Object-oriented modeling and simulation of the closed loop cardiovascular system by using SIMSCAPE

The modeling of physiological systems via mathematical equations reflects the calculation procedure more than the structure of the real system modeled, with the simulation environment SIMULINK™ being one of the best suited to this strategy. Nevertheless, object-oriented modeling is spreading in current simulation environments through the use of the individual components of the model and its interconnections to define the underlying dynamic equations. In this paper we describe the use of the SIMSCAPE™ simulation environment in the object-oriented modeling of the closed loop cardiovascular system. The described approach represents a valuable tool in the teaching of physiology for graduate medical students

Modeling and simulation of the short-term arterial pressure control system using an object oriented approach

Object-oriented modeling is spreading in current simulation environments through the use of the individual components of the model and its interconnections to define the underlying dynamic equations. In this paper we describe the use of the SIMSCAPE simulation environment in the objectoriented modeling of the short-term arterial pressure control system when is applied to patients undergoing different situations as hemorrhage, liquid uptake or hemodialysis treatment. Results show the effectiveness of the baroreceptor control mechanism to compensate for the hypotension induced by the hemodialysis treatment. The described approach represents a valuable tool in the teaching of physiology for graduate medical and biomedical engineering students when facing to alternate hemodialysis treatment

MODERNIZATION OF THE MOCK CIRCULATORY LOOP: ADVANCED PHYSICAL MODELING, HIGH PERFORMANCE HARDWARE, AND INCORPORATION OF ANATOMICAL MODELS

A systemic mock circulatory loop plays a pivotal role as the in vitro assessment tool for left heart medical devices. The standard design employed by many research groups dates to the early 1970\u27s, and lacks the acuity needed for the advanced device designs currently being explored. The necessity to update the architecture of this in vitro tool has become apparent as the historical design fails to deliver the performance needed to simulate conditions and events that have been clinically identified as challenges for future device designs. In order to appropriately deliver the testing solution needed, a comprehensive evaluation of the functionality demanded must be understood. The resulting system is a fully automated systemic mock circulatory loop, inclusive of anatomical geometries at critical flow sections, and accompanying software tools to execute precise investigations of cardiac device performance. Delivering this complete testing solution will be achieved through three research aims: (1) Utilization of advanced physical modeling tools to develop a high fidelity computational model of the in vitro system. This model will enable control design of the logic that will govern the in vitro actuators, allow experimental settings to be evaluated prior to execution in the mock circulatory loop, and determination of system settings that replicate clinical patient data. (2) Deployment of a fully automated mock circulatory loop that allows for runtime control of all the settings needed to appropriately construct the conditions of interest. It is essential that the system is able to change set point on the fly; simulation of cardiovascular dynamics and event sequences require this functionality. The robustness of an automated system with incorporated closed loop control logic yields a mock circulatory loop with excellent reproducibility, which is essential for effective device evaluation. (3) Incorporating anatomical geometry at the critical device interfaces; ascending aorta and left atrium. These anatomies represent complex shapes; the flows present in these sections are complex and greatly affect device performance. Increasing the fidelity of the local flow fields at these interfaces delivers a more accurate representation of the device performance in vivo

Global Object Oriented Modelling of the Cardiorespiratory System

Se ha realizado el modelado orientado a objetos del sistema cardiorrespiratorio, usando analogía eléctrica basada en la interconexión de elementos, actuadores y sensores eléctricos. En dicho modelado físico están representadas implícitamente las diferentes ecuaciones diferenciales que describen el comportamiento de este sistema así como el control que se realiza cuando el sistema debe adaptarse a diferentes situaciones. Esto permite obtener el comportamiento del sistema conjunto tanto en condiciones fisiológicas como ante diferentes condiciones de trabajo físico y patologías, lo que lo convierte en una herramienta útil para la docencia o investigación en fisiología cardiorrespiratoria. En los resultados obtenidos se aprecian la estabilidad del sistema en reposo así como la adaptación que se realiza ante circunstancias de estrés físico donde es necesario la variación de diferentes parámetros físicos para alcanzar un estado estable o las dificultades que presentaría un individuo con una patología, ya sea de carácter respiratorio o cardiaco, a diferencia de un individuo sano

Modelling the ventilation-perfusion mismatch of the cardiopulmonary system in Matlab Simscape

A novel model of perfusion distribution in the lung and a novel model of ventilation distribution are developed in this thesis. Both models are focused on the pressure distribution along the thorax due to the gravitation. The lung is divided into three zones: upper zone, middle zone and lower zone. Blood flow increses with the distance from the top of the lung. The upper zone is characterized by a complete collapse of the pulmonary capillary vasculature, thus there is no flow in this zone. The second zone have a “Waterfall effect”, the blood flow is determinated by the difference between the pulmonary artery and alveolar pressures. In the lower zone, the flow is purely driven by the difference between the pulmonary artery pressure and the pulmonary vein pressure. In ventilation, the upper lobe of the lung are more expanded than the middle and lower lobes at resting position. Consequently, ventilation during spontaneous breathing was found nonuniform with more air entering the lower lobes than the middle and upper lobes. As a result, a complete model of perfusion and ventilation in the lung is created and the results obtained in both models are in good agreement with the litetature. Both models are implemented in the object-oriented modeling and simulation module Matlab Simscape.Ingeniería de Telecomunicació

