Israel D J, Pozos R S
Department of Physiology, School of Medicine, University of Minnesota, Duluth 55812.
J Appl Physiol (1985). 1989 May;66(5):2358-63. doi: 10.1152/jappl.1989.66.5.2358.
The electromyograms (EMG) of shivering human subjects exposed to 0 degrees C air in an environmental chamber were analyzed to detect slow-amplitude modulations (SAMs, less than 1 Hz) in the EMGs of widely separated muscles and to study the relationship of these SAMs to respiration rate and skin temperature. Distinct amplitude modulations were observed in the raw EMGs during shivering. The peaks in EMG activity occurred simultaneously in the majority of the monitored muscles in all subjects. Pearson correlations between the average rectified EMGs of 93% of the muscles were significant (P less than 0.05). Visual analysis of the EMG and respiration signals indicated that the peaks in muscular activity occurred 6-12 times/min, whereas respiration ranged from 10 to 23 cycles/min. For all subjects respiration was at a higher frequency than amplitude modulation in the EMG. Comparison of EMG records with expiratory flow rate traces in shivering subjects indicated no one-to-one correlation between the occurrence of respiration and EMG amplitude modulations. Respiratory flow rate and average rectified EMG showed significant correlation in only 33% of the cases. In addition, skin temperature changes could not be correlated with the SAMS.
对在环境舱中暴露于0摄氏度空气的颤抖人体受试者的肌电图（EMG）进行了分析，以检测广泛分离的肌肉的肌电图中的慢幅度调制（SAMs，小于1赫兹），并研究这些SAMs与呼吸频率和皮肤温度之间的关系。在颤抖过程中，原始肌电图中观察到明显的幅度调制。所有受试者中，大多数监测肌肉的肌电活动峰值同时出现。93%的肌肉的平均整流肌电图之间的皮尔逊相关性显著（P小于0.05）。对肌电图和呼吸信号的视觉分析表明，肌肉活动峰值出现的频率为每分钟6 - 12次，而呼吸频率为每分钟10 - 23次。对于所有受试者，呼吸频率高于肌电图中的幅度调制频率。将颤抖受试者的肌电图记录与呼气流量曲线进行比较表明，呼吸的发生与肌电图幅度调制之间不存在一一对应关系。呼吸流量率与平均整流肌电图仅在33%的情况下显示出显著相关性。此外，皮肤温度变化与慢幅度调制无相关性。
