Patent Grant
4017192
The subject matter of this application is related to that of U.S. Pat. No. 3,765,775 to Eugene R. Gannssle and Donald R. Webster, issued Oct. 16, l973 entitled "Optical Quality Analyzer", U.S. Pat. No. 3,861,788 issued Jan. 21, l975 to Donald R. Webster entitled "Optical Analyzer for Agricultural Products", and U.S. patent application, Ser. No. 283,270, filed Aug. 24, l972 by Donald R. Webster, assigned to the assignee of this application. U.S. Pat. No. 3,861,788 in its entirety is incorporated herein by reference. The invention relates generally to the field of biomedical pathology and instruments for measuring and analyzing the optical properties of organic materials. In the past, abnormalities in biomedical cellular material, for example malignant cells in a cervical biopsy, have had to be subjected to microscopic investigation by laboratory technicians specially trained in pathology. The use of qualitative visible and near-infrared spectrophotometry is, however, well established in the clinical laboratory for certain kinds of tests. Nevertheless, the use of spectral absorption techniques for quantitative analysis has had little, if any, clinical application. U.S. Pat. No. 3,861,788 describes an optical analyzer designed to obtain reflectivity data from agricultural specimens such as grain and to determine the percent of various constitutents, particularly protein, water and oil by means of analog computation of the values of linear functions of the variables .DELTA.OD, the difference in optical density at several characteristic wavelength pairs. Cancer of the uterus is the number one killer of women in the U.S.. Pap smears and cervical scrapings provide tissue specimens which are analyzed in the laboratory to diagnose uterine cancer. Only a small percentage of the nation's women have pap smears or scrapings taken regularly. If every woman in the U.S. had a pap smear taken and analyzed once a year, the death rate from uterine cancer would be drastically reduced because it is susceptible to early treatment. However, because pap smears and cervical scrapings require tedious microscopic analysis by trained laboratory technicians, there is no way that pap smears from every woman in the United States just once a year could ever be analyzed, given the limited availability of laboratory technicians and facilities. Hence, the interest in developing an instrument which will automatically, instantaneously diagnose cancerous biopsies is grounded in the realization that this is the only way that an effective nationwide program of uterine cancer detection can be carried out at all. No previous systems are adequate to this challenge. In a technique for automatic detection of abnormalities, particularly pathology, in biomedical specimens, light transmittance or reflectance data over a large number of wavelengths for numerous samples are correlated, for example by multiple linear regression analysis, with conventional clinical results to select test wavelengths and constants for a correlation equation. Optical instrumentation with an analog or digital computer applies the resulting correlation equation to the spectral data on a given specimen at the test wavelengths determine quantitatively the presence of the abnormality. Specific examples are given for cervical cancer, cancer in mice and rats, and contaminated serum. In one form of instrumentation, an automatic monochromator, in the form of a rotatable paddlewheel of filters, illuminates the specimen with progressively shifting narrow band radiation. The output of a photodetector, positioned to receive light transmitted through the specimen, is sampled to yield values indicative of transmissivity at the test wavelengths. In one embodiment, these values are converted to optical density and a plurality of stored optical density values at different wavelengths are manipulated by an analog computer programmed to perform a linear calculation. In another embodiment, the output of the photodetector is converted to digital form and fed to a digital computer adapted to store a plurality of values about each test wavelength and to perform a programmed sequence of operations to produce values at each test wavelength of the ratio of a derivative of transmissivity of the specimen to absolute transmissivity. The value of a linear function of these ratios indicates a specific abnormality.
| Number | Name | Date | Kind |
|---|---|---|---|
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| 3861788 | Webster | Jan 1975 | |
| 3877818 | Button et al. | Apr 1975 |
