Real-time Continuous Monitoring System Research Articles

Optical Nanosensors for the Detection of Quaternary Ammonium Compounds

Quaternary ammonium compounds (QACs) are common active ingredients in chemical disinfectants, household cleaners, cosmetics, pesticides, etc. Recently QACs have been detected in human blood and breast milk during the COVID-19 pandemic. Humans can be exposed to QACs through dermal adsorption during application, hand-to-mouth ingestion of disinfectant residues, and inhalation of indoor air upon treatment with disinfectant spray. Exposure to these chemicals can cause respiratory illness such as asthma and chronic obstructive pulmonary disease, increase inflammatory cytokines, decrease mitochondrial function, and disrupt cholesterol biosynthesis. However, the complete biological fate of QACs is currently unknown. Therefore, a real-time continuous monitoring system in complex biological environments is crucial to learn the long-term effects of QACs on human health.Photoluminescent single-walled carbon nanotubes (SWCNTs) are great candidates for developing optical probes to monitor biological systems due to their outstanding photophysical properties in the tissue-transparent near-infrared spectral region, high sensitivity, and high stability. Furthermore, nanotube-based sensors exhibit a great potential for an implantable, real-time, wireless optical detection technology. Herein, we developed a carbon nanotube-based optical sensor for the detection of QACs in complex solution. Our findings from this research could provide a basis for engineering an optical detection technology to gain insight on the long-term effects of QACs to human health.

Precision Livestock Farming Applications (PLF) for Grazing Animals

Over the past four decades the dietary needs of the global population have been elevated, with increased consumption of animal products predominately due to the advancing economies of South America and Asia. As a result, livestock production systems have expanded in size, with considerable changes to the animals’ management. As grazing animals are commonly grown in herds, economic and labour constraints limit the ability of the producer to individually assess every animal. Precision Livestock Farming refers to the real-time continuous monitoring and control systems using sensors and computer algorithms for early problem detection, while simultaneously increasing producer awareness concerning individual animal needs. These technologies include automatic weighing systems, Radio Frequency Identification (RFID) sensors for individual animal detection and behaviour monitoring, body temperature monitoring, geographic information systems (GIS) for pasture evaluation and optimization, unmanned aerial vehicles (UAVs) for herd management, and virtual fencing for herd and grazing management. Although some commercial products are available, mainly for cattle, the adoption of these systems is limited due to economic and cultural constraints and poor technological infrastructure. This review presents and discusses PLF applications and systems for grazing animals and proposes future research and strategies to improve PLF adoption and utilization in today’s extensive livestock systems.

A Wireless Real-Time Continuous Monitoring System for the Internal Movements of Mountain Glaciers Using Sensor Networks

With the escalation of global warming, the shrinkage of mountain glaciers has accelerated globally, the water volume from glaciers has changed, and relative disasters have increased in intensity and frequency (for example, ice avalanches, surging glaciers, and glacial lake outburst floods). However, the wireless monitoring of glacial movements cannot currently achieve omnidirectional, high-precision, real-time results, since there are some technical bottlenecks. Based on wireless networks and sensor application technologies, this study designed a wireless monitoring system for measuring the internal parameters of mountain glaciers, such as temperature, pressure, humidity, and power voltage, and for wirelessly transmitting real-time measurement data. The system consists of two parts, with a glacier internal monitoring unit as one part and a glacier surface base station as the second part. The former wirelessly transmits the monitoring data to the latter, and the latter processes the received data and then uploads the data to a cloud data platform via 4G or satellite signals. The wireless system can avoid cable constraints and transmission failures due to breaking cables. The system can provide more accurate field-monitoring data for simulating glacier movements and further offers an early warning system for glacial disasters.

