No. 1

No. 2

       No. 3         

  Measurement in Biomedicine

   Pages

Ganesh R. Naik, Dinesh K. Kumar, Sridhar P. Arjunan:

Abstract: The presence of noise and cross-talk from closely located and simultaneously active muscles is exaggerated when the level of muscle contraction is very low. Due to this the current applications of surface electromyogram (sEMG) are infeasible and unreliable in pattern classification. This research reports a new technique of sEMG using Independent Component Analysis (ICA). The technique uses blind source separation (BSS) methods to classify the patterns of Myo-electrical signals during different Maximum Voluntary Contraction (MVCs) at different low level finger movements. The results of the experiments indicate that patterns using ICA of sEMG is a reliable (p<0.001) measure of strength of muscle contraction even when muscle activity is only 20% MVC. The authors propose that ICA is a useful indicator of muscle properties and is a useful indicator of the level of muscle activity.

Keywords:  surface electromyography, independent component analysis, blind source separation, gestures, maximum voluntary contractions, RMS, motor unit action potential

You Kok Yeow, Zulkifly Abbas, Kaida Khalid:

Application of Microwave Moisture Sensor for Determination of Oil Palm Fruit Ripeness

Abstract: This paper describes the development of a low cost coaxial moisture sensor for the determination of moisture content (30 % to 80 % wet-weight basis) of the oil palm fruits of various degree of fruit ripeness. The sensor operating between 1 GHz and 5 GHz was fabricated from an inexpensive 4.1 mm outer diameter SMA coaxial stub contact panel which is suitable for single fruit measurement. The measurement system consists of the sensor and a PC-controlled vector network analyzer (VNA). The actual moisture content was determined by standard oven drying method and compared with predicted value of fruit moisture content obtained using the studied sensor. The sensor was used to monitor fruit ripeness based on the measurement of the phase or magnitude of reflection coefficient and the dielectric measurement software was developed to control and acquire data from the VNA using Agilent VEE. This software was used to calculate the complex relative permittivity from the measured reflection coefficient between 1GHz and 5 GHz.

Keywords:  Vector network analyzer, moisture content, reflection coefficient, oil palm fruits, microwave sensors, dielectric constant

  Measurement of Physical Quantities

A. Abu_Al_Aish, M. Rehman, M. Z. Abdullah and A. H. Abu Hassan:

Microcontroller Based Capacitive Mass Measuring System

Abstract: The paper deals with a new design of a capacitive sensor developed for the accurate and precise measurement of mass. It employs a co-axial cylinder based capacitive sensor whose capacitance decreases linearly with mass, due to the shielding effect of the conducting shield, which moves between the stationary cylinders of the capacitor with the movement of the mass holder. An accurate capacitance to voltage converting system is used to detect the mass in terms of voltage. Linear relationship between mass and output signal is obtained with the help of microcontroller. The presented sensor has high order of linearity, flexibility in design and controllable damping. The overall size of the sensor may be reduced to very small values by this design. It is highly robust and may be attached to any complex system. For the spring, used in the system, mass sensor can measure up to 7 kg.

Keywords:  capacitive sensor; mass sensor; capacitance measuring system; microcontroller; spring

J. Song, T. Vorburger, R. Thompson, T. Renegar, A. Zheng, L. Ma, J. Yen, M. Ols:

Three Steps towards Metrological Traceability for Ballistics Signature Measurements

Abstract: The National Institute of Standards and Technology (NIST) in collaboration with the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) has developed the Standard Reference Material (SRM) bullets and casings.  NIST and ATF are proposing to establish a National Ballistics Measurement Traceability and Quality System for ballistics signature measurements and correlations using these materials.  In this paper, three key steps towards metrological traceability for ballistics signature measurements are discussed that include: 1) Establishing a reference standard; 2) Establishing an unbroken chain of calibrations; and 3) Evaluating measurement uncertainty.

