Pantelis Angelidis

MR image compression using a wavelet transform coding algorithm

We present here a technique for MR image compression. It is based on a transform coding scheme using the wavelet transform and vector quantization. Experimental results show that the method offers high compression ratios with low degradation of the image quality. The technique is expected to be particularly useful wherever storing and transmitting large numbers of images is necessary.

Energy-Efficiency Evaluation of a Medium Access Control Protocol for Cooperative ARQ

We present in this paper the evaluation of the energy consumption of PRCSMA, an 802.11-based medium access control protocol designed to coordinate the retransmissions from the relays in a wireless network implementing a Cooperative Automatic Retransmission Request (C-ARQ) scheme. A comparison in terms of energy efficiency with non-cooperative ARQ schemes (retransmissions performed only from the source) and with ideal C-ARQ (with perfect scheduling among the relays) is included in this paper. The main results show the conditions under which a C-ARQ scheme with PRCSMA outperforms, in terms of energy efficiency, non-cooperative ARQ schemes and also show that the overhead of the MAC layer cannot be neglected in order to accurately evaluate the performance of a C-ARQ scheme.

Overview on telecommunications regulation framework in south-eastern Europe

Over the last few years all South-Eastern European (SEE) countries have started an effort that involves complete transition of telecom regulations, in order to comply with European Union rules. Towards this direction, the majority of the SEE governments have proceeded in the establishment of independent Regulative Authorities. In addition, a set of Telecommunications Acts was entered into force in all SEE countries, while the mobile market is fully liberalised. This paper presents an overview of the regulation and institutional telecommunications framework in the SEE region.

eHealth service support in IPv6 vehicular networks

Recent vehicular networking activities include public vehicle to vehicle/infrastructure (V2X) large scale deployment, machine-to-machine (M2M) integration scenarios and more automotive applications. eHealth is about the use of the Internet to disseminate health related information, and is one of the promising Internet of Things (IoT) applications. Combining vehicular networking and eHealth to record and transmit a patients vital signs is a special telemedicine application that helps hospital resident health professionals to optimally prepare the patients admittance. From the automotive perspective, this is a typical Vehicle-to-Infrastructure (V2I) communication scenario. This proposal provides an IPv6 vehicular platform which integrates eHealth devices and allows sending captured health-related data to a Personal Health Record (PHR) application server in the IPv6 Internet. The collected data is viewed remotely by a doctor and supports a diagnostic decision. This paper introduces the integration of vehicular and eHealth testbeds, describes related work and presents a lightweight auto-configuration method based on a DHCPv6 extension to provide IPv6 connectivity for resource constrained devices.

CAROTID - A web-based platform for optimal personalized management of atherosclerotic patients

Carotid atherosclerosis is the main cause of fatal cerebral ischemic events, thereby posing a major burden for public health and state economies. We propose a web-based platform named CAROTID to address the need for optimal management of patients with carotid atherosclerosis in a twofold sense: (a) objective selection of patients who need carotid-revascularization (i.e., high-risk patients), using a multifaceted description of the disease consisting of ultrasound imaging, biochemical and clinical markers, and (b) effective storage and retrieval of patient data to facilitate frequent follow-ups and direct comparisons with related cases. These two services are achieved by two interconnected modules, namely the computer-aided diagnosis (CAD) tool and the intelligent archival system, in a unified, remotely accessible system. We present the design of the platform and we describe three main usage scenarios to demonstrate the CAROTID utilization in clinical practice. Additionally, the platform was evaluated in a real clinical environment in terms of CAD performance, end-user satisfaction and time spent on different functionalities. CAROTID classification of high- and low-risk cases was 87%; the corresponding stenosis-degree-based classification would have been 61%. Questionnaire-based user satisfaction showed encouraging results in terms of ease-of-use, clinical usefulness and patient data protection. Times for different CAROTID functionalities were generally short; as an example, the time spent for generating the diagnostic decision was 5min in case of 4-s ultrasound video. Large datasets and future evaluation sessions in multiple medical institutions are still necessary to reveal with confidence the full potential of the platform.

Lowest mutual coupling between closely spaced loop antennas

The conditions for zeroing the mutual flux between two closely spaced coil antennas are examined. The analysis is expanded to examine the case of multiple linear antenna coils. Array antennas are used in many areas including magnetic resonance imaging (MRI). Theoretical and experimental results are presented and compared. Good agreement between theory and measurements has been confirmed. A two-dimensional receiving array antenna is proposed. >

The hackathon model to spur innovation around global mHealth

Abstract The challenge of providing quality healthcare to underserved populations in low- and middle-income countries (LMICs) has attracted increasing attention from information and communication technology (ICT) professionals interested in providing societal impact through their work. Sana is an organisation hosted at the Institute for Medical Engineering and Science at the Massachusetts Institute of Technology that was established out of this interest. Over the past several years, Sana has developed a model of organising mobile health bootcamp and hackathon events in LMICs with the goal of encouraging increased collaboration between ICT and medical professionals and leveraging the growing prevalence of cellphones to provide health solutions in resource limited settings. Most recently, these events have been based in Colombia, Uganda, Greece and Mexico. The lessons learned from these events can provide a framework for others working to create sustainable health solutions in the developing world.

Denoising simulated EEG signals: A comparative study of EMD, wavelet transform and Kalman filter

Electrooculographic (EOG) artefact is one of the most common contaminations of Electroencephalographic (EEG) recordings. The corruption of EEG characteristics from Blinking Artefacts (BAs) affects the results of EEG signal processing methods and also impairs the visual analysis of EEGs. In this paper, our scope was a comparative analysis of the performance of three standard denoising methods like continuous Empirical Mode Decomposition (EMD), Discrete Wavelet Transform (DWT) and Kalman Filter (KF). In order to evaluate the performance of EMD, DWT and KF of noise reduction and to express the quality of the denoised EEG, we calculate several indexes such as the Signal-to-Noise Ratio (SNR). All the results obtained from noise simulated EEG data show that WT achieved the greatest SNR difference and also the mode mixing issue of EMD affected this methods performance.

Analysis of queue load effect on channel access prioritization in Wireless Sensor Networks

Resource allocation in Wireless Sensor Networks (WSNs) is certainly a challenging issue. WSNs are characterized by special features, like energy constraints and limited computing resources. Latest trends define that sensors should be able to provide Quality of Service (QoS) demanding data transmission. A modern approach in bandwidth sharing considers both the packet queue load as well as the traffic priority. A new QoS aware channel sharing approach is introduced, analyzing the effect of queue load in WSN Medium Access Control (MAC). The analysis reveals that the queue load factor has a great impact on QoS provision in bandwidth sharing, while packet priorities are also considered.

Personalised physical exercise regime for chronic patients through a wearable ICT platform.

Todays state of the art in exercise physiology, professional athletics and sports practice in general clearly shows that the best results depend on the personalisation and continuous update of the recommendations provided to an athlete training, a sports lover or a person whose medical condition demands regular physical exercise. The vital signs information gathered in telemonitoring systems can be better evaluated and exploited if processed along with data from the subjects electronic health records, training history and performance statistics. In this context, the current paper intends to exploit modern smart miniaturised systems and advanced information systems towards the development of an infrastructure for continuous, non-invasive acquisition and advanced processing of vital signs information. In particular, it will look into wearable electronics embedded in textile capable of performing regular or exceptional measurements of vital physiological parameters and communicating them to an application server for further processing.