Patents by Inventor Cheng H. Liu

Cheng H. Liu 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: 5656810
    Abstract: A method and apparatus for evaluating the composition of an oil sample. The method and apparatus are premised on the discovery that spectral differences can be observed in the luminescence, excitation, light scattering and absorption spectra in the near UV, visible and near IR regions for various crude oil components, such as asphaltenes, deasphalted crude oil and organic solid residues. Accordingly, in one preferred embodiment the method comprises illuminating an oil sample with light of a suitable excitation wavelength, measuring the resultant fluorescence therefrom and comparing the resultant fluorescence to appropriate standards derived from known components of crude oil.
    Type: Grant
    Filed: November 22, 1993
    Date of Patent: August 12, 1997
    Assignee: The Research Foundation of City College of New York
    Inventors: Robert R. Alfano, Cheng H. Liu
  • Patent number: 5635402
    Abstract: A technique for determining whether a cell is malignant as opposed to non-malignant using extrinsic fluorescence spectroscopy. The technique is premised on the principle that certain fluorescent dyes preferentially stain malignant cells as opposed to non-malignant cells. Accordingly, by exposing a cell to the fluorescent dye, irradiating the cell with light of such a wavelength as to cause the dye to fluoresce, measuring the intensity of fluorescence at a wavelength indicative of fluorescence of the dye, and comparing the fluorescence intensity to standards obtained from malignant cells and non-malignant cells, it is possible for one to accurately classify the cell as being either malignant or non-malignant. The present invention also relates to an automated system which applies the principles of the aforementioned technique to depict the spatial distribution of cells within an area of a Pap smear-type sample and to characterize each of the cells as being malignant or non-malignant.
    Type: Grant
    Filed: April 29, 1994
    Date of Patent: June 3, 1997
    Inventors: Robert R. Alfano, Cheng H. Liu, Wei L. Sha, Yury Budansky
  • Patent number: 5293872
    Abstract: A method for distinguishing between calcified atherosclerotic tissue and either fibrous atherosclerotic tissue or normal cardiovascular tissue. The present method is based on the discovery that, when irradiated with a beam of monochromatic infrared light, calcified atherosclerotic human aortic tissue produces a Fourier Transform Raman spectrum which is distinguishable from analagous spectra obtained from fibrous atherosclerotic human aortic tissue and normal human aortic tissue. Some salient differences in the respective Raman spectra are the presence of five Raman bands at Raman shifts of 957, 1071, 1262-1300, 1445, and 1659 cm.sup.-1 (.+-.4 cm.sup.-1 for all shifts) for the calcified tissue as compared to three Raman bands at Raman shifts of 1247-1270, 1453 and 1659 cm.sup.-1 (.+-.4 cm.sup.-1 for all shifts) for the fibrous tissue and three Raman bands at Raman shifts of 1247-1270, 1449 and 1651 cm.sup.-1 (.+-.4 cm.sup.-1 for all shifts) for the normal tissue.
    Type: Grant
    Filed: April 3, 1991
    Date of Patent: March 15, 1994
    Inventors: Robert R. Alfano, Cheng H. Liu
  • Patent number: 5261410
    Abstract: A method for determining if a tissue is a malignant tumor tissue, a benign tumor tissue, or a normal or benign tissue. The present method is based on the discovery that, when irradiated with a beam of infrared, monochromatic light, malignant tumor tissue, benign tumor tissue, and normal or benign tissue produce distinguishable Raman spectra. For human breast tissue, some salient differences in the respective Raman spectra are the presence of four Raman bands at a Raman shift of about 1078, 1300, 1445, and 1651 cm.sup.-1 for normal or benign tissue, the presence of three Raman bands at a Raman shift of about 1240, 1445, and 1659 cm.sup.-1 for benign tumor tissue, and the presence of two Raman bands at a Raman shift of about 1445 and 1651 cm.sup.-1 for malignant tumor tissue. In addition, it was discovered that for human breast tissue the ratio of intensities of the Raman bands at a Raman shift of about 1445 and 1659 cm.sup.-1 is about 1.25 for normal or benign tissue, about 0.
    Type: Grant
    Filed: February 7, 1991
    Date of Patent: November 16, 1993
    Inventors: Robert R. Alfano, Cheng H. Liu, Wenling S. Glassman