hamid reza marateb
-
Background
Diabetes mellitus (DM) is a chronic disease that affects public health. The prediction of blood glucose concentration (BGC) is essential to improve the therapy of type 1 DM (T1DM).
MethodsHaving considered the risk of hyper‑ and hypo‑glycemia, we provide a new hybrid modeling approach for BGC prediction based on a dynamic wavelet neural network (WNN) model, including a heuristic input selection. The proposed models include a hybrid dynamic WNN (HDWNN) and a hybrid dynamic fuzzy WNN (HDFWNN). These wavelet‑based networks are designed based on dominant wavelets selected by the genetic algorithm‑orthogonal least square method. Furthermore, the HDFWNN model structure is improved using fuzzy rule induction, an important innovation in the fuzzy wavelet modeling. The proposed networks are tested on real data from 12 T1DM patients and also simulated data from 33 virtual patients with an UVa/Padova simulator, an approved simulator by the US Food and Drug Administration.
ResultsA comparison study is performed in terms of new glucose‑based assessment metrics, such as gFIT, glucose‑weighted form of ESODn (gESODn), and glucose‑weighted R2 (gR2). For real patients’ data, the values of the mentioned indices are accomplished as gFIT = 0.97 ± 0.01, gESODn = 1.18 ± 0.38, and gR2 = 0.88 ± 0.07. HDFWNN, HDWNN and jump NN method showed the prediction error (root mean square error [RMSE]) of 11.23 ± 2.77 mg/dl, 10.79 ± 3.86 mg/dl and 16.45 ± 4.33 mg/dl, respectively.
ConclusionFurthermore, the generalized estimating equation and post hoc tests show that proposed models perform better compared with other proposed methods
Keywords: Blood glucose prediction, diabetes mellitus, fuzzy rule induction, fuzzy wavelet neural network, wavelet neural network -
IntroductionBrain-Computer Interface (BCI) systems provide a communication pathway between users and systems. BCI systems based on Steady-State Visually Evoked Potentials (SSVEP) are widely used in recent decades. Different feature extraction methods have been introduced in the literature to estimate SSVEP responses to BCI applications.MethodsIn this study, the new algorithms, including Canonical Correlation Analysis (CCA), Least Absolute Shrinkage and Selection Operator (LASSO), L1-regularized Multi-way CCA (L1-MCCA), Multi-set CCA (MsetCCA), Common Feature Analysis (CFA), and Multiple Logistic Regression (MLR) are compared using proper statistical methods to determine which one has better performance with the least number of EEG electrodes.ResultsIt was found that MLR, MsetCCA, and CFA algorithms provided the highest performances and significantly outperformed CCA, LASSO, and L1-MCCA algorithms when using 8 EEG channels. However, when using only 1 or 2 EEG channels d, CFA method provided the highest F-scores. This algorithm not only outperformed MLR and MsetCCA when applied on different electrode montages but also provided the fastest computation time on the test set.ConclusionAlthough MLR method has already demonstrated to have higher performance in comparison with other frequency recognition algorithms, this study showed that in a practical SSVEP-based BCI system with 1 or 2 EEG channels and short-time windows, CFA method outperforms other algorithms. Therefore, it is proposed that CFA algorithm is a promising choice for the expansion of practical SSVEP-based BCI systems.Keywords: Brain-Computer Interface (BCI), Electroencephalogram (EEG), Feature extraction, Steady-State Visually Evoked Potential (SSVEP)
-
