A protocol has been developed to measure blood volume flow and to estimate vessel wall stiffness and stiffness changes of the brachial artery in response to injection of pharmacological agents. The intra-arterial blood pressure was continuously recorded by an analog pressure transducer at the end of an arterial catheter placed in each of the subjects. Simultaneously, video ultrasound was used to record images of the brachial artery pulsations and index finger pulse oxymetry was performed to allow the computation of the blood pressure wavespeed. The data were used to compute blood volume flow and arterial wall elastic modulus using the Womersley mathematical model for blood flow.
