Sadık Kara

In this study, the EEG signals of major depression (MD) patients and healthy control subjects were investigated using different chaotic features. The acquired signals during 3 minutes were compared using complexity measures such as Katz fractal, Higuchi fractal dimension, Lempel-Ziv complexity (LZC) and Kolmogorov complexity (KC) in MATLAB between two groups. In order to determine which complexity measure is more effective in discriminating MD patients from control subjects, statistical variance analyses were performed. As a result, it was found that patients had increased EEG complexity and better discrimination were obtained using the LZC and KC.

Electrogastrography (EGG) is a noninvasive technique to record the gastric electrical activity. In recent years, researchers have proved that EGG has great clinical potentials to evaluate the gastric disorders. However, it has still not been used in clinic to diagnoses of diabetic gastroparesis or some other disorders. One of the reasons of this can be related to methods using for EGG signal analyzing. Normal gastric myoelectrical activity consists of a slow wave or Electrical Control Activity (ECA) and spikes or Electrical Response Activity (ERA) potentials. Although ERA could be responsible for some changes in EGG signals, it is ignored and neither First furrier transform (FFT) based running spectral analysis (RSA) nor can discrete wavelet transform (DWT) reflect the ERA effect. Line length is an amplitude- and frequency-dependent linear feature therefore it reflects the waveform dimensionality changes. The aim of this study was to investigate the line length feature of the EGG whether it has potential for discriminate the healthy subjects (CT) from diabetic gastroparesis (GP) patients and discuss the line length capability to reflect the ERA effect on EGG. For this aim EGG signals were recorded from 20 CT and 20 GP patients who had delayed gastric emptying. The recordings were analyzed and compared in both groups' pre- and post-prandial states. The results we obtained from line length analysis of EGG signals proved that there are significant differences between the GP and CT groups is statistically significant for pre and post-prandial condition (p = 0,0298∗ for pre-prandial and p= 0,0032∗ for post-prandial). The proposed method confirmed that line length feature is useful for detecting delayed gastric emptying and using with some other features more successful computer-aided detection system can design.

A portable and wireless surface electromyography device was developed for tracking the regional muscular activities of lumbar disc herniated patients. Previous studies showed that there is relation between paraspinal muscular activities and lumbar disc herniation. These studies encouraged us to develop a novel wireless surface electromyography device to follow muscular activities of lumbar disc herniated patients. Using such kind of wireless system in lumbar disc herniation studies leads to follow muscular activities practically. The overall system would lead to make diagnosis of lumbar disc herniation with a novel approach. The developed system consists of four major stages; amplification, filtering, A/D conversion, and the wireless communication stages. Bluetooth technology is chosen for communication between the proposed device and the computer. The designed device can be fully controlled within MATLAB software, and measured data can be directly streamed to computer environment. ...

Özetçe Sistematik hastalıkların göz damarlarında meydana getirdiği değişiklikleri izleyebilmek için damar noktalarının tayin edilmesi önemlidir. Bu çalışma da gözdeki damar merkez noktalarının çıkarılmasını içermektedir.Gözdeki damarlar kalınlıkları ince ve kontrast dağılımı zayıf olduklarından dolayı damar noktalarının çıkarılması için çok ölçekli eşlemeli (matched) filtre ile eşikleme metodu kullanılmıştır. Daha sonra görüntü işleme tekniklerinde biri olan inceltme işlemi uygulanarak damar merkez noktaları çıkarılmış ve damarların çıkarılma doğruluğunun görsel tespiti için bu noktalar orjinal resim üzerinde gösterilmiştir. Bu çalışma toplam 20 renkli fundus görüntüsü üzerine uygulanmış ve 16 tanesinde başarılı sonuç alınmıştır. Anahtar Kelimeler: Çok ölçekli filtre, inceltme algoritması, damar merkezlerinin çıkarılması

Glucose homeostasis requires the tight regulation of glucose utilization by liver, muscle and fat tissue, and glucose production and release in the blood by liver. The major goal of maintaining glycemia at ~90 mg/dl is to ensure a sufficient flux of glucose to the brain. Activation or inhibition of the sympathetic or parasympathetic branches of the autonomic nervous systems are controlled by glucose-excited or glucose-inhibited neurons located at different anatomical sites, mainly in the brainstem and the hypothalamus. Glucose is imperative metabolic substrates for brain and visceral organ function and so glucose homeostasis is regulated with high precision by hormones and ANS activities. As shown, hypoglycemia (low blood glucose) has autonomic and neuroglicopenic effects. In this study we recorded reaction times against a particular sound stimulating in order to the effects of hypoglycemia on perception and learning. To this end, reaction times of 7 patients who required testing with Insulin- Induced Hypoglycemia in Clinics of Endocrinology and Metabolism Diseases of Bezmialem Foundation University (Istanbul, Turkey), are recorded. Our preliminary results indicate that hypoglycemia has negative effects on perception of delay and learning.

Chiari Malformations are serious neurological defects involving herniation of hindbrain tissues such as cerebellar tonsils, brainstem and IV ventricle into the spinal canal through the foramen magnum. By the severity of cerebellar descent, these malformations are classified into four different types. Clinically the least obvious and the mildest one is named as type I and defined as the descent of cerebellar tonsils into the cervical canal more than 5 mm. Magnetic Resonance Images (MRI) of brain in the sagittal plane provides the best clues in the diagnosis of the Chiari Malformation type I (CM-I). Previous studies investigated the morphological characteristics of cerebellum and nearby regions such as brain stem and fourth ventricle. Aim of this study is to analyze the cerebellar regions in chiari patients and healthy controls to search for the discriminative properties between the two groups. Sagittal brain MRI of eleven chiari patients and gender matched controls were used in order...

Mechanical heart valves are a substitute for malfunctional native heart valves. In this study, the spectral features of S1 and S2 component of the mechanical heart valve sounds obtained after aortic valve replacement (AVR) and mitral valve replacement (MVR) are compared. For this aim, AR methods are applied on the S1 and S2 components of heart sounds taken from 68 recording of 8 patients with AVR and 87 recordings from 11 patients with MVR, thereby yielding power spectrum of the heart sound and six different features are obtained from power spectrum of the heart sounds. Using these features, S1 and S2 components are compared. 1. Giris

Medical image analysis to aid in clinical diagnosis is one of the research areas currently drawing intense interests of scientists. The retinal fundus photographs are widely used in the diagnosis and treatment of various eye diseases in clinics. OD detection is a main step while developing automated screening systems for a lot of eye diseases. This study describes the methods to detect OD and fovea regions main features of fundus images. To determine the OD we find the brightest part of the fundus. The candidate region of fovea is defined and area circle. The detection of fovea is done by using its spatial relationship with OD. 1. Giris

In this paper, we purpose a diagnostic procedure to identify the optic nerve disease from visual evoked potential (VEP) signals using an Artificial Neural Network (ANN). Multilayer feed forward ANN trained with a Levenberg Marquart backpropagation algorithm was implemented. The correct classification rate was 96.87% for subjects having optic nerve disease and 96.66% for healthy subjects. The end results are classified as healthy and diseased. Testing results were found to be compliant with the expected results that are derived from the physician’s direct diagnosis, angiography, VEP and pattern electroretinography. The stated results show that the proposed method could point out the ability of design of a new intelligent assistance diagnosis system.

