A single photon emission computed tomography (SPECT) system for producing transaxial images in a plurality of transaxial planes through a body. The SPECT system includes a detector system with an in-plane spatial resolution that is determined by the in-plane spatial resolution of collimator modules disposed in a ring around the body to be imaged. Photon detectors and related circuits merely determine a position in a photon detector matrix having discrete azimuthal positions that correspond to the physical size of a collimator module. Axial spatial resolution or slice thickness for the detector system is determined either by collimator modules or by collimator modules in conjunction with the intrinsic resolution of the photon detectors.

1. Field of Invention
This invention generally relates to single photon emission computed tomography (SPECT) systems and more specifically to multi-slice systems for acquiring image data from parallel, transaxial planes in tomographic slices.
2. References
Reference is made to the following United States Letters Patent and publications:
Ter-Pogossian, Imaging Device for Computerized Tomography, U.S. Pat. No. 4,150,292 (1979).
Williams et al, Introducing SPRINT: A Single Photon Ring System for Emission Tomography, NS-29 I.E.E.E. TRANS.NUCL.SCI. 628, (1979).
Hattori et al, Emission Computed Tomograph, U.S. Pat. No. 4,389,569 (1979).
Jaszczak et al, "SPECT: Single Photon Emission Computed Tomography", NS-27 I.E.E.E. Trans.Nucl.Sci. 1137 (1980)
Hirose et al, A Hybrid Emission CT Headtome II, NS-29 I.E.E.E. Trans.Nucl.Sci. 520 (1982).
Milster et al, A Modular Scintillation Camera For Use in Nuclear Medicine, NS-31 I.E.E.E. Trans.Nucl.Sci. 578, (1984).
Wong et al, Characteristics of Small Barium Fluoride (BaF) Scintillator for High Intrinsic Resolution Time-of-Flight Positron Emission Tomography, NS-31 I.E.E.E. Trans.Nucl.Sci. 381 (1984).
Burnham et al, Design of a Cylindrical Scintillation Camera for Positron Tomographs, NS-32 I.E.E.E. Trans.Nucl.Sci. 889 (1985).
Lim et al, Triangular SPECT System for 3-D Total Organ Volume Imaging: Design Concept and Preliminary Imaging Result, NS-32 I.E.E.E. Trans.Nucl.Sci. 741 (1985)
Casey et al, A Multicrystal Two Dimensional BGO Detector System for Positron Emission Tomography, NS-33 I.E.E.E. Trans.Nucl.Sci. 460 (1986).
Chang et al, Design and Investigation of a Modular Focused Collimator Based Multiple Detector Ring System for SPECT Imaging of the Brain, 671 SPIE 200 (1986).
Genna et al, Radionuclide Annular Single Crystal Scintillator Camera with Rotating Collimator, U.S. Pat. No. 4,584,478 (1986).
Casey et al, Two Dimensional Photon Counting Position Encoder System and Process, U.S. Pat. No. 4,743,764 (1988).
Chang et al, Single Photon Emission Computed tomograph Using Focused Modular Collimators, U.S. Pat. No. 4,748,328 (1988).
Genna et al, The Development of Aspect, an Annular Single Crystal Brain Camera for High Efficiency SPECT, NS-35 I.E.E.E. Trans.Nucl.Sci. 654 (1988).
Rogers et al, SPRINT II: A Second Generation Ring-Geometry SPECT Instrument for Brain Imaging, 29 J.Nucl.Med. 760 (1988).
3. Description of Related Art
Single Photon Emission Computed Tomography (SPECT) and Positron Emission Tomography (PET) are two imaging techniques for the noninvasive imaging of a distribution of tracers in accordance with a physiological function, particularly in humans. Both systems generate tomographic images that represent the distribution of a radioisotope in one or more transaxial, and normally transverse, thin planar sections through a portion of the anatomy, such as the brain or heart. This distribution corresponds qualitatively, and in some cases quantitatively, to physiological functions being imaged.
SPECT and PET systems differ because, as their names imply, PET imaging relies upon the characteristic emission of a positron during each disintegration of a positron-emitting isotope, such as carbon-11, nitrogen-13, oxygen-15, fluorine-18, rubidium-82 or gallium-68, and the subsequent emission of two photons in opposite directions along an essentially straight line. SPECT systems rely upon the emission of a single photon that characterizes the decay of certain other isotopes, such as technetium-99m, iodine-123, thallium-201 and xenon-133.
If two photon detectors in a PET system, normally comprising scintillating crystals and photomultiplier tubes in an appropriate spatial relationship, sense the arrival of two photons within a predetermined time interval (i.e., in "coincidence"), it is assumed that a disintegration occurred in a volume between those two photon detectors. This requirement for coincidence establishes an "electronic collimation" for PET systems and eliminates the need for mechanical collimation within a transaxial plane defined by the photon detectors. The spatial resolution of PET systems in the transverse plane (i.e., a measure of the ability or uncertainty of the system to resolve small objects) is primarily dependent on the intrinsic resolution of the photon detectors. Intrinsic resolution represents a limit on the system resolving power and the possible resolution in a reconstructed image with sufficient image data. In such systems the intrinsic spatial resolution normally is stated to be a percentage (e.g., 50 to 60 percent) of the crystal size. These systems are described in the Ter-Pogossian, Wong et al, Burnham et al and Casey et al patents and publications listed above.
SPECT systems also use scintillating crystals and photomultiplier tubes as photon detectors. However, as SPECT systems rely on the emission of single photons, they can not benefit from PET's inherent electronic collimation. Rather a mechanical collimator between the photon detectors and an object being imaged limits the photons that are received by the photon detectors. More specifically, the collimator defines a number of sampling volumes through openings in the collimator that define a photon aperture. Each photon detector "sees" through such a photon aperture in the collimator only that sampling volume that lies along a corresponding sampling axis. If a photon emitted from the sampling volume travels along the sampling axis toward the collimator opening, it passes through the collimator into the corresponding photon detector. The collimator blocks photons emitted from other sites and along other directions from reaching that photon detector.
Originally discrete detector banks and conventional Anger cameras were adapted to SPECT imaging by mounting photon detectors as a head on a rotatable gantry. This gave rise to "moving detector head" systems. In such moving detector head systems, one or more detector heads including a collimator and a photon detector comprising a large flat scintillating crystal, or multiple small crystals, and photomultiplier tubes move and rotate around an object to be imaged. The photon detector localizes a scintillation event in the crystal with sufficient precision to associate each scintillation event with a specific one of the sampling volumes defined by the collimator. The head or heads rotate to sample the emitted photons from the object from many different directions. Electronics use the signals from the photomultiplier tubes to localize each scintillation event on the face of the detector head. Acquired data then is reconstructed into a tomographic image or multiple planar tomographic images each corresponding to a thin slice of the object being imaged.
More recently "fixed detector ring" systems have been developed with a stationary ring of, or cylindrical arrangement of, photon detectors in a two-dimensional form. In such systems, a rotating collimator defines, either by hardware or software means, a two-dimensional matrix of imaging positions about a cylinder while photon detectors, comprising one or more scintillating crystals and photomultiplier tubes, are disposed about the collimator's periphery. These systems define either a single transaxial planar slice or multiple, axially displaced, transaxial planar slices that tomographic image can be formed to represent the distribution of the isotope in a corresponding portion of the body.
Williams et al introduced a single-slice SPECT system of the "fixed detector ring" type. The Hattori patent also discloses a similar system with a different collimator design. In both systems, a single photon detector, including a crystal and photomultiplier tube, is associated with each imaging position in the matrix. Rogers et al and Genna et al disclose a geometry with a fixed cylindrical two-dimensional position-sensitive detector system for multi-slice imaging capability.
According to the disclosures in the Genna patent and publication, for example, a multi-slice SPECT system, also of the "fixed detector ring" type, comprises a collimator with a basically parallel hole configuration in the transaxial plane and a photon detector including a single cylindrical crystal around the collimator and large photomultiplier tubes about the periphery of the single crystal. Digital electronics apply a position determination algorithm, similar to that used in Anger logic to the information gathered by the photomultiplier tubes. These electronics localize each event to a imaging position and its associated sampling volume in a particular transaxial plane. Rogers et al describe a system comprising multiple flat modular scintillation cameras to form a polygonal cylinder for the position sensitive photon detection and a rotating slit collimator.
In all these systems each photomultiplier tube is associated with a number of imaging positions in the matrix. In such variants of gamma cameras the relationship between the spatial resolutions of the system, the collimator and the photon detectors can be given by: EQU R.sub.s.sup.2 =(R.sub.i.sup.2 +R.sub.c.sup.2) Eq. 1
where R.sub.s is the spatial resolution for the detector system, R.sub.i is the intrinsic resolution of a photon detector and R.sub.c is the collimator resolution, all in terms of the full-width at half-maximum (FWHM) of a line spread function (LSF) or the uncertainty of localization. In these gamma cameras using position sensing logic, the system resolution relies equally on both the collimator and intrinsic resolutions as defined in Eq. 1. In accordance with Eq. 1, in PET systems with no mechanical collimator, the electronic collimation basically has little uncertainty in defining the direction of photons, (i.e. as an approximation, R.sub.c .fwdarw.0), so the detector system spatial resolution is entirely dependent upon the intrinsic spatial resolution of the detectors (i.e, R.sub.s =R.sub.i).
Thus, both intrinsic and collimator resolution influence the detector system spatial resolution in each of the foregoing references. The intrinsic resolution of the photon detectors was generally comparable to or better than the resolution of the collimator over an effective collimation and SPECT imaging range (i.e., R.sub.i .ltoreq.R.sub.c). However, improvements in collimator resolution have been limited because such improvements generally are offset by decreases in system sensitivity. Thus, most of the effort for improving detector system spatial resolution has been directed to improving the intrinsic resolution of the photon detectors.
The accuracy of position determination in a position sensitive scintillating crystal system depends upon the spatial resolving capability of the detector with respect to multiple scintillation events that occur within the crystal. In gamma camera systems, each scintillation event produces responses in several photomultiplier tubes simultaneously. Over time the position determinations of those events within the crystal that occur at exactly the same interaction site have an uncertainty caused by the statistical variation of photon distribution among the photomultiplier tubes involved; that is, a map of the positions produced by the electronics will be dispersed for scintillation events actually occurring at the same site within the crystal. The degree of dispersion determines the intrinsic resolution (R.sub.i) of the photon detector system and acts to broaden the system resolution (R.sub.s) as predicted in Eq. 1.
Moreover, the uncertainty or dispersion of determined positions from adjacent imaging or collimator positions can cause overlap of data from different sites and produce significant crossover or mixing of the identifications of sampling volumes. Work to improve the intrinsic resolution has continued and continues even though it has been realized improved intrinsic resolution of a photon detector involves compromises. Specifically, improving intrinsic resolution complicates calibration procedures and correction schemes and, in some applications, can introduce limits on counting rates (i.e., the rate at which scintillation events can be recorded). If an error exists in a correction scheme or calibration procedure or a counting rate is exceeded, the resulting images could be distorted.
The Chang et al patent and publication disclose a fixed detector ring system with a single ring of collimator modules for producing a single tomographic slice. The collimator comprises a series of focused collimator modules each of which define a sampling volume; and the in-plane spatial cross-section of these sampling volumes directly determines the in-plane detector system resolution. Each collimator module also defines one imaging position in the ring. Photon detectors, comprising a single crystal and photomultiplier tube for each collimator module position, localize the collimator module and corresponding sampling volume associated with each scintillation event.
Several problems are introduced if this approach is expanded into a multiple ring configuration for imaging several planar slices simultaneously. First, the number of collimator module positions, that correspond to imaging positions in a matrix, increase proportionally with the number of rings. A corresponding increase is required in the number of photomultiplier tubes, thereby making the system more costly. Moreover, the physical size of available photomultiplier tubes limits the packing of adjacent photomultiplier tubes and has a negative impact on the overall system resolution or sensitivity. Thus, it is desirable to produce such a SPECT system in which the photomultiplier tube size is not a factor in system performance and in which photomultiplier tube costs are reduced. Moreover, it is desirable to produce a system that is adapted for implementation with other photon detector schemes.
A variety of position decoding systems have been suggested for SPECT and PET systems. In these systems the intrinsic spatial resolution of the detectors in the image plane either (1) determines detector system spatial resolution because R.sub.s =R.sub.i when R.sub.c =0 as in PET systems, or (2) strongly influences the detector spatial resolution as in prior gamma camera based SPECT systems. None of these systems suggests the use of their disclosed detector systems in a single-slice system described in the Chang et al references where the spatial resolution of the detector system depends primarily upon the spatial resolution of the collimator (i.e., R.sub.s =R.sub.c). In a design as disclosed in the Chang et al references Eq. 1 does not apply, because each detector in the transverse plane is not position sensitive. In addition, the collimator module is a discrete unit quite different from a large conventional gamma camera collimator.

