Portable Electronic System Research Articles

Rapid freshness prediction of crab based on a portable electronic nose system

In this paper, an automatic freshness prediction system for the living Chinese mitten crab was explored, which was formed from an electronic nose based on seven metal oxide semiconductor sensors. Prediction system acquired test data from the characteristic compounds in the headspace of crabs, and then was dealt with four different dimension reduction algorithms including PCA, LDA, KPCA and LE to reduce dimensions and extract effective features of sensor scores. Experimental results illustrated that the prediction system sensitively responded to crabs. PCA and LDA results failed to differentiate the response data of the living crabs. LE and KPCA were able to identify the different response data of crab samples. Back propagation neural network was used as a prediction model after dimension reduction. The model based on LE-BPNN reached a high identification rate of 90.6%. The simulation and experiment results showed that the prediction system can estimate the freshness of the living crab.

Rapid freshness prediction of crab based on a portable electronic nose system

In this paper, an automatic freshness prediction system for the living Chinese mitten crab was explored, which was formed from an electronic nose based on seven metal oxide semiconductor sensors. Prediction system acquired test data from the characteristic compounds in the headspace of crabs, and then was dealt with four different dimension reduction algorithms including PCA, LDA, KPCA and LE to reduce dimensions and extract effective features of sensor scores. Experimental results illustrated that the prediction system sensitively responded to crabs. PCA and LDA results failed to differentiate the response data of the living crabs. LE and KPCA were able to identify the different response data of crab samples. Back propagation neural network was used as a prediction model after dimension reduction. The model based on LE-BPNN reached a high identification rate of 90.6%. The simulation and experiment results showed that the prediction system can estimate the freshness of the living crab.

Rapid sensing of total theaflavins content in black tea using a portable electronic tongue system coupled to efficient variables selection algorithms

This study attempted to detect the total theaflavins content in black tea using a portable electronic tongue integrated with chemometric algorithms. Glassy carbon as a working electrode was used to collect the cyclic voltammetry current signals from the black tea samples. The synergy interval partial least square with competitive adaptive reweighted sampling (Si-CARS-PLS) was attempted to optimize and select the most informative current signal variables at special potentials for the prediction of the total theaflavins content in black tea. Models were optimized via cross validation. Compared with other characteristic variables selection methods, Si-CARS-PLS showed the best performance, employing only 13 variables (0.23% of the total variables), to achieve Rp = 0.8302 and RMSEP = 0.257 in the prediction set. The portable electronic tongue based on glassy carbon electrode and cyclic voltammetry combined with variable selection algorithm Si-CARS-PLS, proved a promising, rapid and cost-effective method to measure the total theaflavins content in black tea.

Electrical Impedance Spectroscopy (EIS) characterization of saline solutions with a low-cost portable measurement system

Electrical Impedance Spectroscopy (EIS), a powerful technique used for wide range of applications, is usually carried out by means of benchtop instrumentation (LCR meters and ìmpedance analyzers), not suited for in-the-field measurements performed outside a laboratory.In this paper a new portable electronic system for EIS on liquid and semi-liquid media is presented that is capable to produce an electrical fingerprint of the sample under investigation. The proposed system was used for the characterization of four different saline solutions (NaCl, Na2CO3, K2HPO4 and CuSO4). A multi-frequency approach, based on the measurement of maximum value of the impedance imaginary component and its corresponding frequency, was tested for the first time to discriminate different saline solutions. The results show that the proposed method is capable to discriminate the different solutions and to measure the concentration (R2 = 0.9965) independently of the type of saline solution.

Novel Gas Sensor Arrays Based on High-Q SAM-Modified Piezotransduced Single-Crystal Silicon Bulk Acoustic Resonators.

This paper demonstrates a novel micro-size (120 μm × 200 μm) piezoelectric gas sensor based on a piezotransduced single-crystal silicon bulk acoustic resonator (PSBAR). The PSBARs operate at 102 MHz and possess high Q values (about 2000), ensuring the stability of the measurement. A corresponding gas sensor array is fabricated by integrating three different self-assembled monolayers (SAMs) modified PSBARs. The limit of detection (LOD) for ethanol vapor is demonstrated to be as low as 25 ppm with a sensitivity of about 1.5 Hz/ppm. Two sets of identification code bars based on the sensitivities and the adsorption energy constants are utilized to successfully discriminate isopropanol (IPA), ethanol, hexane and heptane vapors at low and high gas partial pressures, respectively. The proposed sensor array shows the potential to form a portable electronic nose system for volatile organic compound (VOC) differentiation.

