Dartmouth College

University Health Network

Art, Advanced Research Technologies Inc.

Softscan Healthcare Group Ltd.

Frederic Leblond

Keith Douglas Paulsen

David W Roberts

Pablo A Valdes

Brian William Pogue

Kenneth M Tichauer

Robert W Holt

Brian Campbell Wilson

Michael Jermyn

Scott Christian Davis

Alex Hartov

Dax Kepshire

Niculae Mincu

Simon Fortier

Mario Khayat

Salim Djeziri

Xavier Intes

Olga Guilman

A method of generating corrected fluorescence data of concentrations of a targeted fluorophore in tissue of a subject includes administering first and second fluorescent contrast agents to the subject, the first contrast agent targeted to tissue of interest, the second agent untargeted. The tissue is illuminated with light of a first stimulus wavelength and first data is acquired at an appropriate emissions wavelength; the tissue is illuminated at a second stimulus wavelength and second data is acquired at a second emissions wavelength associated with the second agent, the first and second emissions wavelength differ. Difference data is generated by subtracting the second data from the first data. A system provides for stimulus and capture at multiple wavelengths, with image storage memory and subtraction code, to perform the method. Corrected data may form an fluorescence image, or is used to generate fluorescence tomographic images.

Method and apparatus for medical imaging using differencing of multiple fluorophores

An imaging system includes an illumination device for illuminating a target. A surgical microscope receives light from the target, the surgical microscope comprising at least one optical output port at which at least a portion of the received light is provided as an output from the surgical microscope. A tunable filter receives the portion of the received light provided as the output from the surgical microscope, the tunable filter being tunable to pass a filtered portion of the received light, the filtered portion of the received light having a plurality of wavelengths selected by the tunable filter and provided as output from the tunable filter. A high-resolution, broad-bandwidth electronic camera receives the light of a plurality of wavelengths selected by the tunable filter, the electronic camera converting the light of a plurality of wavelengths selected by the tunable filter to a plurality of electrical signals. A processor processes the plurality of electrical signals to form an image of the target.

Method and apparatus for quantitative hyperspectral fluorescence and reflectance imaging for surgical guidance

An imaging system, such as a surgical microscope, laparoscope, or endoscope or integrated with these devices, includes an illuminator providing patterned white light and/or fluorescent stimulus light. The system receives and images light hyperspectrally, in embodiments using a hyperspectral imaging array, and/or using narrowband tunable filters for passing filtered received light to an imager. Embodiments may construct a 3-D surface model from stereo images, and will estimate optical properties of the target using images taken in patterned light or using other approximations obtained from white light exposures. Hyperspectral images taken under stimulus light are displayed as fluorescent images, and corrected for optical properties of tissue to provide quantitative maps of fluorophore concentration. Spectral information from hyperspectral images is processed to provide depth of fluorophore below the tissue surface. Quantitative images of fluorescence at depth are also prepared. The images are displayed to a surgeon for use in surgery.

Method and apparatus for quantitative and depth resolved hyperspectral fluorescence and reflectance imaging for surgical guidance

A tomographic fluorescent imaging device for imaging fluorophores in biological tissues has a scanned laser for scanning the tissue and a camera for receiving light from the biological tissue at an angle to the beam at a second wavelength ten or more nanometers greater in wavelength than the wavelength of the laser. Use of both intrinsic and extrinsic fluorophores is described. Images are obtained at each of several positions of the beam. An image processing system receives the series of images, models a path of the beam through the tissue, and determines depth of fluorophore in tissue from intersections of the modeled path of the beam and the path of the received light. The laser is of 600 nm or longer wavelength, to provide penetration of tissue. The imaging device is used during surgery to visualize lesions of various types to ensure complete removal of malignant tumors. An alternative embodiment uses differences in intensity of fluorescent radiation from tissue as observed at different wavelengths to determine depth of fluorophore in tissue. An embodiment operates at multiple wavelengths to construct tomographic images of chromophores, such as hemoglobin, and is capable of dynamic imaging.

Method and apparatus for depth-resolved fluorescence, chromophore, and oximetry imaging for lesion identification during surgery

A fluorescence optical tomography system and method uses a photon migration model calculator for which absorption and reduced scattering coefficient values are determined for each source/detector pair. The coefficient values may be determined by measurement, in which a time resolved detector detects the excitation wavelength and generates temporal point spread functions from which the coefficient values are found. Alternatively, the coefficient values may be determined by calculating them from a dataset containing a spatial distribution of absorption and reduced scattering coefficients in a volume of interest. The fluorescence detection may be continuous wave, time resolved, or a combination of the two. An estimator uses a detected fluorescence signal and an estimated fluorescence signal to estimate the image values.

Fluorescence tomography using line-by-line forward model

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Montreal, Canada

Frederic Leblond