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Wyszukujesz frazę "VAD" wg kryterium: Temat


Tytuł:
Surface modifications for inflow cannulas of ventricular assist devices – comparison of latest solutions
Autorzy:
Kurtyka, Przemysław
Kustosz, Roman
Kaczmarek, Marcin
Gonsior, Małgorzata
Tokarska, Klaudia
Powiązania:
https://bibliotekanauki.pl/articles/283866.pdf
Data publikacji:
2019
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Polskie Towarzystwo Biominerałów
Tematy:
surface modification
VAD inflow cannula
tissue-implant interface
porous surface
Opis:
Nowadays, the Mechanical Circulatory Support (MCS) within the Ventricular Assist Devices (VAD) appears to be a reliable and effective solution for patients with advanced heart failure (HF). After many years of work, extracorporeal pulsatile VADs have been replaced by new generations of implantable continuous flow (CF) pumps. Clinical experience has shown that present-day pump constructions still need to be improved to minimize the risk of complications during heart assistance. One of the complications is the pump inflow obstruction caused by the ingrowth of tissue into the blood inflow path and pump thrombosis. The main goal is to develop a coating for the external surface of the inflow cannula to provide controlled tissue ingrowth. The smooth surface of the cannula external wall results in the tissue overgrowth into the pump inflow orifice, and may be a source of emboli. The paper presents external surface modifications of the inflow cannula performed by different VAD manufacturers within the topography characterization. The inflow cannulas used in CF VADs are mainly made of titanium alloy due to its mechanical properties and high biocompatibility. In general, the discussed surface coatings were characterized by the roughness of about ≈ Ra = 15 μm, high porosity and good wettability Φ ≈ 60°. The surface was covered with titanium microspheres or titanium mesh. The developed surfaces and clinical experience confirm the ability to control the tissue ingrowth along the external surfaces of the inflow cannula at the tissue-implant interface.
Źródło:
Engineering of Biomaterials; 2019, 22, 151; 17-23
1429-7248
Pojawia się w:
Engineering of Biomaterials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Acoustic System of Determining the Instantaneous Volume of the Blood Part of the Ventricular Assist Device POLVAD-EXT
Autorzy:
Konieczny, G.
Pustelny, T.
Opilski, Z.
Gawlikowski, M.
Powiązania:
https://bibliotekanauki.pl/articles/176599.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
acoustic Helmholtz’s
resonator
blood volume estimation
VAD
ventricular assist device
Opis:
The paper presents the results of investigations concerning the noninvasive method of estimating the actual volume of the blood chamber of the POLVAD-EXT type ventricular assist device (VAD) during its operation. The proposed method is based on the principle of Helmholtz’s acoustic resonance. Both the theory, main stages of the development of the measurement method as well as the practical implementation of the proposed method in the physical model of the POLVAD-EXT device are dealt with. The paper contains the results of static measurements by means of the proposed method (conducted at the Department of Optoelectronics, Silesian University of Technology) as well as the dynamic measurements taken at the Foundation of Cardiac Surgery Development (Zabrze, Poland) with the professional model of the human cardiovascular system. The results of these measurements prove that the proposed method allows to estimate the actual blood chamber volume with uncertainties below 10%.
Źródło:
Archives of Acoustics; 2014, 39, 4; 541-548
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Angular position determination of heart valves in the pediatric ventricular assist device with use of computational fluid dynamics
Autorzy:
Jodko, D.
Obidowski, D.
Reorowicz, P.
Kłosiński, P.
Jóźwik, K.
Powiązania:
https://bibliotekanauki.pl/articles/98935.pdf
Data publikacji:
2014
Wydawca:
Politechnika Śląska. Katedra Biomechatroniki
Tematy:
CFD
pediatric VAD
heart valve
blood stagnation
sztuczna komora serca
zastawka serca
zastój krwi
Opis:
This study shows a method than can be used to determine the best angular position of heart valves installed at the inlet and the outlet of a blood chamber during the diastolic phase with use of Computational Fluid Dynamics (CFD). Steady state simulations of the blood flow through the blood chamber of Pediatric Ventricular Assist Device (PVAD) have been performed with ANSYS CFX 14.0. Main assumptions in the present paper have included: motionless discs, rigid walls, non-Newtonian model of blood. The obtained results show that areas of blood stagnation in the blood chamber are smallest for one particular angular position of the inlet valve and are not significantly dependent on the angular position of the outlet valve.