Portable electronic vision enhancement systems in comparison with optical magnifiers for near vision activities: an economic evaluation alongside a randomized crossover trial.

PurposeTo determine the incremental cost‐effectiveness of portable electronic vision enhancement system (p‐EVES) devices compared with optical low vision aids (LVAs), for improving near vision visual function, quality of life and well‐being of people with a visual impairment.MethodsAn AB/BA randomized crossover trial design was used. Eighty‐two participants completed the study. Participants were current users of optical LVAs who had not tried a p‐EVES device before and had a stable visual impairment. The trial intervention was the addition of a p‐EVES device to the participant's existing optical LVA(s) for 2 months, and the control intervention was optical LVA use only, for 2 months. Cost‐effectiveness and cost‐utility analyses were conducted from a societal perspective.ResultsThe mean cost of the p‐EVES intervention was £448. Carer costs were £30 (4.46 hr) less for the p‐EVES intervention compared with the LVA only control. The mean difference in total costs was £417. Bootstrapping gave an incremental cost‐effectiveness ratio (ICER) of £736 (95% CI £481 to £1525) for a 7% improvement in near vision visual function. Cost per quality‐adjusted life year (QALY) ranged from £56 991 (lower 95% CI = £19 801) to £66 490 (lower 95% CI = £23 055). Sensitivity analysis varying the commercial price of the p‐EVES device reduced ICERs by up to 75%, with cost per QALYs falling below £30 000.ConclusionPortable electronic vision enhancement system (p‐EVES) devices are likely to be a cost‐effective use of healthcare resources for improving near vision visual function, but this does not translate into cost‐effective improvements in quality of life, capability or well‐being.

A Practical and Portable Solids-State Electronic Terahertz Imaging System.

A practical compact solid-state terahertz imaging system is presented. Various beam guiding architectures were explored and hardware performance assessed to improve its compactness, robustness, multi-functionality and simplicity of operation. The system performance in terms of image resolution, signal-to-noise ratio, the electronic signal modulation versus optical chopper, is evaluated and discussed. The system can be conveniently switched between transmission and reflection mode according to the application. A range of imaging application scenarios was explored and images of high visual quality were obtained in both transmission and reflection mode.

Facile large-scale synthesis of core–shell structured sulfur@polypyrrole composite and its application in lithium–sulfur batteries with high energy density

In this context, we report a novel one-pot synthesis of S@Polypyrrole core–shell spheres as the cathode material in lithium–sulfur battery, designed by polypyrrole (PPy) wrapping on the formed nano-sulfur via the facile wet chemical strategy. The in-situ polymerized PPy layer in this special structure is helpful to inhibit aggregation of sulfur particles with small size, the polysulfide dissolution and shuttling, and offer fast and efficient transport of electron/lithium ion within the electrode. Besides, the flexible PPy layer effectively accommodates the volume expansion. PPy with partial PO43− doping was also employed to improve cycling stability and C-rate performance of S@PPy composite by exchanging Cl− with PO43−. Thus, the sulfur electrode with a high sulfur loading of 80% delivered an initial discharge capacity of 1142mAhg−1 and maintained a high capacity of 805mAhg−1 after 50 cycles at 0.1C. The corresponding capacity retention over 100 cycles was about 65%, with a limited decay of 0.3% per cycle. Even at a high current density of 1.5C, the composite still exhibited a high discharge capacity of about 700mAhg−1. This results mean that the designed electrode can achieve a high practical specific energy density of more than 400Wh/kg, far beyond the commercial LiCoO2 batteries. Due to low cost, facile large-scale synthesis and superior electrochemical performance of S@PPy cathode with high sulfur loading, this work will provide a very promising method to further promote the Li–S batteries in the practical application of portable electronic devices, electric devices and energy storage system.

