19 research outputs found

    Simple and universal current modulator circuit for indoor mobile free-space-optical communications testing

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    The use of LED for illumination and communication together is more and more interesting with the increasing deployment of LEDs to our homes and industrial buildings. Modulation of this kind of light sources is difficult because of high voltage and current demands. Since the LED configurations and values of current and voltage are different, our universal modulator has to be able to operate even under these circumstances. This paper proposes simple and universal current modulator for LED lighting modulation for frequencies around 1MHz. Main objective is to allow initial testing of different types of High Power LEDs and different photodetector configurations and circuits in diffusive based Free-Space-Optical networks. In the experimental part we also compare results for some different types of LED light sources

    Breathing Out Completely Before Inhalation: The Most Problematic Step in Application Technique in Patients With Non-Mild Chronic Obstructive Pulmonary Disease

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    Background: Patient adherence to an inhaled medication application technique (A-ApplT) represents a major health-care issue in patients with chronic obstructive pulmonary disease (COPD). However, there is a lack of studies evaluating this issue thoroughly. The aim of our study was to introduce a universal easy-to-use method of assessing the A-ApplT to chronic medication in moderate to very severe COPD individuals.Methods: The Czech Multicenter Research Database of COPD (COPD CMRD), a large observational prospective study, was used as a source of clinical data. A-ApplT was evaluated using our Five Steps Assessment. This measure is based on dichotomous evaluation of each of five predefined consecutive application technique steps and can be used in all settings for all currently available inhalation systems in COPD subjects.Results: A total of 546 participants (75.0% men; mean age 66.7 years; mean forced expiratory volume in 1s 44.7%) were available for analysis. This represents 69.6% of all patients recruited in the COPD CMRD. Less than one third of patients presented their application technique without any erroneous steps. The most problematic steps were breathing out completely in one breath immediately before inhalation (step No. 3), and the actual inhalation maneuver (step No. 4). The total number of errors was similar for dry powder inhalers and pressurized metered-dose inhalers.Conclusion: Our novel instrument, Five Steps Assessment, is comfortable for use in routine clinical practice to explore A-ApplT. The A-ApplT in real-life patients with non-mild COPD was inadequate and patients should be repeatedly trained by properly (re-)educated medical staff

    Low noise omnidirectional optical receiver for the mobile FSO networks

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    A high sensitive optical receiver design for the mobile free space optical (FSO) networks is presented. There is an array of photo-detectors and preamplifiers working into same load. It is the second stage sum amplifier getting all signals together. This topology creates a parallel amplifier with an excellent signal to noise ratio (SNR). An automatic gain control (AGC) feature is included also. As a result, the effective noise suppression at the receiver side increases optical signal coverage even with the transmitter power being constant. The design has been verified on the model car which was able to respond beyond the line of sight (LOS)

    Sinteza nanostrukturiranog TiO2 dobivenog sol-gel metodom na bio-predlošku membrane ljuske jaja

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    Biomimikrija je nova grana znanosti uz pomoć koje se nastoje oponašati održiva rješenja iz prirode kako bi se stvorili materijali poboljšanih svojstava. Membrana ljuske jaja predstavlja jedinstveni 198 biomaterijal koji se zbog svoje vlaknaste i porozne mikrostrukture može koristiti kao bio- predložak za sintezu hijerarhijski strukturiranih nanomaterijala. U ovom radu sintetiziran je nanostrukturirani titanijev dioksid sol-gel/sonokemijskom sintezom pomoću membrane ljuske jaja kao bio- predloška. Za pripravu sola korišten je titanov izopropoksid kao prekursor, 2-propanol kao otapalo, acetilaceton kao kelirajući reagens uz dodatak nitratne kiseline kao katalizatora. U pripremljenu sol dodane su membrane ljuske jaja kao bio-predložak. Nakon infiltriranja, geliranja i sušenja uzorak je toplinski obrađen na temperaturi od 500 °C. Karakterizacija nanostrukturiranog TiO2 sintetiziranog na bio- predlošku provedena je pretražnim elektronskim mikroskopom s emisijom polja (FE-SEM), XRD analizom te FT-IR i mikro-Raman spektroskopijom. Dobiveni rezultati pokazuju da je sintetizirani nanostrukturirani TiO2 na bio- predlošku u kristalnoj formi anatasa s veličinom kristalita od 29 nm

