Sensor System For Monitoring Research Articles

Novel implementation of IoT based non-invasive sensor system for real-time monitoring of intravenous fluid level for assistive e-healthcare

PurposeThe purpose of the study is to design and develop an pervasive and smart Internet of Things (IoT)-based sensor system to monitor he real-time intravenous (IV) fluid bag level.Design/methodology/approachThis paper investigates such issue and performs several experiments to develop a non-invasive, semi-automatic system to monitor IoT-based IV fluid level in real-time.FindingsThe outcome of this study is a prototype hardware that includes an ESP8266 based embedded Web server to disseminate the fluid exhaust status flag to its connected users. Nurses can get the prompt intimation about the status of IV fluid bag whether it is about to get empty.Research limitations/implicationsIoT is the backbone of the proposed system. Multi-master system need to be studied in future.Practical implicationsNon-invasive and real-time IoT-based novel technique is developed with power-efficient and cost-effective pervasive sensors.Social implicationsThis is applicable for pervasive and assistive e-health-care services by care givers and medical professionals.Originality/valueThe deployed system is controlled by ATtiny85 with help of LM35 temperature sensor. The results show a promising future of the proposed development in enhancing IoT-based smart health-care service in the coming days.

Power-efficient piezoelectric fatigue measurement using long-range wireless sensor networks

In this paper we describe the design of a proof-of-concept wireless embedded sensor system for continuous strain cycle monitoring as a method for fatigue life assessment on civil structures. Monitoring of strain cycles is energy demanding, and therefore not suited to energy-constrained devices, as it requires continuous acquisition of strain data with a high sampling rate, followed by data processing using algorithms for peak-trough detection and cycle counting. To overcome this drawback, at the core of our proposed design is a piezoelectric-based analogue sensor system that can achieve as much as a factor of 9 increase in energy efficiency compared with the conventional approach. The key component is an analogue peak-trough detector that offloads the computation in peak-trough detection from the microcontroller, thus eliminating the need for continuous sampling. The function of the detector is coupled with an energy-efficient interrupt-driven software design for acquisition and strain cycles calculation, which is carried out by using a standard form of the rainflow cycle counting algorithm. For wireless communication and networking, LoRa and LoRaWAN are adopted as core modules. We illustrate the performance of our proposed solution by way of simulation and laboratory experiments. Results show a good agreement in measurement of strain cycles between our proposed system and the conventional approach. Thus, our solution proves to be promising for real fatigue measurement applications.

A low-cost IoT-based wireless sensor system for bridge displacement monitoring

The intelligent monitoring of bridges has become vital as the number of bridges increases. Displacement measurements are useful information for structural health monitoring, which is the key method to ensure structural safety. However, most cable-based displacement measurements are costly and labor-intensive, and wireless measurements are limited by transmission distance and have difficulties in equipment maintenance and data management. The Internet of things approach provides a new technical method for addressing this challenge. This paper designs a low-cost IoT-based sensor system for bridge displacement monitoring, which consists of a sensor transducer, an amplifier circuit, an microprogrammed control unit module, an IoT wireless communication module and a cloud server. The proposed system can collect the displacement data accurately and send the data to the server by utilizing low-power wireless communication technology-NB-IoT. The analysis and visualization can be remotely performed via a web interface. Experiments and field tests show that the system can be successfully implemented in bridge displacement monitoring applications.

Bioresorbable optical sensor systems for monitoring of intracranial pressure and temperature.

Continuous measurements of pressure and temperature within the intracranial, intraocular, and intravascular spaces provide essential diagnostic information for the treatment of traumatic brain injury, glaucoma, and cardiovascular diseases, respectively. Optical sensors are attractive because of their inherent compatibility with magnetic resonance imaging (MRI). Existing implantable optical components use permanent, nonresorbable materials that must be surgically extracted after use. Bioresorbable alternatives, introduced here, bypass this requirement, thereby eliminating the costs and risks of surgeries. Here, millimeter-scale bioresorbable Fabry-Perot interferometers and two dimensional photonic crystal structures enable precise, continuous measurements of pressure and temperature. Combined mechanical and optical simulations reveal the fundamental sensing mechanisms. In vitro studies and histopathological evaluations quantify the measurement accuracies, operational lifetimes, and biocompatibility of these systems. In vivo demonstrations establish clinically relevant performance attributes. The materials, device designs, and fabrication approaches outlined here establish broad foundational capabilities for diverse classes of bioresorbable optical sensors.