Functional appliance therapy has become an accepted method for treatment of malocclusion in children. The myofunctional changes that occur during orthodontic treatment with functional appliances have not been sufficiently investigated. The purpose of this study is to evaluate the effect of the Twin-Block and Herbst appliances on jaw-closing muscles in children with class II malocclusion. The study group consists of 20 children aged between 9–15 with Class II malocclusion. Electromyography (EMG) signals of right anterior temporal ...

Bu calismada kalp seslerinin EKG isaretleri ile birlikte eszamanli olarak alinmasi icin bir enstrumantasyon sistemi tasarlanmistir. Donanimin amaci kalp kapagi fonksiyonsuzlugu olan hastalardan kalbe ait ses ve EKG bilgilerinin alinarak bilgisayara aktarilmasi ve goruntulenmesini saglamaktir. Kalp seslerinin alinabilmesi icin ortamdan yalitilmis kapasitif bir donusturucu kullanilmistir. EKG isaretleri ise yuzey elektrotlari ile alinmistir. Her iki isaret de ayri ayri kuvvetlendirme ve filtreleme bolumlerinden gecirilmistir. Elde edilen kalp sesi ve EKG bilgileri tasarlanan bir Giris/Cikis karti araciligiyla sayisal forma donusturulerek bilgisayara aktarilmaktadir. Ayrica elde edilen ses, EKG ve hastaya ait cesitli bilgilerin goruntulenebilmesi, islenebilmesi ve kaydedilebilmesi icin Delphi programinda yazilmis bir yazilim olusturulmustur. Yapilan bu calismayla hasta ses bilgilerinin dinlenerek degil, gorsel olarak degerlendirilmesine imkan saglanmistir

— Repeated movements of upper extremities cause to overuse injuries however, it is really challenging to determine which of them do so. Primary aim of the project is to determine the effect of different shoulder positions on gripping capability of hand and electro physiologic activity of upper extremity muscles. 23 case report data which have ages ranging between 18 and 30 are analyzed. According to our results, as the shoulder flexion increases, muscular activity and depending on this the muscular exhaustion also increases whereas the functional quality of hand decreases. The case is both a risk factor for an occupational disease and a situation that decreases skillful functioning of hands. For the next researches, advantages of exhaustion reducing apparatus and ergonomic systems, which can be used during works requiring over shoulder movements, are EMG results.

This study was conducted to investigate whether two electrophysiological signals, which are galvanic skin response (GSR) and skin temperature could be altered when exposed to different auditory stimuli such as Classical Turkish Music (CTM) and acoustic white noise. We measured physiological responses of the twenty-three schizophrenic patients and twenty-three healthy subjects in rest and auditory stimulation conditions. Our results showed that patients have greater skin temperature values than controls. We found elevated skin conductivity in response to the white noise and CTM exposure in both groups. Although schizophrenic patients had greater values of skin temperature, healthy subjects exhibited greater skin conductivity in response to the white noise and CTM exposure than did patients. In conclusion, our study has shown that skin conductance responses to CTM might be used as an index of person’s stress level and this type of stimuli could be called as relaxing music.

Heart rate variability (HRV) is a signal obtained from RR intervals of electrocardiography (ECG) signals to evaluate the balance between the sympathetic nervous system and the parasympathetic nervous system; not only HRV but also pulse rate variability (PRV) extracted from finger pulse plethysmography (PPG) can reflect irregularities that may occur in heart rate and control procedures. The purpose of this study is to compare the HRV and PRV during hypoglycemia in order to evaluate the features that computed from PRV that can be used in detection of hypoglycemia. To this end, PRV and HRV of 10 patients who required testing with insulin-induced hypoglycemia (IIHT) in Clinics of Endocrinology and Metabolism Diseases of Bezm-i Alem University (Istanbul, Turkey), were obtained. The recordings were done at three stages: prior to IIHT, during the IIHT, and after the IIHT. We used Bland-Altman analysis for comparing the parameters and to evaluate the correlation between HRV and PRV if exist...

Image segmentation has importance role for medical image analysis. Because increasing image-processing methods can provide more reliable information for the best interpretation of diseases. Therefore correct segmentation of the pathological and anatomical structures has critical importance in medical images. Additionally, CT scan interpretation requires lots of time and energy because the large number scans are generated for each patient. For this reasons, in this study a robust and reliable fast algorithm was proposed for the lung segmentation from low-dose HRCT images. Fuzzy C-means method, which is based on image histogram, was used in this study. Algorithm was evaluated on 20 asthma patients. The accuracy is approximately 93.7% and it takes almost a second for each slice.

Complexity measures have been enormously used in schizophrenia patients to estimate brain dynamics. However, the conflicting results in terms of both increased and reduced complexity values have been reported in these studies depending on the patients’ clinical status or symptom severity or medication and age status. The objective of this study is to investigate the nonlinear brain dynamics of chronic and medicated schizophrenia patients using distinct complexity estimators. EEG data were collected from 22 relaxed eyes-closed patients and age-matched healthy controls. A single-trial EEG series of 2[Formula: see text]min was partitioned into identical epochs of 20[Formula: see text]s intervals. The EEG complexity of participants were investigated and compared using approximate entropy (ApEn), Shannon entropy (ShEn), Kolmogorov complexity (KC) and Lempel–Ziv complexity (LZC). Lower complexity values were obtained in schizophrenia patients. The most significant complexity differences b...

Although patients with major depressive disorder (MDD) have dysfunctions in cognitive behaviors and the regulation of emotions, the underlying brain dynamics of the pathophysiology are unclear. Therefore, nonlinear techniques can be used to understand the dynamic behavior of the EEG signals of MDD patients. To investigate and clarify the dynamics of MDD patients׳ brains during different emotional states, EEG recordings were analyzed using nonlinear techniques. The purpose of the present study was to assess whether there are different EEG complexities that discriminate between MDD patients and healthy controls during emotional processing. Therefore, nonlinear parameters, such as Katz fractal dimension (KFD), Higuchi fractal dimension (HFD), Shannon entropy (ShEn), Lempel-Ziv complexity (LZC) and Kolmogorov complexity (KC), were computed from the EEG signals of two groups under different experimental states: noise (negative emotional content) and music (positive emotional content) per...