    Introducing a new prognostic instrument for long-term mortality prediction in COPD patients: the CADOT index

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    Objectives. The BODE (BMI, Obstruction - FEV1, Dyspnoea - mMRC, Exercise - 6-MWT) and the ADO (Age, Dyspnoea - mMRC, Obstruction - FEV1) indices are widely used prognosis assessment tools for long-term mortality prediction in COPD patients but subject to limitations for use in daily clinical practice. The aim of this research was to construct a prognostic instrument that prevents these limitations and which would serve as a complementary prognostic tool for clinical use in these patients. Methods and Participants. The data of 699 COPD subjects were extracted from the Czech Multicentre Research Database (CMRD) of COPD patients (the derivation cohort) and analysed to identify factors associated with the long-term risk of mortality. These were entered into the ROC analysis and reclassification analysis. Those with the strongest discriminative power were used to construct the new index (CADOT). The new index was validated on 187 patients of the CIROCO+ cohort (Netherlands; the validation cohort). Results. The CADOT was constructed by adding two newly identified prognosis-determining factors, chronic heart failure (CHF) and TLCO, to the ADO index. In a head-to-head comparison, the CADOT index showed highest c-statistic values compared to the BODE and ADO indices (0.701 vs 0.677 vs 0.644, respectively). The prognostic power was more definitive when applied to the Dutch validation (CIROCO+) cohort (0.842 vs 0.799 vs 0.825, respectively). Conclusions. The CADOT index has comparable prognostic power to the BODE and ADO indices. The CADOT is complementary/an alternative to the BODE (if 6-MWT is not feasible) and ADO (with less dependence on the age factor) indices. Trial registration: ClinicalTrials.gov (NCT01923051)

    Introducing a new prognostic instrument for long-term mortality prediction in COPD patients: the CADOT index

    No full text
    Objectives. The BODE (BMI, Obstruction - FEV1, Dyspnoea - mMRC, Exercise - 6-MWT) and the ADO (Age, Dyspnoea - mMRC, Obstruction - FEV1) indices are widely used prognosis assessment tools for long-term mortality prediction in COPD patients but subject to limitations for use in daily clinical practice. The aim of this research was to construct a prognostic instrument that prevents these limitations and which would serve as a complementary prognostic tool for clinical use in these patients. Methods and Participants. The data of 699 COPD subjects were extracted from the Czech Multicentre Research Database (CMRD) of COPD patients (the derivation cohort) and analysed to identify factors associated with the long-term risk of mortality. These were entered into the ROC analysis and reclassification analysis. Those with the strongest discriminative power were used to construct the new index (CADOT). The new index was validated on 187 patients of the CIROCO+ cohort (Netherlands; the validation cohort). Results. The CADOT was constructed by adding two newly identified prognosis-determining factors, chronic heart failure (CHF) and TLCO, to the ADO index. In a head-to-head comparison, the CADOT index showed highest c-statistic values compared to the BODE and ADO indices (0.701 vs 0.677 vs 0.644, respectively). The prognostic power was more definitive when applied to the Dutch validation (CIROCO+) cohort (0.842 vs 0.799 vs 0.825, respectively). Conclusions. The CADOT index has comparable prognostic power to the BODE and ADO indices. The CADOT is complementary/an alternative to the BODE (if 6-MWT is not feasible) and ADO (with less dependence on the age factor) indices. Trial registration: ClinicalTrials.gov (NCT01923051)
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