatus of claim 1, further including the memory circuit, wherein the processing circuit is configured and arranged to

store, in the memory circuit, data that represents and links the at least one of the ECG signals and the sound recorded in response to the input, thereby linking each captured ECG signal with sound recorded in connection with the captured ECG signal, and

communicate the stored data that represents and links ECG signals with recorded sound, via the communication circuit.

3. The apparatus of claim 1, further including a transducer configured and arranged to generate audible sound, wherein the at least one processor is configured and arranged to evaluate signal quality of the digitized ECG signal and to audibly communicate an indication of the evaluated quality of the signal via the transducer.

4. The apparatus of claim 1, wherein the at least one processor is configured and arranged to evaluate the signal quality of the digitized ECG signal by:

decomposing the digitized ECG signal into subcomponents,

computing a statistical variance of the subcomponents over a time interval, and

assessing signal quality based upon the statistical variance of the subcomponents.

5. The apparatus of claim 1, wherein the at least one processor is configured and arranged to remove noise from the digitized ECG signal by

decomposing the signal into subcomponents;

identifying a location of the QRS complex of a cardiac cycle in the ECG signal;

identifying a first time window in the cardiac cycle that includes the QRS complex;

identifying at least one time window in the cardiac cycle that does not include the QRS complex;

for each of the identified time windows, identifying target subcomponents as subcomponents that contain more energy that is within a band of frequencies characteristic of a desired ECG signal in the time window than energy that is outside the band of frequencies characteristic of the desired ECG signal; and

reconstructing a denoised physiological signal using at least two of the identified target subcomponents.

6. The apparatus of claim 1, wherein the audio circuit includes a microphone and wherein the input circuit includes at least one manual switch configured and arranged to provide the input in response to the subject manually activating the at least one switch.

7. The apparatus of claim 1 further including a housing that includes the digitizing circuit, audio circuit, processing circuit and communication circuit, the housing being constructed primarily of a non-conductive material and having at least one conductive pin embedded into the non-conductive material and configured and arranged to electrically conduct the sensed ECG signals from outside the housing to the digitizing circuit within the housing, the at least one conductive pin being sealed within and configured and arranged with the non-conductive exterior to prevent penetration of fluid into the housing.

8. The apparatus of claim 7, further including a fastener configured and arranged to mechanically support the housing proximate the subject'"'"'s thorax.

9. The apparatus of claim 8, wherein

the fastener includes the first electrode and is configured and arranged to adhere to the subject'"'"'s skin,

the housing includes a conductive snap at an outer surface thereof;

and

the fastener includes a conductive snap that is configured and arranged to mate with the conductive snap in the housing, and to provide both mechanical support for the housing and electrical connection from the first electrode to the digitizing circuit contained within the housing.

10. The apparatus of claim 8,

wherein the fastener includes the first electrode and is configured and arranged to adhere to the subject'"'"'s skin,

further including a conductive lead wire that extends through the housing, and a conductive snap connected to the conductive lead wire;

and

wherein the fastener includes a conductive snap that is configured and arranged to

mate with the conductive snap connected to the conductive lead wire, and

provide both mechanical support for the housing and electrical connection from the first electrode to the digitizing circuit contained within the housing.

11. The apparatus of claim 1, wherein the processing circuit is configured and arranged to evaluate the quality of the digitized ECG signal by providing an indication that at least one of the first and second electrodes is disconnected from the subject, and by placing the apparatus in a low power mode in response thereto.