Single photon emission computed tomography system

The University of Iowa Research Foundation


A dampening water feed roller, characterized by a process of manufacturing which comprises forming a flame sprayed layer of a ceramic material composed of Al.sub.2 O.sub.3, TiO.sub.2, or a mixture of Al.sub.2 O.sub.3 and TiO.sub.2 on the peripheral surface of a metallic roller, subjecting the flame sprayed ceramic layer to a pore-occluding treatment with a hydrophilic SiO.sub.2 type inorganic pore-occluding agent, and grinding the treated layer to surface roughness of not more than 1.6 S. The roller permits supply of the dampening water without using the additives such as isopropyl alcohol in the dampening water.

1. Field of the Invention
This invention relates to dampening water feed rollers such as a master water roller and a water spreading roller which are used in a continuous water feed device in a planographic printing press.
The planographic printing is a process of printing which utilizes the nature of an oily ink to repel water and uses a printing plate having an oleophilic picture formed on a hydrophilic base. The printing is effected by indirect printing of the so-called offset printing technique which comprises alternately feeding water and ink to the plate surface, causing the ink selectively adhering to the picture portion of the plate surface to be transferred tentatively to a blanket, and transferring the ink from the blanket to an object of printing. The printing press to be used for the planographic printing, therefore, is inherently provided with a dampening mechanism for feeding water to the non-picture portion of the printing plate and an inking mechanism for feeding ink to the picture portion.
A notable example of the conventional dampening mechanism is configured as follows.
This dampening mechanism is provided with a metallic master water roller which is rotated while it is partly submerged in a water supply pan disposed underneath, together with a metering roller of rubber and a water applying roller of rubber which are both held in contact with the master water roller. In this mechanism, the water adhering to the surface of the master water roller and consequently ascending with the rotation of this roller is deprived of an excess portion thereof in consequence of its contact with the metering roller. The remaining water, owing to the contact of the master water roller and the water applying roller, is transferred to the water applying roller. The water applying roller, on contact with the plate cylinder, passes the water to the non-picture portion of the surface of plate cylinder. The water which remains after failure to adhere to the surface of the plate cylinder is returned from the plate cylinder back to the water supply pan through the medium of the intervening rollers.
Another dampening mechanism comprises a metallic water discharging roller which is rotated while it is partly submerged in a water supply pan installed underneath, a water transferring roller of rubber held in contact with the water discharging roller, a metallic water spreading roller held in contact with the water transferring roller, and a water applying roller of rubber held in contact with the water spreading roller. In this dampening water mechanism, the water adhering to the surface of the water discharging roller and consequently ascending from the water supply pan with the rotation of the water discharging roller is deprived of an excess portion thereof during the course of transfer through the medium of the water discharging roller and the water spreading roller, then guided to the water applying roller, and passed from the water applying roller to the non-picture portion of the surfaces of the plate cylinder with which the water applying roller comes into contact. The water which remains after failure to reach the picture portion of the surface of the plate cylinder is returned from the plate cylinder back to the water supply pan through the medium of the intervening rollers.
As described above, the dampening mechanism, owing to the alternate arrangement of rubber rollers and metallic rollers, is enabled to feed the water in the water supply pan to the non-picture portion of the plate cylinder and return the water remaining after failure to reach the picture portion back to the water supply pan through the medium of the intervening rollers.
2. Description of the Prior Art
It has been heretofore customary for the metallic rollers used in the dampening mechanism of the planographic printing press to have their surfaces coated with a hard chromium plating to acquire improved resistance to corrosion and abrasion and enhanced affinity for water.
In spite of the hard chromium plating of the nature described above, such metallic rollers as the master water roller and the water spreading roller which are used in the dampening mechanism are still deficient in hydrophilicity and water-retaining property and, therefore, entail the following difficulties in printing. The water film on these rollers draws into drops or loss uniformity and impairs the uniformity of density of the ink film on the plate cylinder; the uniformity of supply of the dampening water is disrupted and, as the result, the so-called halftone of the picture portion is deprived of definition; and the dampening water is not fed sufficiently to the non-picture portion of the plate and, as the result, the ink adheres to the non-picture portion and smears the plate surface.
Further, when the water which remains after failure to reach the picture portion of the plate cylinder is returned to the water supply pan through the medium of the intervening rollers as described above, the ink on the picture portion of the plate cylinder is partly entrained by the water applying roller and passed in the form of emulsified ink to the surfaces of the rollers. Since these metallic rollers are deficient in hydrophilicity, they do not manifest the action of repelling the emulsified ink sufficiently and consequently suffer from fast deposition of the emulsified ink. Once the ink is deposited fast, the supply of the dampening water to the non-picture portion of the plate can no longer be continued. Thus, the non-picture portion of the plate is smeared with the adhering ink. For the plate cylinder to provide fine printing at all times, therefore, the printing press must be stopped periodically to permit cleaning of the defiled plate surface.
From this point of view, the idea of incorporating isopropyl alcohol or other similar alcohol and a surfactant in the dampening water thereby lowering the water surface tension and enhancing the water's ability to wet the metallic rollers has found acceptance. The incorporation of such substances as alcohol and surfactant in the dampening water, however, adds to cost and jeopardizes the hygienic condition of the workshop environment and causes the undesirable phenomenon of swelling in the rubber rollers which are exposed to the dampening water.
Japanese Utility Model Publication SHO 55(1980)-14,518 discloses a water spreading roller having a porous layer formed on the surface of a steel pipe or stainless steel pipe by the flame spraying of ceramic, and Japanese Utility Model Unexamined Publication SHO 62(1987)-116,869 discloses a master water roller having a layer of an oxide type ceramic formed by plasma flame spraying. These rollers merely have layers formed on metallic pipes by the flame spraying of ceramic. These layers are claimed to possess a porous surface. As recited in Japanese Utility Model Publication SHO 55(1980)-14,518, the porosity of surface is aimed at enhancing the rollers' water-retaining property. The enhancement of the water-retaining property due to the porous ceramic coating, however, is excessive for the master water roller or the water spreading roller. The water is suffered to ascend overly to the plate cylinder and the ink is rendered susceptible to emulsification. Since the master water roller and the water spreading roller are rotated as held in contact with the water applying roller, the ink adhering to the surface of the water applying roller permeates into the pores of the ceramic coating on the rollers and manifests an action of repelling water and impairs the hydrophilicity required of these rollers. Thus, the stable supply of the dampening water can be no longer be attained unless the dampening water incorporates therein an alcohol.
Japanese Utility Model Unexamined Publication SHO 62(1987)-116,868 discloses a dampening roller provided with a coating layer of an oxide type ceramic composed of 40 to 80% by weight of Cr.sub.2 O.sub.3, 10 to 30% by weight of Al.sub.2 O.sub.3, and 10 to 30% by weight of SiO.sub.2, and Japanese Utility Model Unexamined Publication SHO 62(1987)-136,353 discloses a dampening roller having a layer of an oxide type ceramic formed by plasma flame spraying and having the porous part of the flame sprayed layer occluded with an oxide type ceramic coating agent composed of 40 to 80% by weight of Cr.sub.2 O.sub.3, 10 to 30% by weight of Al.sub.2 O.sub.3, and 10 to 30% by weight of SiO.sub.2. These dampening rollers have a surface layer formed of a compact oxide complex ceramic material using Cr.sub.2 O.sub.3 as a matrix or a surface layer formed of an oxide ceramic material by flame spraying and additionally have the pores in the surface layer occluded with a coating agent, so as to acquire enhanced hydrophilicity owing to the use of a ceramic layer on the surface. The Cr.sub.2 O.sub.3 ceramic substance has no conspicuous effect in improving the rollers wettability with water. Even by the use of rollers of such a structure, the dampening mechanism cannot be operated satisfactorily when the dampening water incorporates absolutely no alcohol therein. Moreover, the oxide composite ceramic layer of compact texture using Cr.sub.2 O.sub.3 as a matrix is expensive because the production thereof requires the immersion in the Cr.sub.2 O.sub.3 slurry and the heating to 400.degree. to 500.degree. C. to be alternately repeated several to ten or more times.

