Abstract
The social and economic impact of cardiovascular diseases and the importance of efficient early diagnostic tools are self-evident. This project finds its motivation in the foreseeable impact that an accurate, non-invasive and easy-to-use instrument for hemodynamic condition assessment could introduce on the diagnosis and follow-up of these diseases. It aims at developing and testing of a microcontroller based signal monitoring device for cardiovascular studies. The advantages of this system show up in decreasing the associated cost, as well as in increasing its functionality, making the necessary human intervention minimal. The algorithmic component of the project will focus on the main hemodynamic issues currently addressed in literature: separating incident from reflected pulse waves (augmentation index), waveform variability and transfer function Although, additional studies are still required to attain clinical validation, this system seems to be a valid, low cost and easy to use alternative to the highly costly devices in the market. © 2011 IEEE.

Abstract
Four optical probes were developed to measure the arterial distension waveform generated by the ventricular contraction and assess clinically relevant information. The pressure wave propagates through the arterial tree and can be measured in the peripheral arteries. The probes make use of two distinct photo-detectors: planar and avalanche photodiodes. Independently, two different light sources were tested: visible and infrared light. Performance of the probes was evaluated in a test setup that simulates the fatty deposits commonly seen in the obese, between skin and the artery. The probes show good overall performance in the test setup with less than 8% root mean square error (RMSE). However, the probes lit with IR sources show better results for the more extreme cases, with a better resolution in the waveform, higher definition of notable points and higher SNR when compared to the visible source signals. In vivo, the IR probes allow easier waveform detection, even more relevant with the increasing of the deposit structures.

Abstract
A new algorithm is proposed for the semi-automatic segmentation of the near-end and the far-end adventitia boundary of the common carotid artery in ultrasound images. It uses the random sample consensus method to estimate the most significant cubic splines fitting the edge map of a longitudinal section. The consensus of the geometric model (a spline) is evaluated through a new gain function, which integrates the responses to different discriminating features of the carotid boundary: the proximity of the geometric model to any edge or to valley shaped edges; the consistency between the orientation of the normal to the geometric model and the intensity gradient; and the distance to a rough estimate of the lumen boundary. A set of 50 longitudinal B-mode images of the common carotid and their manual segmentations performed by two medical experts were used to assess the performance of the method. The image set was taken from 25 different subjects, most of them having plaques of different classes (class II to class IV), sizes and shapes. The quantitative evaluation showed promising results, having detection errors similar to the ones observed in manual segmentations for 95% of the far-end boundaries and 73% of the near-end boundaries.

Abstract

Abstract
fischeri Background: Photodynamic antimicrobial chemotherapy (PACT) combines light, a light-absorbing molecule that initiates a photochemical or photophysical reaction, and oxygen. The combined action of these three components originates reactive oxygen species that lead to microorganisms' destruction. The aim was to evaluate the efficiency of PACT on Vibrio fischeri: 1) with buffer solution, varying temperature, pH, salinity and oxygen concentration values; 2) with aquaculture water, to reproduce photoinactivation (PI) conditions in situ. Methodology/Principal Findings: To monitor the PI kinetics, the bioluminescence of V. fischeri was measured during the experiments. A tricationic meso-substituted porphyrin (Tri-Py(+)-Me-PF) was used as photosensitizer (5 mu M in the studies with buffer solution and 10-50 mu M in the studies with aquaculture water); artificial white light (4 mW cm(-2)) and solar irradiation (40 mW cm(-2)) were used as light sources; and the bacterial concentration used for all experiments was approximate to 10(7) CFU mL(-1) (corresponding to a bioluminescence level of 10(5) relative light units - RLU). The variations in pH (6.5-8.5), temperature (10-25 degrees C), salinity (20-40 g L(-1)) and oxygen concentration did not significantly affect the PI of V. fischeri, once in all tested conditions the bioluminescent signal decreased to the detection limit of the method (approximate to 7 log reduction). The assays using aquaculture water showed that the efficiency of the process is affected by the suspended matter. Total PI of V. fischeri in aquaculture water was achieved under solar light in the presence of 20 mu M of Tri-Py(+)-Me-PF. Conclusions/Significance: If PACT is to be used in environmental applications, the matrix containing target microbial communities should be previously characterized in order to establish an efficient protocol having into account the photosensitizer concentration, the light source and the total light dose delivered. The possibility of using solar light in PACT to treat aquaculture water makes this technology cost-effective and attractive.

Abstract
In this work, we discuss an algorithm that reliable and accurately identifies the prominent points of the cardiac cycle: the systolic peak (SP), reflection point (RP), dicrotic notch, (DN) and dicrotic peak (DP). The prominent point's identifier algorithm (PPIA) action is based on the analysis a number of features of the arterial pressure waveform and its first derivative, and is part of the fundamental software analysis pack for a new piezoelectric probe designed to reproduce the arterial pressure waveform from the pulsatile activity taken non-invasively at the vicinity of a superficial artery. The output PPIA is the coordinates (in time and amplitude) of the above referred points. To assess the accuracy of the algorithm, a reference database of 173 pulses from eight volunteers, was established and the values yielded by the PPIA were compared to annotations from a human expert engineer (HEE). The quality of the results is statistically quantified either in time as in amplitude. Average values of 4.20% for error, 99.09% for sensitivity and 96.77% for positive predictive value were found to be associated to time information while amplitude yields averages of 2.68%, 99.08% and 98.22%, respectively, for the same parameters.