A flexible single-electrode-based triboelectric nanogenerator based on double-sided nanostructures

In this study, we report a flexible single-electrode-based triboelectric nanogenerator based on double-sided polymer surface nanostructures. The triboelectric nanogenerators have been applied to harvest all kinds of mechanical energy in our daily life and convert them into electricity, and also used as a self-powered sensor system for touching pad and smart skin technologies. To enhance the performance of triboelectric nanogenerator, we fabricate a single-electrode-based triboelectric nanogenerator based on double-sided polydimethylsiloxane nanostructures and indium tin oxide electrode film using nanoimprint lithography. The nanostructures are nanopillar arrays with the diameter of about 200 nm to enhance the triboelectric effect. Open-circuit voltage and short-circuit current of the as-prepared samples are recorded using an oscilloscope with applying different external force at room temperature. The single-electrode-based triboelectric nanogenerator delivers an open-circuit voltage up to about 160 V, a short-circuit current of about 3 μA, and power density of 423.8 mW/m2, which provides an attractive solution to work as self-powered devices. This study greatly expands the applications of triboelectric nanogenerator as energy harvesting, environmental monitoring, and self-powered sensor systems.

Application of MEMS‐based accelerometer wireless sensor systems for monitoring of blast‐induced ground vibration and structural health: a review

Ubiquitous wireless sensor network (WSN) enables low-cost monitoring applications such as blast-induced ground vibration (BIGV) and structural health monitoring (SHM). In particular, monitoring and analysing the ambiguous BIGV waves are essential requisite to control and protect surrounding grievous damage structures. Similarly, improving health and longevity of structures using WSN is a new facet that owes to diminish the low-cost installation. Recent advances in WSNs are forging new prospects for sensors. A variety of intelligent sensors are integrated into the wireless system to monitor environmental, and health of civil infrastructures. Considering the current trends in the area of development of wireless monitoring prototypes, Micro-Electro-Mechanical-Systems (MEMS) accelerometer sensors are widely prevalent owing to the small size and inexpensive. In general, BIGV waves are less intensity and low-frequency signals. Hence, it is essential to select an appropriate accelerometer to detect micro-vibration waves. The study exemplifies a summarised review of recently made MEMS-based accelerometer wireless systems for intelligent and reliable monitoring of BIGV and SHM since the last decade. This research effort focuses on the numerous adopted accelerometers and their characteristics such as sensitivity, noise density, measurement range, bandwidth, resolution, network topologies, and performance of designed systems to analyse the micro-vibration levels comprehensively.

957-P: Differences in Glucose Level between Left Arm and Right Arm Using Continuous Glucose Monitors

