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1.
Sensors (Basel) ; 22(3)2022 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-35162030

RESUMO

Hospitals, especially their emergency services, receive a high number of wrist fracture cases. For correct diagnosis and proper treatment of these, images obtained from various medical equipment must be viewed by physicians, along with the patient's medical records and physical examination. The aim of this study is to perform fracture detection by use of deep-learning on wrist X-ray images to support physicians in the diagnosis of these fractures, particularly in the emergency services. Using SABL, RegNet, RetinaNet, PAA, Libra R-CNN, FSAF, Faster R-CNN, Dynamic R-CNN and DCN deep-learning-based object detection models with various backbones, 20 different fracture detection procedures were performed on Gazi University Hospital's dataset of wrist X-ray images. To further improve these procedures, five different ensemble models were developed and then used to reform an ensemble model to develop a unique detection model, 'wrist fracture detection-combo (WFD-C)'. From 26 different models for fracture detection, the highest detection result obtained was 0.8639 average precision (AP50) in the WFD-C model. Huawei Turkey R&D Center supports this study within the scope of the ongoing cooperation project coded 071813 between Gazi University, Huawei and Medskor.


Assuntos
Aprendizado Profundo , Humanos , Radiografia , Punho/diagnóstico por imagem , Articulação do Punho , Raios X
2.
J Med Syst ; 40(7): 166, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27229489

RESUMO

Neonatal jaundice is a common condition that occurs in newborn infants in the first week of life. Today, techniques used for detection are required blood samples and other clinical testing with special equipment. The aim of this study is creating a non-invasive system to control and to detect the jaundice periodically and helping doctors for early diagnosis. In this work, first, a patient group which is consisted from jaundiced babies and a control group which is consisted from healthy babies are prepared, then between 24 and 48 h after birth, 40 jaundiced and 40 healthy newborns are chosen. Second, advanced image processing techniques are used on the images which are taken with a standard smartphone and the color calibration card. Segmentation, pixel similarity and white balancing methods are used as image processing techniques and RGB values and pixels' important information are obtained exactly. Third, during feature extraction stage, with using colormap transformations and feature calculation, comparisons are done in RGB plane between color change values and the 8-color calibration card which is specially designed. Finally, in the bilirubin level estimation stage, kNN and SVR machine learning regressions are used on the dataset which are obtained from feature extraction. At the end of the process, when the control group is based on for comparisons, jaundice is succesfully detected for 40 jaundiced infants and the success rate is 85 %. Obtained bilirubin estimation results are consisted with bilirubin results which are obtained from the standard blood test and the compliance rate is 85 %.


Assuntos
Interpretação de Imagem Assistida por Computador/métodos , Icterícia Neonatal/diagnóstico , Fotografação/métodos , Pigmentação da Pele , Smartphone , Diagnóstico Precoce , Humanos , Recém-Nascido , Icterícia Neonatal/diagnóstico por imagem , Fotografação/instrumentação
3.
J Med Syst ; 40(6): 149, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27137786

RESUMO

This study aims investigating adjustable distant fuzzy c-means segmentation on carotid Doppler images, as well as quaternion-based convolution filters and saliency mapping procedures. We developed imaging software that will simplify the measurement of carotid artery intima-media thickness (IMT) on saliency mapping images. Additionally, specialists evaluated the present images and compared them with saliency mapping images. In the present research, we conducted imaging studies of 25 carotid Doppler images obtained by the Department of Cardiology at Firat University. After implementing fuzzy c-means segmentation and quaternion-based convolution on all Doppler images, we obtained a model that can be analyzed easily by the doctors using a bottom-up saliency model. These methods were applied to 25 carotid Doppler images and then interpreted by specialists. In the present study, we used color-filtering methods to obtain carotid color images. Saliency mapping was performed on the obtained images, and the carotid artery IMT was detected and interpreted on the obtained images from both methods and the raw images are shown in Results. Also these results were investigated by using Mean Square Error (MSE) for the raw IMT images and the method which gives the best performance is the Quaternion Based Saliency Mapping (QBSM). 0,0014 and 0,000191 mm(2) MSEs were obtained for artery lumen diameters and plaque diameters in carotid arteries respectively. We found that computer-based image processing methods used on carotid Doppler could aid doctors' in their decision-making process. We developed software that could ease the process of measuring carotid IMT for cardiologists and help them to evaluate their findings.


