Patents by Inventor David Y. H. Pui
David Y. H. Pui 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: 7279322Abstract: An electrospraying apparatus and/or method is used to coat particles. For example, a flow including at least one liquid suspension may be provided through at least one opening at a spray dispenser end. The flow includes at least particles and a coating material. A spray of microdroplets suspending at least the particles is established forward of the spray dispenser end by creating a nonuniform electrical field between the spray dispenser end and an electrode electrically isolated therefrom. The particles are coated with at least a portion of the coating material as the microdroplet evaporates. For example, the suspension may include biological material particles.Type: GrantFiled: March 25, 2004Date of Patent: October 9, 2007Assignee: Regents of the University of MinnesotaInventors: David Y. H. Pui, Da-Ren Chen
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Patent number: 7247338Abstract: Methods and systems for coating at least a portion of a medical device (e.g., a stent structure) include providing a plurality of coating particles (e.g., monodisperse coating particles) in a defined volume. For example, the particles may be provided using one or more nozzle structures, wherein each nozzle structure includes at least one opening terminating at a dispensing end. The plurality of coating particles may be provided in the defined volume by dispensing a plurality of microdroplets having an electrical charge associated therewith from the dispensing ends of the one or more nozzle structures through use of a nonuniform electrical field between the dispensing ends and the medical device. Electrical charge is concentrated on the particle as the microdroplet evaporates. With a plurality of coating particles provided in the defined volume, such particles can be moved towards at least one surface of the medical device to form a coating thereon (e.g.Type: GrantFiled: November 21, 2002Date of Patent: July 24, 2007Assignee: Regents of the University of MinnesotaInventors: David Y. H. Pui, Da-Ren Chen
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Publication number: 20040241315Abstract: Spraying apparatus and methods that employ multiple nozzle structures for producing multiple sprays of particles, e.g., nanoparticles, for various applications, e.g., pharmaceuticals, are provided. For example, an electrospray dispensing device may include a plurality of nozzle structures, wherein each nozzle structure is separated from adjacent nozzle structures by an internozzle distance. Sprays of particles are established from the nozzle structures by creating a nonuniform electrical field between the nozzle structures and an electrode electrically isolated therefrom.Type: ApplicationFiled: July 12, 2004Publication date: December 2, 2004Applicant: Regents of the University of MinnesotaInventors: David Y.H. Pui, Da-Ren Chen
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Publication number: 20040177807Abstract: An electrospraying apparatus and/or method is used to coat particles. For example, a flow including at least one liquid suspension may be provided through at least one opening at a spray dispenser end. The flow includes at least particles and a coating material. A spray of microdroplets suspending at least the particles is established forward of the spray dispenser end by creating a nonuniform electrical field between the spray dispenser end and an electrode electrically isolated therefrom. The particles are coated with at least a portion of the coating material as the microdroplet evaporates. For example, the suspension may include biological material particles.Type: ApplicationFiled: March 25, 2004Publication date: September 16, 2004Applicant: Regents of the University of MinnesotaInventors: David Y.H. Pui, Da-Ren Chen
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Patent number: 6764720Abstract: Spraying apparatus and methods that employ multiple nozzle structures for producing multiple sprays of particles, e.g., nanoparticles, for various applications, e.g., pharmaceuticals, are provided. For example, an electrospray dispensing device may include a plurality of nozzle structures, wherein each nozzle structure is separated from adjacent nozzle structures by an internozzle distance. Sprays of particles are established from the nozzle structures by creating a nonuniform electrical field between the nozzle structures and an electrode electrically isolated therefrom.Type: GrantFiled: May 16, 2001Date of Patent: July 20, 2004Assignee: Regents of the University of MinnesotaInventors: David Y.H. Pui, Da-Ren Chen
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Patent number: 6746869Abstract: An electrospraying apparatus and/or method is used to coat particles. For example, a flow including at least one liquid suspension may be provided through at least one opening at a spray dispenser end. The flow includes at least particles and a coating material. A spray of microdroplets suspending at least the particles is established forward of the spray dispenser end by creating a nonuniform electrical field between the spray dispenser end and an electrode electrically isolated therefrom. The particles are coated with at least a portion of the coating material as the microdroplet evaporates. For example, the suspension may include biological material particles.Type: GrantFiled: June 3, 2002Date of Patent: June 8, 2004Assignee: Regents of the University of MinnesotaInventors: David Y. H. Pui, Da-Ren Chen
