Patents by Inventor David Nhiem

David Nhiem 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: 11192070
    Abstract: A method of integrity testing a porous material is disclosed, providing a porous material suitable for filtration to be tested, said porous material having a first surface and a second surface; wetting said porous material with a wetting liquid; providing a gas stream comprising at least first and second gases humidified with said wetting liquid below the saturation vapor pressure of said wetting liquid and wherein said humidified gas stream has a humidity of 50-99%; introducing said gas stream to said first surface of said porous material; causing said first and second gases to flow through said porous material; measuring the concentration of at least one of said first and second gases in the permeate stream exiting said second surface of said porous material; and comparing the measured concentration to a predetermined concentration.
    Type: Grant
    Filed: April 29, 2020
    Date of Patent: December 7, 2021
    Assignee: EMD Millipore Corporation
    Inventors: Salvatore Giglia, David Nhiem
  • Patent number: 11154821
    Abstract: A composite liquid filtration platform including a composite filtration medium featuring an electrospun polymeric nanofiber layer collected on a porous membrane. When in use, the porous membrane acts as a prefilter used upstream from the polymeric nanofiber layer to remove particles from a liquid stream flowing through the composite filtration structure. The nanofiber layer, positioned downstream from the porous membrane, is used as the retentive layer for critical filtration to provide biosafety assurance, and is responsible for capturing microorganisms like bacteria, mycoplasma or viruses. The composite liquid filtration platform provided herein exhibits permeability advantages over conventional porous membranes or nanofiber mats spun on coarse non-wovens.
    Type: Grant
    Filed: March 30, 2012
    Date of Patent: October 26, 2021
    Assignee: EMD Millipore Corporation
    Inventors: Onur Y. Kas, Mikhail Kozlov, Gabriel Tkacik, David Nhiem, Philip Goddard, Sherry A. Leon
  • Publication number: 20210254248
    Abstract: Provided herein are sterilizable porous filtration media and methods of making and using the same.
    Type: Application
    Filed: February 4, 2021
    Publication date: August 19, 2021
    Inventors: Nitin Satav, Martin Cuddy, JR., Xiaozhu Zhou, Saptarshi Chattopadhyay, William Trinh, Onur Y. Kas, David Nhiem
  • Publication number: 20200254392
    Abstract: A method of integrity testing a porous material is disclosed, providing a porous material suitable for filtration to be tested, said porous material having a first surface and a second surface; wetting said porous material with a wetting liquid; providing a gas stream comprising at least first and second gases humidified with said wetting liquid below the saturation vapor pressure of said wetting liquid and wherein said humidified gas stream has a humidity of 50-99%; introducing said gas stream to said first surface of said porous material; causing said first and second gases to flow through said porous material; measuring the concentration of at least one of said first and second gases in the permeate stream exiting said second surface of said porous material; and comparing the measured concentration to a predetermined concentration.
    Type: Application
    Filed: April 29, 2020
    Publication date: August 13, 2020
    Inventors: Salvatore Giglia, David Nhiem
  • Patent number: 10702832
    Abstract: A method of integrity testing porous materials that is non-destructive to the material being tested. The method includes humidifying the inlet gas stream to minimize or prevent the porous material from drying out. The inlet gas stream includes at least two gases, wherein one of the gases has a different permeability in liquid than the other, such as oxygen and nitrogen. The permeate gas stream may be subjected to a driving force such as reduced pressure to increase the flow of gases and reduce test time. Multiple porous materials can be integrity tested at the same time, such as by manifolding a plurality of them together. The integrity test is capable of detecting the presence of oversized pores or defects that can compromise the retention capability of the porous material.
    Type: Grant
    Filed: September 12, 2016
    Date of Patent: July 7, 2020
    Assignee: EMD Millipore Corporation
    Inventors: Salvatore Giglia, David Nhiem
  • Patent number: 10151679
    Abstract: A method of aerosol integrity testing of filters, capable of detecting single defects that are less than 20 ?m in diameter, and even as small as 2 ?m in diameter, in liquid sterilizing grade filters such as filter cartridges. The method challenges the filter in a dry state with a particle stream of aerosol particles of the appropriate size and in the appropriate concentration, such that at least one or more of the particles in the stream will penetrate a defective region or regions within the membrane but will not penetrate in the integral region of the membrane. Wetting of the filter is not required.
