Cuffless blood pressure measurement using handheld device

1. A method for determining blood pressure, the method comprising:

determining a plurality of heart sounds using a microphone of a handheld device;

determining a pulse wave using a camera of the handheld device;

determining an ejection time (ET), a vascular transit time (VTT), and a heart rate from any of the plurality of heart sounds and the pulse wave; and

performing regression analysis on received user-specific data, the ET, the VTT, and the heart rate to determine the blood pressure.

2. The method of claim 1 , wherein determining an ejection time (ET) comprises:

determining the ET as a time difference between a first heart sound and a second heart sound of the plurality of heart sounds.

3. The method of claim 2 , wherein determining a vascular transit time (VTT) comprises:

determining the VTT as a time difference between the first heart sound and the pulse wave.

4. The method of claim 1 , wherein determining a heart rate comprises:

determining the heart rate as an average of a reciprocal of a time difference between any of a first heart sound of one heartbeat and a first heart sound of an adjacent heartbeat, a second heart sound of one heartbeat and a second heart sound of an adjacent heartbeat, and a pulse wave of one heartbeat and a pulse wave of an adjacent heartbeat.

5. The method of claim 1 , wherein the received user-specific data includes any of height, weight, age, and gender.

6. The method of claim 1 , wherein the regression analysis comprises any of statistical linear regression and statistical non-linear regression.

7. The method of claim 1 , further comprising:

utilizing calibration values received from a reference device, the ET, the VTT, and the heart rate to determine the blood pressure.

8. The method of claim 1 , wherein determining a plurality of heart sounds using a microphone of a handheld device comprises:

determining the plurality of heart sounds when the microphone is placed on a chest of a user.

9. The method of claim 1 , wherein determining a pulse wave using a camera of the handheld device comprises:

determining the pulse wave when a finger of the user is placed over the camera.

10. The method of claim 8 , further comprising:

filtering an audio signal detected by the microphone to provide a phonocardiogram (PCG) signal; and

performing peak detection on the PCG signal to determine the plurality of heart sounds.

11. The method of claim 9 , further comprising:

filtering color components obtained by the camera;

calculating a weighted average of the filtered color components to provide a photoplethysmogram (PPG) signal; and

performing peak detection on the PPG signal to determine the pulse wave.

12. The method of claim 1 , further comprising:

performing noise cancellation using another microphone of the handheld device; and

performing common mode noise cancellation using another camera of the handheld device.