title: [Methods for discriminating flow direction with continuous wave Doppler equipment].
abstract: The application of ultrasound Doppler units for the localization of incompetent venous valves, the examination of extracranial vessels, and the evaluation of the hemodynamic effect of certain cardiac dysfunctions requires directional models with the possibility of recording Doppler wave forms. Various techniques are used to determine flow direction all of them presenting specific advantages and disadvantages in practical use. After briefly explaining the basic Doppler technique, the three most commonly used methods, the two-channel filter technique, the McLeod system, and the outphaser system, are described. The characteristics of the various signal processing techniques are discussed, particularly in the case of complex hemodynamic conditions.
authors.affiliation: Kranzbühler GmbH, Solingen.
authors.forename: H
authors.initials: H
authors.lastname: Dudwiesus
authors.forename: M J
authors.initials: MJ
authors.lastname: Teague
mesh_terms: D001783:Blood Flow Velocity / Q000502:physiology; D015150:Echocardiography, Doppler / Q000295:instrumentation*; D004867:Equipment Design; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D012039:Regional Blood Flow / Q000502:physiology; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation; D018608:Ultrasonography, Doppler / Q000295:instrumentation*