融合特征空间最小方差波束形成和广义相干系数的超声成像方法

为了进一步提高超声成像的质量,提出了融合特征空间最小波束形成和广义相干系数的成像方法。首先利用最小方差法计算回波数据的协方差矩阵和加权向量;然后对协方差矩阵进行特征分解得到信号子空间,并将加权向量投影到信号子空间,得到特征空间方法的加权向量;同时把阵元数据变换到波束域用于广义相干系数的计算,最后用广义相干系数作为加权系数对特征空间最小方差波束形成的结果进行优化。为了验证算法的有效性,对医学成像上常用的点目标和斑目标进行了成像,仿真实验结果表明：与特征空间最小方差算法和融合特征空间与相干系数的算法相比,本研究提出的方法提高了对比度以及稳健性,其代价是略微降低了成像分辨率。     

图像分割技术在中医舌诊客观化研究中的应用

舌诊是中医四诊的主要内容,是辨证论治的主要依据。客观化研究对中医辨证规范化及中医临床、教学和科研手段的现代化具有重要意义。对舌诊客观化研究中涉及的图像预处理的重要内容——舌体分割提取和舌苔舌质同类区域划分——进行了深入研究,提出了相应算法,通过实验充分证明了算法具有很好的鲁棒性。这给进一步的自动特征提取提供了保障和重要信息。     

基于特征聚类的舌下络脉自动提取方法

舌下络脉诊是中医舌诊中十分重要的一种手段，本研究提出了一种基于特征聚类分析的舌下络脉自动提取方法，该算法在L＊a＊b＊色彩空间下，利用K-均值聚类算法对舌下区域按颜色进行聚类，根据聚类中心的位置，确定舌下络脉所在的聚类，并计算出舌下络脉的特征参数，对每一例舌下数据给出6个参数，表征络脉的长度，宽度以及颜色。应用此算法对北京东直门医院886例肝病病人的舌下图像数据进行分析，经中医医生判断，成功提取舌下络脉839例，成功率达96．88％。     

B型超声心动图中心脏组织及结构的识别

本文描述了一种从B型超声心动图识别心脏组织及结构的方法。该方法融合了空间特征信息及纹理特征信息，并经神经网络进行识别进而给出心脏组织及结构的类别标号图象，在空间特征提取中，采用了基于模糊的模型分割方法，该方法可将各类组织交界附近隶属度带识别过程中并融保纹理特征，因而有较好的识别率，该方法已在一台PentiumⅡPC机上进行了模拟，并获得了较好的实验结果。     

中医诊断的思想模型与数学模型：中医专家系统知识描述初论

本文从中医诊断的思维方式,主要不是推理而是模式识别及中医辨证记忆方式是以“证”(模式)为组块结构的理论观点出发,采用语言变量及模糊逻辑原理,提出中医辨证的多级语言结构,作为人工智能中医专家系统的知识描述系统。文中讨论了根据医理与经验计算非数值基础变量(症状)与语言值(证)隶属度的方法,用之解决由诸特征构成一个模糊模式的问题。方法简捷实用,符合医生诊断时的思维方式。这样,也将多阈元表示法统一于模糊逻辑中了。中医辨证的语言变量系统与模糊逻辑,就是中医诊断思想模型——中医辨证理论的数学模型。提出这样的模型可以以知识的描述与表达为中心,从本质上(专家经验规范形式等)与知识获取统一起来,并由前者统领后者。这样的数学模型,除对中医外,对其它专业,组织管理工作等也有广泛的应用前景。     

非言语型学习障碍儿童视觉空间认知特征与行为问题

目的:对我国汉族非言语型学习障碍(nonverbal learning disorder, NLD)儿童视觉空间认知特征以及行为问题进行分析,以探讨其相互之间关系。方法:三组儿童(NLD组,VLD组和正常对照,每组40人)进行智力测定、绘人测验和CBCL儿童行为量表测量,根据智力结构模型分析其视空间能力与行为问题。结果:NLD儿童在空间能力、视动协调、视动速度、图形认知、视觉记忆、非言语推理、视觉组合方面都比正常儿童和VLD儿童差(P<0.05),而VLD儿童则与正常儿童无差别(P>0.05)。NLD儿童在分裂焦虑、强迫性、社交退缩、多动、攻击性等行为方面较其他两组儿童多(P<0.05)。结论:我国汉族NLD儿童视觉空间认知存在缺陷,其行为问题可能与此有关。     

