In Ultra high-field MRI scanners (3T and higher), parallel RF transmission techniques using multiple RF chains with multiple transmit elements are a promising approach to overcome the high-field MRI challenges in terms of inhomogeneity in the RF magnetic field and SAR. However, mutual coupling between the transmit array elements disturbs the desirable independent control of the RF waveforms for...

25 Humans are able to learn tool-handling tasks, such as carving, demonstrating 26 their competency to make movements in unstable environments with varied 27 directions. When faced with a single direction of instability, humans learn to 28 selectively co-contract their arm muscles tuning the mechanical stiffness of the 29 limb endpoint to stabilize movements. This study examines, for the first ...

Impedance control is a well-established framework to manage the interaction of the end effector of a robot manipulator with the environment. For the execution of six-degree-offreedom (DOF) tasks, both the end-effector position and orientation must be handled. The operational space control schemes typically utilize minimal representations of end-effector orientation; however, such representation...

Estimation of total body water by measuring bioelectrical impedance at a fixed frequency of 50 kHz is useful in assessing body composition in healthy populations. However, in cirrhosis, the distribution of total body water between the extracellular and intracellular compartments is of greater clinical importance. We report an evaluation of a new multiple-frequency bioelectrical-impedance analys...

In this paper, a new impedance function is proposed to achieve accurate force tracking under the presence of uncertainties in robot dynamics and environment models. The new impedance function is formulated on the basis of PID control of the force tracking error which compensates for the unknown environment stiiness and position. The robot dynamics uncertainties are compensated by a simple time-...

To increase the mobility of on-orbit robotic systems, Space Free-Flying Robots (SFFR) in which one or more manipulators are mounted on a thruster-equipped base, have been proposed. Unlike fixedbased manipulators, the robotic arms of SFFR are dynamically coupled with each other and the freeflying-base, hence the control problem becomes more challenging. In this paper, the Multiple Impedance Cont...

There are a large number of people with movement disorders who have difficulties doing their daily tasks independently. Much research has been devoted to the therapy of these people, and rehabilitation robots have been developed to assist with therapy. In robotic rehabilitation, since the human body is interacting with a mechanical device, safety issues in the design of appropriate control stra...

Radiofrequency catheter ablation of accessory pathways and the atrioventricular junction often requires multiple applications of energy. The inability to determine the effects of any given application on the underlying tissue may contribute to this problem. In the present study, impedance was monitored in 20 patients undergoing radiofrequency catheter ablation, and the relationship between an i...