The barrel of a pistol, specifically in a short recoil operated pistol, is comprised of multiple bearings surfaces comprised of cams and lugs that allow the pistol to function. The surfaces mechanically delay the pistol enough to allow the pistol to reliably function in the manner of an automatic firearm, chambering a round at the end of each cycle of operation. A barrel that locates a forward lug positioned horizontally in front of the trigger guard of the pistol with side cams that are shallow and interact in a way to provide the pistol with a robust and consistent lock up from shot to shot to provide an advantage in the function of the firearm.

The barrel of a pistol, specifically in a short recoil operated pistol, is comprised of multiple bearings surfaces comprised of cams and lugs that allow the pistol to function. The surfaces mechanically delay the pistol enough to allow the pistol to reliably function in the manner of an automatic firearm, chambering a round at the end of each cycle of operation.
Pistol barrels, in short recoil operated pistols, have traditionally located their cam and lug surfaces as near to the bore of the pistol as possible. These surfaces are usually comprised of an easily machined single or double lug surface that locks into the frame of the pistol. This action, traditionally, happens above the trigger guard, which increases the bore axis of these traditional designs.
The traditional lock up system constricts the ability to lower the bore axis with a robust barrel design. The present invention provides a barrel that locates a forward lug positioned horizontally in front of the trigger guard of the pistol with side cams that are shallow and interact in a way to provide the pistol with a robust and consistent lock up from shot to shot.


Provided are a variety of chemically sensitive, stable (insoluble over a specified period of time), nontoxic, and non-antigenic hydrogel particles which undergo a measurable change in at least one electrochemical or optical property as a function of interaction with one or more substance(s) to be detected. Also provided are methods of using these hydrogel particles to detect one or more selected analytes, and in certain aspects detect one or more analytes in vivo. Further provided are devices used to detect and measure the optical or electrochemical changes.

