PHYSIOLOGICAL CHARACTERISTICS DETERMINATOR
One or more wearable devices may measure real-time blood pressure in a body using signals from multiple sensors including but not limited to a multi-axis accelerometer, a bioimpedance (BI) sensor, a capacitive touch sensor, an electrocardiography sensor (ECG), a ballistocardiograph sensor (BCG), a photoplethysmogram (PPG), a pulse oximetery sensor, and a phonocardiograph sensor (PCG), for example. Accelerometry data (e.g., from a multi-axis accelerometer or BCG sensor) may be used to derive effects of acceleration (e.g., gravity) on changes in blood pressure (e.g., due to changes in blood volume as measured using BI signals). The accelerometry data may be used to determine a baseline value for BI voltage signals that are indicative of diastolic and systolic blood pressure (e.g., in mmHg). Combinations of methods, such as BCG, ECG, PPG, blood pressure Pulse Wave and others may be used to determine pulse transit time (PTT), pulse arrival time (PAT), and pre-ejection period (PET). The wearable devices may be born on one or more body parts, such as the wrist, arm, leg, ankle, neck, chest, thorax, head, and ear.
1 . A system, comprising:
a wearable device being configured to be associated with a body;
a biometric sensor included in the wearable device, the biometric sensor being configured to generate a biometric signal indicative of biometric activity generated by a portion of the body;
a motion sensor being configured to generate a motion signal indicative of motion of the body; and
a processor being configured to:
receive the biometric signal and the motion signal,
generate data representing a difference between a first value and a second value of the biometric signal,
receive calibration data,
determine a calibration factor based on the calibration data and the data representing the difference between the first value and the second value of the biometric signal,
calculate, using the motion signal and the calibration factor, data representing a motion-related artifact in the biometric signal, and
factor the motion-related artifact out of the biometric signal to generate data representing blood pressure indicative of blood pressure in the portion of the body.
2 . The system of claim 1 , wherein the signal indicative of the biometric activity comprises a bioimpedance signal.
3 . The system of claim 1 , wherein the motion sensor is disposed in another wearable device being configured to be associated with the body.
4 . The system of claim 1 , wherein the motion sensor is disposed external to the body.
5 . The system of claim 1 , wherein the motion signal comprises accelerometry data associated with the motion of the body.
6 . The system of claim 1 , wherein the biometric sensor includes a plurality of electrode pairs, each electrode pair including a drive electrode and a receive electrode.
7 . The system of claim 1 , wherein the motion sensor comprises an accelerometer being configured to sense acceleration along at least one axis of motion.
8 . The system of claim 1 , wherein the calibration factor comprises the calibration data multiplied by the data representing the difference between the first value and the second value of the biometric signal.
9 . The system of claim 1 , wherein the biometric signal comprises a blood pressure signal.
10 . The system of claim 1 , wherein the biometric sensor comprises an optical sensor being configured to sense blood flow in the portion of the body.
11 . The system of claim 1 , wherein the processor is further configured to:
input the data representing the difference between the first value and the second value of the biometric signal to a data resource being configured to match the data representing the difference between the first value and the second value with data representing a matching value stored in the data resource, the data representing the matching value being associated with data representing an output value; and
receive the data representing the output value as the correlation data.