Apparatuses, systems, and methods described herein can enable reliable estimation of pulse transit time (PTT) for a user in motion for cuffless blood pressure estimation. In one embodiment, a method involves receiving an electrocardiographic (ECG) signal and a photoplethysmographic (PPG) signal and detecting R-wave peaks in the ECG signal. The method further involves identifying multiple segments of the PPG signal based on detection of the R-wave peaks of the ECG signal, wherein a given segment of the PPG signal comprises multiple samples and is aligned with a corresponding R-wave. The method also involves generating an averaged PPG wave based on the multiple segments of the PPG signal, wherein a given element of the averaged PPG wave comprises an average of corresponding elements from the multiple segments of the PPG signal, and computing the blood pressure value based on the averaged PPG wave.
