Patents by Inventor Aizhong Zhang
Aizhong Zhang 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: 12029489Abstract: A method performed by a multispectral or hyperspectral meibomian gland imaging device is disclosed, which comprises directing light having visible and infrared spectra from a broadband illuminator toward an everted eyelid; forming images of the everted eyelid using an imaging system; recording the images using a detection system, which separates the images into spectral channels, which include at least one visible spectral channel and at least one infrared spectral channel; displaying the recorded images to adjust the position of the subject to optimize image quality; digitally processing the recorded images to obtain spatial and spectral information; evaluating the health of at least one meibomian gland of the eyelid by analyzing the information. Also disclosed is a multispectral or hyperspectral meibomian gland imaging device, comprising a broadband illuminator directing light that covers visible and infrared spectra; an imaging system, and a detection system.Type: GrantFiled: September 20, 2022Date of Patent: July 9, 2024Inventor: Aizhong Zhang
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Patent number: 11644412Abstract: A method and device of thin film spectroellipsometric imaging are disclosed. The device comprises an illuminator to direct light through a polarization generator system toward an extended area of a sample; an imaging system to form images; a detection system to record in a plurality of spectral channels; a computer to display and analyze the recorded images; and at least one reference phantom with known optical properties to replace the sample for calibration. The method comprises directing light from an illuminator through a polarization generator system toward an extended area of a sample having a geometrical shape; forming images with an imaging system; adjusting a polarization generator system and a polarization analyzer system to obtain a series of polarimetric setups; recording the images with a detection system in a plurality of spectral channels; replacing the sample with at least one reference phantom; and analyzing the recorded images with a computer.Type: GrantFiled: August 2, 2020Date of Patent: May 9, 2023Inventor: Aizhong Zhang
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Patent number: 11564563Abstract: A multifunctional ophthalmic instrument and method for assessing ocular surface health is disclosed. The instrument includes an illumination projector, which contains broadband light sources, covering visible and near infrared spectra, a zoom lens system with continuously variable magnification, a detection system to record said images, and a computer to display and analyze said images. Preferably, an eye alignment system with a beamsplitter is used to provide a fixation target for the eye under assessment. An optional thermal camera, operating in the long wave infrared spectrum is aligned paraxially to the zoom lens system. Further, an optional separate video camera is used to monitor the blink rate. Corneal topography and tear break up time could be evaluated with a low magnification, and microscopic features, such as tear meniscus height, meibomian gland orifices, are imaged at a high magnification. Meibomian glands and lipid layer thickness are analyzed with visible and near infrared spectra.Type: GrantFiled: February 16, 2019Date of Patent: January 31, 2023Inventor: Aizhong Zhang
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Patent number: 11478145Abstract: A method performed by a multispectral or hyperspectral meibomian gland imaging device is disclosed, which comprises directing light having visible and infrared spectra from a broadband illuminator toward an everted eyelid; forming images of the everted eyelid using an imaging system; recording the images using a detection system, which separates the images into spectral channels, which include at least one visible spectral channel and at least one infrared spectral channel; displaying the recorded images to adjust the position of the subject to optimize image quality; digitally processing the recorded images to obtain spatial and spectral information; evaluating the health of at least one meibomian gland of the eyelid by analyzing the information. Also disclosed is a multispectral or hyperspectral meibomian gland imaging device, comprising a broadband illuminator directing light that covers visible and infrared spectra; an imaging system, and a detection system.Type: GrantFiled: May 15, 2019Date of Patent: October 25, 2022Inventor: Aizhong Zhang
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Publication number: 20220125300Abstract: The present disclosure provides systems and methods for characterizing thin films, such as, for example, diagnosis of dry eye syndrome, thin-film optical metrology testing, etc. The present disclosure may be embodied as a tearscope, which is sometimes referred to herein as a Macroscopic Imaging Ellipsometer (MIE) because it may be considered to be an imaging ellipsometer with, for example, a field-of-view on the order of tens of millimeters or more (i.e., macroscopic), compared with conventional imaging ellipsometers, which usually employ microscope objectives and have fields-of-view of up to several hundred microns.Type: ApplicationFiled: January 4, 2022Publication date: April 28, 2022Inventors: James M. Zavislan, Aizhong Zhang
