Patents by Inventor Toshihiko Yoshioka
Toshihiko Yoshioka has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
-
Publication number: 20040005721Abstract: The present invention provides a highly sensitive biosensor capable of yielding good response even when the amount of a sample is extremely small. The biosensor of the present invention includes: a first insulating base plate which has a working electrode comprising a plurality of branches and a first counter electrode comprising a plurality of branches, the branches of the working electrode and the first counter electrode being arranged alternately; a second insulating base plate which has a second counter electrode and which is disposed at a position opposite to the first insulating base plate; a reagent system comprising an oxidoreductase; and a sample supply pathway formed between the first and second insulating base plates, wherein the branches of the working electrode and the first counter electrode that are arranged alternately, the second counter electrode, and the reagent system are exposed in the sample supply pathway.Type: ApplicationFiled: January 15, 2003Publication date: January 8, 2004Inventors: Yuko Tanike, Shin Ikeda, Toshihiko Yoshioka
-
Patent number: 6656702Abstract: A biosensor that enables rapid and simple quantitation of a substrate with high accuracy and demonstrates an excellent preservation characteristic by best retaining enzyme activity is disclosed. The biosensor comprises an electrically insulating base plate, an electrode system including at least a working electrode and a counter electrode formed on the base plate, and a reaction layer containing at least an enzyme and a sugar. The reaction layer may be formed on the electrode system. The enzyme may be selected from glucose oxidase, glucose dehydrogenase, and fructose dehydrogenase. The sugar is trehalose, sucrose, glycerol, mannitol, and ribose. If the enzyme selected is glucose dehydrogenase whose coenzyme is pyrrolo-quinoline quinone, the use of trehalose is preferable.Type: GrantFiled: June 30, 1999Date of Patent: December 2, 2003Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Keiko Yugawa, Toshihiko Yoshioka, Shiro Nankai
-
Publication number: 20030183519Abstract: There is provided a cholesterol sensor with high-accuracy and excellent response, whose object to be measured is whole blood, where plasma with hemocytes therein filtered can rapidly reach an electrode system. In a biosensor where plasma with hemocytes therein filtered with a filter is sucked into a sample solution supply pathway due to capillarity, there are formed: a first pressing part for holding a primary side portion of the filter from the bottom; a second pressing part for holding a secondary side portion of the filter from the top and the bottom; a third pressing part for holding the central portion of the filter from the top; and a void for surrounding the filter between the second pressing part and third pressing part.Type: ApplicationFiled: March 4, 2003Publication date: October 2, 2003Inventors: Miwa Hasegawa, Tomohiro Yamamoto, Motokazu Watanabe, Takahiro Nakaminami, Shin Ikeda, Toshihiko Yoshioka, Shiro Nankai
-
Patent number: 6547954Abstract: A biosensor includes: an insulating substrate; an electrode system formed on the insulating substrate which has a working electrode and a counter electrode; and a reaction layer formed on the insulating substrate which contains an oxidoreductase and an electron acceptor. The electron acceptor is ferricinium ion derived from ferrocene electrolyte.Type: GrantFiled: January 18, 1999Date of Patent: April 15, 2003Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Shin Ikeda, Tomohiro Yamamoto, Toshihiko Yoshioka, Shiro Nankai, Shigeki Joko, Junko Iwata
-
Publication number: 20030000834Abstract: A biosensor enabling accurate measurement of the concentration of a substrate contained in a trace amount of a sample solution is disclosed. The electrochemical analysis element in accordance with the present invention which should be included in the biosensor comprises a sensor body having a hollow space which space is open at its both ends, an electrode system having a working electrode and a counter electrode, a reagent segment containing an enzyme, wherein the electrode system and the reagent segment are disposed on an inner wall of the hollow space.Type: ApplicationFiled: September 4, 2002Publication date: January 2, 2003Applicant: Matsushita Electric Industrial Co., Ltd.Inventors: Toshihiko Yoshioka, Shin Ikeda, Motokazu Watanabe, Shiro Nankai
-