Background: Continuous glucose monitoring (CGM) is an emerging technology that provides real-time interstitial glucose levels through a sensor with a thin filament inserted under the skin. It is customary for patients to rotate sensor application sites between arms to minimize skin irritation. However, the degree of inter-arm differences with CGM technology remains unknown. Materials and Methods: Self-proclaimed right-handed (n=5) and left-handed (n=5) subjects, regardless of concurrent comorbidities, were enrolled for CGM. A FreeStyle Libre Pro Flash Glucose Monitoring System sensor was simultaneously placed on each arm for all subjects. The sensors were worn for a maximum of 14 days with measurements taken every 15 minutes. Muscle mass and body fat analysis was conducted using a multi-frequency segmental body composition analyzer. Glucose levels from the right and left arms were time-matched with the first 12 hours eliminated from analysis. Results: A total of 9830 paired glucose levels were included for analysis. Glucose levels were outside the euglycemic range (70-140 mg/dL) for 14.5% of the time in the right arm compared to 20.0% in the left arm (P<0.001). The glucose level in the right arm was higher than the left arm in 67% (range 46 - 98%) of the measurements (P<0.001). The absolute difference in glucose level between the right and left arms was >10 mg/dL, >20 mg/dL, and >30 mg/dL, for 19.4%, 3.4%, and 0.32% of the time, respectively. The mean glucose level in the right arm was higher than the left arm by 3.75 mg/dL [SD, 8.51 mg/dL] in right-handed subjects, and by 3.84 mg/dL [SD, 7.09 mg/dL] in left-handed subjects (P=0.54). Conclusion: Time in euglycemic range could significantly differ based on arm selection when using a CGM. While the absolute difference in glucose levels between arms appears small, this degree of variability would have significant implications for clinical trial design using CGM technology. Arm dominance does not explain the inter-arm glucose level discordance. Disclosure N. Kim: None. K. Pham: None. A. Shek: None. J.J. Lim: Employee; Self; Genentech, Inc. Stock/Shareholder; Self; F. Hoffmann-La Roche Ltd. S.A. Shah: None. Funding University of the Pacific

Wireless sensor monitoring system of Canadian Poplar Forests based on Internet of Things

In the current ecological measurement of commonweal forest, there are many problems such as high intensity of operation and continuous measurement of environmental factors. In this paper, the technology of Internet of Things is applied to the automatic measurement of ecological cultivation of public-welfare forest, and the structure of automatic monitoring system of ecological cultivation based on Internet of Things is put forward. Implementation in production practice: according to the basic flow of the ecological cultivation of commonweal forest, the cultivation environment of the ecological cultivation link of the Canadian Poplar Forests was analyzed. The environmental factors influencing the growth of trees in the Canadian Poplar Forests were summarized and the best environment for the ecological cultivation was established. The preliminary experiments show that the system has the advantages of low power consumption, flexible networking, scalable and friendly human–machine interface, and can meet the application requirements of ecological cultivation information monitoring of Canadian Poplar Forests.

Continuous Monitoring of pH and Blood Gases Using Ion-Sensitive and Gas-Sensitive Field Effect Transistors Operating in the Amperometric Mode in Presence of Drift.

Accurate and cost-effective integrated sensor systems for continuous monitoring of pH and blood gases continue to be in high demand. The capacity of ion-selective and Gas-sensitive field effect transistors (FETs) to serve as low-power sensors for accurate continuous monitoring of pH and blood gases is evaluated in the amperometric or current mode of operation. A stand-alone current-mode topology is employed in which a constant bias is applied to the gate with the drain current serving as the measuring signal. Compared with voltage-mode operation (e.g., in the feedback mode in ion-selective FETs), current-mode topologies offer the advantages of small size and low power consumption. However, the ion-selective FET (ISFET) and the Gas-sensitive FET (GasFET) exhibit a similar drift behavior, imposing a serious limitation on the accuracy of these sensors for continuous monitoring applications irrespective of the mode of operation. Given the slow temporal variation associated with the drift characteristics in both devices, a common post-processing technique that involves monitoring the variation of the drain current over short intervals of time can potentially allow extraction of the measuring signal in presence of drift in both sensor types. Furthermore, in the amperometric mode the static sensitivity of a FET-based sensor, given by the product of the FET transconductance and the sensitivity of the device threshold voltage to the measurand concentration, can be increased by adjusting the device design parameters. Increasing the sensitivity, while of interest in its own right, also enhances the accuracy of the proposed method. Rigorous analytical validation of the method is presented for GasFET operation in the amperometric mode. Moreover, the correction algorithm is verified experimentally using a Si3N4-gate ISFET operating in the amperometric mode to monitor pH variations ranging from 3.5 to 10.

