Tuba Yilmaz

Tuba Yilmaz
Istanbul Technical University · Department of Electronics and Communication Engineering

PhD

About

68
Publications
18,209
Reads
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980
Citations
Citations since 2017
47 Research Items
759 Citations
2017201820192020202120222023050100150
2017201820192020202120222023050100150
2017201820192020202120222023050100150
2017201820192020202120222023050100150

Publications

Publications (68)
Article
Full-text available
Mammary carcinoma, breast cancer, is the most commonly diagnosed cancer type among women. Therefore, potential new technologies for the diagnosis and treatment of the disease are being investigated. One promising technique is microwave applications designed to exploit the inherent dielectric property discrepancy between the malignant and normal tis...
Article
Full-text available
Microwave hyperthermia (MH) requires the effective calibration of antenna excitations for the selective focusing of the microwave energy on the target region, with a nominal effect on the surrounding tissue. To this end, many different antenna calibration methods, such as optimization techniques and look-up tables, have been proposed in the literat...
Article
In this work, we proposed a general guideline and a technique for retrieving the complex permittivities (CPs) of material under test (MUT) from the measured reflection coefficients (RCs) obtained with the openended coaxial probe (OECP) through a deep learning model (DLM). Particularly, lossy materials such as phantoms mimicking the biological tissu...
Article
Using artificial neural networks (NNs) in microwave medical diagnosis is recently of great interest in various problems such as early breast cancer detection, brain stroke, and leukemia monitoring. NNs facilitate the process by directly assessing the presence and properties of the tissues based on the scattered field values. Although the reported s...
Article
Full-text available
Microwave breast hyperthermia (MH) aims to increase the temperature at the tumor location with minimal change in the healthy tissue. To this end, the specific absorption rate (SAR) inside the breast is optimized. The choice of the MH applicator design is important for a superior energy focus on the target. Although hyperthermia treatment planning (...
Article
Full-text available
Qualitative microwave imaging methods provide a fast and accurate reconstruction of the shapes of the targets from scattered electric field measurements. In this paper, a qualitative imaging method, the singular sources method (SSM), is analyzed for two-dimensional transverse magnetic electromagnetic (2D-TM EM) inverse scattering scenarios. The con...
Article
Purpose: Microwave imaging of breast cancer is considered and a new microwave imaging prototype including the imaging algorithm, the antenna array, and the measurement configuration is presented. The prototype aims to project the geometrical features of the anomalies inside the breast to a single-slice image at the coronal plane depending on the c...
Preprint
p>Microwave hyperthermia (MH) treatment for breast cancer is a research interest due to its capability to initiate cell necrosis in malignant tumor or to enhance the effect of other treatment modalities such as chemotherapy. The goal of MH treatment is to increase temperature of malignant tumor up to 45°C based on the treatment plan; however, micro...
Preprint
p>Microwave hyperthermia (MH) treatment for breast cancer is a research interest due to its capability to initiate cell necrosis in malignant tumor or to enhance the effect of other treatment modalities such as chemotherapy. The goal of MH treatment is to increase temperature of malignant tumor up to 45°C based on the treatment plan; however, micro...
Preprint
p>Microwave hyperthermia (MH) requires the effective calibration of the antenna excitations for selective focusing of the microwave energy to the target region with a nominal effect on the surrounding tissue. To this end, many different antenna calibration methods such as optimization techniques and lookup tables have been proposed in the literatur...
Preprint
p>Microwave hyperthermia (MH) requires the effective calibration of the antenna excitations for selective focusing of the microwave energy to the target region with a nominal effect on the surrounding tissue. To this end, many different antenna calibration methods such as optimization techniques and lookup tables have been proposed in the literatur...
Article
Full-text available
The open-ended coaxial probe (OECP) method is frequently used for the microwave dielectric property (DP) characterization of high permittivity and conductivity materials due to inherent advantages including minimal sample preparation requirements and broadband measurement capabilities. However, the OECP method is known to suffer from high measureme...
Article
Full-text available
The use of mobile phones is becoming widespread with the development of technology, and as a result, its effects on human health are becoming more and more important every day. Studies have reported that the electromagnetic field (EMF) emitted by mobile phones may have adverse effects on the biological systems. In order to evaluate the effect of zi...
Preprint
This study proposes a new method based on deep learning to determine whether the temperature values are at an appropriate level during the use of microwave hyperthermia method in the treatment of breast cancer. To implement our method, we utilize the temperature dependent dielectric properties of biological tissues to generate the heating scenarios...
Preprint
This study proposes a new method based on deep learning to determine whether the temperature values are at an appropriate level during the use of microwave hyperthermia method in the treatment of breast cancer. To implement our method, we utilize the temperature dependent dielectric properties of biological tissues to generate the heating scenarios...
Article
