Optical Imaging or Spectroscopy Systems and Methods

Abstract

Optical imaging or spectroscopy described can use laminar optical tomography (LOT), diffuse correlation spectroscopy (DCS), or the like. An incident beam is scanned across a target. An orthogonal or oblique optical response can be obtained, such as concurrently at different distances from the incident beam. The optical response from multiple incident wavelengths can be concurrently obtained by dispersing the response wavelengths in a direction orthogonal to the response distances from the incident beam. Temporal correlation can be measured, from which flow and other parameters can be computed. An optical conduit can enable endoscopic or laparoscopic imaging or spectroscopy of internal target locations. An articulating arm can communicate the light for performing the LOT, DCS, or the like. The imaging can find use for skin cancer diagnosis, such as distinguishing lentigo maligna (LM) from lentigo maligna melanoma (LMM).

1 . An imaging method, comprising:
 scanning an excitation beam through an objective lens causing a point of incidence of the excitation beam to move across a target;   using the objective lens, imaging a region of interest of the target onto a light detector to capture image light caused by optical responses induced by the excitation beam;   the imaging including de-scanning the image light so that the region of interest moves with the point of incidence thereby holding the image's position on the light detector;   the scanning and de-scanning including positioning a beam splitter to direct the excitation beam toward the objective and direct the image light from the objective such that the image light and the excitation beam can be deflected by a moving deflector element.   
     
     
         2 . An imaging method, comprising:
 scanning an excitation beam through an objective lens causing a point of incidence of the excitation beam to move across a target;   using the objective lens, imaging a region of interest of the target onto a light detector to capture image light caused by optical responses caused by the excitation beam;   the imaging including de-scanning the image light so that the region of interest moves with the point of incidence thereby holding the image's position on the light detector.   
     
     
         3 . The method of  claim 2 , wherein the scanning and de-scanning include deflecting the image light and the excitation beam with a same one or more moving deflecting elements. 
     
     
         4 . The method of  claim 3 , wherein the scanning and de-scanning further include directing the excitation beam and the image light using a beam splitter to permit both to pass through the objective. 
     
     
         5 . The method of  claim 4 , wherein the image, at any instant in time, resolves the optical responses at the multiple depths within the target. 
     
     
         6 . The method of  claim 5 , further comprising storing image data responsive to output from the light detector and using the image data to construct a two or three-dimensional representation of a distribution of the optical responses in the target. 
     
     
         7 . The method of  claim 2 , further comprising repeating the scanning and de-scanning over multiple cycles and constructing a dynamic two or three-dimensional representation of the distribution of optical responses in the target. 
     
     
         8 . The method of  claim 1 , wherein the scanning the excitation beam includes scanning multiple axes. 
     
     
         9 . An imaging device, comprising:
 an objective;   a light source;   a scanning/de-scanning optical assembly having a first moving light-redirecting element that directs illumination light from the light source, through the objective, and scans a resulting beam across a target region;   a light detector with a one or two dimensional array of detector elements, each providing a respective luminance signal;   the scanning/de-scanning optical assembly being arranged with respect to the objective, the light source, and the light detector such that the first moving light-redirecting element conveys received light, from optical responses arising at multiple depths in the target region, passing through the objective, to the light detector imaging a region of interest of the target region on the light detector such that a resulting resolves depth information about the optical responses at the multiple depths;   a beam splitter arranged to convey the illumination light through the objective and to convey received light from the objective to the light detector.   
     
     
         10 . The device of  claim 9 , further comprising a processor connected to the light detector programmed to calculate, from the luminance signals, a distribution of the optical responses at the multiple depths. 
     
     
         11 . The device of  claim 9 , wherein the first moving light-redirecting element scans the resulting beam across the target region and de-scans received light from the region of interest to maintain a position of an image of the image region of interest on the light detector as the resulting beam is scanned such that the region of interest moves across the target region as the resulting beam is scanned. 
     
     
         12 . The device of  claim 9 , further comprising a wavelength dispersive element, the light detector having a two-dimensional array of detector elements, one dimension of which resolves light from respective depths and an orthogonal dimension of which receives light from respective wavelengths. 
     
     
         13 . The device of  claim 9 , wherein the beam splitter is a dichroic beam splitter and a wavelength of the light source is selected to excite fluorescence in a predefined fluorescing material selected by the properties of the dichroic beam splitter. 
     
     
         14 . The device of  claim 9 , wherein the scanning/de-scanning optical assembly has a second light-redirecting element, the first and second light-redirecting elements moving independently to scan across respective lateral dimensions of the target volume. 
     
     
         15 . A method comprising:
 scanning an incident beam laterally across multiple beam locations of a target generating optical responses at various depths within the target;   imaging returned light resulting from the optical responses onto a light detector;   de-scanning the returned light so as to maintain a fixed position of the image on the light detector as the incident beam is scanned;   sampling images, each at a respective time, and processing each image to resolve depth information from each image; and   continuing the scanning to generate further images corresponding to each of the multiple beam locations and further processing the further images to resolve dynamic changes in the depth information.   
     
     
         16 . The method of  claim 15 , wherein the processing and/or further processing are effective for generating a three dimensional rendered image of the target region or an image representing chemical composition of the target region. 
     
     
         17 . The method of  claim 15 , wherein the scanning and de-scanning include reflecting light from one or more moving reflectors simultaneously such that the scanning and de-scanning share at least one of the one or more moving reflectors. 
     
     
         18 . A method comprising:
 sourcing light to form an incident beam;   scanning the incident beam across a target region to cause it to be incident at multiple beam locations on the target, each penetrating the target to cause optical responses at respective depths in the target;   capturing returned light resulting from the incident beam, the capturing including receiving returned light at different distances in a first lateral direction from each of the beam locations, each corresponding to one of the respective depths;   directing the returned light corresponding to the respective beam locations to respective portions of a light detector such that the optical responses at the respective depths are simultaneously acquired and indicated by signals from the respective portions.