Keywords: traceability, forensic science, ballistics signature, standard reference material, standard bullet, standard casing

R. M. Radetic, D. R. Milivojevic, V. M. Despotovic:

Optimization of Measuring Current for Chopper Low Resistance Comparator

Abstract: The article describes systematic error analysis for realized chopper low-resistance comparator. The objective was to determine optimal working conditions, considering limited resolution (about 10 nV) and resistance variation due to self-heating caused by increase of measuring current. The analysis and performances of realized chopper low-resistance comparator prototype instrument confirmed the initial assumptions of applied principles. The error for 1 A measuring current is 1.15 ppm in the measuring range of 10 mW. It is possible to use the same principle for calculation of optimal measuring current and measurement error in other measurement ranges, as well.

Keywords:  low-resistance measurement, chopper comparator, error analysis

R. M. Radetic, D. R. Milivojevic, M. Pavlov:

The New Bridge Converter Control Method

Abstract: The article describes a new control method of transistor power bridge converter. It is a new one, because of some original solutions and its difference in comparison to existing methods. It’s irrelevant of load, similar to the “phase shifted” control method. It is easy to realize using ordinary electronic elements. A significant advantage of method is the possibility of permanent output current monitoring by measuring the voltage sag on a pair of transistors. That allows a very efficient current protection.

Keywords:  control method, bridge converter, PWM

  Measurement in Biomedicine

S. Štolc, I. Bajla:

On the Optimum Architecture of the Biologically Inspired Hierarchical Temporal Memory Model Applied to the Hand-Written Digit Recognition        Invited paper

Abstract: In the paper we describe basic functions of the Hierarchical Temporal Memory (HTM) network based on a novel biologically inspired model of the large-scale structure of the mammalian neocortex.The focus of this paper is in a systematic exploration of possibilities how to optimize important controlling parameters of the HTM model applied to the classification of hand-written digits from the USPS database. The statistical properties of this database are analyzed using the permutation test which employs a randomization distribution of the training and testing data. Based on a notion of the homogeneous usage of input image pixels, a methodology of the HTM parameter optimization is proposed. In order to study effects of two substantial parameters of the architecture: the patch size and the overlap in more details, we have restricted ourselves to the single-level HTM networks. A novel method for construction of the training sequences by ordering series of the static images is developed. A novel method for estimation of the parameter maxDist based on the box counting method is proposed. The parameter sigma of the inference Gaussian is optimized on the basis of the maximization of the belief distribution entropy. Both optimization algorithms can be equally applied to the multi-level HTM networks as well. The influences of the parameters transitionMemory and requestedGroupCount on the HTM network performance have been explored. Altogether, we have investigated 2736 different HTM network configurations. The obtained classification accuracy results have been benchmarked with the published results of several conventional classifiers.

Keywords:  hierarchical temporal memory (HTM); optimum network architecture, visual pattern recognition, USPS hand-written digits

  Measurement of Physical Quantities

M. Jurčević, H. Hegeduš, M. Golub:

Generic System for Remote Testing and Calibration of Measuring Instruments: Security Architecture

Abstract: Testing and calibration of laboratory instruments and reference standards is a routine activity and is a resource and time consuming process. Since many of the modern instruments include some communication interfaces, it is possible to create a remote calibration system. This approach addresses a wide range of possible applications and permits to drive a number of different devices. On the other hand, remote calibration process involves a number of security issues due to recommendations specified in standard ISO/IEC 17025, since it is not under total control of the calibration laboratory personnel who will sign the calibration certificate. This approach implies that the traceability and integrity of the calibration process directly depends on the collected measurement data. The reliable and secure remote control and monitoring of instruments is a crucial aspect of internet-enabled calibration procedure.