Elevated rates of cardiac morbidity have been frequently reported in major depressive disorder (MDD) patients as a result of the relationship between autonomic dysfunctions and varied cardiovascular activity. Heart rate variability (HRV) analysis is an important and non-invasive way for assessing the variances in autonomic nervous system activity of MDD patients. In spectral domain, HRV analysis is usually done by either Fourier transformation (FT) or discrete wavelet transformation (DWT) to divide the data into lowfrequency (LF) and high-frequency (HF) bands. However, while FT is not a proper method for non-stationary HRV data, DWT does not exactly produce required frequency ranges of each LF and HF bands. The purpose of the present study is to investigate the spectral HRV measures obtained by wavelet packet transform (WPT) with absolutely excellent approximation to predefined frequency ranges of bands. Eighteen healthy controls and age- and gender-match eighteen patients with MDD were participated in this study. Sympathovagal balance (LF/HF ratio) that reflects the variation of sympathetic and parasympathetic activities was compared between two groups. Individuals with depression had a significantly higher LF/HF ratio. Our findings suggest that dysfunctions in coordination between sympathetic and parasympathetic nervous system activity in MDD patients can be evaluated by WPT based HRV analysis with high resolution decomposition for required LF and HF bands.

In forensic medicine, estimation of the time of death (ToD) is one of the most important and challenging medico-legal problems. Despite the partial accomplishments in ToD estimations to date, the error margin of ToD estimation is still too large. In this study, electrical conductivity changes were experimentally investigated in the postmortem interval in human cases. Electrical conductivity measurements give some promising clues about the postmortem interval. A living human has a natural electrical conductivity; in the postmortem interval, intracellular fluids gradually leak out of cells. These leaked fluids combine with extra-cellular fluids in tissues and since both fluids are electrolytic, intracellular fluids help increase conductivity. Thus, the level of electrical conductivity is expected to increase with increased time after death. In this study, electrical conductivity tests were applied for six hours. The electrical conductivity of the cases exponentially increased during the tested time period, indicating a positive relationship between electrical conductivity and the postmortem interval.

Major depressive disorder (MDD) is a psychiatric mood disorder characterized by cognitive and functional impairments in attention, concentration, learning and memory. In order to investigate and understand its underlying neural activities and pathophysiology, EEG methodologies can be used. In this study, we estimated the nonlinearity features of EEG in MDD patients to assess the dynamical properties underlying the frontal and parietal brain activity. EEG data were obtained from 16 patients and 15 matched healthy controls. A wavelet-chaos methodology was used for data analysis. First, EEGs of subjects were decomposed into 5 EEG sub-bands by discrete wavelet transform. Then, both the Katz's and Higuchi's fractal dimensions (KFD and HFD) were calculated as complexity measures for full-band and sub-bands EEGs. Last, two-way analyses of variances were used to test EEG complexity differences on each fractality measures. As a result, a significantly increased complexity was found in both parietal and frontal regions of MDD patients. This significantly increased complexity was observed not only in full-band activity but also in beta and gamma sub-bands of EEG. The findings of the present study indicate the possibility of using the wavelet-chaos methodology to discriminate the EEGs of MDD patients from healthy controls.

In this study, blood volume pulse and galvanic skin response (GSR) of patients with ST elevation myocardial infarction before angiography and before discharged periods from hospital were acquired and investigated. The purpose of this study was to investigate discriminating features for markers of acute cardiac pain. The recordings were lasted in 5 minutes. We found that Welch PSD and mean GSR values were different in MI patients during this two measurement periods. Further studies are needed to increase our understanding of the causes of these differences in relation to clinical state.

Chiari Malformation type I (CM-I) is a serious neurological disorder that is characterized by hindbrain herniation. Our aim was to evaluate the usefulness of fractal analysis in CM-I patients. To examine the morphological complexity features of this disorder, fractal dimension (FD) of cerebellar regions were estimated from magnetic resonance images (MRI) of 17 patients with CM-I and 16 healthy control subjects in this study. The areas of white matter (WM), gray matter (GM) and cerebrospinal fluid (CSF) were calculated and the corresponding FD values were computed using a 2D box-counting method in both groups. The results indicated that CM-I patients had significantly higher (p<0.05) FD values of GM, WM and CSF tissues compared to control group. According to the results of correlation analysis between FD values and the corresponding area values, FD and area values of GM tissues in the patients group were found to be correlated. The results of the present study suggest that FD values of cerebellar regions may be a discriminative feature and a useful marker for investigation of abnormalities in the cerebellum of CM-I patients. Further studies to explore the changes in cerebellar regions with the help of 3D FD analysis and volumetric calculations should be performed as a future work.

Abstract: Music has a myriad of health-related benefits, both psychological and physiological. However, because the healthful effects of music have not been fully explored scientifically, many questions about the clinical efficacy of music are yet to be answered. ...

Doppler signals from the umbilical artery of 20 women with normal pregnancy between 18-20 weeks of gestation were recorded. As a new alternative technique to take the place of traditional short-time Fourier transform (STFT) method, the application of fractal analysis method to the umbilical artery Doppler signals is presented. Traditional Doppler indexes which are resistance index (RI), pulsality index (PI),

