Mustafa Zahid Yıldız

Sakarya University of Applied Sciences · Electrical and Electronics Engineering Faculty of Technology

External focusing (directs focus to apparatus, environment or the effect of the action)enhances motor skill learning and reduces muscular activity compared to internal focusing (leads focus to the movement or the action itself). Nevertheless, in case of electromyography (EMG) based systems such as prosthetic arms, robotic controllers, and robot-ass...

Watermarking is one of the most common techniques used to protect data's authenticity, integrity, and security. The obfuscation in the frequency domain used in the watermarking method makes the watermarking stronger than the obfuscation in the spatial domain. It occupies an important place in watermarking works in imperceptibility, capacity, and ro...

This issue is dedicated to the memory of Prof. Tenreiro Machado. https://dergipark.org.tr/en/pub/chaos/issue/64884

Objective: Hand vein images have become important biometric signs used for identification systems. Also, dorsal hand vein images have noteworthy advantages in terms of reliability and contactless procedure. Surgically changing the vascular pattern under the skin is extremely difficult. Therefore, the use of such patterns in identity recognition app...

Classification and counting of cells in the blood is crucial for diagnosing and treating diseases in the clinic. A peripheral blood smear method is a fast, reliable, robust diagnostic tool for examining blood samples. However, cell overlap during the peripheral smear process may cause incorrectly predicted results in counting blood cells and classi...

Complex biorhythms are characteristic of ubiquitous phenomena appearing in many disciplines of human knowledge. This Special Issue collects articles devoted to different complex biorhythms phenomena such as cardiac dynamics, Covid-19 dynamics, dynamics of neural networks, cell dynamics, and a few articles devoted to general methods. It furnishes a...

Hepatocellular carcinoma (HCC) is a heterogeneous type of cancer and current treatment options limit successful therapy outcomes. Photodynamic therapy (PDT) has attracted attention as an alternative approach in the treatment of different types of cancer. However, there is no study in the literature regarding the effect of PDT on HCC, in vitro. Ther...

Öklid geometrisi kullanılarak düzensiz ve kompleks şekillerin modellenmesi eksik kalmaktadır. Fraktal geometri düzensiz, karmaşık ve kompleks yapıların matematiksel olarak ifade edilebilmesine imkan vermektedir. Fraktal geometri doğanın içinde düzensizmiş gibi görünmesine rağmen incelendiğinde düzenli bir şeklin tüm görüntüde tekrarlandığı yapılard...

The purpose of this paper is to present an overview of problems and some research gaps for better understanding of piezoelectric micropump studies. Micropumps have important and diverse application areas in health and engineering applications. In recent years, researchers have carried out simulations, analytical and experimental studies to develop...

Chaos Theory and Applications (November 2021 - Volume 3 - Issue 2) https://dergipark.org.tr/en/pub/chaos/issue/58077

Hücre kültürlerinin görüntülenmesi ve canlılık analizlerinin yüksek doğruluk ile yapılması etkin ilaçlar geliştirilmesi süreçlerinde oldukça önemlidir. Bu amaç doğrultusunda lenssiz dijital holografik mikroskopi sistemleri, hücrelerin görüntülenmesinde ve karakterize edilmesinde yaygın olarak kullanılmaktadır. Bu sistemlerin düşük maliyeti, kullanı...

Rehabilitasyon cihazlarını destekleyen robotik sistemler ve el fonksiyonlarını karşılayan robotik protezleri iyileştirme arzusu, iskelet cihazlarının geliştirilmesinde büyük rol oynamıştır. Yüzey Elektromiyografi (sEMG) sinyallerinin kullanıldığı bu tür cihazlarda protez kontrolünün gerçekleşebilmesi için sinyallerin özelliklerinin bilinmesi ve bu...

Cell studies play an important role in the basis of studies on cancer diagnosis and treatment. Reliable viability assays on cancer cell studies are essential for the development of effective drugs. Lens-less digital in-line holographic microscopy (DIHM) has become a powerful tool in the characterization and viability analysis of microparticles such...

In this study, a low cost and portable general-purpose lens-less microscopy system suitable for clinical conditions was designed and its performance was increased with the help of image processing algorithms without using numerical approaches. In order to avoid the noises caused by the light source or the imaging sensor, the flat field correction m...

Mem-elements play an important part in the design of high-density memory systems and low power memory. In this paper, we created a novel fractional-order chaotic circuit with a memristor and a memcapacitor with a linear inductor. The various dynamical properties of the fractional-order system are investigated by using some dynamic analysis methods...

