Subcutaneous insertable electrocardiography monitor

• US 10,736,529 B2
• Filed: 11/01/2018
• Issued: 08/11/2020
• 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: Bardy, Gust H.
• Primary Examiner(s): Getzow, Scott M.
• Application Number:
  US16/178,444
• Publication Number:
  US 20190069798A1
• Time in Patent Office: 649 Days
• CPC Class Codes: A61B 2505/07 Home care
• CPC Class Codes: A61B 2560/0271 using a remote monitoring unit
• CPC Class Codes: A61B 2560/0412 Low-profile patch shaped housings
• CPC Class Codes: A61B 2560/045 with a separable interface unit, e.g. for communication
• CPC Class Codes: A61B 2560/0468 Built-in electrodes
• CPC Class Codes: A61B 2562/0219 Inertial sensors, e.g. accelerometers, gyroscopes, tilt switches
• CPC Class Codes: A61B 2562/164 the sensor is mounted in or on a conformable substrate or carrier
• CPC Class Codes: A61B 5/0006 ECG or EEG signals
• CPC Class Codes: A61B 5/0022 Monitoring a patient using a global network, e.g. telephone networks, internet
• CPC Class Codes: A61B 5/01 Measuring temperature of body parts ; Diagnostic temperature sensing, e.g. for malignant or inflamed tissue clinical contact thermometers G01K13/20
• CPC Class Codes: A61B 5/02055 Simultaneously evaluating both cardiovascular condition and temperature
• CPC Class Codes: A61B 5/021 Measuring pressure in heart or blood vessels A61B5/0205 takes precedence
• CPC Class Codes: A61B 5/0816 Measuring devices for examining respiratory frequency measuring frequency of electric signals G01R23/00
• CPC Class Codes: A61B 5/087 Measuring breath flow
• CPC Class Codes: A61B 5/091 Measuring volume of inspired or expired gases, e.g. to determine lung capacity
• CPC Class Codes: A61B 5/1116 Determining posture transitions
• CPC Class Codes: A61B 5/1117 Fall detection
• CPC Class Codes: A61B 5/1118 Determining activity level
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/14542 for measuring blood gases A61B5/14551 takes precedence
• CPC Class Codes: A61B 5/14551 : for measuring blood gases
• 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 5/287 : Holders for multiple electrodes, e.g. electrode catheters for electrophysiological study [EPS]
• CPC Class Codes: A61B 5/303 : Patient cord assembly, e.g. cable harness
• 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 5/349 : Detecting specific parameters of the electrocardiograph cycle
• CPC Class Codes: A61B 5/35 : by template matching
• CPC Class Codes: A61B 5/4809 : Sleep detection, i.e. determining whether a subject is asleep or not
• CPC Class Codes: A61B 5/6801 : specially adapted to be attached to or worn on the body surface
• CPC Class Codes: A61B 5/6823 : Trunk, e.g., chest, back, abdomen, hip
• CPC Class Codes: A61B 5/6833 : Adhesive patches
• CPC Class Codes: A61B 5/686 : Permanently implanted devices, e.g. pacemakers, other stimulators, biochips A61B5/6861 takes precedence
• CPC Class Codes: A61B 5/6867 : specially adapted to be attached or implanted in a specific body part A61B5/6847 takes precedence
• CPC Class Codes: A61B 5/7455 : characterised by tactile indication, e.g. vibration or electrical stimulation
• CPC Class Codes: G01N 27/307 : Disposable laminated or multilayered electrodes G01N27/3272 takes precedence

Abstract

Long-term electrocardiographic and physiological monitoring over a period lasting up to several years in duration can be provided through a continuously-recording subcutaneous insertable cardiac monitor (ICM). The sensing circuitry and the physical layout of the electrodes are specifically optimized to capture electrical signals from the propagation of low amplitude, relatively low frequency content cardiac action potentials, particularly the P-waves that are generated during atrial activation. The ICM is intended to be implanted centrally and positioned axially and slightly to either the left or right of the sternal midline in the parasternal region of the chest, with at least one of the ECG sensing electrodes of the ICM being disposed for being positioned in a region overlying the sternum or adjacent to the sternum and the other of the electrodes also being disposed for being positioned over the sternum or adjacent to the sternum of on the patient'"'"'s chest.

