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Present wearable sensors are able to measure the frequency of vital signs such as respiration rate and heartbeat rate, but unable to measure those quantitatively, e.g. respiratory volume and heartbeat strength. Meanwhile, airflow at mouth contains both the respiration and the heartbeat quantitative signals. In this study, we propose a calibration method for a wearable vital sensor attached on the chest using the airflow at the mouth for quantitative respiration monitoring. An artificial ventilator and an experimental animal were introduced as test benches prior to human clinical experiment. As a proof of concept, a micro‐electro mechanical systems (MEMS) airflow sensor and a wearable accelerometer were implemented to both the test benches. The velocity output of the piston motion measured by the wearable sensor conformed with the airflow rate output, and the obtained results indicated that the wearable sensor can monitor not only the frequency of vital signs but also quantitative magnitudes such as the respiratory volume. © 2024 Institute of Electrical Engineer of Japan and Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

Abstract In this work, a computer vision sensor for the extraction of slug length, slug velocity and phase ratio from capillary liquid–liquid slug flows from video feeds in real-time, including the necessary post-processing algorithms, is developed. The developed sensor is shown to be capable of simultaneously monitoring multiple capillaries and provides reasonable accuracy at less than 3.5% mean relative error. Subsequently, the sensor is used for the control of a parallelized and actively regulated dual-channel slug flow capillary microreactor setup. As a model reaction, the solvent-free epoxidation of methyl oleate with hydrogen peroxide and a phase-transfer catalyst based on tungstophosphoric acid and a quaternary ammonium salt to yield the product 9,10-epoxystearic acid methyl ester is conducted. A space–time yield of 0.679 kg L−1 h−1 is achieved.

In a world grappling with the dire consequences of poor sanitation and inadequate water conditions, there is an urgent need for a comprehensive solution. The staggering statistics of over 400 million affected cases and 15–25 million lives lost worldwide underscore the gravity of the situation. This paper addresses this critical issue by introducing a novel approach to water quality monitoring that leverages wireless sensor networks. Traditional monitoring techniques have proven inefficient in combating the proactive contamination of water sources. These methods often involve the cumbersome grouping of various points within the distribution network, resulting in delayed outcomes, labour-intensive processes and a lack of real-time data. To overcome these limitations, this study presents a paradigm shift by employing wireless sensor networks as a viable alternative. Our proposed system boosts capability to measure a range of physicochemical parameters linked to water quality, including reductions in potential, conductivity, pH level, temperature and flow rate. By scrutinising these parameters, our sensors effectively detect water contaminants, enabling a proactive response to potential threats. To achieve this, we have meticulously designed and implemented sensors equipped with signal conditioning circuits. These sensors are seamlessly integrated into a network, with each node connected to a microcontroller responsible for data analysis and processing. This integration ensures real-time monitoring, the rapid detection of water quality deviations and swift response mechanisms. [ABSTRACT FROM AUTHOR]

With the wide application of flow sensors, their reliability under extreme conditions has become a concern in recent years. The reliability of a Micro Electro Mechanical Systems (MEMS) flow sensor under temperature (T s) is researched in this paper. This flow sensor consists of two parts, a sensor chip and a signal-processing system (SPS). Firstly, the step-stress accelerated degradation test (SSADT) is implemented. The sensor chip and the flow sensor system are tested. The results show that the biggest drift is 3.15% for sensor chips under 150 °C testing conditions, while 32.91% is recorded for the flowmeters. So, the attenuation of the SPS is significant to the degeneration of this flowmeter. The minimum drift of the SPS accounts for 82.01% of this flowmeter. Secondly, using the Coffin–Manson model, the relationship between the cycle index and T s is established. The lifetime with a different T s is estimated using the Arrhenius model. In addition, Weibull distribution (WD) is applied to evaluate the lifetime distribution. Finally, the reliability function of the WD is demonstrated, and the survival rate within one year is 87.69% under 85 °C conditions. With the application of accelerated degradation testing (ADT), the acquired results are innovative and original. This research illustrates the reliability research, which provides a relational database for the application of this flow sensor. [ABSTRACT FROM AUTHOR]

In this work, a computer vision sensor for the extraction of slug length, slug velocity and phase ratio from capillary liquid–liquid slug flows from video feeds in real-time, including the necessary post-processing algorithms, is developed. The developed sensor is shown to be capable of simultaneously monitoring multiple capillaries and provides reasonable accuracy at less than 3.5% mean relative error. Subsequently, the sensor is used for the control of a parallelized and actively regulated dual-channel slug flow capillary microreactor setup. As a model reaction, the solvent-free epoxidation of methyl oleate with hydrogen peroxide and a phase-transfer catalyst based on tungstophosphoric acid and a quaternary ammonium salt to yield the product 9,10-epoxystearic acid methyl ester is conducted. A space–time yield of 0.679 kg L−1 h−1 is achieved.Article highlights: A computer vision sensor is developed to accurately measure slug characteristics in real-time, facilitating efficient monitoring of multiple capillaries. The sensor enables effective control of a dual-channel slug flow capillary microreactor setup, improving operational performance. The successful model reaction yields a significant amount of 9,10-epoxystearic acid methyl ester, showcasing the system’s high productivity. [ABSTRACT FROM AUTHOR]

