Patents by Inventor Leland C. Clark, Jr.
Leland C. Clark, Jr. 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).
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Patent number: 6815186Abstract: The sensitivity of enzyme-based polarographic electrodes to oxygen concentration can be significantly reduced or eliminated by providing an oxygen-reservoir in intimate contact with the oxidative enzyme. This is achieved by making a stabilized emulsion between the enzyme and a compound in which oxygen is extremely soluble. An aqueous glucose oxidase solution is emulsified with a perfluorocarbon liquid, and the resulting emulsion is stabilized by chemically crosslinking the mixture to form a gel. Thin layers of the emulsion are fabricated by spreading a layer of the liquid emulsion before gelation occurs. Additional carrier proteins such as albumin may be added to the enzyme prior to crosslinking to protect enzymatic activity and enhance gel strength. Additional electron transport compounds may be added to further reduce sensitivity to oxygen concentration.Type: GrantFiled: January 28, 2002Date of Patent: November 9, 2004Assignee: Implanted Biosystems, Inc.Inventor: Leland C Clark, Jr.
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Patent number: 6343225Abstract: The sensitivity of enzyme-based polarographic electrodes to oxygen concentration can be significantly reduced or eliminated by providing an oxygen-reservoir in intimate contact with the oxidative enzyme. This is achieved by making a stabilized emulsion between the enzyme and a compound in which oxygen is extremely soluble. An aqueous glucose oxidase solution is emulsified with a perfluorocarbon liquid, and the resulting emulsion is stabilized by chemically crosslinking the mixture to form a gel. Thin layers of the emulsion are fabricated by spreading a layer of the liquid emulsion before gelation occurs. Additional carrier proteins such as albumin may be added to the enzyne prior to crosslinking to protect enzymatic activity and enhance gel strength. Additional electron transport compounds may be added to further reduce sensitivity to oxygen concentration.Type: GrantFiled: September 14, 1999Date of Patent: January 29, 2002Assignee: Implanted Biosystems, Inc.Inventor: Leland C. Clark, Jr.
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Patent number: 5840767Abstract: Perfluorotetramethylcyclohexane shows improved properties for use in biological gas exchange, both as a blood substitute and as perfluorocarbon for intra-pulmonary applications. The material has an adequately low vapor pressure to completely avoid causing hyperinflated lung damage and to increase the interval between required applications. However, the compound has a sufficiently high vapor pressure to produce acceptably brief residence time within the body. A method has been developed for using this novel compound to accelerate the exhalation of very low vapor pressure compounds such as perfluorophenanthrene from the lungs. The addition of perfluorotetramethylcyclohexane, along with perfluorophenanthrene, greatly increases the rate at which the perfluorophenanthrene is exhaled.Type: GrantFiled: December 1, 1995Date of Patent: November 24, 1998Assignee: Synthetic Blood International, Inc.Inventor: Leland C. Clark, Jr.
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Patent number: 5824703Abstract: A method of assisting a mammal having a lung disorder to breathe ambient gas normally, i.e., without the assistance of a ventilator. The method includes providing an animal having a lung disorder, such as surfactant deficiency, stiff lung, or hyperinflated lung syndrome, and instilling a minimum effective dose of a perfluorochemical liquid or emulsion through the trachea for coating the alveolar sacs of a lung of the mammal. The preferred perfluorochemicals have a very low vapor pressure to avoid inducing hyperinflated lung syndrome and are supplied in a minimum effective dosage sufficient to coat the inner lung surfaces. The perfluorochemicals are permeable to the ambient gas and reside substantially permanently within the alveolar sacs without inducing hyperinflated lung syndrome. The liquid is instilled in an amount sufficient to enable the animal to breathe the ambient gas normally with O.sub.2 /CO.sub.2 blood gas exchange. Effective coating of the lungs with a small (generally <0.Type: GrantFiled: December 27, 1996Date of Patent: October 20, 1998Assignee: Synthetic Blood International, Inc.Inventor: Leland C. Clark, Jr.
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Patent number: 5684050Abstract: Stable emulsions of highly fluorinated organic compounds for use as oxygen transport agents, "artificial bloods" or red blood cell substitutes and as contrast agents for biological imaging. The emulsions comprise a highly fluorinated organic compound, an oil that is not substantially surface active and not significantly soluble in water, a surfactant and water.Type: GrantFiled: May 15, 1995Date of Patent: November 4, 1997Assignee: HemaGen/PFCInventors: Leland C. Clark, Jr., Robert Francis Shaw
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Patent number: 5674913Abstract: A method of assisting a mammal having a lung disorder to breathe ambient gas normally, i.e., without the assistance of a ventilator. The method includes providing an animal having a lung disorder, such as surfactant deficiency, stiff lung or hyperinflated lung syndrome, and instilling a perfluorochemical liquid into the trachea for administration in the alveolar sacs of a lung of the animal. The perfluorochemical is permeable to the ambient gas and resides substantially permanently within the alveolar sacs without inducing hyperinflated lung syndrome. The liquid is instilled in an amount sufficient to enable the animal to breathe the ambient gas normally with O.sub.2 /CO.sub.2 blood gas exchange. In another aspect of the invention, the method further includes the step of alleviating the lung disorder without inducing hyperinflated lung syndrome.Type: GrantFiled: May 13, 1994Date of Patent: October 7, 1997Assignee: Synthetic Blood International, Inc.Inventor: Leland C. Clark, Jr.
