Systems methods and devices of various embodiments enable measurement of blood pressure from an artery. The various embodiments may measure using a non interfering arterial measurement sensor a first change in distension of the artery at a measurement location without interference to an arterial pressure at the measurement location during a series of pulses. A first pulse rate and estimated pulse pressures may be determined from the first change in distension. A coefficient may be determined fitting an exponentially decaying function representing an exponential decay of a portion of a diastolic phase to select ones of the estimated pulse pressures corresponding to the diastolic phase. An absolute blood pressure may be determined by applying the coefficient to a select mathematical model expressing a first relationship between the first change in distension of the artery and the pulse pressure in the artery at the measurement location.
