Flow And Pressure Transducers
Mostrando 13-20 de 20 artigos, teses e dissertações.
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13. A pulsatile flow model for in vitro quantitative evaluation of prosthetic valve regurgitation
A pulsatile pressure-flow model was developed for in vitro quantitative color Doppler flow mapping studies of valvular regurgitation. The flow through the system was generated by a piston which was driven by stepper motors controlled by a computer. The piston was connected to acrylic chambers designed to simulate "ventricular" and "atrial" heart chambers. In
Brazilian Journal of Medical and Biological Research. Publicado em: 2000-03
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14. Atrial Fibrillation in the Intact Unanesthetized Dog: Hemodynamic Effects during Rest, Exercise, and Beta-Adrenergic Blockade*
The effects of atrial fibrillation were studied in 12 healthy unanesthetized dogs, 9 to 49 days after surgical implantation of transducers for measurement of aortic flow and left ventricular diameter. Atrial fibrillation and pacing at comparable ventricular rates were induced by electrical stimulation of the right atrial appendage, and their effects were com
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15. Extent of Carotid Sinus Regulation of the Myocardial Contractile State in Conscious Dogs
The effects of bilateral carotid artery occlusion (BCO) and carotid sinus nerve stimulation (CSNS) on left ventricular (LV) pressure (P), diameter (D), velocity of contraction (V), rate of change of pressure (dP/dt), and cardiac output were studied in conscious dogs instrumented with ultrasonic diameter gauges, miniature pressure gauges, and aortic electroma
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16. Effects of systemic hypoxia on the distribution of cardiac output in the rat.
1. Studies were made in unanaesthetized rats of cardiovascular responses induced during 3 min periods of systemic hypoxia (inspirate 8 or 6% O2). Arterial pressure and heart rate were recorded continuously; cardiac index and regional blood flows were measured in normoxia and at the 2nd min of hypoxia by injection of radiolabelled microspheres. Comparisons ar
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17. Reversible depression in myocardial performance in dogs with experimental phosphorus deficiency.
The effects of phosphorus depletion on cardiac muscle function in six awake dogs were evaluated with surgically implanted transducers to serially measure ascending aortic root blood flow and high fidelity left ventricular pressure. After the animals recovered from surgery, phosphorus depletion was induced by feeding them a synthetic phosphorus-deficient diet
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18. Static lung compliance in chronic heart failure: relation with dyspnoea and exercise capacity.
BACKGROUND--The pathogenesis of dyspnoea in patients with chronic heart failure is poorly understood. Static lung compliance is reduced in chronic heart failure. The relation between static lung compliance and exercise capacity and dyspnoea in chronic heart failure has been investigated. METHODS--Static lung compliance was calculated from expiratory pressure
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19. Alterations in the Baroreceptor Reflex in Conscious Dogs with Heart Failure
The effectiveness of the baroreceptor reflex in conscious dogs with experimental cardiac hypertrophy and heart failure was compared with that in a group of normal conscious dogs. Cardiac hypertrophy and heart failure were produced by tricuspid avulsion and progressive pulmonary stenosis. The sensitivity of the baroreceptor reflex to transient hypertension wa
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20. Hypoxic vasodilatation in isolated, perfused guinea-pig heart: an analysis of the underlying mechanisms.
1. The mechanisms underlying hypoxic dilatation of coronary arteries were studied in isolated guinea-pig hearts perfused with physiological salt solution at 37 degrees C. The hearts were perfused at a constant rate of 3-10 ml min-1; coronary perfusion pressure (CPP) and isovolumetric left ventricular pressure (LVP) were measured with piezoresistive transduce