Model Of Human Cardiovascular System Research Articles

Design and Development of 3-Dimensional Model of Human Circulatory System to Teach a Concept of Biology in Senior Secondary Schools

Instructional resources guarantee maximum value and effectiveness in the teaching and learning process. The instrument of instruction is communication which must be skillfully designed and developed if the objective of the instruction is to be accomplished. Models are a direct replica of real objects or figures. They are made in place of the original figure or object and used as such in place of the original. Inability to have access to mammalian internal organs is one of the challenges in teaching some concepts in Biology. Hence, we need to develop a 3-dimensional model of the human circulatory system to teach a concept in Biology. The findings revealed that the 3-dimensional automated model of the human circulatory system was successfully developed with materials sourced from the environment. Such materials include Plaster of Paris (POP), Top gum, White Cement, Car Paint (white), Acrylic Paint (Blue and Red), Tissue Paper, Binding Wire, Painting Brush, Silicon Gum, Sandpaper. This study recommended among others that management of secondary schools should make provision for the local 3-D model to be used as teaching aids for effective instructional delivery in their respective schools.

RF40 LEFT VENTRICULAR UNLOADING DURING ECMO: ATRIAL SEPTAL DEFECT VS IMPELLA. A SIMULATION STUDY

Aim: VA ECMO causes increase of LV afterload. Realization of ASD or Implantation of Impella have been proposed for LV unloading in combination with VA ECMO. Our aim is to study haemodynamic changes in VA ECMO patients after Impella or ASD realization using numerical model of cardiovascular system. Methods: A previously developed lumped parameter model of human cardiovascular system was adopted to this specific study. Heart chambers are represented by variable elastance models, while peripheral sections are represented by windkessel models. ASD was modelled as resistance separating the two atria. VA ECMO and Impella were modelled starting from their pressure-flow characteristics. Baseline condition of patient undergoing VA ECMO implantation was reproduced starting form haemodynamic and echocardiographic data and then the effect of different size ASD or different Impella support were simulated. Results: Impella implantation on VA ECMO patient caused an increment of mean arterial pressure up to 67%, a decrement in mean pulmonary pressure up to 8%, a decrement in LV end systolic volume up to 11% with reduction up to 97% of LV cardiac output. The realization of a calibrated ASD reduces the LA pressure up to 19%, increases right atrial pressure up to 22%, increases the MAP up to 18%, decreases the LVESV up to 11%, increase the RV volume up to 33% and decreases the LVCO up to 55%. Conclusion: Simulations results showed a higher capability of Impella in LV unloading during VA ECMO in comparison to ASD with a concomitant lower right ventricular overload.

Analytical modeling of the human cardiovascular system with real-time implementation using NI ELVIS-II

Cardiovascular System, which consists of the heart, the systematic circulation and the pulmonary circulation is said to be the transport system for the human body. Modeling of cardiovascular system has become important for clinical researchers and for deeper understanding of blood circulation in the human body. This paper uses the lumped method which is also known as an electrical analogy for modeling and simulation of human cardiovascular system. A simplified complete lumped parameter model of the Human Cardiovascular System has been developed with real time implementation focusing mainly on blood flows. A resistor, an inductor and a capacitor are used to model every blood vessel, ventricles, atrium and set of all veins and capillaries. A pulse generating circuit is also modeled which acts as a power supply for the heart that controls the contraction of heart muscles.

ДИАГНОСТИКА НАПРАВЛЕННОЙ СВЯЗИ КОНТУРОВ РЕГУЛЯЦИИ КРОВООБРАЩЕНИЯ ПО ВРЕМЕННЫМ РЯДАМ МАТЕМАТИЧЕСКОЙ МОДЕЛИ СЕРДЕЧНО-СОСУДИСТОЙ СИСТЕМЫ ЧЕЛОВЕКА

ДИАГНОСТИКА НАПРАВЛЕННОЙ СВЯЗИ КОНТУРОВ РЕГУЛЯЦИИ КРОВООБРАЩЕНИЯ ПО ВРЕМЕННЫМ РЯДАМ МАТЕМАТИЧЕСКОЙ МОДЕЛИ СЕРДЕЧНО-СОСУДИСТОЙ СИСТЕМЫ ЧЕЛОВЕКА

A model of human cardiovascular system containing a loop for the autonomic control of mean blood pressure

We proposed a model of human cardiovascular system that describes the cardiac cycle, the autonomic regulation of heart and vessels, the baroreflex, and the formation of arterial pressure. The model also makes allowance for the influence of respiration on these processes. It was found that an allowance for nonlinearity and insertion of a loop for the autonomic control of mean arterial pressure (having the form of self oscillating time-delay system) enables to obtain model signals with statistical and spectral characteristics that are qualitatively and quantitatively similar to.those for experimental signals. The model reproduces the phenomenon of synchronization of the loop for mean arterial pressure regulation with a basic frequency of approximately 10 s by the signal of respiration.

Model of human cardiovascular system with a loop of autonomic regulation of the mean arterial pressure

A model of human cardiovascular system is proposed which describes the main heart rhythm, the regulation of heart function and blood vessels by the autonomic nervous system, baroreflex, and the formation of arterial blood pressure. The model takes into account the impact of respiration on these processes. It is shown that taking into account nonlinearity and introducing the autonomous loop of mean arterial blood pressure in the form of self-oscillating time-delay system allow to obtain the model signals whose statistical and spectral characteristics are qualitatively and quantitatively similar to those for experimental signals. The proposed model demonstrates the phenomenon of synchronization of mean arterial pressure regulatory system by the signal of respiration with the basic period close to 10 seconds, which is observed in the physiological experiments.

