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Knowledge based system with embedded intelligent heart sound analyser for diagnosing cardiovascular disorders

Journal of Medical engineering and Technology 2007年第5期31卷 341-350页

作者： Javed, F. Venkatachalam, P.A. Hani, A.F.M. Signal and Image Processing and Tele-medicine Technology Research Group Electrical and Electronics Engineering Programme Universiti Teknologi PETRONAS 31750 Tronoh Perak Malaysia

Cardiovascular disease (CVD) is the leading cause of death worldwide, and due to the lack of early detection techniques, the incidence of CVD is increasing day by day. In order to address this limitation, a knowledge based system with embedded intelligent heart sound analyser (KBHSA) has been developed to diagnose cardiovascular disorders at early stages. The system analyses digitized heart sounds that are recorded from an electronic stethoscope using advanced digital signal processing and artificial intelligence techniques. KBHSA takes into account data including the patient's personal and past medical history, clinical examination, auscultation findings, chest x-ray and echocardiogram, and provides a list of diseases that it has diagnosed. The system can assist the general physician in making more accurate and reliable diagnosis under emergency conditions where expert cardiologists and advanced equipment are not readily available. To test the validity of the system, abnormal heart sound samples and medical data from 40 patients were recorded and analysed. The diagnoses made by the system were counter checked by four senior cardiologists in Malaysia. The results show that the findings of KBHSA coincide with those of cardiologists. © 2007 Informa UK Ltd.

关键词： Intelligent systems

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A Multi-Resolution Mean Field Annealing Algorithm for Motion Estimation in Medical CT image Sequences

A Multi-Resolution Mean Field Annealing Algorithm for Motion...

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International Symposium on signals, Circuits and Systems (ISSCS)

作者： Cristian Grava Vasile Buzuloiu Bertrand Augereau Christine Fernandez-Maloigne Department of Electronics Faculty of Electrical Engineering and Information Technology Oradea Romania Image Processing and Analysis Laboratory Politehnica University of Bucharest Romania Signal Image Communication Laboratory University of Poitiers France

The paper describes a multi-resolution mean field annealing (MFA) algorithm to solve the motion estimation problem in medical image sequences. The proposed algorithm ensures a satisfying trade-off between precision and computational time, in other words, it ensures a good efficiency when compared to other deterministic algorithms and also stochastic ones. The results are compared in terms of precision and computational time with those of other basic algorithms, such as the basic block-matching and Horn & Schunck algorithm. The results are illustrated on CT medical image sequences.

关键词： Annealing Motion estimation Biomedical imaging Computed tomography image sequences Stochastic processes Pixel Equations image motion analysis Laboratories

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Opportunistic Access with Random Subchannel Backoff (OARSB) for OFDMA Uplink

Opportunistic Access with Random Subchannel Backoff (OARSB) ...

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IEEE GLOBECOM 2007 - IEEE Global Telecommunications Conference

作者： Yu-Jung Chang Feng-Tsun Chien C.-C. Jay Kuo Ming Hsieh Department of Electrical Engineering and Signal and Image Processing Institute University of Southern California Los Angeles CA USA Department of Electronics Engineering National Chiao Tung University Taiwan

A distributed medium access control (MAC) algorithm for uplink OFDMA networks under the IEEE 802.16 framework is proposed and analyzed in this work. We present a simple yet efficient algorithm to enhance the system throughput by integrating opportunistic medium access and collision resolution through random subchannel backoff. Consequently, the resulting algorithm is called the opportunistic access with random subchannel backoff (OARSB) scheme. OARSB not only achieves distributed coordination among users but also reduces the amount of information exchange between the base station and users. The throughput and delay performance analysis of OARSB is conducted using a Markov chain model. The superior performance of OARSB over an existing scheme is demonstrated by analysis as well as computer simulation.

关键词： Throughput Base stations Downlink Bandwidth Performance analysis Channel allocation Switches signal processing image processing USA Councils

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Multiplication-Free One-Bit Transform and Diamond Search Combination for Fast Binary Block Motion Estimation

Multiplication-Free One-Bit Transform and Diamond Search Com...