Assuntos
Espessura Intima-Media Carotídea , Diagnóstico por Computador , Processamento de Imagem Assistida por Computador , Algoritmos , Humanos
4.
J Med Syst ; 40(1): 31, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26553064

RESUMO

In this study, a novel system was created to localize cancerous regions for stomach images which were taken with computed tomography(CT). The aim was to determine the coordinates of cancerous regions which spread in the stomach area in the color space with using this system. Also, to limit these areas with a high accuracy ratio and to feedback to the user of this system were the other objectives. This integration was performed with using energy mapping, analysis methods and multiple image processing methods and the system which was consisted from these advanced algorithms was appeared. For this work, in the range of 25-40 years and when gender discrimination was insignificant, 30 volunteer patients were chosen. During the formation of the system, to exalt the accuracy to the maximum level, 2 main stages were followed up. First, in the system, advanced image processing methods were processed between each other and obtained data were studied. Second, in the system, FFT and Log transformations were used respectively for the first two cases, then these transformations were used together for the third case. For totally three cases, energy distribution and DC energy intensity analysis were done and the performance of this system was investigated. Finally, with using the system's unique algorithms, a non-invasive method was achieved to detect the gastric cancer and when FFT and Log transformation were used together, the maximum success rate was obtained and this rate was calculated as 83,3119 %.


Assuntos
Algoritmos , Análise de Fourier , Processamento de Imagem Assistida por Computador/métodos , Neoplasias Gástricas/diagnóstico por imagem , Neoplasias Gástricas/patologia , Humanos , Sensibilidade e Especificidade , Tomografia Computadorizada por Raios X
5.
J Med Syst ; 39(2): 17, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25644668

RESUMO

Due to the importance of cirrhosis evolution, this study examined cirrhotic patients using Self Organizing Mapping (SOM) based on the Child-Pugh scoring method. Because Colored Doppler Ultrasound (CDU) has too many parameters, scoring can be a very difficult task. Classifying cirrhotic patients via SOM and investigating weights of the cirrhotic CDU parameters are aimed in this study. SOM was used to map high dimensional cirrhotic data onto two dimensional clustered data. These clusters provided a feature map of cirrhotic patients. In this study, 103 cirrhotic patients and a control group of 44 healthy individuals were examined in the hospital, and parameters were analyzed using SOM. These data were obtained using CDU, and age and sex parameters were analyzed in this study. Cirrhotic patients were histopathologically separated into subgroups using the Child-Pugh scoring method, and the presence of ascites was determined using SOM. In this study, differences between the control group and cirrhotic patients with their subgroups were investigated using SOM, and the results were discussed. Renal artery indices, hepatic artery indices, portal vein parameters, age and the degree of ascites were analyzed using SOM for a total of 147 individuals. The combination of SOM and Child-Pugh scoring method can be useful for the interpretation of cirrhotic patient's evolution. Computer-based SOM algorithm and negative effectiveness of a large scale dataset could be minimized by adjusting the weight of the parameters. This study will faciliate doctors to make better decisions for their patients.