In this study, the images of the wrist vein taken from the individuals were subjected to various pre-processings and then encrypted with random numbers obtained from the chaotic system. Before encryption, random numbers were generated using a chaotic system. The random numbers produced have successfully passed the NIST 800-22 tests. Images encrypte...

Chaos Theory and Applications (June 2021 - Volume 3 - Issue 1) https://dergipark.org.tr/tr/pub/chaos/issue/56378

There are many control methods for systems that have been developed and continued to be developed, linear or non-linear, time-varying or invariant. In this study, in the control of the nonlinear Lorenz Chaotic system, model predictive control method with integrator action, which has not been applied to this system before, is applied. In addition to...

Photodynamic therapy (PDT) is based on special light source, photosensitizer (PS), and in the presence of oxygen. Different light sources have been used for PDT applications. Recent studies have focused on LED light sources for PDT applications due to reducing the cost of laser-based PDT and providing easy access for research laboratory or clinic f...

Editor in Chief Dr. Mustafa CAN, Sakarya University of Applied Sciences, Turkey mustafacan@subu.edu.tr Editors Dr. Kamal YUSOH, University Malaysia Pahang, Malaysia University Malaysia Pahang Dr. Mustafa Zahid YILDIZ, Sakarya University of Applied Sciences, Turkey mustafayildiz@sakarya.edu.tr Dr. Tetiana TEPLA, Lviv Polytechnic National Universi...

Dorsal hand vein pattern is a physiological feature that can distinguish and define one person from another. Feature extraction from images is considered as the most important step in biometric systems. In this study, a fractal technique, which is both an advanced and a complex method, is proposed for feature extraction from the images of hand vess...

The purpose of this study is the development of a novel tactile probe for detection of lumps in soft tissue. The tactile probe includes an inductive sensor inside of an artificial tissue-like silicon rubber cushioning and a square shaped multi-metal-array to increase sensitivity. Firstly, a thermoplastic polymer probe was fabricated for housing and...

Earlier studies showed that external focusing enhances motor performance and reduces muscular activity compare to internal one. However, low activity is not always desired especially in case of Human Machine Interface applications. This study is based on investigating the effects of attentional focusing preferences on EMG based control systems. For...

In this paper, we introduce a novel 3D chaotic oscillator which shows megastability without any external excitation. Some important dynamical properties of the proposed novel system were derived and investigated. Data protection application and its security analysis were realized for electrophysiological signals such as ECG, EEG and EMG on a microc...

50 adults participated in the study. The procedures posed no harm for the participants. To get the Sakarya Touchless Fingerprint Database, *Send an e-mail which includes your purpose of usage to oboyraz@sakarya.edu.tr and the signed “Sakarya_Touchless_Fİngerprint_Database_License_Agreement.pdf”. Please note that: (1) The agreement must be signed by...

Early detection of melanoma has critical importance for the success of the treatment. However, a successful early diagnosis is only possible with the existence of discriminative features. In this study, a new descriptor based on the number of colors was developed in order to successfully diagnose lesions of melanoma. The number of colors is the mai...

In this paper, a new memristive chaotic system was constructed from three-dimensional Lorenztype system. The system has infinitely many equilibria and exhibits coexisting attractors. The dynamic evolution corresponds to the parameters and the coupling strength indicate that the system is easy to generate chaos. Also the bifurcation diagrams from di...

https://dergipark.org.tr/en/pub/chaos ----- https://www.researchgate.net/project/Chaos-Theory-and-Applications-CHTA

Background Photodynamic therapy (PDT) is a new therapeutic strategy for the treatment of cancer. 5-aminolevulinic acid (5-ALA) as a precursor of the protoporphyrin IX (PpIX) has a great potential for PDT application. Although 5-ALA-based PDT has been studied in many pre-clinical and clinical studies for breast cancer, there are different PDT applic...

Partially insufficient is the modelling of irregular and complex forms using Euclidean geometry. On the other hand, fractal geometry allows irregular complex forms and structures to be expressed in mathematical terms. While fractal geometry appears to be irregular in nature, when analyzed, it is the structures in which a regular form is replicated...

This paper presents the diaphragm displacement analysis of multi-layered circular piezoelectric actuator (MCPA) using analytical, numerical and experimental methods. The Piezoelectric Zirconate Titanate (PZT) actuator model examined in this study consists of a structure with 3 different diameters and 7 layers. The multi-layered and multi-covered th...

