Patents by Inventor Masao Kitajima

Masao Kitajima 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).

  • Patent number: 6962819
    Abstract: A method of measuring an analyte using a dry analytical element which comprises, a process of supplying a measuring reagent solution to the anlaytical element comprising at least a hydrophilic polymer layer and a microporous layer having a surface rendered hydrophilic and having a blood cell-separating ability laminated onto a water-impermeable support and not containing the measuring reagents to which a liquid sample has been supplied and thereby reaction occuring, and a process of measuring the analytical element wherein the reaction occurred by an optical means. According the above method, the shelf life of the analytical element is greatly improved. Besides, since the measuring reagnts used in the conventional wet analysis can be used, it is not necessary to develop analytical elements for each measuring item. Moreover, one kind of analytical element can be applied to many items.
    Type: Grant
    Filed: March 20, 1995
    Date of Patent: November 8, 2005
    Assignee: Fuji Photo Film Co., Ltd.
    Inventor: Masao Kitajima
  • Patent number: 6225130
    Abstract: A method for separating serum from whole blood in a vessel at an insertion speed of 30 cm/sec or less and maintaining the suction pressure of the suction nozzle at 400 mm Hg or less. Improved analytical results are obtained because the serum can be produced without hemolysis.
    Type: Grant
    Filed: February 18, 1999
    Date of Patent: May 1, 2001
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Masao Kitajima, Akemi Higo, Shigeru Tezuka
  • Patent number: 6220453
    Abstract: This invention provides a blood filter unit capable of obtaining a necessary volume of a plasma or serum sample from blood to be assayed easily at any place, which comprises a blood filtering material and a holder accommodating the blood filtering material and having a nozzle for sucking blood and a filtrate outlet, and the inside of the holder being kept reduced pressure conditions.
    Type: Grant
    Filed: April 7, 1999
    Date of Patent: April 24, 2001
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Masao Kitajima, Sigeru Tezuka, Yasuo Washizawa, Kenichiro Yazawa
  • Patent number: 6217540
    Abstract: The invention provides a blood filter cartridge which is made so that the filtrate discharged from the filtrate outlet is not drawn back to the inside of the filtering chamber. The blood filter cartridge includes a blood filtering material, a holder containing the blood filtering material and having a blood inlet and a filtrate outlet, and a filtrate receiver which receives the filtrate discharged from the filtrate outlet. The blood filter catridge is provided with a means for preventing the filtrate in the filtrate receiver from returning to inside of the holder upon finishing filtration. Such means include the following: removing opposite faces around the filtrate outlet, making length of lower end of the filtrate outlet 0.8 mm or more, smoothing surface around the filtrate outlet, and forming surface around the filtrate outlet by a material having a small surface energy.
    Type: Grant
    Filed: July 9, 1999
    Date of Patent: April 17, 2001
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Kenichiro Yazawa, Keiichi Ishizaki, Takeshi Igarashi, Masao Kitajima, Shigeru Tezuka, Takaki Arai, Toshihisa Ito, Osamu Seshimoto
  • Patent number: 6170671
    Abstract: The blood filter unit of the invention is composed of a blood filtering material made of glass fiber filter and microporous membrane and a holder having a blood inlet and a filtrate outlet. The holder accommodates the blood filtering material so that the microporous membrane is located on the filtrate outlet side, provides a space between the blood filtering material and the filtrate outlet, and provides a means for preventing adhesion of the blood filtering material on the filtrate outlet side. By using the blood filter unit, a necessary volume of plasma or serum for analysis can be separated surely, irrespective of hematocrit value of the blood.
    Type: Grant
    Filed: April 12, 1999
    Date of Patent: January 9, 2001
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Masao Kitajima, Kenichiro Yazawa, Shigeru Tezuka, Fumio Sugaya, Akemi Higo, Kiyotaka Fujiwara
  • Patent number: 6045699
    Abstract: This invention provides a method of filtering blood using a filtering material comprising glass fiber filter, capable of obtaining a desired amount of plasma or serum without hemolysis and leakage of blood cells easily which comprises keeping pressure difference between blood inlet side and filtrate outlet side 50 mmHg or less at least for 5 seconds from contacting the blood to be filtered, and keeping the pressure difference 200 mmHg or less throughout the filtering of the blood.
    Type: Grant
    Filed: July 17, 1998
    Date of Patent: April 4, 2000
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Kenichiro Yazawa, Fumio Sugaya, Masao Kitajima
  • Patent number: 5996811
    Abstract: This invention relates to a plasma-collecting device which comprises a blood filtering material comprising glass fiber filter and microporous membrane, a holder having a blood inlet and a plasma outlet accommodating the blood filtering material, a blood-collecting needle being connected to the blood inlet, and a plasma receiver being provided on the plasma outlet side. The plasma-collecting device can collect a necessary amount of plasma for analysis from blood vessel directly, easily and surely.
