Systems and methods for hyperspectral analysis of cardiac tissue

Abstract

Systems and methods for hyperspectral analysis of cardiac tissue are provided. In some embodiments, a method for visualizing ablation lesions includes illuminating at one or more illumination wavelengths a surface of tissue having an ablation lesion; collecting a spectral data set comprising spectral images of the illuminated tissue acquired at multiple spectral bands each at one or more acquisition wavelengths; distinguishing between the ablation lesion and an unablated tissue based on one or more spectral differences between the ablation lesion and unablated tissue; and creating a composite image of the tissue showing the ablation lesion and the unablated tissue.

What is claimed is: 
     
         1 . A method for visualizing ablation lesions, the method comprising:
 illuminating at one or more illumination wavelengths a surface of tissue having an ablation lesion;   collecting a spectral data set comprising spectral images of the illuminated tissue acquired at multiple spectral bands each at one or more acquisition wavelengths;   distinguishing between the ablation lesion and an unablated tissue based on one or more spectral differences between the ablation lesion and unablated tissue; and   creating a composite image of the tissue showing the ablation lesion and the unablated tissue.   
     
     
         2 . The method of  claim 1  wherein the surface of tissue is an endocardial surface of atrial tissue. 
     
     
         3 . The method of  claim 1  wherein the one or more illumination wavelengths are between about 350 nm and about 400 nm. 
     
     
         4 . The method of  claim 1  wherein the one or more illumination wavelengths are between about 400 nm and about 700 nm. 
     
     
         5 . The method of  claim 1  wherein the one or more illumination wavelengths are between about 700 nm and about 900 nm. 
     
     
         6 . The method of  claim 1  wherein the one or more illumination wavelengths are below a range of acquisition wavelengths by between about 10 nm and about 50 nm. 
     
     
         7 . The method of  claim 1  further comprising filtering light returning from the illuminated heart tissue using a set of bandpass filters. 
     
     
         8 . The method of  claim 1  further comprising filtering light returning from the illuminated heart tissue using a tunable filter. 
     
     
         9 . The method of  claim 1  further comprising detecting a light returning from the illuminated heart tissue, the detected light including fluorescence, reflectance and scattering components, wherein the fluorescence component being detected at the acquisition wavelength between about 400 nm to about 500 nm, the reflectance component being detected at the acquisition wavelength between about 450 nm and about 700 nm, and the scattering component detected across the entire visible spectra. 
     
     
         10 . The method of  claim 1  further comprising classifying each pixel of a digital image of the illuminated tissue as either ablated or unablated tissue. 
     
     
         11 . The method of  claim 10  further comprising constructing a depth map of the ablation lesion from the image based on a bulk density of the pixels of the digital image classified as ablated tissue. 
     
     
         12 . The method of  claim 1  further comprising identifying the ablated lesion as a lesion created by radiofrequency; and setting the illumination wavelength to between about 400 nm and about 700 nm and the acquisition wavelength to about 400 nm and about 700 nm. 
     
     
         13 . The method of  claim 1  further comprising identifying the ablation lesion as a lesion created by cryoablation or radiofrequency; and setting the illumination wavelength to between about 350 nm to 400 nm and the range of acquisition wavelengths to about 380 nm to 500 nm. 
     
     
         14 . The method of  claim 1  further comprising illuminating at one or more illumination wavelengths a specific wavelength or using wide band illumination with a known spectral distribution. 
     
     
         15 . The method of  claim 1  further comprising distinguishing between the ablation lesion and an unablated tissue based on one or more spectral differences of a pre-selected set of multiple spectral differences. 
     
     
         16 . A method for visualizing atrial ablation lesion, the method comprising:
 illuminating one or more discrete illumination wavelengths a surface of heart tissue having an ablation lesion;   collecting a spectral data from the illuminated heart tissue;   distinguishing between the ablation lesion and an unablated tissue based on one or more spectral differences between the ablation lesion and unablated tissue; and   creating an image of the heart tissue illustrating ablated tissue and unablated tissue.   
     
     
         17 . The method of  claim 16  wherein the collecting of the spectral data includes one of a detector-based Hyperspectral Imaging (HSI) system, a detector-based HSI system using static devices with tunable filters, an alternative source-based HSI including a changeable wavelength of illuminating light or some combination thereof. 
     
     
         18 . The method of  claim 16  wherein the collected spectra data is one of matched to existing spectral libraries, subjected to a principal component analysis, subjected to related principal component analysis algorithms or some combination thereof. 
     
     
         19 . A system for imaging tissue comprising:
 a catheter having a distal region and a proximal region;   a light source;   an optical fiber extending from the light source to the distal region of the catheter to illuminate a tissue having a lesion site in proximity to the distal end of the catheter;   an image bundle for collecting light reflected from the illuminated tissue;   a camera connected to the image bundle, the camera being configured to gather hyperspectral data comprising spectral images of the illuminated tissue acquired at multiple spectral bands or at each illumination wavelength;   an image processing unit in communication with the camera, the unit being configured to distinguish between the ablation lesion and an unablated tissue based on one or more spectral differences between the ablation lesion and unablated tissue and creating an image of the heart tissue illustrating the ablated tissue and the unablated tissue.   
     
     
         20 . The system of  claim 19  wherein the light source includes one of one or more bands, a set of switchable light sources or a light source with at least one tunable filter. 
     
     
         21 . A system for imaging heart tissue comprising:
 an illumination device configured to illuminate a tissue having a lesion site;   an imaging device configured to gather hyperspectral data;   an image processing unit in communication with the imaging device, the image processing unit configured to processing gathered hyperspectral data to generate an image that reveals the lesion site,   wherein the generated image enabling to distinguish between an ablation lesion and an unablated tissue based on one or more spectral differences between the ablation lesion and unablated tissue and creating an resulting image of the heart tissue illustrating the ablated tissue and the unablated tissue.   
     
     
         22 . The system of  claim 21  wherein the imaging device is configured to gather hyperspectral data dependent by either spectrally selective illumination or dependent spectrally selective filtering prior to image acquisition.