Portable Test Equipment Research Articles

Balance evaluation system using wearable IMU sensing

The evaluation of balance and postural stability holds significant importance in both medical rehabilitation and daily life. However, the clinical method is hindered by the inconvenience of immobility and relatively high costs associated with the force platforms. Wearable sensors, such as accelerometers, have emerged as an alternative solution, overcoming the limitations of traditional force platforms. Thus, the purpose of this study is to utilize data obtained from a low-cost, portable, small-sized IMU (specifically an accelerometer) to predict indicators derived from force platform devices. A miniaturized and portable acceleration test equipment was proposed. Together with the random forest algorithm, our classification method achieved classification results with accuracy, recall, precision, f1-score, and specificity scores above 95%, This study provides a more portable and highly accurate tool for assessing balance ability.

Rapid differential diagnosis of periprosthetic joint infection by microdroplet reaction on portable biochip and indicator

Periprosthetic joint infection (PJI) is a catastrophic complication after joint arthroplasty. A key step to treat PJI is accurate diagnosis. However, according to the existing guidelines, no biomarker has been used to diagnose PJI alone and autoimmune diseases such as rheumatoid arthritis (RA) often interfere with the diagnosis. Patients with PJI often still face issues such as misdiagnosis and delayed treatment after a comprehensive scoring diagnosis. Thus, a rapid quantitative detection method based on excellent biomarker is needed. Here, an all-printed photonic crystal (PC) biochip is reported. Through the fluorescence enhancement effect of the photonic crystals and the design of the hydrophilic and hydrophobic patterning structure, trace detection of lactoferrin (LTF) in a drop of viscous synovial fluid can be achieved within 10 min by the biochip. The detection limit is as low as 4.6 ng/mL. For more intuitive results, portable testing equipment is developed with indicator light displays of three colors (green = NPJI, yellow = RA, and red = PJI) to indicate the diagnosis depending on the biochip’s fluorescence intensity. Furthermore, 79 clinical synovial fluid samples are tested with PC biochips, and the PC results are in good agreement with the ELISA results. Due to the microdroplet reaction on PCs, biochips are suitable for the detection of the selected markers in the synovial fluid. The use of the three-color portable testing equipment avoids the need for professional testing devices. Overall, this strategy provides a new paradigm for the early and differential diagnoses of PJI.

NOx Emission Prediction for Heavy-Duty Diesel Vehicles Based on Improved GWO-BP Neural Network

NOx is one of the main sources of pollutants for motor vehicles. Nowadays, many diesel vehicle manufacturers may use emission-cheating equipment to make the vehicles meet compliance standards during emission tests, but the emissions will exceed the standards during actual driving. In order to strengthen the supervision of diesel vehicles for emission monitoring, this article intends to establish a model that can predict the transient emission characteristics of heavy-duty diesel vehicles and provide a solution for remote online monitoring of diesel vehicles. This paper refers to the heavy-duty vehicle National VI emission regulations and uses vehicle-mounted portable emission testing equipment (PEMS) to conduct actual road emission tests on a certain country’s VI heavy-duty diesel vehicles. Then, it proposes a new feature engineering processing method that uses gray correlation analysis and principal component analysis to eliminate invalid data and reduce the dimensionality of the aligned data, which facilitates the rapid convergence of the model during the training process. Then, a double-hidden-layer BP (Back propagation) neural network was established, and the improved gray wolf algorithm was used to optimize the threshold and weight of the neural network, and a heavy-duty diesel vehicle NOx emission prediction model was obtained. Through the training of the network, the root mean square error (RMSE) of the improved model on the test set between the predicted value and the true value is 1.9144 (mg/s), and the coefficient of determination (R2) is 0.87024. Compared with single-hidden-layer network and double-hidden-layer BP neural network models, the accuracy of the model has been improved. The model can well predict the actual road NOx emissions of heavy-duty diesel vehicles.

