Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
214 words
Method for the spectroscopic examination of a biological tissue comprising the steps of: (a) irradiating a tissue region with non-ionizing radiation having an intensity l 0 (λ) and a wavelength λ while varying said wavelength; (b) registering a spectrum l(λ) from an element selected from the group consisting of a transmission spectrum and a reflection spectrum by an element selected from the group consisting of measuring the intensity of the radiation transmitted by the tissue and radiation reflected by the tissue dependent on the wavelength λ; (c) employing an analytical function to approximately describe a quantity from an element selected from the group consisting of said spectrum l(λ), said spectrum l(λ)/l 0 (λ) normed to the incident radiation intensity, and log {l(λ)/l 0 (λ)}, said analytical function having a Beer-Lambert dependency on a first parameter describing the absorption properties of the tissue and a second parameter representing a slice thickness, the first parameter being dependent on identified concentrations c i of a plurality i of selected tissue components employed as fit parameters as well as on specific absorption coefficients α i (λ) according to the relationship ##EQU6## with an average path length L(λ) of the photons in the tissue comprising the second parameter; and (d) comparing the identified concentration c i to reference values.
Claim 2
Dependent Claim
214 words
Method for the spectroscopic examination of a biological tissue comprising the steps of: (a) irradiating a tissue region with non-ionizing radiation having an intensity l 0 (λ) and a wavelength λ while varying said wavelength; (b) registering a spectrum l(λ) from an element selected from the group consisting of a transmission spectrum and a reflection spectrum by an element selected from the group consisting of measuring the intensity of the radiation transmitted by the tissue and radiation reflected by the tissue dependent on the wavelength λ; (c) employing an analytical function to approximately describe a quantity from an element selected from the group consisting of said spectrum l(λ), said spectrum l(λ)/l 0 (λ) normed to the incident radiation intensity, and log {l(λ)/l 0 (λ)}, said analytical function having a Beer-Lambert dependency on a first parameter describing the absorption properties of the tissue and a second parameter representing a slice thickness, the first parameter being dependent on identified concentrations c i of a plurality i of selected tissue components employed as fit parameters as well as on specific absorption coefficients α i (λ) according to the relationship ##EQU6## with an average path length L(λ) of the photons in the tissue comprising the second parameter; and (d) comparing the identified concentration c i to reference values.
Claim 3
Dependent Claim
31 words
Method according to claim 1, characterized in that the analytical function is established by the equation l(λ)=l.sub.0 (λ)·x.sub.1 ·exp{-μ.sub.s (λ)·L(λ)·x.sub.2 } whereby x 1 , x 2 reference wavelength-independent correction factors.
Claim 4
Dependent Claim
49 words
Method according to claim 1 wherein the average path length L(λ) of the photons in the tissue is dependent on a thickness d of the transilluminated tissue, a reduced scatter coefficient μ s '(λ) and on the absorption coefficient μ a of the tissue according to the relationship ##EQU7##
Claim 5
Dependent Claim
30 words
Method according to claim 1 wherein the tissue is approximated as a uniform mixture of water, fat, hemoglobin and oxyhemoglobin, whereby volume parts of water and fat supplement to 100%.
Claim 6
Dependent Claim
37 words
Method according to claim 1 comprising modulating the intensity of the incident radiation at a modulation frequency and registering an amplitude of an output signal of a detector system exhibiting the modulation frequency dependent on the wavelength.