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Yih-choung Yu - One of the best experts on this subject based on the ideXlab platform.

  • Performance Prediction of a Percutaneous Ventricular Assist System Using Nonlinear Circuit Analysis Techniques
    IEEE Transactions on Biomedical Engineering, 2008
    Co-Authors: Yih-choung Yu, Marwan A. Simaan, S. Mushi, N.v. Zorn
    Abstract:

    A percutaneous ventricular assist device (pVAD) is an extracorporeal cardiac assist system that supports the failing ventricle in advanced stage heart failure by bypassing blood from the venous to the arterial circulation through a blood pump. The system can be implanted in a Cath lab using standard interventional techniques, and typically consists of a venous or atrial drainage cannula, the VAD (or blood pump), and an arterial perfusion cannula. Because the device allows clinicians the freedom of choosing the configuration and size of the cannulae based on the patient's body size and the size of the artery, it is extremely difficult but important to be able to predict the amount of blood flow that the device can provide before it is implanted to support the patient. In this paper, we develop a novel method that can be used to accurately predict the mean flow rate that the device can provide to the patient based on the size and configuration of the arterial cannula, the pump speed, and the patient's left atrial and mean arterial pressures. To do this, we first develop a nonlinear electric circuit model for the pVAD. This model includes a speed Dependent Voltage Source and flow Dependent resistors to simulate the pressure-flow relationship in the various cannulae in the device. We show that the flow rate through the device can be determined by solving a quadratic equation whose coefficients are scaled depending on the size and configuration of the arterial cannula. The model and prediction method were tested experimentally on a test loop supported by the TandemHeart pVAD (Cardiacassist, Inc., Pittsburgh, PA). A comparison of the predicted flow rates obtained from our method with experimental data shows that our method can predict the flow rates accurately with error indices less than 6% for all test conditions over the entire range of intended use of the device. Computer simulations of the pVAD model coupled to a cardiovascular model showed that the accuracy of the method in estimating the mean flow rate is consistent over the normal range of operation of the device regardless of the pulsatility introduced by the cardiovascular system. This method can be used as an additional too to assist cardiologists in choosing a proper arterial cannulae configurations and sizes for pVAD patients. It can also be used as a tool to train clinical personnel to operate the device under different physiological conditions.

  • Model-based prediction of a percutaneous ventricular assist device performance
    Proceedings of the 2005 American Control Conference 2005., 2005
    Co-Authors: Yih-choung Yu, Marwan A. Simaan, N.v. Zorn, S. Mushi
    Abstract:

    A percutaneous ventricular assist system is an external heart assist device that bypasses blood from the left atrium and returns it to the femoral artery to support patients who suffer from acute heart failure. The system consists of a centrifugal blood pump, an atrial drainage cannula, and various sizes of arterial perfusion cannula. Because the device allows cardiologists the freedom choosing the arterial cannula based on a patient's body size, it is extremely difficult but important to predict the level of support the device can provide to the patient before the devise is up and running. In this paper, the TandemHeart pVAD (Cardiacassist Inc. Pittsburgh, PA) is modeled as a nonlinear electric circuit, including a speed Dependent Voltage Source and current Dependent resistors to predict the performance of the system by specifying pump speed, mean arterial pressure (MAP), and mean left atrial pressure (LAP). The model structure is developed based upon the pipeline theory while the model parameters are identified by least-squares fit of the model to the experimental data. The flow rate is predicted by solving a quadratic equation while coefficients in the equation are scaled, depending on the arterial cannula configurations. The model can predict the flow rates accurately with error indices of all test conditions less than 6%, comparing the predicted flow from the model with the experimental data.