Dampening water feed roller for planographic printing press

Akiyama Printing Machinery Manufacturing Corp.


A secure personal wearable carrier for valuable items is disclosed. The wearable carrier includes a secure compartment for valuable item storage to be worn by users during their common activities, including physical exercises. The carrier is constructed to maintain the security and safety of the valuable item while withstanding strenuous activity.

Wearing valuable items, such as jewelry by many individuals during common activities is well known. Due to the high cost of jewelry and proliferation of physical exercises many individuals in general, and female athletes in particular, are often exposed to uneasy choices about what to do with such valuables during sometime vigorous physical routines. For such individuals, it is not uncommon to occasionally find themselves in situations where safekeeping and storage facilities are not readily available. For example, female athletes often train or exercise in sport facilities such as gyms, athletic clubs, etc. that do not offer secure places to store small valuable personal items, including jewelry. Moreover, traditional workout clothing rarely, if ever, has secure pockets that accommodate valuable small items, such as jewelry, including rings.
Accordingly, there has been a long felt and unsolved need for a lightweight, unobtrusive secure and effective carrier or storage arrangement for valuable items or jewelry which can be worn by a user during everyday activities. There is also a further need for such a carrier arrangement which can be used by a common person in a simple and effortless manner with little or no training.
Efforts have been previously made to attempt to solve the issue of storing personal valuables during activities. Prior art such as those shown in Roegner, U.S. Pat. No. 6,227,424 and Rogers, U.S. Pat. Pub. No. 2004/0206791 attempt to resolve secure storage issues, but fail to provide a compact and sleek design with a fully secure storage component. Rather, their disclosure provides for a large cumbersome pouch arrangement, without the security and ease of use provided by the present invention. Similarly, the prior art personal storage devices detailed in Mazzo, U.S. Pat. No. 5,755,366, Carter, U.S. Pat. No. D371,675 and Law, U.S. Pat. No. D442,365 lack the sleek compact and secure design provided by the present invention.
The present invention provides a useful, novel and unique personal storage arrangement that is aesthetically-pleasing, secure, lightweight and comfortable for the user to wear while performing varied high stress tasks. These attributes of the present invention are not found in the prior art devices.


A filter disposed at the distal end of an elongate guidewire. Catheters are provided for delivering the filter to, and retrieving the filter from, a treatment site. The catheters can be over-the-wire or single operator exchange. The catheters include a housing for receiving the filter therein. The housing has an atraumatic distal end.

The present invention relates to the field of minimally invasive, percutaneous procedures such as angioplasty. In particular, the invention relates to a distal filter for use during such a procedure.
Angioplasty, atherectomy and stent placement, among other procedures, have become well accepted for treatment of coronary lesions. These procedures are often performed as an alternative to coronary bypass. It is also possible, however, that a saphenous vein graft, which is used to bypass coronary lesions, may itself develop a lesion. These lesions may also be treated by minimally invasive procedures such as angioplasty, atherectomy and/or stent placement.
When lesions are treated by these minimally invasive, percutaneous methods, it is possible that particles of plaque, thrombus or other material may break loose from the lesion and drift distally into the smaller coronary arteries. When these minimally invasive methods are performed on native arteries, the plaque or thrombus released during the procedure rarely cause embolization. When these procedures are performed on saphenous vein grafts, however, the incidence of embolism due to the breaking off of plaque or thrombus from the vein graft is substantially greater than from native arteries.
The increased incidence of embolization is believed to be due, at least in part, to the larger diameter of the bypass graft relative to the native artery. The larger diameter of the graft results in a slower blood flow velocity through the graft than the native artery. In addition, the plaque and thrombus of vein grafts is somewhat more fragile than that found in native arteries.
As the difference in embolism associated with treatment of native arteries and vein grafts has been noted, it would be desirable to develop techniques to reduce embolism associated with treatment of vein graft lesions. Additionally, where stent placement or other minimally invasive treatments are performed on the carotid artery, it would be desirable to limit the drift of plaque and thrombus toward the brain.


The present invention is directed to methods of treatment for scabies using different concentrations of lindane lotions for varying contact times. Compositions of low concentration lindane lotions are also included.

