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Impeller Position in a Magnetically Levitated Rotodynamic Blood Pump and Its Impact on In-Silico Hemocompatibility

ASAIO Journal 2025年 2025 Apr 3页

作者： Grujic, Marko Schoefbeck, Rosmarie Thamsen, Bente Aigner, Philipp Röhrich, Michael Jakubek, Stefan Zimpfer, Daniel Granegger, Marcus Christian Doppler Laboratory for Mechanical Circulatory Support Department of Cardiac Surgery Medical University of Vienna Vienna Austria Department of Anaesthesia Intensive Care Medicine and Pain Medicine Medical University of Vienna Vienna Austria Division of Control and Process Automation Institute of Mechanics and Mechatronics Vienna University of Technology Vienna Austria

In magnetically levitated rotodynamic blood pumps (RPBs), the impeller position depends on a balance of electromagnetic and fluid dynamic forces. The aim of this study was to describe the impeller position of the HeartMate 3 over a wide range of operating conditions and assess its potential impact on hemocompatibility. Three-dimensional impeller positions were measured using a transparent HeartMate 3 pump casing, laser distance measurements, and a high-speed camera. Accompanying computational fluid dynamic (CFD) hemocompatibility predictions of a displaced and centered impeller at a typical operating point were compared. Impeller positions vary substantially with different operating points with a maximum axial displacement of 223 µm at 7 L/min and 7,000 rpm and a maximum radial displacement of 145 µm at 0 L/min and 7,000 rpm. In CFD, a displaced impeller had only a minor influence on global pump parameters ( © ASAIO 2025.

关键词： Computational fluid dynamics

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In-vitro Hemocompatibility Evaluation of the HeartMate 3 under Realistic Operating Conditions

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IEEE Transactions on Biomedical Engineering 2025年 PP卷 PP页

作者： He, Xiangyu Narayanaswamy, Krishnaraj Fischer, Michael B. Schmitt, Leonie Ruthmeier, Teresa Messner, Barbara Jakubek, Stefan Zimpfer, Daniel Granegger, Marcus Medical University of Vienna Christian Doppler Laboratory for Mechanical Circulatory Support Department of Cardiac Surgery Vienna Austria Medical University of Vienna Clinic for Transfusion Medicine and Cellular Therapy Vienna Austria Medical University of Vienna Department of Cardiac Surgery Vienna Austria Vienna University of Technology Division of Control and Process Automation Institute of Mechanics and Mechatronics Vienna Austria

Objective: Operating conditions significantly influence hemolysis generation in rotodynamic blood pumps (RBPs). Previous experiments conducted under constant operating conditions have demonstrated that lower flow rates are associated with a higher normalized index of hemolysis (NIH). However, in clinical scenarios, the pump flow rate fluctuates in response to the residual cardiac function. This study aims to investigate the effects of various pulsatile operating conditions on hemolysis generation and von Willebrand Factor (vWF) degradation of RBP. Methods: To investigate these conditions, pulsatile flow experiments were conducted for 12 hours using HeartMate 3 (HM3, Abbott Inc, USA) in a hybrid mock circulatory loop with citrated human blood from hemochromatosis patients. Three operating conditions (high, low, and no residual cardiac function) were examined under two pump speed settings: normal (5400rpm, 4.3L/min) and low (4800rpm, 2.5L/min). Hemolysis was assessed by measuring delta free hemoglobin every 30 minutes (dfHb30min) and calculating NIH. High molecular weight (HMW) vWF multimer degradation was assessed using immunoblotting. Results: There was no significant difference in dfHb30min (p>0.388), NIH (p>0.382), and HMW vWF multimers degradation (p>0.364) between the three operating conditions, but differences in these parameters were observed between the normal and low speed settings. Meanwhile, a consistent trend in the hemolysis outcomes was observed with slightly elevated hemolysis in no and high pulsatility conditions of both speed settings. Conclusion: Hemocompatibility of the HM3 is not significantly affected by periodic high/low flow or backflows through the pump in in-vitro evaluation but rather by the pump operating condition: flow rate and pump speed. © 1964-2012 IEEE.