In this study, it is aimed to store and use hand vein images which were microcomputer based encrypted with a novel chaotic system in a secure database. In the scope of the study, the images of the dorsal hand vein taken from the subjects by an infrared camera were improved by pre-processing methods. The pre-processed vein images were then encrypted...

Editor in Chief Dr. Mustafa CAN, Sakarya University of Applied Sciences, Turkey mustafacan@subu.edu.tr Editors Dr. Kamal YUSOH, University Malaysia Pahang, Malaysia University Malaysia Pahang Dr. Mustafa Zahid YILDIZ, Sakarya University of Applied Sciences, Turkey mustafayildiz@sakarya.edu.tr Dr. Tetiana TEPLA, Lviv Polytechnic National Universi...

Makine öğrenmesi yöntemlerinin sınıflandırma ve tanımlama açısından başarısının artması, bilgisayar teknolojisine karar verme yeteneği kazandırmış ve analiz yapma metotlarını geliştirmiştir. Makine öğrenmesi yöntemlerinin bu avantajları, medikal alanda hastalıkların teşhis ve tedavi süreçlerinde uzmanlara yardımcı olabilecek gelişmiş karar destek s...

Damar tanıma sistemleri, insanları damar yapılarına göre ayırabilen bir biyometrik tanıma biçimidir. El-bilek damar deseninden kimlik tanıma da bu sistemlerden birisidir. Bu çalışmada 850 nm dalgaboyuna sahip kızılötesi ışık kaynağı kullanılarak kişilerden alınan el-bilek damar görüntüleri çeşitli görüntü işleme algoritmalarından geçirilerek segm...

zet: Bu çalışmada balina sürüsü algoritması kullanılarak ölü zamanlı sistemlerin denetlenmesinde kullanılan Smith Öngörücüsü için PID denetleyicisinin parametreleri belirlenmiştir. Ayrıca Smith Öngörücüsü için kullanılan Zeigler-Nichols veya AMIGO yöntemleri ile yapılan PID tasarımında kontrol işareti sınırlandırılmamaktadır. Bu kısıt aşımı ise kon...

A commercial micropump should provide properties that justify the simple structure and miniaturization, high reliability, simple working principle, low cost and no need for complex controller. In this study, two novel piezoelectric actuated (lead zirconate titanate-PZT) valveless micropumps that can achieve high flow rates by pumping chambers and f...

Micropumps have wide range of novel applications in medical field. The main purpose of this study was to find potential electro-mechanical design aspects of a micropump for Glaucoma disease treatment. We suggested four new micropump designs, namely, single diaphragm micropumps at two different Piezoelectric Lead Zirconate Titanate (PZT-2) thickness...

In this study, a lorenz-like chaotic system was developed to encrypt the dorsal hand patterns on a microcomputer. Firstly, the dorsal hand vein images were taken from the subjects via an infrared camera. These were subjected to two different processes called as contrast enhancement and segmentation of vein regions. Secondly, the pre-and post-proces...

In this study, a low-cost microcomputer based dorsal hand-vein imaging system was developed by utilizing non-invasive near infrared imaging technology for the patients having hand vein visibility problems. On the microcomputer, we established a new database with high-quality dorsal-hand vein images. Pre- and post-processing were accomplished in Pyt...

Editor in Chief Dr. Mustafa CAN, Sakarya University of Applied Sciences, Turkey mustafacan@subu.edu.tr Editors Dr. Mustafa Zahid Yıldız, Sakarya University of Applied Sciences, Turkey mustafayildiz@sakarya.edu.tr Dr. Tuğrul ÇETİNKAYA, Sakarya University, Turkey tcetinkaya@sakarya.edu.tr Dr. Erol ALVER, Hitit University, Turkey erolalver@hitit.edu...

Metilen mavisi (MB) klinik tıpta yıllardır kullanılan bir boyadır ve fotodinamik terapi (FDT) için bir ilaç olarak kabul edilmiştir. Bu çalışmada HT-29 kolon kanseri hücrelerine MB ekilerek terapötik etkisi in vitro olarak araştırılmıştır. Son yıllarda FDT'de ışık kaynağı olarak LED'ler (Light Emitting Diodes) kullanılmaya başlanmıştır. Ancak FDT'n...

The Scale invariant feature transform (SIFT) method is a technique used for local feature detection. This technique is used in object recognition and image matching in computer vision applications. In addition, SIFT features are also used in biometric authentication systems such as face, fingerprint and palm vein identification. In this study, the...