1. Field of the Invention
The present invention relates generally to the fields of chemistry, biology, biochemistry, medical devices and chemical detection devices. More particularly, it concerns polymeric compositions, methods and devices for the detection of one or more selected analyte(s), preferably detection of one or more analyte(s) in vivo. The present invention also concerns polymeric constructs for analyte detection and concentration measurement using visualization or production of electrochemical signals from a construct after implantation in vivo. In particular, the invention concerns detection or measurement of blood glucose levels in vivo for the management of diabetes. Additionally, devices are provided to detect and measure the optical or electrochemical changes in polymeric constructs.
2. Description of Related Art
Diagnosis of various disease and injury conditions are often made on the basis of the detection and measurement of the concentration of one or more body chemicals or analytes. Currently, the levels of numerous selected body chemicals or analytes are measured manually and invasively by withdrawing a sample of blood. For most analytes the sample is usually sent to a centrally located lab where it is typically analyzed with large and expensive machines using wet chemistry, immunoassays, and/or enzyme electrode based biosensing. This mode of operation is expensive and time consuming, and therefore represents a significant hazard to critically ill patients in operating rooms, intensive care units and trauma/critical care units. In particular, for trauma/critical care cases it is known that survival rates decrease dramatically if treatment is delayed for more than one hour. For instance, the measurement of arterial blood gases is a primary indicator of respiratory function, and lactate values are used as an indicator of shock. Therefore, the frequent assessment of these and other analytes is essential to clinical diagnosis and management.
Exemplary of diseases that require frequent monitoring of analytes is diabetes mellitus. Diabetes mellitus is a chronic disease that, if unregulated, can give rise to large fluctuations in blood glucose levels. This disease currently afflicts over 100 million people worldwide and nearly 14 million in the United States (National Institute of Diabetes and Kidney Diseases, 1994). In the U.S. this disorder, along with its associated complications, is ranked as the seventh leading cause of death (Cotran et al., 1989). In order to maintain normal glucose levels, blood glucose must be monitored frequently throughout the day. Self-monitoring of blood glucose is recommended for diabetic patients as the current standard of care and, since the announcement of the Diabetes Control and Complications Trial results (National Institute of Diabetes and Digestive and Kidney Diseases, 1993), there is now no question that intensive management of blood sugars is an effective means to prevent or at least slow the progression of diabetic complications such as kidney failure, heart disease, gangrene, and blindness (National Institute of Diabetes and Digestive and Kidney Diseases, 1993; Wysocki, 1989; Speicher, 1991).
The goal of diabetes therapy is to approximate the 24-hour blood glucose profile of a normal individual. Without regulation, hypoglycemia, a condition in which the blood glucose level falls well below normal, can result, which can cause the patient to slip into a coma and eventual death. Alternatively, a condition known as hyperglycemia can develop, in which blood glucose levels can rise considerably above normal levels. If left untreated, these abnormally high blood glucose levels may result in long-term complications such as an increased risk of coronary artery disease, hypertension, retinopathy, neuropathy, and nephropathy (National Institute of Diabetes and Kidney Diseases, 1994; Cotran et al., 1989; National Institute of Diabetes and Digestive and Kidney Diseases, 1993; Hanssen, 1986).
Proper treatment includes maintaining blood glucose levels near normal levels. This can only be achieved with frequent blood glucose monitoring so that appropriate actions can be taken, such as insulin injections, proper diet, or exercise. Unfortunately, the currently preferred method of sensing is an invasive technique, requiring a finger stick to draw blood each time a reading is needed. This approach is both time-consuming and painful. Therefore, there is a lack of compliance among the diabetic population for even monitoring their levels once per day, not to mention the recommended five or more times daily (National Institute of Diabetes and Digestive and Kidney Diseases, 1993).
One potential method of achieving tighter metabolic control in diabetic patients is a closed-loop insulin delivery system, incorporating a microprocessor-controlled insulin pump and a glucose sensor. Various amperometric devices have been fabricated based upon the electrochemical oxidation of H2O2 generated during a reaction between glucose and oxygen catalyzed by glucose oxidase (Tatsuma et al., 1994). The focus of amperometric biosensors appears to have shifted towards the incorporation of charge mediators as electron xe2x80x9cshuttlesxe2x80x9d between the redox center of the enzyme and the electrode surface (Hale et al., 1991; Pishko et al., 1991). These H2O2 and mediator based biosensors have taken on many forms, including covalent immobilization directly to the electrode surface, retention by a membrane, or entrapment in a polymer hydrogel (Henning, T. and Cunningham, D., 1998).
Glucose sensors, which use an enzyme (glucose oxidase) to achieve specificity, are currently not stable or sensitive enough to meet the demands of a closed-loop delivery system. As a result, the application of glucose biosensors has been primarily limited to home glucose test meter and blood-gas instruments containing sensors for glucose (Rouhi, 1997). There are a number of reasons for this lack of commercial progress, both technical and economic. Technically, many proposed biosensors for glucose simply do not have the accuracy and stability (operational or storage) to meet the desired need. Inaccuracy and imprecision in sensor performance are frequently due to imprecision in sensor manufacturing, e.g. immobilized biomolecules cannot be deposited on transducer surfaces at the same density and with the same mass transfer limitations. Instability is often a problem inherent in the biomolecule, the result of poor immobilization methods resulting in leaching, or inactivation of the biomolecule by species present in the sensing environment (Pishko, M. V., 1995).
Glucose detection devices have been reported that quantify glucose concentration in blood and body fluids. One such device uses fluorescence resonance energy transfer (FRET) between a labelled ligand and a labelled carbohydrate-containing receptor (U.S. Pat. No. 5,342,789). The binding of glucose to the receptor prevents energy transfer from the labelled receptor to the labelled ligand, and thus prevents the quenching of the flourescence of the labelled receptor.
Noninvasive methods to quantify blood chemicals, particularly glucose, have been attempted using various optical approaches. Four primary approaches being investigated, including near-infrared (NIR) absorption spectroscopy (Small et al., 1993; Marbach et al., 1993; Robinson et al., 1992; McShane et al., 1997), NIR scattering (Kohl and Cope, 1994; Maier et al., 1994), polarimetry (March et al., 1982; Gough, 1982; Cameron and Cotxc3xa9, 1997; King et al., 1994; Cotxc3xa9 et al., 1992), and Raman spectroscopy (Goetz, Jr. et al., 1995; Berger et al., 1997).
Each of these approaches suffer primarily from a lack of specificity. The NIR scatter approach is confounded by changes in indices of refraction, since tissue scattering is also caused by a variety of substances and organelles which all have different refractive indices. The Raman approach is non-specific, lacks good sensitivity, requires high powers, and suffers from large background autofluorescence of the tissue in vivo (Cotxc3xa9, G. L., 1997).
Although reports have been given for in vivo near-infrared (NIR) absorption spectroscopy data, these results have been primarily based on bolus injections of intravenous glucose (Marbach, 1993; Robinson 1992). Since the multivariate statistics can produce strong temporal correlation due to independent factors these results are suspect and could likely be due to temporal variations other than glucose. Another drawback to the NIR approach is a lack of repeatability of the NIR signal in vivo both within and especially between patients (Day, 1996; Sabatini, 1996). Thus, the main drawback for the NIR technique is again the lack of specificity as well as of lack of sensitivity in the presence of these confounders.
For polarimetry to be used as a noninvasive technique for blood glucose monitoring, the signal must be able to pass from the source, through the body, and to a detector without total depolarization of the beam. Both the skin and eye have been used as detection sites for this technique. Overall, tissue birefringence and motion artifact are sources of error for this approach regardless of the sensing site. The change in rotation due to other chiral molecules such as proteins creates problems of specificity. Thus, as with all the previously described potentially noninvasive optically based approaches the primary drawback is not only the lack of sensitivity but the lack of specificity of these approaches.
The use of fluorescence was investigated for glucose monitoring in vivo using an indwelling fiber optic approach and a membrane (Mansouri and Schultz, 1984; Schultz et al., 1982), however, to date it has not been developed as a noninvasive technique. In this approach the fluorophore was bound on the inner surface of the membrane at the tip of the fiber. Glucose had a higher affinity for the membrane base molecule and displaced the fluorophore causing the fluorescent light to be returned through the fiber and thus had good specificity. However, the indwelling optical fiber-based approach has many of the same problems associated with previous electrochemical approaches, including membrane fouling, encapsulation, and decrease in response time, as well as opening the body to potential infection. In addition, the fiber was intravenously implanted and thus was small, yielding very low signal-to-noise-ratios (Mansouri and Schultz, 1984; Schultz et al., 1982).
Biosensor applications for the detection and identification of pathogens by DNA or RNA hybridization, or rapid DNA sequencing require a high-density pattern of individual sensing elements (Chee et al., 1996; Yershov et al., 1996). Thick film technology have been used for a number of years to fabricate single biosensors for the home glucose test market, but this technology is not amenable to the fabrication of micrometer scale arrays of sensors. Biotin/Avidin systems have been utilized to immobilize enzymes in an ordered fashion, albeit without charge mediators (Dontha et al., 1997). If biosensors are to see more wide spread application, sensor fabrication technologies must be developed that allow the development of stable, easily manufactured multisensor arrays (Madou and Tierney, 1993).
Recent research on patterning biomolecules on surfaces has focused primarily on self-assembled monolayers (SAMs; Mooney et al., 1996; Whitesides et al., 1991), and tethered biomolecules on surfaces that may potentially form addressable patterned arrays (Mooney et al., 1996; Britland et al., 1992; McLean et al., 1993). These patterned surfaces are formed, particularly using alkane thiols and their derivatives on gold-coated surfaces. SAMs also permit the site specific immobilization and orientation of biomolecules on a surface. However, two-dimensional approaches such as SAMs may limit the number of biomolecule recognition sites on the sensor surface, and thus may have low signal levels and require shielding or other measures to reduce noise. The structure of self-assembled molecules on a surface can also result in defects or xe2x80x9cpinholesxe2x80x9d in the monolayer and contribute to instability, particularly at applied potentials. The current adhesion chemistry used in the fabrication of SAMs also permits monolayer formation only on a limited number of surfaces, most commonly gold. In addition to monolayers, photolithography and other photoinduced patterning chemistries were highlighted in a few studies, demonstrating the formation of patterned biomolecule surfaces (Sundberg et al., 1995; Dontha et al., 1997) and micropatterned polymers for optical chemical sensing (Healey et al., 1995).
In prior research of biosensors based upon redox polymers coupled to biorecognition molecules such as oxidoreductases, the polymer served to immobilize the enzyme via formation of an insoluble protein/polymer complex (Pishko et al., 1990a; Pishko et al., 1990b; Tatsuma et al., 1994), through the physical entrapment of the enzyme in a polymer film (Hale et al., 1990; 1991), and/or through the covalent cross-linking of the enzyme and polymer (Gregg and Heller, 1991b; Ohara et al., 1993). Amperometric biosensors based on redox polymer/enzyme complexes were shown to be miniaturizable (Pishko et al., 1991) and could measure analytes either intravenously or subcutaneously when implanted in rats (Csoregi et al., 1994; Kerner et al., 1993; Linke et al., 1994; Quinn et al., 1995b; Schmidtke et al., 1996). In all of these studies, the redox polymers were synthesized by heat-induced free radical polymerization. Electropolymerization of vinyl-containing redox monomers was used to polymerize and deposit redox polymers on electrodes but was not demonstrated as an effective method of immobilizing enzymes or forming patterned films (Denisevich et al., 1982; Abruna et al., 1981). The photopolymerization of redox polymers was previously reported for vinylferrocene/acrylamide copolymers (Nakayama et al., 1995).
One technique in biosensor construction involves the building of individual monolayers on surfaces based upon the attraction between oppositely charged species. Issues involved in the development of patterned polyion multilayers that have been examined include solution ionic strength and number of multilayers (Hammond and Whitesides, 1995; Clark and Hammond, 1998; Gregoriou et al., 1997). Typically, these systems utilized Sulfonated Polystyrene as the polyanionic component and compounds such as Poly(allylamine hydrochloride) as the polycationic component. These polyion multilayers were grown in distinct patterns through the use of micro-contact printing and blocking agents anchored to a gold substrate. The effect of solution ionic strength on these multilayers has been examined (Clark et al., 1997; Sukhorukov et al., 1996) as well as the attachment of redox-active osmium complexes via similar techniques (Bretz and Abruna, 1996). Alternating glucose oxidase (GOX) and charge mediator layers for the fabrication of a glucose enzyme electrode have been utilized (Chen et al., 1969; Hou et al., 1997; Hou et al., 1998). Other groups have also performed similar work utilizing a ferrocene derivative as their poly-cationic charge mediator (Hodak et al., 1997).
PEG-based coatings have been used to improve the biocompatibility of implanted glucose sensors and demonstrated that these hydrogels were not glucose mass transfer limiting (Quinn et al., 1995). PEG-based polymers have previously been evaluated for in vivo use as protein drug delivery devices, for postoperative adhesion prevention, and for biocompatible membranes over electrochemical sensors (West and Hubbell, 1995; Pathak et al., 1992; Sawhney et al., 1994). The stability and solubility of numerous proteins, including bovine serum albumin, catalase, and interleukin-2, is reportedly increased upon conjugation to PEG (Delgado et al., 1992). Monomethoxy poly(ethylene glycol)-5000 has been conjugated to Con A while retaining Con A""s sugar binding abilities (Mattiasson and Ling, 1980). Lakowicz and co-workers (Lakowicz and Maliwal, 1993) have also developed fluorescent assays for glucose, based on phase-modulation fluorimetry and Con A/dextran moieties. These studies were conducted in an aqueous solution, and it was indicated that a polymeric acceptor may be used to shield the glucose sensor behind a glucose-permeable barrier (Lakowicz and Maliwal, 1993).
Work invoking PEG and glucose oxidase focused on pH-sensitive hydrogels which swelled and shrank as a result of glucose concentration. The large physical changes needed to measure glucose concentrations were slow to develop, and limited due to the swelling resulting in an influx of buffered solution, which reduced or eliminated the small change in pH (Hassen et al., 1997).
Despite these attempts at alternative methods of analyte detection, there is still a need to design and develop technology that would provide an either minimally invasive or noninvasive method to measure biological analytes or external chemicals. There is a need for devices and methods to easily allow an increase in the accuracy and frequency of measurement, identify potentially hazardous compounds, provide for tighter control of patient compliance, while fostering fewer secondary complications than current methods. Such devices and methods would thus represent a significant advance in the art.