The effect of the W-shape stirrups shear reinforcement on the dynamic behavior of RC flat solid slab subjected to the low-velocity impact loading

Reinforced concrete flat solid slabs may experience explosive and impact loads. Reinforced concrete flat solid slabs have been studied under static and dynamic loads. Researchers have widely explored numerous reinforcing strategies to strengthen RC slabs exposed to impact loads, yet gaps remain. Internal anchorage stirrups (W-stirrups shear reinforcement) is still rarely used to strengthen slabs against impact loading. Consequently, this study emphasized the influence of W-stirrups shear reinforcement on the dynamic response and failure modes of RC slabs subjected to impact loads.The first part examined the impact behavior of fully fixed RC flat solid slabs reinforced with W-stirrups shear reinforcement experimentally. Slabs were impacted using portable drop-weight testing equipment. Six 800-x-800-x-90-mm RC slabs were made. Three samples were reinforced with a W-stirrups orthogonally oriented in two directions, whereas three controls were without any type of strengthening. The eccentric vertical displacement of slabs, strain at four points on the W-stirrups, two on main steel, and two on concrete, and acceleration at one point over a slab were measured; also, failure modes were monitored.In the second section, ABAQUS software was used to generate finite element models of slab study samples. Numerical model results matched experimental results. Thus, the suggested finite element model may assess reinforced RC slabs under low-velocity impact loads. Finally, a parametric study was conducted in the third part to address the issue of over-reinforced design in slabs with W-stirrups. The parametric study aimed to determine the optimal steel ratio of flexural and shear reinforcement and its influence on the behavior of RC flat solid slabs reinforced with W-stirrups shear reinforcement.

Multi working mode SPR chip laboratory for high refractive index detection.

The Fiber SPR chip laboratory has become a popular choice in biochemical detection. To meet the needs of different kinds of analytes for the detection range and number of channels of the chip, we proposed a multi-mode SPR chip laboratory based on microstructure fiber in this paper. The chip laboratory was integrated with microfluidic devices made from PDMS and detection units made of bias three-core fiber and dumbbell fiber. By injecting light into different cores of a bias three-core fiber, different detection areas of dumbbell fiber can be selected, enabling the chip laboratory to enter high refractive index detection, multi-channel detection and other working modes. In the high refractive index detection mode, the chip can detect liquid samples with a refractive index range of 1.571-1.595. In multi-channel detection mode, the chip can achieve dual parameter detection of glucose and GHK-Cu, with sensitivities of 4.16 nm/(mg/mL) and 9.729 nm/(mg/mL), respectively. Additionally, the chip can switch to temperature compensation mode. The proposed multi working mode SPR chip laboratory, based on micro structured fiber, offers a new approach for the development of portable testing equipment that can detect multiple analytes and meet multiple requirements.

DNA hydrogels combined with microfluidic chips for melamine detection

The illegal addition of melamine (MEL) into pet foods and infant milk powder has caused great concern among people. In this study, a point-of-care testing (POCT) method was developed by combining stimuli-responsive deoxyribonucleic acid (DNA) hydrogels with microfluidic chips to achieve portable and sensitive detection of MEL. With the MEL aptamer (MA) acting as a cross-linker, DNA hydrogel-coated gold nanoparticles (AuNPs) served as a basis for colorimetric detection and quantitative analysis. In the presence of MEL, it competitively binds to the aptamer, causing disintegration of the DNA hydrogels and a release of the coated AuNPs, making it possible to visually detect and quantitatively measure the MEL. Under optimal conditions, the detection range of MEL using DNA hydrogels was 0.1–100 μM and the limit of detection (LOD) was 42 nM. This portable, sensitive, and user-friendly field test equipment was developed to avoid the use of non-portable laboratory instruments. Furthermore, we combined microfluidic chips with the properties of DNA hydrogels, making it possible to quantitatively detect MEL by taking photos and analyzing the gray value using software in accordance with the different colors of copolymerization solutions after the reaction. The detection range of MEL using the microfluidic chip-based method was 0.2–50 μM, and the LOD was 37 nM. Neither trained operators nor large-scale instruments are needed for using this method to conduct portable and sensitive field detection of the targets, which highlights the methods excellent potential in food security, clinical tests, environmental monitoring, and other aspects.

