An experimental investigation on pulse transit time and pulse arrival time using ecg, pressure and ppg sensors

Abstract

Pulse transit time (PTT) and pulse arrival time (PAT) are explored using multiple sensors connected to the human body. Pulse wave velocity (PWV) is indirectly computed using PTT. We conducted a study using ECG, Pressure, and PPG sensor to capture the PAT and PTT information noninvasively. Three PAT and three PTT values were obtained from the body. An electrocardiograph (ECG/EKG) is used as a reference signal for three PAT values. PTT values were obtained using pressure and PPG sensors connected at the wrist and fingertip respectively. A pressure sensor module was constructed to measure PTT at the wrist and the results were compared with the other standard reference values. Heart rate variability was found to be relatively lower in both ECG and PPG sensors as compared with pressure sensors at the wrist. The PAT obtained from ECG and PPG sensor was found to have the least variation of 0.386±0.037 sec with 9.58% of the variation. PTT at the wrist captured using a pressure sensor was recorded to be 0.026±0.013 sec with 50% of the variation. PTT values measured using ECG and pressure sensor were found to be correlating with ECG and PPG. The experimental result indicates different ranges of the PWV which indicates that the flow velocity of the blood varies with different arteries. PTT can be effectively computed from pressure and PPG sensors, and this makes it possible to extract different pulse features in the wearable devices without the need of ECG signal or PAT as reference.

Keywords

• Pressure
• Sensor
• Pulse
• Artery
• Wrist
• Signal