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Cenk M. Çavuşoğlu - One of the best experts on this subject based on the ideXlab platform.

  • Analysis of Dynamic Response of an MRI-Guided Magnetically-Actuated Steerable Catheter System
    2018 IEEE RSJ International Conference on Intelligent Robots and Systems (IROS), 2018
    Co-Authors: Erdem E. Tuna, Nate Lombard Poirot, Russell C. Jackson, Mac Russell, Cenk M. Çavuşoğlu
    Abstract:

    This paper presents a free-space open-loop dynamic response analysis for an MRI -guided magnetically-actuated Steerable intra-vascular Catheter system. The Catheter tip is embedded with a set of current carrying micro-coils. The Catheter is directly actuated via the magnetic torques generated on these coils by the magnetic field of the magnetic resonance imaging (MRI)scanner. The relationship between the input current commands and Catheter tip deflection angle presents an inherent nonlinearity in the proposed Catheter system. The system nonlinearity is analyzed by utilizing a pendulum model. The pendulum model is used to describe the system nonlinearity and to perform an approximate input-output linearization. Then, a black-box system identification approach is performed for frequency response analysis of the linearized dynamics. The optimal estimated model is reduced by observing the modes and considering the Nyquist frequency of the camera system that is used to track the Catheter motion. The reduced model is experimentally validated with 3D open-loop Cartesian free-space trajectories. This study paves the way for effective and accurate free-space closed-loop control of the robotic Catheter with real-time feedback from MRI guidance in subsequent research.

  • Iterative Jacobian-Based Inverse Kinematics and Open-Loop Control of an MRI-Guided Magnetically Actuated Steerable Catheter System
    IEEE ASME Transactions on Mechatronics, 2017
    Co-Authors: Russell Jackson, Nate Lombard Poirot, Dominique Franson, Nicole Seiberlich, Mark A. Griswold, Reinhardt Kam Criss, Cenk M. Çavuşoğlu
    Abstract:

    This paper presents an iterative Jacobian-based inverse kinematics method for a magnetic resonance imaging (MRI) guided magnetically actuated Steerable intravascular Catheter system. The Catheter is directly actuated by magnetic torques generated on a set of current-carrying microcoils embedded on the Catheter tip by the magnetic field of the MRI scanner. The Jacobian matrix relating changes of the currents through the coils to changes of the tip position is derived using a three-dimensional kinematic model of the Catheter deflection. The inverse kinematics is numerically computed by iteratively applying the inverse of the Jacobian matrix. The damped least square method is implemented to avoid numerical instability issues that exist during the computation of the inverse of the Jacobian matrix. The performance of the proposed inverse kinematics approach is validated using a prototype of the robotic Catheter by comparing the actual trajectories of the Catheter tip obtained via open-loop control with the desired trajectories. The results of reproducibility and accuracy evaluations demonstrate that the proposed Jacobian-based inverse kinematics method can be used to actuate the Catheter in an open loop to successfully perform complex ablation trajectories required in atrial fibrillation ablation procedures. This study paves the way for effective and accurate closed-loop control of the robotic Catheter with real-time feedback from MRI guidance in subsequent research.

  • Modeling and Validation of the Three-Dimensional Deflection of an MRI-Compatible Magnetically Actuated Steerable Catheter
    IEEE Transactions on Biomedical Engineering, 2016
    Co-Authors: Nate Lombard Poirot, Dominique Franson, Nicole Seiberlich, Mark A. Griswold, Cenk M. Çavuşoğlu
    Abstract:

    Objective: This paper presents the 3-D kinematic modeling of a novel Steerable robotic ablation Catheter system. The Catheter, embedded with a set of current-carrying microcoils, is actuated by the magnetic forces generated by the magnetic field of the magnetic resonance imaging (MRI) scanner. Methods: This paper develops a 3-D model of the MRI-actuated Steerable Catheter system by using finite differences approach. For each finite segment, a quasi-static torque-deflection equilibrium equation is calculated using beam theory. By using the deflection displacements and torsion angles, the kinematic model of the Catheter system is derived. Results: The proposed models are validated by comparing the simulation results of the proposed model with the experimental results of a hardware prototype of the Catheter design. The maximum tip deflection error is 4.70 mm and the maximum root-mean-square error of the shape estimation is 3.48 mm. Conclusion: The results demonstrate that the proposed model can successfully estimate the deflection motion of the Catheter. Significance: The presented 3-D deflection model of the magnetically controlled Catheter design paves the way to efficient control of the robotic Catheter for the treatment of atrial fibrillation.

Rajni V. Patel - One of the best experts on this subject based on the ideXlab platform.