A real-time continuous monitoring system for long-term voltage stability with sliding 3D convolutional neural network

A real-time continuous monitoring system (CMS) for long-term voltage stability assessment with sliding three-dimensional convolutional neural network (3D-CNN) is proposed in this paper. Given a power system, its dynamic responses and topological information are strategically fused and converted into sequential state images, which constitute the learning input of the sliding 3D-CNN. In this way, both spatial and temporal correlation are considered in the CMS. The bus indices are reordered to strengthen the topology information in these images. With the localized weight-shared convolution operations, 3D-CNN can be conducted more efficiently with fewer parameters, and extract features independently of spatial locations. The translation invariance characteristic makes 3D-CNN highly generic to unknown scenarios, which is further enhanced after bus indices reordering. The sliding window of the 3D-CNN enables the CMS to handle varying degrees of disturbance and performs continuous online monitoring. Numerical tests are carried out on the New England 10-generator-39-bus system to demonstrate the effectiveness. Test results also show the potential of the CMS in robustness to PMU measurement errors and information losses.

Twenty-four-hour real-time continuous monitoring of acute focal cerebral ischemia in rabbits based on magnetic inductive phase shift

BackgroundAs a serious clinical disease, ischemic stroke is usually detected through magnetic resonance imaging and computed tomography. In this study, a noninvasive, non-contact, real-time continuous monitoring system was constructed on the basis of magnetic induction phase shift (MIPS) technology. The “thrombin induction method”, which conformed to the clinical pathological development process of ischemic stroke, was used to construct an acute focal cerebral ischemia model of rabbits. In the MIPS measurement, a “symmetric cancellation-type” magnetic induction sensor was used to improve the sensitivity and antijamming capability of phase detection.MethodsA 24-h MIPS monitoring experiment was carried out on 15 rabbits (10 in the experimental group and five in the control group). Brain tissues were taken from seven rabbits for the 2% triphenyl tetrazolium chloride staining and verification of the animal model.ResultsThe nonparametric independent-sample Wilcoxon rank sum test showed significant differences (p < 0.05) between the experimental group and the control group in MIPS. Results showed that the rabbit MIPS presented a declining trend at first and then an increasing trend in the experimental group, which may reflect the pathological development process of cerebral ischemic stroke. Moreover, TTC staining results showed that the focal cerebral infarction area increased with the development of timeConclusionsOur experimental study indicated that the MIPS technology has a potential ability of differentiating the development process of cytotoxic edema from that of vasogenic edema, both of which are caused by cerebral ischemia.

Dispersion of passive tracers from long-range HF radar systems along the east coast of Korea

We have conducted a virtual surface layer dispersion experiment using the long-range High Frequency radar (HFR) measurements off the east coast of Korea, and investigated the spreading characteristics of the surface waters in the vicinity of two cities, YoungDuk and UlJin for three days of experiments utilizing with random flight model (Markovian stochastic model). The diffusion coefficient was estimated as (Kx , Ky ) = (192, 251) m 2 /s with zonal and meridional dispersions ( σ² u, σ²υ ) = (0.0013, 0.017) m/s and turbulence time scales (Tu , Tv ) = (4, 4) hours derived from exponential fitting of lagged autocorrelation of difference between the HFR-derived and surface drifter-derived currents. During the experiment period, the centroid of the spatial particle distribution moved northward 80 km from the initial position following the East Korea Warm Current (EKWC) and its area became more than 500 times than the initial area. The trajectory and distribution of the surface particles are dependent on the EKWC and diffusion coefficient. Long-term and real-time continuous monitoring system of HFR needs to be combined into national system to improve search and rescue (SAR), and prevent coastal disasters (e.g., oil spill, marine litter) for risk management.

