Bio-information measuring apparatus and bio-information measuring method
An apparatus for measuring bio-information in a non-invasive manner includes: a pulse wave sensor configured to measure a plurality of pulse wave signals having different wavelengths from an object; a contact pressure sensor configured to measure contact pressure of the object while the plurality of pulse wave signals are measured; and a processor configured to obtain an oscillometric waveform based on the contact pressure and the plurality of pulse wave signals having the different wavelengths, and obtain bio-information based on the oscillometric waveform.
1. A bio-information measuring apparatus comprising:
a pulse wave sensor configured to measure a plurality of pulse wave signals having different wavelengths from an object, the plurality of pulse wave signals comprising a first pulse wave signal and a second pulse wave signal;
a contact pressure sensor configured to measure a contact pressure between the bio-information measuring apparatus and the object while the plurality of pulse wave signals are measured; and
a processor configured to:
obtain a difference signal by subtracting an n-th order differential signal of the second pulse wave signal from an n-th order differential signal of the first pulse wave signal, n being an integer equal to or greater than 1;
obtain an oscillometric waveform based on the difference signal and the contact pressure; and
obtain bio-information using the oscillometric waveform,
wherein the bio-information comprises at least one of blood pressure, vascular age, arterial stiffness, aortic pressure waveform, vascular compliance, stress index, and degree of fatigue.
2. The bio-information measuring apparatus of claim 1 , wherein the pulse wave sensor comprises:
a first pulse wave sensor comprising a first light source configured to emit a light of a first wavelength onto the object, and a first detector configured to measure the first pulse wave signal in response to the light of the first wavelength returning from the object; and
a second pulse wave sensor comprising a second light source configured to emit a light of a second wavelength, which is different from the first wavelength, onto the object, and a second detector configured to measure the second pulse wave signal in response to the light of the second wavelength returning from the object.
3. The bio-information measuring apparatus of claim 2 , wherein the first wavelength is longer than the second wavelength.
4. The bio-information measuring apparatus of claim 1 , wherein the processor is further configured to normalize the first pulse wave signal and the second pulse wave signal, and obtain the difference signal based on the normalized first pulse wave signal and the normalized second pulse wave signal.
5. The bio-information measuring apparatus of claim 1 , wherein the processor is further configured to exclude a portion, where noise occurs, from the plurality of pulse wave signals based on the contact pressure.
6. The bio-information measuring apparatus of claim 1 , wherein the processor is further configured to provide contact pressure guide information to a user while the plurality of pulse wave signals are measured.
7. The bio-information measuring apparatus of claim 6 , further comprising an output interface configured to provide at least one of the measured plurality of pulse wave signals, the measured contact pressure, the contact pressure guide information, and a measurement result of bio-information to the user.
8. The bio-information measuring apparatus of claim 1 , further comprising a communication interface configured to transmit at least one of the plurality of pulse wave signals and the bio-information to an external device.
9. The bio-information measuring apparatus of claim 1 , wherein the pulse wave sensor comprises a plurality of light sources configured to emit a light of different wavelengths onto the object, and a detector configured to measure the plurality of pulse wave signals from the light of the different wavelengths which is emitted to and then returns from the object.
10. The bio-information measuring apparatus of claim 9 , wherein the processor comprises a sensor controller configured to sequentially switch on the plurality of light sources based on driving conditions of the plurality of light sources.
11. The bio-information measuring apparatus of claim 10 , further comprising a storage configured to store the driving conditions comprising at least one of a driving order and a driving time of the plurality of light sources.
12. The bio-information measuring apparatus of claim 1 , wherein the pulse wave sensor comprises a light source configured to emit a light onto the object, and a plurality of detectors configured to measure the plurality of pulse wave signals from the light which is emitted to and then returns from the object.
13. The bio-information measuring apparatus of claim 12 , wherein at least one of the plurality of detectors comprises a color filter configured to pass a predetermined wavelength band to measure the plurality of pulse wave signals of the different wavelengths.
14. The bio-information measuring apparatus of claim 12 , wherein the plurality of detectors are disposed at different distances from the light source.
15. The bio-information measuring apparatus of claim 14 , wherein:
the light source is further configured to emit a first light of a first wavelength and a second light of a second wavelength onto the object;
the first wavelength is longer than the second wavelength; and
the plurality of detectors comprise a first detector configured to measure the first pulse wave signal and a second detector configured to measure the second pulse wave signal, and a distance between the first detector and the light source is longer than a distance between the second detector and the light source.
16. The bio-information measuring apparatus of claim 1 , wherein the processor is further configured to normalize the n-th order differential signal of the first pulse wave signal and the n-th order differential signal of the second pulse wave signal and obtain the difference signal by subtracting the normalized n-th order differential signal of the second pulse wave signal from the normalized n-th order differential signal of the first pulse wave signal.
17. A bio-information measuring method that is performed by a bio-information measuring apparatus, the bio-information measuring method comprising:
measuring a plurality of pulse wave signals having different wavelengths from an object, the plurality of pulse wave signals comprising a first pulse wave signal and a second pulse wave signal;
measuring a contact pressure between the bio-information measuring apparatus and the object while the plurality of pulse wave signals are measured;
obtaining a difference signal by subtracting an n-th order differential signal of the second pulse wave signal from an n-th order differential signal of the first pulse wave signal, n being an integer equal to or greater than 1;
obtaining an oscillometric waveform based on the difference signal and the contact pressure; and
obtaining bio-information using the oscillometric waveform,
wherein the bio-information comprises at least one of blood pressure, vascular age, arterial stiffness, aortic pressure waveform, vascular compliance, stress index, and degree of fatigue.
18. The bio-information measuring method of claim 16 , further comprising normalizing the first pulse wave signal and the second pulse wave signal, and obtaining the difference signal based on the normalized first pulse wave signal and the normalized second pulse wave signal.
19. The bio-information measuring method of claim 16 , wherein the measuring the plurality of pulse wave signals comprises:
emitting a light of a first wavelength onto the object and measuring the first pulse wave signal in response to the light of the first wavelength returning from the object; and
emitting a light of a second wavelength, which is shorter than the first wavelength, onto the object, and measuring the second pulse wave signal in response to the light of the second wavelength returning from the object.
20. The bio-information measuring method of claim 19 , wherein the obtaining the oscillometric waveform comprises excluding a portion, where noise occurs, from the plurality of pulse wave signals based on the contact pressure.
21. The bio-information measuring method of claim 19 , further comprising providing contact pressure guide information to a user while the plurality of pulse wave signals are measured.
22. The bio-information measuring method of claim 21 , further comprising providing at least one of the plurality of pulse wave signals, the contact pressure, the contact pressure guide information, and a measurement result of the bio-information to the user.