Contactless inspection of reproductive cellular structures using optical measurement of biomechanical properties
A method of measuring at least one biomechanical property of a reproductive cellular structure is provided. The method includes illuminating the reproductive cellular structure with radiation; detecting at least a portion of radiation scattered from the illuminated reproductive cellular structure; analyzing a frequency spectrum of the detected scattered radiation to identify at least one Brillouin frequency shift in the frequency spectrum; and determining the at least one biomechanical property based on the Brillouin frequency shift. The method further includes determining a viability index of the reproductive cellular structure based on the at least one biomechanical property.
1. A method of measuring at least one biomechanical property of a reproductive cellular structure, the method comprising:
illuminating the reproductive cellular structure with radiation;
detecting at least a portion of radiation scattered from the illuminated reproductive cellular structure;
analyzing a frequency spectrum of the detected scattered radiation to identify at least one Brillouin frequency shift in the frequency spectrum;
obtaining a modulus of elasticity of at least a portion of the reproductive cellular structure based on the at least one Brillouin frequency shift; and
determining viability of the reproductive cellular structure based on the modulus of elasticity.
2. The method of claim 1 , further comprising obtaining a modulus of viscosity of at least a portion of the reproductive cellular structure.
3. The method of claim 2 , further comprising:
deriving the modulus of elasticity M′ using the following formula:
M
′
=
ρ
(
λ
2
n
)
2
Δ
v
B
2
wherein Δv B is the at least one Brillouin frequency shift, ρ is a density of the at least a portion of the reproductive cellular structure, λ is a vacuum wavelength of the radiation, and n is a refractive index of the at least a portion of the reproductive cellular structure.
4. The method of claim 3 , further comprising:
measuring a width of at least one Brillouin peak in the frequency spectrum of the detected scattered radiation;
deriving the modulus of viscosity M″ using the following formula:
M
″
=
ρ
(
λ
2
n
)
2
Δ
v
B
Γ
B
wherein Γ B is the width of the at least one Brillouin peak; and
deriving a complex modulus M* using the following formula:
M*=M′+i M″
wherein said i denotes a unit imaginary number which satisfies i 2 =−1.
5. The method of claim 2 , wherein at least one of the modulus of elasticity or the modulus of viscosity is determined with a sub-cellular resolution.
6. The method of claim 5 , further comprising:
determining at least one of the modulus of elasticity or the modulus of viscosity at a plurality of sub-cellular locations of the reproductive cellular structure.
7. The method of claim 1 , wherein the illuminating radiation is laser radiation.
8. The method of claim 7 , wherein the laser radiation includes at least one frequency component corresponding to a vacuum wavelength in a range of about 400 nm to about 800 nm.
9. The method of claim 1 , further comprising:
filtering out radiation that is elastically scattered from the reproductive cellular structure to facilitate detection of the at least one Brillouin frequency shift.
10. The method of claim 1 ,
wherein the frequency spectrum of the scattered radiation is obtained using a spectrometer.
11. A method comprising:
obtaining a modulus of elasticity of at least a portion of a reproductive cellular structure using Brillouin spectroscopy; and
determining a viability index of the reproductive cellular structure based on the modulus of elasticity.
12. The method of claim 11 , further comprising obtaining a modulus of viscosity of at least a portion of the reproductive cellular structure using the Brillouin spectroscopy.
13. The method of claim 11 , wherein the reproductive cellular structure includes one selected from the group consisting of an embryo, a morula, a blastula, gastrula, a zygote, an ovum, and an oocyte.
14. The method of claim 11 , wherein the reproductive cellular structure comprises an oocyte, and
wherein the method is performed to select the oocyte to be fertilized with a male gamete.
15. The method of claim 11 , wherein the reproductive cellular structure comprises a zygote, and
wherein the method is performed to select the zygote to proceed further into in vitro fertilization.
16. The method of claim 11 , wherein the reproductive cellular structure comprises an embryo, and
wherein the method is performed to select the embryo to be transferred to a uterus.