Scabies Infestation
Scabies is a public health concern of global proportion, affecting an estimated 300 million people worldwide each year [Chosidow, O., Clinical practices. Scabies"; N. Engl. J. Med.; Vol. 354, pp. 1718-1727, 2006]. The disease dates back to the 1700's when the Sarcoptes scabiei mite was first identified as the culprit pathogen. As a highly contagious infectious disease of the skin, scabies is readily spread by direct physical contact. It affects people of all races and social classes and occurs in all age groups and both genders [Wendell, K. et al., "Scabies and pediculosis pubis: an update of treatment regimens and general review"; Clin. Infect. Dis.; Vol. 35; pp. S146-S151, 2002]. It is a common sexually transmitted disease; however, it is often transmitted nonsexually and is easily spread within families and among people living in crowded conditions [Wendell, K. et al., 2002]. Hospitals, nursing homes, and long-term care facilities are likely sites of scabies epidemics [Habif, T. P., "Scabies"; Clinical Dermatology, 4th ed., New York: Mosby; pp. 497-505, 2004; Wendell, K. et al., 2002]. Often referred to as the "itch mite," scabies can cause intense, unbearable itching, clinically described as pruritis [McCarthy, J. S., et al., "Scabies: more than just an irritation"; Postgrad. Med. J.; Vol. 80, pp. 382-387, 2004; Orion, E., et al., "Ectoparasitic sexually transmitted diseases: scabies and pediculosis"; Clin Dermatol.; Vol. 22, No. 6, pp. 513-519, 2004]. Complications include bacterial superinfection, sepsis, glomerulonephritis and progression to Norwegian or crusted scabies—a more severe, life-threatening form of the disease [Walton, S. F., et al., "Scabies: new future for a neglected disease", Adv Parasitol., Vol. 57, pp. 309-376, 2004; Chosidow, O., Scabies and pediculosis; Lancet, Vol. 355, pp. 819-26, 2000; Habif, T. P., 2004; Wendell, K. et al., 2002; McCarthy, J. S., et al., 2004].
Today, scabies is increasingly found among immunocompromised patients (i.e., those with HIV infection, cancer, diabetes, organ transplant and those receiving immunosuppressive therapies), where mite burdens can rise to thousands or millions and infestation becomes much more diffuse and widespread over the body. This not only increases the risk of secondary bacterial infection, a potentially serious outcome, but also increases the likelihood of transmission to noninfected individuals [Mathisen G., "Of mites and men: lessons in scabies for the infectious diseases clinician" (Editorial response); Clin. Infect. Dis., Vol. 27, pp. 646-647, 1998].
The scabies mite (i.e., Sarcoptes scabiei) is a small, rounded, 8-legged parasitic insect that is too small to be seen by the naked eye without magnification. Attracted to warmth and odor, the female mite burrows into the skin, lays eggs, and produces toxins that cause a hypersensitivity reaction and the cardinal symptom of pruritis. Larvae, or newly hatched mites, travel to the skin surface, lying in shallow pockets where they mature into adult mites. Within 2 months, an infected individual may have 25 adult female mites living in the superficial layers of their skin. Within 3 to 4 months, as many as 500 mites may be present [Orion, E., et al., 2004]. Symptoms may not be initially noticeable, especially among patients with good hygiene and those who bathe regularly. Within several weeks, however, pruritis often becomes unbearable, keeping sufferers awake all night.
Scabies is almost always transmitted by close personal contact; only rarely is it contracted by way of contaminated clothing, towels or bedding [Johnston, G., et al., "Scabies: diagnosis and treatment"; BMJ; Vol. 331, pp. 619-622, 2005; U.S. Centers for Disease Control and Prevention (CDC). Parasitic Disease Information: Head Lice Fact Sheet. 2005]. Although scabies is not a condition exclusive to low-income families, it is more often associated with crowded living environments and poor hygienic conditions.
The most common site of scabies infestation in older children and adults, include the genitals, buttocks, fingers, wrists, elbows, armpits, knees and ankles [Habif, T. P., 2004]. Younger children and infants show more widespread involvement, including the palms and soles of the feet [Paller, A. S., et al., "Insect bites and parasitic infestations"; Hurwitz Clinical Pediatric Dermatology: A Textbook of Skin Disorders of Childhood and Adolescence; London: Elsevier, Ch. 18, p. 479, 2006]. However, scratching can spread scabies to non-infected areas of the body [Habif, T. P., 2004].
Diagnosis and Treatment
Diagnosis of scabies is generally made clinically by observing the skin burrows created by scabies mites, having the appearance of an excoriated papular rash [Flinders, D. C., et al., "Pediculosis and scabies"; Am. Family Physician, 2004]. Nodules, vesicles, pustles and eczema may also be present but are less specific signs of the disease. Lesions are most often symmetrical in distribution, affecting both the left and right sides of the body [Johnston, G., et al. 2005; Orion E, et al. 2004] Scraping of the burrows and subsequent examination under a microscope for mites, their eggs or fecal matter ("scybala") leads to a definitive diagnosis [Rosen, T., et al., "Cutaneous manifestations of sexually transmitted diseases: scabies"; Med. Clin. North Am.; Vol. 82, pp. 1098-1099, 1998]. However, this technique may not always be revealing and is challenging to perform, even for highly-trained healthcare professionals [Karthikeyan, K., "Treatment of scabies: newer perspectives"; Postgrad. Med. J.; Vol 81, pp. 7-11, 2005]. As such, a definitive diagnosis is not always possible and clinicians must often rely exclusively on the physical examination and patient history.
A number of agents have been used for the management of scabies infestation, with varying rates of efficacy and varying labeled restrictions. Topical therapy is considered the mainstay of treatment, although oral medications are sometimes employed. In the U.S., relatively few agents are FDA approved for this indication. Commonly used treatments include topical permethrin 5% cream*, topical lindane (gamma benzene hexachloride) 1% lotion*, topical benzyl benzoate 10% and 25% lotion or emulsion, topical crotamiton 10% cream*, topical precipitated sulphur 3%-6% lotion or 5%, 10% or 40% in petrolatum, topical allethrin 0.6% aerosol, and oral ivermectin (*FDA-approved indication) [Chosidow 0.2006]. The current treatment for scabies using 1% lindane lotion or cream involves application and then rinsing off after eight hours [Chosidow O. 2006].
Lindane and permethrin are the best studied topical therapies, with comparable rates of efficacy noted in the largest comparative trial to date [Chosidow O. 2006; Schultz, M. W., et al., "Comparative study of 5% permethrin cream and 1% lindane lotion for the treatment of scabies"; Arch Dermatol.; Vol. 126, pp. 167-170, 1990]. Permethrin is approved as a first-line treatment. Lindane is indicated second line because of a relatively greater potential for neurologic side effects, although the vast majority of serious events have almost always resulted from product misuse [U.S. Food and Drug Administration (FDA). Lindane Post Marketing Safety Review. 2003]. Crotamiton is also FDA approved as a first-line intervention but is less effective and not often used. In select patients and settings, oral ivermectin has been shown to be efficacious; however, in the U.S., this is an off-label use [Chosidow O. 2006].
In many parts of the world, including the U.S., drug-resistant forms of scabies have been documented, further complicating disease management and containment of scabies outbreaks. Drug resistance has been reported for all of the commonly used agents, including permethrin, crotamiton, ivermectin and lindane. [Johnston G, et al. 2005; McCarthy J S, et al. 2004] The unpredictable nature of resistance and geographical variability necessitates the need for a variety of approved treatment options.
Lindane (gamma-HCH or BHC)
Lindane is an insecticide, also known as gamma-hexachlorocyclohexane (HCH) and benzene hexachloride (BHC). Its empirical formula is C6H6Cl6 and it has the following structural formula:

Lindane exerts its pharmacologic effects via absorption through the chitinous exoskeleton of arthropods (e.g, scabies mite) and subsequent stimulation of the central nervous system (CNS), resulting in convulsion and death.
Lindane Lotion, USP, 1% ("lindane lotion") is approved by the FDA and strictly regulated as a prescription medication for the "second-line" treatment of scabies, meaning it is only indicated after first-line medicines have failed or cannot be tolerated. Lindane lotion has been used successfully in clinical practice for more than 50 years and has proven safe and effective when used as directed. However, systemic drug exposure and the potential risk for neurologic side effects have been raised as a concern. Young children, elderly and individuals of slight stature (weighing less than 50 kg) may be more susceptible to these adverse effects, and cautious use is recommended in these patient types [FDA Public Health Advisory, 2003]. Increased systemic exposure resulting from a higher surface-to-volume ratio has been proposed as a potential underlying factor.
Central nervous system stimulation, with symptoms ranging from dizziness to seizures, has been reported in association with the use of lindane lotion. However, the vast majority of medically significant neurologic events have almost always resulted from accidental oral ingestion or misuse of the product. Indeed, the FDA has quantified serious neurologic side effects associated with the proper use of lindane lotion as rare. [U.S. FDA Postmarketing Safety Review, 2003]. The most common side effects of topical lindane are non-serious reactions of the skin, such as dryness, itching and rash. Nonetheless, lindane medications were relegated to second-line treatment status in 1995 because of concerns relating to product misuse and associated risks. [U.S. Food and Drug Administration (FDA) Public health advisory: Safety of topical lindane products for the treatment of scabies and lice. Mar. 28, 2003]. Lindane medications were also limited to small, single-use 2 oz. bottles (compared with the original 16 oz. multi-dose bottles) in 2003 to further mitigate the risk of improper drug use.
Currently approved guidelines for lindane lotion instruct patients and caregivers to apply a thin film of medicine to the entire body from the neck down and then wash off after 8-12 hours. However, data show that peak blood levels of Lindane are achieved within 4-6 hours following topical application of 1% lindane in a lotion vehicle. [Ginsburg, et al., "Absorption of Lindane in infants and children"; J. of Pediatrics; Vol. 91, pp. 998-1000, 1977]. Moreover, inflammatory skin conditions, such as scabies, alter the epidermal barrier, making skin more permeable to topical therapies. [Ginsburg et al., 1977]
The literature reveals few studies of 1% lindane applied for less than 8 hours. For example, an unpublished report by Taplin et al. apparently alleges that there was little difference in the cure rate with application of a 1% lindane lotion for 6 hours, as compared with 24 hours [Shacter, B.; "Treatment of scabies and pediculosis with lindane preparation. An evaluation", J. Am. Acad. Dermatol., Vol. 5, pp. 517-527, 1981]. Similarly, a branded 1% lindane solution marketed in France under the tradename Scabecid®, requires only a single 6-12 hour skin application [Buffet, M. et al., "Current treatment for scabies," Fundamental & Clinical Pharmacology, Vol. 17 (2003), pp. 217-225].
There are also published reports of the use of lindane at concentrations less than 1% for the treatment of ectoparasitic disease. Specifically, the use of a 0.5% lindane lotion as a topical treatment for head lice has been described; however, the researchers concluded that the formulation was not sufficiently effective against head lice to justify its use for this particular indication. [Stichele, H. et al., "Systematic review of clinical efficacy of head lice," British Medical Journal (1995), Vol. 311, pp. 604-608].
In light of these limited and somewhat conflicting reports, there remains a need to further explore methods of enhancing the risk-benefit balance of lindane lotion for the treatment of scabies infestation.


Efficient delivery of large amounts of pump laser power distributed along the cladding (11, 54) of a single core (6) or multiple core (7, 51) laser fiber, without degrading the fiber integrity or compromising the fiber""s waveguiding property, is accomplished by injecting the power into the cladding via delivery fibers (18, 30, 42, 62) permanently affixed to a peripheral wall (20, 56) at an angle that satisfies the condition for total internal reflection of the pump radiation so that it is confined within the inner cladding of the laser fiber. In one embodiment, the laser fiber (51) is wrapped around a drum (53). Each delivery fiber has a numerical aperture (NA) less than half the NA of the laser fiber, and a core 21 having a refractive index substantially the same as that of the inner cladding (11) of the laser fiber.

