386 research outputs found

    A Preliminary Study on Flexible Temperature Sensors for Eskin Medical Devices

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    In the latest years, the need of a renewed paradigm for healthcare arose promoting the research towards the idea of remote diagnosis, care and monitoring of physiological parameters. Thus, the wearable and eskin devices arose to be embedded in the standard medical equipment. In this work, a preliminary study on flexible AJP-printed temperature sensors is reported in order to propose a novel approach to evaluate infection sites, monitor the body temperature and compensate the effects of temperature on other on-body sensors. Two different geometries are proposed, designed, produced, evaluated and compared. The results shown a similar dependance on temperature (average TCR = 2.5 ∙ 10 -3 °C-1) and the dependance on substrate deformation was enquired as well as the geometrical features of the sensors

    Smart Brace for Static and Dynamic Knee Laxity Measurement

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    Every year in Europe more than 500 thousand injuries that involve the anterior cruciate ligament (ACL) are diagnosed. The ACL is one of the main restraints within the human knee, focused on stabilizing the joint and controlling the relative movement between the tibia and femur under mechanical stress (i.e., laxity). Ligament laxity measurement is clinically valuable for diagnosing ACL injury and comparing possible outcomes of surgical procedures. In general, knee laxity assessment is manually performed and provides information to clinicians which is mainly subjective. Only recently quantitative assessment of knee laxity through instrumental approaches has been introduced and become a fundamental asset in clinical practice. However, the current solutions provide only partial information about either static or dynamic laxity. To support a multiparametric approach using a single device, an innovative smart knee brace for knee laxity evaluation was developed. Equipped with stretchable strain sensors and inertial measurement units (IMUs), the wearable system was designed to provide quantitative information concerning the drawer, Lachman, and pivot shift tests. We specifically characterized IMUs by using a reference sensor. Applying the Bland–Altman method, the limit of agreement was found to be less than 0.06 m/s2 for the accelerometer, 0.06 rad/s for the gyroscope and 0.08 μT for the magnetometer. By using an appropriate characterizing setup, the average gauge factor of the three strain sensors was 2.169. Finally, we realized a pilot study to compare the outcomes with a marker-based optoelectronic stereophotogrammetric system to verify the validity of the designed system. The preliminary findings for the capability of the system to discriminate possible ACL lesions are encouraging; in fact, the smart brace could be an effective support for an objective and quantitative diagnosis of ACL tear by supporting the simultaneous assessment of both rotational and translational laxity. To obtain reliable information about the real effectiveness of the system, further clinical validation is necessary

    preliminary study of inkjet printed sensors for monitoring cell cultures

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    Abstract An extremely promising methodology able to obtain feedbacks from cell cultures is represented by the direct integration within culture substrates of specific sensitive elements capable to provide information related to cell adhesion, migration, differentiation and growth. At present, the most common materials used in the implementation of sensors monitoring 2D cell culture are noble metals. However, printed electronics allow instead an innovative approach, from both sensor realization technique and utilization of sensitive materials. This project aims to develop and test 2D ink-jet printed sensors, focusing on biocompatible substrates and conductive inks. Both biocompatibility and printability of two different sensor designs were evaluated, followed by electronic measurements that estimate fibroblast adhesion. Preliminary findings show a good biocompatibility of the Kapton® substrate coupled with PEDOT:PSS ink. This solution allowed us to correlate cell adhesion with an increase of impedance module, in agreement with the optical observation. On-going works rely on the evaluation of different materials used for both substrates and inks, addressing the possibility to monitor cardiomyocyte activity

    Data analysis of Permanent GPS networks in Italy and surrounding region: application of a distributed processing approach

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    We describe the procedures used to combine into a uniform velocity solution the observations of more than 80 continuous GPS stations operating in the central Mediterranean in the 1998-2004 time interval. We used a distributed processing approach, which makes efficient use of computer resources, while producing velocity estimates for all stations in one common reference frame, allowing for an effective merging of all the observations into a self-consistent network solution. We describe the CGPS data archiving and processing procedures, and provide main results in terms of position time-series and velocities for all stations that observed more than three years. We computed horizontal and vertical velocities accounting for the seasonal (annual and semi-annual) signals, and considering the off-sets in the coordinate time-series caused by station equipment changes. Weighted post-fit RMS of the north, east and vertical velocity components are in the range of 1.57-2.08 mm, 1.31-3.28 mm, and 3.60-7.24 mm, respectively, which are reduced by solving for seasonal signals in the velocity estimates. The annual and semi-annual signals in the height components, with amplitudes up to 4.8 mm, are much stronger than those in the horizontal components. The mean amplitudes of annual and semi-annual signals are within 0.18-0.47 mm, 0.23-0.52 mm and 0.55-1.92 mm in the north, east and vertical components, respectively

    Screen-Printed Biosensors for the Early Detection of Biomarkers Related to Alzheimer Disease: Preliminary Results

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    Abstract Alzheimer disease (AD), despite representing the most common type of dementia in elderly, is still lacking reliable methodologies for early diagnosis. A potential biomarker associated to AD development has been recently identified in the open isoform of p53, redox sensitive protein, currently quantified using a specific blood-based enzyme-linked immunosorbent assay (ELISA). In order to overcome ELISA limitations (level of detection, standardization and reliability), this study aimed to realize a low cost highly sensitive portable point-of-care (PoC) testing system based on screen printed electrochemical sensors (SPES). The study specifically reported the design of the platform, including the sensing probe and the electronic circuit devoted to the conditioning of the electric signal. Preliminary results were obtained from circuit testing by using controlled concentrations of electrolytic solutions and from an initial calibration stage by using Anodic Stripping Voltammetry (ASV) measurements. Future works will address the quantification of unknown concentration of unfolded p53 in peripheral blood samples, thus to validate the here-presented low cost, easy to use and highly precise platform

