医学数据挖掘技术与应用研究

计算机技术的发展,促进医疗数据由传统的纸质模式发展成电子模式,信息化后的医疗数据的有效利用将带动医疗事业的发展。本文首先阐述医学数据挖掘现状与特点,然后从分类、聚类与预测三个方面论述了医学数据挖掘的关键方法,并介绍了决策树、聚类分析、关联规则、智能算法及混合算法在内的五类算法在医学数据挖掘中的应用及评价,最后对数据挖掘技术在医学领域的应用前景进行了展望。     

图像数据挖掘的模型和技术

目的:介绍图像数据挖掘的模型及核心技术。方法:原始图像不能直接用于图像数据挖掘,必须进行预处理以生成用于高层次挖掘的图像特征库。一个图像挖掘系统应该包括图像的存储、预处理、检索、挖掘和展示等功能。它主要涉及图像数据挖掘模型和图像数据挖掘技术。结果:MultiMediaMiner是以DBMiner系统和C-BIRD系统为基础发展起来的图像数据挖掘系统,它是典型的功能驱动模型。在信息驱动模型中,象素层和对象层主要进行图像处理、对象识别和特征提取,而语义概念层和模式知识层主要进行图像数据挖掘和知识集成,该模型不仅只在图像的高层次进行挖掘,而且还可以扩展此模型以使挖掘能够在每个层次以及不同层次间进行。基于图像的数据挖掘核心技术涉及:图像处理技术,如去噪、对比度增强、图像分割等技术;特征提取和优化技术;分类、规则提取、预测和聚类等。结论:理论上图像数据挖掘是数据挖掘的一个分支,但是由于挖掘对象的复杂性,所以图像数据挖掘不是传统的数据挖掘理论与技术在图像数据上的简单应用和延伸,而是一个具有自己独特研究内容、理论与技术框架的新的研究领域。     

核磁共振图像分割算法及应用进展

核磁共振成像(MRI)以其无辐射、多方位成像、空间分辨率高等优点在影像医学领域广泛应用,核磁共振图像的分割也发挥着越来越重要的作用.对应用较广的核磁图像的分割算法的原理和应用进行了系统的综述,将核磁图像分割算法分为5个主要研究方面:基于阈值,基于模式识别,基于活动轮廓模型,基于马尔科夫随机场(MRF),基于图切割;给出了不同算法分割特点和相关应用范围,并将部分算法应用在腹部核磁图像上进行分割实验,展示了不同算法分割核磁图像后的效果和特点.最后,展望了核磁图像分割的未来的发展趋势.     

基于运动量的神经网络心率预测器的设计及对比研究

目的 利用神经网络建立有效的基于运动量的心率预测模型,分析运动量与心率变化之间的关系.方法 通过对运动量信号进行不同分析（预处理）,并采用不同的神经网络的结构及学习算法,单步或多步预测方式建立了6个预测模型,然后利用采集到的真实数据进行测试,并对各模型结构框架及预测结果进行了对比.结果 建立的模型平均预测误差均保持在一个很小的范围内.结论 利用神经网络建立心率预测模型可有效地反映运动量如何影响心率变化.对比结果表明,在单步预测中,利用神经网络拓扑增强技术（neuro-evolution of augmenting topologies,NEAT）建立的心率预测模型可达到最佳的预测效果,而多步预测利用Adams-Bashforth技术得到的预测结果是最好的.     

数据挖掘研究及在医学中的应用

本文对数据挖掘的功能、挖掘过程及挖掘步骤进行了阐述,对常用的数据挖掘算法进行了研究.从数据挖掘角度列举了医学数据的独特性,提出了数据挖掘应用于医学的特点.指出数据挖掘与医学的发展将会起到相互促进的作用.     

