289 research outputs found
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Breast tumour detection using a flat 16 element array
A new experimental prototype of a breast cancer detection technique using real aperture multi-static radar is presented. The system comprises a fully-populated 16 element flat array and an associated system to switch between different transmit and receive elements. 3D images are produced using backscatter signals from a synthetic breast phantom. After suppression of skin reflections, initial images demonstrate the successful detection of 4-mmdiameter tumours
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Breast cancer tumour detection using microwave radar techniques
A breast cancer detection technique using multi-static radar is proposed herein. Images of a breast tumour are produced using this technique, with backscatter data. A wideband antenna design suitable for a breast cancer detection system is also described. Practical measurements are performed using a network analyser and a pair of antennas that are used to simulate an array. These initial images demonstrate the successful detection of a tumour phantom immersed in a liquid phantom with similar dielectric properties as the breast tissues
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Microwave detection of breast tumours
Copyright @ 2003 European Bioelectromagnetics Association
Numerical analysis of microwave detection of breast tumours using synthetic focussing techniques
Microwave detection of breast tumours is a non-ionising and potentially low-cost and more certain alternative to X-ray mammography. Analogous to ground penetrating radar (GPR), microwaves are transmitted using an antenna array and the reflected signals, which contain reflections from tumours, are recorded. The work presented here employs a post reception synthetically focussed detection method developed for land mine detection (R. Benjamin et al., IEE Proc. Radar, Sonar and Nav., vol. 148, no.4, pp. 233-40, 2001); all elements of an antenna array transmit a broadband signal in turn, the elements sharing a field of view with the current transmit element then record the received signal. By predicting the path delay between transmit and receive antennas via any desired point in the breast, it is then possible to extract and time-align all signals from that point. Repeated for all points in the breast, this yields an image in which the distinct dielectric properties of malignant tissue are potentially visible. This contribution presents a theoretical evaluation of the breast imaging system using FDTD methods. The FDTD model realistically models a practical system incorporating wide band antenna elements. One major challenge in breast cancer detection using microwaves is the clutter arising from skin interface. Deeply located tumours can be detected using windowing techniques (R. Nilavalan et al., Electronics Letters, vol. 39, pp. 1787-1789, 2003); however tumours closer to the skin interface require additional consideration, as described herein
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Wideband microstrip patch antenna design for breast cancer tumour detection
A patch antenna is presented which has been designed to radiate into human breast tissue. The antenna is shown by means of simulation and practical measurement to possess a wide input bandwidth, stable radiation patterns and a good front-to-back ratio. Consideration is also given to its ability to radiate a pulse, and in this respect it is also found to be suitable for the proposed application
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Experimental investigation of real aperture synthetically organised radar for breast cancer detection
Breast cancer is the most common cancer in woman, and early detection increases the likelihood of successful treatment and long-term survival screen film mammography is currently the most effective method for detecting breast tumours, however this technique suffers from relatively high false negative and positive detection rates, and it involves uncomfortable compression of the breast. This paper presents the experimental investigation of real aperture synthetically organised radar for breast cancer detection. The work presented herein originated as a theoretical study employing FDTD models. This contribution presents subsequent experimental validation using a mechanically-scanned 2 element antenna array and a breast phantom consisting of synthetic biological materials
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A wideband planar antenna for in-body imaging
Breast cancer is the most common cancer in women. X-ray mammography is currently the most effective detection technique, however it suffers from a relatively high missed- and false-detection rates, involves uncomfortable compression of the breast and also entails exposure to ionizing radiation. Microwave detection of breast tumours is a potential non-ionising alternative being investigated by a number of groups. In these microwave-based systems, in a similar fashion to ground penetrating radars, microwaves are transmitted from an antenna or antenna array, and the received signals, which contain reflections from tumours, are recorded and analysed. A pre-requisite for all of these systems is a suitable antenna. This contribution presents in detail for the first time, an inexpensive, wideband, planar antenna design, specifically designed to radiate into breast tissue
A novel Coltivirus-related virus isolated from free-tailed bats from CĂŽte dâIvoire is able to infect human cells in vitro
Background: Zoonotic transmission events play a major role in the emergence of
novel diseases. While such events are virtually impossible to predict,
wildlife screening for potential emerging pathogens can be a first step.
Driven by recent disease epidemics like severe acute respiratory syndrome
(SARS), Middle East respiratory syndrome (MERS), and Ebola, bats have gained
special interest as reservoirs of emerging viruses. Methods: As part of a
bigger study investigating pathogens in African bats we screened animals for
the presence of known and unknown viruses. Results: We isolated and
characterised a novel reovirus from blood of free-tailed bats (Chaereophon
aloysiisabaudiae) captured in 2006 in CĂŽte dâIvoire. The virus showed closest
relationship with two human pathogenic viruses, Colorado tick fever virus and
Eyach virus, and was able to infect various human cell lines in vitro.
Conclusion: The study shows the presence of a coltivirus-related virus in bats
from Sub-Sahara Africa. Serological studies could help to assess its impact on
humans or wildlife health
No evidence for transmission of SIVwrc from western red colobus monkeys (piliocolobus badius badius) to wild west african chimpanzees (pan troglodytes verus) despite high exposure through hunting
<p>Abstract</p> <p>Background</p> <p>Simian Immunodeficiency Viruses (SIVs) are the precursors of Human Immunodeficiency Viruses (HIVs) which have lead to the worldwide HIV/AIDS pandemic. By studying SIVs in wild primates we can better understand the circulation of these viruses in their natural hosts and habitat, and perhaps identify factors that influence susceptibility and transmission within and between various host species. We investigated the SIV status of wild West African chimpanzees (<it>Pan troglodytes verus) </it>which frequently hunt and consume the western red colobus monkey (<it>Piliocolobus badius badius</it>), a species known to be infected to a high percentage with its specific SIV strain (SIVwrc).</p> <p>Results</p> <p>Blood and plasma samples from 32 wild chimpanzees were tested with INNO-LIA HIV I/II Score kit to detect cross-reactive antibodies to HIV antigens. Twenty-three of the samples were also tested for antibodies to 43 specific SIV and HIV lineages, including SIVwrc. Tissue samples from all but two chimpanzees were tested for SIV by PCRs using generic SIV primers that detect all known primate lentiviruses as well as primers designed to specifically detect SIVwrc. Seventeen of the chimpanzees showed varying degrees of cross-reactivity to the HIV specific antigens in the INNO-LIA test; however no sample had antibodies to SIV or HIV strain - and lineage specific antigens in the Luminex test. No SIV DNA was found in any of the samples.</p> <p>Conclusions</p> <p>We could not detect any conclusive trace of SIV infection from the red colobus monkeys in the chimpanzees, despite high exposure to this virus through frequent hunting. The results of our study raise interesting questions regarding the host-parasite relationship of SIVwrc and wild chimpanzees in their natural habitat.</p
Evaluation of Two Approaches for Breast Surface Measurement Applied to a Radar-Based Imaging System
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