振动法血压测量中血压的判定方法

讨论了振动法血压测量中血压的判定方法，并提出了一种基于宽松规一化准则用幽会法判定收缩压和舒张压的新方法，初步实验表明，该方法是可行的。     

柯氏音法与示波法相结合的新型血压测量仪研究

为提高电子血压计的准确性,研制出将柯氏音法与示波法结合的新型血压测量装置.首先在研究测量过程和信号处理方法的基础上,设计基于驻极体麦克风和电容式压力传感器的电子血压计系统架构;再利用柯氏音和脉搏波的密切相关性,建立基于统计规律的时域窗函数对柯氏音声强信号进行选择性放大,并设计相关实验验证了该方法的有效性;然后提出利用柯氏音法准确性和示波法稳定性的血压值综合求算逻辑.通过初步测试实验和分析,证实了该装置测量结果具有较高的准确性和稳定性.研究表明,利用柯氏音与脉搏波的关系进行综合信号处理和血压值测算,有望获得高准确性的血压自动测量方法.     

心电同步在脉搏血氧测试中的应用

本文讨论了血氧饱和度测量中的一种新方法；心电信号的Ｒ波来同步脉表示皮信号，更好地从脉搏波信号中提取物征值。更进一步，根据Ｒ波对脉搏波中平均，提高信噪比，利用平均后的脉搏波计算血氧饱和度，经证明可得到更好的结果。     

基于脉搏波信号和血管弹性腔模型的动脉血压连续测量方法

目的为满足健康监护中的连续测量血压的要求,研究并实现一种基于脉搏波信号和血管弹性腔模型的动脉血压拟合计算方法。方法利用自制的穿戴式人体生理参数监测系统收集测试对象的脉搏波信号、心电信号以及血压数据。根据心电信号与脉搏波信号的时间关系,推导出收缩压和脉搏波传导时间的回归分析方程,而舒张压的测量,则是通过脉搏波的波形系数分析以及血管单弹性腔模型的参数计算完成。结果试验结果表明,该方法血压测量结果的平均偏差和标准偏差为(0.51±0.74)kPa([384±5.54)mmHg],达到了美国医疗仪器促进协会建议的(0.665±1.064)kPa([5±8)mmHg]标准。结论结合脉搏波信号和弹性腔模型可以估算人体血压值,为连续血压测量提供了新的实现方法。     

高介神经网络用于心电信号的识别

心电图（ＥＣＧ）的自动识别用分类长期以来一直是较难解决问题，特别是当截取ＥＣＧ信号的起点不同（相当于信号发生平移）及有基线漂移（相当于信号发生旋转）时，在不作预处理情况下要求仍能正确识别及分类，即要求识别过程具有平移不变性和旋转不变性，更是困扰生物医学工程工作者的困难问题之一。作者采用高阶神经网络（二阶）、对五类（正常类，高Ｒ波类、高Ｔ波类、Ｔ波倒置类及心律不齐类）具有平移及旋转的ＥＣＧ信号进行分     

小波变换在心电图QRS波检测中的应用

作者利用信号的小波变换在多尺度边沿上的综合特性，提出了一种新的ＱＲＳ波检测法。有要用Ｍａｌｌａｔ快速算法获得原始ＥＣＧ信号在不同尺度上小波分解信号，将含有大部分高频ＱＲＳ波在多尺度上的分解信号送和一个线性自适应匹配滤波器，匹配滤波器的输出用于检测Ｒ波的位置。对ＭＩＴ数据库中的数据进行了检测，Ｒ波的检测率可达９９．８％。     

脑电棘波识别和噪声消除的小波变换方法

研究了利用二进小波变的的模极大值识别脑电信号奇异点如棘波和消除噪声的方法，该方法在较好保留原脑电信号奇异信息的同时能有效地消除噪声，进一步讨论了信号与白噪声的奇异性指数的区别，以及小波变换模极大值沿各变换尺度传递的不同特性，并利用该特性区分信号中的奇异点和噪声，能准确识别奇异点的位置，这种奇异性识别技术在信号的特征提取和消除噪声方面有广阔的应用前景。     

基于光电容积脉搏波的无袖带血压测量技术研究进展

无袖带血压监测技术由于低生理/心理负荷等特点，在健康监测领域具有广阔的应用前景。其中，基于光电容积脉搏波的无袖带血压测量技术能够获取连续动态的血压参数，有效弥补传统袖带血压测量不便、间断测量等不足。本文对基于光电容积脉搏波的无袖带血压测量技术的研究进展进行综述。首先从传感测量和数据处理方面介绍了光电容积脉搏波信号的获取与分析方法。然后简述了传统的基于脉搏波速度理论进行血压测量的研究，重点分析了该领域的主要研究方向：基于形态学参数的机器学习方法研究以及基于序列学习的深度网络研究。最后对基于光电容积脉搏波的无袖带血压测量技术所面临的挑战及其应对策略进行了深入分析和详细讨论，以期为该领域的相关研究提供参考。     

利用脉搏波连续检测家兔血压的实验研究

目的:研究利用脉搏波连续检测血压方法的准确性和可行性.方法:采用动脉插入法连续测量10只健康成年家兔的血压,并同步记录脉搏波信号.提取某一时段的每搏血压值及相应的脉搏波特征参数进行逐步回归分析,并形成回归方程.利用该回归方程和另一时段的脉搏波特征参数计算该时段的每搏血压值.结果:计算血压值与真实血压值的偏差很小.平均偏差在1 mmHg以内.结论:该方法具有良好的准确性,今后有望应用于实际.     

