Various embodiments enable calibrating a non-invasive blood pressure measurement device by determining multiple parameters defining a stress-strain relationship of an artery of a patient. The device may obtain output signals from a blood pressure sensor at two or more measurement elevations. The obtained measurement signals may be filtered into AC and quasi-DC components, and results fit to exponential functions to calculate an arterial time constant and a veinous time constant related to vein draining/filling rates. The arterial and veinous time constants may be used to calculate an infinity ratio. The infinity ratio and the obtained sensor output may be used to calculate values for multiple parameters defining a stress-strain relationship of a measured artery. Once defined, this stress-strain relationship may be stored and applied to future sensor output signals (e.g., blood pressure measuring sessions) to infer patient blood pressure.