Energy Consumption Analysis of DBR and VBF Protocols in Underwater Sensor Networks Using Aqua-Sim at Network Simulator 2

For decades, there have been significant interests in monitoring the aquatic environment for scientific exploration, commercial exploitation, coastline protection, and even disasters prevention and mitigation such as tsunami warnings. Highly precise, real-time, and temporal-spatial continuous aquatic environment monitoring system is extremely important for underwater life. To support and simulate such monitoring system, underwater sensor networks (UWSN) have emerged as a very powerful technique for many applications on underwater environment, including monitoring, measurement, surveillance, and control by using Aqua-Sim. Aqua-Sim is a simulator for UWSN developed on Network Simulator 2 platform which effectively simulates the attenuation of underwater acoustic channels and the collision behaviors in long delay acoustic networks. Currently, there are several routing protocols for UWSN which are implemented in Aqua-Sim. On this research, we did a simulation on Aqua-Sim by performing Vector-based Forwarding (VBF) protocol and Depth-based Routing (DBR) protocol performance analysis based on energy consumption parameter. Based on the result, it can be concluded that the VBF routing protocol requires more energy consumption than the DBR routing protocol.

Estimating fungal growth in submerged fermentation in the presence of solid particles based on colour development

ABSTRACTThis study examines and evaluates a colourimetric technique that could be implemented as a real-time continuous monitoring system for fungal culture growth in submerged fermentation (SmF) with the presence of solid particles. Fungal SmF of Aspergillus awamori and Aspergillus oryzae was carried out on complex heterogeneous solid media: wheat bran, soybean hull and rapeseed meal, which were constituted of various soluble and insoluble solid particles. As a comparison, another set of experiments in SmF using synthetic medium was carried out. The theory of measuring colour changes in SmF by UV-Vis spectroscopy demonstrates that this colourimetric technique provides valuable information complementary to visual observations. Typical normalized UV absorption spectra were obtained using a scanning spectrophotometer for each colour solution. These demonstrated that samples used in this work have very similar patterns. The typical normalized optical density spectra show a local absorbance maximum near 300 nm, a region where colour absorbance rapidly increases. It was suggested that the colour developed during the progress of fermentation is closely related to either or both of the growth and the actual biomass of the fungus. The findings show that colour-based methods seem to be the most promising approach for biomass estimation in SmF in the presence of solid particles.

Application of real-time continuous glucose monitoring in outpatient management system for type 1 diabetes mellitus

Objective To evaluate the effect of continuous glucose monitoring system(CGMS) in improving the current status of type 1 diabetes mellitus(T1DM) control and reducing the economic burden of the patients. Methods One hundred and fifteen patients with T1DM were randomly assigned to the CGMS group and the self-monitoring of blood glucose(SMBG) group respectively. The patients in CGMS group were on 72 h CGMS every 6 months, while SMBG group only with SMBG to guide the insulin dose adjustment. The levels of blood glucose and the statistics of the number of hypoglycemia and diabetic ketoacidosis were taken as the main observational indexes every 6 months. The chronic complication and the statistics of the number of hospitalizations and the total cost of treatment were made as the secondary observational index every 12 months. Results 2 h postprandial plasma glucose(2hPG) and mean blood glucose(MBG) in the CGMS group were lower than those in the SMBG group [(10.7±1.9 vs 11.5±2.7) mmol/L, (9.7±0.5 vs 10.6±0.7) mmol/L, P<0.05] in the clinical follow-up visit after 6 months. The per capita number of hypoglycaemia in the CGMS group was lower than that in the SMBG group[(7.9±2.6 vs 9.2±3.4) times, P<0.05]. In the outpatient follow-up re-visit to the patients after 6 months, fasting plasma glucose(FPG), 2hPG, MBG, and HbA1C of the patients in the CGMS group were lower than those in the SMBG group(t=4.71~9.75, P<0.05), the per capita numbers of hypoglycemia and DKA in the CGMS group were lower than those in the SMBG group(t=3.61~4.37, P<0.05). Conclusion The application of real-time continuous glucose monitoring in T1DM outpatient management may reduce the whole-day blood glucose of the patients, decrease the incidence risk of hypoglycemia, and improve the compliance of the treatment while without increasing the economic burden of the disease. (Chin J Endocrinol Metab, 2017, 33: 367-371) Key words: Real-time continuous glucose monitoring system; Diabetes mellitus, type 1; Outpatient management system; Control status; Economic burden of disease

Detection of occult atrial fibrillation in patients with embolic stroke of uncertain source: a work in progress.

