Diagnostica-a Bayesian decision-aid system-applied to hypertensiondiagnosis

Diagnostica is a Bayesian statistical tool designed to collect and store the patient's data, suggest a diagnosis, and explain the decision in terms of density distributions. The program is written in C language on MacIntosh support. It is describes using a case study of differential diagnosis between essential and secondary hypertensions. Seventeen experimental parameters were taken into consideration, all of them available during the first medical examination. The density distributions of all items were established from the ARTEMIS experimental database. Both a priori probabilities of different types of hypertension and loss coefficients are taken into account in the calculations. Diagnostica can be used in a `make diagnosis' mode or in an `edition' mode. In the first case it can serve a physician in everyday practice; in the second it becomes a tool for medical research     

急性冠脉综合征、肾动脉狭窄、急性左心衰三联征的临床研究

目的提高对急性冠脉综合征、肾动脉狭窄、急性左心衰三联征的诊治率。方法回顾性分析25例急性冠脉综合征、肾动脉狭窄、急性左心衰三联征患者的临床资料,分析基线资料与预后的关系。结果高血压、陈旧性心梗、陈旧性脑梗、高脂血症、糖尿病、吸烟、周围血管病等危险因素的发生率分别为100%、54.0%、60.0%、40.0%、48.0%、36%;出现典型心绞痛症状至冠心病确诊(发生心梗/冠脉造影/冠脉CT确诊)平均为5.3年,冠心病确诊-肾动脉狭窄确诊约6.2年,心绞痛症状至肾动脉狭窄确诊约11.5年。造影结果13例为双侧肾动脉狭窄,平均冠脉病变为2.6支,确诊后所有患者进行了冠脉和(或)肾动脉介入或冠脉搭桥术。2例治疗无效死亡,其余23例好转出院,其中3例肾功能较入院时恶化。2年随访期内12例病情好转或稳定,4例死亡,7例发生次级终点事件;因小样本及选择偏倚,无基线资料与预后相关。结论三联征术后及两年预后较差,早期诊断、治疗才能减少发病率及改善预后。     

Isosurfaces as deformable models for magnetic resonance angiography

Vascular disease produces changes in lumenal shape evident in magnetic resonance angiography (MRA). However, quantification of vascular shape from MRA is problematic due to image artifacts. Prior deformable models for vascular surface reconstruction primarily resolve problems of initialization of the surface mesh. However, initialization can be obtained in a trivial manner for MRA using isosurfaces. We propose a methodology for deforming the isosurface to conform to the boundaries of objects in the image with minimal a priori assumptions of object shape. As in conventional methods, external forces attract the surface toward edges in the image. However, smoothing is produced by a moment that aligns the normals of adjacent surface triangles. Notably, the moment produces no translational motion of surface triangles. The deformable isosurface was applied to a digital phantom of a stenotic artery, to MRA of three renal arteries with atherosclerotic disease and MRA of one carotid artery with atherosclerotic disease. Results of the surface reconstruction from the deformable model were compared with conventional X-ray angiography for the renal arteries. Measurement of the degree of stenosis of the renal arteries was within 12% +/- 6%. The deformable model provided improvements over the isosurface in all cases in terms of measurement of the degree of stenosis or improving the surface smoothness.     

飞行人员变应性鼻炎的临床诊治和医学鉴定

目的总结飞行人员变应性鼻炎的临床诊治和健康鉴定经验。方法分析飞行人员因变应性鼻炎而住院诊治的病历资料53份,对其进行分类、分型和分度,并分析与继发性气压伤之间的关系。结果飞行人员变应性鼻炎Ⅰ类（飞行中无继发性气压伤表现）30例,Ⅱ类（飞行中出现继发性气压伤表现）23例;常年性变应性鼻炎28例,花粉症25例。44例继续飞行．9例永久停飞。结论飞行人员变应性鼻炎常见,继发性气压伤和常年性变应性鼻炎是医学停飞的重要原因.     