Keywords:   internet-enabled testing and calibration, travelling standard, hardware security module (HSM), ISO/IEC 17025

K. Hariharan, P. Vasanthakumar, G. Varun, V. Abhaikumar:

A Method for ADC Error Testing and its Compensation in Ratiometric Measurements

Abstract: Errors induced due to ratiometric measurements are discussed and a simplified compensation method to reduce the various static errors of ADC, voltage reference errors in ratiometry and resistance mismatch errors is proposed. Curve fitting is done for the error samples and the system is modelled in comparison to an ideal system. Static errors and other ratiometric errors, thus modelled are derived into a corrective equation in comparison with an errorless system. Implementation of the proposed method is discussed for a resistance measurement system and analyzed. This paper also discusses the usage of the proposed system with successive approximation ADCs for ratiometric measurement operations against the conventional requirement dual slope ADCs for the same.

Keywords:  ratio-metric measurements, curve fitting, ADC error testing, error compensation

E. Kuvaldin:

Counting Method for Measuring and Linearity Checking Photometry Devices

Abstract: The possibility of calibration and linearity check of optical detectors in a wide dynamic range by method of counting separate parts of energy is investigated. Counting method permits nonselective energy change  of measuring optical pulse more then 105 times. A construction of working source of radiation with GaAs LED is described. Results of experimental investigation are presented.

Keywords:  optical measurement, check linearity, energy meter, calibration, pulse count

A. Kavitha, C. M. Sujatha and S. Ramakrishnan:

Prediction of Spirometric Forced Expiratory Volume (FEV1)  Data Using Support Vector Regression

Abstract: In this work, prediction of forced expiratory volume in 1 second (FEV1) in pulmonary function test is carried out using the spirometer and support vector regression analysis. Pulmonary function data are measured with flow volume spirometer from volunteers (N=175) using a standard data acquisition protocol. The acquired data are then used to predict FEV1. Support vector machines with polynomial kernel function with four different orders were employed to predict the values of FEV1. The performance is evaluated by computing the average prediction accuracy for normal and abnormal cases. Results show that support vector machines are capable of predicting FEV1 in both normal and abnormal cases and the average prediction accuracy for normal subjects was higher than that of abnormal subjects. Accuracy in prediction was found to be high for a regularization constant of C=10. Since FEV1 is the most significant parameter in the analysis of spirometric data, it appears that this method of assessment is useful in diagnosing the pulmonary abnormalities with incomplete data and data with poor recording.

Keywords:  spirometry, forced expiratory maneuver, support vector regression

S. Kosarevsky,  V. Latypov:

Inertia Compensation While Scanning Screw Threads on Coordinate Measuring Machines

Abstract: Usage of scanning coordinate-measuring machines for inspection of screw threads has become a common practice nowadays. Compared to touch trigger probing, scanning capabilities allow to speed up the measuring process while still maintaining high accuracy. However, in some cases accuracy drastically depends on the scanning speed. In this paper a compensation method is proposed allowing to reduce the influence of inertia of the probing system while scanning screw threads on coordinate-measuring machines.

Keywords:  scanning, CMM, accuracy, screw thread

  Measurement in Biomedicine

J. Přibil, A. Přibilová:

An Experiment with Evaluation of Emotional Speech Conversion by Spectrograms

Abstract:The spectrogram is a useful tool for visual quality comparison of different types of emotional synthetic speech. This paper is focused on application of this method to evaluation of sentences after spectral and prosodic modifications for emotional speech conversion. Performed experiments with spectrogram evaluation for several male and female speakers and four emotional states (joy, sadness, anger, neutral state) are also described.

K. Sapozhnikova, R. Taymanov:

Improvement of Traceability of Widely-Defined Measurements in the Field of Humanities

Abstract: In the last decades, a tendency to extend the domain of “fuzzy” measurements of multiparametric quantities to the field of humanities has been observed. In the measurement process, the “fuzzy” measurements should meet the requirements of metrological traceability. The paper deals with the approach proposed for developing a measurement model of “fuzzy” measurements. The approach suggested is illustrated by an example of a model for measuring the emotions contained in musical fragments. The model is based on the hypothesis that permits to explain the origination of emotions in the evolution process.