    Sea level change and vertical land movements since the last two millennia along the coasts of southwestern Turkey and Israel

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    This paper provides new relative sea-level data inferred from coastal archaeological sites located along the Turkish coasts of the Gulf of Fethye (8 sites), and Israel, between Akziv and Caesarea (5 sites). The structures selected are those that, for effective functioning, can be accurately related to sea level at the time of their construction. Thus their positions with respect to present sea level provide a measure of the relative sea level change since their time of construction. Useful information was obtained from the investigated sites spanning an age range of ~2.3 to ~1.6 ka BP. The inferred changes in relative sea level for the two areas are distinctly different, from a rise of 2.41 to 4.50 m in Turkey and from 0 to 0.18 m in Israel. Sea level change is the combination of several processes, including vertical tectonics, glacio–hydro-isostatic signals associated with the last glacial cycle, and changes in ocean volume. For the Israel section, the present elevations of the MIS 5.5 Tyrrhenian terraces occur at a few meters above present sea level and vertical tectonic displacements are small. Data from GPS and tide gauge measurements also indicate that any recent vertical movements are small. The MIS-5.5 shorelines are absent from the investigated section of the Turkish coast, consistent with crustal subsidence associated with the Hellenic Arc. The isostatic signals for the Israel section of the coast are also small (ranging from -0.11 mm/year to 0.14 mm/year, depending on site and earth model) and the observed (eustatic) average sea level change, corrected for this contribution, is a rise of 13.5±2.6 cm during the past ~2 ka. This is attributed to the time-integrated contribution to sea level from a combination of thermal expansion and other increases in ocean volume. The observed sea levels from the Turkish sites, in contrast, indicate a much greater rise of up to 2.2 mm/yr since 2.3 ka BP occurring in a wide area between Knidos and Kekova. The isostatic signal here is also one of a rising sea level (of up to ~ 1mm/year and site and earth-model dependent) and the corrected tectonic rate of land subsidence is ~1.48 mm/year. This is the primary cause of dramatic relative sea level rise for this part of the coast

    Active strain-rate Across the Messina Straits and Kinematics of Sicily and Calabria From GPS Data

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    The Messina Straits is the locus of one of the strongest seismic event that ever hit Italy during historical times, the 1908 Mw 7.1 earthquake, and the same region also suffered major damage from other strong earthquakes in the last few centuries. However, despite the large amount of data and studies carried out, our knowledge of the present-day deformation of this area is still debated. While a general consensus has been reached about the kinematics of the 1908 causative fault, less is known about the rate and shape of interseismic loading across the Straits, and debate continues also about the general kinematics and geodynamic framework of this region which are strongly influenced by subduction and retreat of Ionian lithosphere. Thanks to the increasing number of GPS Networks in the study region it is now possible to study both the regional kinematics and strain loading across active faults. In this work we analyze all the observations collected over the Messina non-permanent GPS Network for the 1994-2008 time span, and data from about 600 CGPS stations in the Euro-Mediterranean region, using the GAMIT software. The output of our analysis is a new and denser velocity field, which is used to study the plate kinematics and the rate of interseismic strain building across the Straits. GPS velocities show a sudden change in their orientation across the Straits moving to NNW-ward, in Estern Sicily, to NNE-ward in Western Calabria, depicting this area as a primary boundary between two different tectonic domains. The maximum strain-rates observed across the Straits are about 120 nanostrain/yr, with extension oriented about normal to the coasts of Sicily according to the presence of a normal fault. The measured velocity gradient can be used to model the creeping dislocation at depth, however, over the Messina Straits the interseismic elastic strains accumulating across other nearby active faults can significantly affect the observed velocity gradient.For this reason we investigate, using a regional elastic block-modeling approach, these effects. We use the block model to test for different microplates configurations and to account for nearby active faults while inverting for optimal fault geometry and intersismic slip-rates across the Straits

    Magnetic localization system for short-range positioning: a ready-to-use design tool

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    Magnetic localization is used in many indoor positioning applications, such as industrial, medical, and IoT, for its benefits related to the absence of line of sight needs, multipath and fading, the low cost of transmitters and receivers, and the simple development of setups made of coils and magnetic sensors. In short-range applications, this technology could bring some advantages with respect to ultrasound, laser, or RF ones. Nevertheless, fixed both the desired accuracy and the energy constraints, the optimal design of a localization system based on magnetic measurement depends on several factors: the dimension, the number and the optimal positions of the anchors, the uncertainties due to the sensing elements, and the data acquisition systems (DAQs). To preliminary fix all these parameters, suitable simulation environments allow developers to save time and money in developing localization applications. Many magnetic field simulators are available, but it is rare to find those that, considering the uncertainty due to the receiver and DAQs, are able to provide optimal anchors scenario given a target accuracy. To address this problem, this article presents a simulation tool providing the user with design requirements for given target accuracy. The aim of this article is to perform the first steps in providing a ready-to-use specification framework that given the localization domain, the mobile sensors, the DAQ characteristics, and the target accuracy and helps the developer of indoor magnetic positioning systems. The actual validity of the simulation model has been tested on a real setup.Postprint (published version
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