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Patent number: 11253151Abstract: A multispectral or hyperspectral ocular surface evaluating device is disclosed, comprising an illumination projector, which comprises a broadband illumination source panel and a polarizing structure to illuminate an ocular surface and adjacent structures of an eye and project a pattern on the ocular surface; an imaging system to form images; a detection system to record the images with a plurality of spectral channels in visible and near infrared spectra; and a computer to display and analyze the images. Also disclosed is a method of evaluating ocular surface health using a multispectral or hyperspectral ocular surface evaluating device, which comprises illuminating an ocular surface and adjacent structures of an eye with polarized light from an illumination projector; forming images with the imaging system; recording images formed on the detection system; digitally processing the recorded images; and analyzing the recorded images to evaluate ocular surface health with the computer.Type: GrantFiled: September 8, 2019Date of Patent: February 22, 2022Inventor: Aizhong Zhang
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Patent number: 11256073Abstract: A zoom lens system with a large zoom ratio is disclosed, which operates in a broad spectral range, including visible and infrared spectra. The zoom lens system comprises, in order from the object side to the image side, a positive first lens group, a negative second lens group, a positive third lens group, a positive fourth lens group, and a detection system, wherein zooming from a wide-angle end to a telephoto end is performed by axially moving the second and third lens groups. The system has a relatively long back focal length, and satisfies the following conditions: 0.2<|f2|/(fW*fT)½<2, 1<f4/|f2|<8, 0.3<|f2|/f3<1.5, where fW is the system focal length at the wide-angle end, fT is the system focal length at the telephoto end, (fW*fT)1/2 is the geometric mean of the two focal lengths, and fi is the focal length of the i-th lens group.Type: GrantFiled: June 15, 2019Date of Patent: February 22, 2022Inventor: Aizhong Zhang
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Publication number: 20220047449Abstract: A dry eye treatment device, comprising a roller, a holder, wherein the roller contacts and rolls over an eyelid in a plurality of directions in a treatment; a heating element to generate heat, wherein at least a portion of the heat is transferred to the roller; a temperature monitoring system, which comprises a thermal sensor and a temperature control circuit; and an electric power source. The roller is of a convex cylindrical or concave cylindrical shape. A method for dry eye treatment, comprising: cleaning an eyelid with a first cleansing wipe; heating a roller to a predetermined temperature; applying thermally conductive gel between the roller and the eyelid; rolling the roller over the eyelid in a plurality of directions; and removing the thermally conductive gel and expressed debris with a second cleansing wipe; and further, increasing the temperature by an increment and repeating the treatment method.Type: ApplicationFiled: August 14, 2021Publication date: February 17, 2022Inventor: Aizhong ZHANG
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Patent number: 11246481Abstract: The present disclosure provides systems and methods for characterizing thin films, such as, for example, diagnosis of dry eye syndrome, thin-film optical metrology testing, etc. The present disclosure may be embodied as a tearscope, which is sometimes referred to herein as a Macroscopic Imaging Ellipsometer (MIE) because it may be considered to be an imaging ellipsometer with, for example, a field-of-view on the order of tens of millimeters or more (i.e., macroscopic), compared with conventional imaging ellipsometers, which usually employ microscope objectives and have fields-of-view of up to several hundred microns.Type: GrantFiled: May 29, 2019Date of Patent: February 15, 2022Assignee: University of RochesterInventors: James M. Zavislan, Aizhong Zhang
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Publication number: 20220034791Abstract: A method and device of thin film spectroellipsometric imaging are disclosed. The device comprises an illuminator to direct light through a polarization generator system toward an extended area of a sample; an imaging system to form images; a detection system to record in a plurality of spectral channels; a computer to display and analyze the recorded images; and at least one reference phantom with known optical properties to replace the sample for calibration. The method comprises directing light from an illuminator through a polarization generator system toward an extended area of a sample having a geometrical shape; forming images with an imaging system; adjusting a polarization generator system and a polarization analyzer system to obtain a series of polarimetric setups; recording the images with a detection system in a plurality of spectral channels; replacing the sample with at least one reference phantom; and analyzing the recorded images with a computer.Type: ApplicationFiled: August 2, 2020Publication date: February 3, 2022Inventor: Aizhong Zhang