  Measurement of Physical Quantities

D. Sumina, A. Šala, R. Malarić:

Determination of Load Angle for Salient-pole Synchronous Machine

Abstract: This paper presents two methods for load angle determination for salient-pole synchronous generator. The first method uses optical encoder to detect the rotor position. In some cases the end of the rotor shaft is not free to be used and mounting of an encoder is impossible. Therefore, the second method proposes estimation of the load angle based on the measured electrical values that have been already used in excitation control system of the synchronous generator. Estimation method uses corresponding voltage-current vector diagram and parameters of the synchronous generator, transformer and transmission lines. Both methods were experimentally verified on the digital control system and synchronous generator connected to power system. The estimation and measured results were compared. The accuracy of load angle estimation method depends on voltage and current measurement accuracy as well as generator, transformer and transmission line parameter accuracy. The estimation method gives satisfactory accuracy for load angles less than 120º el. Thus, it can be applied in excitation control system to provide stable work of synchronous generator in under-excitation operating area.

I. Frollo,  P. Andris, J. Přibil, L. Vojtíšek, T. Dermek, L. Valkovič:

Measurement and Imaging of Planar Electromagnetic Phantoms Based on NMR Imaging Methods

Abstract: Planar electromagnetic phantom design for measurement and imaging using NMR has been performed. Electromagnetic phantom computation and testing on a NMR 0.178 Tesla Esaote Opera imager were accomplished. The classical geometrical and chemical phantoms are generally used for testing of NMR imaging systems. They are simple cylindrical or rectangular objects with different dimensions and shapes with holes filled with specially prepared water solutions. In our experiments a homogeneous phantom (reference medium) - a container filled with water - was used. The resultant image represents the magnetic field distribution in the homogeneous phantom.  An image acquired by this method is actually a projection of the sample properties onto the homogeneous phantom. The goal of the paper is to map and image the magnetic field deformation using NMR imaging methods. We are using a double slender rectangular vessel with constant thickness filled with specially prepared water solution in our experiments. For detection a carefully tailored gradient-echo imaging method, susceptible to magnetic field homogeneity, was used.

V.P. Lukin, N.N. Botygina, O.N. Emaleev, P.A. Konyaev:

Wavefront sensors for adaptive optical systems

Abstract: A high precision Shack-Hartmann wavefront (WF) sensor has been developed on the basis of a low-aperture off-axis diffraction lens array. The device is capable of measuring WF slopes at array sub-apertures of 640х640 mm in size with an error not exceeding 4.80 arcsec (0.15 pixel), which corresponds to the standard deviation equal to 0.017 λ at the reconstructed WF with wavelength λ. Also the modification of this sensor for adaptive system of solar telescope using extended scenes as tracking objects, such as sunspot, pores, solar granulation and limb, is presented. The software package developed for the proposed WF sensors includes three algorithms of local WF slope estimation (modified centroids, normalized cross-correlation and fast Fourier-demodulation), as well as three methods of WF reconstruction (modal Zernike polynomial expansion, deformable mirror response function expansion and phase unwrapping), that can be selected during operation with accordance to the application.

V.E. Privalov, V.G. Shemanin, E.I.Voronina:

Iodine Molecules Differential Absorption Cross section Lidar Studies

Abstract: Lidar monitoring of the gaseous molecules in atmosphere can be used for concentration measurements of the toxic pollutants in air of the urban and industrial regions. Such a concentration study in the multi-components gaseous mixture by lidar technique is a complex problem in atmospheric pollution monitoring. The differential absorption lidar (DA-lidar) is the most preferable for the detection of iodine molecules at very low concentration levels. The iodine molecules absorption cross section in the laboratory lidar studies and lidar equation simulation in this lidar variant corresponds with earlier data.

