Ballistocardiography (BCG) and seismocardiography (SCG) assess vibrations produced by cardiac contraction and blood flow, respectively, through micro-accelerometers and micro-gyroscopes. BCG and SCG kinetic energies (KE), and their temporal integrals (iK) during a single heartbeat are computed in linear and rotational dimensions. Multiunit muscle sympathetic nerve traffic (BF, burst frequency; tMSNA, total muscular sympathetic nerve activity) was measured by microneurography during normal breathing and apnea (n=28, healthy men). iK of BCG and SCG were simultaneously recorded along with oxygen saturation (SatO₂) and systolic blood pressure (SBP).The mean duration of apneas was 25.4±9.4s. SBP, BF, tMSNA increased during the apnea compared to baseline (p=0.01, p=0.002, p=0.001, respectively), while SatO₂ decreased (p=0.02). At the end of the apnea compared to normal breathing, changes of iK computed from BCG were related to changes of tMSNA and BF only in the linear dimension (r=0.85, p<0.0001; r=0.72, p=0.002, respectively), while changes of linear iK of SCG were related only to changes of tMSNA (r=0.62, p=0.01).Maximal end expiratory apnea increases cardiac kinetic energy computed from BCG and SCG, along with sympathetic activity. The novelty of the present investigation is that linear iK of BCG is directly and more strongly related to the rise in sympathetic activity than the SCG, mainly at the end of a sustained apnea, likely because the BCG is more affected by the sympathetic and hemodynamic effects of breathing cessation. BCG and SCG may prove useful to assess sympathetic nerve changes in patients with sleep disturbances.

中文翻译：

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在持续呼气末期呼吸暂停期间，用心动描记法和地震心动图测量的交感神经激活对心肌收缩力的影响。

冲击心动描记法（BCG）和地震心动描记法（SCG）通过微加速度计和微陀螺仪分别评估由心脏收缩和血流产生的振动。BCG和SCG动能（KE）以及它们在单个心跳期间的时间积分（iK）均以线性和旋转尺寸进行计算。在正常呼吸和呼吸暂停期间（n = 28，健康男性），通过微神经测量术测量多单位肌肉交感神经交通（BF，猝发频率； tMSNA，总肌肉交感神经活动）。同时记录BCG和SCG的iK值以及血氧饱和度（SatO ₂）和收缩压（SBP），平均呼吸暂停时间为25.4±9.4s。与基线相比，呼吸暂停期间的SBP，BF，tMSNA升高（分别为p = 0.01，p = 0.002，p = 0.001），而SatO ₂降低（p = 0.02）。与正常呼吸相比，在呼吸暂停结束时，从BCG计算出的iK变化仅与线性维度上的tMSNA和BF变化相关（分别为r = 0.85，p <0.0001； r ​​= 0.72，p = 0.002）， SCG的线性iK变化仅与tMSNA的变化相关（r = 0.62，p = 0.01）。最大呼气末呼吸暂停会增加由BCG和SCG计算的心脏动能以及交感神经活动。本研究的新颖性在于，与SCG相比，BCG的线性iK与交感神经活动的增加直接且更密切相关，主要是在持续性呼吸暂停结束时，可能是因为BCG受交感神经和血液动力学影响更大停止呼吸 BCG和SCG可能有助于评估睡眠障碍患者的交感神经变化。