Azuwa Ali

The Use of a Human Body Model to Determine the Variation of Path Losses in the Human Body Channel in Wireless Capsule Endoscopy

Presently, wireless capsule endoscopy (WCE) is the sole technology for inspecting the human gastrointestinal (GI) tract for diseases painlessly and in a non-invasive way. For the further development of WCE, the main concern is the development of a high- speed telemetry system that is capable of transmitting high-resolution images at a higher frame rate, which is also a concern in the use of conventional endoscopy. A vital task for such a high-speed telemetry system is to be able to determine the path loss and how it varies in a radio channel in order to calculate the proper link budget. The hostile nature of the human bodys channel and the complex anatomical structure of the GI tract cause remarkable variations in path loss at difierent frequencies of the system as well as at capsule locations that have high impacts on the calculation of the link budget. This paper presents the path loss and its variation in terms of system frequency and location of the capsule. Along with the guideline about the optimum system frequency for WCE, we present the difierence between the maximum and minimum path loss at difierent anatomical regions, which is the most important information in the link-margin setup for highly e-cient telemetry systems in next-generation capsules. In order

Development Of Pyramidal Microwave Absorber Using Sugar Cane Bagasse (SCB)

The need to flnd ways to efiectively utilize the large quantities of agricultural waste that are produced is indicative of the huge potential associated with producing an alternative pyramidal microwave absorber for anechoic chamber-testing applications. We propose the development of a pyramidal microwave absorber that can use sugar cane bagasse (SCB), a byproduct from the production and processing of sugar cane, as the absorbent. In this paper, we report the results of our use of dielectric probe measurement to determine the dielectric constant and loss tangent of SCB. These values were used to model and simulate an SCB pyramidal microwave absorber in Computer Simulation Technologys (CSTs) Microwave Studio. This absorber was operated in the microwave frequency range between 0.1GHz and 20.0GHz.

Modified cuckoo search algorithm in weighted sum optimization for linear antenna array synthesis

In this study, we proposed a bio-inspired technique known as modified cuckoo search (MCS)-based weighted sum algorithm towards synthesizing symmetric linear array geometry with minimum side lobe level (SLL) and/or nulls control. The newly evolved metaheuristic algorithm was primarily based on the natural obligate brood parasitic behavior of some cuckoo species in combination with the Lévy flight behavior of some birds and fruit flies. Through the integration with the Roulette wheel selection operator and the inertia weight controlling the position (solution) exploration, the MCS-based weighted sum approach optimized concurrently the array element excitation locations, amplitudes, and phases within the uniform pattern and Dolph-Chebyshev window, respectively. The optimal solutions obtained were then compared against the conventional (with λ/2 inter-element distance) and other chosen evolutionary algorithms-based arrays.

A Novel, High-Speed Image Transmitter for Wireless Capsule Endoscopy

Wireless capsule endoscopy (WCE) was developed as a painless diagnostic tool for endoscopic examination of the gastrointestinal (GI) tract, but, to date, the low operating power of the capsule and the high data rate of the RF telemetry system are still key concerns. Innovative, novel solutions must be developed to address these concerns before WCE can be used extensively in clinical applications. In this paper, we propose a novel RF transmitter for WCE applications that only requires 1.5V to transmit the required data as opposed to using a DC power supply. Our proposed, direct- conversion transmitter system consists of a current reuse oscillator, an envelope fllter, and an L-section matching network. The oscillator is powered by the transmitting data which keep the oscillator in turned on and ofi for the transmitting 1 and 0bit respectively and results in the on-ofi keying (OOK) of the modulated signal at the output of the oscillator. The rate of data transmission at the modulated signal is limited by the transient period of the oscillator start-up. When the start-up time of the oscillator is optimized, an OOK modulation rate of 100Mb/s can be attained. In order to eliminate the oscillator decay noise, we used an envelope fllter connected in series with the oscillator to fllter out the decay part of the oscillation. Finally, the output impedance of the envelope fllter is matched to the 50-› antenna with an L-section, low-pass, matching network to ensure maximum

Effect of different substrate materials on a wearable textile monopole antenna

In this paper the investigation of the effect using different substrate materials on a textile monopole antenna is discussed. This textile monopole antenna is designed to be used for Body-Centric Wireless Communications (BCWC) at 2.45 GHz. Three types of non-conductive materials were selected: felt, fleece and foam. The textile monopole was benchmarked against a conventional FR-4 monopole antenna. The results demonstrated a good agreement between simulated return loss of all three substrates used for textile monopole antenna and conventional monopole antenna. The felt-based textile monopole antenna offered higher return loss compared to other substrates and conventional monopole antenna. Moreover, the substrate materials gained bandwidths of up to 1000 MHz in free space where fleece fabric produced broader bandwidth compared to other substrates. The simulated gain characteristics for all three types of substrates agreed reasonably well with conventional monopole antenna.

