Apparatus and method for estimating bio-information
A blood pressure monitor may include a photoplethysmogram (PPG) sensor to obtain a PPG sensor and at least one processor configured to extract characteristic points from the PPG signal, determine internally dividing points of the characteristic points based on time values of the characteristic points, extract feature values from the PPG signal based on the internally dividing points, and determine a blood pressure based on the extracted feature values of the PPG signal. The blood pressure monitor may further include a display configured to provide a graphical user interface that displays a vertical line that is movable in a timeline over a graph that shows a change in the blood pressure over time, a blood pressure value corresponding to a position of the vertical line, and component pulses constituting the PPG signal, together with the graph and the vertical line.
1. A blood pressure monitor comprising:
a photoplethysmogram (PPG) sensor configured to emit a light to a user and acquire a PPG signal by detecting the light reflected or scattered from the user;
at least one processor configured to
extract a plurality of characteristic points from the PPG signal;
determine internally dividing points of the plurality of characteristic points based on time values of the plurality of characteristic points;
extract feature values from the PPG signal based on the internally dividing points; and
determine a blood pressure based on the extracted feature values of the PPG signal; and
a display configured to provide a graphical user interface that displays
a vertical line that is movable in a timeline over a graph that shows a change in the blood pressure over time,
a blood pressure value corresponding to a position of the vertical line, and
component pulses constituting the PPG signal, together with the graph and the vertical line.
2. The blood pressure monitor of claim 1 , wherein the at least one processor is further configured to:
apply weights respectively to the time values of the plurality of characteristic points; and
determine the internally dividing points of the plurality of characteristic points based on a sum of the weights.
3. The blood pressure monitor of claim 2 , wherein the at least one processor is further configured to calculate the weights based on amplitude values of the plurality of characteristic points.
4. The blood pressure monitor of claim 2 , wherein the at least one processor is further configured to calculate the weights based on differences between first amplitudes at a plurality of points in a derivative signal of the PPG signal and a second amplitude at a predetermined point in the derivative signal, and
wherein the plurality of points in the derivative signal correspond to the plurality of characteristic points extracted from the PPG signal.
5. The blood pressure monitor of claim 1 , wherein the plurality of characteristic points comprise at least one of points associated with the component pulses constituting the PPG signal, and a point at which an amplitude has a maximum value in a systolic region of the PPG signal.
6. The blood pressure monitor of claim 5 , wherein the at least one processor is further configured to determine local minimum points in a second derivative signal of the PPG signal as the points associated with the component pulses.
7. The blood pressure monitor of claim 5 , wherein the at least one processor is further configured to extract the feature values based on at least one of a ratio of an area of the PPG signal to an amplitude value at the point at which an amplitude has the maximum value in the systolic region of the PPG signal and a difference in time value between the internally dividing points the PPG signal.
8. A method of estimating blood pressure, the method comprising:
acquiring a photoplethysmogram (PPG) signal;
extracting a plurality of characteristic points from the PPG signal;
determining internally dividing points of the plurality of characteristic points based on a time values of the plurality of characteristic points;
extracting feature values from the PPG signal based on the internally dividing points to estimate the PPG signal;
determining a blood pressure based on the extracted feature values of the PPG signal; and
providing a graphical user interface that displays
a vertical line that is movable in a timeline over a graph that shows a change in the blood pressure over time,
a blood pressure value corresponding to a position of the vertical line, and
component pulses constituting the PPG signal, together with the graph and the vertical line.
9. The method of claim 8 , the determining of the internally dividing points comprises:
applying weights respectively to the time values of the plurality of characteristic points; and
determining the internally dividing points of the plurality of characteristic points based on a sum of the weights.
10. The method of claim 9 , wherein the determining the internally dividing points comprises calculating the weights based on amplitude values of the plurality of characteristic points.
11. The method of claim 9 , wherein the determining the internally dividing points comprises calculating the weights based on differences between first amplitudes at a plurality of points in a derivative signal of the PPG signal and a second amplitude at a predetermined point in the derivative signal, and
wherein the plurality of points in the derivative signal correspond to the plurality of characteristic points extracted from the PPG signal.
12. The method of claim 8 , wherein the plurality of characteristic points comprise at least one of points associated with the component pulses constituting the PPG signal, and a point at which an amplitude has a maximum value in a systolic region of the PPG signal.
13. The method of claim 12 , further comprising determining local minimum points in a second derivative signal of the PPG signal as the points associated with the component pulses.
14. The method of claim 12 , further comprising extracting the feature values based on at least one of a ratio of an area of the PPG signal to an amplitude value at the point at which an amplitude has the maximum value in the systolic region of the PPG signal and a difference in time value between the internally dividing points of the PPG signal.
15. A blood pressure monitor comprising:
a photoplethysmogram (PPG) sensor configured to emit a light to a user and acquire a PPG signal by detecting the light reflected or scattered from the user;
at least one processor configured to
convert the PPG signal to a second derivative signal of the PPG signal;
extract a plurality of characteristic points from the second derivative signal;
determine internally dividing points of the plurality of characteristic points based on time values of the plurality of characteristic points;
extract feature values from the second derivative signal based on the internally dividing points; and
determine a blood pressure based on the extracted feature values of the second derivative signal; and
a display configured to provide a graphical user interface that displays
a vertical line that is movable in a timeline over a graph that shows a change in the blood pressure over time,
a blood pressure value corresponding to a position of the vertical line, and
component pulses constituting the PPG signal, together with the graph and the vertical line.