Personal hydration monitor

Patent metadata

Field	Value
Publication number	US-10888273-B2
Application number	US-201615160594-A
Country	US
Kind code	B2
Filing date	May 20, 2016
Priority date	May 20, 2015
Publication date	Jan 12, 2021
Grant date	Jan 12, 2021

Abstract

Disclosed are various embodiments for a flexible hydration sensor that can be implemented in a wearable device. A hydration monitoring device can include at least one flexible electrode comprising a plurality of silver nanowires embedded within a polydimethylsiloxane (PDMS) substrate. Processing circuitry can be configured to measure a hydration level of an individual wearing the hydration monitoring device based at least in part on a measurement of a skin impedance of the individual. In some embodiments, the hydration monitoring device can also generate a hydration metric based on the level of hydration and display the hydration metric.

First claim

Therefore, the following is claimed:

1. A monitoring device, comprising:
a flexible electrode configured to conform with a surface of skin, the flexible electrode comprising nanowires or nanoparticles embedded within a polydimethylsiloxane (PDMS) substrate and presenting a complex impedance when positioned in contact with skin;
a housing configured to be positioned against the surface of skin with a band that secures the flexible electrode in position on the surface of skin, wherein the band comprises a wristband, an armband, a chest strap, or a headband; and
processing circuitry positioned within the housing, the processing circuitry being communicatively coupled to the flexible electrode and configured to:
present an excitation frequency to the complex impedance of the flexible electrode;
sample a response of the complex impedance to the excitation frequency; and
measure a level of hydration using the flexible electrode based on the response.

2. The monitoring device of claim 1 , wherein the flexible electrode comprises silver nanowires or nanoparticles embedded within the PDMS substrate.

3. The monitoring device of claim 1 , wherein the flexible electrode comprises at least two interdigitated silver nanowire electrodes that are electrically isolated from each other in a common layer of the PDMS substrate.

4. The monitoring device of claim 1 , wherein the processing circuitry comprises impedance converter network analyzer circuitry.

5. The monitoring device of claim 4 , further comprising a battery operable to power the processing circuitry.

6. The monitoring device of claim 1 , wherein the processing circuitry is further configured to generate a hydration metric based on the level of hydration.

7. The monitoring device of claim 6 , further comprising a display device configured to display the hydration metric.

8. The monitoring device of claim 6 , further comprising a communication module configured to communicate the hydration metric to an external device.

9. The monitoring device of claim 1 , wherein the flexible electrode is adapted for contact with skin.

10. The monitoring device of claim 1 , within a smartwatch, a fitness band, or a patch.

11. A method, comprising:
positioning a housing comprising a flexible electrode against a surface of skin, the flexible electrode positioned on a bottom side of the housing in contact with the skin;
presenting, by processing circuitry, an excitation frequency to a complex impedance of the flexible electrode;
sampling, by the processing circuitry, a response of the complex impedance to the excitation frequency; and
measuring, by the processing circuitry, a level of hydration based on the response, wherein the flexible electrode is configured to conform with the surface of skin, comprises nanowires or nanoparticles embedded within a polydimethylsiloxane (PDMS) substrate, and presents the complex impedance when positioned in contact with skin.

12. The method of claim 11 , wherein the flexible electrode comprises silver nanowires or nanoparticles embedded within the PDMS substrate.

13. The method of claim 11 , wherein the excitation frequency is in the range of about 10-100 kHz.

14. The method of claim 11 , further comprising displaying the level of hydration on a display device.

15. A monitoring device, comprising:
a flexible electrode configured to conform with a surface of skin, the flexible electrode comprising at least two interdigitated silver nanowire or nanoparticle electrodes in a substrate comprising a polydimethylsiloxane (PDMS) substrate and presenting a complex impedance when positioned in contact with skin, the at least two interdigitated silver nanowire or nanoparticle electrodes being electrically isolated from each other in a common layer of the PDMS substrate; and
processing circuitry configured to measure a level of hydration using the flexible electrode.

16. The monitoring device of claim 15 , wherein the processing circuitry is configured to:
present an excitation frequency to the complex impedance of the flexible electrode;
sample a response of the complex impedance to the excitation frequency; and
measure the level of hydration based on the response.

17. The monitoring device of claim 15 , wherein the processing circuitry comprises impedance converter network analyzer circuitry.

18. The monitoring device of claim 15 , further comprising a battery operable to power the processing circuitry.

19. The monitoring device of claim 15 , wherein the processing circuitry is further configured to generate a hydration metric based on the level of hydration.

20. The monitoring device of claim 19 , further comprising a display device configured to display the hydration metric.

Assignees

• Univ North Carolina State

Inventors

• Myers Amanda
• Malhotra Abhishek
• Muth John
• Zhu Yong
• Yao Shanshan

Classifications

• A61B2503/40

  Animals · CPC title

• A61B5/6824

  Arm or wrist · CPC title

• A61B5/4875 Primary

  Hydration status, fluid retention of the body · CPC title

• A61B5/681

  Wristwatch-type devices · CPC title

• A61B5/0531

  Measuring skin impedance · CPC title