Giris; Biyomedikal mühendisliği, tıp ve biyoloji alanlarındaki problemleri çözmek için mühendislik yöntemlerini bilim ve teknolojiye uygulayan çok disiplinli bir bilim dalı olup, gelişmiş ülkelerde sağlık hizmetlerinde çok önemli bir yere sahiptir. Diğer bir söyleyişle biyomedikal mühendisliği, mühendislik, tıp ve biyoloji arasında bir köprüdür [1]. Biyomedikal mühendisleri insan vücudunu modelleyebilmek için matematiksel argümanlar kullanırlar. Böylece klinik bulguları daha doğru yorumlayarak vücut fonksiyonlarını daha iyi anlamaya imkân sağlamış olurlar. Biyomedikal mühendisleri aynı zamanda hastalıklara tanı koyabilmek için vücuttan bilgi toplayabilen cihaz ve sistemler tasarlarlar [2]. Amerika da Mühendislik 1800 lü yılların ortalarında ayrı ayrı disiplinlere dönüşmeye başladı. 20. asrın başında mühendisler elektrik üretip uzak bölgelere taşımayı başardılar. Benzer şekilde mühendisler bu asrın içinde köprü, yol, otomobil, uçak yapmaya başladılar. Bunları yaparken çelik, polimer, seramik vs, gibi yeni malzemelerden ve bilgisayar gibi yarıiletken teknolojisine sahip yeni sistemlerden yararlandılar [3]. 20. asırda vuku bulan bir kazanımda ortalama insan ömrünün uzamasıdır. 1700 lü yıllar öncesi insan ömrü ortalaması 40 yılı pek aşmaz iken bugün en az 80 yıllık bir ömür her bir insanın beklentisi olmuştur. İnsan ömrünün uzamasında bulaşıcı hastalıklarla yapılan mücadelede başarılı olunması en önemli etkendir. Mesela; 1665 yılında Londra da bulaşıcı hastalığa yakalanan insanların % 93'ü hayatını kaybederken, 2000'li yıllarda bu oran % 4'lere gerilemiştir. Penicillin, Erythromycin gibi hastalık yapan mikroorganizmaları öldüren antibiyotiklerin keşfedilmesi bulaşıcı hastalıkların yayılmasını önlemiştir. Laboratuar maliyeti çok yüksek olan ilaçlar, biyomedikal mühendislerinin geliştirdikleri teknolojilerle toplu üretim yapılarak toplumun satın alabileceği makul seviyelere düşürülmektedir. Biyomedikal mühendislerinin çok büyük katkı sağladıkları alanlardan biriside kızamık, veba gibi o günün şartlarında öldürücü hükmünde olan hastalıklardan korunmak için geliştirilen aşılardır. Fakat günümüzde de kanser öldürücü rol oynamaktadır. Endüstrileşme, yaşadığımız çevreyi çok değiştirdi. İnsanların kullandıkları eşyalardan tükettikleri gıdalara kadar birçok şey doğallığından uzaklaştırılmış, işlem görmüş, kanser oluşturma ihtimali olan malzemelerdir. 1650'li yıllarda kanser tanımlanmamış iken, bugün geliştirilmiş görüntüleme cihazları ile kansere tanı konabilmekte, hastalığın evreleri tespit edilebilmekte veya tedavi süreci takip edilebilmektedir [3]. Bugün gelişmiş ülkelerde en yaygın ölüm sebeplerinden bir diğeri de kardiyovasküler hastalıklardır. Aşırı şişmanlık olarak tanımlanan obezite, hareketsiz yaşam tarzı, stres gibi faktörler insanları çoğu zaman ölümcül sonuçlanan enfarktüs gibi kalp hastalıklarıyla yüzyüze getirmektedir. Ancak elektrokardiyogram (EKG), ultrasonik doppler gibi cihazlarla bu hastalıklara erken dönemde tanı konabilmekte ve kalp/akciğer pompası, anjiyografi gibi gelişmiş biyomedikal sistemler kullanılarak cerrahi işlem yapılabilmekte ve tedavi edilebilmektedir [3].

Image segmentation has importance role for medical image analysis. Because increasing image-processing methods can provide more reliable information for the best interpretation of diseases. Therefore correct segmentation of the pathological and anatomical structures has critical importance in medical images. Additionally, CT scan interpretation requires lots of time and energy because the large number scans are generated for each patient. For this reasons, in this study a robust and reliable fast algorithm was proposed for the lung segmentation from low-dose HRCT images. Fuzzy C-means method, which is based on image histogram, was used in this study. Algorithm was evaluated on 20 asthma patients. The accuracy is approximately 93.7% and it takes almost a second for each slice.

Amaç: Daha önceki çalışmalarda yüzeysel EMG kullanılarak Tüm Vücut Vibrasyonun (TVV) refleks kas aktivitesini indüklediği gösterilmiştir. Bu çalışmanın amacı vibrasyonun indüklediği refleks kas aktivitesi amplitüdünü etkileyen vibrasyon parametrelerini belirlemekti. Gereç-Yöntem: Çalışma 19 genç erişkin sağlıklı erkek dahil edildi. Amplitüdü 2.2 mm olan ve 25, 30, 35, 40, 45 ve 50 Hz frekanslarında vibrasyon uygulandı. Her vibrasyon frekansı için onaltı saniye vibrasyon uygulandı. Vibrasyon frekansları rastgele sıra ile uygulandı. Katılımcılar vibrasyon platformu üzerinde dizleri kilitli halde ayakta dik durdu. Sağ soleus yüzeyel EMG, vibrasyon platformu ile katılımcının topuğu arasındaki çarpışma kuvveti ve vibrasyon ivmesi, TVV öncesi ve sonrası eş zamanlı olarak kayıt edildi. Hareket artefaktını ortadan kaldırmak için EMG kayıtlarına 80-500 Hz band-geçişli filtre ve akabinde tam-dalga rektifikasyon uygulandı. EMG sinyal amplitüdü, filtrelenmiş sinyalin karekök ortalaması (EMGrms) olarak ifade edildi. Çarpışma kuvvetinin amplitüdü kuvvet algılayıcı kullanılarak ölçüldü ve tepe-tepe amplitüd olarak ifade edildi. Vibrasyon ivmesi, vibrasyon platformu üzerine fikse edilen ivmeölçer ile ölçüldü ve tepe-tepe amplitüd olarak ifade edildi. Bulgular: TVV sırasında soleus miyoelektriksel aktivitesinde (EMGrms) anlamlı artış saptandı. EMGrms ile çarpışma kuvveti amplitüdü arasında (R=-0.637, p<0.0001), EMGrms ile ivmelenme amplitüdü arasında (R= 0.352, p<0.0001) ve EMGrms ile vibrasyon frekansı arasında (R= 0.333, p<0.0001) korelasyon saptandı. Çoklu doğrusal regresyon analizi, EMGrms için ana bağımsız prediktörün çarpışma kuvveti amplitüdü olduğu gösterdi (R 2 =0.43, F=350.6, p<0.0001). Sonuç: Bu çalışma vibrasyonun indüklediği refleks kas aktivitesini etkileyen başlıca vibrasyon parametresinin vibrasyon platformu ve topuk arasındaki çarpışma kuvveti olduğunu göstermiştir. Objective: Previous studies have shown that Whole Body Vibration (WBV) induces a reflex muscle activity by using surface electromyography. Aim this study was to determine the vibration parameters affecting amplitude of the vibration-induced reflex muscle activity. Materials-Methods: Nineteen healthy young adult male participants were included in this study. Vibration amplitude of 2.2 mm and vibration frequencies of 25, 30, 35, 40, 45 and 50 Hz were used. Vibration exposure was sixteen seconds for each vibration frequency and they were applied in a random fashion. Participants stood upright with their knees locked on the vibration platform. The right soleus surface EMG, impact force data between vibration platform and participant's heel and acceleration of vibration were simultaneously recorded before and after WBV. EMG recordings were 80–500 Hz band-pass filtered and then full-wave rectified to overcome movement artifact. The amplitude of the EMG signal was expressed as the root mean squared (EMGrms) form of the filtered signal. Amplitude of the impact force was measured by using a force sensor and it was expressed as the peak to peak amplitude. The vibration acceleration was measured by using an accelerometer fixed to vibration platform and it was expressed as the peak to peak amplitude. Results: A significant increase in myoelectrical activity (EMGrms) of the soleus was found during WBV. There were significant correlations between EMGrms and impact force amplitude (R=-0.637, p<0.0001), between EMGrms and the acceleration amplitude (R= 0.352, p<0.0001) and, between EMGrms and the vibration frequency (R= 0.333, p<0.0001). Multiple linear regression analysis indicated that the main independent predictor of the EMGrms was impact force amplitude (R 2 =0.43, F=350.6, p<0.0001). Conclusion: This study showed that the essential parameter of vibration affecting the vibration-induced reflex muscle activity is the impact force between vibration platform and subject's heel.