In the present study the dynamic behavior of a piezoelectric flow micro sensor based on vortex-induced vibrations (VIV) is investigated. This sensor is made by a cantilever beam, piezoelectric layer and a cylinder at free end which is used to measure the fluid velocity. The proposed VIV sensors have nonlinear dynamic behavior for different flow velocities therefore in designing VIV micro sensors obtaining linear operational working range is an important parameter. In this paper the dynamic behavior of micro flow sensors based on the modified couple stress theory (MCST) is investigated and linear operational working span is derived. The coupled governing equations of silicon based and piezoelectric layer cantilever beam, gauss electric and Van der pol equation are derived. Utilizing the derived equations the dynamic behavior of the micro sensor on the basis of parameters such as damping coefficient, cantilever beam length, material length scale parameter and tip cylinder mass is analyzed. The operational work range of the micro sensor, the acceptable linear behavior domain and error of linear behavior assumption of the device is investigated. According to the results the maximum linearization error is 3.5%. In addition to that reduction in cantilever beam length and tip cylinder mass increase the operational working range of the micro sensor. Analyzing the effect of damping coefficient on the dynamic behavior of micro flow sensor show that increasing the damping coefficient decreases the beam deflection and output voltage, but has no effect on the operational working span of the system and in order to obtain precise output from this sensor the damping coefficient must be reduced. Findings indicate that parameters which make the device behave stiffer such as reduction in beam length or tip cylinder mass or considering non-classical stresses gives a wider acceptable voltage range at higher flow velocities for the micro sensor.

A modular microfluidic system can be used to quickly set up an individually adaptable microfluidic network by linking and delinking different functional building blocks. We present a convenient and reliable connection technology, which is based on magnets and casted O-ring-like structures leading to a sealed connection without the need of additional sealing materials. Based on an improved, previously presented fabrication technology, modular microfluidic polydimethylsiloxane (PDMS) blocks using a polyurethane (PU) mold, 3D printed acrylonitrile butadiene styrene (ABS) channel structures and a magnetic connection system in combination with a casted O-ring link, featuring various integration technologies have now been designed and experimentally evaluated. In particular, this paper will address the realization of directional valves, reciprocating pumps, finger pumps, directly-cast check- and Tesla-valves, fluidic flow sensors, fluidic mixers, commercial valves, and various sensors. By using different measurement setups, the feasibility of these devices is demonstrated. Moreover, limitations and issues encountered during fabrication as well as future work are discussed.

The present research work proposes the design, mathematical formulation, simulation, experimental results and validation of a novel Target Flow Measurement Sensor (TFMS). TFMS is designed and developed based on the magnetic flux experienced by the magnetic sensor, which will be employed for the evaluation of the flow rate of the water for a range of 0lt/s to 4lt/s. A novel transduction methodology is employed in the present study to transduce the water flow rate in a pipe into a translational motion of a magnet towards a magnetic sensor, which results in the form of an increase in the magnetic flux of the sensor output. Mathematical formulations are derived to simulate the response of the TFMS for varying flow rates. The simulated response of TFMS is found to be in good agreement with the experimental results obtained. Further, experimentally the evaluated flow rate response of the TFMS is compared with the flow rates evaluated from a commercial flow meter when both are mounted in-line pipe. Furthermore, the response of the TFMS is studied with varying target plate areas via experimental trials as well as simulations. Collectively, the excellent agreement between the simulation results, TFMS experimental results and commercial flowmeter measurements prove the efficacy of the developed TFMS to measure the water flow rate. Further, the design of the TFMS has the capability of tuneable sensitivity to measure flow rates of varying ranges, which has been proved with the results obtained from varying target plate area trials.

Indirect calorimetry (IC) is considered the gold standard for measuring resting energy expenditure (REE). This review presents an overview of the different techniques to assess REE with special regard to the use of IC in critically ill patients on extracorporeal membrane oxygenation (ECMO), as well as to the sensors used in commercially available indirect calorimeters. The theoretical and technical aspects of IC in spontaneously breathing subjects and critically ill patients on mechanical ventilation and/or ECMO are covered and a critical review and comparison of the different techniques and sensors is provided. This review also aims to accurately present the physical quantities and mathematical concepts regarding IC to reduce errors and promote consistency in further research. By studying IC on ECMO from an engineering point of view rather than a medical point of view, new problem definitions come into play to further advance these techniques. [ABSTRACT FROM AUTHOR]

We developed a flow and pressure measurement device for detection of extravasation by intravenous injection of anticancer drugs at an early stage. Intravenous injection of a drug solution using a syringe pump enables a low‐speed and highly accurate drug‐administration rate. However, because the syringe pump forcibly delivers the drug solution, the drug solution is administrated at a constant administration rate regardless of the leakage of the drug solution to the outside of the blood vessel (extravasation) due to the indwelling needle coming out of the blood vessel. The proposed device is integrated into a flow‐channel structure consisting of a PDMS layer in which a MEMS thermal‐flow sensor formed on thin polyimide film and a pressure sensor are stacked on a plastic plate as a substrate. Therefore, it is possible to measure both the drug‐administration rate and injection pressure. Early detection of extravasation can be achieved by identifying the state of needle‐puncture based on changes in injection pressure. Then, the amount of leaked drug after leak occurs can be accurately measured with a flow sensor. We evaluated the flow and pressure detection function of the proposed device and confirmed that it is possible to detect extravasation early through an experiment involving a piece of raw chicken simulating human skin and flesh. © 2022 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

