Hydraulic Test Stand to Model Circulatory System Dynamics for Artificial Heart Evaluation

2021 ◽  
Author(s):  
Joseph T. Howard ◽  
Seth Thomas ◽  
James C. Gallentine ◽  
Eric J. Barth
Keyword(s):  
Artificial Heart ◽  
Dynamic Pressure ◽  
Circulatory System ◽  
Working Fluid ◽  
Windkessel Model ◽  
Hydraulic Test ◽  
Dynamic Impedance ◽  
Test Platform ◽  
Energy Domain ◽  
Circuit Analogy

Abstract This work proposes the theory and design of an experimental setup to mimic the dynamic impedance of the human circulatory system for testing the dynamic characteristics of an artificial heart. This platform has the same resistance, compliance, and inertance elements as the well-studied 4-element Windkessel model. As opposed to a circuit analogy model commonly seen in the literature, our platform remains within the same energy domain as the circulatory system. This allows an artificial heart designer to test pump performance and dynamic pressure characteristics under realistic loading. A test platform is designed using a non-hazardous working fluid with the same density and viscosity as blood. The system uses as few custom components as possible and interchangeable parts allow for system tuning.

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.

MEASUREMENT OF FLOW IN CIRCULAR ELASTIC TUBE

2015 ◽  
Vol 76 (10) ◽  
Author(s):  
Muhamad Mazwan Mahat ◽  
Salmiah Kasolang ◽  
Izdihar Tharazi ◽  
R. Nazirul Izzati
Keyword(s):  
Structural Parameters ◽  
Circulatory System ◽  
Elastic Tube ◽  
Tube Length ◽  
Working Fluid ◽  
Circulatory Support ◽  
Pump System ◽  
Initial Work ◽  
Impedance Pump ◽  
Set Up

 Impedance pump is a simple valveless pumping mechanism which typically used in viscosity measurement device to assist pumping of fluid. It is typically connected to an elastic tube in a circulatory system of a more rigid tube. In conventional mechanical circulatory support systems using rotary pump, the pumping mechanism was exposed to turbulent stresses. Hence,  this may cause damage to blood cells flowing through the impeller. There has been initial work on finding alternative solution using the impedance pump system. However,  substantial findings are not yet sufficient to fully understand the mechanism. The purpose of this research is to extend the investigation on impedance pump by specifically looking at the effect of structural parameters on the elastic tube and the flow behaviour. In this study, a closed loop impedance pump system was set up to demonstrate blood flow circulatory system where the mixture of glycerine and water was used as the working fluid. Three variables were regulated namely voltage, tube thickness, and tube length was used in order to get the flowrate of the working fluid. Based on the results, it was found that  tube thickness of 1 mm and a length of 200 mm had produced the highest flowrate in the region 75 ml/min.

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.

Research on Control System of Hydraulic Test Platform of Vehicle Shock Absorber Based on DSP

2018 ◽  
Vol 11 (1) ◽  
pp. 67-75 ◽  
Author(s):  
Bing Zhang ◽  
Hongtuo Liu ◽  
Fangwei Xie ◽  
Cuntang Wang
Keyword(s):  
Control System ◽  
Shock Absorber ◽  
Hydraulic Test ◽  
Test Platform

scholarly journals Experimental evaluation of mechanical heart support system based on viscous friction disc pump

2017 ◽  
Vol 19 (1) ◽  
pp. 28-34
Author(s):  
A. M. Chernyavskiy ◽  
T. M. Ruzmatov ◽  
A. V. Fomichev ◽  
A. E. Medvedev ◽  
Yu. M. Prikhodko ◽  
...  
Keyword(s):  
Experimental Evaluation ◽  
Experimental Studies ◽  
Peripheral Resistance ◽  
Circulatory System ◽  
Viscous Friction ◽  
Working Fluid ◽  
Pump Efficiency ◽  
Pump Design ◽  
Pump Performance ◽  
Mechanical Heart Support

Aim. Experimental evaluation of the viscous friction disk pump efficiency, studying the relationship between inter-disk clearance and sizes of input and output ports and pump performance parameters.Materials and methods. To assess the characteristics and to optimize the disk friction pump design the pump model and experimental stand were created. Pump dimensions were set on the basis of medical and biological requirements for mechanical heart support systems and with due consideration of the experimental studies of our colleagues from Pennsylvania. Flow volume of the working fluid was measured by float rotameter Krohne VA-40 with measurement error of not more than 1%. The pressure values in the hydrodynamic circuit were measured using a monitor manufactured by Biosoft-M. Expansion device allowed changing the flow resistance of the system simulating the total peripheral resistance of the circulatory system.Results. Linear direct correlation between the pump performance and the pressure drop of liquid being created at the inlet and outlet of the pump was obtained. The required flow rate (5–7 l/min) and pressure (90–100 mmHg) were reached when the rotor speed was in the range of 2500–3000 rev/min. It has been shown that the increase of the inlet diameter to 15 mm has not resulted in a significant increase in the pump performance, and that the highest efficiency values can be obtained for the magnitude of inter-disk gap of 0.4–0.5 mm.Conclusion. Designed and manufactured experimental disc pump model for pumping fluid has showed the fundamental possibility to use this model as a system for mechanical support of the heart.

