Apparatus and method for estimating bio-information

1. An apparatus for estimating bio-information, the apparatus comprising:

an image sensor configured to acquire a first contact image of an object, based on the object being in contact with the image sensor;

an actuator; and

a processor configured to:

determine a contact position and a direction of the object, based on the acquired first contact image;

control the actuator to adjust a position of the image sensor, based on the determined contact position and the determined direction of the object so that a field of view (FOV) of the image sensor moves to a predefined measurement area on the object;

control the image sensor to acquire a second contact image of the object, based on the position of the image sensor being adjusted,

extract a pulse wave signal based on a pixel intensity of the second contact image; and

estimate the bio-information based on the pulse wave signal.

2. The apparatus of claim 1 , wherein the processor is further configured to:

extract a characteristic point of the object, from the acquired first contact image; and

determine the contact position and the direction, based on the extracted characteristic point.

3. The apparatus of claim 2 , wherein the characteristic point of the object comprises a fingerprint center point of a finger.

4. The apparatus of claim 2 , wherein the processor is further configured to:

determine whether the extracted characteristic point exists in the first contact image; and

based on the extracted characteristic point being determined to not exist in the first contact image, guide a user to bring the object into contact with the image sensor.

5. The apparatus of claim 2 , wherein the processor is further configured to:

determine whether the extracted characteristic point exists in the first contact image; and

based on the extracted characteristic point being determined to not exist in the first contact image, repeat a predetermined number of times of controlling the actuator to adjust the position of the image sensor to an arbitrary position and then extracting the characteristic point, from the acquired first contact image acquired after the position of the image sensor is adjusted.

6. The apparatus of claim 2 , wherein the processor is further configured to:

determine whether the extracted characteristic point exists in the first contact image; and

based on the extracted characteristic point being determined to not exist in the first contact image, estimate a position of the characteristic point by comparing a reference contact image and the acquired first contact image.

7. The apparatus of claim 1 , wherein the processor is further configured to:

determine a displacement of the image sensor, based on the determined contact position and the determined direction; and

control the actuator to adjust the position of the image sensor, based on the determined displacement.

8. The apparatus of claim 1 , wherein the processor is further configured to:

generate an oscillogram, based on the pulse wave signal and a contact pressure of the object; and

estimate the bio-information, based on the generated oscillogram.

9. The apparatus of claim 8 , further comprising a force/pressure sensor configured to measure a contact force or the contact pressure that is applied between the object and the image sensor, based on the object in contact with the image sensor changing a force.

10. The apparatus of claim 8 , wherein the processor is further configured to acquire the contact pressure, based on the pixel intensity of the acquired second contact image and using a predefined contact pressure conversion equation.

11. The apparatus of claim 1 , wherein the bio-information comprises any one or any combination of a blood pressure, a vascular age, an arterial stiffness, an aortic pressure waveform, a blood vessel elasticity, a stress index, and a degree of fatigue.

12. A method of estimating bio-information, the method comprising:

acquiring, by an image sensor, a first contact image of an object, based on the object being in contact with the image sensor;

determining, by a processor, a contact position and a direction of the object, based on the acquired first contact image;

controlling, by the processor, an actuator to adjust a position of the image sensor, based on the determined contact position and the determined direction of the object so that a field of view (FOV) of the image sensor moves to a predefined measurement area on the object;

acquiring a second contact image of the object based on the position of the image sensor being adjusted;

extracting a pulse wave signal based on a pixel intensity of the second contact image; and

estimating bio-information based on the pulse wave signal.

13. The method of claim 12 , wherein the determining of the contact position and the direction comprises:

extracting a characteristic point of the object, from the acquired first contact image; and

determining the contact position and the direction, based on the extracted characteristic point.

14. The method of claim 13 , further comprising:

determining whether the extracted characteristic point exists in the first contact image; and

based on the extracted characteristic point being determined to not exist in the first contact image, guiding a user to bring the object into contact with the image sensor.

15. The method of claim 13 , further comprising:

determining whether the extracted characteristic point exists in the first contact image; and

based on the extracted characteristic point being determined to not exist in the first contact image, repeating a predetermined number of times of controlling the actuator to adjust the position of the image sensor to an arbitrary position and then extracting the characteristic point, from the acquired first contact image acquired after the position of the image sensor is adjusted.

16. The method of claim 13 , further comprising:

determining whether the extracted characteristic point exists in the first contact image; and

based on the extracted characteristic point being determined to not exist in the first contact image, estimating a position of the characteristic point by comparing a reference contact image and the acquired first contact image.

17. The method of claim 12 , wherein the controlling of the actuator comprises:

determining a displacement of the image sensor, based on the determined contact position and the determined direction; and

controlling the actuator to adjust the position of the image sensor, based on the determined displacement.

18. The method of claim 12 , wherein the estimating of the bio-information comprises:

generating an oscillogram, based on the pulse wave signal and a contact pressure of the object; and

estimating the bio-information, based on the generated oscillogram.