A tube-integrated flow sensor is proposed in this study by integrating a micro-electro mechanical systems (MEMS) flow-sensing element and electrical wiring structure on the same copper on polyimide (COP) substrate. The substrate was rolled into a circular tube with the flow-sensing element installed at the center of the tube. The signal lines were simultaneously formed and connected to the Cu layer of the substrate during the fabrication of the sensing structure, thus simplifying the electrical connection process. Finally, by rolling the fabricated sensor substrate, the flow sensor device itself was transformed into a circular tube structure, which defined the airflow region. By implementing several slits on the substrate, the sensing element was successfully placed at the center of the tube where the flow velocity is maximum. Compared to the conventional sensor structure in which the sensor was placed on the inner wall surface of the tube, the sensitivity of the sensor was doubled. [ABSTRACT FROM AUTHOR]

With the wide application of flow sensors, their reliability under extreme conditions has become a concern in recent years. The reliability of a Micro Electro Mechanical Systems (MEMS) flow sensor under temperature (Ts) is researched in this paper. This flow sensor consists of two parts, a sensor chip and a signal-processing system (SPS). Firstly, the step-stress accelerated degradation test (SSADT) is implemented. The sensor chip and the flow sensor system are tested. The results show that the biggest drift is 3.15% for sensor chips under 150 °C testing conditions, while 32.91% is recorded for the flowmeters. So, the attenuation of the SPS is significant to the degeneration of this flowmeter. The minimum drift of the SPS accounts for 82.01% of this flowmeter. Secondly, using the Coffin–Manson model, the relationship between the cycle index and Ts is established. The lifetime with a different Ts is estimated using the Arrhenius model. In addition, Weibull distribution (WD) is applied to evaluate the lifetime distribution. Finally, the reliability function of the WD is demonstrated, and the survival rate within one year is 87.69% under 85 °C conditions. With the application of accelerated degradation testing (ADT), the acquired results are innovative and original. This research illustrates the reliability research, which provides a relational database for the application of this flow sensor.

Booster pump system (BPS) can control the number of revolutions through an inverter by combining two or more vertical or horizontal centrifugal pumps in a series. Efficiency and energy savings, the most appealing aspects of booster pump systems, can be improved by controlling the operating conditions of individual pumps by measuring the flow rate of each pump. For improved operation, a booster pump system with a flow sensor to detect individual pump flow rates and a control algorithm to manage each low and high flow rate pump’s revolutions per minute are critical. To achieve this, first, the turbine-type flow sensor was developed through computational fluid dynamics and experimentation. The flow sensor was improved using computational fluid dynamics, and its accuracy was validated through experiments. The resulting flow measurement accuracy of the designed flow sensor was within 4%, with a measurement uncertainty of 0.4%. In addition, an experimental pump facility was built and used to evaluate booster pump system performance to investigate the energy saving rate. Then, after driving one low-flow rate pump at a set pressure, the flow and frequency control operation algorithm was used. This algorithm increased the allowed output of the drive pump by increasing the inverter’s frequency. When the frequency corresponding to the allowed output is achieved in the low-flow rate pump rather than the high flow rate pump, power savings increased due to the low-flow rate pump’s extended drive range. The investigations on the developed system’s energy consumption revealed that the energy savings were approximately 6.2% compared to the conventional system, depending on the system in question. The development of a booster pump system with a flow sensor was tested, and it was found to be effective.

The paper is the study of electric resistance of a graphene layer washed by a liquid with different flow rate parameters. Experiments demonstrate that if the fabricated composite (graphene upon a PET/EVA polymeric substrate) is submerged into distilled water, the sample resistance increases by 120 %. Meanwhile, the flow of liquid near the graphene layer decreases this gain in the electric conductivity. The effect offers a general design of a flow rate sensor based on the graphene layer taken as a flow-sensitive matrix. The study demonstrates that this design of graphene flow sensor (tested for distilled water) exhibits a linear dependency of the sensor resistance on the flow rate. [ABSTRACT FROM AUTHOR]

A novel flexible thermocouple film sensor on a polyimide substrate is proposed that is simple and flexible for monitoring the respiratory signal. Several thermocouples were connected in series and patterned on the polyimide substrate, and each one is formed by copper and a constant line connected to each other at two nodes. The respiratory signal was measured by the output voltage, which resulted from the temperature difference between the hot and cold junctions. The sensors were fabricated with surface-microfabrication technology with three sputtering steps. The measurement results showed that the peak voltage decreased by 90% in the case of apnea compared with normal breathing. The sensor has potential application for wearable detection of sleep apnea hypopnea syndrome (OSAHS). [ABSTRACT FROM AUTHOR]