Towards efficient data collection mechanisms in the vehicular ad hoc networks

Recently, the fast growth of communication technology has led to the design and implementation of different types of networks in different environments. One of these remarkable networks is vehicular ad hoc network (VANET). The ubiquitous connectivity among vehicles is possible through VANET in the absence of fixed infrastructure. Moreover, it provides safety and comfort to people sitting in the vehicles. In this regard, collecting information from vehicles that are moved constantly is an essential challenge. To develop an efficient method for data collection in the VANET, some parameters must be considered such as data aggregation, latency, packet delivery ratio, packet loss, scalability, security, transmission overhead, and vehicle density. Since data collection has a significant importance in the VANET, the aim of this study is to investigate the existing methods and describe the types of important issues and challenging problems that can be addressed in data collection in the VANET. The data collection techniques are investigated in four primary groups, namely, topology‐based, cluster‐based, geocast‐based, and fog‐based. Also, the mentioned parameters are important to compare all of the presented techniques.     

HELLP综合征合并急性肾功能衰竭10例分析

目的探讨HELLP综合征合并急性肾功能衰竭(ARF)的临床特点、诊断、治疗和孕产妇及新生儿预后。方法对我院2005年1月-2008年12月以来HELLP综合征合并ARF的10例患者临床资料进行回顾性分析。结果多为妊娠期高血压疾病的并发症,以血压升高、恶心、呕吐、水肿、皮下淤斑或黏膜出血、少尿或无尿为特点,乳酸脱氢酶、转氨酶、血小板、血肌酐等均为诊断及监测疾病变化及预后的指标;在常规治疗HELLP的基础上及时终止妊娠、行血液净化治疗,是防止病情恶化降低孕产妇及围产儿死亡率的关键。结论HELLP综合征合并ARF发病急而凶险,早期诊断、综合治疗、及时终止妊娠及血液净化治疗是改善孕产妇及新生儿预后的关键。     

Waveform preserving encoders for the compression of EEG data

This paper discusses several approaches to the redundancy reduction of clinical electroencephalographic (EEG) data. The encoders presented here are basically of two types. The first type compresses EEG data with very little visual or spectral information present in the original lost in the compression/decompression process. The other type compresses EEG data with some loss of visual reconstruction quality (although still acceptable) but with the advantage of achieving high compression ratios, and providing a convenient and natural way for subsequent automated EEG diagnosis. In deriving redundancy reduction encoders, the efficiency of several digital compression techniques has been compared by encoding EEG data. The general approach adopted, however, is not restricted to this class of data, but can be applied (with minor modifications) to other data of similar characteristics.     

冷球蛋白血症肾损害的超微结构特征及其诊断意义

为探讨冷球蛋白血症肾损害的超微结构特征及其在本病诊断中的作用,对冷球蛋白血症肾损害的肾活检标本进行系统的电镜超微结构观察,并分析其临床、病理特点及超微结构的改变。12例冷球蛋白血症肾损害病例中,原发性冷球蛋白血症5倒,继发性冷球蛋白血症7例。膜增生性肾小球肾炎是其最常见的病理类型。其次为非典型膜性肾病及毛细血管内增生性肾小球肾炎;可见肾小球内皮细胞下及毛细血管腔内大量嗜复红蛋白沉积形成白金耳或微血栓样结构。电镜检查可见肾小球内的电子致密物形成多种有形结构,包括微管状、纤维状、晶格样及颗粒样结构等,主要分布于肾小球内皮细胞下及毛细血管腔内,也可见于上皮细胞下、基底膜内及系膜区;并可见毛细血管腔内含大量吞噬溶酶体的单核细胞浸润。肾组织内形成特殊有形结构的电子致密沉积物是冷球蛋白血症肾损害的突出超微结构特征,在冷球蛋白血症肾损害的诊断中具有重要意义。     

Multiple Incidence Angle SIR-B Experiment Over Argentina: Mapping of Forest Units

Multiple incidence angle SIR-B data of the Cordón la Grasa region of the Chubut Province of Argentina are used to discriminate nate various forest types by their relative brightness versus incidence angle signatures. The region consists of several species of Nothofagas which change in canopy structure with elevation, slope, and exposure. In general, the factors that appear to impact the radar response most are canopy structure, density, and ground cover (presence or absence of dead trunks and branches in particular). The results of this work indicate that 1) different forest species, and structures of a singlee-species, may be discriminated using multiple incidence angle radar-imagery and 2) it is essential to consider the variation in backscatter due to incidence angle when analyzing and comparing data collected at varying frequencies and polarizations.     

