Sawsan Sadek

A Modified Bowtie Antenna Design for Wi-Fi and WiMAX Applications

This paper presents a new approach for the design of a multi-band bowtie antenna. By incorporating slots with different shapes and sizes on the arms of the bowtie, resonance is obtained in the 2.4 GHz, 3.5 GHz, and 5 GHz bands corresponding to Wi-Fi 802.11a, 802.11b, 802.11g , 802.11n, and WiMAX 802.16-2004 standards. A study of the effect of circular and triangular slots, their size and their location on the return loss of the antenna is presented. The designed antenna enjoys advantages such as low profile, low cost of fabrication, and high radiation efficiency.

A wireless microwave sensor for remote monitoring of heart and respiration activity

The aim of this paper is to present a new microwave contactless sensor for heartbeat and respiration activities. The system is operating on 9 GHz. Its composed of two parts: a hardware one based on Doppler radar with a Digital Multimeter, and a software one based on the acquisition of the signals and the separation of the 2 informations of heartbeat and respiratory signals using simple filtering method with Labview.

Contact-less measurement system for cardiopulmonary activity

This paper presents a wireless cardiopulmonary activity measurement system. This system generates a continuous wave toward a persons chest set at a distance of 1 m, then reflected to the system. Using a vector network analyzer, the phase of S21 is computed. The phase variation of S21 contains information about cardiopulmonary activity. Several processing techniques are used to separate heartbeat signal from cardiorespiratory signal either in frequency or in temporal domain. The measurements were performed simultaneously with a PC-based electrocardiogram to validate the heartbeat rate detection techniques. In conclusion, processing techniques used in this paper give accurate results.

Microstrip back-cavity Hilbert Fractal Antenna for experimental detection of breast tumors

This paper presents a miniaturized microstrip back-cavity Hilbert Fractal Antenna specifically designed for breast cancer detection. This antenna is used to investigate on the possibility of detecting the presence of breast tumors by directly measuring the shift of the antenna resonance frequency. First, simulations are performed on a multi-layer breast model; then the proposed approach was applied for in vivo measurements on two different patients diagnosed with breast cancer, followed by ex vivo characterization of the electrical properties of excised tumors.

A UWB antenna in direct breast contact for cancer detection

In this paper, a Ultra-Wide-Band (UWB) antenna of dimensions 3cm × 3cm, designed to be used in direct contact with the breast is presented. The breast phantom model, on which the antenna was designed, consists of four layers (skin, fat, glandular tissues and muscle with their specific thicknesses) taking into account the dielectric properties for each layer and their dependence versus frequency. The antenna has been optimized for many reasons: enhance the matching to the human body and maximize the transfer of energy into the breast phantom to increase the detection potential.

Position-Free Vital Sign Monitoring: Measurements and Processing

As traditional electrodes are perturbing for patients in critical cases such as for burn victims or newborn infants, and even to detect life sign under rubble, a contactless monitoring system for the life signs is a necessity. The aim of this chapter is to present a complete process used in detecting cardiopulmonary activities. This includes a microwave Doppler radar system that detects the body wall motion and signal processing techniques in order to extract the heartbeat rate. Measurements are performed at different positions simultaneously with a PC-based electrocardiogram (ECG). For a distance of 1 m between the subject and the antennas, measurements are performed for breathing subject at four positions: front, back, left, and right. Discrete wavelet transform is used to extract the heartbeat signal from the cardiopulmonary signal. The proposed system and signal processing techniques show high accuracy in detecting the cardiopulmonary signals and extracting the heartbeat rate.

Miniature antenna for breast tumor detection

Microwave imaging is recognized as a potential candidate for biomedical applications, such as breast cancer detection. In this context a miniature antenna is used for quantitative imaging of inhomogeneous tissues. Microwave breast imaging (MBI) uses low power and longer wavelength signals to obtain information about breast tissues, and promises a safer and more accurate modality for regular breast scanning. This paper presents a miniature microstrip antenna that can be placed in contact with the breast model to investigate the presence of malignant tissues. A miniature antenna has been designed, and placed toward a breast phantom model with inhomogeneous tissues. Images are successfully obtained by using scattering electromagnetic waves (S11) from the designed model. The antenna was then manufactured and tested.

Investigation of tumor using an antenna scanning system

The physical basis for tumor detection with microwave imaging is the contrast in dielectric properties of normal and malignant tissues. Confocal microwave imaging involves illuminating the target with propagating electromagnetic waves using an antenna, and then synthetically focusing reflections from the target. The detection of malignant tumors is achieved by the coherent addition of returns from these strongly scattering objects. In this paper, we demonstrate the feasibility of detecting and localizing small (<;1 cm) tumors or inhomogeneous cells using a radiating patch antenna.

Investigation of Kidney Stone Using a Microstrip Patch Antenna Scanning System

The abnormalities of the kidney can be identified by ultrasound imaging. The kidney may have structural abnormalities like kidney swelling, or change in its position and appearance. Kidney abnormality may also arise due to the formation of stones, congenital anomalies, blockage of urine etc. For surgical operations it is very important to identify the exact and accurate location of stone in the kidney. The ultrasound images are of low contrast and contain speckle noise and could affect human body in some situations like pregnancy. This makes the detection of kidney abnormalities rather challenging task. Thus, microwave imaging could be a good alternative. A microstrip patch antenna scanning system allows to identify the exact and accurate location of stone in the kidney. A physical testing system will be developed in order to generate antenna response surfaces on material which could represent the human body. The serum is used in the experimental measurement because it has similar dielectric properties as human body. In order to represent stone presence in an homogenous medium, small calcium sto ne bearings of different sizes embedded are used to simulate the abnormality. Compact microstrip patch antenna were designed and tested at different frequencies in ISM band : 2.26 GHz, 2.38 GHz, 2.5 GHz, and 2.62 GHz for the RF investigation imaging system in order to detect and localize stones in the kidney.