As anti-RNA polymerase (RNAP) antibodies are detected with high frequency in patients suffering from cutaneous scleroderma where skin sclerosis progresses rapidly, supervenes scleroderma renal crisis at a high rate, and associates with clinical entities whose prognoses are extremely bad, it is intended to provide a convenient method of detecting an anti-RNAP antibodies, which is extremely useful in diagnosing and classifying clinical entities of scleroderma, and predicting organ failure, in particular scleroderma renal crisis. In order to identify an epitope recognized commonly by anti-RNAP antibodies, the full length of RPC62 and a partial fragment of RPC155, that are 2 subunits of 62-kDa and 155-kDa of RNAP III, are expressed in Escherichia coli as recombinant proteins, and the reactivities to sera positive and negative to anti-RNAP antibody from patients suffering from scleroderma are examined by immunoblotting method to confirm that an epitope recognized by anti-RNAP antibodies in the sera from the patients suffering from scleroderma exists in 891 to 1020 amino acid residues of RPC155.

Scleroderma (systemic sclerosis) is a type of collagen diseases which is a disease whose major symptoms are fibrosis of skin and organs of viscera such as lung, intestine and the like, and disturbances of peripheral circulation. In Japan, it is speculated that there are approximately 10,000 patients, and approximately 500 to 1,000 of new cases are developing every year. Along with the advance in medical science, improvement of the prognoses of various types of collagen diseases have been reported, but the fundamental therapeutic method for scleroderma has not been yet established, and it is a disease whose prognosis is so bad that 10-year survival rate is less than 70%. Symptoms in patients suffering from scleroderma vary and have a wide range from the patients with only extremely light disturbances of circulation who require no treatment at all to the patients who die of respiratory failure, renal failure, cardiac failure or the like within a short period. Therefore, it is extremely important to predict what kind of organ failure will progress in the future of a patient diagnosed as having scleroderma.
In the sera from the patients suffering from scleroderma, autoantibodies (antinuclear antibodies) against nuclear protein which have important biological activities such as topoisomerase I, centromere and the like, are detected with high frequency. As these autoantibodies are specific to scleroderma, they are used in its diagnosis. Further, as anti-topoisomerase I antibodies are associated with diffuse cutaneous scleroderma accompanying pulmonary fibrosis where its range of skin sclerosis is wide, while anti-centromea antibodies are associated with limited cutaneous scleroderma where visceral lesions are few and skin sclerosis is localized in fingers, detecting these antinuclear antibodies are also useful in classifying clinical entities and predicting future organ failures (Arthritis Rheum, 37:75-83, 1994). The antinuclear antibodies, which are specific to scleroderma and useful in diagnosing and classifying clinical entities, are shown in table 1, and among them whose measuring kits are released, and it is measurable in general practice, are only 3 kinds, i.e., anti-topoisomerase I antibodies, anti-centromere antibodies and anti-U1RNP antibodies.
TABLE 1Range ofAntinuclearPositiveskinVisceralantibodyfrequencysclerosislesionAnti-topoisomerase25%DiffusePulmonaryI antibodiesfibrosis,(Anti-Scl-70Skinantibody)ulcerAnti-centromere20%LimitedRareantibodiescardiac,renal andpulmonary,failures,PrimarybiliarycirrhosisAnti-U1RNP20%LimitedMyositis,antibodiesPulmonaryhypertensionAnti-RNA 5%DiffuseSclerodermpolymerasea renalantibodiescrisis,MyocardialfailureAnti-U3RNP 3%DiffuseFewantibodyvisceralfailuresAnti-Th/To 2%LimitedFewantibodyvisceralfailuresAnti-PM-Scl<1%LimitedMyositisantibodiesAnti-Ku antibodies 2%LimitedMyositis
Anti-RNAP antibodies are antibodies found in the sera from patients suffering from scleroderma were identified as antinuclear antibodies recognizing several RNA polymerases (RNAPs) simultaneously for the first time in 1993 by the present inventors (J Clin Invest 91:1399-404, 1993). RNAP is an enzyme catalyzing the transcription of RNA, and RNAP I, RNAP II and RNAP III transcribe ribosomal RNA, messenger RNA and transfer RNA, respectively. Antibodies that simultaneously recognizing RNAP I and RNAP III were detected in the sera from patients suffering from scleroderma, and a part of which also reacts to RNAP II. Anti-RNAP antibodies have extremely high specificity to scleroderma, which has not been reported heretofore except in patients suffering from scleroderma. Anti-RNAP antibodies are detected with high frequency in diffuse cutaneous scleroderma where skin sclerosis progresses rapidly, and they supervene scleroderma renal crisis at a high rate and associate with clinical entities whose prognoses are extremely bad. Before 1980s when there was no therapeutic method for scleroderma renal crisis, the 5-year survival rate was only 30%. Many of fatal cases die of complication called scleroderma renal crisis where blood pressure rises acute, and renal failures are accompanied. Since the beginning of 1990s, a specific medicine against scleroderma renal crisis (ACE inhibitor) was found, and it was shown that administrating them in the early phase of sideration of scleroderma renal crisis allowed the patients to survive without leaving a sequela. However, although an ACE inhibitor is administered after the symptoms of scleroderma, renal crisis progress and renal function changed for the worse. Effectiveness of the ACE inhibitor is not expected. Even including fatal cases, although the patients can recover, dialysis is necessary for many of them. Therefore, the patients detected anti-RNAP antibodies related to scleroderma renal crisis recommended ensuring the self-blood pressure measurement for early detection of scleroderma renal crisis. Consequently, anti-RNAP antibodies are extremely useful antinuclear antibodies in diagnosing and classifying clinical entities of scleroderma, and predicting organ failure of scleroderma, in particular scleroderma renal crisis. Further, it is thought that examining the presence of anti-RNAP antibodies in diagnosing brings about the early detection of scleroderma renal crisis, decrease of the fatal cases by early therapy and improvement of life prognoses of scleroderma.
It has been reported by the present inventors that positive frequency of anti-RNAP antibodies in Japanese patients suffering from scleroderma is as low as about 5%, while in Caucasian patients in Europe and the United States, the rate is as high as 20-30%, whose frequency is higher than that of anti-topoisomerase I antibodies, anti-centromere antibodies and anti-U1RNP antibodies, and that anti-RNAP antibodies are the highest detected antinuclear antibodies in scleroderma in Caucasian in Europe and the United States (Arthritis Rheum 37, 902-6, 1994). Then, these results have been confirmed by the supplementary examinations in several facilities in Europe and the United States (Ann Intern Med, 119, 1005-13, 1993, Clin Exp Immunol, 105, 468-74, 1996).
Although anti-RNAP antibodies are clinically very useful antinuclear antibodies, a cumbersome immunoprecipitation which uses large amount of isotopes and cultured cells is the only method of detecting currently, therefore the present situation is that detecting anti-RNAP antibodies in a general clinical laboratory is thought to be impossible, and the detection can be performed only in specialized laboratories. Consequently, the development of a convenient method of detecting anti-RNAP antibodies is thought to be an urgent task. However, anti-RNAP antibodies cannot be detected by double immunodiffusion and immunoblotting by using crude antigens which are commonly performed for detecting antinuclear antibodies. The both of RNAP I and RNAP III are giant complexes comprising 10 or more subunits, and the number of molecules of respective subunits per cell are extremely few, can be exemplified as its reasons. In order to solve this point, identifying antigenic sites (epitopes) which are commonly recognized by anti-RNAP antibodies in the sera from patients suffering from scleroderma is essential. Development of the method of detecting including enzyme linked immunoassay (ELISA) is thought to be possible by expressing the sites in a large amount as recombinant proteins, when epitope regions on the RNAP I and RNAP III molecules become clear. An object of the present invention is to provide a convenient method of detecting anti-RNAP antibodies, which is extremely useful in diagnosing and classifying clinical entities of scleroderma, and predicting organ failure, in particular scleroderma renal crisis, and which has extremely high specificity to scleroderma, as they are detected with high frequency in the patients suffering from diffuse cutaneous scleroderma where skin sclerosis progresses rapidly, and they supervene scleroderma renal crisis at a high rate and related to clinical entities whose prognoses are extremely bad.
A basic study by the present inventors resulted in the elucidation that anti-RNAP antibodies in the sera from patients suffering from scleroderma recognize 2 subunits of 155-kDa and 62-kDa (RPC155, RPC62) of RNAP III with high frequency (Arthritis Rheum, 42, 275-84, 1999). In addition, cDNA sequence of human RPC155 was reported by Setareh and Hernandez in 1997 (Genome Res, 7, 1006-19, 1997), and it is registered to database of NCBI (accession No. AF021351). Then, in order to identify the epitopes existing on RPC155 and RPC62 in more detail, the full-length protein of RPC62 and a partial fragment of RPC155 were expressed as recombinant proteins in Escherichia coli and the reactivities to sera positive and negative to the anti-RNAP antibody from patients suffering from scleroderma were examined by immunoblotting. First, study using the recombinant proteins of RPC155-A (Seq. ID No. 8), RPC155-B2 (Seq. ID No. 10), RPC155-C (Seq. ID No. 12), RPC155-D (Seq. ID No.14) and RPC62 (full-length) shown in FIG. 1, led to the result shown in Table. 2. Each recombinant protein was recognized by sera positive to anti-RNAP antibody, while all of 11 sera positive to anti-RNAP antibodies reacted to RPC155-C.
TABLE 2SclerodermaSclerodermaRecombinantAnti-RNAPAnti-RNAPNormalRNAP IIIAntibody(+)Antibody(−)PersonFragment(n = 11)(n = 10)(n = 6)RPC155-A2(18%)1(10%)0RPC155-B21(9%) 00RPC155-C11(100%)00RPC155-D3(27%)00RPC626(55%)00
There, in order to examine epitopes contained in RPC155-C in more detail, 5 recombinant fragments of C1-C5 shortened from N- and C-terminals of RPC155-C were newly generated. When the reactivities to 11 sera that were positive to anti-RNAP antibodies were studied by immunoblotting, all of the sera recognized C3 and C4, while they did not react to C1, C2 and C5. Further, 7 recombinants of C-a to C-g encoding the common site of C3 and C4 were generated to examine the reactivities to sera positive to anti-RNAP antibody similarly. All of the sera reacted to C-c and C-g, while they did not recognize other recombinant fragments. Consequently, it was revealed that there are epitopes recognized commonly by anti-RNAP antibodies in the sera from patients suffering from scleroderma, at No. 891-1020 amino acid residues of RPC155 encoded by C-c. However, as the reactivity to C-c was weaker than that to C-g in certain sera, it was predicted that an amino acid site contained additionally in C-g was also necessary for strong binding to antibodies in the sera from patients. Therefore, it was revealed that C-g is more suitable than C-c for detecting anti-RNAP antibodies.
In order to confirm that the reactivity to C-g is specific to anti-RNAP antibodies in the sera from patients suffering from scleroderma, the study by immunoblotting with more examples was performed. As a result, the reactivity to C-g was detected in all of the 16 positive cases of scleroderma to anti-RNAP antibody, while it was not detected in 55 negative cases to anti-RNAP antibody scleroderma and 26 cases of normal person. Consequently, it was thought that C-g comprises epitopes recognized commonly by anti-RNAP antibodies in the sera from patients suffering from scleroderma, and recombinant proteins expressing the same sites are useful as antigens in methods of detecting anti-RNAP antibodies. Then, after C-g was expressed in Escherichia coli, it was purified by affinity column, and used as an antigen for ELISA. As shown in FIG. 2, reactivity to C-g in sera negative to anti-RNAP antibody scleroderma, the sera from patients suffering from systemic lupus erythematosus and sera from normal person used as controls tested by conventional immunoprecipitation were at a low level. When 4.15 units represented by the average of data+5×standard deviation from normal person was made to be cutoff, positive frequency of anti-C-g antibodies showed 100% in examples positive to anti-RNAP antibody and showed 0% in other examples, which revealed that ELISA by using C-g is an extremely superior method of detecting anti-RNAP antibodies where both sensitivity and specificity were 100%. The present invention has been completed based on these knowledges.


