System and Method for Multi-Color Laser Imaging and Ablation of Cancer Cells Using Fluorescence

Abstract

A fluorescence imaging device detects fluorescence in parts of the visible and invisible spectrum, and projects the fluorescence image directly on the human body, as well as on a monitor, with improved sensitivity, video frame rate and depth of focus, and enhanced capabilities of detecting distribution and properties of multiple fluorophores. Direct projection of three-dimensional visible representations of fluorescence on three-dimensional body areas advantageously permits view of it during surgical procedures, including during cancer removal, reconstructive surgery and wound care, etc. A NIR laser and a human visible laser (HVL) are aligned coaxially and scanned over the operating field of view. When the NIR laser passes over the area where the fluorescent dye is present, it energizes the dye which emits at a shifted NIR frequency detected by a photo diode. The HVL is turned on when emission is detected, providing visual indication of those positions.

We claim: 
     
         1 . A method for three-dimensional imaging of cancer of a target surgical area comprising:
 introducing fluorophores having affinity for targeted cancer cells into biologic tissues of internal body structures of the target surgical area;   emitting light from a first laser at an infrared wavelength selected for causing excitation of the fluorophores and emitting of a fluorescent excitation wavelength of light by the excited fluorophores;   scanning said emitted light at the infrared wavelength, using a means for scanning, in a two dimensional pattern, spanning across the target surgical area;   using a lens for receiving and focusing, onto a detector, the fluorescent excitation wavelength of light emitted by the excited fluorophores;   converting into a signal, by said detector, of an image of the fluorophores formed by said focused excitation wavelength of light;   transmitting the signal output from the detector to a processing unit;   selectively emitting light from a second laser at one or more visible wavelengths;   co-axially aligning said selectively emitted light from the second laser with said emitted light from the first laser, using a means for aligning, for scanning of said selectively emitted visible wavelength of light in the pattern, using the means for scanning; and   using the signal, by said processing unit, for causing said selectively emitting of light by the second laser at a first visible wavelength to only occur when directed at a position in said scanning corresponding to the received excitation wavelength of light from the fluorophores, to create a visible three-dimensional projection on the target surgical area of the targeted cancer cells.   
     
     
         2 . The method according to  claim 1  further comprising:
 capturing a color image of the target surgical area using a camera; and 
 displaying the captured color image of the target surgical area on a monitor. 
 
     
     
         3 . The method according to  claim 2  further comprising:
 alternately turning off said emitting of light at said infrared wavelength from the first laser; and 
 performing said capturing of the color image when the first laser is timed off for capturing the color image of the target surgical without said emitting of the fluorescent excitation wavelength of light. 
 
     
     
         4 . The method according to  claim 3  further comprising:
 capturing only ambient noise using the detector when the first laser is turned off; and 
 subtracting said captured noise from the signal by the processing unit, thereby removing the noise from the visible three-dimensional projection on the target surgical area of the targeted cancer cells. 
 
     
     
         5 . The method according to  claim 1  further comprising:
 selectively emitting light, by a third laser, at a selective wavelength for causing ablation of the targeted cancer cells; 
 co-axially aligning said selectively emitted light of said ablation laser with said emitted light of said first laser, using said means for aligning, for selectively scanning of said selective wavelength of light in said pattern, for three-dimensional projecting onto the target surgical area; and 
 causing, by said processing unit, of said selectively emitting of said light at said selective wavelength by said third laser for only occurring when directed at a position in said scan corresponding to said received excitation wavelength of light from said fluorophores, for ablating the targeted cancer cells. 
 
     
     
         6 . The method, according to  claim 5  further comprising: aiming said emitted light from said third laser for a period of time at said position in said scan corresponding to said received second wavelength of light of said fluorophores, for causing sufficient heating for ablating the targeted cancer cells. 
     
     
         7 . The method according to  claim 1   wherein said one or more wavelengths emitted by said second laser comprises a second visible wavelength being a red wavelength, a third visible wavelength being a green wavelength, and a fourth visible wavelength being a blue wavelength; and   wherein said process further comprises;
 using a second detector, a third detector, and a fourth detector being sensitive to said red, said green, and said blue wavelengths of light, respectively, for receiving the visible color characteristics of the target surgical area; 
 converting said received red, green, and blue colors of light into a signal by said second, third, and fourth detectors, respectively; 
 transmitting said respective signals to said processing unit; and 
 receiving, by a monitor, of said respective signals from said processing unit, for displaying thereon of the visible color characteristics of the target surgical area. 
   
     
     
         8 . The method according to,  claim 7  further comprising:
 separately storing a time sequence of said output from said first, second, third, and fourth detectors, as an image frame, in a respective desired-color memory, a red frame memory, a green frame memory, and a blue frame memory; 
 performing image processing of said stored image frames in each said memory to augment said image frame of said fluorophores; and 
 outputting said augmented image frames to said second laser for said three-dimensional projecting onto the target surgical area. 
 
     
     
         9 . The method according to  claim 8  further comprising: communicating said augmented image frame to a monitor for displaying of said image frame thereon. 
     
     
         10 . The method according to  claim 9  further comprising: using a camera for capturing a combined image of the target surgical area, when said second laser is projecting said visible wavelength of light thereon, and displaying said captured image on a monitor. 
     
     
         11 . The method according to  claim 10  further comprising synchronizing a frame rate of the camera with a frame rate of said means for scanning. 
     
     
         12 . The method according to  claim 11  wherein said first laser is a semiconductor laser diode configured for emitting said first wavelength of light at a wavelength of 780 nm. 
     
     
         13 . The method according to  claim 12  wherein said second laser is a semiconductor laser diode configured for emitting said visible wavelength, of light at a wavelength of 640 nm. 
     
     
         14 . The method according to  claim 13  further comprising emitting, by said fluorophores, of said excitation light at said second wavelength being in a band of wavelength centered upon 820 nm.