1. CardioLab Content Introduction Objectives Cardiov. System Cardiov. System Virtual Lab. Virtual Lab. Conclusions CARDIOLAB: A VIRTUAL LABORATORY FOR THE ANALYSIS OF HUMAN CIRCULATORY SYSTEM Alher Mauricio Hernandez 1, Gino Pierfranco Herrera 1, Miguel Angel Mañanas 2, Ramon Costa-Castelló 3 1 Bioelectronics and Clinical Engineering Research (GIBIC), Universidad de Antioquia (UdeA), Colombia 2 Department of Automatic Control (ESAII), Biomedical Engineering Research Center (CREB) 3 Institute of Industrial and Control Engineering (IOC), Universitat Polit`ecnica de Catalunya (UPC), Spain I O C I n s t i t u t e o f I n d u s t r i a l a n d C o n t r o l E n g i n e e r i n g GIBIC Bioelectronic and Clinical Engineering

2. CardioLab Content Introduction Objectives Cardiov. System Cardiov. System Virtual Lab. Virtual Lab. Conclusions I.Introduction II.Objectives III.The Cardiovascular System Model descriptionModel description Cardiovascular stimuliCardiovascular stimuli IV.Virtual Lab Description Tool developmentTool development Interactive elementsInteractive elements Plots and examplesPlots and examples V.Conclusions Content Objectives Cardiov. System Cardiov. System Virtual Lab. Virtual Lab. Conclusions

3. CardioLab Content Introduction Objectives Cardiov. System Cardiov. System Virtual Lab. Virtual Lab. Conclusions Christian Darkin / Science Photo Library ® Introduction Biomedical Engineering (BME) is the application of engineering sciences and technology to medicine and biology. The interdisciplinary nature of this activity implies interplay and overlapping of interest and effort between engineering and biologic points of view. Engineers do not need a deep knowledge of certain medical topics (and vice versa). BME is different to other engineering areas in the sense of obtaining results from experimental procedures and reproducing real physiological situations.

4. CardioLab Content Introduction Objectives Cardiov. System Cardiov. System Virtual Lab. Virtual Lab. Conclusions Introduction It is very difficult and expensive to interact with the human being body and even dangerous in certain situations. The field of BME includes many career areas, and one of them is the application of engineering system analysis (physiologic modeling, simulation, and control) to biologic problems. The Autonomic Nervous system interacts with the cardiovascular system in order to control the heart rate and force of heart contraction, constriction and dilatation of blood vessels. BSIP, VILLAREAL/ Science Photo Library ® Roger Harris/Science Photo Library ®

5. CardioLab Content Introduction Objectives Cardiov. System Cardiov. System Virtual Lab. Virtual Lab. Conclusions Objectives Developing a virtual laboratory to study the cardiovascular system and the effect of stimuli applied to the autonomic nerve system. Proposing the use of Virtual Labs in the study of cardiovascular system in BME programs, in order to overcome the drawbacks of interaction with human body. Designing a Virtual Lab in a visually attractive and interactive way.

6. CardioLab Content Introduction Objectives Cardiov. System Cardiov. System Virtual Lab. Virtual Lab. Conclusions The Cardiovascular System 1. Model Description (I) The cardiovascular system is structured in different intermediate processes: Ursino [1998] and Cavalcanti and Belardinelli [1996]

7. CardioLab Content Introduction Objectives Cardiov. System Cardiov. System Virtual Lab. Virtual Lab. Conclusions The central autonomic control determines the total α-sympathetic, ftas, β-sympathetic, ftbs, and parasympathetic, ftp, influences on heart rate and peripheral resistance from the baroreflexes, chemoreflexes and lung stretch receptors reflexes. 1. Model Description (II) The Cardiovascular System Autonomic control afferent signals, ftas, ftbs and ftp allow simulation of different stimuli related with the sympathetic and parasympathetic systems.

8. CardioLab Content Introduction Objectives Cardiov. System Cardiov. System Virtual Lab. Virtual Lab. Conclusions Sino Auricular Node (S.A.) translates changes in α-sympathetic, and parasympathetic, efferent activity into changes in Heart Period (HP): 1. Model Description (III) The Cardiovascular System 0.58s

9. CardioLab Content Introduction Objectives Cardiov. System Cardiov. System Virtual Lab. Virtual Lab. Conclusions The α-sympathetic nerves control the peripheral vascular activities. During hypotension or hypertension, vasoconstriction or vasodilatation occurs to prevent further decreasing or increasing in the blood pressure. 1. Model Description (IV) The Cardiovascular System This subsystem is modeled using a first-order dynamic system:

