The Experts below are selected from a list of 78510 Experts worldwide ranked by ideXlab platform
Elhussein Elbadry Mahmoud - One of the best experts on this subject based on the ideXlab platform.
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cell Magnetic targeting system for repair of severe chronic osteochondral defect in a rabbit model
Cell Transplantation, 2016Co-Authors: Nobuo Adachi, Goki Kamei, Ryo Shimizu, Naosuke Kamei, Elhussein Elbadry Mahmoud, Yohei Harada, N A Misk, Mitsuo OchiAbstract:The aim of this study was to investigate a cell delivery system for repair of severe chronic osteochondral defects using Magnetically labeled mesenchymal stem cells (m-MSCs), with the aid of an external Magnetic Device, through the accumulation of a small number of m-MSCs into a desired area and to detect the suitable number of autologous m-MSCs needed for repair of the defect. Twenty-six male Japanese white rabbits aged 6 months were used. An osteochondral defect was created bilaterally at the weight-bearing surface of the medial femoral condyle of the rabbits' knees (3 mm diameter; 4 mm depth). At 4 weeks after creation of the defect, autogenic transplantation of the m-MSCs into the defect area was performed, followed by 10-min exposure to an external Magnetic Device, where animals were divided into four groups: high (1 × 10(6) m-MSCs), medium (2 × 10(5) m-MSCs), low (4 × 10(4) m-MSCs), and control (PBS injection). At 4 and 12 weeks posttransplantation of m-MSCs, repaired tissue was assessed histologically using the Fortier score with toluidine blue staining. Transplantation of a low number of m-MSCs was not enough to improve osteogenesis and chondrogenesis, but the medium and high groups improved repair of the chronic defect with chondrogenic tissues and showed histologically significantly better results than the control and low groups. The use of a Magnetic targeting system for delivering m-MSCs has the potential to overcome the clinical hurdles for repair of the severe chronic osteochondral defect. Furthermore, this system is predicted to produce good clinical outcomes for humans, not only to repair osteochondral defects but also to repair a variety of damaged tissues.
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cell Magnetic targeting system for repair of severe chronic osteochondral defect in a rabbit model
Cell Transplantation, 2016Co-Authors: Nobuo Adachi, Goki Kamei, Ryo Shimizu, Naosuke Kamei, Elhussein Elbadry Mahmoud, Yohei Harada, N A Misk, Mitsuo OchiAbstract:The aim of this study was to investigate a cell delivery system for repair of severe chronic osteochondral defects using Magnetically labeled mesenchymal stem cells (m-MSCs), with the aid of an external Magnetic Device, through the accumulation of a small number of m-MSCs into a desired area and to detect the suitable number of autologous m-MSCs needed for repair of the defect. Twenty-six male Japanese white rabbits aged 6 months were used. An osteochondral defect was created bilaterally at the weight-bearing surface of the medial femoral condyle of the rabbits' knees (3 mm diameter; 4 mm depth). At 4 weeks after creation of the defect, autogenic transplantation of the m-MSCs into the defect area was performed, followed by 10-min exposure to an external Magnetic Device, where animals were divided into four groups: high (1 × 106 m-MSCs), medium (2 × 105 m-MSCs), low (4 × 104 m-MSCs), and control (PBS injection). At 4 and 12 weeks posttransplantation of m-MSCs, repaired tissue was assessed histologically us...
Jake J Abbott - One of the best experts on this subject based on the ideXlab platform.
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the spherical actuator magnet manipulator a permanent magnet robotic end effector
IEEE Transactions on Robotics, 2017Co-Authors: Samuel E Wright, Arthur W Mahoney, Katie M Popek, Jake J AbbottAbstract:A variety of Magnetic Devices can be manipulated remotely using a single permanent “actuator” magnet positioned in space by a robotic manipulator. This paper describes the spherical-actuator-magnet manipulator (SAMM), which is designed to replace or augment the singularity-prone spherical wrist used by prior permanent-magnet manipulation systems. The SAMM uses three omniwheels to enable holonomic control of the heading of its magnet's dipole and to enable its magnet to be rotated continuously about any axis of rotation. The SAMM performs closed-loop control of its dipole's heading using field measurements obtained from Hall-effect sensors as feedback, combined with modeled dynamics, using an extended Kalman filter. We describe the operation and construction of the SAMM, develop and characterize controllers for the SAMM's spherical magnet, and demonstrate remote actuation of an untethered Magnetic Device in a lumen using the SAMM.