The present invention overcomes these and other deficiencies present in the art by providing a variety of chemically sensitive, stable (insoluble over a specified period of time), nontoxic, and non-antigenic hydrogel structures, wherein the structure may be, for example, in the form of a particle or in the form of a hydrogel adherent to a substrate, such as an electrode substrate. In preferred embodiments, two or more electodes are used. However, electrodes that are not in contact with the hydrogel may also be used in certain embodiments. The hydrogel structure may undergo a measurable change in at least one electrochemical or optical property as a function of interaction with one or more substance(s) to be detected. Also provided are methods of using these hydrogel particles to detect one or more selected analytes, either in in vivo or external to a living organism. The present invention provides an implantable non-invasive monitoring approach, which may provide better compliance and reduce the risk of infection. Additionally provided are devices used to detect and measure the optical or electrochemical changes.
The present invention first provides a composition comprising an analyte sensitive compound comprised within a hydrogel, wherein the hydrogel comprises a polymerized material including but not limited to poly(ethylene glycol), poly(ethylene glycol)-co-anhydride, poly(ethylene glycol)-co-lactide, poly(ethylene glycol)-co-glycolide, poly(ethylene glycol)-co-orthoester, poly isopropylacrylamide, polyHEMA, polyacrylamide, sodium alginate or a combination thereof. In certain embodiments, the hydrogel is a macromer, or construct made of polymerized material or polymers that are themselves polymerized by covalent attachment at the ends of the individual polymers that comprise the macromer. Polymerized material or polymers that may be polymerized in the macromer, include but are not limited to, poly(ethylene glycol), poly(ethylene glycol)-co-anhydride, poly(ethylene glycol)-co-lactide, poly(ethylene glycol)-co-glycolide, poly(ethylene glycol)-co-orthoester, poly isopropylacrylamide, polyHEMA, polyacrylamide, sodium alginate or a combination thereof. As defined herein, a xe2x80x9chydrogelxe2x80x9d refers to a polymeric material that allows a fluid or aqueous medium to diffuse throughout the material. This property of rapid diffusion allows rapid contact of the hydrogel and its components with substances dissolved or dispersed within the fluid or aqueous medium. The hydrogel may be polymerized by any technique known to those of ordinary skill in the art, such as for example, chemical induced polymerization or photopolymerization. The hydrogel may act as a support or framework for additional components, such as analyte sensitive compounds, monomers, comonomers, and other materials. The hydrogel support may covalently bind or non-convalently entrap the additional materials.
In various embodiments of the present invention, the composition may further comprise additional monomers to alter the properties of the hydrogel in advantageous ways. A monomer that is contemplated as being useful in the present invention include, but is not limited to, a vinyl-containing monomer, an acrylate-containing monomer, a methacrylate-containing monomer or a combination thereof. The hydrogel may be copolymerized with a monomer, including but not limited to, a vinyl-containing monomer, acrylate-containing monomer, ethacrylate-containing monomer or combination thereof. A monomer may function to cross-link the hydrogel, or foster contact and/or binding of multiple hydrogels. Such contact may be fostered by cross-linking the plurality of hydrogels with the monomers and/or enhancing the affinity of an at least first body of hydrogel material for an at least second body of hydrogel material by conferring opposite charges to each successive body or layer of hydrogel material. Additionally, a monomer may have specific affinity for, or be capable of chemically linking to, an analyte sensitive compound or additional material.
In certain aspects, a vinyl-containing monomer is acrylic acid, allyl amine, styrene, allyl alcohol, acrylamide, acrylate-PEG-hydroxysuccinimde ester, Os(vinyl pyridine)(bis-bipyridine)2Cl, vinyl imidazole, vinyl bipyridine, vinyl ferrocene, styrene, pentadiene, methyl pentadiene or polyacrylated monomer. In other aspects, one or more monomers comprise the composition. As used herein certain embodiments, a comonomer is two or more monomers used to comprise the composition. In certain embodiments, the hydrogel comprises a copolymer of two or more polymers. The copolymer may further comprise a monomer or comonomers. The monomer or comonomer may include, but is not limited to, a hydrophobic, a cationic, an anionic, a neutral but hydrophilic, a biomolecule reactive, a redox, or a multifunctional crosslinking monomer or comonomer, or a combination thereof. As used herein certain embodiments, a biomolecule reactive monomer or comonomer contains a reactive group such a vinyl, methylacrylate or acrylate moiety to covalently bond to the hydrogel composition, as well as being able to bind to a biomolecule, including but not limited to, proteins, nucleic acids or lipids. As used herein certain embodiments, a redox reactive monomer or comonomer contains a chemical group such a vinyl, methylacrylate or acrylate moiety to covalently bond to the hydrogel composition, as well as being able to bind to a redox reactive moiety, i.e. a compound selected for its ability to undergo oxidation or reduction, or oxidize or reduce other compounds. As used herein certain embodiments, a multifunctional monomer or comonomer contains more than one reactive groups such a vinyl, methylacrylate or acrylate moiety to covalently bond to one or more the hydrogel composition(s), as well as being able to bind to other agents, such as, for example, a analyte detection agent. In some embodiments, the hydrogel is copolymerized with one or more comonomers or monomers. A preferred hydrophobic comonomer includes styrene, acrylic acid, methacrylic acid, an alkene, or a combination thereof. A preferred alkene is pentene. A preferred cationic comonomer includes allyl amine or acrylamide. A preferred anionic comonomer is styrene sulphonate. A preferred neutral but hydrophilic comonomer is allyl alcohol. A preferred biomolecule reactive comonomer is acrylate-PEG-hydroxysuccinimide ester, wherein the acrylate moeity is preferred to bind to the hydrogel, and the hydroxysuccinimide is preferred as a biomolecule reactive or binding moiety. A preferred redox comonomer includes vinyl ferrocene, an Os derivative of vinyl pyridine, an Os derivative of vinylimidazole, a Ru derivative of vinyl pyridine or a Ru derivative of vinylimidazole. A preferred multifunctional crosslinking comonomer includes trimethylol propane triacrylate or pentaerythritol triacrylate.
In certain aspects, the hydrogel may further comprise a positively charged polyelectrolyte, a negatively charged polyelectrolyte or a combination thereof.
The analyte sensitive material may be attached to hydrogel or comprised within the hydrogel. In certain preferred aspects, the analyte sensitive compound is non-covalently entrapped in the hydrogel and/or covalently attached to the hydrogel. In a preferred aspect, analyte sensitive compound binds at least one selected analyte. An analyte that may be detected include, but is not limited to, a carbohydrate, a protein, a nucleic acid, a lipid, a chemical (in solid, or preferably, liquid or gas form), or a combination thereof.
The analyte sensitive material may be any compound or grouping of compounds that binds to or interacts with a substance to be detected. The analyte sensitive material may also detect the analyte indirectly by detecting a by-product of its presence, including but not limited to, a chemical degradation product of the analyte or a change in the pH of the medium in contact with the composition. As used herein xe2x80x9cdetect an analytexe2x80x9d or xe2x80x9cdetect a substancexe2x80x9d will be understood to encompass direct detection of the analyte itself or indirect detection of the analyte by detecting its by-product(s). Detection of an analyte may be by contact of the analyte sensitive material with the analyte or its by-product. The analyte sensitive material may be a protein that binds an analyte or its by-product, including but not limited to an enzyme, an antibody, or a lectin. In a preferred aspect, the enzyme is a glucose oxidase or an organophosphate hydrolase enzyme.
In certain embodiments of the present invention, the analyte sensitive compound produces an electrochemical change upon contact with a selected analyte. In a preferred aspect, the composition may further comprise one or more electrodes in operational association with the hydrogel. In a particularly preferred aspect, the electrode detects an electochemical change upon contact of the analyte sensitive compound with a selected analyte.
In certain embodiments of the present invention, the analyte sensitive compound produces an optical change upon contact with a selected analyte. In a preferred aspect, the optical change is a fluorescence change upon contact with the selected analyte. In one aspect, the composition may further comprise an optical detection device in operational association with said hydrogel. In a particularly preferred aspect, the optical detection device comprises an one or more electrodes, transistors, diodes, or photoelectric cells that detects or communicates the detection of an optical change upon contact of said analyte sensitive compound with a selected analyte.
Various mechanisms may be used to produce an optical change upon contact of the analyte sensitive material with the analyte. The analyte may, for example, change the pH of the medium in contact with the analyte sensitive material. The analyte sensitive material may, for example, comprise a pH sensitive dye that undergoes a change in color, fluorescence or phosphorescence upon change of the medium""s pH. In a preferred aspect, the analyte produces a change in pH upon contact with the analyte sensitive material or hydrogel.
In certain aspects, the analyte sensitive compound and/or the hydrogel is in operable association with at least a first fluorescent label. In a preferred aspect the analyte sensitive compound binds an analyte, and the binding of the analyte to the analyte sensitive compound alters, increases and/or reduces the fluorescence of the at least a first fluorescent label. In particularly preferred aspects, the first fluorescent label is HPTS or SNAFL-1.
In certain embodiments, the composition comprises a component that binds to the analyte sensitive compound, wherein binding of the analyte to the analyte sensitive compound decreases the binding of the analyte sensitive compound and the component. In one aspect, the analyte competes with the component for binding to the analyte sensitive compound.
In a preferred aspect, the analyte sensitive compound or construct comprises a first conjugate that produces an optical change or electrochemical change. In another aspect, the analyte sensitive compound or construct comprises a second conjugate that produces an optical change or electrochemical change. The first or second conjugate may comprise a component that binds to the analyte sensitive compound or construct. The component may bind the first or second conjugate. In a preferred aspect, the first and/or second conjugate is a fluorophore conjugate. In another preferred aspect, the fluorescence of the first fluorophore conjugate is quenched by the second fluorophore conjugate. In a particularly preferred aspect, the first conjugate comprises dextran and the second conjugate is concanavalin A. Preferred fluorophores include, but are not limited to, FITC or TRITC. In a particularly preferred aspect, the first fluorophore conjugate comprises FITC and the second fluorophore conjugate comprises TRITC.
An analyte sensitive compound or construct of analyte sensitive compounds for use in the present invention include, but are not limited to, a nucleic acid, a protein, Con A, a Os(vinyl bipyridine)(bis pyridine)2 derivative or Os(vinyl bipyridine)(bis-phenathroline)2. The analyte sensitive protein may bind to a particular analyte, including but not limited to, a lectin that binds to glucose, or an enzyme that binds to a specific analyte, including but not limited to, glucose oxidase, galactose oxidase, cholesterol oxidase, cholesterase, lactate oxidase, glucose dehydrogenase, pyruvate oxidase, lactate dehydrogenase or bilirubin oxidase. In certain preferred aspects, the analyte sensitive compound is an oxidoreductase or a glucose oxidase. In additional aspects of the invention, the analyte sensitive protein is an antibody. In certain preferred aspects, the antibody is a monoclonal antibody. Monoclonal antibodies can be tailor made to preferentially or specifically bind a particular epitope or compound, and thus may be used to grant the same specificity in the detection of a particular analyte in the present invention. The amino acid and nucleotide sequences for various proteins, enzymes and antibodies are well known to those of ordinary skill in the art, and may be found at computerized databases known to those of ordinary skill in the art. One such database is the National Center for Biotechnology Information""s Genbank and GenPept databases (http://www.ncbi.nlm.nih.gov/). The coding regions for these known genes may be amplified and/or expressed using the techniques disclosed herein or as would be know to those of ordinary skill in the art. The expression of proteins, including enzymes, is generally known to those of skill in the art of molecular biology, for example, see Sambrook et al. (1989), incorporated herein by reference. The technique for preparing new monoclonal antibodies to a particular epitope to be detected as an analyte is quite straightforward, and may be readily carried out using techniques well known to those of skill in the art, as exemplified by the technique of Kohler and Milstein (1975), incorporated herein by reference.
In a preferred embodiment, the hydrogel is further defined as a hydrogel microsphere. In particularly preferred aspects of this embodiment, the hydrogel is fabricated from poly(ethylene glycol) diacrylate, sodium alginate (a.k.a. alginic acid) or a combination thereof. In other preferred aspects the hydrogel further comprises acrylic acid, allyl amine, styrene, allyl alcohol, acrylamide or a combination thereof. In a particularly preferred aspect, the hydrogel microsphere surrounds a liquid core. In certain aspects, the liquid core comprises water, alginic acid, or a co-polymer of poly ethylene glycol and poly isopropyl acrylamide, or a combination thereof. In certain aspects, it is preferred that the analyte sensitive compound or construct is contained or entrapped within said liquid core.
In other embodiments, the hydrogel undergoes a phase change to a solid state at a temperature from about 22xc2x0 C. to about 37xc2x0 C. This embodiment allows the hydrogel to remain in a fluid state until placed within a living organism, or other environment at or about 22xc2x0 C. or greater in temperature. This embodiment allows the creation of particularly shaped hydrogel structures in living organisms or environments at or about 22xc2x0 C. or greater in temperature. This embodiment is particularly useful to prepare the hydrogel materials at low temperatures for storage until use, or for molding the hydrogel into a desired shape.
In other embodiments, the composition is further defined or shaped as an at least one layer of hydrogel material. The hydrogel may further comprise a plurality of layers. In a preferred aspect, at least one layer contacts at least one successive layer to form a plurality of layers. A layer may be a net positively charged layer, a net negatively charged layer or an essentially neutrally charged layer. In a preferred aspect, the positively charged layer comprises an osmium derivative, a ruthenium derivative, a ferrocene derivative, a positively charged protein or a combination thereof. In another preferred aspect, the negatively charged layer comprises a negatively charged protein, such as for example, glucose oxidase. The positively or negatively charged protein or agent may provide the net positive or negative charge to the layer, respectively. Thus, for example, a layer that comprises a negatively charged protein may have a net negative charge because of its negatively charged protein content.
In certain aspects, the composition is shaped into a pattern, particularly to aid in the conveyance of information upon binding of an analyte to the composition, or to enhance sensitivity of analyte detection. The layer may be any shape, but recognizable symbols such as numbers, letters, geometric shapes, such as circles, squares, stars, and the like are preferred. In another aspect, the composition comprises a central body of hydrogel material. In another aspect, the composition comprises more than one body of hydrogel material. The more than one body of hydrogel material may be placed in multiple locations to form a pattern. In a particularly preferred aspect, the hydrogel is patterned as an array. The hydrogel matterial may be placed on a substrate or mold to aid its retention of shape or pattern. In certain preferred aspects, at least one arm of hydrogel material extends from central body of material. In a particularly preferred aspect, the least one arm comprises the analyte sensitive material. Such a configuration of projecting hydrogel material may enhance the speed and sensitivity of the analyte sensitive compound in detection of an analyte by aiding the ability of the material to contact the analyte.