    Type: Grant
    Filed: December 19, 1997
    Date of Patent: December 7, 1999
    Assignee: Fuji Photo Film Co. Ltd.
    Inventors: Masao Kitajima, Akemi Higo
  • Patent number: 5979669
    Abstract: A blood filter unit having a blood filter holder containing a blood filtering material of a glass fiber filter and a microporous membrane is described. The holder has a blood inlet and a filtrate outlet, and accommodates the blood filtering material so that the microporous membrane is located on the filtrate outlet side and has a space between the blood filtering material and the filtrate outlet. The holder provides means for preventing adhesion of the blood filtering material on the filtrate outlet side. The inventive blood filter unit allows separation of a desired volume of plasma or serum for analysis without interference by the hematocrit value of the blood.
    Type: Grant
    Filed: January 17, 1997
    Date of Patent: November 9, 1999
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Masao Kitajima, Kenichiro Yazawa, Shigeru Tezuka, Fumio Sugaya, Akemi Higo, Kiyotaka Fujiwara
  • Patent number: 5876605
    Abstract: The method of the invention is for preparing a plasma or serum sample from whole blood and includes mixing an aqueous solution of an inorganic salt or an amino acid or salt thereof with the whole blood in an amount of 20% or less of the whole blood volume so that concentration of the inorganic salt or the amino acid or salt thereof becomes 10 to 200 .mu.mol/1 ml whole blood, and then, filtering the whole blood to remove blood cell components. According to the method of the invention, plasma separation from whole blood can be achieved efficiently, and recovered volume of plasma can be increased. By selecting reagent, good plasma which has no deviation in component viewpoint, and which is possible to measure in the same level accuracy as a plasma obtained by centurifuging, can be obtained through a simple filtration operation.
    Type: Grant
    Filed: January 17, 1997
    Date of Patent: March 2, 1999
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Masao Kitajima, Kenichiro Yazawa
  • Patent number: 5569287
    Abstract: A means for collecting and spotting a small amount of blood which comprises a cylinder, a piston, and a puncturing tip, wherein: the piston is inserted airtightly into one end of the cylinder; the puncturing tip is airtightly and exchangeably fitted onto another end of the cylinder; the puncturing tip comprises a blood conduit and a needle suspended by a spring within the blood conduit; the blood conduit has a volume which is equal to a volume of blood to be spotted to analytical means; and the needle is arranged to be pushed out from the puncturing tip by descent of the piston and then return back by ascent of the piston.
    Type: Grant
    Filed: December 9, 1994
    Date of Patent: October 29, 1996
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Shigeru Tezuka, Hikaru Tsuruta, Teruaki Koizumi, Masao Kitajima
  • Patent number: 5460777
    Abstract: An analytical element for whole blood which comprises a blood cell-separating layer having a volume smaller than the upper limit of the diffused volume of a whole blood sample having a hematocrit value of 70% provided on a porous layer, and a method of measuring an analyte which comprises spotting a whole blood sample onto the above analytical element removing the blood cell-separating layer after blood plasma portion of the sample is diffused into the porous layer, supplying a fixed amount of measuring reagent solution having a diffused area smaller than the diffused area of the blood plasma to measure the analyte. According to the invention, the analytical error caused by scattering of hematocrit values is removed, and analysis can be conducted in a high accuracy.
    Type: Grant
    Filed: March 11, 1993
    Date of Patent: October 24, 1995
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Masao Kitajima, Masashi Ogawa, Osamu Seshimoto
  • Patent number: 5443988
    Abstract: A high speed analyzer for a dry analytical element comprising a movable sample tray onto which the dry analytical element is placed, a sample-pipetting apparatus which spots a plurality of samples onto the dry analytical element placed onto the movable sample tray, an incubator which dries the dry analytical element onto which the samples have been spotted, a reagent-pipetting apparatus which spots a plurality of measuring reagent solutions onto the dry analytical element which has already been dried and a measuring part which measures a plurality of the dry analytical elements wherein reaction proceeds or has already been finished, and evaporation-preventing members which are attached to the dry analytical element onto which the reagents have been spotted to prevent evaporation of moisture from the spotted parts, and a method for measuring a plurality of analytical items of samples using the same.
    Type: Grant
    Filed: August 30, 1993
    Date of Patent: August 22, 1995
    Assignee: Fuji Photo Film Co., Ltd.
    Inventor: Masao Kitajima
  • Patent number: 5336468
    Abstract: A pipette tip is obtained from molding of a plastic material. At least part of the outer surface of the pipette tip has been treated with a water repellent material. The pipette tip is suitable for applying a predetermined amount of a liquid sample during chemical analyses, particularly for applying a measured amount of a liquid having a small surface tension and a high viscosity.