Electrical Simulation of Human Cardio-Vascular System and Real-Time Tele-Monitoring of Cardiac Status of the Patients

This paper proposes an electrical model of human cardio-vascular system for the diagnosis of various cardiac diseases, like endocarditis, atherosclerosis, etc. Here, Atherosclerosis has been dealt with specifically. It is the hardening and narrowing of arteries, which slowly blocks the arteries and put blood flow at risk. An innovative electrical model has been developed which is analogous to physiological structure of human cardio-vascular system. This model comprises of passive electrical components (R, L & C), 555-Timer, opamp, and potentiometer. This electrical model has been simulated in PSPICE and two different time-domain responses are generated, for qualitative analysis of cardiac disorders. For analyzing the disease, authors have considered its different qualitative stages, e.g. good and poor, for productive analysis. Deviation of responses from healthy cardiac output enables detection of the cardiac problem (atherosclerosis). Authors have further extended the work for real-time transmission of patient's cardiac status to a distantly located doctor. A micro-controller based device has been designed that receives the cardiac pulses from an optical sensor, and under abnormal condition, it communicates the information to the patient's mobile phone via XBEE transceiver. The patient's mobile phone is preloaded with a JAVA based software application. It receives the data from the transceiver and automatically transmits it to distantly located doctor's mobile phone.

The Optimization Study on Time Sequence of Enhanced External Counter-Pulsation in AEI-CPR

To improve the aortic pressure and myocardial perfusion pressure during cardiac arrest, this study is designed to optimize sequence of Enhanced External Counter- Pulsation (EECP) for a cardiopulmonary resuscitation (CPR) technique — Active Compression-Decompression CPR coupled with EECP and Inspiratory Impedance Threshold Valve (AEI-CPR). EECP is lower-limbs compression equipment for AEI-CPR that enhanced blood regurgitation during chest decompression. Different occasion for EECP performance would bring different hemodynamic effect. A mathematical model of human circulatory system used to research AEI-CPR has been established. And then the AEI-CPR hemodynamic effect to the blood circulatory system is performed on the model. A genetic algorithm (GA) that used to find optimum sequence of the EECP is performed on the model when other parameters of external force for AEI-CPR are definite. At first, set the maximum strength of chest compression, chest decompression and lower-limbs compression at 400Nt, 160Nt and 300mmHg, respectively. Set the frequency of CPR at 100min-1 and the ratio of chest compression compared to LLCP at 1:1. Then, after genetic algorithm is performed on the established model, fifty groups of optimal results are obtained. The maximum coronary perfusion pressure (CPP) takes place when the EECP begin its compression at 0.2s and the interval among crural, femoral and iliac compression is 0.05s. By applying the optimization algorithm on the CPR mathematical model, the optimum sequence of the EECP could be found. And the experiment results indicate that obvious hemodynamic effect is attained when the EECP began compression at the end of chest compression.

Multiple modeling in the study of interaction of hemodynamics and gas exchange

Circulation plays an important rule in gas exchange. Therefore, there is an interaction between circulation and gas exchange. To understand the dynamic effect of these two physiological systems, a computer simulation model of hemodynamics and gas exchange is established in this work. This model includes two physiological systems, namely the respiratory and circulatory systems. It consists of five parts: the model of gas transport, exchange and storage within the body, the multi-element nonlinear mathematical model of human circulatory system, an alveolar ventilation controller, a cardiac output controller, and a controller of breathing frequency. Model simulations provide results consistent with both dynamic and steady-state responses under hypoxia. Simulation results can reflect the interaction of hemodynamics and gas exchange. Using this model, the changes of pulmonary arterial pressure and right ventricular pressure in high altitude are studied. The optimal mode of breathing extra oxygen using nasal prongs or a facial mask is studied. This model may provide a useful tool to study reaction of hypoxia and the oxygen inhalation mode under hypoxia environments.

Mathematical modeling of human cardiovascular system for simulation of orthostatic response.

This paper deals with the short-term response of the human cardiovascular system to orthostatic stresses in the context of developing a mathematical model of the overall system. It discusses the physiological issues involved and how these issues have been handled in published cardiovascular models for simulation of orthostatic response. Most of the models are stimulus specific with no demonstrated capability for simulating the responses to orthostatic stimuli of different types. A comprehensive model incorporating all known phenomena related to cardiovascular regulation would greatly help to interpret the various orthostatic responses of the system in a consistent manner and to understand the interactions among its elements. This paper provides a framework for future efforts in mathematical modeling of the entire cardiovascular system.

Simulation and Parameter-Identification of the Closed-Loop Cardiovascular System by the Use of a Nonlinear Mathematical Model

A non-linear model of human cardio-vascular system, which includes the short-term pressure regulation mechanism was mathematically derived and implemented on a PDP-11/45 in a block-oriented, interactive programming language. In this way the behaviour of the arterial and venous pressures, cardiac output, stroke volume, total peripheral resistance and heart-rate under ergometric workload was studied by simulation, and experimentally proved, that the model matches the system with good accuracy. In a second phase the parameters of the model were identified by the use of the output-error method. For this purpose a non-linear system identification programming package was applied. The parameter values, identified in this way are in good agreement with the relevant physiological data.