对人体血液及不同组成、生理和病理(糖尿病)状态的电频谱特性(幅频特性和相频特性),在1 H z^20MH z范围进行了检测分析。血液组成中电阻抗血清最小,其次是血浆、全血、红细胞最大,负相移基本满足血清最大,其次是血浆,全血,最小是红细胞...对人体血液及不同组成、生理和病理(糖尿病)状态的电频谱特性(幅频特性和相频特性),在1 H z^20MH z范围进行了检测分析。血液组成中电阻抗血清最小,其次是血浆、全血、红细胞最大,负相移基本满足血清最大,其次是血浆,全血,最小是红细胞。但问题是血清、血浆中恰无细胞、细胞膜,何来容性效应最大呢;糖尿病属内分泌(血液改变较明显)疾病,糖尿病患者血液电频谱特性有明显且典型性改变:血液电阻抗下降(低频端更显著),负相移增加(高频端更明显)。表明糖尿病人的血液交流导电性增加主要是容性导电的增加,应与红细胞膜变化,红细胞变形能力和聚集性改变相关。相关实验表明,血液电频谱特性的研究,使我们有可能利用电学强有力的理论和手段,从另一个视角去认识血液的一些重要性质,并和其它一些检测分析方法相互补充和印证。展开更多
To implement the primary signal without interference in cognitive radio systems, cognitive radios can detect the presence of the primary user in low SNR. Currently, energy detector is the most common way of spectrum s...To implement the primary signal without interference in cognitive radio systems, cognitive radios can detect the presence of the primary user in low SNR. Currently, energy detector is the most common way of spectrum sensing because of its low computational complexity. However, performunce of the method will be possibly degraded due to the uncertainty noise. This paper illustrates the benefits of one-order and two-order cyclostationary properties of primary user＇s signals in time domain. These feature detection techniques in time domain possess the advantages of simple structure and low computational complexity comparing with spectral feature detection methods. Furthermore, performance of the one-order and two-order feature detection is studied and the analytical results are given. Our analysis and numerical results show that the sensing performance of the one-order feature detection is improved significantly comparing with conventional energy detector since it is robust to noise. Meanwhile, numerical results show that the two-order feature detection technique is better than the one-order feature detection. However, this benefit comes at the cost of hardware burdens and power consumption due to the additional multiplying algorithm.展开更多
文摘对人体血液及不同组成、生理和病理(糖尿病)状态的电频谱特性(幅频特性和相频特性),在1 H z^20MH z范围进行了检测分析。血液组成中电阻抗血清最小,其次是血浆、全血、红细胞最大,负相移基本满足血清最大,其次是血浆,全血,最小是红细胞。但问题是血清、血浆中恰无细胞、细胞膜,何来容性效应最大呢;糖尿病属内分泌(血液改变较明显)疾病,糖尿病患者血液电频谱特性有明显且典型性改变:血液电阻抗下降(低频端更显著),负相移增加(高频端更明显)。表明糖尿病人的血液交流导电性增加主要是容性导电的增加,应与红细胞膜变化,红细胞变形能力和聚集性改变相关。相关实验表明,血液电频谱特性的研究,使我们有可能利用电学强有力的理论和手段,从另一个视角去认识血液的一些重要性质,并和其它一些检测分析方法相互补充和印证。
基金the National Natural Science Foundation of China (No. 60972039)the National High Technology Research and Development Program (863) of China (No. 2009AA01Z241)+1 种基金the Key Project of Nature Science Foundation of Jiangsu Province(No. BK2007729)the National Postdoctoral Research Program (No. 20090451239)
文摘To implement the primary signal without interference in cognitive radio systems, cognitive radios can detect the presence of the primary user in low SNR. Currently, energy detector is the most common way of spectrum sensing because of its low computational complexity. However, performunce of the method will be possibly degraded due to the uncertainty noise. This paper illustrates the benefits of one-order and two-order cyclostationary properties of primary user＇s signals in time domain. These feature detection techniques in time domain possess the advantages of simple structure and low computational complexity comparing with spectral feature detection methods. Furthermore, performance of the one-order and two-order feature detection is studied and the analytical results are given. Our analysis and numerical results show that the sensing performance of the one-order feature detection is improved significantly comparing with conventional energy detector since it is robust to noise. Meanwhile, numerical results show that the two-order feature detection technique is better than the one-order feature detection. However, this benefit comes at the cost of hardware burdens and power consumption due to the additional multiplying algorithm.
