Methods of blood flow measurement in the arterial circulatory system

Tabrizchi, Reza; Pugsley, Michael K.

doi:10.1016/s1056-8719(00)00123-4

Cited by 49 publications

(32 citation statements)

References 31 publications

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“…Aortic blood flow was monitored using a flowmeter (Model T420, Transonic Systems) coupled to the universal interface module. 19 The data were collected using the AcqKnowledge system. Heart rate and cardiac contractility (dP/ dt max ) were calculated from the blood pressure and left ventricular pressure signal, respectively, and the ECG was analyzed with the aid of the AcqKnowledge system.…”

Section: Animals and Preparationmentioning

confidence: 99%

The Effect of Fat Emulsion on Hemodynamics Following Treatment With Propranolol and Clonidine in Anesthetized Rats

Macala

Tabrizchi

2014

Academic Emergency Medicine

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Objectives: There is evidence indicating that intravenous fatty emulsion (IFE) is beneficial in restoring circulatory function in certain types of drug overdose. The authors investigated the hemodynamic effects of IFE compared to epinephrine in rats treated with propranolol and clonidine.Methods: Anesthetized male Sprague-Dawley rats were instrumented for measurement of hemodynamics. Rats were randomly assigned to one of six groups (n = 6-8), and each received a clonidine infusion (150 lg/kg) or an equivalent volume of normal saline (0.9% NaCl) over 1 hour. Each rat then received normal saline (1.0 mL/kg) or propranolol (15 to 20 mg/kg). Thereafter, each rat received a dose of IFE (20% solution; 1.0 mL/kg) or epinephrine (2.0 lg/kg) or an equivalent volume of normal saline (1.0 mL/kg).Results: Propranolol alone or with clonidine significantly (p < 0.05) reduced a number of hemodynamic parameters (mean arterial pressure, 37% to 70%; heart rate, 30% to 51%; cardiac contractility [dP/ dtmax], 50% to 67%; and abdominal aortic blood flow, 50% to 83%), while increasing PR intervals (65% to 85%) and QTc intervals (26% to 64%). Saline and epinephrine treatment after propranolol and clonidine combined resulted in no survivors in saline and two out of six in epinephrine group. IFE resulted in significant survival (seven out of eight) for 30 minutes in rats treated with propranolol alone, and propranolol combined with clonidine (seven out of eight).Conclusions: These data demonstrate that IFE is effective for resuscitating rats overdosed on propranolol combined with clonidine. The effect of IFF is unlikely due to a direct positive inotropic or chronotropic action on the myocardium. IFE is also more effective than epinephrine treatment in this paradigm.

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Section: Animals and Preparationmentioning

confidence: 99%

The Effect of Fat Emulsion on Hemodynamics Following Treatment With Propranolol and Clonidine in Anesthetized Rats

Macala

Tabrizchi

2014

Academic Emergency Medicine

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“…Positron emission tomography is also part of a review of Zhao et al (2002). Ultrasonic and electromagnetic point velocity and volume flow rate measurement techniques as well as a microsphere reference sample method are reviewed by Tabrizchi and Pugsley (2000). Pulsed Doppler ultrasound systems enable the noninvasive measurement of instantaneous flow profiles along the ultrasonic beam.…”

Section: Measurement Techniquesmentioning

confidence: 99%

In vivo whole-field blood velocity measurement techniques

2007

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In this article a number of whole-field blood velocity measurement techniques are concisely reviewed. We primarily focus on optical measurement techniques for in vivo applications, such as laser Doppler velocimetry (including time varying speckle), laser speckle contrast imaging and particle image velocimetry (including particle tracking). We also briefly describe nuclear magnetic resonance and ultrasound particle image velocimetry, two techniques that do not rely on optical access, but that are of importance to in vivo whole-field blood velocity measurement. Typical applications for whole-field methods are perfusion monitoring, the investigation of instantaneous blood flow patterns, the derivation of endothelial shear stress distributions from velocity fields, and the measurement of blood volume flow rates. These applications require individual treatment in terms of spatial and temporal resolution and number of measured velocity components. The requirements further differ for the investigation of macro-, meso-, and microscale blood flows. In this review we describe and classify those requirements and present techniques that satisfy them.

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“…The main commercial systems available for this purpose are ultrasonic and electromagnetic devices. The electromagnetic flowmeter is efficient in detecting graft stenosis; however, it is sensitive to the patient hematocrit rate, especially in smaller vessels, such as the internal thoracic artery (Canver et al, 1997;Hirotani et al, 2001;Tabrizchi and Pugsley, 2000).…”

Section: Introductionmentioning

confidence: 99%

Continuous flow phantom for the calibration of an ultrasonic transit-time flowmeter

Silva¹,

Krüger²,

Pereira³

2014

RBEB

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Introduction: Ultrasound Transit-Time flowmeters are based on the fact that the time required for an ultrasound pulse to propagate through a given distance in a moving medium is a function of the vectorial sum of pulse propagation velocity and medium velocity. The most common application of this flowmeter in medicine is in the evaluation of blood flow in arteries and veins during heart vascular surgery. The present article describes the design, construction and evaluation of a flow phantom for transit-time flowmeters calibration. Methods: Basically, it is a hydraulic circuit containing degassed and distilled water. In such a circuit, a constant differential water level is established between two columns that are interconnected by tubes with defined resistance, which determines a known flow rate. A basic theoretical model to estimate the system Reynolds Number and resistance was developed. Results: A flow range between 4.43 ± 0.18 ml.min -1 and 106.88 ± 0.27 ml.min -1 was found to be compatible with physiological values in small vessels. The pressure range was between 0.20 ± 0.03 cmH 2 O and 12.53 ± 0.07 cmH 2 O, and the larger Reynolds Number was 1134.07. Experimental and theoretical resistance values were similar. Conclusion: A reproducible phantom was designed and built to be assembled with standard low-cost materials and is capable of generating adjustable and continuous flows that can be used to calibrate TTFM systems.

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Methods of blood flow measurement in the arterial circulatory system

Cited by 49 publications

References 31 publications

The Effect of Fat Emulsion on Hemodynamics Following Treatment With Propranolol and Clonidine in Anesthetized Rats

The Effect of Fat Emulsion on Hemodynamics Following Treatment With Propranolol and Clonidine in Anesthetized Rats

In vivo whole-field blood velocity measurement techniques

Continuous flow phantom for the calibration of an ultrasonic transit-time flowmeter

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