GDOT: gated diffuse optical tomography
A system for imaging a target embedded in a scattering media includes: one or more light sources that are pulsed lights at one or more wavelengths in a range of visible to near-infrared; a detector, including a photodetector array with a time-gating function, configured to collect a scattered light after a gate start time; and a processor configured to determine an image of the target based on the scattered light.
1 . A system for imaging a target embedded in a scattering media, comprising:
one or more light sources that are pulsed lights at one or more wavelengths in a range of visible to near-infrared;
a detector, including a photodetector array with a time-gating function, configured to collect a scattered light after a gate start time; and
a processor configured to use an algorithm to determine an image of the target based on the scattered light,
wherein
the system has a confocal geometry using spatial filtering through a pinhole rejecting out-of-plane scattered photons, and
the algorithm includes a forward model based on Monte Carlo and applying convolutional approximation.
2 . The system according to claim 1 , wherein the light sources and the detector are disposed on a surface of the scattering media.
3 . The system according to claim 1 , wherein the light sources and the detector are in form of an array of light source and detector pairs.
4 . The system according to claim 1 , wherein the detector is configured to stop collecting the scattered light after a gate close time.
5 . The system according to claim 4 , wherein gate start time and the gate close time for each source-detector pair are separately configured.
6 . The system according to claim 1 , wherein the light sources are configured to switch on simultaneously.
7 . The system according to claim 1 , wherein the light sources are configured to switch on one after another and the detector are configured to collect the scattered light correspondingly.
8 . The system according to claim 1 , wherein the time-gating function is hardware-based by an on-chip delay on the photodetector array.
9 . The system according to claim 1 , wherein the time-gating function is software-based by data processing.
10 . The system according to claim 1 , wherein the processor is configured to determine a two-dimensional image or a three-dimensional image of the target.
11 . The system according to claim 1 , wherein the target is a human tissue or an animal tissue.
12 . The system according to claim 1 , wherein the target is fluorescent.
13 . A method of imaging a target in a scattering media, comprising:
generating one or more light sources that are pulsed lights at one or more wavelengths in a range of visible to near-infrared;
detecting a scattered light after a gate start time with a detector, including a photodetector array with a time-gating function;
rejecting out-of-plane scattered photons in the scattered light using spatial filtering through a pinhole; and
determining an image of the target based on the scattered light, using an algorithm including a forward model based on Monte Carlo and applying convolutional approximation.
14 . The method according to claim 13 , wherein the detecting of the scattered light stops after a gate close time.
15 . The method according to claim 13 , wherein the light sources and the detector are in form of an array of light source and detector pairs.
16 . The method according to claim 13 , further comprises:
detecting two or more of the scattered light with different wavelengths or at different times; and
determining an image of the target based on a difference or a ratio of the two or more scattered lights.
17 . The method according to claim 13 , further comprises determining an image of the target based on a change in absorption or reflection properties of the target.