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Sensors (Basel, Switzerland) Nov 2022In a smart grid communication network, positioning key devices (routers and gateways) is an NP-Hard problem as the number of candidate topologies grows exponentially...
In a smart grid communication network, positioning key devices (routers and gateways) is an NP-Hard problem as the number of candidate topologies grows exponentially according to the number of poles and smart meters. The different terrain profiles impose distinct communication losses between a smart meter and a key device position. Additionally, the communication topology must consider the position of previously installed distribution automation devices (DAs) to support the power grid remote operation. We introduce the heuristic method AIDA (AI-driven AMI network planning with DA-based information and a link-specific propagation model) to evaluate the connectivity condition between the meters and key devices. It also uses the link-received power calculated for the edges of a Minimum Spanning Tree to propose a simplified multihop analysis. The AIDA method proposes a balance between complexity and efficiency, eliminating the need for empirical terrain characterization. Using a spanning tree to characterize the connectivity topology between meters and routers, we suggest a heuristic approach capable of alleviating complexity and facilitating scalability. In our research, the interest is in proposing a method for positioning communication devices that presents a good trade-off between network coverage and the number of communication devices. The existing literature explores the theme by presenting different techniques for ideal device placement. Still rare are the references that meticulously explore real large-scale scenarios or the communication feasibility between meters and key devices, considering the detailed topography between the devices. The main contributions of this work include: (1) The presentation of an efficient AMI planning method with a large-scale focus; (2) The use of a propagation model that does not depend on an empirical terrain classification; and (3) The use of a heuristic approach based on a spanning tree, capable of evaluating a smaller number of connections and, even so, proposing a topology that uses fewer router and gateway positions compared to an approach that makes general terrain classification. Experiments in four real large-scale scenarios, totaling over 230,000 smart meters, demonstrate that AIDA can efficiently provide high-quality connectivity demanding a reduced number of devices. Additional experiments comparing AIDA's detailed terrain-based propagation model to the Erceg-SUI Path Loss model suggest that AIDA can reach the smart meter's coverage with a fewer router positions.
Topics: Electricity
PubMed: 36501807
DOI: 10.3390/s22239105 -
Journal of Vascular Surgery Jan 2021The 6-minute walk test is a common outcome measure in clinical trials of people with lower extremity peripheral artery disease (PAD). However, what constitutes a... (Observational Study)
Observational Study
OBJECTIVE
The 6-minute walk test is a common outcome measure in clinical trials of people with lower extremity peripheral artery disease (PAD). However, what constitutes a meaningful change in the 6-minute walk distance has not been well defined for people with PAD. The present study related the change in the 6-minute walk distance to the degree of participant-reported improvement or decline in the 6-minute walk distance to define a meaningful change in the 6-minute walk distance for those with PAD.
METHODS
Participants with PAD from three observational longitudinal studies completed the walking impairment questionnaire (WIQ) distance score and 6-minute walk at baseline and 1 year later. The WIQ distance score measures participants' perceived difficulty walking seven different distances without stopping (ranging from walking around the home to walking 5 blocks) on a 0 to 4 Likert scale, with 0 representing an inability to walk the distance and 4 representing no difficulty. The mean changes in the 6-minute walk distance corresponding to the participants' report of no change, 1-unit change, or 2-unit change, respectively, in the Likert scale score between the baseline and 1-year follow-up measures were calculated for each WIQ distance.
RESULTS
A total of 777 participants with PAD (mean age, 71.2 ± 8.8 years; mean baseline 6-minute walk distance, 350.1 ± 118.1 meters) completed 5439 questions about their difficulty walking each WIQ distance at baseline and follow-up. Participants with PAD who reported no change in their difficulty in walking each WIQ distance between baseline and follow-up had a decline of 7.2 meters (95% confidence interval [CI], -11.6 to -2.8 meters) in the 6-minute walk test. Relative to those reporting no change in difficulty walking, the participants reporting 1- and 2-point improvements in walking ability showed 6-minute walk distance improvements of 7.8 meters (95% CI, -0.3 to 15.9 meters) and 20.1 meters (95% CI, 1.1-39.2 meters), respectively. Relative to those reporting no change in walking difficulty, those reporting 1- and 2-point declines in perceived walking difficulty showed declines of -11.2 meters (95% CI, -19.0 to -3.4 meters) and -23.8 meters (95% CI, -37.4 to -10.3 meters) in the 6-minute walk distance.
CONCLUSIONS
Among people with PAD, ∼8- and ∼20-meter improvements in the 6-minute walk distance represent small and large improvements in walking ability, respectively. People with PAD who reported no change in their ability to walk distances over 1 year simultaneously declined by a mean of 7 meters in the 6-minute walk test. These findings will be useful for interpreting the results from randomized trials of interventions to improve the walking performance of people with PAD.