The invention also provides a composition comprising an analyte sensitive detection system comprised within a hydrogel, wherein the hydrogel material includes but is not limited to, poly(ethylene glycol), poly(ethylene glycol)-co-anhydride, poly(ethylene glycol)-co-lactide, poly(ethylene glycol)-co-glycolide, poly(ethylene glycol)-co-orthoester, poly isopropylacrylamide, polyHEMA, polyacrylamide, sodium alginate or a combination thereof. The analyte sensitive detection system produces an optical or an electrochemical change upon contact with a selected analyte. In a preferred aspect, the hydrogel comprises polymerized poly isopropylacrylamide, polymerized poly(ethylene glycol) or sodium alginate.
In certain embodiments, the analyte sensitive detection system comprises an enzyme, such as glucose oxidase, galactose oxidase, cholesterol oxidase, cholesterase, lactate oxidase, lactate dehydrogenase or bilirubin oxidase, with glucose oxidase being preferred in certain aspects. Organophosphatase(s) are preferred enzymes to detect chemicals associated with chemical weapons. Paraxaon, sarin, tabun and samon are preferred organophosphate analytes, associated with chemical weapons, to be detected.
In preferred aspects of the invention, the analyte sensitive detection system produces a fluorescence change upon contact with the selected analyte. In these aspects, the analyte sensitive detection system or the hydrogel is in operable association with at least a first fluorescent label.
In certain aspects of the invention, the analyte sensitive detection system comprises at least a first component, the at least a first component described as an analyte binding component, wherein binding of an analyte to the analyte binding component alters the fluorescence of the analyte sensitive detection system. Depending on the particular system utilized, binding of the analyte to the analyte binding component can either increase or decrease the fluorescence of the analyte sensitive detection system.
In additional embodiments, the analyte sensitive detection system further comprises a second component that binds to the analyte binding component, wherein binding of the analyte to the analyte binding component decreases the binding of the analyte binding component and the second component. In certain aspects, the analyte competes with the second component for binding to the analyte binding component.
In particular embodiments, the analyte binding component comprises a first fluorophore conjugate and the second component comprises a second fluorophore conjugate. In preferred aspects, the fluorescence of the first fluorophore conjugate is quenched by the second fluorophore conjugate, exemplified by systems wherein the first fluorophore conjugate is FITC-dextran and the second fluorophore conjugate is TRITC-concanavalin A.
In particularly preferred aspects of the present invention, the compositions are formulated for implantation into an animal. In certain embodiments, the animal is a human.
The present invention also provides methods of detecting an analyte, comprising contacting a sample suspected of containing the analyte with an analyte sensitive detection system comprised within a hydrogel, wherein the hydrogel includes but is not limited to poly(ethylene glycol), poly(ethylene glycol)-co-anhydride, poly(ethylene glycol)-co-lactide, poly(ethylene glycol)-co-glycolide, poly(ethylene glycol)-co-orthoester, poly isopropylacrylamide, polyHEMA, polyacrylamide, sodium alginate or a combination thereof. An analyte that is detectable by the methods of the present invention may include, but is not limited to, a carbohydrate, a protein, a nucleic acid, a lipid, a gas or a chemical. Among the preferred analytes detected in the methods of the present invention are glucose, galactose, cholesterol, lactate, bilirubin, a blood gas, urea, creatinine, phosphate, myoglobin or a hormone, such as estrogen or progesterone. In particularly preferred aspects of the invention, the analyte detected is glucose. In other particularly preferred aspects, the analyte is an organophosphate. Organophosphatase(s) are preferred enzymes to detect chemicals associated with chemical weapons. Paraxaon, sarin, tabun and samon are preferred analytes, associated with chemical weapons, to be detected.
In certain aspects, the analyte sensitive detection system produces an electrochemical or optical change upon contact with the analyte. In a preferred aspect, the analyte sensitive detection system produces a fluorescence change upon contact with the analyte. In some aspects, the analyte sensitive detection system comprises at least a first component, the first component further described as an analyte binding component. In other aspects, the analyte sensitive detection system further comprises at least a second component. In additional aspects, the analyte binding component comprises at least a first fluorophore conjugate. In further aspects, the second component comprises at least a second fluorophore conjugate. In a preferred aspect, the fluorescence of the first fluorophore conjugate is quenched by the second fluorophore conjugate. In a particularly preferred aspect, the analyte is glucose, the first fluorophore conjugate is FITC-dextran and the second fluorophore conjugate is TRITC-concanavalin A.
In certain aspects, the sample suspected of containing the analyte is comprised within an animal. In this aspect, the analyte sensitive detection system may be formulated for implantation into an animal.
The invention further provides a method of using a smart tattoo, comprising implanting below the surface of the epidermis of the animal a smart tattoo comprising a hydrogel and an analyte detection compound, wherein the hydrogel comprises a polymerized material including but not limited to poly(ethylene glycol), poly(ethylene glycol)-co-anhydride, poly(ethylene glycol)-co-lactide, poly(ethylene glycol)-co-glycolide, poly(ethylene glycol)-co-orthoester, poly isopropylacrylamide, polyHEMA, polyacrylamide, sodium alginate or a combination thereof, and wherein the smart tattoo is implanted between about 0.05 mm and about 4 mm below the surface of the epidermis of the animal. As used herein certain embodiments, a xe2x80x9csmart tattooxe2x80x9d refers to a hydrogel and an analyte detection compound that may be implanted in the epidermis or dermis of an animal.
The epidermis may vary in thickness depending upon its location and the animal, but is generally up to about 1 mm thick in a human. When implanted in the epidermis, it is preferred that the tattoo is placed or implanted of from about 0.05 mm, about 0.06 mm, about 0.07 mm, about 0.08 mm, about 0.09 mm, about 0.1 mm, about 0.12 mm, about 0.14 mm, about 0.16 mm, about 0.18 mm, about 0.2 mm, about 0.22 mm, about 0.24 mm, about 0.26 mm, about 0.28 mm, about 0.3 mm, about 0.32 mm, about 0.34 mm, about 0.36 mm, about 0.38 mm, about 0.40 mm, about 0.42 mm, about 0.44 mm, about 0.46 mm, about 0.48 mm, about 0.50 mm, about 0.52 mm, about 0.54 mm, about 0.56 mm, about 0.58 mm, about 0.6 mm, about 0.62 mm, about 0.64 mm, about 0.66 mm, about 0.68 mm, about 0.7 mm, about 0.72 mm, about 0.74 mm, about 0.76 mm, about 0.78 mm, about 0.80 mm, about 0.82 mm, about 0.84 mm, about 0.86 mm, about 0.88 mm, about 0.90 mm, 0.92 mm, about 0.94 mm, about 0.96 mm, about 0.98 mm, to about 1 mm below the outer surface of the epidermis of an animal. In another preferred aspect, the smart tattoo is implanted between about 0.1 mm and about 0.25 mm below the surface of the epidermis of the animal. In a particularly preferred aspect, the smart tattoo is implanted about 0.15 mm below the surface of the epidermis of the animal. Preferred animals include sheep, goats, cats, dogs, birds, cows, horses or pigs. A particularly preferred animal is a human.
When implanted in the epidermis of an animal, the smart tattoo may exist only days or weeks before the cells containing or surrounding the tattoo are shed from the animal. In this embodiment, the tattoo will exist up to about 2 weeks before removal through natural replacement of epidermal layers.
In another embodiment, the tattoo is implanted in the dermis or dermal layers of an animal. The dermis may vary in thickness depending upon its location and the animal, but is generally from about 1 mm to about 4 mm thick in a human. The dermis is located beneath the epidermis, often generally beginning about 1 mm beneath the outer surface of the epidermis. The dermis does not actively shed, so that a tattoo may exist semi-permanently or permanently in an animal, i.e. remain in the dermis for months or years. Depending on the thickness of the epidermis and dermis, in certain embodiments, the tattoo may be implanted or placed in the dermis of from about 1 mm, about 1.1 mm, about 1.2 mm, about 1.3 mm, about 1.4 mm, about 1.5 mm, about 1.6 mm, about 1.7 mm, about 1.8 mm, about 1.9 mm, about 2 mm, about 2.1 mm, about 2.2 mm, about 2.3 mm, about 2.4 mm, about 2.5 mm, about 2.6 mm, about 2.7 mm, about 2.8 mm, about 2.9 mm, about 3 mm, about 3.1 mm, about 3.2 mm, about 3.3 mm, about 3.4 mm, about 3.5 mm, about 3.6 mm, about 3.7 mm, about 3.8 mm, about 3.9 mm, about 4 mm, about 4.1 mm, about 4.2 mm, about 4.3 mm, about 4.4 mm, about 4.5 mm, about 4.6 mm, about 4.7 mm, about 4.8 mm, about 4.9 mm, to about 5 mm beneath the outer surface of the epidermis. In certain preferred embodiments the tattoo would be implanted of from about 1 mm to about 5 mm beneath the surface of the epidermis, with 2 mm to about 3 mm being particularly preferred.
When implanted in tissues, the composition may be taken into a cell or remain external to a cell. The particle size of the composition, and its size ratio to that of the size of an adjacent cell will determine whether the composition is taken into a cell or remains external to the cell. In certain embodiments wherein the composition is implanted adjacent to epidermal and dermal cells, compositions of an average particle size up to about 10 microns in diameter or so may be taken into cells. In certain other embodiments, a composition of an average particle size of from about 0.5 microns, about 1 microns, about 2 microns, about 3 microns, about 4 microns, about 5 microns, about 6 microns, about 7 microns, about 8 microns, about 9 microns, to about 10 microns or so may be taken into cells. In certain embodiments, it is preferred that the composition is taken into a cell to measure the intracellular concentration of an analyte. For example, intracellular glucose levels may vary more relative to plasma glucose concentrations in diabetics. Detection of low intracellular glucose levels may aid in monitoring changes in glucose in diabetes or the effectiveness of medications.
In certain other embodiments, it is preferred that the composition remains external to the cells of the tissue that the composition is implanted. A larger average particle size is preferred for the composition in this embodiment, to prevent the composition""s uptake by cells. In certain embodiments for epidermal or dermal cells, a composition greater than about 10 microns in average particle size diameter is preferred. In certain embodiments, a composition of about 10 microns, about 11 microns, about 12 microns, about 13 microns, about 14 microns, about 15 microns, about 16 microns, about 17 microns, about 18 microns, about 19 microns, about 20 microns, about 22 microns, about 24 microns, about 26 microns, about 28 microns, about 30 microns, about 35 microns, about 40 microns, about 45 microns, about 50 microns, about 55 microns, about 60 microns, about 65 microns, about 70 microns, about 75 microns, about 80 microns, about 85 microns, about 90 microns, about 95 microns, about 100 microns, about 110 microns, about 120 microns, about 130 microns, about 140 microns, about 150 microns, about 160 microns, about 170 microns, about 180 microns, about 190 microns, about 200 microns, about 225 microns, about 250 microns, about 275 microns, about 300 microns, about 350 microns, about 400 microns, about 450 microns, about 500 microns, about 550 microns, about 600 microns, about 650 microns, about 700 microns, about 800 microns, about 850 microns, about 900 microns, about 950 microns, about 1 mm, about 1.1 mm, about 1.2 mm, about 1.3 mm,
about 1.4 mm, about 1.5 mm, about 1.6 mm, about 1.7 mm, about 1.8 mm, about 1.9 mm, to about 2 mm or more average particle size is preferred.
Of course, different analyte detection compounds may be combined with different particle sizes in various combinations. In one embodiment, particles of one average sized diameter may detect a different analyte than another composition with a different average particle size diameter. Alternatively, detection compounds that detect the same analyte may comprise compositions of functionally similar size. In certain embodiments, a different optical and/or electrochemical detection agent comprises the analyte detection compound. Thus, by combining various particle sizes with different analyte detection compounds, composition with different detection properties may be created. For example, fluorescence at one wavelength in a composition with an average particle size less than about 10 microns may denote the presence of a certain concentration of an analyte in the intracellular spaces, while fluorescence at a different wavelength in a composition with an average particle size greater than about 10 microns may denote the concentration and the intercellular spaces of a tissue. In another example, the composition may comprise more than one analyte detection compounds to detect different concentrations of an analyte, and/or different analytes.
In certain aspects, the smart tattoo may detect an analyte that may include, but is not limited to a carbohydrate, a protein, a nucleic acid, a lipid or a gas. In preferred aspects, the analyte is glucose, cholesterol, lactate, bilirubin, a blood gas, urea, creatinine, phosphate, myoglobin or a hormone. In a particularly preferred aspect, the analyte is glucose. In a preferred aspect, the smart tattoo produces an electrochemical or an optical change upon contact with the analyte. A preferred optical change is a fluorescence change upon contact with the analyte.
In certain aspects, the smart tattoo comprises at least a first component, the first component further described as an analyte binding component In additional aspects, the smart tattoo further comprises at least a second component. In a preferred aspect, the analyte binding component comprises at least a first fluorophore conjugate. In another preferred aspect, the second component comprises at least a second fluorophore conjugate. In certain aspects, the fluorescence of the first fluorophore conjugate is quenched by the second fluorophore conjugate. In a particularly preferred aspect, the analyte is glucose, the first fluorophore conjugate is FITC-dextran and the second fluorophore conjugate is TRITC-concanavalin A.
The efficiency of detection of an optical change in an analyte is dependent upon the wavelength of light used to visualize the composition. Shorter wavelengths, such as the near UV to blue part of the spectrum, i.e. about 350 nm to about 450 nm, are preferred to detect optical changes in a composition implanted up to about 0.4 mm beneath the surface of the epidermis. Longer wavelengths may penetrate deeper into tissue, and wavelengths of the yellow-orange-red-near infrared part of the spectrum, i.e. greater than about 450 nm to about 2 mm or greater, are preferred to detect optical changes in a composition implanted up to about 2 or about 3 mm beneath the surface of the epidermis. In certain embodiments, compositions may be created that are normally be invisible to the naked eye without illumination with a light source, detection with one or more electrodes, or fluorescence or phosphorescence of the composition.
In certain embodiments, the analyte sensitive detection system produces an electrochemical change upon contact with the analyte, while in other embodiments, the analyte sensitive detection system produces an optical change, for example a fluorescence change, upon contact with the analyte. In a preferred embodiment, the hydrogel wherein the analyte sensitive detection system is contained or attached is in contact with a substrate, such as for example, an electrode.
In particular aspects, the analyte sensitive detection system comprises at least a first component, the first component further described as an analyte binding component, while in additional aspects, the analyte sensitive detection system further comprises at least a second component. In certain embodiments, the analyte binding component comprises at least a first fluorophore conjugate. In other aspects, the second component comprises at least a second fluorophore conjugate. In particularly preferred aspects of the invention, the fluorescence of the first fluorophore conjugate is quenched by the second fluorophore conjugate, exemplified by embodiments wherein the analyte is glucose, the first fluorophore conjugate is FITC-dextran and the second fluorophore conjugate is TRITC-concanavalin A.
In preferred embodiments of the present invention, the sample suspected of containing the analyte is comprised within an animal. In further preferred embodiments, the analyte sensitive detection system is formulated for implantation into an animal. In certain embodiments, the animal is a human.
Following long-standing patent law convention, the word xe2x80x9caxe2x80x9d and xe2x80x9canxe2x80x9d mean xe2x80x9cone or morexe2x80x9d in this specification, including the claims.