  • Performance prediction of a percutaneous ventricular assist system - a nonlinear circuit analysis approach
    Proceedings of the IEEE 28th Annual Northeast Bioengineering Conference (IEEE Cat. No.02CH37342), 2002
    Co-Authors: Yih-choung Yu, Marwan A. Simaan
    Abstract:

    A percutaneous ventricular assist system, consisting of a centrifugal blood pump, an atrial drainage cannula, and various sizes of arterial perfusion cannulae, is modeled as a nonlinear circuit, including a speed Dependent Voltage Source and current Dependent resistors. This model is used to predict the performance of the system in terms of blood flow rate through the system by specifying pump speed, mean arterial pressure and left atrial pressure. The predicted pump flow is obtained by solving the current through the circuit using an optimization routine. It is shown that the model predicted flow rates accurately with mean error less than 2%, when the predicted flows from the model are compared to the experimental data.

N.v. Zorn - One of the best experts on this subject based on the ideXlab platform.

  • Performance Prediction of a Percutaneous Ventricular Assist System Using Nonlinear Circuit Analysis Techniques
    IEEE Transactions on Biomedical Engineering, 2008
    Co-Authors: Yih-choung Yu, Marwan A. Simaan, S. Mushi, N.v. Zorn
    Abstract:

    A percutaneous ventricular assist device (pVAD) is an extracorporeal cardiac assist system that supports the failing ventricle in advanced stage heart failure by bypassing blood from the venous to the arterial circulation through a blood pump. The system can be implanted in a Cath lab using standard interventional techniques, and typically consists of a venous or atrial drainage cannula, the VAD (or blood pump), and an arterial perfusion cannula. Because the device allows clinicians the freedom of choosing the configuration and size of the cannulae based on the patient's body size and the size of the artery, it is extremely difficult but important to be able to predict the amount of blood flow that the device can provide before it is implanted to support the patient. In this paper, we develop a novel method that can be used to accurately predict the mean flow rate that the device can provide to the patient based on the size and configuration of the arterial cannula, the pump speed, and the patient's left atrial and mean arterial pressures. To do this, we first develop a nonlinear electric circuit model for the pVAD. This model includes a speed Dependent Voltage Source and flow Dependent resistors to simulate the pressure-flow relationship in the various cannulae in the device. We show that the flow rate through the device can be determined by solving a quadratic equation whose coefficients are scaled depending on the size and configuration of the arterial cannula. The model and prediction method were tested experimentally on a test loop supported by the TandemHeart pVAD (Cardiacassist, Inc., Pittsburgh, PA). A comparison of the predicted flow rates obtained from our method with experimental data shows that our method can predict the flow rates accurately with error indices less than 6% for all test conditions over the entire range of intended use of the device. Computer simulations of the pVAD model coupled to a cardiovascular model showed that the accuracy of the method in estimating the mean flow rate is consistent over the normal range of operation of the device regardless of the pulsatility introduced by the cardiovascular system. This method can be used as an additional too to assist cardiologists in choosing a proper arterial cannulae configurations and sizes for pVAD patients. It can also be used as a tool to train clinical personnel to operate the device under different physiological conditions.

  • ACC - A Nonlinear Model for Flow Estimation and Control in a Percutaneous Heart Assist System
    2007 American Control Conference, 2007
    Co-Authors: Marwan A. Simaan, S. Mushi, N.v. Zorn
    Abstract:

    A percutaneous ventricular assist device (pVAD) is an external heart assist system that bypasses blood from left atrium, right atrium, or femoral vein, and returns it to femoral artery to support patients who suffer from acute heart failure. The system typically consists of a blood pump (the VAD), a venous or atrial drainage cannula, and an arterial perfusion cannula. Because the device usually allows cardiologists the freedom of choosing the arterial cannula size and configuration based on a patient's body size, it is extremely difficult but important to predict the amount of blood flow the device can provide to the patient before the device is implanted and is up and running. In this paper, the pVAD system is modeled as a nonlinear electric circuit, including a speed Dependent Voltage Source and current Dependent resistors to simulate the pressure- flow relationship in the cannulae. The model structure is developed based upon the theory of fluid flow in pipes and the model parameters are identified by least-squares fit of the model to the experimental data. The blood flow rate provided by the system is determined by solving a quadratic equation whose coefficients are determined based on the sizes and configurations of the arterial cannulae. The model was tested on the tandem heart pVAD (Cardiac Assist Inc., Pittsburgh, PA) and was shown to be able to predict the flow rates accurately with error indices for all test conditions less than 6%, when comparing the predicted flow rates from the model with the experimental data. Also, computer simulation of the pVAD system with a cardiovascular model showed that the accuracy of the model in estimating the flow rate is robust regardless of the interaction between the device and the cardiovascular system. In addition to being able to estimate the flow given the sizes of the cannulae, this model can also be used to control the pump speed to achieve a desired flow for a given cannula configuration.