Topics: Aged; Female; Follow-Up Studies; Humans; Leg; Male; Peripheral Arterial Disease; Surveys and Questionnaires; Walk Test; Walking
PubMed: 32335305
DOI: 10.1016/j.jvs.2020.03.052 -
Diabetes Technology & Therapeutics May 2020People with diabetes-related ulcers may benefit from hyperbaric oxygen (HBO) therapy and from continuous glucose monitors (CGM). Although blood glucose (BG) meters...
People with diabetes-related ulcers may benefit from hyperbaric oxygen (HBO) therapy and from continuous glucose monitors (CGM). Although blood glucose (BG) meters based on glucose oxidase (GO) report erroneously low values at high pO, BG meters based on glucose dehydrogenase (GD) do not. We therefore examined the performance of a GO-based CGM system in comparison to GO-based and GD-based BG systems in normobaric air (NBAir), hyperbaric air (HBAir), and HBO environments. Twenty-six volunteers without diabetes mellitus (DM) wore Dexcom G6 CGM systems and provided periodic blood samples before, during, and after a standard HBO treatment consisting of three 30-min intervals of HBO separated by two 5-min intervals of HBAir. Accuracy of the CGM and GO-based BG meter were assessed by comparisons with the GD-based values. The mean absolute relative difference for the CGM system was 15.96% and for the GO-based meter was 8.52%. Compared to NBAir, HBO exposure resulted in significantly higher CGM values (+3.76 mg/dL, < 0.001) and significantly lower GO-based meter values (-10.38 mg/dL, < 0.001). Pre-HBO and post-HBO values obtained in NBAir were also significantly different when measured by CGM (+4.13 mg/dL, = 0.015) or the GO-based meter (-9.04 mg/dL, < 0.001). In volunteers without DM, HBO exposure results in statistically significant differences in glucose measurements obtained with GO-based devices, but not a GD-based device. Standard HBO treatment results in statistically significant effects on glucose concentrations. These differences are of unlikely clinical significance.
Topics: Adult; Aged; Blood Glucose; Blood Glucose Self-Monitoring; Female; Humans; Hyperbaric Oxygenation; Male; Middle Aged; Reproducibility of Results; Young Adult
PubMed: 31916854
DOI: 10.1089/dia.2019.0390 -
Journal of Diabetes Science and... Jan 2011Glucose testing in the hospital with point-of-care devices presents multiple opportunities for error. Any device can fail under the right conditions. For glucose... (Review)
Review
Glucose testing in the hospital with point-of-care devices presents multiple opportunities for error. Any device can fail under the right conditions. For glucose monitoring in the hospital, with thousands of operators, hundreds of devices, and dozens of locations involved, there is ample opportunity for errors that can impact the quality of test results. Errors can occur in any phase of the testing process: preanalytic, analytic, or postanalytic. Common sources of meter error include patient or methodology interferences, operator mistakes, environmental exposure, and device malfunction. Early models of glucose meters had few internal checks or capability to warn the operator of meter problems. The latest generation of glucose monitors has a number of internal checks and controls engineered into the testing process to prevent serious errors or warn the operator by suppressing test results. Some of these control processes are built into the software and data management system of the meters, others require the hospital to do something, such as regularly clean the meter or analyze control samples of known glucose concentration, to verify meter performance. Hospitals need to be aware of the potential for errors by understanding weaknesses in the testing process that could lead to erroneous results and take steps to prevent errors from occurring or to minimize the harm to patients when errors do occur. The reliability of a glucose result will depend on the balance of internal control features available from manufacturers in conjunction with the liquid control analysis and other control processes (operator training, device validation, and maintenance) utilized by the hospitals.
Topics: Blood Glucose; Clinical Laboratory Techniques; Hospitals; Humans; Medical Staff; Monitoring, Physiologic; Patients; Research Design; Risk Management
PubMed: 21303641
DOI: 10.1177/193229681100500124 -
Frontiers in Public Health 2022To understand the blood glucose meter buying behavior of type 2 diabetic patients with poor glycemic control (two or more HbA1c ≥ 8% during visits in one year) and...
OBJECTIVE
To understand the blood glucose meter buying behavior of type 2 diabetic patients with poor glycemic control (two or more HbA1c ≥ 8% during visits in one year) and identify factors influencing it.
METHODS
A survey was conducted among 585 diabetic patients with poor glycemic control who were treated in the outpatient or inpatient clinics of the Department of Endocrinology, Taizhou Hospital, Zhejiang Province from June 2020 to May 2021. The questionnaire collected general information and clinical data, and assessed blood glucose meter buying behavior. Chi-square test was used to compare the essential characteristics and clinical data between buyers and non-buyers of blood glucose meters. Additionally, stepwise logistic regression was used to analyze the factors influencing purchase.
