基于连续小波变换的中医脉象信号处理

应用连续小波变换的一般算法和梅林算法分析了 15例海洛因吸毒者和 15例正常人的脉象信号。两种算法均在 4个尺度下 ,对每一例脉象信号进行了处理 ,从两种算法分析的结果均发现 ,在 0 .2～ 0 .4 s时间间隔内 ,海洛因吸毒者和正常人脉象信号的连续小波变换系数间存在显著差异 ,并为每一算法提出了用于划分海洛因吸毒者与正常人的临界参数。研究结果表明 ,连续小波变换是处理脉象信号的有效方法     

海洛因成瘾者的心率变异性研究

利用功率谱估计的方法 ,对 15例海洛因成瘾者和 15例正常人的 HRV信号进行分析。分析结果表明 ,在海洛因成瘾者和正常人心率变异性信号功率谱间存在高频谱峰位置的显著差异 ,即海洛因成瘾者 HRV信号功率谱的高频谱峰位于 0 .437± 0 .0 6 4Hz,而正常人的 HRV信号功率谱的高频谱峰位于 0 .32 5± 0 .0 5 2 Hz     

基于小波分解的颈动脉波特征提取算法

目的:利用小波变换的时频局域化性质,检测出存在于颈动脉波信号(CAP)中的奇异点和奇异角,并且精确检测奇异角出现的位置。方法:小波变换具有多分辨率等特点,能够通过放大信号的任意细节部分进行时域分析。采用离散小波变换法结合db1小波能够检出脉搏信号中的奇异U角。利用计算CAP时域特征点的小波变换极大值坐标来精确定位脉搏时域特征点,通过检测脉搏的特征参数以及脉搏的突变特征参数,可以客观判定人体脉搏变化规律。结果:CAP信号WT分解很好地抑制了各种病理性、基线漂移等干扰,为进一步进行特征提取创造了条件,基于第一细节信号d1的特征点定位几乎不受各种病理性、基线漂移等干扰的影响,定位比其他传统处理技术更为准确。结论:本文提出了基于小波分解的颈动脉波特征点提取算法,取得高达100%的检测率。在含有大量噪声和伪差的脉搏信号中,仍具有较高正确检出率和良好的抗噪性。根据计算得到CAP信号时域特征点的小波变换极大值的坐标,再利用极大值表征准确测定脉象时域特征点的坐标,能够克服脉搏时域特征点定位不准的问题。     

基于小波变换与基于短时傅立叶变换的超声多普勒血流信号时频分布比较研究

本研究讨论了一种改进的Morlet(MMORL)小波变换在分析超声多普勒血流信号时的优点。用小波变换和短时傅立叶变换计算得出时频分布与理论的时频分布进行了比较。结果得出小波变换能提供较好的时频分辨率的折中效果，能产生更精确的平均频率和带宽。     

小波变换用于豚鼠脑干听觉诱发电位信号的特征提取

本文基于正交小波变换、分析了三类共３０例豚鼠脑干听觉诱发电位信号，表明这种信号经正交小波变换后，不但能够利用近似信号更简单准确地得到传统判别参数，而且能够利用不同尺度细节信号提取出原始信号在不同频带的能量之比为有效的新判据     

基于光电容积脉搏波特征信息的睡眠呼吸事件判别

研究脉搏波特征信息与睡眠呼吸事件的关系,实现对呼吸事件的初步判别。采用小波变换的方法分析光电容积脉搏波,提取特征参量,结合专家经验校正后的呼吸事件分布,寻找这些参量与睡眠呼吸事件的相关关系,确立呼吸事件的初步判据,并用于呼吸事件初步判别。研究了5位受试者夜间脉搏波信号,专家校正的一晚呼吸事件总数为1239次。结果表明,呼吸事件初步判别的符合率在91%以上,尤其对于患有中重度OSAHS的病人,符合率可达96.1%。本研究提供了利用脉搏波特征参量进行呼吸事件初步判别的理论根据和实现方法。     

多采样率线性小波变换及其对心电信号的应用

Ｃｏｈｎｅ类变换使在时频两域同时分析信号成为可能。其中，小波变换相比维格纳分布没有交叉项干扰，更具有优越性。因此本文讨论了多采样率线性小波变换及其特性，并将它和其它变换作了比较，最后将它应用于心电信号的高频成分分析。     

心音的分析

自上世纪70年代以来,由于计算机和现代数字信号处理技术的发展,生物医学工作者对心音进行了大量的分析研究,相继运用了谱分析、时频分析、小波变换和最优匹配法等方法.谱分析不适合对非平稳随机心音信号的分析.国内外工作者通过加核函数和采用模糊函数等方法来减少时频分布中的交叉项.具有自适应性时-频窗的小波变换可以得到更能反映心音病例特征的信息.最优匹配法是一种没有交叉项的时频分析方法.     

