多参数监测仪生理信号检测技术的研究

介绍了多参数监测仪主要生理信号检测技术的方法及特点，分析这些方法在实际应用中的效果和研究方向。     

Electrocardiogram‐based emotion recognition system using empirical mode decomposition and discrete Fourier transform

Emotion recognition using physiological signals has gained momentum in the field of human computer–interaction. This work focuses on developing a user‐independent emotion recognition system that would classify five emotions (happiness, sadness, fear, surprise and disgust) and neutral state. The various stages such as design of emotion elicitation protocol, data acquisition, pre‐processing, feature extraction and classification are discussed. Emotional data were obtained from 30 undergraduate students by using emotional video clips. Power and entropy features were obtained in three ways – by decomposing and reconstructing the signal using empirical mode decomposition, by using a Hilbert–Huang transform and by applying a discrete Fourier transform to the intrinsic mode functions (IMFs). Statistical analysis using analysis of variance indicates significant differences among the six emotional states (p < 0.001). Classification results indicate that applying the discrete Fourier transform instead of the Hilbert transform to the IMFs provides comparatively better accuracy for all the six classes with an overall accuracy of 52%. Although the accuracy is less, it reveals the possibility of developing a system that could identify the six emotional states in a user‐independent manner using electrocardiogram signals. The accuracy of the system can be improved by investigating the power and entropy of the individual IMFs.     

Effects of avatar character performances in virtual reality dramas used for teachers’ education

Virtual reality drama has the benefit of enhancing immersion, which was lacking in original e-Learning systems. Moreover, dangerous and expensive educational content can be replaced by stimulating users’ interest. In this study, we investigate the effects of avatar performance in virtual reality drama. The hypothesis that the psychical distance between virtual characters and their viewers changes according to the size of video shots is tested with an autonomic nervous system function test. Eighty-four college students were randomly assigned to three groups. Virtual reality drama is used to train teachers concerning school bullying prevention, and deals with the dialogue between teachers and students. Group 1 was provided with full-shot video clips, Group 2 was shown various clips from full shots to extreme close-ups, and Group 3 was provided with close-up shots. We found that the virtual reality drama viewers’ levels of stimulation changed in relation to the size of the shots. The R-R (between P wave and P wave) intervals of the electrocardiograms (ECGs, bio-signal feedback) became significantly narrower as the shot size became smaller.     

基于互信息最小的非线性混合胎儿心电信号提取方法

胎儿心电信号提取具有重要的临床意义。目前大多数胎儿心电信号提取方法是基于线性瞬时混合模型,使用多路信号实现.本文基于更符合实际情况的非线性混合模型,使用两路心电信号,提出一种新颖的从母体腹部混合信号中提取胎儿心电信号方法。首先,在假定母体和胎儿两个心电信号相互独立的基础上,基于互信息最小原则,提出一种新的目标函数;然后,利用多层感知机拟合母体心电信号传导至腹部所经历的非线性变换,从而得到母体腹部混合信号中母体心电成分的最优估计;最后,从母体腹部混合信号中减去母体心电信号的最优估计,实现胎儿心电信号的成功提取。实验结果验证了该方法的正确性和有效性。     

基于高阶统计量的心电信号R波检测

心电信号的检测对于临床心脏疾病的检验和确诊有很重要的作用,所以目前有关心电信号检测方法的研究很多。本文针对心电信号R波的检测,采用了一种基于高阶统计量的检测方法。使用MATLAB编程软件实现了心电信号R波检测,采用非参数直接法心电信号R波进行双谱估计,并将实验运行结果作以比较。实验结果表明高阶统计量是一种十分有效的信号检测和系统分析方法。     

Noninvasive fetal ECG estimation using adaptive comb filter

This paper describes a robust and simple algorithm for fetal electrocardiogram (FECG) estimation from abdominal signal using adaptive comb filter (ACF). The ACF can adjust itself to the temporal variations in fundamental frequency, which makes it qualified for the estimation of quasi-periodic component from physiologic signal, such as ECG. The validity and performance of the described method are confirmed through experiments on real fetal ECG data. A comparison with the well-known independent component analysis (ICA) method has also been presented.     

WSN24-Link无线传感器网络在心电监护系统中的应用

随着无线通信技术和电子器件技术的快速发展,促进了由传感器组成的无线传感网（WSN）的应用。由许多无线传感器组成的无线传感器网络被广泛应用于各种领域,如医疗、军事、化工、商业等。介绍了应用WSN24-Link无线传感器网络实现远程心电监护的设计,讨论了传感器网络的工作原理、硬件结构和软件系统。     

新型心电信号前置放大电路设计

基于经典的仪表放大器基本框架,改进和设计了一种可用于心电信号采集的前置放大器。根据心电信号采集的特点,通过增加射频滤波器、右腿驱动电路和高通负反馈滤波器等措施,提高了放大器的共模抑制比,对被测的人体具有更安全的保护作用。结果表明该放大器在频率响应特性、共模抑制比等性能参数方面符合标准,可用于ECG监护仪中。     

心电图信号采集与存储系统的设计

采用低功耗AVR单片机、点阵液晶、存储记录卡以及实时时钟芯片等器件设计了心电图信号采集与存储系统，对心电图信号采集与存储系统从重量、体积、功耗以及功能等方面进行改善，方便使用、对心电图信号采集与存储系统的工作原理、工作流程以及抗干扰等问题进行了分析。