Designing for usability: development and evaluation of a portable minimally-actuated haptic hand and forearm trainer for unsupervised stroke rehabilitation

In stroke rehabilitation, simple robotic devices hold the potential to increase the training dosage in group therapies and to enable continued therapy at home after hospital discharge. However, we identified a lack of portable and cost-effective devices that not only focus on improving motor functions but also address sensory deficits. Thus, we designed a minimally-actuated hand training device that incorporates active grasping movements and passive pronosupination, complemented by a rehabilitative game with meaningful haptic feedback. Following a human-centered design approach, we conducted a usability study with 13 healthy participants, including three therapists. In a simulated unsupervised environment, the naive participants had to set up and use the device based on written instructions. Our mixed-methods approach included quantitative data from performance metrics, standardized questionnaires, and eye tracking, alongside qualitative feedback from semi-structured interviews. The study results highlighted the device's overall ease of setup and use, as well as its realistic haptic feedback. The eye-tracking analysis further suggested that participants felt safe during usage. Moreover, the study provided crucial insights for future improvements such as a more intuitive and comfortable wrist fixation, more natural pronosupination movements, and easier-to-follow instructions. Our research underscores the importance of continuous testing in the development process and offers significant contributions to the design of user-friendly, unsupervised neurorehabilitation technologies to improve sensorimotor stroke rehabilitation.

Self-Diagnosis of SARS-CoV-2 from Saliva Samples at Home: Isothermal Amplification Enabled by Do-It-Yourself Portable Incubators and Laminated Poly-ethyl Sulfonate Membranes

COVID-19 made explicit the need for rethinking the way in which we conduct testing for epidemic emergencies. During the COVID-19 pandemic, the dependence on centralized lab facilities and resource-intensive methodologies (e.g., RT-qPCR methods) greatly limited the deployment of widespread testing efforts in many developed and underdeveloped countries. Here, we illustrate the development of a simple and portable diagnostic kit that enables self-diagnosis of COVID-19 at home from saliva samples. We describe the development of a do-it-yourself (DIY) incubator for Eppendorf tubes that can be used to conduct SARS-CoV-2 detection with competitive sensitivity and selectivity from saliva at home. In a proof-of-concept experiment, we assembled Eppendorf-tube incubators at our home shop, prepared a single-tube mix of reagents and LAMP primers in our lab, and deployed these COVID-19 detection kits using urban delivery systems (i.e., Rappifavor or Uber) to more than 15 different locations in Monterrey, México. This straightforward strategy enabled rapid and cost-effective at-home molecular diagnostics of SARS-CoV-2 from real saliva samples with a high sensitivity (100%) and high selectivity (87%).

Development of a low-cost, compact, wireless, 16 - channel biopotential data acquisition, signal conditioning and arbitrary waveform stimulator

The health and fitness of the human body rely heavily on physiological parameters. These parameters can be measured using various tools such as ECG, EMG, EEG, EOG, among others, to obtain real-time physiological data. Analysing the bio-signals obtained from these measurements can provide valuable information that can be used to improve health-care in terms of observation, diagnosis, and treatment. In bio-signal pattern recognition applications, more channels provide multiple information simultaneously. Different biosignal acquisition devices are available in the market, most of which are designed for specific signals like ECG, EMG, EEG etc The gain of the amplifiers and frequency of the filters are designed as per the targeted signals; due to which one device cannot be used for other signals. Also, most of the systems are wired system which is not comfortable for animal studies. In this paper, a low-cost, compact, wireless, 16 channel biopotential data acquisition system with integrated electrical stimulator is designed and implemented. There are several novel and flexible design approaches were incorporated in the proposed design like (1) It has user selectable digital filter in each channel based on the signal frequencies like ECG, EMG, EEG, EOG. The same system will be used to acquire different signals simultaneously. (2) It has variable gain with a configurable analog bandpass filter. (3) It can acquire signals from 4 patients simultaneously. (4) The system is capable to acquire signal from both two-electrode as well as three-electrode configurations. (5) It has integrated stimulator with trapezoidal, charge-balanced, biphasic stimulus output with near zero DC level and user selectable pulse duration or frequency of the stimulus. The developed system has the ability to acquire and transmit data wirelessly in real-time at a high transfer rate. To validate the performance of the system, tests were conducted on the acquired signals using a simulator.