    Type: Grant
    Filed: March 1, 2016
    Date of Patent: December 11, 2018
    Assignee: EMD Millipore Corporation
    Inventors: Salvatore Giglia, David Nhiem, Gabriel Tkacik
  • Patent number: 10119897
    Abstract: A method of aerosol integrity testing of filters, capable of detecting single defects that are less than 20 ?m in diameter, and even as small as 2 ?m in diameter, in liquid sterilizing grade filters such as filter cartridges. The method challenges the filter in a dry state with a particle stream of aerosol particles of the appropriate size and in the appropriate concentration, such that at least one or more of the particles in the stream will penetrate a defective region or regions within the membrane but will not penetrate in the integral region of the membrane. Wetting of the filter is not required.
    Type: Grant
    Filed: March 1, 2016
    Date of Patent: November 6, 2018
    Assignee: EMD Millipore Corporation
    Inventors: Salvatore Giglia, David Nhiem, Gabriel Tkacik
  • Publication number: 20180257039
    Abstract: A method of integrity testing porous materials that is non-destructive to the material being tested. The method includes humidifying the inlet gas stream to minimize or prevent the porous material from drying out. The inlet gas stream includes at least two gases, wherein one of the gases has a different permeability in liquid than the other, such as oxygen and nitrogen. The permeate gas stream may be subjected to a driving force such as reduced pressure to increase the flow of gases and reduce test time. Multiple porous materials can be integrity tested at the same time, such as by manifolding a plurality of them together. The integrity test is capable of detecting the presence of oversized pores or defects that can compromise the retention capability of the porous material.
    Type: Application
    Filed: September 12, 2016
    Publication date: September 13, 2018
    Inventors: Salvatore Giglia, David Nhiem
  • Publication number: 20170173509
    Abstract: A fluid filtration device containing a composite filter media having a coarse porous polymeric nonwoven interlayer located between first and second polymeric fiber containing filter mats. The fiber diameters of the fibers in the first and second filter mats are different from each other, and each filter mat has a different pore size rating. The first and second polymeric fibers in the filter mats can be electrospun nanofibers. The interlayer has a coarser pore size when compared to the either the first or second filter mats, such that the resulting composite media has an increased dirt holding capacity compared to filter layers that are layered directly over each other without the presence of a coarse interlayer therebetween.
    Type: Application
    Filed: June 23, 2015
    Publication date: June 22, 2017
    Inventors: Sal GIGLIA, David NHIEM, Sherry ASHBY LEON, Gabriel TKACIK
  • Publication number: 20160299048
    Abstract: A method of aerosol integrity testing of filters, capable of detecting single defects that are less than 20 ?m in diameter, and even as small as 2 ?m in diameter, in liquid sterilizing grade filters such as filter cartridges. The method challenges the filter in a dry state with a particle stream of aerosol particles of the appropriate size and in the appropriate concentration, such that at least one or more of the particles in the stream will penetrate a defective region or regions within the membrane but will not penetrate in the integral region of the membrane. Wetting of the filter is not required.
    Type: Application
    Filed: March 1, 2016
    Publication date: October 13, 2016
    Inventors: Salvatore Giglia, David Nhiem, Gabriel Tkacik
  • Publication number: 20140116945
    Abstract: A nanofiber liquid filtration medium featuring an electrospun polymeric nanofiber layer produced on a smooth non-woven substrate.
    Type: Application
    Filed: July 23, 2012
    Publication date: May 1, 2014
    Applicant: EMD Millipore Corporation
    Inventors: Onur Y. Kas, Mikhail Kozlov, Gabriel Tkacik, David Nhiem, Philip Goddard, Sherry Ashby Leon
  • Publication number: 20130092622
    Abstract: A composite liquid filtration platform including a composite filtration medium featuring an electrospun polymeric nanofiber layer collected on a porous membrane. When in use, the porous membrane acts as a prefilter used upstream from the polymeric nanofiber layer to remove particles from a liquid stream flowing through the composite filtration structure. The nanofiber layer, positioned downstream from the porous membrane, is used as the retentive layer for critical filtration to provide biosafety assurance, and is responsible for capturing microorganisms like bacteria, mycoplasma or viruses. The composite liquid filtration platform provided herein exhibits permeability advantages over conventional porous membranes or nanofiber mats spun on coarse non-wovens.
    Type: Application
    Filed: March 30, 2012
    Publication date: April 18, 2013
    Applicant: Millipore Corporation
    Inventors: Onur Y. Kas, Mikhail Kozlov, Gabriel Tkacik, David Nhiem, Philip Goddard, Sherry Ashby Leon