Exhaust gas flow takes a vital position in the assessment of ship exhaust emissions, and it is essential to develop a self-powered and robust exhaust gas flow sensor in such a harsh working environment. In this work, a bearing type triboelectric nanogenerator (B-TENG) for exhaust gas flow sensing is proposed. The rolling of the steel balls on PTFE film leads to an alternative current generated, which realizes self-powered gas flow sensing. The influence of ball materials and numbers is systematically studied, and the B-TENG with six steel balls is confirmed according to the test result. After design optimization, it is successfully applied to monitor the gas flow with the linear correlation coefficient higher than 0.998 and high output voltage from 25 to 106 V within the gas flow of 2.5–14 m/s. Further, the output voltage keeps stable at 70 V under particulate matter concentration of 50–120 mg/m3. And the output performance of the B-TENG after heating at 180 °C for 10 min is also surveyed. Moreover, the mean error of the gas flow velocity by the B-TENG and a commercial gas flow sensor is about 0.73%. The test result shows its robustness and promising perspective in exhaust gas flow sensing. Therefore, the present B-TENG has a great potential to apply for self-powered and robust exhaust gas flow monitoring towards Green Ship. [ABSTRACT FROM AUTHOR]

Wireless sensor networks have enabled smart infrastructures and novel applications. With the recent roll-out of Narrowband IoT (NB-IoT) cellular radio technology, wireless sensors can be widely deployed for data collection in cities around the world. However, empirical evidence regarding the coverage and connectivity of NB-IoT in dense urban areas is limited. This article presents an empirical study that focuses on evaluating the coverage and connectivity of NB-IoT in a dense urban environment. We have designed an NB-IoT sensor node and deployed over 100 of them in high-rise apartment buildings in Hong Kong. These sensor nodes utilize a commercial NB-IoT network to collect high-resolution water flow data for machine learning model training and provide timely feedback to users. We collect and analyze the empirical NB-IoT signal measurements from the sensor nodes deployed in various challenging outdoor and indoor environments for over three months. These empirical measurements reveal correlations between NB-IoT connectivity and sensor installation environments. We also observe that inter-cell interference, as a result of coverage by multiple neighboring NB-IoT cells in a dense urban environment, is a source of connectivity degradation. We discuss potential issues that IoT application designers and system integrators might encounter in practical NB-IoT devices deployment, and we propose a transmission decision algorithm based on signal measurements for mitigating energy wasted due to transmission failures. Finally, we demonstrate the results and the benefits of using high-resolution water flow data collected by our purpose-built NB-IoT sensor nodes for studying the patterns of domestic water consumption in Hong Kong. [ABSTRACT FROM AUTHOR]

Now a days there is a rapid development in the field of urban residential areas whereas, in case of water distribution system people are using the traditional method itself which is not atomized. As the population grew, the demand for water has also increased and hence many efforts were made towards the development of water distribution system in order to meet the user demand. The existing water distribution system is facing many problems such as water theft, leakage of water leading to wastage etc. Therefore, an atomized system is proposed which is more effective and convenient for water distribution. In this system we have mainly used microcontroller along with the solenoid valves, flow sensors and relay. The microcontroller monitors the overall system. As these components make the system advance by reducing the operating time, preventing theft, avoiding water wastage and eliminating the man power thus the system is completely automatic.. [ABSTRACT FROM AUTHOR]

The complementary metal-oxide-semiconductor (CMOS) process is the main stream to fabricate integrated circuits (ICs) in the semiconductor industry. Microelectromechanical systems (MEMS), when combined with CMOS electronics to form the CMOS MEMS process, have the merits of small features, low power consumption, on-chip circuitry, and high sensitivity to develop microsensors and micro actuators. Firstly, the authors review the educational CMOS MEMS foundry service provided by the Taiwan Semiconductor Research Institute (TSRI) allied with the United Microelectronics Corporation (UMC) and the Taiwan Semiconductor Manufacturing Company (TSMC). Taiwan's foundry service of ICs is leading in the world. Secondly, the authors show the new flow sensor integrated with an instrumentation amplifier (IA) fabricated by the latest UMC 0.18 µm CMOS MEMS process as the case study. The new flow sensor adopted the self-heating resistive-thermal-detector (RTD) to sense the flow speed. This self-heating RTD half-bridge alone gives a normalized output sensitivity of 138 µV/V/(m/s)/mW only. After being integrated with an on-chip amplifier gain of 20 dB, the overall sensitivity of the flow sensor was measured and substantially improved to 1388 µV/V/(m/s)/mW for the flow speed range of 0–5 m/s. Finally, the advantages of the CMOS MEMS flow sensors are justified and discussed by the testing results. [ABSTRACT FROM AUTHOR]

At the time of COVID-19 pandemic onset in spring 2020 a project CoroVent was initiated with the aim to design and produce emergency lung ventilators and distribute them to hospitals. No flow and tidal volume sensors were available for the project. The lack of tidal volume sensors was a consequence of the rapidly increased demand for mechanical lung ventilators and their consumables. The aim of the study was to develop a special flow sensor CoroQuant for the CoroVent ventilators. The sensor based on pneumotachographic principle, manufactured by the plastic injection moulding of polypropylene, meets the requirements for precision of tidal volume measurement defined by international standard ISO 80601-2-12 for mechanical lung ventilators. CoroVent ventilators with CoroQuant sensors were distributed to 27 hospitals in the Czech Republic for free upon the requests from the medical facilities and started to be clinically used, thus preventing lack of lung ventilators in hospitals in the Czech Republic.

