Patents by Inventor Timothy J. Fischer

Timothy J. Fischer 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: 5686308
    Abstract: A lytic reagent composition is provided which selectively stromatolyses red blood cells in a blood sample. In addition, a lytic reagent system is provided which enable the differentiation of at least two subpopulations of leukocytes. A method for using the lytic reagent system is also provided. Still further, the lytic reagent system find use in the determination of the hemoglobin in the blood. The lytic reagent system utilizes an ethoxylated long chain compound based lysis reagent with an acid and a hypertonic, alkaline, stabilizing reagent. The system and analysis method maintains the cellular morphology of the leukocytes and can be used to analyze normal and abnormal blood samples, fresh and aged blood, human and non-human animal blood samples, as well as other fluid samples such as bone marrow.
    Type: Grant
    Filed: June 8, 1995
    Date of Patent: November 11, 1997
    Assignee: Coulter Corporation
    Inventors: Yi Li, Carole Young, Timothy J. Fischer, James H. Carter
  • Patent number: 5646046
    Abstract: This invention relates to a novel, fully automated spectrophotometric analyzer and method used for testing blood samples in the clinical laboratory for thrombosis and hemostasis properties. The analyzer tests samples in a fully randomized format, and is fully automated in the areas of specimen handling, sample preparation, optical inspection, data analysis and total quality control for imprecision and bias.
    Type: Grant
    Filed: February 14, 1995
    Date of Patent: July 8, 1997
    Assignee: AKZO Nobel N.V.
    Inventors: Timothy J. Fischer, Janet B. Callahan, Paul Joseph Braun, Thomas Beecher Givens, Julie F. Hoffman, William Chester Hulette, John Glenn Link, Charles Hermas Swope
  • Patent number: 5529933
    Abstract: A hematology control product comprising leukocyte analogs and an aqueous solution of a plasma substance for use in a blood counting instrument is described. The instrument employs a lytic reagent system for the lysable red blood cells in the control product. The plasma substance is in an amount effective to enable the differentiation of each of said leukocyte analogs relative to the physical attributes of the analogs, said physical attributes of the analog are similar to human leukocytes. Preferably, the plasma substance comprises cholesterol or its derivatives.A method for using the cell suspension media comprising an aqueous solution of a plasma substance is also described. The method provides a quality control to determine whether an instrument is operating within manufacturer's specifications.
    Type: Grant
    Filed: February 8, 1995
    Date of Patent: June 25, 1996
    Assignee: Coulter Corporation
    Inventors: Carole Young, Michael N. Elliott, Nancy R. Naylor, Timothy J. Fischer
  • Patent number: 5512485
    Abstract: A hematology control product comprising leukocyte analogs is described. The analogs comprise red blood cells which simulate at least two physical properties of human leukocytes. A method for making leukocyte analogs from blood cells having desired physical properties is also described. The process comprises expanding the cell volume, changing the hemoglobin content of the cell and fixing the cell. Generally, the monocyte and lymphocyte analogs leak hemoglobin from the cell while the eosinophil analog has the hemoglobin precipitated in the cell. A further method is described to use the control product to determine whether an automatic instrument is operating within manufacturer's specification.
    Type: Grant
    Filed: November 21, 1994
    Date of Patent: April 30, 1996
    Assignee: Coulter Corporation
    Inventors: Carole Young, Michael N. Elliott, Timothy J. Fischer, Nancy R. Naylor
  • Patent number: 5437985
    Abstract: The method of this invention is directed to the rapid preparation of a whole blood sample for photooptical analysis. In the preferred embodiments of this method, a whole blood sample, lytic reagent system and immunological stain (optional) are contacted with the sample in a common reaction vessel (i.e. cuvette or test tube), with gentle asymmetric vortex mixing, so as to maintain the particulate matter of the sample at an essentially homogeneous concentration throughout the sample. An aliquot of the contents of the reaction vessel can, thereafter, be analyzed for identification and/or quantification of the analyte of interest.
