PDF(Pubmed)
Abstract：
BACKGROUND: Post-occlusive reactive hyperemia (PORH) test with signal spectral analysis coupled provides potential indicators for the assessment of microvascular functions.
OBJECTIVE: The objective of this study is to investigate the variations of skin blood flow and temperature spectra in the PORH test. Furthermore, to quantify the oscillation amplitude response to occlusion within different frequency ranges.
METHODS: Ten healthy volunteers participated in the PORH test and their hand skin temperature and blood flow images were captured by infrared thermography (IRT) and laser speckle contrast imaging (LSCI) system, respectively. Extracted signals from selected areas were then transformed into the time-frequency space by continuous wavelet transform for cross-correlation analysis and oscillation amplitude response comparisons.
RESULTS: The LSCI and IRT signals extracted from fingertips showed stronger hyperemia response and larger oscillation amplitude compared with other areas, and their spectral cross-correlations decreased with frequency. According to statistical analysis, their oscillation amplitudes in the PORH stage were obviously larger than the baseline stage within endothelial, neurogenic, and myogenic frequency ranges (p < 0.05), and their quantitative indicators of oscillation amplitude response had high linear correlations within endothelial and neurogenic frequency ranges.
CONCLUSIONS: Comparisons of IRT and LSCI techniques in recording the reaction to the PORH test were made in both temporal and spectral domains. The larger oscillation amplitudes suggested enhanced endothelial, neurogenic, and myogenic activities in the PORH test. We hope this study is also significant for investigations of response to the PORH test by other non-invasive techniques.
OBJECTIVE: The objective of this study is to investigate the variations of skin blood flow and temperature spectra in the PORH test. Furthermore, to quantify the oscillation amplitude response to occlusion within different frequency ranges.
METHODS: Ten healthy volunteers participated in the PORH test and their hand skin temperature and blood flow images were captured by infrared thermography (IRT) and laser speckle contrast imaging (LSCI) system, respectively. Extracted signals from selected areas were then transformed into the time-frequency space by continuous wavelet transform for cross-correlation analysis and oscillation amplitude response comparisons.
RESULTS: The LSCI and IRT signals extracted from fingertips showed stronger hyperemia response and larger oscillation amplitude compared with other areas, and their spectral cross-correlations decreased with frequency. According to statistical analysis, their oscillation amplitudes in the PORH stage were obviously larger than the baseline stage within endothelial, neurogenic, and myogenic frequency ranges (p < 0.05), and their quantitative indicators of oscillation amplitude response had high linear correlations within endothelial and neurogenic frequency ranges.
CONCLUSIONS: Comparisons of IRT and LSCI techniques in recording the reaction to the PORH test were made in both temporal and spectral domains. The larger oscillation amplitudes suggested enhanced endothelial, neurogenic, and myogenic activities in the PORH test. We hope this study is also significant for investigations of response to the PORH test by other non-invasive techniques.
摘要：
背景：结合信号谱分析的闭塞后反应性充血（PORH）测试为评估微血管功能提供了潜在的指标。
目的：本研究的目的是研究PORH测试中皮肤血流和温度光谱的变化。此外，量化不同频率范围内对阻塞的振荡幅度响应。
方法：10名健康志愿者参加了PORH测试，并通过红外热成像（IRT）和激光散斑对比成像（LSCI）系统捕获了他们的手部皮肤温度和血流图像，分别。然后通过连续小波变换将来自选定区域的提取信号转换为时频空间，以进行互相关分析和振荡幅度响应比较。
结果：与其他区域相比，从指尖提取的LSCI和IRT信号显示出较强的充血反应和较大的振荡幅度，并且它们的频谱互相关随着频率而降低。根据统计分析,它们在PORH阶段的振荡幅度明显大于内皮内的基线阶段，神经性，和肌源性频率范围(p<0.05)，它们的振荡振幅反应的定量指标在内皮和神经源性频率范围内具有高度的线性相关性。
结论：在时域和谱域中对IRT和LSCI技术在记录对PORH测试的反应方面进行了比较。较大的振荡幅度表明内皮增强，神经性，和PORH测试中的肌源性活动。我们希望这项研究对于调查其他非侵入性技术对PORH测试的反应也很重要。
目的：本研究的目的是研究PORH测试中皮肤血流和温度光谱的变化。此外，量化不同频率范围内对阻塞的振荡幅度响应。
方法：10名健康志愿者参加了PORH测试，并通过红外热成像（IRT）和激光散斑对比成像（LSCI）系统捕获了他们的手部皮肤温度和血流图像，分别。然后通过连续小波变换将来自选定区域的提取信号转换为时频空间，以进行互相关分析和振荡幅度响应比较。
结果：与其他区域相比，从指尖提取的LSCI和IRT信号显示出较强的充血反应和较大的振荡幅度，并且它们的频谱互相关随着频率而降低。根据统计分析,它们在PORH阶段的振荡幅度明显大于内皮内的基线阶段，神经性，和肌源性频率范围(p<0.05)，它们的振荡振幅反应的定量指标在内皮和神经源性频率范围内具有高度的线性相关性。
结论：在时域和谱域中对IRT和LSCI技术在记录对PORH测试的反应方面进行了比较。较大的振荡幅度表明内皮增强，神经性，和PORH测试中的肌源性活动。我们希望这项研究对于调查其他非侵入性技术对PORH测试的反应也很重要。
