Abstract
Blood flow velocity measured by Doppler ultrasound is the relative velocity dependent on the path of the ultrasound beam, which should be influenced by its angle of incidence against the blood flow in the vessel. The angle of incidence generates varying changes in flow velocities that can be measured by the Doppler device. The aim of our study was to develop a new ultrasonic Doppler catheter which could provide a true flow velocity independently of the angle of the ultrasound beam against the flow direction, and to assess the validity of the true flow velocity obtained by a new device using the electromagnetic flowmeter. The newly developed Doppler catheter has a pair of adjoining ultrasonic crystals located on one side of the catheter at right angles to each other. Each Doppler shift, which is detected by two transducers (Δf1, Δf2) that sample the flow velocity at two closely spaced points, is used to compute two velocity measurements (V1 and V2); these are the velocities detected by the transducers. The true velocity was calculated using the following equation: V=((V1)2+(V2)2)1/2, where V = true velocity. The velocities were calculated by newly developed phase differential techniques. Using a continuous flow model, we compared the flow velocity measured by the new Doppler catheter with that assessed by an electromagnetic flow probe placed into the circuit. At between 0.42 and 4.49 l·min−1, the flow velocity measured by the new Doppler catheter (Doppler velocity) at five sampling depths was compared with the mean velocity calculated from the volumetric flow rate measured by an electromagnetic flowmeter (EMF velocity). The Doppler velocity (y) strongly correlated with the EMF velocity (x) at five sampling depths (r 2=0.99, respectively). At the maximal velocity sampling depth, the regression equation was y=1.29x+2.47 (r 2=0.99,P<0.0001,n=41, SEE=0.015). The Doppler velocity also correlated with the volumetric flow rate measured by the electromagnetic flowmeter (r 2=0.99). The flow velocity measurements using the new Doppler catheter and device we have developed can provide more instantaneous and useful information on hemodynamics.
Similar content being viewed by others
References
Hatle L, Brubakk A, Trombsdal A, Angelsen B (1978) Noninvasive assessment of pressure drop in mitral stenosis by Doppler ultrasound. Br Heart J 40:131–140
Oliveira LC, Sahn DJ, Valdes-Cruz LM, Goldberg JS, Vargas BJ, Allen DH, Grennadier E (1983) Noninvasive prediction of transvalvular pressure gradient in patients with pulmonary stenosis by quantitative two-dimensional echocardiography. Circulation 67:866–871
Yoganathan AP, Valdes-Cruz, LM, Schmidt-Dohna J, Jimoh A, Berry C, Tamura T, Sahn DJ (1987) Continuous-wave Doppler velocities and gradients across fixed tunnel obstructions: studies in vitro and in vivo. Circulation 76:657–666
Levenson JA, Peronneau PA, Simon A, Safer ME (1981) Pulsed Doppler determination of diameter, blood flow, velocity, and volume flow of brachial artery in man. Cardiovasc Res 15:164–170
Shoor PM, Fronek A, Bernstein EF (1979) Quantitative transcutaneous arterial velocity measurements with Doppler flowmeters. Arch Surg 114:922–928
Tamura T, Fronek A (1988) New method for Doppler probe angle determination. J Biomed Eng 10:271–274
Wang WQ, Yao LX (1982) A double beam Doppler ultrasound method for quantitative blood flow velocity measurement. Ultrasound Med Biol 8:421–425
Tamura T, Johnston KW (1990) Determination of 2-D velocity vectors using color Doppler ultrasound. IEEE Ultrasonics 1537–1540
Tamura T, Yoganathan A, Sahn DJ (1987) In vitro methods for studying the accuracy of velocity determination and spatial resolution of a color Doppler flow mapping system. Am Heart J 114:152–158
Furuhata H, Kanno R, Kodaira K, Aoyagi T, Matsumoto H, Hayashi J, Yoshimura S (1978) Ultrasonic Doppler method aimed at the absolute measurement of blood velocity. Jpn J Med Biomed Eng 16:264–268
Chillian WM, Marcus ML (1982) Phasic coronary blood flow velocity in intramural and epicardial coronary arteries. Circ Res 50:775–781
McGinn AL, White CW, Wilson RF (1990) Interstudy variability of coronary flow reserve: Influence of heart rate, arterial pressure, and ventricular preload. Circulation 81:1319–1330
Johnson EL, Yock PG, Hargrave VK, Srebro JP, Manubens SM, Seitz W, Ports TA (1989) Assessment of severity of coronary stenoses using a Doppler catheter. Validation of a method based on the continuity equation. Circulation 80:625–635
Hartley CJ, Cole JS (1974) An ultrasonic pulsed Doppler system for measuring blood flow in small vessels. J Appl Physiol 37:626–629
Cole JS, Hartley CJ (1977) The pulsed Doppler coronary artery catheter: Preliminary report of a new technique for measuring rapid changes in coronary artery flow velocity in man. Circulation 56:18–25
Sibley DH, Millar HD, Hartley CJ, Whitlow PL (1986) Subselective measurement of coronary blood flow velocity using a steerable Doppler catheter. J Am Coll Cardiol 8:1332–1340
Tadaoka S, Kagiyama M, Hiramatsu O, Ogasawara Y, Tsujioka K, Wada Y, Sawayama T, Kajiya F (1990) Accuracy of 20-MHz Doppler catheter coronary artery velocimetry for measurement of coronary blood flow velocity. Cathet Cardiovasc Diagn 19:205–213
Doucette JW, Corl PD, Payne HM, Flynn AE, Goto M, Nassi M, Segal J (1992) Validation of Doppler guide wire for intravascular measurement of coronary artery flow velocity. Circulation 85:1899–1911
Segal J, Pearl RG, Ford AJ, Stern RA, Gehlbach SM (1989) Instantaneous and continuous cardiac output with a Doppler pulmonary artery catheter. J Am Coll Cardiol 13:1382–1392
van Keulen P, Fast JH, Lambert FM (1992) Continuous assessment of phasic mitral volumetric flow by ultrasound. Circulation [Suppl] 86:I-870
Author information
Authors and Affiliations
About this article
Cite this article
Akamatsu, S., Kondo, Y. & Dohi, S. Velocity measurements with a new ultrasonic Doppler method independent of angle of incidence. J Anesth 10, 133–139 (1996). https://doi.org/10.1007/BF02483350
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF02483350