Continuous Measurement System Research Articles

Highlighting Unseen Activity Through 48-Hour Continuous Measurement in Subacute Stroke Rehabilitation: Preliminary Cohort Study.

Motor impairments not only lead to a significant reduction in patient activity levels but also trigger a further deterioration in motor function due to deconditioning, which is an issue that is particularly pronounced during hospitalization. This deconditioning can be countered by sustaining appropriate activity levels. Activities that occur outside of scheduled programs, often overlooked, are critical in this context. Wearable technology, such as smart clothing, provides a means to monitor these activities. This study aimed to observe activity levels in patients who had strokes during the subacute phase, focusing on both scheduled training sessions and other nontraining times in an inpatient rehabilitation environment. A smart clothing system is used to simultaneously measure heart rate and acceleration, offering insights into both the amount and intensity of the physical activity. In this preliminary cohort study, 11 individuals undergoing subacute stroke rehabilitation were enrolled. The 48-hour continuous measurement system, deployed at admission and reassessed 4 weeks later, monitored accelerometry data for physical activity (quantified with a moving SD of acceleration [MSDA]) and heart rate for intensity (quantified with percent heart rate reserve). The measurements were performed using a wearable activity monitoring system, the hitoe (NTT Corporation and Toray Industries, Inc) system comprising a measuring garment (wear or strap) with integrated electrodes, a data transmitter, and a smartphone. The Functional Independence Measure was used to assess the patients' daily activity levels. This study explored factors such as differences in activity during training and nontraining periods, correlations with activities of daily living (ADLs) and age, and changes observed after 4 weeks. A significant increase was found in the daily total MSDA after the 4-week program, with the average percent heart rate reserve remaining consistent. Physical activity during training positively correlated with ADL levels both at admission (ρ=0.86, P<.001) and 4 weeks post admission (ρ=0.96, P<.001), whereas the correlation between age and MSDA was not significant during training periods at admission (ρ=-0.41, P=.21) or 4 weeks post admission (ρ=-0.25, P=.45). Conversely, nontraining activity showed a negative correlation with age, with significant negative correlations with age at admission (ρ=-0.82, P=.002) and 4 weeks post admission (ρ=-0.73, P=.01). Inpatient rehabilitation activity levels were positively correlated with ADL levels. Further analysis revealed a strong positive correlation between scheduled training activities and ADL levels, whereas nontraining activities showed no such correlation. Instead, a negative correlation between nontraining activities and age was observed. These observations suggest the importance of providing activity opportunities for older patients, while it may also suggest the need for adjusting the activity amount to accommodate the potentially limited fitness levels of this demographic. Future studies with larger patient groups are warranted to validate and further elucidate these findings.

A Wireless Noninvasive Blood Pressure Measurement System Using MAX30102 and Random Forest Regressor for Photoplethysmography Signals

Hypertension, often termed “the silent killer”, is associated with cardiovascular risk and requires regular blood pressure (BP) monitoring. However, existing methods are cumbersome and require medical expertise, which is worsened by the need for physical contact, particularly during situations such as the coronavirus pandemic that started in 2019 (COVID-19). This study aimed to develop a cuffless, continuous, and accurate BP measurement system using a photoplethysmography (PPG) sensor and a microcontroller via PPG signals. The system utilizes a MAX30102 sensor and ESP-WROOM-32 microcontroller to capture PPG signals that undergo noise reduction during preprocessing. Peak detection and feature extraction algorithms were introduced, and their output data were used to train a machine learning model for BP prediction. Tuning the model resulted in identifying the best-performing model when using a dataset from six subjects with a total of 114 records, thereby achieving a coefficient of determination of 0.37/0.46 and a mean absolute error value of 4.38/4.49 using the random forest algorithm. Integrating this model into a web-based graphical user interface enables its implementation. One probable limitation arises from the small sample size (six participants) of healthy young individuals under seated conditions, thereby potentially hindering the proposed model’s ability to learn and generalize patterns effectively. Increasing the number of participants with diverse ages and medical histories can enhance the accuracy of the proposed model. Nevertheless, this innovative device successfully addresses the need for convenient, remote BP monitoring, particularly during situations like the COVID-19 pandemic, thus making it a promising tool for cardiovascular health management.

