Abstract: An apparatus for classifying polydisperse aerosols includes aerosol and sheath gas conduits for conducting a sample aerosol and a sheath gas toward a merger area. At the merger area the sheath gas and about ten percent of the sample aerosol merge, then travel through a differential mobility analyzer (DMA) and along a tubular electrode of the DMA. Selected particles, i.e. particles having electrical mobilities within a narrow range, pass through a collection aperture of the electrode. The DMA output, an aerosol consisting of the selected particles, is provided to a condensation particle counter or other device for determining the aerosol concentration. The remainder of the sample aerosol is conducted away from the merger area along a bypass flow conduit. The bypass flow and an improved aerodynamic design provide for a slit at the merger area that is sufficiently narrow to minimize unwanted electric field penetration at the slit and DMA entrance.

Abstract: A facility monitoring system includes a monitoring station receiving inputs from different control panels, each panel supporting detectors and other devices. Data from the panels are scanned, segmented into categories and presented in a standard format including a category identifying devices by type and state or condition. The monitoring station stores graphic information including site maps and floor plans to provide backgrounds, and device images positionable on the backgrounds to accurately depict device locations in the facility.

Abstract: A magnetic data storage medium includes a dedicated transducing head contact zone for engaging an air bearing slider, primarily when the disk is stationary. The contact zone is textured with at least one elongate ridge extending in the circumferential direction. When a single ridge is formed, it runs in a spiral path in multiple turns with a predetermined radial pitch at least ten times the nominal ridge width. The ridge protrudes axially outward from a nominal surface plane of the contact zone, and is rounded and free of sharp edges. The ridge, or plurality of ridge sections, can be formed by a texturing process that includes directing a laser beam, focused, onto the contact zone surface. While the disk is rotated to maintain a constant circumferential speed relative to the laser, it also is translated radially to provide the desired radial pitch. The laser is operated in a CW (continuous wave) mode, to create a more uniform ridge.

Abstract: Magnetic data storage disks, particularly along dedicated transducing head contact regions, are laser textured according to a process in which beam shaping optical components impart an elliptical or otherwise elongated cross-section to the laser beam. Consequently, individual texturing features such as rims and nodules are elliptical or elongate, with more gradual height gradients in directions parallel to their major axes. The texturing features further are oriented with respect to the direction of transducing head accelerations and decelerations, which yields high performance in terms of reduced flying height, improved glide avalanche, reduced dynamic friction, reduced stiction and better wear characteristics. Texturing features are formed in a variety of patterns, including patterns with adjacent features contacting one another. A further refinement involves forming features with substantially different slopes on opposites sides of a maximum height region.

Abstract: The invention relates to a braided implantable endoprosthesis such as a stent or stent-graft with selectively terminated elongated member ends to aid orientation and control. A saw-tooth or crown pattern is formed on an end or on an edge of an opening in the generally tubular body. The pattern is defined by a series of terminus on the elongated members at a predetermined distance from respective control points. The termini cooperate with the control points and provide layers when constrained. The invention also relates to methods of making a braided implantable endoprosthesis with patterned terminated ends.

Abstract: A tissue cutting device includes a catheter with a window at its distal tip for admitting tissue into a catheter compartment. A cylindrical cartridge in the compartment has a cutting edge that supports an electrically conductive cutting element, e.g. a band or wire. The cutting element and adjacent tissue can be heated to a selected temperature by generating an electrical current through the cutting element. The catheter is maneuverable to position its distal end near the tissue to be cut. The catheter incorporates a dilatation balloon or other feature to urge the catheter against the tissue, so that at least part of the tissue may enter the compartment through the window. Then, the cartridge is manipulated from the catheter's proximal end to move the cutting edge across the window, cutting the tissue. According to alternative embodiments, the cartridge is either rotated or moved axially relative to the catheter and, in either event may be capable of closing the catheter window when the cut is complete.

