Electrical and Electronic Engineering, National University of Ireland Galway, Ireland; Translational Medical Device Lab, National University of Ireland Galway, Ireland.
Translational Medical Device Lab, National University of Ireland Galway, Ireland; School of Medicine, National University of Ireland Galway, Ireland.
Med Eng Phys. 2020 Apr;78:21-28. doi: 10.1016/j.medengphy.2020.01.014. Epub 2020 Feb 7.
The objective of this study is to determine whether in vitro dielectric properties of human trabecular bones, can distinguish between osteoporotic and osteoarthritis patients' bone samples. Specifically this study enlightens intra-patient variation of trabecular bone microarchitecture and dielectric properties, inter-disease comparison of bone dielectric properties, and finally establishes the correlation to traditional bone histomorphometry parameter (bone volume fraction) for diseased bone tissue. Bone cores were obtained from osteoporotic and osteoarthritis patients (n = 12). These were scanned using microCT to examine bone volume fraction. An open-ended coaxial probe measurement technique was employed to measure dielectric properties over the 0.5 - 8.5 GHz frequency range. The dielectric properties of osteoarthritis patients are significantly higher than osteoporotic patients; with an increase of 41% and 45% for relative permittivity and conductivity respectively. The dielectric properties within each patient vary significantly, variation in relative permittivity and conductivity was found to be greater than 25% and 1.4% respectively. A weak correlation (r = 0.5) is observed between relative permittivity and bone volume fraction. Osteoporotic and osteoarthritis bones can be differentiated based on difference of dielectric properties. Although these do not correlate strongly to bone volume fraction, it should be noted that bone volume fraction is a poor predictor of fracture risk. The dielectric properties of bones are found to be influenced by mineralization levels of bones. Therefore, dielectric properties of bones may have potential as a diagnostic measure of osteoporosis.
本研究旨在确定人小梁骨的体外介电特性是否可以区分骨质疏松症和骨关节炎患者的骨样本。具体而言，本研究阐明了小梁骨微观结构和介电特性的患者内变异性、骨介电特性的疾病间比较，最后建立了与病变骨组织传统骨组织形态计量学参数（骨体积分数）的相关性。从骨质疏松症和骨关节炎患者（n=12）中获得了骨芯。使用 microCT 对这些骨芯进行扫描，以检查骨体积分数。采用开放式同轴探头测量技术在 0.5-8.5GHz 频率范围内测量介电特性。骨关节炎患者的介电特性明显高于骨质疏松症患者；相对介电常数和电导率分别增加了 41%和 45%。每位患者内部的介电特性变化很大，发现相对介电常数和电导率的变化分别大于 25%和 1.4%。相对介电常数与骨体积分数之间观察到弱相关性（r=0.5）。可以根据介电特性来区分骨质疏松症和骨关节炎的骨骼。尽管这些与骨体积分数没有很强的相关性，但值得注意的是，骨体积分数是骨折风险的预测指标较差。骨骼的介电特性被发现受骨骼矿化水平的影响。因此，骨骼的介电特性可能有作为骨质疏松症诊断措施的潜力。
