976 research outputs found
An e-health driven laboratory information system to support HIV treatment in Peru: E-quity for laboratory personnel, health providers and people living with HIV
<p>Abstract</p> <p>Background</p> <p>Peru has a concentrated HIV epidemic with an estimated 76,000 people living with HIV (PLHIV). Access to highly active antiretroviral therapy (HAART) expanded between 2004-2006 and the Peruvian National Institute of Health was named by the Ministry of Health as the institution responsible for carrying out testing to monitor the effectiveness of HAART. However, a national public health laboratory information system did not exist. We describe the design and implementation of an e-health driven, web-based laboratory information system - NETLAB - to communicate laboratory results for monitoring HAART to laboratory personnel, health providers and PLHIV.</p> <p>Methods</p> <p>We carried out a needs assessment of the existing public health laboratory system, which included the generation and subsequent review of flowcharts of laboratory testing processes to generate better, more efficient streamlined processes, improving them and eliminating duplications. Next, we designed NETLAB as a modular system, integrating key security functions. The system was implemented and evaluated.</p> <p>Results</p> <p>The three main components of the NETLAB system, registration, reporting and education, began operating in early 2007. The number of PLHIV with recorded CD4 counts and viral loads increased by 1.5 times, to reach 18,907. Publication of test results with NETLAB took an average of 1 day, compared to a pre-NETLAB average of 60 days. NETLAB reached 2,037 users, including 944 PLHIV and 1,093 health providers, during its first year and a half. The percentage of overall PLHIV and health providers who were aware of NETLAB and had a NETLAB password has also increased substantially.</p> <p>Conclusion</p> <p>NETLAB is an effective laboratory management tool since it is directly integrated into the national laboratory system and streamlined existing processes at the local, regional and national levels. The system also represents the best possible source of timely laboratory information for health providers and PLHIV, allowing patients to access their own results and other helpful information about their health, extending the scope of HIV treatment beyond the health facility and providing a model for other countries to follow. The NETLAB system now includes 100 diseases of public health importance for which the Peruvian National Institute of Health and the network of public health laboratories provide testing and results.</p
A robust wavelet-based approach for dominant frequency analysis of atrial fibrillation in body surface signals
This is an author-created, un-copyedited versÃon of an article published in Physiological Measurement. IOP Publishing Ltd is not responsÃble for any errors or omissÃons in this versÃon of the manuscript or any versÃon derived from it. The VersÃon of Record is available online at https://doi.org/10.1088/1361-6579/ab97c1.[EN] Objective: Atrial dominant frequency (DF) maps undergoing atrial fibrillation (AF) presented good
spatial correlation with those obtained with the non-invasive body surface potential mapping
(BSPM). In this study, a robust BSPM-DF calculation method based on wavelet analysis is
proposed. Approach: Continuous wavelet transform along 40 scales in the pseudo-frequency range
of 3¿30 Hz is performed in each BSPM signal using a Gaussian mother wavelet. DFs are estimated
from the intervals between the peaks, representing the activation times, in the maximum energy
scale. The results are compared with the traditionally widely applied Welch periodogram and the
robustness was tested on different protocols: increasing levels of white Gaussian noise, artificial DF
harmonics presence and reduction in the number of leads. A total of 11 AF simulations and 12 AF
patients are considered in the analysis. For each patient, intracardiac electrograms were acquired in
15 locations from both atria. The accuracy of both methods was assessed by calculating the
absolute errors of the highest DFBSPM (HDFBSPM) with respect to the atrial HDF, either simulated
or intracardially measured, and assumed correct if ¿1 Hz. The spatial distribution of the errors
between torso DFs and atrial HDFs were compared with atria driving mechanism locations. Torso
HDF regions, defined as portions of the maps with |DF ¿ HDFBSPM| ¿ 0.5 Hz were identified and
the percentage of the torso occuping these regions was compared between methods. The robustness
of both methods to white Gaussian noise, ventricular influence and harmonics, and to lower spatial
resolution BSPM lead layouts was analyzed: computer AF models (567 leads vs 256 leads down to
16 leads) and patient data (67 leads vs 32 and 16 leads). Main results: The proposed method
allowed an improvement in non-invasive estimation of the atria HDF. For the models the median
relative errors were 7.14% for the wavelet-based algorithm vs 60.00% for the Welch method; in
patients, the errors were 10.03% vs 12.66%, respectively. The wavelet method outperformed the
Welch approach in correct estimations of atrial HDFs in models (81.82% vs 45.45%, respectively)
and patients (66.67% vs 41.67%). A low positive BSPM-DF map correlation was seen between the
techniques (0.47 for models and 0.63 for patients), highlighting the overall differences in DF
distributions. The wavelet-based algorithm was more robust to white Gaussian noise, residual
ventricular activity and harmonics, and presented more consistent results in lead layouts with low
spatial resolution. Significance: Estimation of atrial HDFs using BSPM is improved by the proposed
wavelet-based algorithm, helping to increase the non-invasive diagnostic ability in AF.This study was supported in part by grants from Sao Paulo Research Foundation (2017/19775-3), Instituto de Salud Carlos III FEDER (Fondo Europeo de Desarrollo Regional PI17/01106) and Generalitat Valenciana Grants (AICO/2018/267).Marques, V.; Rodrigo Bort, M.; Guillem Sánchez, MS.; Salinet, J. (2020). A robust wavelet-based approach for dominant frequency analysis of atrial fibrillation in body surface signals. Physiological Measurement. 41(7):1-14. https://doi.org/10.1088/1361-6579/ab97c1S11441
Double glass transition in polyethylene naphthalate structural relaxation by MDSC, BDS and TSDC