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five degree of freedom manipulation of an untethered Magnetic Device in fluid using a single permanent magnet with application in stomach capsule endoscopy
The International Journal of Robotics Research, 2016Co-Authors: Arthur W Mahoney, Jake J AbbottAbstract:This paper demonstrates Magnetic three-degree-of-freedom 3-DOF closed-loop position and 2-DOF open-loop orientation control of a mockup Magnetic capsule endoscope in fluid with a single permanent magnet positioned by a commercial 6-DOF robotic manipulator, using feedback of only the 3-DOF capsule position measured by a localization system, with application in capsule endoscopy of a fluid-distended stomach. We analyze the kinematics of Magnetic manipulation using a single permanent magnet as the end-effector of a serial-link robot manipulator, and we formulate a control method that enables the capsule's position and direction to be controlled when the robot manipulator is not in a kinematic singularity, and that sacrifices control over the capsule's direction to maintain control over the capsule's position when the manipulator enters a singularity. We demonstrate the method's robustness to a reduced control rate of 25 Hz, reduced localization rates down to 30 Hz, deviation in the applied Magnetic field from that expected, and the presence of manipulator singularities. Five-DOF manipulation of an untethered Magnetic Device has been previously demonstrated by electroMagnetic systems only.
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managing Magnetic force applied to a Magnetic Device by a rotating dipole field
Applied Physics Letters, 2011Co-Authors: Arthur W Mahoney, Jake J AbbottAbstract:We demonstrate that the attractive Magnetic force acting on a rotating Magnetic Device (e.g., a Magnetic microrobot), actuated using a rotating magnet dipole, can be converted into a lateral force by rotating the actuator dipole according to a specific open-loop trajectory. Results show rotating Magnetic Devices can be rolled and simultaneously pushed along a surface by the lateral force, resulting in significant increase in velocity. We also demonstrate that the lateral force magnitude can be sufficient to levitate the Magnetic Device. The results apply to rotating Magnetic Devices of any size provided inertia has a negligible contribution to its dynamics.
Mitsuo Ochi - One of the best experts on this subject based on the ideXlab platform.
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cell Magnetic targeting system for repair of severe chronic osteochondral defect in a rabbit model
Cell Transplantation, 2016Co-Authors: Nobuo Adachi, Goki Kamei, Ryo Shimizu, Naosuke Kamei, Elhussein Elbadry Mahmoud, Yohei Harada, N A Misk, Mitsuo OchiAbstract:The aim of this study was to investigate a cell delivery system for repair of severe chronic osteochondral defects using Magnetically labeled mesenchymal stem cells (m-MSCs), with the aid of an external Magnetic Device, through the accumulation of a small number of m-MSCs into a desired area and to detect the suitable number of autologous m-MSCs needed for repair of the defect. Twenty-six male Japanese white rabbits aged 6 months were used. An osteochondral defect was created bilaterally at the weight-bearing surface of the medial femoral condyle of the rabbits' knees (3 mm diameter; 4 mm depth). At 4 weeks after creation of the defect, autogenic transplantation of the m-MSCs into the defect area was performed, followed by 10-min exposure to an external Magnetic Device, where animals were divided into four groups: high (1 × 10(6) m-MSCs), medium (2 × 10(5) m-MSCs), low (4 × 10(4) m-MSCs), and control (PBS injection). At 4 and 12 weeks posttransplantation of m-MSCs, repaired tissue was assessed histologically using the Fortier score with toluidine blue staining. Transplantation of a low number of m-MSCs was not enough to improve osteogenesis and chondrogenesis, but the medium and high groups improved repair of the chronic defect with chondrogenic tissues and showed histologically significantly better results than the control and low groups. The use of a Magnetic targeting system for delivering m-MSCs has the potential to overcome the clinical hurdles for repair of the severe chronic osteochondral defect. Furthermore, this system is predicted to produce good clinical outcomes for humans, not only to repair osteochondral defects but also to repair a variety of damaged tissues.
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cell Magnetic targeting system for repair of severe chronic osteochondral defect in a rabbit model
Cell Transplantation, 2016Co-Authors: Nobuo Adachi, Goki Kamei, Ryo Shimizu, Naosuke Kamei, Elhussein Elbadry Mahmoud, Yohei Harada, N A Misk, Mitsuo OchiAbstract:The aim of this study was to investigate a cell delivery system for repair of severe chronic osteochondral defects using Magnetically labeled mesenchymal stem cells (m-MSCs), with the aid of an external Magnetic Device, through the accumulation of a small number of m-MSCs into a desired area and to detect the suitable number of autologous m-MSCs needed for repair of the defect. Twenty-six male Japanese white rabbits aged 6 months were used. An osteochondral defect was created bilaterally at the weight-bearing surface of the medial femoral condyle of the rabbits' knees (3 mm diameter; 4 mm depth). At 4 weeks after creation of the defect, autogenic transplantation of the m-MSCs into the defect area was performed, followed by 10-min exposure to an external Magnetic Device, where animals were divided into four groups: high (1 × 106 m-MSCs), medium (2 × 105 m-MSCs), low (4 × 104 m-MSCs), and control (PBS injection). At 4 and 12 weeks posttransplantation of m-MSCs, repaired tissue was assessed histologically us...