12. An apparatus comprising:

first and second electrodes configured and arranged to sense ECG signals from a subject;

a digitizing circuit configured and arranged to digitize each sensed ECG signal;

an audio circuit configured and arranged to capture sounds from the subject and to convert the sounds into electrical audio signals;

a wireless communication circuit configured and arranged to wirelessly transmit data to an external device;

an input device configured and arranged to receive a tactile input from the subject and to convert the tactile input to an input signal;

at least one processor configured and arranged to;

in response to each input signal, record a digitized ECG signal sensed from the subject via the electrodes, and record the subject'"'"'s voice via the audio circuit,

process the digitized ECG signal by at least one of;

removing noise from the digitized ECG signal, storing the digitized ECG signal in a memory circuit, detecting a QRS complex in the digitized ECG signal, evaluating quality of the digitized ECG signal, and detecting arrhythmia in the digitized ECG signal,

wirelessly transmit the recorded voice and digitized ECG signal to the external device via the wireless communication circuit, thereby providing access to ECG signals and the subject'"'"'s voice as recorded in conjunction with each ECG signal recorded in response to tactile input from the subject;

a power supply configured and arranged to provide power to the digitizing circuit, the audio circuit, the communication circuit, the input device, and the at least one processor;

a housing that houses at least the input device, audio circuit, communication circuit, power supply and the at least one processor; and

a mechanical support structure configured and arranged to support the housing proximate the subject'"'"'s thorax.

13. The apparatus of claim 12 wherein

the housing is constructed primarily of a non-conductive material,

at least one conductive pin is embedded into the non-conductive material and configured and arranged to electrically conduct a sensed ECG signal from the electrodes outside the housing to the digitizing circuit, and

the at least one conductive pin is sealed within and configured with the non-conductive material to prevent penetration of fluid into the housing.

14. The apparatus of claim 12, further including a transducer configured and arranged to generate audible sound, wherein the at least one processor is configured and arranged to evaluate signal quality of the digitized ECG signal and to audibly communicate an indication of the evaluated quality of the signal via the transducer.

15. The apparatus of claim 14, wherein the at least one processor is configured and arranged to evaluate the signal quality of the digitized ECG signal by:

decomposing the digitized ECG signal into subcomponents,

computing a statistical variance of the subcomponents over a time interval, and

assessing signal quality based upon the statistical variance of the subcomponents.

16. The apparatus of claim 12, wherein the at least one processor is configured and arranged to evaluate the signal quality of the digitized ECG signal by:

decomposing the digitized ECG signal into subcomponents,

computing a statistical variance of the subcomponents over a time interval, and

assessing signal quality based upon the statistical variance of the subcomponents.

17. The apparatus of claim 16, wherein the at least one processor is configured and arranged to determine whether one of the at first and second electrodes is disconnected from the subject based upon a ratio of the statistical variance of a subset of the subcomponents to total statistical variance of the subcomponents, the subset including subcomponents that form between 30-70% of the total statistical variance of a noise-free reference ECG signal.

18. The apparatus of claim 12, wherein the at least one processor is configured and arranged to receive and store operating parameters from an external device via the wireless communication circuit, and to process the digitized ECG signal based on the stored operating parameters.

19. The apparatus of claim 12, further including a memory circuit in the housing, the at least one processor being configured and arranged to store sets of data in the memory circuit, each set of data representing and linking a recorded ECG signal with sound recorded in response to the input signal, wherein the at least one processor is configured and arranged to transmit the sets of data to the external device via the wireless communication circuit.

20. The apparatus of claim 12, wherein the digitizing circuit is configured and arranged to digitize the sensed ECG signal by actively digitizing sensed ECG signals over a period of time, and the at least one processor is configured and arranged with the input device to record the digitized ECG signal by, in response to receiving the tactile input, record ECG signals sensed for a time period beginning before the tactile input is received, and ending after the tactile input is received.

21. The apparatus of claim 12, wherein the at least one processor is configured and arranged to detect arrhythmia in each digitized ECG signal, and wherein the power supply includes a battery configured and arranged to provide power for operating the apparatus, without replacement or recharging, for at least 30 days of continuous sensing, digitizing, and processing to detect the arrhythmia in the digitized ECG signals.

22. The apparatus of claim 12, wherein the mechanical support structure includes an elastic member that encircles at least a portion the thorax and is configured and arranged to hold at least one of the first and second electrodes in contact with the skin.

23. The apparatus of claim 12, wherein the mechanical support structure includes one of a loop or band configured and arranged to encircle the subject'"'"'s thorax, or a lanyard configured and arranged to encircle the subject'"'"'s neck.

