Noninvasive arterial blood pressure waveform monitoring using two- element ultrasound system.

This work details noninvasive arterial blood pressure (ABP) waveform estimation based on an arterial vessel cross-sectional area measurement combined with an elasticity measurement of the vessel, represented by pulse wave velocity (PWV), using a two-element ultrasound system. The overall ABP waveform estimation is validated in a custom-designed experimental setup mimicking the heart and an arterial vessel segment with two single element transducers, assuming a constant hemodynamic system. The estimation of local PWV using the flow-area method produces unbiased elasticity estimation of the tube in a pressure waveform comparison. The measured PWV using 16 cardiac cycles of data is 8.47 + 0.63 m/s with an associated scaling error of -1.56 + 14.0% in a direct pressure waveform comparison, showing negligible bias error on average. The distension waveform obtained from a complex cross-correlation model estimator (C3M) reliably traces small pressure changes reflected by the diameter change. The excellent agreement of an estimated pressure waveform to the reference pressure waveform suggests the promising potential of a readily available, inexpensive, and portable ABP waveform monitoring device.