Wyniki wyszukiwania - BazTech

1

Wybrane przykłady modelowania biomedycznego

Tokarz A.

Symulacja w Badaniach i Rozwoju

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2010

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Vol. 1, nr 2

201-209

PL

W publikacji przedstawiony został przegląd metod modelowania i przykładowych modeli biomedycznych. Przybliżono tu specyfikę, budowę, opis działania oraz zastosowania poszczególnych modeli. Opisano między innymi model układu oddechowego, model układu krążenia, model "wirtualnego pacjenta" podczas terapii nerkozastępczej, model filtracji Dead End Procedure (D.E.). Omówiono również korzyści płynące ze stosowania modeli biomedycznych.

EN

Review of a number of modelling methods as well as examples of biomedical models mathematical and physical was presented in this publication. Specificity, structure, working and applications of particular models can be found in the text. The model of respiratory system, circulatory system, "virtual patient" during renal replacement therapy, and Dead End Procedure (D.E.) plasma fractionation were described. The benefits of application of biomedical models were also showed.

2

EMG frequency during isometric, submaximal activity : a statistical model for biceps brachii

Solnik S., De Vita P., Grzegorczyk K., Koziatek A., Bober T.

Acta of Bioengineering and Biomechanics

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2010

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Vol. 12, no. 3

21-28

EN

The purpose of this study was to develop a statistical model to describe the electromyography (EMG) signal frequency changes during a submaximal isometric contraction. Thirty subjects performed a 30-second isometric contraction of the biceps brachii muscle at 80% of the maximal voluntary isometric force. Surface EMG electrodes recorded electrical activity of the biceps brachii. Zero-Crossing-Rate was calculated to identify EMG frequency shifts. The mean frequencies for every one-second period were used to calculate a linear relationship between frequency and time. A significant relationship ( p < 0.05) between slope and initial frequency value was identified. The model described EMG frequency changes during submaximal effort of biceps brachii up to 15 seconds. The prediction error was 9.8%. Modifying this equation to initial values of frequency of each participant decreased prediction error to 7.2%. These results demonstrate that despite individual differences between subjects it is possible to derive single equation that describes EMG alterations during submaximal, isometric contractions across a homogeneous group of people.

3

Badanie naprężeń i przemieszczeń struktur kostnych

Domagała Z., Drapikowski P.

Studia z Automatyki i Informatyki

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2009

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T. 34

7-20

PL

W pracy przedstawiono biomechaniczny model kości udowej poddany maksymalnym obciążeniom statycznym. Wyznaczono rozkład naprężeń i przemieszczeń korzystając z metody elementów skończonych (MES). Przedstawiono i zbadano różne aspekty modelowania kości udowej takie jak: model geometryczny kości, oszacowanie właściwości mechanicznych, modele obciążeń stawu biodrowego, rodzaj siatki i wielkość elementów skończonych. Porównano rozkład naprężeń i przemieszczeń modelu fragmentu kości rekonstruowanego na podstawie indywidualnych danych pacjenta z modelem całej kości. Wyniki analizy uzyskane dla fragmentu kości znacznie odbiegają od wyników dla całej kości.

EN

The work presents the biomechanical model of the human proximal femur and the Finite Element (FE) results of displacements and strains as the response to quasi-static load. Different aspects of proximal femur modeling as: geometrical model, estimation of mechanical properties of cortical and trabecular regions, load models of hip joint, kind and size of FE mesh are presented and investigated. Displacements and strains of part of the femur reconstructed based on the CT scans were compared to the whole femur. FE results of both models are different.

4

Angiogeneza nowotworów jako obiekt sterowania

Świerniak A., Gala G., Onofrio A., Gandolfi A.

Przegląd Elektrotechniczny

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2008

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R. 84, nr 4

124-127

PL

W pracy przedstawiony i przeanalizowany został model terapii skierowanej przeciwko powstającej w procesie angiogenezy nowotworów sieci naczyniowej i tym samym pośrednio umożliwiającej wyleczenie choroby. Dyskutowany jest model zaproponowany przez Hahnfeldta a także pewna jego modyfikacja. Przedstawiona analiza dotyczy warunków stabilności przekładających się na możliwość asymptotycznej anihilacji guza oraz warunków koniecznych optymalizacji protokołów terapii.

EN

A model of tumor growth taking into account its vascularization due to angiogenesis and antiangiogenic cancer chemotherapy is proposed and analised. The model is a modified Hahnfeldt model and the analysis has two goals: first of all we check stability of the equilibrium point of the model using Lyapunov first and second methods to find conditions leading to tumour eradication, and then we propose an optimization problem and give necessary conditions of its solution basing on the Pontryagin maximum principle.

5

Different Models of Chemotherapy Taking Into Account Drug Resistance Stemming from Gene Amplification

Śmieja J., Świerniak A.

International Journal of Applied Mathematics and Computer Science

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2003

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Vol. 13, no 3

297-305

EN

This paper presents an analysis of some class of bilinear systems that can be applied to biomedical modelling. It combines models that have been studied separately so far, taking into account both the phenomenon of gene amplification and multidrug chemotherapy in their different aspects. The mathematical description is given by an infinite dimensional state equation with a system matrix whose form allows decomposing the model into two interacting subsystems. While the first one, of a finite dimension, can have any form, the other is infinite dimensional and tridiagonal. A methodology of the analysis of such models, based on system decomposition, is presented. An optimal control problem is defined in the l1 space. In order to derive necessary conditions for optimal control, the model description is transformed into an integro-differential form. Finally, biomedical implications of the obtained results are discussed.

6

Optimal multidrug treatment in the presence of drug resistance stemming from gene amplification

Śmieja J., Świerniak A.

Journal of Medical Informatics & Technologies

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2002

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Vol. 3

MI13--19

EN

The paper is concerned with development of optimal treatment protocols that take into account both action of several drugs and the evolution of drug resistance. It is a result of analysis of evolution of drug resistance in cancer population but presented methodology can be applied in any case involving drug resistance stemming from gene amplification. First, a biological background is given. In subsequent sections of the paper, the developed technique is presented and some early analytical results, which form a basis for more precise modeling, are shown. Afterwards, the model description is transformed into a vector integro-differential equation, which makes it possible to define necessary conditions of optimal solution to the minimization problem arising from the search for the optimal treatment. Finally, some remarks on the model applicability are presented.