Development of transparent soil grouting test system and its application in grouted gravel pile

To visualize the grouting process of grouted gravel piles, a transparent soil model test system was developed. This system allows for the study of soil movement around the piles during grouting reinforcement and enables load-bearing capacity testing after grout solidification into piles. The experimental system comprises a grouting system, a vertical load-bearing capacity testing system, a continuous physical field measurement system, and a model box. The grouting system facilitates sequential processes: pre-consolidation, constant-pressure grouting, and vertical loading. In transparent clay with a pre-consolidation pressure of 60 kPa, constant-pressure grouting and vertical load-bearing tests for grouted gravel piles were conducted. The results captured the disturbance deformation of the soil around the pile during both grouting and vertical loading. The study indicates that disturbance deformation of the soil surrounding the pile increases with prolonged grouting time. Soil beneath the pile end predominantly undergoes vertical compression, while soil at the pile sides experiences horizontal compression. The mid-section of the soil adjacent to the pile displays oblique upward bulging and vertical deformation. Under constant-pressure grouting, the filling rate of gravel voids in the pile hole by epoxy resin chemical grout with strong time-dependent viscosity shows a decreasing trend. During vertical loading, the displacement of the soil around the pile is significantly greater than that at the pile end. Consequently, this test system facilitates the visualization and simulation of grouting and vertical load-bearing tests for grouted gravel piles.

Improved continuous measurement system for atmospheric total peroxy and total organic nitrate under the high NOx condition.

We improved the thermal dissociation cavity attenuated phase shift spectroscopy (TD-CAPS) instrument to measure atmospheric total peroxy nitrates (PNs) and organic nitrates (ONs) continuously under the condition of high NOx. In TD-CAPS, PNs and ONs are dissociated in heated quartz tubes to form NO2, and the NO2 concentration is measured by cavity attenuated phase shift spectroscopy (CAPS). The original TD-CAPS system overestimates PN and ON concentrations in the presence of high NO concentrations. Our laboratory experiments and numerical simulations showed that the main cause of the overestimation was NO oxidation to NO2 by peroxy radicals generated in the heated quartz tubes. In the improved system, NO was converted to NO2 by adding excess O3 after the quartz tubes so that CAPS detected NOx (NO and NO2) instead of NO2. The uncertainty of the improved system was less than 20% with ∼15 parts per billion by volume (ppbv) NO and ∼80ppbv NO2. The estimated detection limit (3σ) was 0.018ppbv with an integration time of 2minin the presence of 64ppbv NO2. The improved system was tested for measurement of PNs and ONs in an urban area, and the results indicated that interference from NO was successfully suppressed.

Photosvaltable Characteristics Monitoring System Using the Internet of Things (IOT)

&#x0D; &#x0D; &#x0D; &#x0D; Continuous monitoring of solar panel performance is essential to ensure effective and efficient generation of electrical energy. Developing a monitoring system such as an I-V characteristic curve tracker enables real-time monitoring and identification of potential problems or efficiency improvements. The system utilizes a circuit switching system for accurate and continuous measurement, providing insight into how the solar panel responds to changing environmental and load conditions. The data recorded by temperature, light intensity, current, and voltage sensors on the solar panel provides valuable information about its condition and the environmental factors affecting it. Utilizing IoT technology allows real-time monitoring of the data, accessible via a web page and presented graphically. The data is also stored in Excel format for further analysis, so users can access and monitor continuously as long as they are connected to the internet. From the experimental results, the Voc of the solar panel ranged from 18.7 V to 20.42 V, and Isc between 0.0727 A to 0.2145 A, which were tested under solar irradiation ranging from 100 to 500 W/m². This research demonstrates the importance of continuous monitoring and the effectiveness of the developed monitoring system in providing real-time data for analysis and optimization of solar panel performance. The system has been tested to meet the IEC No. 13B-23 standard for accuracy classes 0.2 and 0.5. A comparison between manual testing and sensor testing shows that despite the difference in accuracy levels, the sensor measurements have a relatively low average error (1.04% for voltage and 0.64% for current) compared to manual measurements, indicating that the sensor is reliable in providing accurate data. This demonstrates the reliability and effectiveness of using the sensor in the solar panel characteristics monitoring system.&#x0D; &#x0D; &#x0D; &#x0D;