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Patent number: 11156501Abstract: A method and device of plant spectropolarimetric imaging is disclosed. A device comprising a first illuminator to direct light toward at least a portion of a plant with epi-illumination, a second illuminator to direct light toward at least a portion of a plant with transillumination, wherein the first and second illuminators are broadband, covering visible and infrared spectra; an imaging system to form images; a detection system to record the images, wherein the detection system measures in a plurality of spectral channels; and a computer to display and analyze the recorded images from the detection system. The detection system or the imaging system, comprises a polarization analyzer system. A method comprising directing light from at least one broadband illuminator toward at least a portion of a plant; forming images with an imaging system; recording the images with a detection system; and analyzing the recorded images with a computer.Type: GrantFiled: June 14, 2020Date of Patent: October 26, 2021Inventor: Aizhong Zhang
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Patent number: 11106056Abstract: The apparatus and design method of a subzonal multifocal diffractive (SMUD) lens is described herein. The apparatus includes a plurality of annular concentric zones. Each zone are further divided into at least two subzones, where the division of the subzones is arbitrary, but the division is consistent with respect to radius squared r2 across all zones. The subzone phase profile is independent with each other within the same zone, and can be optimized to achieve a desired splitting ratio among all foci.Type: GrantFiled: March 28, 2019Date of Patent: August 31, 2021Inventor: Aizhong Zhang
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Publication number: 20210068655Abstract: A multispectral or hyperspectral ocular surface evaluating device is disclosed, comprising an illumination projector, which comprises a broadband illumination source panel and a polarizing structure to illuminate an ocular surface and adjacent structures of an eye and project a pattern on the ocular surface; an imaging system to form images; a detection system to record the images with a plurality of spectral channels in visible and near infrared spectra; and a computer to display and analyze the images. Also disclosed is a method of evaluating ocular surface health using a multispectral or hyperspectral ocular surface evaluating device, which comprises illuminating an ocular surface and adjacent structures of an eye with polarized light from an illumination projector; forming images with the imaging system; recording images formed on the detection system; digitally processing the recorded images; and analyzing the recorded images to evaluate ocular surface health with the computer.Type: ApplicationFiled: September 8, 2019Publication date: March 11, 2021Inventor: Aizhong Zhang
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Publication number: 20200375451Abstract: The present disclosure provides systems and methods for characterizing thin films, such as, for example, diagnosis of dry eye syndrome, thin-film optical metrology testing, etc. The present disclosure may be embodied as a tearscope, which is sometimes referred to herein as a Macroscopic Imaging Ellipsometer (MIE) because it may be considered to be an imaging ellipsometer with, for example, a field-of-view on the order of tens of millimeters or more (i.e., macroscopic), compared with conventional imaging ellipsometers, which usually employ microscope objectives and have fields-of-view of up to several hundred microns.Type: ApplicationFiled: May 29, 2019Publication date: December 3, 2020Inventors: James M. Zavislan, Aizhong Zhang
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Publication number: 20200359890Abstract: A method performed by a multispectral or hyperspectral meibomian gland imaging device is disclosed, which comprises directing light having visible and infrared spectra from a broadband illuminator toward an everted eyelid; forming images of the everted eyelid using an imaging system; recording the images using a detection system, which separates the images into spectral channels, which include at least one visible spectral channel and at least one infrared spectral channel; displaying the recorded images to adjust the position of the subject to optimize image quality; digitally processing the recorded images to obtain spatial and spectral information; evaluating the health of at least one meibomian gland of the eyelid by analyzing the information. Also disclosed is a multispectral or hyperspectral meibomian gland imaging device, comprising a broadband illuminator directing light that covers visible and infrared spectra; an imaging system, and a detection system.Type: ApplicationFiled: May 15, 2019Publication date: November 19, 2020Inventor: Aizhong Zhang