基于稀疏分解的心电信号波形检测及形状识别

为对心电信号进行波形检测和形状识别，解决心电信号自动诊断的重点和难点，在稀疏分解的理论基础上，构造符合心电信号特点的超完备字典，基于此字典，利用匹配追踪算法对心电信号做稀疏分解。根据稀疏分解所得解向量及与解向量在字典中对应的原子找出心电信号的特征波的起点、终点、峰值点等，最终实现心电信号的几种特征波的波形检测及形状识别。实验证明该算法的QRS波群检测率为99％，P波、T波检测率为85％，对P波和T波的形状识别符合人的主观判断。这些检测和识别结果为心脏病的自动诊断提供了依据。     

Adaptive analysis of harmonic oscillation for biological signals

A mathematical method of discrete signal processing of harmonic oscillation in a finite window has been found. The signal is sampled and analysed in the finite window, which is regarded as the basic period of an oscillation. Each instantaneous value of harmonics is successively given by fixed linear transformation of the arithmetic means of the data from frequency sampling. By using this method the fundamental frequency of an oscillation, its harmonics and their mutual phase relationship can be estimated precisely. This method will be applicable to designing electronic circuits and computer programs.     

Cell membrane destabilizes progressively during repetitive mechanical rupture events

The postfusion oscillation cycle method of electrofused cells was applied to red blood cell membranes to induce repetitive membrane ruptures and test the mechanical membrane resistance against sequential events of membrane strain and rupture. After producing doublets from pairs of electrofused cells, they entered the oscillation cycle, providing a sequence of at least four consecutive colloidosmotic-driven rupture events. Different gradations of colloidosmotic pressure loads between 3230 Pa and 8640 Pa were established with various buffer types. The independence of buffer type and geometrical and mechanical observations has been verified independently for both parts of the oscillation sequence. With decreasing colloidosmotic inducement, caused by repetitive oscillation cycles, an increasing susceptibility of the cell membrane against membrane rupture was measurable. Since side-effects had been eliminated, it could be concluded that the cell membrane resistance against repetitive mechanical ruptures decreases.     

Ca2+ oscillation induced by P2Y2 receptor activation and its regulation by a neuron-specific subtype of PKC (gammaPKC)

We found that stimulation of P2Y2 receptor (P2Y2R), which is endogenously expressed in CHO-K1 cells, induced intracellular calcium ([Ca2+]i) oscillation with a low frequency of 11.4 +/- 2.7 mHz. When CHO-K1 cells expressing GFP-tagged kinase-negative gammaPKC (gammaPKC-KN-GFP), which is a neuron-specific subtype of PKC, were stimulated with UDP, gammaPKC-KN-GFP, but not wild-type gammaPKC (gammaPKC-GFP) showed an oscillatory translocation. The oscillatory translocation of gammaPKC-KN-GFP corresponded with [Ca2+]i oscillation, which was not observed in the cells expressing gammaPKC-GFP. We examined the mechanism ofP2Y2R-induced [Ca2+]i oscillation pharmacologically. gammaPKC-KN-GFP oscillation was stopped by an extracellular Ca2+ chelator, EGTA, an antagonist of P2Y2R, Suramin, and store-operated calcium channel (SOC) inhibitors, SKF96365 and 2-ABP. Taken together, P2Y2R-induced [Ca2+]i oscillation in CHO-K1 cells is related with Ca2+ influx through SOC, whose function may be negatively regulated by gammaPKC. This [Ca2]i oscillation was distinct from that induced by metabotropic glutamate receptor 5 (mGluR5) stimulation in the frequency (72.3 +/- 5.3 mHz) and in the regulatory mechanism.     