High spatial resolution temperature variation detection in one direction with a fiber solenoid and RDTS system

Limited by the large bottom width of the pulsed light and the large sampling spacing of the data acquisition card in conventional Raman distributed temperature sensing (RDTS) systems, short straight fibers cannot acquire temperature measurements with high spatial resolution and high temperature accuracy in a single temperature variation region (TVR). In contrast, winding sensing fiber on a screwed tube as a fiber solenoid for temperature sensing can indirectly improve the spatial resolution of the system. However, as the radius of the screwed tube decreases, the ability of the screwed tube to improve the spatial resolution of the system will deteriorate. To break this limitation, we innovatively propose a signal processing scheme to first construct a three-dimensional surface of the sensing length of screwed tube-temperature-area value, then obtain the length of the TVR and the area value of the temperature rise curve generated from a single TVR, and finally demodulate the temperature of the TVR in the surface. The experimental results show that the proposed scheme improves the spatial resolution of the conventional screwed tube from 8 cm to 1 cm, and the average temperature accuracy of the three TVRs with the interval and length of the TVRs in the order of centimeters is ± 0.63 °C. The screwed tube can be used for axial temperature distribution measurements of liquids as well as solids, and the proposed method can further expand the application prospects of the RDTS system for continuous measurement of multiple TVRs with lengths and intervals of centimeters in one direction without changing the internal hardware.

Impact of intra-annual wood density fluctuation on tree hydraulic function: insights from a continuous monitoring approach.

Climate change significantly impacts global forests, leading to tree decline and dieback. To cope with climate change, trees develop several functional traits, such as intra-annual density fluctuations (IADFs) in tree rings. The formation of these traits facilitates trees to optimize resource allocation, allowing them to withstand periods of stress and eventually recover when the conditions become favourable again. This study focuses on a Pinus pinaster Aiton forest in a warm, drought-prone Mediterranean area, comparing two growing seasons with different weather patterns. The innovative continuous monitoring approach used in this study combines high-resolution monitoring of sap flow (SF), analysis of xylogenesis and quantitative wood anatomy. Our results revealed the high plasticity of P. pinaster in water use and wood formation, shedding light on the link between IADFs and tree conductance. Indeed, the capacity to form large cells in autumn (as IADFs) improves the total xylem hydraulic conductivity of this species. For the first time, a continuous SF measurement system captured the dynamics of bimodal SF during the 2022 growing season in conjunction with the bimodal growth pattern observed through xylogenesis monitoring. These results highlight the intricate interplay between environmental conditions, water use, wood formation and tree physiology, providing valuable insights into the acclimation mechanisms employed by P. pinaster to cope with weather fluctuations.

A dynamic electrochemiluminescence system for continuous on-line measurements based on potential stepping pulse strategy

A dynamic electrochemiluminescence (ECL) detection system combining flow injection analysis with a potential stepping pulse strategy was developed. It contains a flow injection unit that carrying the sample solution flow through a specially designed ECL detection cell continuously, ensuring the valid renew of the test solution and thus is favorable for continuous on-line measurements. This dynamic ECL analytical system based on potential stepping pulse strategy is very efficient and time-saving. Taking the ruthenium(II) tris(bipyridine) (Ru(bpy)32+)-tripropylamine (TPA) system as an example, the ECL responses to step pulse potentials and pulse period, as well as the sample flow rate were examined. Under optimized experimental parameters, the proposed protocol was further successfully applied for the continuous detection of TPA, and malachite green based on its inhibitory effect on the ECL of Ru(bpy)32+-TPA system with a limit of detection of 17.77 nM. The relative standard deviation of 97 cycles measurements was only 0.46 % under ideal conditions. The results indicate that this system could provide reproducible and reliable ECL signals. As a versatile and efficient ECL detection protocol, it has a broad prospect of application.