Amaç: Vibrasyon sırasında, kas aktivitesinde artış ile eşzamanlı olarak H-refleks inhibisyonu olması vibrasyon paradoksu olarak tanımlanmaktadır. Tüm vücut vibrasyonu (TVV) sırasında, tibial sinir üzerine yerleştirilen uyarıcı elektrot salınım hareketine maruz kalır. Hipotezimize göre TVV sırasında uyarıcı elektrotun konumu değişebilir ve uyarıcı elektrotun yer değiştirmesi H-refleks amplitüdünü etkiler. Bu araştırmanın amacı bu hipotezi test etmek idi. Gereç-Yöntem: Araştırmaya 15 sağlıklı genç erişkin erkek alındı. Bir TVV vibrasyon cihazı ile vibrasyon (40 Hz, 2.2 mm, vertikal doğrultulu) uygulandı. Sağ soleus kas elektriksel aktivitesi yüzeyel EMG ile değerlendirildi. Sağ soleus H-refleks kaydı ipsilateral bacağa vibrasyon uygulanırken alındı. Akabinde vibrasyonun salınım etkisi ile uyarıcı elektrotun yer değiştirmesini önlemek üzere, sadece sol bacağa vibrasyon uygulanırken sağ soleus H-refleks kaydı alındı. Hmax, Mmax'a göre normalize edildi (Hmax/Mmax). Bulgular: TVV sırasında sağ soleus kas elektriksel aktivitesinde anlamlı artış saptandı. Sağ bacak vibrasyonu öncesi, sağ soleus Hmax/Mmax oranı 0.32±0.14 idi. Sağ bacak vibrasyonu sırasında, sağ soleus Hmax/Mmax oranı 0.14±0.09 idi (p<0.0001). Sol bacak vibrasyonu öncesi, sağ soleus Hmax/Mmax oranı 0.28±0.10 idi. Sol bacak vibrasyonu sırasında, sağ soleus Hmax/Mmax oranı 0.16±0.07 idi (p<0.0001). Sonuç: Bu çalışma vibrasyonun uyarıcı elektrot üzerine salınım etkisi ortadan kaldırılsa bile TVV sırasında H-refleksinin suprese olduğunu gösterdi. Anahtar Kelimeler: Vibrasyon, tonik vibrasyon refleks, hoffmann refleksi, elektromiyografi, nöromüsküler performans Objective: An increase in muscles activity coexists with the inhibition of H-reflex during vibration is defined as vibration paradox. The stimulating electrode placed on tibial nerve is exposed to the oscillatory movement during whole body vibration (WBV). We hypothesize that position of the stimulating electrode may change during WBV and the displacement of stimulating electrode affects H-reflex amplitude. The aim of this study was to test this hypothesis. Materials-Methods: Fifteen healthy young adult males participated in this study. Vibrations (40 Hz, 2.2 mm vertical displacement) were performed by using a WBV device. The right soleus myoelectrical activities were evaluated by surface electromyography (SEMG). The right soleus H-reflex was recorded during ipsilateral leg vibration. Then, the right soleus H-reflex was recorded during the vibration was applied only to the left leg to prevent the movement of stimulating electrode caused by oscillatory effect of vibration. Hmax was normalized to the Mmax (Hmax/Mmax). Results: A significantly increase in the myoelectrical activity was found during WBV. The Hmax/Mmax ratio of the right soleus was 0.32±0.14 before the right leg vibration. It was 0.14±0.09 during the left leg vibration (p<0.0001). The Hmax/Mmax ratio of the right soleus was 0.28±0.10 before the left leg vibration. It was 0.16±0.07 during the left leg vibration (p<0.0001). Conclusion: This study showed that the H-reflex is suppressed during WBV when the oscillatory effects of vibration on the stimulating electrode are eliminated.

Amaç: İkna edici kanıt olmadığı halde tüm vücut vibrasyonun (TVV) indüklediği refleks kas aktivitesi tonik vibrasyon refleksle (TVR) açıklanmaktadır. T-refleks TVR analogudur. Bu çalışmanın hipotezine göre TVV sırasında T-refleks amplitüdü artar. Bu çalışmanın amacı bu hipotezi test etmekti. Gereç-Yöntem: On beş genç erişkin sağlıklı erkek bu çalışmaya dahil edildi. Denekler vibrasyon platformu üzerinde dizleri kilitli halde ayakta dik dururken sağ soleus yüzeyel EMG ve sağ aşil tendonu üzerine yerleştirilen ivme ölçer kayıtları alındı. TVV öncesi T-refleks kayıtları alındı. Akabinde, tüm deneklere bir set TVV uygulandı. Her TVV seti, frekansları farklı (25, 30, 35, 40, 45, 50 Hz) altı vibrasyon seansından oluşmaktaydı. Her vibrasyon seansında Aşil tendonuna refleks çekici ile beş kez vuruldu.

— Repeated movements of upper extremities cause to overuse injuries however, it is really challenging to determine which of them do so. Primary aim of the project is to determine the effect of different shoulder positions on gripping capability of hand and electro physiologic activity of upper extremity muscles. 23 case report data which have ages ranging between 18 and 30 are analyzed. According to our results, as the shoulder flexion increases, muscular activity and depending on this the muscular exhaustion also increases whereas the functional quality of hand decreases. The case is both a risk factor for an occupational disease and a situation that decreases skillful functioning of hands. For the next researches, advantages of exhaustion reducing apparatus and ergonomic systems, which can be used during works requiring over shoulder movements, are EMG results.

