Wearable cardiac monitor

• US 10,413,251 B2
• Filed: 03/15/2013
• Issued: 09/17/2019
• Est. Priority Date: 10/07/2012
• Status: Active Grant

• Current Assignee: RDS
• Original Assignee: Rhythm Diagnostic Systems, Inc.
• Inventors: Golda, George Stefan, Moyer, Daniel Van Zandt, Marriott, Mark P., Eletr, Sam, O'Neil, Bruce
• Primary Examiner(s): Jackson, Gary
• Assistant Examiner(s): Kahng, Youwon
• Application Number:
  US13/837,748
• Publication Number:
  US 20140100432A1
• Time in Patent Office: 2,377 Days
• Field of Search: 600300-301, 600508-528
• CPC Class Codes: A61B 2560/0295 adapted for recording user messages or annotations
• CPC Class Codes: A61B 2560/0412 Low-profile patch shaped housings
• CPC Class Codes: A61B 5/0002 Remote monitoring of patients using telemetry, e.g. transmission of vital signals via a communication network A61B5/07 takes precedence; transmission systems for measured values G08C; transmission H04B; transmission of digital information H04L; wireless communication networks H04W
• CPC Class Codes: A61B 5/0006 ECG or EEG signals
• CPC Class Codes: A61B 5/0059 using light, e.g. diagnosis by transillumination, diascopy, fluorescence A61B5/0093, A61B5/1455, A61B5/02416 and A61B5/0261 take precedence
• 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 5/02125 of pulse wave propagation time
• CPC Class Codes: A61B 5/02141 Details of apparatus construction, e.g. pump units or housings therefor, cuff pressurising systems, arrangements of fluid conduits or circuits A61B5/02233, A61B5/0235 take precedence
• CPC Class Codes: A61B 5/02438 with portable devices, e.g. worn by the patient
• CPC Class Codes: A61B 5/0261 using optical means, e.g. infrared light
• CPC Class Codes: A61B 5/0295 using plethysmography, i.e. measuring the variations in the volume of a body part as modified by the circulation of blood therethrough, e.g. impedance plethysmography
• CPC Class Codes: A61B 5/08 Detecting, measuring or recording devices for evaluating the respiratory organs A61B5/0205 takes precedence
• CPC Class Codes: A61B 5/11 Measuring movement of the entire body or parts thereof, e.g. head or hand tremor, mobility of a limb for measuring pulse A61B5/02 ;A61B5/1038 takes precedence; motion detection to correct for motion artifacts in physiological signals A61B5/721
• CPC Class Codes: A61B 5/1118 Determining activity level
• CPC Class Codes: A61B 5/14551 for measuring blood gases
• CPC Class Codes: A61B 5/14552 Details of sensors specially adapted therefor
• 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 5/318 Heart-related electrical modalities, e.g. electrocardiography [ECG]
• CPC Class Codes: A61B 5/335 using integrated circuit memory devices
• CPC Class Codes: A61B 5/352 : Detecting R peaks, e.g. for synchronising diagnostic apparatus; Estimating R-R interval
• CPC Class Codes: A61B 5/6828 : Leg
• CPC Class Codes: A61B 5/6833 : Adhesive patches
• CPC Class Codes: A61B 5/72 : Signal processing specially adapted for physiological signals or for diagnostic purposes character recognition, recognising digital ink, document-oriented image-based pattern recognition G06V30/00; recognition or understanding of postal images G06V30/424
• CPC Class Codes: A61B 5/7207 : of noise induced by motion artifacts
• 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: A61B 5/7214 : using signal cancellation, e.g. based on input of two identical physiological sensors spaced apart, or based on two signals derived from the same sensor, for different optical wavelengths
• CPC Class Codes: A61B 5/7275 : Determining trends in physiological measurement data; Predicting development of a medical condition based on physiological measurements, e.g. determining a risk factor

Abstract

Systems, methods and devices for reducing noise in cardiac monitoring including wearable monitoring devices having at least one electrode for cardiac monitoring; in some implementations, the wearable device using a composite adhesive having at least one conductive portion applied adjacent the electrode; and, in some implementations, including circuitry adaptations for the at least one electrode to act as a proxy driven right leg electrode.