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Patent number: 5635539Abstract: Stable emulsions of highly fluorinated organic compounds for use as oxygen transport agents, "artificial bloods" or red blood cell substitutes and as contrast agents for biological imaging. The emulsions comprise a highly fluorinated organic compound, an oil that is not substantially surface active and not significantly soluble in water, a surfactant and water.Type: GrantFiled: May 23, 1996Date of Patent: June 3, 1997Assignee: HemaGen/PFCInventors: Leland C. Clark, Jr., Robert F. Shaw
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Patent number: 5536753Abstract: Perfluoroindane is used as a gas transport agent in animals without causing gas or vapor pulmonary embolism. Emulsions containing perfluoroindane as the oxygen carrying component are made and infused into an animal and the perfluoroindane escapes at a very rapid rate from the animal body. The perfluoroindane-containing liquids or emulsions are considered valuable for angioplasty and as a blood substitute.Type: GrantFiled: November 9, 1990Date of Patent: July 16, 1996Assignee: Children's Hospital Research Foundation, a division of Children's Hospital Medical Center and HemaGen/PFCInventor: Leland C. Clark, Jr.
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Patent number: 5514720Abstract: Stable emulsions of highly fluorinated organic compounds for use as oxygen transport agents, "artificial bloods" or red blood cell substitutes and as contrast agents for biological imaging. The emulsions comprise a highly fluorinated organic compound, an oil that is not substantially surface active and not significantly soluble in water, a surfactant and water.Type: GrantFiled: April 7, 1988Date of Patent: May 7, 1996Assignee: HemaGen/PFCInventors: Leland C. Clark, Jr., Robert F. Shaw
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Patent number: 5258412Abstract: A vitreous substitute is disclosed which is introduced into the eye by injection in a liquid form to form a gel in the eye to replace the vitreous. The substitute comprises a silicone liquid which is allowed to gel in the eye. Methods involving the use of these gels during retinal surgery are also disclosed.Type: GrantFiled: March 9, 1992Date of Patent: November 2, 1993Inventors: Gholam A. Peyman, Leland C. Clark, Jr.
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Patent number: 5219844Abstract: A combination of perfluorocarbon liquid and silicone is used to treat ophthalmological disorders of the eye. Perfluorocarbon liquid and silicone are injected into the eye to treat detached or torn retinas. A method of treating ophthalmological disorder of the eye with the combination of perfluorocarbon liquid and silicone is also disclosed.Type: GrantFiled: March 27, 1992Date of Patent: June 15, 1993Inventors: Gholam A. Peyman, Leland C. Clark, Jr.
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Patent number: 4775522Abstract: A novel and improved method to detect and/or measure indirectly at least one gas, particularly dissolved gases, of an animal employing nuclear magnetic resonance techniques (NMR). The method examines an NMR spectrum to determine chemical shift relaxation times or spin-spin couplings for an element of an animal influenced by at least one gas of the animal. Uniquely, the gas detected according to the principles of this invention may be insensitive to present NMR techniques. Further, the present invention discloses a novel method to determine and monitor gaseous physiological states of an animal. Because of the unique and advantageous non-invasive, non-destructive and non-ionizing properties, the present invention may be employed in an animal continuously and in vivo.Type: GrantFiled: December 16, 1985Date of Patent: October 4, 1988Assignee: Children's Hospital Research Foundation, a division of Children's Hospital Medical CenterInventor: Leland C. Clark, Jr.
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Patent number: 4721677Abstract: The present invention relates to a novel implantable biosensor and method for sensing products, such as hydrogen peroxide, generated from an enzymatic reaction between an analyte, like glucose, and an enzyme in the presence of oxygen. The novel implantable biosensor is uniquely equipped with an enclosed chamber for containing oxygen and can be adapted for extracting oxygen from animal tissue adjacent the container. The reservoir of oxygen contained in the enclosed chamber is supplied to the enzymatic reaction from both sides of a membrane. The enclosed chamber is uniquely designed to be impermeable to substances, like liquid and cells, that possibly can interfere with the supply of the oxygen permeating through the membrane to the enzymatic reaction. Also, the implantable biosensor is designed to optically or electrically sense products generated from the enzymatic reaction which serve as a function of the analyte.Type: GrantFiled: May 7, 1987Date of Patent: January 26, 1988Assignee: Children's Hospital Medical CenterInventor: Leland C. Clark, Jr.