An optical disc drive includes a chassis assembly formed of metal and grounded, a tray supporting an optical disc and installed capable of sliding in and out of the chassis assembly, a cover-deck formed of metal and attached on a lower surface of the tray, an eject switch provided on a front surface of the tray to unlock the tray which is inserted in the chassis assembly and locked therein, an eject button provided in front of the tray to press the eject switch, a bracket formed of metal, provided between the eject switch and the eject button, and having a lead formed at one end portion thereof and contacting the cover-deck, and a static electricity discharge wire electrically connecting the cover-deck and the chassis assembly, wherein static electricity generated when the eject button is pressed sequentially flows through the bracket, the cover-deck, and the chassis assembly, and flows out to ground.

1. Field of the Invention
The present invention relates to an optical disc drive, and more particularly, to an optical disc drive which can prevent damage by static electricity not only in a closed state of a tray but also in an open state thereof.
2. Description of the Related Art
In general, optical disc drives record or reproduces information by radiating light onto a recording medium such as CDs (compact discs) and DVDs (digital versatile discs). The optical disc drive includes various structures to discharge static electricity to prevent malfunction or failure of elements due to the static electricity.
FIGS. 1 and 2 show an example of a static electricity discharge structure employed in a conventional optical disc drive. FIG. 1 shows that a tray 30 of the conventional optical disc drive is closed while FIG. 2 shows that the tray 30 is open. The optical disc drive is disclosed in U.S. Pat. No. 5,684,775.
Referring to FIG. 1, the conventional optical disc drive includes a chassis 33 formed of metal, the tray 30 coupled to the chassis 33 to be inserted into the chassis 33 or pulled out of the chassis 33 by being guided by a guide rail 42, and a bezel 35 provided at a front side of the tray 30. An eject button 43 to unlock the tray 30 when inserted in the chassis 33 and locked is provided at the bezel 35. An eject switch 52, which is pressed by the eject button 43, and a circuit board 50, where the eject switch 52 is installed, are provided at a front surface portion of the tray 30 facing the eject button 43. A metal plate member 60 to guide current by static electricity toward the chassis 33 is provided at a rear surface of the bezel 35 facing the front surface portion of the tray 30. The metal plate member 60 is attached to the rear surface of the bezel 35 by a pair of bosses 36 and 37 protruding from the rear surface of the bezel 35.
In a state in which the tray 30 of the optical disc drive having the above structure is inserted in the chassis 33, when the eject button 43 is pressed using a finger tip 17 to open the optical disc drive, as shown in FIG. 1, a discharge of static electricity 80 may be generated by friction between the finger tip 17 and the eject button 43. The static electricity 80 passes through a gap 70 between the bezel 35 and the eject button 43, as indicated by an arrow shown in FIG. 1, to proceed toward a cover portion 61 of the metal plate member 60 located around the eject switch 52. Then, the static electricity 80 is transferred to the chassis 33 via contact leads 64 and 65 at both ends of the metal plate member 60 and discharged through a ground (not shown). Thus, the static electricity 80 is prevented from flowing into the circuit board 50 via the eject switch 52.
However, referring to FIG. 2, when the optical disc drive is in an open state as the tray 30 is pulled out of the chassis 33, since the contact leads 64 and 65 of the metal plate member 60 do not contact the chassis 33, a discharge path of the static electricity is blocked so that the static electricity may flow into the circuit board 50 to malfunction or damage the optical disc drive.

Optical disc drive with static electricity


An electrolyte having a high conductivity, an excellent high-temperature life characteristic and leading to improvement of the shelf characteristic of an aluminum electrolytic capacitor. At least one phosphate ion producing compound and a chelating agent are added using a solvent largely composed of water. Therefor, an aluminum electrolytic capacitor comprising such an electrolyte has a low impedance, an excellent high-temperature life characteristic, and an improved shelf characteristic.

