Abstract: Methods and systems are provided for writing a magnetic servo track. In one example, a system includes a head assembly having first and second write elements, and a controller. The controller operable to receive a position signal associated with a position of the magnetic storage medium and energize the first write element to write a first magnetic servo pattern (e.g., repeating servo frames including a tone field). The controller is further operable to energize the second write element to write a second magnetic servo pattern (e.g., a mid-frame mark) at least partially overlapping the first pattern, wherein the relative position of the second pattern is adjusted in response to the position signal. The second pattern may be displaced relative to the first pattern in response to a lateral displacement of the magnetic storage medium to maintain a desired center line condition of the servo track.

Abstract: A multi-leaflet valve adapted to serve as a prosthesis for diseased native valve of a mammal is incorporated in self-expandable or inflatable endovascular stents or stents to form a combination which is introduced on a catheter with a guide wire into the circulatory system of the mammal to replace the diseased native valve. Once the combination is at the desired location the stent is caused to expand and affix itself to the patient's vessel wall. The prosthetic valve has the shape of a truncated cone that has an inflow and an outflow orifice with leaflets forming the outflow orifice and forming a plurality of commissures. A first flexible circular support is affixed in a substantially circular fashion around the truncated cone in proximity of the inflow orifice, and a second flexible circular support is affixed at the location of the commissures to form a circle around the truncated cone in proximity of the outflow orifice.

Abstract: A multi-leaflet valve adapted to serve as a prosthesis for diseased native valve of a mammal is constructed of biologic membrane or of biocompatible synthetic membrane. The valve has the shape of a truncated cone that has an inflow and an outflow orifice with leaflets forming the outflow orifice and forming a plurality of commissures. A first flexible stent is removably affixed in a substantially circular fashion around the truncated cone in proximity of the inflow orifice, and a second flexible stent is removably affixed at the location of the commissures to form a circle around the truncated cone in proximity of the outflow orifice. The stents maintain the shape of the valve during the surgical implantation procedure. Each stent independently can be left in the valve or can be removed during the implantation procedure based upon the judgement of the cardiac surgeon performing the implantation procedure.

Abstract: Among the four heart valves, the mitral is the most frequently affected by disease resulting in defective valve opening (stenosis) or incomplete closure (insufficiency). Most often this is due to distortion of the valve apparatus secondary to rheumatic or degenerative disease. These lesions, called “organic” require open heart surgery. In patients with coronary disease or with dilated cardiomyopathy the mitral valve can be insufficient although structurally normal. These valves are “functionally” insufficient. Because of the poor condition of these patients where open heart surgery carries a significant operative risk, less invasive percutaneous alternatives are being explored today. The present novel invention represents a radical departure from other procedures because it repositions the posterior papillary muscle utilizing a device located in the interventricular veins.

Abstract: A multi-leaflet valve adapted to serve as a prosthesis for diseased native valve of a mammal is incorporated in self-expandable or inflatable endovascular stents or stents to form a combination which is introduced on a catheter with a guide wire into the circulatory system of the mammal to replace the diseased native valve. Once the combination is at the desired location the stent is caused to expand and affix itself to the patient's vessel wall. The prosthetic valve has the shape of a truncated cone that has an inflow and an outflow orifice with leaflets forming the outflow orifice and forming a plurality of commissures. A first flexible circular support is affixed in a substantially circular fashion around the truncated cone in proximity of the inflow orifice, and a second flexible circular support is affixed at the location of the commissures to form a circle around the truncated cone in proximity of the outflow orifice.

Abstract: A multi-leaflet valve adapted to serve as a prosthesis for diseased native valve of a mammal is constructed of biologic membrane or of biocompatible synthetic membrane. The valve has the shape of a truncated cone that has an inflow and an outflow orifice with leaflets forming the outflow orifice and forming a plurality of commissures. A first flexible stent is removably affixed in a substantially circular fashion around the truncated cone in proximity of the inflow orifice, and a second flexible stent is removably affixed at the location of the commissures to form a circle around the truncated cone in proximity of the outflow orifice. The stents maintain the shape of the valve during the surgical implantation procedure. Each stent independently can be left in the valve or can be removed during the implantation procedure based upon the judgement of the cardiac surgeon performing the implantation procedure.