    Type: Grant
    Filed: July 8, 1991
    Date of Patent: August 1, 1995
    Assignee: Coulter Corporation
    Inventors: Jorge A. Quintana, Thomas R. Russell, Ronald D. Paul, Timothy J. Fischer
  • Patent number: 5344036
    Abstract: A container system for reagents and other substances used in a medical diagnostic apparatus. The container system includes a vial made of blow-molded plastic, which can withstand lyophilization. The bottom portion of the vial has an annular groove and is shaped as a truncated cone below the annular groove. An auxiliary member can be snap-connected to the vial at the annular groove so that the vial will stand upright on a flat surface and contains a central aperture through which the vial remains in contact with the flat surface. The container system also includes a stopper at the mouth of the vial and a snap-on plastic cover to secure the stopper. The cover has a tab which is kept at a raised position by a lifter protrusion which bears against the stopper. The cover has tearslots which are ripped when the tab is pulled. One of the tearslots is shorter than the other and keeps the tab from being entirely detached from the remainder of the cover when the tab is pulled.
    Type: Grant
    Filed: June 4, 1992
    Date of Patent: September 6, 1994
    Assignee: Akzo N.V.
    Inventors: Liana V. Stanescu, Timothy J. Fischer, Kristin L. Leese, Kenneth J. Leonhardt
  • Patent number: 5320964
    Abstract: A hematology control product comprising leukocyte analogs is described. The analogs comprise red blood cells which simulate at least two physical properties of human leukocytes. A method for making leukocyte analogs from blood cells having desired physical properties is also described. The process comprises expanding the cell volume, changing the hemoglobin content of the cell and fixing the cell. Generally, the monocyte and lymphocyte analogs leak hemoglobin from the cell while the eosinophil analog has the hemoglobin precipitated in the cell. A further method is described to use the control product to determine whether an automatic instrument is operating within manufacturer's specification.
    Type: Grant
    Filed: June 23, 1993
    Date of Patent: June 14, 1994
    Assignee: Coulter Corporation
    Inventors: Carole Young, Michael N. Elliott, Timothy J. Fischer, Nancy R. Naylor
  • Patent number: 5155044
    Abstract: A method and reagent system are disclosed for the rapid isolation, identification and/or analysis of leukocytes from a whole blood sample. The method and reagent system of this invention has application to any environment in which the study and/or analysis of the leukocyte fraction of whole blood requires their isolation in their native or near native state. One of the environments in which this invention can be used to advantage is in the performance of white cell differentiation on automated instrumentation designed for that purpose. In one of the preferred embodiments of this invention, the lytic reagent can contain a mixture of both formic and acetic acid, with the formic acid comprising the major component thereof and the acetic acid being present in only minor quantities, (if at all). This reagent system is used to selectively effect stromatolysis of red blood cells and create subtle modifications to the leukocyte population to enable their automated differentiation into five (5) sub-populations.
    Type: Grant
    Filed: December 12, 1991
    Date of Patent: October 13, 1992
    Assignee: Coulter Electronics, Inc.
    Inventors: Stephen L. Ledis, Harold R. Crews, Timothy J. Fischer, Ted Sena
  • Patent number: 5030554
    Abstract: The method of this invention is directed to the rapid preparation of a whole blood sample for photooptical analysis. In the preferred embodiments of this method, a whole blood sample, lytic reagent system and immunological stain (optional) are contacted with the sample in a common reaction vessel (i.e. cuvette or test tube), with gentle asymmetric vortex mixing, so as to maintain the particulate matter of the sample at an essentially homogeneous concentration throughout the sample. An aliquot of the contents of the reaction vessel can, thereafter, be analyzed for identification and/or quantification of the analyte of interest.
    Type: Grant
    Filed: December 4, 1987
    Date of Patent: July 9, 1991
    Assignee: Coulter Corporation
    Inventors: Jorge A. Quintana, Thomas R. Russell, Ronald D. Paul, Timothy J. Fischer