2 research outputs found
Chaotic behaviors of stable second-order digital filters with twoâs complement arithmetic
In this paper, the behaviors of stable second-order digital filters with twoâs complement arithmetic are investigated. It is found that even though the poles are inside the unit circle and the trajectory converges to a fixed point on the phase plane, that fixed point is not necessarily the origin. That fixed point is found and the set of initial conditions corresponding to such trajectories is determined. This set of initial conditions is a set of polygons inside the unit square, whereas it is an ellipse for the marginally stable case. Also, it is found that the occurrence of limit cycles and chaotic fractal pattern on the phase plane can be characterized by the periodic and aperiodic behaviors of the symbolic sequences, respectively. The fractal pattern is polygonal, whereas it is elliptical for the marginally stable case
UvA-DARE (Digital Academic Repository) Clinical evaluation of Duraflo Âź II heparin treated extracorporeal circulation circuits (2nd version) The European working group on heparin coated extracorporeal circulation circuits
Published in: European journal of cardio-thoracic surgery DOI: 10.1016/S1010-7940(96)01122-0 Link to publication Citation for published version (APA): Wildevuur, C. R. H., Jansen, P. G. M., Bezemer, P. D., Kuik, D. J., Eijsman, L., Bruins, P., ... Ahlvin, E. (1997). Clinical evaluation of Duraflo? II heparin treated extracorporeal circulation circuits (2nd version) the European working group on heparin coated extracorporeal circulation circuits. European journal of cardio-thoracic surgery, 11, 616-623. https://doi.org/10.1016/S1010-7940(96)01122-0 General rights It is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), other than for strictly personal, individual use, unless the work is under an open content license (like Creative Commons). Disclaimer/Complaints regulations If you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. Please Ask the Library: https://uba.uva.nl/en/contact, or a letter to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. You will be contacted as soon as possible. Abstract Objectives: To evaluate whether the application of heparin treated circuits for elective coronary artery surgery improves postoperative recovery, a European multicenter randomised clinical trial was carried out. Methods: In 11 European heart centers, 805 low-risk patients underwent cardiopulmonary bypass (CPB) with either an untreated circuit (n= 407) or an identical but heparin treated circuit (n= 398, Duraflo Ÿ II). Results: Significant differences were found among participating centers with respect to patient characteristics, blood handling procedures and postoperative care. The use of heparin treated circuits revealed no overall changes in blood loss, blood use, time on ventilator, occurrence of adverse events, morbidity, mortality, and intensive care stay. These results did not change after adjustment for centers and (other) prognostic factors as analysed with logistic regression. In both groups no clinical or technical (patient or device related) side effects were reported. Because female gender and aortic * Corresponding author. The European Working Group on heparin coated extracorporeal circulation circuits, P.O. Box 169, 5400 AD Uden, Netherlands. Tel.: + 31 413 286621; fax +31 413 250085. 1010-7940/97/$17.00 © 1997 Elsevier Science B.V. All rights reserved. PII S 1 0 1 0 -7 9 4 0 ( 9 6 ) 0 1 1 2 2 -0 C. R.H. Wilde6uur et al. / European Journal of Cardio-thoracic Surgery 11 (1997) 616-623 C.R.H. Wilde6uur et al. / European Journal of Cardio-thoracic Surgery 11 (1997 cross clamp time appeared as prognostic factors in the logistic regression analysis, a subgroup analysis with these variables was performed. In a subpopulation of females (n= 99), those receiving heparin treated circuits needed less blood products, had a lower incidence of rhythm disturbances and were extubated earlier than controls. In another subgroup of patients with aortic cross clamp time exceeding 60 min (n=197), the amount of patients requiring prolonged intensive care treatment (\24 h) was significantly lower when they received heparin treated circuits versus controls. Conclusion: These findings suggest that improved recovery can be expected with heparin treated circuits in specific higher risk patient populations (e.g. females) and when prolonged aortic cross clamp time is anticipated. Further investigations are recommended to analyse the clinical benefit of heparin treated circuits in studies with patients in different well defined risk categories and under better standardised circumstances. © 1997 Elsevier Science B.V