关键词： Flow rate

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Real-time capable nonlinear pantograph models using local model networks in state-space configuration

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IFAC-PapersOnLine 2016年第21期49卷 157-162页

作者： Maier, Clemens C. Schirrer, Alexander Kozek, Martin Technische Universität Wien Institute of Mechanics and Mechatronics Division of Control and Process Automation ViennaA-1060 Austria

Modern pantograph current collectors for high-speed trains are mechatronic systems that are increasingly equipped with active control to maximize their dynamic performance. To realize a high-quality contact, decrease wear, and increase speed, it is necessary to use high-fidelity co-simulation and hardware-in-the-loop (HiL) testing tools, as well as modern model-based control (MBC) concepts. In all these areas, efficient, real-time-capable and accurate models of the pantograph dynamics are required. This paper proposes two different real-time-capable nonlinear pantograph models based on the local model network (LMN) methodology, intended for utilization in co-simulation and control design. They are identifiable by measurement data and applicable for different pantograph geometries. The proposed model structures attain significant improvements in accuracy compared to classical models via global linearization, and they are highly computationally efficient. © 2016

关键词： Electric current collection Fuzzy neural networks MIMO systems Model structures Pantographs Quality control Railroad cars Railroads Computationally efficient Hardware in the loops High speed train (HST) Model based controls Neuro fuzzy network Non linear model Real time capability Subspace identification

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Modeling and control of an industrial continuous furnace

Modeling and control of an industrial continuous furnace

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CSSim 2009 - 1st International Conference on Computational Intelligence, Modelling, and Simulation

作者： Bitschnau, L. Kozek, M. Institute for Mechanics and Mechatronics Vienna University of Technology Division of Control and Process Automation Vienna Austria

ISBN: (纸本)9780769537955

This paper describes a furnace model in state space formulation for a continuous heat treating process specifically suitable for controller design. The model comprises the heat transfer in the conveyed steel strip, the heat transmission from the heating or cooling elements to the steel strip, the inner dynamics of the heating elements and the related furnace portion, heat losses to the ambience, and time-varying parameters of both the strip material and the process (strip velocity, set temperature profile). Model inputs are the heating powers of the individual heaters, and the outputs are either strip or furnace temperatures at specific furnace positions. The model is also suitable for on-line simulation, and due to the flexible and versatile structure of the heater model a wide range of furnace types can be covered with high accuracy. Simulation results for classical PID zone temperature control and a proposed feedforward extension demonstrate the efficiency of the furnace model. © 2009 IEEE.

关键词： controllers

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An advanced criterion for optimal actuator and sensor placement on complex exible structures

An advanced criterion for optimal actuator and sensor placem...

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作者： Westermayer, Christian Schirrer, Alexander Hemedi, Mark Kozek, Martin Institute of Mechanics and Mechatronics Division of Control and Process Automation Vienna University of Technology Vienna Austria

ISBN: (纸本)9783902661425

In a comprehensive control design approach for exible mechanic structures, such as lightweight vehicles or aircraft, a vital decision is the positioning and design of actuators and sensors for the control tasks. This paper proposes an optimal placement approach that exploits the special structure of exible mechanical systems and incorporates controllability/observability based measures as well as further knowledge on actuator and sensor properties. It combines the advantages of state of the art positioning criteria such that a balance between low and high frequency modes is assured and at the same time applicability to complex systems in arbitrary system coordinates is guaranteed. These essential properties are illustrated on a clamped beam. The controlled system is studied in terms of the generalized plant description, as it is common in robust control design. Thus it serves as natural extension to the controller design process later on and enables comprehensive control design optimization at an early stage.

关键词： Robust control

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An actuator fault detection concept for active vibration control of a heavy metro vehicle

An actuator fault detection concept for active vibration con...

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14th International Congress on Sound and Vibration 2007, ICSV 2007

作者： Benatzky, Christian Kozek, Martin Institute of Mechanics and Mechatronics Division of Control and Process Automation Vienna University of Technology Vienna Austria

ISBN: (纸本)9781627480000

This paper proposes a hardware redundancy based actuator fault detection concept for the control of a heavy metro vehicle car body. Because of the specific properties of collocated actuator/sensor pairs it can be shown that the proposed method is simple, reliable and inexpensive. Additionally, it avoids the necessity to accurately model the flexible structure under investigation which would be necessary in analytical redundancy based methods. Furthermore, the concept is validated utilizing a 1/10 scaled laboratory model of a heavy metro vehicle car body.

关键词： Vibrations (mechanical)

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An identification procedure for a scaled metro vehicle - Flexible structure experiment 9

An identification procedure for a scaled metro vehicle - Fle...