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Patent number: 4640833Abstract: Method of X-raying animals using as a contrast agent a perfluorobromoalkyl ether of the formula C.sub.m F.sub.2m+1 OC.sub.n F.sub.2n Br where m and n independently are integers of from 2 to 6, wherein the ether is used either neat or in an aqueous dispersion such as an emulsion.Type: GrantFiled: March 11, 1985Date of Patent: February 3, 1987Assignees: Adamantech, Inc., Children's Hospital Research FoundationInventors: Christ Tamborski, Leland C. Clark, Jr.
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Patent number: 4586511Abstract: A novel and improved method to detect and/or measure indirectly at least one gas, particularly dissolved gases, of an animal employing nuclear magnetic resonance techniques (NMR). The method examines an NMR spectrum to determine chemical shift relaxation times or spin-spin couplings for an element of an animal influenced by at least one gas of the animal. Uniquely, the gas detected according to the principles of this invention may be insensitive to present NMR techniques. Further, the present invention discloses a novel method to determine and monitor gaseous physiological states of an animal. Because of the unique and advantageous non-invasive, non-destructive and non-ionizing properties, the present invention may be employed in an animal continuously and in vivo.Type: GrantFiled: March 4, 1983Date of Patent: May 6, 1986Assignee: Children's Hospital Medical CenterInventor: Leland C. Clark, Jr.
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Patent number: 4558279Abstract: A novel and improved method to detect indirectly a temperature of an object employing nuclear magnetic resonance techniques (NMR). The method involves obtaining an NMR spectrum to determine chemical shift, relaxation times, spin-spin couplings or quadrupole couplings for an element of a compound having at least one conformational isomer wherein the compound is influenced by a temperature of the object. Uniquely, the present invention may detect temperature in the body of an animal. Further, the present invention discloses a novel method to determine and monitor thermal physiological states in an animal as well as determine and monitor thermal states in an object. Because of the unique and advantageous non-invasive, non-destructive and non-ionizing properties, the present invention may be employed in an object or animal continuously.Type: GrantFiled: March 7, 1983Date of Patent: December 10, 1985Assignees: University of Cincinnati, Children's Hospital Research FoundationInventors: Jerome L. Ackerman, Leland C. Clark, Jr., Stephen R. Thomas
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Patent number: 4490351Abstract: Liquid perfluorocarbons and substituted derivatives thereof are used as fluid substitutes for the vitreous or the aqueous of the eye. These liquids are also used to transparentize the cornea or lens when either becomes opacifed due to degeneration or cataract formation. Methods involving the use of these liquids during retinal surgery or diagnostic procedures of the eye are also disclosed.Type: GrantFiled: March 15, 1982Date of Patent: December 25, 1984Assignee: Children's Hospital Medical CenterInventor: Leland C. Clark, Jr.
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Patent number: 4467811Abstract: A method of measuring lactic acid or lactate and derivatives thereof in liquids which is extremely versatile and is suitable for use in a number of areas such as the rapid measurement of lactic acid in whole blood, the ratio of lactic acid to pyruvic acid in whole blood, in-vivo measurement of lactic acid and the study of living lactic acid-producing cells. The acid or lactate is measured by reacting the lactic acid with lactic oxidase to produce pyruvate and H.sub.2 O.sub.2. The H.sub.2 O.sub.2 is then measured polarographically. The current produced is directly proportional to the lactate level. Preferably, the lactic oxidase is trapped between two semi-permeable membranes. One membrane is placed in contact with an electrolyte at the tip of an electrode and the second membrane contacts the liquid being tested.Type: GrantFiled: February 8, 1982Date of Patent: August 28, 1984Assignee: Children's Hospital Medical CenterInventor: Leland C. Clark, Jr.
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Patent number: 4458686Abstract: Cutaneous methods for measurement of substrates in mammalian subjects are disclosed. A condition of the skin is used to measure a number of important substances which diffuse through the skin or are present underneath the skin in the blood or tissue. According to the technique, an enzyme whose activity is specific for a particular substance or substrate is placed on, in or under the skin for reaction. The condition of the skin is then detected by suitable means as a measure of the amount of the substrate in the body. For instance, the enzymatic reaction or by-product of the reaction is detected directly through the skin as a measure of the amount of substrate. Polarographic electrodes or enzyme electrodes are employed as skin-contact analyzers in the transcutaneous measurement of oxygen or hydrogen peroxide to quantitatively determine blood substances such as glucose and alcohol. In a preferred quantitative technique, the skin is arterialized, i.e.Type: GrantFiled: May 4, 1983Date of Patent: July 10, 1984Assignee: Children's Hospital Medical CenterInventor: Leland C. Clark, Jr.
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Patent number: RE33451Abstract: Gas transport agents such as artificial blood containing a perfluorocyclocarbon and an amine oxide are disclosed. These compositions have been found to provide transparent emulsions or solutions for use in oxygen transport, particularly in animals. Large concentrations of perfluorocarbons may be employed even up to 50% or more by volume in preparing emulsions, microemulsions or solutions. The emulsions or solutions have been found to be very stable at room temperature storage conditions thereby providing significant advantages.Type: GrantFiled: July 23, 1985Date of Patent: November 20, 1990Assignee: Children's Hospital Medical CenterInventor: Leland C. Clark, Jr.