  Measurement in Biomedicine

S.-D. Kim, H.-J. Lee, B.-D. Oh:

Investigation on Application of Parshall Flume for Flow Measurement of Low-Flow Season in Korea

Abstract: The accurate determination of the flow rate of the low flow season is a very important factor in setting and running a water resources development plan. Because South Korea undergoes a lot of flood damage due to localized heavy rain during the summer season, flow rates are measured mostly according to flood management, and this allows for a lack in research in understanding low flow season flow rates. In order to estimate the accurate flow rate of a low flow season, the present study has used the Parshall flume that has been used widely in flow measurements, and has reviewed the applicability. A Parshall flume was installed in an actual river and the measured flow rate that was obtained from the flow rate formula and velocity measurements, that were suggested by the ISO and the USBR, were found to be very accurate when compared to the flow rate computation results by the Parshall flume. By using the state-discharge rating curve equation that is most commonly used at the level gauging station, the flow rate was estimated and compared with the flow rate by the Parshall flume. The results showed an approximate 14% error with the estimation from the state-discharge rating curve equation.  Therefore, using the Parshall flume to estimate the flow rate of low flow season is more effective than the state-discharge rating curve equation.

L. Valkovic, C. Windischberger:

Method for geometric distortion correction in fMRI based on three echo planar phase images

Abstract: Functional magnetic resonance imaging (fMRI) is a quickly developing method for non-invasive dynamic brain studies. It uses swift acquisition sequences like echo planar imaging (EPI) that are very sensitive to susceptibility artifacts. These artifacts relate to magnetic field inhomogeneities and may cause geometric distortions. Many methods for correcting these distortions are currently used. Most common are the field mapping methods that use the map of field strength. To create a field map, different approaches can be used and different data must be acquired for each method. This paper compares a commonly used conventional gradient echo (GE) field mapping method with a 3EPI phase images based method. Although the EPI method is more sophisticated and was expected to perform better, the GE field maps showed better results in distortion correction. The cause of this is not in the method’s principle itself, but in its high requirements.

  Measurement of Physical Quantities

Salah H. R. Ali:

Probing System Characteristics in Coordinate Metrology

Abstract: This paper aims at studying the effect of the dynamic errors on surface measurements using three different types of touch trigger probes attached to a bridge-type-CMM. Unforeseeable dynamic root errors of a ductile touch trigger probing system have been characterized theoretically and experimentally as well. The results were employed in validating a developed analytical two-dimensional-model (2DM) of stylus tip to be developed to demonstrate the capability of such approaches of emphasizing the root error concept, and to evaluate the accuracy of the CMM measurements. A set of experiments was conducted; the results were analyzed in order to investigate the effect of the dynamic root errors in the light of probe scanning speed at different stylus tip radii. Variations in the mass and geometry of the stylus have their consequent effects on its inherent intrinsic dynamic characteristics that in turn would cause relevant systematic root errors in the resulting measurements. 3D bore cylindrical surface form undulations were measured by employing a probe on the trajectory of internal surface diameter for the standard reference test gauge ring. Regression analysis was applied on the results of measurement density distribution; uncertainty of measurement repeatability was then evaluated and graphically presented. The results were investigated and optimum strategic measurement parameters could thus have been derived to ensure foreseeable accurate and precise results.

S. Yadav, V. K. Gupta, and A. K. Bandyopadhyay:

Investigations on Measurement Uncertainty and Stability of Pressure Dial Gauges and Transducers

Abstract: Several commercial instruments are available for pressure measurements. As per ISO stipulations, whenever such instruments are used for precise and accurate pressure measurements, it is obligatory on the part of measurement authority to indicate the quality of results. Stability of the pressure measuring instruments over the years is one of the important parameters in defining the quality of results quantitatively. Also, it helps the users to decide the optimum calibration interval of the particular instrument. In the present investigation, we have studied a number of analogue / digital pressure transducers / transmitters / calibrators and pressure dial gauges. The present paper describes the results of the studies carried out on several pressure dial gauges and transducers in the pressure range up to 500 MPa, calibrated several times over the years, as examples. A new approach is proposed for the establishment of measurement uncertainty for such instruments by characterizing the data obtained during calibration over the years using curve fitting.

