Abstract This pilot research examines the motives, the obstacles and the expected outcomes of telemedicine from a medical practitioner’s viewpoint. It is a qualitative study based on interviews of 60 practitioners, all from general hospitals of the metropolitan area of Thessaloniki, Central Macedonia, Northern Greece. The study shows that the vast majority of them disagree with the motives provided for the... This pilot research examines the motives, the obstacles and the expected outcomes of telemedicine from a medical practitioner’s viewpoint. It is a qualitative study based on interviews of 60 practitioners, all from general hospitals of the metropolitan area of Thessaloniki, Central Macedonia, Northern Greece. The study shows that the vast majority of them disagree with the motives provided for the promotion of telemedicine practices in their health units, they differ from the IT experts’ opinion of what the obstacles are leading to the low diffusion of telemedicine and show very low expectations of the benefits yield by its application. The main conclusion is that more work is needed to communicate the positive points of medicine especially to the people mostly related and to be involved with this practice. Read More Read Less

Abstract In telemedicine, the transmission of the cardiac signal or for the diagnosis of an automatic Holter, it is important to model the heartbeat. Our aim in this work is the modeling of the ECG data by polynomial transform. We have developed an algorithm that allows the modeling of the ECG signal with the Chebyshev polynomial. The principle of ECG data... In telemedicine, the transmission of the cardiac signal or for the diagnosis of an automatic Holter, it is important to model the heartbeat. Our aim in this work is the modeling of the ECG data by polynomial transform. We have developed an algorithm that allows the modeling of the ECG signal with the Chebyshev polynomial. The principle of ECG data modeling is presented and the relevant examples for the capability of the method are provided. The modeling algorithm is evaluated using the database of MIT-BIH. The first results obtained exhibit the faithfully reproduction abnormalities included in the ECG signal. Read More Read Less

Abstract Pulse wave velocity (PWV) is a measure of arterial stiffness. A strong correlation between PWV and cardiovascular events that cause mortality, was recognized. The foot-to-foot (f-t-f) method is a standard techniques used for the determination of arterial PWV. This technique offers an estimation of the regional wave speed. F-t-f methods usually require longer vessels to allow the measurements at two... Pulse wave velocity (PWV) is a measure of arterial stiffness. A strong correlation between PWV and cardiovascular events that cause mortality, was recognized. The foot-to-foot (f-t-f) method is a standard techniques used for the determination of arterial PWV. This technique offers an estimation of the regional wave speed. F-t-f methods usually require longer vessels to allow the measurements at two sites. In this work, we present a mathematical description of a new method for the determination of the local PWV; Diameter Velocity loop (Dvcl - loop). The method only requires the measurements of centre line velocity and diameter which can be obtained non-invasively. We conclude that the Dvcl - loop method provides a reliable local pulse wave velocity and has the merits of using non-invasive parameters. Read More Read Less

Abstract This paper presents the results of a study of Quadrature Amplitude Modulation (QAM) coherent reception bit by bit. The research was conducted using statistical modeling methods; the results are compared with the statistical modeling calculation of analytical expression given in previously published documents. In the last year, the discrete signals became widely employed; and with more perspective in the digital... This paper presents the results of a study of Quadrature Amplitude Modulation (QAM) coherent reception bit by bit. The research was conducted using statistical modeling methods; the results are compared with the statistical modeling calculation of analytical expression given in previously published documents. In the last year, the discrete signals became widely employed; and with more perspective in the digital systems for transmission of information, the QAM signals became more beneficial due to its high spectral efficiency. The satellite communications systems are evolving very quickly, so the purpose of developing this kind of research is to maximize the efficiency in the communication rate with the minimal error, during the limited communications time while satellite transits the user´s horizon. Read More Read Less

Abstract The paper addresses the modeling and performance analysis of discrete delay-locked loop (DLL) code tracking for quadrature-spread direct-sequence code division multiple access (CDMA) signals (used in 3G UMTS) over Rayleigh fading channels. A discrete-time stochastic difference equation is derived to model the DLL tracking error dynamics as a firstorder Markovian process. The stationary probability density function of the tracking error... The paper addresses the modeling and performance analysis of discrete delay-locked loop (DLL) code tracking for quadrature-spread direct-sequence code division multiple access (CDMA) signals (used in 3G UMTS) over Rayleigh fading channels. A discrete-time stochastic difference equation is derived to model the DLL tracking error dynamics as a firstorder Markovian process. The stationary probability density function of the tracking error is derivediteratively by solving a Kolmogorov-Chapman integral equation. Numerical examples with different system loading assumptions show that the proposed technique, while having a moderate computational complexity, produces much more accurate results when compared to simplified approximations based on Gaussian models for the DLL tracking error. Read More Read Less