【摘要】 低频脉冲磁场的生物学效应已经在医学领域有了广泛应用,许多研究者开始关注脉冲磁场对心脏的生物学效应。目前应用于心脏刺激的磁场频率都是固定的,而不是根据心脏的生理特征实现的磁场刺激。基于心电信号的特征,提出了在心电图的特定位置同步刺激心脏,即根据需要设定磁场刺激选择在P波、R波、T波。根据这一思想设计并制造了一台R波同步触发的脉冲磁场刺激器。该系统检测被刺激者的心电信号,自动提取R波,用R波作为脉冲磁场工作的触发信号,控制磁场放电的时间,磁场的波形通过软件自动设定。该刺激器的特点是不控制电容的充电过程,而直接控制线圈的放电过程,为了能够跟踪心电信号的频率,并且控制磁场的波形,本文没有采用传统的可控硅控制,而是采用绝缘栅双极型晶体管(IGBT)控制放电。该系统已经用于刺激活体兔心脏的实验中,跟踪心电信号的频率,与R波同步刺激心脏,运行效果很好。更多还原

【Abstract】 Due to the biological effects of low frequency pulsed magnetic field, many researchers have begun to pay attention to the biological effects of pulsed magnetic field on the heart. At present, the frequency of the magnetic field applied to heart stimulation is fixed, not variable according to the physiological characteristic of the heart. A brand new pulsed magnetic heart stimulator with controllable waveform synchronously triggered by electrocardiograph signals such as P wave, R wave or T wave was developed. The stimulator measures electrocardiograph signals, automatically extracts R wave and uses it as the trigger to control the timing of the magnetic field discharge. The waveform of the magnetic field is set automatically with software. The feature of the stimulator is directly controlling the discharge process of the coil, instead of controlling the charge process of the capacitor. To control the waveform of the magnetic field and track the frequency of the electrocardiograph signal, IGBT device is used instead of SCR. The proposed magnetic field stimulator was applied in an experiment to stimulate the heart of a living rabbit and good results were achieved.更多还原