This invention relates to side pumping a dual clad fiber laser through delivery fibers disposed along the length of the laser fiber, the delivery fibers having a numerical aperture of not more than half the numerical aperture of the laser fiber, having a core with a refractive index equal to the refractive index of the inner cladding (the multimode core) of the laser fiber.
High power fiber lasers, including fiber laser amplifiers, are most effectively pumped by semiconductor laser diodes. It is commonplace in the art to use diode laser pumps which are pigtailed, i.e., coupled into a multimode fiber, for ease of power delivery. In a multi-core, laser fiber, the diode pump""s power, at a preselected wavelength, is absorbed by a dopant, or combination of dopants, in a single-mode core of the laser fiber, which emit at a different wavelength, dependent on the dopant. The typical beam shape of an edge emitting semiconductor laser is elliptical and is best matched to the cross section of a rectangular shaped inner cladding. Heretofore, although there are patents and papers describing various schemes to feed the pump light through the side of the laser fiber, all practical systems thus far pump the laser through the end of the laser fiber.
End pumping has its drawbacks. There exist only two ports. The size of the end facets impose a severe limitation on the amount of pump power that can be injected into the fiber laser, which often suffers damage when the pump power exceeds 60W. It has been shown in R. Waarts, xe2x80x9cFiber Laser Technology for Commercial and DoD Applicationsxe2x80x9d, Thirteenth Annual Solid-State and Diode Transfer Laser Technology Review, 2000, that the power damage threshold for cladding materials is approximately 1.9xc3x97109W/m2 by assuming a 60W of pump power launched into a cladding with a diameter of 100 xcexcm. Finally, the absorption of pump power, and therefore the gain of the end pumped system, along the length of fiber, is very non-uniform; thus the system suffers a significant loss in efficiency.
In U.S. Pat. No. 5,864,644, fused tapered couplers are used to combine power, by placing the fibers together, twisting and pulling when heat is applied. However, the dimensions of the fibers are altered and the waveguiding properties of the fibers are consequently changed. Nonetheless, the method allows the power in the fused area to combine and be coupled into the fiber end facet. However, the power must be launched within the numerical aperture of the receiving fiber; power residing outside of this cone will be lost.
U.S. Pat. No. 5,127,068 discloses the use of a cylindrical micro-lens for collimating the output of a diode laser bar so that the pump radiation can be coupled into a double clad fiber laser. Such an arrangement requires a precisely aligned narrow spacing between the lens and the fiber facet. This requirement creates difficulty in making a proper alignment without causing physical damage to the optical components.
Much effort has been made to develop high power fiber lasers by clad pumping, but such effort has only reached limited success.
In a clad pumped laser system, the diode pump power is introduced into an inner cladding region, where it propagates due to internal reflection along its length. While pump power is propagating within the inner cladding region, it undergoes multiple reflections and repetitively passes through a doped core, where it is absorbed.
Side pumping has the ability for use of multiple ports, which has two major advantages: (1) while the pump power density at each port can be maintained well below the material damage thresholds, the sum over multiple inputs can provide extremely large amounts of pump power for the system, and (2) the pump power being distributed along the length of the fiber flattens the spatial gain in the system, thereby increasing the efficiency of the system per unit length. Side pumping can be accomplished by evanescent means or by direct coupling.
One method for side pumping of a clad pumped fiber laser system by evanescent means, disclosed in U.S. Pat. No. 5,999,673, uses fused tapered coupler techniques in which the delivery fiber is heated and pulled at its output end, thereby creating a tapered portion. Tapering the delivery fiber inherently causes a significant loss of pump power, which leaks out of the fiber. The tapered portion of the fiber is placed in contact with the double clad system by twisting the two fibers together, and then heated and pulled, thus causing that portion of the double clad system to be deformed; such deformation on a multicore system may destroy the phase locking of the system.
Another side pumping method, disclosed in U.S. Pat. No. 5,854,865, employs a deep V-groove cut into the inner cladding of a double clad fiber laser. By focusing the diode laser beam onto the V-groove with a lens, the pump light can be coupled into the inner cladding with a coupling efficiency greater than 80%. However, fabrication of V-grooves using an abrasive process to remove a significant amount of material (nearly half) can lead to structural damage to the clad pumped system where localized stresses become a major issue and increase the chance of fiber breakage. Also, V-grooves compromise the waveguiding capabilities of the system; therefore, if multiple V-grooves are used they must be placed far apart, thereby limiting the number of available ports.
Other means of side pumping by direct injection are disclosed in: E. F. Stephens, D. L. Wise, xe2x80x9cA Ruggedized Fiber Laser for Force Protection Capabilitiesxe2x80x9d, Thirteenth Annual Solid State and Diode Laser Technology Review, 2000, T. Weber, W. Luthy, H. P. Weber, xe2x80x9cSide-Pumped Fiber Laserxe2x80x9d, Applied Physics B, Vol. 63, pp. 131-134, 1996, and I. K. IIev, R. W. Waynan, xe2x80x9cGrazing-lncidence-Based Hollow Taper for infrared Laser-to-Fiber Couplingxe2x80x9d, Applied Physics Letters, Vol. 74, pp. 2921-2923, 1999. These either use various external micro optics, such as prisms, lenses and tapering components, or inject the pump power into a closed system with a highly reflecting inner wall. These efforts have not provided a satisfactory solution due to low coupling efficiencies or difficulties in maintaining perfect optical alignments.
U.S. Pat. No. 4,815,079 discloses a clad pumped laser system in which the diode pump power is introduced through side-coupled delivery fibers. However, the laser fiber has a rectangular inner cladding (outer core), and the delivery fibers also have a similar, rectangular core. By making certain assumptions, it is claimed that coupling efficiencies as high as 89% are achievable;
however, in the practical world, that configuration cannot yield efficiencies much over 30%. Further, the rectangular-cored delivery fibers are not well suited to easy interconnection with commercially available diode lasers and their pigtails or connectors.
The various clad pumping schemes for fiber double clad laser fibers known to the prior art are not effective in producing very high power without incorporating additional, necessary features. Very high power cannot be obtained from fiber lasers by end pumping alone, because the high pump power can lead to power damage at the two end facets of the fiber. Side pumping of a fiber laser has heretofore been very inefficient.
Objects of the present invention include: provision of high power fiber lasers; provision of an efficient and robust clad-pumped laser; efficient coupling of pump power from a delivery fiber by directly injecting the power into a laser fiber, through the sidewall, without twisting, tapering or cutting grooves in the fiber; delivering pump power to a laser fiber in a manner satisfying total internal reflection, without using external micro optics, such as lenses and prisms, at the interface; delivering pump power to an optical fiber without the need for subsequent adjustment; providing a more uniform gain profile in fiber lasers including fiber laser amplifiers; allowing large amounts of pump power to be injected into a fiber laser system; injecting high power into a clad pumped laser with very low insertion loss; and clad pumping of a laser using standard size fibers for delivery fibers, whose dimensions are well matched with the commercially available pigtailed diode pumps, so that the connection and disconnection of the two can be made easily by fusion splicing or with standard connectors.
This invention is predicated in part on the recognition that the refractive index of the delivery core should match that of the receiving laser inner cladding to avoid reflection at the interface, and in part on the recognition that the delivery fiber of a side-pumped laser system should have a core with a numerical aperture which is less than half of the numerical aperture of the inner cladding of the laser fiber to ensure total reflection of the delivered light within the laser fiber.
According to the present invention, laser pump power is injected into a clad pumped fiber laser system through at least one delivery fiber which is contiguous with the sidewall of the system, forming an integrated unit, the numerical aperture of the core of the delivery fiber being less than half the numerical aperture of the inner cladding of the laser fiber. According to the present invention, laser pump power is injected into a clad pumped fiber laser system through at least one delivery fiber which is permanently bonded to the sidewall of the system, forming an integrated unit, the index of refraction of the core of the delivery fiber being substantially the same as the index of refraction of the inner cladding of the laser fiber. According further to the present invention, laser pump power is distributed, in one or two directions, along the length of the clad pumped fiber laser system through multiple integrated ports.
In accord with another aspect of the present invention, the pump power is injected into the laser fiber at an angle such that it passes from the delivery fiber to the receiving fiber and is confined within the system by meeting the requirements for total internal reflection with Snell""s Law. With the invention, it is possible to transfer nearly all of the pump power to the core of a double clad fiber laser system of the invention.
A feature of the invention is that by permanently affixing the delivery fiber to the fiber laser, a robust and extremely low maintenance connection is created. Furthermore, this interface does not degrade the fiber structure, has negligible effects upon the waveguiding properties of the inner cladding region, and does not alter the physical dimensions of the cores. Therefore, it will not degrade the phase locking in a multicore fiber laser array. By balancing the indexes of refraction at both interfaces, (i.e., the interface of the core of the power delivery fiber with the inner cladding of the power receiving fiber) with the angle of introduction of the pump power, an efficient power transfer from fiber-to-fiber is accomplished while still meeting the total internal reflection requirement of the receiving fiber.
The invention offers three major advantages: (1) no further adjustment is needed, thus the maintenance cost is reduced; (2) attaching a delivery fiber which closely matches a pigtailed laser diode pump using a commercial fusion splicer reduces the insertion loss significantly (to less than 0.1 dB); and (3) the integrity of the clad pumped fiber system is preserved, despite the bonding of many delivery fibers at any location along the peripheral wall of the system, as desired. Since the cladding has very low insertion loss, the pump power injected according to the invention can travel over a very long fiber length while transferring the power to the doped core(s) to stimulate the ions for laser oscillation or amplification. Although the pump density at each port is below the damage threshold, the sum over all ports can be extremely high, leading to high power output that can exceed multiple kilowatts. Furthermore, extremely large amounts of pump power can be distributed among multiple ports along the length of a single fiber, thereby engendering a uniform gain.
The more uniform the gain in a fiber laser, the better the slope of efficiency. Therefore, the multiple ports of the invention enable the system to operate at efficiencies that can approach the quantum limit: 95% efficiency has been achieved. This highly efficient side pumping technique enables double clad fiber lasers to far surpass power damage limitations inherent in end pumping techniques.
The invention provides a robust method of transferring a large amount of pump power into fiber lasers through the sidewall of the inner cladding of a laser fiber, without degrading the structural integrity or the wave guiding properties of the fiber. The invention may be applied to other systems, such as fiber optical amplifiers and switches. By distributing the pump power through multiple ports along the fiber, this invention provides a significant increase in the total amount of transferred pump power, as compared to end pumping methods. Furthermore, the multiple ports generate a uniform gain that raises the system efficiency. The apparatus is extremely robust because the delivery fibers and the clad pumped system are integrated as a single unit, thus eliminating the use of various external optics, such as lenses and prisms, and avoiding the need for continuous optical alignment and tedious adjustments. The method provides a convenient way to connect/disconnect the pump source with a minimum insertion loss,  less than 0.1 dB.
Other objects, features and advantages of the present invention will become more apparent in the light of the following detailed description of exemplary embodiments thereof, as illustrated in the accompanying drawing.

