فهرست مطالب

  • Volume:7 Issue: 1, 2017
  • تاریخ انتشار: 1395/10/29
  • تعداد عناوین: 8
  • Iman Esmaili, Nader Jafarnia Dabanloo, Mansour Vali Pages 1-7
    In recent years, many methods have been introduced for supporting the diagnosis of stuttering for automatic detection of prolongation in the speech of people who stutter. However, less attention has been paid to treatment processes in which clients learn to speak more slowly. The aim of this study was to develop a method to help speech-language pathologists (SLPs) during diagnosis and treatment sessions. To this end, speech signals were initially parameterized to perceptual linear predictive (PLP) features. To detect the prolonged segments, the similarities between successive frames of speech signals were calculated based on correlation similarity measures. The segments were labeled as prolongation when the duration of highly similar successive frames exceeded a threshold specified by the speaking rate. The proposed method was evaluated by UCLASS and self-recorded Persian speech databases. The results were also compared with three high-performance studies in automatic prolongation detection. The best accuracies of prolongation detection were 99 and 97.1% for UCLASS and Persian databases, respectively. The proposed method also indicated promising robustness against artificial variation of speaking rate from 70 to 130% of normal speaking rate.
    Keywords: Attention, language, learning, pathologists, speech, speech, language pathology, stuttering
  • Mojgan Esna Ashari, Maryam Zekri, Masood Askari Pages 8-20
    Because of increasing risk of diabetes, the measurement along with control of blood sugar has been of great importance in recent decades. In type I diabetes, because of the lack of insulin secretion, the cells cannot absorb glucose leading to low level of glucose. To control blood glucose (BG), the insulin must be injected to the body. This paper proposes a method for BG level regulation in type I diabetes. The control strategy is based on nonlinear model predictive control. The aim of the proposed controller optimized with genetics algorithms is to measure BG level each time and predict it for the next time interval. This merit causes a less amount of control effort, which is the rate of insulin delivered to the patient body. Consequently, this method can decrease the risk of hypoglycemia, a lethal phenomenon in regulating BG level in diabetes caused by a low BG level. Two delay differential equation models, namely Wang model and Enhanced Wang model, are applied as controller model and plant, respectively. The simulation results exhibit an acceptable performance of the proposed controller in meal disturbance rejection and robustness against parameter changes. As a result, if the nutrition of the person decreases instantly, the hypoglycemia will not happen. Furthermore, comparing this method with other works, it was shown that the new method outperforms previous studies.
    Keywords: Algorithms, blood glucose, diabetes mellitus, glucose, humans, hypoglycemia, insulin, meals, nonlinear dynamics, type 1
  • Vahideh Nazari, Seied R. Mahdavi, Ahmad Mostaar, Hassan Nedaei, Mohammad Amin Mosleh Shirazi, Alireza Nikkofar, Golbarg Esmaillie Pages 21-25
    Dosimetric verification of radiation treatment has recently been extended by the introduction of electronic portal imaging devices (EPIDs). Detailed dose response specifications of EPID should be addressed prior to any dosimetric application. The present study evaluates improvements of dosimetric properties of the low elbow camera-based EPID Theraview (Cablon Medical, Leusden, The Netherlands) equipped with a cooled charge coupled device (CCD) for portal dosimetry. The dose response, warm-up behavior, stability over long- and short-term scales (throughout a day) were studied. The field size dependency of the EPID response was also investigated and compared with ion chamber measurements under the same conditions. The EPID response without saturation for doses up to 2 Gy was linear for both beam qualities (6 and 15 MV). There was no evident warm-up characteristic. The detector sensitivity showed excellent stability in short term [standard deviation (SD) 0.38%]. In longterm stability (over a period of approximately 3 months), a negligible linear decline of 0.01% per day was observed. It was concluded that the cooled CCD camera-based EPID could be used for portal dosimetry, after accurate corrections for the field size dependency and sensitivity loss.
    Keywords: Electronic portal imaging devices, elbow, portal dosimetry, radiometry
  • Masoud Kashefpur, Rahele Kafieh, Sahar Jorjandi, Hadis Golmohammadi, Zahra Khodabande, Mohammadreza Abbasi, Ali Akbar Fakharzadeh, Maryam Kashefpoor, Hossein Rabbani Pages 26-31
    An online depository was introduced to share clinical ground truth with the public and provide open access for researchers to evaluate their computer-aided algorithms. PHP was used for web programming and MySQL for database managing. The website was entitled “biosigdata.com.” It was a fast, secure, and easy-to-use online database for medical signals and images. Freely registered users could download the datasets and could also share their own supplementary materials while maintaining their privacies (citation and fee). Commenting was also available for all datasets, and automatic sitemap and semiautomatic SEO indexing have been set for the site. A comprehensive list of available websites for medical datasets is also presented as a Supplementary.