BackgroundIn this study, we aimed to determine comprehensive maternal characteristics associated with birth weight using Bayesian modeling.Materials And MethodsA total of 526 participants were included in this prospective study. Nutritional status, supplement consumption during the pregnancy, demographic and socioeconomic characteristics, anthropometric measures, physical activity, and pregnancy outcomes were considered as e?ective variables on the birth weight. Bayesian approach of complex statistical models using Markov chain Monte Carlo approach was used for modeling the data considering the real distribution of the response variable.ResultsTere was strong positive correlation between infant birth weight and the maternal intake of Vitamin C, folic acid, Vitamin B3, Vitamin A, selenium, calcium, iron, phosphorus, potassium, magnesium as micronutrients, and fber and protein as macronutrients based on the 95% high posterior density regions for parameters in the Bayesian model. None of the maternal characteristics had statistical association with birth weight.ConclusionHigher maternal macro? and micro?nutrient intake during pregnancy was associated with a lower risk of delivering low birth weight infants. Tese fndings support recommendations to expand intake of nutrients during pregnancy to high level.Keywords: Bayesian modeling, bioinformatics, birth weight, maternal characteristics, nutritional risk factors
-
BackgroundTo investigate the associations of genetic polymorphism with high-density lipoprotein-cholesterol (HDL-C) levels in Iranian adolescents.MethodsThis multicentre study was conducted on 10 - 18 year-old students from 27 provinces in Iran. Logic regression approach was used to determine the main effects and interactions of polymorphisms related to HDL-C levels.ResultsThe rs708272 polymorphism was significantly related to HDL-C levels. Moreover, rs708272 increased HDL-C levels and had a protective effect on HDL-C. The interaction of rs2230808 and rs5880 polymorphisms as well as the interaction of rs320 and rs708272 polymorphisms were associated with lower HDL-C levels. Furthermore, the interaction of rs320 and rs1801177 polymorphisms was associated with lower HDL-C levels.ConclusionsWe found that not only single SNPs, but also interactions of several SNPs affect HDL-C levels. Given the high prevalence of low HDL-C in Middle Eastern populations, further genetic studies are required for detailed analysis.Keywords: Polymorphism, High, Density Lipoprotein, Pediatrics, Logic Regression
-
Background
This paper is a meta‑analysis of the published data from in vitro studies to evaluate whether spontaneous apoptosis might be influenced by extremely low frequency (ELF) magnetic fields (MFs).
Materials and MethodsA comprehensive scientific literature search in electronic databases was conducted and studies covering the period 2000–2010 were selected. Then, published studies involving the desired topic were retrieved. The inclusion criteria were percentage of apoptosis in the cells exposed to 50–60 Hz ELF‑MFs. The statistical analysis was performed by comprehensive meta‑analysis version 2.
ResultsThe summary measure of association (95% confidence interval) for all 18 effect estimated from 8 studies was 1.18 (1.15, 1.20). Heterogeneity among studies was found. There was no evidence of publication bias for the association between exposure to MF and apoptosis risk.
ConclusionOur meta‑analysis provided conclusive data that ELF‑MFs can increase apoptosis in cancer and normal cells. Furthermore, there is a possibly individual intensity and time range with maximum created effect according to window effect.
Keywords: Apoptosis, extremely low‑frequency magnetic field exposure, meta‑analysis -