We present the findings from an experimental study of a MEMS flow sensor in which an initially curved, double-clamped bistable microbeam is the primary sensing element. Our research explores how the overheat ratio, direct flow loading, and turbulence-induced vibration affect the sequential snap-through (ST) buckling and snap-back (SB) release of an electrostatically actuated beam heated by an electric current. The sensor is fabricated from highly doped single-crystal silicon using a silicon-on-insulator (SOI) wafer. Positioned at the chip's edge, the microbeam is exposed to airflow, enabling concurrent dynamic response measurements with a laser Doppler vibrometer and a video camera. Our research demonstrates that the overheat ratio can be significantly lower for this sensing principle than conventional thermal sensing elements, pointing to the potential for substantial energy savings. We also emphasize the significant impact of flow angles and vibrations on the critical ST and SB voltages, which are vital for the flow sensor's output. Additionally, we introduce the first direct experimental observation of the beam profile's time history during the snap-through/snap-back transition. The potential impact of this research lies in developing more robust MEMS flow sensors with enhanced sensitivity and a better understanding of their response to environmental factors, which could have broader applications in fields such as aerospace, environmental monitoring, and industrial process control. • Bistable flow sensor based on the initially curved double-clamped beam is presented. • Effects of overheat, flow loading, and vibrations on critical voltages are studied. • Asymmetric beam profile during the dynamic snap-through and snap-back is presented. [ABSTRACT FROM AUTHOR]

Flow sensors are often sensitive to the presence of volatile anesthetics. However, this sensitivity provides a unique opportunity to combine flow sensors of differing technological principles as an alternative to measuring volatile anesthetic gas concentration, particularly for austere settings. To determine the feasibility of flow sensor fusion for volatile anesthetic concentrations monitoring, eight flow sensors were tested with isoflurane, sevoflurane, and desflurane, ranging in concentrations from 0–4.5%, 0–3.5%, and 0–18%, respectively. Pairs of flow sensors were fit to the volatile anesthetic gas concentration with a leave-one-out cross-validation method to reduce the likelihood of overfitting. Bland–Altman was used for the final evaluation of sensor pair performance. Several sensor pairs yielded limits of agreement comparable to the rated accuracy of a commercial infrared spectrometer. The ultrasonic and orifice-plate flowmeters yielded the most combinations of viable sensor pairs for all three volatile anesthetic gases. Conclusion: Measuring volatile anesthetic gases using flow sensor fusion is a feasible low-cost, low-maintenance alternative to infrared spectroscopy. In this study, testing was done under steady-state conditions in 100% oxygen. Further testing is necessary to ensure sensor fusion performance under conditions that are more reflective of the clinical use case. [ABSTRACT FROM AUTHOR]

Accurate perception of flight parameters is essential for the safe and stable flight of small unmanned aerial systems (SUASs). However, traditional flush air data sensing (FADS) systems require complex tubing and fuselage openings. Herein this study, a flexible skin system integrated with a pressure and thermal flow sensor array, and a dual‐sensor fusion algorithm for determining the angle of attack (AOA) and airspeed (V∞), are proposed. By establishing an error back‐propagation neural network, the dual‐sensor fusion modality demonstrates higher estimation accuracy than other modalities that utilize only pressure data or only flow velocity data, achieving mean absolute errors of the AOA and V∞ of less than 0.16° and 0.37 ms−1, respectively. Moreover, the simulation and experimental results show that sensors placed closer to the leading edge of the wing can provide higher estimation accuracy of the flight parameters. The flight parameters determined using the flexible air data sensing system and dual‐sensor fusion algorithm demonstrate potential application in the flight control of SUASs. [ABSTRACT FROM AUTHOR]

A high-speed and high-temperature calorimetric solid-state thermal mass flow sensor (TMFS) design was proposed and its sensitivity to temperature and airflow speed were numerically assessed. The sensor operates at 573.15 Kelvin (300 °C), measuring speeds up to 265 m/s, and is customized to be a transducer for an aircraft Air Data System (ADS). The aim was to enhance the system reliability against ice accretion on pitot tubes' pressure intakes, which causes the system to be inoperative and the aircraft to lose protections that ensure its safe operation. In this paper, the authors assess how the distance between heater and thermal sensors affects the overall TMFS sensitivity and how it can benefit from the inclusion of a thermal barrier between these elements. The results show that, by increasing the distance between the heater and temperature sensors from 0.1 to 0.6 mm, the sensitivity to temperature variation is improved by up to 80%, and that to airspeed variation is improved by up to 100%. In addition, adding a thermal barrier made of Parylene-N improves it even further, by nearly 6 times, for both temperature and air speed variations. [ABSTRACT FROM AUTHOR]

Booster pump system (BPS) can control the number of revolutions through an inverter by combining two or more vertical or horizontal centrifugal pumps in a series. Efficiency and energy savings, the most appealing aspects of booster pump systems, can be improved by controlling the operating conditions of individual pumps by measuring the flow rate of each pump. For improved operation, a booster pump system with a flow sensor to detect individual pump flow rates and a control algorithm to manage each low and high flow rate pump's revolutions per minute are critical. To achieve this, first, the turbine-type flow sensor was developed through computational fluid dynamics and experimentation. The flow sensor was improved using computational fluid dynamics, and its accuracy was validated through experiments. The resulting flow measurement accuracy of the designed flow sensor was within 4%, with a measurement uncertainty of 0.4%. In addition, an experimental pump facility was built and used to evaluate booster pump system performance to investigate the energy saving rate. Then, after driving one low-flow rate pump at a set pressure, the flow and frequency control operation algorithm was used. This algorithm increased the allowed output of the drive pump by increasing the inverter's frequency. When the frequency corresponding to the allowed output is achieved in the low-flow rate pump rather than the high flow rate pump, power savings increased due to the low-flow rate pump's extended drive range. The investigations on the developed system's energy consumption revealed that the energy savings were approximately 6.2% compared to the conventional system, depending on the system in question. The development of a booster pump system with a flow sensor was tested, and it was found to be effective. [ABSTRACT FROM AUTHOR]

