Extended Wear Electrocardiography Monitor Optimized For Capturing Low Amplitude Cardiac Action Potential Propagation

• US 20170303809A1
• Filed: 07/10/2017
• Published: 10/26/2017
• Est. Priority Date: 09/25/2013
• Status: Active Grant

• Current Assignee: Bardy Diagnostics, Inc. (Baxter International Inc.)
• Original Assignee: Bardy Diagnostics, Inc. (Baxter International Inc.)
• Inventors: Bishay, Jon Mikalson, Felix, Jason, Bardy, Gust H.
• Granted Patent: US 10,111,601 B2
• Time in Patent Office: Days
• CPC Class Codes: A61B 2560/0406 specially shaped apparatus housings
• CPC Class Codes: A61B 2560/0443 Modular apparatus
• CPC Class Codes: A61B 5/0006 ECG or EEG signals
• 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 5/259 using conductive adhesive means, e.g. gels
• CPC Class Codes: A61B 5/282 Holders for multiple electrodes for introduction into the body A61B5/287
• CPC Class Codes: A61B 5/349 Detecting specific parameters of the electrocardiograph cycle
• CPC Class Codes: A61B 5/6823 Trunk, e.g., chest, back, abdomen, hip
• CPC Class Codes: A61B 5/7225 Details of analog processing, e.g. isolation amplifier, gain or sensitivity adjustment, filtering, baseline or drift compensation A61B5/30, A61B5/316 take precedence; transformers for specific applications H01F38/00; amplifiers H03F

Abstract

Physiological monitoring can be provided through a lightweight wearable monitor that includes two components, a flexible extended wear electrode patch and a reusable monitor recorder that removably snaps into a receptacle on the electrode patch. The wearable monitor sits centrally on the patient'"'"'s chest along the sternum oriented top-to-bottom. The placement of the wearable monitor in a location at the sternal midline, with its unique narrow “hourglass”-like shape, significantly improves the ability of the wearable monitor to cutaneously sense cardiac electrical potential signals, particularly the P-wave and the QRS interval signals indicating ventricular activity in the ECG waveforms. In particular, the ECG electrodes on the electrode patch are tailored to be positioned axially along the midline of the sternum for capturing action potential propagation in an orientation that corresponds to the aVF lead used in a conventional 12-lead ECG that is used to sense positive or upright P-waves.

Claims

1. An ambulatory electrocardiography and physiology monitor optimized for capturing low amplitude cardiac action potential propagation, comprising:

a disposable extended wear electrode patch comprising;

a flexible backing comprising stretchable material defined as an elongated strip with a narrow longitudinal midsection, each end of the flexible backing comprising an adhesive contact surface;

a pair of electrocardiographic electrodes comprised on the contact surface of each end of the flexible backing, each electrocardiographic electrode conductively exposed for dermal adhesion;

a non-conductive receptacle affixed to a non-contacting surface of the flexible backing;

a docking interface positioned on the non-conductive receptacle and comprising a first set of electrical contact mating pads, a second set of electrical contact mating pads, and at least one additional electrical contact mating pad;

a battery electrically interfaced to the first set of the electrical contact mating pads of the docking interface; and

a flexible circuit comprising a pair of flexible circuit traces affixed at each end of the flexible backing with each circuit trace connecting one of the electrocardiographic electrodes to one of the electrical contact mating pads of the second set of the electrical contact mating pads of the docking interface; and

a physiology sensor adapted to sense physiological data and connecting to the at least one additional electrical contact mating pad; and

an ambulatory electrocardiography monitor recorder comprising;

a wearable housing adapted to securely fit into the non-conductive receptacle;

an external connector comprising a set of electrical contacts protruding from a surface of the wearable housing that fits within the non-conductive receptacle, the set of contacts electrically and mechanically contacting the first set of the electrical contact mating pads of the docking interface, the second set of the electrical contact mating pads of the docking interface, and the additional electrical contact mating pad; and

electronic circuitry provided within the wearable housing and removably connected via the external connector to the electrocardiographic electrodes via the second set of the electrical contact mating pads of the docking interface, to the battery via the first set of the electrical contact mating pads of the docking interface, and to the physiology sensor via the additional electrical contact mating pad, the electronic circuitry further comprising;

a low power microcontroller interfaced to the physiology sensor via the external connector and operable to execute over an extended period under modular micro program control as specified in firmware and to draw power from the battery via the external connector;

an electrocardiographic front end circuit under the control of the microcontroller adapted to sense cardiac electrical potential differentials through the electrocardiographic electrodes, which are provided to the microcontroller as electrocardiographic signals representative of amplitudes of the action potential propagation; and

a non-volatile memory electrically interfaced with the microcontroller and operable to continuously store samples of the electrocardiographic signals and samples of the physiological data throughout the extended period and to draw power from the battery via the external connector.

2. A monitor in accordance with claim 1, wherein the physiology sensor comprises one of an SpO₂ sensor, blood pressure sensor, temperature sensor, respiratory rate sensor, glucose sensor, airflow sensor, and volumetric pressure sensor.

3. A monitor in accordance with claim 1, further comprising:

a moisture-resistant seal formed on a bottom surface of the non-conductive receptacle around the docking interface.