The present invention relates to an electrolytic solution for an electrolytic capacitor.
An aluminum electrolytic capacitor generally has the following constitution. Specifically, a high-purity aluminum foil shaped in a strip form is subjected to a surface-enlargement treatment by chemical or electrochemical etching, and the aluminum foil whose surface has been subjected to an enlargement treatment is subjected to a formation treatment in a forming solution, such as an aqueous ammonium borate solution, to prepare an anodic foil comprising the aluminum foil having an oxide film layer formed thereon. Then, the anodic foil is overlapped and wound with a cathodic foil, which is prepared by subjecting a high-purity aluminum foil to a surface-enlargement treatment in a similar manner, via a separator, to prepare a capacitor element. The capacitor element is then dipped in an electrolytic solution for driving and housed in a metallic sheathed package in a closed-end cylindrical form. Further, a sealing member made of elastic rubber is inserted into an open-end section of the sheathed package, and the open-end section of the sheathed package is sealed by drawing, whereby an aluminum electrolytic capacitor is constituted.
As the electrolytic solution impregnated into the capacitor element of a compact aluminum electrolytic capacitor for low voltage, one having ethylene glycol as a main solvent and an ammonium salt of adipic acid, benzoic acid or the like as a solute, one having xcex3-butyrolactone as a main solvent and a quaternary cyclic amidinium salt of phthalic acid, maleic acid or the like as a solute, and the like have been conventionally known.
Applications of the electrolytic capacitor include an electronic apparatus, such as an output smoothing circuit of a switching power supply or the like. While low impedance characteristics are demanded in these applications, such demand is being increased for an electrolytic capacitor along with the progress of miniaturization of the electronic apparatus. The conventional electrolytic solution cannot deal with the demand, and an electrolytic solution having a higher electroconductivity is demanded. The invention is to solve the problem, and one object thereof is to provide an electrolytic solution for an electrolytic capacitor that can realize a low impedance electrolytic capacitor, has a high electro-conductivity, and is excellent in high-temperature service life characteristics.
The conventional aluminum electrolytic capacitor has such problems that, upon allowing to stand, the capacitance is decreased, and the leakage current characteristics are deteriorated, which finally cause opening of a safety valve, and the reliability of the electrolytic capacitor is greatly influenced by the shelf characteristics, which are the characteristics after lapsing a long period of time under load or under no load.
Accordingly, when an aluminum electrolytic capacitor that had been deteriorated by allowing to stand for a long period of time was analyzed, it was found that the pH of the electrolytic solution is increased, and an anionic component, i.e., the solute, was attached to the surface of the electrode foil. It becomes apparent from these facts that aluminum on the surface of the electrode foil is reacted with the anionic component as the solute to attach on the electrode foil, and aluminum is dissolved to form a hydroxide, part of which is reacted with the anionic component as the solute to form a hydrogen gas through the reaction. The reaction is repeated to increase the pH, and finally it brings about deterioration of the electrode foil and opening of the valve.
Meanwhile, it has been well known that phosphoric acid is effective for prevention of the deterioration of an electrode foil, but it is not sufficient. This is because even when phosphoric acid is added, the phosphoric acid thus added is bonded to aluminum in the electrolytic solution to form a water-insoluble complex, and the insoluble complex is attached to the electrode foil, whereby the phosphoric acid is diminished from the electrolytic solution. Furthermore, when the addition amount is too large, such a problem arises that the leakage current is increased. However, the characteristics of the electrolytic capacitor are maintained in good conditions during the period where the phosphate ions remain in an appropriate amount before diminishment thereof, and therefore, the invention has been completed, another object of which is to improve the shelf characteristics of the electrolytic capacitor.
The electrolytic solution for an aluminum electrolytic capacitor of the invention is characterized by containing a solvent containing water and a water-soluble aluminum complex having a phosphate ion combined thereto.
The water-soluble aluminum complex having a phosphate ion combined thereto can be formed by adding a compound forming a phosphate ion in an aqueous solution (a phosphate ion forming compound) and a chelating agent forming a water-soluble aluminum complex with aluminum. The phosphate ion forming compound can be selected from the phosphorus compounds described later, phosphoric acid, phosphorous acid, hypophosphorous acid, salts thereof, condensates thereof, and salts of the condensates.
In a preferred embodiment of the invention, at least one kind of adipic acid and a salt thereof is used as the solute.
The solvent contains water as a main component (i.e., in an amount of about 25% or more), and the content of water is generally from 35 to 100% by weight of the entire solvent.
The content of adipic acid or a salt thereof is generally from 5 to 20% by weight of the entire electrolytic solution.
The content of the phosphorus compounds, phosphoric acid, phosphorous acid, hypophosphorous acid, salts thereof, condensates thereof, and salts of the condensates is generally from 0.01 to 3.0% by weight of the entire electrolytic solution.
The content of the chelating agent is generally from 0.01 to 3.0% by weight of the entire electrolytic solution.
The electrolytic solution for an aluminum electrolytic capacitor of the invention is an electrolytic solution, in which the compound forming a phosphate ion in an aqueous solution and the chelating agent are added to the solvent containing water to form a combined product of the water-soluble aluminum complex and a phosphate ion, and after being impregnated in the capacitor element, it reacts with aluminum eluted from the aluminum foil used as the electrode foil to the electrolytic solution, so as to form the combined product of the water-soluble aluminum complex and a phosphate ion.
As the solvent, a protonic polar solvent, an aprotonic solvent and a mixture thereof can be used in addition to water. Examples of the protonic polar solvent include a monohydric alcohol (such as methanol, ethanol, propanol, butanol, hexanol, cyclohexanol, cyclopentanol, benzyl alcohol and the like), a polyhydric alcohol and an oxyalcohol compound (such as ethylene glycol, propylene glycol, glycerin, methyl cellosolve, ethyl cellosolve, 1,3-butanediol, methoxypropylene glycol and the like). Representative examples of the aprotic solvent include an amide series (such as N-methylformamide, N,N-dimethylformamide, N-ethylformamide, N,N-diethylformamide, N-methylacetamide, hexamethylphosphoric amide and the like), a lactone compound, a cyclic amide compound, a carbonate compound (such as xcex3-butyrolactone, N-methyl-2-pyrrolidone, ethylene carbonate, propylene carbonate and the like), a nitrile compound (such as acetonitrile and the like), an oxide compound (such as dimethyl sulfoxide and the like) and the like.
As the compound forming a phosphate ion in an aqueous solution (the phosphate ion forming compound), the following compounds can be exemplified. They are the phosphorus compounds described later, phosphoric acid, phosphorous acid, hypophosphorous acid, salts thereof, condensates thereof, and salts of the condensates.
Examples of the above-described phosphorus compound and salt thereof include analkyl phosphate, such as ethyl phosphate, diethyl phosphate, butyl phosphate, dibutyl phosphate and the like; a phosphonate and a diphosphonate or a derivative thereof, such as phosphonic acid, 1-hydroxyethylidene-1, 1-diphosphonic acid, aminotrimethylenephosophonic acid, phenylphosphonic acid and the like; a phosphinate, such as methyl phosphinate, butyl phosphinate and the like; and salts of all of them. Among these, are preferred dibutyl phosphate, 1-hydroxyethylidene-1,1-diphosphonic acid, and salts of them. As the salts of the phosphorus compounds, an ammonium salt, an aluminum salt, a sodium salt, a potassium salt, a calcium salt and the like can be used.
A condensed phosphoric acid, which is a condensate of phosphoric acid, and a salt thereof are used. As the condensed phosphoric acid, a linear condensed phosphoric acid, such as pyrophosphoric acid, tripolyphosphoric acid, tetra-polyphosphoric acid and the like, a cyclic condensed phosphoric acid, such as metaphosphoric acid, hexametaphosphoric acid and the like, and a product formed by combining the linear and cyclic condensed phosphoric acids. As the salts of the condensed phosphoric acid, an ammonium salt, an aluminum salt, a sodium salt, a calcium salt, a potassium salt and the like can be used. Among these, are preferred pyrophosphoric acid, tripolyphosphoric acid, tetrapolyphosphoric acid and salts of them, and are more preferred pyrophosphoric acid, tripolyphosphoric acid and salts of them, with tripolyphosphoric acid being most preferred. As the salts of the condensates, an ammonium salt, an aluminum salt, a sodium salt, a potassium salt, a calcium salt and the like can be used.
Furthermore, as the phosphate ion forming compound, phosphoric acid, phosphorous acid, hypophosphorous acid and salts of them can be used. The salts thereof are an ammonium salt, an aluminum salt, a sodium salt, a calcium salt and a potassium salt. Phosphoric acid and a salt thereof form a phosphate ion through decomposition in an aqueous solution. Phosphorous acid, hypophosphorous acid and salts of them form a phosphite ion and a hypophosphite ion through decomposition in an aqueous solution, which then become phosphate ions through oxidation.
As the condensate other than the condensed phosphoric acid, the phosphorus compounds, phosphorous acid, hypophosphorous acid, salts of them, and condensates of the phosphorus compounds, phosphorous acid, hypophosphorous acid and a salt of hypophosphorous acid can be used. Furthermore, salts of the condensates can also be used. As the salts of the condensates, an ammonium salt, an aluminum salt, a sodium salt, a potassium salt, a calcium salt and the like can be used.
These are also the phosphate ion forming compounds, which form a phosphate ion in an aqueous solution or form a phosphite ion or a hypophosphite ion, which then become a phosphate ion through oxidation.
Among these, phosphoric acid or a salt thereof, condensed phosphoric acid, and a derivative of phosphoric acid, such as a phosphate or an alkyl phosphate, which easily form a phosphate ion, are preferred. Further, a linear condensed phosphoric acid. Such as phosphoric acid, pyrophosphoric acid, tri-polyphosophoric acid or the like, which forms a large amount of phosphate ions in a relatively high rate with respect to the addition amount, and a salt thereof are also preferred. In addition to these phosphate ion forming compounds, the effect of the invention can be obtained by substances that form a phosphate ion in an aqueous solution.
The addition amount of the phosphate ion forming compound is from 0.01 to 3.0% by weight, and preferably from 0.2 to 2.0% by weight, of the entire electrolytic solution. The effect is reduced outside the range.
Similarly, the chelating agent forming a water-soluble aluminum complex with aluminum is used as an additive. As the chelating agent, the following can be exemplified. That is, they are an xcex1-hydroxycaboxylic acid, such as citric acid, tartaric acid, gluconic acid, malic acid, lactic acid, glycolic acid, xcex1-hydroxybutylic acid, hydroxymalonic acid, xcex1-methylmalic acid, dihydroxytartaric acid and the like, an aromatic hydroxycarboxylic acid, such as xcex3-resocylic acid, xcex2-resocylic acid, trihydroxybenzoic acid, hydroxyphthalic acid, dihydroxyphthalic acid, phenoltricarboxylic acid, aluminon, Eriochrome Cyanine R and the like, a sulfocarboxylic acid, such as sulfosalicylic acid and the like, a tannin, such as tannic acid and the like, a guanidine, such as dicyandiamide and the like, a saccharide, such as galactose, glucose and the like, a lignin, such as lignosulfonate and the like, an aminopolycarboxylic acid, such as ethylenediaminetetraacetic acid (EDTA), nitrilotriacetic acid (NTA), glycolether-diaminetetraacetic acid (GEDTA), diethylenetriamine-pentaacetic acid (DTPA), hydroxyethylethylenediamine-triacetic acid (HEDTA), triethylenetetraminehexaacetic acid (TTHA) and the like, and salts of them. As the salts of them, an ammonium salt, an aluminum salt, a sodium salt, a potassium salt and the like can be used. Among these, are preferred tannic acid, trihydroxybenzoic acid, citric acid, tartaric acid, gluconic acid, aurin tricarboxylic acid, xcex3resocylic acid, DTPA, EDTA, GEDTA, HEDTA, TTHA and salts thereof, which easily exert chelate formation with aluminum, and are more preferred tannic acid, trihydroxybenzoic acid, citric acid, tartaric acid, xcex3-resocylic acid, aurin tricarboxylic acid, DTPA, GEDTA, HEDTA, TTHA and salts thereof.
The addition amount of the chelating agent is from 0.01 to 3.0% by weight, and preferably from 0.1 to 2.0% by weight, of the entire electrolytic solution. The effect is reduced outside the range.