In this paper, the effect of wind-induced vibration on measurement range of microcantilever anemometer is investigated for the first time. The microcantilever anemometer is composed of a flexible substrate and a piezoresistor. The wind speed can be detected through the airflow-induced deformation in the flexible substrate. Previous work indicated that the flexible substrate vibrates violently once the wind speed exceeds a critical value, resulting in severe output jitter. This wind-induced vibration limits the measurement range of the anemometer, and the relationship between the anemometer measurement range and its structural parameters has not been explored systematically. Therefore, this paper aims to reveal this relationship theoretically and experimentally, demonstrating that a shorter and thicker cantilever with larger stiffness can effectively suppress the wind-induced vibration, leading to the critical speed rising. By eliminating the wind-induced vibration, the measurement range of the microcantilever anemometer can be increased by up to 697%. These results presented in this paper can pave the way for the design and fabrication of wide-range mechanical anemometers. [ABSTRACT FROM AUTHOR]

Accurate perception of flight parameters is essential for the safe and stable flight of small unmanned aerial systems (SUASs). However, traditional flush air data sensing (FADS) systems require complex tubing and fuselage openings. Herein this study, a flexible skin system integrated with a pressure and thermal flow sensor array, and a dual‐sensor fusion algorithm for determining the angle of attack (AOA) and airspeed (V ∞ ), are proposed. By establishing an error back‐propagation neural network, the dual‐sensor fusion modality demonstrates higher estimation accuracy than other modalities that utilize only pressure data or only flow velocity data, achieving mean absolute errors of the AOA and V ∞ of less than 0.16° and 0.37 ms−1, respectively. Moreover, the simulation and experimental results show that sensors placed closer to the leading edge of the wing can provide higher estimation accuracy of the flight parameters. The flight parameters determined using the flexible air data sensing system and dual‐sensor fusion algorithm demonstrate potential application in the flight control of SUASs.

Underwater robot technology has made considerable progress in recent years. However, due to the harsh environment and noise in the flow field near the underwater robots, it is difficult to measure some basic parameters, including swimming speed. The traditional speed measurement methods for underwater robots have the disadvantages of being limited by the environment and bulky. In order to overcome these shortcomings, an artificial lateral line (ALL) sensor based on cantilever structure was developed in this paper. According to the deformation of cantilever beam under water impact, the swimming speed of underwater robots can be measured. In addition, an ‘end-to-end’ calibration algorithm was proposed to calibrate the ALL sensor in the noisy environment, avoiding the complicated noise modeling and filter design process. To reduce the risk of overfitting, a hybrid loss function based on physical model was adopted. Compared with the classical calibration method, our method can reduce the error by 47.8%. Our sensor achieved an average absolute error of 0.07897 m sâˆ'1, and can measure water speed up to 3 m sâˆ'1. [ABSTRACT FROM AUTHOR]

Yoshikazu Yamaguchi,1– 3 Tetsuya Miyashita,1 Yuko Matsuda,1 Makoto Sasaki,1 Shunsuke Takaki,1 Stephani S Kim,2 Joseph D Tobias,2,3 Takahisa Goto1 1Department of Anesthesiology and Critical Care, Yokohama City University, Kanagawa, Japan; 2Department of Anesthesiology and Pain Medicine, Nationwide Children’s Hospital, Columbus, OH, USA; 3Department of Anesthesiology and Pain Medicine, The Ohio State University Wexner Medical Center, Columbus, OH, USACorrespondence: Yoshikazu YamaguchiDepartment of Anesthesiology and Pain Medicine, Nationwide Children’s Hospital, Columbus, OH 43205, USATel +1 (614) 722-4200Fax +1 (614) 722-4203Email yoshikaz@rd6.so-net.ne.jpBackground: Precise control of tidal volume is one of the keys in limiting ventilator-induced lung injury and ensuring adequate ventilation in mechanically ventilated neonates. The aim of the study was to compare the tidal volume (mVT) measured from the expiratory limb of the ventilator with the actual tidal volume (aVT) that would be delivered to the patient using a lung model to simulate a neonate.Methods: This study was conducted using the ASL5000 lung simulator. Three combinations of parameters were set: resistance (cmH2O/L/sec) and compliance (mL/cmH2O) of 50 and 2 (Group 1), 100 and 1 (Group 2), and 150 and 0.5 (Group 3), respectively. The ASL5000 was connected to each of the ventilators including one anesthesia machine ventilator (Drager Fabius GS) and two ICU ventilators (Servo-i Universal and Evita Infinity V500). Each ventilator was evaluated with a set tidal volume of 30 mL (sVT) and a respiratory rate of 25 breathes/minute in both the volume-controlled ventilation (VCV) and dual-controlled ventilation (DCV) modes.Results: The discrepancies between sVT, mVT and aVT were highest with the Fabius anesthesia machine ventilator and increased in the simulated lung injury groups. When comparing the ICU ventilators, the difference was greater the Servo-i and increased when using the DCV mode and with simulated lung injury.Conclusion: Accurate tidal volumes were achieved only with the Infinity ICU ventilator. This was true regardless of mode of ventilation and even during simulated lung injury.Keywords: mechanical ventilation, pediatric anesthesia, tidal volume, flow sensor, lung protective ventilation, volutrauma

