The Power-Spectrum Centroid Detector: System Considerations,Implementation,and Performance

Abstract

Operation of the √f centroid detector with various doppler systems is discussed, and its design, implementation, and performance are described. It is determined that the detector can be employed in directional detection schemes to measure spectral moments and centroids with correct polarity and with no degradation in accuracy. Narrow- and wideband deterministic signal detection of both stationary and FM information is investigated, and it is found that the centroid detector can also serve as an FM demodulator with high AM rejection.

A versatile √f detector was realized in discrete form and evaluated with deterministic and random signals, and its measured variance agreed closely with the theoretical values. The validity and application of the noise-reduction method was verified on deterministic and random doppler signals. Applications of the detector and the noise-reduction method to blood-flow and velocity measurements are demonstrated.

Keywords

Blood flow blood velocity demodulator doppler frequency modulation noise reduction power-spectrum centroid spectral moments ultrasonic

Get full access to this article

View all access options for this article.

References

Gerzberg

, Monolithic power-spectrum centroid detector, Ph. D. dissertation, TR No. G557-2, Stanford Electronics Laboratories, Stanford University, Stanford, Calif. (1979).

Gerzberg

Meindl

J. D.

, Power-spectrum centroid detection for doppler systems applications. Ultrasonic Imaging 2, 232–261 (1980).

Hottinger

C. F.

Meindl

J. D.

, Blood flow measurement using the attenuation-compensated volume flowmeter. Ultrasonic Imaging 1, 1–15 (1979).

Pappenfus

E. W.

Bruene

W. B.

Schoenike

E. O.

, Single Sideband Principles and Circuits (McGraw-Hill Book Co., New York, 1974).

Gerzberg

Meindl

J. D.

, SSB Mean Doppler Shift Detector for Simultaneous Forward and Reversed Flow-velocity Measurement, in Proceedings of 28th ACEMB, New Orleans, Louisiana, p. 448 (1975).

Nippa

J. H.

Hokanson

Lee

D. R.

Sumner

D. S.

Strandness

D. E.

Jr. , Phase rotation for separating forward and reverse blood velocity signals, IEEE Trans. on Sonics and Ultrasound SU-22, 340–346 (1975).

Gerzberg

Meindl

J. D.

, Mean Frequency Estimator with Applications in Ultrasonic Doppler Flowmeters, in Proceedings of 21st Annual Meeting of AIUM, San Francisco (1976); also in Ultrasound in Medicine, Vol. 3B, White

and Brown

R. E.

, eds., pp. 1173–1180 (Plenum Press, New York, 1977).

Davies

R. D.

Meindl

J. D.

, Integrated circuits for CW bidirectional doppler systems. Third International Symposium on Biotelemetry, Asilomar, Calif. (1976).

Hottinger

C. F.

Gerzberg

Meindl

J. D.

, Calibration of a doppler blood flowmeter for measurement independent of flow, angle, velocity profile and lumen shape, in Ultrasound in Medicine, Vol. 2, White

D. N.

Barnes

, eds., pp. 273–275 (Plenum Press, New York, 1976).

10.

Ponn

R. B.

Zatarian

Gerzberg

Hottinger

C. F.

Haase

W. C.

Nelsen

T. S.

, Systemic air empolism in experimental penetrating lung injuries, J. Thoracic and Cardiovascular Surgery 74, 766–773 (1977).