Źródło:
Aktualne Problemy Biomechaniki; 2014, 8; 57-62
1898-763X
Pojawia się w:
Aktualne Problemy Biomechaniki
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mobilising the Red Cross Journal: A Charity’s Periodical in Wartime
Autorzy:
Gehrhardt, Marjorie
Powiązania:
https://bibliotekanauki.pl/articles/888917.pdf
Data publikacji:
2018
Wydawca:
Uniwersytet Warszawski. Wydawnictwa Uniwersytetu Warszawskiego
Tematy:
The Red Cross Journal
Red Cross Societies
the Great War
relief work
wartime propaganda
VAD
Opis:
The first issue of the Red Cross Journal was published in January 1914, only eight months before the outbreak of the First World War. This article explores the impact of the war on this publication, as the work of the charity it represented dramatically expanded over the course of the conflict. How did the Journal survive the war, at a time when the Red Cross was deeply involved in supporting soldiers? This article examines the genesis of this publication and its evolving role during the war. This periodical, we argue, not only helped raise awareness of the work carried out by the Red Cross, but it also served practical purposes in the areas of training and funding. This publication reveals an increasingly critical stance towards the British Empire’s enemies in the war, as well as the need for the British Red Cross Society to foster a sense of unity amongst members posted around the world.
Źródło:
Anglica. An International Journal of English Studies; 2018, 27/3; 13-32
0860-5734
Pojawia się w:
Anglica. An International Journal of English Studies
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Measurements of blood saturation inside a ventricular assist device
Autorzy:
Mocha, J.
Czerw, M.
Sobotnicki, A.
Powiązania:
https://bibliotekanauki.pl/articles/333266.pdf
Data publikacji:
2012
Wydawca:
Uniwersytet Śląski. Wydział Informatyki i Nauki o Materiałach. Instytut Informatyki. Zakład Systemów Komputerowych
Tematy:
sztuczne serce
urządzenia wspomagające pracę komór
oksymetr tętna
artificial heart
ventricular assist device (VAD)
pulse oximeter
Opis:
Information about the level how well arterial blood is saturated with oxygen, i.e. the overall patient saturation, in particular a patient with a ventricular assist device (VAD) inoculated, is very important for efficient and dependable course of blood circulation support. The paper presents the method for measurement of blood saturation with oxygen that is carried out with use of a commercially available pulse oximetric sensor upon necessary modifications and installed directly on a outflow connector of the VAD. Operability of the presented solution has been verified by experiments on a flow control test bench with use of animal blood. The final validation of the measuring circuit was carried out during experiments with an animal. The completed experiments demonstrated that both the blood saturation with oxygen as well as artificial pulse rate can be measured with accuracy. Unfortunately, similar measurements for venous blood proved infeasible.
Źródło:
Journal of Medical Informatics & Technologies; 2012, 19; 93-99
1642-6037
Pojawia się w:
Journal of Medical Informatics & Technologies
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A study on permanent magnet topologies for hybrid bearings for medical drives applied in Ventricular Assist Devices
Autorzy:
Pohlmann, A.
Hameyer, K.
Powiązania:
https://bibliotekanauki.pl/articles/140406.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
urządzenie wspomagające komorę
metoda elementów skończonych
łożysko magnetyczne
ventricular assist device
VAD
finite element method
FEM
magnetic bearings
Opis:
In industrialized countries cardiovascular diseases are the major cause of death. The last clinical therapy option for some patients, suffering from terminal heart diseases, is donor heart transplantation. As the available number of donor organs is decreasing, many patients die while waiting for a transplant. For this reason Ventricular Assist Devices (VADs), which can mechanically support the human heart to achieve a sufficient perfusion of the body, are under development. For an implantable VAD, design constraints have to be deduced from the physiological conditions in the human body. In case of a VAD drive, these constraints are for example dimensions, electric losses, which might result in an overheating of blood, and a long durability. Therefore a hybrid permanent magnet hydrodynamic bearing is designed in this paper, which works passively and contactless. Based on Finite Element simulations of magnetic fields, various permanent magnet topologies are studied in terms of axial forces and stiffness.
Źródło:
Archives of Electrical Engineering; 2011, 60, 3; 371-380
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of volumetric parameters of the ventricular assist device using bioimpedance method
Autorzy:
Sobotnicki, A.
Pałko, T.
Mocha, J.
Czerw, M.
Powiązania:
https://bibliotekanauki.pl/articles/333273.pdf
Data publikacji:
2012
Wydawca:
Uniwersytet Śląski. Wydział Informatyki i Nauki o Materiałach. Instytut Informatyki. Zakład Systemów Komputerowych
Tematy:
sztuczne serce
urządzenia wspomagające pracę komór
metoda bioimpedancji
artificial heart
ventricular assist device (VAD)
stroke volume estimation
bioimpedance method
Opis:
Volumetric parameters of operation of the pulsatile ventricular assist device (VAD) are the key clinical indicators for the evaluation of adequacy of the process of mechanical heart assistance and ensuring the patient's safety. The bioimpedance method has been proposed to evaluate blood volume changes of the VAD. The method is based on volume electric conductivity of the blood. A change in VAD volume involves changes in impedance. Periodic changes in VAD volume during its operation result in a pulsatile impedance wave; its amplitude in the subperiod of filling and ejection correlates with the volume of blood in the VAD. The paper presents the way of acquisition of the bioimpedance signal. It also presents the results of experimental studies, that were carried out with the use of the flow test stand, and an approach to analysing the bioimpedance signal to evaluate the stroke volume.
