A real-time device for converting Doppler ultrasound audio signals into fluid flow velocity

Herr MD, Hogeman CS, Koch DW, Krishnan A, Momen A, Leuenberger UA. A real-time device for converting Doppler ultrasound audio signals into fluid flow velocity. Am J Physiol Heart Circ Physiol 298: H1626-H1632, 2010. First published February 19, 2010; doi: 10.1152/ajpheart.00713.2009.-A Doppler signal converter has been developed to facilitate cardiovascular and exercise physiology research. This device directly converts audio signals from a clinical Doppler ultrasound imaging system into a real-time analog signal that accurately represents blood flow velocity and is easily recorded by any standard data acquisition system. This real-time flow velocity signal, when simultaneously recorded with other physiological signals of interest, permits the observation of transient flow response to experimental interventions in a manner not possible when using standard Doppler imaging devices. This converted flow velocity signal also permits a more robust and less subjective analysis of data in a fraction of the time required by previous analytic methods. This signal converter provides this capability inexpensively and requires no modification of either the imaging or data acquisition system.