湿骨内压电信号和流动电位耦合关系的实验研究

The electromechanical properties of bone include piezoelectricity and streaming potentials, which are called as SGPs that stress generated potentials. An influential view thinks that the reason of adsorption and growing of bone (remodeling) depending on the potentials generated by stress in bone instead of the stress itself. The SGPs can be found in living and unloving bone and are the intrinsic material properties of bone, which are independent of cell vitality and metabolism. This proposal intends to study the coupling relationship between piezoelectricity and streaming potentials of bone experimentally. Firstly, we will measure the streaming potentials as buffer solution flowing through the microspaces in bone. Then we measure the piezoelectric signals as bone samples are bent by an external force. Finally, we measure the electric signals, including both piezoelectric streaming potentials, as the bone bent and with buffer solution flowing through its microspaces. We hope that the coupling relationship between the two signals can be determined from analyzing the three measured potentials. This study is helpful for understanding the dependence of bone growing on the electric signals and of positive action on clinic application and medical instrument development, which may offer a promising aid for the economy of our country.

湿骨内压电信号和流动电位耦合关骨的力电性质包括压电效应和流动电位。普遍的观点认为应力影响骨吸收和生长（骨重建）的原因可能是应力在骨内产生电位，即电信号可能加速骨生长或促进骨折愈合。骨的压电效应和流动电位统称为骨内应力产生的电位，简称SGPs。它和体内新陈代谢无关，不依赖于细胞的活力，不但存在于生命状态的骨中也存在于非生命状态的骨中，属于骨的材料性质。 此项申请拟研究流动电位和压电信号二者之间的耦合关系。采用对比实验的方法，分别测量缓冲液流过骨试样微孔隙时的流动电位，骨发生弯曲变形时的压电信号和试样既发生变形又有液体流过时的力电信号，此信号包括压电信号和流动电位。目的是分析上述信号的特点，确定二者之间的耦合关系，进而确定骨陷窝周围的力电环境。 此项研究的完成有助于解决骨的生长对力和电信号的依赖关系这一基本问题，会对临床医学治疗及医疗仪器开发有指导意义，在我国的国民经济发展中有良好的发展前景。

主要研究内容是骨内压电信号和流动电位之间的耦合分析，为此研制了可同时测量湿骨压电性和流动点位的实验装置，利用此装置测量骨内压电信号和流动电位，实现两种信号之间的解耦。同时扩展了内容，研究了骨的逆力电性质，这是了解骨的力电性质的重要一步。内容有：发现分离电极电场会诱导骨弯曲，骨试样的挠度与电场方向没有关系，与所加电场电压或电场强度平方成正比，表现为电致伸缩效应；当外电场突然施加到骨试样时，有机的胶原与无机成分羟基磷灰石对骨的弯曲响应的作用不同，本质是骨内极化既包括空间电荷极化也包括电曲极化；附着电极电场电场也会在骨内部诱导应力或应变，而弯曲方向依赖于骨内的位置；附着电极的交变电场，可激励骨发生非线性超谐波振动，振动特征反映了骨的微结构特点；当电场激励频率超过4000Hz时，骨试样不再振动而是发生弯曲，这也是骨特有的性质；所有发现的现象都与骨内极化电荷的分布有关，为此搭建了一套电声脉冲电荷分布测量系统，测量骨内极化电荷沿厚度的分布。