As the solute of the electrolytic solution for an aluminum electrolytic capacitor used in the invention, an ammonium salt, a quaternary ammonium salt or an amine salt of a carboxylic acid, such as adipic acid, formic acid, benzoic acid and the like, can be used. Examples of a quaternary ammonium constituting the quaternary ammonium salt include a tetraalkylammonium (such as tetramethylammonium, tetraethylammonium, tetrapropyl-ammonium, tetrabutylammonium, methyltriethylammonium, di-methyldiethylammonium and the like) and a pyridinium (such as 1-methylpyridinium, 1-ethylpyridinium, 1,3-diethylpyridinium and the like). Examples of an amine constituting the amine salt include a primary amine (such as methylamine, ethylamine, propylamine, butylamine, ethylenediamine, monoethanolamine and the like), a secondary amine (such as dimethylamine, diethylamine, dipropylamine, ethylmethylamine, diphenylamine, diethanolamine and the like), and a tertiary amine (such as trimethylamine, triethylamine, tributylamine, 1,8-diazabicyclo(5,4,0)-undecene, 7-triethanolamine and the like).
Furthermore, the following acids can be used as the carboxylic acid. They are carboxylic acids including glutaric acid, succinic acid, isophthalic acid, phthalic acid, terephthalic acid, maleic acid, toluic acid, enanthic acid, malonic acid, a decanedicarboxylic acid, such as 1,6-decanedicarboxylic acid, 5,6-decanedicarboxylic acid and the like, an octanedicarboxylic acid, such as 1,7-octane-dicarboxylic acid and the like, azelaic acid, sebacic acid and the like. An inorganic acid, such as boric acid, a polyhydric alcohol complex compound of boric acid obtained from boric acid and a polyhydric alcohol, phosphoric acid, carbonic acid, silicic acid and the like, can also be used. Among them, are preferred an organic carboxylic acid, such as a decanedicarboxylic acid, an octanedicarboxylic acid, azelaic acid, sebacic acid, adipic acid, glutaric acid, succinic acid, benzoic acid, isophthalic acid, formic acid and the like, boric acid and a polyhydric alcohol complex compound of boric acid.
A salt having a quaternary cyclic amidinium ion as a cationic component may also be used. Examples of an acid forming an anionic component of the salt include phthalic acid, isophthalic acid, terephthalic acid, maleic acid, benzoic acid, toluic acid, enanthic acid, malonic acid and the like.
The quaternary cyclic amidinium ion as a cationic component is a cation formed by quaternarizing a cyclic compound having an N,N,Nxe2x80x2-substituted amidine group, and the following compounds are exemplified as the cyclic compound having an N,N,Nxe2x80x2-substituted amidine group. They are an imidazole monocyclic compound (for example, an imidazole homologue, such as 1-methylimidazole, 1-phenylimidazole, 1,2-dimethyl-imidazole, 1-ethyl-2-methylimidazole, 1,2,4-trimethylimidazole and the like, an oxyalkyl derivative, such as 1-methyl-2-oxymethylimidazole, 1-methyl-2-oxyethyl-imidazole and the like, a nitro derivative such as 1-methyl-4(5)-nitroimidazole and the like, an amino derivative such as 1,2-dimethyl-5(4)-aminoimidazole and the like), a benzoimidazole compound (such as 1-methylbenzoimidazole, 1-methyl-2-benzoimidazole, 1-methyl-5(6)-nitrobenzo-imidazole and the like), a compound having a 2-imidazoline ring (such as 1-methylimidazoline, 1,2-dimethylimidazoline, 1,2,4-trimethylimidazoline, 1-methyl-2-phenylimidazoline, 1-ethyl-2-methylimidazoline, 1,4-dimethyl-2-ethyl-imidazoline, 1-methyl-2-ethoxymethylimidazoline and the like), a compound having a tetrahydropyrimidine ring (such as 1-methyl-1,4,5,6-tetrahydropyrimidine, 1,2-dimethyl-1,4,5,6-tetrahydropyrimidine, 1,5-diazabicyclo[4,3,0] nonene-5 and the like), and the like.
The aluminum electrolytic capacitor containing the electrolytic solution for an aluminum electrolytic capacitor of the invention described in the foregoing is good in shelf characteristics, i.e., characteristics after a load or no load test for a long period of time, and further the initial capacitance is also increased.
After impregnating a capacitor element with the electrolytic solution for an aluminum electrolytic capacitor of the invention, the chelating agent forms a water-soluble complex with aluminum eluted from the aluminum foil in the electrolytic solution, which forms a combined product through a reaction with a phosphate ion. The combined product is attached to the electrode foil or is dissolved in the electrolytic solution and releases phosphate ions in that state, so as to exert such function that phosphate ions in the electrolytic solution are maintained in a suitable amount. The phosphate ions suppress dissolution of aluminum and formation of a hydroxide of aluminum to suppress deterioration of the electrode foil, whereby the shelf characteristics of the aluminum electrolytic capacitor are improved. The phosphate ions in the electrolytic solution and the phosphate ions in the combined product are detected for a long period of time after allowing to stand in an amount of from 10 to 40,000 ppm in terms of a phosphate radical (the electrolytic solution is diluted with diluted nitric acid of 2 mmol/L to 1,000 times to make pH of from 2 to 3, and phosphate ions are quantitatively determined by an ionic chromatography analysis).
The following experiments clarify these facts. The aluminum electrolytic capacitor of the invention was disassembled, and the electrolytic solution impregnated in the capacitor element was washed and removed. Thereafter, the capacitor element was impregnated with an electrolytic solution containing no phosphate ion to produce an aluminum electrolytic capacitor, and the shelf characteristics of the resulting aluminum electrolytic capacitor were excellent. Phosphate radicals of from 10 to 200 ppm were detected from the electrolytic solution of the aluminum electrolytic capacitor, but substantially no aluminum was detected. That is, the water-soluble complex of the chelating agent and aluminum is combined to phosphate ions to be attached to the electrode foil, and the combined product releases phosphate ions into the electrolytic solution to maintain the suitable phosphate ion concentration for a long period of time, whereby the shelf characteristics of the capacitor are improved.
In the case where the aluminum complex thus formed is not water-soluble, i.e., water-insoluble, the effect of the invention cannot be obtained because it is considered that it has no function of releasing phosphate ions.
In general, when the content of water in the solvent is increased, the presure inside the capacitor is increased due to formation of a hydrogen gas, causing such situation that blister is formed on the package. Particularly, in a high-temperature service life test at 105xc2x0 C. or higher, when the content of water exceeds 15% by weight, a large amount of gas is formed to increase the pressure inside the capacitor to cause such a situation that the safety valve is opened, and thus, it becomes unusable. That is, the state where the cathodic foil is in contact with the electrolytic solution at a high temperature is continued for a long period of time, and under the presence of a large amount of water, water reaches the aluminum foil through the dense oxide film formed on the aluminum film and reacts with aluminum to form aluminum hydroxide. A hydrogen gas is formed at this time. Furthermore, the reaction suddenly proceeds at a high temperature of 105xc2x0 C. or higher to form a large amount of gas, and thus, it results in an increase of the inner pressure of the capacitor and opening of the valve of the capacitor.
However, in the electrolytic solution for an aluminum electrolytic capacitor of the invention, because the phosphate ion forming compound and the chelating agent are added to the solvent containing water as a main component as an electrolytic solution, the specific resistance of the electrolytic solution can be reduced, and the impedance of the electrolytic capacitor can be reduced. Furthermore, because the phosphate ion concentration of the electrolytic solution in the capacitor element can be maintained to a suitable amount for a long period of time by the chelating agent, dissolution and deterioration of the electrode foil can be prevented, and the high-temperature service life characteristics of the aluminum electrolytic capacitor can be maintained in an excellent state.
The chelating agent and the phosphate ion forming compound added upon producing the electrolytic solution provide the chelating agent and a phosphate ion in the electrolytic solution of a molar ratio, chelating agent/phosphate ion, of from {fraction (1/20)} to {fraction (3/1)}. Furthermore, it is preferably from {fraction (1/10)} to {fraction (1/1)}. When the amount of the chelating agent is smaller than the ratio, the leakage current characteristics of the aluminum electrolytic capacitor are lowered. When it is more than the ratio, the high-temperature service life characteristics of the aluminum electrolytic capacitor are deteriorated although the reasons therefor are not clear.
When a large amount of water is contained in the electrolytic solution, deterioration of the electrode foil becomes remarkable, and in particular, when the content of water in the electrolytic solution exceeds 15%, such problem occurs that deterioration of the characteristics of the aluminum electrolytic capacitor becomes remarkable under the conditions for allowing to stand of 125xc2x0 C. or higher. In the invention, however, it has been found that the effect is obtained even in the case where a large amount of water is contained, and thus, an aluminum electrolytic capacitor having low impedance characteristics can be obtained by using the electrolytic solution.
That is, an aluminum electrolytic capacitor having low impedance characteristics can be realized by using a solvent containing water as a main component in the electrolytic solution for a aluminum electrolytic capacitor of the invention.
The content of water is generally from30 to 100% by weight, preferably from 35 to 65% by weight, and more preferably from 55 to 65% by weight, of the entire solvent. The electro-conductivity is lowered outside the range.
As described in the foregoing, in the electrolytic solution for an aluminum electrolytic capacitor of the invention, even when the content of water is 15% by weight or more, an aluminum electrolytic capacitor having excellent high-temperature service life characteristics and withstanding a high-temperature test of 105xc2x0 C. or higher can be obtained. Furthermore, because the content of water in the solvent can be increased to 100% by weight to obtain an electrolytic solution containing water as a main component, the electroconductivity of the electrolytic solution can be increased to obtain an aluminum electrolytic capacitor having low impedance characteristics.
Furthermore, it can be used at 125xc2x0 C. when the content of water is 65% by weight or more. Therefore, the range where it has a high electroconductivity and can be used at 125xc2x0 C. is from 55 to 65% by weight. In the case where the phosphate ion forming compound and the chelating agent, which are used as additives in the invention, are used singly within the range of the content of water of 65% by weight or lower, there are some cases where it withstands the service life test at 105xc2x0 C., but it suffers from opening of the valve in the initial stage on the high-temperature service life test of 125xc2x0 C. or higher. However, it can be used at 125xc2x0 C. owing to the synergistic effect between the phosphate ion forming compound and the chelating agent.
Furthermore, in the conventional aluminum electrolytic capacitor using an electrolytic solution containing water, the leakage current is increased after a high-temperature no load test, but in the aluminum electrolytic capacitor using the electrolytic solution for an aluminum electrolytic capacitor of the invention, the increase of the leakage current is small, and the change of tan xcex4 after the high-temperature test is smaller than the conventional product, whereby the high-temperature service life characteristics are improved.
As described in the foregoing, the content of water in the solvent can be increased to 100% by weight by adding the phosphate ion forming compound and the chelating agent to the solvent containing water as a main component, whereby an electrolytic solution having a high electroconductivity can be obtained, blister and opening of the valve in the package of the capacitor are prevented, and the tan xcex4 and the leakage current characteristics after the high-temperature test are improved. Accordingly, the invention realizes an electrolytic capacitor having impedance characteristics and high-temperature service life characteristics, which cannot be found in the conventional art, owing to the synergistic effect among the solvent containing water as a main component, the phosphate ion forming compound and the chelating agent.
The electrolytic solution for an aluminum electrolytic capacitor of the invention using the solvent containing water as a main component does not suffer from such problem as ignition even in the case where the capacitor is broken down upon using under non-standard conditions, such as use at high voltage. Other components than the solvent are the phosphoric, acid forming compound and the chelating agent, and therefore the components constituting the electrolyte have high safety. It is thus excellent in environmental resistance.
The impedance is further decreased by using at least one kind of adipic acid and a salt thereof as the solute.
The content of adipic acid or a salt thereof is from 5 to 20% by weight, and preferably from 9 to 16% by weight, in the electrolytic solution. The electroconductivity is decreased when it is less than the range, and the solubility is decreased when it exceeds the range. The content of other solute is also about from 5 to 20% by weight, and preferably about from 9 to 16% by weight, in the entire electrolytic solution.
Furthermore, an improvement of the voltage resistance can be attained by adding boric acid, mannitol, a nonionic surfactant, colloidal silica and the like to the electrolytic solution for an electrolytic capacitor of the invention.
By using the electrolytic solution for an aluminum electrolytic capacitor of the invention, such aluminum electrolytic capacitor can be obtained that is excellent in impedance characteristics and further, in high-temperature service life characteristics.