Claims

1. A method for reducing noise in cardiac monitoring using a wearable monitoring device having at least two electrodes for cardiac monitoring;

the method comprising;

applying the wearable monitoring device externally to a subject, the subject having at least a right leg;

operating circuitry adaptations comprising;

operating a first electrode;

operating a second electrode also referred to as a proxy driven-right-leg electrode mimicking a right leg electrode;

the second electrode being the proxy driven-right-leg electrode affixed on the subject other than on the right leg of the subject;

operating a voltage or current driver operatively connected to the first and second electrodes to drive one or both a voltage or current to the second electrode;

operating a reference voltage configured to be operatively associated with the first and second electrodes;

driving by application of a voltage or current, to the second electrode also known as the proxy driven-right-leg electrode,

maintaining the voltage of the first electrode at a relationship, other than a common mode voltage of multiple additional electrodes, to the voltage of an additional electrode;

generating an output representative of a noise-reduced physiological signal for cardiac monitoring.

2. A method according to claim 1 further comprising one or both:

transmitting the data from the wearable device;

or,

transmitting the data from the wearable device; and

,

storing the data prior to one or both of transmitting or analyzing the data.

4. A method according to claim 1 further comprising:

collecting data representative of physiological signals; and

,

analyzing the data.

5. A method according to claim 1 the maintaining operation further comprising one or more of:

maintaining the voltage of the first electrode at a relationship equal to or approximately equal to the bias or reference or ground voltage;

maintaining the voltage of the first electrode at a relationship of one or more of a weighted sum, average, or common-mode voltage of the first electrode and at least one additional voltage; and

,

maintaining the voltage of the first electrode at a relationship;

of one or more of a weighted sum, average, or common-mode voltage of the first electrode and one or more of a number of additional electrodes equal to or approximately equal to the bias voltage and one or more of a number of additional electrodes equal to or approximately equal to the bias voltage.

6. A method according to claim 1 wherein the at least one additional electrode includes one or more of a number of additional electrodes.

7. A method according to claim 1 wherein the physiological signal includes one or both an ECG or a photoplethysmography (PPG) signal.

3. A circuit for mimicking a right leg electrode using a reference electrode as proxy therefor;

the circuit comprising the combination A), B), C), D) with one or more of W), X), Y), Z);

A) a connection to a first electrocardiogram electrode;

B) a connection to a second electrocardiogram electrode;

C) a connection to a reference electrocardiogram electrode; and

,

D) an amplifier;

the electrode connections all connected to the amplifier;

the amplifier maintaining the voltage of the first electrode at a relationship, other than a common mode voltage of multiple additional electrodes, to the voltage of an additional electrode, a proxy driven right leg signal being measurable using a reference electrode and being used in generating an output representative of a noise-reduced physiological signal for cardiac monitoring;

the reference electrode being the proxy driven-right-leg electrode affixed on a subject other than on a right leg of the subject;

and

W) a connection to a sense electrode;

X) a connection to a drive electrode;

Y) a bias voltage input; and

,

Z) an amplifier;

the electrode connections and bias voltage input connected to the amplifier;

the amplifier output connected to the drive electrode, an inverting input to the sense electrode, and a non-inverting input to a bias voltage;

the amplifier maintaining the voltage of the first electrode at a relationship, other than the common mode voltage of multiple additional electrodes, to the voltage of an additional electrode;

the proxy driven right leg signal being measurable using a third electrode and being used in generating an output representative of a noise-reduced physiological signal for cardiac monitoring;

the third electrode being the proxy driven-right-leg electrode affixed externally on a subject other than on a right leg of the subject.