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1.
Indian Heart J ; 2018 Jul; 70(4): 511-518
Article | IMSEAR | ID: sea-191605

ABSTRACT

Objective To develop a mobile app called “TMT Predict” to predict the results of Treadmill Test (TMT), using data mining techniques applied to a clinical dataset using minimal clinical attributes. To prospectively test the results of the app in realtime to TMT and correlate with coronary angiogram results. Methods In this study, instead of statistics, data mining approach has been utilized for the prediction of the results of TMT by analyzing the clinical records of 1000 cardiac patients. This research employed the Decision Tree algorithm, a new modified version of K-Nearest Neighbor (KNN) algorithm, K-Sorting and Searching (KSS). Furthermore, curve fitting mathematical technique was used to improve the Accuracy. The system used six clinical attributes such as age, gender, body mass index (BMI), dyslipidemia, diabetes mellitus and systemic hypertension. An Android app called “TMT Predict” was developed, wherein all three inputs were combined and analyzed. The final result is based on the dominating values of the three results. The app was further tested prospectively in 300 patients to predict the results of TMT and correlate with Coronary angiography. Results The accuracy of predicting the result of a TMT using data mining algorithms, Decision Tree and K-Sorting & Searching (KSS) were 73% and 78%, respectively. The mathematical method curve fitting predicted with 82% accuracy. The accuracy of the mobile app “TMT Predict”, improved to 84%. Age-wise analysis of the results show that the accuracy of the app dips when the age is more than 60 years indicating that there may be other factors like retirement stress that may have to be included. This gives scope for future research also. In the prospective study, the positive and negative predictive values of the app for the results of TMT and coronary angiogram were found to be 40% and 83% for TMT and 52% and 80% for coronary angiogram. The negative predictive value of the app was high, indicating that it is a good screening tool to rule out coronary artery heart disease (CAHD). Conclusion “TMT Predict” is a simple user-friendly android app, which uses six simple clinical attributes to predict the results of TMT. The app has a high negative predictive value indicating that it is a useful tool to rule out CAHD. The “TMT Predict” could be a future digital replacement for the manual TMT as an initial screening tool to rule out CAHD.

2.
An. acad. bras. ciênc ; 90(1): 295-309, Mar. 2018. tab, graf
Article in English | LILACS | ID: biblio-886909

ABSTRACT

ABSTRACT Accurate forest inventory is of great economic importance to optimize the entire supply chain management in pulp and paper companies. The aim of this study was to estimate stand dominate and mean heights (HD and HM) and tree density (TD) of Pinus taeda plantations located in South Brazil using in-situ measurements, airborne Light Detection and Ranging (LiDAR) data and the non- k-nearest neighbor (k-NN) imputation. Forest inventory attributes and LiDAR derived metrics were calculated at 53 regular sample plots and we used imputation models to retrieve the forest attributes at plot and landscape-levels. The best LiDAR-derived metrics to predict HD, HM and TD were H99TH, HSD, SKE and HMIN. The Imputation model using the selected metrics was more effective for retrieving height than tree density. The model coefficients of determination (adj.R2) and a root mean squared difference (RMSD) for HD, HM and TD were 0.90, 0.94, 0.38m and 6.99, 5.70, 12.92%, respectively. Our results show that LiDAR and k-NN imputation can be used to predict stand heights with high accuracy in Pinus taeda. However, furthers studies need to be realized to improve the accuracy prediction of TD and to evaluate and compare the cost of acquisition and processing of LiDAR data against the conventional inventory procedures.


Subject(s)
Trees/growth & development , Models, Statistical , Pinus taeda/growth & development , Remote Sensing Technology/methods , Algorithms , Brazil , Environmental Monitoring/methods , Environmental Monitoring/statistics & numerical data , Forestry/methods , Data Accuracy
3.
Res. Biomed. Eng. (Online) ; 33(1): 78-89, Mar. 2017. tab, graf
Article in English | LILACS | ID: biblio-842482