In compact drive, spiroid gear unit, and method for manufacturing a drive unit that includes at least an electric motor, a brake, a gear unit, and a frequency converter, the output shaft of the gear unit and the rotor shaft are positioned in parallel to each other, and the shaft-center distance is determined by at least one gear stage. The first gear stage includes a first toothed member connected to the rotor shaft, and a second toothed member, which engages with the first toothed member and is connected to an intermediate shaft, the brake, including at least a brake-rotor shaft, being integrated in the housing of the compact drive, the brake-rotor shaft being parallel to the rotor shaft, and the brake-rotor shaft being connected to a toothed member, which engages with the second toothed member.

German Published Patent Application No. 197 14 784 describes a compact drive, which includes an electric motor, at whose one end face a gear unit is arranged, and at whose other end face a frequency converter is arranged. The electronics region and the motor region must be sealed with respect to the gear unit. In this context, it is disadvantageous that the axial length is large and that a power take-off can only be provided at one end face of the compact drive.
Japanese Published Patent Application No. 2002-336305 describes a gear motor, which does not include a frequency converter, however. Between the gear unit, motor, and brake, as well as between the corresponding housing parts, there are also interfaces that must be precisely manufactured and are therefore complex and expensive.
A frequency converter, which is axially mounted to an electric motor behind its blower and is therefore cooled by its air stream, is described in German Published Patent Application No. 196 22 396. However, this therefore requires a large amount of space and, in addition, a fan that must be able to direct ambient air past.
A piezoelectric brake is described in European Published Patent Application No. 0 694 203.
German Published Patent Application No. 102 07 760 describes an adjusting gear, which, however, requires a large amount of space and an interface to the rotor of the motor.
German Published Patent Application No. 198 48 324 describes a coupling, which, however, requires additional, complicated and expensive machining of the rotationally mounted parts. In particular, not only are the sun and the rotor shaft included, but also a coupling sleeve. A higher number of parts also means higher storage costs.
European Published Patent Application No. 1 081 827 describes an electric tool, in which a gear unit can be driven by an electric motor. However, an interface, which is difficult to manufacture, is provided between the housing parts of the motor and the gear unit.
An axially offset right-angle drive, i.e., a spiroid gear unit, which is connectible to an electric motor and can be driven by it, is described in German Published Patent Application No. 43 09 559.

Method for manufacturing a compact drive unit


A segment for lining cavities, in particular tunnels, includes a substantially shell-shaped body bounded by an inner face, an outer face and side faces, with at least one opening in a side face for the purpose of receiving a dowel. The opening being configured as a substantially cylindrical bore into which projects a tube of limited deformability. A gap being provided between the outer circumference of the tube and the wall of the bore.

1. Field of the Invention
The present invention relates to a segment for lining cavities, in particular tunnels, which includes a substantially shell-shaped body bounded by an inner face, an outer face, and side faces, the latter exhibiting at least one opening for receiving a dowel.
2. The Prior Art
A frequently used technique in lining tunnels, shafts, etc., is tubbing. Individual tubbing segments are conveyed into the newly excavated tunnel where they are assembled to form a complete lining. To speed up installation and automatize the lining process, there is an increased use of tubbing segments with which an interlocking connection can be established between adjacent segments. Such a connection is often achieved by a dowel penetrating into a suitable bore in the adjacent segment.
A problem with connections of this kind is that, due to tolerances, measuring errors, etc., it will not always be possible to build or install the individual segments in such a way that the dowels are precisely aligned with the corresponding holes. For this reason allowances should be made for a certain radial displacement between the axis of the dowel and that of the bore into which the dowel is to be fitted, without any functional impairment.
In CH-A 654066 tunnel segments are disclosed which are joined by dowels. Different dowel variants are proposed which are to prevent the segments from falling apart once they have been fastened together. In order to avoid any damage while the dowels are being inserted into their openings, partially funnel-shaped elements are provided to facilitate assembly and prevent the holes and dowels from being damaged during fitting. There are no tolerances for compensating inaccuracies in the assembled state, however. As a consequence, problems are encountered with such segments in certain applications.
EP-A 100 771 describes an invention for connecting segments which is concerned with the above problem. The known connecting means substantially comprise sleeves into which the dowels are inserted so as to provide a force-mediated connection. To allow for variations in radial direction, the dowel sleeves are conical at their open ends, such that the dowels can undergo deformations in this area. This implies that the dowels must be made soft and flexible enough to permit such deformations. As a consequence, a large number of dowels are required to achieve a predetermined holding force. Moreover, this solution does not permit simple manufacture of the dowels, by pouring them as concrete elements integral with the body of the respective segment, for instance. It has further been found that the comparatively thin dowels of this type of construction frequently break upon insertion, thus leading to losses of material and delays in the lining process.
In DE-A 22 38 792 a tunnel lining is described in which the dowel holes are provided with spring rings. Such rings provide for a certain radial adjustment to compensate manufacturing tolerances. However, due to the spring characteristics and the essentially point-type contact between spring ring and dowel, the latter cannot be anchored securely in the segment.
Other solutions are disclosed in FR-A 78 25 472 and in DE-A 20 27 149. None of these solutions have proved completely satisfactory in practical use, however.
It is an object of the present invention to provide a segment of the above type which is easy to manufacture and to handle, and which offers a compensation in the instance of displacements in radial direction of the dowel.
In the invention this object is achieved by configuring the opening as a substantially cylindrical bore into which projects a tube of limited deformability, a gap being provided between the outer circumference of the tube and the wall of the bore.
An essential characteristic of the invention is the special configuration of the opening receiving the dowel. In principle, the invention is suited for assemblies of segments where any two segments to be fastened together are provided with corresponding openings, and where before installation a separately manufactured dowel is driven into one of these openings. According to the invention one of the two openings or both openings may be configured as specified in the invention. Moreover, one of the segments to be connected may include dowels which are moulded integral therewith and which are driven into the appropriately configured openings of the corresponding segment. It is a special advantage of the present invention that the dowel may be designed to suit any special requirements, and particularly, that the dowel may be made completely rigid.
On account of the substantially plastic deformation of the tube, the dowel will be anchored securely once the segments have been connected. Another advantage is that any movement of the tube in radial direction is limited by the wall of the bore, thus preventing any breaking or other damage even in the instance of faulty handling.
Manufacture of a segment of the invention is facilitated by placing a deformable material in the gap between bore and tube. During manufacture the deformable material acts as a lost casing, which will reduce production efforts and costs significantly.
Insertion of the dowel is facilitated by providing that the tube preferably end flush with the side face of the segment, its opening being flared in this area.
Satisfactory deformation of the tube may further be ensured by configuring the tube as a steel element which is embedded in the body of the segment, the depth of the bore exceeding the envisaged penetration depth of the dowel by at least 10 percent, and preferably by at least 20 percent, of the tube diameter. Special preference is given to a variant in which the gap has a width of 5 to 20 percent of the tube diameter.
The present invention is further concerned with an assembly of segments of the type described above, and a segment to be fastened thereto, which is provided with at least one dowel moulded integral with the body. As a result, a particularly stable connection is produced in a simple and cost-effective way.
A further advantage is gained by configuring the segments such that the dowel is provided substantially in one piece with and of the same material as the body of the segment. In this manner an interlocking connection is established utilizing the strength of the basic material. The manufacturing process itself is kept simple in this instance. A further increase in strength is achieved by providing reinforcing elements which extend from the body into the dowel.


Techniques for semantically annotating images in a plurality of images, each image in the plurality of images comprising at least one image region. The techniques include identifying at least two similar images including a first image and a second image, identifying corresponding image regions in the first image and the second image, and assigning, using at least one processor, annotations to image regions in one or more images in the plurality of images by using a metric of fit indicative of a degree of match between the assigned annotations and the corresponding image regions. The metric of fit may depend on at least one annotation for each image in a subset of the plurality of images and the identified correspondence between image regions in the first image and the second image.

Image retrieval techniques are used to help users browse, search, and retrieve images in a large collection of images. Such techniques enable users to search images accessible through the Internet and/or any other collection of images for one or more images that they are seeking. For example, a user may use a search engine to search for images of an object (e.g., a building) or a person (e.g., a celebrity). To this end, a user may input a search query such as "building" or "celebrity" to find the image or images that the user is seeking.
A search engine may identify one or more images in response to a user's search query based on textual annotations associated with the images being searched. In particular, a user's search query may be compared with one or more textual annotations associated with each of the images being searched and search results are presented to the user based on the outcome of the comparison(s). For example, if the user is searching for images by using the search query "building," a search engine may return images that are annotated with text including the word "building."
Consequently, the quality of image search results depends on the annotations associated with the images being searched and how such annotations are identified. Some conventional techniques for image annotation involve associating annotations with an image based on data in the document in which that image appears. For example, a search engine may identify annotations for an image appearing in a webpage from information in the web page such as information in the image tag (e.g., title, metadata, etc.) and/or information surrounding the image in the web page.

System and method for semantically annotating images


A water-based sulfonated polyurethane composition and footwear manufactured using the composition as as an adhesive, coating and primer. The sulfonated polyurethane is a reaction product of. a) at least one polyisocyanate; PA1 b) at least one alkylene diol; PA1 c) at least one sulfonated polyester polyol wherein the sulfo groups thereof are present as alkali metal salts; and PA1 d) at least one dihydroxy carboxylic acid, or salt thereof. The composition may also be modified to include a dispersed polymer or copolymer of an ethylenically unsaturated monomer. Such mofified compositions may be obtained by preparing the sulfonated polyurethane in the presence of an ethylenically unsaturated monomer and subsequently subjecting the mixture to free-radical polymerization conditions.

