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

A multi-layer film-stack and method for forming the multilayer film-stack is given where a series of alternating layers of conducting and dielectric materials are deposited such that the conducting layers can be selectively addressed. The use of the method to form integratable high capacitance density capacitors and complete the formation of an integrated power system-on-a-chip device including transistors, conductors, inductors and capacitors is also given.

/pdf/integrated-power-passives-ak2xvcp7ec.pdf

Integrated power passives

One benefit of switching a converter at very high frequencies—even to the multimegahertz range—is that the loop bandwidth can be increased so that the transient performance is significantly improved. However, using the conventional small-signal model of continuous conduction mode (CCM) for quasi-square-wave (QSW) converters introduces a huge mismatch for the placement of the dominant poles when compared to the experiment results. The double poles in high-frequency QSW converters are split widely which cannot be predicted by the conventional model. A modified small-signal model of the QSW flyback converter is proposed to predict the double-pole splitting phenomenon and to analytically quantify the damping effect. The impacts of deadtime on control-to-output transfer function have been investigated in detail. The conventional CCM model turns out to be a special case of the proposed model. The theoretical analyses were eventually verified by Simplis simulation and experimental results on a 5-MHz QSW flyback converter.

Small-Signal Equivalent Circuit Model of Quasi-Square-Wave Flyback Converter

Two operating modes have been identified for a matrix inductor/transformer made by weaving conductors through the holes perforated in a flat magnetic plate. The Mode-1 perforated-plate matrix transformer (M1PPMT) is analyzed to assess its suitability for low-profile power converters. Analysis and finite-element simulation suggest that this type of transformer may be approximated as a collection of weakly coupled "toroidal" cores. Thus, it is possible to derive closed-form expressions relating typical performance parameters, such as magnetizing inductance and losses, to the hole radius, identified as a meaningful design parameter. High peak flux density around the holes appears to be a problem. Nevertheless, it is possible to design a 100 W M1PPMT with acceptable magnetizing inductance, efficiency, and power density. >

Perforated-plate magnetics. I. Mode-1 inductor/transformer

One-turn inductors must cope with high dc flux in conventional hard-switched point-of-load converters. These inductors need to handle both high dc and ac fluxes in soft-switched converters with high current ripple, for example, resonant cross-commutated buck (rccBuck) converters. In order to understand the losses associated with those fluxes, the winding loss in megahertz range is modeled in this paper through calculating the fringing field in the window area. The dc-biased core loss for resonant waveforms is modeled by the equivalent elliptical loop (EEL) method. According to the loss models, winding and core dimensions are designed systemically to minimize the total loss within a volume smaller than that of a commercial product. Four 1-turn inductors were fabricated for a 12 to 1.2 V rccBuck converter switched at 2 and 2.5 MHz. The designed one-turn inductors demonstrated 2.1% higher efficiency at 20 A output and 50% lower total magnetic volume than commercial inductors with similar inductances, on the same rccBuck converter.

Design Methodology of a One-Turn Inductor With Significant DC and AC Fluxes—Demonstration in a Resonant Cross-Commutated Buck Converter

Due to the thin structure employed in planar packaging, the high electric field intensity may occur inside the power module, leading to degradation of the dielectric performance. To resolve this issue, the Metal-Posts-Interconnected Parallel Plate Structure (MPIPPS) is used to reduce the high field concentration in the power module. However, the high bonding joint in MPIPPS will cause high thermo-mechanical stress in the solder layers. In this paper, a methodology to optimize the joint height based on the trade-off between thermo-mechanical performance and dielectric performance of the power module is proposed. The impact of the joint height on thermo-mechanical stress and dielectric performance of the module is investigated quantitatively using ANSYS and Maxwell simulations. The results show that with 0.4 mm joint height and Nusil R-2188 encapsulation, the power module can achieve 3 kV breakdown voltage. The experimental results agree with the simulation results.

Khai D. T. Ngo

Papers

Integrated power passives

Small-Signal Equivalent Circuit Model of Quasi-Square-Wave Flyback Converter

Perforated-plate magnetics. I. Mode-1 inductor/transformer

Design Methodology of a One-Turn Inductor With Significant DC and AC Fluxes—Demonstration in a Resonant Cross-Commutated Buck Converter

Height Optimization for a Medium-Voltage Planar Package