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

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

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

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

Diseases in wild chimpanzees of the Taï National Park, Côte d Ivoire

Deckblatt-Impressum Inhaltsverzeichnis Abkürzungsverzeichnis Einleitung Literaturübersicht und Hintergrund Material und Methoden Ergebnisse Diskussion Ausblick Zusammenfassung Summary Anhang Literaturverzeichnis Danksagung Lebenslauf SelbständigkeitserklärungWenig ist bekannt über Vorkommen und Bedeutung von Krankheitserregern bei wild leben¬den Menschenaffen, während die Bedrohung der Tiere durch Krankheiten offensichtlich ist. In dieser Arbeit wurden über ein Jahr hinweg drei Gruppen von habituierten Schimpansen, die teilweise seit mehr als 17 Jahren unter menschlicher Beobachtung im Taï-Nationalpark (Côte d Ivoire) leben, gefolgt und systematisch Kot- und Urinproben gesammelt sowie Aufzeich¬nungen über klinisch auffällige Tiere angefertigt. Vier verstorbene Schimpansen und zwei Rote Stummelaffen wurden autopsiert und pathologisch begutachtet. Von zwei zusätzlichen Schimpansen konnten Muskelstücke gewonnen werden, wobei der Großteil dieser beiden Kadaver von Leoparden verzehrt worden war. Die Gewebeproben wurden in Zusammenarbeit mit dem Deutschen Primatenzentrum, Göttingen, histologisch untersucht. Die Proben der im Zeitraum der Felduntersuchungen verstorbe¬nen Tiere sowie einige zusätzliche Proben von Schimpansen, die vor überwiegend 2001 ver¬storben waren, wurden auf Infektionen mit verschiedenen Erregern akuter bzw. chroni¬scher Erkrankungen mit serologischen und molekularen Methoden untersucht. In sechs Fällen konnte anhand der molekularbiologischen Analysen sowie der pathologi¬schen und histologischen Beurteilung Bacillus anthracis als Todesursache identifi¬ziert werden. B. anthracis ist zwar in vielen Regionen Afrikas endemisch, wurde jedoch im Rahmen dieser Studie zum ersten Mal bei wild lebenden Menschenaffen diagnostiziert. Wo¬her der Erreger stammt und wie sich die Schimpansen infizieren konnten, wird Thema weite¬rer Studien sein. Des Weiteren konnte bei den Schimpansen neben anderen Viren eine ungewöhnliche Viel¬zahl unterschiedlicher STLV 1-Stämme festgestellt werden. Ein phylogenetischer Vergleich der Schimpansen-STLV 1-Stämme mit zwei Stämmen, die in Proben von Roten Stummel¬affen erfasst wurden, zeigte, dass Stämme der Stummelaffen teilweise näher mit den Schim¬pansen-STLV 1 verwandt waren als Stämme der Schimpansen untereinander. Da Schim¬pansen regelmäßig Rote Stummelaffen jagen und verzehren, kann hier eine Transspezies-Übertragung von STLV 1 von Beute auf Räuber postuliert werden. Auch Menschen in dieser und in vielen anderen Regionen Afrikas jagen und verzehren Affen; daher kann diese Trans¬spezies- Übertragung auch als Hinweis auf eine mögliche Übertragung auf den Menschen dienen und auf die Gefahren des Verzehrs von Affenfleisch hinweisen. Mit Hilfe eines modifizierten HTLV 1/2-Western Blots konnte die epidemiologische Verbrei¬tung von STLV 1 durch Antikörperbestimmung in Urinproben aller Mitglieder der 3 Schim¬pansengruppen untersucht werden. Derartige Untersuchungen ermöglichen, das Spektrum an neuen Erregern und Varianten bekannter Erreger abzuschätzen und damit sowohl einen Beitrag zum Schutz der bedrohten Menschenaffen als auch zum Erhalt der menschlichen Gesundheit zu leisten.While it is obvious that the survival of wild living primates is endangered, little is known about the prevalence of pathogens in these animals and their significance. In the present study three groups of habituated chimpanzees that had been living for more than 17 years under human observation in the Taï National Park (Côte d Ivoire) were observed and followed and samples of their feces and urine were collected systematically for 13 months. Also detailed observations of animals with clinical symptoms were recorded. Four dead chimpanzees and two western red colobus monkeys underwent autopsy and pathological examination. Samples of muscular tissue could be obtained from two additional chimpanzees although the main part of those two cadavers had been consumed by leopards. The tissue samples were investigated histologically in cooperation with the German Primate Center at Göttingen/Germany. Samples from individuals that had died within the time frame of the field studies were analysed for a range of pathogens causing acute or chronic diseases, as well as several additional samples from chimpanzees that had died before 2001 using serological and molecular methods. In six cases the cause of death could be identified unambiguously as an infection with Bacillus anthracis. While B. anthracis is endemic in many African regions, it was diagnosed for the first time in the context of the present study in wild-living primates. The question about the origin of the pathogen and the route of infection for these chimpanzees will be the focus of further studies. In addition to other viruses, an unusual diversity of different STLV 1 strains could be determined in the chimpanzees. A phylogenetic comparison of the chimpanzee STLV 1 strains with two strains that had been found in red colobus monkeys showed a closer relatedness of the colobus with the chimpanzee strains than that of the chimpanzee strains among each other. Since chimpanzees routinely hunt and consume red colobus monkeys, transspecies transmission of STLV 1 from prey to the hunter could be postulated. In these and other African regions, humans also hunt and consume monkeys, therefore such a transspecies transmission event might also suggest a possible transmission to humans and point towards the risks involved in consuming bushmeat from monkeys. Using a modified HTLV 1/2 Western Blot, the prevalence of STLV 1 could be investigated by determining the antibody status in urine samples from all members of the three chimpanzee groups. It becomes possible by such investigations to assess the range of emerging and variations of well-known pathogens and thereby to contribute to protect endangered primates as well as protect the health of the human population

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

Microwave Radar-Based Breast Cancer Detection:Imaging in Inhomogeneous Breast Phantoms

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