Michele Latasha Mitchell

US Patent:

6697666, Feb 24, 2004

Filed:

Mar 6, 2000

Appl. No.:

09/519153

Inventors:

Michele Follen Mitchell - Houston TX
Urs Utzinger - Bachenbülach, CH

Assignee:

Board of Regents, The University of Texas System - Austin TX

International Classification:

A61B 500

US Classification:

600478, 604 27, 604 48

Abstract:

A method and apparatus for characterizing tissue of epithelial lined viscus in vivo including, for example, the endocervical canal. The method comprises illuminating an interior surface of the viscus with electromagnetic radiation wavelengths to produce a plurality of fluorescence intensity spectra, detecting a plurality of emission wavelengths from the fluorescence intensity spectra, and characterizing the epithelial viscus tissue as a function of the emission wavelengths. The apparatus includes a light source of emitting a plurality of electromagnetic radiation wavelengths, an optical probe connected to the light source, the probe being adapted to apply the plurality of electromagnetic radiation wavelengths to an interior surface of epithelial viscus tissue under test and to gather fluorescence emitted from the tissue, a detector connected to the probe for detecting at least one fluorescence spectrum emitted from the tissue under test and a programmed computer connected to the detector for processing the at least one fluorescence spectrum according to a predetermined algorithm to characterize the tissue under test.

US Patent:

56125402, Mar 18, 1997

Filed:

Mar 31, 1995

Appl. No.:

8/412325

Inventors:

Gregg Staerkel - Houston TX
Youseph Yazdi - Austin TX
Michele F. Mitchell - Houston TX

Assignee:

Board of Regents, The University of Texas Systems - Austin TX

International Classification:

G01N 2164

US Classification:

2504612

Abstract:

A method for detecting tissue abnormality, particularly precancerous cervical tissue, through fluorescence spectroscopy is disclosed. In vitro fluorescence measurements over a variety of different fluorescence spectra are used to screen tissue samples. Using a principal component analysis (PCA), it is possible to discriminate between normal and dysplastic tissues with relatively low false-positive and false-negative results.

US Patent:

56997957, Dec 23, 1997

Filed:

Mar 31, 1995

Appl. No.:

8/415356

Inventors:

Costas Pitris - Austin TX
Michele Follen Mitchell - Houston TX

Assignee:

Board of Regents, The University of Texas System - Austin TX

International Classification:

A61B 600

US Classification:

128634

Abstract:

A probe, and an apparatus incorporating the probe, for detecting tissue abnormality, particularly precancerous cervical tissue, through fluorescence spectroscopy are disclosed. In vivo fluorescence excitation and detection can be accomplished easily and accurately using a probe whose tip conforms to the surface of the cervix. In addition, a higher number of fiber pairs provides more information and, therefore, more accurate diagnosis.

US Patent:

54213398, Jun 6, 1995

Filed:

May 12, 1993

Appl. No.:

8/060432

Inventors:

Nirmala Ramanujam - Austin TX
Anita Mahadevan - Austin TX
Michele F. Mitchell - Houston TX
Sharon Thomsen - Houston TX

Assignee:

Board of Regents, The University of Texas System - Austin TX

International Classification:

A61B 600

US Classification:

128665

Abstract:

Apparatus and in vivo methods to distinguish normal and abnormal cervical tissue and to detect cervical intraepithelial neoplasia (CIN) in a diagnostic cervical tissue sample. Induced fluorescence intensity spectra from known normal cervical tissue and a diagnostic tissue sample are obtained from the same patient. Peak fluorescence intensity values for normal tissue samples are averaged, as are slope measurements from predetermined portions of spectra induced in both known normal cervical tissue and the diagnostic tissue sample. Peak fluorescence intensities of diagnostic tissue spectra are divided by average peak fluorescence intensity values for normal tissue in the same patient to yield relative peak fluorescence intensity values. Normal and abnormal cervical tissues are distinguished using a predetermined empirical discriminant function of slope measurements derived from normal tissue spectra and relative peak fluorescence intensity measurements in the same patient. CIN is distinguished from tissue with human papilloma virus injection or inflammation using a predetermined empirical discriminant function of average slope measurements on spectra from known normal tissue and slope measurements on a diagnostic tissue spectrum.