  • Tendon-sheath analysis for modeling and control of Steerable ablation Catheters
    2016 IEEE International Conference on Advanced Intelligent Mechatronics (AIM), 2016
    Co-Authors: Mahta Khoshnam, Rajni V. Patel
    Abstract:

    Steerable Catheters are key tools in performing cardiac ablation for treating arrhythmia (heart rhythm disorder). The Catheter is steered through the vasculature from the insertion point in the groin area to the atrium. Effective contact between the distal ablation tip and cardiac tissue is established by rotating the Catheter and adjusting the flexion in the Catheter's distal shaft. The manipulation system of unidirectional Steerable Catheters uses a pull-wire mechanism that connects the proximal handle to the distal ablation tip. The mechanical design of this tendon-based transmission system satisfies constraints on the size and diameter of an ablation Catheter, but shows nonlinear effects that introduce difficulties in manipulating the flexible distal tip. In order to control such flexion, in this paper, the Steerable Catheter is considered as a tendon-sheath-driven mechanism. Since it is not possible to affix a force sensor to measure tendon tension at the distal tip, transmission characteristics are obtained using force measurements at the proximal side and visual cues from the distal end. The tendon transmission model is then used to design a control system that compensates for the nonlinear effects of the actuation mechanism and generates the desired flexion at the distal tip. Performance of the proposed controller is evaluated through simulation studies and implementation on an experimental setup. The results show that the proposed control method significantly improves the performance of the system in attaining and tracking the desired tip angle. The results presented in this study contribute towards developing position control schemes for robotics-assisted Catheter manipulation systems.

  • AIM - Tendon-sheath analysis for modeling and control of Steerable ablation Catheters
    2016 IEEE International Conference on Advanced Intelligent Mechatronics (AIM), 2016
    Co-Authors: Mahta Khoshnam, Rajni V. Patel
    Abstract:

    Steerable Catheters are key tools in performing cardiac ablation for treating arrhythmia (heart rhythm disorder). The Catheter is steered through the vasculature from the insertion point in the groin area to the atrium. Effective contact between the distal ablation tip and cardiac tissue is established by rotating the Catheter and adjusting the flexion in the Catheter's distal shaft. The manipulation system of unidirectional Steerable Catheters uses a pull-wire mechanism that connects the proximal handle to the distal ablation tip. The mechanical design of this tendon-based transmission system satisfies constraints on the size and diameter of an ablation Catheter, but shows nonlinear effects that introduce difficulties in manipulating the flexible distal tip. In order to control such flexion, in this paper, the Steerable Catheter is considered as a tendon-sheath-driven mechanism. Since it is not possible to affix a force sensor to measure tendon tension at the distal tip, transmission characteristics are obtained using force measurements at the proximal side and visual cues from the distal end. The tendon transmission model is then used to design a control system that compensates for the nonlinear effects of the actuation mechanism and generates the desired flexion at the distal tip. Performance of the proposed controller is evaluated through simulation studies and implementation on an experimental setup. The results show that the proposed control method significantly improves the performance of the system in attaining and tracking the desired tip angle. The results presented in this study contribute towards developing position control schemes for robotics-assisted Catheter manipulation systems.

  • Modeling of a Steerable Catheter based on beam theory
    2012 IEEE International Conference on Robotics and Automation, 2012
    Co-Authors: Mahta Khoshnam, Mahdi Azizian, Rajni V. Patel
    Abstract:

    Catheter-based cardiac ablation is an interventional treatment for heart arrhythmias. Pull-wire Steerable Catheters are guided to the heart chambers through the vasculature in order to deliver energy to destroy faulty electrical pathways in the heart. The effectiveness of this treatment is dependent on the accuracy of positioning the Catheter tip at the target location and also on maintaining contact with the target while the heart is beating. Therefore, it is desirable to perform hybrid force/position control of the Catheter tip. We have studied the problem of modeling the distal part of a Steerable Catheter using beam theory and have developed and validated a static force-deflection model through extensive experiments. It is shown that the model can estimate the shape of the bending section of a Catheter using force information and without requiring extensive knowledge of the Catheter's internal structure.

  • ICRA - Modeling of a Steerable Catheter based on beam theory
    2012 IEEE International Conference on Robotics and Automation, 2012
    Co-Authors: Mahta Khoshnam, Azizian, Rajni V. Patel
    Abstract:

    Catheter-based cardiac ablation is an interventional treatment for heart arrhythmias. Pull-wire Steerable Catheters are guided to the heart chambers through the vasculature in order to deliver energy to destroy faulty electrical pathways in the heart. The effectiveness of this treatment is dependent on the accuracy of positioning the Catheter tip at the target location and also on maintaining contact with the target while the heart is beating. Therefore, it is desirable to perform hybrid force/position control of the Catheter tip. We have studied the problem of modeling the distal part of a Steerable Catheter using beam theory and have developed and validated a static force-deflection model through extensive experiments. It is shown that the model can estimate the shape of the bending section of a Catheter using force information and without requiring extensive knowledge of the Catheter's internal structure.