Assuntos
Cirrose Hepática/diagnóstico por imagem , Cirrose Hepática/patologia , Redes Neurais de Computação , Adulto , Fatores Etários , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores Sexuais , Ultrassonografia Doppler em Cores
6.
J Med Syst ; 38(8): 85, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24957399

RESUMO

This paper focuses on the issue of extracting retina vessels with supervised approach. Since the green channel in the retina image has the best contrast between vessel and non-vessel, this channel is used to separate vessels. In our approach we are proposing a technique of using gray-level co-occurrence matrix method for composition of the retinal images. It is based on fact that the co-occurrence matrix of retina image describes the transition of intensities between neighbour pixels, indicating spatial structural information of retina image. So, we first extract the features vector based on specified characteristics of the gray-level co-occurrence matrix and then we use these features vector to train a neural network approach for the classification method which makes our proposed approach more effective. Obtained results from the experiments in DRIVE and STARE database shows the advantage of the proposed method in contrast to current methods. This advantage is evaluated by the criteria of sensitivity, specificity, area under ROC and accuracy. The result of such a conversion as the input vector of a multilayer perceptron neural network will be trained and tested. Although in recent years different methods have been presented in this respect, but results of simulation shows that the proposed algorithm has a very high efficiency than the other researches.


Assuntos
Interpretação de Imagem Assistida por Computador/métodos , Redes Neurais de Computação , Vasos Retinianos/anatomia & histologia , Algoritmos , Humanos
7.
J Pers Med ; 14(8)2024 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-39201996

RESUMO

Predicting type 2 diabetes mellitus (T2DM) by using phenotypic data with machine learning (ML) techniques has received significant attention in recent years. PyCaret, a low-code automated ML tool that enables the simultaneous application of 16 different algorithms, was used to predict T2DM by using phenotypic variables from the "Nurses' Health Study" and "Health Professionals' Follow-up Study" datasets. Ridge Classifier, Linear Discriminant Analysis, and Logistic Regression (LR) were the best-performing models for the male-only data subset. For the female-only data subset, LR, Gradient Boosting Classifier, and CatBoost Classifier were the strongest models. The AUC, accuracy, and precision were approximately 0.77, 0.70, and 0.70 for males and 0.79, 0.70, and 0.71 for females, respectively. The feature importance plot showed that family history of diabetes (famdb), never having smoked, and high blood pressure (hbp) were the most influential features in females, while famdb, hbp, and currently being a smoker were the major variables in males. In conclusion, PyCaret was used successfully for the prediction of T2DM by simplifying complex ML tasks. Gender differences are important to consider for T2DM prediction. Despite this comprehensive ML tool, phenotypic variables alone may not be sufficient for early T2DM prediction; genotypic variables could also be used in combination for future studies.

8.
Interdiscip Sci ; 2024 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-39367993

RESUMO

Cardiotocography (CTG) is used to assess the health of the fetus during birth or antenatally in the third trimester. It concurrently detects the maternal uterine contractions (UC) and fetal heart rate (FHR). Fetal distress, which may require therapeutic intervention, can be diagnosed using baseline FHR and its reaction to uterine contractions. Using CTG, a pragmatic machine learning strategy based on feature reduction and hyperparameter optimization was suggested in this study to classify the various fetal states (Normal, Suspect, Pathological). An application of this strategy can be a decision support tool to manage pregnancies. On a public dataset of 2126 CTG recordings, the model was assessed using various standard CTG dataset specific and relevant classifiers. The classifiers' accuracy was improved by the proposed method. The model accuracy was increased to 97.20% while using Random Forest (best classifier). Practically speaking, the model was able to correctly predict 100% of all pathological cases and 98.8% of all normal cases in the dataset. The proposed model was also implemented on another public CTG dataset having 552 CTG signals, resulting in a 97.34% accuracy. If integrated with telemedicine, this proposed model could also be used for long-distance "stay at home" fetal monitoring in high-risk pregnancies.