1. Field of the Invention
This invention relates to water-based adhesives, coatings and primers. Specifically, it relates to water-based polyurethane compositions having improved characteristics such as adhesion, peel strength and heat resistance. More specifically, it relates to one-component water-based sulfonated polyurethane compositions useful as adhesives, coatings and primers in the manufacture of footwear and to footwear and a method of preparing footwear using such compositions.
2. Description of the Prior Art
It is generally known that water-based sulfonated polyurethanes are useful in the manufacture of footwear. References describing such include the following:
U.S. Pat. No. 5,334,690 (Hoechst Aktiengesellschaft, Fed.) discloses water-based sulfonated polyurethanes which are obtained by reacting ionic polyester polyols, polycarbonate polyols and polyether polyols or mixtures thereof with a polyisocyanate or mixtures of polyisocyanates. The water-based sulfonated polyurethane special feature are the ionic groups present in the polyol segment. These polymers are described as being especially useful in the production of adhesive bonds for the shoe industry.
German Pat. No. DE 3930352 (REIA GMBH) discloses a process for bonding parts of shoes by applying water-based sulfonated polyurethane adhesives and drying with a microwave heater before bringing the parts together. The water-based sulfonated polyurethane Dispercoll U KA-8464 from Bayer Corporation is referenced.
"Waterbased high performance adhesive materials", Warrach., Presented at Proceedings of the ASC Division of Polymeric Materials Conference, Miami Beach, Fla., Sep. 11-18, 1989. The article describes water-based sulfonated polyurethane polymers, and their formulations, yielding good adhesion to substrates often used in the manufacture of footwear like PVC, ABS, polyurethanes, nylon, leather and fabrics.
A draw back for these prior art compositions is their failure to pass minimum adhesion standards in footwear applications, set by the Association of European Adhesive Manufacturers (FEICA), as one-component formulations. To pass minimum adhesion standards, two-component adhesive formulations are required. For example, bond strengths when subjected to thermal and mechanical stresses can be improved by the addition of water dispersible polyfunctional crosslinking agents selected from a group consisting of isocyanates, aziridines, melamine resins, epoxies, oxazolines and carbodiimides. However, a disadvantage associated with two component formulations is their limited pot life due to coagulation, gelling and viscosity increase. Furthermore, two-component adhesives have to be mixed from separate components directly before use. This can give rise to unsatisfactory adhesive bonds or a shortened pot life through inexact metering of the components making the system less user friendly. Also, exposure to latent crosslinking agents can pose a health risk through skin contact or inhalation.
There remains a need for improved one-component water-based adhesives, coatings and primers. One-component water-based compositions are easier to handle, safer and generally cost less. The present inventors have now discovered new one-component water-based sulfonated polyurethane adhesives compositions which pass FEICA minimum specifications for sole bonding. The present inventors have also discovered two-component water-based sulfonated polyurethane compositions having improved performance over previously known two-component systems.

H. B. Fuller Licensing & Financing, Inc.


A method includes obtaining rendered image data that includes a representation of an object for display using a see-through display. The see-through display permits ambient light from a physical environment through the see-through display. The method includes sensing a plurality of light superposition characteristic values associated with the ambient light that quantifies the ambient light. The method includes determining a plurality of display correction values associated with the electronic device based on the plurality of light superposition characteristic values and predetermined display characteristics of the representation of the object. The method includes generating, from the rendered image data, display data for the see-through display in accordance with the plurality of display correction values in order to satisfy the predetermined display characteristics of the representation of the object within a performance threshold.

In augmented reality (AR), computer-generated content is composited with a user's physical environment to overlay computer-generated visual content on top of real-world objects. A user may experience AR content by wearing a head mounted display (HMD) that includes a see-through display, which, in turn, allows the pass-through of light from the user's physical environment to the user's eyes. The HMD operates as an additive display by projecting AR content to be guided by the see-through display to the user's eyes; or, directly at the user's retinas, where pass-through light from the physical environment and the projected light of the AR content concurrently reach the retinas. The HMD adds computer-generated content to user's physical environment.
In some circumstances, however, light from the physical environment has a color composition, frequency of spatially varying contrast, and/or luminance property that interferes with computer-generated content in a manner that degrades the AR experience. For example, light from the physical environment may limit the perceived contrast between the physical environment and displayed computer-generated content. As another example, color composition of the physical environment, such as the presence of predominantly one color, may interfere with the color composition of displayed computer-generated content by providing dominant hues that are difficult to mask using additive display methods and hardware.
Using a graphics processing unit (GPU) for processing image data is computationally expensive (e.g., power hungry) and may introduce undesirable latency. For example, per-pixel modification is problematic for a mobile device because the high computational demands result in high levels of heat dissipation.

Modifying rendered image data based on ambient light from a physical environment


Set 2 according to the present invention includes m or more wood type golf clubs (wherein, m is an integer of no less than 2) having a loft angle of greater than 20 degrees. Provided that the face progression b2 of these m clubs is defined as from b2 (1) to b2 (m) following the ascending order of the loft angle of the club from the smallest value, this set 2 satisfies the relationships of:b2 (1) ≧b2 (2) ≧ . . . ≧b2 (m); and b2 (1) >b2 (m).Preferably, in all clubs having a loft angle of greater than 20 degrees, the ratio (a2/b2) of the loft angle a2 (degree) to the face progression (mm) is 0.7 or greater and 2.0 or less in this set 2. This set 2 is superior in ease to address. According to this set 2, the trajectory suited for each numerical designation can be achieved.

1. Field of the Invention
The present invention relates to a wood type golf club set, and golf clubs constituting the set.
2. Description of the Related Art
Conventionally, general golf club sets often include a plurality of wood type golf clubs. As the wood type golf club, number 1 wood, number 3 wood, number 4 wood, number 5 wood, and the like have been known. The number 1 wood is also referred to as driver, in general. The number 3 wood is also referred to as spoon, in general. The number 4 wood is also referred to as baffy, in general. The number 5 wood is also referred to as cleek, in general. The wood type golf clubs other than the driver may be referred to as fairway wood.
Particularly in recent years, wood type golf clubs with a greater loft angle have been increasingly used. Known such wood type golf clubs include number 7 wood, number 9 wood, number 11 wood, and the like.
Generally, notation of "W#1" has been employed for number 1 wood. Similarly, notation has been made "W#3" for number 3 wood, "W#4" for the number 4 wood, "W#5" for the number 5 wood, "W#7" for the number 7 wood, "W#9" for the number 9 wood, and "W#11" for the number 11 wood. In general, the golf club having larger numerical designation number(club number) has greater loft angle. Usually, the golf club having smaller numerical designation has less loft angle. Usually, the golf club having smaller numerical designation has greater club length. However, any unified standard for establishing the loft angle for certain numerical designation has not been present, and the loft angle of each numerical designation can vary depending on the manufacturer, item type, and the like. For example, even though clubs have been sold as the same number 5 wood, their loft angle has not been standardized, and may vary depending on the manufacturer, the product class, and the like. In addition, names that are different from the number as described above (1, 3, 4, 5 etc.) may be adopted as the notation of the numerical designation.
Moreover, recently, golf clubs referred to as "utility" or "utility club" have been on the market. This utility is also referred to as "hybrid" or "hybrid club" in US and the like. In general, this utility (hybrid) has an elongated shape with less width in the anterior-posterior direction of the head, as compared with conventional wood type heads. Herein, such utility (hybrid) is also included in wood type golf club.
Meanwhile, face progression has been known as one speculation of the golf club. Documents in which face progression is considered include Japanese Unexamined Patent Application Publication No. 2003-135628, Japanese Unexamined Patent Application Publication No. Hei 7-328149 and Japanese Unexamined Patent Application Publication No. 2000-93560 (US2001/041625 A1).


An engine cooling module having a radiator and a stone guard. The stone guard protects a core of the radiator from potential damage by foreign objects, such as stones.

This section provides background information related to the present disclosure, which is not necessarily prior art.
Typical vehicles have a condenser at the front of an engine cooling module (ECM) stack. In contrast, many hybrid electric vehicles have a low temperature radiator (LTR) at a front of the ECM stack. While condensers are designed to withstand stone impact, current LTR's are not. The present disclosure advantageously includes an improved engine cooling module that provides numerous advantages over existing engine cooling modules as described herein, and as one skilled in the art will appreciate. For example, the present disclosure includes an improved ECM with an LTR at the front of the ECM stack that is able to withstand stone impact.


A drive circuit having impedance control includes an impedance matching array unit having a plurality of transistors, the plurality of transistors selectively driven in accordance with an array drive control signal generated by control code data, and an update prohibition control unit for generating a transfer control signal to prohibit driving the transistors during a first time interval occurring when internal data transition, and applying the transfer control signal to the impedance matching array unit.