    Type: Grant
    Filed: October 15, 1990
    Date of Patent: August 9, 1994
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Sigeru Tezuka, Masao Kitajima, Nobuyyki Kita
  • Patent number: 5336599
    Abstract: A method for measuring an analyte using a dry analytical element composed of at least a hydrophilic polymer layer and a spreading layer laminated onto a water-impermeable support and to which a liquid sample of the analyte has been supplied, by supplying a measuring reagent solution to the analytical element. The measurement of the analytical element is carried out by optical means.
    Type: Grant
    Filed: December 15, 1993
    Date of Patent: August 9, 1994
    Assignee: Fuji Photo Film Co., Ltd.
    Inventor: Masao Kitajima
  • Patent number: 5192693
    Abstract: A method of using a chemical analysis slide which includes a slide frame and a sheet-like or film-like chemical analysis element for colorimetric determination of a specific component in an aqueous liquid sample, which method includesapplying an aqueous liquid sample to the chemical analysis element, andcovering the upper face of the side of the slide frame to which the sample is applied with a sheet-like, plate-like or block or brick-like cover to thereby ensure a space between the chemical analysis element and the cover and to prevent evaporation of water or to control evaporation rate of water.
    Type: Grant
    Filed: May 7, 1991
    Date of Patent: March 9, 1993
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Kenichiro Yazawa, Masao Kitajima, Asaji Kondo
  • Patent number: 5122969
    Abstract: A biochemical analysis apparatus comprises a movement device which moves analysis media containing a reagent or an electrochemical sensor, which will interact with a specific biochemical substance contained in liquid samples and give rise to changes in the analysis media, along a movement path connecting an introducing section and an ejecting section. While the analysis media are present in the movement path, a measurement device measures changes which have occurred in analysis media. A reading device reads information about correction values, which are to be used in order to correct a calibration curve so that it becomes suitable for analysis media used in analyses, from a correction value recording medium. A correction device corrects the calibration curve on the basis of the correction values.
    Type: Grant
    Filed: February 15, 1990
    Date of Patent: June 16, 1992
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Osamu Seshimoto, Masao Kitajima
  • Patent number: 4981805
    Abstract: A method of using a chemical analysis slide comprising a slide frame and a sheet-like or film-like chemical analysis element for colorimetric determination of a specific component in an aqueous liquid sample, which comprisesapplying an aqueous liquid sample to the chemical analysis element, andcovering the upper face of the side of the slide frame to which the sample is applied with a sheet-like, plate-like or block or brick-like cover to thereby ensure a space between the chemical analysis element and the cover and to prevent evaporation of water or to control evaporation rate of water.
    Type: Grant
    Filed: December 17, 1984
    Date of Patent: January 1, 1991
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Kenichiro Yazawa, Masao Kitajima, Asaji Kondo
  • Patent number: 4884213
    Abstract: In a method for quantitatively analyzing an analyte in a liquid sample by applying the liquid sample on one of a set of analytical elements and measuring a color developed in the analytical element through reflection photometory in which said set of analytical elements are the same elements as a standard element except for deviation of sensitivity to the analyte, but said deviation of sensitivity is essentially equivalent to each other among the set of analytical elements, the calibration curve of the standard element with respect to said analyte being predetermined, an improvement involving the preparation of a linear equation for defining a relationship between an optical reflection density value OD.sub.x to be measured on an analytical element belonging to said set of the analytical elements and an optical reflection density value OD.sub.s being predetermined on the standard analytical element, in which the optical reflection density values OD.sub.x and OD.sub.
    Type: Grant
    Filed: February 15, 1989
    Date of Patent: November 28, 1989
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Yuzo Iwata, Hajime Makiuchi, Masao Kitajima
  • Patent number: 4877579
    Abstract: A method for quantitative determination of bilirubin is disclosed. The method comprises bringing a bilirubin-containing aqueous liquid sample into contact with a hydrophobic bilirubin extracting composition containing a hydrophobic amine capable of extracting bilirubin. The amine extracts the bilirubin in said aqueous liquid sample. Photometry is then used to determine the concentration of bilirubin extracted with the bilirubin extracting composition. A device for use in this method is also disclosed. The device has a layer containing a hydrophobic bilirubin extracting composition containing a hydrophobic amine capable of extracting bilirubin.
    Type: Grant
    Filed: May 23, 1988
    Date of Patent: October 31, 1989
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Kenichiro Yazawa, Osamu Seshimoto, Masao Kitajima, Asaji Kondo
  • Patent number: 4870005
    Abstract: A dry type multilayer analysis element comprises at least one porous medium layer comprising a membrane filter, to which an antigen (or antibody) is immobilized, and at least one reagent layer through which a substance(s) which did not participate in an antigen-antibody reaction can permeate.The multilayer analysis element is effective for assaying components present in body fluids, blood, urine, etc., in a simple manner.
    Type: Grant
    Filed: October 16, 1985
    Date of Patent: September 26, 1989
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Yutaka Akiyoshi, Asaji Kondo, Masao Kitajima