Four time-domain oriented, real-time frequency estimators, based on the detection of phase, zero-crossings, instantaneous frequency or autocorrelation, were simulated on a digital computer and subjected to computer generated Doppler signals, enabling the investigation of the influence of spectral shape, filtering, frequency shift, noise and quantization. Three estimators, the autocorrelator as well as the instantaneous frequency detector and the autocorrelator, both with extended frequency range, appeared to be very accurate. They exhibit a bias in the estimator output of less than 2 percent over a wide frequency range, the former up to nearly the Nyquist frequency, the latter two beyond, even for skew spectra and under poor signal conditions regarding bandwidth and noise.
BlackshearW.J.PhillipsD.J.ChikosP.M.HarleyJ.D.ThieleB.L.StrandnessD.E.Jr., Carotid artery velocity patterns in normal and stenotic vessels, Stroke11, 67–71 (1980).
2.
BrandestiniM., Topoflow - A digital full range Doppler velocity meter, IEEE Trans. Sonics UltrasonicsSU-25, 287–293 (1978).
3.
PeronneauP.A.BournatJ.-P.BugnonA.BarbetA.XhaardM., Theoretical and practical aspects of pulsed Doppler flowmetry: real-time application to the measure of instantaneous velocity profiles in vitro and in vivo, in Cardiovascular Applications of Ultrasound, RenemanR.S. ed., 66–84 (North-Holland Publishing Co., Amsterdam-London, 1974).
4.
HoeksA.P.G.RenemanR.S.PeronneauP.A., A multigate pulsed Doppler system with serial data processing, IEEE Trans. Sonics UltrasonicsSU-28, 242–247 (1981).
5.
AngelsenB.A.J.KristoffersenK., On ultrasonic MTI measurement of velocity profiles in blood flow, IEEE Trans. Biomed. Engin.BME-26, 665–671 (1979).
6.
HoeksA.P.G., On the development of a multigate pulsed Doppler system with serial data processing, Thesis, Univ. of Limburg, The Netherlands (1982).
7.
HoeksA.P.G.PeetersH.P.M.RuissenC.J.RenemanR.S., A novel frequency estimator for sampled Doppler signals, IEEE Trans. Biomed. Engin.BME-31, 212–220 (1984).
8.
GrandchampP.-A., A novel pulsed directional Doppler velocimeter: the phase detection profilometer, in Ultrasonics in Medicine, KaznerE.MüllerH.R.de VliegerM. eds., 122–132 (Excerpta Medica, Amsterdam, 1975).
9.
BrandestiniM., Die Signalverarbeitung in Perkutanen Ultraschall Doppler Blutflussmessgeneräten, Thesis, ETH Zürich, Switzerland (1976).
BarberW.D.EberhardJ.W.KarrS.G., A new time domain technique for velocity measurements using Doppler ultrasound, IEEE Trans. Biomed. Engin.BME-32, 213–229, 1985.
12.
BrandestiniM.ForsterF.K., Blood flow imaging using a discrete time frequency meter, in 1978 IEEE Ultrasonics Symp. Proc. (IEEE cat.no. 78, CH 1344 - ISU).
13.
KasaiC.NamekawaK.KoyaneA.OmotoR., Real-time two-dimensional blood flow imaging using an autocorrelation technique, IEEE Trans. Sonics Ultrasonics, SU-33, 458–463 (1985).
14.
RoevrosJ.M.J.G., Analogue processing of CW-Doppler flowmeter signals to determine average frequency shift momentaneously without the use of a wave analyser, in Cardiovascular Applications of Ultrasound, RenemanR.S., ed., 43–54 (North-Holland Publishing Co., Amsterdam-London, 1973).
15.
AngelsenB.A.J., A theoretical study of the scattering of ultrasound from blood, IEEE Trans. Biomed. Engin.BME-27, 61–67 (1980).
16.
AngelsenB.A.J.KristoffersenK., Discrete time estimation of the mean Doppler frequency in ultrasonic blood velocity measurements, IEEE Trans. Biomed. Eng.BME-30, 207–214 (1983).
17.
BrandestiniM., Application of the phase detection principle in a transcutaneous velocity profile meter, in Ultrasonics in Medicine, KatnerE.MüllerH.R.de VliegerM. eds., 144–152 (Excerpta Medica, Amsterdam, 1975).
18.
GerzbergL.MeindlJ.D., Power-spectrum centroid detection for Doppler systems application, Ultrasonic Imaging2, 232–261 (1980).
19.
McLeodF.D.Jr., A directional flowmeter, Digest 7th Int. Conf. Med. & Biol. Eng., Stockholm, 3–4, p. 213 (1967). Abstract only.
20.
RenemanR.S.SpencerM.P., Difficulties in processing of an analogue Doppler flow signal; with special reference to zero-crossing meters and quantification, in Cardiovascular Applications of Ultrasound, RenemanR.S., ed., 32–42 (North-Holland Publishing Co., Amsterdam-London, 1973).
21.
LuntM.J., Accuracy and limitations of the ultrasonic Doppler blood velocimeter and zero crossing detector, Ultrasound Med. Biol.2, 1–10 (1975).
22.
HartleyC.J., Resolution of frequency aliases in ultrasonic pulsed Doppler velocimeters, IEEE Trans. Sonics UltrasonicsSU-28, 69–75 (1981).
23.
AngelsenB.A.J., Spectral estimation of a narrow-band Gaussian process from the distribution of the distance between adjacent zeroes, IEEE Trans. Biomed. Engin.BME-27, 108–110 (1980).
24.
BurckhardtC.B., Comparison between spectrum and time interval histogram of ultrasound Doppler signals, Ultrasound Med. Biol., 7, 79–82 (1981).
25.
NamekawaK.KasaiC.TsukamotoM.KoyanoA., Real-time blood-flow imaging system utilizing autocorrelation techniques, in Ultrasound ‘82, LerskiR.A.MorleyP., eds., 203–208 (Pergamon Press, Oxford, 1982).
26.
SchwartzM.ShawL., Signal Processing, in Discrete Spectral Analysis, Detection and Estimation, McGraw-Hill, Inc., Tokyo. Int. Students Ed., 5th printing (1981).
27.
AngelsenB.A.J., Instantaneous frequency, mean frequency, and variance of mean frequency estimators for ultrasonic blood velocity Doppler signals, IEEE Trans. Biomed. Engin.BME-28, 733–741 (1981).