Atrial fibrillation accounts for a substantial proportion of ischemic strokes of known etiology and may be responsible for an additional subset of the 25–40% of strokes of unknown cause (so-called cryptogenic). Oral anticoagulation is significantly more effective than antiplatelet therapy in the secondary prevention of atrial fibrillation-related strokes, providing justification for developing more sensitive approaches to detecting occult paroxysms of atrial fibrillation. In this article, we summarize the current state of knowledge regarding the value of in-hospital and out-patient monitoring for detecting atrial fibrillation in the context of cryptogenic stroke. We review the evidence for and against screening with standard Holter monitors, external loop recorders, the newer real-time continuous attended cardiac monitoring systems, cardiac implantable electronic devices, and insertable loop recorders. We review key questions regarding prolonged cardiac arrhythmia monitoring, including the relationship between duration of the atrial fibrillation episode and risk of thromboembolism, frequency of monitoring and its impact on the diagnostic yield in detecting occult or subclinical atrial fibrillation, and the temporal proximity of device-detected atrial fibrillation to stroke events. We conclude by proposing avenues for further research.

Assessment of the accuracy of real-time continuous glucose monitoring system and its correlated factors

Objective To assess the factors that influence the accuracy of real-time continuous glucose monitoring system (RT-CGM).Methods A total of 79 diabetic patients wore RT-CGM for three days continuously while calibrating by interphalangeal glucose values 4-8 times a day.We counted matching rate of interphalangeal glucose values and RT-CGM probe value,and analyzed correlation of the matching rate with MAGE,SDBG,MBG,AUC10,AUC3.9,and NGE by Pearson correlation analysis and multiple linear regression analysis.Then we grouped corresponding match rate by MAGE and MBG,compared the difference among groups.Furthermore,we analyzed correlation of RT-CGM probe values of all-day,fasting-postprandial,and nighttime and the corresponding interphalangeal glucose values by Pearson correlation analysis.Results Pearson correlation analysis showed that the matching rate was negatively correlated with the MAGE,SDBG,MBG,and AUC10.MAGE,MBG,and NGE were in the regression equation.MAGE ＜3.9 mmol/L,matching rate was 81％,3.9 ≤ MAGE＜7 mmol/L,matching rate was 67％,MAGE≥7 mmol/L,the matching rate was 52％,the difference among 3 groups was statistically significant (P＜0.01).MBG＜7.8 mmol/L,matching rate was 78％,7.8 ≤ MBG＜ 10 mmol/L,matching rate was 68％,MBG ≥10 mmol/L,the matching rate was 57％,the difference among 3 groups was statistically significant (P ＜ 0.01).When Youden index was 0.409 and MAGE was less than 3.745 mmol/L,the match rate was more than 75％.When Youden index was 0.369 and MBG was less than 8.38 mmol/L,the matching rate was more than 75％.The correlation coefficients of all day,fasting,postprandial and nighttime probe values and the corresponding interphalangeal glucose values were 0.958,0.963,0.944,and 0.965 (all P＜0.01).Conclusions The probe values show good consistency with the interphalangeal glucose values,are able to be used for blood glucose assessment.Blood glucose fluctuations influences accuracy of RT-CGM,the smaller the blood glucose fluctuations,the smaller the mean glucose concentration,the smaller the effective blood glucose fluctuations in frequency,the higher would be the accuracy.It seems to be more effective to do calibration during fasting and nighttime. Key words: Real-time continuous glucose monitoring; Accuracy; Blood glucose fluctuations; Matching rate