  • Model-based prediction of a percutaneous ventricular assist device performance
    Proceedings of the 2005 American Control Conference 2005., 2005
    Co-Authors: Yih-choung Yu, Marwan A. Simaan, N.v. Zorn, S. Mushi
    Abstract:

    A percutaneous ventricular assist system is an external heart assist device that bypasses blood from the left atrium and returns it to the femoral artery to support patients who suffer from acute heart failure. The system consists of a centrifugal blood pump, an atrial drainage cannula, and various sizes of arterial perfusion cannula. Because the device allows cardiologists the freedom choosing the arterial cannula based on a patient's body size, it is extremely difficult but important to predict the level of support the device can provide to the patient before the devise is up and running. In this paper, the TandemHeart pVAD (Cardiacassist Inc. Pittsburgh, PA) is modeled as a nonlinear electric circuit, including a speed Dependent Voltage Source and current Dependent resistors to predict the performance of the system by specifying pump speed, mean arterial pressure (MAP), and mean left atrial pressure (LAP). The model structure is developed based upon the pipeline theory while the model parameters are identified by least-squares fit of the model to the experimental data. The flow rate is predicted by solving a quadratic equation while coefficients in the equation are scaled, depending on the arterial cannula configurations. The model can predict the flow rates accurately with error indices of all test conditions less than 6%, comparing the predicted flow from the model with the experimental data.

Marwan A. Simaan - One of the best experts on this subject based on the ideXlab platform.

  • Performance Prediction of a Percutaneous Ventricular Assist System Using Nonlinear Circuit Analysis Techniques
    IEEE Transactions on Biomedical Engineering, 2008
    Co-Authors: Yih-choung Yu, Marwan A. Simaan, S. Mushi, N.v. Zorn
    Abstract:

    A percutaneous ventricular assist device (pVAD) is an extracorporeal cardiac assist system that supports the failing ventricle in advanced stage heart failure by bypassing blood from the venous to the arterial circulation through a blood pump. The system can be implanted in a Cath lab using standard interventional techniques, and typically consists of a venous or atrial drainage cannula, the VAD (or blood pump), and an arterial perfusion cannula. Because the device allows clinicians the freedom of choosing the configuration and size of the cannulae based on the patient's body size and the size of the artery, it is extremely difficult but important to be able to predict the amount of blood flow that the device can provide before it is implanted to support the patient. In this paper, we develop a novel method that can be used to accurately predict the mean flow rate that the device can provide to the patient based on the size and configuration of the arterial cannula, the pump speed, and the patient's left atrial and mean arterial pressures. To do this, we first develop a nonlinear electric circuit model for the pVAD. This model includes a speed Dependent Voltage Source and flow Dependent resistors to simulate the pressure-flow relationship in the various cannulae in the device. We show that the flow rate through the device can be determined by solving a quadratic equation whose coefficients are scaled depending on the size and configuration of the arterial cannula. The model and prediction method were tested experimentally on a test loop supported by the TandemHeart pVAD (Cardiacassist, Inc., Pittsburgh, PA). A comparison of the predicted flow rates obtained from our method with experimental data shows that our method can predict the flow rates accurately with error indices less than 6% for all test conditions over the entire range of intended use of the device. Computer simulations of the pVAD model coupled to a cardiovascular model showed that the accuracy of the method in estimating the mean flow rate is consistent over the normal range of operation of the device regardless of the pulsatility introduced by the cardiovascular system. This method can be used as an additional too to assist cardiologists in choosing a proper arterial cannulae configurations and sizes for pVAD patients. It can also be used as a tool to train clinical personnel to operate the device under different physiological conditions.