Neurofeedback is a kind of biofeedback, which teaches self-control of brain functions to subjects by measuring brain waves and providing a feedback signal. Neurofeedback usually provides the audio and or video feedback. Positive or negative feedback is produced for desirable or undesirable brain activities, respectively. In this review, we provided clinical and technical information about the following issues: (1) Various neurofeedback treatment protocols i.e. alpha, beta, alpha/theta, delta, gamma, and theta; (2) Different EEG electrode placements i.e. standard recording channels in the frontal, temporal, central, and occipital lobes; (3) Electrode montages (unipolar, bipolar); (4) Types of neurofeedback i.e. frequency, power, slow cortical potential, functional magnetic resonance imaging, and so on; (5) Clinical applications of neurofeedback i.e. treatment of attention deficit hyperactivity disorder, anxiety, depression, epilepsy, insomnia, drug addiction, schizophrenia, learning disabilities, dyslexia and dyscalculia, autistic spectrum disorders and so on as well as other applications such as pain management, and the improvement of musical and athletic performance; and (6) Neurofeedback softwares. To date, many studies have been conducted on the neurofeedback therapy and its effectiveness on the treatment ofmany diseases. Neurofeedback, like other treatments, has its own pros and cons. Although it is a non-invasive procedure, its validity has been questioned in terms of conclusive scientific evidence. For example, it is expensive, time-consuming and its benefits are not long-lasting. Also, it might take months to show the desired improvements. Nevertheless, neurofeedback is known as a complementary and alternative treatment of many brain dysfunctions. However, current research does not support conclusive results about its efficacy.Keywords: Brain diseases, Brain waves, Complementary therapies, Electroencephalography, Neurofeedback
-
مقدمهدر حال حاضر سیستم های تشخیصی رایانه ای دارای کاربرد وسیعی در علوم پزشکی می باشند. این سیستم ها می توانند در تشخیص درست و به موقع بیماری ها به پزشک یاری رسانند. عملکرد این گونه سیستم ها باید به صورت مناسبی ارزیابی شود. در این مقاله، معیارهای ارزیابی سیستم های تشخیصی پزشکی مورد بررسی قرار می گیرد.روش هابا استفاده از داده استاندارد در هر روش تشخیصی، میزان خطای سیستم بر اساس پارامترهای حساسیت، ویژگی، صحت، دقت ، سطح زیر منحنی (ROC یا receiver operating characteristic) ، F-measure،Matthews correlation coefficient و... محاسبه شد و نقاط قوت و ضعف هر معیار مورد بررسی قرار گرفت. معیارهای ارزیابی در یک مثال پزشکی بر روی مقایسه دو روش در تشخیص عارضه قلبی بیماران، محاسبه و ارزیابی شدند. هم چنین ارجحیت روش های تشخیصی به یکدیگر با استفاده از تست McNemar مشخص گردید.یافته هابه دلیل برابر بودن نسبی تعداد افراد واقعا سالم و مریض در مجموعه داده مورد استفاده، پارامتر صحت، معیار قابل قبولی برای ارزیابی کلی دو روش بود که در دو روش به ترتیب 84 و 86٪ محاسبه شد. هر دو روش از نظر پزشکی، قابل اعتماد نبودند چون میزان خطای نوع اول بیشتر از05/0 بود. با این حال، توان تشخیصی روش دوم چون بالای 80% بود، قابل قبول می باشد. چون سطح زیر منحنی ROC در دو روش بین 8/0 و 9/0 بود، قدرت تشخیصی آن ها «بسیار خوب» می باشد. در نهایت، دو روش تشخیصی از نظر آماری معادل شناخته شدند.نتیجه گیریارزیابی سیستم های تشخیصی باید با روش های مناسب و معیارهای مرتبط انجام گیرد. با بکارگیری معیارهای متعدد قادر خواهیم بود توانایی روش تشخیصی را از زوایای مختلف ارزیابی نماییم.کلید واژگان: سیستم های تشخیصی رایانه ای, داده کاوی, اعتبار سنجی, بازشناخت الگوBackgroundNowadays, computer-aided diagnosis systems are widely used in medicine. These systems could assist medical doctors in early correct diagnosis of diseases. The performance of such systems must be correctly assessed. In this paper, the performance criteria of these diagnosis systems are taken into account.MethodsThe diagnosis error of such systems was estimated based on the gold standard data using measures such as Sensitivity, Specificity, Accuracy, Precision, Area Under curve ROC (receiver operating characteristic), F-measure, Matthews correlation coefficient , etc. The advantages and disadvantages of those criteria were also discussed. Then, the performance of two Coronary Artery Disease diagnosis systems was assessed. The statistically significant superior method was identified using the McNemars test.