S. Kosarevsky, V. Latypov:

Development of an Algorithm to Detect Screw Threads in Planar Point Clouds

Abstract: Measurements in production must be rapid, robust and automated. In this paper a new method is proposed to automatically extract features and parameters of screw threads via Hough transformation from 2D point clouds acquired from profile measuring machines. The described method can be used to automate many operations during screw thread prealignment and drastically reduce operator’s influence on the measurement process resulting in lower measurement times and increased repeatability.

J.-Y. Chen, B.-Y. Lee, K.-C. Lee, Z.-K. Chen:

Development and Implementation of a Simplified Tool Measuring System

Abstract: This paper presents a simplified system for measuring geometric profiles of end mills. Firstly, a CCD camera was used to capture images of cutting tools. Then, an image acquisition card with the encoding function was adopted to convert the source of image into an USB port of a PC, and the image could be shown on a monitor. In addition, two linear scales were mounted on the X-Y table for positioning and measuring purposes. The signals of the linear scales were transmitted into a 4-axis quadrature encoder with 4-channel counter card for position monitoring. The C++ Builder was utilized for designing the user friendly human machine interface of the measuring system of tools. There is a cross line on the image of the interface to show a coordinate for the position measurement. Finally, a well-known tool measuring and inspection machine was employed for the measuring standard. This study compares the difference of the measuring results by using the machine and the proposed system. Experimental results show that the percentage of measuring error is acceptable for some geometric parameters of the square or ball nose end mills. Therefore, the results demonstrate the effectiveness of the presented approach.

  Measurement of Physical Quantities

M.L.H. Gruwel, P. Latta, B. Matwiy, U. Sboto-Frankenstein, P. Gervai,  B. Tomanek:

Measurement of Viscoelastic Properties of Condensed Matter using Magnetic Resonance Elastography

Abstract:  Magnetic resonance elastography (MRE) is a phase contrast technique that provides a non-invasive means of evaluating the viscoelastic properties of soft condensed matter. This has a profound bio-medical significance as it allows for the virtual palpation of areas of the body usually not accessible to the hands of a medical practitioner, such as the brain. Applications of MRE are not restricted to bio-medical applications, however, the viscoelastic properties of prepackaged food products can also non-invasively be determined. Here we describe the design and use of a modular MRE acoustic actuator that can be used for experiments ranging from the human brain to pre-packaged food products. The unique feature of the used actuator design is its simplicity and flexibility, which allows easy reconfiguration.

P. Siffalovic, K. Vegso, M. Jergel, E. Majkova, J. Keckes, G. A. Maier, M. Cornejo, B. Ziberi, F. Frost, B. Hasse, J. Wiesmann:

Measurement of nanopatterned surfaces by real and reciprocal space techniques

Abstract:  A newly developed laboratory grazing-incidence small-angle X-ray scattering GISAXS system capable of statistical measurements of surface morphology at the nanometer scale was developed. The potential of the GISAXS system is compared to the AFM technique for a nanopatterned silicon surface produced by ion-beam erosion. the characteristic period of the ion-beam induced ripples and their lateral correlation length were estimated from AFM. Using GISAXS the reciprocal space map of surface morphology was measured and analyzed. The two microfocus X-ray sources emitting radiation at the Cu‑K and Cr‑K were used. The lateral periods of ripples obtained by the reciprocal space mapping techniques match the results of real space techniques. The setup has the potential to monitor and control the deposition process and formation of nanostructures with sufficient temporal and spatial resolution.

