caa a22 4500 378919083 CHVBK 20180305123600.0 cr unu---uuuuu 161128e20041101xx s 000 0 ger 10.1515/BMT.2004.059 doi (NATIONALLICENCE)gruyter-10.1515/BMT.2004.059 Automatic Control of the Extra-Corporal Bypass: System Analysis, Modelling and Evaluation of Different Control Modes [Elektronische Daten] Automatische Regelung der extrakorporalen Zirkulation: Analyse, Modelbildung und Evaluation von Regelstrategien / [M Hexamer, B Misgeld, A Prenger-Berninghoff, U Schütt, H.J Knobl, R Körfer, J Werner] Automatic control of the blood gas parameters during extracorporeal circulation has the potential to improve the quality of this procedure and to relieve the personnel from a time consuming task. This paper describes a model of the underlying system for a standard clinical setup and pinpoints the major difficulties which are the variations of the process gains and the blood- and gas-flow dependent dead times and time constants. Scheduled PI-controllers both for the arterial oxygen as well as for the carbon dioxide partial pressure were designed. Scheduling was based on the blood flow rate. These controllers were tested in a simulation environment. The control systems remained stable under all tested operating condition, but if the blood flow rate was changed abruptly rather large load errors occurred. The performance was improved markedly by adding a feed-forward control path which directly influences the actuating signals based on the actual blood flow rate and the hemoglobin contents, variables which are measured anyway. The major conclusion of this study is to use such direct feed-forward compensation even if more sophisticated control algorithms are used. Die automatische Blutgasregelung beim Einsatz einer Herz-Lungen Maschine hat das Potential, die Qualität dieser Prozedur zu verbessern und zusätzlich das damit betraute Personal von einer zeitaufwendigen Aufgabe zu entlasten. Dieser Beitrag beschreibt ein an dem klinischen Umfeld orientiertes, regelungstechnisches Modell des zugrunde liegenden Systems und zeigt die hauptsächlichen Schwierigkeiten auf. Es sind dies die starke Variation der Prozessverstärkungen und die blut- und gasflussabhängigen Zeitkonstanten und Totzeiten. Zur Regelung der arteriellen Sauerstoff- und Kohlendioxidpartialdrücke wurden PI-Regler mit gesteuerter Adaption entworfen. Die Adaption basierte auf dem aktuellen Blutfluss. Die Regelsysteme wurden in einer Simulationsumgebung getestet. Sie waren in allen getesteten Arbeitspunkten stabil, allerdings traten relativ große Regelabweichungen nach abrupten Blutflussänderungen auf. Die Regelgüte wurde durch die Erweiterung um eine direkte Störgrößenkompensation erheblich gesteigert. Diese Kompensation basierte auf dem aktuellen Blutfluss und Hämoglobingehalt, also Variablen, die ohnehin gemessen werden. Die wesentliche Schlussfolgerung dieser Studie ist, in jedem Fall eine vergleichbare direkte Störgrößenkompensation, auch bei anderen Regelungsverfahren, einzusetzen. © Walter de Gruyter extra-corporeal circulation nationallicence cardiopulmonary bypass nationallicence automatic blood gas control nationallicence extra-korporale Zirkulation nationallicence Herz-Lungen-Maschine nationallicence automatische Blutgasregelung nationallicence Hexamer M. Department of Biomedical Engineering, Medical Faculty, and University Center of Medical Engineering, Ruhr-University Bochum, Germany. aut Misgeld B. Department of Biomedical Engineering, Medical Faculty, and University Center of Medical Engineering, Ruhr-University Bochum, Germany. aut Prenger-Berninghoff A. Department of Biomedical Engineering, Medical Faculty, and University Center of Medical Engineering, Ruhr-University Bochum, Germany. aut Schütt U. Clinic for Cardiothoracic Surgery, Heart and Diabetes Center NRW, Bad Oeynhausen, Ruhr-University Bochum, Germany. aut Knobl H.J. Clinic for Cardiothoracic Surgery, Heart and Diabetes Center NRW, Bad Oeynhausen, Ruhr-University Bochum, Germany. aut Körfer R. Clinic for Cardiothoracic Surgery, Heart and Diabetes Center NRW, Bad Oeynhausen, Ruhr-University Bochum, Germany. aut Werner J. Department of Biomedical Engineering, Medical Faculty, and University Center of Medical Engineering, Ruhr-University Bochum, Germany. aut Biomedizinische Technik/Biomedical Engineering Walter de Gruyter 49/11(2004-11-01), 316-321 0013-5585 49:11<316 2004 49 bmte https://doi.org/10.1515/BMT.2004.059 text/html Onlinezugriff via DOI 1 research article jats NATIONALLICENCE 856 40 https://doi.org/10.1515/BMT.2004.059 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Hexamer M. Department of Biomedical Engineering, Medical Faculty, and University Center of Medical Engineering, Ruhr-University Bochum, Germany aut NATIONALLICENCE 700 1- Misgeld B. Department of Biomedical Engineering, Medical Faculty, and University Center of Medical Engineering, Ruhr-University Bochum, Germany aut NATIONALLICENCE 700 1- Prenger-Berninghoff A. Department of Biomedical Engineering, Medical Faculty, and University Center of Medical Engineering, Ruhr-University Bochum, Germany aut NATIONALLICENCE 700 1- Schütt U. Clinic for Cardiothoracic Surgery, Heart and Diabetes Center NRW, Bad Oeynhausen, Ruhr-University Bochum, Germany aut NATIONALLICENCE 700 1- Knobl H.J. Clinic for Cardiothoracic Surgery, Heart and Diabetes Center NRW, Bad Oeynhausen, Ruhr-University Bochum, Germany aut NATIONALLICENCE 700 1- Körfer R. Clinic for Cardiothoracic Surgery, Heart and Diabetes Center NRW, Bad Oeynhausen, Ruhr-University Bochum, Germany aut NATIONALLICENCE 700 1- Werner J. Department of Biomedical Engineering, Medical Faculty, and University Center of Medical Engineering, Ruhr-University Bochum, Germany aut NATIONALLICENCE 773 0- Biomedizinische Technik/Biomedical Engineering Walter de Gruyter 49/11(2004-11-01), 316-321 0013-5585 49:11<316 2004 49 bmte CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-gruyter