9.
Diagnostics (Basel) ; 13(11)2023 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-37296783

RESUMO

Cardiotocography (CTG), which measures the fetal heart rate (FHR) and maternal uterine contractions (UC) simultaneously, is used for monitoring fetal well-being during delivery or antenatally at the third trimester. Baseline FHR and its response to uterine contractions can be used to diagnose fetal distress, which may necessitate therapeutic intervention. In this study, a machine learning model based on feature extraction (autoencoder), feature selection (recursive feature elimination), and Bayesian optimization, was proposed to diagnose and classify the different conditions of fetuses (Normal, Suspect, Pathologic) along with the CTG morphological patterns. The model was evaluated on a publicly available CTG dataset. This research also addressed the imbalance nature of the CTG dataset. The proposed model has a potential application as a decision support tool to manage pregnancies. The proposed model resulted in good performance analysis metrics. Using this model with Random Forest resulted in a model accuracy of 96.62% for fetal status classification and 94.96% for CTG morphological pattern classification. In rational terms, the model was able to accurately predict 98% Suspect cases and 98.6% Pathologic cases in the dataset. The combination of predicting and classifying fetal status as well as the CTG morphological patterns shows potential in monitoring high-risk pregnancies.

10.
Diagnostics (Basel) ; 13(3)2023 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-36766537

RESUMO

In recent years, the number of studies for the automatic diagnosis of biomedical diseases has increased. Many of these studies have used Deep Learning, which gives extremely good results but requires a vast amount of data and computing load. If the processor is of insufficient quality, this takes time and places an excessive load on the processor. On the other hand, Machine Learning is faster than Deep Learning and does not have a much-needed computing load, but it does not provide as high an accuracy value as Deep Learning. Therefore, our goal is to develop a hybrid system that provides a high accuracy value, while requiring a smaller computing load and less time to diagnose biomedical diseases such as the retinal diseases we chose for this study. For this purpose, first, retinal layer extraction was conducted through image preprocessing. Then, traditional feature extractors were combined with pre-trained Deep Learning feature extractors. To select the best features, we used the Firefly algorithm. In the end, multiple binary classifications were conducted instead of multiclass classification with Machine Learning classifiers. Two public datasets were used in this study. The first dataset had a mean accuracy of 0.957, and the second dataset had a mean accuracy of 0.954.

11.
Comput Biol Med ; 37(6): 785-92, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16997292

RESUMO

In this study, Doppler signals were recorded from the output of carotid arteries of 40 subjects and transferred to a personal computer (PC) by using a 16-bit sound card. Doppler difference frequencies were recorded from each of the subjects, and then analyzed by using short-time Fourier transform (STFT) and the continuous wavelet transform (CWT) methods to obtain their sonograms. These sonograms were then used to determine the relationships of applied methods with medical conditions. The sonograms that were obtained by CWT method gave better results for spectral resolution than the STFT method. The sonograms of CWT method offer net envelope and better imaging, so that the measurement of blood flow and brain pressure can be made more accurately. Simultaneously, receiver operating characteristic (ROC) analysis has been conducted for this study and the estimation performance of the spectral resolution for the STFT and CTW has been obtained. The STFT has shown a 80.45% success for the spectral resolution while CTW has shown a 89.90% success.


Assuntos
Doenças das Artérias Carótidas/diagnóstico por imagem , Estudos de Casos e Controles , Metodologias Computacionais , Análise de Fourier , Humanos , Pessoa de Meia-Idade , Ultrassonografia Doppler/métodos , Ultrassonografia Doppler/estatística & dados numéricos
12.
Med Biol Eng Comput ; 54(2-3): 453-61, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26093773

