Francesco Lamonaca

Photoplethysmography detection by smartphone's videocamera

Smartphones video cameras become more and more powerful while the devices itself become used by many people. That allows utilizing them for many every-day tasks. One of such suitable application of the widely used smartphones is monitoring the state of the health. In this paper we propose an approach to detect the photoplethysmograph signal from the fingertip using a smartphones camera and built-in LED. The proposed solution allows detecting the proper heart rate and is robust to different situations of wrong-usage of the system.

A Neural Network-based method for continuous blood pressure estimation from a PPG signal

There is a relation, not always linear, between the blood pressure and the pulse duration, obtained from photoplethysmography (PPG) signal. In order to estimate the blood pressure from the PPG signal, in this paper the Artificial Neural Networks (ANNs) are used. Training data were extracted from the Multiparameter Intelligent Monitoring in Intensive Care waveform database for better representation of possible pulse and pressure variation. In total there were analyzed more than 15000 heartbeats and 21 parameters were extracted from each of them that define the input vector for the ANN. The comparison between estimated and reference values shows better accuracy than the linear regression method and satisfy the American National Standards of the Association for the Advancement of Medical Instrumentation.

Detection of the eye blinks for human's fatigue monitoring

This paper presents a non-intrusive vision based system for eye blinks detection and fatigue level monitoring. It uses a web camera positioned in front of the face. A cascade of boosted classifiers based on Haar-like features is used for fast detection of the eyes region. The frames differencing in combination with the thresholding are applied to detect the eyes closure and opening. The frame processing algorithm is pointed out in order to distinguish the involuntary blinks from the voluntary ones. Experimental tests are shown that validate the proposed system.

Reliable pulse rate evaluation by smartphone

The paper deals with the robust and reliable evaluation of the Pulse Rate (PR) with a smartphone. The smartphone camera is used to evaluate the volumetric variation of blood by monitoring the change of light absorption in the tissue. Once assessed the correct working operation, the PhotoPlethysmoGram (PPG) signal is detected and the PR is evaluated on the basis of adaptive and statistical analysis. To validate the pointed out method, the PR, evaluated by smartphone, is compared with the Ambulatory Blood Pressure monitor Spacelabs 90207, that is clinically validated medical device. The experimental results confirm the correctness and suitability of the proposed method.

Clock synchronization protocol for wireless sensor networks with bounded communication delays

In this paper, we address the clock synchronization problem for wireless sensor networks. In particular, we consider a wireless sensor network where nodes are equipped with a local clock and communicate in order to achieve a common sense of time. The proposed approach consists of two asynchronous consensus algorithms, the first of which synchronizes the clocks frequency and the second of which synchronizes the clocks offset. This work advances the state of the art by providing robustness against bounded communication delays. A theoretical characterization of the algorithm properties is provided. Simulations and experimental results are presented to corroborate the theoretical findings and show the effectiveness of the proposed algorithm.

Clock Synchronization in Wireless Sensor Network With Selective Convergence Rate for Event Driven Measurement Applications

In this paper, a novel wireless sensor network synchronization protocol for event-driven measurement applications is proposed. The objective is twofold: 1) to provide high accuracy in the area where an event is detected and 2) to ensure a long network lifetime. The complexity of the problem arises from the fact that these two properties are usually in conflict. To increase the synchronization accuracy, nodes are required to exchange synchronization packets at higher rate, thus impacting the network lifetime. Vice versa to ensure a long network life time, the number of packets to be exchanged should be minimized thus impacting the synchronization accuracy. A tradeoff can be achieved by observing that the packet rate should be increased only for the portion of the network surrounding the detected events as only these nodes require a higher accuracy to collect data. The proposed algorithm represents a formalization of this idea. Numerical and experimental results are provided to fvalidate the effectiveness of the proposed algorithm.

Pre-Processing Correction for Micro Nucleus Image Detection Affected by Contemporaneous Alterations

This paper presents a method that detects and corrects alterations of 1, exposure; 2, out-of-focus; and 3, Gaussian noise affecting, contemporaneously, the images that are acquired in flow cytometer measurement devices. These alterations reduce image quality and interfere with correct micronucleus (MN) detection in a lymphocyte. The objectives of the proposed correction are given as follows: 1, to correctly process the image with the pattern-matching algorithm in order to detect the MN in human lymphocytes; 2, to minimize doubtful detections; and 3, to enhance the confidence that, in rejected images, MNs cannot be detected. Numerical and experimental tests confirm the validity of the proposed correction method and permit the evaluation of the upper and lower bounds of the admissible variation range of each alteration.

Clock synchronization for wireless sensor network with communication delay

In this work, the clock synchronization problem for wireless sensor networks is addressed. In our scenario, we consider a wireless sensor network where nodes are equipped with a local clock hardware and communicate in order to achieve a common sense of time. This work introduces a novel synchronization algorithm able to ensure a good level of synchronization even in the presence of random bounded communication delays. A theoretical analysis of the robustness of the proposed algorithm is proposed along with simulations to corroborate the theoretical finding.

Automatic Detection and Surface Measurements of Micronucleus by a Computer Vision Approach

This paper reports a novel method for nucleus and micronucleus segmentation. These biological structures are useful to biologists for relieving structural chromosome aberration. The adopted method consists of a pipeline of advanced computer vision algorithms, some of them were specifically tailored for the current segmentation problem. Starting from the weak hypotheses on size, shape, and color of micronucleus, it is possible to efficiently segment and measure the image features of interest by a computer vision approach. We report experimental results with a new flow cytometer architecture specifically developed to recognize and measure micronucleus of human lymphocyte. The robustness of the algorithm with respect to various kinds of noise is also reported.

Synchronization of Measurement Instruments Co-operating into the W-DMS

On the basis of the IEEE 1588, the PC in the distributed measurement system can work on synchronized modality. Nevertheless, the hardware and software architecture of the path involved in the communication PC-measurement instrument (MI) can delay the commands. The research aims to investigate about the time delay occurring in the communication between the PC and the Ml. Two different aspects are taken into account: (i) the characterization of the hardware connection PC-MI offering the minimum delay, and (it) the criteria to modify and to set up the software to reduce the delay occurring in the processing steps performed into the PC. In particular, the preliminary experimental results furnished in the paper concern with (i) different hardware connections PC-digital storage oscilloscope (DSO), and (it) different setting up of the Linux operating system (OS). The experimental results obtained on the basis of the selected connection PC-DSO and the set-up of the OS highlight that delay characterized by mean value equal to 4.19 mus and standard deviation of 93.5 ns can be achieved.