NIR clinical opti-scan system

Abstract

The present invention relates to three-dimensional optical imaging techniques and, more particularly, to the detection and three-dimensional imaging of absorbing and/or scattering structures in complex random media, such as human body tissue, by detecting scattered light emerging from the medium. An apparatus for optical tomographic imaging of tissue structures with non-uniform surface geometries in accordance with the invention comprises: an optical source capable of providing light having a wavelength capable of at least attenuated transmission through the tissue; a fiber array consisting of fiber bundles for transmitting light from the optical source to the tissue to be imaged, and a second fiber array consisting of fiber bundles for receiving light scattered by the tissue; an adjustable assembly comprising an adjustable support member supporting one end of each fiber bundle, the fiber bundles being distributed along the portion of each support member which conforms to a surface of a specimen being imaged so as to transmit light into, and collect light emanating from, the surface of the imaged tissue at a multitude of spaced-apart points; and a detector array receiving light collected by the fibers in the second fiber bundle.

1. An apparatus for optical tomographic imaging of tissue structures with non-uniform surface geometries, comprising:
 an optical source capable of providing light having a wavelength capable of at least attenuated transmission through the tissue;  
 a first fiber array including fiber bundles for transmitting light from the optical source to the tissue to be imaged;  
 a second fiber array including fiber bundles for receiving light scattered by the tissue;  
 an adjustable assembly including an at least one adjustable support member supporting one end of each fiber bundle, the fiber bundles being from the first and second fiber array and being distributed along the portion of each said one or more adjustable support member which conforms to a surface of a specimen the tissue being imaged so as to transmit light into, and collect light emanating from, the surface of the imaged tissue at a multitude of spaced-apart points; and  
 a detector array receiving primarily steady-state scattered light collected by the fibers in the second fiber bundle, an output of the detector array that corresponds to the steady-state scattered light useable as a variable in a radiation transport equation array.  
 
     
     
       2. The apparatus of  claim 1  wherein the optical source is selected from the group consisting of: diode lasers, Ti:Sapphire lasers, dye lasers, multi-wavelength lasers, continuous-wave (CW) lasers, and pulsed-power lasers. 
     
     
       3. The apparatus of  claim 2  wherein the optical source emits light in the near infrared portion of the electromagnetic spectrum. 
     
     
       4. The apparatus of  claim 1  wherein the first fiber array has translatable light-receiving ends adjacent to the light source. 
     
     
       5. The apparatus of  claim 1  further comprising a focusing lens disposed between the optical source and the first fiber array. 
     
     
       6. The apparatus of  claim 1  wherein the one or more adjustable support members are constructed of comprise deformable material. 
     
     
       7. The apparatus of  claim 1  wherein the one or more adjustable support members comprise adjustable irises. 
     
     
       8. The apparatus of  claim 1  further comprising an attenuator disposed between the fiber bundles which transmit light away from the adjustable assembly of the second fiber array and the detector array. 
     
     
       9. The apparatus of  claim 8  wherein the attenuator comprises:
 an inner cylinder housing another end the fiber bundles from the adjustable assembly of the second fiber array;  
 an outer cylinder housing the one end of a plurality of fiber bundles that direct light to the detector array; and  
 a plurality of attenuators disposed between the inner and outer cylinders.  
 
     
     
       10. The apparatus of  claim 9  wherein the plurality of attenuators comprise neutral density filters having a respective plurality of density values. 
     
     
       11. The apparatus of  claim 9  wherein the plurality of attenuators comprise polarizers. 
     
     
       12. The apparatus of  claim 1  further comprising a reference detector for monitoring the optical source from a portion of the first fiber array receiving light from the optical source . 
     
     
       13. The apparatus of  claim 1  further comprising an outer housing enclosing the adjustable assembly wherein the outer housing excludes ambient light. 
     
     
       14. The apparatus of  claim 13  wherein the outer housing further comprises a rubber dam for containing submersive index-matching fluid. 
     
     
       15. The apparatus of  claim 1  wherein the detector array is a charge-coupled device (CCD) detector array. 
     
     
       16. The apparatus of claim  15   1  wherein there is a fixed physical relationship between the detector array and the attached ends of the fiber bundles which transmit light away from the adjustable assembly of the second fiber array. 
     