4. A monitor in accordance with claim 1, further comprising:

a seal coupling formed to circumferentially surround the set of electrical contacts and securely mate with the moisture-resistant seal.

5. A monitor in accordance with claim 1, further comprising:

the micro-controller further configured to overwrite in the non-volatile memory at least some of the samples of the electrocardiographic signals recorded in the memory earlier by the samples of the electrocardiographic signals recorded in the memory later upon the memory being filled.

6. A monitor in accordance with claim 1, further comprising:

the micro-controller configured to record the samples of the electrocardiographic signals until the non-volatile memory is filled.

7. A monitor in accordance with claim 1, wherein the docking interface comprises a further electrical contact mating pad, further comprising:

a cryptographic circuit interfaced to the micro-controller via the further electrical contact mating pad and the external connector to the monitor recorder and configured to perform an authentication of the electrode patch.

8. A monitor in accordance with claim 1, wherein the micro-controller is configured to execute a power-up sequence upon the external connector contacting the docking interface.

9. A monitor in accordance with claim 8, wherein the power-up sequence comprises a check of a voltage of the battery, a state of the non-volatile memory, and a diagnostic check of the micro-controller.

10. A monitor in accordance with claim 9, wherein the check of the state of the non-volatile memory comprises a check of an operability and of available capacity.

11. An extended wear electrocardiography monitor optimized for capturing low amplitude cardiac action potential propagation, comprising:

a disposable extended wear electrode patch comprising;

a flexible backing comprising stretchable material defined as an elongated strip with a narrow longitudinal midsection, each end of the flexible backing comprising an adhesive contact surface;

a pair of electrocardiographic electrodes comprised on the contact surface of each end of the flexible backing, each electrocardiographic electrode conductively exposed for dermal adhesion;

a non-conductive receptacle affixed to a non-contacting surface of the flexible backing;

a docking interface positioned on the non-conductive receptacle and comprising a first set of electrical contact mating pads a second set of electrical contact mating pads;

a battery electrically interfaced to the first set of the electrical contact mating pads of the docking interface; and

a flexible circuit comprising a pair of flexible circuit traces affixed at each end of the flexible backing with each circuit trace connecting one of the electrocardiographic electrodes to one of the electrical contact mating pads of the second set of the electrical contact mating pads of the docking interface; and

an ambulatory electrocardiography monitor recorder, comprising;

a wearable housing adapted to securely fit into the non-conductive receptacle;

an external connector comprising a set of electrical contacts protruding from a surface of the wearable housing that fits within the non-conductive receptacle, the set of contacts electrically and mechanically contacting the first set of the electrical contact mating pads of the docking interface and the second set of the electrical contact mating pads of the docking interface; and

electronic circuitry provided within the wearable housing and removably connected via the external connector to the electrocardiographic electrodes via the second set of the electrical contact mating pads of the docking interface, to the battery via the first set of the electrical contact mating pads of the docking interface, and to the physiology sensor the electronic circuitry further comprising;

a low power microcontroller operable to execute over an extended period under modular micro program control as specified in firmware and to draw power from the battery via the external connector;

an electrocardiographic front end circuit under the control of the microcontroller adapted to sense cardiac electrical potential differentials through the electrocardiographic electrodes, which are provided to the microcontroller as electrocardiographic signals representative of amplitudes of the action potential propagation; and

a non-volatile memory electrically interfaced with the microcontroller and operable to continuously store samples of the electrocardiographic signals throughout the extended period and to draw power from the battery via the external connector.

12. A monitor in accordance with claim 11, wherein the docking interface further comprises at least one additional electrical contact mating pad, further comprising:

a physiology sensor adapted to sense physiological data and connecting to the at least one additional electrode mating pad; and

the micro-controller interfaced to the physiology sensor and adapted to record samples of the physiological data throughout the extended period into the non-volatile memory.

13. A monitor in accordance with claim 11, further comprising:

a moisture-resistant seal formed on a bottom surface of the non-conductive receptacle around the docking interface.

14. A monitor in accordance with claim 11, further comprising:

a seal coupling formed to circumferentially surround the set of electrical contacts and securely mate with the moisture-resistant seal.

15. A monitor in accordance with claim 11, further comprising:

the micro-controller further configured to overwrite in the non-volatile memory at least some of the samples of the electrocardiographic signals recorded in the memory earlier by the samples of the electrocardiographic signals recorded in the memory later upon the memory being filled.

16. A monitor in accordance with claim 11, further comprising:

the micro-controller configured to record the samples of the electrocardiographic signals until the non-volatile memory is filled.

17. A monitor in accordance with claim 11, wherein the docking interface comprises a further electrical contact mating pad, further comprising:

a cryptographic circuit interfaced to the micro-controller via the further electrical contact mating pad and the external connector to the monitor recorder and configured to perform an authentication of the electrode patch.

18. A monitor in accordance with claim 11, wherein the micro-controller is configured to execute a power-up sequence upon the external connector contacting the docking interface.

19. A monitor in accordance with claim 18, wherein the power-up sequence comprises a check of a voltage of the battery, a state of the non-volatile memory, and a diagnostic check of the micro-controller.

20. A monitor in accordance with claim 19, wherein the check of the state of the non-volatile memory comprises a check of an operability and of available capacity.