Convergent control of soil temperature on seasonal carbon flux in Tibetan alpine meadows: An in-situ monitoring study

The Tibet Plateau, with its extensive carbon pools, plays a pivotal role in the global carbon budget. Nevertheless, the driving factors of the carbon dioxide budget remain disputed, and the impact of freeze–thaw process on carbon release is still unclear due to the harsh climate and lack of monitoring data. To clarify the primary factors affecting the alpine meadow ecosystems and to examine the impact of freeze–thaw on carbon release, we employed the LI-8150 automated continuous measurement system. This system, in conjunction with eddy covariance meteorological data, The Boosted Regression Tree (BRT) model, and multiple stepwise regression analysis, were used to analyze the seasonal variations in carbon flux (e.g., net ecosystem carbon exchange [NEE], gross primary productivity [GPP], and ecosystem respiration [Reco]). We also investigate the carbon sources and sinks in the alpine meadow ecosystem, as well as the predominant factor of carbon flux. Our findings include: (1) the carbon sources and sinks in the alpine meadow ecosystem shift seasonally on monthly and daily scales. On a monthly scale, the ecosystem functions as a moderate carbon sink in June, July, August, and September and as a weak carbon source from October through May. (2) Overall, the alpine meadow ecosystem, located in the northeastern Qinghai Lake basin, serves as a weak carbon sink (-58.53 g C m−2 year−1). (3) Soil temperature is the primary factor driving most variations observed in NEE, Reco, and GPP, contributing 48.05 %, 78.61 %, and 65.05 %, respectively. Soil temperature, soil water dynamics influenced by freeze and thaw processes, and their interaction with plant growth collectively play a crucial role in regulating the carbon sources and sinks in ecosystems. We provide first-hand observational data for monitoring the carbon sources and sinks in the alpine meadow ecosystem of the Tibet Plateau, as well as offer future guidance for studying the carbon budget of the Tibet Plateau.

Investigation of The Effect of Combined Exercises on Glycemic Control in Individuals with Type 1 Diabetes

The aim of the present study was to investigate the effect of the combined physical exercise protocols on the blood glucose (BG) of children with T1D. The study was conducted over four weeks using self-controlled clinical trials. The first two weeks were control period and the last two weeks were the experimental period. A total of 6 exercise sessions were performed 3 days a week during the experimental period. The exercise program consisted of aerobic, stretching, and resistance exercises. Each exercise session was performed for 40 minutes. A total of 15 children with T1D, whose mean age was 13.3±SD, were included in the study. The blood glucose and insulin dose data of the participants were recorded in both periods through the continuous glucose measurement system and the registry. It was determined that aerobic exercises provided a significant decrease in blood glucose (p &lt; .05). There was no statistically significant difference between the mean BG values in the control (211.7±37.3) and experimental (208.7±40.4) periods (p &gt;0.05). On the other hand, a statistically significant decrease was found in the total daily insulin doses used by participants during the experimental (31.6±20.8 Unit) period (p &lt; 0.001). Physical exercises had an acute positive effect on blood glucose in children with T1D. However, the effect of exercise alone is not sufficient for chronic glycemic control in T1D. For chronic glycemic control, first of all, the injected insulin doses should be carefully regulated according to carbohydrates and exercise.

In Vitro Validation of a Novel Continuous Intra-Abdominal Pressure Measurement System (TraumaGuard).