  • ACC - A Nonlinear Model for Flow Estimation and Control in a Percutaneous Heart Assist System
    2007 American Control Conference, 2007
    Co-Authors: Marwan A. Simaan, S. Mushi, N.v. Zorn
    Abstract:

    A percutaneous ventricular assist device (pVAD) is an external heart assist system that bypasses blood from left atrium, right atrium, or femoral vein, and returns it to femoral artery to support patients who suffer from acute heart failure. The system typically consists of a blood pump (the VAD), a venous or atrial drainage cannula, and an arterial perfusion cannula. Because the device usually allows cardiologists the freedom of choosing the arterial cannula size and configuration based on a patient's body size, it is extremely difficult but important to predict the amount of blood flow the device can provide to the patient before the device is implanted and is up and running. In this paper, the pVAD system is modeled as a nonlinear electric circuit, including a speed Dependent Voltage Source and current Dependent resistors to simulate the pressure- flow relationship in the cannulae. The model structure is developed based upon the theory of fluid flow in pipes and the model parameters are identified by least-squares fit of the model to the experimental data. The blood flow rate provided by the system is determined by solving a quadratic equation whose coefficients are determined based on the sizes and configurations of the arterial cannulae. The model was tested on the tandem heart pVAD (Cardiac Assist Inc., Pittsburgh, PA) and was shown to be able to predict the flow rates accurately with error indices for all test conditions less than 6%, when comparing the predicted flow rates from the model with the experimental data. Also, computer simulation of the pVAD system with a cardiovascular model showed that the accuracy of the model in estimating the flow rate is robust regardless of the interaction between the device and the cardiovascular system. In addition to being able to estimate the flow given the sizes of the cannulae, this model can also be used to control the pump speed to achieve a desired flow for a given cannula configuration.

  • Model-based prediction of a percutaneous ventricular assist device performance
    Proceedings of the 2005 American Control Conference 2005., 2005
    Co-Authors: Yih-choung Yu, Marwan A. Simaan, N.v. Zorn, S. Mushi
    Abstract:

    A percutaneous ventricular assist system is an external heart assist device that bypasses blood from the left atrium and returns it to the femoral artery to support patients who suffer from acute heart failure. The system consists of a centrifugal blood pump, an atrial drainage cannula, and various sizes of arterial perfusion cannula. Because the device allows cardiologists the freedom choosing the arterial cannula based on a patient's body size, it is extremely difficult but important to predict the level of support the device can provide to the patient before the devise is up and running. In this paper, the TandemHeart pVAD (Cardiacassist Inc. Pittsburgh, PA) is modeled as a nonlinear electric circuit, including a speed Dependent Voltage Source and current Dependent resistors to predict the performance of the system by specifying pump speed, mean arterial pressure (MAP), and mean left atrial pressure (LAP). The model structure is developed based upon the pipeline theory while the model parameters are identified by least-squares fit of the model to the experimental data. The flow rate is predicted by solving a quadratic equation while coefficients in the equation are scaled, depending on the arterial cannula configurations. The model can predict the flow rates accurately with error indices of all test conditions less than 6%, comparing the predicted flow from the model with the experimental data.

  • Performance prediction of a percutaneous ventricular assist system - a nonlinear circuit analysis approach
    Proceedings of the IEEE 28th Annual Northeast Bioengineering Conference (IEEE Cat. No.02CH37342), 2002
    Co-Authors: Yih-choung Yu, Marwan A. Simaan
    Abstract:

    A percutaneous ventricular assist system, consisting of a centrifugal blood pump, an atrial drainage cannula, and various sizes of arterial perfusion cannulae, is modeled as a nonlinear circuit, including a speed Dependent Voltage Source and current Dependent resistors. This model is used to predict the performance of the system in terms of blood flow rate through the system by specifying pump speed, mean arterial pressure and left atrial pressure. The predicted pump flow is obtained by solving the current through the circuit using an optimization routine. It is shown that the model predicted flow rates accurately with mean error less than 2%, when the predicted flows from the model are compared to the experimental data.

