During the past several years, there have been increasing research activities in the field of stability analysis and switching stabilization for switched systems. This paper aims to briefly survey recent results in this field. First, the stability analysis for switched systems is reviewed. We focus on the stability analysis for switched linear systems under arbitrary switching, and we highlight necessary and sufficient conditions for asymptotic stability. After a brief review of the stability analysis under restricted switching and the multiple Lyapunov function theory, the switching stabilization problem is studied, and a variety of switching stabilization methods found in the literature are outlined. Then the switching stabilizability problem is investigated, that is under what condition it is possible to stabilize a switched system by properly designing switching control laws. Note that the switching stabilizability problem has been one of the most elusive problems in the switched systems literature. A necessary and sufficient condition for asymptotic stabilizability of switched linear systems is described here.

Stability and Stabilizability of Switched Linear Systems: A Survey of Recent Results

A surgical stapling device particularly suited for endoscopic procedures is described The device includes a handle assembly and an elongated body extending distally from the handle assembly The distal end of the elongated body is adapted to engage a disposable loading unit A control rod having a proximal end operatively connected to the handle assembly includes a distal end extending through the elongated body A control rod locking member is provided to prevent movement of the control rod until the disposable loading unit is fully secured to the elongated body of the stapling device

Surgical Stapling Apparatus

This chapter introduces the finite element method (FEM) as a tool for solution of classical electromagnetic problems. Although we discuss the main points in the application of the finite element method to electromagnetic design, including formulation and implementation, those who seek deeper understanding of the finite element method should consult some of the works listed in the bibliography section.

Introduction to the Finite Element Method

Newness and distinctiveness is claimed in the features of ornamentation as shown inside the broken line circle in the accompanying representation.

Display screen or portion thereof with graphical user interface

A surgical instrument can comprise a channel configured to support a staple cartridge and, in addition, an anvil pivotable between open and closed positions relative to the channel. The surgical instrument can further comprise a cutting member configured to incise tissue positioned captured between the staple cartridge and the anvil and, in addition, means for stopping the cutting member prior to a distal end datum, wherein the distal end datum can be defined by the distal-most staple cavity in the staple cartridge. In such embodiments, the incision within the tissue may not extend beyond the portion of the tissue that has been stapled.

Surgical stapling instrument with an articulatable end effector

Configurations are described for conducting minimally invasive medical interventions utilizing elongate robotically controlled instruments and assemblies thereof. In one embodiment, a junction sheath may be utilized to facilitate surgical triangulation of two interventional instrument assemblies, while also directing them to the surgical theater through a minimal single wound or surgical port. One or more instrument drivers, and one or more master input devices comprising an operator workstation, may be utilized to independently and simultaneously control multiple degrees of freedom pertinent to each instrument comprising one or more instrument assembly.

Multiple flexible and steerable elongate instruments for minimally invasive operations

Haptic rendering allows users to "feel" virtual objects in a simulated environment. We survey current haptic systems and discuss some basic haptic-rendering algorithms. In the past decade we've seen an enormous increase in interest in the science of haptics. Haptics broadly refers to touch interactions (physical contact) that occur for the purpose of perception or manipulation of objects. These interactions can be between a human hand and a real object; a robot end-effector and a real object; a human hand and a simulated object (via haptic interface devices); or a variety of combinations of human and machine interactions with real, remote, or virtual objects. Rendering refers to the process by which desired sensory stimuli are imposed on the user to convey information about a virtual haptic object.

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Haptic rendering: introductory concepts

Rendering stiff virtual objects remains a core challenge in the field of haptics. A study of this problem is presented, which relates the maximum achievable object stiffness to the elements of the control loop. In particular, we examine how the sampling rate, quantization, computational delay, and amplifier dynamics interact with the inertia, natural viscous, and Coulomb damping of the haptic device. Nonlinear effects create distinct stability regions, and many common devices operate stably, yet in violation of passivity criteria. An energy-based approach provides theoretical insights, supported by simulations, experimental data, and a describing function analysis. The presented results subsume previously known stability conditions

Stability of Haptic Rendering: Discretization, Quantization, Time Delay, and Coulomb Effects

This paper explores the use of haptic feedback to teach an abstract motor skill that requires recalling a sequence of forces. Participants are guided along a trajectory and are asked to learn a sequence of one-dimensional forces via three paradigms: haptic training, visual training, or combined visuohaptic training. The extent of learning is measured by accuracy of force recall. We find that recall following visuohaptic training is significantly more accurate than recall following visual or haptic training alone, although haptic training alone is inferior to visual training alone. This suggests that in conjunction with visual feedback, haptic training may be an effective tool for teaching sensorimotor skills that have a force-sensitive component to them, such as surgery. We also present a dynamic programming paradigm to align and compare spatiotemporal haptic trajectories

/pdf/haptic-feedback-enhances-force-skill-learning-4xlmxeb3vm.pdf

Haptic Feedback Enhances Force Skill Learning

A robotic surgical system includes an instrument driver and an instrument assembly operatively coupled to the instrument driver such that mechanisms of the instrument driver operate or control movement, operation, or both, of components of the instrument assembly. The instrument assembly components include an elongate flexible guide instrument, an optical light source, a camera and a working tool, wherein the light source, camera, and working tool are carried in one or more lumens of the guide instrument. An operator control station is operatively coupled to the instrument driver via a remote communication link. The instrument assembly further includes an inflatable visualization balloon carried on a distal end portion of the guide instrument, the light source and camera having distal ends located within an interior of the balloon, the balloon comprising a lumen extending from the guide instrument to a distal facing wall of the balloon, such that the working instrument may extend from a respective lumen of the guide instrument through the balloon lumen to contact body tissue when the distal end of the guide instrument is positioned in an interior body region.

Federico Barbagli

Papers

Multiple flexible and steerable elongate instruments for minimally invasive operations

Haptic rendering: introductory concepts

Stability of Haptic Rendering: Discretization, Quantization, Time Delay, and Coulomb Effects

Haptic Feedback Enhances Force Skill Learning

Systems and methods for performing minimally invasive procedures