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large animal models in experimental knee sports surgery focus on clinical translation
Journal of Experimental Orthopaedics, 2015Co-Authors: Henning Madry, Mitsuo Ochi, Magali Cucchiarini, Dietrich Pape, R SeilAbstract:Large animal models play a crucial role in sports surgery of the knee, as they are critical for the exploration of new experimental strategies and the clinical translation of novel techniques. The purpose of this contribution is to provide critical aspects of relevant animal models in this field, with a focus on paediatric anterior cruciate ligament (ACL) reconstruction, high tibial osteotomy, and articular cartilage repair. Although there is no single large animal model strictly replicating the human knee joint, the sheep stifle joint shares strong similarities. Studies in large animal models of paediatric ACL reconstruction identified specific risk factors associated with the different surgical techniques. The sheep model of high tibial osteotomy is a powerful new tool to advance the understanding of the effect of axial alignment on the lower extremity on specific issues of the knee joint. Large animal models of both focal chondral and osteochondral defects and of osteoarthritis have brought new findings about the mechanisms of cartilage repair and treatment options. The clinical application of a Magnetic Device for targeted cell delivery serves as a suitable example of how data from such animal models are directly translated into in clinical cartilage repair. As novel insights from studies in these translational models will advance the basic science, close cooperation in this important field of clinical translation will improve current reconstructive surgical options and open novel avenues for regenerative therapies of musculoskeletal disorders.
Hamid A. Toliyat - One of the best experts on this subject based on the ideXlab platform.
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Control of an Electric Machine Integrated With the Trans-Rotary Magnetic Gear in a Motor Drive Train
IEEE Transactions on Industry Applications, 2017Co-Authors: Siavash Pakdelian, Morteza Moosavi, H. A. Hussain, Hamid A. ToliyatAbstract:This paper studies the dynamic performance of an electric machine integrated with the transrotary Magnetic gear (MITROMAG) in a motoring mode of operation. MITROMAG is formed by mechanically coupling a rotary electric machine to the rotor of a trans-rotary Magnetic gear (TROMAG). TROMAG is a Magnetic Device that, through Magnetic fields, converts a low-torque, high-speed rotation of its rotor to a high-force, low-speed linear motion of its translator, and vice versa. In a motoring mode of operation, the rotor of the TROMAG is driven by a rotary electric motor, and as a result, its translator drives a reciprocating load. A nonlinear dynamic model is developed for the TROMAG. Oscillation tests are presented as examples of how the model can be used to predict the dynamic behavior of the Device. The model is then linearized to derive system transfer functions and study the dynamic response of the MITROMAG to speed commands. Experimental results confirm the analysis.
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Magnetic Design Aspects of the Trans-Rotary Magnetic Gear
IEEE Transactions on Energy Conversion, 2015Co-Authors: Siavash Pakdelian, Nicolas Walter Frank, Hamid A. ToliyatAbstract:This paper studies several Magnetic design aspects of the trans-rotary Magnetic gear (TROMAG). The TROMAG is a Magnetic Device that converts linear motion to rotation, and vice versa, through Magnetic field while doing a gearing action. This means that a high-force, low-speed translation can be converted to a high-speed low-torque rotation. Once coupled with a conventional rotary machine, the resultant system may be used as a compact electromechanical motion system for high-force linear-motion applications, such as wave energy conversion. The paper investigates the Magnetic design of the TROMAG by means of either two-dimensional (2-D) or three-dimensional (3-D) finite element analysis (FEA), or an accurate analytical model. The impact of nonideal discretized helix and dimensions of magnets and air gap are investigated, as well as scaling rules of the TROMAG and the possibility of demagnetization. Experimental results obtained from a lab prototype are also presented to verify the concept and analysis.
