MONITOR RECORDER OPTIMIZED FOR ELECTROCARDIOGRAPHIC SIGNAL PROCESSING

• US 20180249924A1
• Filed: 04/30/2018
• Published: 09/06/2018
• 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: Felix, Jason, Bishay, Jon Mikalson, Bardy, Gust H.
• Granted Patent: US 10,271,756 B2
• Time in Patent Office: Days
• 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 5/332 Portable devices specially adapted therefor
• CPC Class Codes: A61B 5/335 using integrated circuit memory devices
• 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 5/7232 involving compression of the physiological signal, e.g. to extend the signal recording period
• CPC Class Codes: A61B 5/725 using specific filters therefor, e.g. Kalman or adaptive filters A61B5/316 take precedence

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 (in the midline) 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, to a lesser extent, the QRS interval signals indicating ventricular activity in the ECG waveforms. Additionally, the monitor recorder includes an ECG sensing circuit that measures raw cutaneous electrical signals and performs signal processing prior to outputting the processed signals for sampling and storage.

Claims

1. A monitor recorder optimized for electrocardiographic signal processing, comprising:

a wearable housing adapted to be coupled to a pair of electrocardiographic electrodes that are fitted for dermal placement along the sternal midline; and

an electronic circuitry provided within the wearable housing and comprising;

an electrocardiographic front end circuit under the control of a low-power microcontroller and configured to sense electrocardiographic signals through the electrocardiographic electrodes and to output electrocardiographic signals representative of cardiac activation wave front amplitudes, comprising;

an AC coupling capacitor, a termination resistor, and a filter capacitor through which at least a portion of the electrocardiographic signals pass prior to reaching an operational amplifier;

the operational amplifier that amplifies a current of the sensed electrocardiographic potentials prior to the output of the electrocardiographic potentials as the electrocardiographic signals;

the low-power microcontroller operable to execute over an extended period under modular micro program control as specified in firmware and further operable to acquire samples of the output electrocardiographic signals; and

a non-volatile memory electrically interfaced with the microcontroller and operable to continuously store the samples of the electrocardiographic signals throughout the extended period.

2. A monitor recorder 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.

3. A monitor recorder 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.

4. A monitor recorder in accordance with claim 1, wherein the pair of electrocardiographic electrodes are comprised on a disposable extended wear electrode patch, further comprising:

the micro-controller further operable to perform an authentication of the disposable extended wear electrode patch using a cryptographic circuit provided on the extended wear electrode patch.

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

an analog-to-digital converter operable to convert the electrocardiographic signals into digital representations of the cardiac activation wave front amplitudes;

at least one further low pass filter comprised in the firmware; and

at least one further high pass filter comprised in the firmware,

wherein the cardiac activation wave front amplitudes are passed through the at least one low pass filter and the at least one high pass filter following conversion into the digital representations.

6. A monitor recorder in accordance with claim 1, wherein the pair of electrocardiographic electrodes are comprised on a disposable extended wear electrode patch, and wherein the micro-controller is further interfaced to at least one physiology sensor comprised on at least one of the disposable extended wear electrode patch and the wearable housing, the micro-controller further configured to store data received from the at least one physiology sensor in the non-volatile memory.

7. A monitor recorder in accordance with claim 6, wherein the at least one physiology sensor comprises one of an SpO₂ sensor, blood pressure sensor, temperature sensor, respiratory rate sensor, glucose sensor, airflow sensor, and volumetric pressure sensor.

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

a wireless-transceiver interfaced with the micro-controller and operable to wirelessly interface with an external wireless-enabled device.

9. A monitor recorder in accordance with claim 8, wherein the external wireless-enabled device comprises a physiology monitor.

10. A monitor recorder in accordance with claim 8, wherein the micro-controller offloads the stored samples of the electrocardiographic signals to the external wireless-enabled device.

11. A monitor optimized for electrocardiographic signal processing, comprising:

a disposable extended wear electrode patch, comprising;

a flexible backing comprising stretchable material defined as an elongated strip with a narrow longitudinal midsection;

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 and adapted to be positioned axially along the midline of the sternum for capturing action potential propagation;

a non-conductive receptacle affixed to a non-contacting surface of the flexible backing and comprising an electro mechanical docking interface; and

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 the docking interface; and

an ambulatory electrocardiography monitor recorder, comprising;

16

a wearable housing adapted to be coupled to a pair of electrocardiographic electrodes that are fitted for dermal placement along the sternal midline; and

an electronic circuitry provided within the wearable housing and comprising;

an electrocardiographic front end circuit under the control of a low-power microcontroller and configured to sense electrocardiographic signals through the electrocardiographic electrodes and to output electrocardiographic signals representative of cardiac activation wave front amplitudes, comprising;

an AC coupling capacitor, a termination resistor, and a filter capacitor through which at least a portion of the electrocardiographic signals pass prior to reaching an operational amplifier;

the operational amplifier that amplifies a current of the sensed electrocardiographic potentials prior to the output of the electrocardiographic potentials as the electrocardiographic signals;

the low-power microcontroller operable to execute over an extended period under modular micro program control as specified in firmware and further operable to acquire samples of the output electrocardiographic signals; and

a non-volatile memory electrically interfaced with the microcontroller and operable to continuously store the samples of the electrocardiographic signals throughout the extended period.

12. 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.

13. 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.

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

the micro-controller further operable to perform an authentication of the disposable extended wear electrode patch using a cryptographic circuit provided on the extended wear electrode patch.

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

an analog-to-digital converter operable to convert the electrocardiographic signals into digital representations of the cardiac activation wave front amplitudes;

at least one further low pass filter comprised in the firmware; and

at least one further high pass filter comprised in the firmware,

wherein the cardiac activation wave front amplitudes are passed through the at least one low pass filter and the at least one high pass filter following conversion into the digital representations.

16. A monitor in accordance with claim 11, wherein the pair of electrocardiographic electrodes are comprised on a disposable extended wear electrode patch, and wherein the micro-controller is further interfaced to at least one physiology sensor comprised on at least one of the disposable extended wear electrode patch and the wearable housing, the micro-controller further configured to store data received from the at least one physiology sensor in the non-volatile memory.

17. A monitor in accordance with claim 16, wherein the at least one physiology sensor comprises one of an SpO2 sensor, blood pressure sensor, temperature sensor, respiratory rate sensor, glucose sensor, airflow sensor, and volumetric pressure sensor.

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

a wireless-transceiver interfaced with the micro-controller and operable to wirelessly interface with an external wireless-enabled device.

19. A monitor in accordance with claim 18, wherein the external wireless-enabled device comprises a physiology monitor.

20. A monitor in accordance with claim 18, wherein the micro-controller offloads the stored samples of the electrocardiographic signals to the external wireless-enabled device.