Many researchers have been investigated the effect of focusing type on motor performance and muscular activity. Studies have showed that focusing on movement effects, i.e., an external focus enhances motor performance whereas, reduces muscular activity compare to focusing on body movements, i.e., an internal focus. The purpose of present study was...

Many researchers have been investigated the effect of focusing type on motor performance and muscular activity. Studies have showed that focusing on movement effects, i.e., an external focus enhances motor performance whereas, reduces muscular activity compare to focusing on body movements, i.e., an internal focus. The purpose of present study was...

In this study, a new micropump was designed, which is suitable for medical applications regarding size and flow rate. When a micropump is used to control the amount of drug delivery, the flow rate is a key parameter and can be controlled with the diaphragm displacement. The amount of displacement depends on the thickness of the piezoelectric elemen...

A low cost piezoelectric micropump was designed and fabricated to supply fluid flow rate in micro-sizes and for use in medical purposes. It was designed as disposable in order to prevent contamination and infection. The micropump was fabricated with the Objet260 Connex3 multi-material 3D printer, which was very precise and sensitive. The piezoelect...

İnme, her yıl milyonlarca kişiyi etkilemektedir. Bu kişilerin çoğu, hareket kabiliyetlerini geri kazanabilmek için rehabilitasyona ihtiyaç duymaktadırlar. El kaslarının robotik temelli rehabilitasyonuna yönelik çok sayıda cihaz önerilmiş olmasına rağmen bu cihazların hala geliştirilmesi gereken yönleri vardır. Önceki cihazlarda kuvvet ve hareket ak...

Venipuncture is one of the most used invasive medical procedure but it becomes very hard to conduct. The degree of difficulty of cannulation process depends on factors like vein depth, the amount of fatty tissues, skin pigmentation and blood volume. Finding the vein can be very hard during treatment or examination in children, old persons, obese, s...

A biometric is physical or behavioral traits of a person in the visible or hidden form and are used to identify the user uniquely. Vein recognition is one of a popular Biometrics technique for identifying people. The shape of the vein remains unchanged when human being grows. Vascular patterns are stable, unique to each individual even identical tw...

Bu çalışmada araştırma ekibimiz tarafından geliştirilen bir egzersiz eldivenin el kasları üzerindeki etkinliğinin incelenmesi amaçlanmıştır. Bu doğrultuda sağlıklı gönüllüler üzerinde denemeler yapılmıştır. Gönüllüler, belirlenen egzersizleri hem eldivensiz hem de eldiveni giyerek gerçekleştirmişlerdir. Egzersizler sırasında ekstansör ve fleksör ka...

The purpose of this study is the development of a novel system for detection of breast tumors in non-invasive way that can be used by doctors or patients. Our study consist of two parts. The first part is a specialized sensor containing an inductive sensor inside of a tissue-like silicon rubber robotic fingertip and a square shaped multi-metal-arra...

Ülkemizde ve dünyada nüfusun giderek yaşlanması ve kalp rahatsızlıklarının artması, bu hayati organımızın faaliyetlerini sürekli kontrol altında tutma, tedavi sürecinde ve öncesinde tüm etkileri gözlemleme gibi ihtiyaçları doğurmaktadır. Çalışmanın temel amacı, açık kaynak kodlu, geliştirilmeye açık gömülü sistem tabanlı taşınabilir bir EKG Holter...

Optical parameters of the target tissue are important to know for all kinds of phototherapy. In photodynamic therapy, for example, the knowledge of the penetration depth for the light is needed in order to ensure that the optical energy received by the tumorous tissue. In the present study, the optical penetration depths of 635 nm laser light in ch...

This study is based on measuring the Electrocardiogram (ECG) signals from the human body in real-time with the help of the software called NI LabVIEW. Not only the raw ECG signals, the digital filtered version of the ECG signals can also be displayed in real-time by processing the signals using the digital filtering tools of the program. The ECG it...

MUHAMMED GULER, ALI FURKAN KAMANLI, MUSTAFA ZAHID YILDIZ, AYLA EREN OZDEMIR, HYUN SOO LIM

Photodynamic therapy (PDT) is a cancer treatment requiring a photosensitizing molecule (drug) and a light source to activate the drug. In PDT, the optical energy received by the tumorous tissue is crucial for successful treatment. Therefore, penetration depth of the light in the target tissue is an important parameter for dosimetry calculations. In...

In cancer treatments photodynamic therapy, because of being a minimally invasive method and having no significant harmful side effect to the patient. This method begins with the administration of ALA-5 photosensitizer material prior to treatment in the tissue, which reacts chemically to the specific wavelength light. Dosimeter calculations determin...

