Decision tool for the early diagnosis of trauma patient hypovolemia

We present a classifier for use as a decision assist tool to identify a hypovolemic state in trauma patients during helicopter transport to a hospital, when reliable acquisition of vital-sign data may be difficult. The decision tool uses basic vital-sign variables as input into linear classifiers, which are then combined into an ensemble classifier. The classifier identifies hypovolemic patients with an area under a receiver operating characteristic curve (AUC) of 0.76 (standard deviation 0.05, for 100 randomly-reselected patient subsets). The ensemble classifier is robust; classification performance degrades only slowly as variables are dropped, and the ensemble structure does not require identification of a set of variables for use as best-feature inputs into the classifier. The ensemble classifier consistently outperforms best-features-based linear classifiers (the classification AUC is greater, and the standard deviation is smaller, p < 0.05). The simple computational requirements of ensemble classifiers will permit them to function in small fieldable devices for continuous monitoring of trauma patients.     

Inhibition of thirst in rats following hypovolemia and-or caval ligation

Thirst was elicited in rats by subcutaneous injections of a hyperoncotic polyethylene glycol (PG) solution or by infrahepatic ligation of the inferior vena cava (IVC). Rats given either treatment drank throughout the 24 hr test period when 0.15 m NaCl was the only fluid available but decreased drinking significantly within 6–8 hr when given only water. This inhibition of thirst was associated with an excessive accumulation of ingested water during oliguria. Inhibition cannot be attributed to a general osmotic dilution since plasma osmolalities actually were elevated due to the retention of urea. Instead, the inhibitory mechanism may involve reduction of the effective osmotic pressure of body fluids and cellular overhydration. Rats drinking water following combined IVC ligation and PG injection treatments required a greater degree of cellular overhydration to inhibit drinking than rats given either treatment alone. When saline was presented instead of water, the complex stimulus for thirst elicited more drinking with fluid retention than any other experimental procedure known. The extreme potency of this preparation reflects the comparable strength of the inhibitory mechanisms associated with cellular overhydration.     

Breast-Cancer identification using HMM-fuzzy approach

This paper presents an ensemble of feature selection and classification technique for classifying two types of breast lesion, benign and malignant. Features are selected based on their area under the ROC curves (AUC) which are then classified using a hybrid hidden Markov model (HMM)-fuzzy approach. HMM generated log-likelihood values are used to generate minimized fuzzy rules which are further optimized using gradient descent algorithms in order to enhance classification performance. The developed model is applied to Wisconsin breast cancer dataset to test its performance. The results indicate that a combination of selected features and the HMM-fuzzy approach can classify effectively the lesion types using only two fuzzy rules. Our experimental results also indicate that the proposed model can produce better classification accuracy when compared to most other computational tools.     

Heart disease diagnosis based on mediative fuzzy logic

Mediative fuzzy logic is an approach able to deal with inconsistent information providing a solution when contradiction exists. The aim of this paper is to design an expert system based on this type of fuzzy logic in order to diagnose a possible heart disease for a patient. Our proposed system is an extension of the standard Mamdani fuzzy logic controller and contains 44 rules of the type single input–single output. The system works with 11 variables as inputs and one variable as output.     

Identification of fungal phytopathogens using Fourier transform infrared-attenuated total reflection spectroscopy and advanced statistical methods

The early diagnosis of phytopathogens is of a great importance; it could save large economical losses due to crops damaged by fungal diseases, and prevent unnecessary soil fumigation or the use of fungicides and bactericides and thus prevent considerable environmental pollution. In this study, 18 isolates of three different fungi genera were investigated; six isolates of Colletotrichum coccodes, six isolates of Verticillium dahliae and six isolates of Fusarium oxysporum. Our main goal was to differentiate these fungi samples on the level of isolates, based on their infrared absorption spectra obtained using the Fourier transform infrared-attenuated total reflection (FTIR-ATR) sampling technique. Advanced statistical and mathematical methods: principal component analysis (PCA), linear discriminant analysis (LDA), and k-means were applied to the spectra after manipulation. Our results showed significant spectral differences between the various fungi genera examined. The use of k-means enabled classification between the genera with a 94.5% accuracy, whereas the use of PCA [3 principal components (PCs)] and LDA has achieved a 99.7% success rate. However, on the level of isolates, the best differentiation results were obtained using PCA (9 PCs) and LDA for the lower wavenumber region (800-1775 cm(-1)), with identification success rates of 87%, 85.5%, and 94.5% for Colletotrichum, Fusarium, and Verticillium strains, respectively.     

