Instantaneous Flow Velocity Research Articles

Measurement of phasic carotid artery flow velocity in man

The flow velocity pattern in the common and internal carotid artery is described in seventeen patients using the catheter tip Doppler ultrasonic flowmeter telemetry system. The normal flow velocity pattern in the internal carotid arteries is pulsatile; it is characterized by a major systolic wave which occurs during ventricular systole, representing forward flow. The flow velocity pattern in the internal carotid artery, although phasic, is continuous throughout the cardiac cycle. Ventricular tachycardia results in marked reduction in carotid artery flow velocity, with variation in beat to beat flow velocity. With atrial fibrillation, there is significant variation in beat to beat peak flow velocity, and this is quite pronounced at a rapid heart rate. These variations have a direct correlation with the cycle length and emphasize the importance of diastolic filling time. This device may be used to study instantaneous phasic carotid artery flow velocity in conscious, unanesthetized man without the need for vessel exposure, and has potential value in the study of obstructive disease of the carotid arteries in patients with cerebral vascular insufficiency. The flow velocity pattern in the common and internal carotid artery is described in seventeen patients using the catheter tip Doppler ultrasonic flowmeter telemetry system. The normal flow velocity pattern in the internal carotid arteries is pulsatile; it is characterized by a major systolic wave which occurs during ventricular systole, representing forward flow. The flow velocity pattern in the internal carotid artery, although phasic, is continuous throughout the cardiac cycle. Ventricular tachycardia results in marked reduction in carotid artery flow velocity, with variation in beat to beat flow velocity. With atrial fibrillation, there is significant variation in beat to beat peak flow velocity, and this is quite pronounced at a rapid heart rate. These variations have a direct correlation with the cycle length and emphasize the importance of diastolic filling time. This device may be used to study instantaneous phasic carotid artery flow velocity in conscious, unanesthetized man without the need for vessel exposure, and has potential value in the study of obstructive disease of the carotid arteries in patients with cerebral vascular insufficiency.

Measurement of Instantaneous Blood Flow Velocity and Pressure in Conscious Man with a Catheter-Tip Velocity Probe

Twenty-three patients were investigated during diagnostic right and left cardiac catheterization with an electromagnetic catheter-tip velocity probe. The catheter contained a pressure lumen for simultaneous measurements of intravascular pressure. Average peak and mean blood velocities were 66 and 11 cm/sec in the ascending aorta, 57 and 10 cm/sec in the pulmonary artery, 28 and 12 cm/sec in the superior vena cava, and 26 and 13 cm/sec in the inferior vena cava. The velocity pattern in the ascending aorta was similar to that obtained by other methods. Positioning of the catheter in the ascending aorta required care; in one patient with aortic stenosis the recorded blood velocity pattern was unsatisfactory. In the pulmonary artery flicking of the catheter often produced artifacts in the records. The effect of deep respiration on blood velocity in the ascending aorta and pulmonary artery was studied. In the ascending aorta the highest velocities and stroke volumes were achieved during late expiration while in the pulmonary artery blood velocity and stroke volume were greatest in inspiration. In nine patients the cardiac outputs calculated from the product of mean velocity and radiologically measured cross-sectional area of the ascending aorta or pulmonary artery were compared with cardiac outputs determined by the indicator-dilution method; the correlation coefficient was 0.73. There were no complications, and the probe proved reliable.

Laser Doppler Velocimeter for Measuring Flow-Velocity Fluctuations

Instantaneous flow velocities in an unsteady liquid flow have been measured using optical heterodyning techniques. Flow in the transition region, as well as fully developed turbulence, was measured and compared with existing data and theory.

Evaluation of an electromagnetic catheter tip velocity-sensitive blood flow probe.

ArticleEvaluation of an electromagnetic catheter tip velocity-sensitive blood flow probe.R F Bond, and C A BarefootR F Bond, and C A BarefootPublished Online:01 Sep 1967https://doi.org/10.1152/jappl.1967.23.3.403MoreSectionsPDF (2 MB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInWeChat Previous Back to Top Next Download PDF FiguresReferencesRelatedInformationCited ByElectromagnetic Blood Flow Measurements15 January 2010A Doppler flowmeter for use in theatreUltrasound in Medicine & Biology, Vol. 12, No. 11Characteristics of vascular hydraulic load in patients with heart failure.Circulation, Vol. 72, No. 1Experimental evaluation of a multisensor velocity-pressure catheterMedical & Biological Engineering & Computing, Vol. 23, No. 1Blood flow and blood velocity measurementin vivo by electromagnetic inductionMedical & Biological Engineering & Computing, Vol. 22, No. 3Blood flow and blood velocity measurement in vivo by electromagnetic induction2 July 2016 | Transactions of the Institute of Measurement and Control, Vol. 4, No. 2Quantitation of aortic insufficiency using a catheter-tip velocity transducer.Circulation, Vol. 64, No. 2Contrast echocardiographic evaluation of changes in flow velocity in the right side of the heart.Circulation, Vol. 63, No. 6Estimation of beat-to-beat stroke volume from the pulmonary arterial pressure contour in manMedical & Biological Engineering & Computing, Vol. 16, No. 6Blood Flow MeasurementPhysiologic signal acquisition and processing for human hemodynamic research in a clinical cardiac-catheterization laboratoryProceedings of the IEEE, Vol. 65, No. 5Input impedance of the systemic circulation in man.Circulation Research, Vol. 40, No. 5Continuous measurement of cardiac output with a catheter blood flow probeJournal of Surgical Research, Vol. 21, No. 5ReferencesAssessment of Left Ventricular Performance in ManCirculation, Vol. 47, No. 5Velocity and flow measurements by electromagnetic techniquesThe American Journal of Cardiology, Vol. 29, No. 3Measurement of Pulsatile Flow and Flow VelocityPatient safety during measurement of blood flowAmerican Heart Journal, Vol. 81, No. 3Approaches to blood-flow measurement by means of electromagnetic catheter flow metersIEEE Transactions on Magnetics, Vol. 6, No. 2Measurement of Instantaneous Blood Flow Velocity and Pressure in Conscious Man with a Catheter-Tip Velocity ProbeCirculation, Vol. 40, No. 5Physiologic evaluation of a catheter tip electromagnetic velocity probeThe American Journal of Cardiology, Vol. 23, No. 3The electromagnetic blood flowmeter15 May 2002 | Journal of Physics E: Scientific Instruments, Vol. 1, No. 12 More from this issue > Volume 23Issue 3September 1967Pages 403-9 https://doi.org/10.1152/jappl.1967.23.3.403PubMed6047964History Published online 1 September 1967 Published in print 1 September 1967 Metrics

Analysing blood flow with a sonagraph

In 1968, while cardiologists were focused on cardiac structures imaged by ultrasound, Daniel Kalmanson in Paris, France, devised a new ultrasonic modality, directional continuous-wave Doppler, enabling him to record instantaneous cardiovascular blood flow velocities with recognition of their direction (relative to the transducer) in vessels. An innovative presentation of Doppler data also made velocity traces physiologically understandable. Following the noninvasive study of the arterial and venous beds, flow velocity in the right (1969) and left (1970) cardiac chambers was studied by means of a directional Doppler catheter. The curtain was then raised for the renewal of our pathophysiologic understanding of cardiac dynamics and the adoption of a new methodology. Technological evolution paved the way for clever researchers to pioneer important advances, diversifying the technique. Guided by the early principles, which are still valid in 2018, directional Doppler finally gained acceptance from the entire scientific community.