Side pumping of optical fiber systems via multiple delivery fibers


A method of receiving a sounding reference signal (SRS) in a wireless communication system supporting multiple component carriers by a base station is provided. The method includes determining periodic SRS (P-SRS) transmission or aperiodic SRS (A-SRS) transmission about at least one serving cell (SCell) to be configured for a user equipment (UE), transmitting a triggering message including an activation or deactivation of the at least one SCell and indicating information for the A-SRS transmission according to the determination, and receiving an A-SRS from the UE through an activated SCell from among the at least one SCell configured in the UE. Uplink scheduling for an additional secondary serving cell and data communication through the uplink scheduling can be performed rapidly, as compared with a scheme using only a periodic SRS.

1. Field
This disclosure is directed to a wireless communication system and, more particularly, to a method of aperiodically or periodically transmitting a sounding reference signal in a wireless communication system supporting a plurality of component carriers, a base station and user equipment.
2. Discussion of the Background
Current mobile communication systems, such as 3GPP (3rd Generation Partnership Project), LTE (Long Term Evolution), LTE-A (LTE Advanced), and IEEE (The Institute of Electrical and Electronics Engineers) 802.16, are high-speed and high-capacity communication systems capable of transmitting and receiving data, such as video and radio by a voice-based service. In these mobile communication systems, an error detection scheme for technology capable of transmitting a large amount of data complying with a wired communication network, minimized information loss, and improved system transmission efficiency includes certain elements.
Furthermore, in several current communication systems, through uplink and downlink, the use of several types of reference signals for providing information about a communication environment and other information is used.
For example, in the LTE system, a User Equipment (hereinafter referred to as UE) sends a Sounding Reference Signal (hereinafter referred to as an 'SRS') (i.e., a reference signal used to estimate an uplink channel state) to an eNB, and an eNB sends a Cell-specific Reference Signal (hereinafter referred to as a 'CRS') (i.e., a reference signal used to estimate a downlink channel state) to a UE every subframe.
In addition, reference signals for channel estimation, and so on are periodically generated by, in general, an apparatus for transmitting the reference signals (for example, UE in the case of an uplink reference signal and an eNB in the case of a downlink reference signal).
Unlike a communication system that uses one carrier composed of one frequency band, a scheme capable of using a plurality of Component Carriers (hereinafter referred to as a 'CC') is also being explored.
In a communication system using a plurality of CCs, each of the CCs may function as one cell. A detailed scheme for transmitting a channel estimation reference signal for each CC has not yet been defined.

Apparatus and method for transmitting sounding reference signal in wireless communication system supporting multiple component carriers


A semiconductor memory device, that has a plurality of writing ports and reading ports comprises a first data latch portion, at least one second data latch portions, and communication units. The first data latch portion is directly accessible by externally entering an address signal, and the second data latch portions are parallel connected to the first data latch portion. The communication units is used to access one of the first and second data latch portions. Therefore, according to the semiconductor memory device of the present invention, the amount of hardware of a register file of the processor employing parallel processing and local register architecture can be significantly reduced by providing the first data latch portion and at least one or more of the second data latch portions having communication units and accessing one of the first and second data latch portions.

1. Field of the Invention
The present invention relates to a semiconductor memory device and, more particularly, to a semiconductor memory device having a plurality of writing ports and reading ports.
2. Description of the Related Art
Recently, microprocessors (i.e. arithmetic processing devices, or processors) generally comprise an instruction fetching unit, instruction decoding unit, arithmetic operation executing unit, register file, and the like. Further, these microprocessors have been, for example, designed to execute instructions by pipeline operation.
The conventional microprocessor includes only one arithmetic operation executing unit, and thus the register file comprises a semiconductor memory device (for example, SRAM) having two-read/one-write ports. Such semiconductor memory devices having two-read/one-write ports can effectively carry out three address type arithmetic operations, such as adding instructions.
The microprocessors tend to employ parallel processing architecture, such as VLIW (Very Long Instruction Word) or Superscaler, and the like, to enable higher speed processing. Microprocessors employing such types of architecture include a plurality of arithmetic operation executing units and semiconductor memory devices having a plurality of read/write ports for performing a transfer of data between a plurality of arithmetic operation executing units and semiconductor memory devices (register file).
In general, for n (i.e. number of) arithmetic operation execution units, 2 n reading ports and n writing ports are necessary for the semiconductor memory devices. Note, in order to execute a sub-routine call or so forth, an architecture of a microprocessor having a plurality of local register files has been known. However, such an architecture requires a large number of local register files, since it assigns a specific local register file for each sub-routine. Such a register file is, for example, formed by employing a plurality of two-read ports/one-write port semiconductor memory devices.
On the other hand, in accordance with the progress of semiconductor technology, data processing devices capable of high speed performance have been developed and arithmetic processing devices (microprocessors) that are capable of performing parallel arithmetic operations have been provided. Accordingly, semiconductor memory devices (for example, multi-port SRAM) having a plurality of writing ports and reading ports have been developed. However, these semiconductor memory devices have a large amount of hardware, and they are expensive.

Semiconductor memory device having a plurality of writing and reading ports for decreasing hardware amount


A detecting apparatus includes: a change-over switch for switching on/off display of a scope model on a liquid crystal monitor; a position calculating portion for calculating respective positions of source coils; a scope model generating portion for generating a scope model of an electronic endoscope based on the respective positions of the source coils calculated by the position calculating portion; and a selector for selectively outputting to the liquid crystal monitor a display-pause-time image stored in a display-pause-time image storing portion and a scope model image from the scope model generating portion; and a control portion for controlling each of these portions. The detecting apparatus thus displays an insertion shape of the endoscope at a timing as needed.

In recent years, in diagnosis using an endoscope, endoscope shape detecting apparatuses have come to be used for detecting a shape of an endoscope or the like inserted into a body or the like by using a magnetic field generating device and a magnetic field detecting device and displaying the detected shape by means of a display apparatus.
For example, Japanese Unexamined Patent Publication No. 2003-245243 and others disclose an apparatus for detecting the shape of an endoscope in insertion state by using a magnetic field and displaying the detected endoscope shape. In this apparatus, a plurality of magnetic field generating devices are driven which are disposed at predetermined intervals in an insertion portion of an endoscope to be inserted into the body to generate a magnetic field around the devices. This apparatus further detects respective three-dimensional positions of the magnetic field generating devices by means of magnetic field detecting devices disposed outside the body. The apparatus generates a curved line continually linking each of the magnetic field generating devices based on the three-dimensional positions thus detected, and displays on a display apparatus a modelled three dimensional image of the insertion portion.
By observing the image displayed on the display apparatus, an operator or the like can grasp the position of a distal end portion of the insertion portion inserted into the body and the insertion shape thereof, allowing the work of insertion to a target region or the like to be smoothly performed.
However, in the conventional endoscope shape detecting apparatus, the insertion shape of the endoscope is constantly displayed on the display apparatus. Therefore, during, for example, inspection using the endoscope image, the insertion shape image gets in the field of view in some cases even when it is not necessary to monitor the insertion shape image.
The present invention was made in view of the above-mentioned circumstances and an object thereof is to provide an endoscope shape detecting apparatus capable of displaying an insertion shape of the endoscope at a timing as needed.


A method is provided for enhancing the adhesion of organic polymer coatings to electrolytically passivated (CDC) tin-plated steel strip. The method includes applying a solution comprising 0.1 to 7 percent of an adhesion promoter to the electrolytically tin-plated strip during the processing of the strip on an electrolytic tin-plating line. The adhesion promoter may be at least one selected from the group consisting of: ##STR1##. where n is within a range of from 4 to 99;. (b) C.sub.16 H.sub.33 +N(CH.sub.3) .sub.3 M where M is member of the halogen group; and PA2 (c) R.sub.n --Si--(X).sub.4-n where R is a non-hydrolyzable organic radical selected from the group consisting of glycol, epoxy, amine, diamine or mercapto groups, and mixtures thereof, containing from 3 to 10 carbon atoms; the number n is an integer from 1 to 3; and X is a hydrolyzable group selected from the group consisting of Cl--, OCH.sub.3, OCH.sub.2 CH.sub.5, OOCCH.sub.3, OCH.sub.2 OCH.sub.3, amine, diamine, triamine, acyloxy and alkoxysilanes, and mixtures thereof.