Inhibition of food deprivation induced hypovolemia by saline consumption in rats

Food deprivation hypovolemia has been observed in a variety of mesic and desert adapted rodents. Xeric adapted rodent species appear to lose intravascular volume in proportion with body weight loss during food restriction, while mesically adapted rodent species lose intravascular volume at a rate much in excess to body weight loss. The laboratory rat was chosen as a representative mesically adapted rodent species for the purpose of investigating this phenomenon. Acute isotonic saline stomach loads had no appreciable influence upon intravascular volume reparation induced by either 2 or 4 days of food deprivation. Free and forced choice saline solutions presented during starvation were noted to significantly inhibit hypovolemia, however, there was no evidence for reparation of carcass water losses. It is suggested that the availability of only water during fasting results in the premature termination of drinking due to cellular over-hydration. When water and a source of sodium are available the food deprived rat can more adequately maintain ad lib intravascular volume. There is presently no explanation for the absence of repaired carcass water.     

Diagnostics of pancreatic insufficiency using multivariate statistical and pattern recognition methods

The complex evaluation of Lundh-test data was investigated in patients with pancreatic insufficiency and in controls using multivariate statistical methods. It has been shown that isolated parameters do not give satisfactory separation. The lower limits of the normal values were calculated in advance from the data of 77 control cases with the help of distribution analysis and of 2.5 percentile value for all parameters. On the basis of these normal values, and the results of other examinations, two groups were formed from the data of 137 more patients: (1) certainly pathologic patients, and (2) control cases. The application of multivariate statistical and pattern recognition methods considering the parameters simultaneously led to the correct diagnosis in 88-80-93% of the cases using the centroid, nearest neighbour and linear discriminant analysis, respectively. Linear discriminant analysis successfully separated controls from the patients with pancreatic insufficiency also in mild cases.     

Classification of premature ventricular complexes using filter bank features, induction of decision trees and a fuzzy rule-based system

The classification of heart beats is important for automated arrhythmia monitoring devices. The study describes two different classifiers for the identification of premature ventricular complexes (PVCs) in surface ECGs. A decision-tree algorithm based on inductive learning from a training set and a fuzzy rule-based classifier are explained in detail. Traditional features for the classification task are extracted by analysing the heart rate and morphology of the heart beats from a single lead. In addition, a novel set of features based on the use of a filter bank is presented. Filter banks allow for time-frequency-dependent signal processing with low computational effort. The performance of the classifiers is evaluated on the MIT-BIH database following the AAMI recommendations. The decision-tree algorithm has a gross sensitivity of 85.3% and a positive predictivity of 85.2%, whereas the gross sensitivity of the fuzzy rule-bassed system is 81.3%, and the positive predictivity is 80.6%.     

Classification of premature ventricular complexes using filter bank features, induction of decision trees and a fuzzy rule-based system

The classification of heart beats is important for automated arrhythmia monitoring devices. The study describes two different classifiers for the identification of premature ventricular complexes (PVCs) in surface ECGs. A decision-tree algorithm based on inductive learning from a training set and a fuzzy rule-based classifier are explained in detail. Traditional features for the classification task are extracted by analysing the heart rate and morphology of the heart beats from a single lead. In addition, a novel set of features based on the use of a filter bank is presented. Filter banks allow for time-frequency-dependent signal processing with low computational effort. The performance of the classifiers is evaluated on the MIT-BIH database following the AAMI recommendations. The decision-tree algorithm has a gross sensitivity of 85.3% and a positive predictivity of 85.2%, whereas the gross sensitivity of the fuzzy rule-based system is 81.3%, and the positive predictivity is 80.6%.     

The diagnosis of mania

Manic illnesses are often misdiagnosed, particularly in adolescence when they are commonly and wrongly regarded as schizophrenic. Recent American studies suggest that the presence of Schneiderian and other schizophrenic symptoms has no influence on the duration or the response to treatment of manic illnesses, or on the morbidity of first-degree relatives, and that the concept of schizoaffective disorder, manic type is therefore redundant. Other evidence suggests that, although delusions of reference or persecution have no effect on outcome, the presence of auditory hallucinations or passivity phenomena is associated with a considerably worse outcome over the next few years.     

