Since the traditional single-sensor acquisition for the apex-cardiogram ( ACG) signal is not easy to determine the sensor location and the reliability of the ACG signal is uncertain, we proposes a new method for the ACG signal acquisition. Methods With the sensor array design, three identical piezoelectric sensors are designed as a fixed equilateral triangular structure which can collect three ACG signals synchronously. Meanwhile, the amplitude and frequency attenuation characteristics are analyzed in the transmission process of the ACG signal. Then the hyperbolic position model is established and the true ACG signal is constructed based on this model. Finally, we collect the three ACG signals from 20 subjects and extract three feature points (C, E and 0 point) for each ACG signal. For each subject, the feature points of sensor A is set to be the reference location. Then the feature point location deviations of sensor B and C from reference location are analyzed. Results The t test shows that the deviations of sensor B and C are statistically significant, suggesting that the ACG signal is vulnerable to the sensor position and the reliability of single-sensor ACG signal is not high. Conclusions This paper proposes a new method for ACG signal acquisition to solve the difficult position choice problem for the single-sensor and the hyperbolic position model is used to construct the more reliable ACG signals.%目的 针对传统单一传感器采集心尖搏动信号时因传感器位置不易确定,信号可靠性受质疑的问题,提出一种新的心尖搏动信号获取技术.方法 采用阵列传感器设计,将3片完全相同的压电传感器设计成等边三角形结构,同步采集3路心尖搏动信号,同时对心尖搏动信号在胸腔传播过程中衰减的幅值特性和频率特性进行分析,建立心尖搏动信号的双曲定位模型,然后依据该模型重建出真实的心尖搏动信号.同步采集20例受试者的3路心尖搏动信号,以传感器A为基准信号,统计分析传感器B和C信号的3个特征点(C点、E点和O点)与基准信号的偏差有无显著性差异,进而说明单一传感器信号的可靠性.结果 t检验结果显示传感器B和C信号的3个特征点与基准信号的偏差均有显著的统计学差异,提示心尖搏动信号易受传感器放置位置的影响,信号可靠性不高.结论 本文提出的心尖搏动信号获取技术解决了单一传感器放置位置不易确定的缺陷,利用双曲定位模型重建出可靠性更高的信号波形.
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