生物医学信号的频谱在低频、超低频段。为了无失真地长时间记录和保存生物医学信号,可采用脉冲调制方式将其录制在磁带上。回放时,可通过解调电路重现所需信号以供分析研究或传送给计算机处理。脉冲调制有许多种方法,本文仅讨论脉冲位置调制的原理及其实用电路设计、噪声分析、使用效果等。从而说明脉冲位置调制在磁带记录生物医学信号中的重要性。 Biomedical signal spectrum in the low-frequency, ultra-low frequency band. To record and save biomedical signals for long periods of time without distortion, they can be recorded on tape using pulse modulation. During playback, the desired signal can be reproduced by the demodulation circuit for analysis or transmission to the computer for processing. There are many ways of pulse modulation, this article only discusses the principle of pulse position modulation and its practical circuit design, noise analysis, the use of effects. Thus illustrating the importance of pulse position modulation in recording biomedical signals on magnetic tape.