应用小波变换进行心音三维时频分析的研究

应用小波变换分析方法,对正常人和典型心脏病人的心音数据分组进行不同尺度的小波变换,得出了综合反映心音的时间,频率和强度三维信息的彩色三维心音图,经小波变换的三维心音图更为直观详尽地反映出各组心音信号在不同时域、频域与强度范围内细节性的信息。对提取的时频参数进行分析,各组间存在显著性差异,该研究为临床心脏病诊断和辅助教学提供了一个有效的工具,为心音分析的进一步提供了基础资料与方法。     

高频心电图三维频谱分析方法的研究

小波变换是一种线性运算,它对信号进行不同尺度的分解,可有效地应用于如信噪分离,提高时频两域的分辩率等。本文讨论小波变换用于心电ＱＲＳ波形中细微特征（即高频成份特征）提取的方法。实验结果表明∑Ｕ（８０～３００）Ｈｚ／∑Ｕ（５５～８０）Ｈｚ比值,对于冠心病患者其值普遍大于无冠心病“正常人”的值,差异显著（Ｐ＜０００２）,即（８０～３００）Ｈｚ为ＨＦＥＣＧ中频率分量变化较为敏感的频段。     

诱发脑电信号的滤波－基于小波分析与维纳滤波

本文提出一种新的时变滤波方法，利用小波变换将一维瞬态时变信号变换到时频域，构成信号的时变谱。然后将后验维纳滤波推广至时频域，形成后验时变滤波。此方法应用于诱发电位的提取，证明具有良好的效果。     

青少年吸毒者免疫细胞、细胞因子和生长激素的改变

目的：通过测定青少年吸食海洛因者外周血中T细胞亚群、Th1／1112细胞因子和血清中的生长激素，从分子水平探讨吸食海洛因对青少年免疫功能和生长发育的影响。方法：用微量全血直接免疫荧光染色，用流式细胞术检测外周血中T细胞亚群；流式细胞（Cytometric bead array，CBA）技术测定Th1／Th2细胞因子；化学发光法测定生长激素。结果：青少年吸食海洛因组（n=20）CD3^＋、CD3^＋＋CIM^＋、CD3^＋＋CIM^＋／CD3^＋＋CD8^＋、Th1细胞因子（IL-2，TNF-α和IFN-γ）和Th2细胞因子（IL-4，IL-10）低于健康组（n=23）（P〈0．01或0．05）；且Th1细胞因子下降程度大于Th2细胞因子（P〈0．05）；血清生长激素显著高于健康组（P〈0．01）。结论：海洛因降低青少年机体免疫功能，对细胞免疫的损伤大于体液免疫；海洛因能升高青少年血清生长激素，机制需进一步探讨。     

Time delay estimation using wavelet transform for pulsed-wave ultrasound

The windowed cross-correlation (WCC) technique has recently attracted attention in pulsed-wave (PW) ultrasound for measurement of tissue motion and blood flow velocity because of its performance advantages over the conventional Doppler method. The WCC measures tissue motion and blood flow velocity via estimation of time delays of backscattered signals in two consecutive echoes. In this paper, we propose a wavelet transform-based cross-correlation (WTCC) technique for the time delay estimation in PW ultrasound. The WTCC consists of three steps: (i) computing wavelet transforms (WTs) of received echoes, (ii) computing cross-correlations in the wavelet domain, and (iii) estimating the time delays by maximizing the estimated cross-correlations. Dyadic or continuous wavelets may be used in the proposed approach. The WTCC has a unique feature of using varying time-frequency windows in processing compared with the WCC which only uses a single fixed window. Our computer simulations show that, compared with the WCC, the WTCC provides a better estimation of time delays (lower failure rate and lower estimate error) and its performance is more consistent under various conditions, and more robust with window size. In the simulations, we also tested a specific continuous wavelet for the WTCC that was the emitted pulse itself and found the corresponding WTCC outperforms the WTCC with a regular dyadic wavelet.     

14-3-3zeta facilitates GSK3beta-catalyzed tau phosphorylation in HEK-293 cells by a mechanism that requires phosphorylation of GSK3beta on Ser9

Acupuncture stimulation elicited a composite of sensations termed deqi that is related to clinical efficacy. Neurobiological studies have identified the hypothalamus as an important component in mediating the deqi. Functional changes in hypothalamus persist after abstinence in addicts. We investigated the activation in the hypothalamus associated with acupuncture stimulation in healthy volunteers and heroin addicts by fMRI. Cortisol level and psychophysical responses, including the deqi sensation (an acupuncture effect of needle-manipulation), anxiety, and sharp pain, were also assessed. The activation of the hypothalamus was more robust in the addicts than that in the healthy subjects during acupuncture stimulation. The deqi scores of the heroin addicts were significantly higher than those of the healthy subjects during acupuncture treatment. An acupuncture sensation scale predicted the activation of the hypothalamus associated with the deqi sensation.     

