The Application of Wavelet Transforms to Blood Flow Velocimetry

Abstract This article describes novel measurements of the velocity of whole blood flow in a microchannel during coagulation. The blood is imaged volumetrically using a simple optical setup involving a white light source and a microscope camera. The images are processed using PIV and wavelet-based optical flow velocimetry (wOFV), both of which use images of individual blood cells as flow tracers. Measurements of several clinically relevant parameters such as the clotting time, decay rate, and blockage ratio are computed. The high-resolution wOFV results yield highly detailed information regarding thrombus formation and corresponding flow evolution that is the first of its kind.

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Maternal renal artery blood flow velocimetry in normal and hypertensive pregnancies

Acta Obstetricia Et Gynecologica Scandinavica ◽

10.3109/00016349609065733 ◽

1996 ◽

Vol 75 (8) ◽

pp. 715-719 ◽

Cited By ~ 12

Author(s):

Marius Kublickas ◽

Nils-Olov Lunell ◽

Henry Nisell ◽

Magnus Westgren

Keyword(s):

Blood Flow ◽

Renal Artery ◽

Artery Blood Flow ◽

Flow Velocimetry

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P02.02: Accuracy of middle cerebral artery blood flow velocimetry in determining anemia in fetuses undergoing intrauterine transfusion

Ultrasound in Obstetrics and Gynecology ◽

10.1002/uog.1342 ◽

2004 ◽

Vol 24 (3) ◽

pp. 278-278

Author(s):

P. Vasquez ◽

J. Sanchez ◽

J. Gutierrez ◽

E. Carstens ◽

R. Sandoval ◽

...

Keyword(s):

Blood Flow ◽

Middle Cerebral Artery ◽

Cerebral Artery ◽

Artery Blood Flow ◽

Intrauterine Transfusion ◽

Flow Velocimetry

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Alterations in Segmentary Branch Pulmonary Artery Blood Flow Velocimetry in Fetuses of Diabetic Mothers

Journal of Ultrasound in Medicine ◽

10.7863/jum.2004.23.3.339 ◽

2004 ◽

Vol 23 (3) ◽

pp. 339-345 ◽

Cited By ~ 3

Author(s):

Eyal Sivan ◽

Boaz Weisz ◽

Nitzan Shteinman ◽

Eyal Schiff ◽

Shlomo Lipitz ◽

...

Keyword(s):

Blood Flow ◽

Pulmonary Artery ◽

Artery Blood Flow ◽

Branch Pulmonary Artery ◽

Flow Velocimetry ◽

Diabetic Mothers

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Frequency encoding in renal blood flow regulation

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.00540.2004 ◽

2005 ◽

Vol 288 (5) ◽

pp. R1160-R1167 ◽

Cited By ~ 43

Author(s):

Donald J. Marsh ◽

Olga V. Sosnovtseva ◽

Alexey N. Pavlov ◽

Kay-Pong Yip ◽

Niels-Henrik Holstein-Rathlou

Keyword(s):

Blood Pressure ◽

Blood Flow ◽

Renal Blood Flow ◽

Amplitude Modulation ◽

Wavelet Transforms ◽

Modulation Frequency ◽

Flow Regulation ◽

Tubuloglomerular Feedback ◽

Conscious Rat ◽

Blood Flow Regulation

With a model of renal blood flow regulation, we examined consequences of tubuloglomerular feedback (TGF) coupling to the myogenic mechanism via voltage-gated Ca channels. The model reproduces the characteristic oscillations of the two mechanisms and predicts frequency and amplitude modulation of the myogenic oscillation by TGF. Analysis by wavelet transforms of single-nephron blood flow confirms that both amplitude and frequency of the myogenic oscillation are modulated by TGF. We developed a double-wavelet transform technique to estimate modulation frequency. Median value of the ratio of modulation frequency to TGF frequency in measurements from 10 rats was 0.95 for amplitude modulation and 0.97 for frequency modulation, a result consistent with TGF as the modulating signal. The simulation predicted that the modulation was regular, while the experimental data showed much greater variability from one TGF cycle to the next. We used a blood pressure signal recorded by telemetry from a conscious rat as the input to the model. Blood pressure fluctuations induced variability in the modulation records similar to those found in the nephron blood flow results. Frequency and amplitude modulation can provide robust communication between TGF and the myogenic mechanism.

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Blood Flow Velocimetry in a Microchannel During Coagulation Using PIV and wOFV

Journal of Biomechanical Engineering ◽

10.1115/1.4050647 ◽

2021 ◽

Author(s):

Erdem Kucukal ◽

Yuncheng Man ◽

Umut Gurkan ◽

Bryan Schmidt

Keyword(s):

Blood Flow ◽

Blood Cells ◽

Thrombus Formation ◽

Blockage Ratio ◽

Time Decay ◽

Clotting Time ◽

White Light Source ◽

Flow Velocimetry ◽

Flow Evolution ◽

Time Decay Rate

Abstract This article describes novel measurements of the velocity of whole blood flow in a microchannel during coagulation. The blood is imaged volumetrically using a simple optical setup involving a white light source and a microscope camera. The images are processed using PIV and wavelet-based optical flow velocimetry (wOFV), both of which use images of individual blood cells as flow tracers. Measurements of several clinically relevant parameters such as the clotting time, decay rate, and blockage ratio are computed. The high-resolution wOFV results yield highly detailed information regarding thrombus formation and corresponding flow evolution that is the first of its kind.

Download Full-text