Background The purpose of this study was to evaluate electrode temperatures obtained using a radiofrequency ablation system that incorporates closed loop feedback control to achieve preset target electrode temperatures and to determine if closed loop temperature control results in a lower incidence of developing a coagulum. Methods and Results Two hundred seventy patients underwent catheter abl...

In atomic force microscopy (AFM) the imaging speed is strongly limited by the bandwidth of the feedback loop that controls the interaction between the measurement tip and the sample. A significant increase in closed-loop bandwidth can be achieved by combining a long-range, low-bandwidth actuator with a short-range, high-bandwidth actuator, forming a dual actuated system. This contribution discu...

Control input-output contact systems are the representation of open irreversible Thermodynamic systems whose geometric structure is defined by Gibbs’ relation. These systems are called conservative if furthermore they leave invariant a particular Legendre submanifold defining their thermodynamic properties. In this paper we address the stabilization of controlled input-output contact systems. F...

A standard finite dimensional nonlinear control system is considered, along with a state constraint set S and a target set Σ. It is proven that open loop S-constrained controllability to Σ implies closed loop Sconstrained controllability to the closed δ-neighborhood of Σ, for any specified δ > 0. When the target set Σ satisfies a small time S-constrained controllability condition, conclusions o...

U NDER the assumptions that a plant is completely deterministic and perfectly modeled, either open-loop compensation or closed-loop compensation can be used to achieve a desired overall design. However, the assumptions of determinism and perfect modeling are never satisfied in practice. When these assumptions do not hold, feedback control systems can possess properties such as stability, sensit...

This work focuses on a broad class of nonlinear process systems subject to control actuator faults and disturbances and proposes a method for data-based fault detection and isolation that explicitly takes into account the design of the feedback control law. This method allows isolating specific faults in the closed-loop system; fault detection is done using a purely data-based approach and faul...

Involuntary force variability below 15 Hz arises from, and is influenced by, many factors including descending neural drive, proprioceptive feedback, and mechanical properties of muscles and tendons. However, their potential interactions that give rise to the well-structured spectrum of involuntary force variability are not well understood due to a lack of experimental techniques. Here, we inve...

We review a treatment modality for movement disorders by sensory feedback. The natural closed-loop sensory-motor feedback system is imitated by a wearable virtual reality apparatus, employing body-mounted inertial sensors and responding dynamically to the patient's own motion. Clinical trials have shown a significant gait improvement in patients with Parkinson's disease using the apparatus. In ...

This paper proposes a methodology for the computation of optimal locations of point control actuators for nonlinear feedback controllers in transport-reaction processes described by a broad class of quasi-linear parabolic partial differential equations (PDE). Initially, Galerkin’s method is employed to derive finite-dimensional approximations of the PDE system which are used for the synthesis o...

t In this paper the most general Hz control problem is considered. We derive necessary and sufficient conditions when the infimum is attained by state feedback. We do the same for the measurement feedback case where we derive necessary and sufficient conditions when the infimum is attained by proper dynamic compensators. We also investigate reduced-order compensators if some states are observab...