System for normalizing spectra

Abstract

A method and system for normalizing optical spectra using a non-uniform segment normalization. A spectrum is obtained and is represented as a function of wavelength as an amplitude at each of a plurality of wavelengths. At least one segment of the spectrum is selected, each selected segment being bounded by an upper wavelength and a lower wavelength. A normalization factor is computed as the sum of the areas for each of the selected segments. The spectrum is normalized by dividing at least one amplitude of the spectrum by the normalization factor. Segments can be selected with different wavelength ranges, that is, segments can be non-uniform. Test specimens can be categorized based on an analysis of normalized spectra. In particular, the specimen to be tested can be human cervical tissue, and the state of health of the tissue can be determined.

1 - 21 . (canceled)  
   
   
       22 . A method of performing spectral analysis, the method comprising: 
 obtaining an optical spectrum; and    normalizing said optical spectrum by selecting a plurality of segments from said optical spectrum, determining an area under a curve associated with each segment, summing said areas to determine a normalization factor, and dividing an amplitude of said spectrum by said normalization factor.    
   
   
       23 . The method of  claim 22 , wherein a first segment of said plurality of segments differs in breadth of wavelength range from that of a second segment.  
   
   
       24 . The method of  claim 22 , wherein a first segment of said plurality of segments is substantially equal in breadth of wavelength range to that of a second segment.  
   
   
       25 . The method of  claim 22 , wherein said plurality of segments comprises at least first and second non-contiguous segments.  
   
   
       26 . The method of  claim 22 , wherein said plurality of segments comprises at least first, second, and third segments, where there exists a first span between an upper wavelength of said first segment and a lower wavelength of said second segment, and where there exists a second span between an upper wavelength of said second segment and a lower wavelength of said third segment.  
   
   
       27 . The method of  claim 26 , wherein said first span and said second span differ in magnitude.  
   
   
       28 . The method of  claim 26 , wherein said first span and said second span are substantially equal in magnitude.  
   
   
       29 . The method of  claim 22 , further comprising obtaining said spectrum from a specimen of human cervical tissue.  
   
   
       30 . The method of  claim 22 , further comprising determining a disease status of said test specimen by analyzing said optical spectrum subsequent to said normalizing.  
   
   
       31 . A system for performing spectral analysis comprising: 
 a spectrographic device adapted to obtain an optical spectrum from a test specimen;    a processor adapted to execute a set of machine-readable instructions; and    machine-readable instructions executing on said processor and adapted to select a plurality of segments from said optical spectrum, determine an area under a curve associated with each segment, sum said areas to determine a normalization factor, and divide an amplitude of said spectrum by said normalization factor.    
   
   
       32 . The system of  claim 31 , wherein said machine-readable instructions are adapted to one of select and enable a user to select a first segment of said plurality of segments different in breadth of wavelength range from that of a second segment.  
   
   
       33 . The system of  claim 31 , wherein said machine-readable instructions are adapted to one of select and enable a user to select a first segment of said plurality of segments substantially equal in breadth of wavelength range to that of a second segment.  
   
   
       34 . The system of  claim 31 , wherein said machine-readable instructions are adapted to one of select and enable a user to select said plurality of segments to include at least first and second non-contiguous segments.  
   
   
       35 . The system of  claim 31 , wherein said machine-readable instructions are adapted to one of select and enable a user to select said plurality of segments including at least first, second, and third segments, where there exists a first span between an upper wavelength of said first segment and a lower wavelength of said second segment, and a second span between an upper wavelength of said second segment and a lower wavelength of said third segment.  
   
   
       36 . The system of  claim 35 , wherein said first span and said second span differ in magnitude.  
   
   
       37 . The system of  claim 35 , wherein said first span and said second span are substantially equal in magnitude.  
   
   
       38 . The system of  claim 31 , wherein said spectrographic device is adapted to obtain said optical spectrum from a specimen of human cervical tissue.  
   
   
       39 . The system of  claim 31 , wherein said machine-readable instructions are adapted to extract a test parameter from said optical spectrum.  
   
   
       40 . The system of  claim 31 , wherein said machine-readable instructions are adapted to determine a disease status of said test specimen by analyzing said optical spectrum, subsequent to said normalizing.