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Publication number: 20030143315Abstract: Methods and systems for coating at least a portion of a medical device (e.g., a stent structure) include providing a plurality of coating particles (e.g., monodisperse coating particles) in a defined volume. For example, the particles may be provided using one or more nozzle structures, wherein each nozzle structure includes at least one opening terminating at a dispensing end. The plurality of coating particles may be provided in the defined volume by dispensing a plurality of microdroplets having an electrical charge associated therewith from the dispensing ends of the one or more nozzle structures through use of a nonuniform electrical field between the dispensing ends and the medical device. Electrical charge is concentrated on the particle as the microdroplet evaporates. With a plurality of coating particles provided in the defined volume, such particles can be moved towards at least one surface of the medical device to form a coating thereon (e.g.Type: ApplicationFiled: November 21, 2002Publication date: July 31, 2003Inventors: David Y.H. Pui, Da-Ren Chen
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Publication number: 20020150669Abstract: An electrospraying apparatus and/or method is used to coat particles. For example, a flow including at least one liquid suspension may be provided through at least one opening at a spray dispenser end. The flow includes at least particles and a coating material. A spray of microdroplets suspending at least the particles is established forward of the spray dispenser end by creating a nonuniform electrical field between the spray dispenser end and an electrode electrically isolated therefrom. The particles are coated with at least a portion of the coating material as the microdroplet evaporates. For example, the suspension may include biological material particles.Type: ApplicationFiled: June 3, 2002Publication date: October 17, 2002Applicant: Regents of the University of MinnesotaInventors: David Y. H. Pui, Da-Ren Chen
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Patent number: 6399362Abstract: A method of introducing biological material into cells includes providing one or more target cells and establishing a spray of substantially dispersed particles including biological material. The substantially dispersed particles have an electrical charge applied thereto such that one or,more of the substantially dispersed particles of the spray is introduced into one or more of the target cells. The spray of substantially dispersed particles may be established by dispensing a spray of microdroplets suspending particles. The electrical charge is concentrated on the suspended particles as the microdroplet evaporates. The suspended particles may include carrier particles with biological material or the suspended particles may be particles of biological material alone. The space charge effect of the concentrated electrical charge on the substantially dispersed particles of the spray enable one or more of the particles to be introduced into one or more of the target cells.Type: GrantFiled: May 23, 2000Date of Patent: June 4, 2002Assignee: Regents of the University of MinnesotaInventors: David Y. H. Pui, Da-Ren Chen
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Publication number: 20020007869Abstract: Spraying apparatus and methods that employ multiple nozzle structures for producing multiple sprays of particles, e.g., nanoparticles, for various applications, e.g., pharmaceuticals, are provided. For example, an electrospray dispensing device may include a plurality of nozzle structures, wherein each nozzle structure is separated from adjacent nozzle structures by an internozzle distance. Sprays of particles are established from the nozzle structures by creating a nonuniform electrical field between the nozzle structures and an electrode electrically isolated therefrom.Type: ApplicationFiled: May 16, 2001Publication date: January 24, 2002Inventors: David Y.H. Pui, Da-Ren Chen
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Patent number: 6230572Abstract: An apparatus for classifying polydisperse aerosols includes aerosol and sheath gas conduits for conducting a sample aerosol and a sheath gas toward a merger area. At the merger area the sheath gas and about ten percent of the sample aerosol merge, then travel through a differential mobility analyzer (DMA) and along a tubular electrode of the DMA. Selected particles, i.e. particles having electrical mobilities within a narrow range, pass through a collection aperture of the electrode. The DMA output, an aerosol consisting of the selected particles, is provided to a condensation particle counter or other device for determining the aerosol concentration. The remainder of the sample aerosol is conducted away from the merger area along a bypass flow conduit. The bypass flow and an improved aerodynamic design provide for a slit at the merger area that is sufficiently narrow to minimize unwanted electric field penetration at the slit and DMA entrance.Type: GrantFiled: February 12, 1999Date of Patent: May 15, 2001Assignee: TSI IncorporatedInventors: David Y. H. Pui, Da-Ren Chen, Frederick R. Quant, Gilmore J. Sem, Heinz Fissan, Detlef Hummes, Frank Dorman