Findings: Since the analyzed dataset was balanced, the overall performance of the diagnosis methods was assessed using the accuracy measure. The accuracy of the methods was 84% and 86%, respectively. The entire systems were not reliable since Type I error (Alpha) was not less than 0.05. However, the second system had acceptable statistical power (>80%). The diagnosis performance of those systems was very good (0.8ConclusionThe performance of the diagnosis systems must be assessed using the proper methods and criteria. Using different suitable performance measures, it is possible to assess the diagnosis performance of such systems in details.Keywords: Computer, Aided Diagnosis, Data Mining, Pattern Recognition, Validation -
راه رفتن از پرکاربردترین حرکات انسانی است. از همین رو مطالعه ی عوامل اثرگذار بر این حرکت، همواره مورد توجه بوده است. از آن جا که سرعت بعنوان یک اختلال فیزیکی، ابعاد مختلف راه رفتن را تحت تاثیر قرار می دهد، در این مطالعه هدف بررسی وتحلیل تاثیر سرعت بر ویژگی های فیزیکی و فیزیولوژیکی می باشد. این تحلیل بر مبنای پردازش اطلاعات به دست آمده از یک گام قرار گرفته است. مطالعه بر روی 32 آزمودنی سالم با میانگین سنی 40/20 ± 56/27 سال، میانگین وزنی 59/20 ± 89/54 کیلوگرم و میانگین قدی 83/20 ± 19/158 سانتی متر انجام شد که %59 از آزمودنی ها زن بودند. اطلاعات کینتیکی، کینماتیکی و الکترومایوگرافی هر یک از آزمودنی ها در پنج سرعت مختلف ثبت شده است. هدف اصلی، بررسی تاثیر سرعت بر جنبه های مختلفی از سیستم کنترل حرکت تعریف شده است. بدین منظور تاثیر سرعت بر 46 ویژگی از اطلاعات زمانی- مکانی، سینرژی عضلانی، نرمی حرکت، شکل حرکات مفاصل و همبستگی بین جابه جایی اندام های تحتانی، هم چنین همبستگی بین الگوی فعالیت الکتریکی عضلات بررسی شده است. در بین ویژگی های معرفی شده در این مطالعه، ملهم از مطالعات حوزه ی حرکت از ویژگی های جدیدی نظیر سینرژی عضلانی، نرمی حرکت، همبستگی در اندام های تحتانی و شکل حرکات تولیدی توسط مفاصل، استفاده شد که تا کنون در توصیف اثرگذاری سرعت بر راه افراد سالم مورد استفاده قرار نگرفته است. برای مثال استفاده از مفهوم سینرژی نشان داد که سرعت های بیشتر موجب افزایش سایز فضای سینرژی می شود. همین امر می تواند به عنوان نشانه ای از استراتژی پیچیده تری باشد که توسط سیستم اعصاب مرکزی، اتخاذ شده تا در شرایط ناپایدار که در سرعت های بالا رخ می دهد، در وضعیت مطلوبی باقی بماند. نتایج به دست آمده نشان می دهد که سرعت نقش مهمی در راه رفتن ایفا می کند. روش های مورد بررسی در این مقاله را می توان بر روی آزمودنی-های بیشتر و بیماران درگیر با نقص حرکتی نیز بررسی نمود.
کلید واژگان: راه رفتن, سرعت, کینتیکی, کینماتیکی, الکترومایوگرافیWalking is one of the most widely used movements affecting life quality. Therefore, the study of factors affecting human gait has always been an important issue. Walking speed, as a physical perturbation, affects the quality of human walking. The purpose of this study is to estimate the effects of walking speed on the short-time gait parameters. Thirty-two healthy subjects (mean SD, age: 27.56 ± 20.4 years; body height: 158.19 ± 20.83 cm; body weight: 54.89 ± 20.59 kg; gender: 59% female) participated in this study. Kinetic, kinematic and electromyographic data were recorded at the following five walking speed categories: very slow, slow, medium, fast and very fast. The effect of speed on spatio-temporal parameters, muscle synergy space, walking smoothness, representation of joints displacement and the correlation between lower limb displacement and also correlation between muscles activation patterns were studied. Having being used physical perturbation, 46 predictors were extracted from one gait cycle information, some of which were proposed for the first time in the literature for example size of muscle synergy, minimum angular jerk, lower limb contributions and skewness, kurtosis and curvature of joints movements . Using muscle synergies showed that increasing walking speed leads to increase the size of synergy space. It could be concluded that central nervous system tries to adopt more organaized strategy for recruiting muscles and remaining stable at fast speeds. Our results showed that, speed plays a crucial role in human gait characteristic. We can investigate our methods among more subjects and also patients with gait disorders. We can evaluate other indices like gait stability based on short-term data recording.
