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BBQ (4,4'''-Bis-(2-butyloctyloxy)-p-quaterphenyl) is one of the laser dyes, which appears as white, crystalline solid. A dye laser is a laser which uses an organic dye as the lasing medium, usually as a liquid solution. Some of the dyes are Rhodamine 6G, coumarin, stilbene, umbelliferone, tetracene and others. In this work, BBQ in cyclohexane is investigated in the room temperature spectroscopically...
Polyurethanes (PUs) are able to degrade into harmless molecules upon implantation and have received a significant level of attention as a biomaterial. PUs based on polycaprolactone (PCL) and amino acid derivatives are examples of these polymers. As a potential biomaterial, their biocompatibility coupled with biodegradability attracted attention in tissue engineering applications. In this study, a...
Hard tissue engineering has emerged to compensate for the losses in the properties of damaged bones by using scaffolds and cells. In this study, natural polymers chitosan and gelatin were used as scaffold materials because of their great resemblance to extracellular matrix elements. To enhance the mechanical properties and osteoconductivity of structures hydroxyapatite was added. This study is about...
Extracorporeal Shock Wave Lithotrispy (ESWL) is a procedure based on sound waves to crash kidney stones on the focus. The sound waves are sent to the body of patient when the kidney stone is not even on the focus. When the stone is not on the focus, the sound waves can damage the soft tissue of the kidney. This damage can be prevented by a feedback mechanism that determines the place of kidney stones...
A simple liquid sensing and measurement system for determining the level of cryogen in a tissue cryopreservation container is described. Liquid-gas boundary determination is made by detecting a thermal transient of the series-connected light emitting diodes. An electronic control and display unit located on the outer wall of the container indicates the level of cryogenic liquid, and alarms the operator...
During the X-Ray machines are used, if the protection from X-Ray is insufficient, not only the patient but also the user is exposured with high X-Ray dosage and he/she is affected from X-Ray in related to the dose level. In this study, by testing the radiological leakage in Radiology Departmant of Istanbul Health Faculty in Istanbul University, the effects of X-Ray to both the user and the patients...
In this study, a project was developed for performance control of the medical devices in the Cerrahpasa Health Faculty in Istanbul University. The calibration measurements of these medical devices were performed and the measurement results were interpreted in according to the IPM “Inspection and Preventive Maintenance System” procedures which are developed by ECRI (Emergency Care Research Institute)...
Bioelectric impedance analysis (BIA) is a widely technique in determining body composition. In this method, two electrodes are placed at suitable points on the body and alternating current at different frequencies are passed through those points. Then, the voltage difference between the two points is measured and corresponding bioelectric impedance is calculated. In this study, BIA measurement calculated...
In this study, a single-channel and portable surface electromyography (sEMG) device is designed which could be used as a supporting device in detection of back herniation disease. The sEMG signals those collected with surface electrodes are amplified and isolated. Then, the sEMG signals enter to filtering circuits to eliminate unwanted noise signals. The noise free yEMG signals are digitized with...
Imaging the electrical properties of the human body for diagnostic purposes has been researched since the 1980s with an increasing interest. In recent years, the excitation and measurements were thought to be realized via inductively using coils instead of electrodes. One of the major difficulties of imaging with this method, which is also referred to as magnetic induction tomography (MIT), is the...
Today, the increasing contribution of biomedical devices is well known for diagnosis and treatment of common diseases. The heart rate is an important parameter among this diagnosis. The heart rate is the total number performed heart beats in a minute. In this study, the heart rate is detected proportionally to the intensity oxyhemoglobin inside the finger. Oxygen is greatly carried with the hemoglobin...
Muscle stimulation with a series of electrical shocks is a method which is used mostly in rehabilitation and sport health areas. These devices are used for esthetic purposes beside medicine. In this paper we present a low impact muscle stimulator developed by us. Our portable system has come to the fore among similar products on the market with its low cost, low power consumption and high security...
In this study, we analyzed the MR spectroscopic and MR diffusion weighted imaging parameter differences among the subtypes of grade 3 brain tumor patients (anaplastic astrocytoma, oligodendroglioma, and oligoastrocytoma). We observed higher lipid values in the tumor regions of oligodendrogliomas than both astrocytomas and oligoastrocytomas. According to these results, there were not significant MR...
Endovenous Laser Ablation (EVLA) has become more popular than classical surgial treatment in the management of varicose veins in recent years. Endovenous Laser ablation is safer, more efficient and minimally invasive than classical surgery when the necessity of general anaesthesia, post-operative events and reccurance rate of the classical surgery is considered. Since endovenous laser ablation is...
In this study, simultaneous EEG and fMRI measurements are recorded from 18 healthy subjects during steady state visual stimulation. The stimulation frequencies that belong to the alpha, beta and gamma bands, at which the highest EEG amplitudes were observed, were determined for each subjects. The fMRI responses at those specific stimulation frequencies were anlayzed. Both EEG amplitudes and the fMRI...
In this study, a fuzzy logic technique for classification of different biomedical dataset is optimized for improving performance. Threshold acceptance algorithm is used for optimization process. The proposed method is tested on heart data set and simulation results show that the optimized fuzzy logic approach provides higher classification accuracy compare with that of unoptimized fuzzy logic structure.
Sphingolipids are structural elements of cell membrane and have an important role in signal transmission as second messengers of the cell. Ceramide, which is an important sphingolipid, causes cellular differentiation or apoptosis by activating intracellular enzymes with the influence of extracellular stimulants. Because of these characteristics, it is considered that ceramide is an essential molecule...
Retinotopy is a tool for mapping of the visual cortex which provides detailed information about the correspondence between the visual field and its cortical representation in the visual subject. Therefore, the studies about retinotopic mapping is increasing rapidly as a branch of neuro science. Our study includes three main parts: The first one is the acquiring the data. While subject is stimulated...
In this study, it is aimed to evaluate SAR value occurred in human head in 1800 MHz. First, 3-D basic model of human head was designed by using HFSS (ANSOFT). So, some solutions were obtained from created model with putting source of 1800 MHz electric field in different orientations on 3-plane. This basic approach shows a close agreement with realistic ones.
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