In the production of tin-plated steel for food and beverage cans the steel is plated with tin on an electrolytic tin-plating line. The tin-plate coating is generally melted or "reflowed" and quenched to produce a bright and shiny appearance. As a result of reflowing, a film of tin oxide develops on the surface of the tin-plate. If the growth of this oxide is not stopped or inhibited, it can lead to discoloration when the steel is used for packing certain products. To inhibit oxide growth, the reflowed strip is subjected to a cathodic dichromate treatment in subsequent sequential sections of the electrolytic plating line to passivate the tin-plate surface. After this passivation, a thin film of synthetic oil is electrostatically applied uniformly on the surface before shipment to customers for lacquering with an organic coating. The lacquer may or may not include an adhesion promoter to cause the lacquer to adhere to the dichromate treated surface of the tin-plate. Can manufacturers have experienced sporadic occurrences of poor adhesion of certain epoxy phenolic lacquers despite the inclusion of adhesion promoters in the lacquer. Historically the adhesion problem has been linked to the presence of tin oxide that forms on the surface of the tin-plate and which continues to grow slowly in storage as mentioned above. Varying the solution concentration, temperature, pH, current and current density of the cathodic dichromate treatment as well as the line speed of the strip through the treatment tank has not solved the problem of sporadic poor lacquer adhesion on tin-plate product. It has been further suggested that the adhesion problem could be due to additional tin and chromium oxides that rapidly develop during the lacquer baking cycle. The thermally induced tin oxide is thought to be weak and fragile. However, it has not been possible to fully determine the nature of these oxides and differentiate the thermally induced oxides from the more stable forms. Differences in the formulation of the epoxy phenolic lacquers used by various can manufacturers are also thought to be one cause of the problem. For example, several epoxy phenolic lacquers commonly used for food cans have been found to exhibit differing degrees of sensitivity to variations in the cathodic dichromate treated tin-plate surface. There are many factors that effect the degree of sensitivity of the lacquer to the surface of the tinplate, such as the molecular weight of binders contained in the lacquer, the ratio of different binders in the lacquer, and other factors that appear as numerous as the number of lacquer formulations. To date efforts to solve the adhesion problem have not been successful
U.S. Pat. No. 5,753,779 to Verberg, discloses an aqueous chromium-free coating for treatment, particularly the pretreatment, of metal packaging for the foodstuffs industry, for example tin-plate and aluminum. The coating comprises acrylic acid or a derivative and a crosslinking system comprising at least one hydroxide of a divalent metal and an amine compound. The acrylic acid or derivative and the crosslinking system are used in a ratio of 1.5-4 to 2-4. Preferably the acrylic acid derivative is an acidic resin which comprises 2-8% of the coating solution. The coating solution is applied to a degreased substrate that has been freed of oxide such that the layer has a weight of 25-4000 milligrams per square meter after drying. The coating is safer to use on health grounds than chromium conversion coatings and has comparable properties such as lacquer adhesion.
U.S. Pat. No. 4,104,419 to Tanikawa et al, discloses a method for producing electrolytic tin-plate that is free from discoloration (yellow stain) and having an improved soldering, paint adhesion, resistance to smudges, eye-holeing, and corrosion by sulfides. The electrolytically tin-plated steel is treated with an aqueous solution consisting essentially of 0.1 to 10% of a pyrazole derivative, after which the steel is dried and the tin-plate coating is reflowed and subjected to a conventional chromate treatment. The aqueous solution may also contain 0.1 to 10% of a colloidal substance selected from the group consisting of silica sol and alumina sol.
U.S. Pat. No. 3,138,548 to Ham et al, discloses a method of treating electrolytic tin-plate to improve its lacquer adherent properties. The reference discloses subjecting a tin-plate surface after fusion to treatment by a combination of steps which include: a cathodic treatment in an alkaline electrolyte, a water rinse, a dilute acid dip to bring the surface of the plate to about pH 4-6, and a cathodic chromate treatment in an acidic electrolyte having a pH of about 4-6.
U.S. Pat. No. 3,826,675 to Smith et al, discloses metallic container stock such as tin-plate having a citric acid ester lubricant applied to its surface and which is characterized by excellent wettability and adhesion of organic coatings, especially epoxy resin coating compositions. Preferred citric acid ester lubricants disclosed are triethyl citrate, acetyl triethyl citrate, tributyl citrate, acetyl tributyl citrate, acetyl tri-2-ethylhexyl citrate and mixtures of them. The lubricant is applied to the tin-plated steel strip after flow brightening, quenching and a cathodic dichromate treatment.
U.S. Pat. No. 2,974,091 to Neish, discloses a method of treatment of tin-plate to minimize or eliminate the tendency to "eye-holing" i.e. portions leaving bare spots when lacquered. The steel strip is cleaned, pickled, plated with tin, heated to brighten the deposited tin coating and quenched by a water spray. It is then passed through a stabilizing bath where it is subjected to treatment for the formation of a protective film containing chromium compounds by electrolysis in a solution containing hexavalent chromium. After that the strip is passed through a water rinse and then through a spray or bath of an acidic reducing solution such as a dilute aqueous solution of citric acid or stannous chloride to reduce any free hexavalent chromium to trivalent chromium thereby reducing the tendency to eye-holing on lacquering.
An abstract of Japanese Kokai, JP53084037, assigned to Toyo Ink Manufacturing Company, discloses coating tin-plate with a thin film of metal alcoholate and/or its chelate compound to improve the adherence of ultraviolet curable ink compositions to the tin-plate.
U.S. Pat. No. 4,228,221 to Rohowetz, discloses a method of increasing adhesion of inks and coatings on metal surfaces. The method includes a treatment of the lubricated metal substrate with an organic titanate such as tetrakis (2-ethyl hexyl) titanate and then exposing the surface to ultraviolet light to accelerate the reaction of the titanate with the metal surface.
An abstract of French Patent, FR 2696371, assigned to Ateliers Reunis Caddie SA, discloses applying a varnish underlayer to electrolytic zinc-plated metal to improve the bonding of epoxy resin outer coatings.
U.S. Pat. No. 4,388,158 to Inui et al, discloses steel sheet having an extremely thin tin layer or an extremely thin iron-tin alloy layer having excellent bonding strength after aging in hot water, without deterioration of the bonding strength of organic adhesives. The steel is produced by passing the steel through an acid electrolyte, such as stannous phenolsulfonate or stannous sulfate, to which at least one sulfate selected from the group of sulfates of alkaline metals, ammonium, aluminum, manganese and chromium has been added.
U.S. Pat. No. 4,285,783 to Giza et al, discloses a plastic coating for metal shelving to which an epoxy resin is applied. The metal is plated with a nickel film and a chromium film, which is then treated with an iron phosphate in order to enhance the adhesion of the final outer layer of plastic.
U.S. Pat. No. 3,915,812 to Yamagishi et al, discloses a method for the cathodic treatment of steel strip prior to electrolytic tin-plating to enhance its corrosion resistance. The treating bath comprises an aqueous solution containing from 1 to 10 g/l of caustic soda or sodium orthosilicate and from 5 to 50 g/l of one or more of water soluble oxyacids such as citric acid, gluconic acid, water soluble salts of the oxyacids, a chelating agent having a chelating capability in an alkaline region or an aqueous solution containing from 1 to 10 g/l of sulfuric acid and from 5 to 50 g/l of glucocinic acid, water soluble salts of gluconic acid or a mixture thereof.
U.S. Pat. No. 4,402,747 to Bird et al, discloses a rust inhibiting coating for steel comprising dioctyl sebacate, sodium benzoate and certain sarcosine surfactants.
A literature paper by Barry Arkles entitled "Tailoring Surfaces with Silanes" published by CHEMTEC, December 1977, pages 766-778 discloses organosilanes for altering the wetting or adhesion characteristics of substrates. The reference teaches that organosilanes include R.sub.n nonhydrolyzable organic radical(s) and X.sub.4-n hydrolyzable group(s). The nonhydrolyzble group(s) typically are said to be halogen, alkoxy, acyloxy, or amine. Following hydrolysis, a reactive silanol group is formed, which can condense with other silanol groups, for example, those on the surface of siliceous fillers to form siloxane linkages. Stable condensation products are also formed with other oxides such as those of aluminum, zirconium, tin, titanium and nickel. Less stable bonds are said to be formed with oxides of boron, iron, and carbon. The reference discloses that one can form covalent bonds between an organic moiety and a substrate through an intermediary functional silane, called a coupling agent. Coupling agents are said to be used in enzyme immobilization, solid state synthesis, as antimicrobial agents and dye-fixing agents in textiles, organic surface coatings, and polymer composites and bulk interfaces. The reference states in most cases the substrate is pretreated with the silane-coupling agent, but integral blending accomplished by simple mixing of all the reactants at once, particularly for coatings and composites, is frequently used. The reference does not teach or suggest that the addition of organosilanes to the surface of electrolytic tin-plated steel before, during or after chromate treatment would eliminate poor adhesion of lacquers containing adhesion promoters subsequently applied to the surface.
Various other miscellaneous references are as follows: U.S. Pat. Nos. 3,245,577: 3,227,637; 3,322,656; 4,487,663; 4,812,365; 5,084,358; and 5,248,405.