Abstract: A multi-leaflet valve adapted to serve as a prosthesis for diseased native valve of a mammal is incorporated in self-expandable or inflatable endovascular stents or stents to form a combination which is introduced on a catheter with a guide wire into the circulatory system of the mammal to replace the diseased native valve. Once the combination is at the desired location the stent is caused to expand and affix itself to the patient's vessel wall. The prosthetic valve has the shape of a truncated cone that has an inflow and an outflow orifice with leaflets forming the outflow orifice and forming a plurality of commissures. A first flexible circular support is affixed in a substantially circular fashion around the truncated cone in proximity of the inflow orifice, and a second flexible circular support is affixed at the location of the commissures to form a circle around the truncated cone in proximity of the outflow orifice.

Abstract: The present invention is a method for providing a disk of an optical tester. The disk comprises a transparent substrate that has a first surface and an opposite second surface. The disk also includes a coating on the first surface of the transparent substrate. An identical coating can be applied to the second surface of the transparent substrate. The coating can have multiple layers of thin films. The present invention provides a method to determine the required thickness of the coating to enhance the sensitivity of zero flying height measurement.

Abstract: An interferometer that contains a tri-coupler to mix light from three different waveguides. The light is emitted from a light source and may be reflected from a test surface. The output of the tri-coupler may be three different light beams that have intensities 120 degrees out of phase from each other. The out-of-phase light beams may be detected by a plurality of photodetectors. The detected out-of-phase light beams may be used to determine a height of the test surface. The waveguides and tri-coupler provide a compact and relatively inexpensive interferometer.

Abstract: The present invention is a method for providing a disk of an optical tester. The disk comprises a transparent substrate that has a first surface and an opposite second surface. The disk also includes a coating on the first surface of the transparent substrate. An identical coating can be applied to the second surface of the transparent substrate. The coating can have multiple layers of thin films. The present invention provides a method to determine the required thickness of the coating to enhance the sensitivity of zero flying height measurement.

Abstract: An apparatus that can measure a space between a first surface and a second surface such as the air bearing between a slider and a disk. The apparatus may include a light source that can reflect a light beam from the slider and the disk. By way of example, the light beam can be reflected off of an Al2O3 cap of a slider. A birefringent element such as a Savart plate may split the reflected light beam into an ordinary beam and an extraordinary beam. The ordinary and extraordinary beams may combine to form an interference pattern that is detected by a photodetector. A controller receives data from the photodetector. The apparatus may have a mechanism which can vary a phase between the ordinary and extraordinary beams so that the controller can calculate a phase value &phgr;. The controller then computes the space from the phase value &phgr;. The variation in phase between the beams may be created by tilting the birefringent element, or moving the reflected light beam directed into the birefringent element.

Abstract: An apparatus that can measure a space between a first surface and a second surface. The apparatus may include a light source that can reflect a light beam from the first and second surfaces. A birefringent element may split the reflected light beam into an ordinary beam and an extraordinary beam. The ordinary and extraordinary beams are detected by a photodetector. The apparatus may include a controller that is coupled to the photodetector and which can compute the space from a phase value that is determined from data collected when the mechanism varies the phase between the ordinary and extraordinary beams, and a ratio between a first modulation amplitude detected from light reflected from the first and second surfaces and a second modulation amplitude detected from light reflected from the first surface when the second surface is not adjacent to the first surface. The ratio can also be used to compute the reflectance and index of refraction of the second surface.

Abstract: A calibration medium that is used to calibrate a flying height tester which measures the gap of an air bearing formed between a magnetic recording head and a substrate. The medium contains a first ridge and a second ridge that extend from an underlying substrate. The ridges may be coated with a reflective material. A flying height tester can be calibrated by measuring light reflected from each ridge. The ridges have varying thicknesses so that the calibration medium will produce multiple data points.

Abstract: An apparatus and method for measuring the space between a transparent member such as a substrate, and reflective member such as a slider. The apparatus includes a first optical system which detects a first light beam that is reflected from the substrate and the slider. The reflected light is separated into four separate beams. The intensities of the beams are detected and utilized to determine a first stokes parameter, a second stokes parameter, a third stokes parameter and a fourth stokes parameter of the reflected light. The stokes parameters are used to compute the real index of refraction n, extinction coefficient k and the thickness of the space. The four stokes parameters account for any depolarized light that is reflected from the slider. The first optical system may have a photodetector which detects an image of the slider. The image provides multiple data points that can be used to calculate n, k and the thickness of the air gap without a retract routine.