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Patent number: 6145391Abstract: A method for use in neutralizing a charged discharge includes providing a neutralizer housing having a longitudinal axis extending between an inlet and an outlet thereof. A charged discharge is introduced into the inlet of the neutralizer housing for flow parallel to the inlet of the longitudinal axis from the inlet to the outlet. An alternating electric field is created within the housing parallel to the longitudinal axis for directing bursts of negatively charged ions and positively charged ions alternately towards the inlet for use in neutralizing the charged discharge. An apparatus for carrying out this method is also described.Type: GrantFiled: November 9, 1999Date of Patent: November 14, 2000Assignee: Regents of the University of MinnesotaInventors: David Y. H. Pui, Da-Ren Chen
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Patent number: 6093557Abstract: A method of introducing biological material into cells includes providing one or more target cells and establishing a spray of substantially dispersed particles including biological material. The substantially dispersed particles have an electrical charge applied thereto such that one or more of the substantially dispersed particles of the spray is introduced into one or more of the target cells. The spray of substantially dispersed particles may be established by dispensing a spray of microdroplets suspending particles. The electrical charge is concentrated on the suspended particles as the microdroplet evaporates. The suspended particles may include carrier particles with biological material or the suspended particles may be particles of biological material alone. The space charge effect of the concentrated electrical charge on the substantially dispersed particles of the spray enable one or more of the particles to be introduced into one or more of the target cells.Type: GrantFiled: June 5, 1998Date of Patent: July 25, 2000Assignee: Regents of the University of MinnesotaInventors: David Y. H. Pui, Da-Ren Chen
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Patent number: 5992244Abstract: Neutralizing a charged discharge includes providing a neutralizer housing having a longitudinal axis extending between an inlet and an outlet of the neutralizer housing. A charged discharge having a first polarity is introduced into the inlet of the neutralizer housing for flow parallel to the longitudinal axis from the inlet to the outlet. A stream of ions having a second polarity opposite the first polarity is directed to flow parallel to the longitudinal axis of the neutralizer housing towards the inlet for use in neutralizing the charged discharge. An electrode configuration is operable to create an electric field within the neutralizer housing for use in directing the stream of ions to flow parallel to the longitudinal axis of the neutralizer housing towards the inlet.Type: GrantFiled: March 4, 1998Date of Patent: November 30, 1999Assignee: Regents of the University of MinnesotaInventors: David Y. H. Pui, Da-Ren Chen
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Patent number: 5973904Abstract: A method for charging of aerosol particles includes providing a charger housing having a longitudinal axis extending between an inlet and an outlet of the charger housing with a stream of aerosol particles flowing parallel to the longitudinal axis from the inlet to the outlet. A confined electric field is created within the housing parallel to the longitudinal axis for directing a stream of unipolar ions to flow parallel to the longitudinal axis of the charger housing towards the outlet for use in charging the stream of aerosol particles. To further reduce charged particle loss within the charger housing, a clean sheath may be created between the stream of aerosol particles and the charger housing, an outlet electric field may be created proximate the outlet of the charger housing such that charged particles are forced towards the longitudinal axis, and/or the stream of aerosol is contracted proximate the outlet of the charger housing forcing the charged particles toward the longitudinal axis.Type: GrantFiled: October 10, 1997Date of Patent: October 26, 1999Assignee: Regents of the University of MinnesotaInventors: David Y. H. Pui, Da-Ren Chen