Patent number: 6471839Abstract: The present invention provides a biosensor which enables quick measurement and is excellent in storage characteristic. This biosensor comprises an electrically insulating base plate on which an electrode system having at least a measuring electrode and a counter electrode is formed, a cover member which is integrated to the base plate so as to form a sample solution supply path for supplying a sample solution to the electrode system between the cover member and the base plate, and a carrier composed of fiber supporting a reagent containing at least an oxidoreductase, and the carrier is placed in the sample solution supply path. Preferably, the carrier is constituted at least of two carrier pieces and each carrier piece supports a different reagent.Type: GrantFiled: May 17, 2000Date of Patent: October 29, 2002Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Tomohiro Yamamoto, Toshihiko Yoshioka, Shiro Nankai
-
Publication number: 20020134676Abstract: Disclosed is a highly responsive biosensor comprising a cholesterol-oxidizing enzyme and cholesterol esterase. The biosensor comprises: an electrically insulating base plate; an electrode system including a working electrode and a counter electrode formed on the base plate; a cover member joined with the base plate to define a sample supply pathway through which a sample solution is introduced from a sample supply port to the electrode system, the sample supply pathway being formed between the cover member and the base plate; and a reagent layer formed in the sample supply pathway, wherein the reagent layer contains a cholesterol-oxidizing enzyme, cholesterol esterase, an electron mediator, and a buffer having a buffering capacity in an acidic pH range.Type: ApplicationFiled: March 1, 2002Publication date: September 26, 2002Applicant: Matsushita Electric Industrial Co., Ltd.Inventors: Motokazu Watanabe, Miwa Hasegawa, Tomohiro Yamamoto, Toshihiko Yoshioka, Shiro Nankai
-
Patent number: 6416641Abstract: The present invention relates to a biosensor comprising a working electrode base plate 11, a counter electrode base plate 14 and a reagent layer containing at least an enzyme and an electron mediator, wherein a working electrode 12 disposed on the working electrode base plate and a counter electrode 15 disposed on the counter electrode base plate are positioned so as to mutually face and a terminal of a measuring device can be brought in contact with terminals 13, 16 of both electrodes from through-holes 25, 24. Such a biosensor can produce highly reliable and accurate measuring results with only a small amount of a sample.Type: GrantFiled: June 9, 1999Date of Patent: July 9, 2002Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Shin Ikeda, Motokazu Watanabe, Toshihiko Yoshioka, Shiro Nankai
-
Patent number: 6383819Abstract: The present disclosure relates to a method for determining cholesterol in low density lipoprotein comprising the steps of (a) measuring total cholesterol level in a sample containing at least high density lipoprotein, low density lipoprotein, very low density lipoprotein and chylomicron, and (b) measuring cholesterol levels in the high density lipoprotein, very low density lipoprotein and chylomicron in the sample, wherein the cholesterol level in the low density lipoprotein is determined by subtracting a value obtained in step (b) from a value obtained in step (a). The present invention enables concurrent determination of cholesterol level in low density lipoprotein and total cholesterol level, facilitating acquisition of two types of biological information at a time.Type: GrantFiled: January 27, 2000Date of Patent: May 7, 2002Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Motokazu Watanabe, Toshihiko Yoshioka, Shiro Nankai
-
Publication number: 20020043471Abstract: A method for determining the concentration of a substrate in a sample solution using an electrode system comprising a working electrode and a counter electrode, both being formed on an electrically insulating base plate, and a reaction layer which contains at least an oxidoreductase and an electron mediator and is formed on the electrode system to electrochemically measure a reduced amount of the electron mediator resulting from enzyme reaction in the reaction layer, wherein a third electrode is formed as an interfering substance detecting electrode somewhere apart from the reaction layer to detect supply of the sample solution on the basis of an electrical change between the counter electrode and the third electrode. A current flowing between the counter electrode and the third electrode is measured which is taken as a positive error.Type: ApplicationFiled: December 21, 2001Publication date: April 18, 2002Applicant: Matsushita Electric Industrial Co., Ltd.Inventors: Shin Ikeda, Toshihiko Yoshioka, Shiro Nankai
