Hydration measurement with a watch

Patent metadata

Field	Value
Publication number	US-12484847-B2
Application number	US-202117403677-A
Country	US
Kind code	B2
Filing date	Aug 16, 2021
Priority date	Mar 29, 2018
Publication date	Dec 2, 2025
Grant date	Dec 2, 2025

Abstract

Hydration measurement capabilities can be provided by a wearable electronic device, such as a watch, to allow a user to easily track hydration. A watch can be positioned to receive and measure one or more electrical properties of perspiration produced by the user wearing the watch. The watch provides electrodes for measuring the electrical properties of the perspiration. The electrical properties, such as electrical conductance, can represent a concentration of electrolytes in the perspiration, which in turn represents a hydration level of the user. The hydration tracking can be performed non-invasively, repeatedly, accurately, automatically, and with minimal user intervention. The measurements can be used to provide useful feedback and health tracking information to a user, thereby allowing the user to better manage hydration and overall health.

First claim

What is claimed is:

1 . A wearable electronic device comprising:
a support structure for contacting skin of a user and forming one or more cavities; electrodes positioned within the one or more cavities of the support structure, such that the electrodes do not contact the skin of the user when the wearable electronic device is worn by the user; and a meter operatively coupled to the electrodes to measure electrical conductance of a fluid in contact with the wearable electronic device.

2 . The wearable electronic device of claim 1 , further comprising a processing unit operable to produce a user hydration indicator based on the electrical conductance of the fluid, wherein the wearable electronic device further comprises a user interface configured to output the user hydration indicator to the user wearing the wearable electronic device.

3 . The wearable electronic device of claim 2 , wherein:
the electrodes comprise multiple electrode pairs; and the processing unit is configured to produce the user hydration indicator by averaging electrical conductance measurements from different electrode pairs.

4 . The wearable electronic device of claim 1 , further comprising a sensor configured to measure a health metric of the user wearing the wearable electronic device.

5 . The wearable electronic device of claim 1 , wherein the one or more cavities includes multiple cavities, wherein each of the cavities contains a pair of the electrodes.

6 . A band comprising:
a support structure forming a surface and a cavity recessed from the surface; electrodes positioned within the cavity and being recessed from the surface such that the electrodes do not contact skin of a user when the band is worn by the user, the electrodes being responsive to perspiration from the skin of the user when the perspiration is within the cavity; and a band interface for communicating with a processor.

7 . The band of claim 6 , further comprising a lug configured to attach to a body of a wearable electronic device, wherein the band interface is configured to communicatively couple to a body interface of the body when the lug is attached to the body.

8 . The band of claim 7 , wherein the processor is within the body of the wearable electronic device.

9 . The band of claim 6 , wherein the electrodes extend in parallel along a longitudinal length of the support structure.

10 . The band of claim 6 , wherein the band is configured to bend about an axis to conform to a wrist of the user, and a pair of the electrodes are separated by a gap that is oriented parallel to the axis.

11 . The band of claim 6 , further comprising support members to maintain an adjacent pair of the electrodes a fixed distance away from each other.

12 . The band of claim 6 , wherein the support structure comprises multiple threads that are electrically insulative and woven together around the electrodes.

13 . The band of claim 6 , wherein the electrodes comprise at least four electrodes.

14 . The band of claim 6 , wherein:
the support structure further forms an additional cavity recessed from the surface; and the band further comprises additional electrodes positioned within the additional cavity.

15 . A method of tracking user hydration, the method comprising:
detecting, with electrodes of a wearable electronic device, a presence of perspiration between the electrodes, the wearable electronic device comprising:
a support structure for contacting skin of a user, the support structure forming a surface and one or more cavities recessed from the surface;
the electrodes being positioned within the one or more cavities of the support structure, such that the electrodes are positioned a distance away from the skin of the user when the wearable electronic device is worn by the user; and
a meter operatively coupled to the electrodes to measure electrical conductance of the perspiration in contact with the wearable electronic device;
measuring the electrical conductance of the perspiration between the electrodes; and producing a user hydration indicator based on the electrical conductance of the perspiration.

16 . The method of claim 15 , wherein:
the electrical conductance is a first electrical conductance; the method further comprises:
after measuring the first electrical conductance, measuring a second electrical conductance of the perspiration between the electrodes; and
producing the user hydration indicator is based on a comparison between the first electrical conductance and the second electrical conductance.

17 . The method of claim 15 , wherein the method is performed upon detecting activity of the user with a sensor of the wearable electronic device.

18 . The method of claim 15 , further comprising:
initiating a calibration stage; measuring an electrical conductance of a calibration fluid; and producing a calibration indicator based on the electrical conductance of the calibration fluid.

19 . The method of claim 18 , wherein producing the user hydration indicator comprises comparing the electrical conductance of the perspiration to the electrical conductance of the calibration fluid.

20 . The method of claim 15 , wherein:
the electrodes comprise multiple electrode pairs; and producing the user hydration indicator is based on a combination of electrical conductance measurements from different electrode pairs.

Assignees

• Apple Inc

Inventors

• Williams Alexander W

Classifications

• A61B5/681 Primary

  Wristwatch-type devices · CPC title

• A61B5/0537

  Measuring body composition by impedance, e.g. tissue hydration or fat content · CPC title

• A61B5/6824

  Arm or wrist · CPC title

• A61B5/742

  using visual displays (displays for heart-related electrical signals, e.g. ECG, A61B5/339) · CPC title

• A61B5/0531

  Measuring skin impedance · CPC title