ABSTRACT

Abstract Introduction Sign language is a collection of gestures, postures, movements, and facial expressions used by deaf people. The Brazilian sign language is Libras. The use of Libras has been increased among the deaf communities, but is still not disseminated outside this community. Sign language recognition is a field of research, which intends to help the deaf community communication with non-hearing-impaired people. In this context, this paper describes a new method for recognizing hand configurations of Libras - using depth maps obtained with a Kinect® sensor. Methods The proposed method comprises three phases: hand segmentation, feature extraction, and classification. The segmentation phase is independent from the background and depends only on pixel value. The feature extraction process is independent from rotation and translation. The features are extracted employing two techniques: (2D)2LDA and (2D)2PCA. The classification employs two classifiers: a novelty classifier and a KNN classifier. A robust database is constructed for classifier evaluation, with 12,200 images of Libras and 200 gestures of each hand configuration. Results The best accuracy obtained was 96.31%. Conclusion The best gesture recognition accuracy obtained is much higher than the studies previously published. It must be emphasized that this recognition rate is obtained for different conditions of hand rotation and proximity of the depth camera, and with a depth camera resolution of only 640×480 pixels. This performance must be also credited to the feature extraction technique, and to the size standardization and normalization processes used previously to feature extraction step.

4.
Rev. cuba. inform. méd ; 8(2)jul.-dic. 2016.
Article in Spanish | LILACS, CUMED | ID: lil-787238

ABSTRACT

El cáncer de cérvix uterino representa una de las mayores amenazas de muerte por cáncer entre las mujeres. Con el avance continuo en la medicina y la tecnología, las muertes por esta enfermedad han disminuido significativamente. Las investigaciones referentes a este tema han podido determinar síntomas claves que permiten detectar a tiempo esta enfermedad para darle un tratamiento oportuno. La citología convencional es una de las técnicas más utilizadas, siendo ampliamente aceptada, de bajo costo, y con mecanismos de control. Con el objetivo de aliviar la carga de trabajo a los especialistas, algunos investigadores han propuesto el desarrollo de herramientas de visión computacional para detectar y clasificar las transformaciones en las células de la región del cuello uterino. La presente investigación tiene como objetivo proveer a los investigadores de una herramienta de clasificación automática, aplicable a las condiciones existentes en los centros médicos y de investigación del país. Esta herramienta debe ser capaz de clasificar las células del cuello del útero, basándose solamente en las características extraídas de la región del núcleo y sin utilizar las características del citoplasma, de manera que se reduzca la tasa de falsos negativos en la prueba de Papanicolaou. A partir del estudio realizado, se obtuvo una herramienta haciendo uso de la técnica k-vecinos más cercanos con la distancia manhattan, el cual mostró un alto desempeño manteniendo valores de AUC superiores al 91 por ciento y llegando hasta un 97.1 por ciento con respecto a los clasificadores SVM y RBF Network, los que también fueron analizados(AU)


Cervix cancer is one of the biggest threats of cancer death among women. With continued advances in medicine and technology, deaths from the disease have fallen significantly. The investigations concerning this issue have determined key symptoms to detect the disease in time to give timely treatment. Conventional cytology is one of the most widely used techniques, being widely accepted, inexpensive, and with control mechanisms. In order to alleviate the workload of specialists, some researchers have proposed the development of computer vision tools to detect and classify the changes in the cells of the cervical region. This research aims to provide a tool for automatic classification, applicable to medical conditions and research centers of the country. This tool should be able to classify the cells of the cervix, based solely on the features extracted from the core region without using the characteristics of the cytoplasm, so that the rate of false negative Pap test is reduced. From the study, a tool is obtained using the k nearest-neighbors manhattan distance technique, which showed a high performance maintaining AUC values greater than 91 percent and reaching 97.1 percent over classifiers SVM and RBF Network, which were also analyzed(AU)


Subject(s)
Humans , Female , Medical Informatics Applications , Software , Uterine Cervical Dysplasia , Papanicolaou Test/methods
5.
Journal of Zhejiang Chinese Medical University ; (6): 612-614, 2015.
Article in Chinese | WPRIM | ID: wpr-476557

ABSTRACT

Objective] To discuss application of KNN-kernel clustering methods for diarrhea patients serum immune indexes detection data classification and diagnosis of applicability and clinical significance. [Methods] To reveal the applicability and clinical signnificance of KNN-kernel function clustering method in the diagnosis of serun immune index. In this research, the KNNCLUST algorithm is used to program the serum immune index data of 74 patients with diarrhea by Matlab software. [Results] 74 patients were divided into 5 categories by cluster analysis. The patients with diarrhea were divided into rotavirus negative and positive class, and the patients were further subdivided, especially the three early rotavirus tests were negative but later confirmed positive and were clustered into one group. [Conclusions] This can be seen that the KNN-kernel clustering method is helpful for early screening of rotavirus infection, practical clinical significance on the early treatment of disease.