M. Bittera, V. Smiesko:

Influence of interface cables termination impedance on radiated emission measurement

Abstract:  Interface cables and especially their arrangement and terminations significantly affect the results of the radiated emission measurement of tested equipment. Two types of shortened two-wire interface cables were surveyed to obtain the influence of cable’s termination. Two analyses, based on theoretical knowledge, were performed – the analysis using numerical simulation and the measurement of input impedance of the cable using network analyzer. The methods of analysis were verified and compared with real radiated emission measurements. Finally, the influence of cable termination was obtained and discussed.

L. Chitu, P. Siffalovic, E. Majkova, M. Jergel, K. Vegso, S. Luby, I. Capek, A. Satka, J. Perlich, A. Timmann, S. V. Roth, J. Keckes, G. A. Maier:

Modified Langmuir-Blodgett deposition of nanoparticles – measurement of 2D to 3D ordered arrays

Abstract:  The ordered nanoparticle monolayers and multilayers over macroscopic areas were prepared by the modified Langmuir-Blodgett method. Using this approach, the nanoparticle monolayer is formed on the water surface by compression and subsequently it is transferred onto the substrate by a controlled removal of the water subphase. The ordering and homogeneity of the prepared mono- and multilayers was studied by scanning electron microscope (SEM), grazing-incidence small-angle X-ray scattering (GISAXS) and X-ray reflectivity (XRR) techniques. From the results it follows that an ordered nanoparticle monolayer was formed over a large area. For the multilayer, the layering and lateral ordering of each layer was confirmed by XRR and SEM performed after the deposition of each nanoparticle layer.

  Measurement in Biomedicine

E. Pinheiro, O. Postolache, P. Girão:

Non-Intrusive Device for Real-Time Circulatory System Assessment with Advanced Signal Processing Capabilities

Abstract: This paper presents a device that uses three cardiography signals to characterize several important parameters of a subject’s circulatory system. Using electrocardiogram, finger photoplethysmogram, and ballistocardiogram, three heart rate estimates are acquired from beat-to-beat time interval extraction. Furthermore, pre-ejection period, pulse transit time (PTT), and pulse arrival time (PAT) are computed, and their long-term evolution is analyzed. The system estimates heart rate variability (HRV) and blood pressure variability (BPV) from the heart rate and PAT time series, to infer the activity of the cardiac autonomic system. The software component of the device evaluates the frequency content of HRV and BPV, and also their fractal dimension and entropy, thus providing a detailed analysis of the time series’ regularity and complexity evolution, to allow personalized subject evaluation.

M. Laghrouche , S. Haddab, S. Lotmani, K. Mekdoud, S. Ameur:

Low-Cost Embedded Oximeter

Abstract:  Nowadays, many medical devices have been developed for the purposes of diagnosing and treatment. Wearable sensors and systems have evolved to the point that they can be considered ready for clinical application. The use of wearable monitoring devices that allow continuous or intermittent monitoring of physiological signals is critical for the advancement of both the diagnosis as well as treatment of diseases. Patient vital sign monitoring within hospitals requires the use of noninvasive sensors that are hardwired to bedside monitors. This paper describes the initial bench testing of a wireless wearable pulse oximeter.  Arterial oxygen saturation in the patient's blood signal was measured with an optical sensor, and then converted to digital data using a microcontroller system. The digital data were then sent to a receiver where it is in 433 MHz FM/FSK transmitter. At the receiver, the digital data were reconverted to analog signal to be monitored and recorded on the PC.

  Measurement of Physical Quantities

A. Amann, K. Schwarz, G.Wimmer, V. Witkovský:

Model Based Determination of Detection Limits for Proton Transfer Reaction Mass Spectrometer                                                                       Invited paper

Abstract:  Proton Transfer Reaction Mass Spectrometry (PTR-MS) is a chemical ionization mass spectrometric technique which allows to measure trace gases as, for example, in exhaled human breath. The quantification of compounds at low concentrations is desirable for medical diagnostics. Typically, an increase of measuring accuracy can be achieved if the duration of the measuring process is extended. For real time measurements the time windows for measurement are relatively short, in order to get a good time resolution (e.g. with breath-to-breath resolution during exercise on a stationary bicycle). Determination of statistical detection limits is typically based on calibration measurements, but this approach is limited, especially for very low concentrations. To overcome this problem, a calculation of limit of quantification (LOQ) and limit of detection (LOD), respectively, based on a theoretical model of the measurement process is outlined.