基于Local Jet变换空间纹理特征的肺结节分类方法

为了在纹理特征下改善肺结节良、恶性的模式识别,提出一种基于local jet变换空间的纹理特征提取方法。首先利用二维高斯函数的前三阶偏微分函数将结节原图像变换到local jet纹理图像空间,然后利用纹理描述子在该空间提取特征参数。以灰度值的前四阶矩和基于灰度共生矩阵的特征参数作为纹理描述子,分别提取结节原图像和变换后纹理图像的特征参数,以BP神经网络作为分类器,对同一纹理描述子下的2个不同图像空间的经核主成分分析优化后的特征参数集进行结节良、恶性分类。以157个肺结节(51个良性,106个恶性)作为实验数据进行对比实验,结果显示:两种纹理描述子基于local jet变换空间提取的特征参数分别获得82.69%和86.54%的分类正确率,较原图像空间提高6%～8%,同时AUC值提高约10%。实验结果表明,基于local jet变换空间提取的纹理特征可以有效地改善肺结节良、恶性的模式识别。     

中医舌象自动分类方法研究

研究计算机舌象分析方法,对进一步推动中医现代化,有重要作用.本文提出了一种同时包含位置和颜色信息的舌象特征表示方法,实现了中医观点下舌色的自动分类.提出把HSV颜色空间中极坐标系下的H、S分量转化为直角坐标系的X、y分量,并以此作为颜色特征,比较了这两种颜色特征表达方法对分类结果的影响.实验结果表明,(X,y,V)颜色特征表示方法具有更好的分类效果.     

股骨头坏死松质骨生物力学特征的空间分布规律

目的 探究股骨头坏死松质骨微观结构参数和力学性能的空间分布规律,为临床诊断中科学评估病灶对病情的影响提供理论依据。方法 结合影像学测量和数值模拟方法,定量分析不同区域松质骨的微观结构参数和力学性能,分别从冠状面、矢状面和水平面投影方向上探究松质骨生物力学特征的空间分布特点。结果 在股骨头冠状面和矢状面投影方向上,松质骨的微观结构特征与力学性能大致呈Y型分布,Y形区域内松质骨的力学性能高于其他区域,该分布特点与股骨头内的主压应力束的位置相吻合。结论 位于股骨头Y形区域内的坏死灶对股骨头内应力分布的影响程度会更大,更有可能导致病情恶化。临床诊断中应充分考虑坏死灶和Y形区域的位置关系。     

基于四阶累积量矩阵子空间分解的脑电逆问题算法

根据头表观测电位反演脑电源的空间位置是脑电研究中的一个重要问题,基于四阶累积量矩阵的子空间分解,提出了一种新的脑电问题算法,与现有的基于二阶统计量矩阵的子空间分解算法相比,二阶方法存在对空间相关噪音敏感的问题,而阶方法可以抑制在时间方向上呈高斯分析,在空间方向相关的噪音,从而显示了四阶方法的较好性能。     

Topical organization of the projections of neurons of the substantia nigra and the ventral field of the tegmentum of the midbrain to the head of the caudate nucleus of the cat

Neuroscience and Behavioral Physiology -     

Asymmetry of the internal connections of the striate cortex of the cat in the projection zone of the center of the field of vision

