Exploration of Audible Sound, Time-Delay Spectroscopy in Assessing Bone Health

Osteoporosis is a progressive skeletal disorder characterized by decreased bone density (BD) and structural deterioration of bone tissue, leading to increased fracture risk. It affects over 200 million individuals globally and contributes to approximately 8.9 million fractures each year. High-risk populations include postmenopausal women, individuals with diabetes, and the elderly, demographics prevalent in rural regions such as Maine, where access to diagnostic imaging is limited. Current BD assessment modalities, quantitative computed tomography (QCT), dual-energy X-ray absorptiometry (DXA), and quantitative ultrasound (QUS), are clinically effective but have notable drawbacks. QCT and DXA expose patients to ionizing radiation and require costly, specialized equipment, while QUS suffers from measurement variability due to sensitivity to soft tissue composition and reliance on external coupling mediums. This project explores the development of a portable, radiation-free, and cost-effective diagnostic device using audible sound and time-delay spectroscopy (TDS) for assessing calcaneal BD. The proposed system employs a dual-path configuration to improve sensitivity to internal bone morphology while eliminating the need for external coupling media, enhancing ease of use and measurement consistency. Preliminary testing of iterative prototypes included evaluation of signal phase and frequency detection, interface coupling force measurement, and material geometry analysis. Results demonstrated that audible sound attenuation is responsive to variations in bone-like materials and that the device reliably captures acoustic parameters and structural geometries. If validated against established QUS and DXA techniques, this technology could offer a clinically viable solution for routine osteoporosis screening, particularly in underserved and resource-constrained healthcare settings.