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Hybrydowy detektor zespołu QRS wykorzystujący dynamicznie rekonfigurowalną matrycę analogową

Machler A., Pietraszek S., Przybyła T.

Pomiary Automatyka Kontrola

2011

R. 57, nr 1

22-24

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.

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.

Real time QRS detector based on field programmable analog array

Malcher A., Pietraszek S., Przybyła T., Kidoń Z.

Journal of Medical Informatics & Technologies

2009

Vol. 13

183--188

In some 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 that introduce delays up to parts of a second. On the other hand, hardware QRS detectors fulfil 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 detector is based on a Field Programmable Analog Array (FPAA). This solution makes it possible to modify the parameters of particular blocks of the detector or even the whole structure without any changes in hardware, while the processing path is fully analog and does not introduce an additional delay. The most interesting feature of the FPAA is the dynamic reconfigurability. The parameters can be changed during runtime without any reset of the circuit or any other disturbances of the system functionality. The prototype QRS detector was built using the AN221E04 circuit from the Anadigm company.

A newly-designed myocardial assist device using a sophisticated shape memory alloy fibre

Shiraishi Y., Yambe T., Sekine K., Ogawa D., Nagatoshi J., Itoh S., Park Y., Uematsu M., Sakata R., Wada Y., Saijo Y., Higa M., Hori Y., Liu H., Wang Q., Konno S., Kuwayama T., Olegario P., Tanaka A., Masumoto N., Ibuki R., Maruyama S., Okamoto E., Fujimoto T., Yoshizawa M., Umezu M., Imachi K., Nitta S.-I., Sasada H., Tabayashi K., Homma D.

Biocybernetics and Biomedical Engineering

2007

Vol. 27, no. 1-2

147-154

Recently, the ventricular assist devices are widely applied for a surgical treatment of the final stage of severe heart failure as the bridge to heart transplantation or the destination therapy. However, it was anticipated that the artificial components in the ventricular assist devices might cause the problems concerning thrombosis and infection. As heart failure involves the decrease in myocardial contractile function, the mechanical assistance by using an artificial myocardium might be effective. In this study, the authors developed a mechano-electric artificial myocardial assist system (artificial myocardium), which is capable of supporting natural contractile function from the outside of the ventricle.