RESUMO

There are various methods and algorithms to detect the optic discs in retinal images. In recent years, much attention has been given to the utilization of the intelligent algorithms. In this paper, we present a new automated method of optic disc detection in human retinal images using the firefly algorithm. The firefly intelligent algorithm is an emerging intelligent algorithm that was inspired by the social behavior of fireflies. The population in this algorithm includes the fireflies, each of which has a specific rate of lighting or fitness. In this method, the insects are compared two by two, and the less attractive insects can be observed to move toward the more attractive insects. Finally, one of the insects is selected as the most attractive, and this insect presents the optimum response to the problem in question. Here, we used the light intensity of the pixels of the retinal image pixels instead of firefly lightings. The movement of these insects due to local fluctuations produces different light intensity values in the images. Because the optic disc is the brightest area in the retinal images, all of the insects move toward brightest area and thus specify the location of the optic disc in the image. The results of implementation show that proposed algorithm could acquire an accuracy rate of 100 % in DRIVE dataset, 95 % in STARE dataset, and 94.38 % in DiaRetDB1 dataset. The results of implementation reveal high capability and accuracy of proposed algorithm in the detection of the optic disc from retinal images. Also, recorded required time for the detection of the optic disc in these images is 2.13 s for DRIVE dataset, 2.81 s for STARE dataset, and 3.52 s for DiaRetDB1 dataset accordingly. These time values are average value.


Assuntos
Algoritmos , Vaga-Lumes/anatomia & histologia , Interpretação de Imagem Assistida por Computador , Disco Óptico/anatomia & histologia , Animais , Bases de Dados como Assunto , Humanos , Fatores de Tempo
13.
Turk J Gastroenterol ; 26(4): 315-21, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26039001

RESUMO

BACKGROUND/AIMS: We aimed to assess the effect of azathioprine on mucosal healing in patients with inflammatory bowel diseases (IBD). Artificial neural networks were applied to IBD data for predicting mucosal remission. MATERIALS AND METHODS: Two thousand seven hundred patients with IBD were evaluated. According to the computer-based study, data of 129 patients with IBD were used. Artificial neural networks were performed and tested. RESULTS: Endoscopic mucosal healing was found in 37% patients with IBD. Male gender group showed a negative impact on the efficacy of azathioprine (p<0.05). Responder patients with IBD were older than the nonresponder (p<0.05) patients. According to this study, the cascade-forward neural network study provides 79.1% correct results. In addition to a 0.16033 training error, mean square error (MSE) was taken at the 16th epoch from the feed-forward back-propagation neural network. This neural structure, used for predicting mucosal remission with azathioprine, was also validated. CONCLUSION: Analyzing all parameters within each other to azathioprine therapy were shown that which parameters gave better healing were determined by statistical, and for the most weighted six input parameters, artificial neural network structures were constructed. In this study, feed-forward back-propagation and cascade-forward artificial neural network models were used.


Assuntos
Antimetabólitos/uso terapêutico , Azatioprina/uso terapêutico , Doenças Inflamatórias Intestinais/classificação , Mucosa Intestinal , Redes Neurais de Computação , Adolescente , Adulto , Idoso , Criança , Feminino , Humanos , Doenças Inflamatórias Intestinais/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Indução de Remissão , Reprodutibilidade dos Testes , Estudos Retrospectivos , Resultado do Tratamento , Adulto Jovem
14.
Comput Biol Med ; 32(6): 435-44, 2002 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12356493

RESUMO

Doppler signals, recorded from the output of tricuspid, mitral, and aorta valves of 60 patients, were transferred to a personal computer via 16-bit sound card. The fast Fourier transform (FFT) method was applied to the recorded signal from each patient. Since FFT method inherently cannot offer a good spectral resolution at highly turbulent blood flows, it sometimes leads to wrong interpretation of cardiac Doppler signals. In order to avoid this problem, firstly six known diseased heart signals such as hypertension, mitral stenosis, mitral failure, tricuspid stenosis, aorta stenosis, aorta insufficiency were introduced to fuzzy algorithm. Then, the unknown heart diseases from 15 patients were applied to the same fuzzy algorithm in order to detect the kinds of diseases. It is observed that the fuzzy algorithm gives true results for detecting the kind of diseases.


