Method for measuring scattering medium and apparatus for the same

Claim 1

A method of measuring a scattering medium comprising: emitting light having a plurality of predetermined wavelengths, λ j , said wavelengths having transport scattering coefficients, μ S ', in the scattering medium that are almost equal to each other; causing said light to be incident on the scattering medium at a light incidence position to propagate said light through the scattering medium; detecting said light which has propagated through the scattering medium at at least two photodetection points, with distances ρ i , between the light incidence position and each of the photodetection points being different from each other, to obtain at least three detected signals; and extracting internal information of the scattering medium with respect to each of said wavelengths of said light, by converting said at least three detected signals to at least three measured values, I(ρ i , λ j ), and then performing arithmetic processing to said at least three measured values, I(ρ i , λ j ), based on a simultaneous relation of the following equation: ##EQU7## where I(ρ i , λ j ) represents each of the measured values, i is an integer running from one to an integer greater than one, j is an integer running from one to an integer greater than one, μ effj represents an effective attenuation coefficient for light having wavelength λ j μ.sub.effj =(3μ.sub.aj (μ.sub.aj +μ.sub.S ')).sup.1/2, where μ aj is an absorption coefficient for light having wavelength λ j , μ S ' is the transport scattering coefficient, and z 0 =1/μ s '.

Claim 2

A method of measuring a scattering medium comprising: emitting light having a plurality of predetermined wavelengths, λ j , said wavelengths having transport scattering coefficients, μ S ', in the scattering medium that are almost equal to each other; causing said light to be incident on the scattering medium at a light incidence position to propagate said light through the scattering medium; detecting said light which has propagated through the scattering medium at at least two photodetection points, with distances ρ i , between the light incidence position and each of the photodetection points being different from each other, to obtain at least three detected signals; and extracting internal information of the scattering medium with respect to each of said wavelengths of said light, by converting said at least three detected signals to at least three measured values, I(ρ i , λ j ), and then performing arithmetic processing to said at least three measured values, I(ρ i , λ j ), based on a simultaneous relation of the following equation: ##EQU7## where I(ρ i , λ j ) represents each of the measured values, i is an integer running from one to an integer greater than one, j is an integer running from one to an integer greater than one, μ effj represents an effective attenuation coefficient for light having wavelength λ j μ.sub.effj =(3μ.sub.aj (μ.sub.aj +μ.sub.S ')).sup.1/2, where μ aj is an absorption coefficient for light having wavelength λ j , μ S ' is the transport scattering coefficient, and z 0 =1/μ s '.

Claim 7

An apparatus for measuring a scattering medium comprising: light-emitting means for emitting light having a plurality of predetermined wavelengths, λ j , said wavelength having transport scattering coefficients, μ S ', in the scattering medium that are almost equal to each other; light-incident means for causing said light to be incident on the scattering medium at a light incidence position to propagate said light through the scattering medium; photodetecting means for detecting said light which has been propagated through the scattering medium at at least two photodetection points, with distances, ρ i , between the light incidence position and each of the photodetection points being different form each other, to obtain at least three detected signals; and first arithmetic processing means for extracting internal information of the scattering medium with respect to each of said wavelengths of said light, by converting said at least three detected signals to at least three measured values, I(ρ i , λ j ), and then performing arithmetic processing to said at least three measured values, I(ρ i , λ j ), based on a simultaneous relation of the following equation: ln(I(ρ.sub.i,λ.sub.j))=ln(z.sub.0 /(2π))-3/2ln(z.sub.0.sup.2 +ρ.sub.i.sup.2)+ln(μ.sub.effj (z.sub.0.sup.2 +ρ.sub.i.sup.2).sup.1/2 +1)-μ.sub.effj (z.sub.0.sup.2 +ρ.sub.i.sup.2).sup.1/2 where I(ρ i , λ j ) represents each of the measured values, i is an integer running from one to an integer greater than one, j is an integer running from one to an integer greater than one, μ effj represents an effective attenuation coefficient for light having wavelength λ i μ.sub.effj =(3μ.sub.aj (μ.sub.aj +μ.sub.S ')).sup.1/2, where μ aj designates an absorption coefficient for light having wavelength λ j , μ S ' is the transport scattering coefficient, and z 0 =1/μ S '.