Energy Efficient Solutions in Wireless Sensor Systems for Water Quality Monitoring: A Review

This paper presents energy-efficient solutions for wireless sensor systems intended for the monitoring of water quality at water stations. Energy problems, such as energy scarcity and energy consumption in wireless sensor networks, are critical issues that raise concerns when it comes to defining the lifetime of a network. This can be attributed to the finite energy budget of water quality sensor nodes and also the lack of energy-efficient schemes. To address these energy problems, a detailed study has been carried out in this paper on some of the major approaches developed to address energy issues in wireless sensor systems, and dedicated to the monitoring of water quality applications in a way that contextualizes the considered solution methods. Furthermore, the solution methods are classified, while their strengths and weaknesses are also identified. Also, several suggestions are made on solution methods toward further improvement. Therefore, this paper suggests a reasonable direction for future studies on developing energy-efficient solutions in wireless sensor systems for monitoring water quality applications.

Laser speckle photometry – Optical sensor systems for condition and process monitoring

Abstract Laser speckle photometry (LSP) is an innovative, non-destructive monitoring technique based on the detection and analysis of thermally or mechanically activated speckle dynamics in a non-stationary optical field. With the development of speckle theories, it has been found that speckle patterns carry information about surface characteristics. Therefore, LSP offers a great potential for the characterization of material properties and monitoring of manufacturing processes. In contrast to the speckle interferometry method, LSP is very simple and robust. The sample is illuminated by only one laser beam to generate a speckle pattern on the surface. The signals obtained are directly recorded by a CCD or CMOS camera. By appropriate optical solutions for the beam path, typically, resolutions of less than 10 μm are reached if larger areas are illuminated. LSP is definitely a contactless, quick and quality relevant material characterization and defect detection method, allowing process monitoring in many industrial fields. Examples from online biotechnological monitoring and laser based manufacturing demonstrate further potentials of the method for process monitoring and controlling.

Vis–NIR-based optical sensor system for estimation of primary nutrients in soil

A Vis–NIR-based optical sensor system for monitoring of soil nutrients has been developed in this work. This instrument allows the measurement of three nutrients: nitrogen, phosphorous and potassium in soil. The sensing is based on the diffused reflectance obtained from the sample when illuminated with source of appropriate wavelength. Based on extensive experimentation and analysis, the selectivity of the nutrients to specific wavelengths was found to be 850 nm for nitrogen, 620–630 nm for phosphorous and 460–470 nm for potassium. These three wavelength ranges have been selected considering the cross-sensitivity issue such that the sensor response to a target nutrient does not interfere with other nutrients present in the sample. Distinct mathematical models were developed for each of the three nutrients based on the reflectance characteristics curves of the nutrients. A full description of the instrument, methodology adopted, mathematical modelling and characterization has been carried out and is reported here. The response behavior of the system was studied based on parameters such as repeatability, reproducibility, sensitivity, linearity, R2, root-mean-square error, standard error of estimate and limit of detection. The results obtained validate the satisfactory performance of the system in monitoring soil nutrients and the promising future application in precision agriculture and site-specific crop management systems.

Structural monitoring of an onshore wind turbine foundation using strain sensors

To date, the vast majority of onshore wind turbines are cast integrally with the foundations through embedded rings. Local damage around the bottom flange of the embedded ring was observed in a large number of existing foundations. Wind turbine foundations lack structural redundancy. The tower-foundation interface is the weak point and the deterioration of the interface will reduce the foundation’s effectiveness. This study is focused on structural health monitoring of a 1.5-MW onshore wind turbine foundation with embedded ring, on the basis of strain signals acquired continuously from the turbine foundation. A strain sensor monitoring system was installed in field to monitor the concrete status by measuring strain patterns and subsequently alerting any abnormal state of concrete in long term. It was integrated with a dynamic strain acquisition system to develop a real time relationship between the behaviour of local concrete deformation and the characteristics of loads exerted on the foundation. The performance of the foundation was simulated through numerical calculations. The results obtained from the sensors, numerical model and environmental operating data showed that the wind speed and direction dominated the loads exerted on foundation and local concrete deformation inside the foundation. The concrete deformation varied around the circumference of the embedded ring resulting from changes of wind direction and rotor position. The overall distribution pattern correlated roughly with peaks and troughs of calculated forces as well as the mean wind speed. Moreover, cracks were detected to occur in both sides of the bottom flange of the embedded ring and those cracks outside the flange were observed to fluctuate correlated to the change of wind speed. The field test demonstrates that the long-term monitoring of the local concrete deformation is necessary to ensure the safety of the foundation.

