Cartilage-tissue analysis device
A cartilage-tissue analysis device includes: an illuminating fiber that emits, from a light-emission surface thereof, laser light coming from a laser light source; two light-collecting fibers that receives scattered light at respective light-receiving surfaces the distances from which to the light-emission surface differ from each other; and detector that detects Raman spectra from the scattered light received by the light-collecting fibers. The cartilage-tissue analysis device is configure to: calculate an intensity ratio between two Raman bands originating from cartilage tissue and subchondral bone tissue, respectively, from each of the two Raman spectra; and evaluate a state of the cartilage tissue by selecting, from among the two Raman spectra, a Raman spectrum the intensity ratio of which is within a prescribed range and that analyzes the selected Raman spectrum, to analyze the selected Raman spectrum.
1. A cartilage-tissue analysis device for analyzing a first Raman spectrum and a second Raman spectrum,
wherein a detector is configured to detect the first Raman spectrum from scattered light from a biological tissue, including cartilage tissue, received by a light-receiving surface at a distal end of a first light-collecting fibers,
wherein the detector is configured to detect the second Raman spectrum from the scattered light from the biological tissue received by a light-receiving surface at a distal end of a second light-collecting fibers,
wherein the biological tissue scatters laser light emitted towards the biological tissue from a light-emission surface at a distal end of an illuminating fiber as the scattered light, and
wherein each of the first and the second Raman spectra includes a first Raman band corresponding to the cartilage tissue and a second Raman band corresponding to subchondral bone tissue,
the cartilage-tissue analysis device comprising:
one or more processors each comprising hardware, wherein the one or more processors are configured to:
calculate a first intensity ratio between the first Raman band and the second Raman band of the first Raman spectrum;
determine whether the first intensity ratio is greater than a predetermined threshold;
in response to determining that the first intensity ratio is greater than the predetermined threshold, select the first Raman spectrum;
calculate a second intensity ratio between the first Raman band and the second Raman band of the second Raman spectrum;
determine whether the second intensity ratio is greater than the predetermined threshold;
in response to determining that the second intensity ratio is greater than the predetermined threshold, select the second Raman spectrum; and
evaluate a state of the cartilage tissue by analyzing the one or more the first Raman spectrum selected and the second Raman spectrum selected.
2. The cartilage-tissue analysis device according to claim 1 , wherein, when the first intensity ratio or the second intensity ratio is calculated, the calculating of the first intensity ratio or the second intensity ratio uses an intensity of a Raman band of type II collagen as the Raman band corresponding to the cartilage tissue and uses an intensity of a Raman band of hydroxyapatite as the Raman band corresponding to the subchondral bone tissue.
3. The cartilage-tissue analysis device according to claim 1 , wherein, when the first intensity ratio or the second intensity ratio is calculated, the calculating of the first intensity ratio or the second intensity ratio uses an intensity of a Raman band of glycosaminoglycan as the Raman band corresponding to the cartilage tissue and uses an intensity of a Raman band of hydroxyapatite as the Raman band corresponding to the subchondral bone tissue.
4. The cartilage-tissue analysis device according to claim 1 , wherein the evaluating of the state of the cartilage tissue calculates an intensity ratio between two types of Raman bands that originate from the cartilage tissue and that have Raman shifts different from each other in the selected Raman spectrum and evaluates the state of the cartilage tissue on a basis of the calculated intensity ratio.
5. The cartilage-tissue analysis device according to claim 4 , wherein the two types of Raman bands are a Raman band of collagen and a Raman band of glycosaminoglycan.
6. The cartilage-tissue analysis device according to claim 4 , wherein the two types of Raman bands are a Raman band of amino acid contained in proteins and a Raman band of glycosaminoglycan.
7. The cartilage-tissue analysis device according to claim 4 , wherein the two types of Raman bands are a Raman band of amino acid contained in proteins and a Raman band of collagen.
8. The cartilage-tissue analysis device according to claim 4 , wherein the two types of Raman bands are a Raman band of a methylene group and a Raman band of a methyl group.
9. The cartilage-tissue analysis device according to claim 4 , wherein the two types of Raman bands are Raman bands of amide III in collagen.
10. The cartilage-tissue analysis device according to claim 1 , wherein, by performing multivariate analysis of the selected Raman spectra, evaluating the state of the cartilage tissue estimates an amount of glycosaminoglycan contained in the cartilage tissue or calculates a feature quantity of the Raman spectra by multivariate analysis , said feature quantity correlating with the amount of glycosaminoglycan, and evaluates the state of the cartilage tissue on a basis of the obtained amount of glycosaminoglycan or the feature quantity of the Raman spectra.
11. The cartilage-tissue analysis device according to claim 1 , wherein, by performing multivariate analysis of the selected Raman spectra, evaluating of the state of the cartilage tissue estimates an amount of collagen contained in the cartilage tissue or calculates a feature quantity of the Raman spectra by multivariate analysis, said feature quantity correlating with the amount of collagen, and evaluates the state of the cartilage tissue on a basis of the obtained amount of collagen or the feature quantity of the Raman spectra.
12. The cartilage-tissue analysis device according to claim 1 , wherein, by performing multivariate analysis of the selected Raman spectra, evaluating of the state of the cartilage tissue estimates an amount of cells contained in the cartilage tissue or calculates a feature quantity of the Raman spectra by multivariate analysis, said feature quantity correlating with the amount of cells, and evaluates the state of the cartilage tissue on a basis of the obtained amount of cells or the feature quantity of the Raman spectra.
13. The cartilage-tissue analysis device according to claim 1 , wherein, from each of the first Raman spectrum and the second Raman spectrum, the evaluating of the state of the cartilage tissue calculates an intensity ratio between a Raman band originating from the cartilage tissue and a Raman band originating from the subchondral bone tissue and estimates the thickness of the cartilage tissue on a basis of the two calculated intensity ratios.
14. The cartilage-tissue analysis system comprising:
the cartilage-tissue analysis device according to claim 1 ;
the illuminating fiber;
the first light-collecting fiber;
the second light-collecting fiber; and
the detector.
15. A non-transitory computer-readable storage device storing instructions for analyzing a first Raman spectrum and a second Raman spectrum,
wherein a detector is configured to detect the first Raman spectrum from scattered light from a biological tissue, including cartilage tissue, received by a light-receiving surface at a distal end of a first light-collecting fiber,
wherein the detector is configured to detect the second Raman spectrum from the scattered light from the biological tissue received by a light-receiving surface at a distal end of a second light-collecting fiber,
wherein the biological tissue scatters laser light emitted towards the biological tissue from a light-emission surface at a distal end of an illuminating fiber as the scattered light, and
wherein each of the first and the second Raman spectra includes a first Raman band corresponding to the cartilage tissue and a second Raman band corresponding to subchondral bone tissue,
the instructions causing a computer to perform, at least:
calculate a first intensity ratio between the first Raman band and the second Raman band of the first Raman spectrum;
determine whether the first intensity ratio is greater than a predetermined threshold;
in response to determining that the first intensity ratio is greater than the predetermined threshold, select the first Raman spectrum;
calculate a second intensity ratio between the first Raman band and the second Raman band of the second Raman spectrum;
determine whether the second intensity ratio is greater than the predetermined threshold;
in response to determining that the second intensity ratio is greater than the predetermined threshold, select the second Raman spectrum; and
evaluate a state of the cartilage tissue by analyzing the one or more the first Raman spectrum selected and the second Raman spectrum selected.