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Health Physics Aug 2013This paper reviews radiofrequency (RF) field levels produced by electric utility meters equipped with RF transceivers (so-called Smart Meters), focusing on meters from...
This paper reviews radiofrequency (RF) field levels produced by electric utility meters equipped with RF transceivers (so-called Smart Meters), focusing on meters from one manufacturer (Trilliant, Redwood City, CA, USA, and Granby, QC, Canada). The RF transmission levels are summarized based on publicly available data submitted to the U.S. Federal Communications Commission supplemented by limited independent measurements. As with other Smart Meters, this meter incorporates a low powered radiofrequency transceiver used for a neighborhood mesh network, in the present case using ZigBee-compliant physical and medium access layers, operating in the 2.45 GHz unlicensed band but with a proprietary network architecture. Simple calculations based on a free space propagation model indicate that peak RF field intensities are in the range of 10 mW m or less at a distance of more than 1-2 m from the meters. However, the duty cycle of transmission from the meters is very low (< 1%). Limited measurements identified pulses from the meter that were consistent with data reported by the vendor to the U.S. Federal Communications Commission. Limited measurements conducted in two houses with the meters were unable to clearly distinguish emissions from the meters from the considerable electromagnetic clutter in the same frequency range from other sources, including Wi-Fi routers and, when it was activated, a microwave oven. These preliminary measurements disclosed the difficulties that would be encountered in characterizing the RF exposures from these meters in homes in the face of background signals from other household devices in the same frequency range. An appendix provides an introduction to Smart Meter technology. The RF transmitters in wireless-equipped Smart Meters operate at similar power levels and in similar frequency ranges as many other digital communications devices in common use, and their exposure levels are very far below U.S. and international exposure limits.
Topics: Electricity; Environmental Exposure; Radio Waves; Radiometry
PubMed: 23799502
DOI: 10.1097/HP.0b013e31828f5805 -
Sensors (Basel, Switzerland) Apr 2023This paper addresses the current challenges in cybersecurity of smart metering infrastructure, specifically in relation to the Czech Decree 359/2020 and the DLMS...
This paper addresses the current challenges in cybersecurity of smart metering infrastructure, specifically in relation to the Czech Decree 359/2020 and the DLMS security suite (device language message specification). The authors present a novel testing methodology for verifying cybersecurity requirements, motivated by the need to comply with European directives and legal requirements of the Czech authority. The methodology encompasses testing cybersecurity parameters of smart meters and related infrastructure, as well as evaluating wireless communication technologies in the context of cybersecurity requirements. The article contributes by summarizing the cybersecurity requirements, creating a testing methodology, and evaluating a real smart meter, using the proposed approach. The authors conclude by presenting a methodology that can be replicated and tools that can be used to test smart meters and the related infrastructure. This paper aims to propose a more effective solution and takes a significant step towards improving the cybersecurity of smart metering technologies.
PubMed: 37112383
DOI: 10.3390/s23084043 -
Ghana Medical Journal Mar 2018Metered dose inhalers are cornerstone in effective management of bronchial asthma when correctly used. Most studies hitherto have focused on assessing patient's...
BACKGROUND
Metered dose inhalers are cornerstone in effective management of bronchial asthma when correctly used. Most studies hitherto have focused on assessing patient's knowledge of inhaler technique. We sought to assess the knowledge of inhaler technique, spacer device and peak flow meter among doctors and nurses in a tertiary healthcare institution in Nigeria.
METHOD
A cross sectional survey of nurses and doctors from emergency department, family and internal medicine; who were attending a continuous professional development lecture, was carried out. From a total of 100 questionnaires administered, we retrieved 87 of which 75 were completed, giving a response rate of 75%. It was a self-administered questionnaire. Data was analysed with SPSS version 21.0. Descriptive statistics were done. Association was examined using chi-square test.
RESULT
Mean age of respondent was 35.8 years ± 8.7, 47(62.7%) were < 40 years, 33(44%) were male, nurses were 30(40.0%). Only 28(37.3%) had ever used a peak flow meter. Only 4(14.3%) used peak flow meter frequently, while 12(26.7%) checked patient's inhaler technique often. Only 9 out of the 75 (12%) participants all of who are doctors knew at least 3 essential steps of the techniques in using the metered dose inhaler correctly. None of the participants got all the steps for the use of pMDI totally correct.
CONCLUSION
Knowledge regarding the use of the metered dose inhaler and spacer device was poor. Health practitioners should have constant reminders in the form of continuous medical education to update their knowledge regarding correct inhaler technique.
FUNDING
self-funded.