联合稀疏表示的医学图像融合及同步去噪

将多模态医学图像的互补信息有机地融合在一起,可为临床诊断和辅助治疗提供丰富信息和有效帮助。基于联合稀疏模型,提出一种联合稀疏表示的医学图像融合算法,当图像被噪声污染时,该算法在融合的同时兼有去噪功能。首先,将配准的源图像编纂成列向量并组成联合矩阵,通过在线字典学习算法(ODL)得到该矩阵的超完备字典;其次,利用该字典得到联合稀疏模型下的联合字典,之后利用最小角回归算法(LARS)计算基于联合字典的公共稀疏系数和各图像的独特稀疏系数,并根据“选择最大化”融合规则得到融合图像的稀疏系数;最后,根据融合系数和超完备字典重构融合图像。将该算法与3种经典算法比较,结果显示其主观上亮度失真和对比度失真较小,边缘纹理清晰,客观参数指标MI、Q^AB/F在无噪声干扰和有噪声干扰时的统计均值分别为：3.992 3、2.896 4、2.505 5和0.658、0.552 4、0.439 6,可以为临床诊断和辅助治疗提供有效帮助。     

基于CUDA的快速三维医学图像分割

目的:三维分割是医学图像分析和可视化中的重要组成部分,也是医学图像分割中的一个难点。水平集方法在三维医学图像分割中有很广阔的应用前景,但是该算法的计算量大,不能达到实时处理的要求。针对这个问题,提出了一种基于CUDA的并行加速方法。方法:采用NVIDIA公司的GPGPU模型CUDA,利用图像像素的独立性和偏微分方程求解的并发性,提高C-V水平集算法的分割速度。给出了并行计算的流程图,并对C-V水平集算法在CUDA上的实现进行了详细介绍。结果:实现了C-V水平集并行加速算法,该方法在保证分割效果的前提下,具有更快的分割速度。结论:所提出的方法是切实可行的,实现了快速的三维医学图像分割。     

人工智能方法在医学图像处理中的研究新进展

目的:随着医学影像智能化诊断的快速发展,为了满足愈加复杂的医学图像分析和处理要求,人工智能方法成为近年来医学图像处理技术发展的一个研究热点。本文对近五年来人工智能方法在医学图像处理领域应用的新进展进行综述。方法:将应用在医学图像处理领域主要的几种人工智能方法进行了分类总结,讨论了这些方法在医学图像处理各分支领域的应用,分析比较了不同方法间的优缺点。结果:人工智能方法应用主要在医学图像分割、图像配准、图像融合、图像压缩、图像重建等领域;包括蚁群算法、模糊集合、人工神经网络、粒子群算法、遗传算法、进化计算、人工免疫算法、粒计算和多Agent技术等;涉及MR图像、超声图像、PET图像、CT图像和医学红外图像等多种医学图像。结论:由于医学影像图像对比度较低,不同组织的特征可变性较大,不同组织间边界模糊、血管和神经等微细结构分布复杂,尚无通用方法对任意医学图像都能取得绝对理想的处理效果。改进的人工智能方法与传统图像处理方法的结合,在功能上相互取长补短,将是医学图像处理技术重要的发展趋势。     

基于决策树的外科手术信息挖掘与研究

本文首先介绍了数据挖掘和决策树的概念及其在医学领域的应用,之后结合实际医学资料,详细阐述决策树算法在外科手术信息资源挖掘中的具体应用.     

基于神经动力学的医学图像增强技术

目的探讨基于视觉神经元模型的图像增强算法在医学图像处理中的效果和自动实现的方便性。方法用基于视觉神经元ON—OFF模型的图像增强算法处理医学图像，实现对医学图像的自动增强；探讨增强算法的处理机制；分析衰减常数、增益系数和空间常数对图像增强处理的影响。结果选1例左额胶质瘤患者的T1W序列MR图像，1例右眶周及右额顶血管瘤患者的CTA图像。经图像增强处理，MR图像颅脑内部的结构更加清晰可见，图像层次丰富，组织边界分明，内容纹理层次丰富，易于观察。CTA图像处理后，血管瘤病变部位组织轮廓变得完整清晰，图像层次变得更加丰富。同时，整体对比度下降，图像视觉柔和。结论通过对大量医学图像的处理计算，证明选择适当的衰减常数、增益系数和空间常数，可以得到比较显著的图像增强效果。     