Semi-conductor metal oxide gas sensors for online monitoring of oak wood VOC emissions during drying

This study presents a semi-conductor metal oxide gas sensor system for the online flue gas monitoring during oak wood drying. Oak wood flakes and solid oak wood were heated on laboratory scale. The emissions were analyzed by gas chromatography–mass spectrometry and monitored by a semi-conductor metal oxide gas sensor setup. The calibrated sensor system was able to detect different drying and degradation stages of the oak wood flakes by online monitoring acetic acid and furans/methoxyphenols at 25–240 °C. The system also allowed a monitoring of acetic acid emission from solid wood at 75 °C. This sensor application has the potential to online monitor the flue gas of oak lumber drying and optimize the drying process.

A low-cost wireless sensor network for long term monitoring of energy performance and sustainability of buildings

This manuscript describes the development of a wireless sensor system for long term monitoring of temperature, humidity and heat flux reading within building structural elements, including places that are hard to reach using wired sensors. The system was tested in cold Latvian climate in 3 different buildings. The main objectives during the development phase were the maximization of network operational lifetime, ensurance of work stability and maintenance cost reduction to make the system feasible for wide use in practical applications. An optimal radio module and microcontroller combination yielded sufficient signal range and data transfer stability, as well as efficient control of energy consumption.

Capturing the Random Changes in Process Parameters in the Stochastic Grey-box Model of the Flow-Front Dynamics

Abstract With the continuously increasing size of the wind turbine blades, the complexity of the casting process and the risk of failures has also increased. The IntegralBlades® vacuum assisted resin transfer moulding (VATRM) production process at the Siemens Gamesa Renewable Energy facility in Aalborg, Denmark, does not permit the visual inspection of the process. Hence a sensor system (possibly virtual) for process control and monitoring is highly prized. Furthermore, the effect of material handling, variations in permeability of the casting media and the material (epoxy) properties affect the outcome of the casting process. Therefore, it is necessary to analyse the effect of such variations at an early stage of the design process (e.g. during the simulations) of such a sensor system. Therefore, in this paper, we first describe an effective method to simulate the random changes in the permeability and viscosity in high-dimensional partial differential equations based model of the fluid flow. Next, a low-dimensional grey-box (cyber-physical) spatiotemporal model is proposed to capture the effect of random change in permeability and viscosity during the progression of the flow-front. Finally, a numerical case-study is presented demonstrating the effectiveness of the proposed methodology.

Environmental Testing of a FBG Sensor System for Structural Health Monitoring of Building and Transport Structures

Recently, there has been an increased interest in structural health monitoring (SHM) of building and transport structures. Standard strain gauges placed on a beam surface are mostly used to monitor the mechanical stresses of timber or concrete structures. However, these sensors are susceptible to mechanical damage, electromagnetic interference or negative influences of the measured data during the measurement, such as temperature variations or potential loss of data due to explosive environment. The fibre optic sensor system offers a more suitable and reliable solution – the sensors can be integrated directly into the load bearing structure during its production and thus protected by the construction material against ambient environmental conditions. The first part of this paper presents series of environmental tests of a measuring system based on Fibre Bragg Grating principle performed from 2016 to 2018 in a climate chamber. The chamber can generate defined humidity and/or temperature cycles, which can simulate the behavior of the structure under real environmental conditions. The tested fibre optic sensor system is suitable for load bearing timber (glued laminated timber beams) and concrete structures. In the second part of this paper, mechanical loading tests of glued laminated timber beam with integrated fiber optic sensors performed in 2016, 2017 and 2018 are presented. The article describes the design of test cycles, gives the results of testing, and is concluded with the discussion of given results together with the outline of the future research directions.

