Vibration control for an experimental off-road vehicle using magnetorheological dampers

The paper presents research studies in the field of semiactive vibration control of an experimental off-road vehicle which is equipped with suspension magnetorheological (MR) dampers. Accelerometers and vehicle progressive velocity sensors are installed in body and underbody parts of the vehicle and are used in control scheme. Furthermore, IMU modules and suspension deflection sensors were used for validation of measurement part of the system. Semiactive Skyhook control algorithm, including on/off and smooth suspension MR damper control, was implemented in order to validate the control system. Quality of measurements is deteriorated by multiple factors including vehicle engine and shape of tires which was examined. Experimental results indicated better vibration suppression of vehicle body part for smooth Skyhook controller compared with passive soft and hard suspension. The presented semiactive suspension control system can be applied for complex vehicle dynamics analysis and control schemes dedicated to both the ride comfort and ride safety issues

Multicenter registry of Impella-assisted high-risk percutaneous coronary interventions and cardiogenic shock in Poland (IMPELLA-PL)

Background: Impella is a percutaneous mechanical circulatory support device for treatment of cardiogenic shock (CS) and high-risk percutaneous coronary interventions (HR-PCIs). IMPELLA-PL is a national retrospective registry of Impella-treated CS and HR-PCI patients in 20 Polish interventional cardiological centers, conducted from January 2014 until December 2021.Aims: We aimed to determine the efficacy and safety of Impella using real-world data from IMPELLA-PL and compare these with other registries.Methods: IMPELLA-PL data were analyzed to determine primary endpoints: in-hospital mortality and rates of mortality and major adverse cardiovascular and cerebrovascular events (MACCE) at 12 months post-discharge.Results: Of 308 patients, 18% had CS and 82% underwent HR-PCI. In-hospital mortality rates were 76.4% and 8.3% in the CS and HR-PCI groups, respectively. The 12-month mortality rates were 80.0% and 18.2%, and post-discharge MACCE rates were 9.1% and 22.5%, respectively. Any access site bleeding occurred in 30.9% of CS patients and 14.6% of HR-PCI patients, limb ischemia in 12.7% and 2.4%, and hemolysis in 10.9% and 1.6%, respectively.Conclusions: Impella is safe and effective during HR-PCIs, in accordance with previous registry analyses. The risk profile and mortality in CS patients were higher than in other registries, and the potential benefits of Impella in CS require investigation

Model identification for active noise control in the presence of primary noise Metody identyfikacji modelu w układach aktywnego tłumienia hałasu z zakłóceniami w postaci szumu pierwotnego /

Tyt. nagł.STRESZCZENIE: W artykule omówiono problem identyfikacji obiektów elektroakustycznych dla celów projektowania układów aktywnego tłumienia hałasu. Przyjęto, że dane pochodzące z eksperymentu identyfikacyjnego są zakłócone przez szum pierwotny, który powinien być później tłumiony. Rozpatrzono trzy przykłady takiego zakłócenia: sinusoida (widmo dyskretne), hałas generowany przez silnik (zmienne w czasie widmo wąskopasmowe) oraz szum szerokopasmowy (pseudolosowy). Pokazano, że stosując wstępne przetwarzanie danych, polegające na odpowiedniej filtracji sygnałów, możliwe jest znaczne poprawienie dokładności wyników w przypadku szumów wąskopasmowych. Filtracja ta realizowana jest w dziedzinie częstotliwości i polega na usunięciu z widma wszystkich linii odpowiadających częstotliwościom zakłócenia. Wyniki doświadczeń przeprowadzonych na obiekcie rzeczywistym (pomieszczenie laboratoryjne) potwierdziły, że dzięki tej metodzie można uzyskać modele o odpowiednio dokładnej charakterystyce amplitudowo-fazowej. Przedstawiona procedura może być stosowana w przypadku, gdy obiekt pobudzany był sygnałem wielosinusoidalnym. SŁOWA KLUCZOWE: hałas, tłumienie hałasu, aktywne tłumienie hałasu, układy aktywnego tłumienia hałasu, zakłócenia, szum pierwotny, obiekty elektroakustyczne, metody identyfikacji. ABSTRACT: A problem of electro-acoustic plant identification for active noise control is discussed. It is assumed that data from identification experiment are contaminated by a primary noise that should be attenuated later. Three examples of such a noise are considered: sine (discrete spectrum), noise generated by a motor (narrowband time-varying spectrum) and broadband noise (pseudorandom). It is shown that thanks to preprocessing the data by disturbance adjusting filtration (DAF) it is possible to improve the results significantly when the data are contaminated by a narrowband primary noise. DAF is the procedure of selective filtration in frequency domain consisting in removing from the spectra all lines for frequencies corresponding to the noise. The results of real-world experiments carried on in a laboratory enclosure show the accuracy of estimated frequency responses obtained in the proposed approach. The procedure is efficient when multisine signals are used to excite the plant. KEYWORDS: active noise control, process identification, frequency response, models

Cardiovascular risk factors as determinants of cerebral blood flow - a cross-sectional and 6-year follow-up study

Purpose: The parameters of cerebral blood flow are modulated by many factors. The aim of the study was to prospectively assess the relationship between the number of the established cardiovascular risk factors and hemodynamic parameters of cerebral blood flow. Material and methods: The study was cross-sectional baseline and 6-year follow-up data analysis. We analyzed data regarding cardiovascular risk factors, medications use, and ultrasonographically (transcranial Doppler) obtained mean cerebral blood flow velocity (mCBFV), pulsatility (PI), resistance (RI) indexes of middle cerebral artery. Results: After 6.0 ± 0.6 years of follow-up, there was increase in systolic (p = .047), and decrease in diastolic (p = .005) blood pressure, resulting in greater pulse pressure (p < .001). Although intima-media thickness increased during follow-up (p = .019), PI, RI and mCBFV did not differ between baseline and follow-up. In the cohort without follow-up (n = 112), we observed strong association between number of studied cardiovascular risk factors and lower mCBFV, and higher PI and RI (all p < .001), in the cohort with 6 year follow-up (n = 53), we confirmed similar association for mCBFV and PI (p = .002) at baseline, and mCBFV (p = .024) after follow-up. During follow-up, more patients were treated with vasoactive medications (p < .05). Also the median (interquartile range) of total number of taken drugs at follow-up 2 (1–3) was greater than at baseline 1 (0–2), (p < .001). The addition of vasoactive medications during follow-up was associated with increase of the mCBFV (0.012 ± 0.02 m/s, p = .013). Conclusion: The parameters of the cerebral blood flow are adversely influenced by accretion of cardiovascular risk factors, both at baseline and after 6 years of follow-up. The addition of a vasoactive medication during follow-up is associated with an increase of the mCBFV, a possibly beneficial effect