Modeling of the arterial pressure control system in patients undergoing hemodialysis treatment using an object oriented approach

Se ha realizado el modelado orientado a objetos del sistema de control cardiovascular en situaciones de diálisis aplicando una analogía eléctrica en el que se emplean componentes conectados mediante interconexiones. En este modelado se representan las ecuaciones diferenciales del sistema cardiovascular y del sistema de control barorreceptor así como las ecuaciones dinámicas del intercambio de fluidos y solutos del sistema hemodializador. A partir de este modelo se ha realizado experiencias de simulación en condiciones normales y situaciones de hemorragias, transfusiones de sangre y de ultrafiltración e infusión de fluido durante tratamiento de hemodiálisis. Los resultados obtenidos muestran en primer lugar la efectividad del sistema barorreceptor para compensar la hipotensión arterial inducida por los episodios de hemorragia y transfusión de sangre. En segundo lugar se muestra la respuesta del sistema de control ante diferentes tasas de ultrafiltración durante la hemodiálisis y se sugieren valores óptimos para la adecuada operación

Využití tenchnologie GRID při zpracování medicínské informace

Práce se soustředí na vybrané oblasti biomedicínského výzkumu, které mohou profitovat ze současných výpočetních infrastruktur vybudovaných ve vědecké komunitě v evropském a světovém prostoru. Teorie výpočtu, paralelismu a distribuovaného počítání je stručně uvedena s ohledem na počítání v gridech a cloudech. Práce se zabývá oblastí výměny medicínských snímků a představuje propojení Gridového PACS systému s existujícími distribuovanými systémy pro sdílení DICOM snímků. Práce se dál zaměřuje na studium vědy týkající se lidského hlasu. Práce představuje vzdálený způsob přístupu k aplikaci pro analýzu hlasu v reálném čase pomocí úpravy protokolů pro vzdálenou plochu a pro přenos zvukových nahrávek. Tento dílčí výsledek ukazuje možnost využití stávajících aplikací na dálku specialisty na hlas. Oblast lidské fyziologie a patofyziologie byla studována pomocí přístupu tzv. systémové biologie. Práce přispívá v oblasti metodologie modelování lidské fyziologie pro tvorbu komplexních modelů založených na akauzálním a objektově orientovaném modelovacím přístupu. Metody pro studium parametrů byly představeny pomocí technologie počítání v gridech a v cloudech. Práce ukazuje, že proces identifikaci parametrů středně komplexních modelů kardiovasculárního systému a komplexního modelu lidské fyziologie lze významně zrychlit...This thesis focuses on selected areas of biomedical research in order to benefit from current computational infrastructures established in scientific community in european and global area. The theory of computation, parallelism and distributed computing, with focus on grid computing and cloud computing, is briefly introduced. Exchange of medical images was studied and a seamless integration of grid-based PACS system was established with the current distributed system in order to share DICOM medical images. Voice science was studied and access to real-time voice analysis application via remote desktop technology was introduced using customized protocol to transfer sound recording. This brings a possibility to access current legacy application remotely by voice specialists. The systems biology approach within domain of human physiology and pathophysiology was studied. Modeling methodology of human physiology was improved in order to build complex models based on acausal and object-oriented modeling techniques. Methods for conducting a parameter study (especially parameter estimation and parameter sweep) were introduced using grid computing and cloud computing technology. The identification of parameters gain substantial speedup by utilizing cloud computing deployment when performed on medium complex models of...nezařazení_neaktivníFirst Faculty of Medicine1. lékařská fakult

Modelling and control of a UAV-USV collaboration scheme for fluvial operations

This thesis focuses on a Model Based Design approach to the dynamic modelling and control design of a multi-robot solution based on a collab- oration scheme between a UAV and USV. The purpose of the system is to provide a suitable platform to autonomously perform limnology related surveys. The dynamic models of both platforms are derived from a Newton- Euler formalism and implemented through block oriented modelling us- ing the Simscape Multibody toolset within Simulink. The implementation of both the simulation architecture and the control architecture are de- scribed and explained. This control architecture is based on PID feedback loops that are used for achieving control of the UAV and USV dynamics. Finally, the built simulator is used to asses the performance and relia- bility of the designed controllers and the dynamic modelling approaches selectedIngeniería en Tecnologías Industriale

Towards computer-automated mechatronic design and optimization using linear graphs and evolutionary computing

A comparison of literature between the linear graph (LG) and bond graph (BG) approaches shows that the surpassing of BGs to LGs in applications related to the modeling of mechatronic systems is driven primarily by a lack of available LG-based software. As a result, a robust software toolbox called LGtheory has been developed for automating the evaluation of LG models in the MATLAB programming environment. This thesis details the development of LGtheory, and the algorithms and procedures employed for the evaluation of LG models. In addition, demonstrations of this toolbox to a process for automating the design of electronic filter circuits, as well as, the modeling and simulation of the dynamics of a mobile robotic system are presented. The results of these demonstrations validate the accuracy of the LGtheory toolbox for modeling complex multi-domain systems, and provides the methodological basis for the automated design of mechatronic systems using LGs