Coronary Artery Stenosis Quantification for Computed Tomography Angiography Based on Modified Student's t‐Mixture Model

Coronary artery disease (CAD) is a major cause of death in the world. As a non‐invasive imaging modality, computed tomography angiography (CTA) is now usually used in clinical practice for CAD diagnosis. Precise quantification of coronary stenosis is of great interest for diagnosis and treatment planning. In this paper, a novel cluster method based on a Modified Student's t‐Mixture Model is applied to separate the region of vessel lumen from other tissues. Then, the area of the vessel lumen in each slice is computed and the estimated value of it is fitted with a curve. Finally, the location and the level of the most stenoses are captured by comparing the calculated and fitted areas of the vessel. The proposed method has been applied to 17 clinical CTA datasets and the results have been compared with reference standard degrees of stenosis defined by an expert. The results of the experiment indicate that the proposed method can accurately quantify the stenosis of the coronary artery in CTA.     

Implementation of security policy for clinical information systems over wireless sensor networks

Various healthcare areas such as diagnosis, surgery, intensive care and treatment, and patient monitoring in general, would greatly benefit from light, autonomous devices which can be unobtrusively mounted on the patient’s body in order to monitor and report health-relevant variables to an interconnection device in the vicinity. This interconnection device should be able to connect to access points at different locations within the healthcare institution. In this manner, health-relevant measurements can be forwarded to the central medical database and stored therein. In this scenario, integrity and privacy of personal medical data is of utmost importance. In this paper we address the networking and security architecture of a healthcare information system comprised of patients’ personal sensor networks, department/room networks, hospital network, and medical databases. We discuss confidentiality and integrity policies for clinical information systems and propose the feasible enforcement mechanisms over the wireless hop. We also compare two candidate technologies, IEEE 802.15.1 and IEEE 802.15.4, from the aspect of resilience to jamming and denial-of-service attacks.     

A Theoretical Study of Arterial Disease by Transfer Function Analysis

A general method is proposed for a theoretical evaluation of the hemodynamic effects of stenosis on the arterial subsystem affected by it. In particular, it is applied to a lower limb stenosis, so as to compare the results of the theoretical analysis to those that other authors have obtained experimentally by processing Doppler ultrasound blood flow velocity measurements proximal and distal to a stenosis in the superficial femoral artery (SFA).     

电镜检查在小儿肾活检病理诊断中的作用

应用常规电镜技术对329例小儿肾活检病例进行了检查。结果表明：在小儿肾活检病例中，通过电镜检查可对微小病变性肾小球病、薄基底膜肾病、Alport综合征、早期膜性肾病等做出明确诊断；电镜检查还可提示部分肾小球疾病的病因，如lgA肾病、乙肝病毒相关性肾炎、狼疮性肾炎等。因此，电镜检查是小儿肾活检病理诊断中一种必要的手段。     

Extinction Behavior of Dry Snow in the 18-to 90-GHz Range

The extinction properties of several dry snow types were examined in the 18-to 90-GHz range. The snow types ranged from newly fallen snow to refrozen snow, and the density and mean grain size varied from 0.17 to 0.39 g/cm3 and from 0.2 to 1.6 mm, respectively. From measurements of the transmission loss as a function of sample thickness at a temperature of -15°C, the extinction coefficient and the surface scattering loss (due to surface roughness at the front and back surfaces of the snow slab) were determined for each snow type. The experimental values were compared against theoretical results computed according to the strong fluctuation theory. In general, good agreement with the experimental data was obtained at 18, 35, and 60 GHz when the grain size used in the theoretical calculations was chosen to be slightly smaller than the observed snow-particle size. However, the extinction coefficient of large-grained refrozen snow as predicted by the strong fluctuation theory is much larger at 90 GHz than the values determined experimentally. The attenuation in snow was observed to increase only slightly with increasing temperature in the -35 to -1°C range.     

