目的颈动脉在振动较弱情况下仍保留大多数的主波、潮波、重搏波等完整信息。本文提出通过Blinn-Phong模型放大颈动脉皮肤表面振动的原始信号来获取颈动脉脉搏波。方法在近红外光照明环境中,在颈动脉皮肤上静电吸附一张光滑圆形薄膜片,...目的颈动脉在振动较弱情况下仍保留大多数的主波、潮波、重搏波等完整信息。本文提出通过Blinn-Phong模型放大颈动脉皮肤表面振动的原始信号来获取颈动脉脉搏波。方法在近红外光照明环境中,在颈动脉皮肤上静电吸附一张光滑圆形薄膜片,建立一个局部Blinn-Phong模型。使用相机连续拍摄颈动脉处皮肤振动的图像序列,再通过对图像序列选取感兴趣区域(region of interest,ROI)的像素变化获取脉搏波原始信号。采用带通滤波和经验模态分解与重构算法,最后得到特征点保留完整及周期状态稳定的脉搏波信号。在采集颈动脉脉搏波信号时,同时用一款目前临床使用的接触式动脉血压及血流动力学检测设备TL-400,测量桡动脉脉搏波及心率等生理参数并与实验数据对比。结果在获取的15名弱脉搏受试者的颈部脉搏波信号中,其中13名受试者主波信号可以完全测得,信号周期稳定且特征点明显,潮波和重搏波信号的获取率分别为81%和72%。2名受试者由于体脂过高,获取了较少完整周期的脉搏波。与TL-400设备获取的心率具有一致性,且获取的脉搏波波形与TL-400所获取的波形特征细节及趋势一致。结论本文提出的方法可以获取颈动脉弱振动下,周期稳定并保留大多数潮波和重搏波等特征的完整脉搏波信号,为后续的心率、心率变异性、血氧甚至血压等生理参数的测量提供稳定和可靠的信号源。展开更多
The mixed noise in the acquisition process of pulse wave signals will affect the signal analysis, how to effectively eliminate the noise and complete the pulse wave analysis has important practical significance. In th...The mixed noise in the acquisition process of pulse wave signals will affect the signal analysis, how to effectively eliminate the noise and complete the pulse wave analysis has important practical significance. In this paper, empirical mode decomposition(EMD) and ensemble empirical mode decomposition(EEMD) were used to realize scale decomposition of pulse wave signals to obtain intrinsic mode function(IMF). A band-pass filter was implemented according to the characteristic time scale parameters of the IMF. After filtering and reconstruction, the pulse wave denoising was completed. The denoising effects of EMD, EEMD and wavelet transform were compared in terms of mean square error and signal-to-noise ratio. The result shows that EMD and EEMD are better than wavelet transform, and the effects are similar. Further comparing the Hilbert-Huang spectrum of EMD and EEMD, it can be seen that EEMD can not only avoid mode mixing, but also facilitate the analysis of pulse wave signals.展开更多
文摘目的颈动脉在振动较弱情况下仍保留大多数的主波、潮波、重搏波等完整信息。本文提出通过Blinn-Phong模型放大颈动脉皮肤表面振动的原始信号来获取颈动脉脉搏波。方法在近红外光照明环境中,在颈动脉皮肤上静电吸附一张光滑圆形薄膜片,建立一个局部Blinn-Phong模型。使用相机连续拍摄颈动脉处皮肤振动的图像序列,再通过对图像序列选取感兴趣区域(region of interest,ROI)的像素变化获取脉搏波原始信号。采用带通滤波和经验模态分解与重构算法,最后得到特征点保留完整及周期状态稳定的脉搏波信号。在采集颈动脉脉搏波信号时,同时用一款目前临床使用的接触式动脉血压及血流动力学检测设备TL-400,测量桡动脉脉搏波及心率等生理参数并与实验数据对比。结果在获取的15名弱脉搏受试者的颈部脉搏波信号中,其中13名受试者主波信号可以完全测得,信号周期稳定且特征点明显,潮波和重搏波信号的获取率分别为81%和72%。2名受试者由于体脂过高,获取了较少完整周期的脉搏波。与TL-400设备获取的心率具有一致性,且获取的脉搏波波形与TL-400所获取的波形特征细节及趋势一致。结论本文提出的方法可以获取颈动脉弱振动下,周期稳定并保留大多数潮波和重搏波等特征的完整脉搏波信号,为后续的心率、心率变异性、血氧甚至血压等生理参数的测量提供稳定和可靠的信号源。
文摘The mixed noise in the acquisition process of pulse wave signals will affect the signal analysis, how to effectively eliminate the noise and complete the pulse wave analysis has important practical significance. In this paper, empirical mode decomposition(EMD) and ensemble empirical mode decomposition(EEMD) were used to realize scale decomposition of pulse wave signals to obtain intrinsic mode function(IMF). A band-pass filter was implemented according to the characteristic time scale parameters of the IMF. After filtering and reconstruction, the pulse wave denoising was completed. The denoising effects of EMD, EEMD and wavelet transform were compared in terms of mean square error and signal-to-noise ratio. The result shows that EMD and EEMD are better than wavelet transform, and the effects are similar. Further comparing the Hilbert-Huang spectrum of EMD and EEMD, it can be seen that EEMD can not only avoid mode mixing, but also facilitate the analysis of pulse wave signals.