Nate Lombard Poirot - One of the best experts on this subject based on the ideXlab platform.

  • IROS - Analysis of Dynamic Response of an MRI-Guided Magnetically-Actuated Steerable Catheter System
    Proceedings of the ... IEEE RSJ International Conference on Intelligent Robots and Systems. IEEE RSJ International Conference on Intelligent Robots an, 2020
    Co-Authors: Erdem E. Tuna, Nate Lombard Poirot, Russell C. Jackson, Mac Russell, M. Cenk Cavusoglu
    Abstract:

    This paper presents a free-space open-loop dynamic response analysis for an MRI -guided magnetically-actuated Steerable intra-vascular Catheter system. The Catheter tip is embedded with a set of current carrying micro-coils. The Catheter is directly actuated via the magnetic torques generated on these coils by the magnetic field of the magnetic resonance imaging (MRI)scanner. The relationship between the input current commands and Catheter tip deflection angle presents an inherent nonlinearity in the proposed Catheter system. The system nonlinearity is analyzed by utilizing a pendulum model. The pendulum model is used to describe the system nonlinearity and to perform an approximate input-output linearization. Then, a black-box system identification approach is performed for frequency response analysis of the linearized dynamics. The optimal estimated model is reduced by observing the modes and considering the Nyquist frequency of the camera system that is used to track the Catheter motion. The reduced model is experimentally validated with $3D$ open-loop Cartesian free-space trajectories. This study paves the way for effective and accurate free-space closed-loop control of the robotic Catheter with real-time feedback from MRI guidance in subsequent research.

  • Analysis of Dynamic Response of an MRI-Guided Magnetically-Actuated Steerable Catheter System
    2018 IEEE RSJ International Conference on Intelligent Robots and Systems (IROS), 2018
    Co-Authors: Erdem E. Tuna, Nate Lombard Poirot, Russell C. Jackson, Mac Russell, Cenk M. Çavuşoğlu
    Abstract:

    This paper presents a free-space open-loop dynamic response analysis for an MRI -guided magnetically-actuated Steerable intra-vascular Catheter system. The Catheter tip is embedded with a set of current carrying micro-coils. The Catheter is directly actuated via the magnetic torques generated on these coils by the magnetic field of the magnetic resonance imaging (MRI)scanner. The relationship between the input current commands and Catheter tip deflection angle presents an inherent nonlinearity in the proposed Catheter system. The system nonlinearity is analyzed by utilizing a pendulum model. The pendulum model is used to describe the system nonlinearity and to perform an approximate input-output linearization. Then, a black-box system identification approach is performed for frequency response analysis of the linearized dynamics. The optimal estimated model is reduced by observing the modes and considering the Nyquist frequency of the camera system that is used to track the Catheter motion. The reduced model is experimentally validated with 3D open-loop Cartesian free-space trajectories. This study paves the way for effective and accurate free-space closed-loop control of the robotic Catheter with real-time feedback from MRI guidance in subsequent research.

  • Design of a Magnetic Resonance Imaging Guided Magnetically Actuated Steerable Catheter.
    Journal of Medical Devices-transactions of The Asme, 2017
    Co-Authors: Nate Lombard Poirot, Tipakorn Greigarn, M. Cenk Cavusoglu
    Abstract:

    : This paper presents design optimization of a magnetic resonance imaging (MRI) actuated Steerable Catheter for atrial fibrillation ablation in the left atrium. The Catheter prototype, built over polymer tubing, is embedded with current-carrying electromagnetic coils. The prototype can be deflected to a desired location by controlling the currents passing through the coils. The design objective is to develop a prototype that can successfully accomplish the ablation task. To complete the tasks, the Catheter needs to be capable of reaching a set of desired targets selected by a physician on the chamber and keeping a stable contact with the chamber surface. The design process is based on the maximization of the steering performance of the Catheter by evaluating its workspace in free space. The selected design is validated by performing a simulation of an ablation intervention on a virtual model of the left atrium with a real atrium geometry. This validation shows that the prototype can reach every target required by the ablation intervention and provide an appropriate contact force against the chamber.