RESULTS
Of the 585 questionnaires distributed, 527 (90.09%) valid questionnaires were collected. Of the 527 respondents, 285 (54.08%) had purchased blood glucose meters. Not receiving insulin therapy (OR: 1.77, 95% CI: 1.13-2.77) and unawareness of self-monitoring of blood glucose (OR: 19.46, 95% CI: 12.51-30.26) were risk factors for non-purchase.
CONCLUSION
There is a need to actively increase the purchase of glucose meters among diabetic patients, by educating them about the importance of self-monitoring of blood glucose.
Topics: Blood Glucose; Blood Glucose Self-Monitoring; Diabetes Mellitus; Humans; Hyperglycemia; Outpatients
PubMed: 35651857
DOI: 10.3389/fpubh.2022.880088 -
Sensors (Basel, Switzerland) Jul 2021At present, pointer meters are still widely used because of their mechanical stability and electromagnetic immunity, and it is the main trend to use a computer...
At present, pointer meters are still widely used because of their mechanical stability and electromagnetic immunity, and it is the main trend to use a computer vision-based automatic reading system to replace inefficient manual inspection. Many correction and recognition algorithms have been proposed for the problems of skew, distortion, and uneven illumination in the field-collected meter images. However, the current algorithms generally suffer from poor robustness, enormous training cost, inadequate compensation correction, and poor reading accuracy. This paper first designs a meter image skew-correction algorithm based on binary mask and improved Mask-RCNN for different types of pointer meters, which achieves high accuracy ellipse fitting and reduces the training cost by transfer learning. Furthermore, the low-light enhancement fusion algorithm based on improved Retinex and Fast Adaptive Bilateral Filtering (RBF) is proposed. Finally, the improved ResNet101 is proposed to extract needle features and perform directional regression to achieve fast and high-accuracy readings. The experimental results show that the proposed system in this paper has higher efficiency and better robustness in the image correction process in a complex environment and higher accuracy in the meter reading process.
PubMed: 34300630
DOI: 10.3390/s21144891 -
Journal of Diabetes Science and... Sep 2019Glucose meter evaluations are common and provide important information about glucose meter performance versus standards. Although some meters meet guidelines and others...
Glucose meter evaluations are common and provide important information about glucose meter performance versus standards. Although some meters meet guidelines and others fall short in these evaluations, most results are within the A and B zones of a glucose meter error grid. Another data source that is seldom used is the FDA adverse event database (MAUDE). This database describes glucose meter malfunctions and injury as reported by actual users and returned 10 837 adverse events across all meters for the first 7 months of 2018. Reliability growth management is an established tool to reduce failure rates. A reliability growth example is presented followed by a discussion of how this tool could be applied to reduce glucose meter failure events using the MAUDE database.
Topics: Algorithms; Blood Glucose; Blood Glucose Self-Monitoring; Data Management; Databases, Factual; Humans; Internet of Things; Quality Assurance, Health Care; Reproducibility of Results; United States; United States Food and Drug Administration
PubMed: 30580582
DOI: 10.1177/1932296818814457 -
Journal of Dairy Science Nov 2016The objective of this study was to evaluate 4 handheld ketone meters for use in on-farm β-hydroxybutyrate (BHB) monitoring of hyperketonemia in transition dairy cows....
The objective of this study was to evaluate 4 handheld ketone meters for use in on-farm β-hydroxybutyrate (BHB) monitoring of hyperketonemia in transition dairy cows. Blood samples taken from 250 Holstein cows between 262d pregnant and 15d in milk were evaluated on 4 different handheld ketone meters: Precision Xtra (Abbott Laboratories, Abbott Park, IL), TaiDoc (Pharmadoc, Lüdersdorf, Germany), Nova Max (Nova Biomedical, Billerica, MA), and Nova Vet (Nova Biomedical). Samples were screened using the Precision Xtra and tested on the remaining 3 m if the sample BHB concentration fell into predetermined ranges. A total of 89 samples were used for analysis. Performance of each meter was compared with the average of 2 plasma BHB concentrations both determined by a gold standard spectrophotometric Randox assay performed at 2 independent laboratories. Agreement between the 2 laboratories was very strong (Pearson correlation=0.998). All meters had Pearson correlation coefficients greater than 0.95. The Precision Xtra and TaiDoc meters were 100.0% sensitive and 73.5% specific at a BHB concentration cut point of 1.2mmol/L. The Nova Vet and Nova Max meters had sensitivities of 94.9 and 74.4% and specificities of 91.8 and 100.0%, respectively, at the same cut point. Agreement between the gold standard and the handheld meter was the best for the Nova Vet meter when evaluated using a Bland Altman graph with a mean BHB difference of 0.08mmol/L. Trends in bias were noted with the Precision Xtra and Nova Max meters resulting in increasing average discrepancy between the gold standard and the meter for both at higher plasma BHB concentrations and mean BHB differences of -0.34 and 0.26mmol/L, respectively. The coefficient of variation was <10% for the Precision Xtra, TaiDoc, and Nova Vet meters, and <15% for the Nova Max meter. We conclude that the TaiDoc and Nova Vet meters, similar to the already validated Precision Xtra meter, are acceptable for use in on-farm testing for monitoring and treatment of hyperketonemia.
