Mock circulatory system with a silicon tube for the study of pulse waves in an arterial system

2014 ◽  
Vol 65 (7) ◽  
pp. 1134-1141 ◽  
Author(s):  
Ju-Yeon Lee ◽  
Min Jang ◽  
Sang-Hoon Shin
Keyword(s):  
Circulatory System ◽  
Arterial System ◽  
Mock Circulatory System ◽  
Silicon Tube ◽  
Pulse Waves

Use of a Catecholamine Sensor in the Control of an Artificial Heart System

1997 ◽  
Vol 20 (1) ◽  
pp. 37-42 ◽  
Author(s):  
K. Mabuchi ◽  
T. Chinzei ◽  
Y. Abe ◽  
K. Imanishi ◽  
T. Isoyama ◽  
...  
Keyword(s):  
Control System ◽  
Plasma Proteins ◽  
Artificial Heart ◽  
Circulatory System ◽  
Reference Electrode ◽  
Mock Circulatory System ◽  
Real Time Measurement ◽  
Artificial Hearts ◽  
Set Up ◽  
Catecholamine Concentration

An electrochemical sensor system to allow real-time measurement and feedback of catecholamine concentrations was developed for use in the control of artificial hearts. Electrochemical analyses were carried out using a carbon fiber working electrode, an Ag-AgCI reference electrode, and a potentiostat. The operating parameters of the pneumatically-driven artificial heart system were altered in accordance with the algorithm for changes in the catecholamine concentration. The minimum detectable concentrations of both adrenaline and noradrenaline in a mock circulatory system using a phosphate-buffered solution were approximately 1-2 ng/ml (10-8 mol/L). An artificial heart control system utilizing this set-up performed satisfactorily without delay, although sensor sensitivity decreased when placed in goat plasma instead of a phosphate-buffered solution, due to the adsorption of various substances such as plasma proteins onto the electrodes. This study demonstrated the future feasibility of a feedback control system for artificial hearts using catecholamine concentrations.

scholarly journals Effect of Pulsatile Flow Waveform and Womersley Number on the Flow in Stenosed Arterial Geometry

2012 ◽  
Vol 2012 ◽  
pp. 1-17 ◽  
Author(s):  
Moloy Kumar Banerjee ◽  
Ranjan Ganguly ◽  
Amitava Datta
Keyword(s):  
Pulsatile Flow ◽  
Physiological State ◽  
Circulatory System ◽  
The Body ◽  
Arterial System ◽  
Hemodynamic Parameters ◽  
Flow Waveform ◽  
Womersley Number ◽  
Flow Features ◽  
Hemodynamic Flow

The salient hemodynamic flow features in a stenosed artery depend not only on the degree of stenosis, but also on its location in the circulatory system and the physiological condition of the body. The nature of pulsatile flow waveform and local Womersley number vary in different regions of the arterial system and at different physiological state, which affects the local hemodynamic wall parameters, for example, the wall shear stress (WSS) and oscillatory shear index (OSI). Herein, we have numerically investigated the effects of different waveforms and Womersley numbers on the flow pattern and hemodynamic parameters in an axisymmetric stenosed arterial geometry with 50% diametral occlusion. Temporal evolution of the streamlines and hemodynamic parameters are investigated, and the time-averaged hemodynamic wall parameters are compared. Presence of the stenosis is found to increase the OSI of the flow even at the far-downstream side of the artery. At larger Womersley numbers, the instantaneous flow field in the stenosed region is found to have a stronger influence on the flow profiles of the previous time levels. The study delineates how an approximation in the assumption of inlet pulsatility profile may lead to significantly different prediction of hemodynamic wall parameters.

The Cardiac System

2017 ◽  
Author(s):  
David C Mauchley
Keyword(s):  
Sinoatrial Node ◽  
Circulatory System ◽  
Atrioventricular Node ◽  
Atrial Septum ◽  
The Body ◽  
Arterial System ◽  
Pulmonic Valve ◽  
Anatomy And Physiology ◽  
Cardiac System ◽  
Cardiac Operations

The circulatory system, which consists of the heart, arterial system, venous system, and lymphatics, constitutes a complicated network of vessels and ducts that are responsible for the delivery of oxygenated blood to the body and return of deoxygenated blood to the heart and lungs. The heart is at the center of the circulatory system, and its pumping mechanism provides energy and nutrition to all organs in the body. This review focuses on the anatomy and physiology of the heart and describes anatomic details that are important to the planning of many common cardiac operations.    This review contains 28 figures, and 25 references. Key words: aortic root, aortic valve, atrial septum, atrioventricular node, coronary artery, fibrous skeleton of heart, mitral valve, myocardium, pericardium, pulmonic valve, sinoatrial node, tricuspid valve, ventricular septum 

scholarly journals In vitro study of trileaflet polytetrafluoroethylene conduit and its valve-in-valve transformation

