Method and system for spectral unmixing of tissue images

Patent metadata

Field	Value
Publication number	US-9377613-B2
Application number	US-201214112354-A
Country	US
Kind code	B2
Filing date	May 4, 2012
Priority date	May 6, 2011
Publication date	Jun 28, 2016
Grant date	Jun 28, 2016

Abstract

A method and system for spectral demultiplexing of fluorescent species, such as quantum dots, conjugated with a biological tissue. The process of demultiplexing involves a non-liner regression based on curve-fitting of estimated spectra of the quantum dots and confidence intervals describing the parameters of such fitting curve for typical quantum dots.

First claim

The invention claimed is:

1. An apparatus for imaging a biological sample, comprising:
an input configured to receive at least one of imaging data acquired from and an image of the biological sample illuminated with first and second light sources located on the biological sample,
wherein said first light source has a first mean wavelength and a first spectral intensity described by a first statistical distribution,
wherein the second light source has a second mean wavelength and a second spectral intensity described by a second statistical distribution;
and

a processor adapted
(i) to receive the at least one of the imaging data and the image from the input, to non-linearly regress spectral data associated with the at least one of the imaging data and the image, and to generate data representing a target image of the biological sample at a first mean wavelength, and
(ii) to non-linearly regress the imaging data by fitting said imaging data to a function representing a combination of the first and second statistical distributions within confidence intervals corresponding to parameters of the first and second statistical distributions.

2. An apparatus according to claim 1 , further comprising a display operably connected to the processor and configured to display said target image of the biological sample.

3. An apparatus according to claim 2 , wherein the display is further configured to display an image of a light source, from the first and second light source, superimposed on said target image.

4. An apparatus according to claim 1 , wherein the image of the biological sample includes a multispectral image representing a plurality of spectrally-discrete images acquired in a corresponding plurality of discrete spectral bandwidths.

5. A method for transforming a pathology image, the method comprising:
receiving a set of images of a tissue sample having a first fluorescent species disposed thereon to acquire a spectral distribution of light intensity representing said tissue sample, wherein the receiving includes receiving a hypercube image of a tissue sample having a second fluorescent species;
modifying the acquired spectral distribution of intensity based on at least non-linear regression and data confidence intervals defined by said fluorescent species such as to derive a target distribution of light intensity representing said tissue image in a target spectral band; and
mapping said target distribution of light intensity into a visually-perceivable representation of an optical response of said tissue sample to light emitted by said fluorescent species.

6. A method according to claim 5 , further comprising
conjugating said fluorescent species with the surface of said tissue sample, wherein the conjugating is representative of a material structure of said tissue sample.

7. A method according to claim 5 , wherein the receiving the set of images includes receiving a plurality of two-dimensional (2D) images acquired in a plurality of discrete spectral bandwidths.

8. A method according to claim 5 , wherein the target spectral band and data confidence intervals define a fluorescence spectrum of said fluorescent species.

9. A method according to claim 8 , wherein the target spectral band defines a statistical distribution chosen from a group consisting of a Gaussian distribution, an inverse Gaussian distribution, an exponentially modified Gaussian distribution, a Gamma distribution, an inverse Gamma distribution, a logarithmic distribution, a t-distribution, a chi-square distribution, an f-distribution, an exponential distribution, a Laplace distribution, a Rayleigh distribution, a logistic distribution, a Maxwell distribution, a beta distribution, a Cauchy distribution, a Pareto distribution, a Levy distribution, an extreme value distribution, a Weibull distribution, and a Gumbell distribution.

10. A method according to claim 5 , wherein the mapping includes off-setting said target distribution of light intensity to derive an off-set light intensity distribution that is devoid of intensity distribution representing background image noise.

11. A method according to claim 10 wherein the off-setting includes:
assigning values of said target distribution of light intensity to elements of a data array;
determining a mean value of non-zero-element of said data array; and
zeroing elements of said data array that contain values lower than said mean value.

12. A method according to claim 10 , wherein the mapping further includes transforming the off-set light intensity distribution with a use of an order 1 cross matrix.

13. A method according to claim 5 wherein the modifying the acquired spectral distribution of intensity includes a non-linear regression of said acquired spectral distribution to a fitting function that defines a linear superposition of estimated fluorescent spectra of the first and second fluorescent species.

14. A method according to claim 13 , wherein at least some of parameters defining said estimated fluorescent spectra are fixed within said data confidence intervals.

15. A system for imaging a biological sample, the system comprising:
an optical system including:
an input configured to receive light from the biological sample that contains at least one light source on a surface thereof, said at least one light source including a quantum dot;
an output in optical communication with the input along at least one optical axis;
a spectrally-selective system disposed along the at least one optical axis between said input and said output and configured to process the light in a plurality of spectral bandwidths to form a plurality of image-forming signals corresponding to said plurality of spectral bandwidths;
a detector configured to receive, from the output, the plurality of image-forming signals corresponding to said plurality of spectral bandwidths and to form a plurality of images therefrom;

a computer processor operably connected with the detector; and
a tangible non-transitory storage medium having computer-readable instructions embedded therein which, when loaded onto the computer processor, cause the processor to:
derive, from the plurality of images, a spectral distribution of intensity representing the biological sample; and
apply a non-linear regression algorithm to a curve-fit equation to determine a distribution of intensity of light, emitted by said at least one light source, across the biological sample.

16. A system according to claim 15 , wherein said at least one light source includes a source of fluorescent light.

17. A system according to claim 15 , wherein said at least one light source includes multiple light sources and the curve-fit equation defines spectral distributions of light emitted by said multiple light sources.

18. A method for identifying a biological structure of a tissue sample with the use of a quantum dot (QD), the method comprising:
receiving image-forming light from the tissue sample, said image-forming light including light emitted by a QD species conjugated with a component of the tissue sample in accordance with a predetermined affinity between said QD species and said component;
analyzing said image-forming light in a plurality of spectral bands to determine a spectral distribution of intensity thereof;
estimating a spectral distribution of said QD species with a parametric fitting function and confidence intervals defining parameters of said parametric fitting function;
deriving image data representing spatial position of the component of the tissue sample in a spectral bandwidth

Assignees

• Bamford Pascal
• Otter Michael
• Kurnik Ronald T
• Ventana Med Syst Inc

Inventors

• Bamford Pascal
• Otter Michael
• Kurnik Ronald T

Classifications

• G02B21/361 Primary

  Optical details, e.g. image relay to the camera or image sensor (G02B21/364 takes precedence; illumination details G02B21/06 and subgroups) · CPC title

• G06V20/695 Primary

  Preprocessing, e.g. image segmentation · CPC title

• G06V10/58

  relating to hyperspectral data · CPC title

• G06K2009/4657

  Physics · mapped topic

• G06K9/0014

  Physics · mapped topic