Wyniki wyszukiwania - BazTech

1

Membrane model of peritoneal barrier

Weryński A., Gałach M.

Biocybernetics and Biomedical Engineering

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2008

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Vol. 28, no. 2

3-9

EN

Peritoneal tissue, which structure is rather complicated, creates a barrier between blood and dialysate for transport of fluid and solutes during peritoneal dialysis. The aim of this study was to investigate to what extent peritoneal barrier can be modeled as a semipermeable membrane, which permits the application of thermodynamic description of fluid and solutes transport. Using data from the previous studies it has been demonstrated that peritoneal membrane model proved to be useful in interpretation of clinical and experimental on rats investigation. However, limitations of membrane model of peritoneal barrier have been specified.

2

Development of "virtual patient" model for simulation of solute and fluid transport during dialysis

Gałach M., Weryński A.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2005

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Vol. 53, nr 3

283-292

EN

Optimization of dialysis needs methods for quantitative assessment of fluid and solutes transport in body compartments and solute and fluid exchange between body and dialysate. A mathematical model describing the dynamics of these quantities during dialysis is presented. This model is first and foremost based on the existing models, but also includes some new solutions. All parts were combined and extended by the detailed descriptions of selected aspects. The "virtual patient" model was applied to simulate and test different methods of treatment and their influence on the condition of the patient. The purpose of this model is to serve as a decision support system for selection of "optimal" treatment options for particular patient.

3

Compartmental model of fluid and solute absorption in peritoneal dialysis

Gałach M., Weryński A.

Bio-Algorithms and Med-Systems

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2005

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Vol. 1, no. 1/2

209--212

EN

Solute and fluid transport during peritoneal dialysis can be predicted using various models developed in the past. They were very helpful in understanding the principles of peritoneal dialysis as well as in clinical patient treatment. However, these models have specific tasks or explain specific phenomena, for example membrane model is used for estimation of the peritoneal transport parameters and the three-pore model was very helpful in explaining sodium sieving, yet these models do not cover processes in the peritoneal interstitium. Also in three-pore model the fluid uptake is described inadequately by assuming that fluid absorption is by systemic lymphatics only. Numerous studies with macromolecular volume marker have shown that the fluid absorption rate is well above 1 ml/min, whereas rate of fluid absorption via lymphatics according to physiological investigations is approximately 0.3 ml/min. In this study we propose a theoretical model in which interstitium was included as a separate compartment, and beside the lymphatic absorption, the absorption due to Starling forces was taken into account. With the help of this model the discrepancy mentioned above could be explained.

PL

W przeszłości powstało wiele modeli opisujących transport substancji oraz płynu podczas dializy otrzewnowej. Modele te były bardzo przydatne dla zrozumienia zasad działania dializy otrzewnowej. Wykorzystywane też były w trakcie leczenia pacjentów. Jednakże modele te mają określone zadania i opisują pewne wybrane aspekty dializy otrzewnowej. Na przykład model membranowy używany jest do estymacji parametrów opisujących transport płynu i substancji, a model trójporowy pomógł w wyjaśnieniu tzw. przesiewania sodu. Te modele jednakże nie opisują procesów zachodzących w tkance otrzewnej. Dodatkowo model trójporowy zakłada, że absorpcja płynu z przestrzeni otrzewnowej zachodzi jedynie w procesie absorpcji limfatycznej. Jednak wiele studiów z wykorzystaniem znacznika objętości pokazało, że szybkość absorpcji płynu wynosi ponad 1 ml/min, podczas gdy szybkość absorpcji limfatycznej wynosi jedynie 0.3 ml/min. W pracy proponujemy model, w którym tkanka otrzewnowa potraktowana jest jako dodatkowy kompartment. Dodatkowo oprócz absorpcji limfatycznej brana jest pod uwagę również absorpcja za pomocą sił Starlinga. Dzięki temu prezentowany model pozwala na wyjaśnienie wspomnianych wcześniej niezgodności.

4

Mathematical modeling of renal replacement therapies

Gałach M., Weryński A.

Biocybernetics and Biomedical Engineering

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2004

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Vol. 24, no. 4

3-18

EN

Optimization of dialysis needs methods for quantitative assessment of hydraulic and oncotic pressure well as fluid and solute transport in body compartments. A mathematical model describing dynamics of these quantities during dialysis is presented. During dialysis, the blood volume often decreases; therefore, model includes the cardiovascular system. Mechanisms which react to blood volume loses are also taken into account. The purpose of this model is to serve as a decision support system for selection of "optimal" treatment options for particular patient.

5

Dynamics of the Tumor-Immune System Competition-the Effect of Time Delay

Gałach M.

International Journal of Applied Mathematics and Computer Science

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2003

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Vol. 13, no 3

395-406

EN

The model analyzed in this paper is based on the model set forth by V.A. Kuznetsov and M.A. Taylor, which describes a competition between the tumor and immune cells. Kuznetsov and Taylor assumed that tumor-immune interactions can be described by a Michaelis-Menten function. In the present paper a simplified version of the Kuznetsov-Taylor model (where immune reactions are described by a bilinear term) is studied. On the other hand, the effect of time delay is taken into account in order to achieve a better compatibility with reality.