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IEEE signal processing and Communications Applications (SIU)

作者： Eun-Seo Lee Oguzhan Urhan Tae-Gyu Chang School of Electrical and Electronics Engineering Chung-Ang University Seoul South Korea Kocaeli University Laboratory of Image and Signal Processing (KULIS) Electronics and Telecom. Eng. Dept Kocaeli University Istanbul Turkey

Combination of multiplication-free one-bit transform based block estimation with the diamond sparse search pattern is presented is this paper. Unification of sparse search patterns with low-bit representation motion estimation methods are rarely investigated and therefore one-bit transform based approaches are executed using full-search approach mostly. Our experiments show that such a combination can be carried out with acceptable performance fall.

关键词： Motion estimation Video compression Band pass filters image coding Video coding Filtering Laboratories signal processing Telecommunications Aging

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LANDING AN UNMANNED AIR VEHICLE: VISION BASED MOTION ESTIMATION AND NONLINEAR CONTROL

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Asian Journal of Control 2008年第3期1卷

作者： Omid Shakernia Yi Ma T. John Koo Shankar Sastry Dept. of Electrical Engineering & Computer Science University of California at Berkeley Berkeley CA94720-1774 U.S.A. Tak-Kuen John Koo received the B.Eng. degree in 1992 in Electronic Engineering and the M.Phil. in 1994 in Information Engineering both from the Chinese University of Hong Kong. From 1994 to 1995 he was a graduate student in Signal and Image Processing Institute at the University of Southern California. He is currently a Ph.D. Candidate in Electrical Engineering and Computer Sciences at the University of California at Berkeley. His research interests include nonlinear control theory hybrid systems inertial navigation systems with applications to unmanned aerial vehicles. He received the Distinguished M.Phil. Thesis Award of the Faculty of Engineering The Chinese University of Hong Kong in 1994. He was a consultant of SRI International in 1998. Currently he is the team leader of the Berkeley AeRobot Team and a delegate of The Graduate Assembly University of California at Berkeley. He is a student member of IEEE and SIAM. S. Shankar Sastry received his Ph.D. degree in 1981 from the University of California Berkeley. He was on the faculty of MIT from 1980-82 and Harvard University as a Gordon McKay professor in 1994. He is currently a Professor of Electrical Engineering and Computer Sciences and Bioengineering and Director of the Electronics Research Laboratory at Berkeley. He has held visiting appointments at the Australian National University Canberra the University of Rome Scuola Normale and University of Pisa the CNRS laboratory LAAS in Toulouse (poste rouge) and as a Vinton Hayes Visiting fellow at the Center for Intelligent Control Systems at MIT. His areas of research are nonlinear and adaptive control robotic telesurgery control of hybrid systems and biological motor control. He is a coauthor (with M. Bodson) of “Adaptive Control: Stability Convergence and Robustness Prentice Hall 1989.” and (with R. Murray and Z. Li) of “A Mathematical Introduction to Robotic Manipulati

In this paper, we use computer vision as a feedback sensor in a control loop for landing an unmanned air vehicle (UAV) on a landing pad. The vision problem we address here is then a special case of the classic ego-motion estimation problem since all feature points lie on a planar surface (the landing pad). We study together the discrete and differential versions of the ego-motion estimation, in order to obtain both position and velocity of the UAV relative to the landing pad. After briefly reviewing existing algorithm for the discrete case, we present, in a unified geometric framework, a new estimation scheme for solving the differential case. We further show how the obtained algorithms enable the vision sensor to be placed in the feedback loop as a state observer for landing control. These algorithms are linear, numerically robust, and computationally inexpensive hence suitable for real-time implementation. We present a thorough performance evaluation of the motion estimation algorithms under varying levels of image measurement noise, altitudes of the camera above the landing pad, and different camera motions relative to the landing pad. A landing controller is then designed for a full dynamic model of the UAV. Using geometric nonlinear control theory, the dynamics of the UAV are decoupled into an inner system and outer system. The proposed control scheme is then based on the differential flatness of the outer system. For the overall closed-loop system, conditions are provided under which exponential stability can be guaranteed. In the closed-loop system, the controller is tightly coupled with the vision based state estimation and the only auxiliary sensor are accelerometers for measuring acceleration of the UAV. Finally, we show through simulation results that the designed vision-in-the-loop controller generates stable landing maneuvers even for large levels of image measurement noise. Experiments on a real UAV will be presented in future work.

