title: Dorsal aortic flow velocity in chick embryos of stage 16 to 28.
abstract: The objective of this study was to evaluate two Doppler frequency-detection methods to measure blood flow velocity in the developing chick embryo. We compared the commonly used directional zero-crossing counter and a customized digital bidirectional spectrum analyzer. At development stages 16 up to 28 (2.5 to 6 days incubation), a reversed flow component in the dorsal aorta was demonstrated using the bidirectional spectrum analyzer. Dorsal aortic velocities obtained with the directional zero-crossing counter were significantly lower than with the bidirectional spectrum analyzer in stages 16, 20 and 28. In addition to the differences in the absolute velocity values, there was also a remarkable discrepancy in the velocity waveform shape using the two Doppler frequency processors. The calculated heart rate using the two Doppler frequency processors was identical. It is concluded that a Doppler velocity detector based on spectral analysis is superior to the hitherto used zero-crossing counter in the chick embryo. With the customized digital bidirectional spectrum analyzer, we can accurately measure the hemodynamics of the developing chick embryo.
authors.affiliation: Department of Obstetrics and Gynecology, Academic Hospital Rotterdam-Dijkzigt, Rotterdam, The Netherlands. ursem@azr.gyna.nl
authors.forename: N T
authors.initials: NT
authors.lastname: Ursem
authors.forename: P C
authors.initials: PC
authors.lastname: Struijk
authors.forename: R E
authors.initials: RE
authors.lastname: Poelmann
authors.forename: A C
authors.initials: AC
authors.lastname: Gittenberger-de Groot
authors.forename: J W
authors.initials: JW
authors.lastname: Wladimiroff
mesh_terms: D000818:Animals; D001011:Aorta / Q000000981:diagnostic imaging* / Q000196:embryology*; D001783:Blood Flow Velocity; D002642:Chick Embryo; D005583:Fourier Analysis; D006339:Heart Rate; D012815:Signal Processing, Computer-Assisted; D018617:Ultrasonography, Doppler, Pulsed / Q000295:instrumentation