Amaç: Daha önceki çalışmalarda yüzeysel EMG kullanılarak Tüm Vücut Vibrasyonun (TVV) refleks kas aktivitesini indüklediği gösterilmiştir. Bu çalışmanın amacı vibrasyonun indüklediği refleks kas aktivitesi amplitüdünü etkileyen vibrasyon parametrelerini belirlemekti. Gereç-Yöntem: Çalışma 19 genç erişkin sağlıklı erkek dahil edildi. Amplitüdü 2.2 mm olan ve 25, 30, 35, 40, 45 ve 50 Hz frekanslarında vibrasyon uygulandı. Her vibrasyon frekansı için onaltı saniye vibrasyon uygulandı. Vibrasyon frekansları rastgele sıra ile uygulandı. Katılımcılar vibrasyon platformu üzerinde dizleri kilitli halde ayakta dik durdu. Sağ soleus yüzeyel EMG, vibrasyon platformu ile katılımcının topuğu arasındaki çarpışma kuvveti ve vibrasyon ivmesi, TVV öncesi ve sonrası eş zamanlı olarak kayıt edildi. Hareket artefaktını ortadan kaldırmak için EMG kayıtlarına 80-500 Hz band-geçişli filtre ve akabinde tam-dalga rektifikasyon uygulandı. EMG sinyal amplitüdü, filtrelenmiş sinyalin karekök ortalaması (EMGrms) olarak ifade edildi. Çarpışma kuvvetinin amplitüdü kuvvet algılayıcı kullanılarak ölçüldü ve tepe-tepe amplitüd olarak ifade edildi. Vibrasyon ivmesi, vibrasyon platformu üzerine fikse edilen ivmeölçer ile ölçüldü ve tepe-tepe amplitüd olarak ifade edildi. Bulgular: TVV sırasında soleus miyoelektriksel aktivitesinde (EMGrms) anlamlı artış saptandı. EMGrms ile çarpışma kuvveti amplitüdü arasında (R=-0.637, p<0.0001), EMGrms ile ivmelenme amplitüdü arasında (R= 0.352, p<0.0001) ve EMGrms ile vibrasyon frekansı arasında (R= 0.333, p<0.0001) korelasyon saptandı. Çoklu doğrusal regresyon analizi, EMGrms için ana bağımsız prediktörün çarpışma kuvveti amplitüdü olduğu gösterdi (R 2 =0.43, F=350.6, p<0.0001). Sonuç: Bu çalışma vibrasyonun indüklediği refleks kas aktivitesini etkileyen başlıca vibrasyon parametresinin vibrasyon platformu ve topuk arasındaki çarpışma kuvveti olduğunu göstermiştir. Objective: Previous studies have shown that Whole Body Vibration (WBV) induces a reflex muscle activity by using surface electromyography. Aim this study was to determine the vibration parameters affecting amplitude of the vibration-induced reflex muscle activity. Materials-Methods: Nineteen healthy young adult male participants were included in this study. Vibration amplitude of 2.2 mm and vibration frequencies of 25, 30, 35, 40, 45 and 50 Hz were used. Vibration exposure was sixteen seconds for each vibration frequency and they were applied in a random fashion. Participants stood upright with their knees locked on the vibration platform. The right soleus surface EMG, impact force data between vibration platform and participant's heel and acceleration of vibration were simultaneously recorded before and after WBV. EMG recordings were 80–500 Hz band-pass filtered and then full-wave rectified to overcome movement artifact. The amplitude of the EMG signal was expressed as the root mean squared (EMGrms) form of the filtered signal. Amplitude of the impact force was measured by using a force sensor and it was expressed as the peak to peak amplitude. The vibration acceleration was measured by using an accelerometer fixed to vibration platform and it was expressed as the peak to peak amplitude. Results: A significant increase in myoelectrical activity (EMGrms) of the soleus was found during WBV. There were significant correlations between EMGrms and impact force amplitude (R=-0.637, p<0.0001), between EMGrms and the acceleration amplitude (R= 0.352, p<0.0001) and, between EMGrms and the vibration frequency (R= 0.333, p<0.0001). Multiple linear regression analysis indicated that the main independent predictor of the EMGrms was impact force amplitude (R 2 =0.43, F=350.6, p<0.0001). Conclusion: This study showed that the essential parameter of vibration affecting the vibration-induced reflex muscle activity is the impact force between vibration platform and subject's heel.

Özetçe DNA'sı değişen kanser tümörleri vücutta ilk yerleştikleri yerden vücudun farklı bölgelerine yayılımda bulunabilir. Yayılım sonucu oluşan yeni kanser türü genellikle ilk kanser türüne göre isimlendirilir. Akciğer kanserinin lenf sistemini kullanarak Beyin Omurilik Sıvısını (BOS) barındıran meningeal yüzeye bulaşması yeni bir kanserin habercisidir. Kanser tümörleri üç katmanlı meningeal katmanının leptomeningeal katmanına bulaşır. Leptomeningeal karkinomatosis (yaygın adıyla leptomeningeal metastaz) olarak adlandırılan yeni kanser türünün tanısı BOS sıvısı incelemesi ya da MR görüntüleme sistemi ile yapılır. BOS sıvısı incelemesinde hücre sayımı yapıldığı için MR görüntüleme sistemine göre daha kesin bir sonuç vermektedir. Çalışmamızda logaritmik dönüşüm metodu ile zengin içerikli MR görüntülerinde saklı bulunan tümörlü alanların ortaya çıkartılması amaçlanmış ve çıkan sonuçlar kesin özelliği bulunan BOS patoloji sonuçları ile karşılaştırılmıştır. Çalışmada iyileştirilmiş görüntülerin BOS patoloji sonuçlarına yakın olduğu belirli bir patolog ve radyolog tarafından rapor edilmiştir. Abstract The cancer tumor which DNA is changed can disseminate different parts of body from where they first settled in the body. The new cancer name which is caused by the first cancer is generally related to old cancer. Lung cancer tumor disseminates to cerebrospinal fluid which circulates in the meningeal layer by lymphatic system and is the herald of a new cancer. Cancer tumor contaminated to leptomeningeal layer of three-tier meningeal layer. Leptomeningeal carcinomatosis as known leptomeningeal metastases is new cancer caused by dissemination of lung cancer and diagnosed with CSF fluid examination or MRI imaging system. The CSF examination is more accurate than MRI imaging system because of counting of the cells in the CSF. In our study, it is aimed that the logarithmic transformation method is used to reveal the detail of affluent MRI images and obtained results were compared with accurate CSF pathology results. In the study, the results of enhanced MRI images have been reported to be closed to the CSF examination by specific a pathologist and a radiologist.

Obsessive Compulsive Disorder (OCD) is a neuropsychiatric brain disorder disease and diagnosis, treatment process of the disease is used EEG analysis. Recent studies suggested that the OCD is caused by dysfunction in brain's frontal lobe. The GFS that was developed as a novel synchronization criteria, computes phase difference between neural oscillations in the brain. Studies were published that indicates fall of GFS values. In this study, it was investigated how OCD effect phase difference between neuronal oscillations. For this purpose, results of the GFS method was applied to 19 channels EEG, indicates OCD decrease of neural synchronization in brain's frontal lobe at Delta and Beta 3 frequency bands.