Claim 8

An apparatus for measuring a scattering medium comprising: light-emitting means for emitting light having a plurality of predetermined wavelengths, λ j , said wavelength having transport scattering coefficients, μ S ', in the scattering medium that are almost equal to each other; light-incident means for causing said light to be incident on the scattering medium at a light incidence position to propagate said light through the scattering medium; photodetecting means for detecting said light which has been propagated through the scattering medium at at least two photodetection points, with distances, ρ i , between the light incidence position and each of the photodetection points being different form each other, to obtain at least three detected signals; and first arithmetic processing means for extracting internal information of the scattering medium with respect to each of said wavelengths of said light, by converting said at least three detected signals to at least three measured values, I(ρ i , λ j ), and then performing arithmetic processing to said at least three measured values, I(ρ i , λ j ), based on a simultaneous relation of the following equation: ln(I(ρ.sub.i,λ.sub.j))=ln(z.sub.0 /(2π))-3/2ln(z.sub.0.sup.2 +ρ.sub.i.sup.2)+ln(μ.sub.effj (z.sub.0.sup.2 +ρ.sub.i.sup.2).sup.1/2 +1)-μ.sub.effj (z.sub.0.sup.2 +ρ.sub.i.sup.2).sup.1/2 where I(ρ i , λ j ) represents each of the measured values, i is an integer running from one to an integer greater than one, j is an integer running from one to an integer greater than one, μ effj represents an effective attenuation coefficient for light having wavelength λ i μ.sub.effj =(3μ.sub.aj (μ.sub.aj +μ.sub.S ')).sup.1/2, where μ aj designates an absorption coefficient for light having wavelength λ j , μ S ' is the transport scattering coefficient, and z 0 =1/μ S '.

Claim 14

An apparatus for measuring a scattering medium comprising: light-emitting means for emitting light having a plurality of predetermined wavelengths, λ j , of which transport scattering coefficients, μ S ', to the scattering medium are to be almost equal to each other; light incident means for causing said light to be incident on the scattering medium at a light incidence position to propagate said light through the scattering medium; photodetecting means for detecting said light which has been propagated through the scattering medium at a plurality of photodetection points, with distances, ρ i , between the light incidence position and each of the photodetection points being different from each other, to obtain at least three detected signals; and arithmetic processing means for extracting internal information of the scattering medium with respect to each of said wavelength of said light used, by converting said at least three detected signals to at least three measured values, I(ρ i , λ j ), and then performing arithmetic processing to said at least three measured values, I(ρ i , λ j ), based on a simultaneous relation of the following equation: ln(I(ρ.sub.i,λ.sub.j))=ln(z.sub.0 /(2π))-3/2ln(z.sub.0.sup.2 +ρ.sub.i.sup.2)+ln(μ.sub.effj (z.sub.0.sup.2 +ρ.sub.i.sup.2).sup.1/2 +1)-μ.sub.effj (z.sub.0.sup.2 +ρ.sub.i.sup.2).sup.1/2 where I(ρ i , λ j ) represents each of the measured values, i is an integer running from one to an integer greater than two, j is an integer running from one to an integer greater than two, μ effj represents an effective attenuation coefficient for light having wavelength λ j μ.sub.effj =(3μ.sub.aj (μ.sub.aj +μ.sub.S ')).sup.1/2, where μ aj designates an absorption coefficient for light having wavelength λ j , and z 0 =1/μ s ', wherein said at least three measured values, I(ρ i , λ j ), comprise I(ρ 1 , λ 1 ), I(ρ 2 , λ 1 ), I(ρ 1 , λ 2 ), and I(ρ 2 , λ 2 ); and the arithmetic processing means obtains a ratio of absorption coefficient, μ a1 , μ a2 as said internal information based on the following equation: ##EQU8##

Claim 15

An apparatus for measuring a scattering medium comprising: light-emitting means for emitting light having a plurality of predetermined wavelengths, λ j , of which transport scattering coefficients, μ S ', to the scattering medium are to be almost equal to each other; light incident means for causing said light to be incident on the scattering medium at a light incidence position to propagate said light through the scattering medium; photodetecting means for detecting said light which has been propagated through the scattering medium at a plurality of photodetection points, with distances, ρ i , between the light incidence position and each of the photodetection points being different from each other, to obtain at least three detected signals; and arithmetic processing means for extracting internal information of the scattering medium with respect to each of said wavelength of said light used, by converting said at least three detected signals to at least three measured values, I(ρ i , λ j ), and then performing arithmetic processing to said at least three measured values, I(ρ i , λ j ), based on a simultaneous relation of the following equation: ln(I(ρ.sub.i,λ.sub.j))=ln(z.sub.0 /(2π))-3/2ln(z.sub.0.sup.2 +ρ.sub.i.sup.2)+ln(μ.sub.effj (z.sub.0.sup.2 +ρ.sub.i.sup.2).sup.1/2 +1)-μ.sub.effj (z.sub.0.sup.2 +ρ.sub.i.sup.2).sup.1/2 where I(ρ i , λ j ) represents each of the measured values, i is an integer running from one to an integer greater than two, j is an integer running from one to an integer greater than two, μ effj represents an effective attenuation coefficient for light having wavelength λ j μ.sub.effj =(3μ.sub.aj (μ.sub.aj +μ.sub.S ')).sup.1/2, where μ aj designates an absorption coefficient for light having wavelength λ j , and z 0 =1/μ s ', wherein said at least three measured values, I(ρ i , λ j ), comprise I(ρ 1 , λ 1 ), I(ρ 2 , λ 1 ), I(ρ 1 , λ 2 ), and I(ρ 2 , λ 2 ); and the arithmetic processing means obtains a ratio of absorption coefficient, μ a1 , μ a2 as said internal information based on the following equation: ##EQU8##