Schizophrenia in a North Swedish geographical isolate, 1900–1977. Epidemiology, genetics and biochemistry

Over 200 schizophrenic patients belonging to three major and interrelated pedigree complexes have been investigated over the past 30 years in a North Swedish geographically isolated population, presently numbering about 6,000. An intensive investigation of a number of biochemical correlates and genetic markers in a few selected families belonging to one of the major pedigrees has indicated new strategies for the current research program.
Schizophrenia, as defined operationally, is significantly associated with decreased activities of two enzymes (1) blood platelet monoamine oxidase, (2) plasma dopamine-β-hydroxylase, and (3) with the genetic marker Gc² (group specific antigen). Both enzymes are subject to genetic variation. A positive score for linkage between schizophrenia and low plasma DBH activity has been calculated, but, so far, available data are insufficient for discrimination between linkage and partial contribution of genetically controlled low plasma DBH to the pathogenesis of the disease. Alternatively, both mechanisms could be involved.
As a model for continued research, schizophrenia is explained as based on a double dominant-recessive genotype (Aabb), representing a vulnerability which in about 50 % of cases develops into clinical schizophrenia. It is suggested that the dominant mutation (A) operates on or affects MAO activity, and that the recessive genotype (bb) is instrumental in low variates of DBH activity and very likely such variates within the normal range of physiological variation. Moreover, it is suggested that the combined effects of MAO- and DBH-reduced efficiency on the metabolism of e.g. dopamine could be an essential pathogenic mechanism for the schizophrenic illness which is segregating in this population.     

The dominant diseases of modernized societies as omega-3 essential fatty acid deficiency syndrome: Substrate beriberi

About 1900, modern food selection and processing caused widespread $\text{epidemics}$ of the B vitamin deficiency diseases of beriberi and pellagra which, for genetic reasons, often expressed as different diseases ranging from bowel and heart disease to dermatoses and psychoses. But the B vitamins merely help convert essential fatty acids (EFA) into the prostaglandin (PG) tissue regulators and it now turns out that, through hydrogenation, milling and selection of w3-poor southern foods, we have also been systematically depleting, by as much as 90%, a newly discovered trace Nordic EFA (w3) of special importance to primates and sole precursor of the PG3(4) series, even as a concurrent fiber deficiency increases body demand for EFA. Since substrate EFA is processed by many B vitamin catalysts, an EFA deficiency will mimic a $\text{panh}$ypovitaminosis B, i.e., a mixture of $\text{substrate}$ beriberi and $\text{substrate}$ pellagra resembling vitamin beriberi and pellagra but exhibiting as even more diverse $\text{endemic}$ disease. This would consitute a second stage of the Modern Malnutrition and explain why some workers now hold the dominant diseases of modermized societies to be new, nutritionally based, pellagraform yet lipid-related and to range, once again, from heart disease to psychosis. It is an assumption that our dominant diseases are unrelated to each other or are merely revealed by our diagnostic acumen and therapeutic success; and that hydrogenating millions of tons of food oils annually, to destroy the rancidity producing w3-EFA, is safe for $\text{primates}$. Extensive beriberiform disease is reported here in 32 typical cases taken from medical practice which responds strikingly to linseed oil supplements (60% w3-EFA) in confirmation of identical results in Capuchins.     

The universal muscular chain reaction,muscle spasm,Torsions, ruptures and extravasations. Chameleons of pathology and some manifestations of simple muscular disorders

Most bodily functions require the coordinated actions of complementary and supplementary paired muscle groups. Where this essential muscular cooperation is lacking, hollow organs may burst and others become literally screwed up, giving rise to many similar spastic diseases such as Torticollis, Twisted ovarian cyst, Torsion of the Testis, Volvulus of the intestines, Varicose Veins, Megacolon, Aortamegaly, Scoliosis, Erb's Palsy, Peyronie's Disease, Main-en-Griffe, Undescended Foot (Pes Cavus), Talipes, Strabismus. Spasm is “panenepidemic” and unclassified examples of Torsion Dystonia and Dyskinesia really are as common as debt and taxes.     

