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1

Hybrid cardiovascular simulator as a tool for physical reproduction of the conditions prevailing in the apex of the heart

Siewnicka A., Janiszowski K., Pałko T., Wnuk P.

Biocybernetics and Biomedical Engineering

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2016

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Vol. 36, no. 3

473--481

EN

This paper presents the results of research focused on the adaptation of a hybrid simulator of the human circulatory system to the physical reproduction of the haemodynamic conditions prevailing in the apex of the heart. This report describes the principle of operation of the hybrid simulator and presents two methods of its modification. The work includes analysis of the algorithm verification and describes problems that appeared during research. A comparison of the results obtained for both modification methods is shown, as well as preliminary simulation results for a constant-flow ventricle assist device joined to the hybrid simulator operating in the apex of the heart-aorta configuration.

2

Diagnostyka stanu napełnienia sztucznej komory serca POLVAD

Siewnicka A., Fajdek B., Janiszowski K., Chołost K.

Pomiary Automatyka Kontrola

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2012

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R. 58, nr 1

40-43

PL

Niniejszy artykuł zawiera opis przeprowadzonego eksperymentu identyfikacyjnego dla sztucznej komory serca POLVAD-MEV oraz opracowanych algorytmów wykrywania stanu całkowitego napełnienia oraz wyrzutu z komory krwistej tego urządzenia. Przedstawiono metody diagnostyczne bazujące na różnych sygnałach wejściowych oraz ich implementację w programie symulacyjnym PExSim. Zawarto oraz omówiono uzyskane wyniki oraz opracowano wnioski dotyczące poszczególnych metod wyznaczania stanów granicznych napełnienia komory.

EN

The paper presents an identification experiment for the POLVAD-MEV artificial heart and the developed detection algorithms for complete filling and full emptying the device blood chamber. In Section 1 the subject is presented and the problem of thrombus formation, as a result of incomplete range of the assist device membrane motion, is discussed. Section 2 presents the research methodology. In Subsection 2.1 the ventricle assist device construc-tion (Fig. 1) and the test bench are described. The stand consists of a hybrid model of the circulatory system [10] with attached POLVAD device and the following measuring equipment: ultrasonic flow measurements at the inlet and outlet cannula, pressure sensors at the inlet and outlet of the blood chamber and the air pressure in pneumatic drain. In Subsection 2.2 the impact of complete filling and full ejection on the transients of the measured values is dis-cussed (Fig. 2). Two algorithms for detection of complete filling and full ejection are presented. One of them is based on the analysis of pressure changes in the cannulas and pneumatic drain, the second one is based only on the pneumatic pressure variation. Section 3 presents the results of the diagnostic algorithm examination. The effectiveness of the proposed methods is compared. In the last section the obtained results are summarized and some proposals for further improvements are given when focusing on the development of diagnostic features based on analysis of the pneumatic pressure variation only.

3

Hybrydowy detektor zespołu QRS wykorzystujący dynamicznie rekonfigurowalną matrycę analogową

Machler A., Pietraszek S., Przybyła T.

Pomiary Automatyka Kontrola

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2011

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R. 57, nr 1

22-24

PL

W artykule zaprezentowano nową koncepcję układu detekcji w czasie rzeczywistym zespołu QRS z przebiegu elektrokardiograficzngo. W detektorze wykorzystano programowalną matrycę analogową AN221E04 firmy Anadigm. Parametry wybranych bloków są na bieżąco zmieniane w zależności od zmian parametrów przebiegu EKG dzięki dynamicznej rekonfigurowalności układu. Uzyskano bardzo krótki czas reakcji detektora na wykryty zespół QRS przy zadowalającej skuteczności detekcji. Opracowany detektor może znaleźć zastosowanie w aplikacjach biomedycznych wymagających wykrywania zespołu QRS w przebiegu EKG z małym opóźnieniem czasowym.

EN

In many applications it is important to detect the QRS complex in the ECG waveform with possibly low time delay. Traditional software detectors of the QRS complex implement algorithms, usually based on cascades of digital filters, introduce delays up to parts of a second. Hardware QRS detectors (Fig. 1) fulfill the low delay requirements, but have worse adaptive features for the changing ECG shape. In this paper a new approach to QRS detection is presented. The proposed solution implements a classical detector structure in a Field Programmable Analog Array (FPAA) i.e. AN221E04 circuit from the AnadigmŽ company - Fig. 3. The most interesting feature of the FPAA is the dynamic reconfigurability. This solution makes it possible to modify the parameters of particular blocks of the detector or even the whole structure during runtime, without any changes in hardware and disturbance of the system functionality. Important parameters of particular blocks of the QRS detector are modified on-the-fly according to changes observed in the ECG signal. New data are calculated by the AD7020 microcontroller and downloaded to the FPAA using dynamic reconfigurability after each QRS detection. The prototype QRS detector was tested using a real ECG signal taken from Mit-Bih Arrythmia Database. The results obtained in the prototype circuit (Table 1) show that the detection delay is really small. The error rate of the QRS detection is low and can be acceptable in most real time applications.

4

Vacuum powered tubular pump for ventricular assist

Del Canizo J. F., Desco M. M., Rodriguez-Martinez D.

Biocybernetics and Biomedical Engineering

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2003

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Vol. 23, no. 2

43-50

EN

A new vacuum powered tubular pump for mechanical circulatory support has been developed. The blood chamber is a tube made of highly elastic biocompatible polyurethane and placed into a rigid chamber. The filling of the blood chamber is achieved by means of vacuum avoiding the possibility of air embolism and stagnation points. Mechanical valves have been replaced by clip valves placed over the input and output cannulae of the device. The final cost of the disposable parts of the device is very low and allows its use in other applications like extra corporeal circulation or haemodialysis.