  • Iterative Jacobian-Based Inverse Kinematics and Open-Loop Control of an MRI-Guided Magnetically Actuated Steerable Catheter System
    IEEE ASME Transactions on Mechatronics, 2017
    Co-Authors: Russell Jackson, Nate Lombard Poirot, Dominique Franson, Nicole Seiberlich, Mark A. Griswold, Reinhardt Kam Criss, Cenk M. Çavuşoğlu
    Abstract:

    This paper presents an iterative Jacobian-based inverse kinematics method for a magnetic resonance imaging (MRI) guided magnetically actuated Steerable intravascular Catheter system. The Catheter is directly actuated by magnetic torques generated on a set of current-carrying microcoils embedded on the Catheter tip by the magnetic field of the MRI scanner. The Jacobian matrix relating changes of the currents through the coils to changes of the tip position is derived using a three-dimensional kinematic model of the Catheter deflection. The inverse kinematics is numerically computed by iteratively applying the inverse of the Jacobian matrix. The damped least square method is implemented to avoid numerical instability issues that exist during the computation of the inverse of the Jacobian matrix. The performance of the proposed inverse kinematics approach is validated using a prototype of the robotic Catheter by comparing the actual trajectories of the Catheter tip obtained via open-loop control with the desired trajectories. The results of reproducibility and accuracy evaluations demonstrate that the proposed Jacobian-based inverse kinematics method can be used to actuate the Catheter in an open loop to successfully perform complex ablation trajectories required in atrial fibrillation ablation procedures. This study paves the way for effective and accurate closed-loop control of the robotic Catheter with real-time feedback from MRI guidance in subsequent research.

  • Modeling and validation of the three-dimensional deflection of an MRI-compatible magnetically actuated Steerable Catheter
    IEEE Transactions on Biomedical Engineering, 2016
    Co-Authors: Taoming Liu, Nate Lombard Poirot, Dominique Franson, Nicole Seiberlich, Mark A. Griswold, M. Cenk Çavuşoĝlu
    Abstract:

    OBJECTIVE: This paper presents the 3-D kinematic modeling of a novel Steerable robotic ablation Catheter system. The Catheter, embedded with a set of current-carrying microcoils, is actuated by the magnetic forces generated by the magnetic field of the magnetic resonance imaging (MRI) scanner. METHODS: This paper develops a 3-D model of the MRI-actuated Steerable Catheter system by using finite differences approach. For each finite segment, a quasi-static torque-deflection equilibrium equation is calculated using beam theory. By using the deflection displacements and torsion angles, the kinematic model of the Catheter system is derived. RESULTS: The proposed models are validated by comparing the simulation results of the proposed model with the experimental results of a hardware prototype of the Catheter design. The maximum tip deflection error is 4.70 mm and the maximum root-mean-square error of the shape estimation is 3.48 mm. CONCLUSION: The results demonstrate that the proposed model can successfully estimate the deflection motion of the Catheter. SIGNIFICANCE: The presented 3-D deflection model of the magnetically controlled Catheter design paves the way to efficient control of the robotic Catheter for the treatment of atrial fibrillation.

Gijs Van Soest - One of the best experts on this subject based on the ideXlab platform.

  • Volumetric ultrasound image reconstruction from a single-element forward-looking intracardiac Steerable Catheter using 3D adaptive normalized convolution
    2018 IEEE International Ultrasonics Symposium (IUS), 2018
    Co-Authors: Jovana Janjic, Paul Breedveld, Frits Mastik, Merel D. Leistikow, Johan G. Bosch, Antonius F. W. Van Der Steen, Gijs Van Soest
    Abstract:

    In interventional cardiology Catheters are routinely used to access and treat defects and diseases in the heart. Image guidance using forward-looking (FL)ultrasound transducers at the tip of the Catheter could give the physician visual feedback during complex procedures such as valve replacement or transseptal puncture. In this work, we investigate FL 3D imaging by integrating a 7 MHz single-element ultrasound transducer at the tip of a novel multi-Steerable intracardiac Catheter together with an optical shape sensing fiber (OSS). We tested the imaging capability of the integrated device on an ex-vivo pig heart. By acquiring ultrasound A-lines at different locations while steering the Catheter tip, a sparse 3D image is obtained. To reconstruct a volumetric image from the sparse data we implemented an adaptive Normalized Convolution (NC)algorithm were the dimension, orientation and angle of the 3D anisotropic kernel changes dynamically according to the scanning path. We acquired ultrasound A-lines of the tricuspid valve and we computed the 3D image using NC with both an isotropic kernel and an anisotropic kernel. We successfully interpolated the sparse data obtaining 3D volumes of the heart. By using an anisotropic kernel better 3D reconstruction is achieved with higher detail information compared to the reconstruction obtained using an isotropic kernel. This pilot experiment demonstrates the potential of FL image guidance during intracardiac procedures using a single-element transducer integrated in a Steerable Catheter with an OSS fiber.