Compositions and methods for analyte detection


A method and apparatus for facilitating application recovery using configuration information is described. In one embodiment, a method for facilitating application recovery using configuration information includes accessing information in memory associated with an application configuration that correlates with source computer hardware for operating an application using at least one processor, identifying at least one portion that is to be restored of the application configuration using the at least one processor and applying the at least one portion of the application configuration in the memory to destination computer hardware using the at least one processor.

1. Field of the Invention
Embodiments of the present invention generally relate to datacenter management systems and, more particularly, to a method and apparatus for facilitating application recovery using configuration information.
2. Description of the Related Art
In a typical computing environment (e.g., a datacenter), administrators and/or users desire highly available applications and quick recovery of host computers after a disaster (e.g., power failure, hurricane and/or the like). Various software programs (e.g., an application) as well as one or more hardware devices (e.g., a server, an array, a switch, a firewall and/or the like) are employed to provide data and application services to client computers.
Current disaster recovery systems (e.g., SYMANTEC NetBackUp Bare Metal Recovery (NBU-BMR)) store a backup of the host computer (e.g., a physical machine or a virtual machine). When a hardware failure or software fault occurs that disables the host computer, these current disaster recovery systems provisions a bare metal server to restore operations at the host computer or another host computer. Generally, the bare metal server is a computer that does not contain an operating system or any software applications. The bare-metal server may be a computer in which a virtual machine is installed directly on computer hardware rather than within the host operating system (OS). The bare metal server provisioned with an appropriate operating system, application software, file data and a host computer configuration. Configurations associated with the various hardware devices and/or software programs are backed up regularly to facilitate restoration of one or more hardware and/or software programs during a failure.
Currently, various recovery techniques (i.e., Bare Metal Host Recovery (BMR) and/or the like) are employed, but such techniques are restricted to recovering an entire host computer but not an application that is running on the host computer. In addition, an application configuration simply includes configuration information that only the application may view and/or comprehend. For example, a database name and location, among other application specific parameters, are of significance from the application perspective but not from the file system, logical volume, LUN and/or a zone on which a storage device associated with the database is assigned.
Disaster recovery techniques for host computers are not flexible and are unable to assure a full application recovery in an efficient manner. For instance, the host may operate three instances of a database application and each instance uses different volumes to storage data. If such host is restored using current techniques, then the new host is configured with all three database instances, but the new host may not have a sufficient amount of storage resources to operate all three database instances. In other words, the current techniques are unable to recover an instance of an application. For example, restoration of only one of the three database instances and any associated volumes is impossible using the current techniques.
Therefore, there is a need in the art for a method and apparatus for facilitating application recovery in a datacenter using configuration information.

Method and apparatus for facilitating application recovery using configuration information


Tuning circuit in which a local oscillator is constituted by an amplifier which is coupled to a resonant circuit of the variable capacitance and inductance type, the amplifier having a first stage formed by at least one differential pair of bipolar transistors (T1, T2). The amplifier has also a second stage with another differential pair of transistors whose linked emitters are fed by the collector current of one (T2) of the transistors of the first stage. A transistor (T3) of the differential pair of the second stage has its collector coupled to a main load resistor (RL) and its base coupled to the collector of the other transistor (T1) of the first stage, which feeds a supplementary load resistor (Rb). The base of the other transistor (T4) of the differential pair of the second stage may be polarized at a fixed voltage (Vref2) or at a variable voltage, having the appropriate.

