Pulse Compression Favourable Thermal Wave Imaging Approach for Estimation of Osteoporosis: A Numerical Study

Infrared thermography is emerging as a vital noninvasive testing and evaluation tool in biomedical applications in order to identify surface and sub-surface abnormalities in biomaterials. Among various active infrared thermographic approaches, recently introduced aperiodic modulated pulse compression favorable thermographic techniques gained their importance as these approaches provide higher sensitivity and resolution for the extraction of anomalies located deep inside the material under test. Further, these techniques facilitate the usage of moderate heat inputs unlike traditional pulse-based thermographic methods and provide better depth resolution compared to lock-in thermography. This paper highlights the merits of novel pulse compression favorable frequency modulated thermal wave imaging method, a widely accepted non-stationary thermographic approach, to detect the severity of osteoporosis in modeled human bone. Detection is achieved by estimating the effusivity of the bone at different stages of osteoporosis with the help of correlation coefficient values obtained from the compressed pulse. A 3-D finite element analysis is carried out on a multilayer bone model with different thermo-physical properties of bone to characterize different stages of the osteoporosis. The obtained correlation-based results are compared with the extensively used principal component analysis approach.