Kenney M J, Fedde M R
Department of Anatomy and Physiology, College of Veterinary Medicine, Kansas State University, Manhattan 66506.
Biomed Sci Instrum. 1994;30:111-6.
Autospectral analysis reveals that most of the power in sympathetic nerve discharge (SND) is contained between 1 and 10 Hz in anesthetized animals. The synchronized discharge bursts of the fibers comprising sympathetic nerves are usually recorded after capacity-coupled preamplification with a bandpass of 1-1000 Hz. However, cardiac- and respiratory-related movement artifacts can adversely affect the signal when this wide bandpass (1-1000 Hz) is used. To eliminate the influence of movement artifacts on the basic pattern of SND, we have routed the output of a preamplifier (bandpass 30-1000 Hz) through a frequency analyzer which measures the frequency of spike discharges exceeding a threshold voltage. After the impulses are rectified and integrated a smooth envelope of the synchronized sympathetic nerve discharge bursts is produced. The following observations have been made: 1) The autospectra of SND constructed after either wide-band preamplification or 30-1000 Hz using the frequency analyzer are similar and 2) Narrow-band preamplification (30-1000 Hz) eliminates movement-related artifacts which adversely influence the sympathetic nerve signal. These results indicate that the basic pattern of SND can be faithfully recorded after narrow-band preamplification which eliminates potential movement-related artifacts.
自谱分析显示，在麻醉动物中，交感神经放电（SND）的大部分功率集中在1至10赫兹之间。组成交感神经的纤维的同步放电脉冲串通常在经过1 - 1000赫兹带通的电容耦合前置放大后进行记录。然而，当使用这种宽带通（1 - 1000赫兹）时，与心脏和呼吸相关的运动伪影会对信号产生不利影响。为了消除运动伪影对SND基本模式的影响，我们将前置放大器（带通30 - 1000赫兹）的输出接入一个频率分析仪，该分析仪测量超过阈值电压的尖峰放电频率。在脉冲经过整流和积分后，产生了同步交感神经放电脉冲串的平滑包络。已得出以下观察结果：1）使用频率分析仪在宽带前置放大或30 - 1000赫兹带通后构建的SND自谱相似；2）窄带前置放大（30 - 1000赫兹）消除了对交感神经信号产生不利影响的与运动相关的伪影。这些结果表明，在消除潜在的与运动相关的伪影的窄带前置放大后，可以如实地记录SND的基本模式。
