Study on the piezoelectric properties of cancellous bone

本研究项目与电刺激髋关节内假体的发展密切相关。然而，研究结果有更广泛的含义。随着人口老龄化的增长，越来越多的整容手术可能是必要的。通常在内假体附近会发现较大的骨损伤。这种骨损伤也可能由疾病（如骨癌、酗酒造成的损伤）或事故造成。在之前的工作中，与骨科同事密切合作，开发了用于电刺激髋关节置换的电极系统的第一个设计。虽然电刺激促进骨骼生长的方法在原则上已经被发现和实现了近四十年，但关于其基本作用机制仍有许多问题有待解决。此外，经验刺激参数在临床上显示是有效的，但这些参数是否是最佳参数以及它们与生理过程的确切关系尚不清楚。因此，该项目的目标是准确地研究骨组织的压电行为，并指定适当的压电组织参数。在这里，将使用深田和安田的实验测试装置，他们在1957年首次实验证明了骨的压电特性，并且实验也将在计算机上重现。在模拟中，进行了广泛的参数研究。所得组织参数可用于其他工程，以便以往经验优化增产参数。

The research project is closely linked with the development of electro-stimulative endoprostheses for the hip joint. The results, however, have a much broader meaning. With a growing aging population, increasingly, revision surgery may be necessary. Often large bone damage is found in the immediate vicinity of the endoprosthesis. Such bone damage may also be caused by disease (eg, bone cancer, damages from alcohol abuse) or accident. In previous work, working closely with colleagues from orthopedics, a first design of an electrode system for a electro-stimulative hip replacement was developed. Although in principle the method of electrical stimulation to enhance bone growth has been known and attained for nearly four decades, many questions still remain open regarding the basic mechanism of action. Furthermore, the empirical stimulation parameters clinically showed to be effective, but it remains unclear whether these are the optimal parameters and how they are exactly related to the physiological processes. Therefore, the goal of this project is to accurately investigate the piezoelectric behavior of bone tissue and to specify appropriate piezoelectric tissue parameters. Here, an experimental test set-up of Fukada and Yasuda, who were the first in 1957 to demonstrate the piezoelectric properties of bone experimentally, will be used and the experiments are reproduced in silico as well. In the simulations, extensive parametric studies are carried out. The resulting tissue parameters should be used in other projects in order to optimize the stimulation parameters previously empirically.