-
Publication number: 20020025584Abstract: The present disclosure relates to a method for determining cholesterol in low density lipoprotein comprising the steps of (a) measuring total cholesterol level in a sample containing at least high density lipoprotein, low density lipoprotein, very low density lipoprotein and chylomicron, and (b) measuring cholesterol levels in the high density lipoprotein, very low density lipoprotein and chylomicron in the sample, wherein the cholesterol level in the low density lipoprotein is determined by subtracting a value obtained in the step (b) from a value obtained in the step (a). The present invention enables concurrent determination of cholesterol level in low density lipoprotein and total cholesterol level, facilitating acquisition of two types of biological information at a time.Type: ApplicationFiled: September 24, 2001Publication date: February 28, 2002Applicant: Matsushita Electric Industrial Co., Ltd.Inventors: Motokazu Watanabe, Toshihiko Yoshioka, Shiro Nankai
-
Patent number: 6349229Abstract: An examination system for bodily fluids includes a vessel-like examination unit having an opening, a sensor for examining the bodily fluids, and a bodily-fluids-oozing device. This system is further provided with a pump for decompressing the inside of the unit and an electromagnetic cross-valve for releasing the decompressed condition, or still further provided with humidifying means for supplying vapor inside the unit, in addition to the pump and the valve. As a result, the system produces a precise measurement with a little amount of bodily fluid.Type: GrantFiled: March 7, 2000Date of Patent: February 19, 2002Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Motokazu Watanabe, Shin Ikeda, Toshihiko Yoshioka
-
Patent number: 6340428Abstract: A method for determining the concentration of a substrate in a sample solution using an electrode system comprising a working electrode, a counter electrode, and a reaction layer which contains at least an oxidoreductase and an electron mediator and is formed on the electrode system to electrochemically measure a reduced amount of the electron mediator resulting from enzyme reaction in the reaction layer, wherein a third electrode is formed as an interfering substance detecting electrode. A current flowing between the counter electrode and the third electrode is measured which is taken as a positive error. Subsequently, voltage application between the counter electrode and the third electrode is released and a voltage for oxidizing the reduced form electron mediator is applied between the working electrode and the counter electrode to measure a current flowing between the two electrodes.Type: GrantFiled: November 29, 1999Date of Patent: January 22, 2002Assignee: Matsushita Electric Industrial Co., Inc.Inventors: Shin Ikeda, Toshihiko Yoshioka, Shiro Nankai
-
Publication number: 20010052472Abstract: A biosensor includes: an insulating substrate; an electrode system formed on the insulating substrate which has a working electrode and a counter electrode; and a reaction layer formed on the insulating substrate which contains an oxidoreductase and an electron acceptor. The electron acceptor is ferricinium ion derived from ferrocene electrolyte.Type: ApplicationFiled: January 18, 1999Publication date: December 20, 2001Inventors: SHIN IKEDA, TOMOHIRO YAMAMOTO, TOSHIHIKO YOSHIOKA, SHIRO NANKAI, SHIGEKI JOKO, JUNKO IWATA
-
Publication number: 20010049110Abstract: The present invention provides a sample solution treating instrument facilitating rapid and simplified adjustment of the condition of a sample solution proper for analysis with a biosensor before supply to the biosensor. The sample solution treating instrument in accordance with the present invention comprises control means, such as a catalyst or an adsorbent, for example, which can remove any interfering substance for adjusting the sample solution proper for measurement with a biosensor.Type: ApplicationFiled: October 20, 1999Publication date: December 6, 2001Inventors: MARIKO MIYASHITA, TOSHIHIKO YOSHIOKA, SHIRO NANKAI
-
Patent number: 6258254Abstract: A method using a biosensor is disclosed which facilitates high accuracy quantitation of a substrate by best eliminating adverse effects of red blood cell existing in blood together with the substrate. The biosensor comprises an electrode system including a working electrode and a counter electrode formed on an electrically insulating base plate, and a reaction layer containing at least an oxidoreductase and an electron acceptor, wherein the electron acceptor is a sodium salt.Type: GrantFiled: July 27, 1998Date of Patent: July 10, 2001Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Yoshiko Miyamoto, Shin Ikeda, Toshihiko Yoshioka, Shiro Nankai