S. Mushi - One of the best experts on this subject based on the ideXlab platform.

  • Performance Prediction of a Percutaneous Ventricular Assist System Using Nonlinear Circuit Analysis Techniques
    IEEE Transactions on Biomedical Engineering, 2008
    Co-Authors: Yih-choung Yu, Marwan A. Simaan, S. Mushi, N.v. Zorn
    Abstract:

    A percutaneous ventricular assist device (pVAD) is an extracorporeal cardiac assist system that supports the failing ventricle in advanced stage heart failure by bypassing blood from the venous to the arterial circulation through a blood pump. The system can be implanted in a Cath lab using standard interventional techniques, and typically consists of a venous or atrial drainage cannula, the VAD (or blood pump), and an arterial perfusion cannula. Because the device allows clinicians the freedom of choosing the configuration and size of the cannulae based on the patient's body size and the size of the artery, it is extremely difficult but important to be able to predict the amount of blood flow that the device can provide before it is implanted to support the patient. In this paper, we develop a novel method that can be used to accurately predict the mean flow rate that the device can provide to the patient based on the size and configuration of the arterial cannula, the pump speed, and the patient's left atrial and mean arterial pressures. To do this, we first develop a nonlinear electric circuit model for the pVAD. This model includes a speed Dependent Voltage Source and flow Dependent resistors to simulate the pressure-flow relationship in the various cannulae in the device. We show that the flow rate through the device can be determined by solving a quadratic equation whose coefficients are scaled depending on the size and configuration of the arterial cannula. The model and prediction method were tested experimentally on a test loop supported by the TandemHeart pVAD (Cardiacassist, Inc., Pittsburgh, PA). A comparison of the predicted flow rates obtained from our method with experimental data shows that our method can predict the flow rates accurately with error indices less than 6% for all test conditions over the entire range of intended use of the device. Computer simulations of the pVAD model coupled to a cardiovascular model showed that the accuracy of the method in estimating the mean flow rate is consistent over the normal range of operation of the device regardless of the pulsatility introduced by the cardiovascular system. This method can be used as an additional too to assist cardiologists in choosing a proper arterial cannulae configurations and sizes for pVAD patients. It can also be used as a tool to train clinical personnel to operate the device under different physiological conditions.

  • ACC - A Nonlinear Model for Flow Estimation and Control in a Percutaneous Heart Assist System
    2007 American Control Conference, 2007
    Co-Authors: Marwan A. Simaan, S. Mushi, N.v. Zorn
    Abstract:

    A percutaneous ventricular assist device (pVAD) is an external heart assist system that bypasses blood from left atrium, right atrium, or femoral vein, and returns it to femoral artery to support patients who suffer from acute heart failure. The system typically consists of a blood pump (the VAD), a venous or atrial drainage cannula, and an arterial perfusion cannula. Because the device usually allows cardiologists the freedom of choosing the arterial cannula size and configuration based on a patient's body size, it is extremely difficult but important to predict the amount of blood flow the device can provide to the patient before the device is implanted and is up and running. In this paper, the pVAD system is modeled as a nonlinear electric circuit, including a speed Dependent Voltage Source and current Dependent resistors to simulate the pressure- flow relationship in the cannulae. The model structure is developed based upon the theory of fluid flow in pipes and the model parameters are identified by least-squares fit of the model to the experimental data. The blood flow rate provided by the system is determined by solving a quadratic equation whose coefficients are determined based on the sizes and configurations of the arterial cannulae. The model was tested on the tandem heart pVAD (Cardiac Assist Inc., Pittsburgh, PA) and was shown to be able to predict the flow rates accurately with error indices for all test conditions less than 6%, when comparing the predicted flow rates from the model with the experimental data. Also, computer simulation of the pVAD system with a cardiovascular model showed that the accuracy of the model in estimating the flow rate is robust regardless of the interaction between the device and the cardiovascular system. In addition to being able to estimate the flow given the sizes of the cannulae, this model can also be used to control the pump speed to achieve a desired flow for a given cannula configuration.

