Ağaoğlu, Şükrüye Nihal | Özer, Mahmut | Çalım, Ali | Uzuntarla, Muhammet

Proceedings | 2017 | 2017 25th Signal Processing and Communications Applications Conference, SIU 2017

In this paper, the phenomena of Vibrational Resonance is investigated in an excitable system which consists of FitzHugh-Nagumo neurons with electrical coupling. Weak signal detection performance of excitable system is examined in scale-free network (unweighted or weighted) topology. The simulation results show that; weighting the scale-free network, average connectivity degree, amplitude and frequency of weak signal play an active role to determine the data carrying performance of neurons based on Vibrational Resonance. It is determined that, the amount of required energy for creating resonance peaks of excitable system is decreased . . . significantly by choosing the correct value of weight control parameter in a weighted network especially. © 2017 IEEE Daha fazlası Daha az

Çalım, Ali | Özer, Mahmut | Uzuntarla, Muhammet

Proceedings | 2017 | 2017 25th Signal Processing and Communications Applications Conference, SIU 2017

Nowadays, neurodegenerative diseases which affect human life quite negatively with motor, cognitive and psychiatric disorders are becoming widespread. One of the most common neurodegenerative disorder is Parkinson's disease. Recent electrophysiological experiments have shown that Basal Ganglia, a special region in the midbrain, is related to Parkinsonism. Beta frequency oscillations, which are important symptoms of Parkinson's disease, emerge intensively in Globus Pallidus and Subtalamus nuclei. In this study, anatomical connections of Globus Pallidus and Subtalamus are constructed computationally, and the cellular properties that g . . .ive rise to emergence of beta oscillations are investigated. © 2017 IEEE Daha fazlası Daha az

Çalım, Ali | Özer, Mahmut | Uzuntarla, Muhammet

Proceedings | 2018 | 26th IEEE Signal Processing and Communications Applications Conference, SIU 2018 , pp.1 - 4

Experimental and theoretical studies in recent years suggest that the first spike latency is an effective information carrier and contains more neural information than other spikes. Noise Delayed Decay (NDD) phenomenon emerges when the first spike latency of the neuron exposed to the periodic driving is maximum at a certain noise intensity interval. In this study, the latency dynamics of a single Hodgkin-Huxley neuron is investigated under periodic driving, background activity through dynamic synapses, and channel noise. The system response with first spike latency is investigated as a function of the presynaptic firing rate, the pa . . .rameter with an appropriate biophysical reality to control the level of activity in the nervous system. First, NDD behavior is investigated under suprathreshold stimulation in the presence of synapses at different levels of depression and channel noise. It is then desired to observe the NDD phenomenon under subthreshold stimulation with the same strategy. Our results have shown that the background activity occurring in the presence of dynamic synapses and the channel noise are significant system dynamics in observing the NDD behavior. © 2018 IEEE Daha fazlası Daha az

Baysal, Veli | Özer, Mahmut | Yılmaz, Ergin

Proceedings | 2017 | 2017 Medical Technologies National Conference, TIPTEKNO 20172017-January , pp.1 - 4

In this paper, the effects of autapse (a kind of synapse formed between the axon or soma of a neuron and its own dendrites) on the weak signal detection capacity of a Hodgkin-Huxley (H-H) neuron are investigated. In the study, we consider that the H-H neuron has an inhibitory autapse modeled as a chemical synapse. The subthreshold sine wave is injected to the H-H neuron as a weak signal. Obtained results indicate that inhibitory autapse prominently increases the weak signal detection capacity of a H-H neuron when the proper autaptic time delay and autaptic conductance values are choosen. © 2017 IEEE.

Çalım, Ali | Özer, Mahmut | Uzuntarla, Muhammet

Proceedings | 2017 | 2017 Medical Technologies National Conference, TIPTEKNO 20172017-January , pp.1 - 4

Parkinson's disease is a neurodegenerative disorder that affect human life quite negatively with motor, cognitive and psychiatric way. Recent electrophysiological experiments have shown that Basal Ganglia, spaced in the midbrain, can lead to Parkinsonism. Beta frequency oscillations and irregular burstings are most important symptoms of Parkinson's disease. They appear in Globus Pallidus and Subtalamus nuclei during the disease. In this study, anatomical connection features that may give rise to emergence of burstings are investigated, simulating Globus Pallidus and Subtalamus nuclei numerically. © 2017 IEEE.

Baysal, Veli | Yılmaz, Ergin | Özer, Mahmut

Proceedings | 2017 | 2017 Medical Technologies National Conference, TIPTEKNO 20172017-January , pp.1 - 4

In this paper, the effects of autapse on the first spike latency of the stochastic H-H neuron are examined. In the study, it is considered that H-H neuron has an electrical autapse and by applying a suprathreshold periodic signal to neuron the first spike times has been observed. Obtained results show that the first spike latency of H-H neuron increases prominently in a certain autaptic time delay with the increasing of autaptic conductance. Also, the first spike latency decreases with the increasing of autaptic conductance in a different autaptic time delay interval. In the context of these results, we come to conclusion that the a . . .utapse have played important roles on the control of first spike latency of stochastic H-H neurons. © 2017 IEEE Daha fazlası Daha az

Çalım, Ali | Özer, Mahmut | Uzuntarla, Muhammet

Proceedings | 2017 | 2017 Medical Technologies National Conference, TIPTEKNO 20172017-January , pp.1 - 4

In this study, vibrational resonance phenomena is investigated in excitable neuron population. Synapses where complex electrochemical events take place in is modelled dynamically, not statically by contrast with early studies. Effect of short-Term synaptic depression which is a prominent feature of dynamic synapses on vibrational resonance is studied. The results of numerical simulations that silencing effect of shortterm depression emerges in the cases where static synapses lead to vibrational resonance. © 2017 IEEE.

