Antioxidant sensor and method of measuring antioxidant value

1. An antioxidant sensor comprising:

a pressure sensor configured to obtain a contact pressure between an object and an optical sensor;

a processor configured to:

set a first threshold pressure and a plurality of second threshold pressures;

determine whether the object is in contact with the optical sensor based on the obtained contact pressure exceeding the first threshold pressure, and determine a contact portion of the object in contact with the optical sensor; and

select a second threshold pressure, among the plurality of second threshold pressures, according to the determined contact portion, wherein the plurality of second threshold pressures respectively correspond to different contact portions, and

the optical sensor configured to, based on the obtained contact pressure exceeding a set the selected second threshold pressure, emit a first light of a first wavelength to the object, and to receive the first light reflected or scattered from the object,

wherein the processor is configured to determine an antioxidant value based on the received first light.

2. The antioxidant sensor of claim 1 , wherein the processor is further configured to control operation to guide a user such that the contact pressure between the object and the optical sensor exceeds the set first threshold pressure.

3. The antioxidant sensor of claim 2 , wherein the processor is further configured to, based on the obtained contact pressure being less than or equal to the set first threshold pressure, adjust at least one of a quantity of light and a flickering speed of the optical sensor.

4. The antioxidant sensor of claim 2 , wherein the processor is further configured to, based on the obtained contact pressure being less than or equal to the set first threshold pressure, output information indicating that the contact pressure between the object and the optical sensor is to be increased.

5. The antioxidant sensor of claim 1 , wherein the first wavelength is included in an absorption band of an antioxidant substance.

6. The antioxidant sensor of claim 5 , wherein the first wavelength is a blue wavelength.

7. The antioxidant sensor of claim 1 , wherein the processor is further configured to control to inquire a user about the contact portion of the object and determine the contact portion of the object based on a response from the user.

8. The antioxidant sensor of claim 1 , wherein the optical sensor is further configured to emit a second light of a second wavelength and a third light of a third wavelength to the object, and receive the second light and the third light reflected or scattered from the object; and

the processor is further configured to obtain a hemoglobin index based on the received second light and the received third light, and determine the contact portion of the object based on the obtained hemoglobin index.

9. The antioxidant sensor of claim 8 , wherein the second wavelength is included in an absorption band of hemoglobin; and

the third wavelength is different from the second wavelength.

10. The antioxidant sensor of claim 9 , wherein the second wavelength is a green wavelength; and

the third wavelength is a blue wavelength, the green wavelength, or a red wavelength.

11. The antioxidant sensor of claim 8 , wherein the processor is further configured to obtain a hemoglobin signal based on the received second light, obtain a preprocessing signal based on the received third light, normalize the obtained hemoglobin signal by using the preprocessing signal, and obtain the normalized hemoglobin signal as the hemoglobin index.

12. The antioxidant sensor of claim 8 , wherein the processor is further configured to determine the contact portion of the object based on a value of the hemoglobin index.

13. A method of obtaining an antioxidant value, the method comprising:

obtaining a contact pressure between an object and an optical sensor;

setting a first threshold pressure and a plurality of second threshold pressures;

based on the obtained contact pressure exceeding the first threshold pressure, determining that the object is in contact with the optical sensor and determining a contact portion of the object in contact with the optical sensor;

selecting a second threshold pressure, among the plurality of second threshold pressures, according to the determined contact portion, wherein the plurality of second threshold pressures respectively correspond to different contact portions;

based on the obtained contact pressure exceeding the selected second threshold pressure, emitting a first light of a first wavelength to the object, and receiving the first light reflected or scattered from the object; and

determining an antioxidant value based on the received first light.

14. The method of claim 13 , further comprising controlling to guide a user such that the contact pressure between the object and the optical sensor exceeds the set first threshold pressure.

15. The method of claim 14 , wherein the controlling comprises, based on the obtained contact pressure being less than or equal to the set first threshold pressure, adjusting at least one of a quantity of light and a flickering speed of the optical sensor.

16. The method of claim 14 , wherein the controlling comprises, based on the obtained contact pressure being less than or equal to the set first threshold pressure, outputting information indicating that the contact pressure between the object and the optical sensor is to be increased.

17. The method of claim 13 , wherein the first wavelength is a blue wavelength included in an absorption band of an antioxidant substance.

18. The method of claim 13 , wherein the determining the contact portion comprises:

inquiring a user about the contact portion of the object; and

determining the contact portion of the object based on a response from the user.

19. The method of claim 13 , wherein the determining the contact portion comprises:

emitting a second light of a second wavelength and a third light of a third wavelength to the object;

receiving the second light and the third light reflected or scattered from the object;

obtaining a hemoglobin index based on the received second light and the received third light; and

determining the contact portion of the object based on the obtained hemoglobin index.

20. The method of claim 19 , wherein the second wavelength is a green wavelength included in an absorption band of hemoglobin; and

the third wavelength is a blue wavelength, the green wavelength, or a red wavelength which is different from the second wavelength.

21. The method of claim 19 , wherein the obtaining the hemoglobin index comprises:

obtaining a hemoglobin signal based on the received second light;

obtaining a preprocessing signal based on the received third light;

normalizing the obtained hemoglobin signal by using the preprocessing signal; and

obtaining the normalized hemoglobin signal as the hemoglobin index.

22. The method of claim 19 , wherein the determining the contact portion comprises determining the contact portion of the object based on a value of the hemoglobin index.