骨内压电电位的波形分析

Analysis of the Waveforms of Piezoelectric Voltage of Bone

骨内应力产生的电信号影响骨细胞的生长已被多方面证明,但其作用机理尚未完全确定．近年来,测试技术的进步为骨压电信号的实验研究提供了新手段．用超高输入阻抗的生物电压放大器测试研究了干牛骨试样在梯形波我荷作用下发生三点弯曲变形时压电电压的变化．测试发现,骨受力变形时产生的压电电荷在两电极间产生压电电压,同时电极间的电荷还会经过自身泄放．对应加栽稳态过程,两电极间的压电电荷会经自身泄放,从而表现为一松弛过程,0．1～0．4s后电压降为零,所以只能够在加载的动态过程测量到压电电压．显然在活体骨中压电电压也必然只会表现为脉冲的形式．

It has been demonstrated that the electric signals influence bone remodelling, however its mechanism has not been determined now. With the development of measurement technique in recent years, some suitable instruments are available in the study of bone piezoelectric signal. An ultra-high input impedance bioamplitier is used to test the piezoelectric voltages from dry bovine bone specimens, which deform in three points bending under trapezoid loading wave. The results show that voltages originate from piezoelectric polarization charge between two electrodes and the charge between these electrodes will release by self resistance. Therefore within the steady state of loading the voltages show relaxations, arise from the charge releases. The relaxation time is from 0.1 to 0.4 s, then the voltage drops to zero. The piezoelectric voltages only can be captured during the dynamic loading process, and it can be deduced that the piezoelectric voltages in live body occur in pulses.