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2007 9th European control Conference, ECC 2007

作者： Benatzky, Christian Kozek, Martin Institute of Mechanics and Mechatronics Division of Control and Process Automation Vienna University of Technology Vienna Austria

ISBN: (纸本)9783952417386

This paper deals with the experimental setup and the identification of a flexible structure laboratory experiment of a 1/10 scaled metro vehicle car body. The test bed setup as well as the measurement equipment are described to point out that the identification of a system description is difficult because not only control inputs and measurements are considered but additionally the excitation inputs and the performance variables have to be incorporated. Where standard state of the art identification techniques fail to obtain a model of the structure a simple yet efficient procedure is given to identify the flexible structure experiment at hand. Finally, closed loop experimental and simulation results are utilized to validate the suitability of the proposed identification procedure. © 2007 EUCA.

关键词： Flexible structures

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A hierarchical MPC for multi-objective mixed-integer optimisation applied to redundant refrigeration circuits

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IFAC-PapersOnLine 2017年第1期50卷 9058-9064页

作者： Luchini E. Schirrer A. Kozek M. Institute of Mechanics and Mechatronics Division of Control and Process Automation Getreidemarkt 9/325-A5 Vienna A-1060 Austria

Temperature control of an insulated cool box (ICB) can be efficiently provided by model predictive control. However, if the cooling capacity is supplied by redundant refrigeration circuits (RCs) with both continuous and switched control variables, the overall control design becomes complex: 1) Time constants of the ICB and RCs differ by a factor of approximately 100. 2) Switched and continuous control variables require mixed-integer optimisation. 3) Power consumption, wear, control performance and output tracking call for multi-objective optimisation. In this work a global linear Model Predictive controller (MPC) is designed to compute a desired cooling capacity at a low sampling frequency for a long prediction horizon, while a mixed-integer MPC (MI-MPC) provides the actual cooling capacity utilising a fast sampling frequency and a short prediction horizon. The control concept is presented, a stability prove is given and simulation results demonstrate the performance of the concept. © 2017

关键词： hierarchical MPC mixed-integer optimisation multiple sampling rates refrigeration system

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Disturbance observer and ageing estimation for a temperature controlled food transporter

Disturbance observer and ageing estimation for a temperature...

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2018 SICE International Symposium on control Systems, SICE ISCS 2018

作者： Luchini, Elisabeth Kozek, Martin Institute of Mechanics and Mechatronics Division of Control and Process Automation Getreidemarkt 9/325-A5 ViennaA-1060 Austria

ISBN: (纸本)9784907764586

Temperature control of a food transport system with an insulated cool box (ICB) can be efficiently provided by model predictive control (MPC). However, disturbances like solar irradiation or deterioration of the heat transfer coefficient α of the ICB are typically not detected by sensors. In this paper a disturbance observer for solar irradiation is used to design a fast sampled disturbance compensation obtaining a fast response of the system. Two specific characteristics of the disturbance are utilized to estimate α: 1) During nighttime solar irradiation has its minimum. 2) α declines at a very slow rate. The MPC, irradiation estimation, and α estimation are implemented with different sampling rates. This enables separate and robust estimation and efficient implementation. The system and control architecture is presented, the concept of the observer and estimation is given and simulation results demonstrate the performance of the concept. © 2018 The Society of Instrument and control Engineers - SICE.

关键词： Model predictive control

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Model predictive control of a battery emulator for testing of hybrid and electric powertrains

Model predictive control of a battery emulator for testing o...

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7th IEEE Vehicle Power and Propulsion Conference, VPPC 2011

作者： König, Oliver Jakubek, Stefan Prochart, Günter Institute of Mechanics and Mechatronics Division of Control and Process Automation Vienna University of Technology Austria AVL List GmbH Graz Austria

ISBN: (纸本)9781612842486

Thorough testing of the powertrain is a key aspect for the development of reliable hybrid and electric vehicles. Instead of a real traction battery, a battery emulator is used to supply the electric motor inverters of hybrid powertrains on a testbed. This approach avoids time-consuming preconditioning of batteries and allows automated testing of hybrid powertrains. An electric motor inverter acts as a constant power load towards the battery emulator. This degrades the dynamic performance and can even destabilize a supply with a conventional controller. The contributions are a model predictive controller design approach that includes a model of the system and the constant power load. A robustness concept is utilized in order to achieve stable operation. An algorithm for real-time execution of constrained model predictive control is proposed as well. Simulation results and experimental results are presented. © 2011 IEEE.

关键词： Traction motors

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