'Very sore nights and days': the child's experience of illness in early modern England, c.1580-1720

Sick children were ubiquitous in early modern England, and yet they have received very little attention from historians. Taking the elusive perspective of the child, this article explores the physical, emotional, and spiritual experience of illness in England between approximately 1580 and 1720. What was it like being ill and suffering pain? How did the young respond emotionally to the anticipation of death? It is argued that children’s experiences were characterised by profound ambivalence: illness could be terrifying and distressing, but also a source of emotional and spiritual fulfilment and joy. This interpretation challenges the common assumption amongst medical historians that the experiences of early modern patients were utterly miserable. It also sheds light on children’s emotional feelings for their parents, a subject often overlooked in the historiography of childhood. The primary sources used in this article include diaries, autobiographies, letters, the biographies of pious children, printed possession cases, doctors’ casebooks, and theological treatises concerning the afterlife.     

Guidelines for the Validation and Use of Immunoassays for Determination of Introduced Proteins in Biotechnology Enhanced Crops and Derived Food Ingredients

Recent advancements in agricultural biotechnology have created a need for analytical techniques to determine introduced proteins in crops enhanced through modern biotechnology techniques. These proteins are expressed in plant tissues and may be present in food ingredients. Immunoassays are ideally suited for protein detection and may be used as both quantitative and threshold methods. Microplate ELISA and lateral flow devices are two of the most commonly used immunoassay formats for agricultural biotechnology applications. This paper provides general background information and a discussion of criteria for the validation and application of immunochemical methods to the analysis of proteins introduced into plants and food ingredients using biotechnology methods. It is the result of a collaborative effort of members of the Analytical Environmental Immunochemical Consortium. This collaborative effort represents the combined expertise of several organizations to reach consensus on establishing guidelines for the validation and use of immunoassays. Further, the paper offers developers and users a consistent approach to adopting the technology as well as aid in producing accurate and meaningful results.     

Ultracryotomy: development and application (with examples from the yeast cytology) (author's transl)

The preparation steps usually necessary for obtaining ultrathin frozen sections of biological material (chemical prefixation, enclosing, cryoprotective treatment, freezing, sectioning, and post-staining the sections for transmission electron microscopy) are submitted to a critical analysis. The application of cryo-ultramicrotomy, in particularly for cytochemical purposes, is reviewed. Fundamental considerations of chemical prefixation and poststaining are supported by examples from yeast cytology. Furthermore, the efficiency of the cryo-ultramicrotomy (electron optical resolution of ultrastructural details) is demonstrated on yeast cells and protoplasts.     