  • Sparse Ultrasound Image Reconstruction From a Shape-Sensing Single-Element Forward-Looking Catheter
    IEEE Transactions on Biomedical Engineering, 2018
    Co-Authors: Jovana Janjic, Frits Mastik, Merel D. Leistikow, Johan G. Bosch, Antonius F. W. Van Der Steen, Geert Springeling, Gijs Van Soest
    Abstract:

    Objective: Minimally invasive procedures, such as intravascular and intracardiac interventions, may benefit from guidance with forward-looking (FL) ultrasound. In this work, we investigate FL ultrasound imaging using a single-element transducer integrated in a Steerable Catheter, together with an optical shape sensing (OSS) system. Methods: We tested the feasibility of the proposed device by imaging the surface of a tissue-mimicking (TM) phantom and an ex vivo human carotid plaque. While manually steering the Catheter tip, ultrasound A-lines are acquired at 60 Hz together with the Catheter shape from the OSS system, resulting in a two-dimensional sparse and irregularly sampled data set. We implemented an adaptive Normalized Convolution (NC) algorithm to interpolate the sparse data set by applying an anisotropic Gaussian kernel that is rotated according to the local direction of the Catheter scanning pattern. To choose the Gaussian widths tangential (σt) and normal (σn) to the scanning pattern, an exhaustive search was implemented based on RMSE computation on simulated data. Results: Simulations showed that the sparse data set contains only 5% of the original information. The chosen widths, σn = 250 μm and σt = 100 μm, are used to successfully reconstruct the surface of the phantom with a contrast ratio of 0.9. The same kernel is applied successfully to the carotid plaque data. Conclusion: The proposed approach enables FL imaging with a single ultrasound element, mounted on a Steerable device. Significance: This principle may find application in a variety of image-guided interventions, such as chronic total occlusion (CTO) recanalization.

  • 3D Imaging with a single-element forward-looking Steerable IVUS Catheter: initial testing
    2016 IEEE International Ultrasonics Symposium (IUS), 2016
    Co-Authors: Jovana Janjic, Frits Mastik, Merel D. Leistikow, Johan G. Bosch, Antonius F. W. Van Der Steen, Aimée Sakes, Nico De Jong, Gijs Van Soest
    Abstract:

    In the field of vascular interventions, forward-looking intravascular ultrasound transducers (FL-IVUS) are needed for better visualization of complex lesions, such as chronic total occlusions. In this work, we propose a strategy for 3D imaging using a single-element transducer and an optical shape sensing fiber (OSS) in a Steerable Catheter tip. We evaluate the performance of the integrated device by imaging a six-wire phantom submerged in water. While steering the Catheter tip across the wires, ultrasound and OSS data are acquired continuously. We combine the distance information obtained from the ultrasound data with the tip position and direction obtained from the OSS data to reconstruct the wires in 3D space. We quantify the accuracy of the imaging technique by the distance between the wires, and find a mean relative error of 36%. We discuss how this estimate can be further improved by modifications of the probe. This proof-of-principle test demonstrates the feasibility of FL-IVUS imaging using a single-element transducer integrated in a Steerable Catheter together with an OSS fiber.

Kyung Hyun Choi - One of the best experts on this subject based on the ideXlab platform.

  • Omni Directional Multimaterial Soft Cylindrical Actuator and Its Application as a Steerable Catheter
    Soft Robotics, 2017
    Co-Authors: Jahan Zeb Gul, Young Jin Yang, Kim Young-suk, Kyung Hyun Choi
    Abstract:

    Soft actuators with complex range of motion lead to strong interest in applying devices like biomedical Catheters and Steerable soft pipe inspectors. To facilitate the use of soft actuators in devices where controlled, complex, precise, and fast motion is required, a structurally controlled Omni directional soft cylindrical actuator is fabricated in a modular way using multilayer composite of polylactic acid based conductive Graphene, shape memory polymer, shape memory alloy, and polyurethane. Multiple fabrication techniques are discussed step by step that mainly include fused deposition modeling based 3D printing, dip coating, and UV curing. A mathe-matical control model is used to generate patterned electrical signals for the Omni directional deformations. Characterizations like structural control, bending, recovery, path, and thermal effect are carried out with and without load (10 g) to verify the new cylindrical design concept. Finally, the application of Omni directional actuator as a Steerable Catheter is explored by fabricating a scaled version of carotid artery through 3D printing using a semitransparent material.