    Keywords: Algorithms, computers, dataset, online
  • Hossein Reza Jahanshahloo, Mousa Shamsi, Elham Ghasemi, Abolfazl Kouhi Pages 32-38
    Event-related potential (ERP) is one of the most informative and dynamic methods of monitoring cognitive processes, which is widely used in clinical research to deal with a variety of psychiatric and neurological disorders such as attention-deficit/hyperactivity disorder (ADHD). In this study, there were 60 participants including 30 patients with ADHD and 30 subjects as a control group. Their ERP signals were recorded by three electrodes in two modalities. After a preprocessing step, several features such as band power, fractal dimension, autoregressive (AR) model coefficients and wavelet coefficients were extracted from recorded signals. The aim of this study is to achieve a high classification rate. The results show that the fractal dimension–wavelet combination features provided a good discriminative capability; it should be noted that this improvement was achieved by combining all sets of features and applying a feature selection algorithm, which resulted in a maximum accuracy rate of 88.77 and 95.39% in support vector machine (SVM) and v_SVM classification algorithms using a 10-fold cross-validation approach, respectively. ERP has been widely used for clinical diagnosis and cognitive processing deficits in children with ADHD. To increase the accuracy of the diagnostic process of ADHD, ERP signals were recorded to extract some specific ERP features related to this disease for classifying the two groups. The results show that the Fra-wave characterization produced the best average accuracy with an efficiency of 99.43% for v_SVM classifier, compared with 97.65% efficiency for the wavelet features and the other features.
    Keywords: Algorithms, attention, attention deficit disorder with hyperactivity child, cognition, cognition disorders, control groups, electrodes, evoked potentials, fractals, humans, nervous system diseases, support vector machine
  • Zahra Emrani, Soroosh Bateni, Hossein Rabbani Pages 39-48
    Real-time image processing is used in a wide variety of applications like those in medical care andindustrial processes. This technique in medical care has the ability to display important patientinformation graphi graphically, which can supplement and help the treatment process. Medical decisionsmade based on real-time images are more accurate and reliable. According to the recent researches,graphic processing unit (GPU) programming is a useful method for improving the speed and quality ofmedical image processing and is one of the ways of real-time image processing. Edge detection is anearly stage in most of the image processing methods for the extraction of features and object segmentsfrom a raw image. The Canny method, Sobel and Prewitt filters, and the Roberts’ Cross technique aresome examples of edge detection algorithms that are widely used in image processing and machinevision. In this work, these algorithms are implemented using the Compute Unified Device Architecture(CUDA), Open Source Computer Vision (OpenCV), and Matrix Laboratory (MATLAB) platforms. Anexisting parallel method for Canny approach has been modified further to run in a fully parallel manner.This has been achieved by replacing the breadth-first search procedure with a parallel method. Thesealgorithms have been compared by testing them on a database of optical coherence tomography images.The comparison of results shows that the proposed implementation of the Canny method on GPU usingthe CUDA platform improves the speed of execution by 2–100× compared to the central processing unitbasedimplementation using the OpenCV and MATLAB platforms.
    Keywords: Algorithms, computer systems, computers, humans computer, assisted, image processing, optical coherence, tomography
  • Mohammad Jalali, Hamid Behnam, Maryam Shojaeifard, Zahra A. Sani Pages 49-52
    Coronary artery occlusion has a direct effect on cardiac activity and is a well-known reason forventricular motion disorder, specifically left ventricle (LV) wall motion dysfunction. In stress echocardiography,wall motion abnormality is exaggerated when stress is applied to the heart, and therefore,it is easier to diagnose abnormality in ventricular motion. In this study, we have presented a newparameter that measures LV function. We have shown that LV function can be measured using avariation of endocard borders during a cardiac cycle in standard stress echocardiography frames. Thisparameter shows a meaningful difference between ischemic and normal hearts and is calculated atdifferent heart rates (HRs). In conclusion, ischemic hearts cannot keep up with the required increase inactivity when reaching peak levels of stress.
    Keywords: Coronary occlusion, coronary vessels, echocardiography, heart, heart rate, heart ventricles, ventricular function, stress
  • Hamid R. Kobravi, Ali Moghimi, Zahra Khodadadi Pages 53-57
    Both treadmill training and epidural stimulation can help to reactivate the central pattern generator (CPG) inthe spinal cord after a spinal cord injury. However, designing an appropriate training approach and astimulation profile is still a controversial issue. Since the spinal afferent signals are the input signals of CPGin the spinal cord, it can be concluded that the number of input afferent signals can affect the quality ofmovement recovery, such a phenomenon is in accordance with Hebbian theory. Therefore, at first in thispaper, through some simulation studies on a model of CPGs, the effective influence of increasing theafferent input weight onactivatingCPGmodel was certified. Then, the performance of twodifferent types oftreadmill training along with epidural stimulation was compared. The numbers of spinal afferents involvedduring each designed training approach were different. Experiments were conducted on two groups ofspinalized rats. Three quantized integer qualitative measures, with 0–2 scales, were envisioned to evaluatethe performance of training protocols. According to the experimental results, the assigned scales to the ratsusing the training approach involving more afferents, the rats have been creeping on a treadmill, was 2. Also,the assigned scales to the rats using the training approach involving less afferents, the rats have beenperforming bipedal locomotion, was 0 or 1. Such experimental results coincide with achieved simulationresults elucidating the effect of increasing the afferent input weights on activating CPG model.
    Keywords: Animals, central pattern generators, dinucleoside phosphates locomotion, rats, spinal cord injuries, cytidylyl-3′-5′-guanosine