抄録
Bone tissue is composed of bone matrix. Bone matrix is mainly composed of apatite and type I collagen. Apatite is inorganic matrix. Type I collagen is organic matrix. Therefore, microscopic molecular structure and crystal structure are related to macroscopic bone stress. Structural information of organic and inorganic state are useful to estimate bone stress. Raman spectroscopy is non-invasive structural analysis method based on molecule inherence Raman scattered light generated by irradiating the laser with a single wavelength to the material. In previous study, the relationship between Raman shift and mechanical stress was investigated. Raman spectrum was obtained from single measurement point. However, the change of Raman shift related to stress is varied at different measurement point. In this study, to improve the repeatability of mechanical analysis by using Raman spectroscopy, we propose the statistical method by Raman imaging system. Raman spectroscopies for bovine cortical bone specimens were carried out under tensile load. Three types of specimens were prepared for circumferential irradiation under axial tensile loading, radial irradiation under axial tensile loading and radial irradiation under circumferential tensile loading. Measurement area was 60 × 60 μm, scanning interval was 1.5 μm and measurement points was 41 × 41 points. Changes of Raman shift of specific 7 peaks derived from apatite or type I collagen under stress were analyzed. Changes of Raman shift with applied tensile stress at bone circumferential direction were lager than changes of Raman shift applied tensile stress at bone axial. The difference between measurements of radial section and circumferential were mostly little.
