Ambulatory Electrocardiography Monitoring Patch Optimized For Capturing Low Amplitude Cardiac Action Potential Propagation

• US 20160007875A1
• Filed: 09/16/2014
• Published: 01/14/2016
• 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 9,717,433 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A61B 2560/0412 Low-profile patch shaped housings
• CPC Class Codes: A61B 2560/0456 Apparatus provided with a docking unit
• CPC Class Codes: A61B 5/0006 ECG or EEG signals
• 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 5/30 Input circuits therefor
• CPC Class Codes: A61B 5/316 Modalities, i.e. specific diagnostic methods
• CPC Class Codes: A61B 5/335 using integrated circuit memory devices
• CPC Class Codes: A61B 5/339 Displays specially adapted therefor
• CPC Class Codes: A61B 5/6823 Trunk, e.g., chest, back, abdomen, hip
• CPC Class Codes: A61B 5/6832 using adhesives A61B5/259 takes 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 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 monitoring patch 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 adapted to serve as a crimp relief;

a pair of flexile wires;

a pair of electrocardiographic electrodes, one such electrocardiographic electrode comprising one of the flexile wires provided on the distal end of the elongated strip and interlaced along an axial path through the narrow longitudinal midsection to serve as a strain relief, another such electrocardiographic electrode comprising the other flexile wire provided on the proximal end of the elongated strip, 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; and

a non-conductive receptacle affixed to a non-contacting surface of the flexible backing and comprising an electro mechanical docking interface, the non-conductive receptacle comprising electrode terminals aligned to electrically interface the pair of the flexile wires to the docking interface; and

an ambulatory electrocardiography monitor comprising;

a wearable housing adapted to securely fit into the receptacle; and

electronic circuitry provided within the wearable housing and comprising an external interface configured to be removably connected to the electrocardiographic electrodes via the docking interface, further comprising;

a low power microcontroller operable to execute over an extended period under modular micro program control as specified in firmware;

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

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

2. An electrocardiography monitoring patch in accordance with claim 1, wherein the electrocardiographic front end circuit is optimized to sense P-wave signals in the electrocardiographic signals.

3. An electrocardiography monitoring patch in accordance with claim 1, wherein the disposable extended wear electrode patch is disposed for being adhered to a patient'"'"'s chest positioned axially along the midline of the sternum with one of the electrocardiographic electrodes overlying the region of the manubrium and one of the electrocardiographic electrodes overlying the region of the lower sternum.

4. An electrocardiography monitoring patch in accordance with claim 1, wherein orientation of the monitor recorder is compensated if installed upside down.

5. An electrocardiography monitoring patch in accordance with claim 1, the microcontroller 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 low pass filter comprised in the firmware; and

at least one 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. An electrocardiography monitoring patch in accordance with claim 5, the microcontroller further comprising:

a compression algorithm comprised in the firmware,

wherein the cardiac activation wave front amplitudes are compressed with the compression algorithm into compressed digital representations prior to being stored in the non-volatile.

7. An electrocardiography monitoring patch in accordance with claim 1, further comprising:

a direct current power cell comprised in the non-conductive receptacle and connected to the docking interface; and

the external interface further configured to removably and electronically couple the power cell with the electronic circuitry through the docking interface.

8. An electrocardiography monitoring patch in accordance with claim 1, further comprising at least one of:

at least one of the electrocardiographic electrodes being interlaced into the stretchable material; and

at least one of the electrocardiographic electrodes being positioned on the stretchable material and imbedded in an electrically conductive adhesive.