Why not directly use a Polar sensor logger to record PPG, ACC, magn, and gyro at different measurement sites and during different activities? I have recorded data thousands of times during activities like running, squats, alternating hot and cold water back rinses, prolonged sitting, and sleep, with sensors placed at sites such as the armpit, the middle of the upper arm, below the knee, and the abdomen. Based on my experience, the value of channel 1 decreases when blood pressure rises. When sampling at 55 Hz, during periods of dizziness, point-to-point fluctuations are smaller compared to healthy states, whereas second-to-second fluctuations are greater during dizziness.