Vertical Graphene Canal Mesh for Strain Sensing with a Supereminent Resolution.

The development of microstrain sensors offers significant prospects in diverse applications, such as microrobots, intelligent human-computer interaction, health monitoring, and medical rehabilitation. Among strain sensor materials, vertical graphene (VG) has demonstrated considerable potential as a resistive material; however, VG-based strain sensors with high resolution are yet to be developed. In addition, the detection mechanism of VG has not been extensively investigated. Herein, we developed a VG canal mesh (VGCM) to fabricate a flexible strain sensor for ultralow strain sensing, achieving an accurate response to strains as low as 0.1‰ within a total strain range of 0%-4%. The detection of such low strains is due to the rigorous structural design and strain concentration effect of the three-dimensional micronano structure of the VGCM. Through experimental results and theoretical simulation, the evolution of microcracks in VG and the sensing mechanism of VG and VGCM are elaborated, and the unique advantages of VGCM are revealed. Finally, the VGCM-based strain sensors are proposed as portable breathing test equipment for rapid breathing detection.

Research on rail crack detection technology based on magneto-optical imaging principle

The detection of rail top crack is of great significance in ensuring the safe operation of railway. Based on the principle of magnetic flux leakage detection and Faraday magneto-optical effect, a high-resolution and non-destructive magneto-optical imaging detection method is proposed in this paper. This paper analyses the principle of magneto-optical imaging, establishes a rail magnetic flux leakage detection experimental system based on magneto-optical effect, and detects the rail specimen with crack through experiment. The experimental results show that the change of crack width and depth will affect the magneto-optical imaging results, and the minimum crack size that can be detected by this experimental system is 0.4mm wide and 0.5mm deep. This paper realizes the detection of rail crack defects by using magneto-optical imaging method, and provides the basis for building an efficient, portable and high-resolution rail non-destructive testing equipment.

Impact of cyanosis on ventilatory responses during stair climb exercise in Eisenmenger syndrome and idiopathic pulmonary arterial hypertension

Studies assessing exercise ventilatory responses during real-life exercise in pulmonary arterial hypertension (PAH) which include patients with cyanotic congenital heart disease are scarce. We assessed the ventilatory response to stairclimbing in patients with idiopathic PAH (IPAH) and congenital heart disease-associated PAH with Eisenmenger (EIS) physiology compared to healthy controls. Fifteen adults with IPAH, six EIS and 15 age and body mass index (BMI) matched controls were prospectively recruited. Participants completed spirometry and a self-paced stair-climb (48 steps) with portable cardiopulmonary exercise testing (CPET) equipment in-situ. Borg dyspnoea scores were measured at rest and on stair-climb cessation. Both IPAH and EIS groups had amplified ventilatory responses compared to Controls. The rate of increase in minute ventilation (VE) was exaggerated in EIS driven by an early increase in tidal volume (Tv) and more gradual increase in respiratory rate (RR). Peak Tv, RR, Tv: forced vital capacity (FVC) ratio, VE/VCO2 slope and stairclimb duration were significantly higher in EIS and IPAH compared to controls despite similar baseline spirometry and change in oxygen uptake on exercise. A decline in end-tidal carbon dioxide (CO2) and arterial oxygen saturations in early exercise distinguished EIS and IPAH patients. Significant correlations were observed between peak exercise Borg score and stair-climb time (r = 0.73, p = 0.002), peak end-tidal CO2 (r = −0.73, p = 0.001), peak VE (r = 0.53, p = 0.008), peak RR (r = 0.42, p = 0.011) and VE/VCO2 slope (r = 0.54, p = 0.001). Patients with IPAH and EIS have exaggerated ventilatory responses to stair-climbing compared to the controls with more severe levels of dyspnoea perception in Eisenmenger syndrome for equivalent oxygen uptake and work.

