Miyamoto Y, Tamura T, Mikami T
Biotelem Patient Monit. 1981;8(4):189-203.
A computer-based system which calculates stroke volume, heart rate and cardiac output automatically from the transthoracic impedance variation has been developed. A beat-by-beat determination was performed on several healthy subjects and patients with atrial fibrillation during spontaneous breathings at rest. The respiratory artifact appearing on the impedance cardiogram was canceled by (1) correcting the base line of dZ/dt for each cardiac cycle on the basis of assumption that the dZ/dt values at ECG-R waves would be invariable regardless of the respiratory phase when the respiratory movement ceases, and (2) averaging the signals for a number of cardiac cycles. Comparisons between the computed stroke volumes and those obtained from a manual calculation showed good agreement.
已开发出一种基于计算机的系统，该系统可根据经胸阻抗变化自动计算每搏输出量、心率和心输出量。对几名健康受试者和房颤患者在静息时自主呼吸过程中进行逐搏测定。通过以下方法消除阻抗心动图上出现的呼吸伪影：（1）基于呼吸运动停止时，无论呼吸相位如何，心电图R波处的dZ/dt值不变这一假设，对每个心动周期的dZ/dt基线进行校正；（2）对多个心动周期的信号进行平均。计算得到的每搏输出量与手动计算得到的每搏输出量之间的比较显示出良好的一致性。