Keywords: Gait, Speed, Kinetic, Kinematic, Electromyographic -
In current years, the application of biopotential signals has received a lot of attention in literature. One of these signals is an electromyogram (EMG) generated by active muscles. Surface EMG (sEMG) signal is recorded over the skin, as the representative of the muscle activity. Since its amplitude can be as low as 50 µV, it is sensitive to undesirable noise signals such as power‑line interferences. This study aims at designing a battery‑powered portable four channel sEMG signal acquisition system. The performance of the proposed system was assessed in terms of the input voltage and current noise, noise distribution, and synchronization and input noise level among different channels. The results indicated that the designed system had several inbuilt operational merits such as low referred to input noise (lower than 0.56 µV between 8 Hz and 1000 Hz), considerable elimination of power‑line interference and satisfactory recorded signal quality in terms of signal‑to‑noise ratio. The muscle conduction velocity was also estimated using the proposed system on the brachial biceps muscle during isometric contraction. The estimated values were in then normal ranges. In addition, the system included a modular configuration to increase the number of recording channels up to 96.
-
مقدمهوزن کم نوزاد در زمان تولد را می توان مهم ترین عامل در بیماری و مرگ ومیر نوزادان دانست. نوزادانی که در زمان تولد وزن کمی دارند، بیشتر در معرض بیماری ها قرار می گیرند. به همین دلیل، پیش بینی احتمال کم وزن بودن نوزاد پیش از تولد، از اهمیت بالایی برخوردار است.روش هادر این مطالعه، یک سیستم تشخیصی به کمک رایانه ارایه شد که به کمک آن می توان گروه وزنی نوزاد را در زمان تولد پیش بینی کرد و نوزادان را در دو گروه نوزاد با وزن کم و وزن طبیعی طبقه بندی نمود. همچنین، ارتباط میان وزن کم نوزاد در زمان تولد و فاکتورهای ثبت شده از مادران باردار در سه ماهه ی اول، دوم و سوم بارداری مورد بررسی قرارگرفت. مجموعه ی داده های مورد استفاده در این مطالعه شامل اطلاعات گرفته شده از 526 زن باردار با 95 متغیر مختلف ثبت شده از آن ها است. برای طبقه بندی نمونه های این مطالعه از روش های کلاس بندی نزدیک ترین همسایه ها، شبکه های عصبی احتمالاتی و دو نوع کلاس بند عصبی- فازی انطباقی استفاده گردیده است. علاوه بر آن، انتخاب ویژگی به روش پی درپی نیز برای کاهش اندازه ی فضای ویژگی ها مورد استفاده قرار گرفته است.یافته هاصحت طبقه بندی با استفاده از کلاس بندهای نزدیک ترین همسایه ها، شبکه ی عصبی احتمالاتی و کلاس بند عصبی- فازی انطباقی با استفاده از دو الگوریتم گرادیان مزدوج مدرج و شرایط زبانی، با انتخاب ویژگی به ترتیب برابر با 93، 83، 80 و 83 درصدگزارش شده است.نتیجه گیریاز میان کلاس بندهای مورد استفاده، توان بهترین کلاس بند مورد استفاده در این مطالعه با استفاده از روش های مناسب اعتبارسنجی، 96 درصد و خطای نوع اول آن 1/ 0 بوده است. با توجه به این نتایج، سیستم تشخیصی ارائه شده از لحاظ بالینی معتبر می باشد.