Reduced Complexity Optimum Detector for Block Data Transmission System Using An Lattice Sphere Detection Technique

Block Data Transmission Systems (BDTS) are used in high speed wireless communication systems with time dispersive channel characteristics. Since Maximum Likelihood Block Detection (MLBD) requires huge amount of computation, Sphere Detection (SD) technique has been introduced as an alternative. This paper proposes an An Lattice Sphere Detection (AnLSD) technique for detection in block data transmission systems (BDTS). The An lattice structure offers more dense constellation points than the customary Zn lattice in SD technique. Thus, the proposed AnLSD uses An lattice generator matrix as the channel matrix, and uses the Gram matrix which is obtained from the generator matrix as part of the detection process. Simulation results show that the proposed AnLSD performs very close to the Exhaustive search (ES) using block size of 20 bits. It is also performing better than the other renowned methods tested under a channel with spectral nulls. The proposed AnLSD technique offers significant reduction in term of objective functions evaluation as compared to the other renowned methods.

Frequency selective surface for enhance WLAN applications

This paper proposes the deployment of frequency selective surface (FSS) structure in WLAN device. Objectives to create a band pass square-loop filter FSS in WLAN device to increase the received signal strength of WLAN signal 2.4GHz. FSS works to enhance the 2.4 GHz signal and attenuate the rest signal other than 2.4 GHz. The WLAN signals increasing more than 50 % when pass through the FSS structure.

Defect Segmentation of Semiconductor Wafer Image Using k-Means Clustering

Nowadays, quality control becomes an important issue in semiconductor manufacturing industry. The rate of production with respect to time gives a lot of issues in the industry. In most semiconductor assemblies, a lot of defects generated from various processes in semiconductor wafer manufacturing need to be inspected manually using human experts and this process required full concentration of the operators. This human inspection procedure, however, is time consuming and highly subjective. In order to overcome this problem, implementation of machine vision will be the best solution. This paper presents defect segmentation of semiconductor wafer image based on colour features with k-Means clustering algorithm which can be adopted in machine vision system. In this work, the segmentation process is carried out in two stages. The first stage comprised of clustering the pixels in the image based on their colour and spatial features. Then the clustered pixels are merged to a specific number of regions. The proposed approach is being evaluated using defected wafer image. The experimental results show that it can be used to segment the defect correctly. By using this method, it is possible to increase the computational efficiency since it will avoid feature extraction for every pixel in the image.

Matlab Simulink Simulation of Respiratory Effort Energy Harvester Using Electromagnetic Generator

Electromagnetic generator as respiratory effort energy harvester is designed as a renewable energy source to generate a low power and exploiting human motion to extract energy. By selecting respiratory effort as energy harvester it can be carried out 24 hours as long as the electromagnetic generator is wearing on the human chest. It is because the electromagnetic generator functions when there is a motion of the chest wall. The electromagnetic generator basically constructed with two miniature dc motor generator, pulley, belt, gear and chest belt. The generator operates when there is change in chest wall circumstance during exhalation breathing process. The low power that produces can be apply on low power devices such as sensor or microcontroller. Simulation is done using Matlab Simulink to verify that respiratory effort able to produce the minimum required power to power up low power devices. Result from the simulation showing good outcome with 2.5mW of output power.

Parametric studies of bismuth titanate (BiT) microstrip patch array antenna

A design of a 2×3 ceramic microstrip patch array antenna with a 50 Ω microstrip transmission line feed is presented. The antenna was designed to operate at the Worldwide Interoperability for Microwave Access (WiMAX) application. The proposed ceramic which was Bismuth Titanate (BiT) was designed in rectangular form, with high dielectric constant of 21. Simulation using CST Microwave Studio has been carried out in order to verify this design. Due to high dielectric constant values, BiT elements on antenna had been tested as building blocks for miniaturized antenna solutions. The various dimensions of the BiT for both branching strips and radiating patches were investigated and found that different sizes of BiT lead to different resonant frequency. The simulation results were in good agreement with the desired frequency band of 2.3-2.5 GHz.