DIAGNOSIS OF PSYCHO-EMOTIONAL STRESS IN PROFESSIONAL RECRUITMENT

2021 ◽  
Author(s):  
O.V. Zhbankova ◽  
◽  
O.I. Yushkova ◽  
A.V. Kapustina
Keyword(s):  
Cardiovascular System ◽  
Acute Stress ◽  
Dynamic Pressure ◽  
Peripheral Resistance ◽  
Circulatory System ◽  
Minute Volume ◽  
The Body ◽  
Psychological Status ◽  
Psychomotor Skills ◽  
Resistance To Stress

Abstract. Introduction. Professional selection of workers in extreme occupations associated with increased danger and responsibility is an important task of labor physiology. The study of psychomotor skills under conditions of acute stress, the assessment of the physiological reactions of the cardiovascular system will determine the professional suitability of candidates for various specialties (technical or intellectual-analytical). Purpose of work. The study of diagnostic methodological approaches to assessing the professional suitability of persons in hazardous professions in psychophysiological professional selection. Materials and methods. Psychophysiological studies included the study of psychomotor skills, psychological testing according to the MMIL and 16 FLO tests, physiological studies of hemodynamic features in candidates with different resistance to stress (calculation of stroke blood volume - SV, MC blood minute volume and peripheral resistance of PS), professional analysis of the labor activity of workers to identify the requirements that hazardous professions place on the body of workers, Research results. In candidates for engineering and technical specialties, the tension of the circulatory system reflected high values of the average dynamic pressure (105.73 ± 1.45 mm Hg), changes in the optimal hyperkinetic type of blood circulation to hypokinetic: 66.7% of those examined with low resistance to stress. In candidates for communicative specialties, a sufficient level of physical activity contributed to the stability of the indicators of the cardiovascular system. Conclusions. Informative indicators have been established for assessing the professional suitability of candidates to perform official tasks in extreme conditions: changes in handwriting signs, peculiarities of psychological status (anxiety, conformism), hemodynamic characteristics

The Windkessel model revisited: A qualitative analysis of the circulatory system

2009 ◽  
Vol 31 (5) ◽  
pp. 581-588 ◽  
Author(s):  
Athanasios Tsanas ◽  
John Y. Goulermas ◽  
Vassiliki Vartela ◽  
Dimitrios Tsiapras ◽  
Georgios Theodorakis ◽  
...  
Keyword(s):  
Qualitative Analysis ◽  
Circulatory System ◽  
Windkessel Model

Model-Based Estimation of Mechanical Characters of Arterial Vessels Using Experimental Dynamic Response Data

2011 ◽  
Author(s):  
Rahil Vali ◽  
Takashi Saito
Keyword(s):  
Mechanical Model ◽  
Damping Ratio ◽  
Elastic Shell ◽  
Measurement Data ◽  
Circulatory System ◽  
Stiffness Index ◽  
Working Fluid ◽  
Model Based ◽  
Ring Model ◽  
Downhill Simplex

As both the geometric and stiffness changes may occur in atherosclerosis, it is necessary to estimate respective contribution from structural and material characteristics in the stiffness index. In this study, we employ the primary mechanical model based on one of elastic shell theory, Love’s theory and look upon a blood vessel as a ring model. Furthermore in order to confirm validity of the model, the experiments were carried out on artificial tubes. The circulating circuit is applied as the circulatory system of human body including tubes, and water is designated as the working fluid of the circulating circuit. Experimental data are applied for mechanical model and mechanical parameters are identified using Downhill simplex method as the inverse problem. In this study stiffness index and damping ratio were identified and the result of Love’ theory was compared with measurement data and Donnell’s theory. The result shows that present study can confirm the measurement data with the fine approximation.

Vibration Modeling and Experimental Results of Two-Phase Twin-Screw Pump

2016 ◽  
Vol 138 (9) ◽  
Author(s):  
Ameen Muhammed ◽  
Dara W. Childs
Keyword(s):  
Gas Turbines ◽  
Critical Speed ◽  
Two Phase Flow ◽  
Dynamic Pressure ◽  
Working Fluid ◽  
Phase Flow ◽  
Running Speed ◽  
Two Phase ◽  
Screw Pump ◽  
Twin Screw

In turbomachines, the transfer of energy between the rotor and the fluid does not—in theory—result in lateral forces on the rotor. In positive displacement machines, on the other hand, the transfer of energy between the moving components and the working fluid usually results in unbalanced pressure fields and forces. Muhammed and Childs (2013, “Rotordynamics of a Two-Phase Flow Twin Screw Pump,” ASME J. Eng. Gas Turbines Power, 135(6), p. 062502) developed a model to predict the dynamic forces in twin-screw pumps, showing that the helical screw shape generates hydraulic forces that oscillate at multiples of running speed. The work presented here attempts to validate the model of Muhammed and Childs (2013, “Rotordynamics of a Two-Phase Flow Twin Screw Pump,” ASME J. Eng. Gas Turbines Power, 135(6), p. 062502) using a clear-casing twin-screw pump. The pump runs in both single and multiphase conditions with exit pressure up to 300 kPa and a flow rate 0.6 l/s. The pump was instrumented with dynamic pressure probes across the axial length of the screw in two perpendicular directions to validate the dynamic model. Two proximity probes measured the dynamic rotor displacement at the outlet to validate the rotordynamics model and the hydrodynamic cyclic forces predicted by Muhammed and Childs (2013, “Rotordynamics of a Two-Phase Flow Twin Screw Pump,” ASME J. Eng. Gas Turbines Power, 135(6), p. 062502). The predictions were found to be in good agreement with the measurements. The amplitude of the dynamic pressure measurements in two perpendicular plans supported the main assumptions of the model (constant pressure inside the chambers and linear pressure drop across the screw lands). The predicted rotor orbits at the pump outlet in the middle of the rotor matched the experimental orbits closely. The spectrum of the response showed harmonics of the running speed as predicted by the model. The pump rotor's calculated critical speed was at 24.8 krpm, roughly 14 times the rotor's running speed of 1750 rpm. The measured and observed excitation frequencies extended out to nine times running speed, still well below the first critical speed. However, for longer twin-screw pumps running at higher speed, the coincidence of a higher-harmonic excitation frequency with the lightly damped first critical speed should be considered.

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