Journal Article

Transfer‐function‐free technique for the noninvasive determination of the human arterial pressure waveform

Wilkinson, Ian B., Palombo, Carlo, Khir, Ashraf W., Cruickshank, J. Kennedy, Morizzo, Carmela, Kozakova, Michaela, Giudici, Alessandro

2021

Overview

The estimation of central aortic blood pressure is a cardinal measurement, carrying effective physiological, and prognostic data beyond routine peripheral blood pressure. Transfer function‐based devices effectively estimate aortic systolic and diastolic blood pressure from peripheral pressure waveforms, but the reconstructed pressure waveform seems to preserve features of the peripheral waveform. We sought to develop a new method for converting the local diameter distension waveform into a pressure waveform, through an exponential function whose parameters depend on the local wave speed. The proposed method was then tested at the common carotid artery. Diameter and blood velocity waveforms were acquired via ultrasound at the right common carotid artery while simultaneously recording pressure at the left common carotid artery via tonometer in 203 people (122 men, 50 ± 18 years). The wave speed was noninvasively estimated via the lnDU‐loop method and then used to define the exponential function to convert the diameter into pressure. Noninvasive systolic and mean pressures estimated by the new technique were 3.8 ± 21.8 (p = 0.015) and 2.3 ± 9.6 mmHg (p = 0.011) higher than those obtained using tonometery. However, differences were much reduced and not significant in people >35 years (0.6 ± 18.7 and 0.8 ± 8.3 mmHg, respectively). This proof of concept study demonstrated that local wave speed, estimated from noninvasive local measurement of diameter and flow velocity, can be used to determine an exponential function that describes the relationship between local pressure and diameter. This pressure‐diameter function can then be used for the noninvasive estimation of local arterial pressure. The noninvasive determination of local arterial pressure is of great interest to both clinicians and physiologists. In this work we present a novel technique for the determination of arterial pressure using direct and noninvasive local measurements. The results are encouraging and warrant further investigation to establish the full extent of benefits of this method.

• Publisher: John Wiley & Sons, Inc,John Wiley and Sons Inc,Wiley
• Subject: Adolescent / Adult / Aged / Aorta / Arterial Pressure / Blood pressure / Blood Pressure Determination - methods / Blood Pressure Determination - standards / Carotid arteries / Carotid Arteries - physiology / Carotid artery / Cerebrovascular Circulation / Collaboration / Coronary vessels / Distension / Female / Flow velocity / Humans / Hypertension / local wave speed / Male / Methods / Models, Cardiovascular / noninvasive estimation of pressure / Original / Peripheral blood / Physiology / pressure / Ultrasonic imaging / Veins & arteries / Velocity