Wrist-mounted electrocardiography device

• US 9,526,433 B2
• Filed: 09/12/2014
• Issued: 12/27/2016
• Est. Priority Date: 09/12/2014
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Verily Life Sciences LLC (Alphabet Inc.)
• Inventors: Lapetina, John, Mirov, Russell Norman
• Primary Examiner(s): Cohen, Lee S
• Application Number:
  US14/485,392
• Publication Number:
  US 20160073914A1
• Time in Patent Office: 837 Days
• Field of Search: 600/390, 600/509
• US Class Current: 1/1
• CPC Class Codes: A61B 2560/0443 Modular apparatus
• CPC Class Codes: A61B 5/282 Holders for multiple electrodes for introduction into the body A61B5/287
• CPC Class Codes: A61B 5/681 Wristwatch-type devices
• CPC Class Codes: A61B 5/6824 Arm or wrist

Abstract

Wearable devices are described herein including a housing and a mount configured to mount the housing to a wrist of a wearer. The wearable devices further include first and second electrical contacts configured such that the first electrical contact is in contact with skin proximate of the wrist when the wearable device is so mounted. The second electrical contact is disposed on a surface of the wearable device away from the wrist such that, when the wearer contacts the second electrical contact with a finger or other element of the arm opposite the wrist, an electrocardiographic waveform of the wearer can be extracted from voltage fluctuations between the first and second electrodes. Such wearable devices can be used for periodic logging or other applications of the electrocardiographic waveforms of the wearer. Such logged electrocardiographic waveforms could be used to determine a medical or health state of the wearer.

Claims

1. A wearable device, comprising:

a housing;

a modular mount for mounting the housing to a first external body surface, wherein the first external body surface is a wrist location of a first arm of a wearer, wherein the modular mount comprises a band and a frame, wherein the housing is removably seated in the frame, and wherein the band can encircle a wrist of the first arm of the wearer;

a first electrical contact disposed on the housing, wherein the first electrical contact contacts skin at the first external body surface when the housing is mounted on the first external body surface;

a second electrical contact disposed on an outside surface of the modular mount, wherein the second electrical contact can be contacted by skin of a second external body surface, wherein the second external body surface is a location of a second arm of the wearer; and

a signal conditioner disposed in the housing and electrically connected to the first and second electrical contacts, wherein the signal conditioner extracts an electrocardiographic waveform from voltage fluctuations between the first electrical contact and the second electrical contact;

wherein the signal conditioner is in electrical contact with the second electrical contact when the housing is seated in the frame, and wherein unseating the housing from the frame removes electrical contact between the signal conditioner and the second electrical contact.

2. The wearable device of claim 1, wherein the signal conditioner is in electrical contact with the second electrical contact via at least one spring-loaded contact, wherein the spring loaded contact is disposed in the wearable device such that it is compressed when the housing is seated in the frame.

3. The wearable device of claim 1, further comprising a display, wherein the display is disposed on an outside surface of the housing, and wherein the second electrical contact is disposed proximate to a peripheral edge of the display and at least partially encircles the display.

4. The wearable device of claim 1, wherein the second electrical contact is disposed on an outside surface of the band.

5. The device of claim 1, wherein at least one of the first and second electrical contacts has a surface comprising silver/silver-chloride.

6. The device of claim 1, wherein at least one of the first and second electrical contacts capacitively couples to skin at the first and second locations, respectively.

7. The device of claim 1, further comprising a wireless transmitter that transmits data related to the extracted electrocardiographic waveform.

8. The device of claim 1, further comprising a data storage that logs data related to the extracted electrocardiographic waveform.

9. The device of claim 1, wherein the signal conditioner comprises at least one amplifier, at least one high-pass filter, and at least one low-pass filter.

10. The device of claim 9, wherein the signal conditioner comprises fast recovery circuitry, wherein the fast recovery circuitry detects when the signal conditioner is electronically saturated and responsively controls one or more properties of the signal conditioner to reduce the electronic saturation of the signal conditioner.

11. The device of claim 1, further comprising a further sensor.

12. The device of claim 11, wherein the further sensor comprises a light source and a light sensor, and wherein the further sensor detects a volume of blood in subsurface vasculature by emitting light into the subsurface vasculature through an overlying skin location and receiving light from the subsurface vasculature through the overlying skin location.

13. The device of claim 1, wherein the signal conditioner determines whether the first and second electrical contacts are in contact with skin at the first and second external body surfaces, respectively.

14. A method comprising:

mounting a wearable device to a wrist of a first arm of a wearer, wherein the device comprises;

a housing;

a modular mount, wherein the modular mount comprises a band and a frame, wherein mounting the wearable device to the wrist comprises removably seating the housing in the frame and encircling the band around the wrist;

a first electrical contact disposed on the housing, wherein the first electrical contact contacts skin at a first external body surface when the wearable device is mounted to the wrist;

a second electrical contact disposed on an outside surface of the modular mount, wherein the second electrical contact can be contacted by skin of a second external body surface, wherein the second external body surface is a location of a second arm of the wearer; and

a signal conditioner disposed in the housing and electrically connected to the first and second electrical contacts, wherein the signal conditioner extracts an electrocardiographic waveform from voltage fluctuations between the first electrical contact and the second electrical contact;

wherein removably seating the housing in the frame causes the signal conditioner to be in electrical contact with the second electrical contact, and wherein unseating the housing from the frame removes electrical contact between the signal conditioner and the second electrical contact;

while the wearable device is mounted to the wrist location of the first arm of the wearer such that the first electrical contact is in contact with skin at the first external body surface, placing skin of the second external body surface in contact with the second electrical contact; and

while the first electrical contact is in contact with skin at the first external body surface and the second electrical contact is in contact with skin of the second external body surface, using the signal conditioner to extract the electrocardiographic waveform.

15. The method of claim 14, further comprising indicating information related to the extracted electrocardiographic waveform using a display disposed in the wearable device.

16. The method of claim 14, wherein the device further comprises a wireless transmitter, and further comprising:

transmitting data related to the extracted electrocardiographic waveform using the wireless transmitter.

17. The device of claim 14, wherein the device further comprises a data storage, and further comprising:

logging data related to the extracted electrocardiographic waveform using the data storage.

18. The method of claim 14, wherein the device further comprises a light source and a light sensor, and further comprising:

operating the light source to emit light into subsurface vasculature of the wearer through an overlying skin location of the wearer;

operating the light sensor to receive light from the subsurface vasculature through the overlying skin location;

determining a photoplethysmographic signal related to the volume of blood in the subsurface vasculature based at least on the light received from the subsurface vasculature by the light sensor; and

determining a blood pressure of the wearer based at least on the determined photoplethysmographic signal and the extracted electrocardiographic waveform.

19. The method of claim 14, wherein the signal conditioner can further determine whether the first and second electrical contacts are in contact with skin at the first and second external body surfaces, respectively, and further comprising:

determining, using the signal conditioner, that the first and second electrical contacts are in contact with skin at the first and second external body surfaces, respectively.

20. The method of claim 14, wherein removably seating the housing in the frame causes the signal conditioner to be in electrical contact with the second electrical contact via at least one spring-loaded contact, wherein the spring loaded contact is disposed in the wearable device such that it is compressed when the housing is seated in the frame.