Bone samples' behavior in sunlight, IR light, and temperature increase with FEM simulation.

Biological and environmental factors produce biochemical processes that modify the bone structure. A few studies have attempted to show the adverse biological effects of sun radiation. The bone tissue exposures to infrared and sunlight radiation are analyzed by using focused sound, characterization spectroscopy techniques, and image processing. The study is complemented with a finite element method simulation on temperature behaviors. The crystal morphology on the bone hydroxyapatite and functional groups was characterized by X-ray diffraction and infrared spectroscopy. The infrared spectra confirmed the hydroxyl group of bovine hydroxyapatite, amines, and lipids are also correlated with modifications of the hydroxyapatite. The diffractograms showed the characteristic peaks of hydroxyapatite, with the main intensity at 2θ = 32.02°. Bone samples exposed to sun radiation presented a peak at 2θ = 27.5°, evidencing the possible formation of ß-TCP y α-TCP. The analysis with the spectroscopy techniques about the structural changes in the samples suggests interpreting an increase of sound obtained by expanding the exposure time. It is possible to verify that there are some structural changes in the bone samples due to exposure to non-ionizing radiation. These results show an increase in the registered intensity sound correlated with the interpretation of the structural changes of bone. Thanks to the different novel analysis techniques established in the present study, it could establish the changes that experienced the bone structure under different sources of radiation, which will help to better detect scenarios of bone deficiency.

Focused ultrasound simulation through cortical bone by finite element method.

Bone tissue is constantly changed adapting to its mechanical environment and capable of repairing itself. Ultra-sound has recently been used as a diagnostic technique to assess bone conditions. To optimize the experimental model as best as possible computational simulation techniques have been focused on clinical applications in bone. This study aims to analyze by finite element method the propagation of ultrasound waves along the cortical bone. The wave propagation phenomenon is well studied and described by the Helmholtz equation. The first part of the work analytically solves the Helmholtz equation, and later the COMSOL Multiphysics software is used. It was established a cylindrical geometry as the bone sample. The software analyzes with "Pressure Acoustic, Frequency Domain" module. An extremely fine mesh is used for the solution in order not to lose information. According to the analytical solution, the results show the behavior of the acoustic pressure waves throughout the samples. In addition, attenuation coefficients are calculated for biological materials such as bone and muscle. Simulation methods allow to analyze adjustable parameters in the development of new devices. Thus, optimizing resources and allowing the researcher to better understanding the problem to be solved.