Synchronization of illumination source and sensor for improved visualization of subcutaneous structures

Abstract

System and method are described for synchronizing a pulsed source of the near infrared illumination used in visualizing subcutaneous structures with the background illumination normally extant in medical treatment settings that allow both enhanced image acquisition and use of higher power pulsed infrared illumination sources.

What is claimed is: 
     
         1 . A method for enhancing the visualization of veins, arteries and other subcutaneous natural or foreign structures in the body under artificial lighting conditions, comprising the steps of:
 (a) providing a light source for illuminating a portion of the body in at least one of a reflection mode and a transillumination mode, and illuminating the portion of the body with said light source;   (b) detecting the pulsed output of the artificial lighting under which the method is performed, and defining the maxima and minima of the output of the artificial lighting;   (c) pulsing said light source in synchronization with the minima of the output from the artificial lighting; and   (d) detecting the light from said light source reflected from or transilluminated through the body portion.   
     
     
         2 . The method of  claim 1  wherein light from said light source is in the near infrared. 
     
     
         3 . The method of  claim 1  wherein the step of detecting the light from said light source reflected from or transilluminated through the body portion is performed using an image detector selected from the group consisting of a charged coupled device array, a metal on silicon array, and an image intensifier tube. 
     
     
         4 . The method of  claim 3  further comprising the step of gating said image detector in synchronization with the pulsing of said light source. 
     
     
         5 . The method of  claim 1  wherein said light source is pulsed in the range of about 10 Hz to 10 kHz. 
     
     
         6 . The method of  claim 2  wherein said light source is selected from the group consisting of a light emitting diode, a xenon source, a chemical based light source, and a chemiluminescent source. 
     
     
         7 . The method of  claim 1  further comprising the step of displaying an image of the light from said light source reflected from or transilluminated through the body portion. 
     
     
         8 . A system for enhancing the visualization of veins, arteries and other subcutaneous natural or foreign structures in the body under artificial lighting conditions, comprising:
 (a) a light source for illuminating a portion of the body in at least one of a reflection mode and a transillumination mode;   (b) first light detection means for detecting the pulsed output of the artificial lighting, and defining the maxima and minima of the output of the artificial lighting;   (c) means for pulsing said light source and means for synchronizing the pulsing of said light source with the minima of the output of the artificial lighting; and   (d) second light detection means for detecting the light from said light source reflected from or transilluminated through the body portion.   
     
     
         9 . The system of  claim 7  wherein light from said light source is in the near infrared. 
     
     
         10 . The system of  claim 8  wherein said second light detection means is an image detector selected from the group consisting of a charged coupled device array, a metal on silicon array, and an image intensifier tube. 
     
     
         11 . The system of  claim 10  further comprising means for gating said image detector in synchronization with said means for pulsing said light source. 
     
     
         12 . The system of  claim 8  wherein said light source is pulsed in the range of about 10 Hz to 10 kHz. 
     
     
         13 . The system of  claim 9  wherein said light source is selected from the group consisting of a light emitting diode, a xenon source, a chemical based light source, and a bioluminescent source. 
     
     
         14 . The system of  claim 8  further comprising means for displaying an image of the light from said light source reflected from or transilluminated through the body portion. 
     
     
         15 . A system for visualizing a structure inside a body portion, the system comprising:
 (a) an illumination source for illuminating a body portion;   (b) a receiver for receiving light from the body portion during at least two discrete temporal intervals;   (c) a light intensifier coupled to the receiver; and   (d) a display that displays an image including information about the structure.   
     
     
         16 . The system of  claim 15  further comprising a detector for detecting background illumination, and a source controller in communication with said detector for selectively synchronizing the source illumination with a temporal feature of the background illumination. 
     
     
         17 . The system of  claim 15  further comprising a detector for detecting background illumination, and a receiver controller in communication with said detector for selectively synchronizing the source illumination with a temporal feature of the background illumination. 
     
     
         18 . The system of  claim 15  wherein the illumination source is in a wavelength range of from about 400 nm to about 1400 nm. 
     
     
         19 . The system of  claim 18  wherein the illumination source is pulsed in a frequency range of from about 10 Hz to 10 kHz. 
     
     
         20 . The system of  claim 16  wherein the pulse has a time of substantially the temporal length of the corresponding interval.