Introduction: Intra-abdominal pressure (IAP) has been recognized as an important vital sign in critically ill patients. Due to the high prevalence and incidence of intra-abdominal hypertension in surgical (trauma, burns, cardiac) and medical (sepsis, liver cirrhosis, acute kidney injury) patients, continuous IAP (CIAP) monitoring has been proposed. This research was aimed at validating a new CIAP monitoring device, the TraumaGuard from Sentinel Medical Technologies, against the gold standard (height of a water column) in an in vitro setting and performing a comparative analysis among different CIAP measurement technologies (including two intra-gastric and two intra-bladder measurement devices). A technical and clinical guideline addressing the strengths and weaknesses of each device is provided as well. Methods: Five different CIAP measurement devices (two intra-gastric and three intra-vesical), including the former CiMON, Spiegelberg, Serenno, TraumaGuard, and Accuryn, were validated against the gold standard water column pressure in a bench-top abdominal phantom. The impacts of body temperature and bladder fill volume (for the intra-vesical methods) were evaluated for each system. Subsequently, 48 h of continuous monitoring (n = 2880) on top of intermittent IAP (n = 300) readings were captured for each device. Using Pearson's and Lin's correlations, concordance, and Bland and Altman analyses, the accuracy, precision, percentage error, correlation and concordance coefficients, bias, and limits of agreement were calculated for all the different devices. We also performed error grid analysis on the CIAP measurements to provide an overview of the involved risk level due to wrong IAP measurements and calculated the area under the curve and time above a certain IAP threshold. Lastly, the robustness of each system in tracking the dynamic variations of the raw IAP signal due to respirations and heartbeats was evaluated as well. Results: The TraumaGuard was the only technology able to measure the IAP with an empty artificial bladder. No important temperature dependency was observed for the investigated devices except for the Spiegelberg, which displayed higher IAP values when the temperature was increased, but this could be adjusted through recalibration. All the studied devices showed excellent ability for IAP monitoring, although the intra-vesical IAP measurements seem more reliable. In general, the TraumaGuard, Accuryn, and Serenno showed better accuracy compared to intra-gastric measurement devices. On average, biases of +0.71, +0.93, +0.29, +0.25, and -0.06 mm Hg were observed for the CiMON, Spiegelberg, Serenno, TraumaGuard, and Accuryn, respectively. All of the equipment showed percentage errors smaller than 25%. Regarding the correlation and concordance coefficients, the Serenno and TraumaGuard showed the best results (R2 = 0.98, p = 0.001, concordance coefficient of 99.5%). Error grid analysis based on the Abdominal Compartment Society guidelines showed a very low associated risk level of inappropriate treatment strategies due to erroneous IAP measurements. Regarding the dynamic tracings of the raw IAP signal, all the systems can track respiratory variations and derived parameters; however, the CiMON was slightly superior compared to the other technologies. Conclusions: According to the research guidelines of the Abdominal Compartment Society (WSACS), this in vitro study shows that the TraumaGuard can be used interchangeably with the gold standard for measuring continuous IAP, even in an empty artificial bladder. Confirmation studies with the TraumaGuard in animals and humans are warranted to further validate these findings.

Development of a Real-Time Continuous Measurement System for Tree Radial Direction

Development of a Real-Time Continuous Measurement System for Tree Radial Direction

Development of continuous measurement system for hydrogen and impurity gases using detector tube.

A relatively accurate, inexpensive, simple, and continuous quantification system for hydrogen and impurity gas(es) using a detector tube was developed in this study. Additionally, different detector tubes can be applied to measure different types of gases in a wide range from ppm order to % level. We optimized this system and evaluated its accuracy as well as the behavior of released H2 and impurity (NH3) gases from a hydrolysis of ammonia borane using a Pt/Al2O3 catalyst. The accuracy of hydrogen quantitation achieved by this system was comparable to that of commercial mass flow meters, and the accuracy of ammonia quantitation was 10% or 5% relative standard deviation, which depends on the detector tube. The concentration of released NH3 was evaluated by image analysis with a time-lapse video of the detector tube and succeeded in analyzing from ppm to % order. The H2 and NH3 release behaviors agreed with pH, and the percentage of reaction was estimated by NMR measurement of the reacted solution. These results confirmed the accuracy of this system.

Online monitoring of higher alcohols and esters throughout beer fermentation by commercial Saccharomyces cerevisiae and Saccharomyces pastorianus yeast.