Topics: 3-Hydroxybutyric Acid; Animals; Cattle; Cattle Diseases; Female; Ketosis; Milk; Sensitivity and Specificity
PubMed: 27568045
DOI: 10.3168/jds.2016-11077 -
Journal of Aerosol Medicine and... Apr 2010Conventional aerosol delivery systems and the availability of new technologies have led to the development of "intelligent" nebulizers such as the I-neb Adaptive Aerosol... (Review)
Review
Conventional aerosol delivery systems and the availability of new technologies have led to the development of "intelligent" nebulizers such as the I-neb Adaptive Aerosol Delivery (AAD) System. Based on the AAD technology, the I-neb AAD System has been designed to continuously adapt to changes in the patient's breathing pattern, and to pulse aerosol only during the inspiratory part of the breathing cycle. This eliminates waste of aerosol during exhalation, and creates a foundation for precise aerosol (dose) delivery. To facilitate the delivery of precise metered doses of aerosol to the patient, a unique metering chamber design has been developed. Through the vibrating mesh technology, the metering chamber design, and the AAD Disc function, the aerosol output rate and metered (delivered) dose can be tailored to the demands of the specific drug to be delivered. In the I-neb AAD System, aerosol delivery is guided through two algorithms, one for the Tidal Breathing Mode (TBM), and one for slow and deep inhalations, the Target Inhalation Mode (TIM). The aim of TIM is to reduce the treatment time by increasing the total inhalation time per minute, and to increase lung deposition by reducing impaction in the upper airways through slow and deep inhalations. A key feature of the AAD technology is the patient feedback mechanisms that are provided to guide the patient on delivery performance. These feedback signals, which include visual, audible, and tactile forms, are configured in a feedback cascade that leads to a high level of compliance with the use of the I-neb AAD System. The I-neb Insight and the Patient Logging System facilitate a further degree of sophistication to the feedback mechanisms, by providing information on long term adherence and compliance data. These can be assessed by patients and clinicians via a Web-based delivery of information in the form of customized graphical analyses.
Topics: Administration, Inhalation; Aerosols; Algorithms; Drug Delivery Systems; Equipment Design; Humans; Medication Adherence; Nebulizers and Vaporizers; Pharmaceutical Preparations; Respiratory Mechanics; Technology, Pharmaceutical; Time Factors
PubMed: 20373904
DOI: 10.1089/jamp.2009.0791 -
Sensors (Basel, Switzerland) Dec 2022Nowadays the rationalization of electrical energy consumption is a serious concern worldwide. Energy consumption reduction and energy efficiency appear to be the two...
Nowadays the rationalization of electrical energy consumption is a serious concern worldwide. Energy consumption reduction and energy efficiency appear to be the two paths to addressing this target. To achieve this goal, many different techniques are promoted, among them, the integration of (artificial) intelligence in the energy workflow is gaining importance. All these approaches have a common need: data. Data that should be collected and provided in a reliable, accurate, secure, and efficient way. For this purpose, sensing technologies that enable ubiquitous data acquisition and the new communication infrastructure that ensure low latency and high density are the key. This article presents a sensing solution devoted to the precise gathering of energy parameters such as voltage, current, active power, and power factor for server farms and datacenters, computing infrastructures that are growing meaningfully to meet the demand for network applications. The designed system enables disaggregated acquisition of energy data from a large number of devices and characterization of their consumption behavior, both in real time. In this work, the creation of a complete multiport power meter system is detailed. The study reports all the steps needed to create the prototype, from the analysis of electronic components, the selection of sensors, the design of the Printed Circuit Board (PCB), the configuration and calibration of the hardware and embedded system, and the implementation of the software layer. The power meter application is geared toward data centers and server farms and has been tested by connecting it to a laboratory server rack, although its designs can be easily adapted to other scenarios where gathering the energy consumption information was needed. The novelty of the system is based on high scalability built upon two factors. Firstly, the one-on-one approach followed to acquire the data from each power source, even if they belong to the same physical equipment, so the system can correlate extremely well the execution of processes with the energy data. Thus, the potential of data to develop tailored solutions rises. Second, the use of temporal multiplexing to keep the real-time data delivery even for a very high number of sources. All these ensure compatibility with standard IoT networks and applications, as the data markup language is used (enabling database storage and computing system processing) and the interconnection is done by well-known protocols.
PubMed: 36616716
DOI: 10.3390/s23010119