Abstract
The problem of using a piezoelectric (PZ) probe to non-invasively measuring the pressure wave propagation through a fluid contained in an elastic tube is considered in this paper. In particular, we describe a probe system designed to non-invasively reproduce the morphology of the pulsatile arterial pressure waveform (APW). The study is focused in three main issues: the mechanical interface that transmits the forces associated to the distension of the wall of the tube to the sensor, the electronic conditioning circuit and the methods to assess the global accuracy of the system. The circuit, incorporates a, new to our knowledge, baseline restorer (BLR) that contributes to maintaining a stable (non-floating) baseline of the cardiac pressure pulses, making real-time observations more effective. Identification and correction of the systematic errors, responsible for deviations of the correct output morphology, are also discussed and tested for different waveforms. To assess the performance of the probe a special purpose test bench was developed that can originate an arbitrarily shaped pressure wave and launch it through a silicone-rubber tube. Finally, preliminary results, taken at the carotid site of a set of human volunteers, are shown. The probe can be incorporated in a collar, and its pulse waveforms exhibit high intra-patient repeatability. It has the potential of being used as an alternative to costly techniques such as ultrasound or applanation tonometry. The root mean square error (RMSE) of the probe when reproducing cardiac-like pressure waveforms yielded a value of 1.8 +/- 0.22%.

Abstract
An arterial pressure waveform recorder and analyser based on a Microchip PIC microcontroller (mu C), dsPIC33FJ256GP710 is described in this article. Our purpose is to develop a dsPIC based signal monitoring and processing system for cardiovascular studies, specially dedicated to arterial pressure waveform (APW) capture. We developed a piezoelectric (PZ) probe designed to reproduce the APW from the pulsatile activity taken non-invasively at the vicinity of a superficial artery. The advantages in developing a microcontroller based system show up in decreasing the associate cost, as well as in increasing the functionality of the system. Based on a MathWorks Simulink platform, the system supports the development and transfer of program code from a personal computer to the microcontroller, and evaluation of its execution on rapid prototyping hardware. Results demonstrate that embedded system can be an alternative to be used in autonomous cardiovascular probes. Although additional studies are still required, this probe seems to be a valid, low cost and easy to use alternative to expensive and hard to manipulate devices in the market.

Abstract
Over the last years, great emphasis has been placed on the role of arterial stiffness in the development of cardiovascular diseases. This hemodynamic parameter, generally associated to age and blood pressure increase, can be assessed by the measurement of pulse wave velocity (PWV). Currently available devices that measure PWV are expensive and need to be operated by skilled medical staff, reducing the potential of ambulatory setting. This research project aims at developing and testing the sensoring and algorithmic basis of an alternative and non-invasive device for PWV assessment. The proposed device is based on a double-headed sensor probe and allows the assessment of PWV in one single location, providing important information on local arterial hemodynamics. Although studies to validate the clinical use of this system are still required, it has already demonstrated good performance on a dedicated test bench system, capable of reproducing a range of relevant cardiovascular system's properties. © 2011 IEEE.

Abstract
The feasibility of optical amplification solutions for extended reach next generation access networks in C + L bands is studied. Amplification schemes based on Raman fiber amplifier and their combination with remotely pumped erbium-doped fiber amplifiers are assessed and optimized. The results concerning a ring with 80 km for rural scenario demonstrate gain equalization over a bandwidth of 50 urn. The survey was complemented with experimental results. (C) 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:2414-2418, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26251

Abstract
In this paper, we investigate by simulation the feasibility of gain enlargement and equalization on extended reach WDM-ring PON by means of hybrid Raman/EDFA amplification. The system under analysis is composed by a bidirectional pump at 1480 nm and 16 channels (8 C band + 8 L band). The simulation describes an 80 km WDM ring with 8 nodes in which 2 channels are added/dropped. The results demonstrate gain equalization with a ripple of 2.54 dB over a bandwidth of 50 nm by using a 1480 nm bidirectional pump with 1 W and spans of EDF with a total length of 22 m.

Abstract
We experimentally demonstrate the accuracy of an all-optical S-R latch and an optical S-R flip-flop based on hybrid integrated Mach-Zehnder Interferometers, with Semiconductor Optical Amplifier in each arm (MZI-SOA). The performance of both bistable devices will be studied and compared in terms of extinction ratio and switching times. © 2011 IEEE.