Wearable device capable of monitoring perspiration

• US 9,724,037 B2
• Filed: 06/30/2015
• Issued: 08/08/2017
• Est. Priority Date: 09/02/2014
• Status: Active Grant

• Current Assignee: Hon Hai Precision Industry Co., Ltd.
• Original Assignee: Hon Hai Precision Industry Co., Ltd.
• Inventors: Chang, Jen-Tsorng
• Primary Examiner(s): JANG, CHRISTIAN YONGKYUN
• Application Number:
  US14/754,980
• Publication Number:
  US 20160058360A1
• Time in Patent Office: 770 Days
• CPC Class Codes: A61B 2562/125 characterised by the manufacture of electrodes
• CPC Class Codes: A61B 5/0537 Measuring body composition by impedance, e.g. tissue hydration or fat content
• CPC Class Codes: A61B 5/4266 sweat secretion
• CPC Class Codes: A61B 5/6824 Arm or wrist

Abstract

A wearable device includes a main body, a support portion, an electrode assembly, and a processor. The main body can be worn by a user. The support portion is secured to the main body and faces the user. The electrode assembly is secured to the support portion, and includes two electrode arrays and a plurality of carbon nanotubes arranged in arrays. Each electrode array includes arranged electrodes electrically connected to each other. The electrodes of each electrode array include at least two first electrodes each electrically connected to one carbon nanotube. The carbon nanotubes electrically connected to the two electrode arrays are alternatively arranged on the support portion and spaced from each other to form a detecting surface. The processor detects a resistance value of each electrode assembly, and determines an amount of the perspiration corresponding to the detected resistance value.

Claims

1. A wearable device configured to monitor perspiration from a user, the wearable device comprising:

a main body able to be worn by the user;

a support portion protruding from an interior surface of the main body facing the user;

at least one electrode assembly secured to the support portion, each of the at least one electrode assembly including two electrode arrays and a plurality of carbon nanotubes arranged in arrays, each electrode array including a plurality of arranged electrodes electrically connected to each other, the plurality of electrodes of each electrode array including at least two first electrodes each electrically connected to one of the plurality of carbon nanotubes, the plurality of carbon nanotubes electrically connected to the two electrode arrays being alternatively arranged on the support portion and spaced from each other to form a detecting surface, the plurality of carbon nanotubes configured to be electrically connected to each other when perspiration from the user is absorbed by the detecting surface, thereby causing a resistance value of the electrode assembly to decrease;

a memory for storing a relationship between different resistance values of the electrode assembly and amounts of the perspiration, each amount of the perspiration corresponding to one resistance value of the electrode assembly; and

a processor configured to detect a resistance value of each of the at least one electrode assembly and determine an amount of the perspiration corresponding to the detected resistance value according to the stored relationship.

2. The wearable device of claim 1, wherein the two electrode arrays of each of the at least one electrode assembly face each other and are spaced from each other;

the plurality of carbon nanotubes are located between the two electrode arrays;

an extension direction of each of the plurality of electrodes of the two electrode arrays is parallel to a radial direction of the plurality of carbon nanotubes.

3. The wearable device of claim 1, wherein the two electrode arrays of each of the at least one electrode assembly face each other and are spaced from each other;

the plurality of carbon nanotubes are located between the two electrode arrays;

an extension direction of each of the plurality of electrodes of the two electrode arrays is perpendicular to an axial direction of the plurality of carbon nanotubes.

4. The wearable device of claim 1, wherein the plurality of electrodes of each electrode array further comprise a second electrode electrically disconnected from each of plurality of carbon nanotube;

the resistance value of each of the at least one electrode assembly is equal to a resistance value between two second electrodes of the electrode assembly.

5. The wearable device of claim 4, wherein the processor comprises at least one detecting circuit and a control unit;

each detecting circuit is a Wheatstone Bridge which includes a resistor R₁, a resistor R₂, a resistor R₃, a voltmeter, and a DC power source;

the two second electrodes of each of the at least one electrode assembly are connected to the detecting circuit;

the resistor R₁ and the resistor R₃ are connected to each other in series to form a first branch;

the electrode assembly and the resistor R₂ are connected to each other in series to form a second branch;

the first branch and the second branch are connected to each other in parallel, and the connected first and the second branches are connected between an input terminal and an output terminal of the DC power source;

two ends of the voltmeter are connected between the resistor R₁ and the resistor R₃ and between the electrode assembly and the resistor R₂;

the control unit is configured to obtain a reading V₀ of the voltmeter, and calculate the resistance value of the electrode assembly according to the resistance values of the resistor R₁, the resistor R₂, and the resistor R₃, the reading V₀ of the voltmeter, and the output voltage V_in of the DC power source.

6. The wearable device of claim 5, wherein more than two electrode assemblies are located on and secured to the support portion;

the electrode assemblies have detecting surfaces of different area sizes;

the less the area size of the detecting surface, the higher a priority is assigned to the electrode assembly;

the processor comprises a plurality of detecting circuits each electrically connected to one of the at least one electrode assembly;

when the processor determines that one electrode assembly with a higher priority reaches a minimum resistance value, the processor is configured to subsequently detect the resistance value of a next electrode assembly with a lower priority, and determine the amount of the perspiration corresponding to the detected resistance value according to the stored relationship.

7. The wearable device of claim 6, wherein the processor is further configured to control the electrode assemblies which have already reached the minimum resistance value to heat, thereby causing the perspiration adhered to the plurality of carbon nanotubes to evaporate, and is configured to subsequently use the electrode assemblies with a higher priority to determine the perspiration again when the electrode assembly with the lowest priority reaches the minimum resistance value.

8. The wearable device of claim 4, wherein the processor comprises at least one detecting circuit and a control unit;

the two second electrodes of each of the at least one electrode assembly are connected to the detecting circuit;

the detecting circuit is an ohmmeter configured to determine the resistance value of the electrode assembly;

the control unit is configured to directly obtain the resistance value of the electrode assembly from the ohmmeter.

9. The wearable device of claim 1, wherein the main body is a wristband.

10. The wearable device of claim 1, wherein the support portion is made of glass or plastic.

11. The wearable device of claim 1, wherein a protective layer is covered on the detecting surface, and is configured to secure the plurality of carbon nanotubes to the support portion, and allow the perspiration from the user to be absorbed by the plurality of carbon nanotubes via the protective layer.

12. The wearable device of claim 11, wherein the protective layer comprises a non-woven fabric located on the plurality of carbon nanotubes and a wear resistant layer located on the non-woven fabric and with micropores.

13. The wearable device of claim 12, wherein the wear resistant layer is made of glass or polymethyl methacrylate.

14. The wearable device of claim 11, wherein the protective layer is a ceramic layer with micropores.

15. The wearable device of claim 1, wherein the processor is further configured to calculate a velocity of the perspiration according to the determined amount of perspiration.