1. Technical Field
The present invention relates to impedance control in semiconductor devices and, more particularly, to an impedance controllable output drive circuit and an impedance control method, which is capable of checking a process, voltage and temperature (PVT) variation and automatically performing an impedance matching.
2. Discussion of Related Art
A semiconductor device can include pins to transmit data from or to the outside, and a data output circuit functioning as a data output buffer and driver circuit to provide internal data to the outside. The pins can be connected to transmission lines such as printed wiring provided on a mounting substrate in the semiconductor device incorporated into an electrical appliance. The pins can charge or discharge a floating capacitance or load capacitance (parasitic capacitance) existing on the mounting substrate. In an output drive circuit, output impedance ZQ can be controlled to match the output impedance with the transmission line to minimize distortion in the output signal caused by impedance mismatch.
When semiconductor devices are operated at higher speeds, the signal pulse width decreases, the influence of external noise increases, and the reflection of an output signal from an impedance mismatch in an interface terminal becomes a concern. Thus, a programmable impedance control scheme is employed to perform an input/output impedance matching. An example of a programmable impedance control (PIC) is disclosed in U.S. Pat. No. 6,307,424.
Another impedance control method is by use of a high speed transceiver logic (HSTL) interface, wherein one extra pin is used to control a desired output impedance value within a tolerance of about dozens of ohms. In such a scheme, it is often difficult to obtain a precise output impedance value due to changes in operating parameters such as power source voltage, operating temperature and manufacturing process.
U.S. Pat. No. 6,466,487 discloses in FIGS. 1a and 1b a programmable impedance control circuit, which includes an impedance update based on PVT variations, i.e., when a PVT variation is detected through a ZQ pad, up/down counting data is generated by counters 224 and 225. An update controller 52 receiving the counting data through registers 51 and 53 of FIG. 1b transmits control code data for an impedance update to an output drive circuit 1. In performing the impedance control by transmitting digitally coded control code data as described above, a change in the digitally coded control code data momentarily causes an impedance mismatch and may have an undesirable influence upon the data transmission.
FIG. 2 is a block diagram of a conventional impedance controllable output drive circuit. The circuit of FIG. 2 includes pull-up units 10-14 and pull-down units 20-24 corresponding to a pull-up transistor group 1a and a pull-down transistor group 1b within an output buffer 1 as in FIG. 1b, and an output pad 30 corresponding to the input/output pad 20 of FIG. 1B.
FIG. 2 illustrates a block configuration of an impedance controlled output driver, wherein a plurality of pull-up units 10-14 and a plurality of pull-down units 20-24 are connected commonly to the output pad 30. Pull-up control code data P[0:n] control impedance of pull-up units 10-14, and pull-down control code data N[0:n] control impedance of pull-down units 20-24. The pull-up control code data P[0:n] and pull-down control code data N[0:n] are changed from a high logic level to a low logic level, or from a low logic level to a high logic level, in conformity with a PVT variation, and are allocated to the corresponding pull-up units 10-14 and pull-down units 20-24. Thus, the number of activated transistor arrays of the pull-up units 10-14 and pull-down units 20-24 is controlled to update the impedance.
A control code to control the pull-up and pull-down impedances depends upon a value of internal data DinB, and performs an update for one of the pull-up and pull-down units. For example, when the internal data DinB is '1' or 'high' logic level, output data represented on the output pad 30 is output as a value of '0' or 'low' logic level. Thus a pull-down control code is not updated, but a pull-up control code is updated. On the contrary, when the internal data DinB is '0', an output data is '1', thus a pull-down impedance code is updated.
FIG. 3 is a circuit diagram illustrating an example of the configuration of pull-up and pull-down units shown in FIG. 2. For example, FIG. 3 illustrates a detailed configuration of one pull-up unit 10a and one pull-down unit 20a. With reference to FIG. 3, the pull-up unit 10a includes a pass transistor P1, a latch L1 constructed of two inverters IN2 and IN3, a NOR gate NOR1, an inverter IN4, a P-type metal oxide semiconductor (MOS) transistor PM1, and a resistance R1 connected to an output pad 30. The pull-down unit 20a includes a pass transistor P2, a latch L2 constructed of two inverters IN11 and IN12, a NAND gate NAN1, an inverter IN13, an N-type MOS transistor NM1, and a resistance R2 connected to the output pad 30.
In FIG. 3, when internal data DinB is '1', the pass transistor P1 within the pull-up unit 10a is activated, and a correspondingly applied pull-up control code P_CODE is updated to the latch L1, and output data is output as '0' by an activation of N-type MOS transistor NM1. When the internal data DinB is '0', the pass transistor P2 within the pull-down unit 20a is activated, a pull-down control code N_CODE is updated to the latch L2, and output data is output as '1' by an activation of P-type MOS transistor PM1.
The circuits of FIGS. 2 and 3 can experience difficulties when a pull-up code and a pull-down code are simultaneously updated during a time interval when data transition, or when an interim value of an abnormal code is transferred during a code transition. An undesired impedance may be provided momentarily, causing an output signal from the semiconductor device to be distorted or have noise. When a semiconductor device receives a distorted or noisy output signal, a set-up/hold failure or input logic level decision error may be caused.
In performing an impedance update in conformity with a PVT variation, it is desired to reduce an impedance matching error caused during a data transition. Also, a technique to perform an impedance update without a training sequence during a reset operation is desired.

Impedance controllable ouput drive circuit in semiconductor device and impedance control method therefor


A vehicle motion control apparatus is provided with an anti-skid control device and a steering angle adjusting device, which adjusts the steering angle of at least one of the front and rear wheels to cancel a yaw deviation between a desired yaw factor and an actual yaw factor, to be substantially zero. An incompatibility between the devices is determined on the basis of a state of the wheel adjusted by the steering angle adjusting device to cancel the yaw deviation. And, a predetermined parameter provided between a vehicle stability directive parameter and a brake directive parameter is set on the basis of the incompatibility. Then, the anti-skid control device controls the braking force applied to each wheel of the vehicle on the basis of the predetermined parameter. Consequently, the anti-skid control giving importance to the braking force can be performed, as long as the steering angle adjusting device is operative.

1. Field of the Invention
The present invention relates to a vehicle motion control apparatus, and particularly relates to a vehicle motion control apparatus provided with a steering angle adjusting device for adjusting a steering angle of a front or rear wheel of a vehicle, and an anti-skid control device for controlling braking force applied to each wheel.
2. Description of the Related Arts
With respect to a vehicle provided with the steering angle adjusting device and anti-skid control device, it has been proposed to provide an apparatus for controlling them appropriately. In Japanese Patent Laid-pen Publication No. 5-105055, for example, in order to control both of right and left wheels individually to be braked with a minimal stopping distance even if the vehicle was running on a split road surface, and to prevent unintentional yaw moment form being produced on the vehicle, there is proposed such an apparatus for controlling a running condition during braking operation as the one provided with a wheel steering device for adjusting a steered angle of a wheel so as to cancel a yaw rate deviation, and an anti-skid control device for controlling the braking force applied to right and left wheels individually.
Although it has been proposed to ensure both of a minimal braking distance and a stability in the Japanese Publication No. 5-105055 as described above, the wheel steering apparatus is designed to be controlled on the basis of the yaw rate deviation, so that it is actually actuated after an unexpected vehicle behavior was occurred. Therefore, it is difficult to actuate the apparatus in response to a rapid change of the vehicle behavior. On the contrary, although the anti-skid control device has been constituted basically to control the individual braking force for each wheel of right and left wheels, it is not easy to obtain the minimal braking distance, with the vehicle stability being ensured, depending upon conditions of the wheel steering device, including a case where the steering angle adjustment was inoperative, for example, so that other countermeasures might be required, separately.


Compounds of Formula (I) are disclosed herein and their use in inhibiting quorum sensing in bacteria.

Quorum sensing (QS) is a type of bacterial cell-to-cell signaling pathway mediated through the production, release and detection of the small signaling molecules called autoinducers (AIs) (reviewed in (1)). Such communication allows bacterial control of crucial functions in united communities for enhancement of symbiosis, virulence, antibiotic production, biofilm formation, and many other processes. The recent increase in prevalence of bacterial strains resistant to antibiotics emphasizes the need for the development of a new generation of antibacterial agents. As QS is utilized by number of pathogenic bacteria to direct virulence and biofilm formation, inhibitors/modulators of QS may serve as tools to study or intercept such community behaviors and might be beneficial as antibacterial agents (2). One of the chemical signals, or autoinducers (AIs) used by Gram-negative bacteria are acyl homoserine lactones (AHLs), which are detected by their cognate regulator (R) proteins (1).
The QS system Vibrio fischeri (recently reclassified as Aliivibrio fisheri) serves as the paradigm upon which all other QS systems are based. It is composed of a transcriptional regulator protein (R) and a synthetase (I). The R protein is unstable unless it binds to the AHL which is produced by the synthetase. V. fischeri produces N-3-(oxo-hexanoyl)-homoserine lactone (3OC6HSL), V. harveyi synthesizes N-3-hydroxybutanoil-homoserine lactone (HAI-1), and Pseudomonas aeruginosa produces two distinct AHLs: N-3-oxo-dodecanoyl-L-homoserine lactone (3-OC12-HSL) and N-butyryl-L-homoserine lactone (C4-HSL). V. harveryi produces a second signalling molecule, a furnosyl borate diester, termed autoinducer-2 (AI-2), and a third CAI-1. CAI-1 has been identified in V. cholerae to be (s)-3 hydroxytridecan-4-one. P. aeruginosa also has a third QS signaling molecule, 2-heptyl-3-hydroxy-4-quinolone (PQS), which is induced and repressed by the las and rhl systems, respectively.
Pseudomonas aeruginosa is an important human opportunistic pathogen affecting immunocompromised individuals, cancer patients, burn victims, cystic fibrosis patients and patients with impaired lung function. It uses two AHL systems called, las and rhl to mediate QS. LasI/R synthesizes and detects N-(3-oxo-dodecanoyl)-L-homoserine lactone (3-oxo-C12-AHL) while RhlI/R synthesizes and detects N-butanoyl-L-homoserine lactone (C4-AHL) (FIG. 1a). In addition, P. aeruginosa has a third QS-dependent pathway, Pseudomonas quinolone signal (PQS) that uses 2-heptyl-3-hydroxy-4-quinolone as an autoinducer (reviewed in (3)). Although, certain genes appear to be regulated by one pathway, for example regulation of genes involved in rhamnolipid synthesis by the rhl pathway (4), there is much overlap between the pathways and what was once thought to be a hierarchical pathway, with las activating rhl, is now known to be much more complex (5). Accumulated evidences clearly indicate the importance of P. aeruginosa QS in disease (6).
Over two decades, several small molecules have been identified by many research groups as inhibitors of the AHL:R protein complex. These are mostly AHL-based structures with moderate changes on the acyl side chain and amide linkage. Some of the most potent inhibitors prepared by Geske and Blackwell are shown in FIG. 1b (7). Recently, Meijler and co-workers designed a ligand, 3, which covalently modified LasR (8). Since AHL is the pharmacophore present in the natural substrates, AHL-based inhibitors are likely to modulate R protein activation.
Studies of structural features other than the AHL scaffold as tools to understand the R type protein interaction with AHLs are limited, although they might aid in rational design of QS inhibitors. Only a few examples of inhibitors with the altered lactone ring structure of AHL have been reported (9-12). For example, Smith et al reported 3-oxo-C12-(2-aminocyclohexanone) (FIG. 1c, 4) as a strong antagonist of LasR system (9), while Muh et al identified two LasR inhibitors having a phenyl and stetrazole ring (e.g. FIG. 1c, 5), with IC50 in nM range (FIG. 1c) (10). It is noteworthy that γ-thiolactone analogue of 1 (FIG. 1b) showed inhibition of LuxR while the corresponding ε-lactam (caprolactam) analogue was reported to lack LuxR binding (13). Thus, a need exists for new QS inhibitors.