Źródło:
Journal of Medical Informatics & Technologies; 2012, 19; 117-123
1642-6037
Pojawia się w:
Journal of Medical Informatics & Technologies
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hybrid system of ECG signal acquisition and QRS complexes detection for special medical devices synchronization
Autorzy:
Komorowski, D.
Malcher, A.
Pietraszek, S.
Powiązania:
https://bibliotekanauki.pl/articles/334040.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Śląski. Wydział Informatyki i Nauki o Materiałach. Instytut Informatyki. Zakład Systemów Komputerowych
Tematy:
ECG
QRS detector
ventricular assist device
VAD
defibrillation
cardioversion
EKG
detektor QRS
urządzenie wspomagające pracę komór serca
defibrylacja
kardiowersja
Opis:
Some medical devices such as mechanical circulatory support systems and defibrillators require synchronization with the appropriate phase of the cardiac cycle of the patient. This paper presents a description of the electrocardiographic (ECG) signal amplifier and QRS detector designed for use with such devices. The detector system was built using a programmable analog array AN231E04 and the ECG amplifier with an analog-digital (A/D) converter based on a programmable circuit (front-end) ADS129x. By using the programmable elements and exploiting the potential of dynamic analog matrix reconfiguration, the presented detector achieved the desired features, such as low latency of QRS detection, automatic gain control and the ability to change the time constant by software. High-resolution of the A/D converter in the ADS1298x and the possibility of programming the gain of the amplifier allow the acquisition of the ECG signal acquired from different types of electrodes: disposable standard, epicardial or endocavitary. The tests of the prototype system proved that it is highly effective for the detection of QRS complexes in ECG waveforms recorded from all kinds of electrodes.
Źródło:
Journal of Medical Informatics & Technologies; 2013, 22; 227-234
1642-6037
Pojawia się w:
Journal of Medical Informatics & Technologies
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Pomiar dokładności odwzorowania kształtu membrany wiotkiej pompy wspomagania serca
Autorzy:
Sulej, Wojciech.
Powiązania:
Biuletyn Wojskowej Akademii Technicznej 2017, nr 4, s. 43-56
Współwytwórcy:
Murawski, Krzysztof (budowa i eksploatacja maszyn). Autor
Data publikacji:
2017
Tematy:
Optymalizacja
Przepona (budowa maszyn)
Urządzenie wspomagające pracę komór serca (VAD)
Artykuł problemowy
Artykuł z czasopisma naukowego
Artykuł z czasopisma technicznego
Opis:
Rysunki, tabela.
Bibliografia na stronach 55-56.
Dostawca treści:
Bibliografia CBW
Artykuł
Tytuł:
Digital image correlation of coated and uncoated Religa Heart_Ext ventricular assist device
Autorzy:
Kopernik, M.
Gawlikowski, M.
Milenin, A.
Altyntsev, I.
Kustosz, R.
Kąc, S.
Powiązania:
https://bibliotekanauki.pl/articles/307138.pdf
Data publikacji:
2015
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
komorowe wspomaganie pracy serca
VAD
korelacja obrazów
DIC
azotek tytanu
Tin
złoto
ventricular assist device
digital image correlation
titanium nitride
TiN
gold
Opis:
The digital image correlation is used to estimate influence of deposited heamocompatible coatings (gold and titanium nitride) on mechanical response of ventricular assist device Religa Heart_Ext made of Bionate II (thermoplastic polycarbonate urethane) under working conditions by comparison of the coated Religa Heart_Ext with uncoated Religa Heart_Ext. The DIC is applied for experimental investigation of the strains and displacements distribution on external surface of the blood chamber of ventricular assist device during loading. The experiment was conducted in a hydraulic system with water at operating temperatures of 25 and 37 °C, as well as under static pressures: 80, 120, 180, 220 and 280 mmHg, and static underpressures: –25, –45, –75 mmHg. The subsequent images were taken after stabilization of pressure on a set level. The applied research method shows that the nano-coating of 30 nm in thickness significantly affects deformation of the blood chamber of Religa Heart_Ext in macro scale. The proposed composition of coatings increases strain on external surface of the ventricular assist device.
Źródło:
Acta of Bioengineering and Biomechanics; 2015, 17, 4; 49-58
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł

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