Research progress of dead-in-bed syndrome in type 1 diabetes

Dead-in-bed syndrome (DBS) is a rare but devastating sudden death condition that mainly affects young patients with type 1 diabetes.Its mechanism is quite complicated and may involve multiple factors.Acute onset of recurrent and severe nocturnal hypoglycemia,abnormal cardiac repolarization,genetic factors,and obstructive sleep apnea may all contribute to ventricular arrhythmias and even sudden death.The future research plans include elucidating and understanding the underlying mechanisms and triggers for DBS,developing a risk stratification system,using real-time continuous glucose monitoring system to detect severe nocturnal hypoglycemia,and initiating appropriate therapeutic interventions to uhimately prevent the tragedy. Key words: Dead-in bed syndrome; Diabetes mellitus, type 1 ; Sudden death; Mechanism

Multi-objective optimization for conjunctive placement of hydraulic and water quality sensors in water distribution systems

Near real-time continuous monitoring systems have been proposed as a promising approach for enhancing drinking water utilities detect and respond efficiently to threats on water distribution systems. Water quality sensors are aimed at revealing contamination intrusions, while hydraulic pressure and flow sensors are utilized for estimating the hydraulic system state. To date optimization models for placing sensors in water distribution systems are targeting separately water quality and hydraulic sensor network goals. Deploying two independent sensor networks within one distribution system is expensive to install and maintain. It might thus be beneficial to consider mutual sensor locations having dual hydraulic and water quality monitoring capabilities (i.e. sensor nodes which collect both hydraulic and water quality data at the same locations). In this study a multi-objective sensor network placement model for conjunctive monitoring of hydraulic and water quality data is developed and demonstrated using the multi-objective non-dominated sorted genetic algorithm NSGA II methodology. Two water distribution systems of increasing complexity are explored showing tradeoffs between hydraulic and water quality sensor location objectives. The proposed method provides a new tool for sensor placements.

The accuracy of real-time continuous monitoring system at different stages and its association with glucose excursion

Objective To study the accuracy of real-time continuous monitoring system (RT-CGMS) at different stages and its association with glucose excursion. Methods Totally 33 patients with type 1 diabetes or type 2diabetes were under surveillance of RT-CGMS for 5 d. Capillary glucose values were measured 7 times daily.Correlation coefficient, error grid analysis (EGA), and Bland-Altman analysis methods were used to assess the correlation, accuracy and agreement of RT-CGMS at different stages and in general level; The mean amplitude of glucose excursion (MAGE) and the frequency of glucose excursion ( FGE ) were also calculated. Results ( 1 ) The correlation coefficient of RT-CGMS with capillary glucose values at fasting, postprandial stages, and in general level were 0.94,0.92, and 0.93 respectively( P＜0.01 ). (2) EGA showed that 98.82%, 98.39%, and 98.64% of the results fell in the A and B zones and 1. 18%, 1.61%, and 1.36% fell in the D zone respectively at fasting,postprandial stages, and in general level. There is no result fell in C and E zones. ( 3 ) The agreement analysis showed that RT-CGMS readings were in close agreement with capillary glucose values at fasting, postprandial periods, and in general level. (4)The MAGE at fasting, postprandial periods, and in general level were (3.57±2.66), (4.07±3.09), and (4. 02 ±3.04) mmol/L (P＞0. 05), (0±0. 5), (3± 1), and( 1 ±3) d for FGE (P＜0. 01 ).Conclusion RT-CGMS at fasting stage has higher accuracy than postprandial stage and general level, FGE at fasting stage is higher than postprandial stage and general level. Key words: Real-time continuous monitoring system; Fasting periods; Postprandial periods; Accuracy; Glucose excursion

Correlation of real-time continuous monitoring system with venous glucose and capillary glucose values

To study the correlation of real-time continuous monitoring system (RT-CGMS) with venous glucose and capillary glucose values. A total of 33 diabetics received RT-CGMS for 5 days. Fasting venous glucose values were measured at Days 1, 3 and 5 and capillary glucose values recorded 7 times daily. The methods of correlation coefficient, error grid analysis (EGA) and Bland-Altman analysis were employed to assessed the correlation, accuracy and agreement of RT-CGMS with venous glucose and capillary glucose values respectively. The mean amplitude of glucose excursions (MAGE) was calculated during RT-CGMS testing periods. (1) The correlation coefficient of RT-CGMS with vein glucose and capillary glucose values were 0.936, 0.933 (P < 0.01); (2) The analysis results of EGA showed that 98.67%, 98.64% of venous and capillary values fell in the A and B zones and 1.33%, 1.36% fell in the D zone; (3) The agreement analysis showed that RT-CGMS readings were in close agreement with venous glucose and capillary glucose results; (4) The patients at the same MAGE levels had obvious differences in HbA1C. There is a high level of correlation, accuracy and agreement between RT-CGMS and venous glucose and capillary glucose values.