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Principles of the trans-rotary Magnetic gear
IEEE Transactions on Magnetics, 2013Co-Authors: Siavash Pakdelian, Nicolas Walter Frank, Hamid A. ToliyatAbstract:This paper introduces the concept of the trans-rotary Magnetic gear (TROMAG). The TROMAG is a Magnetic Device consisting of a rotor and a translator with an air gap in between, capable of converting linear motion to rotation, and vice versa, and doing the gearing action at the same time. Although its structure suggests that the TROMAG is simply the Magnetic dual to the mechanical lead-screw, the authors show that the concept could also be derived from the elementary magnet arrays. The paper tries to establish an analogy between the TROMAG and the ordinary electrical machines with respect to the number of poles and the stack length, thus providing a deeper insight into the Device operation. Three-dimensional (3-D) finite element analysis (FEA) is deployed to obtain the torque and force characteristics. Furthermore, it is shown that in addition to the permanent magnet (PM) TROMAG, developing the reluctance and the induction TROMAG is possible as well, but at a lower force density.
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Trans-rotary Magnetic gear for wave energy applicaion
IEEE Power and Energy Society General Meeting, 2012Co-Authors: Siavash Pakdelian, Hamid A. ToliyatAbstract:This paper proposes a new Device named Trans-Rotary Magnetic Gear (TROMAG) for use in Wave Energy Conversion (WEC) systems. With very low speed and high force being the main characteristics of the linear motion delivered by several types of WEC systems, the required linear machines to resist such motion have so far turned out to be bulky and cumbersome. To enable deployment of tried-and-true low torque rotary machines, it is necessary to develop a Magnetic Device to convert such motion to high speed, low torque rotation in a reliable and efficient way. The TROMAG does the conversion through a Magnetic field and with high force density. Structure of the Device, as well as its main operating characteristics is presented here. Results are obtained by Three-Dimensional (3D) Finite Element Analysis (FEA).
Arthur W Mahoney - One of the best experts on this subject based on the ideXlab platform.
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the spherical actuator magnet manipulator a permanent magnet robotic end effector
IEEE Transactions on Robotics, 2017Co-Authors: Samuel E Wright, Arthur W Mahoney, Katie M Popek, Jake J AbbottAbstract:A variety of Magnetic Devices can be manipulated remotely using a single permanent “actuator” magnet positioned in space by a robotic manipulator. This paper describes the spherical-actuator-magnet manipulator (SAMM), which is designed to replace or augment the singularity-prone spherical wrist used by prior permanent-magnet manipulation systems. The SAMM uses three omniwheels to enable holonomic control of the heading of its magnet's dipole and to enable its magnet to be rotated continuously about any axis of rotation. The SAMM performs closed-loop control of its dipole's heading using field measurements obtained from Hall-effect sensors as feedback, combined with modeled dynamics, using an extended Kalman filter. We describe the operation and construction of the SAMM, develop and characterize controllers for the SAMM's spherical magnet, and demonstrate remote actuation of an untethered Magnetic Device in a lumen using the SAMM.
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five degree of freedom manipulation of an untethered Magnetic Device in fluid using a single permanent magnet with application in stomach capsule endoscopy
The International Journal of Robotics Research, 2016Co-Authors: Arthur W Mahoney, Jake J AbbottAbstract:This paper demonstrates Magnetic three-degree-of-freedom 3-DOF closed-loop position and 2-DOF open-loop orientation control of a mockup Magnetic capsule endoscope in fluid with a single permanent magnet positioned by a commercial 6-DOF robotic manipulator, using feedback of only the 3-DOF capsule position measured by a localization system, with application in capsule endoscopy of a fluid-distended stomach. We analyze the kinematics of Magnetic manipulation using a single permanent magnet as the end-effector of a serial-link robot manipulator, and we formulate a control method that enables the capsule's position and direction to be controlled when the robot manipulator is not in a kinematic singularity, and that sacrifices control over the capsule's direction to maintain control over the capsule's position when the manipulator enters a singularity. We demonstrate the method's robustness to a reduced control rate of 25 Hz, reduced localization rates down to 30 Hz, deviation in the applied Magnetic field from that expected, and the presence of manipulator singularities. Five-DOF manipulation of an untethered Magnetic Device has been previously demonstrated by electroMagnetic systems only.
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managing Magnetic force applied to a Magnetic Device by a rotating dipole field
Applied Physics Letters, 2011Co-Authors: Arthur W Mahoney, Jake J AbbottAbstract:We demonstrate that the attractive Magnetic force acting on a rotating Magnetic Device (e.g., a Magnetic microrobot), actuated using a rotating magnet dipole, can be converted into a lateral force by rotating the actuator dipole according to a specific open-loop trajectory. Results show rotating Magnetic Devices can be rolled and simultaneously pushed along a surface by the lateral force, resulting in significant increase in velocity. We also demonstrate that the lateral force magnitude can be sufficient to levitate the Magnetic Device. The results apply to rotating Magnetic Devices of any size provided inertia has a negligible contribution to its dynamics.