D. Agrež:

Estimation and Tracking of the Power Quality Disturbances in the Frequency Domain

Abstract: In this paper, simple algorithms for fast measurement and estimation of the unknown changing frequency, amplitude, and phase difference of the sinusoidal signals from two channels with the same frequency, as well as other parameters for evaluation of the power quality disturbances, are presented. Parameters are calculated from the DFT coefficients around the component peaks. The improvement for reducing the influences of the harmonic components is the estimation with the three-point interpolation and the Hann window.

A. Odon:

Modelling and Simulation of the Pyroelectric Detector Using MATLAB/Simulink

Abstract:  An attempt was made to obtain a simple Laplace transfer function model of a pyroelectric detector which would make an excellent basis for the analysis of its dynamic behaviour. Knowledge of the transfer function model of the pyroelectric detector is necessary for its simulation studies in MATLAB/Simulink environment. A simple model of the pyroelectric detector was implemented in MATLAB/Simulink and some exemplary results of investigation of its voltage response to incident radiation and frequency characteristics were presented.

P. Espel, A. Poletaeff, H. Ndilimabaka:

Traceability of Voltage Measurements for Non-Sinusoidal Waveforms

Abstract:  This paper describes the result of work performed at the Laboratoire National de Métrologie et d’Essais (LNE) aiming at developing a standard system to measure RMS value and harmonic contents of distorted voltage waveforms by means of a sampling voltmeter. Thermal converters are used to trace the RMS value to the SI units. The error of the DVM has been generally found less than 10 μV/V up to 2 kHz but can reach about 50 μV/V at 2.5 kHz for RMS voltage measurements for sine waves. For distorted waveforms, deviations within 15 μV/V have been obtained whatever the total harmonic distortion of the waveforms.

M. Komárek, J. Roztočil:

Frequency Selection of Sine Wave for Dynamic ADC Test

Abstract:  The paper deals with determination of an optimum frequency for the time domain and frequency domain ADC testing. Proposed algorithm for selection of test signal frequency fulfills two common requirements. The first requirement is to get maximum quantity of distinct phases of the sampled values which are uniformly distributed between 0 and 2π; the second one is to avoid overlapping of higher harmonic components aliased in the first Nyquist zone. The algorithm was verified using MATLAB simulations and practical measurements.

A. Lay-Ekuakille, P. Vergallo, A. Trotta:

Impedance Method for Leak Detection in Zigzag Pipelines

Abstract: Transportation of liquids is a primary aspect of human life. The most important infrastructure used accordingly is the pipeline. It serves as an asset for transporting different liquids and strategic goods. The latter are for example: chemical substances, oil, gas and water. Thus, it is necessary to monitor such infrastructures by means of specific tools. Leakage detection methods are used to reveal liquid leaks in pipelines for many applications, namely, waterworks, oil pipelines, industry heat exchangers, etc.. The configuration of pipelines is a key issue because it impacts on the effectiveness of the method to be used and, consequently, on the results to be counterchecked. This research illustrated an improvement of the impedance method for zigzag pipeline by carrying out an experimental frequency analysis that has been compared with other methods based on frequency response. Hence, the impedance method is generally used for simple (straight) pipeline configurations because complicated pipelines with many curves introduce difficulties and major uncertainties in the calculation of characteristic impedance and in the statement of boundary conditions. The paper illustrates the case of a water pipeline where the leakage is acquired thanks to pressure transducers.

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