Abstract: A magnetic data storage medium includes a dedicated transducing head contact zone for engaging an air bearing slider, primarily when the disk is stationary and also during disk accelerations and decelerations. The contact zone has a dual baseline texture, formed by first creating a recessed region within the transducing head contact zone, and then by forming multiple nodules or other texturing features within the recessed region. The texturing features project upwardly from a recessed surface of the recessed region, and also project above an upper surface of the disk by an amount less than the texturing feature height. Consequently, the texturing features are large enough to counteract stiction due to liquid lubricant meniscus formation, yet also have heights sufficiently low relative to the upper surface to allow reduced transducer flying heights.

Abstract: The invention relates to a radiopaque catheter tip and catheter assembly having radiopaque elements associated with a catheter. The preferred materials for the radiopaque elements are made of a 90% platinum and 10% nickel composite structure or a 90% platinum and 10% iridium composite structure.

Abstract: A system and process for respirator fit-testing are disclosed. The system includes conduits for taking first and second aerosol samples, from inside of the respirator mask and from outside of the mask, respectively. The samples are provided to a radial differential mobility analyzer for generating first and second modified samples corresponding to the aerosol samples. The modified samples are provided to a condensation particle counter, which generates first and second concentration values representing concentrations of suspended elements in the respective modified samples. Comparison of the concentration values yields a fit factor indicating how effectively the respirator seals against leaks. Alternative embodiment systems employ a cylindrical DMA, an electrical precipitator, or an inertial separating device in lieu of the radial DMA. For generating concentration values, an electrometer, a photometer or an optical particle counter can be used in lieu of the condensation particle counter.

Abstract: A wheelchair seat back having width adjustable wings, a mechanism to permit forward and backward angular adjustment of the wheelchair seat back, a clamping assembly for mounting the wheelchair seat back to wheelchair uprights, and a width adjustable cushion for a width adjustable wheelchair seat back.

Abstract: A system is disclosed, for administering a therapeutic agent locally and to a depth within cardiac tissue. An elongate, flexible catheter contains a flexible electric conductor and supports at its distal end an implantable electrode incorporating a penetrating element, typically a fixation helix or a linear needle that penetrates cardiac tissue as the electrode is implanted. A therapeutic agent is delivered through the electrode, to the cardiac tissue surrounding the penetrating element. The electrode acts as a sensor, electrically coupled through the flexible conductor, and monitors an electrical condition of the surrounding cardiac tissue. A controller is coupled to the sensor and to a pump or reservoir containing the therapeutic agent, to control delivery of the agent responsive to the sensed electrical condition. The implanted electrode further can be used to deliver RF current to ablate the surrounding tissue.

Abstract: A structural member for use in a wheelchair which includes an elongate section having side members connected by at least one central member and movement accommodating channels. Preferably, the elongate section has a W-shaped cross-sectional configuration. The preferred cross-section has a generally round outline. The preferred wheelchair structural member also includes a mechanism for imparting torsional stiffness thereto. Preferably, that mechanism includes stiffening disks which have a solid, circular cross-sectional appearance, and which are formed integrally with the elongate section. Similarly, the preferred structural member may include a mechanism for imparting bending strength. Stiffening disks, as well as increased cross-sectional diameter and increased wall thickness may be used to reduce the tendency of a structural member to bend. A preferred injection molding method and the preferred use of fiber-reinforced plastic materials are also disclosed.

Abstract: A surface treatment process employing pulsed laser energy enables selective texturizing and polishing of non-magnetizable substrate disks used in fabricating magnetic reading and recording media. Substrate surfaces are texturized over dedicated head contact zones to form multiple nodules that are highly uniform to precisely control surface roughness. Laser polishing of data zones causes localized flow of the substrate material, to remove the residual scratches of mechanical polishing without altering the non-magnetic character of the substrate at large. Between the data zones and contact zones, transition zones can be formed by selectively graduating the nodule heights in the radial direction. The rounded structure of the nodules increases surface resistance to intended or incidental transducing head contact.