Claim 18

A method of measuring a scattering medium comprising: emitting light having a plurality of predetermined wavelengths, λ j , said wavelengths having transport scattering coefficients, μ s ', in the scattering medium that are almost equal to each other; causing said light to be incident on the scattering medium at a light incidence position to propagate said light through the scattering medium; detecting said light which has propagated through the scattering medium at at least two photodetection points, with distances ρ i , between the light incidence position and each of the photodetection points being different from each other, to obtain at least three detected signals; and extracting internal information of the scattering medium with respect to each of said wavelengths of said light, by converting said at least three detected signals to at least three measured values, I(ρ i , λ j ), and then performing arithmetic processing to said at least three measured values, I(ρ i , λ j ), based on a simultaneous relation of the following equation: ln(I(ρ.sub.i,λ.sub.j))=ln(z.sub.o /(2π))-3/2ln(z.sub.o.sup.2 +ρ.sub.i.sup.2)+ln(μ.sub.effj (z.sub.o.sup.2 +ρ.sub.i.sup.2).sup.1/2 +1)-μ.sub.effj (z.sub.o.sup.2 +ρ.sub.i.sup.2).sup.1/2 where I(ρ i , λ j ) represents each of the measured values, i is an integer running from one to an integer greater than one, j is an integer running from one to an integer greater than one, μ effj represents an effective attenuation coefficient for light having wavelength λ j μ.sub.effj =(3μ.sub.aj (μ.sub.aj +μ.sub.s ')).sup.1/2, where μ aj is an absorption coefficient for light having wavelength λ j , μ S ' is the transport scattering cofficient, and z 0 =1/μ s ' wherein said at least three measured values, I(ρ i , λ j ), comprises I(ρ 1 , λ 1 ), I(ρ 2 , λ 1 ), I(ρ 1 , λ 2 ), and I(ρ 2 , λ 2 ); and a ratio of absorption coefficients, μ a1 , μ a2 is obtained as said internal information in said extracting step based on the following equation: ##EQU9##

Claim 19

A method of measuring a scattering medium comprising: emitting light having a plurality of predetermined wavelengths, λ j , said wavelengths having transport scattering coefficients, μ s ', in the scattering medium that are almost equal to each other; causing said light to be incident on the scattering medium at a light incidence position to propagate said light through the scattering medium; detecting said light which has propagated through the scattering medium at at least two photodetection points, with distances ρ i , between the light incidence position and each of the photodetection points being different from each other, to obtain at least three detected signals; and extracting internal information of the scattering medium with respect to each of said wavelengths of said light, by converting said at least three detected signals to at least three measured values, I(ρ i , λ j ), and then performing arithmetic processing to said at least three measured values, I(ρ i , λ j ), based on a simultaneous relation of the following equation: ln(I(ρ.sub.i,λ.sub.j))=ln(z.sub.o /(2π))-3/2ln(z.sub.o.sup.2 +ρ.sub.i.sup.2)+ln(μ.sub.effj (z.sub.o.sup.2 +ρ.sub.i.sup.2).sup.1/2 +1)-μ.sub.effj (z.sub.o.sup.2 +ρ.sub.i.sup.2).sup.1/2 where I(ρ i , λ j ) represents each of the measured values, i is an integer running from one to an integer greater than one, j is an integer running from one to an integer greater than one, μ effj represents an effective attenuation coefficient for light having wavelength λ j μ.sub.effj =(3μ.sub.aj (μ.sub.aj +μ.sub.s ')).sup.1/2, where μ aj is an absorption coefficient for light having wavelength λ j , μ S ' is the transport scattering cofficient, and z 0 =1/μ s ' wherein said at least three measured values, I(ρ i , λ j ), comprises I(ρ 1 , λ 1 ), I(ρ 2 , λ 1 ), I(ρ 1 , λ 2 ), and I(ρ 2 , λ 2 ); and a ratio of absorption coefficients, μ a1 , μ a2 is obtained as said internal information in said extracting step based on the following equation: ##EQU9##