Özetçe Bu çalışmada, majör depresif bozukluğu (MDB) olan hastalardan ve sağlıklı kişilerden elektroensefalogram sinyalleri (EEG) alınarak ayırt edici özniteliklerin araştırılması amaçlanılmıştır. Bu doğrultuda katılımcılardan iki dakika boyunca kaydedilen EEG sinyalleri, MATLAB ortamında ayrık dalgacık dönüşümü ile alt bandlarına ayrıştırılıp fraktal boyut analizi yapılarak iki grup arasındaki farklılıklar incelenmiştir. Her iki grup arasında frontal ve parietal bölgelerde anlamlı farklılıklar bulunmuştur. Abstract In this study, it is aimed to investigate distinctive criteria intended for the diagnosis of the major depression getting brain signals (EEG) from major depressive disorder patients and healthy subjects. For this aim, recorded EEG signals were decomposed by discrete wavelet transform in MATLAB and in each band fractal dimension values were compared between two groups. Significant differences were observed between groups especially in frontal and parietal regions.

Özetçe Leptomeningeal metastaz (LM) hastalığı bazı kanser hastalarında görülen ve kanseri ilerleyen aşamalarında, kanserli hücrelerin hastanın vücudunda farklı bir bölgesine yayılmasıyla ortaya çıkan bir hastalıktır. Çok sık rastlanmamakla beraber tıbbi operasyonla tedavisi diğer kanser hastalıklarına göre bir o kadar da zordur. Bunun sebebi beyin-omurilik sıvısına kanserli hücrelerin bulaşmasıdır. Kanserin tanı yöntemlerinden biri olan MR görüntüleme sistemi içerdiği zengin bilgi bakımından birçok detayı vermektedir. Bazı detaylar MR görüntülerinin karanlık kısmında kaldığından bu görüntüleri yorumlayan radyologlar hastalığı çoğu zaman tespit edememektedirler. LM hastalığı belirtisi ise bu detaylarda gizlidir. Bu çalışmada Histogram eşitleme (HE) metoduna benzer bir işleve sahip olan logaritmik dönüşüm metodu ile MR görüntülerinde gizli kalan detaylar ortaya çıkartılmış ve sonuçlar HE metodundan elde edilen sonuçlarla kıyaslanmıştır. Abstract Leptomeningeal metastases is observed in some cancer patients and this is cancer in later stages, it is a disease caused by proliferation of cancer cells in different parts of patient's body. Although it is not very common cancer type and the treatment of this disease with medical operation is much difficult than other cancer types. The reason is that the malignant cells is contaminated to cerebrospinal fluid. MR imaging system one of the diagnostic methods of cancer contains very rich information and details. Some details remain in the dark part of the MR images that radiologists to review these images often do not detect disease. LM disease's symptoms remains in that details. The hidden details in dark side is revealed with logarithmic transformation (LT) method having a similar function with histogram equalization (HE) method and the results compared with the results obtained by HE method.

Özetçe Nüfusun yaklaşık yüzde yirmisi anüs ve rektumun fonksiyonel bozukluklarından etkilenmektedir. Kabızlığın iki genel kategorisi tanımlanmıştır, kolonik geçiş süresinin azalması ve çıkış yerinde engelleme. Kolonik tembellik dışkının kolon içerisinde yavaş ilerlemesine neden olur. Anüsteki engelleme ise rektumun tamamen boşalmasındaki zorluktur. Bu çalışma da internal ve external anal sfinkter kaslarının fiziksel basıncını ölçmek için bir elektronik sistem tasarlanmıştır. Üzerine basınç algılayıcıları ve elektrotlar yerleştirilen özel tasarlanmış bir prob yardımıyla biosinyaller alınmaktadır. Biosinyallerin genlikleri 500 kat kazançlı bir yükselteç ile kuvvetlendirilmekte ve hasta güvenliğinin sağlanabilmesi için izole edilmektedir. Daha sonra sinyaller sayısala dönüştürülerek bilgisayara gönderilmektedir. Hazırlanan yazılım ise ilgili sinyallerin kaydedilmesine ve tanı amaçlı izlenebilmesine imkân tanımaktadır. Abstract Approximately twenty percent of population is affected by functional disorders of the anus and rectum. Constipation is described with two broad categories, a decreased colonic transit time and outlet obstruction. Colonic inertia cause a slow transit of feces. Outlet obstruction is a failure of relaxation of the pelvic floor or anus during defecation. In this study, an electronic system is designed to meassure physical pressure of internal and external anal sphincters. The bio-signals are taken by using a special probe which has pressure sensors and electrodes on itself. These signals are amplified approximately 500 times by using an instrumentation amplifier and the signals are isolated for safety of person. Then, the signals are converted to digital and sent to Personal Computer (PC). PC software provides recording and monitoring of the related signals for diagnostic purposes

Özetçe Bu çalışmada yüksek çözünürlüklü tomografi.görüntülerinden (HRCT) akciğerlerin segmentasyonu yapılarak, akciğer sınırlarının belirlenmesi gerçekleştirilmiştir. Akciğer segmentasyonu için bulanık C-ortalamaları algoritması kullanılmıştır. Diğer bulanık C-ortalamaları algoritmalarından farklı olarak bu çalışmada sınıflandırma yaparken resmin yoğunluk değerleri yerine histogram değerleri kullanılmıştır. Böylece algoritma daha kısa sürede daha verimli bir sonuç vermektedir. Bu algoritma ile HRCT görüntülerinden akciğerler %90.6 başarı oranı ile doğru tespit edilmiştir ve tek bir HRCT görüntüsü için akciğerlerin çıkarılması 2.2sn gibi kısa bir sürede gerçekleştirilmektedir. Abstract In this study, lung segmentation and lung extraction have been done from High resolution computer tomography (HRCT). Fuzzy C-means Clustering (FCM) has been used for lung segmentation. In this study, histogram based fuzzy C-means clustering (fast fuzzy C means Clustering-FFCM) has been used instead of normal FCM. Histogram based FCM is faster and more efficient than FCM. Lung segmentation has been done with %90.6 accuracy with FFCM and the algorithm takes approximately 2.2s just for one HRCT slice.

Özetçe Bu çalışmada MATLAB arayüzü kullanılarak Manyetik Rezonans (MR) beyin görüntülerinin bölütlenip yapısal analiz çalışmalarında kullanılabileceği bir görüntü işleme kullanıcı arayüzü tasarlanmıştır. Bir ön uygulama olarak bir beyincik sarkması hastasından alınan beyin MR görüntülerinin alan analiz çalışmaları yapılmıştır. Sağlıklı ve hasta MR beyin görüntüleri kullanılarak beyincik bölütlemesi gerçekleştirilmiştir. Bölütleme işlemi manüel ve yarı otomatik bir yöntem kullanılarak gerçekleştirilmiştir. Çıkarılan beyincik alanı bir hasta ve bir sağlıklı kişide her iki yöntem için hesaplanmış ve karşılaştırılmaları yapılmıştır. Bu çalışma ile geliştirilen kullanıcı arayüzü ileride uygulanacak yöntem ve analizler için bir temel teşkil etmektedir. Abstract In this study, using MATLAB interface, an image processing user interface was designed by which brain MR images are segmented and used for morphological studies. As an initial implementation, area analysis works performed on the MR brain images taken from one Chiari Type I Malformation patient. Cerebellum segmentation was carried out using MR brain images of one patient and one control subject. Segmentation operation was implemented manually and using a semi-automated method. The area of extracted cerebellum parts of both patient and the control subject were calculated and compared. The user interface designed in this study will build the foundation for the methods and analyses that will be implemented in the future.