1. Field of the Invention
The invention relates to a tuning circuit for a receiver, in which a local oscillator, having a voltage-controlled frequency, is constituted by an amplifier which is coupled to a resonant circuit of the variable capacitance and inductance type, an output terminal of the amplifier being positively fed back to an input of the amplifier and to a terminal of the resonant circuit, in which circuit the amplifier has a first stage formed by a differential pair of bipolar transistors whose linked emitters are connected to a current source, which pair is formed by a first transistor whose base is connected to an input terminal of the amplifier and a second transistor whose collector is coupled to a main load resistor having one end connected to a power supply terminal and the other end connected to an output terminal of the amplifier.
The invention also relates to an integrated circuit for a receiver comprising elements of the tuning circuit mentioned above, as well as to a television receiver in which such a tuning circuit is used.
2. Description of the Related Art
A tuning circuit of the type mentioned above is present in practically all radio or television receivers in which it is used for user selection of one of the available channels. In this tuning circuit, the local oscillator plays a very important role for producing an intermediate frequency signal by means of a frequency difference between the signal to be received and the signal of this local oscillator. Particularly in television receivers, it is often difficult to obtain an oscillator which is capable of functioning in a wide range of high frequencies.
As is known, the local oscillator of a receiver is constituted by an amplifier device coupled to a resonant circuit most frequently constituted by a capacitance-inductance combination. It is nowadays preferred to construct this amplifier from a differential pair of transistors instead of using a single transistor. Better performances are obtained particularly as regards the absence of even harmonics in the signal produced by the local oscillator, and due to the fact that the input impedance of the amplifier, which remains high for the greater part of a period of the output signal, is thus high on average.
An oscillator activated by means of a differential pair of transistors is known from the document EP-A-0 412, corresponding to U.S. Pat. No. 5,034,706, in which a resonant circuit of the LC type is indicated.
When it is attempted to extend the range of frequencies covered by an LC resonant circuit oscillator in which the variable element is a variable capacity diode as a function of a control voltage, it will be experienced that there is a considerable limitation at the lowest frequencies where the oscillator ceases to function. This phenomenon is related to a resonant circuit coefficient of insufficient quality, which is due to high losses in the variable capacity diode.
As the variable capacitor C is arranged in parallel with an inductance L, the equivalent parallel loss resistance Rp of this capacitor may be evaluated by means of a simple computation based on the series loss resistance R.sub.s resulting in: EQU Rp=L/(R.sub.s .multidot.C)
It will be noted that the parallel loss resistance Rp decreases when R.sub.s and/or C increase and that an oscillation is thus difficult at the low frequencies in the wanted range, under which circumstances, the capacitor has a high value.
A first approach to solving this difficulty may be the use of several series-parallel diodes for obtaining a variable capacitance of a better quality.
However, this solution is hardly satisfactory because the losses are only reduced to a small extent as a function of the number of diodes used, which solution would be costly and cumbersome if a very large number of diodes had to be used.
A second approach which is frequently used is to arrange a fixed capacitance (substantially free from losses) in series with the variable capacitor, which fixed capacitance is known as a "padder". In accordance with this solution, the losses are effectively reduced but the bandwidth of the frequencies covered is also reduced, which is contrary to the envisaged object.

Tuning circuit for a receiver, particularly a television receiver


Some demonstrative embodiments of the invention include a method device and/or system of secure communication in a wireless network using a spatial division multiple access transmission scheme. The method, according to some demonstrative embodiments may include allocating transmission power to N channels to be transmitted to one or more destination stations by N antennas, such that the power to be received by each one of the one or more destination stations is not greater, by more than a predefined power margin, than a minimum power required for reception at a desired quality of service. Other embodiments are described and claimed.

In a wireless local area network (WLAN), an access point (AP) may communicate with one or more mobile stations (STA) over a wireless communication link. In non-secure systems, signals transmitted by the AP may be detected by any station within range of the AP, including outside listening parties and unauthorized users. This raises a concern for secure WLAN communication.
For example, in a single-antenna WLAN system, the AP may transmit a signal at its maximum power output to increase network coverage and range of the communication link. The transmitted signal energy will propagate in an isotropic pattern and may be detected anywhere within the reach radius of the AP, regardless of the location of the intended recipient. Thus, transmissions in a single-antenna WLAN system may be easily intercepted by parties other than the intended recipient.
As is known in the art, beamforming may allow a collection of omni-directional simple antennas to act like a single, highly focused, directional antenna. Each transmit antenna may transmit the intended signal multiplied by a certain weight, and by dynamically controlling the weights of each antenna the transmission may be directed to a desired location. While each antenna transmits an electromagnetic wave that propagates isotropically, the assignment of different amplitudes and phases to simultaneous transmissions from the multiple antennas can create a wave interference pattern which combines coherently at a desired location to reproduce the intended signal.
Spatial division multiple access (SDMA), also known as spatial-division multiplex (SDM), is a method for multiplexing several signal streams, each one targeted to a different destination, simultaneously, by utilizing multiple antennas. A SDMA channel access method may enable the use of the same frequency at the same time in different spaces. For example, multiple formed beams may be transmitted to several remote stations simultaneously. Typically, a plurality of orthogonal beams may be formed such that power directed towards intended destination stations is maximized, while the interference generated to other stations may be minimized.
In a multiple-antenna communication system, beamforming may be used to increase the link budget of a communication link by directing the emitted energy towards the location of an intended recipient. Thus, a potential interceptor, having a spatial signature different from that of the intended recipient, may receive a lower energy signal, resulting in a somewhat diminished signal-to-noise ratio (SNR). However, the interceptor may still be able to decode the signal.
In a SDMA system, an interceptor, having a different spatial signature than an intended recipient, may receive additional interference caused by superposition of the other station signals, resulting in a degraded signal-to-noise ratio (SNR) due to both decreased energy and increased noise. Still, there are many situations in which this SNR degradation is limited, for example, when the number of intended recipients, K, is significantly smaller than the number of transmitting antennas, thereby undesirably improving the chances of the interceptor to detect the SDMA signal.

This patent is subject to a terminal disclaimer.


A recording and reproducing system for performing the reproduction using an optical recording medium. A physical feature of a ROM type disk is extracted and enciphered before being recorded in an optical disk. The cipher reproduced and converted into a plain text physical feature, which in turn, is compared with the physical feature information detected from the ROM disk. When both are coincident with each other, the operation of the system stops, thereby preventing the use of an illegally duplicated disk. The physical feature information, recorded on a magnetic recording layer 4 of the optical recording medium 2, is reproduced by an optical head 8 and compared with the information measured by a physical feature information detector, thereby detecting a duplicated medium.

1. Industrial Application Field
The present invention relates to prevention of illegal copies of disc-like optical recording media and prevention of illegal install of information into information processing systems or the like, and more particularly to a method and system for preventing recorded music on optical disks, as well as projected images and various sorts of programs, such as game softwares (softs) and computer softwares, from being illegally copied and utilized without permission of the copyrighters, and further relates to an optical recording medium incapable of copy.
2. Description of the Prior Art
In recent years, optical disks are widely being employed in a variety of fields. The optical disks are generally classified into record-possible RAM disks and record-impossible ROM disks, while the manufacturing cost of the RAM disks is from five times to ten times that of the ROM disks. Accordingly, the ROM disks tend to be chiefly used in applications that supply a large number of people with a large quantity of information, for example, an electronic publication application and a medium cost-limited application that supplies music softwares and projected image softwares. On the other hand, as obvious from CD-ROM game machines and CD-ROM contained personal computers, there is a need for a RAM function being incorporated into the ROM disks, as an extension is more being made to interactive use. Home-use systems seldom require a large RAM capacity, for which reason great interest is focused on the advent of a new medium concept capable of realizing the three conditions: a small capacity RAM function, a large capacity ROM function, and a low cost. In addition, illegal duplicates of ROM disks such as CDs are recently put in the market so that the copyrighters suffer serious damage. Thus, a countermeasure has been needed for the duplicate prevention. Moreover, a soft distribution method has come into wide spread use where a plurality of encrypted (enciphered) programs are incorporated into disks and decrypted (deciphered) through passwords, and for improving the security of the password there is a need for a different ID number being recorded in each ROM.
One possible way to realize this concept is that one magnetic recording layer is equipped on the rear surface of a ROM disk, in which case the formation cost of the recording layer is less than one-tenth that of the ROM disk itself, thus realizing a partial RAM disk without greatly raising the cost of the ROM disk. Actually, as disclosed in Japanese Patent Laid-Open Nos. 56-163536, 57-6446, 57-212642, 2-179951, in terms of ROM disks such as CD-ROM not having a cartridge, there have already been proposed approaches wherein an optical recording section is provided on a front surface of a CD-ROM and a magnetic recording section is added on the rear surface thereof. In addition, Japanese Patent Laid-Open No. 60-70543 discloses an attempt to accomplish magnetic recording by means of a combination of a disk wherein, like optical disks of amorphous material, an optical recording section, made of a nonmagnetic material, is placed on its surface and a magnetic recording layer is located on its rear surface and a magnetic head which is equipped in a mechanical section facing the rear surface.
On the other hand, for the duplicate prevention, only means is known which is made to manufacture a special disk through a special process, such as intentionally making a cut or openwork on the disk, so that difficulty is encountered to manufacture it without a special manufacturing apparatus.
However, the aforesaid methods are merely based on a combination of a magnetic recording section and an optical recording section, while not containing the important requirements for definite realization of the equipment at all, such as the ways of avoiding the mutual interference between the optical recording section and magnetic recording section, permitting access to magnetic tracks with a simple arrangement, sharing a circuit, protecting magnetically recorded information on media from the external environment including magnetism and abrasion without the use of a cartridge, compressing information to be recorded in a RAM area, accelerating the access, and concretely making out a physical track format.
Furthermore, in the prior art examples, disclosure is hardly made in terms of the ways of realizing a home-use partial RAM disk in a concrete form, such as the method of mass-producing media at a low cost, which is important in realization of the media, and the method of making the media conformable with the CD standards. Therefore, there remains a problem which arises with the conventional examples in that difficulty is experienced in concrete realization of media and systems capable of home use.