6.
Ciênc. Saúde Colet. (Impr.) ; 19(4): 1295-1304, abr. 2014. graf
Article in Portuguese | LILACS | ID: lil-710506

ABSTRACT

Na maioria dos países, o câncer de mama entre as mulheres é predominante. Se diagnosticado precocemente, apresenta alta probabilidade de cura. Diversas abordagens baseadas em Estatística foram desenvolvidas para auxiliar na sua detecção precoce. Este artigo apresenta um método para a seleção de variáveis para classificação dos casos em duas classes de resultado, benigno ou maligno, baseado na análise citopatológica de amostras de célula da mama de pacientes. As variáveis são ordenadas de acordo com um novo índice de importância de variáveis que combina os pesos de importância da Análise de Componentes Principais e a variância explicada a partir de cada componente retido. Observações da amostra de treino são categorizadas em duas classes através das ferramentas k-vizinhos mais próximos e Análise Discriminante, seguida pela eliminação da variável com o menor índice de importância. Usa-se o subconjunto com a máxima acurácia para classificar as observações na amostra de teste. Aplicando ao Wisconsin Breast Cancer Database, o método proposto apresentou uma média de 97,77% de acurácia de classificação, retendo uma média de 5,8 variáveis.


In the majority of countries, breast cancer among women is highly prevalent. If diagnosed in the early stages, there is a high probability of a cure. Several statistical-based approaches have been developed to assist in early breast cancer detection. This paper presents a method for selection of variables for the classification of cases into two classes, benign or malignant, based on cytopathological analysis of breast cell samples of patients. The variables are ranked according to a new index of importance of variables that combines the weighting importance of Principal Component Analysis and the explained variance based on each retained component. Observations from the test sample are categorized into two classes using the k-Nearest Neighbor algorithm and Discriminant Analysis, followed by elimination of the variable with the index of lowest importance. The subset with the highest accuracy is used to classify observations in the test sample. When applied to the Wisconsin Breast Cancer Database, the proposed method led to average of 97.77% in classification accuracy while retaining an average of 5.8 variables.


Subject(s)
Female , Humans , Breast Neoplasms/diagnosis , Data Mining/methods , Data Mining/statistics & numerical data , Early Detection of Cancer/methods , Early Detection of Cancer/statistics & numerical data
7.
Rev. mex. ing. bioméd ; 35(1): 41-51, abr. 2014. ilus, tab
Article in English | LILACS-Express | LILACS | ID: lil-740164

ABSTRACT

Using the k-NN classifier in combination with the first Minkowski metric, in addition to techniques of digital image processing, we developed a computational system platform-independent, which is able to identify, to classify and to count five normal types of leukocytes: neutrophils, eosinophils, basophils, monocytes and lymphocytes. It is important to emphasize that this work does not attempt to diferentiate between smears of leukocytes coming from healthy and sick people; this is because most diseases produce a change in the differential count of leukocytes rather than in theirs forms. In the other side, the system could be used in emerging areas such as the topographic hematology and the chronobiology.


Mediante un clasificador k-NN en combinación con la primera métrica de Minkowski y técnicas de procesamiento digital de imágenes, se desarrolló un sistema computacional independiente de la plataforma, capaz de identificar, clasificar y contar cinco formas normales de leucocitos: neutrófilos, eosinófilos, basófilos, monocitos y linfocitos. Es importante enfatizar que este trabajo no intenta diferenciar entre muestras de leucocitos provenientes de gente sana y enferma, debido a que la mayoría de las enfermedades se detectan principalmente por un cambio en el conteo diferencial de leucocitos más que por cambios en su forma. Finalmente, el contador de leucocitos puede ser usado en áreas emergentes como la hematología topográfica y la cronobiología.

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