Elektronik ve Haberleşme Mühendisliği

Bu koleksiyon için kalıcı URI

http://hdl.handle.net/11527/18001

Gözat

Yazar "Akduman, İbrahim" ile Elektronik ve Haberleşme Mühendisliği'a göz atma
  • Öge
    In vitro dielectric properties of rat skin tissue for microwave skin cancer detection
    (IEEE, 2019) Aydınalp, Cemanur ; joof, Sulayman ; Yılmaz, Tuba ; Pastacı Özsobacı, Nural ; Ateş Alkan, Fatma ; Akduman, İbrahim ; Elektronik ve Haberleşme Mühendisliği ; Electronics and Communication Engineering
    Dermal tissue characterization based on dielectric properties can be utilized as a non-invasive method for diagnosis of skin cancers. To enable such technology, there is a need to develop techniques that can rapidly and accurately collect the dielectric properties of the skin tissues. Therefore, the current measurement techniques and tools has to be optimized for skin cancer detection. To this end, this study presents dielectric property measurements with open-ended coaxial probes having small apertures customized for detection of skin cancer. Relative permittivity and conductivity of rat skin tissue is characterized with open-ended coaxial probes with outer diameters of 0.9mm and 0.5mm between 0.5GHz6GHz and the measurement results are compared with the traditional probes having diameter of 2.2mm. The results agree well with the reported literature data.
  • Öge
    Microwave dielectric property based classification of renal calculi: Application of a kNN algorithm
    (Elsevier, 2019) Saçlı, Banu ; Aydınalp, Cemanur ; Cansız, Gökhan ; joof, Sulayman ; Yılmaz, Tuba ; Çayören, Mehmet ; Önal, Bülent ; Akduman, İbrahim ; Elektronik ve Haberleşme Mühendisliği ; Electronics and Communication Engineering
    The proper management of renal lithiasis presents a challenge, with the recur- rence rate of the disease being as high as 46%. To prevent recurrence, the first step is the accurate categorization of the discarded renal calculi. Currently, the discarded renal calculi type is determined with the X-ray powder diffraction method which requires a cumbersome sample preparation. This work presents a new approach that can enable fast and accurate classification of discarded renal calculi with minimal sample preparation requirements. To do so, first, the measurements of the dielectric properties of naturally formed renal calculi are collected with the open-ended contact probe technique between 500 MHz to 6 GHz with 100 MHz intervals. Cole–Cole parameters are fitted to the measured dielectric properties with the generalized Newton–Raphson method. The re- nal calculi types are classified based on their Cole–Cole parameters as calcium oxalate, cystine, or struvite. The classification is performed using nearest neigh- bors (kNN) machine learning algorithm with the 10 nearest neighbors, where accuracy as high as 98.17% is achieved.
  • Öge
    Microwave dielectric spectroscopy of renal calculi: A large scale study on dielectric properties from 500 MHz to 18 GHz
    (IEEE, 2019) Yılmaz, Tuba ; Saçlı, Banu ; Cansız, Gökhan ; joof, Sulayman ; Aydınalp, Cemanur ; Çayören, Mehmet ; Akduman, İbrahim ; Önal, Bülent ; Elektronik ve Haberleşme Mühendisliği ; Electronics and Communication Engineering
    Inherent dielectric property discrepancy between biological anomalies and healthy tissue enables the microwave diagnostic and therapeutic technologies. To reveal this discrepancy, microwave dielectric properties of many different biological tissues are tabulated. Although the dielectric properties of biological tissues are well documented in the literature, the knowledge on microwave dielectric property behavior of the renal calculi is limited. This work presents ultra wideband dielectric properties of three renal calculi types between 500 MHz to 18 GHz to pave the way for possible application of microwave technologies for diagnosis, treatment, and prevention of urolithiasis. Microwave dielectric spectroscopy is performed on a total of 66 natural stone samples with open-ended coaxial probe technique. The samples belong to three commonly diagnosed renal calculi categories, namely calcium oxalate, cystine, struvite. Analysis of variance (ANOVA) test is performed on fitted Cole-Cole parameters and it was concluded that there is a statistically significant difference between the dielectric properties of the renal calculi types. A patient-to-patient statistical test is also performed and it was concluded that there is no statistical difference between the samples belonging to the same renal calculi category. To this end, based on the relative permittivity discrepancy between the renal calculi types, the category of renal calculi can be identified by measuring the dielectric properties of renal calculi with open-ended coaxial probe technique.
  • Öge
    Sensitivity and sensing depth analysis of open-ended contact probes for cancer diagnosis
    (İstanbul Teknik Üniversitesi, 2019) Aydınalp, Cemanur ; joof, Sulayman ; Akduman, İbrahim ; Yılmaz, Tuba ; Elektronik ve Haberleşme Mühendisliği ; Electronics and Communication Engineering
    Open-ended contact probes have been widely utilized in laboratory environment to quantify the dielectric properties of high permittivity and lossy materials such as biological tissues and other lossy liquids. At microwave frequencies, the dielectric properties of biologi- cal tissues have been quantified with open-ended contact probes method with the motivation of building microwave diagnostic and therapeutic technologies. The method is preferred to other microwave dielectric property measurement techniques due to broadband measurement capabil- ities and minimal sample preparation requirements. However, the measurement procedure is cumbersome and the measurements tend to be error-prone. The commercial probes can have error rates as high as 5% and it can increase with the cable movements, calibration degradation, and probe wear-off. Although the technique is powerful and able to measure the inherent dielec- tric property discrepancy between different tissues the applications are confined to laboratory use. To explore the true potential of this technique and enable the transition of this technique to a diagnostic technology, there is a need to improve the technique and analyze the performance in a layered heterogeneous medium. In this work, we performed simulations and measurements with open-ended contact probes having different aperture diameters. The probes are built with copper and Teflon sandwiched between inner and outer conductors. Measurements with open- ended coaxial probes are performed on layered medium emulating the dielectric properties of the biological tissues to analyze the sensing depth and sensitivity of four in-house fabricated open- ended coaxial probes. An in-house algorithm is utilized to retrieve the dielectric properties of the mediums utilized during this study.