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Page 852 of 936 Results 8511 - 8520 of 9356

J. Germano, M. S. Piedade, L. Sousa, T. M. Almeida, P. Lopes, F. A. Cardoso, H. A. Ferreira, P. P. Freitas
MICROSYSTEM FOR BIOLOGICAL ANALYSIS BASED ON MAGNETORESISTIVE SENSING

This paper presents a microsystem for biomolecular recognition (DNA, enzymes) based on a biochip, which uses magnetic field arraying of magnetically tagged biomolecules and high sensitivity sensors for single biomolecule detection. The microsystem provides the electronic circuitry for addressing, reading out and sensing each of the 16 x 16 magnetoresistive sensors that compose the biochip. A prototype of the microsystem was developed and experimental results show that it is able of nanoparticle detection and, consequently, be used for magnetic labelled based bioassays.

Luigi Rovati , Nicola Zambelli, Stefano Cattini, Giorgia Salvatori
HOLLOW BEAM GEOMETRY FOR DIFFUSING TEMPORAL LIGHT CORRELATION

The paper presents an optical setup for diffusing temporal light spectroscopy of living tissues. The system allows to study the dynamical properties of living tissues molecules. The proposed approach exploits the hollow beam geometry in conjunction to mode-selective detection. First experiments, aimed to demonstrate the functionality of the measuring system, have been performed.

Erwin Peiner, Arti Tibrewala, Holger Lüthje, Ralf Bandorf, Saskia Biehl, Lutz Doering
PIEZORESITIVE DIAMOND-LIKE CARBON MICRO STRAIN GAUGES

Hydrogenated (a-C:H) and hydrogen-free (a-C) amorphous diamond-like carbon (DLC) strain gauges have been successfully integrated on micromachined silicon bossmembrane force sensors. DLC strain gauges were investigated under vertical and horizontal connection as well as longitudinal and transversal orientation at temperatures between RT and 60°C revealing piezoresistive gauge factors typically in the range of 50-90 (a-C:H) and 20-30 (a-C).

Erwin Peiner, Lutz Doering, Uwe Brand, Andreas Christ, Gerrit Isenberg, Michael Balke
FORCE CALIBRATION OF MICRO PIPETTES FOR SINGLE-CELL PROBING

Force calibration of micro pipettes is described used for the application of mechanical stress to isolated ventricular cardiomyocytes which are immobilized on glass substrates. For this purpose two methods have been developed based on a nano-Newton compensation balance at PTB and cantilever-type silicon sensors used as transferable force standards, respectively.

Barbara Juroszek
ABOUT SOME METROLOGICAL ASPECTS OF STANDARDIZATION IN SPIROMETRY

Almost all of the spirometric parameters are measured or calculated during forced expiration because it is one of the most popular and most valuable tests. The American Thoracic Society (ATS) together with The European Respiratory Society (ERS) formulated the technical requirements, which should be fulfilled in spirometry today. The author shows how these requirements can be fulfilled in modern digital spirometers.

Satu Kärki, Jukka Lekkala
PRESSURE MAPPING SYSTEM FOR PHYSIOLOGICAL MEASUREMENTS

Pressure mapping provides knowledge about interface pressure between a person and the surface person is laying or sitting on. In medical applications the surface is commonly a bed or a wheelchair. The distribution of pressure applied to the skin by a supporting surface can be measured with a pressure mapping system. Depending on the magnitude and duration of the pressure, it can cause pain and tissue injuries, such as pressure ulcers to the person. By means of pressure mapping technology, it is possible to detect the areas where the pressure is concentrated and thus prevent the development of pressure ulcer. However, the properties of the commercial pressure mapping systems are usually inadequate for physiological measurements. In this study, properties of a commercial Xsensor pressure mapping system were studied. Measurements with test persons as well as measurements with a constant measurement load were carried out. Repeatability, sensitivity, temperature sensitivity and hysteresis of the pressure sensor were determined. Only the hysteresis was noticed to be poor while the other properties were satisfactory.

Tomasz Koszmider, Krzysztof Strzecha
3D LUNGS SURFACE RECONSTRUCTION FROM COMPUTED TOMOGRAPHY IMAGES

New 3D medical images reconstruction algorithm is presented in this paper. It concerns utilization of digital processing and analysis of Computed Tomography images in process of 3D lungs reconstruction.

S. Osowski, T. Markiewicz, L. Tran Hoai
ENSEMBLE OF NEURAL NETWORKS FOR IMPROVED RECOGNITION AND CLASSIFICATION OF ARRHYTHMIA

The paper presents different methods of combining many neural classifiers into one ensemble system for recognition and classification of arrhythmia. Majority and weighted voting, Kullback-Leibler divergence and modified Bayes methods will be presented and compared. The numerical experiments will be performed for the problems concerning the recognition of different types of arrhythmia on the basis of ECG waveforms of MIT BIH AD.

Milan Tysler, Vladimir Rosik, Peter Kneppo
MULTICHANNEL ECG MEASUREMENT FOR NONINVASIVE IDENTIFICATION OF HEART REGIONS WITH CHANGED REPOLARIZATION

Multichannel system for ECG measurement and body surface potential mapping is introduced and its application for noninvasive identification of ischemic heart regions with changed repolarization is presented. The system uses up to 128 active electrodes, separate common mode signal sensing and active neutralization of the patient to get optimal signal quality. Microprocessor controlled and battery powered data acquisition module is connected through an optical extension cable to the USB port of a personal computer with Windows based measuring and data analysis software. In 11 patients with myocardial infarction, integral maps of the QRST interval of the ECG signal were measured before and after the percutaneous cardiac intervention. Changes in the maps together with information on a model of the patients’ torso volume conductor were used to calculate an equivalent current dipole characterizing the region influenced by the therapy. In this way, the affected ischemic region could be noninvasively identified in 7 patients.

Matteo Bonaiuti, Luigi Rovati, Charles Riva
A PC-CONTROLLED REFLECTOMETER FOR FUNCTIONAL IMAGING OF OCULAR FUNDUS

The paper presents an imaging reflectometer designed to detect flicker-induced reflectance changes of the ocular fundus. The system is based on a modified fundus camera completely controlled by a personal computer via USB interface.
The system allows in-vivo functional imaging of the ocular fundus in the near-infrared region with flicker light stimulus in the visible spectrum.

Page 852 of 936 Results 8511 - 8520 of 9356