2020 ◽  
Vol 30 (3) ◽  
pp. 408-416 ◽  
Author(s):  
Te-I Chang ◽  
Kang-Hong Hsu ◽  
Chi-Wen Luo ◽  
Jen-Hong Yen ◽  
Po-Chien Lu ◽  
...  
Keyword(s):  
Pressure Gradient ◽  
Stent Graft ◽  
Peak Pressure ◽  
Circulatory System ◽  
Valve Design ◽  
Mock Circulatory System ◽  
Valved Conduit ◽  
Valve In Valve ◽  
In Vitro Performance

Abstract OBJECTIVES Handmade trileaflet expanded polytetrafluoroethylene valved conduit developed using the flip-over method has been tailored for pulmonary valve reconstruction with satisfactory outcomes. We investigated the in vitro performance of the valve design in a mock circulatory system with various conduit sizes. In our study, the design was transformed into a transcatheter stent graft system which could fit in original valved conduits in a valve-in-valve fashion. METHODS Five different sizes of valved polytetrafluoroethylene vascular grafts (16, 18, 20, 22 and 24 mm) were mounted onto a mock circulatory system with a prism window for direct leaflets motion observation. Transvalvular pressure gradients were recorded using pressure transducers. Mean and instant flows were determined via a rotameter and a flowmeter. Similar flip-over trileaflet valve design was then carried out in 3 available stent graft sizes (23, 26 and 28.5 mm, Gore aortic extender), which were deployed inside the valved conduits. RESULTS Peak pressure gradient across 5 different sized graft valves, in their appropriate flow setting (2.0, 2.5 and 5.0 l/min), ranged from 4.7 to 13.2 mmHg. No significant valve regurgitation was noted (regurgitant fraction: 1.6–4.9%) in all valve sizes and combinations. Three sizes of the trileaflet-valved stent grafts were implanted in the 4 sizes of valved conduits except for the 16-mm conduit. Peak pressure gradient increase after valved-stent graft-in-valved-conduit setting was <10 mmHg in all 4 conduits. CONCLUSIONS The study showed excellent in vitro performance of trileaflet polytetrafluoroethylene valved conduits. Its valved stent graft transformation provided data which may serve as a reference for transcatheter valve-in-valve research in the future.

Analysis of an Artificial Ventricle and Mock Circulatory System

1977 ◽  
Vol 99 (4) ◽  
pp. 184-188 ◽  
Author(s):  
K. M. High ◽  
J. A. Brighton ◽  
A. D. Brickman ◽  
W. S. Pierce
Keyword(s):  
Artificial Heart ◽  
Circulatory System ◽  
Experimental Tests ◽  
Mean Flow ◽  
Actual System ◽  
Mock Circulatory System ◽  
System A ◽  
The Mean ◽  
Artificial Ventricle ◽  
Good Agreement

A mathematical model is developed for calculating the pressures and flows in an artificial heart, its pneumatic drive unit, and a mock circulatory system. The system is divided into convenient subsystems to facilitate the analysis, and each subsystem is then analyzed separately. The set of independent equations developed is solved on a computer and corresponding experimental tests are made on the actual system. A comparison of the experimental and computer results shows good agreement for the mean flow rate through the pump and also for several instantaneous pressures and flow rates in the system.

Designing a Patient-Specific Paediatric Mock Circulatory System to Study the Norwood Circulation

2011 ◽  
Author(s):  
Giovanni Biglino ◽  
Silvia Schievano ◽  
Catriona Baker ◽  
Alessandro Giardini ◽  
Richard Figliola ◽  
...  
Keyword(s):  
Ductus Arteriosus ◽  
Pulmonary Arteries ◽  
Circulatory System ◽  
Innominate Artery ◽  
Systemic Circulation ◽  
Norwood Procedure ◽  
Patient Specific ◽  
Mock Circulatory System ◽  
Pulmonary Flow ◽  
Left Heart Syndrome

The Stage I of Fontan palliation for neonates with hypoplastic left heart syndrome, namely the Norwood procedure, aims to improve the flow of oxygenated blood in the systemic circulation while at the same time providing blood flow to the pulmonary circulation1. This surgical operation usually involves enlargement of the hypoplastic aorta by means of a patch, reconstruction of aortic coarctation and increase pulmonary flow. The latter point, at present, is achieved in three different ways: i) a Blalock-Taussig (BT) shunt from the innominate artery to the pulmonary artery, ii) an atrio-pulmonary shunt, referred to as Sano modification2 and iii) stenting the ductus arteriosus and banding the pulmonary arteries, referred to as “hybrid” Norwood3. In general, it is clear that the circulation following the Norwood procedure presents a very specific and complex arrangement.

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