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Patent number: 5146244Abstract: A purging air flow system that causes air to pass over a pyrometer lens or window to keep it clean and free from particulate contaminants has an annular, continuous slot for air inlet around the periphery of the lens to permit flow of air across the lens without any obstructions in the path of flow inwardly from the outer edge of the lens. An asymmetric flow pattern is established across the lens surface, either by having a differential size slot at different peripheral portions of the peripheral edge of the lens or window, or by providing a radial swirl about the axis of the window so that when the air goes through the slot, the tangential velocity creates a moving asymmetric flow pattern on the window surface.Type: GrantFiled: January 23, 1990Date of Patent: September 8, 1992Assignee: Rosemount Inc.Inventors: Douglas C. Myhre, Richard J. O'Brien, David Y. H. Pui, Chuen-Jinn Tsai
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Patent number: 4786188Abstract: A radiation instrument has a purging air flow system for passing air over the lens to keep it clean and free from particulate contaminants and also for providing a positive flow of air away from the lens. The air supply used for such purging is controlled adequately so the flow changes direction and particles are removed from the main flow of purge air by inertial separation prior to the time the air contacts the lens. Such air entrained particles might otherwise deposit on the lens. A flow control orifice provides a secondary flow to carry the particles separated from the main flow out of the flow passageway.Type: GrantFiled: February 27, 1986Date of Patent: November 22, 1988Assignee: Rosemont Inc.Inventors: Douglas C. Myhre, David Y. H. Pui, Larry V. Miller
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Patent number: 4355504Abstract: Apparatus for controlling particulate emissions from a combustion apparatus, such as a diesel engine. Diesel engine exhaust particles are electrically charged during the formation of the particles in the engine combustion chambers. A particle collector is used to collect the electrically charged particles on collecting structures connected to a high voltage power supply and ground. The collecting structures of the particle collector can be a plurality of parallel metal plates, spaced cylindrical rods, or concentrically located cylindrical members. A fibrous matrix can be located adjacent the particle collecting structure to collect the charged particles as they move through the matrix. In one embodiment, the collected particles separate from the collecting structures and return to the engine intake. In another embodiment, a removable collecting cartridge has electrically conductive plates for collecting the charged particles. The entire cartridge is removed for cleaning or replacement.Type: GrantFiled: December 11, 1980Date of Patent: October 26, 1982Assignee: The Regents of the University of MinnesotaInventors: Benjamin Y. H. Liu, David B. Kittelson, Daniel F. Dolan, David Y. H. Pui
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Patent number: 4338784Abstract: The method and apparatus for controlling particulate emissions from a combustion apparatus, as a diesel engine. Diesel engine exhaust particles are electrically charged during the formation of the particles in the engine combustion chamber. A particle collector is used to collect the electrically charged particles on collecting structures connected to a high voltage power supply and ground. The collecting structures of the particle collector can be a plurality of parallel metal plates, spaced cylindrical rods, or concentrically located cylindrical members. A fibrous matrix can be located adjacent the particle collecting structure to collect the charged particles as they move through the matrix. In one embodiment, the collected particles separate from the collecting structures and return to the engine intake. In another embodiment, a removable collecting cartridge has electrically conductive plates for collecting the charged particles. The entire cartridge is removed for cleaning or replacement.Type: GrantFiled: December 11, 1980Date of Patent: July 13, 1982Assignee: The Regents of the University of Minn.Inventors: Benjamin Y. H. Liu, David B. Kittelson, Daniel F. Dolan, David Y. H. Pui
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Patent number: 4316360Abstract: The method and apparatus for controlling particulate emissions from a combustion apparatus, as a diesel engine. Diesel engine exhaust particles are electrically charged during the formation of the particles in the engine combustion chamber. A particle collector is used to collect the electrically charged particles on collecting structures connected to a high voltage power supply and ground. The collecting structures of the particle collector can be a plurality of parallel metal plates, spaced cylindrical rods, or concentrically located cylindrical members. A fibrous matrix can be located adjacent the particle collecting structure to collect the charged particles as they move through the matrix. In one embodiment, the collected particles separate from the collecting structures and return to the engine intake. In another embodiment, a removable collecting cartridge has electrically conductive plates for collecting the charged particles. The entire cartridge is removed for cleaning or replacement.Type: GrantFiled: August 22, 1979Date of Patent: February 23, 1982Assignee: The Regents of the University of Minn.Inventors: Benjamin Y. H. Liu, David B. Kittelson, Daniel F. Dolan, David Y. H. Pui