The photoacoustic (PA) technique is uniquely positioned for biomedical applications primarily due to its ability to visualize optical absorption contrast in deep tissue at ultrasound resolution. In this work, via both three-dimensional (3D) numerical simulations and in vivo experiments on human subjects, we investigated the possibility of PA measurement of human calcaneus bones in vivo in a non-invasive manner, as well as its feasibility to differentiate osteoporosis patients from normal subjects. The results from the simulations and the experiments both demonstrated that, when one side of the heel is illuminated by laser with light fluence under the ANSI safety limit, the PA signal generated in the human calcaneus bone can be detected by an ultrasonic transducer at the other side of the heel (i.e. transmission mode). Quantitative power spectral analyses of the calcaneus bone PA signals were also conducted, demonstrating that the microarchitectural changes in calcaneus bone due to osteoporosis can be detected, as reflected by enhanced high frequency components in detected PA bone signal. Further statistical analysis of the experimental results from 10 osteoporosis patients and 10 healthy volunteers showed that the weighted frequency as a quantified PA spectral parameter can differentiate the two subject groups with statistical significance.

光声 (PA) 技术在生物医学应用中具有独特的地位，主要是因为它能够以超声分辨率可视化深层组织中的光学吸收对比度。在这项工作中，我们通过三维（3D）数值模拟和人体体内实验，研究了以非侵入性方式在体内对人体跟骨进行PA测量的可能性，以及其区分骨质疏松症的可行性来自正常受试者的患者。仿真和实验结果均表明，当脚跟的一侧受到ANSI安全限值下光通量的激光照射时，另一侧的超声波换能器可以检测到人体跟骨中产生的PA信号。鞋跟侧（即传动方式）。还对跟骨 PA 信号进行了定量功率谱分析，表明可以检测到骨质疏松引起的跟骨微结构变化，如检测到的 PA 骨信号中增强的高频成分所反映的那样。对10名骨质疏松症患者和10名健康志愿者的实验结果进行进一步统计分析表明，加权频率作为量化的PA谱参数可以区分两个受试者组，具有统计学意义。