Hypo- und Hypermagnesämie aus kardiologischer Sicht

Zusammenfassung Eine Reihe pathologischer Zustände bedingen Magnesiummangel. Zustände mit Hypermagnesämie sind ebenfalls bekannt, doch wesentlich seltener. Für den Kardiologen beachtenswert ist, daß unter Therapie mit bestimmten Diuretica bei Herzinsuffizienz, bei Herzinfarkt, Kardiomyopathie, Digitalisintoxikation und bestimmten Herzrhythmusstörungen Hypomagnesämie beobachtet wurde. Leider kann in der klinischen Routine nur ein extracelluläres Magnesiumdefizit durch Serumbestimmungen gemessen werden; über Magnesiummangel einzelner Organe kann nichts ausgesagt werden. Hinweise für Magnesiummangel geben aber neben der Messung des Serumspiegels Anamnese, klinischer Befund, bestimmte EKG-Veränderungen wie auch evtl. Hypokalämie, ein Zustand, bei dem sich oft — besonders bei Aldosteronismus — parallele Veränderungen zeigten.Tierexperimente deuten darauf hin, daß infarktähnliche Läsionen unter Magnesiummangel entstehen, doch ob Herzinfarkt beim Menschen durch Magnesiummangel ausgelöst werden kann, ist noch ungeklärt. In Leichenherzen zeigte sich im Infarktgebiet neben Calciumakkumulation signifikanter Magnesiumverlust, wobei unklar blieb, ob sich Ursache oder Folge des Infarktes widerspiegelten. Falls ein ursächlicher Zusammenhang besteht, ist er im Myokardstoffwechsel selbst zu suchen, wie bei der Alkoholkardiomyopathie, wo myokardialer Magnesiummangel zumindest als pathogenetischer Teilfaktor anerkannt wird. Andererseits versucht man aber auch Beziehungen zwischen Atherosklerose, Blutgerinnung und Hypomagnesämie herzustellen, in der Meinung, daß Magnesiummangel auch über den coronaren Pathomechanismus des Herzinfarktes wirken könnte. Sicher scheint, daß gewisse EKG-Veränderungen und Herzrhythmusstörungen durch einen irritierten Magnesiumhaushalt bedingt sein können, da sie bei Gabe bzw. Entzug von Magnesium verschwinden. Daß Magnesiummangel die Glykosidtoleranz verringert, wird tierexperimentell bestätigt. Unter Hypomagnesämie bewirkt Acetylstrophanthidin eher und länger Rhythmusstörungen als ohne, außerdem lassen diese sich durch Magnesiumgaben eliminieren. Da in gewissen Fällen spontane und digitalisinduzierte Herzrythmusstörungen durch Magnesiuminjektionen beseitigt wurden, scheint Magnesium als Therapeuticum angebracht. Einsatz verschiedener Magnesiumsalze bei Angina pectoris, degenerativen Herzerkrankungen und Herzinsuffizienz ohne geprüften und offensichtlich gestörten Magnesiumhaushalt ist fragwürdig, weil keine eindeutigen klinischen Erfolgsbeweise vorliegen. Immerhin mag es aber larvierte, durch Serumbestimmungen nicht erfaßbare Mangelzustände geben. Allgemein erscheint es aus kardiologischer Sicht ratsam, den Magnesiumhaushalt zu überwachen und in entsprechenden Fällen auszugleichen, um möglichen Myokardläsionen oder fatalen Herzrhythmusstörungen entgegenzuwirken.     

HLA in North Colombia Chimila Amerindians

HLA-A,-B,-C,-DRB1 and -DQB1 alleles have been studied in Chimila Amerindians from Sabana de San Angel (North Colombian Coast) by using high resolution molecular typing. A frequent extended haplotype was found:HLA-A*24:02-B*51:10-C*15:02-BRB1*04:07-DQB1*03:02 (28.7%) which has also been described in Amerinndian Mayos Mexican population (Mexico, California Gulf, Pacific Ocean). Other haplotypes had already been found in Amerindians from Mexico (Pacific and Atlantic Coast), Peru (highlands and Amazon Basin), Bolivia and North USA. A geographic pattern according to HLA allele or haplotype frequencies is lacking in Amerindians, as already known. Also, five new extended haplotypes were found in Chimila Amerindians. Their HLA-A*24:02 high frequencies characteristic is shared with aboriginal populations of Taiwan; also, HLA-C*01:02 high frequencies are found in New Zealand Maoris, New Caledonians and Kimberly Aborigines from Australia. Finally, this study may show a model of evolutionary factors acting and rising one HLA allele frequency (-A*24:02), but not in others that belong to the same or different HLA loci.     

The case for allele‐specific recognition by the TCR

There is a sharp difference in how one views TCR structure–function–behaviour dependent on whether its recognition of major histocompatibility complex‐encoded restriction elements (R) is germline selected or somatically generated. The generally accepted or Standard model is built on the assumption that recognition of R is by the V regions of the αβ TCR, which is not driven by allele specificity, whereas the competing model posits that recognition of R is allele‐specific. The establishing of allele‐specific recognition of R by the TCR would rule out the Standard model and clear the road to a consideration of a competing construct, the Tritope model. Here, the case for allele‐specific recognition (germline selected) is detailed making it obvious that the Standard model is untenable.