Detection, imaging and characterization of brain tissue

Abstract

An optical examination technique employs an optical system for in vivo non-invasive transcranial examination of brain tissue of a subject. The optical system includes an optical module arranged for placement on the exterior of the head, a controller and a processor. The optical module includes an array of optical input ports and optical detection ports located in a selected geometrical pattern to provide a multiplicity of photon migration paths inside the biological tissue. Each optical input port is constructed to introduce into the examined tissue visible or infrared light emitted from a light source. Each optical detection port is constructed to provide light from the tissue to a light detector. The controller is constructed and arranged to activate one or several light sources and light detectors so that the light detector detects light that has migrated over at least one of the photon migration paths. The processor receives signals corresponding to the detected light and forms at least two data sets, a first of said data sets representing blood volume in the examined tissue region and a second of said data sets representing blood oxygenation of the examined tissue. The processor is arranged to correlate the first and second data sets to detect abnormal tissue in the examined tissue.

1 . An optical system for in vivo, non-invasive transcranial examination of brain tissue of a subject comprising:
 an optical module including an array of optical input ports and detection ports located in a selected geometrical pattern to provide a multiplicity of photon migration paths inside an examined region of the biological tissue, each said optical input port being constructed to introduce visible or infrared light emitted from a light source, each said optical detection port being constructed to receive photons of light that have migrated in the examined tissue region from at least one of said input ports and provide said received light to a light detector;   a controller constructed and arranged to control operation of said light source and said light detector to detect light that has migrated over at least one of said photon migration paths; and   a processor connected to receive signals from said detector and arranged to form at least two data sets, a first of said data sets representing blood volume in the examined tissue region and a second of said data sets representing blood oxygenation in the examined tissue region; said processor being arranged to correlate said first and second data sets to detect abnormal tissue in the examined tissue region.   
     
     
         2 . The optical system of  claim 1  wherein said second data set includes hemoglobin deoxygenation values. 
     
     
         3 . The optical system of  claim 1  wherein said processor is arranged to form a third data set being collected by irradiating a reference tissue region. 
     
     
         4 - 8 . (canceled) 
     
     
         9 . The optical system of  claim 1  wherein said processor is programmed to order said first and second data sets as two-dimensional images and to determine said congruence using the following formula: 
       
         
           
             
               1 
                
               
                 ( 
                 
                   
                     maximum 
                      
                     
                         
                     
                      
                     overlap 
                      
                     
                         
                     
                      
                     residual 
                   
                   
                     maximum 
                      
                     
                         
                     
                      
                     selected 
                      
                     
                         
                     
                      
                     tissue 
                      
                     
                         
                     
                      
                     signal 
                   
                 
                 ) 
               
               × 
               100 
             
           
         
       
     
     
         10 - 35 . (canceled) 
     
     
         35 . An optical method for in vivo, non-invasive transcranial examination of brain tissue of a subject comprising:
 providing an optical module including an array of optical input ports and detection ports located in a selected geometrical pattern to provide a multiplicity of photon migration paths inside an examined region of the tissue;   placing said optical module on the exterior of the head of the subject;   introducing visible or infrared light from at least one said optical input port into an examined tissue region and receiving photons of light that have migrated in the examined tissue region to at least one of said detection ports;   detecting said received photons by at least one optical detector optically coupled to said least one said detection port;   controlling said introducing and detecting steps to collect optical data corresponding to photons of light that have migrated between selected input and detection ports;   processing said optical data to form at least two data sets, a first of said data sets representing blood volume in the examined tissue region and a second of said data sets representing blood oxygenation in the examined tissue region; and   correlating said first and second data sets to detect abnormal tissue in the examined tissue region.   
     
     
         36 . The optical method of  claim 35  including ordering said first and second data sets as two-dimensional images and determining said congruence using said two-dimensional images. 
     
     
         37 . The optical method of  claim 35  including ordering said first and second data sets as two-dimensional images and determining said congruence using a formula: 
       
         
           
             
               1 
               - 
               
                 
                   ( 
                   
                     
                       maximum 
                        
                       
                           
                       
                        
                       overlap 
                        
                       
                           
                       
                        
                       residual 
                     
                     
                       maximum 
                        
                       
                           
                       
                        
                       selected 
                        
                       
                           
                       
                        
                       tissue 
                        
                       
                           
                       
                        
                       signal 
                     
                   
                   ) 
                 
                 × 
                 100 
               
             
           
         
       
     
     
         38 . The optical method of  claim 35  including determining a location of said abnormal tissue within the examined tissue region.