A multi-user computing device, such a communal computing device like an interactive digital whiteboard, can execute single user aware (“SUA”) applications and multi-user aware (“MUA”) applications. Instances of SUA applications execute in the context of a single user. MUA applications can execute in the contexts of multiple authenticated users simultaneously. A multi-user aware OS platform authenticates and de-authenticates users of the multi-user computing device. The multi-user aware OS platform provides notifications to MUA applications when users are authenticated and de-authenticated. When a new user is authenticated, MUA applications begin executing in the context of the newly authenticated user and any other previously authenticated users. When users are de-authenticated, MUA applications stop executing in the context of the de-authenticated user but continue executing in the context of the remaining authenticated users of the multi-user computing device. Data associated with the de-authenticated user is removed from the multi-user computing device.

Computing systems supporting multiple simultaneous users ("multi-user computing systems") are commonly utilized in the workplace and other types of environments. For example, a communal computing device, such as an interactive digital whiteboard, might be installed in a conference room of an enterprise. Employees of the enterprise can utilize the communal computing device individually or in collaboration with one another. Such a computing system might be utilized throughout the day by many different employees or groups of employees.
Multi-user computing systems such as those described above typically utilize the concept of an "active" user when multiple users are utilizing the device simultaneously. For instance, a multi-user computing system can identify the current user of the system using a variety of technologies such as facial recognition. Input made to the multi-user computing system is then attributed to that user. If another user begins to utilize the multi-user computing system, that user will be identified as the active user and input to the device will be attributed to that user.
Maintaining the identity of an active user and attributing user input to the active user as described above can cause a number of technical problems. For example, significant processor cycles and memory can be consumed when an operating system ("OS") continually identifies active users and notifies applications of the current active user, particularly when many users are working with a multi-user computing system simultaneously. As another example, a multi-user computing system might identify the active user incorrectly, thereby causing input to be attributed to the wrong user. Processor cycles and memory can then be utilized unnecessarily to identify the correct active user and properly attribute the user input to that user.
Some multi-user computing systems do not utilize the concept of an active user. In these multi-user computing systems, applications are executed in the context of single users and, consequently, only have access to data associated with a single user at a time. As a result, users of these types of multi-user computing systems commonly must share documents for collaboration on a multi-user computing system via email or other file sharing mechanisms. This also unnecessarily utilizes memory, processor cycles, and network bandwidth.
It is with respect to these and other technical challenges that the disclosure made herein is presented.

Multi-user computing device configured for executing applications in multiple user contexts simultaneously


Methods and apparatus for improving transmission channel efficiency are provided. In an example, a digital signal is received. A leading portion of a bit in the digital signal is pre-emphasized. The received digital signal is modulated with a pre-emphasis signal to pre-emphasize a leading portion of the bit in the digital signal. The pre-emphasis signal provides pre-emphasis substantially when a clock is high and the received digital signal transitions. The pre-emphasis signal does not provide pre-emphasis when the received digital signal is low or the received digital signal is unchanged. The pre-emphasized digital signal is then transmitted via the transmission channel. In an example, the received digital signal us a pulse-amplitude modulated multilevel signal.

In high-speed digital data communications, a transmitted digital signal is attenuated by the transmission channel (i.e, transmission medium) through which the digital signal travels. The attenuation causes intersymbol interference (ISI) and increases jitter.
ISI arises because of temporal "spreading" of a transmitted symbol pulse due to a dispersive nature of the channel, which results in an overlap of adjacent symbol pulses. In other words, ISI occurs when a portion of a digital signal representative of one piece of information interferes with a different portion of the digital signal representative of a different piece of information. The transmitted symbol pulses may arrive at a receiver at different times. Components of adjacent symbol pulses may interfere constructively or destructively. Adverse effects of ISI are pronounced when a signal to noise ratio is high and the channel is relatively noise-free. In relatively noise-free channels, the presence of ISI greatly degrades performance of the communication system.
Timing jitter is a temporal disorder related to variability in a latency time of the transmitted digital signal. In other words, the transmission medium through which the digital signal travels introduces a variable phase delay into the transmitted digital signal.
An eye diagram provides a convenient way to evaluate the impact of ISI and jitter-related impairments. The eye diagram is formed by superimposing waveforms of multiple pulse sequences of the transmitted digital signal. The eye diagram typically looks like an eye between a pair of rails. An eye diagram is useful to a circuit designer, because the eye diagram indicates levels of ISI and jitter imparted by the transmission medium into the transmitted digital signal. An open eye pattern indicates minimal signal distortion. A closed eye pattern indicates levels of ISI and jitter so severe that a received signal may be unintelligible.
Once a level of ISI and jitter is determined, full-bit pre-equalization can be used to minimize the effects of ISI. Full-bit pre-equalization in a transmitter boosts the amplitude of the digital signal prior to transmission, so that the digital signal may be more easily decoded at the receiver. The digital signal is altered at the transmitter so that the influence of the channel on the digital signal yields a received digital signal capable of being decoded at the receiver. Conventionally, full-bit pre-equalization increases the amplitude of the digital signal at every digital data transition, and leaves the amplitude unchanged when there is no transition of the digital data.
FIG. 1 illustrates conventional full-bit pre-equalization 100. An input digital data signal 105 (Data_in) to be transmitted is shown. A full-bit pre-emphasis signal 110 (Pre-emph) is also illustrated. When the full-bit pre-emphasis signal 110 is high, full-bit pre-emphasis is enabled, and the amplitude of the state of the input digital data signal 105 is increased for the full duration of each pre-emphasized bit, as shown in the full-bit emphasis data out waveform 115 (Data_out).
An effect of full-bit pre-emphasis is increased noise of the transmitted digital data signal, particularly when multi-level data is transmitted. The added noise decreases a sampling margin at the receiver. For example, in a 4-PAM (4-level pulse-amplitude modulation) output driver, the conventional full-bit pre-emphasis method introduces noise to each of the four logic levels, which leads to data sampling errors at the receiver.
Accordingly, there are long-felt industry needs for apparatus and methods to improve transmission channel efficiency, and improve the eye opening of a transmitted pulse amplitude modulated signal, without affecting the sampling margin.

Method of half-bit pre-emphasis for multi-level signal


A compliant seal device for sealing a high pressure area from a low pressure area. The compliant seal device comprises a base member including an annular base wall, a first wall extending radially inward from the base wall proximate the high pressure area and a second wall extending radially inward from the base wall proximate the low pressure area, the base member having a cavity formed therein between the first wall and the second wall. The compliant seal device further comprises a plurality of flexible sheet members extending between the first wall and the second wall, each of the plurality of flexible sheet members having a base end fixed to the first wall and a moveable free end in sealing engagement with the second wall to substantially enclose the cavity with an adjustable pressure therein.

1. Field of the Invention
The present invention relates to gas or liquid seals and, more specifically, to gas or liquid compliant seals for sealing high pressure areas from low pressure areas.
2. Description of the Related Art
Many classes of machinery use clearance seals to contain a gas under pressure. Often these seals are simple labyrinth seals which break down pressure by using a series of teeth or blades in close proximity to a rotating shaft. Such devices are well known and reliable, but allow high rates of gas leakage. Typically, clearances between the blade tips of a labyrinth seal and the shaft are as high as 0.001-0.002 inches per inch of shaft diameter.
Much work has been done to reduce the leakage of labyrinth seals. Typically, the approach of past efforts has been directed toward improved blade geometry (e.g., backward angled blade designs), step seals, or interlocking blade designs to reduce losses. Abradable labyrinth seal designs have also been developed and are employed, particularly, on jet engines. The blades of such abradable seals are initially installed with a line-to-line clearance, and then wear in to their own clearance as the machine rotates. However, after the rotor has gone through an operating history of radial vibration combined with axial excursions, a crescent-shaped clearance is often cut into the abradable seal, and leakage can increase dramatically. In spite of many improved designs, therefore, leakage losses for labyrinth seals continue to represent a considerable energy loss in rotating machinery.
Another significant problem with high pressure labyrinth seals is the occurrence of rotordynamic effects. Since high pressure gas is quite dense, a labyrinth seal begins to act as a bearing with high gas pressures, but tends to destabilize the rotor due to a lack of concentricity with the actual machine bearings. Significant effort has been made recently to decrease rotordynamic excitation effects. The product of these efforts includes swirl breaks in front of a labyrinth, reverse swirl inducers, and injecting tangentially non-moving gas into the first stagnant region of the labyrinth. Other work has been concentrated on optimized geometry and creating a rough surface within the labyrinth seal to retard circumferential gas velocity buildup. Also, honeycomb design labyrinth seals have been developed to reduce rotordynamic excitation effects. However, further reduction of rotordynamic effects is needed.
As an alternative to the labyrinth seal, applicant has proposed a seal having compliant fingers which ride upon a thin gas or liquid film between the fingers and a rotating shaft. Such a compliant finger seal is disclosed in U.S. Pat. No. 5,100,158.