Topics: Administration, Inhalation; Adult; Asthma; Cross-Sectional Studies; Female; Health Knowledge, Attitudes, Practice; Humans; Male; Metered Dose Inhalers; Middle Aged; Nigeria; Nurses; Physicians; Surveys and Questionnaires
PubMed: 30013256
DOI: 10.4314/gmj.v52i1.4 -
Journal of Diabetes Science and... Mar 2014Glucose meter performance specifications provide limits for 95% of results, which is the same as total error. A popular total error model is that total error equals...
Glucose meter performance specifications provide limits for 95% of results, which is the same as total error. A popular total error model is that total error equals (average) bias plus 2 times imprecision. This model has been used to specify combinations of average bias and imprecision that satisfy total error goals. But this model is incomplete and its conclusions are suspect. It is shown that when interferences occur in glucose meters as exemplified by hematocrit interference, the total error model proposed by Boyd and Bruns cannot distinguish between meters that differ in performance. The CLSI standard EP21-A, does not have this problem because it directly estimates total error bypassing the need for a model. An example illustrates these points.
PubMed: 24876596
DOI: 10.1177/1932296813518673 -
Diabetes Technology & Therapeutics Dec 2004Glucose meters have unquestionable clinical utility, particularly in management of diabetes mellitus. U.S. Food and Drug Administration (FDA) surveillance activities...
OBJECTIVE
Glucose meters have unquestionable clinical utility, particularly in management of diabetes mellitus. U.S. Food and Drug Administration (FDA) surveillance activities include monitoring adverse event reports from healthcare professionals, manufacturers, and lay users.
METHODS
To gain insight into problems reported to FDA on glucose meters, we analyzed reports received over a 3-year period (2000-2002) from all sources (mandatory and voluntary) and focused on reports from users.
RESULTS
The vast majority of in vitro diagnostic device (IVD) reports (84%, n = 18,959) were on glucose meters, with 333 glucose meter reports from users. Among the user reports, the most common problems were false high or low values and erratic values. Unique issues reported included purchase of incorrect glucose meter strips, calibration problems, and misunderstanding how FDA regulates glucose device performance.
CONCLUSION
The FDA gains valuable insight from and encourages user reports.
Topics: Blood Glucose Self-Monitoring; Community Participation; Humans; Quality Assurance, Health Care; United States; United States Food and Drug Administration
PubMed: 15684627
DOI: 10.1089/dia.2004.6.767 -
Pulmonary Medicine 2017Portable inhalers are divisible into those that deliver medication by patient triggering (pMDIs: a gentle slow inhalation) and those that use the patient's inspiratory... (Review)
Review
Portable inhalers are divisible into those that deliver medication by patient triggering (pMDIs: a gentle slow inhalation) and those that use the patient's inspiratory effort as the force for deaggregation and delivery (DPIs: a stronger deeper inspiratory effort). Patient confusion and poor technique are commonplace. The use of training tools has become standard practice, and unique amongst these is an inspiratory flow meter (In-Check) which is able to simulate the resistance characteristics of different inhalers and, thereby, guide the patient to the correct effort. In-Check's origins lie in the 1960s peak flow meters, the development of the Mini-Wright peak flow meter, and inspiratory flow assessment via the nose during the 1970s-1980s. The current device (In-Check DIAL G16) is the third iteration of the original 1998 training tool, with detailed and ongoing assessments of all common inhaler resistances (including combination and breath-actuated inhaler types) summarised into resistance ranges that are preset within the device. The device works by interpolating one of six ranges with the inspiratory effort. Use of the tool has been shown to be contributory to significant improvements in asthma care and control, and it is being advocated for assessment and training in irreversible lung disease.
Topics: Administration, Inhalation; Dry Powder Inhalers; Equipment Design; Humans; Inhalation; Metered Dose Inhalers; Patient Education as Topic; Respiratory Therapy
PubMed: 29348936
DOI: 10.1155/2017/1495867 -
Journal of Aerosol Medicine : the... 1991Reformulation of metered-dose inhalers (MDIs) without the use of chlorofluorocarbon (CFC) propellants presents numerous obstacles because there are no alternative... (Review)
Review
Reformulation of metered-dose inhalers (MDIs) without the use of chlorofluorocarbon (CFC) propellants presents numerous obstacles because there are no alternative propellants that can serve as immediate replacements for pharmaceutical use. Hydrofluorocarbons (HFCs), hydrochlorofluorocarbons (HCFCs) and hydrocarbons (HCs) are all under consideration as possible alternatives for CFC propellants. However, no single propellant or combination of propellants has been identified with all of the physical-chemical properties of CFCs. Based on their zero ozone depletion potentials, relatively low global warming potentials, non-flammabilities, densities, and vapor pressures, HFA-134a and HFA-227 are the most attractive replacement propellants identified to date. Yet, their use in MDIs will still require: (1) identification of a metering valve with propellant and formulation-compatible gaskets, (2) use of current suspending agents at levels much lower than in present MDIs or identification (and characterization) of new suspending agents, and (3) modification of existing manufacturing technologies. Demonstration of acceptable final product stability, safety and efficacy will be necessary prior to submission to worldwide registration authorities.