24. The apparatus of claim 12, further including a transducer configured and arranged to generate audible sound, wherein the at least one processor is configured and arranged to process the digitized ECG signal by detecting the arrhythmia in the digitized ECG signal, and to notify the subject that an arrhythmia has occurred and to prompt the subject to verbally describe symptoms by generating sound via the transducer.

25. The apparatus of claim 12, wherein the at least one processor is configured and arranged to process each electrical audio signal by at least one of:

identifying the presence of a human voice in the audio signal, saving the audio signal in memory, converting voice in the audio signal to text, and compressing the audio signal to reduce data volume, prior to the recorded voice being transmitted to the external device.

26. A method comprising:

sensing ECG signals from a subject via first and second electrodes;

receiving and digitizing the ECG signals sensed by the electrodes via a digitizing circuit;

using an audio circuit, capturing sounds from the subject and converting the sound into electrical audio signals;

in a processing circuit operable with the electrodes and digitizing circuit, digitizing the ECG signals and processing each digitized ECG signal by at least one of;

removing noise from the digitized ECG signal, storing the digitized ECG signal in a memory circuit, detecting a QRS complex in the digitized ECG signal, evaluating quality of the digitized ECG signal, and detecting arrhythmia in the digitized ECG signal;

in response to receiving an input from the subject via an input circuit, recording at least one of the ECG signals and the sound via the processing circuit and the audio circuit; and

communicating each processed digitized ECG signal and a corresponding one of the audio signals, via a communication circuit, for receipt by an external device.

27. The method of claim 26, wherein

processing each digitized ECG signal includes storing data that represents and links the at least one of the ECG signals and the sound recorded in response to the input, thereby linking each captured ECG signal with sound recorded in connection with the captured ECG signal, and

communicating the processed digitized ECG signals includes communicating the stored data that represents and links ECG signals with recorded sound.

28. The method of claim 26, wherein processing each digitized ECG signal includes evaluating signal quality of the digitized ECG signal, further including audibly communicating an indication of the evaluated quality of the signal using a transducer.

29. The method of claim 26, wherein processing each digitized ECG signal includes evaluating the signal quality of the digitized ECG signal by:

decomposing the digitized ECG signal into subcomponents,

computing a statistical variance of the subcomponents over a time interval, and

assessing signal quality based upon the statistical variance of the subcomponents.

30. The method of claim 26, wherein processing each digitized ECG signal includes removing noise from the digitized ECG signal by

decomposing the signal into subcomponents;

identifying a location of the QRS complex of a cardiac cycle in the ECG signal;

identifying a first time window in the cardiac cycle that includes the QRS complex;

identifying at least one time window in the cardiac cycle that does not include the QRS complex;

for each of the identified time windows, identifying target subcomponents as subcomponents that contain more energy that is within a band of frequencies characteristic of a desired ECG signal in the time window than energy that is outside the band of frequencies characteristic of the desired ECG signal; and

reconstructing a denoised physiological signal using at least two of the identified target subcomponents.

31. The method of claim 26,

wherein the steps of receiving and digitizing, using an audio circuit, digitizing the ECG signals and processing each digitized ECG signal, recording at least one of the ECG signal and the sound, and communicating the processed digitized ECG signals and the audio signals are carried out within a housing constructed primarily of a non-conductive material, and

further including supporting the housing near the subject'"'"'s thorax.

32. The method of claim 31, wherein supporting the housing near the subject'"'"'s thorax includes snapping the housing to a fastener adhered to the subject'"'"'s skin and using the fastener to provide both mechanical support for the housing and electrical connection from the first electrode to the digitizing circuit contained within the housing.

33. The method of claim 31, wherein the housing has at least one conductive pin embedded into the non-conductive material, further including using the at least one conductive pin to couple the digitizing circuit to the first and second electrodes.

34. The method of claim 26, wherein processing each digitized ECG signal includes evaluating the quality of the digitized ECG signal by providing an indication that at least one of the first and second electrodes is disconnected from the subject, and by processing circuit in a low power mode in response thereto.