Histophysiological effects of fluid resuscitation on heart, lung and brain tissues in rats with hypovolemia

The efficacy of using colloids and crystalloids in the treatment of hypovolemia still remains controversial. An important aspect in treating hypovolemia is to re-establish normal tissue hemodynamics after fluid resuscitation. Production of nitric oxide (NO) or growth factors such as transforming growth factor beta (TGF-beta) has been identified as a key mechanism in physiological and pathological processes in the different systems. This study was designed to investigate the histophysiological effects of resuscitation with different plasma substitutes on the heart, lung and brain tissues following acute blood loss in male Sprague-Dawley rats weighing 250-280g (n=30). After anesthesia with sodium pentobarbital, the left femoral vein and artery were cannulated for the administration of volume expanders and for direct measurement of arterial pressure and heart rate. Twenty rats were bled (5ml/10min) and infused (5ml/10min) with one of four randomly selected solutions, (a) human albumin, (b) gelatin (Gelofusine), (c) dextran-70 (Macrodex); or (d) physiological saline (0.9% isotonic saline). Five control rats were bled without infusion. Tissue samples were taken and fixed in 10% formalin solution, then processed for embedding in paraffin wax. Sections were cut and stained with hematoxylin and eosin. Indirect immunohistochemical labelling was performed to reveal binding of primary antibodies against endothelial nitric oxide synthase (eNOS), inducible nitric oxide synthase (iNOS) and TGF-beta. Mild immunoreactivity of eNOS was observed in endothelial cells of vessels in brain, heart and lung tissues. Increased immunoreactivities of eNOS, iNOS and TGF-beta were observed in the non-fluid resuscitated group in these organs; mild, moderate, moderate and strong immunoreactivities were seen in the albumin, gelatin, physiological saline and dextran-70 treated groups, respectively. Immunoreactivities of iNOS and TGF-beta in the non-fluid resuscitated group were increased significantly, in comparison to the other groups, apart from the dextran-70 treated group. The results of this study show that gelatin solution and physiological saline may be of use after acute blood loss, and dextran-70 is not the preferred resuscitation fluid in the early stages of acute blood loss. It was concluded that albumin solution is the preferred fluid for resuscitation.     

Three-dimensional segmentation of tumors from CT image data using an adaptive fuzzy system

A new segmentation method using a fuzzy rule based system to segment tumors in a three-dimensional CT data was developed. To initialize the segmentation process, the user selects a region of interest (ROI) within the tumor in the first image of the CT study set. Using the ROI's spatial and intensity properties, fuzzy inputs are generated for use in the fuzzy rules inference system. With a set of predefined fuzzy rules, the system generates a defuzzified output for every pixel in terms of similarity to the object. Pixels with the highest similarity values are selected as tumor. This process is automatically repeated for every subsequent slice in the CT set without further user input, as the segmented region from the previous slice is used as the ROI for the current slice. This creates a propagation of information from the previous slices, used to segment the current slice. The membership functions used during the fuzzification and defuzzification processes are adaptive to the changes in the size and pixel intensities of the current ROI. The method is highly customizable to suit different needs of a user, requiring information from only a single two-dimensional image. Test cases success in segmenting the tumor from seven of the 10 CT datasets with <10% false positive errors and five test cases with <10% false negative errors. The consistency of the segmentation results statistics also showed a high repeatability factor, with low values of inter- and intra-user variability for both methods.     

苯丙酮尿症新生儿筛查及诊断方法研究进展

【摘要】苯丙酮尿症（PKU）是最常见的先天性氨基酸代谢异常疾病,会引起智力发育迟缓、肤色异常、小头畸形、语言障碍、癫痫等症状,但通过及时诊断,并结合有效的治疗方法能使PKU患者保持相对正常发育。目前,利用细菌抑制、化学荧光、酶定量、高效液相、质谱等技术对血液苯丙氨酸（Phe）水平测定,实现PKU筛查和诊断的方法已经比较成熟。随着分子生物学的发展,PKU的基因诊断、尿液代谢物分析方法也被成功建立和发展。就PKU的筛查和诊断方法的最新研究进展进行综述。     

Automatic identification of motor unit action potential trains from electromyographic signals using fuzzy techniques

A technique is proposed that allows automatic decomposition of electromyographic (EMG) signals into their constituent motor unit action potential trains (MUAPTs). A specific iterative algorithm with a classification method using fuzzy-logic techniques was developed. The proposed classification method takes into account imprecise information, such as waveform instability and irregular firing patterns, that is often encountered in EMG signals. Classification features were determined by the combining of time position and waveform information. Statistical analysis of inter-pulse intervals and spike amplitude provided an accurate estimation of features used in the classification step. Algorithm performance was evaluated using simulated EMG signals composed of up to six different discharging motor units corrupted with white noise. The algorithm was then applied to real signals recorded by a high spatial resolution surface EMG device based on a Laplacian spatial filter. On six groups of 20 simulated signals, the decomposition algorithm performed with a maximum and an average mean error rate of 2.13% and 1.37%, respectively. On real surface EMG signals recorded at different force levels (from 10% to 40% of the maximum voluntary contraction), the algorithm correctly identified 21 MUAPTs, compared with the 29 MUAPTs identified by an experienced neurophysiologist. The efficiency of the decomposition on surface EMG signals makes this method very attractive for non-invasive investigation of physiological muscle properties. However, it can also be used to decompose intramuscularly recorded EMG signals.     

