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This paper presents an analysis of different methodologies for modelling pharmacokinetic systems under the context of a telemedicine system oriented to the on-line and personalized knowledge generation. We use a simplified 3-pool kinetic system for a better clarification of several relevant modelling formalisms. A more complete 3-pool urea kinetic model is built simply connecting EL components pertaining...
In this paper an axisymmetrical, linear, finite element model of human crystalline lens and zonules is constructed to simulate the accommodation process of the lens, based on the published experimental data. Some detailed modeling procedure and data processing differ from previous studies. Our results show that the optical power increases when ciliary body moves away from the lens. The outcome of...
In order to study the mechanism of the aqueous humor circulation and its relationship to the glaucoma macroscopically with engineering methods, a dynamistic model was presented, which can be used to simulate the situation and the treatment of the primary open angle glaucoma (POAG). The frame of the model was built based on the ophthalmically accepted feedback mechanism between the aqueous humor circulation...
System identification involves creating mathematical models of systems using measurements of their inputs and outputs. Linear time-varying systems form an important sub-class of models that require the use of specialized system identification techniques. One such approach involves expanding the time-varying parameters onto a set of temporal basis functions and then estimating the resulting expansion...
Automatic detection of microcalcifications in mammograms constitutes a helpful tool in breast cancer diagnosis. Radiologist's confidence level on microcalcification detection would be improved if a probability estimate of its presence could be obtained from computer-aided diagnosis. In this paper we explore detection performance of a simple Bayesian classifier based on Gaussian mixture probability...
The extravascular matrix is believed to carry negative charge due to its glycosaminoglycans (GAGs) composition. In the present study, we developed an electrodiffusion-convection model to investigate the mechanisms by which this negative charge affects the charged molecule transport through the interstitial space. The model predictions demonstrate that the apparent tissue diffusion coefficient of negatively...
In this paper, we present three different compartmental models to model the pharmacokinetics of Indocyanine green (ICG) in cancerous tumors. We introduce a systematic and robust method to analyze ICG pharmacokinetics based on extended Kalman filtering (EKF) framework. We introduced information theoretic criteria for best compartmental model selection in terms of statistical fit. We tested our approach...
In terms of the characteristic of anesthetic operation, this paper propose new physiologically based pharmacokinetics/ pharmacodynamics (PBPK/PD) model that focus on the important role of autonomic nervous system (ANS) more. Automatic nervous system that is divided into the sympathetic nervous system and the parasympathetic nervous system, at the same time, is the important target of drug effect in...
TNFalpha stimulates SPHK in the monocyte, which leads to the expression of adhesion molecules on the cell surface. The adhesion of leukocytes to the endothelium is one of the early stages of the onset of atherosclerosis. In this paper, we have delineated the TNFalpha-induced and SPHK-dependent signaling pathway. In addition, we have developed a biomathematical model to qualify the SPHK time-dependent...
A novel advisory system, the Anesthesia Advisory Display (AAD) has been recently developed. It displays information about actual and future predictions of anesthetic drug concentrations mapped to clinical end-points such as BIS, basing on the actual infusion rate combined with population pharmacokinetic and interaction pharmacodynamic (PKPD) models. According to the large variability observed among...
We have developed a computational model for the rat cardiac ventricular cell by using electrophysiology data. Our control model (Pandit et al., 2001). The model represents the bioelectric activity in the left ventricular cells in adult male rats. We have described the differences in the membrane properties within the left ventricle to simulate the action potential variations of the endocardial and...
In this study, we investigate the role of sinoatrial node (SAN) cellular heterogeneity in normal cardiac pacemaker function. Using detailed ionic models of electrical activity in SAN and atrial myocytes, we have formulated a number of models of SAN heterogeneity based on discrete-region (in which central and peripheral SAN type cell are separated into discrete regions), gradient and mosaic models...
Action potential duration (APD) alternans is believed to be a loss of stability and contributes much to the reentry arrhythmias. The purpose of this study is to analyze the stability conditions for one-dimension model and higher dimension model. These criterions are concluded by linear stability analysis in nonlinear dynamics. They should be useful for finding of cardiac control algorithms in low...
Small animal imaging systems now allow researchers to non-invasively monitor the progression of diseases in living small animals and study the efficacy of drugs and treatment protocols. Magnetic resonance imaging (MRI) is an established imaging modality capable of obtaining high resolution anatomical images which are sensitive to blood volume, blood flow, and metabolic rate of oxygen. Optical tomography,...
In this paper, a simulation model of glucose-insulin metabolism for Type 1 diabetes patients is presented. The proposed system is based on the combination of compartmental models (CMs) and artificial neural networks (NNs). This model aims at the development of an accurate system, in order to assist Type 1 diabetes patients to handle their blood glucose profile and recognize dangerous metabolic states...
The objective of this study was to simulate clamping of the aorta. It is computationally demanding and involves contact between clamp and aorta, large deformations, and fluid-structure interactions (FSI). Models of the aortic root and clamp were created and solve in ADINA, a finite element analysis package. The tissue model was created using a non-linear material. Fluid-structure interactions (FSI)...
We built a pulmonary and cardiovascular integrated model which is driven by O2 consumption. The integrated model consists of a pulmonary model, a cardiovascular model, a gas exchange model, a respiratory control system model and a cardiovascular control model. To verify the integrated model, we calculated ventilations and cardiac outputs in different O2 consumptions and compared the results with literature...
The biological meaning of follicular development is to free fertilizable oocytes at the time of ovulation. The selection of ovulatory follicles in mammal ovaries is an FSH-dependent selection process. In this paper, we design a multi-scale model of follicular development, where selection arises from the feedback between the ovaries and the pituitary gland and appeals to control theory concepts. Each...
This paper presents simulation study of the action potential waveforms of different ventricular cell types based on experimental studies of transmural electrophysiological heterogeneities in control and failing human hearts. The results show that prolonged action potential duration (APD) and APD rate-adaptation are markedly transmural heterogeneous in heart failure than those in controlled heart which...
Methods have been developed for modeling cardiac activation which accounts for detailed myocardial geometric structures derived from specific tissue samples. This modeling allows both study and analysis of the effects of cleavage planes and other structural barriers to myocardial current flow. Specialized numerical and computational procedures have been developed to enable this modeling. The results...
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