Nowadays, water leakage has become one of the major issues in the water distribution system, and it can cause a lot of water loss through water pipelines. Hence, causing financial loss if it goes undetected at an early stage. In this project, we present the principle of realtime monitoring water leakage systems via the Internet of Things (IoT). IoT is an important component of smart tracking and real time monitoring, which connects people and systems through wireless technologies. The device used to analyse the water leakage in the pipeline is the water flow sensor. The water flow sensor is utilised in this research to measure the water flow rate in the pipeline in order to solve all water-related issues such as leakage and usage. The system focuses on standard housing pipes, and the collected data is displayed through a smartphone. In addition, a newly developed fully integrated water leakage system had been designed and built. The result shows that the system is fully function and provide high accuracy and stability of water flow rate with 98% of accuracy. The system is also capable of transferring real-time data to smartphones via the Blynk application and alert the users when leaks are detected, and the reading is more than the lower and upper limit of the threshold data. [ABSTRACT FROM AUTHOR]

This paper reports upon a new process for the flow sensor fabrication of a thermal microelectromechanical systems (MEMS) and its performance improvement. A unique feature of the proposed process is the silicon etching, which is a combination of normal crystal-oriented silicon etching and isotropic etching of polycrystalline silicon (poly-Si). The poly-Si layer works as a sacrificial layer and promotes etching of the silicon substrate in the horizonal direction, thereby enabling location of the etching holes in the membrane of the flow sensor without the conventional etching rules. Some designs for the flow sensors, which have been infeasible with normal processes, were thus fabricated and evaluated. Hence, the new process improves the design flexibility of the membrane and enhances flow sensor performance, such as 38.3% reduction in power consumption. [ABSTRACT FROM AUTHOR]

Most of the existing flow sensors are expensive and limited in their capabilities for sensing bidirectional flow. Low-cost and accurate flow sensors with bidirectional sensing capability have numerous applications in the residential and irrigation sectors. Evaluation of a low-cost, cantilever-based sensor, suitable for measuring flow rates under turbulent flow conditions is presented in this article. Such sensors are reported for micro-fluidic applications but its potential application in large diameter pipes under turbulent flow has not been studied yet. A cantilever formed using a thin stainless-steel strip is used as the sensing element in the proposed sensor. One of the ends of the cantilever is firmly fitted to the inner wall of the pipe, and it bends or deflects towards the direction of the flow as a function of the flow rate. To experimentally evaluate the sensor in detail, the mean deflection angle of the cantilever is measured using a camera, and an image processing algorithm. In practice, the angle can be sensed using simpler methods. The performance of the prototype sensor has been evaluated after building an appropriate regression model. The results are subsequently expressed in terms of the mean flow velocity, thereby providing its potential utility in pipes of other dimensions. The shape of the mean flow velocity with respect to the mean angle of deflection characteristic of the proposed sensor matched well with the theoretical deflection computed. The sensor developed has given an accuracy of 3 % of full scale, for flow rates in the range of 2–15.5 m3/hr. The proposed sensing mechanism can realize cost-effective, simple, and reliable flow sensors. Such sensors will find applications in residential and industrial domains. [ABSTRACT FROM AUTHOR]

External ventricular drains (EVDs) are used clinically to relieve excess fluid pressure in the brain. However, EVD outflow rate is highly variable and typical clinical flow tracking methods are manual and low resolution. To address this problem, we present an integrated multi-sensor module (IMSM) containing flow, temperature, and electrode/substrate integrity sensors to monitor the flow dynamics of cerebrospinal fluid (CSF) drainage through an EVD. The impedimetric sensors were microfabricated out of biocompatible polymer thin films, enabling seamless integration with the fluid drainage path due to their low profile. A custom measurement circuit enabled automated and portable sensor operation and data collection in the clinic. System performance was verified using real human CSF in a benchtop EVD model. Impedimetric flow sensors tracked flow rate through ambient temperature variation and biomimetic pulsatile flow, reducing error compared with previous work by a factor of 6.6. Detection of sensor breakdown using novel substrate and electrode integrity sensors was verified through soak testing and immersion in bovine serum albumin (BSA). Finally, the IMSM and measurement circuit were tested for 53 days with an RMS error of 61.4 μL/min. [ABSTRACT FROM AUTHOR]

