An experiment of digital video distribution through a PON has been carried out in the framework of the European Project CRABS. The system uses cheap components and permits distribution to 128/256 users over 174 m multimode fibre. A good agreement between measurements and simulations has been obtained.
A realistic uplink FDMA scenario for NG-PON2 is demonstrated with low speed electronics in the ONU (500 MHz) and high per wavelength aggregate capacity (12 to 15 Gbps). Stability over field deployed fiber is proven.
We describe the implementation on FPGA platform of the Digital Signal Processing required by the PON architecture proposed by the FABULOUS European Project, comparing the results with off-line processing and evaluating the related ASIC requirements.
The presence of late potentials (LP) after myocardial infarction (MI) is related to an occluded infarct-related coronary artery (IRA). However, the effects of the signal-averaged electrocardiogram (SAECG) of systemic thrombolysis are contradicting. Reperfusion in the IRA is more frequently observed after primary percutaneous transluminal coronary angioplasty (PTCA) than after systemic thrombolysis. The aim of this prospective study was to compare the prevalence of LP in survivors of acute MI treated with either systemic thrombolysis or primary PTCA.Between October 1994 and January 1997, 134 patients (pts) with acute MI were treated with reperfusion therapy within 12 hours of the onset of symptoms: seventy-four pts received systemic thrombolysis and 60 underwent primary PTCA. All pts (mean age 61 +/- 10 years, 120 males) had a control coronary angiography 9 +/- 5 and 10 +/- 4 days after acute MI, respectively. The recorded signals were amplified, averaged and filtered with bi-directional Butterworth filtering (band-pass filter range of 40-250 Hz). LPs were defined as the presence of 2 or 3 of the following criteria: filtered duration of the QRS complex > 114 ms, root mean square voltage of signals in the last 40 ms of the QRS < or = 20 mV and duration of the low amplitude signals > 38 ms.The two groups of pts did not differ significantly with respect to age, gender, presence of either diabetes or hypertension, site of MI, previous MI, Killip class, time to treatment, peak CK-MB level, incidence of reinfarction, extent of coronary artery disease and left ventricular ejection fraction. One hundred pts (75%) had patency (TIMI 3 grade flow) of the IRA at control coronary angiography. Twenty-seven pts (20%) had LP: 16 pts (22%) among those treated with systemic thrombolysis and 11 pts (18%) among those treated with primary PTCA (p = ns). Pts treated with primary PTCA had higher patency rates [95% (57/60) vs 58% (43/74); p = 0.00002] and less severe residual stenosis (19 +/- 15% vs 72 +/- 18%; p = 0.0001) in the IRA. LP were found in 15 pts (15%) with TIMI 3 grade flow and in 12 pts (35%) with TIMI 0-2 grade flow (p = 0.017). By multivariate analysis, including 18 clinical and electrocardiographic variables, an occluded IRA was the only independent predictor of the development of LP (Wald chi 2: 6.1453; p = 0.0132).Results of this prospective study suggest that primary PTCA alone does not reduce the prevalence of LP when compared to systemic thrombolysis. Only the patency of the IRA, as determined before the hospital discharge, affected the development of LP after acute MI.
The early invasive diagnostic approach with extensive use of myocardial revascularization in patients with unstable angina is a matter of debate. Both the advantages of this strategy and the choice of the best candidates are controversial. The widespread applicability of this approach in Italian hospitals is also questionable, due to limited availability of facilities for interventional cardiology.A prospective, observational study was done on a cohort of consecutive patients, who were admitted with a diagnosis of unstable angina and treated with an early aggressive approach at a center with interventional cardiology facilities without cardiac surgery. The aim of the study was to evaluate both the immediate and long-term clinical outcome of patients and the efficiency of our therapeutic approach.Two-hundred and two patients were enrolled and 85% were in Braunwald class III. Coronary angiography was performed in 171 patients (85%) at 2.1 +/- 2.4 days after admission: it showed one-, two- and three-vessel disease in 40, 29 and 22% of cases, respectively; 9% of patients had no severe coronary lesion. Left ventricular ejection fraction was 0.58 +/- 0.13. Medical treatment, coronary by-pass surgery and percutaneous myocardial revascularization were chosen in 36, 24 and 40% of cases, respectively. Coronary angioplasty was performed in our center in 58 (73%) of 80 patients at 6.8 +/- 5.6 days after admission and stents were used in 42 cases (74%). Overall hospital stay was 10.4 +/- 4 days. Cumulated adverse events (death and non-fatal myocardial infarction) occurred in 2.5 and 7% of patients during the initial admission and in the following year, respectively.An early aggressive approach to patients with unstable angina is feasible in a hospital with interventional cardiology in the absence of cardiac surgical facilities. The immediate favorable clinical results of this strategy in an intermediate-risk cohort seem to persist at one-year follow-up.
In this paper, we present the most comprehensive system demonstrator realized so far inside the FABULOUS project, an EU 7th Framework Program European research project. The architecture proposed in FABULOUS is based on frequency division multiplexed PON and uses a self-coherent and reflective approach in the upstream. The demonstration presented in this paper uses discrete optoelectronics components. We will show system experiments realized with five active optical network units, together with the emulation of other 27 ONUs ASE noise, demonstrating that such network is capable of an upstream transmission of 32 Gb/s over 40 km of dark fiber and an attenuation of 31 dB, in compliancy with ODN class N2 of the latest PON standards. In addition, we will demonstrate, thanks to the flexibility of frequency multiplexing, that the network can adapt its performances to the link conditions, achieving higher aggregate bit rates or higher losses depending on the link quality that every user in the network experiences. To conclude, we will investigate on the feasibility of the required digital signal processing onto FPGA or ASIC platforms.
A 20-Gb/s quadrature phase-shift keying (QPSK) homodyne coherent system was analyzed and experimentally demonstrated. This system is based on subcarrier optical phase-locked loop (SC-OPLL) and it works in real time. In this letter, we present a brief optical receiver analysis and the transmission system performance in terms of simulations and experimental results. We also show that the QPSK system works but it is affected by loop propagation delay effects due to the prototypal implementation. The delay loop effects can be mitigated by an SC-OPLL integrated realization.
