Multispectral medical imaging devices and methods thereof

Abstract

A multispectral medical imaging device includes illumination devices arranged to illuminate target tissue. The illumination devices emit light of different near-infrared wavelength bands. The device further includes an objective lens, a near-infrared image sensor positioned to capture image frames reflected from the target tissue, and a visible-light image sensor positioned to capture image frames reflected from the target tissue. A processor is configured to modulate near-infrared light output of the plurality of illumination devices to illuminate the target tissue. The processor is further configured to determine reflectance intensities from the image frames captured by the near-infrared image sensor and to generate a dynamic tissue oxygen saturation map of the target tissue using the reflectance intensities. The device further includes an output device connected to the processor for displaying the dynamic tissue oxygen saturation map.

1 - 40 . (canceled) 
     
     
         41 . A multispectral medical imaging device comprising:
 a plurality of illumination devices arranged to illuminate a target tissue, the plurality of illumination devices comprising near-infrared illumination devices configured to emit light of different near-infrared wavelength bands and a visible-light illumination device configured to emit visible light to illuminate the target tissue;   an objective lens;   a near-infrared image sensor positioned to capture image frames of near-infrared light reflected from the target tissue through the objective lens;   a visible-light image sensor positioned to capture image frames of visible light reflected from the target tissue through the objective lens;   a laser positioning array comprising:
 a first positioning laser positioned at a first offset distance from an optical axis of the objective lens and aimed at a first angle with respect to the optical axis to emit a first positioning laser mark on a skin surface over the target tissue; and 
 a second positioning laser positioned at a second offset distance from the optical axis of the objective lens and aimed at a second angle with respect to the optical axis to emit a second positioning laser mark on the skin surface; 
 wherein the first and second offset distances and angles are selected to cause the first positioning laser mark and the second positioning laser mark to be coincident at the optical axis when the target tissue is a target distance from the objective lens; 
   a processor connected to the near-infrared image sensor, the visible-light image sensor, and the plurality of illumination devices, the processor configured to modulate near-infrared light output of the plurality of illumination devices to illuminate the target tissue, the processor further configured to determine reflectance intensities from the image frames captured by the near-infrared image sensor and to generate a dynamic tissue oxygen saturation map of the target tissue using the reflectance intensities; and   an output device connected to the processor for displaying the dynamic tissue oxygen saturation map.   
     
     
         42 . The device of  claim 41 , wherein the first and second angles lay in different planes that contain the optical axis, and the first and second offset distances and angles are configured to position the first and second positioning laser marks on one side of the optical axis of the objective lens when a distance from the objective lens to the target tissue is greater than the target distance and to position the first and second positioning laser marks on an opposite side of the optical axis when the distance from the objective lens to the target tissue is less than the target distance. 
     
     
         43 . The device of  claim 42 , wherein the first and second positioning lasers are positioned at about 90 degrees apart on a circle centered at the optical axis of the objective lens. 
     
     
         44 . The device of  claim 41 , wherein the first and second positioning laser marks comprise visible-light laser marks, the visible-light image sensor is configured to capture the first and second positioning laser marks reflected from the target tissue through the objective lens, and the processor is configured to output an indication of the position of the first and second positioning laser marks. 
     
     
         45 . The device of  claim 44 , wherein the indication comprises a visual indication displayed at the output device. 
     
     
         46 . The device of  claim 41 , wherein the processor is configured to turn off the first and second positioning lasers following the target tissue being positioned a target distance from the objective lens. 
     
     
         47 . An apparatus for assisting with positioning of a medical imaging device, the apparatus comprising:
 an objective lens positioned to receive light reflected from a target tissue;   a first positioning laser positioned at a first offset distance from an optical axis of the objective lens and aimed at a first angle with respect to the optical axis to emit a first positioning laser mark on a skin surface over the target tissue; and   a second positioning laser positioned at a second offset distance from the optical axis of the objective lens and aimed at a second angle with respect to the optical axis to emit a second positioning laser mark on the skin surface;   wherein the first and second offset distances and angles are selected to cause the first positioning laser mark and the second positioning laser mark to be coincident at the optical axis when the target tissue is a target distance from the objective lens.   
     
     
         48 . The apparatus of  claim 47 , wherein the first and second angles lay in different planes that contain the optical axis, and the first and second offset distances and angles are configured to position the first and second positioning laser marks on one side of the optical axis of the objective lens when a distance from the objective lens to the target tissue is greater than the target distance and to position the first and second positioning laser marks on an opposite side of the optical axis when the distance from the objective lens to the target tissue is less than the target distance. 
     
     
         49 . The apparatus of  claim 48 , wherein the first and second positioning lasers are positioned at about 90 degrees apart on a circle centered at the optical axis of the objective lens. 
     
     
         50 . A method for positioning an imaging device, the method comprising:
 emitting first and second positioning laser marks on a surface of a target tissue from first and second positioning lasers offset from an optical axis of an objective lens of the imaging device by first and second offset distances and aimed at first and second angles with respect to the optical axis;   moving the imaging device to cause the first positioning laser mark to traverse along a first path and the second positioning laser mark to traverse along a second path; and   causing the first positioning laser mark and the second positioning laser mark to be coincident at the optical axis when the target tissue is a target distance from the objective lens.   
     
     
         51 . The method of  claim 50 , wherein the first and second angles lay in different planes that contain the optical axis, and wherein the moving the imaging device comprises positioning the first and second positioning laser marks on one side of the optical axis when a distance from the objective lens to the target tissue is greater than the target distance and positioning the first and second positioning laser marks on an opposite side of the optical axis when the distance from the objective lens to the target tissue is less than the target distance. 
     
     
         52 . The method of  claim 50 , further comprising outputting an indication of the position of the first and second positioning laser marks. 
     
     
         53 . The method of  claim 52 , wherein the outputting comprises outputting an indication of a direction in which to move the imaging device to arrive at the target distance.