A new capacitive microelectromechanical system (MEMS) microcantilever gas flow sensor is introduced for application in industrial gas flow measurement pipelines. The chip encompasses microcantilevers with different lengths (50, 100, 250, and $400~\mu \text{m}$) and the same thickness and wideness of 2 and $50~\mu \text{m}$ , respectively. Besides MEMS sensor development, we have designed a customized bypass channel based on the orifice principle for the placement of the MEMS sensor chip. Accordingly, a minibypass has been designed, which alleviates the harsh flow condition on the sensor that will be placed in the flowmeter housing. Simulations and the experimental study revealed that the sensor is capable of measuring airflows from 0 to 25 m/s with a sensitivity of $2\times 10 ^{-4}$ pF/m/s, and this can be expanded to other gas flow measurements with a certain bandwidth. This measurement allows us to apply this sensor for measuring moderate flows up to ~200 m/s in ~10-cm diameter pipes based on the current design for bypass. According to experimental results, the sensor output capacitance varied from 3.3445 to 3.350 pF for a range of airflow between 0 and 25 m/s. We have shown that capacitive microcantilever MEMS flow sensors could be used for flow measurements in heavy-load industrial applications. [ABSTRACT FROM AUTHOR]

A tube-integrated flow sensor is proposed in this study by integrating a micro-electro mechanical systems (MEMS) flow-sensing element and electrical wiring structure on the same copper on polyimide (COP) substrate. The substrate was rolled into a circular tube with the flow-sensing element installed at the center of the tube. The signal lines were simultaneously formed and connected to the Cu layer of the substrate during the fabrication of the sensing structure, thus simplifying the electrical connection process. Finally, by rolling the fabricated sensor substrate, the flow sensor device itself was transformed into a circular tube structure, which defined the airflow region. By implementing several slits on the substrate, the sensing element was successfully placed at the center of the tube where the flow velocity is maximum. Compared to the conventional sensor structure in which the sensor was placed on the inner wall surface of the tube, the sensitivity of the sensor was doubled.

A novel flexible thermocouple film sensor on a polyimide substrate is proposed that is simple and flexible for monitoring the respiratory signal. Several thermocouples were connected in series and patterned on the polyimide substrate, and each one is formed by copper and a constant line connected to each other at two nodes. The respiratory signal was measured by the output voltage, which resulted from the temperature difference between the hot and cold junctions. The sensors were fabricated with surface-microfabrication technology with three sputtering steps. The measurement results showed that the peak voltage decreased by 90% in the case of apnea compared with normal breathing. The sensor has potential application for wearable detection of sleep apnea hypopnea syndrome (OSAHS).

Exhaust gas flow takes a vital position in the assessment of ship exhaust emissions, and it is essential to develop a self-powered and robust exhaust gas flow sensor in such a harsh working environment. In this work, a bearing type triboelectric nanogenerator (B-TENG) for exhaust gas flow sensing is proposed. The rolling of the steel balls on PTFE film leads to an alternative current generated, which realizes self-powered gas flow sensing. The influence of ball materials and numbers is systematically studied, and the B-TENG with six steel balls is confirmed according to the test result. After design optimization, it is successfully applied to monitor the gas flow with the linear correlation coefficient higher than 0.998 and high output voltage from 25 to 106 V within the gas flow of 2.5–14 m/s. Further, the output voltage keeps stable at 70 V under particulate matter concentration of 50–120 mg/m3. And the output performance of the B-TENG after heating at 180 °C for 10 min is also surveyed. Moreover, the mean error of the gas flow velocity by the B-TENG and a commercial gas flow sensor is about 0.73%. The test result shows its robustness and promising perspective in exhaust gas flow sensing. Therefore, the present B-TENG has a great potential to apply for self-powered and robust exhaust gas flow monitoring towards Green Ship.

This article presents a waterflow sensor for marine biologging. Although biologging methods have attracted attention in evaluating marine animals’ swimming performance, it has been difficult to directly measure the long-term waterflow velocity against a swimming animal. This is because the sensors require strict specifications, such as sufficient sensitivity and accuracy, small size and light weight, ability to move between water and air for breathing, and sufficient water pressure resistance. Here, we propose a waterflow sensor based on a closed-inlet Pitot-static tube structure that satisfies these requirements. The tube is filled with incompressible liquid. Silicone membranes are attached to the inlets to prevent air bubble infiltration. A differential pressure sensor chip, which works as the Pitot-static tube’s sensing element, is built into the tube housing to measure the pressure difference between the inlets. Due to the fluid incompressibility, the required pressure resistance is realized. The developed sensor responded to waterflow from 0.2 m/s to 1.6 m/s with sufficiently high sensitivity. Therefore, the proposed sensor can be utilized for the biologging of marine animals. [ABSTRACT FROM AUTHOR]

In this paper, an experimental demonstration was developed, to measure the velocity of a fluid by using a sensor based on the spherical parallel mechanism with three degrees-of-freedom. This sensor transforms the kinetic energy of the fluid into potential energy by deforming the parallel mechanism. This deformation is due to the impact of the fluid on a sphere attached to the platform of the parallel mechanism. Through the acquisition of data from an inertial measurement unit in the sphere, an algorithm calculates the velocity and direction of the fluid. The mathematic model and algorithm of the velocity measurement was developed in a previous article. This paper built and tested the sensor with the objective of demonstrating the theoretical basis for the sensor. The experiment is based on the underwater movement of the sensor in a linear way along a rail. The velocity that is measured by the linear encoder is equal to the fluid's relative velocity that is measured by the sensor. The measurements taken by the encoder and the sensor were compared in three experiments. The results show that the two measurements were similar, demonstrating that the sensor can accurately measure the velocity of the fluid.