Apparatus and method for measuring biosignal
An apparatus and a method of measuring a biosignal are provided. The apparatus of measuring a biosignal includes an optical source configured to emit a first light and a second light towards a target, an inserted layer configured to transmit the first light and to reflect the second light, and an optical detector configured to detect a first received light that corresponds to the first light reflected by or transmitted through the target, and to detect a second received light that corresponds to the second light reflected by the inserted layer.
1. An apparatus for measuring a biosignal, comprising:
an optical source configured to emit a first light and a second light towards a target;
an inserted layer configured to transmit the first light and to reflect the second light; and
an optical detector configured to detect a first received light that corresponds to the first light reflected by or transmitted through the target, and to detect a second received light that corresponds to the second light reflected by the inserted layer.
2. The apparatus of claim 1 , wherein a wavelength of the first light is longer than a wavelength of the second light.
3. The apparatus of claim 1 , wherein the first light is a light polarized at a first angle;
the second light is a light polarized at a second angle different from the first angle; and
the inserted layer is configured to transmit the light polarized at the first angle and reflect the light polarized at the second angle.
4. The apparatus of claim 1 , wherein the first received light has an optical property that varies based on a change in blood flow in the target.
5. The apparatus of claim 1 , wherein the second received light has an optical property that varies based on a change in surface displacement of the target or a change in contact force on a surface of the target.
6. The apparatus of claim 1 , wherein the inserted layer is physically deformable by an external force.
7. The apparatus of claim 1 , wherein the inserted layer is either a sticker or a tattoo attached to a surface of the target.
8. The apparatus of claim 1 , further comprising:
a signal processor configured to extract biosignal information based on at least one signal input from the optical detector.
9. The apparatus of claim 1 , wherein the apparatus for measuring a biosignal operates through being comprised in a mobile device or a wearable device.
10. The apparatus of claim 1 , further comprising:
a shield configured to prevent an inflow of an external light into the optical detector.
11. The apparatus of claim 10 , wherein the optical source comprises:
a first optical source disposed on one side of the shield and configured to emit the first light towards the target; and
a second optical source disposed on another side of the shield and configured to emit the second light towards the target.
12. The apparatus of claim 10 , wherein the optical detector comprises:
a first optical detector disposed on one side of the shield and configured to detect the first light transmitted through the target; and
a second optical detector disposed on another side of the shield and configured to detect the second light reflected by the inserted layer.
13. The apparatus of claim 1 , wherein the insertion layer is configured to transmit the first light and to reflect the second light based on a wavelength of a light incident on the insertion layer.
14. An apparatus for measuring a biosignal, comprising:
an optical source configured to emit a light towards a target;
an inserted layer configured to transmit the light;
an optical detector configured to detect a light reflected by the target or a light transmitted through the target; and
a displacement and force detector configured to detect either a change in displacement on a surface of the target or a change in contact force on the surface of the target.
15. The apparatus of claim 14 , wherein the displacement and force detector is disposed in a single layer structure or a multilayer structure in the inserted layer.
16. The apparatus of claim 14 , wherein the displacement and force detector is configured to detect either the change in displacement or the change in contact force by using a piezoelectric element or a piezoresistive element.
17. The apparatus of claim 14 , wherein the displacement and force detector comprises:
a first electrode formed on the inserted layer; and
a second electrode located to be spaced apart from the first electrode.
18. The apparatus of claim 17 , wherein the displacement and force detector is configured to detect at least one of the change in displacement and the change in contact force based on a change in capacitance based on a change in distance between the first electrode and the second electrode.
19. The apparatus of claim 14 , further comprising:
a signal processor configured to obtain biosignal information of the target based on either a signal to be input from the optical detector or a signal to be input from the displacement and force detector.
20. A method of a biosignal measuring apparatus to measure a biosignal, the method comprising:
emitting a first light towards a target;
detecting a first received light corresponding to the first light either reflected by the target or transmitted through the target;
emitting a second light towards the target;
detecting a second received light corresponding to the second light that is reflected by an inserted layer; and
obtaining biosignal information of the target based on at least one of the detected first light and the detected second light,
wherein the inserted layer is configured to transmit the first light and to reflect the second light.