A computer approach to laser design

The problem of maximizing laser efficiency is usually approached through experimental study. The method proposed in this paper permits us to approximate the optimum design prior to the actual physical construction of the system. The efficiency of a four-level laser system is first defined as a product of six subefficiencies, each associated with one of the loss mechanisms operative in the system. Equations which relate the subefficiencies to physically measurable parameters are derived. The set of these equations constitutes the model for system efficiency. Based on the model, a program is written for the IBM 1620 digital computer. A sample problem involving the design of a neodymium doped glass laser oscillator is solved to illustrate the use of the model. The results are in general agreement with known theoretical and experimental properties of the pulsed four-level laser. In general, the efficiency increases with length, radius, doping density and pumping energy, and decreases as end reflectivities and pumping pulse time constant increase, within the restrictions imposed on the model by assumptions and approximations.     

Dispersion of Blood Pressure and Heart Rate in Essential Hypertension

The dispersion of the cardiovascular control system variables of heart period, systolic and diastolic blood pressure in a group of resting essential hypertensives has been compared with a group of normotensive subjects. Controlled variable dispersion in the absence of external perturbation was considered to be a measure of short term cardiovascular control system offset (error) from reference values (setpoint). The high blood pressure group demonstrated a greatly decreased controlled variable dispersion compared with the normal, implying the operation of a control system having a high closed loop gain, low system error and poor stability secondary to perturbation or stress. The extent of the changes in control system performance in essential hypertension was reduced by the adrenergic neuron blocking agent, guanethidine. These conclusions are consistent with and are discussed in relation to the known dynamic responses of heart rate and blood pressure to stress, together with the pathophysiology of the forward and feedback pathways of the cardiovascular control system, in essential hypertension.     

43例歼(强)击机飞行员肾结石的诊治及医学鉴定

目的探讨歼（强）击机飞行员肾结石的诊断治疗及医学鉴定原则。方法回顾分析1982年-2008年43名患肾结石的歼（强）击机飞行员病史资料、诊治过程及医学鉴定结论。结果23名肾结石飞行员经治疗结石排出,4例确诊为肾钙化,均飞行合格;3人因结石长期治疗无效予以停飞,1人因其他疾病停飞;12例处于治疗、观察期,结论为飞行暂不合格。结论歼（强）击机飞行员（含飞行教员）患肾结石影响飞行安全,应在结石排出后方可恢复飞行远离集合系统的肾钙化灶可放飞,但应定期复查,掌握其变化情况。     

Primary service outage and secondary service performance in cognitive radio networks

In this work, we have used stochastic geometry to analyze the effects of the radio environment and the secondary service sensing error on the primary service outage probability. We have also obtained a closed form expression for the primary service outage probability in a Rayleigh fading channel. Furthermore, an approximation was formulated for a general fading channel. The results obtained were used to drive an expression for the secondary service successful transmission density. Finally, we formulated an optimization problem to achieve highest density of secondary service successful transmissions while keeping the primary service outage probability in check by adjusting sensing error and secondary service node density to their optimal values. Copyright © 2014 John Wiley & Sons, Ltd.     

Deformable boundary detection of stents in angiographic images

In this paper, a procedure is described for deformable boundary detection of medical tools, called stents, in angiographic images. A stent is a surgical stainless steel coil that is placed in the artery in order to improve blood circulation in regions where a stenosis has appeared. Assuming initially a set of three-dimensional (3-D) models of stents and using perspective projection of various deformations of the 3-D model of the stent, a large set of synthetic two-dimensional (2-D) images of stents is constructed. These synthetic images are then used as a training set for deriving a multivariate Gaussian density estimate based on eigenspace decomposition and formulating a maximum-likelihood estimation framework in order to reach an initial rough estimate for automatic object recognition. The silhouette of the detected stent is then refined by using a 2-D active contour (snake) algorithm integrated with a novel iterative initialization technique, which takes into consideration the geometry of the stent. The algorithm is experimentally evaluated using real angiographic images containing stents.