Studies were carried out on the organization of the internal connections of the striate cortex in cats in the projection zone of the center (0–5°) of the field of vision by microintophoretic application of horseradish peroxidase to electrophysiologically identified orientational columns. The area containing neurons showing retrograde labeling in most cases extended in the mediolateral direction. Labeled cells were located in the upper (II, III) and lower (V, VI) layers of the cortex, and the shapes and orientations of the areas containing labeled neurons in these layers coincided. Spatial asymmetry was detected in the distribution of labeled neurons relative to the orientational column studied. Labeled cells were located predominantly medial to the columns, regardless of the distance from the projection of the area centralis. Considering the visuotopical map of field 17, the asymmetry detected here provides evidence that neurons in orientational columns have more extensive connections with neurons of the peripheral part of the cortex. An asymmetrical distribution of “silent” zones around the receptive fields of neurons in orientational columns is suggested, and that these appear to receive influences from the periphery of the visual field. Laboratory of Visual Physiology and Laboratory of Central Nervous System Morphology, I. P. Pavlov Institute of Physiology, Russian Academy of Sciences, 6 Makarov Bank, 199034 St. Petersburg, Russia. Translated from Fiziologicheskii Zhurnal imeni I. M. Sechenova, Vol. 82, No. 12, pp. 23–29, December, 1996.     

Characteristics of the topographic interrelation of the head of the pancreas and the duodenum and pathology of the organs of the pancreatoduodenal area

Seventy pancreatoduodenal complexes of 55 patients with chronic pancreatitis and tumours of this zone and 15 patients died from other diseases are studies histotopographically . The pieces of the pancreatic head tissue in the medial wall of the duodenum were found in 12 cases of the first group and in 4 control cases. The pancreatic tissue consisted either of all elements of this organ or cystically dilated ducts and seemed to infiltrate different layers of the duodenum wall. Three variants of the pancreatic head structure are suggested on the basis of anatomo-topographical interrelationships of the pancreatic head and duodenum. In 12 out of 14 cases chronic pancreatitis and carcinoma of organs of this zone were combined with the variants of the pancreatic head structure, in 2 cases there was a true heterotopy . Pathogenetic significance of these variants for the development of chronic pancreatitis is discussed.     

Influence of the level of the transmembrane potential on the dynamics of the extinction of the amplitude of the synaptic reactions of the snail under voltage clamping conditions

The influence of the level of the transmembrane potential on the dynamics of the extinction of the amplitudes of summary excitatory postsynaptic currents arising in identified giant parietal neurons in response to rhythmic stimulation of the intestinal nerve was investigated in a preparation of the isolated CNS of the common snail in order to identify the possibility of the participation of the postsynaptic element in synaptic plasticity. It was demonstrated that, at a greater value of the transmembrane potential, the decrease in the amplitudes of the postsynaptic currents which have been induced by rhythmic stimulation takes place more rapidly. It was also demonstrated that at a higher frequency of stimulation of the nerve, the effect of the influence of the membrane potential level on the dynamics of the synaptic reactions is more prominent. The data obtained may be regarded as an argument in favor of the possibility of the participation of the post-synapse in plasticity. This study was partially supported by the Russian Basic Research Fund (project No. 94-04-12209). Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow. Translated from Zhurnal Vysshei Nervnoi Deyatel'nosti imeni I. P. Pavlova, Vol. 45, No. 1, pp. 171–179, January–February, 1995.     

Effects of the lesion of the postcommissural part of the septum on the behavior of the rat.

The effects of the lesion of the postcommissural part of the septum on behavior of the rat has been studied. Results may be summarized as follows. An increase in the exploratory behavior in the open field which decreases rapidly; a decrease in the number of defecations in this test and a decrease in time leaving a dark environment for exploration. In the shuttle box test, no facilitation of the acquisition, but a permanent and quite significant increase in the intertrial activity has been found. We conclude that the lesions tend to decrease the emotivity of the subjects. An interpretation on the basis of the species -- specific defensive reactions explains the transitory and permanent effects of the lesions on the spontaneous activity.     

Effect of the conditions of adaptation of the optic analyzer to the function of the thermoreceptors of the human skin

Summary A discussion is presented of the effect produced by light stimulation applied to the optic analyzer alone on the function of the temperature analyzer. The cutaneous-temperature analyzer was kept on constant illumination and temperature. The light effects from the retinal photoreceptors on the cutaneous thermoceptor system led to reflex changes of the functional rate of the latter. Conditions of the optic analyzer of light adaptation caused reflex adjustment of cold receptors as to heating. Dark adaptation of the eyes changed the functional state of the cold receptors, corresponding to their adjustment to low temperatures.(Presented by Active Member AMN SSSR V. V. Parin) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 57, No. 3, pp. 3–6, March, 1964