Experimental and numerical investigation of micro-environmental conditions in public transportation buses

This study examines both numerically and experimentally the micro-environmental conditions in public transportation buses. A Computational Fluid Dynamics (CFD) model was developed and experimentally validated. The developed CFD model was used to calculate the spatial distributions of the mean age and mean residual lifetime of air in the bus environment and evaluate the efficiency of the bus ventilation system. Additionally, the passengers’ exposures to a variety of environmental conditions were experimentally monitored in “real world” field campaigns using the Harvard University shuttle bus system. Real time continuous monitoring systems were used to assess indoor environmental quality in the buses. It was found that CO levels were very low, while the levels of particulate matter varied and were influenced by the ambient air penetrated into the bus through the operation of the doors and the ventilation system. The CO 2 level was found elevated and greatly affected by occupancy conditions. The elevated CO 2 level indicates that the current bus ventilation is insufficient to dilute air pollutants in the bus especially under heavy occupancy conditions. This lack of sufficient ventilation indicates an elevated risk for airborne transmitted diseases in such a popular public transportation system.

Near Real-Time Monitoring of Bead Area Damage in Rolling Tires Using a Rotating Wheel Model and Multi-Directional Vibration Data

In current tire durability tests, technicians must stop tests periodically to inspect each tire, resulting in a time consuming, expensive, and relatively subjective process. Online tire monitoring would thus be a dramatic improvement over the current methodology. If such a system could be extended to on-line vehicle use, it could dramatically increase safety, reduce downtime, and lead to better fuel efficiency in commercial and passenger cars and trucks. A near real-time system to monitor the initiation of bead area damage in rolling tires was developed using vibration data collected from the wheel end spindle. To generate an accurate model of the forced response of the wheel end spindle, a tire on a fixed spindle was impacted with a modal punch while the tire was preloaded against a plate. The frequency response functions acquired from this system were then used to develop a rotating tire model consisting of time-delayed forcing functions applied to the tire patch at the rolling frequency; this model was used to assist in interpreting the results from the near real-time monitoring system. The near real-time continuous monitoring system has been deployed in a manufacturing test environment and utilizes frequency data from three mutually orthogonal acceleration measurements. These data are combined to create a highly sensitive composite index that identifies when the initiation of bead area damage has occurred.

Monitoring the collision of a cargo ship with the Vincent Thomas Bridge

On 27 August 2006, the Vincent Thomas Bridge, a 1850-m suspension bridge located in the larger metropolitan Los Angeles region, was struck by a large cargo ship passing under the bridge. Moderate damage to the maintenance scaffolding at the main span of the bridge was observed. This incident left transportation authorities wondering about the structural integrity of the bridge. A real-time continuous monitoring system that had been recently installed on the bridge successfully recorded dynamic response before and after the incident, as well as during the collision. Analysis of these valuable data allows transportation authorities to quantify the effects of the collision on the bridge structural condition, which would otherwise be infeasible with traditional visual bridge inspection approaches. A forensic study was performed to assess the structural condition of the bridge before and after the incident. Both global (multi-sensor) and local (single-sensor) identification methods were applied to detect whether significant changes occurred in the bridge vibration signature. Copyright © 2007 John Wiley & Sons, Ltd.

Development and Deployment of a Real-Time Remote Continuous Monitoring System for Manholes

Development and Deployment of a Real-Time Remote Continuous Monitoring System for Manholes