Erkaymaz, Hande | Özer, Mahmut | Kaya, Ceren

Conference Object | 2015 | 2015 19TH NATIONAL BIOMEDICAL ENGINEERING MEETING (BIYOMUT) , pp.1 - 4

The eye, which has the most advanced features among sense organs, has a perfect functioning on people. Furthermore, as it is placed in the lead role of vision, shows the importance for people is quite big. Nowadays, biomedical devices developed for patients who have mobility are benefiting from eye movements. Electrooculogram studies are especially designed on the basis of the signal depending on the movement of your eyes. Electrical origin of EOG biological signal, that occur around the eye pupil, makes an attempt to meet the needs of patients by the right, left, up, down and blinking action. In this study, 4 basic differences exis . . .ting in the direction of movement using voltage controlled EOG signal studies have tried to determine the Neuro-Fuzzy model. Determining the direction of Neuro-Fuzzy control system demonstrates how it can be successfully used as. In addition, control algorithms of artificial intelligence systems that use this kind of eye signals benefiting from the input of the detection process is advantageous in the classification of complex environment Daha fazlası Daha az

Baysal, Veli | Yılmaz, Ergin

Article | 2020 | Physica A: Statistical Mechanics and its Applications537 , pp.1 - 4

In this paper, Vibrational Resonance (VR), in which the response of some dynamical systems to a weak, low frequency signal can be enhanced by the optimal amplitude of high frequency signal, is investigated under the effects of electromagnetic induction in both single neurons and small-world networks. We find that the occurrence of VR in single neurons requires less energy in the presence of electromagnetic induction, although the resonant peak of the response reduces. Besides, VR can be obtained in small-world networks both with and without electromagnetic induction. In small-world neuronal networks, the highest resonance peak of VR . . . enhances with an increase in the probability of adding link in case of without electromagnetic induction. On the other hand, with the increasing of the probability of adding link, VR disappears in the presence of relatively strong electromagnetic induction, while it enhances in the presence of relatively weak electromagnetic induction. © 2019 Elsevier B.V Daha fazlası Daha az

Akbuğday, Burak | Yılmaz, Ergin

Proceedings | 2019 | TIPTEKNO 2019 - Tip Teknolojileri Kongresi , pp.1 - 4

Obstructive sleep apnea defined as a medical condition caused by loss of muscle tone in upper airway dilator muscles. There are various treatment methods exist for this condition both invasive and non-invasive, but they all have their weaknesses and strengths. Electrical stimulation method seems to be the most promising non-invasive method in terms of efficiency and adherence rate. This study introduces a low-cost, easy-to-use and wireless novel device to treat obstructive sleep apnea based on electrical stimulation method. The developed device uses an accelerometer to track respiration and apnea episodes and when an apnea episode i . . .s detected delivers a small electric current to dilator muscles to make them regain their muscle tone, thus treating obstructive sleep apnea. The device also communicates with a smartphone application to keep a recording of respiration and apnea data to enable further studying of data by medical professionals and researchers. © 2019 IEEE Daha fazlası Daha az

Erkan, Yasemin | Saraç, Zehra | Yılmaz, Ergin

Proceedings | 2018 | 26th IEEE Signal Processing and Communications Applications Conference, SIU 2018 , pp.1 - 4

In this study, the effects of electrically non-excitable astrocyte cell on the weak signal detection capacity of Hodgkin-Huxley neuron are investigated. To do this, by applying a subthreshold weak signal to neuron, we investigate the weak signal detection capacity of the neuron depending on calcium channel noise stemmed from random open-close fluctuations of calcium channels. Obtained results show that astrocyte decreases the weak signal detection capacity of Hodgkin-Huxley neuron. © 2018 IEEE.

Palabaş, Tuğba | Gürleyen, Hatice Hilal | Uzuntarla, Muhammet

Proceedings | 2019 | TIPTEKNO 2019 - Tip Teknolojileri Kongresi , pp.1 - 4

It is known that activity is terminated abruptly as a result of strong synchronization in bistable neuron populations when there is sufficient current stimulation. The aim of this study is to investigate the effect of ion channel blocking on the phenomenon of spontaneous termination of ongoing activity in the bistable neural network connected by excitatory chemical synapses using stochastic Hodgkin-Huxley (H-H) equations. The obtained results show that significant changes in the dynamics of neurons occur due to the blocking of potassium ion channels at different rates depending on the coupling strength. As the coupling of synaptic i . . .nteraction increases, the synchronization between neurons increases and the activity terminates. Simulation results showed that sodium ion channels are not effective on this phenomenon. © 2019 IEEE Daha fazlası Daha az