This work presents a new method to measure the complex dielectric permittivity (CDP) variation of materials under test (MUTs) with open-ended coaxial probes. The CDP variation of an MUT is a continuous function of frequency as modeled with various dielectric relaxation models. Hence, the accuracy and the repeatability of CDP measurements can be imp...
Article
Full-text available
This work presents a technique for dielectric property retrieval through Debye parameter reconstruction from open-ended coaxial probe (OECP) response. Debye parameters were obtained with the application of a deep learning (DL) model to the reflection coefficient response of the OECP when terminated with a material under test. The OECP was modelled...
Preprint
In the manuscript, we propose a new technique for determination of Debye parameters, representing the dielectric properties of materials, from the reflection coefficient response of open-ended coaxial probes. The method retrieves the Debye parameters using a deep learning model designed through utilization of numerically generated data. Unlike real...
Preprint
In the manuscript, we propose a new technique for determination of Debye parameters, representing the dielectric properties of materials, from the reflection coefficient response of open-ended coaxial probes. The method retrieves the Debye parameters using a deep learning model designed through utilization of numerically generated data. Unlike real...
Article
Mikrodalga frekanslarında sert ve yumuşak dokular arasındaki dielektrik özellik farkı yumuşak dokularin sert dokulardan ayrılması için kullanılanılabilme potansiyeline sahiptir. Biyolojik dokuların mikrodalga frekanslarda dielektrik özellikleri geleneksel olarak açık uçlu koaksiyel prob tekniği ile ölçülür. Bununla birlikle, doku heterojenitesi, ku...
Article
Full-text available
SAFE (Scan and Find Early) is a novel microwave imaging device intended for breast cancer screening and early detection. SAFE is based on the use of harmless electromagnetic waves and can provide relevant initial diagnostic information without resorting to X-rays. Because of SAFE’s harmless effect on organic tissue, imaging can be performed repeate...
Article
Full-text available
Microwave hyperthermia (MH) requires the selective focusing of microwave energy on the targeted region while minimally affecting the healthy tissue. Emerging from the simple nature of the linear antenna arrays, this work demonstrates focusing maps as an application guide for MH focusing by adjusting the antenna phase values. The focusing of the hea...
Article
Full-text available
Dielectric properties of biological materials are commonly characterized with open-ended coaxial probes due to the broadband and non-destructive measurement capabilities. Recently, potential diagnostics applications of the technique have been investigated. Although the technique can successfully classify the tissues with different dielectric proper...
Article
Full-text available
Dielectric properties of biological tissues are traditionally measured with open-ended coaxial probes. Despite being commercially available for laboratory use, the technique suffers from high measurement error. This prevents the practical applications of the open-ended coaxial probes. One such application is the utilization of the technique for ski...
Article
With the advancements in machine learning (ML) algorithms, microwave dielectric spectroscopy emerged as a potential new technology for biological tissue and material categorization. Recent studies reported the successful utilization of dielectric properties and Cole-Cole parameters. However, the role of the dataset was not investigated. Particularl...
Article
Full-text available
This work investigates the in vivo dielectric properties of healthy and benign rat mammary tissues in an attempt to expand the dielectric property knowledge of animal models. The outcomes of this study can enable testing of microwave medical technologies on animal models and interpretation of tissue alteration-dependent in vivo dielectric propertie...
Article
Full-text available
Open-ended coaxial probes can be used as tissue characterization devices. However, the technique suffers from a high error rate. To improve this technology, there is a need to decrease the measurement error which is reported to be more than 30% for an in vivo measurement setting. This work investigates the machine learning (ML) algorithms’ ability...
Article
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 li...
Conference Paper
Broadband dielectric property measurements of biological tissues is mostly performed with open ended coaxial probe technique due to a number of advantages such as flexible sample shape and size. However, the technique is known to suffer from high error rates; thus, envisioned applications of the technique remains hampered by this problem. One way t...
Article
The proper management of renal lithiasis presents a challenge, with the recurrence 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 cumberso...
Conference Paper
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 biological tissues have been quantified with open-ended contact probes method with the...
Article
Full-text available
This paper reviews non-invasive blood glucose measurements via dielectric spectroscopy at microwave frequencies presented in the literature. The intent is to clarify the key challenges that must be overcome if this approach is to work, to suggest some possible ways towards addressing these challenges and to contribute towards prevention of unnecess...
Conference Paper
Development of new modalities for breast cancer detection have been a research interest due to the drawbacks of existing diagnostic technologies such as imaging with ionizing waves. In particular, microwave imaging has been investigated in the literature as a new modality for breast cancer detection. Microwave imaging is a promising technique due t...
Article
Recent expansion of emerging Wireless Power Transfer (WPT) technology has not been followed by an adequate systematic approach to the magnetic couplers design. The relation between design parameters (mutual inductance, coupling coefficient, leakage field flux density, coil quality factor, etc.) and structural parameters (coils and ferrite shape, si...
