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Medical Microwave Imaging and Analysis
Published in de Azevedo-Marques Paulo Mazzoncini, Mencattini Arianna, Salmeri Marcello, Rangayyan Rangaraj M., Medical Image Analysis and Informatics: Computer-Aided Diagnosis and Therapy, 2018
Rohit Chandra, Ilangko Balasingham, Huiyuan Zhou, Ram M. Narayanan
Microwave Imaging is an imaging technique using nonionizing electromagnetic (EM) signals in the frequency range of hundreds of megahertz to a few gigahertz. It is emerging as an alternative imaging technique to the aforementioned medical imaging techniques due to several advantages. As it uses nonionizing, low power EM signals, it is a low health-risk method. Moreover, the microwave imaging equipment consists of a microwave source, a receiver, an antenna-array for transmitting the signals, and a radiofrequency switch to switch between different antenna elements in the antenna-array. This equipment usually costs a fraction of the cost of the equipment for other diagnostic methods, making the microwave imaging a cost-effective technique. Moreover, the equipment is portable and can fit inside an ambulance for fast diagnosis of life-threatening conditions, like stroke while a patient is still on the way to the hospital [3]. However, there are some disadvantages and challenges for medical microwave imaging. The biggest disadvantage is that the images obtained from microwave imaging are low spatial resolution images.
Radar for Disease Detection and Monitoring
Published in Moeness G. Amin, Radar for Indoor Monitoring, 2017
Huiyuan Zhou, Ram M. Narayanan, Ilangko Balasingham, Rohit Chandra
Microwave imaging of the human body, such as human breast, head, and intestine, for tumor and other disease detection has been a topic of interest for several decades. Its advantages include nonionizing and low-risk nature of microwave signals at low levels, low-cost implementation of practical systems, and the exploitation of high dielectric contrast between normal and abnormal human tissue (Rosen et al. 2002). Signals in the microwave frequency range are able to penetrate the human body and are able to collect useful information for detection and imaging of anomalies. Frequencies up to 4 GHz can penetrate skin, tissues, and clothing and can ease the requirement for the preferred half-wavelength spacing when architecting aperture antenna arrays (Zhuge et al. 2008). Good down-range resolution requires a wide operational bandwidth, whereas good cross-range resolution requires large physical or synthetic aperture.
Overlapped stepped frequency train of flam pulses for microwave imaging
Published in Kennis Chan, Testing and Measurement: Techniques and Applications, 2015
K.V. Nikitin, A. Dewantari, S.Y. Jeon, T.Y. Lee, S. Kim, J. Yu, M.H. Ka
Presently, there is a significant growth of interest in high-resolution microwave imaging systems for non-destructive studying of composed objects. The most successful experiments were made using ultra wideband pulsed signals [1, 2] and continuous wave stepped frequency (CWSF) signals [3, 4, 5, 6]. Recently, implementations of a synthetic bandwidth technique have been reported in [7, 8]. One of the important components of a microwave imaging system is a high-resolution short-range radio ranging unit, which includes the signal forming and processing part, transceiver, and antenna subsystem. For practical applications, the ranging unit must handle the signals which satisfy the following requirements: 1 2 3 4 5 High range resolution (1 cm and better); Short minimum detection range (below 1 m); Unambiguous range measurement; Safety to biological objects and living tissues; Robustness to unintentional jamming.
Breast Tissue Tumor Analysis Using Wideband Antenna and Microwave Scattering
Published in IETE Journal of Research, 2021
Vanaja Selvaraj, Divya Baskaran, P.H. Rao, Poonguzhali Srinivasan, Rahul Krishnan
Studies have shown that breast cancer is the second leading cause of cancer death among women. Early detection and early treatment is the only solution. X-ray mammogram is currently the most popular diagnostic tool for breast cancer detection. Various reports show that this method involves high false-negative rates and -positive rates. It is attributed to small intrinsic contrast between normal and malignant breast tissues in X-ray frequencies. This procedure also involves the use of ionizing radiation and breast compression. Many researchers have proposed that there exists a significant dielectric constant contrast between the normal and malignant tissue in microwave frequencies, even in early stages [1]. Microwave imaging technique does not involve any ionizing radiation and breast compression, so it can be used as a very effective alternative to X-ray mammography.
A novel gain enhanced Vivaldi antenna for a breast phantom measurement system
Published in Electromagnetics, 2023
Hüseyin Özmen, M. Bahaddin Kurt
Radar systems have attracted the interest of many researchers since they have recently become a very critical tool in military, GPS, satellite technology, meteorology, biomedical applications, etc (Skolnik 2001). One important example to biomedical applications is detection and screening of breast cancer by microwave imaging technique (Li and Hagness 2001). According to estimates, in the USA in 2022, breast cancer among women has the highest incidence rate with 31% and the second highest mortality rate with 15% among other cancer types (Siegel et al. 2022). However, with early detection, the disease can be cured. Therefore, early detection methods are of great importance. Today, the most used method for early diagnosis screening is X-ray mammography. However, X-rays used in mammography are ionizing and can be dangerous for human health. For this reason, the development of a microwave imaging (MWI) method that does not use ionizing waves has gained great importance. Microwave imaging is divided into two as microwave tomography and radar-based microwave imaging. Radar systems are used to detect range and velocity of certain targets. In order to detect range and position of a certain target pulsed radars are used. Pulsed radar is composed of signal transmitting, receiving and signal processing units. Signal generators creates pulse signal, and this pulse is emitted by transmitter antenna and backscattered signal received by receiving antenna. Then receiving antenna transfers this signal to the signal processing unit to detect range between radar system and scatterer object. An important use of pulsed radar is detection of tumor in the breast. Breast tumors have relatively bigger permittivity and conductivity according to healthy tissue. By this way, when electromagnetic wave impinges in the breast, tumors make bigger scattering than healthy tissues. After signal processing techniques, only backscattered signal from tumor can be extracted. Therefore position of tumors can be detected (Hagness, Taflove, and Bridges 1998). As the bandwidth of the pulse used increases, its duration becomes shorter and a narrower pulse is obtained. Use of short-duration pulse increases the resolution of the image in radar-based microwave imaging applications. Thus, the tumor location can be found more accurately. In this study, a high-gain ultra-wide band (UWB) antenna covering the entire frequency band of 3.1–10.6 GHz, which the Federal Communications Commission (FCC) allows for unlicensed use, is proposed for this aim.