Higher alcohols and esters are among the predominant classes of volatile organic compounds (VOCs) that influence the quality of beer. The concentrations of these compounds are determined through a specific yeast strain selection and fermentation conditions. The effect of yeast strains on the formation of higher alcohols and esters throughout fermentations (at 20°C) was investigated. Flavour-relevant esters (ethyl acetate, isoamyl acetate, ethyl hexanoate and ethyl octanoate) and higher alcohols (isoamyl alcohol, isobutyl alcohol and phenylethyl alcohol) were monitored throughout the fermentation using proton transfer reaction-time of flight-mass spectrometry (PTR-ToF-MS) coupled with an automated sampling system for continuous measurements. Compound identification was confirmed by analysis of samples using gas chromatography-mass spectrometry (GC-MS). Results demonstrated the specific time points where variation in higher alcohol and ester generation between yeast strains occurred. In particular, the concentrations of isoamyl acetate, ethyl octanoate and isoamyl alcohol between yeast strains were significantly different over the first 2 days of fermentation; whereas, after Day 3, no significant differences were observed. The two Saccharomyces pastorianus strains produced comparable concentrations of the key higher alcohols and esters. However, the key higher alcohol and ester concentrations varied greatly between the two S.cerevisiae strains. The use of PTR-ToF-MS to rapidly measure multiple yeast strains provides new insights on fermentation for brewers to modify the sensory profile and optimise quality.

Temperature influence on optical fiber and temperature compensation method for a frequency modulation continuous wave absolute distance measurement system.

A temperature compensation method is proposed to solve the ranging precision decrease problem of the frequency-modulated continuous wave distance measurement system. The set of phases spread frequency sampling method is used to correct the beat frequency signal non-linearity. The influence model of temperature on the optical fiber auxiliary interferometer is studied. The experimental results show that distance measurement error decreases from 0.3432 mm to 0.02260 mm, and the mean measurement standard deviation decreases from 0.1088 mm to 0.01733 mm on a maximum measurement range of 1.6 m after compensation.

An IoT-Based Automatic and Continuous Urine Measurement System

Urine output is an important indicator of renal function. In hospitals, urine is collected using a catheter connected to a urine collection bag that has volume gradation markings. This type of visual measurement has low levels of accuracy and is labor-intensive. This paper developed an Internet-of-Things enabled system that continuously monitors the urine volume collected via the urine collection system. The device is built utilizing a strain gauge load cell, an integrated circuit that contains an amplifier, analog-to-digital converter, and a WiFi-enabled microcontroller. The data is sent via wireless networking to a data collection and analysis server, which provides accurate analyses of urine output. A mobile application utilizing the Blynk.io system is used to display the data. This device and mobile application were built at a minimal cost of 26 USD. The device has been tested multiple times and reported urine output accurately, with minimal difference between actual versus measured volumes. In the future, further development of this device can provide hospitals and physicians worldwide with easy access to affordable, accurate, and real-time urine measurement, which would translate into better, life-saving medical care.

The temporal variation of radon concentration at different depths of soil: A case study in Beijing

Variations in soil radon concentrations are a potential precursor of earthquake and volcanic events. However, the unclear migration and variation mechanisms of radon concentrations in soil still limit its effective application. To elucidate the temporal variation and its possible influence factors on radon concentrations at different soil depths, a case study was performed at a suburban site in Beijing. A long-term continuous measurement system consisting of ten radon-in-soil monitors at depths from 0.1 to 5.0 m and other meteorological sensors was employed. The monitoring was carried out from January 8th to July 29th, 2022, covering 3445 h in total. Radon concentrations generally increased with soil depth. Diurnal variation of soil radon concentrations at depths of 1.2 and 1.6 m in winter and spring was observed, and a negative correlation between the soil radon concentration and the residual air pressure was found. This finding indicates a possible air exchange channel between the soil and the atmosphere at the study site. In addition, the soil radon concentration at 4.0 m depth was unexpectedly lower than that of neighboring depths and was steady throughout the measurement period. This is attributed to a possible clay layer in the soil structure at 4.0 m depth. The results of this field study indicate that the complexity of temporal variation of soil radon concentrations should be considered for its application in predicting earthquake and volcanic events.