US Patent:

59916532, Nov 23, 1999

Filed:

Jun 19, 1996

Appl. No.:

8/667993

Inventors:

Nirmala Ramanujam - Philadelphia PA
Michele Follen Mitchell - Houston TX

Assignee:

Board of Regents, The University of Texas System - Austin TX

International Classification:

A61B 600

US Classification:

600475

Abstract:

Early diagnosis of cervical precancer is an important clinical goal. Optical spectroscopy has been suggested as a new technique to overcome limitations of current clinical practice. Herein, NIR Raman spectroscopy is applied to the diagnosis of cervical precancers. Using algorithms based on empirically selected peak intensities, ratios of peak intensities and a combination of Principal Component Analysis (PCA) for data reduction and Fisher Discriminant Analysis (FDA), normal tissues, inflammation and metaplasia were distinguishable from low grade and high grade precancers. The primary contributors to the tissue spectra appear to be collagen, nucleic acids, phospholipids and glucose 1-phosphate. These results suggest that near infrared Raman spectroscopy can be used effectively for cervical precancer diagnosis.

US Patent:

62585762, Jul 10, 2001

Filed:

Jun 19, 1996

Appl. No.:

8/666021

Inventors:

Nirmala Ramanujam - Philadelphia PA
Michele Follen Mitchell - Houston TX

Assignee:

Board of Regents, the University of Texas System - Austin TX

International Classification:

G01N 2164
A61B 500

US Classification:

435172

Abstract:

The present invention involves the use of fluorescence spectroscopy in the diagnosis of cervical cancer and precancer. Using multiple illumination wavelengths, it is possible to (i) differentiate normal or inflamed tissue from squamous intraepithelial lesions (SILs) and (ii) to differentiate high grade SILs from non-high grade SILs. The detection may be performed in vitro or in vivo. Multivariate statistical analysis was employed to reduce the number of fluorescence excitation-emission wavelength pairs needed to re-develop algorithms that demonstrate a minimum decrease in classification accuracy. Fluorescence at excitation-emission wavelength pairs was used to redevelop and test screening and diagnostic algorithms that have a similar classification accuracy to those that employ fluorescence emission spectra at three excitation wavelengths. Both the full-parameter and reduced-parameter screening algorithms discriminate between SILs and non-SILs with a similar specificity and a substantially improved sensitivity relative to Pap smear screening and differentiate high grade SILs from non-high grade SILs.

US Patent:

56973730, Dec 16, 1997

Filed:

Mar 14, 1995

Appl. No.:

8/403446

Inventors:

Nirmala Ramanujam - Austin TX
Anita Mahadevan - Austin TX
Michele Follen Mitchell - Houston TX

Assignee:

Board Of Regents, The University Of Texas System - Austin TX

International Classification:

A61B 600
G01N 2162

US Classification:

128664

Abstract:

A method and apparatus for detecting tissue abnormality, particularly precancerous cervical tissue, through fluorescence or Raman spectroscopy, or a combination of fluorescence and Raman spectroscopy. In vivo fluorescence measurements were followed by in vitro NIR Raman measurements on human cervical biopsies. Fluorescence spectra collected at 337, 380 and 460 nm excitation were used to develop a diagnostic method to differentiate between normal and dysplastic tissues. Using a fluorescence diagnostic method, a sensitivity and specificity of 80% and 67% were observed for differentiating squamous intraepithelial lesions (SILs) from all other tissues. In accordance with another aspect of the invention, using Raman scattering peaks observed at selected wavenumbers, SILs were separated from other tissues with a sensitivity and specificity of 88% and 100%. In addition, inflammation and metaplasia samples are correctly separated from the SILs.

US Patent:

62416626, Jun 5, 2001

Filed:

Oct 20, 1998

Appl. No.:

9/175232

Inventors:

Anant Agrawal - Austin TX
Costas Pitris - Austin TX
Urs Utzinger - Austin TX
Carrie Brookner - Missouri City TX
Michele Follen Mitchell - Houston TX

Assignee:

Lifespex, Inc. - Kirkland WA

International Classification:

A61B 500

US Classification:

600310

Abstract:

A method for using acetic acid as a signal enhancing contrast agent during fluorescence spectroscopy of normal and neoplastic tissue, particularly epithelium. In one aspect, the invention includes a method of detecting tissue abnormality in a diagnostic tissue sample in a patient, comprising the steps of obtaining a first fluorescence intensity spectrum from the diagnostic tissue sample; thereafter, applying acetic acid to the diagnostic tissue sample in sufficient concentration to alter the response of such diagnostic tissue sample to electromagnetic radiation for at least an effective period of time; during the effective period of time, obtaining a second fluorescence intensity spectrum from the diagnostic tissue sample; determining a parameter indicative of a change between the first and second fluorescence emission intensity spectra; and analyzing the determined parameter to determine a probability that the diagnostic tissue sample is normal or abnormal.