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Publication number: 20200310159Abstract: The apparatus and design method of a subzonal multifocal diffractive (SMUD) lens is described herein. The apparatus includes a plurality of annular concentric zones. Each zone are further divided into at least two subzones, where the division of the subzones is arbitrary, but the division is consistent with respect to radius squared r2 across all zones. The subzone phase profile is independent with each other within the same zone, and can be optimized to achieve a desired splitting ratio among all foci.Type: ApplicationFiled: March 28, 2019Publication date: October 1, 2020Inventor: AIZHONG ZHANG
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Patent number: 10709327Abstract: A thin film analysis apparatus and method for a curved surface is disclosed. The apparatus includes an illuminator, a sample, an imaging group, one or more beamsplitters, optional focusing groups, polarization analyzers, detectors and optional display and analysis systems. The image series are recorded, preferably substantially synchronously. The system can be calibrated by as few as one reference phantom that has the same or substantially similar geometry as the sample under test. Based on calibration, a lookup table of the effective reflectance can be created, which is proportional to the portion of the light that reaches the detectors, or the mutual subtraction of the effective reflectance values of all possible combinations of the unknown optical parameters within certain search ranges of the sample. The experimentally measured results are compared with the lookup table, and optical properties, for example, the thicknesses and refractive indices of the thin film can be determined.Type: GrantFiled: December 4, 2018Date of Patent: July 14, 2020Inventor: Aizhong Zhang
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Publication number: 20190384044Abstract: A zoom lens system with a large zoom ratio is disclosed, which operates in a broad spectral range, including visible and infrared spectra. The zoom lens system comprises, in order from the object side to the image side, a positive first lens group, a negative second lens group, a positive third lens group, a positive fourth lens group, and a detection system, wherein zooming from a wide-angle end to a telephoto end is performed by axially moving the second and third lens groups. The system has a relatively long back focal length, and satisfies the following conditions: 0.2<|f2|/(fW*fT)½<2, 1<f4/|f2|<8, 0.3<|f2|/f3<1.5, where fW is the system focal length at the wide-angle end, fT is the system focal length at the telephoto end, (fW*fT)1/2 is the geometric mean of the two focal lengths, and fi is the focal length of the i-th lens group.Type: ApplicationFiled: June 15, 2019Publication date: December 19, 2019Inventor: Aizhong ZHANG
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Publication number: 20190254515Abstract: A multifunctional ophthalmic instrument and method for assessing ocular surface health is disclosed. The instrument includes an illumination projector, which contains broadband light sources, covering visible and near infrared spectra, a zoom lens system with continuously variable magnification, a detection system to record said images, and a computer to display and analyze said images. Preferably, an eye alignment system with a beamsplitter is used to provide a fixation target for the eye under assessment. An optional thermal camera, operating in the long wave infrared spectrum is aligned paraxially to the zoom lens system. Further, an optional separate video camera is used to monitor the blink rate. Corneal topography and tear break up time could be evaluated with a low magnification, and microscopic features, such as tear meniscus height, meibomian gland orifices, are imaged at a high magnification. Meibomian glands and lipid layer thickness are analyzed with visible and near infrared spectra.Type: ApplicationFiled: February 16, 2019Publication date: August 22, 2019Inventor: Aizhong Zhang
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Publication number: 20190183332Abstract: A thin film analysis apparatus and method for a curved surface is disclosed. The apparatus includes an illuminator, a sample, an imaging group, one or more beamsplitters, optional focusing groups, polarization analyzers, detectors and optional display and analysis systems. The image series are recorded, preferably substantially synchronously. The system can be calibrated by as few as one reference phantom that has the same or substantially similar geometry as the sample under test. Based on calibration, a lookup table of the effective reflectance can be created, which is proportional to the portion of the light that reaches the detectors, or the mutual subtraction of the effective reflectance values of all possible combinations of the unknown optical parameters within certain search ranges of the sample. The experimentally measured results are compared with the lookup table, and optical properties, for example, the thicknesses and refractive indices of the thin film can be determined.Type: ApplicationFiled: December 4, 2018Publication date: June 20, 2019Inventor: Aizhong Zhang