کلید واژگان: سیستم های تشخیصی پزشکی به کمک رایانه, روش اعتبارسنجی متقاطع, وزن کم نوزاد در زمان تولد, روش پی درپی انتخاب ویژگیBackgroundBirth weight is probably the most important factor affecting neonatal mortality and morbidity. Compared with normal weight infants, low-birth-weight (LBW) infants may be more at risk for many health problems. The prediction of low birth weight is important as it may cause mental and physical health problems in childhood and adulthood. We assessed a computer-aided diagnosis system to classify infants to low or normal birth weight categories.MethodsIn the present study, the association between the low birth weight and the intake of about 40 types of macro- and micronutrients during the first (1st Tr), second (2nd Tr.) and third (3rd Tr.) trimesters was assessed based on demographic and reproductive characteristics, physical activity and nutrients intake in pregnant women. The dataset used in this study contained 526 pregnant women with 95 input features. The used classifiers were k-Nearest Neighbors (kNN), Probabilistic Neural Network (PNN), and two Adaptive Neuro-Fuzzy Classifiers (ANFC-SCG: Scaled Conjugate Gradient, ANFC-LHs: Linguistic Hedges). Also, sequential feature selection (FS) was applied on the low birth weight risk factors to reduce the feature space.FindingsThe accuracy of the classifiers kNN, PNN, ANFC-SCG and ANFC-LHs were 48%, 50%, 50% and 50% without feature selection and 93%, 83%, 80% and 83% with feature selection, respectively.ConclusionAmong the tested classifiers, the statistical power and type I error (α) of the best configuration (FS-kNN; k = 3) were 96% and 0.10 in the Leave-One-Out validation framework, showing that the proposed diagnosis system is clinically reliable. Also, using Leave-One-Out cross-validation, the guarding against Type III error was granted.Keywords: Computer, aided medical diagnosis, Leave, one, out cross validation, Low birth weight, Sequential feature selection -
BackgroundCoronary heart diseases/coronary artery diseases (CHDs/CAD), the most common form of cardiovascular disease (CVD), are a major cause for death and disability in developing/developed countries. CAD risk factors could be detected by physicians to prevent the CAD occurrence in the near future. Invasive coronary angiography, a current diagnosis method, is costly and associated with morbidity and mortality in CAD patients. The aim of this study was to design a computer-based noninvasive CAD diagnosis system with clinically interpretable rules.Materials And MethodsIn this study, the Cleveland CAD dataset from the University of California UCI (Irvine) was used. The interval-scale variables were discretized, with cut points taken from the literature. A fuzzy rule-based system was then formulated based on a neuro-fuzzy classifier (NFC) whose learning procedure was speeded up by the scaled conjugate gradient algorithm. Two feature selection (FS) methods, multiple logistic regression (MLR) and sequential FS, were used to reduce the required attributes. The performance of the NFC (without/with FS) was then assessed in a hold-out validation framework. Further cross-validation was performed on the best classifier.ResultsIn this dataset, 16 complete attributes along with the binary CHD diagnosis (gold standard) for 272 subjects (68% male) were analyzed. MLR + NFC showed the best performance. Its overall sensitivity, specificity, accuracy, type I error (?) and statistical power were 79%, 89%, 84%, 0.1 and 79%, respectively. The selected features were “age and ST/heart rate slope categories,” “exercise-induced angina status,” fluoroscopy, and thallium-201 stress scintigraphy results.ConclusionThe proposed method showed “substantial agreement” with the gold standard. This algorithm is thus, a promising tool for screening CAD patients.Keywords: Classifi cation, clinical prediction rule, coronary artery disease, data mining, fuzzy logic
-
