In this notebook, Mathematica was applied to a set of problems in biomedical signal processing. Echocardiosignals of the left ventricle, left ventricular posterior wall, and septum were interpolated by means of the Mathematica function Fit. In addition, velocities and accelerations of the heart chamber's walls were calculated and graphed. These velocities and accelerations carry potentially useful clinical information; in particular, the upstroke of the ventricular diameter curve and the minimum diameter achieved are important for noninvasive heart transplant rejection surveillance.