Development of an ultrasonic linear encoder

PurposeIn this investigation, a linear encoder system based on the ultrasonic transducer has been proposed. Ultrasonic transducers are usually designed for distance measurements, such as the time of flight method and sonar system. These applications are defined as discrete-length measurement technologies. The purpose of this study is to develop a continuous displacement measurement system using ultrasonic transducers.Design/methodology/approachA modified signal processing based on heterodyne signaling is implemented in this system. In the proposed signal processing, there is an automatic gain control module, a phase-shifting module, a phase detection module, an interpolation module and especially a frequency multiplication module, which can enhance the resolution and reduce the interpolation error simultaneously.FindingsThe proposed system can generate the encoding signals and is compatible with most motion control systems. For the experimental result, the maximum measurement error and standard deviation are about −0.027 and 0.048 mm, respectively. It shows that the proposed encoder system has the potential for displacement measurement tasks.Originality/valueThis study reveals an ultrasonic linear encoder that is capable of generating an incremental encoding signal, accompanied by a corresponding signal processing methodology. In contrast to the conventional heterodyne signal processing approach, the proposed multiplication method effectively reduces the interpolation error that arises because of multiple reflections.

Battery-less optically-powered miniaturized glucose sensor with 12 mm diameter for continuous glucose measurement system

Diabetes is a typical lifestyle-related disease and blood glucose measurement plays an important role in daily health management and appropriate treatment for patients. Continuous glucose monitoring system (CGMS) is becoming common for general patients. In this paper, an optically-powered battery-less glucose sensor device with a 12 mm diameter is presented. The sensor is expected to be used for next-generation CGMS. The sensor is equipped with series-connected ultra-small photovoltaic cells as the power source. Circuit design and characterization, fabrication, and evaluation of a wireless sensor device are presented to demonstrate the feasibility of the proposed sensor architecture.

Calibration procedure for ultrasonic sensors for precise thickness measurement

The conveyor belt, the most expensive element of the conveyor, during many years of operation is subject to complex wear processes related to the processes of its friction against the debris and structural elements, fatigue processes related to its bending on drums and idler sets, and repeated changes in tension when starting the conveyor and passing through the driving drums. The rate of wear processes is proportional to the time and intensity of the belt operation (the number of cycles of the belt loop around the conveyor). Another character, sudden and random, is the belt damage that occurs during the fall of the spoil onto the belt. Smaller lumps accelerate the friction processes by damaging the surface of the covers (rubber cracks, small tears) and intense friction caused by the acceleration of the excavated material. Larger lumps with energy exceeding the limit values cause the belt to puncture through, tearing out parts of the cover or rim, and damage to the core. As the belt wears off, the energy limits decrease (due to the decreasing belt thickness), which significantly accelerates the rate of its degradation processes. Identifying the rate of change in belt thickness over the entire surface is therefore critical to estimating the remaining life of the belt. The implementation of non-invasive diagnostics of conveyor belts to assess the condition of its core and the degree of abrasion allows for a significant reduction in belt operating costs. It can contribute to the extension of its life by reducing uneven wear and damage to the core. The decision to replace the belt at the right moment allows it to be regenerated. Regular control of the condition of damage and abrasions of the belt can prevent the occurrence of major failures and plan the moments of preventive replacements, which are much cheaper than expensive emergency replacements that can additionally cause enormous production losses. Prediction of the replacement of belt sections and their length allows for proper management of the budget allocated to repair and replacement of belts. Thanks to the obtained detailed information on the degree of belt wear, it is possible to take ad hoc corrective actions to extend the life of the belts and to predict the remaining time of its failure-free operation in the adopted replacement strategy. In Poland, at the Wrocław University of Science and Technology, as a result of many years of research work financed by the National Center for Research and Development, diagnostic systems have been developed to assess the technical condition of conveyor belts. One of such devices is the ultrasonic system for continuous belt thickness measurement, which is being built under the LIDER X project, called BeltSonic. This article presents the method of calibrating this device and the obtained measurement accuracy. Accurately measuring the thickness of the strip over its entire surface is critical to forecasting its remaining life.