Method and apparatus for rapid detection and diagnosis of tissue abnormalities

Abstract

A method and apparatus are provided that interrogate, receive, and analyze full emission spectra for at least one fluorescence excitation wavelength and for at least one reflectance measurement to determine tissue characteristics and correlate same to photographic images. Further, the system and method accomplish this measurement rapidly by increasing the light throughput by integrating optics into a hand held unit and avoiding the need for a coherent fiber optic bundle being used. The method includes illuminating a first portion of a target tissue with optical energy, forming a first image of the target tissue, illuminating a second portion of the target tissue with optical energy, performing spectroscopic measurements on optical energy reflected and/or emitted by the target tissue upon illumination of the second portion of the target tissue with optical energy, and determining tissue characteristics of the target tissue based on the results of the spectroscopic measurements.

1 . An apparatus for determining tissue characteristics, comprising: a base unit comprising an illumination unit, a separate tissue interface unit comprising and excitation unit for delivering illumination from the illumination unit to the tissue and a detection unit capable of detecting responses in the tissue resulting from the illumination, said excitation and detection units being confocal so that they converge at the tissue.  
   
   
       2 . The apparatus according to  claim 1 , further including a hollow stand off tube, configured to space the separate interface unit a predetermined distance from the tissue.  
   
   
       3 . The apparatus according to  claim 1  further including an imaging device capable of recording images of the tissue.  
   
   
       4 . The apparatus of  claim 3  wherein said image device is located at least in part in said separate interface unit and is confocal with said detection unit so that the image of said image unit can be spacially correlated with data from said detection unit.  
   
   
       5 . The apparatus according to  claim 3  wherein said stand off tube includes a removeable calibration target.  
   
   
       6 . The apparatus according to  claim 4  wherein said stand off tube is sized to be of equal or larger diameter relative to the target tissue size.  
   
   
       7 . The apparatus according to  claim 1 , wherein the illumination unit comprises an illumination source and an illumination filter wheel.  
   
   
       8 . The apparatus according to  claim 1 , wherein the illumination unit further comprises a mask that provides for selective illumination of the target tissue.  
   
   
       9 . The apparatus according to  claim 1 , wherein the detection unit comprises a collection filter wheel coupled to the pathway that couples the base unit and the tissue interface unit.  
   
   
       10 . The apparatus according to  claim 1 , wherein the detection unit further comprises a spectrograph coupled to the collection filter wheel.  
   
   
       11 . The apparatus according to  claim 1 , wherein the detection unit further comprises a reimaging device coupled to the collection filter wheel and the spectrograph that reimages the collected optical energy prior to the collected optical energy entering the spectrograph.  
   
   
       12 . A method of detecting movement during a measurement of tissue characteristics, comprising the steps of: a) forming a first image of the target tissue; b) illuminating a target tissue with optical energy; c) performing spectroscopic measurements on optical energy received from the target tissue from illumination; d) forming a second image of the target tissue, e) comparing the first and second images to determine the degree of movement of the tissue, if any; f)comparing the degree of movement to a predetermined standard; g) if the movement is less than said standard, determining tissue characteristics of the target tissue based on the results of the spectroscopic measurements.  
   
   
       13 . The method of  claim 12 , wherein the step of performing spectroscopic measurements includes illuminating a first portion of a target tissue with optical energy from a first illumination source and illuminating a second portion of the target tissue with optical energy comprises illuminating a second portion of the target tissue with optical energy with a second illumination source.  
   
   
       14 . A method of determining locating and differentiating normal and abnormal cervical tissue by optical interrogation of target tissue comprising the steps of: 
 a) illuminating a portion of the target tissue along a band of spaced apart, generally horizontal line of points and measuring optical energy received from said points,    b) shifting said line of points generally vertically, illuminating a new portion of the target tissue, vertically offset from the previous illumination, and measuring optical energy received from said points, to create a matrix of measured points    c) repeating the step of shifting generally vertically until at least a portion of the cervix has been interrogated;    d) determining the presence of abnormal tissue by comparing adjacent measured horizontal and vertical points based on the assumption that abnormal tissue is more likely to spread vertically than horizontally.    
   
   
       15 . A method of detecting tissue characteristics, comprising: dividing an area of target tissue into a plurality of detection points arranged in columns; illuminating the plurality of detection points one column at a time; performing spectroscopic measurements on optical energy received from the target tissue; and determining tissue characteristics of the target tissue based on the results of the spectroscopic measurements including the step detecting tissue characteristics using the rule that the adjacent horizontal points are more likely to be the boundary between normal and abnormal tissue than adjacent vertical points.  
   
   
       16 . The method of  claim 15 , wherein the plurality of detection points are separated from each other by approximately 3 mm.  
   
   
       17 . The method of  claim 15 , wherein the plurality of detection points are illuminated using a probe positioned a predetermined distance from the target tissue.