مقدمهچاقی یکی از مهم ترین مشکلات تغذیه ای در سراسر دنیاست. اگرچه مطالعات به غیراز مشکلات فیزیکی و حرکتی، گزارشی مبنی بر بروز بیماری های مزمن ناشی از چاقی در دوران کودکی ارائه نداده اند؛ اما چاقی در کودکی می تواند منجر به طیف وسیعی از مشکلات در آینده شود. در این مطالعه با هدف تشخیص زود هنگام بر آنیم تا با طراحی یک سیستم هوشمند احتمال وقوع چاقی را بر اساس اطلاعات اولیه ای بر اساس نحوه شیوه زندگی و یا سایر متغیرهای عمومی اولیه، پیش بینی کنیم.روشدر این مطالعه 9795 نفر (49/17% پسر) در گروه های سنی 6 تا 18 سال بر اساس چهارمین فاز مطالعه ملی گسترده کاسپین، مورد بررسی قرار گرفته اند. متغیرهای ورودی سیستم بر اساس عادات تغذیه ای، فعالیت ورزشی، اطلاعات وراثتی، وضعیت اجتماعی و اقتصادی و سابقه چاقی و دیابت مشخص گردیده اند. سپس بر اساس روش های داده کاوی و هوش مصنوعی، مشکل چاقی شناسایی و بررسی شده است. روش های انتخاب ویژگی نیز برای بهینه سازی سیستم طراحی شده در نظر گرفته شده است.یافته هاعملکرد روش های دسته بندی موردمطالعه توسط روش ارزیابی متقابل دولایه ای موردبررسی قرار گرفت. با توجه به نتایج حاصل از ارزیابی، بهترین نتیجه توسط روش دسته بندی ماشین بردار پشتیبان به دست آمده است. دقت و صحت این روش شناسایی پس از انتخاب ویژگی به ترتیب 63/3 و 83/7 درصد بوده است.نتیجه گیریویژگی هایی از قبیل سن، فعالیت ورزشی، نوع تغذیه در دوران نوزادی و سابقه دیابت در خانواده به عنوان تاثیرگذارترین ویژگی ها در ایجاد روند چاقی در دو گروه دختر و پسر شناسایی شده اند.
کلید واژگان: داده کاوی, چاقی, روش های دسته بندی, سیستم تشخیصی, هوش مصنوعیBackgroundObesity represents one of the most important nutritional problems worldwide.Obesity in childhood can cause variety of health issues such as orthopedic, neurological, pulmonary and gastroenterological disorders in the future, although no side effects were reported from malignant obesity during childhood. In this paper, we presented a computer-aided diagnosis system to predict the obesity based on input features obtained from the life style and other factors of the subjects.MethodsThe total number of 9795 subjects (49.17% boy) aged 6 to 18 years taken from the CASPIAN IV study participated in this study. The input parameters of the proposed system were taken from the dietary habit, physical activity, family history, social economic status, and other features. Then, the obesity was predicted using the data mining and artificial intelligence techniques. Feature Selection (FS) methods were also used to improve the performance of the proposed system. The performance of the diagnosis system was assessed based on the hold-out validation framework.FindingsThe performance of the classifications method has been validated by hold-out cross validation. Among the different classification techniques tested, SVM with FS showed the best performance. The accuracy and precision of this method were 63.3% and 83.7%, respectively. Some features such as age, physical activities, birth feeding and family history of diabetes mellitus detected as the most effectivefactors with obesity in both gender.ConclusionDesigning of an intelligentdiagnosis system with the input parameter such as life-style, socioeconomic status and genetic information can help predict obesity in children to modify their life-style to improve theirqualityof life in the future. A web-based version of this intelligent system can easily provide the obesity prediction facilities for the families at home.Keywords: Classification, Obesity, Data Mining, Medical Diagnosis System, Artificial Intelligence -
A cochlear implant is an implanted electronic device used to provide a sensation of hearing to a person who is hard of hearing. The cochlear implant is often referred to as a bionic ear. This paper presents an undecimated wavelet‑based speech coding strategy for cochlear implants, which gives a novel speech processor. The undecimated wavelet packet transform (UWPT) is computed like the wavelet packet transform except that it does not down‑sample the output at each level. The speech data used for the current study consists of 30 consonants, sampled at 16 ksps. The performance of our proposed UWPT method was compared to that of infinite impulse response (IIR) filter in terms of mean opinion score (MOS), short‑time objective intelligibility (STOI) measure and segmental signal‑to‑noise ratio (SNR). Undecimated wavelet had better segmental SNR in about 96% of the input speech data. The MOS of the proposed method was twice in comparison with that of the IIR filter‑bank. The statistical analysis revealed that the UWT‑based N‑of‑M strategy significantly improved the MOS, STOI and segmental SNR (P < 0.001) compared with what obtained with the IIR filter‑bank based strategies. The advantage of UWPT is that it is shift‑invariant which gives a dense approximation to continuous wavelet transform. Thus, the information loss is minimal and that is why the UWPT performance was better than that of traditional filter‑bank strategies in speech recognition tests. Results showed that the UWPT could be a promising method for speech coding in cochlear implants, although its computational complexity is higher than that of traditional filter‑banks
-
The purpose of this study was to estimate the torque from high‑density surface electromyography signals of biceps brachii, brachioradialis, and the medial and lateral heads of triceps brachii muscles during moderate‑to‑high isometric elbow flexion‑extension. The elbow torque was estimated in two following steps: First, surface electromyography (EMG) amplitudes were estimated using principal component analysis, and then a fuzzy model was proposed to illustrate the relationship between the EMG amplitudes and the measured torque signal. A neuro‑fuzzy method, with which the optimum number of rules could be estimated, was used to identify the model with suitable complexity. Utilizing the proposed neuro‑fuzzy model, the clinical interpretability was introduced; contrary to the previous linear and nonlinear black‑box system identification models. It also reduced the estimation error compared with that of the most recent and accurate nonlinear dynamic model introduced in the literature. The optimum number of the rules for all trials was 4 ± 1, that might be related to motor control strategies and the % variance accounted for criterion was 96.40 ± 3.38 which in fact showed considerable improvement compared with the previous methods. The proposed method is thus a promising new tool for EMG‑Torque modeling in clinical applications.
-
Backgroundselecting the correct statistical test and data mining method depends highly on the measurement scale of data, type of variables, and purpose of the analysis. Different measurement scales are studied in details and statistical comparison, modeling, and data mining methods are studied based upon using several medical examples. We have presented two ordinal–variables clustering examples, as more challenging variable in analysis, using Wisconsin Breast Cancer Data (WBCD). Ordinal-to-Interval scale conversion example: a breast cancer database of nine 10-level ordinal variables for 683 patients was analyzed by two ordinalscale clustering methods. The performance of the clustering methods was assessed by comparison with the gold standard groups of malignant and benign cases that had been identified by clinical tests.Resultsthe sensitivity and accuracy of the two clustering methods were 98% and 96%, respectively. Their specificity was comparable.Conclusionby using appropriate clustering algorithm based on the measurement scale of the variables in the study, high performance is granted. Moreover, descriptive and inferential statistics in addition to modeling approach must be selected based on the scale of the variables.Keywords: Biostatistics, breast cancer, cluster analysis, data mining, research design
- در این صفحه نام مورد نظر در اسامی نویسندگان مقالات جستجو میشود. ممکن است نتایج شامل مطالب نویسندگان هم نام و حتی در رشتههای مختلف باشد.
- همه مقالات ترجمه فارسی یا انگلیسی ندارند پس ممکن است مقالاتی باشند که نام نویسنده مورد نظر شما به صورت معادل فارسی یا انگلیسی آن درج شده باشد. در صفحه جستجوی پیشرفته میتوانید همزمان نام فارسی و انگلیسی نویسنده را درج نمایید.
- در صورتی که میخواهید جستجو را با شرایط متفاوت تکرار کنید به صفحه جستجوی پیشرفته مطالب نشریات مراجعه کنید.