Innovative sensor system and evaluation procedure for monitoring of food processing

There is a broad field of economic online and in-situ field analysis applications like the online monitoring of volatile components for quality monitoring in food processing. Looking to beer production, for example, the quality of the raw materials like grain, hops and yeast have to be investigated because these items could be the source of a contamination with 2,4,6-Trichloranisol (TCA). TCA is a chloric aromatic hydrocarbon with intensive mildewed and moldy smell and, therefore, leads to immense damage of the product not only limited to beer production. Another field of application is the monitoring of food transport and store chains to guarantee the quality of food and to avoid harm for the consumers. Typically, Volatile Organic Compounds (VOCs) are often evaporated, which can be measured by sophisticated gas sensor systems and therefore used for investigations of the mentioned problems. The purpose of this paper is to introduce a sophisticated sensor system which was developed to measure VOCs. The principal sensing element is a four-fold sensor array on a 4x4 mm2 alumina chip (Figure 1), which comprises four micro-dispensed thickfilm sensing layers of different SnO2/additive-composites. Operating MOG sensors thermo-cyclically and simultaneous sampling of the conductance yields gas specific Conductance-over-Time-Profile (CTP) features. Further-more, an innovative calibration and evaluation procedure ProSens will be introduced, which enables substance identification and concentration determination even in the case of varying environmental conditions from the characteristic CTP shapes. Many field analysis problems like those mentioned above are looking for innovative solutions. The above described sensor chip in combination with the numerical procedure ProSens is a powerful tool to solve existing problems in the area of food monitoring and food processing.

A Dual-Parameter Fusion Distributed Optical Fiber Sensor System for Oil and Gas Pipeline Monitoring

For oil and gas pipeline monitoring applications, this paper proposed a dual-parameter fusion distributed fiber optic sensor system that enables distributed temperature and distributed vibration measurements in a single fiber. Through the fiber-scattering spectrum time domain detection combined with coded pulse sequence and Raman scattering spectrum is obtained, which realizes high-resolution temperature measurement and wide-band vibrational wave measurement. The experimental results show that, on 10 km optical fiber measurement, temperature resolution up to 0.1?C and vibration response frequency range 20 Hz - 5 kHz. This sensing system achieves temperature and vibration dual-parameter measurements with fiber optics, greatly simplifying the system and facilitating installation and it can be widely used in oil and gas pipeline monitoring.

Wireless Sensor and Beidou Satellite Short Message Communication-based Cotton Picker Remote Monitoring and Management System

Abstract. Cluster operation of a cotton picker requires production monitoring, work area statistics, and the collection of work status information. Traditional cotton pickers are either not equipped with a production inspection system or use approximate statistics only. To achieve accurate monitoring of the output of cotton pickers and ensure the accuracy and reliability of remote communication, this study designed a laser- and sensor-based flow-monitoring device that uses a wireless sensor and proposed the use of an image data processing method to accurately calculate cotton flow. BeiDou Navigation Satellite System positioning technology is used to determine the position and area of a cotton picker, and the collected data are transmitted to the dispatch center using BeiDou short message communication technology. The remote monitoring system of the cotton picker includes an onboard vehicle subsystem and a dispatch center. The onboard vehicle subsystem can acquire acquisition information and remotely transmit location information, acquisition area, and acquisition traffic. The dispatch center mainly sends instructions to the cab of the cotton picker for remote management, scheduling, and visual imaging of the track and production statistics of the cotton picker. The monitoring system was installed in the pilot of the 8th Division of Xinjiang Production and Construction Corps in China. The cotton quality monitoring accuracy reached 97%, the positioning and ranging errors were less than 1%, and the system can communicate smoothly without a General Packet Radio Service (GPRS) network area. Keywords: Cotton, Image processing, Production statistics, Remote scheduling, Short message communication, Traffic monitoring.