Design of A Portable Electronic Nose system and Application in K Value Prediction for Large Yellow Croaker (Pseudosciaena crocea)

In this paper, a portable electronic nose (E-nose) system was designed, and its application in K value prediction for large yellow croaker (Pseudosciaena crocea) was also explored. E-nose responses to croaker samples were measured for 8 days. Microbiological and chemical indexes including total viable count (TVC), K value, and GC-MS were synchronously examined. Principal component analysis (PCA) and stochastic resonance (SR) were utilized for E-nose measurement data analysis. Results suggested that croaker’s K value increased rapidly due to microbial propagation. GC-MS results presented the information of volatile gas emitted by croaker samples, and provided reliable references for E-nose responses. PCA method could not discriminate all croaker samples, while SR signal-to-noise ratio (SNR) maximum (Max SNR ) values quantitatively discriminated all samples. Large yellow croaker K value predictive model was developed by linear fitting regression between K values and Max SNR values with a regression coefficient (R 2 ) of 0.96. Validating experiment results demonstrated that the forecasting accuracy of this model is 83 % the regression coefficient of the developed model was 0.83. E-nose is a useful tool for food quality examination. But, there are no such standard references for E-nose examination, which limits the applications of this technique. The method proposed here will promote the applications of E-nose in aquatic product quality rapid analysis.

A portable electronic system for in-situ measurements of oil concentration in MetalWorking fluids

MetalWorking fluids (MWFs) are widely used to cool and lubricate machines and tools. By far, the most common MWFs are oil-in-water emulsions with oil concentration (Coil) in the range from 1% to 10%, depending on type of oil, material to be worked, etc. In order to optimize emulsion and machine performance, as well as for good waste policy, the right value of Coil should be kept (approximately) constant during the MWF’s lifecycle to compensate inevitable changes due to water evaporation, bacterial attack, oil adhesion to metal parts, etc. This, however, requires periodic measurements, often skipped because they require unhandy operations and produce inaccurate results. In this context, a new system is presented that is based on the falling ball principle, normally used for viscosity measurements, shown to be suitable also for accurate Coil measurements. In our system, the transit time of the sphere within the instrument is determined by means of inductive proximity sensors, a PT100 sensor is used for temperature whose effects on Coil are accounted for by means of an ad-hoc algorithm. A battery-operated electronic board has been designed that allows rapid and user-friendly “in-situ” measurements and a prototype of an whole portable and automatic instrument, suitable for in-situ measurements, has been fabricated.

Research on Tactile Sensors Interface - Review of Theoretical and Practical Approach

The research presented in this paper aims to review the theoretical and practical approach for one of method to create the interface, to condition and to gather the data from the resistive force tactile sensor, in for the measuring of the vertical reaction force to the ground during human walking. The project result is a portable electronic system which allows the gathering, storing and transmission of the data from the force sensors mounted in an “overshoe” holder [1]. The article presents the research methods for the measured parameters as vertical reaction force to the ground, measured in 10 contact points between the foot sole and the ground by the help of some tactile sensors. The paper analysis all issues related to providing an optimal solution for the support with sensors and presents the conclusions for practical design.

Towards Point-of-Use Dielectrophoretic Methods: A New Portable Multiphase Generator for Bacteria Concentration

This manuscript presents a portable and low cost electronic system for specific point-of-use dielectrophoresis applications. The system is composed of two main modules: a) a multiphase generator based on a Class E amplifier, which provides 4 sinusoidal signals (0°, 90°, 180°, 270°) at 1 MHz with variable output voltage up to 10 Vpp (Vm) and an output driving current of 1 A; and b) a dielectrophoresis-based microfluidic chip containing two interdigitated electrodes. The system has been validated by concentrating Escherichia coli (E. coli) at 1 MHz while applying a continuous flow of 5 µL/min. The device functionalities were verified under different conditions, achieving an 83% trapping efficiency when counter-phased signals are used.

The p-EVES study design and methodology: a randomised controlled trial to compare portable electronic vision enhancement systems (p-EVES) to optical magnifiers for near vision activities in visual impairment.