Application of Acoustic Spectrum Analysis in Detection of Porcelain Post Insulators Based on a portable insulator detection equipment

Fault detection of porcelain post insulators has always been the research direction of power industry. At present, the related equipment for flaw detection of porcelain insulators still has some defects, such as high equipment cost, complex operation and poor detection effect. For the fault detection of porcelain post insulators, this paper will put forward a complete set of fault detection methods based on the application of acoustic spectrum analysis in the fault detection of porcelain post insulators. The equipment used is a portable insulator testing equipment independently designed by the research team based on the basic principle. Based on this method, a large number of comparative experiments and testing applications have been carried out, which verifies the effectiveness and reliability of the vibroacoustic testing method in the detection of porcelain post insulators.

A Portable Bender Element-Double Cone Penetration Testing Equipment for Measuring Stiffness and Shear Strength of In-Situ Soft Soil Deposits

A portable bender element-double cone penetration (BE-DCP) testing equipment, which is invented as a prototype model for measuring the small-strain stiffness (shear wave velocity, Vs) and shear strength of in-situ soft soil deposits (loose sand and soft clay) is developed in this study. The shear wave velocity in two orthogonal directions (Vs-hv and Vs-hh) of the in-situ soils is measured from paired bender elements (BE) installed on the side of the cone shaft. The bender elements are housed in a mechanically controlled sliding block in the shaft which not only protects bender elements while the BE-DCP apparatus is being pushed into the ground, but also ensures a good contact between adjacent soil particles and benders when the target depth is reached. The real-time relationship of the pushing force and penetration depth is recorded by force transducer and laser displacement sensor and graphed in LabVIEW. Based on the cone penetration testing (CPT) theory, two formulas are derived to calculate the shear strength parameters of the in-situ soils. Test results obtained from both the portable bender element-double cone penetration (BE-DCP) testing apparatus and conventional laboratory experiments on Ottawa sand 20/30, four different sizes of Dolomite sands in various packing densities and Kaolinite under different water contents and densities as well as a field testing were compared and validated, indicating that the novel designed portable bender elementdouble cone penetration (BE-DCP) apparatus is robust, fast, and cost-efficient for measurement of small-strain stiffness and shear strength of in-situ soils.

The design of a Portable Automatic Test Equipment for Operational Availability of Combat System

The design of a Portable Automatic Test Equipment for Operational Availability of Combat System

Characteristic Analysis and Implementation of 30kW Portable Test Equipment for Performance Evaluation in Energy Storage System

Characteristic Analysis and Implementation of 30kW Portable Test Equipment for Performance Evaluation in Energy Storage System

Uniaxial Compressive Strength of Antarctic Peninsula Rocks: Schmidt Hammer Rebound Test

The uniaxial compressive strength test is a destructive and time consuming test. A number of non-destructive methods using portable testing equipment are more applicable and easier to conduct. This paper presents the results of a systematic approach to determine the uniaxial compressive strength of rock material using the Schmidt hammer rebound test. A total of five distinct locations (Graham Coast, Davis Coast, Nanson Island, Danco Coast and Trinity Island) were tested using the Schmidt rebound hammer test. Peninsula Antarctic located at northwest of Antarctic region comprising of igneous and metamorphic rocks. Statistical analysis of the results at 95% confidence level showed the Schmidt rebound value of the Graham Coast ranges from 40±1.7 to 41±1.3 with standard deviation of 8.2 to 6.4. The rebound value for Davis Coast was 39±1.6 with standard deviation of 7.7. Rocks from Nanson Island and Danco Coast have the Schmidt rebound value of 54±1.7 with standard deviation of 8.0 and 36±1.3 with standard deviation of 6.2, respectively. The Schmidt rebound value of rocks at Trinity Island ranges from 29±1.4 to 32±1.7 with standard deviation of 6.8 to 8.1. Thus, the respective uniaxial compressive strengths of rock materials from Graham Coast, Davis Coast, Danco Coast, Nanson Island and Trinity Island were 73-108, 50, 59, 164 and 45-59 MPa. The respective ISRM strength classification of rock materials of Graham Coast, Davis Coast, Danco Coast, Nanson Island and Trinity Island were strong (R4) to very strong rock (R5), medium strong rock (R3), strong rock (R4), very strong rock (R5) and medium strong (R3) to strong rock (R4). The results showed a mean of quantification of rock material strength based on the Schmidt Hammer rebound test in Antarctic Peninsula.