The main objective of the project is to develop an open source embedded system based ECG holter device for the patients. Since the population of the elderly people is getting higher, heart related diseases has also been increasing in the world. Due to the limited opportunities and challenges of hospitals, patients are having difficulties for contin...

Hastalık, travma, kaza veya doğuştan gelen bir takım kusurlardan dolayı el parmakları ve el bileğinde hareket kayıpları yaşanmaktadır. Bu cihaz, kaybedilen hareket yeteneğinin yeniden kazandırılması için gerekli egzersizleri sağlayacak aktif, dinamik, ev ortamında kullanıma uygun, taşınabilir, düşük maliyetli ve yetişkin bireylerin antropometrik öz...

Pulse-oksimetreler kan aktivitesi, kalp hızının ölçümü ve bu ölçümün sonucunda nasıl bir tedavi yöntemi izlenebileceği konusunda klinik doktorlara fikir veren cihazlardır. Bu tip cihazlar aktif satürasyonun ölçümünde %1’lik bir belirsizliğe sahiptir. Pulse oksimetre ameliyathanelerde bir standart haline gelmeden önce başka yerlerde de kullanılmıştı...

Millions of people suffer a stroke each year. One of the problems after stroke is hemiplegic hand. In previous studies a lot of robotic based devices has been suggested for rehabilitation of hemiplegic hand. Actuators using for force transmitting in previous devices have some disadvantages. One of them is misalignment on the centre of rotation betw...

Geleneksel yöntemler kullanılarak çocuklarda, yaşlılarda, obezlerde, ağır yanık vakalarında veya koyu tenli kişilerde gerek tedavi gerekse de muayene esnasında damarların bulunması oldukça güç olabilmektedir. Bu gibi dezavantajları ortadan kaldırmak için birçok damar görüntüleme yaklaşımı geliştirilmiştir. Bu çalışmada da bunlardan birisi olan yakı...

The identification of the finger joint torque is important for hand rehabilitation devices, ergonomic studies and humanoid mechanism. Researchers in previous studies have suggested different biomechanical models and equations in order to specify mechanics of human fingers. Some external devices also could be used to determine the joint torques. How...

Determining the joint torques of the hand is useful for humanoid mechanism, rehabilitation robots and orthotic and prosthetic devices. In previous studies, different methods have been suggested for estimating joint torques of the hand such as mathematical models and simulation models. This paper presents a 16 DOF hand kinematic model and its simula...

The purpose of this study is the development of a novel system for detection of breast tumors in non-invasive way that can be used by doctors or patients. Our study consist of two parts. The first part is a specialized sensor containing an inductive sensor inside of a tissue-like silicon rubber robotic fingertip and a square shaped multi-metal-arra...

We investigated the gating effect of passive and active movement on the vibrotactile detection thresholds of the Pacinian (P) psychophysical channel and forward masking. Previous work on gating mostly used electrocutaneous stimulation and did not allow focusing on tactile submodalities. Ten healthy adults participated in our study. Passive movement...

The wrist links hand and forearm to each other and it allows movements in two different planes. Thus it has an important role in the mobility of the hand. In previous studies, researchers have analysed the movement of the wrist joint using different mathematical models and methods. In this study, the hand and the wrist have been modelled as a simpl...

The wrist links hand and forearm to each other and it allows movements in two different planes. Thus it has an important role in the mobility of the hand. In previous studies, researchers have analysed the movement of the wrist joint using different mathematical models and methods. In this study, the hand and the wrist have been modelled as...

In today’s world, rapidly evolving visualization and calculation technologies are used in the healthcare field. The veins can be detected hardly in children, elder, obese, severely burned people or dark colored people. Many vein imaging systems were developed for eliminating the disadvantages in the clinics. In this study, the hand images from the...

Tactile feedback is becoming more important in clinical devices and engineer- ing. Therefore, studies on basic sensory processing in the somatosensory system are essential. In this thesis, the mechanical and temporal parameters a􏰂ecting the absolute tactile detection threshold of human Pacinian (P) channel were investigated. Temporal summation in P...

The goal of this study was to investigate the relationship between the psychophysical vibrotactile thresholds of the Pacinian (P) channel and the mechanical properties of the skin at the fingertip. Seven healthy adult subjects (age: 23-30) participated in the study. The mechanical stimuli were 250-Hz sinusoidal bursts and applied with cylindrical c...