To describe the study design and methodology for the p-EVES study, a trial designed to determine the effectiveness, cost-effectiveness and acceptability of portable Electronic Vision Enhancement System (p-EVES) devices and conventional optical low vision aids (LVAs) for near tasks in people with low vision. The p-EVES study is a prospective two-arm randomised cross-over trial to test the hypothesis that, in comparison to optical LVAs, p-EVES can be: used for longer duration; used for a wider range of tasks than a single optical LVA and/or enable users to do tasks that they were not able to do with optical LVAs; allow faster performance of instrumental activities of daily living; and allow faster reading. A total of 100 adult participants with visual impairment are currently being recruited from Manchester Royal Eye Hospital and randomised into either Group 1 (receiving the two interventions A and B in the order AB), or Group 2 (receiving the two interventions in the order BA). Intervention A is a 2-month period with conventional optical LVAs and a p-EVES device, and intervention B is a 2-month period with conventional optical LVAs only. The study adopts a mixed methods approach encompassing a broad range of outcome measures. The results will be obtained from the following primary outcome measures: Manchester Low Vision Questionnaire, capturing device 'usage' data (which devices are used, number of times, for what purposes, and for how long) and the MNRead test, measuring threshold print size, critical print size, and acuity reserve in addition to reading speed at high (≈90%) contrast. Results will also be obtained from a series of secondary outcome measures which include: assessment of timed instrumental activities of daily living and a 'near vision' visual functioning questionnaire. A companion qualitative study will permit comparison of results on how, where, and under what circumstances, p-EVES devices and LVAs are used in daily life. A health economic evaluation will provide results on: the incremental cost-effectiveness of p-EVES compared to optical magnifiers; cost-effectiveness; and cost-utility. The evidence base in low vision rehabilitation is modest and further high quality clinical trials are required to inform decisions on healthcare provision. The p-EVES study findings are anticipated to contribute to this broader evidence requirement, with the methodological issues evident here being relevant to other trials within the field.

Development of Portable Electronic Nose for VOC Detection

In order to detect Volatile Organic Compounds (VOC) quickly and accurately, a portable electronic nose system was developed which including signal acquisition module, valve control module, embedded modules. Three sensors were used to measure methane, ethanol and formaldehyde gas. We used a three-way valve to control two kinds of gas, in order to avoid the system noise the zero reference was subtracted with the gas being tested. The system could quickly detect the three kinds VOC. The system can play a positive role in the rapid assessment of pollution in industrial parks.

Quantitative electrochemical detection of cathepsin B activity in complex tissue lysates using enhanced AC voltammetry at carbon nanofiber nanoelectrode arrays

The proteolytic activity of a cancer-related enzyme cathepsin B is measured with alternating current voltammetry (ACV) using ferrocene (Fc) labeled tetrapeptides attached to nanoelectrode arrays (NEAs) fabricated with vertically aligned carbon nanofibers (VACNFs). This combination enables the use of high AC frequencies (~1kHz) with enhanced electrochemical signals. The specific proteolysis of the Fc–peptide by cathepsin B produces decay in the ACV peak current versus the reaction time. The exponential component of the raw data can be extracted and defined as the “extracted proteolytic signal” which allows consistent quantitative analyses using a heterogeneous Michaelis–Menten model. A “specificity constant” kcat/KM=(3.68±0.50)×104M−1s−1 for purified cathepsin B was obtained. The detections of cathepsin B activity in different concentrations of whole lysate of human breast tissue, tissue lysate spiked with varied concentrations of cathepsin B, and the tissue lysate after immunoprecipitation showed that there is ~13.4nM higher cathepsin B concentration in 29.1µgmL−1 of whole tissue lysate than the immunoprecipitated sample. The well-defined regular VACNF NEAs by e-beam lithography show a much faster kinetics for cathepsin B proteolysis with kcat/KM=9.2×104M−1s−1. These results illustrate the potential of this technique as a portable multiplex electronic system for cancer diagnosis by rapid protease profiling of serum or blood samples.

<b>Design of a low cost measurement system based on accelerometers for gait analysis</b> - doi: 10.4025/actascitechnol.v36i1.18581

Current research reports on the development of a portable electronic system to assess the kinematics of the lower limb joints at the sagittal plane. The electronic device characteristics and the different communication protocols to transfer data are also reported. Research obtained the hip and knee angles to analyze the lower limb kinematics during multiple gait cycles. Results showed that the movement patterns, found in the analysis made on people from central Mexico, were cyclical and alternating. The knee described a one third curve in flexion-extension movements just before the start of the flexion-extension curve in the swing phase. Moreover data obtained showed a correlation of movement between hip and knee during walking.

