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

Most of the signal processing that we will study in this course involves local operations on a signal, namely transforming the signal by applying linear combinations of values in the neighborhood of each sample point. You are familiar with such operations from Calculus, namely, taking derivatives and you are also familiar with this from optics namely blurring a signal. We will be looking at sampled signals only. Let's start with a few basic examples. Local difference Suppose we have a 1D image and we take the local difference of intensities, DI(x) = 1 2 (I(x + 1) − I(x − 1)) which give a discrete approximation to a partial derivative. (We compute this for each x in the image.) What is the effect of such a transformation? One key idea is that such a derivative would be useful for marking positions where the intensity changes. Such a change is called an edge. It is important to detect edges in images because they often mark locations at which object properties change. These can include changes in illumination along a surface due to a shadow boundary, or a material (pigment) change, or a change in depth as when one object ends and another begins. The computational problem of finding intensity edges in images is called edge detection. We could look for positions at which DI(x) has a large negative or positive value. Large positive values indicate an edge that goes from low to high intensity, and large negative values indicate an edge that goes from high to low intensity. Example Suppose the image consists of a single (slightly sloped) edge:

http://ieeexplore.ieee.org/iel5/5/31307/01456462.pdf

Linear systems

Wide bandgap semiconductors show superior material properties enabling potential power device operation at higher temperatures, voltages, and switching speeds than current Si technology. As a result, a new generation of power devices is being developed for power converter applications in which traditional Si power devices show limited operation. The use of these new power semiconductor devices will allow both an important improvement in the performance of existing power converters and the development of new power converters, accounting for an increase in the efficiency of the electric energy transformations and a more rational use of the electric energy. At present, SiC and GaN are the more promising semiconductor materials for these new power devices as a consequence of their outstanding properties, commercial availability of starting material, and maturity of their technological processes. This paper presents a review of recent progresses in the development of SiC- and GaN-based power semiconductor devices together with an overall view of the state of the art of this new device generation.

A Survey of Wide Bandgap Power Semiconductor Devices

Light-Emitting Diodes. (Monographs in Electrical and Electronic Engineering.) By A. A. Bergh and P. J. Dean. Pp. viii+591. (Clarendon: Oxford; Oxford University: London, 1976.) £22.

/pdf/light-emitting-diodes-ubzde6g9qc.pdf

Light-emitting diodes

A surgical stapling instrument (1) comprises a body portion (2, 3), a handle (4) and a staple fastening assembly (8). The staple fastening assembly (8) includes a curved cartridge (10), which comprises at least one curved open row of staples, and a curved anvil (22), which is adapted to cooperate with the cartridge (10) for forming the ends of the staples exiting from the cartridge (10). The staple fastening assembly (8) is adapted to allow unobstructed access towards the concave inner faces of the cartridge (10) and the anvil (22). The cartridge (10) can be moved towards the anvil (22) from a spaced position for positioning tissue therebetween to a closed position for clamping the tissue. Preferably, a knife is contained within the cartridge (10) and is positioned such that there is at least one row of staples on at least one side of the knife.

Surgical stapling instrument

Pulse width modulation (PWM) and current-controlled switching are applied to a full-bridge series resonant converter to regulate the output from no load to full load with low switching loss and with a narrow range of frequency variation. Drive strategies, control law, component stress, and other steady-state functions are analyzed for both switching modes. The range of frequency variation of the resulting switching scheme is narrower than that of a normal square-wave drive. It is noted that the advantages of low switching stress and narrow band frequency variation can be extended over the entire range of voltage gain or load by combining PWM with current-controlled switching. >

Analysis of a series resonant converter pulse width-modulated or current-controlled for low switching loss

A novel silicon-based inductor, power inductor in silicon (PIiS) has been proposed and experimentally demonstrated. The PIiS is fabricated at wafer level using a silicon-molding micromachining technique in which 200-μm-thick copper windings are embedded into a silicon substrate and both sides of the substrate are capped with a polymer-magnetic power composite. Through-silicon vias (TSVs) and copper routings are also added so that a PIiS can be directly used as a surface-mountable packaging substrate. A 3 ×3 ×0.6 mm3 PIiS with a measured inductance of 390 nH has been fabricated. The Q factor of this PIiS is 10 at 6 MHz. An ultracompact buck converter has been made by surface mounting off-shelf power ICs and capacitors on a PIiS. The buck converter is 3 ×3 ×1.2 mm3, which has successfully delivered 500 mA at 1.8 V with an 80% efficiency at 6 MHz.

A Surface-Mountable Microfabricated Power Inductor in Silicon for Ultracompact Power Supplies

A control circuit for a full bridge switching converter including power FET switching devices. The control circuit including a gate driver with a voltage sensor circuit which senses the precise instant to gate the power FET on in order to achieve substantially lossless switching by the converter.

Gate driver for a full-bridge lossless switching device

A methodology to develop subcircuit models of magnetic cores with hysteresis using analog behavioral modeling (ABM) in PSpice is presented. A subcircuit equivalent to the Jiles-Atherton model is developed to model the static ferromagnetic hysteresis. The Hammerstein configuration, which includes a nonlinear static block followed by a linear dynamic block, is further employed to capture the rate dependencies. The nonlinear static block is realized by the Jiles-Atherton model, and linear dynamic block by a low-pass filter. Interface subcircuits are provided to couple the voltage induced by the magnetic flux to the winding model of an inductor or a transformer. The hysteresis-related waveforms predicted by the developed inductor and transformer subcircuit models have been verified experimentally.

Khai D. T. Ngo

Papers

Analysis of a series resonant converter pulse width-modulated or current-controlled for low switching loss

A Surface-Mountable Microfabricated Power Inductor in Silicon for Ultracompact Power Supplies

Gate driver for a full-bridge lossless switching device

Subcircuit modeling of magnetic cores with hysteresis in PSpice

A compact mechanical power take-off for wave energy converters: Design, analysis, and test verification