Light reflection imaging method for acquiring optical parameters and microstructures of tissues in a large area

• US 10,288,562 B2
• Filed: 10/29/2015
• Issued: 05/14/2019
• Est. Priority Date: 10/15/2015
• Status: Active Grant

• Current Assignee: Wenzhou Medical University
• Original Assignee: Wenzhou Medical University
• Inventors: Xu, Min
• Primary Examiner(s): Akanbi, Isiaka O
• Application Number:
  US15/768,445
• Publication Number:
  US 20180321148A1
• Time in Patent Office: 1,293 Days
• Field of Search: 356334-338, 356445-446, 356369
• CPC Class Codes: A61B 5/00 Measuring for diagnostic purposes radiation diagnosis A61B6/00; diagnosis by ultrasonic, sonic or infrasonic waves A61B8/00; Identification of persons
• CPC Class Codes: A61B 5/0059 using light, e.g. diagnosis by transillumination, diascopy, fluorescence A61B5/0093, A61B5/1455, A61B5/02416 and A61B5/0261 take precedence
• CPC Class Codes: A61B 5/0075 by spectroscopy, i.e. measuring spectra, e.g. Raman spectroscopy, infrared absorption spectroscopy A61B5/0071 takes precedence
• CPC Class Codes: G01N 21/4738 Diffuse reflection precedence is given to G01N21/55 - G01N21/57 if specular component is taken into consideration, e.g. also for testing fluids, fibrous materials
• CPC Class Codes: G01N 21/4795 spatially resolved investigating of object in scattering medium in vivo A61B
• CPC Class Codes: G01N 21/55 Specular reflectivity

Abstract

A light reflection imaging method for acquiring optical parameters and microstructures of tissues in a large area, comprising a turbid medium reflectance calculation method applicable at a random spatial distance and in an entire spatial frequency domain, and a method of measuring the reflectance of a turbid medium at high and low spatial frequencies and inverting the obtained light reflectance to obtain optical parameters of the medium. The inversion method may be a table lookup method or a formula fitting method. The measurement of sub-diffuse and diffuse light reflectance of the turbid medium can be used for measuring the optical properties of the turbid medium and microstructures including a phase function and the like in a large area.

Claims

1. A light reflection imaging method for acquiring optical parameters and microstructures of tissues in a large area, comprising:

directing a collimated beam of light at a forward peak scattering medium;

detecting a first order non-diffuse photon in a backscattered direction;

detecting a second order non-diffuse photon in the backscattered direction;

detecting a diffuse photon in the backscattered direction;

determining a low-frequency reflectance formula

I_snake(q)+I_diffuse(q)+μ

_b/2μ

_t

and a high-frequency reflectance formula

I_SAA(q),

according to

2. The light reflection imaging method for acquiring optical parameters and microstructures of tissues in a large area according to claim 1, wherein the inversion method is a table lookup method or a formula fitting method.

3. The light reflection imaging method for acquiring optical parameters and microstructures of tissues in a large area according to claim 1, wherein a high-frequency reflectance formula

4. The light reflection imaging method for acquiring optical parameters and microstructures of tissues in a large area according to claim 3, wherein, assuming that p_Forward(θ

) satisfies Gaussian distribution, the random phase function p(θ

) of the scattering medium is modified into;

5. The light reflection imaging method for acquiring optical parameters and microstructures of tissues in a large area according to claim 3, wherein when ql_t>

>

1 and p<

<

l_t, the high-frequency reflectance can be simplified into

6. The light reflection imaging method for acquiring optical parameters and microstructures of tissues in a large area according to claim 5, wherein parameters characterizing the microstructure of the system or a combination of these parameters are/is directly obtained using the high-frequency formulas I_SAA (q) and I_SAA (ρ

) from high-frequency reflection maps of two or more media.

7. The light reflection imaging method for acquiring optical parameters and microstructures of tissues in a large area according to claim 1, wherein the low-frequency reflectance formulas

8. The light reflection imaging method for acquiring optical parameters and microstructures of tissues in a large area according to claim 7, wherein the absorption coefficient and the reduced scattering coefficient are directly obtained using the formula I_{snake, diffuse}(q) or I_{snake, diffuse}(ρ

) from a low-frequency reflection map of one or more media.

9. The light reflection imaging method for acquiring optical parameters and microstructures of tissues in a large area according to claim 1, wherein in addition, the sub-diffuse scattering light reflectance can be first fitted to obtain the values of μ

_b/μ

_s, μ

_a/μ

_s and Θ

/μ

_s;

after the μ

_b/μ

_s is determined, it is supposed that

g=(1−

2p_b)(1−

Θ

²/2);

and then the sub-diffuse light and diffuse light reflectance distribution is fitted using least squares fitting to obtain all optical parameters.