ABSTRACTBackground: cochlear implants are electronic devices that convert sound energy into electrical signals to stimulate ganglion cells and cochlear nerve fibers. These devices are indicated for patients with severe to profound sensorineural hearing losses who receive little or no benefit from hearing aids. The implant basically takes over the function of the cochlear hair cells. The implant consists of external components (microphone, speech processor and transmitting coil) and internal components (receiver stimulator and electrode array). The implant is inserted via a trans mastoid facial recess approach to the round window and scala tympani.Objectives: to determine the effectiveness and safety of non fixation method in cochlear implantation.Methods: a prospective study carried out from September 2009 to September 2012 in Gazi Hariri Hospital. Eighty patients with congenital severe –profound sensorineural hearing loss prepared for cochlear implantation involved in the study and divided into 2 groups. Group A includes 40 patients in whom the internal device was fixed to the skull by nylon suture materials through small burr holes on both sides of the well. Group B includes 40 patients in whom the internal device placed in a tight sub pericranial pocket without nylon fixation to the skull. All patients followed postoperatively for 6 months observing wound healing and local complications (hematoma, infection, wound dehiscence, device extrusion and migration).Results: mean age 4.2 years and male-female ratio was 1.3:1.Group A: 1 patient (2.5%) developed minor wound infection treated conservatively. Three patients (7.5%) developedsevere wound infection with wound breakdown and device extrusion despite the use of antibiotics and local rotational flaps, the device was explanted in those 3 patients. Two patients (5%) developed hematoma without history of trauma and treated conservatively. One patient (2.5%) had device migration without affection of its function.Group B: 2 patients developed minor wound infection treated conservatively. One patient (2.5%) had severe wound infection ends up with wound dehiscence and device extrusion despite the use of antibiotics and local rotational flaps. Explantation of the device was done for this patient. Hematoma occurred in one patient (2.5%) without history of trauma and treated conservatively. Another one patient (2.5%) developed device migration without impairment of its function.Conclusion: creation of sub pericranial pocket without internal device fixation by nylon materials is an effective and reliable method in cochlear implantation without compromising the patient safety or device performance.Key words: cochlear implantation, non- fixation, sub pericranial pocket
Background and Aim: due to the rapid growth of data communication and multimedia system applications, security becomes a critical issue in the communication and storage of images. This study aims to improve encryption and decryption for various types of images by decreasing time consumption and strengthening security. Methodology: An algorithm is proposed for encrypting images based on the Carlisle Adams and Stafford Tavares CAST block cipher algorithm with 3D and 2D logistic maps. A chaotic function that increases the randomness in the encrypted data and images, thereby breaking the relation sequence through the encryption procedure, is introduced. The time is decreased by using three secure and private S-Boxes rather than using si
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This paper investigates the experimental response of composite reinforced concrete with GFRP and steel I-sections under limited cycles of repeated load. The practical work included testing four beams. A reference beam, two composite beams with pultruded GFRP I-sections, and a composite beam with a steel I-beam were subjected to repeated loading. The repeated loading test started by loading gradually up to a maximum of 75% of the ultimate static failure load for five loading and unloading cycles. After that, the specimens were reloaded gradually until failure. All test specimens were tested under a three-point load. Experimental results showed that the ductility index increased for the composite beams relative to the reference specim
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Glass Fiber Reinforced Polymer (GFRP) beams have gained attention due to their promising mechanical properties and potential for structural applications. Combining GFRP core and encasing materials creates a composite beam with superior mechanical properties. This paper describes the testing encased GFRP beams as composite Reinforced Concrete (RC) beams under low-velocity impact load. Theoretical analysis was used with practical results to simulate the tested beams' behavior and predict the generated energies during the impact loading. The impact response was investigated using repeated drops of 42.5 kg falling mass from various heights. An analysis was performed using accelerometer readings to calculate the generalized inertial load
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In this work, optical system with different aperture shapes (circular, square, elliptical and triangle aperture) has been used for efficiency evaluation when the system involved moving factor in ideal case (aberration free). The optical system evaluate far moving object, therefore the image forming at image plane due to point spread function (image formula of incoherently illuminated point object). A mathematical treatment has been used to getting results by Gaussian numerical calculations method. The results show priority of circular aperture when optical system that submits of moving factor.
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Flexible pavements are considered an essential element of transportation infrastructure. So, evaluations of flexible pavement performance are necessary for the proper management of transportation infrastructure. Pavement condition index (PCI) and international roughness index (IRI) are common indices applied to evaluate pavement surface conditions. However, the pavement condition surveys to calculate PCI are costly and time-consuming as compared to IRI. This article focuses on developing regression models that predict PCI from IRI. Eighty-three flexible pavement sections, with section length equal to 250 m, were selected in Al-Diwaniyah, Iraq, to develop PCI-IRI relationships. In terms of the quantity and severity of eac
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