Recent Developments in the Measurement of Low Particulate Emissions from Mobile Sources: A Review of Particle Number Legislations

The combination of modern engine technologies, efficient aftertreatment, and tighter emission standards resulted in drastically lower particulate emission levels in Europe today. The conventional methods defined to test particulate emissions fail at such low levels as they are aimed at determining the mass of the particles collected on a filter (PM). This led to particle number (PN) measurement having become established as the method of choice to test for low particulate emissions from mobile sources. At present, there are several emission legislations that have added PN as an additional emission parameter, while there are no mandatory regulations for ambient air monitoring anywhere in the world so far. An overview of already enforced as well as an outlook of upcoming emission legislations for mobile sources that will require PN measurement will be given in this review and corresponding test solutions are described. Special emphasis is given to emission testing of construction machinery diesel particle filters in the field. Portable test equipment capable of measuring nonvolatile PN from such combustion sources is explained. Despite the progress, challenges in the measurement of low particle emissions remain, including the fact that solid particles that exist in the sub-23-nm-size range could be of more importance than originally thought.

Design of Interlnk Protocol Packet at Embedded Linux

Aiming at the file transmission problem between electronic controller for an engine and the portable test equipment based on AT91SAM9263 and Linux, the Interlnk/Intersvr software and their communicating protocol are analyzed and studied which used by electronic controller. The message format and communicating process are made clear by putting up protocol analysis environment at laboratory and source code analysis, FAT file system structure and its access methods are studied, and the file transmission function of test equipment has been fulfilled. The results of test indicate that the desired goals have been reached.

Patients Who Seem Sick and Tired Usually Are

Patients Who Seem Sick and Tired Usually Are

Improvement of Mechanical Properties and Lateral Resistance of Brick Masonry Walls by Using Indigenous Materials

In this paper, improvement of mechanical properties of unreinforced masonry walls based on the laboratory test results is discussed. Various masonry specimens have been tested by Portable Structural Testing Equipment (PSTE). Masonry prisms have been reinforced with indigenous materials (wire mesh and bamboo) and confined with reinforced concrete elements. The tensile strength, shear strength and lateral resistance of masonry walls increases up to 5.4, 2.73 and 5.65 times respectively by using plaster, wire mesh, bamboo and confinement. The Indigenous materials used in this research work are cheap and easily available as compared to FRP and other materials. Analysis for lateral resistance of masonry walls has been made by using different relationships.

Random-Walk Technique for Measuring the Electromagnetic Environment in Electrically Large Reflective Spaces

An efficient and accurate “walk-around” technique is presented for making on-site measurements of the electromagnetic environment in enclosed reflective spaces found in ship below-deck compartments, aircraft cabins and bays, and buildings such as hangars and prefabricated metal storage facilities. To assess the potentially disruptive or harmful effects to electronics equipment or ordnance from accumulated radio frequency emissions, these reverberant spaces are characterized as overmoded complex cavities, and a statistical analysis is exercised to obtain important information about maximum and average power densities in the space and their associated uncertainties. This new technique utilizes lightweight and portable test equipment, and is particularly well suited for measurements in field-operational spaces, where the use of more conventional techniques has been proven to be very difficult due to severe constraints on time, working volume, equipment size and weight, and test costs. The efficiency and accuracy of the walk-around technique are demonstrated in this paper by comparison to measurements obtained by the more conventional techniques in a large reverberation chamber. Results indicate a substantial reduction in test time, a vast improvement in the ease of test execution that can be realized at remote sites, and equal or better accuracy in the characterization of the electromagnetic environment.

Design and development of portable intelligent testing and charging equipment for nickel-cadmium battery

Design and development of portable intelligent testing and charging equipment for nickel-cadmium battery