应用ROC曲线评价化学发光法及酶联免疫法对HCV感染的诊断价值

目的 探讨国内五种主流丙型肝炎病毒抗体(抗-HCV)酶联免疫法(ELISA)试剂与进口化学发光法(CLIA)检测性能的可比性及其对HCV感染的诊断价值.方法 应用CLIA及五种ELISA(编号为A、B、C、D、E),同时检测免疫印迹法(RIBA)确认的抗-HCV阳性、阴性血清样本各68例,应用受试者工作特征曲线(ROC)评价其性能指标.结果 CLIA及A、B、C、D、E五种ELISA试剂ROC曲线下面积(AUC)分别为:0.989、0.784、0.945、0.841、0.890、0.883(P ＜0.05),差异有统计学意义;CLIA的敏感性大于五种ELISA试剂(P＜0.05),差异有统计学意义,差异主要在于CLIA 8＞S/CO值≥1标本的符合率较低;几种试剂间特异性无显著性差异(P=0.75).结论 国内五种主流HCV抗体ELISA试剂与进口CLIA对HCV感染均具有较高的诊断价值,利用CHA高敏感性及ELISA的高特异性联合检测抗-HCV,可提高HCV感染的诊断效率.     

cDNA微阵列实验分析中常用的统计方法

针对cDNA微阵列杂交实验从设计、收集样本到数据的采集、整理和分析等全过程,介绍了 如何基于统计学原理对各个过程常见的问题进行处理,并对各种方法的优缺点简要概述,为研究者有效 进行微阵列实验提供参考。     

Adaptive frequency decomposition of EEG with subsequent expert system analysis

We present a hybrid system for automatic analysis of clinical routine EEG, comprising a spectral analysis and an expert system. EEG raw data are transformed into the time–frequency domain by the so-called adaptive frequency decomposition. The resulting frequency components are converted into pseudo-linguistic facts via fuzzification. Finally, an expert system applies symbolic rules formulated by the neurologist to evaluate the extracted EEG features. The system detects artefacts, describes alpha rhythm by frequency, amplitude, and stability and after artefact rejection detects pathologic slow activity. All results are displayed as linguistic terms, numerical values and maps of temporal extent, giving an overview about the clinical routine EEG.     

Gripping-force identification using EEG and phase-demodulation approach

In this paper we investigate the fuzzy identification of brain-code during simple gripping-force control tasks. Since the synchronized oscillatory activity and the phase dynamics between the brain areas are two important mechanisms in the brain’s function and information transfer, we decided to examine whether it is possible to extract the encoded information from the EEG signals using the phase-demodulation approach. The EEG was measured during the performance of different visuomotor tasks and the information we were trying to decode was the gripping force as applied by the subjects. The study revealed that it is possible, by using simple beta-rhythm filtering, phase demodulation, principal component analysis and a fuzzy model, to estimate the gripping-force response by using EEG signals as the inputs for the proposed model. The presented study has shown that even though EEG signals represent a superposition of all the active neurons, it is still possible to decode some information about the current activity of the brain centers. Furthermore, the cross-validation showed that the information about the gripping force is encoded in a very similar way for all the examined subjects. Thus, the phase shifts of the EEG signals seem to have a key role during activity and information transfer in the brain, while the phase-demodulation method proved to be a crucial step in the signal processing.     

Plasma hyperosmolality at the onset of drinking during starvation induced hypovolemia

Elevations of 2–4% in plasma osmolality were noted at the initiation of drinking following 4 days of fasting in rats. Paired animals food deprived for identical time periods but not drinking when blood sampled revealed ad lib levels of osmolality. Drinking initiation by 4 day food deprived rats following access to dry food was also accompanied by 2–4% elevations in plasma osmotic pressure. Substantial decreases in daily water consumption were observed during the 4 day food deprivation period accompanied by a mean plasma volume loss of 32% determined by T-1824 dye injection. Total blood volume loss was estimated to by 27%. Hematocrit was found to be the best estimator of plasma volume in starved rats. The elevations in plasma osmolality did not appear to be the result of uremia due to starvation induced protein catabolism. The data support the position that elevated plasma osmolality accompanies the initiation of drinking during extended fasting while return to ad lib set point osmolality accompanies cessation of drinking.