We present the experimental study of the primary, , and secondary,
, relaxations of the glassy polymer polyethylene naphthalate (PEN), by
Modulated Differential Scanning Calorimetry (MDSC), Thermally Stimulated
Discharge Currents (TSDC) and Broadband Dielectric Spectroscopy (BDS). Results
show how the and relaxations can be considered part of a
very broad and distributed relaxation. The relaxation is composed of
a main contribution () and two additional ones ( and
) and each elementary mode of the relaxation has its own glass
transition temperature. This scenario gives rise to an extended glass
transition mainly centered in K and K
Non-invasive Mechanism Classification and Localization in Supraventricular Cardiac Arrhythmias
[EN] In this study, we investigated the most relevant biomarkers for noninvasive classification and mechanism location in atrial tachycardia (AT), flutter (AFL) and fibrillation (AF). Biomarkers were calculated using noninvasive body surface (BSPM) dominant frequency and phase
maps. We used 19 simulations of 567 to 64-lead BSPMs,
from which were extracted 32 biomarkers. Biomarker
ranking was performed with ANOVA, Kendall and Lasso
techniques. The best four biomarkers were identified and
used to classify the arrhythmias in all combinations, and
the best two used for noninvasive driver localization. Arrhythmia classification accuracy was 94.74%. The feature
combination which best distinguish AF from non-AF were
mean filament displacement and mean OI, while those that
best distinguish AFL from AT were mean and SD of SP
distribution. There was good agreement across ranking
techniques. Mechanism location accuracy was 78.95%,
with the most important biomarkers being percentage SPs
within each torso division, and SD of filament histogram
cluster area. This study highlights that organization related features well identifies AF and spatial SP distribution
discriminate AT from AFL and also it¿s localization.VGM is funded by the European Union's Horizon
2020 research and innovation programme under the Marie
Skodowska-Curie grant agreement No. 860974. IS, JAS
and JS are supported by grant #2018/25606-2, Sao Paulo Research Foundation (FAPESP).Sandoval, I.; Marques, VG.; Sims, JA.; Rodrigo, M.; Guillem Sánchez, MS.; Salinet, J. (2021). Non-invasive Mechanism Classification and Localization in Supraventricular Cardiac Arrhythmias. 1-4. https://doi.org/10.22489/CinC.2021.2261
Airborne RF Measurement System and Analysis of Representative Flight RF Environment
Environmental radio frequency (RF) data over a broad band of frequencies were needed to evaluate the airspace around several airports. An RF signal measurement system was designed using a spectrum analyzer connected to an aircraft VHF/UHF navigation antenna installed on a small aircraft. This paper presents an overview of the RF measurement system and provides analysis of a sample of RF signal measurement data over a frequency range of 30 MHz to 1000 MHz
Theoretical and perceived balance of power inside Spanish public hospitals
BACKGROUND: The hierarchical pyramid inside Spanish public hospitals was radically changed by the Health Reform Law promulgated in 1986. According to it, the manpower of the hospitals was divided into three divisions (Medical, Nursing, General Services/Administration), which from then on occupied the same level, only subject to the general manager. Ten years after the implementation of the law, the present study was designed in order to investigate if the legal changes had indeed produced a real change in the balance of power inside the hospitals, as perceived by the different workers within them. MATERIALS AND METHODS: A questionnaire was administered to 1,027 workers from four different public hospitals (two university-based and two district hospitals). The participants belonged to all divisions, and to all three operative levels (staff, supervisory and managerial) within them. The questionnaire inquired about the perceived power inside each division and hierarchical level, as well as about that of the other divisions and hierarchical levels. RESULTS: Every division attributed the least power to itself. The Nursing and the Administrative division attributed the highest power to the physicians, and these attributed the highest power to the General Services/Administrative division. All hierarchical levels (including the formal top of the pyramid) attributed significantly more power to the other than to them. CONCLUSIONS: More than ten years after the implementation of the new law, the majority of workers still perceive that the real power within the hospitals is held by the physicians (whereas these feel that it has shifted to the administrators). No division or hierarchical level believes it holds any significant degree of power, and this carries with it the danger of also not accepting any responsibility
Small Aircraft RF Interference Path Loss
Interference to aircraft radio receivers is an increasing concern as more portable electronic devices are allowed onboard. Interference signals are attenuated as they propagate from inside the cabin to aircraft radio antennas mounted on the outside of the aircraft. The attenuation level is referred to as the interference path loss (IPL) value. Significant published IPL data exists for transport and regional category airplanes. This report fills a void by providing data for small business/corporate and general aviation aircraft. In this effort, IPL measurements are performed on ten small aircraft of different designs and manufacturers. Multiple radio systems are addressed. Along with the typical worst-case coupling values, statistical distributions are also reported that could lead to better interference risk assessment
Wireless Phone Threat Assessment for Aircraft Communication and Navigation Radios
Emissions in aircraft communication and navigation bands are measured for the latest generation of wireless phones. The two wireless technologies considered, GSM/GPRS and CDMA2000, are the latest available to general consumers in the U.S. A base-station simulator is used to control the phones. The measurements are conducted using reverberation chambers, and the results are compared against FCC and aircraft installed equipment emission limits. The results are also compared against baseline emissions from laptop computers and personal digital assistant devices that are currently allowed to operate on aircraft
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