Method and apparatus for preventing illegal copy or illegal installation of information of optical recording medium

Matsushita Electric Industrial Co., Ltd.


A circuit arrangement which comprises at least two acceleration sensors for measuring an acceleration of at least one part of the hazardous device, at least one logic circuit for evaluating measured values of the at least two acceleration sensors, at least one memory for storing a comparison value, and at least one safety device controlled by an output of the logic circuit. The safety device is adapted to bring the hazardous device into a safe state in response to a switching command received via the output of the logic circuit. The logic circuit transmits the switching command to the safety device when the measured acceleration of the part of the hazardous device or a value derived from the measured acceleration has a predetermined ratio to the stored comparison value. Furthermore, a method for monitoring a hazardous device is also disclosed.

The detection of movements is typically carried out in safety technology today via rotary encoders, resolvers or initiators. Acceleration sensors are frequently used today in mobile telephones, game consoles and in motor vehicle navigation.
From DE 10 2008 062 978 A1 a handling machine and a method for the operation thereof are known, wherein for the automatic recognition of an exceptional situation, such as, for example, exceeding a specified acceleration value, a sensor is provided, via which a device is activated, which realizes, for example, the function of a safety relay for stopping a robot arm movement.

Circuit arrangement and method for monitoring a hazardous device by evaluating the acceleration


In a mobile navigation system, it is possible to judge as to whether or not either a traffic jam region or a traffic restriction region is reduced until a moving object reaches this traffic jam region, or traffic restriction region. The mobile navigation system comprises present position detecting means, map information storage means, route searching means, and traffic information receiving means. Further, the navigation system comprises specific region judging means for judging as to whether or not a traffic jam or restriction region is present within the route searched by the route searching means; arrival time calculating means for calculating time required such that the moving object reaches the traffic jam or restriction region; decreasing time detecting means for detecting time during which the traffic jam or restriction region is decreased based upon the traffic jam or restriction information received by the traffic information receiving means; and re-searching control means for causing the route searching means to re-search the route in accordance with a relationship between the output from the decreasing time detecting means and the output from the arrival time calculating means when the specific region judging means judges that the traffic jam or restriction region is present.

The present invention relates to a navigation system mounted on a mobile, e.g., an automobile and a vehicle. More specifically, the present invention is directed to a mobile navigation system capable of judging an end of a traffic jam until an automobile approaches such place.
A mobile navigation system is widely utilized in the field. For instance, one conventional mobile navigation system is described in Japanese Unexamined Patent Publication 6-180796, the schematic system diagram of which is shown in FIG. 1. In this drawing, reference numeral 1 indicates the map data storage unit for storing the map data, reference numeral 2 represents the GPS (Global Positioning System) receiver unit arranged by the GPS system, for detecting a present position of a vehicle (not shown in detail), and reference numeral 3 shows the traffic information receiving unit for receiving the transmitted traffic information.
Also, reference numeral 4 indicates the navigation unit for calculating the present position of the vehicle based upon the signal outputted from the GPS receiver unit 2, and for entering therein this present position information and the map data stored in the map data storage unit 1 to thereby search a route from this present position to a target (destination) position. Reference numeral 5 shows the system control unit for controlling an information display by the display unit 6 in response to the outputs derived from the navigation unit 4 and the traffic information receiving unit 3. The display unit 6 is constructed of the LCD (liquid crystal display). Reference numeral 7 is the voice unit for producing alarm sound.
Subsequently, the operations of this conventional mobile navigation system will now be explained.
First, the navigation unit 4 searches the optimum route defined from the present position up to the destination place, and the road information receiving unit 3 receives the traffic jam information.
Then, the system control unit 5 judges as to whether or not a region indicative of the above-described traffic jam information is contained in the route. If the system control unit 5 judges that the region indicative of the traffic jam is not contained in the route, then this route is displayed on the display unit 6. Conversely, if the system control unit 5 judges that the traffic-jam region is contained in the route, then the navigation unit 4 is brought into the standby state in order to re-search the route, and furthermore the voice unit 7 is actuated, so that the operator is requested to judge as to whether or not the route is again searched.
As described above, since the conventional mobile navigation system is so arranged, this navigation system never considers such a case that the traffic jam will be solved until the moving object reaches this traffic jam region. As a consequence, there is a problem that the operator must judge as to whether or not the route is required to be again searched under the following initial condition. That is, the traffic jam region is still present in the route even in the above-explained case.


A paint can incorporates a rim having one or more drain holes formed therein to allow paint to drain into the interior of the can under the influence of gravity. The invention also encompasses a tool for forming the drain holes.

Paint cans and similar receptacles typically employ inwardly extending, annular liquid receptacle rims defining an opening communicating with the interior of the receptacle. The rim bottom wall defines an open-topped, circular channel for releasably receiving a closure in the form of a lid.
One of the problems with such an arrangement is that paints or other liquids held by the receptacle often spill into the rim when the paint or other product in the can is being utilized. This can cause problems when the lid is re-applied. Spilled paint or other liquid in the rim can be displaced by the lid and spill over the sides of the receptacle, not only resulting in wasted paint or other liquid but also creating an unsightly mess both on the container, the surrounding area, and the person closing the container. Also, one may have problems removing the lid from the receptacle at a future date due to the fact that the paint or other spillage in the rim adhesively secures the lid in place. Furthermore, paint or other liquid in the rim can fall from the rim even when the container is open.

Paint can with drain holes and tool for forming the holes


An apparatus for checking concentricity between a barrel holder and a lens barrel rotatably engaging with the barrel holder is provided. The lens barrel includes at least one lens coaxially received therein. The apparatus includes a barrel holder retaining member, a rotating member, a driving unit, a light source, and an image sensor. The barrel holder retaining member is used for fixedly retaining the barrel holder in position. The rotating member is structured for meshing with the lens barrel. The driving unit is used for driving the rotating member to rotate, thereby rotates the lens barrel. The light source is configured for emitting light toward a first end of the lens barrel. The image sensor is arranged to face toward an opposite second end of the lens barrel. The image sensor is configured for sensing the light emitted from the light source.

1. Field of the Invention
The present invention relates to testing apparatuses, more particularly to an apparatus for checking concentricity between the lens barrel and the barrel holder.
2. Description of Related Art
With the ongoing development of microcircuitry and multimedia technology, digital cameras are now in widespread use. High-end portable electronic devices, such as mobile phones and PDAs (Personal Digital Assistants), are being developed to be increasingly multi-functional. Many of these portable electronic devices are now equipped with a digital camera. The camera generally includes an optical module.
Optical modules used for digital camera modules typically include a lens barrel, a lens module, a spacer, a filter, and a lens holder. The lens module, the spacer, and the filter are engagingly received in the lens barrel one on top of one another, in the order written. Generally, the lens barrel is mounted in the lens holder through thread grooves. In an assembly process of the optical module, checking concentricity between the lens barrel and the barrel holder is always needed.
Generally, a method for checking concentricity between the lens barrel and the barrel holder includes following steps: firstly, a light source is disposed at an object side of the optical module and an image sensor is disposed at an image side of the optical module; secondly, light beams emitted from the light source pass through the lens module to form a first spot on the image sensor, meanwhile the position of the spot is recorded; thirdly, the lens barrel is rotated at an angle relative to the lens holder by hand, and a second spot is formed on the image sensor; finally, a distance between the positions of the first spot and the second spot is measured and compared with a predetermined acceptable range to determine whether the concentricity will be accepted.
However, rotating the lens barrel by hand is inefficient and inaccurate due to man-made errors. Thus, the efficiency and precision for checking concentricity are decreased.
What is needed, therefore, is an apparatus for checking concentricity between the lens barrel and the barrel holder with high efficiency and precision.

Apparatus for checking concentricity between lens barrel and barrel holder


An air bag device which, at the time of a collision, unfolds a curtain-shaped air bag body which is mounted and accommodated at a roof side rail of a vehicle, including: an air bag body having a roof side rail mounting portion which is mounted to the roof side rail and a pillar mounting portion which is mounted to at least one of a front pillar and a rear pillar, and the roof side rail mounting portion and the pillar mounting portion are formed on a same straight line, and a curtain-shaped bag body main body is formed beneath the roof side rail mounting portion and the pillar mounting portion, and the air bag body is mounted and accommodated by being folded from bottom to top and thereafter by being bent so as to run along the roof side rail and the at least one of the front pillar and the rear pillar.

1. Field of the Invention
The present invention relates to an air bag device, and in particular, to an air bag device having a curtain-shaped air bag body which is mounted and accommodated so as to extend between a front pillar and a roof side rail of a vehicle.
2. Description of the Prior Art
There exist conventional air bag devices for vehicles which, at the time of a collision, unfold a curtain-shaped air bag body which is mounted and accommodated at the roof side rail of the vehicle. An example of such an air bag device is disclosed in Japanese Patent Application Laid-Open (JP-A) No. 6-340241.
As illustrated in FIG. 8, in the air bag device of JP-A No. 6-340241, a housing 72 which accommodates an air bag body 70 is mounted to a roof side rail 74. The air bag body 70 is accommodated in a folded state within the housing 72. The housing 72 is positioned at a rear, upper corner 76A of a side window 76. Two long, thin guide elements 80, 82 extend from the housing 72 along the roof side rail 74 and a B pillar 78. A plurality of retaining elements of the air bag body 70 move slidingly along the guide elements 80, 82, and the air bag body 70 unfolds.
However, the air bag body 70 of the air bag device cannot cover a front, upper portion 76B of the side window 76. As a result, the entire region of the substantial upper half of the side window 76 may be covered by an air bag body 86 as illustrated by the imaginary line in FIG. 8. In this case, an upper side 86A of the air bag body 86 forms a curve along a line extending from a front pillar 88 (also called an "A pillar") to the roof side rail 74, such that the air bag body 86 is mounted so as to extend from the front pillar 88 to the roof side rail 74. Further, when the air bag body 86 is to be accommodated in a housing (unillustrated) which is mounted so as to extend between the front pillar 88 and the roof side rail 74, the air bag body 86 is folded, for example, in a bellows-like shape from the lower side toward the upper side thereof, and is accommodated in the housing. However, because the mounting portion runs along the front pillar 88, it is difficult to fold up the air bag body 86 to a uniform thickness, and the ease and convenience of mounting and accommodating the air bag body 86 deteriorates.


