Figure 1
From: Oscillometric blood pressure measurements on smartphones using vibrometric force estimation
Project Overview. (A) Simplified diagram of the smartphone vibrometric force estimation, where the vibration motor drives oscillatory motion and the finger applies a force. The smartphone Inertial Measurement Unit (IMU) records the motion and the smartphone camera records PPG. (B) Applied finger force and linear y-axis acceleration of smartphone IMU are plotted vertically. As force increases, the oscillation amplitude of the y-axis acceleration decreases. The raw PPG signal is also plotted vertically to show how increased force affects the blood volume. (C) Smartphone app with visual queue for finger, guideline for applied force, and plot of PPG signal. (D) Amplitude of blood volume oscillations plotted against applied finger pressure. The approximate points of Diastolic Blood Pressure (DBP), Mean Arterial Pressure (MAP), and Systolic Blood Pressure (SBP) are indicated for interpretability.