Classification of rice wine according to different marked ages using a portable multi-electrode electronic tongue coupled with multivariate analysis

A developed multi-electrode electronic tongue combined with multivariate analysis was attempted to classify Chinese rice wine according to four different marked ages (3, 5, 8 and 10years) for authentication. The electronic tongue consisted of three working electrodes (glassy carbon, gold and platinum) in a standard three-electrode configuration, using cyclic voltammetry technique to record signals. Characteristic values were extracted from the raw data signals for further multivariate analysis. In developing the discrimination models, linear (SIMCA, PLSDA and KNN) and nonlinear (BPANN and SVM) pattern recognition methods were comparatively employed, and they were optimized by cross-validation. Compared with other models, BPANN model achieved the best result, with the identification rate of 100% in the calibration set, and 100% in the prediction set. The overall results showed that this portable multi-electrode electronic tongue system with BPANN classification tool could successfully be used in identification of rice wine with different marked ages.

Peak shift measurement of localized surface plasmon resonance by a portable electronic system

In recent years, the characterization of surface molecular layers by localized surface plasmon resonance (LSPR) has attracted a lot of interest thanks to its ability to provide a higher spatial resolution with respect to standard SPR. LSPR can be observed as a peak in the extinction spectrum of metal nanoparticles such as gold non-connected surface patterns. A plasmon peak red shift is caused both by the presence of molecular layers on the gold surface and by molecular binding events. The current study presents a portable transmission system to observe the LSPR phenomenon that extracts the peak location employing a discrete number of light sources. The peak location extraction is performed by an algorithm that takes into account the spectral characteristics of all the components. The performance of our LSPR measurement system has been characterized on a set of Fluorinated Tin Oxide-coated slides covered with nanoislands with a diameter of approximately 30 nm. The samples have been modified with a single-stranded DNA layer and the plasmonic peak location has been determined before and after surface treatment. The samples have been characterized in parallel with a high-end spectrophotometer. The results presented demonstrated the performance of our measurement system in determining the peak location with 1 nm precision. (C) 2012 Elsevier B.V. All rights reserved.

Monitor de señales de electrocardiografía y frecuencia cardiaca mediante un teléfono móvil con el protocolo de comunicación Bluetooth

To develop a portable signal monitoring equipment for electrocardiography (ECG) and heart rate (HR), communicated with a mobile phone using the Bluetooth (BT) communication protocol for display of the signal on screen. A monitoring system was designed in which the electronic section performs the ECG signal acquisition, as well as amplification, filtering, analog to digital conversion and transmission of the ECG and HR using BT. Two programs were developed for the system. The first one calculates HR through QRS identification and sends the ECG signals and HR to the mobile, and the second program is an application to acquire and display them on the mobile screen. We developed a portable electronic system powered by a 9 volt battery, with amplification and bandwidth meeting the international standards for ECG monitoring. The QRS complex identification was performed using the second derivative algorithm, while the programs allow sending and receiving information from the ECG and HR via BT, and viewing it on the mobile screen. The monitoring is feasible within distances of 15 m and it has been tested in various mobiles telephones of brands Nokia®, Sony Ericsson® and Samsung®. This system shows an alternative for mobile monitoring using BT and Java 2 Micro Edition (J2ME) programming. It allows the register of the ECG trace and HR, and it can be implemented in different phones.

Portable Measurement System for Voltammetry and Impedance Spectroscopy. Application for TNT Detection

Abstract This paper presents the design of a portable low-cost electronic tongue system that includes an electronic equipment based on a 16 bits microcontroller and a software application that runs on a personal computer. The designed system is able to carry out voltammetry and impedance spectroscopy measurements with different electrodes configurations in a single device, allowing the implementation of both techniques in a convenient and easy way. The designed system has been electrically characterize and has shown good levels of accuracy and reliability. It is composed by an electronic equipment, the electrodes and a software application. This system has been successfully used in various applications in the field of chemical analysis, food quality and environmental. In this communication the results of the application of the designed electronic tongue system to explosive compounds detection are shown.