Assuntos
Diagnóstico por Computador/instrumentação , Ecocardiografia Doppler/instrumentação , Doenças das Valvas Cardíacas/diagnóstico por imagem , Hemodinâmica/fisiologia , Hipertensão/diagnóstico por imagem , Processamento de Sinais Assistido por Computador/instrumentação , Algoritmos , Conversão Análogo-Digital , Diástole/fisiologia , Análise de Fourier , Lógica Fuzzy , Doenças das Valvas Cardíacas/fisiopatologia , Valvas Cardíacas/diagnóstico por imagem , Valvas Cardíacas/fisiopatologia , Humanos , Hipertensão/fisiopatologia , Microcomputadores , Sensibilidade e Especificidade , Sístole/fisiologia , Interface Usuário-Computador
15.
Comput Biol Med ; 32(6): 445-53, 2002 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12356494

RESUMO

In this work, transcranial Doppler signals recorded from the temporal region of the brain on 35 patients were transferred to a personal computer by using a 16-bit sound card. Fast Fourier transform and adaptive auto regressive-moving average (A-ARMA) methods were applied to transcranial Doppler frequencies obtained from the middle cerebral artery in the temporal region. Spectral analyses were obtained to compare both methods for medical diagnoses. The sonograms obtained using A-ARMA method give better results for spectral resolution than the FFT method. The sonograms of A-ARMA method offer net envelope and better imaging, so that the determination of blood flow and brain pressure can be calculated more accurately. All diseases show higher resistance to flow than controls with no difference between males and females. Whereas values between disease classes differed, resistance within each class was remarkably constant.


Assuntos
Encéfalo/irrigação sanguínea , Processamento de Sinais Assistido por Computador/instrumentação , Ultrassonografia Doppler Transcraniana/instrumentação , Ultrassonografia Doppler/instrumentação , Adolescente , Adulto , Idoso , Velocidade do Fluxo Sanguíneo/fisiologia , Encefalopatias/diagnóstico por imagem , Criança , Pré-Escolar , Feminino , Análise de Fourier , Humanos , Masculino , Microcomputadores , Pessoa de Meia-Idade , Artéria Cerebral Média/diagnóstico por imagem , Análise de Regressão , Sensibilidade e Especificidade , Lobo Temporal/irrigação sanguínea
16.
Comput Biol Med ; 32(6): 419-34, 2002 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12356492

RESUMO

In this study, Doppler signals recorded from ophthalmic artery of 86 patients were processed by personal computer using fast Fourier transform, Burg autoregressive (AR), and least-squares AR methods. By using these spectrum analysis techniques, the variations in the shape of the Doppler spectrums as a function of time were presented in the form of sonograms in order to obtain medical information. These sonograms were then used to compare the applied methods in terms of their frequency resolution and the effects in determination of Behcet disease.


Assuntos
Síndrome de Behçet/diagnóstico por imagem , Artéria Oftálmica/diagnóstico por imagem , Processamento de Sinais Assistido por Computador/instrumentação , Ultrassonografia Doppler em Cores/instrumentação , Adulto , Conversão Análogo-Digital , Síndrome de Behçet/fisiopatologia , Velocidade do Fluxo Sanguíneo/fisiologia , Feminino , Análise de Fourier , Humanos , Masculino , Computação Matemática , Microcomputadores , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Valores de Referência , Análise de Regressão , Transdutores , Interface Usuário-Computador
17.
Comput Biol Med ; 34(5): 389-405, 2004 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15145711

RESUMO

The blood flow hemodynamics of carotid arteries were obtained from carotid arteries of 168 individuals with diabetes using the 7.5 MHz ultrasound Doppler M-unit. Fast Fourier Transform (FFT) methods were used for feature extraction from the Doppler signals on the time-frequency domain. The parameters, obtained from the Doppler sonograms, were applied to the mathematical models that were constituted to analyze the effect of diabetes on internal carotid artery (ICA) stenosis. In this study, two different mathematical models such as the traditional statistical method based on logistic regression and a Multi-Layer Perceptron (MLP) neural network were used to classify the Doppler parameters. The correct classification of these data was performed by an expert radiologist using angiograpy before they were executed by logistic regression and MLP neural networks. We classified the carotid artery stenosis into two categories such as non-stenosis and stenosis and we achieved similar results (correctly classified (CC) = 92.8%) in both mathematical models. But, as the degree of stenosis had been increased to 4 (0-39%, 40-59%, 60-79% and 80-99% diameter stenosis), it was found that the neural network (CC = 73.9%) became more efficient than the logistic regression analysis (CC = 67.7%). These outcomes indicate that the Doppler sonograms taken from the carotid arteries may be classified successfully by neural network.