2-methylthiopyrrolidines and their use for modulating bacterial quorum sensing

THE FLORIDA INTERNATIONAL UNIVERSITY BOARD OF TRUSTEES


A system and method for a secondary water drainage system with street level leak detection positioned between spaced apart prefabricated building panels is disclosed herein. In the space between two adjacent prefabricated building panels, an inner line of caulk is formed from the top to the bottom of the panels. Next, a porous drain strip is positioned adjacent to a first side of the inner line of caulk, also extending vertically from the top to the bottom of the panels. Lastly, an exterior line of caulk if formed adjacent to the porous drain strip extending vertically from the top of the panels to a point just above the bottom of the panels. The porous drain strip is extended through this space formed in the exterior line of caulk and allows the water collected to exit through the same space.

1. Field of the Invention
The present invention relates to a water drainage and leak detection system for building panels. In particular, the invention is concerned with a system and method for sealing a space between two precast concrete panels while allowing water drainage to occur. The drain strip/weep system allows street level detection of caulking leaks.
2. Background Description
Prefabricated building panels are commonly used in the construction of buildings. These panels can be manufactured using a wide variety of materials. However, prefabricated building panels are preferably composed of concrete (i.e., precast concrete panels), especially if used in the construction of exterior building structures. As is shown in U.S. Pat. No. 5,699,644, a prefabricated building panel is formed of a concrete slab that is connected to a series of reinforcing beams or studs by a plurality of thermally non-conductive projections, which are embedded in the slab. To reinforce these concrete panels, wire mesh or steel beams are either embedded in or attached externally to the concrete panels. These panels are then connected to a steel channel by anchors. The steel channel acts to separate the prefabricated building panel from the wall formed on the interior of the building, as well as to hold insulating material. This invention can be used with conventional building panels of concrete or other materials from 2″ to 12″ thickness.
In order to construct the exterior perimeter of a building, these panels are "locked" in place by using bolted and welded attachment plates. Outer and inner lines of water sealing material (e.g., caulk) are then used to seal the edges of adjacent panels to prevent water leakage. However, the existing methods of caulking may allow water to penetrate the outer line of caulk due to poor workmanship or deterioration over time. When penetration occurs, it causes water to lay between the lines of caulk under hydrostatic pressure. This causes the water to work its way through an inner layer of caulk and through the interior of the building, resulting in damage to the insulation and other features of the building (e.g., corrosion, short circuits, mold, etc.). Moreover, water-related corrosion and rust formed on the interior of the wall due to water migration from within the two lines of caulk can cause structural damage.

System and method for a secondary water drainage system with street level leak detection


There are many different serious cardiac arrhythmias. The present invention uses measurements of RR intervals (interbeat intervals) to detect, in particular but not exclusively, atrial fibrillation of a patient. Atrial fibrilation is a serious ailment in which the heartbeat is generally rapid and irregular. Probability density histograms of ΔRRs (difference between two successive RR intervals) collected during atrial fibrillation of a plurality of subjects are used as a template for the detection of atrial fibrillation. In one implementation, there are 16 standard probability density ΔRRs histograms every 50 ms of mean RR interval of a certain number of beats, where the mean RR interval ranges from 350 ms to 1149 ms. Similarity between the standard probability density histograms and a test density probability histogram of ΔRRs of a patient is estimated by the Kolmogorov-Smirnov test. If the test density histogram is not significantly different from the standard density histogram, atrial fibrillation is detected.

1. Field of the Invention
The present invention relates to a method and a system for detecting cardiac arrhythmias from internally and/or externally detected activity of the heart.
2. Brief Description of the Prior Art
Atrial fibrillation is a serious and common cardiac arrhythmia. Atrial fibrillation is associated with rapid, irregular atrial activation with life threatening sequelae such as stroke. The atrial activations are irregularly transmitted through the atrioventricular node leading to a correspondingly irregular sequence of ventricular activations as monitored by the ventricular interbeat (RR) intervals on the surface electrocardiogram (ECG). An RR interval is an interval between two successive heart beats. Clinically, in the surface ECG, atrial fibrillation is diagnosed by absence of P waves (normally associated with the near synchronous activation of the atria) and a rapid irregular ventricular rate. P waves are difficult to determine automatically and irregular baseline activity of the ECG is common in atrial fibrillation.
Although a number of different methods have been proposed to test for atrial fibrillation based on knowledge of the RR intervals and/or the surface ECG, the detection of atrial fibrillation based on this data nevertheless poses substantial problems (Murgatroyd, et al. "Identification of Atrial Fibrillation Episodes in Ambulatory Electrocardiographic Recordings: Validation of a Method for Obtaining Labeled R—R Interval Files," Pacing and Clinical Electrophysiology, (1995), pp. 1315–1320). In the following description, the main strategies that have been proposed to assess atrial fibrillation based on knowledge of the RR intervals and/or ECG will be briefly reviewed.
Since RR intervals during atrial fibrillation have a larger standard deviation and a more rapid decay of the autocorrelation function, there are proposals that the standard deviation and the autocorrelation function can be used to distinguish atrial fibrillation from sinus rhythm (Bootsma, et al. "Analysis of RR Intervals in Patients with Atrial Fibrillation at Rest and During Exercise," Circulation, (1970), pp. 783–794). Since other abnormal rhythms also have a large standard deviation of RR intervals and a rapid decay of the autocorrelation function, these methods are difficult to apply in concrete situations.
Moody and Mark (G. Moody, et al. "A New Method for Detecting Atrial Fibrillation Using R—R Intervals," Computers in Cardiology, (1983), pp. 227–230) classify RR intervals as short, long or regular. They then construct a Markov model for the probabilities for transitions between RR intervals in each of the three different length classes. Atrial fibrillation data has typical transition probabilities not shared by normal rhythms or other arrhythmia. Although the Markov model has high sensitivity for detecting atrial fibrillation, it tends to have a relatively low predictive value of a positive test.
Pinciroli and Castelli have investigated the morphology of histograms of RR intervals collected during atrial fibrillation and other arrhythmia (F. Pinciroli, et al. "Pre-clinical Experimentation of a Quantitative Synthesis of the Local Variability in the Original R—R Interval Sequence in the Presence of Arrhythmia," Automedica, (1986), vol.6, pp. 295–317. Pinciroli and Castelli, 1986). They demonstrated that the histograms of the ratio between successive RR intervals show characteristic differences between normal rhythm and atrial fibrillation. The histogram of the ratio between successive RR intervals is symmetrical to the mean value. No quantitative methods were proposed to quantify the symmetry or to use it to develop a quantitative test.
Since the baseline of the ECG is irregular during atrial fibrillation, Slocum (J. Slocum, et al. "Computer Detection of Atrial Fibrillation on the Surface Electrocardiogram," Computers in Cardiolody, (1987), pp. 253–254) has proposed that the regularity of the baseline, as determined by the power spectrum of the residual ECG after subtraction of the baseline of the QRS complexes can be used to detect atrial fibrillation. This method is necessarily sensitive to small amounts of noise that might corrupt the baseline of the ECG.
Implantable ventricular and atrial defibrillators are devices that distinguish atrial and ventricular fibrillation from other rhythms. Typically, electrodes in these devices record intracardiac activity directly from the atria and ventricles. The methods that are used to detect atrial fibrillation in these devices cannot be easily applied to recordings that give information about the timing of the QRS complexes (U.S. Pat. No. 6,144,878, issued to Schroeppel on Nov. 7, 2000, U.S. Pat. No. 6,035,233 issued to Schroeppel on Mar. 7, 2000, U.S. Pat. No. 5,749,900 issued to Schroeppel on May 24, 1998, U.S. Pat. No. 6,064,906 issued to Langberg et al. on May 16, 2000, U.S. Pat. No. 5,772,604 issued to Langberg et al. on Jun. 30, 1998, U.S. Pat. No. 6,061,592 issued to Nigam on May 9, 2000, U.S. Pat. No. 5,951,592 issued to Murphy on Sep. 14, 1999, U.S. Pat. No. 5,941,831 issued to Turcoft on Aug. 24, 1999, U.S. Pat. No. 5,591,215 issued to Greenhut et al. on Jan. 7, 1997).
Analysis of a histogram of the interbeat intervals can be used to discriminate between ventricular fibrillation and ventricular tachycardia. By counting the number of beats in predetermined interval classes, an algorithm identifies a given sequence as ventricular fibrillation or ventricular tachycardia (U.S. Pat. No. 5,330,508 issued to Gunderson on Jul. 19, 1994). While this patent suggests that the invention is of value in detecting and treating atrial fibrillation (column 2, lines 29–31), it does not provide specific embodiment for detecting and treating atrial fibrillation.
Based on the foregoing review of the prior art, it is apparent that there is a need to develop a method and a system for determining whether or not a given recording is atrial fibrillation based on the timing of the QRS complexes as measured from an internal and/or external monitor. Assessment of whether a patient is in atrial fibrillation based on the timing of the QRS complexes would be extremely useful, for example, for assessing the efficacy of specific drugs on a patient fitted with a monitoring device that measures the timing of the QRS complexes.

Method and system for detection of cardiac arrhythmia