Jerzy Wtorek

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The main aim of the study is to establish a relation between different sources of Impedance cardiogram (ICG) as function of spatial distribution of conductivity. A three-dimensional model of a human thorax using the finite element method has been constructed. The model includes 35 horizontal layers consisting of up to 519 pentahedral elements that are(More)
Monitoring system for detection of person and his/her activity in the bathroom is described in the paper. It also detects and monitors person taking bath. The system consists of sensors measuring humidity, air and water temperature, spilled water, and state of bathtub. The bathtub state detector (BSD) allows controlling water level and its temperature. It(More)
A FEM has been used to examine influence of tissues' conductivities and electrodes' array configurations on the results obtained by Impedance Cardiography. A Geselowitz's relationship has been applied to estimate partial contributions from each region of thorax. The obtained results have indicated the strong dependence of ICG signal on factors mentioned(More)
The results obtained using the Technical University of Gdansk Electroimpedance Mammograph (TUGEM) of a 3D phantom study are presented. The TUGEM system is briefly described. The hardware contains the measurement head and DSP-based identification modules controlled by a PC computer. A specially developed reconstruction algorithm, Regulated Correction(More)
The paper considers the contribution of conductivity changes undergone in an anisotropical medium to measured resistance. This was achieved by extending the relationship proposed by Geselowitz to anisotropical materials described, therefore, by a conductivity tensor. It was found that each element of a conductivity change tensor contributed to the measured(More)
The construction of the cell for measurement of complex electric conductivity is described. Two-chamber and four-electrode system with temperature stabilisation is developed. Guarding chamber and electrodes are used to minimise the leakage of current from the measurement chamber. The cell construction is examined by use of Finite Element Method. The model(More)
The aim of the paper is to analyze validity of new methods applicable for cardiac surgery intra-operation inspection. In vivo measurements on pigs using passive and active thermography as well as electroimpedance spectroscopy applied to investigation of the heart tissue properties during open chest cardiac surgery are related. The measurement results(More)
INTRODUCTION Using a novel method called near-infrared transillumination backscattering sounding (NIR-T/BSS) that allows for the non-invasive measurement of pial artery pulsation (cc-TQ) and subarachnoid width (sas-TQ) in humans, we assessed the influence of sympathetic activation on the cardiac and respiratory contribution to blood pressure (BP) cc-TQ(More)
The dynamics of cardiovascular responses to postural stress have not been fully recognized. To determine whether coronary artery bypass grafting (CABG) has any effect on stroke volume variability (SVV), the power spectrum components of SVV were measured in 60 patients before and at 6 weeks after CABG. Stroke volume was assessed by means of the thoracic(More)