Abstract: A prothesis for transluminal implantation consists of a flexible tubular interbraided structure of metal or polymeric monofilaments, and polymeric multifilament yarns. The prosthesis can be elastically deformed to reduce its diameter through axial elongation. The monofilaments and multifilament yarns are arranged in axially spaced apart helices, concentric on a common central axis of the prosthesis. The monofilaments are selectively shaped before their interbraiding with the multifilament yarns, either by an age-hardening or other heat-setting stage, or a cold-working stage that controllably plastically deforms the strands. The shaped structural strands cooperate to impart to the prosthesis its nominal shape and resilience. The textile strands cooperate to provide a sheeting that occupies interstices between adjacent structural strands, to reduce permeability and thereby enhance the utility of the prosthesis as a vascular graft.

Abstract: An electro-optical aerosol characterizing system includes a continuous wave laser for generating two beams in the red wavelength range, intersecting a particle stream at slightly spaced apart locations. A pulsed UV laser generates a beam that intersects the particle stream at a third location downstream. Laser energy scattered by each particle as it passes the first two locations, is used to compute aerodynamic sizes and UV laser pulsing times, so that in each case the UV beam irradiates the particle at the downstream location. Particles containing biological materials or other fluorescing components emit fluorescence signals in response to the irradiation. Accordingly, the system provides information about particle composition as well as particle size.

Abstract: A prosthetic stent with a tubular wall having local inwardly or outwardly formed elevations. Stents having such elevations have a higher mechanical stability if bend according to the curvature of the body vessels to be supported or repaired. Also a method for manufacturing a stent with such elevations is described.

Abstract: A device for reading and recording magnetic data includes an aerodynamically supported slider with an air bearing surface, and a transducer mounted to the slider for movement toward and away from the air bearing surface responsive to changes in the slider operating temperature. In one embodiment, the transducer movement is primarily due to a difference in thermal expansion coefficients between a transducing region of the slider incorporating the transducer, and the remainder of the slider body. In another embodiment, a strip of thermally expansive material is incorporated into the slider near the transducer to contribute to the displacement by its own expansion. A temperature control circuit, coupled to the strip of thermally expansive material or to a resistance heating element on the slider, employs a variable current source to control the slider temperature and transducer displacement.

Abstract: A tubular, radially self-expanding stent includes a latticework of interbraided, helically wound resilient structural strands. An axial control member is secured to the tubular latticework at axially spaced apart proximal and distal coupling locations. At the proximal location, the control member is coupled slidably, to permit an adjustment of the axial distance between the coupling locations, thus to selectively adjust the radius profile of the latticework between the two locations. To set a desired radius profile, the control member either is crimped near the proximal location or fixed within a self-locking connector. The control members, preferably monofilament strands, can be elastic or substantially inextensible. Two or more control members can be used if desired. In an alternative embodiment, recovery metal control members are fixed at their opposite ends to the latticework, then plastically deformed by elongation to axially elongate and radially reduce the latticework.

Abstract: A system for magnetically evaluating magnetic data storage media includes a spindle for rotatably supporting magnetic disks, a read/write transducer, and an erasing transducer, both supported for radial movement relative to the disk. The read/write transducer records a sequence of magnetically isolated transitions. When sensing the sequence, the read/write transducer generates a fringing field signal which is low pass filtered and RMS processed to provide a voltage proportional to the remanence-thickness product. The erasing transducer is a ring head transducer having a substantially larger gap and transducer/disk spacing as compared to an aerodynamically supported transducer. Consequently a Hall effect probe is positionable within the gap to directly measure the magnetic intensities of erase fields.

Abstract: A process for fabricating a magnetic data storage medium includes formation of a controlled texture, either over an annular transducing head contact area or the entire surface of a substrate. The texture layer is formed by vacuum deposition of a texturing material onto a smooth surface of a non-magnetic substrate. The texturing material has a surface energy greater than that of the substrate, and the texturing material and substrate material have different linear coefficients of thermal expansion. Just before deposition of the texture layer, the substrate is heated to a temperature of 200-600.degree. C., then allowed to cool during texture layer deposition. The substrate and texture layer contract at different rates as they cool, inducing mechanical stresses within the texture layer sufficient to plastically deform the texture layer, creating multiple dome-like bumps.