关键词： Motion estimation computer vision based control unmanned air vehicle differential flatness

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Corrections to “Robust Detection in DS-CDMA”

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IEEE Transactions on Vehicular Technology 2005年第3期54卷 1223-1223页

作者： H. Delic A. Hocanin Signal and Image Processing Laboratory Department of Electrical and Electronics Engineering Boğaziçi University Istanbul Turkey Department of Electrical and Electronics Engineering Eastern Mediterranean University Gazi Magusa Turkey

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Blind collision multiplicity detection for wireless access with retransmission diversity

Blind collision multiplicity detection for wireless access w...

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IEEE Conference on Vehicular Technology (VTC)

作者： B. Ozgul H. Delic Signal and Image Processing Laboratory (BUSIM) Department of Electrical and Electronics Engineering Boğaziçi University Istanbul Turkey

Multiple access protocols with retransmission diversity resolve packet collisions through source separation techniques. The number of retransmissions to achieve the necessary diversity level equals the collision multiplicity, whose proper detection is essential for good performance. The well-known network-assisted diversity multiple access employs the rank test method to detect the multiplicity blindly, but constant channel parameters throughout the retransmissions and the tight control of the transmitter phase are required. In this paper, a superior blind collision multiplicity detection technique is introduced for per-slot varying channels by combining the minimum description length (MDL) criterion and the rank test method. The proposed method and the rank test are compared both theoretically and experimentally.

关键词： Diversity reception Covariance matrix Testing Access protocols Transmitters Throughput Delay signal processing algorithms Detectors Eigenvalues and eigenfunctions

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Space-frequency coding for the HIPERLAN/2 standard

Space-frequency coding for the HIPERLAN/2 standard

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Mediterranean Electrotechnical Conference (MELECON)

作者： C. Esli G. Ay B. Ozgul H. Delic Signal and Image Processing Laboratory (BUSIM) Department of Electrical and Electronics Engineering Boğaziçi University Istanbul Turkey

This paper attempts to provide an evaluation of high performance local area network (HIPERLAN/2), equipped with space-frequency coded transmit diversity. The HIPERLAN/2 physical layer entities with two antennas are simulated for frequency-selective fading channels for the standard's digital modulation schemes of BPSK, QPSK, 16-QAM and 64-QAM. Packet error rate comparisons of HIPERLAN/2 with and without space frequency coding reveal the potential gains and caveats.

关键词： OFDM Physical layer Fading Quadrature amplitude modulation image coding Local area networks Binary phase shift keying Quadrature phase shift keying Telecommunication standards IP networks

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On symbol collisions in FH-OFDMA

On symbol collisions in FH-OFDMA

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IEEE Conference on Vehicular Technology (VTC)

作者： T. Kurt H. Delic Communications and Signal Processing Laboratory School of Information Technology and Engineering University of Ottawa ONT Canada Signal and Image Processing Laboratory Department of Electrical and Electronics Engineering Boğaziçi University Istanbul Turkey

A frequency-hopping orthogonal frequency-division multiple access (FH-OFDMA) system is considered. Each user transmits by hopping randomly from one cluster of subcarriers to the next. The subcarrier clusters may be fixed groups, or they may be formed randomly at each hopping instant. It is shown analytically that the expected number of collisions per symbol is independent of the hopping strategy. Bit error rate computations via simulations in a frequency-selective fading channel indicate that space-frequency coding reduces the expected number of symbols involved in a cluster collision when the subcarriers are hopped independently.

关键词： OFDM signal processing Radio spectrum management Interference elimination GSM Information technology image processing Laboratories Bit error rate Computational modeling

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Packet reservation window multiple access with capture

Packet reservation window multiple access with capture

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IEEE International Conference on Communications (ICC)

作者： D.E. Ayyzldzz H. Delic Dept. of Electr. Eng. Nebraska Univ. Lincoln NE USA Signal and Image Processing Laboratory Department of Electrical and Electronics Engineering Bogazici University Istanbul Turkey

We consider the packet reservation window multiple access protocol (PRWMA) that successfully combines voice and data traffic over a cellular network. In agreement with the mobile channel environment, the presence of capture is also modeled. PRWMA is modified to accommodate the advantages presented by the capture effect. The proposed protocol's capacity and average delay performance is studied under the power capture model through simulations. Experiments indicate that significant performance gains are offered by the new algorithm.

关键词： Delay Access protocols Time division multiple access Propagation losses Power system modeling image processing Laboratories Data engineering Telecommunication traffic Traffic control

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