Noshiro M, Inaoka H, Yoshida Y, Ryumae S, Shimizu M, Hoshino H, Hosaka H
Department of Clinical Engineering, School of Allied Health Sciences, Kitasato University, Kanagawa, Japan.
Front Med Biol Eng. 1996;7(3):207-19.
We examined a new method for estimating tidal volume from the electrocardiogram (ECG) in order to dispense with the need for sensors used exclusively for tidal volume measurement. The direction of the vector loop in the QRS complex (DVL) was defined as the direction of the diagonal line of the rectangle which circumscribed the vector loop obtained from two orthogonal leads. Two leads of the ECG were transformed into the orthogonal leads using Einthoven's triangle. The peak-to-peak change in the direction (the change in the DVL) was highly correlated with tidal volume. Low-pass filtering of the ECG produced a better correlation between tidal volume and the change in the DVL, when the cutoff frequency was set at 20-45 Hz. A tidal volume of less than 1.21 was correlated more highly with the change in the DVL than a tidal volume of more than 1.21 A combination of leads I and III produced the best correlation between tidal volume and the change in the DVL, compared with other combinations. The posture of the subject had some effects on the slope of the linear regression between tidal volume and the change in the DVL.
我们研究了一种从心电图（ECG）估算潮气量的新方法，以便无需专门用于潮气量测量的传感器。QRS波群中向量环的方向（DVL）定义为从两个正交导联获得的外接向量环的矩形对角线方向。利用艾因托芬三角将心电图的两个导联转换为正交导联。方向上的峰峰值变化（DVL的变化）与潮气量高度相关。当截止频率设置为20 - 45Hz时，对心电图进行低通滤波可使潮气量与DVL的变化之间具有更好的相关性。与大于1.21的潮气量相比，小于1.21的潮气量与DVL的变化相关性更高。与其他组合相比，导联I和III的组合在潮气量与DVL的变化之间产生了最佳相关性。受试者的姿势对潮气量与DVL的变化之间线性回归的斜率有一定影响。
