System and method for blood pressure monitoring
A device ( 110 ), method and system ( 100 ) for calculating, estimating, or monitoring the blood pressure of a subject. At least one processor, when executing instructions, may perform one or more of the following operations. A first signal representing heart activity of the subject may be received. A second signal representing time-varying information on at least one pulse wave of the subject may be received. A first feature in the first signal may be identified. A second feature in the second signal may be identified. A pulse transit time based on a difference between the first feature and the second feature may be computed. The blood pressure of the subject may be calculated according to a first model based on the computed pulse transit time and a first set of calibration values, the first set of calibration values relating to the subject.
1. A device comprising
memory storing instructions; and
at least one processor that executes the instructions to perform operations comprising:
receiving a first signal representing heart activity of a subject;
receiving a second signal representing time-varying information on at least one pulse wave of the subject;
identifying, using the at least one processor, a first feature in the first signal;
identifying, using the at least one processor, a second feature in the second signal;
computing, using the at least one processor, a pulse transit time based on a difference between the first feature and the second feature;
receiving a first set of calibration values relating to the subject, wherein the first set of calibration values include a first calibration pulse transit time, a first variation between the first calibration pulse transit time and the computed pulse transit time; and determining if the first variation is equal to or lower than a first threshold; and
calculating, using the at least one processor, a blood pressure of the subject according to a first model based on the computed pulse transit time and the first set of calibration values.
2. The device of claim 1 , the receiving the first signal comprising communicating with a first sensor configured to acquire the first signal at a first location on the body of the subject.
3. The device of claim 2 , the receiving the second signal comprising communicating with a second sensor configured to acquire the second signal at a second location on the body of the subject.
4. The device of claim 3 , the first location and the second location being the same part of the body.
5. The device of claim 1 , the first signal or the second signal comprising an optical signal.
6. The device of claim 1 , the first signal or the second signal comprising an electrical signal.
7. The device of claim 1 , wherein
the first feature of the first signal corresponds to a first time point;
the identifying the second feature comprises:
selecting a segment of the second signal, the segment occurring within a time window from the first time point; and
locating the second feature corresponding to a second time point in the segment; and
the computing the pulse transit time comprises determining a time interval between the first time point and the second time point.
8. The device of claim 1 , the at least one processor further
retrieving, from a plurality of sets of calibration values, a second set of calibration values comprising a second calibration pulse transit time; and
deriving the first model based on the first set of calibration values and the second set of calibration values.
9. The device of claim 1 , wherein the first model is specific to the subject.
10. The device of claim 1 , wherein the first signal or the second signal comprises a PPG waveform, an ECG waveform, or a BCG waveform.
11. A method comprising:
receiving a first signal representing heart activity of a subject;
receiving a second signal representing time-varying information on at least one pulse wave of the subject;
identifying a first feature in the first signal;
identifying a second feature in the second signal;
computing a pulse transit time based on a difference between the first feature and the second feature;
receiving a first set of calibration values relating to the subject, wherein the first set of calibration values include a first calibration pulse transit time, a first variation between the first calibration pulse transit time and the computed pulse transit time; and determining if the first variation is equal to or lower than a first threshold; and
calculating a blood pressure of the subject according to a first model based on the computed pulse transit time and the first set of calibration values.
12. The method of claim 11 further comprising acquiring the first signal at a first location on the body of the subject.
13. The method of claim 12 further comprising acquiring the second signal at a second location on the body of the subject.
14. The method of claim 13 , the first location and the second location being the same part of the body.
15. The method of claim 11 , the first signal or the second signal comprising an optical signal.
16. The method of claim 11 , the first signal or the second signal comprising an electrical signal.
17. The method of claim 11 , wherein
the first feature of the first signal corresponds to a first time point;
the identifying the second feature comprises:
selecting a segment of the second signal, the segment occurring within a time window from the first time point; and
locating the second feature corresponding to a second time point in the segment; and
the computing the pulse transit time comprises determining a time interval between the first time point and the second time point.
18. The method of claim 11 further comprising receiving information relating to the subject or a condition when the first signal or the second signal is acquired.
19. The method of claim 18 , the calculating the blood pressure of the subject comprising applying the received information relating to the subject.
20. A system comprising:
an acquisition module configured to receive a first signal representing heart activity of a subject, and a second signal representing time-varying information on at least one pulse wave of the subject; and
an analysis module configured to
identify a first feature in the first signal;
identify a second feature in the second signal;
compute a pulse transit time based on a difference between the first feature and the second feature;
receive a first set of calibration values relating to the subject, wherein the first set of calibration values include a first calibration pulse transit time, a first variation between the first calibration pulse transit time and the computed pulse transit time; and determine if the first variation is equal to or lower than a first threshold; and
calculate a blood pressure of the subject according to a model based on the computed pulse transit time and a first set of calibration values.