Entity

Time filter

Source Type


Konieczny G.,Silesian University of Technology | Opilski Z.,Silesian University of Technology | Pustelny T.,Silesian University of Technology | Gacek A.,Institute of Medical Technology and Equipment | And 2 more authors.
Acta Physica Polonica A | Year: 2010

The following paper introduces the problem of noninvasive pressure measurements in Polish artificial heart prosthesis. The pressure sensor is proposed and introduced, and preliminary tests are shown. The paper deals with the proposed sensing elements, requirement noninvasive solution and preliminary tests of polyurethane membrane transmission. The paper includes also experimental results of a fiber pressure sensor introducing noninvasive pressure measurements with pressure transmission through a polyurethane tube wall. Source


Gawlikowski M.,Foundation of Cardiac Surgery Development | Pustelny T.,Silesian University of Technology
Metrology and Measurement Systems | Year: 2012

Nowadays the "gold clinical standard" of hemodynamics diagnostic and cardiac output measurements is pulmonary artery catheterization by means of the Swan-Ganz catheter and thermodilution. The method itself is sensitive to numerous disturbances which cause inaccurate results. One of the well-known disadvantages of thermodilution is the overestimation of results at low values of cardiac output. This effect may concern the limited slew rate of the thermoelement mounted at the tip of the catheter. In this paper the relationship between the dynamic response of the thermoelement and the uncertainty of cardiac output measurements by means of thermodilution has been investigated theoretically and experimentally. © 2012 Polish Academy of Sciences. All rights reserved. Source


Konieczny G.,Silesian University of Technology | Opilski Z.,Silesian University of Technology | Pustelny T.,Silesian University of Technology | Gawlikowski M.,Foundation of Cardiac Surgery Development
BioMedical Engineering Online | Year: 2012

Background: The paper presents a newly researched acoustic system for blood volume measurements for the developed family of Polish ventricular assist devices. The pneumatic heart-supporting devices are still the preferred solution in some cases, and monitoring of their operation, especially the temporary blood volume, is yet to be solved.Methods: The prototype of the POLVAD-EXT prosthesis developed by the Foundation of Cardiac Surgery Development, Zabrze, Poland, is equipped with the newly researched acoustic blood volume measurement system based on the principle of Helmholtz's acoustic resonance. The results of static volume measurements acquired using the acoustic sensor were verified by measuring the volume of the liquid filling the prosthesis. Dynamic measurements were conducted on the hybrid model of the human cardiovascular system at the Foundation, with the Transonic T410 (11PLX transducer - 5% uncertainty) ultrasound flow rate sensor, used as the reference.Results: The statistical analysis of a series of static tests have proved that the sensor solution provides blood volume measurement results with uncertainties (understood as a standard mean deviation) of less than 10%. Dynamic tests show a high correlation between the results of the acoustic system and those obtained by flow rate measurements using an ultrasound transit time type sensor.Conclusions: The results show that noninvasive, online temporary blood volume measurements in the POLVAD-EXT prosthesis, making use of the newly developed acoustic system, provides accurate static and dynamic measurements results. Conducted research provides the preliminary view on the possibility of reducing the additional sensor chamber volume in future. © 2012 Konieczny et al.; licensee BioMed Central Ltd. Source


Opiela J.,National Research Institute of Animal Production | Samiec M.,National Research Institute of Animal Production | Bochenek M.,National Research Institute of Animal Production | Lipinski D.,University of Life Sciences in Poznan | And 2 more authors.
Cellular Reprogramming | Year: 2013

In this study, we estimated the distribution of DNA diploidy and aneuploidy in porcine mesenchymal stem cells (pMSCs) that were subjected to osteoblast/osteocyte and adipocyte differentiation to determine the impact of long-term in vitro culture and differentiation on the cell cycle distribution and nuclear DNA profile. This determination could be helpful to confirm or exclude the suitability of physico-chemical culture conditions for the purposes of both the maintenance of an undifferentiated state and to promote differentiation in pMSCs. Flow cytometry was applied to analyze the cell cycle and occurrence of aneuploidy/diploidy, and real-time PCR was used to quantify aP2 and osteocalcin, markers of adipocytes and osteocytes, respectively. The chi-squared test was used to compare the total rates of G0/G1-, S-, and G2/M-phase cell fractions with diploid and aneuploid DNA and the DNA index ratios between three experimental groups of pMSCs. Five weeks of in vitro culture under differentiating conditions resulted in a considerable reduction of DNA stability and a remarkable increase in the rate of cells exhibiting an aneuploid DNA stem line; however, a similar dependence was not found in the nondifferentiated MSCs. Furthermore, the cell fraction rates in each phase of the mitotic cycle and the DNA index (DI) were calculated. The results of real-time PCR for aP2 and osteocalcin proved positive MSC differentiation toward adipocytes and osteocytes. In terms of the possible use of differentiated MSC lines in tissue engineering and regenerative medicine, we propose cytokinetic diagnostics using flow cytometry as an objective and useful method for screening the tumor-forming capacity and malignancy potential of both in vitro long-term cultured MSCs and MSCs subjected to ectopic differentiation. © Mary Ann Liebert, Inc. Source


Gawlikowski M.,Foundation of Cardiac Surgery Development | Pustelny T.,Silesian University of Technology
Bulletin of the Polish Academy of Sciences: Technical Sciences | Year: 2012

The essential examination in hemodynamic monitoring of the patient is the cardiac output (CO) measurement. Nowadays, in clinical practice the most popular method is indicator dilution, particularly thermodilution. It is realized by applying the Swan-Ganz catheter and observing changes of the indicator concentration. This method is sensitive to many factors and the obtained results should be treated cautiously. The paper presents theoretical and experimental studies of metrological phenomena in CO measurements by means of thermodilution, paying special attention to medical aspects of the measurements. It has been pointed out that the actual unreliability of the mentioned method reaches values from 20% to 45%, which is in opposition to the technical data of patient's monitors (typical accuracy about 5%). Source

Discover hidden collaborations