10. CardioLab Content Introduction Objectives Cardiov. System Cardiov. System Virtual Lab. Virtual Lab. Conclusions The stroke volume and the heart period determine the cardiac output (CO) whereas arterial blood pressure (abp) is modulated by the vasculature and cardiac output. The model determines abp by means of the following expression: 1. Model Description (V) The Cardiovascular System Where C art represents the Arterial Compliance and R TPR the Total Peripheral Resistance. The stroke volume (SV) is determined by the venous return (Vn), the heart period and the heart contractility (Cn)

11. CardioLab Content Introduction Objectives Cardiov. System Cardiov. System Virtual Lab. Virtual Lab. Conclusions 1. Cardiovascular Stimuli (I)  Exercise: Heart rate (HR) and stroke volume (SV ) increase during exercise, which produces an increase in cardiac output.  Cholinergic intoxication: Produces one increase of parasympathetic activity and produces also an increase of the cardiac period and hypotension.  Caffeine: Xanthines such as caffeine and theophylline block adenosine receptors increasing the activity that produces vasoconstriction, higher heart rate and increased heart contraction force.  Hemorrhage: An acute blood volume loss (10% of total or more), modifies the systemic arterial pressure, cardiac output and total systemic resistance.  Panic: The autonomic system switched to an alert situation characterized by higher and sympathetic activity. Almost every process that affects the autonomic control system also affects the cardiovascular system through the vagal and sympathetic activity. Five stimuli are considered in Cardiolab: The Cardiovascular System

12. CardioLab Content Introduction Objectives Cardiov. System Cardiov. System Virtual Lab. Virtual Lab. Conclusions Virtual Lab Description 1. Tool Development Presented software application is based on Easy Java Simulations (EJS), an open source java-based tool that allows creating interactive dynamic simulations. SIMULINK Model (Ursino et al., 1998) EASY JAVA The model is based on MATLAB/Simulink®. The simulation runs in Simulink while is controlled by Easy Java. The interface to the user has been designed and implemented in EJS.

13. CardioLab Content Introduction Objectives Cardiov. System Cardiov. System Virtual Lab. Virtual Lab. Conclusions Virtual Lab Description 2. Interactive Elements (I) In the interactive module parameters can be changed by means of sliders and tabs in order to simulate different ventilatory conditions. A multisignal scope can be seen when this option is selected by the user.

14. CardioLab Content Introduction Objectives Cardiov. System Cardiov. System Virtual Lab. Virtual Lab. Conclusions Virtual Lab Description 2. Interactive Elements (II) From Autonomic Control

15. CardioLab Content Introduction Objectives Cardiov. System Cardiov. System Virtual Lab. Virtual Lab. Conclusions Virtual Lab Description 3. Plots and Examples (I) One of the two kinds of plots are shown when the corresponding tab of signal scope is selected by the user: A change from normal conditions (Toxicity Level = 0mg) to a specific amount of pesticides in contact with the human body (Toxicity Level = 5mg) is produced at 60 seconds in order to simulate a cholinergic intoxication.

16. CardioLab Content Introduction Objectives Cardiov. System Cardiov. System Virtual Lab. Virtual Lab. Conclusions Virtual Lab Description 3. Plots and Examples (II) After cholinergic intoxication begins, blood pressure and cardiac output remain in a lightly lower value (see the figure on the right). In order to simulate the treatment of this intoxication, a second stimulus is applied at 180s: the concentration of pesticides = 0 and the gain of the parasympathetic system is eliminated in order to produce a blockade (gain = 0) related with the Atropine administration.

17. CardioLab Content Introduction Objectives Cardiov. System Cardiov. System Virtual Lab. Virtual Lab. Conclusions Virtual Lab Description 4. Cardiolab Demo

18. CardioLab Content Introduction Objectives Cardiov. System Cardiov. System Virtual Lab. Virtual Lab. Conclusions This laboratory is completely graphic and interactive, so it can be used to illustrate the behavior of human cardiovascular system under certain stimuli.This laboratory is completely graphic and interactive, so it can be used to illustrate the behavior of human cardiovascular system under certain stimuli. CardioLab allows the students and researchers obtain sensations and experience that would be very difficult otherwise because of the difficulties in performing experimental human studies.CardioLab allows the students and researchers obtain sensations and experience that would be very difficult otherwise because of the difficulties in performing experimental human studies. The use of virtual laboratories and interactivity in BME has proved to be an efficient way to shortcut the learning process an improve the students capabilities.The use of virtual laboratories and interactivity in BME has proved to be an efficient way to shortcut the learning process an improve the students capabilities. The tool has been built combining MATLAB/Simulink and EJS. While MATLAB/Simulink allows to implement complex models in straightforward manner, EJS allows to design attractive views and introduce interactivity easily.The tool has been built combining MATLAB/Simulink and EJS. While MATLAB/Simulink allows to implement complex models in straightforward manner, EJS allows to design attractive views and introduce interactivity easily.