Disorders in the immune status and hepatic pathologies in young heroin addicts

The immunocytograms of 166 patients with opiomania, primarily of the heroin variation, aged 15 to 19, were examined. 18 healthy teenagers of the same age were in the control group. The sampling comprised both patients without any signs of infectious diseases (86 persons) and patients with viral hepatitis B and C. The deviations of the immune-cellular status comprised, in drug addicts, a deficit of T-helpers and NK-cells as well as an increased quantity of "zero" lymphocytes. An essential reduction in the level of T-suppressors (killers) was additional found in the group of drug-addicts with viral hepatices. The signs of cytolysis of hepatocytes were detected in young heroin addicts. The contents of lipid peroxides was significantly higher in the blood plasma of teenagers abusing the opium drugs; while the concentration of antioxidant factor was as follows: Vitamin E, sulfhydric proteins and urate were found to be decreased. A reliable correlation was found between the changes of the quantity of T-helpers, T-suppresses (killers) and 0-lymphocytes, on the one hand, and the activity of hepatic transaminases, on the other hand, (for AST = 0.65-0.70; p < 0.01). The disorders in the immune-cellular status persist for as long as three to four weeks after the refusal from drug consumption; it is noteworthy, that their severity can essentially go up. The activity of 5'-nucleotidase, involved in the transformation of receptor signals in T- and B-lymphocytes, was histochemically studied in immunocytes. The activity of the enzyme essentially went down in both populations of lymphocytes by the 7th day of abstinence; it remained at the mentioned level up to the 14th day (in patients with hepatitis) or up to 21st day (in patients without hepatitis). Therefore, the quantitative deficit of immunocytes in drug addicts was accompanied, during the abstinence period, by an inhibition of their functional activity.     

海洛因依赖者环境诱发渴求感的相关因素研究

目的：研究海洛因依赖者环境诱发渴求感的相关因素。方法：对87名男性劳教患者进行环境诱发实验，比较诱发成功组（n=25）与诱发失败组（n=62）在人口学资料、吸毒相关特征、戒毒相关资料等方面的差异。结果：诱发成功组的毒品依赖程度强于诱发失败组，平均戒断时间短于诱发失败组。父母有烟酒嗜好以及首次吸毒有“飘”感的戒毒者，更容易诱发渴求感。结论：海洛因依赖者对于环境诱发刺激具有不同的易感性。对于预防复吸具有指导意义。     

Time-frequency analysis of the second cardiac sound in phonocardiogram signals

The paper is concerned with the analysis of the phonocardiogram signals (PCG) in the time-frequency domain. Three techniques are studied and evaluated in PCG signal analysis. These are the short time Fourier transform (STFT), the Wigner distribution function (WD) and the continuous wavelet transforms (CWTs). The analysis is first carried out on the second cardiac sound (S2) in order to show the aptitude of each method in distinguishing the internal components of this sound. The results we obtain show that the STFT cannot detect the two internal components of S2 (A2 and P2, respectively, the aortic and pulmonary components). The WD can provide time-frequency characteristics of S2, but with insufficient diagnostic information: the two components are not accurately detected and appear to be only one component. It is found that the CWT (it can also provide the time-frequency characteristic of S2) is capable of detecting its two components, A2 and P2, allowing therefore the measurement of the delay between them. This delay, called the split, is very important in the diagnosis of many pathological cases, as it is emphasized in the results we obtain by applying the CWT on different pathological cases (mitral stenosis, pulmonary stenosis and atrial septal defect).     

Personality differences among black, white, and Hispanic-American male heroin addicts on MMPI content scales

Used MMPI Content Scale scores (Wiggins, 1966) to assess personality differences among black, white, and Hispanic-American heroin addicts. Ss were 423 male veterans who volunteered for the first time for treatment between 1972 and 1979 to an inpatient Drug Dependence Treatment Program (DDTP) of a Veterans Administration Medical Center. Two hypotheses were tested: First, that minority group heroin addicts (blacks and Hispanics) will show better adjustment than majority group (white) heroin addicts; second, that Hispanic-American heroin addicts will evidence personality characteristics unlike those of either whites or blacks. Both hypotheses were confirmed. Results were interpreted as supporting cultural theories of substance abuse and providing implications for diagnosis and treatment of substance abuse disorders among minority ethnic groups.