This work presents a system which estimates blood pressure variability (BPV) via pulse arrival time (PAT) using two distinct methods. Three heart rate estimates are acquired, from beat-to-beat time interval extraction of electrocardiogram (ECG), finger photoplethysmogram (PPG), and ballistocardiogram (BCG), thus using both ECG and BCG as reference signals PAT is computed. Since PAT variability is correlated to blood pressure variability, the system obtains an estimation of both heart rate variability (HRV) and BPV, parameters which carry vast information to characterize physiological and pathological state. Given that BCG has not been studied yet has an alternative to EGG in PAT calculations, this study focus on the correlation of these two PATV estimates.