Claims

1. A subcutaneous insertable electrocardiography (ECG) monitor, comprising:

an implantable housing comprised of a biocompatible material that is suitable for implantation within a living body in at least one of the sternal midline and the parasternal region of the chest of the body;

at least a pair of ECG sensing electrodes provided on a ventral surface and on opposite ends of the implantable housing operatively placed to facilitate sensing in closest proximity to the low amplitude, low frequency content cardiac action potentials that are generated during atrial activation, one of the electrodes being disposed for being positioned in at least one a region overlying the inferior sternum and the parasternal region of a patient'"'"'s chest when the housing has been implanted, the other of the electrodes being disposed for being positioned in at least one of the superior sternal region and the parasternal region of the patient'"'"'s chest when the housing has been implanted;

an extension formed on a distal end of the implantable housing;

at least one additional ECG sensing electrode provided on a distal end of the extension, the at least one additional ECG sensing electrode comprising a pair of crescent-shaped electrodes surrounding a central oval electrode that can be programmatically combined by the microcontroller to form a single electrode; and

electronic circuitry provided within the housing assembly comprising the low power microcontroller operable to execute under modular micro program control as specified in firmware, an ECG front end circuit interfaced to the microcontroller and configured to capture the cardiac action potentials sensed by the pair of ECG sensing electrodes which are output as ECG signals, and non-volatile memory electrically interfaced with the microcontroller and operable to continuously store samples of the ECG signals, wherein the firmware comprises programmatic selection of one or more pairings of the ECG sensing electrodes.

2. A monitor in accordance with claim 1, wherein the implantable housing is configured to be positioned between the second and the sixth rib of the body.

3. A monitor in accordance with claim 1, wherein the biocompatible material comprises at least one of titanium and stainless steel.

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

a wireless antenna positioned to wrap around an internal periphery of the implantable housing.

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

at least one further ECG sensing electrode further provided to wraparound an end of the implantable housing circumferentially about one of the pair of ECG sensing electrodes, continue around the sides and ends of the implantable housing, and over the planar surface of the implantable housing.

6. A monitor in accordance with claim 5, wherein one of the ECG sensing electrodes and the at least one ECG sensing electrode are logically combined to form a single virtual electrode.

7. A monitor in accordance with claim 5, wherein the at least one further ECG sensing electrode is electrically insulated from at least one of the ECG sensing electrodes.

8. A monitor in accordance with claim 1, wherein the pair of the ECG sensing electrodes are operatively coupled to the implantable housing.

9. A rectangular subcutaneous insertable electrocardiography monitor, comprising:

a hermetically sealed implantable housing defining a rectangular shape with rounded edges and comprised of a biocompatible material that is suitable for implantation within a living body of a patient in at least one of the sternal midline and the parasternal region of the chest of the body;

at least a pair of ECG sensing electrodes provided on a ventral surface and on opposite ends of the implantable housing operatively placed to facilitate sensing in closest proximity to the low amplitude, low frequency content cardiac action potentials that are generated during atrial activation, one of the electrodes being disposed for being positioned in at least one a region overlying the inferior sternum and the parasternal region of a patient'"'"'s chest when the housing has been implanted, the other of the electrodes being disposed for being positioned in at least one of the superior sternal region and the parasternal region of the patient'"'"'s chest when the housing has been implanted;

an extension formed on a distal end of the implantable housing and tapering from a proximal end of the extension and towards a distal end of the extension, the distal end of the tapered extension comprising a substantially cylindrical structure;

at least one additional ECG sensing electrode provided on a distal end of the cylindrical structure, the at least one additional ECG sensing electrode comprising a pair of crescent-shaped electrodes surrounding a central oval electrode that can be programmatically combined by a low-power microcontroller to form a single electrode; and

electronic circuitry provided within the housing assembly comprising the low power microcontroller operable to execute under modular micro program control as specified in firmware, an ECG front end circuit interfaced to the microcontroller and configured to capture the cardiac action potentials sensed by the pair of ECG sensing electrodes which are output as ECG signals, and non-volatile memory electrically interfaced with the microcontroller and operable to continuously store samples of the ECG signals, wherein the firmware comprises programmatic selection of one or more pairings of the ECG sensing electrodes.

10. A monitor in accordance with claim 9, wherein the implantable housing is configured to be positioned between the second and the sixth rib of the body.

11. A monitor in accordance with claim 9, wherein the biocompatible material comprises at least one of titanium and stainless steel.

12. A monitor in accordance with claim 9, further comprising:

a wireless antenna positioned to wrap around an internal periphery of the implantable housing.

13. A monitor in accordance with claim 9, further comprising:

at least one further ECG sensing electrode further provided to wraparound an end of the implantable housing circumferentially about one of the pair of ECG sensing electrodes, continue around the sides and ends of the implantable housing, and over the planar surface of the implantable housing.

14. A monitor in accordance with claim 13, wherein one of the ECG sensing electrodes and the at least one ECG sensing electrode are logically combined to form a single virtual electrode.

15. A monitor in accordance with claim 13, wherein the at least one further ECG sensing electrode is electrically insulated from at least one of the ECG sensing electrodes.

16. A monitor in accordance with claim 9, wherein the pair of the ECG sensing electrodes are operatively coupled to the implantable housing.