     
       17. The apparatus of  claim 1  further comprising a second adjustable assembly to form a dual-head scanner. 
     
     
       18. The apparatus of  claim 8  wherein the attenuator further comprises a wavelength-selective filter. 
     
     
       19. The apparatus of  claim 1  wherein the fiber bundles comprise multiple small-diameter fibers, each with a diameter of less than 200 microns, and wherein the fiber bundles each have a total active surface area of at least 2 square millimeters. 
     
     
       20. The apparatus of  claim 19  wherein there is a minimum of 100 fiber bundles. 
     
     
       21. The apparatus of  claim 1  further comprising computing means for three-dimensional image reconstruction and display of data received from the detector array. 
     
     
       22. A method of optical tomographic imaging of tissue structures with non-uniform surface geometries, comprising:
 using an adjustable assembly to snugly conform to the geometry of a specimen under test tissue structure;  
 illuminating the specimen tissue structure with light from a source via transmitting fiber bundles contained within the adjustable assembly;  
 collecting primarily steady-state scattered light from the specimen tissue structure at the source wavelength using receiving fiber bundles contained within the adjustable assembly;  
 detecting the steady-stage scattered light with a detector array;  
 analyzing an output of the detector array that corresponds to the steady-state scattered light as a variable in a radiation transport equation with a computer capable of constructing and displaying a three-dimensional an image from the steady-state scattered light.  
 
     
     
       23. The method of  claim 22  wherein the steady-state scattered light from the specimen tissue structure is at a wavelength other than the source wavelength. 
     
     
       24. The method of  claim 22  wherein the specimen tissue structure is illuminated at a plurality of source wavelengths. 
     
     
       25. The method of  claim 22  further comprising monitoring the source light by diverting a portion of the source light to a reference detector. 
     
     
       26. The method of  claim 22  further comprising selectively attenuating the steady-state scattered light from the specimen tissue structure. 
     
     
       27. The method of  claim 22  further comprising excluding ambient light from the adjustable assembly by enclosing the adjustable assembly with an outer housing. 
     
     
       28. The method of  claim 27  further comprising index matching the specimen under test tissue structure by filling the outer housing with index matching fluid. 
     
     
       29. The method of  claim 22  further comprising using two adjustable assemblies to form a dual-head scanner. 
     
     
       30. The method of  claim 22  further comprising using a wavelength-selective filter. 
     
     
       31. The method of  claim 22  further comprising using fiber bundles comprising multiple small-diameter fibers, each with a diameter of less than 200 microns, and wherein the fiber bundles each have a total active surface area of at least 2 square millimeters. 
     
     
       32. The method of  claim 31  further comprising using a minimum of 100 fiber bundles. 
     
     
       33. The apparatus according to  claim 1 , wherein the detector array is operative to produce an output that corresponds to the steady- state scattered light and is useable as a variable in a radiation transport equation.   
     
     
       34. The method according to  claim 22  wherein analyzing an output of the detector array that corresponds to the steady- state scattered light comprises analyzing said output as a variable in a radiation transport equation.   
     
     
       35. The method according to  claim 22  wherein said computer is capable of constructing and displaying a two- dimensional image from the steady - state scattered light.   
     
     
       36. The method according to  claim 22  wherein said computer is capable of constructing and displaying a three- dimensional image from the steady - state scattered light.   
     
     
       37. An apparatus for optical tomographic imaging of tissue structures with non- uniform surface geometries, comprising:      an optical source capable of providing light having a wavelength capable of at least attenuated transmission through the tissue;        a first fiber array including fiber bundles for transmitting light from the optical source to the tissue to be imaged;        a second fiber array including fiber bundles for receiving light scattered by the tissue;        an adjustable assembly including one or more adjustable support members supporting one end of each fiber bundle, the fiber bundles being from the first and second fiber array and being distributed along a portion of each said one or more adjustable support member which conforms the tissue being imaged to a regular geometry, so as to transmit light into, and collect light emanating from, the surface of the imaged tissue at a multitude of spaced - apart points; and        a detector array receiving primarily steady - state scattered light collected by the fibers in the second fiber array.     
     
     
       38. A method of optical tomographic imaging to tissue structures with non- uniform surface geometries, comprising:      using an adjustable assembly to snugly conform a tissue structure to a regular geometry;        illuminating the tissue strength with light from a source via transmitting fiber bundles contained within the adjustable assembly;        collecting primarily steady - state scattered light from the tissue structure at the source wavelength using receiving fiber bundles contained within the adjustable assembly;        detecting the steady - state scattered light with a detector array;        analyzing an output of the detector array that corresponds to the steady - state scattered light with a computer capable of constructing and displaying an image from the steady - state scattered light.