Article
In the past decade, extensive research on dielectric properties of biological tissues led to characterization of dielectric property discrepancy between the malignant and healthy tissues. Such discrepancy enabled the development of microwave therapeutic and diagnostic technologies. Traditionally, dielectric property measurements of biological tissu...
Conference Paper
RF sensing of glucose dependent dielectric properties is emerging as an alternative non-invasive technique to the existing measurement methods. In this study, the dielectric properties of dextrose solutions are investigated with an open ended slim form dielectric probe in order to identify the most suitable frequency of operation for an RF sensor....
Article
This paper proposes a stochastic method - particle swarm optimization (PSO) and Pareto front technique, to conduct a multivariable optimization and design an inductively coupled power transfer system. Previously, design methods have been proposed which require designer experience; they are not only computationally challenging, but also frequently r...
Conference Paper
In this paper, a patch resonator is presented that operates in the Industrial, Scientific, Medical (ISM) band at 2.45–2.48 GHz, when placed on a four-layered (skin, fast, blood, and muscle) tissue. The patch resonator was simulated on a square digital phantom and, for a more realistic scenario, on the digital human phantom ‘Hugo’. To ensure that th...
Article
Tissue mimicking phantoms (TMPs) replicating the dielectric properties of wet skin, fat, blood, and muscle tissues for the 0.3 to 20 GHz frequency range are presented in this paper. The TMPs reflect the dielectric properties with maximum deviations of 7.7 units and 3.9 S/m for relative dielectric constant and conductivity, respectively, for the who...
Conference Paper
Recent activities at Queen Mary, University of London, relating to wearable wireless sensors research for healthcare applications are reviewed in this paper. The monitoring of blood glucose levels using non-invasive radio-based sensors is discussed. The analysis of on-body radio propagation channels is then presented, with an emphasis on variations...
Chapter
It has been recognised that body-centric communications (BCC) will play a significant role in 4G and subsequent technologies. BCC is an area of much interest globally, with applications in military, security, space, health care, sports and entertainment already identified. From a technical perspective, many of the problems encountered in BCC system...
Conference Paper
This paper presents a review of some current work conducted at Queen Mary University of London, related to antennas and propagation for body-centric wireless communications. Aspects related to measurement setup, numerical modelling, channel characteristics are briefly discussed. Applications and future trend of this research will be also presented.
Conference Paper
In this study, a patch resonator with two ports is proposed for retrieving the dielectric properties of biological tissues. The resonator is designed to operate in the 2.45 GHz Industrial, Scientific, and Medical band when placed on the tissue. CST Microwave Studio was used to simulate the structure with five layers of tissue above. Two via pins ar...
Conference Paper
In this paper, testing of an open ended spiral resonator for electrical property retrieval of biological tissues is presented. A spiral open ended resonator operating at 630 MHz when placed on human skin is tested with high water content phantoms. Phantoms are prepared by mixing water and flour and adding 5%, 10%, 15%, 20%, 25%, 30% sugar to the mi...
Conference Paper
In this paper, a patch resonator is proposed for non-invasive measurement of dielectric properties of biological tissues. Resonator is operating at 2.4 GHz when placed on tissue. The patch resonator is simulated in HFSS with four layered tissue mimicking material (skin, fat, blood, muscle) placed on top. The electrical properties of blood layer is...
Article
In this study, we present characterization of electrical properties through S parameter measurements of a sensor. Sugar and de-ionized water solutions with 10, 20, 30, 40, 50 percent by weight sugar is prepared and electrical properties of the solutions is measured with MCL slim dielectric probe kit [1]. An open ended transmission line is designed...
Conference Paper
The performance of a dipole antenna is evaluated for different distances from the human body by using the Method of Moments ( MoM ) in the 2.45 ISM band. This is done by considering the antenna in close vicinity to a homogeneous lossy cylinder and the calculated total radiated field around the body is validated through comparison with CST Microwave...
Article
Full-text available
The emergence of wireless technologies and advancements in on-body sensor design can enable change in the conventional health-care system, replacing it with wearable health-care systems, centred on the individual. Wearable monitoring systems can provide continuous physiological data, as well as better information regarding the general health of ind...
Conference Paper
In vitro testing is crucial to verify the proper functioning of the implantable antennas. In this work, we give the recipes of human fat and muscle mimicking gels for in-vitro testing of implantable antennas operating at Medical Implant Communication Service (MICS) and Industrial Scientific and Medical (ISM) bands. Approximate electrical properties...
Article
In this study, we present a simple recipe for a skin mimicking material intended for in vitro testing of implantable antennas operating at Industrial, Scientific, and Medical (ISM) (2.4 GHz2.48 GHz) band. The material is composed of de-ionized water, Triton X-100, and Diethylene Glycol Butyl Ether (DGBE). The relative dielectric constant and conduc...

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