Assuntos
Estenose das Carótidas/classificação , Complicações do Diabetes , Redes Neurais de Computação , Estenose das Carótidas/complicações , Estenose das Carótidas/diagnóstico por imagem , Análise de Fourier , Humanos , Modelos Logísticos , Ultrassonografia Doppler
18.
J Med Syst ; 32(2): 137-45, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18461817

RESUMO

Transcranial Doppler signals recorded from cerebral vessels of 110 patients were transferred to a personal computer by using a 16 bit sound card. Spectral analyses of Transcranial Doppler signals were performed for determining the Multi Layer Perceptron (MLP) neural network and neuro Ankara-fuzzy system inputs. In order to do a good interpretation and rapid diagnosis, FFT parameters of Transcranial Doppler signals classified using MLP neural network and neuro-fuzzy system. Our findings demonstrated that 92% correct classification rate was obtained from MLP neural network, and 86% correct classification rate was obtained from neuro-fuzzy system.


Assuntos
Veias Cerebrais/diagnóstico por imagem , Lógica Fuzzy , Redes Neurais de Computação , Processamento de Sinais Assistido por Computador , Ultrassonografia Doppler Transcraniana , Humanos
19.
J Med Syst ; 29(6): 679-708, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16235821

RESUMO

The aim of this study is to determine lipid peroxidation and antioxidant enzyme levels in spleen and testis tissues of guinea pigs which were exposed to different intensities and periods of DC (direct current) and AC (alternating current) electric fields. The experimental results are applied to neural networks as learning data and the training of the feed forward neural network is realized. At the end of this training; without applying electric field to the tissues, the determination of the effects of the electric field on tissues by using computer is predicted by the neural network. After the experiments, the prediction of the neural network is averagely 99%.


Assuntos
Campos Eletromagnéticos/efeitos adversos , Redes Neurais de Computação , Animais , Cobaias , Peroxidação de Lipídeos , Masculino , Malondialdeído/análise , Baço/metabolismo , Baço/efeitos da radiação , Superóxido Dismutase/análise , Testículo/metabolismo , Testículo/efeitos da radiação
20.
J Med Syst ; 29(2): 155-64, 2005 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15931801

RESUMO

Cardiac Doppler signals recorded from aorta valve of 60 patients were transferred to a personal computer by using a 16 bit sound card. The fast Fourier transform (FFT) method was applied to the recorded signal from each patient. Since FFT method inherently cannot offer a good spectral resolution at jet blood flows such as cardiac Doppler signals, it sometimes causes wrong interpretation. In order to do a good interpretation and rapid diagnosis, cardiac Doppler blood flow signals were statistically arranged and then classified using neuro-fuzzy system. The NEFCLASS model, which is used to create a fuzzy classification system from data, was used. The classification results show that neuro-fuzzy system offers best results in the case of diagnosis.


Assuntos
Insuficiência da Valva Aórtica/classificação , Estenose da Valva Aórtica/classificação , Redes Neurais de Computação , Insuficiência da Valva Aórtica/diagnóstico por imagem , Insuficiência da Valva Aórtica/fisiopatologia , Estenose da Valva Aórtica/diagnóstico por imagem , Estenose da Valva Aórtica/fisiopatologia , Velocidade do Fluxo Sanguíneo , Diagnóstico por Computador , Ecocardiografia Doppler , Análise de Fourier , Lógica Fuzzy , Humanos
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