Topics: Administration, Inhalation; Aerosol Propellants; Equipment Design; Humans; Hydrocarbons, Fluorinated; Nebulizers and Vaporizers
PubMed: 10147677
DOI: 10.1089/jam.1991.4.181 -
Diagnostics (Basel, Switzerland) Apr 2024Glucose meters provide a rapid blood glucose status for evidence-based diagnosis, monitoring, and treatment of diabetes mellitus. We aimed to evaluate the commutability...
Glucose meters provide a rapid blood glucose status for evidence-based diagnosis, monitoring, and treatment of diabetes mellitus. We aimed to evaluate the commutability of processed blood materials (PBMs) and their use in the performance evaluation of glucose meters. Two PBMs obtained by the fixed-cell method were analyzed for homogeneity, stability, and commutability. The compatibility of ten pairs between mass spectrometry and each glucose meter was categorized as compatible (mean paired difference ≤ 5%) and incompatible (mean paired difference > 5%). The performance of glucose meter 1 ( = 767) and glucose meter 2 ( = 266) was assessed. The glucose in the PBMs remained homogenized and stable for at least 180 days. Six out of ten pairs had commutable PBMs. Commutability of PBMs was observed in both well-compatible and incompatible glucose results. Target glucose values from mass spectrometry were significantly different ( ≤ 0.05) from consensus values in one group of glucose meters. When commutable PBMs were used, glucose meter 1 showed better performance than glucose meter 2, and the percentage of satisfaction was associated when using target values for glucose from mass spectrometry and consensus values, but the performance of glucose meter 2 was not associated. PBM from a fixed-cell method could be mass produced with acceptable homogeneity and stability. Commutability testing of PBMs is required prior to use in the performance evaluation of glucose meters, as the commutability of glucose in the PBMs obtained by a fixed-cell method was variable and depended on the individual glucose meter.
PubMed: 38667445
DOI: 10.3390/diagnostics14080799 -
Skin Research and Technology : Official... Aug 2011The measurement of transepidermal water loss (TEWL) is used to monitor changes in the stratum corneum's permeability to water vapor. This measurement is widely used in... (Comparative Study)
Comparative Study
BACKGROUND
The measurement of transepidermal water loss (TEWL) is used to monitor changes in the stratum corneum's permeability to water vapor. This measurement is widely used in the cosmetics industry and in dermatology research. However, only limited work has been undertaken to assess the comparability of results from different TEWL meters over an extended range of measurements.
METHODS
This study compared the results of TEWL measurements between two commonly used open-chamber and closed-chamber TEWL devices. Five hundred and forty measurements were taken in 17 participants on the dorsum and palm of both hands on two different days and the order of the devices was randomized.
RESULTS
The results showed that the open TEWL meter's capacity for measuring high values of TEWL was restricted, and that the closed-chamber TEWL meter was less sensitive to differences in the lower range of measurements.
CONCLUSION
Both devices have their strengths for different applications, but their results cannot be directly compared. We were unable to find a statistical model that would allow us to transform the measurements made on one device for a comparison with the results generated by the other device.
Topics: Adult; Body Water; Dermatology; Equipment Design; Equipment Failure Analysis; Female; Humans; Male; Middle Aged; Physical Examination; Reproducibility of Results; Sensitivity and Specificity; Water; Water Loss, Insensible
PubMed: 21492241
DOI: 10.1111/j.1600-0846.2011.00509.x -
International Journal of Pharmaceutical... 2016Topical metered-dosing dispensers are designed for dosing accuracy and ease-of-use by the patients while protecting the packaged products from environmental exposure and...
Topical metered-dosing dispensers are designed for dosing accuracy and ease-of-use by the patients while protecting the packaged products from environmental exposure and contamination. The objective of this study was to evaluate the accuracy, precision, and residual of available topical metered-dosing dispensers with different types of topical cream for practical application. Triplicate samples of five different dispensers were tested. This test was completed using three types of commercial topical cream-bases of dissimilar Total Active Pharmaceutical Ingredient Load Percentages, Transdermal Penetration Percentages, and Specific Gravities. The dispensers were evaluated according to specified dose-uniformity criteria for a total dispensing capacity of 30 mL at 0.5 mL per dose for 60 doses. The study shows Topi-CLICK performed with the best precision and accuracy of dosing in comparison to the airless-pump type dispensers. While the dispensing was highly variable with airless pumps and may require calibration for each packaged product, remarkably the performance of Topi-CLICK was not affected by different types of cream-bases and does not require additional metering calibration.
Topics: Administration, Topical; Pharmaceutical Preparations
PubMed: 28333665
DOI: No ID Found