  • Model-based prediction of a percutaneous ventricular assist device performance
    Proceedings of the 2005 American Control Conference 2005., 2005
    Co-Authors: Yih-choung Yu, Marwan A. Simaan, N.v. Zorn, S. Mushi
    Abstract:

    A percutaneous ventricular assist system is an external heart assist device that bypasses blood from the left atrium and returns it to the femoral artery to support patients who suffer from acute heart failure. The system consists of a centrifugal blood pump, an atrial drainage cannula, and various sizes of arterial perfusion cannula. Because the device allows cardiologists the freedom choosing the arterial cannula based on a patient's body size, it is extremely difficult but important to predict the level of support the device can provide to the patient before the devise is up and running. In this paper, the TandemHeart pVAD (Cardiacassist Inc. Pittsburgh, PA) is modeled as a nonlinear electric circuit, including a speed Dependent Voltage Source and current Dependent resistors to predict the performance of the system by specifying pump speed, mean arterial pressure (MAP), and mean left atrial pressure (LAP). The model structure is developed based upon the pipeline theory while the model parameters are identified by least-squares fit of the model to the experimental data. The flow rate is predicted by solving a quadratic equation while coefficients in the equation are scaled, depending on the arterial cannula configurations. The model can predict the flow rates accurately with error indices of all test conditions less than 6%, comparing the predicted flow from the model with the experimental data.

Lipei Huang - One of the best experts on this subject based on the ideXlab platform.

  • improved modeling of medium Voltage sic mosfet within wide temperature range
    IEEE Transactions on Power Electronics, 2014
    Co-Authors: Kai Sun, Hongfei Wu, Juejing Lu, Yan Xing, Lipei Huang
    Abstract:

    An improved model of medium Voltage (1200 V) silicon carbide (SiC) MOSFET based on PSpice is proposed in this paper, which is suitable for wide temperature range applications especially at low temperature. The static characteristics of SiC MOSFET are described by introducing temperature-Dependent Voltage Source and current Source. The effect of negative turn-off gate drive Voltage is also taken into account in the modeling. In order to reflect the low-temperature characteristics of SiC MOSFET accurately, low temperature (-25 °C) measurements are carried out, which provide the modeling basis. The determinations of key parameters in the model are analyzed in detail, including the on-state resistor, internal gate resistor, temperature Dependent Sources, and some capacitors. The proposed model is verified by the experimental tests on a buck converter prototype at different input Voltages, input currents, and temperatures. Simulation results on the proposed model coincide well with the experimental test results, in terms of switching waveforms and power losses even at low temperature (-25 °C). These results demonstrate that the proposed model exhibits high accuracy within wide temperature range.

  • Modeling of SiC MOSFET with temperature Dependent parameters and its applications
    2013 Twenty-Eighth Annual IEEE Applied Power Electronics Conference and Exposition (APEC), 2013
    Co-Authors: Kai Sun, Yang Xing, Lipei Huang
    Abstract:

    A model of Silicon carbide (SiC) MOSFET based on PSpice is proposed in this paper, which is suitable for a wide temperature range especially at low temperature. The static characteristics of SiC MOSFET are described by introducing temperature Dependent Voltage Source and current Source. The effect of negative turn-off gate drive Voltage is also taken into account in the modeling. In order to reflect the low temperature characteristics of SiC MOSFET accurately, low temperature (-25°C) measurements are carried out, which provide the modeling basis. The determinations of key parameters in the model are analyzed in detail, including on-state resistor, internal gate resistor, temperature Dependent Sources, and some capacitors. The proposed model is verified by the experimental tests on a Buck converter prototype at different input Voltages, input currents and temperatures. Simulation results on the proposed model coincide well with the experimental results, in terms of switching waveforms and power losses even at low temperature. The comparison between SiC MOSFET and Si MOSFET on switching characteristics and the efficiency comparison of Buck converter using SiC devices and Si devices are presented, which demonstrate the attractive advantage of SiC devices in power loss reduction.