A one- and two-way pet screen door kit is provided for installation in an existing screen door or window screen to allow pets to pass through in one or both directions. The door is made up of a rectangular metal frame having a pair of magnetic latches located at the base of the door. The door is supported by a pair of symmetrically and horizontally disposed hinge members located near the top sides of the frame and strengthened at its center by a horizontal luminous crossbar. In the lower portion of the pet door, a pair of slide locks is positioned to lock each side to keep the pet either outside or inside. A pair of swivel locks are located on both sides of the door with locking ears on both inside and outside surfaces for one-way traffic. The magnetic latches maintain the pet door in a closed position when the pet is not using the door, and do not present a hindrance for the pet in using the door. Besides the factory made framed pet door, the installation kit contains a pair of side bars, a double-sided spline roller, a length of spline, a single edged razor blade, a fluorescent crossbar, fasteners, and instructions. An optional portable pet ramp is provided for elevated screen doors inaccessable by diminutive pets.

1. Field of the Invention
The present invention relates generally to pet doors. More specifically, the invention is a pet door kit for installation of a durable and safe one- and two-way prefabricated screen door that can be installed in an existing screen door or window-screen by a do-it yourself owner to allow pets to pass through. The prefabricated door consists of a rectangular metal frame with a fiberglass screen having a pair of magnetic latches located near the base corners of the frame. The door can be structurally supported by an optional horizontal crossbar coated with a fluorescent tape. A pair of symmetrically and horizontally disposed hinge members located near the top sides of the frame enable swinging of the pet door. In the lower portion of the pet door, a pair of slide locks with finger pulls is positioned to lock each side to keep the pet either outside or inside. A pair of swivel locks are located on both sides of the door with locking ears on both inside and outside surfaces for monitoring one-way traffic. The magnetic latches maintain the two-way door in a closed position when the pet is not using the door, and do not present a hindrance for the pet to use the door. Besides the factory made framed pet door, the installation kit contains a double-bladed spline roller, a length of spline, a single edged razor blade, fasteners, the crossbar, and instructions. An optional pet ramp is provided for elevated screen doors for diminutive pets.
2. Description of the Related Art
The related art of interest describes various pet doors. However, there is a need for a pet door kit which provides the necessary tools to install the pet door in a screened window or door, and various locking alternatives, such as to prevent one-way or two-way use. The related art will be discussed in the order of perceived relevance to the present invention.
U.S. Pat. No. 4,053,007 issued on Oct. 11, 1977, to Raymond E. Griffth describes an animal access door kit for either a corner or central location adjacent the lower edge of a screen door. For a corner installation, a horizontal rail traversing the width of the screen door is attached. A short vertical rail is attached to the lower door rail and the horizontal rail to define the pet door which has its own square frame. The cut screen edges are tucked into flanged channels of the outer and inner frames and sealed with a resilient seal strip. A horizontal rod traversing the pet door stiles serves to permit swinging of the pet door. The pet door kit is distinguishable for its horizontal rail traversing the main door frame, a horizontal swing rod and the lack of closures.
U.S. Pat. No. 4,603,724 issued on Aug. 5, 1986, to Michael J. Borwick describes a plastic pet door for a screen door. The rectangular door frame and the outer fixed frame clamp onto the screening material with male and female members having a rectangular cross-section. In a second embodiment, the door frame has protruding hinge portions at the top region and embedded magnets in the bottom region. A first embodiment shows a conventional pivotal lever on the outside of the bottom door frame which locks with an offset arm on the outer fixed frame. The plastic pet door is distinguishable for the difference in anchoring the screening in two-piece frame members.
U.K. Patent Application No. 2,101,182 A published on Jan. 12, 1983, for James K. Dunlop et al. describes a cat door with a two-part locking mechanism which permits in a first condition to move the door flap only inward. A second condition permits the door flap to move in either direction. A third condition permits the door flap to move only outward. A fourth condition prohibits movement of the door flap. Two interlocking tabs shaped either triangularly or elliptically are positioned on both sides of the lower rail of the outer pet door frame. The locking mechanism is distinguishable for its particular interlocking structure. U.S. Pat. No. 5,535,804 issued on Jul. 16, 1996, to Robert J. Guest describes a pet door kit made of two identical integral moldings of rectangular frame sides and door sides which are assembled onto a mesh screen panel by pins of one molding interfitting bores of the other molding before cutting the screen around the door except for the top portion. The frame moldings have two flexible webs acting as hinges on the top portion of the door. A sliding latch and enclosed magnets are provided at the bottom. The pet door kit is distinguishable for its non-metallic composition and two-piece molding construction.
U.S. Pat. No. 5,269,097 issued on Dec. 14, 1993, to George N. Davlantes describes a pet access door modular unit consisting of five rectangular frames, wherein the exterior frames can carry an access door. Two pairs of magnets are located on the lower portions of the pet access door. The modular unit is distinguishable for its multiple frames.
U.S. Pat. No. 3,797,554 issued on Mar. 19, 1974, to Frances H. Johnson describes a solid pet door structure wherein the door swings from a cane shaped hinge structure on the top portion of the frame. The pet door is distinguishable for its dissimilar hinge structure and its solid composition.
U.S. Pat. No. 4,480,407 issued on Nov. 6, 1984, to Robert J. Needham et al. describes a top-hinged swinging trapeziform door for a door, wall or window lined with either one or two pairs of coacting plastic magnet strips along the vertical sides or three sides around the door. The door is distinguishable by its unique configuration with plastic magnet strips. U.S. Pat. No. 3,985,174 issued on Oct. 12, 1976, to Charles O. Bricker describes a pet door installed in a corner of a window or screen consisting of a screen frame member having a frame track in which a spline cord can hold the edge of a cut off screen portion together with first and second outer members which are coupled to the center screen frame member. One of the outer frame members having a hinged center portion for allowing passage. The pet door is distinguishable for having three rectangular mounting frames and a solid top-hung swinging door.
U.S. Pat. No. 4,334,573 issued on Jun. 15, 1982, to La Vona R. Hackman et al. describes a swinging pet access door kit for installation in a corner of a screen door. A pair of L-shaped frame members are secured on either side of the screen in a corner of the screen door. The enclosed screen portion is cut along the sides and bottom. A weight member is attached to the lower edge. The pet door is distinguishable for its unframed swinging door.
U.S. Pat. No. 5,701,813 issued on Dec. 30, 1997, to John M. Smith describes a solid vinyl or rubber pet door for a screen door or window by framing the pet door in a corner with a horizontal rail and a vertical stile connected to each other and to the main door or window corner by three brackets. The framing rail and stile have rectangular hollow cross-sections with a flange for accepting the spline to trap the screen edges. The pet door is distinguishable for its requirement of a flexible solid door and the lack of any closures.
U.K. Patent Application No. 2,236,135 A published on Mar. 27, 1991, for Christopher P. Kirk describes an injection molded plastic cat door installed in a wall or solid door. The solid swinging pet: door is lockable by a locking unit in an extensive compartment: below the pet door comprising double discs having parallel straight edges on a spindle. The locking mechanism is distinguishable for its unique disc structure and placement in solid walls.
None of the above inventions and patents, taken either singularly or in combination, is seen to describe the instant invention as claimed. Thus, a one-way or two-way pet screen door solving the aforementioned problems is desired.


Backup applications that use externally connected hard disk drives for storing full image backups of a windows system disk or compressed image or file by file backups of a windows system disk. A system incrementally updates the images, including the system registry, and puts information on the external drive that makes it bootable.

1. Field of the Invention
The present invention relates generally to software utilities for backup of operating system hard disk drives and bare metal restore.
2. Description of Prior Art
Prior art exists that relates to making external USB attached hard disk drives bootable under various operating systems, including Windows.
Some of the art requires a person very skilled in computers, using a manual procedure(s) that may or may not work. Much of the prior art contains some element of folklore that may or may not allow an external disk to be bootable on all systems.
Nedprod.com contains instructions that could help a person to construct a bootable US drive.
911.cd dot net is a forum of experimenters who have had varying amounts of success in creating bootable USB drives.
Published patent application 20070136568 describes a methodology similar to that found on nedprod.com. 20070136568 Ding illustrates creating a bootable drive that will boot when a person skilled in the art changes the boot order of the computer system bios. 20070136568 illustrates booting an external USB drive to the point of a DOS prompt. It does not describe how a Graphical Users Interface (GUI) operating system can be executed. 20070136568 Ding will not allow the user to launch programs using a mouse point and click.
An issue with these software backup solutions is when the system disk becomes corrupted due to software errors or outside influences such as virus' the backed up image cannot be booted unless the full image backup disk is removed from its enclosure and placed into the system case. This task is often beyond the capabilities of the person who uses the system. Another approach some companies have taken is to provide a bootable CD or DVD that transfers the backed up image or the compressed image from the external hard disk drive onto the old system drive or new system drive. This method can take minutes per gigabyte to restore the system drive and if the data or applications residing on the image need to be accessed immediately the user is prevented from accessing them until the restore operation is completed which may take several hours. Embodiments overcome both issues of accessibility and quick restoration of the system.

Method and apparatus for creating a self booting operating system image backup on an external USB hard disk drive that is capable of performing a complete restore to an internal system disk