-
Patent number: 6225078Abstract: The invention provides a method for quantitative measurement of a substrate with high accuracy by electrochemically oxidizing an electron mediator which has been reduced by enzyme reaction thereby determining the substrate concentration based on a current flowing during electrochemical oxidation from which adverse effects of an easy-to-oxidize substance on the oxidation process have been minimized. The quantitating method in accordance with the present invention comprises a first step for causing a substrate contained in a sample to react with a specific oxidoreductase to the substrate in the presence of an electron mediator in oxidized state, and a second step for electrochemically reducing the electron mediator in oxidized state which remains non-reduced by the enzyme reaction in the first step, thereby obtaining a current flowing during electrochemical reduction.Type: GrantFiled: July 27, 1998Date of Patent: May 1, 2001Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Shin Ikeda, Toshihiko Yoshioka, Shiro Nankai
-
Patent number: 6214612Abstract: A cholesterol sensor for quantitative determination of cholesterol is provided containing an electrode system and a reaction reagent system. The electrode system contains a measuring electrode such as a carbon electrode and a counter electrode, and the reaction reagent system contains cholesterol dehydrogenase, nicotinamide adenine dinucleotide and an oxidized electron mediator. Electron mediators include ferricyanide, 1,2-naphthoquinone-4-sulfonate, 2,6-dichlorophenol indophenol, dimethylbenzoquinone, 1-methoxy-5-methylphenazinium sulfate, methylene blue, gallocyanine, thionine, phenazine methosulfate and Meldola's blue. Diaphorase, cholesterol esterase and a surfactant may also be present. The electrode system is on an insulating base plate, and the base plate has a covering member containing a groove that is a sample supplying channel which extends from an end of the base plate to the electrode system.Type: GrantFiled: March 3, 1997Date of Patent: April 10, 2001Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Tomohiro Yamamoto, Shin Ikeda, Toshihiko Yoshioka, Shiro Nankai, Junko Iwata
-
Patent number: 6212417Abstract: A highly reliable biosensor is provided which is reduced in influences of any interfering substance or preexisting oxygen in a sample solution. The biosensor comprises an electrode system including a working electrode, a counter electrode and a third electrode also usable as an interfering substance detecting electrode, a reagent layer containing at least an oxidoreductase and an electron mediator, and an electrically insulating base plate for supporting the electrode system and the reagent layer, wherein the third electrode is arranged at an opposing position to that of at least one of the working electrode and the counter electrode and the reagent layer is arranged at a predetermined position apart from the third electrode.Type: GrantFiled: August 20, 1999Date of Patent: April 3, 2001Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Shin Ikeda, Toshihiko Yoshioka, Shiro Nankai
-
Patent number: RE37002Abstract: .[.There is disclosed an aqueous dispersed solution as a standard solution for determining lipid levels, having a dispersion form and a particle size, which are similar to those of serum lipids. A lipid-dispersed solution is obtained by evaporating an organic solvent from a mixture prepared by adding cholesterol, a phospholipid, a bile acid or bile acid salt, and a neutral lipid and/or a cholesterol ester in the organic solvent, swelling the resultant thin-film like mixture with water or buffer heated at a temperature higher than a phase transition temperature of the lecithin, and then dispersing the solution by a physical shear force. There can be easily obtained a solution having a cholesterol concentration of about less than 1,000 mg/dl, which is extremely stable and can be stored for a long period of time..]. .Iadd.There is disclosed an aqueous dispersed solution as a standard solution for determining lipid levels, having a dispersion form and a particle size, which are similar to those of serum lipids.Type: GrantFiled: June 7, 1999Date of Patent: December 26, 2000Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Tomohiro Yamamoto, Toshihiko Yoshioka, Shiro Nankai