Özetçe Tüm vücut vibrasyon uygulamas nöromüskülar performansn artlmas amacyla terapötik kullan gittikçe yaygnlaan bir yöntemdir. Tüm vücut vibrasyon uygulamalar esnasnda kas faaliyetlerinde belirgin bir art ortaya çkmaktadr ve bu uygulamalarn kas dayanklnda ve kas kuvvetinde belirgin art salad da ortaya koyulmutur. Daha önce yaplan çalmalarda tüm vücut vibrasyon uygulamalarn istemli kas aktivitesine olan etkileri incelenmitir. Yaplan bu çalmada tüm vücut vibrasyon uygulamalarn istemli kas faaliyetlerine ilaveten istirahat kas faaliyetlerine olan etkileri de incelendi. Bu balamda yaplan çalmada soleus kas aktiviteleri deerlendirildi. Abstract Whole body vibration is a method that its therapeutic use is becoming more common in order to increase neurmuscular performance. Significant muscular activity increase appear during whole body vibration applications and it was revealed that these applications induce significant muscle durability and muscle force increase. It was researched that the effects of whole body vibration to voluntary muscular activites in

A female breast hyperthermia applicator is designed with twelve microstrip spiral antennas embedded in distilled water and operating at 434 MHz. The antennas are directed towards the tumor and its phases are individually adjusted to have a positive interference at the tumor location. The simulated temperature distribution and SAR values at the tissues obtained by means of SEMCAD X are presented.

A mechanical heart valve is a device substituted for native heart valve. These valves are generally replaced with mitral or aorta valves. To found whether aorta or mitral heart valve replaced with mechanical one of patients is easy for specialist using stethoscope or chest X-ray. Expert system evaluating mechanical heart valve disease cannot deduce position of replaced heart valve. Thus, we aimed to determine which heart valve of patients was replaced with mechanical one to use preprocessing step in expert systems finding malfunctioning mechanical valve in this study. Electrocardiogram signal and 6 features extracted from power density of heart sounds were used to determine replaced heart valve using artificial neural networks. The heart sounds were separated into four parts according to recording area and sound component. Then, artificial neural networks was separately trained and tested for four sounds using the 6 features. As a result, the mechanical heart valve of patients was detected with 96.55% accuracy from the features of second heart sounds recorded from mitral area. Keywords—Heart sounds, mechanical heart valve replacement.

Figure 1. Electric Field lines of the patch antenna into tissues at 0 φ = and 90 φ = planes at 434 MHz. Abstract—The adequateness of a circularly shaped spiral microstrip antenna and a conventional patch antenna is investigated for hyperthermia applicator design. A head model is simulated by using of both antenna types to observe the field distributions. The results show that the novel spiral antenna is more adequate for hyperthermia applicator

—This paper presents the design of a circularly shaped spiral microstrip antenna and a conventional patch antenna both are embedded inside a distilled water bolus. The adequateness of the antennas is investigated for hyperthermia applications. The novelty of the spiral antenna is, it has a narrower radiation pattern and resonates at multiple frequencies to have a better control over the penetration depth and focusing considerations.

Özetçe Spontane Beyin Omurilik Sıvısı Sızıntısı Hastalığı Beyin Omurilik Zarının yırtılması sonucu oluşan nörolojik bir hastalıktır. İlk tanımlandığı günden bu yana oldukça tanınsa da, hala doktorlar tarafından kolaylıkla teşhis edilen bir hastalık değildir. Teşhis için, girişimsel lombar ponksiyon ve girişimsel olmayan Manyetik Rezonans görüntüleme tekniği kullanılmaktadır. Hastalığın MR bulgularına dair yapılmış kapsamlı çalışmalar olmasına rağmen, bu çalışmalar tıp doktorları tarafından yürütülmüş olup görsel izlenimlere dayanmaktadır. Bu çalışmada, doktorlara teşhiste yardımcı olması amacıyla bilgisayarlı, sayısal bir analiz metodu geliştirilmiştir. Bu metotta MR görüntüleri kullanılarak beyine ait her piksel için beyin sınırına asgari uzaklık değeri hesaplanmış, ardından uzaklığa karşılık ortalama piksel yoğunluk değeri grafiği çizdirilmiştir. Grafik üzerindeki iki bölge oranlanarak öznitelik elde edilmiştir. Gerçek bir hastaya ait tedavi öncesi ve tedavi sonrası MR görüntüleri üzerinde inceleme yapılarak bu sayısal değerin hastalıkla ilişkili olduğu doğrulanmıştır. Abstract Spontaneous Spinal Cerebrospinal Fluid Leaks is a neurological syndrome based on cerebrospinal fluid leaks from tears on the meninges. Since it was first described, the disease recognized better, but it hasn't been an easily diagnosed disorder by medicine doctors yet. An invasive method, lumbar puncture and a noninvasive method, MR imaging is used for diagnosis. There are well documented studies which states MRI findings pertaining to this disease, but they have been conducted by medicine doctors and based upon visual inspection. In this study, a computerized and quantitative method has been developed to help medicine doctors in diagnosis. In this method, using MR images, boundary of brain is detected automatically. Then, a graph is plotted with axes of average intensity value versus distance from brain boundary. A feature related with disease is obtained by proportioning two regions in the graph. Correlation between the disease and the feature is verified by examining pre-treatment and after-treatment images of a real patient.

Stress Urinary Incontinence is a common form of women urinary incontinence and has some surgical therapeutic methods. The quality of surgery merely depends on the quality of diagnosis. Before deciding a surgery type, urodynamic testing is applied. Since urodynamic testing is invasive, and difficult to apply, many subjects do not seek therapy. A noninvasive method can encourage more subjects for searching a remedy. At this point, Doppler ultrasound can be a good choice. In this study, we have demonstrated that the blood flow characteristics of healthy subjects and intrinsic sphincter deficiency type stress urinary incontinence subjects have different characteristics and can be classified by using Doppler ultrasound recording.

Bu projede iki adet manyetik alan sensörünün birbirine dik konumlandırılarak yön tayininde kullanılması çalışılmıştır. Bu elektronik sistem sayesinde mekanik pusulalardan çok daha hassas ve diğer elektronik sistemlere geri besleme yapabilecek bir pusula modülü elde edilmiştir. Bu modüle bir LCD arayüz de eklenerek kullanıcının yön bilgisini okuyabilmesi sağlanmıştır