Influence of design parameters on cup-stem orientations for impingement free RoM in hip implants

This study was conducted to study the influence of design parameters namely; the head/neck ratio (R), neck-shaft angle (NSA), oscillation angle (OsA) and stem offset (Sθ) on cup-stem orientations namely; the cup inclination (CI), cup anteversion (CA) and stem antetorsion (SA). R is often linked to influence NSA, OsA and impingement. An effort has been made to analyze range of motion (RoM) with NSA greater than 135° and R lower than 2.3 that may produce impingement. This study attempted to answer the following assumptions whether (a) implants with higher H-N ratio can achieve higher oscillations and higher stem antetorsion, (b) stems with higher neck shaft angle can achieve higher cup anteversion with lower stem offset and stem antetorsion, (c) stem with higher offsets can achieve lower cup anteversion with higher stem antetorsion, and (d) lower cup anteversion can be achieved when stem antetorsion is higher. A theoretical and a simulated method were implemented to anaylze RoM until impingement between cup and neck occurred. Cup abduction and anterior opening were held constant for this study. Multivariate prediction models were developed to predict optimal cup-stem orientations for the chosen design parameters of 12 hip implants. Optimal design parameters to achieve an impingement free RoM were as follows: NSA=139.25°, R=3.08, OsA=119.83°, Sθ=34.45mm, CA(predicted)=16.26°, CI(predicted)=42.77° and SA(predicted)=30.37°, respectively. Multivariate models may be further developed for use in surgery planning to achieve optimal component placement.     

Neuronal organization of the reticular nucleus of the thalamus in adult humans

The neuronal composition of the thalamic reticular nucleus was studied in serial sections of the sagittal and frontal projections impregnated with silver nitrate by the Golgi method. The neuronal composition of the reticular nucleus of the human thalamus was wider than has previously been described in animals and humans. This nucleus, apart from two types of large, sparsely branched, long-dendrite, reticular, aspiny, neurons, i.e., types R1 and R2, contained cells with spines. Intermediate and small, sparsely-branched, short-dendrite neurons and densely-branched cells with spines were demonstrated. The principles of the organization of the reticular nucleus of the human thalamus are described. __________ Translated from Morfologiya, Vol. 127, No. 3, pp. 21–26, May–June, 2005. Candidate of Biological Sciences     

Cerebellar network plasticity: from genes to fast oscillation

The role of the cerebellum has been increasingly recognized not only in motor control but in sensory, cognitive and emotional learning and regulation. Purkinje cells, being the sole output from the cerebellar cortex, occupy an integrative position in this network. Plasticity at this level is known to critically involve calcium signaling. In the last few years, electrophysiological study of genetically engineered mice has demonstrated the topical role of several genes encoding calcium-binding proteins (calretinin, calbindin, parvalbumin). Specific inactivation of these genes results in the emergence of a fast network oscillation (ca. 160 Hz) throughout the cerebellar cortex in alert animals, associated with ataxia. This oscillation is produced by synchronization of Purkinje cells along the parallel fiber beam. It behaves as an electrophysiological arrest rhythm, being blocked by sensorimotor stimulation. Pharmacological manipulations showed that the oscillation is blocked by GABA(A) and NMDA antagonists as well as gap junction blockers. This cerebellar network oscillation has also been documented in mouse models of human conditions with complex developmental cerebellar dysfunction, such as Angelman syndrome and fetal alcohol syndrome. Recent evidence suggests a relationship between fast oscillation and cerebellar long term depression (LTD). This may have major implications for future therapeutic targeting.     

Direct readout of respiratory impedance

Because the technique of forced oscillations requires little co-operation from the patient it is frequently employed in the diagnosis and treatment of respiratory diseases. To make routine use of this method possible, by medical researchers as well as clinicians, a special-purpose computer has been developed to determine those parameters of interest. The total respiratory resistance and the phase angle of the respiratory system are read out directly in one of three possible ways; over each cycle of imposed oscillation, averaged over inspiration or expiration, or averaged over several breaths. The frequency of imposed oscillation is variable from 4–16 Hz. Over this band of frequencies, resistance calculations have a dynamic range of 20∶1, while phase angle is measured between ±90°.     

Propagating wave and irregular dynamics: spatiotemporal patterns of cholinergic theta oscillations in neocortex in vitro

Neocortical "theta" oscillation (5-12 Hz) has been observed in animals and human subjects but little is known about how the oscillation is organized in the cortical intrinsic networks. Here we use voltage-sensitive dye and optical imaging to study a carbachol/bicuculline induced theta ( approximately 8 Hz) oscillation in rat neocortical slices. The imaging has large signal-to-noise ratio, allowing us to map the phase distribution over the neocortical tissue during the oscillation. The oscillation was organized as spontaneous epochs and each epoch was composed of a "first spike," a "regular" period (with relatively stable frequency and amplitude), and an "irregular" period (with variable frequency and amplitude) of oscillations. During each cycle of the regular oscillation, one wave of activation propagated horizontally (parallel to the cortical lamina) across the cortical section at a velocity of approximately 50 mm/s. Vertically the activity was synchronized through all cortical layers. This pattern of one propagating wave associated with one oscillation cycle was seen during all the regular cycles. The oscillation frequency varied noticeably at two neighboring horizontal locations (330 microm apart), suggesting that the oscillation is locally organized and each local oscillator is about 相似文献