Examination of biological tissue using non-contact optical probes

Abstract

An optical system for examination of biological tissue includes a light source, a light detector, optics and electronics. The light source generates a light beam to be transmitted to the biological tissue spaced apart from the source. The light detector is located away (i.e., in a non-contact position) from the examined biological tissue and is constructed to detect light that has migrated in the examined biological tissue. The electronics controls the light source and the light detector, and a system separates the reflected photons (e.g., directly reflected or scattered from the surface or superficial photons, i.e., “noise” photons) from the photons that have migrated in the examined biological tissue. This system prevents detection of the “noise” photons by the light detector or, after detection, eliminates the “noise” photons in the detected optical data used for tissue examination.

1 . An optical system for examination of biological tissue, comprising:
 a light source for generating a light beam to be transmitted to the biological tissue spaced apart from said source;   a light detector located away from the examined biological tissue and constructed to detect light that has migrated in the examined biological tissue; and   electronics for controlling said light source and said light detector and a system for separating reflected photons from photons that have migrated in the examined biological tissue to prevent detection of the reflected photons by the light detector or elimination after detection of the reflected photons in the detected optical data used for tissue examination.   
     
     
         2 . The optical system of  claim 1  further including a fresnel lens associated with said light detector. 
     
     
         3 . The optical system of  claim 1 , wherein said light detector includes an intensified charge coupled device (ICCD). 
     
     
         4 . The optical system of  claim 1 , wherein said light source is associated with a scanning system for scanning the emitted light beam over a tissue area. 
     
     
         5 . The optical system of  claim 1 , wherein said electronics includes a TRS system. 
     
     
         6 . The optical system of  claim 1 , wherein said electronics includes a phase modulation system (PMS). 
     
     
         7 . The optical system of  claim 1 , wherein said electronics includes a phased array system. 
     
     
         8 . The optical system of  claim 1 , wherein said electronics includes a CW system. 
     
     
         9 . An optical system for examination of brain tissue of a subject undergoing a security check, comprising:
 a light source for generating a light beam to be transmitted to the head of the subject spaced apart from said source;   a light detector located away from the head and constructed to detect light that has migrated in the examined biological tissue; and   electronics for controlling said light source and said light detector and a system for separating reflected photons from photons that have migrated in the examined biological tissue to prevent detection of the reflected photons by the light detector or elimination after detection of the reflected photons in the detected optical data used for tissue examination.   
     
     
         10 . The optical system of  claim 9  further including a fresnel lens associated with said light detector. 
     
     
         11 . The optical system of  claim 9 , wherein said light detector includes an intensified charge coupled device (ICCD). 
     
     
         12 . The optical system of  claim 9 , wherein said light source is associated with a scanning system for scanning the emitted light beam over a tissue area. 
     
     
         13 . The optical system of  claim 9 , wherein said electronics includes a TRS system. 
     
     
         14 . The optical system of  claim 9  further including a tissue tracking system tracking constructed to tract position of the tissue area. 
     
     
         15 . cancelled 
     
     
         16 . An optical method for examination of brain tissue of a subject undergoing a security check, comprising:
 generating a light beam from a light source and transmitting said light beam to the head of the subject spaced apart from said source;   detecting by a light detector, located away from the head, light that has migrated in the examined tissue;   controlling operation of said light source and said light detector; and   separating reflected photons from photons that have migrated in the examined biological tissue to prevent detection of the reflected photons by the light detector or eliminating after detection the reflected photons in the detected optical data used for tissue examination.   
     
     
         17 . The method of  claim 16  including evaluating said detected light to determine a brain function of the subject. 
     
     
         18 . The method of  claim 17  including evaluating said detected light to determine truthfulness of statements by the subject. 
     
     
         19 . The method of  claim 16  including providing brain stimulation. 
     
     
         20 . The method of  claim 19 , wherein said providing said brain stimulation includes providing visual stimulation. 
     
     
         21 . The method of  claim 19 , wherein said providing said brain stimulation includes stimulating cognitive function of the brain. 
     
     
         22 . The method of  claim 19 , wherein said providing said brain stimulation includes stimulating memories stored in the brain. 
     
     
         23 . The method of  claim 19 , wherein said providing brain stimulation includes providing auditory stimulation. 
     
     
         24 . The method of  claim 19 , wherein said acts of introducing and detecting optical radiation are performed while providing said brain stimulation. 
     
     
         25 . The method of  claim 19 , wherein said acts of introducing and detecting optical radiation are performed without said brain stimulation to obtain “rest” optical data, and said acts of introducing and detecting optical radiation are performed while providing said brain stimulation to obtain “functional” optical data. 
     
     
         26 . The method of  claim 16  further including introducing and detecting optical radiation to obtain “background” optical data. 
     
     
         27 - 29 . (canceled) 
     
     
         30 . The method of  claim 16 , wherein said act of detecting includes detecting fluorescent light emitted from the examined tissue.