摘要:
An endolumenal medical device assembly is provided for use in a bifurcation region of a body lumen. An expandable prosthesis, preferably an endolumenal support device such as a stent, is included in the assembly and is adjustable from a radially collapsed condition to a radially expanded condition. The expandable prosthesis further includes a prosthesis passageway and a side port through which the prosthesis passageway communicates externally of the prosthesis. A dilator or an access device is engaged within the prosthesis passageway and also through the side port while the expandable prosthesis is in the radially collapsed condition. By coupling a guidewire to an access device engaged within the side port and positioning the guidewire therein, the expandable prosthesis may be positioned in the bifurcation region such that its distal end portion is in a first branch lumen extending from the bifurcation, its proximal end portion is in a common proximal lumen of the bifurcation region, and the side port is aligned with an entrance zone to a second branch lumen extending from the bifurcation. When the expandable prosthesis is positioned at the bifurcation region in this orientation, the access device maintains percutaneous translumenal access to the second branch lumen through the prosthesis passageway and the side port while the expandable prosthesis is adjusted from the radially collapsed condition to the radially expanded condition. In addition, a dilator when engaged within the side port is adapted to expand the bore formed by the side port from an initial inner diameter to a larger expanded inner diameter. A second, lateral expandable prosthesis can also be coupled to the first expandable prosthesis at a location adjacent to the side port such that the dilator or access device extending through the side port is engaged within a lateral prosthesis lumen, extending through the lateral expandable prosthesis.
摘要:
A flyback generator for a television receiver, in a sweep system driving the vertical-deflection yoke of a cathode-ray tube, comprises a storage capacitor with a low-voltage side grounded through a charging transistor and a high-voltage side connected through an isolating diode to the live terminal of a d-c supply. The charging transistor conducts during scanning but is cut off during flyback by the operation of a first switching transistor while a second switching transistor connects the low-voltage side of the charged storage capacitor to the live supply terminal whereby its high-voltage side is carried to a voltage V.sub.f equaling twice the supply voltage V.sub.s, less any voltage drop across the charging transistor. This high-voltage side is connected to the yoke through an output stage of a power amplifier saturated during flyback. The coupling between the first switching transistor and the charging transistor comprises a voltage-regulating network including a Zener diode connected across the supply; when the supply voltage V.sub.s rises above a threshold V.sub.t established by the Zener diode, a branch current mirroring the Zener current reduces the conductivity of the charging transistor to generate during scanning a voltage V.sub.s =2(V.sub.s -V.sub.t) thereacross which results in a partial discharge of the storage capacitor; thus, the maximum V.sub.F of the flyback voltage V.sub.f, occurring upon switchover, is twice the threshold voltage V.sub.t.
摘要:
For the periodic suppression of the beam of a cathode-ray tube in a television receiver during flyback, in response to a blanking pulse V.sub.2 normally accompanied by a flyback pulse V.sub.1 of shorter duration, a control transistor T.sub.11 is saturated to render conductive a master transistor T.sub.7 in series therewith, together with several slave transistors T.sub.6, T.sub.8 and T.sub.13 forming current mirrors with transistor T.sub.7. Slave transistor T.sub.13 lies in series with a Zener diode DZ across which the beam-suppressing signal V.sub.3 is generated; slave transistor T.sub.6 activates a comparator CMP having an input A connected to a biasing circuit PL1 including slave transistor T.sub.8. Another input B of the comparator receives from a voltage divider PL2 a biasing voltage of such magnitude that an output C of the comparator feeds back a holding signal to another control transistor T.sub.12, in parallel with transistor T.sub.11, to maintain the conduction of master transistor T.sub.7 until a flyback pulse V.sub.1 applied to biasing circuit PL1 reverses the comparator whereby the beam-suppressing signal V.sub.3 disappears with the blanking pulse V.sub.2. In the absence of flyback pulse V.sub.1, signal V.sub.3 persists for an indefinite period.
摘要:
An endolumenal medical device assembly is provided for use in a bifurcation region of a body lumen. An expandable prosthesis, such as a stent, is included in the assembly and is adjustable from a radially collapsed condition to a radially expanded condition. The expandable prosthesis includes a prosthesis passageway and a side port. A dilator or an access device is engaged within the prosthesis passageway and also through the side port while the expandable prosthesis is in the radially collapsed condition. The expandable prosthesis may be positioned in the bifurcation region such that its distal end portion is in a first branch lumen extending from the bifurcation, its proximal end portion is in a common proximal lumen of the bifurcation region, and the side port is aligned with an entrance zone to a second branch lumen extending from the bifurcation. When the expandable prosthesis is so positioned the access device maintains percutaneous translumenal access to the second branch lumen through the prosthesis passageway and the side port while the expandable prosthesis is adjusted from the radially collapsed condition to the radially expanded condition. A dilator may also to expand the bore formed by the side port from an initial inner diameter to a larger expanded inner diameter. A second, lateral expandable prosthesis can also be coupled to the first expandable prosthesis at a location adjacent to the side port and engaged by the dilator or access device extending through the side port.
摘要:
Improved creasing machine, particularly for use in industry of cardboard articles and packages, comprising a sliding creasing roller and a fixed or stationary counter-roller, wherein the creasing roller is driven by the pistons of pneumatic, hydraulic or fluid-dynamic cylinders having the same axis of translation but different stroke.