Detecting Respiratory Viruses Using a Portable NIR Spectrometer-A Preliminary Exploration with a Data Driven Approach

Respiratory viruses' detection is vitally important in coping with pandemics such as COVID-19. Conventional methods typically require laboratory-based, high-cost equipment. An emerging alternative method is Near-Infrared (NIR) spectroscopy, especially a portable one of the type that has the benefits of low cost, portability, rapidity, ease of use, and mass deployability in both clinical and field settings. One obstacle to its effective application lies in its common limitations, which include relatively low specificity and general quality. Characteristically, the spectra curves show an interweaving feature for the virus-present and virus-absent samples. This then provokes the idea of using machine learning methods to overcome the difficulty. While a subsequent obstacle coincides with the fact that a direct deployment of the machine learning approaches leads to inadequate accuracy of the modelling results. This paper presents a data-driven study on the detection of two common respiratory viruses, the respiratory syncytial virus (RSV) and the Sendai virus (SEV), using a portable NIR spectrometer supported by a machine learning solution enhanced by an algorithm of variable selection via the Variable Importance in Projection (VIP) scores and its Quantile value, along with variable truncation processing, to overcome the obstacles to a certain extent. We conducted extensive experiments with the aid of the specifically developed algorithm of variable selection, using a total of four datasets, achieving classification accuracy of: (1) 0.88, 0.94, and 0.93 for RSV, SEV, and RSV + SEV, respectively, averaged over multiple runs, for the neural network modelling of taking in turn 3 sessions of data for training and the remaining one session of an 'unknown' dataset for testing. (2) the average accuracy of 0.94 (RSV), 0.97 (SEV), and 0.97 (RSV + SEV) for model validation and 0.90 (RSV), 0.93 (SEV), and 0.91 (RSV + SEV) for model testing, using two of the datasets for model training, one for model validation and the other for model testing. These results demonstrate the feasibility of using portable NIR spectroscopy coupled with machine learning to detect respiratory viruses with good accuracy, and the approach could be a viable solution for population screening.

A low-cost, portable, dual-function readout device for amplification-based point-of-need diagnostics

IMPORTANCE

The first critical step in timely disease management is rapid disease identification, which is ideally on-site detection. Of all the technologies available for disease identification, nucleic acid amplification-based diagnostics are often used due to their specificity, sensitivity, adaptability, and speed. However, the modules to interpret amplification results rapidly, reliably, and easily in resource-limited settings at point-of-need (PON) are in high demand. Therefore, we developed a portable, low-cost, and easy-to-perform device that can be used for amplification readout at PON to enable rapid yet reliable disease identification by users with minimal training.

Portable capillary LC for in-line UV monitoring and MS detection: Comparable sensitivity and much lower solvent consumption

Pharmaceutical development currently relies on quality separation methods from early discovery through to line-of-site manufacturing. There have been significant advancements made regarding the column particle packing, internal diameter, length connectivity, the understanding of the impact key parameters like void volume, flow rate, and temperature all that affects the resultant separation quality, that is, resolution, peak shape, peak width, run time, and signal-to-noise ratio. There is however a strong need to establish better alternatives to large bulky high-performance liquid chromatography racks either for process analytical reaction monitoring or mass spectrometry analysis in establishing product quality. Compact, portable high-pressure liquid chromatography can be a more efficient alternative to traditional ultra-high pressure liquid chromatography and traditional liquid chromatography. The compact versatile instrument evaluated here allows good separation control with either the on-board column with fixed ultra-violet wavelength cartridge or for use with a high-resolution mass spectrometry. Significant space reduction results in greener lab spaces with improved energy efficiency for smaller labs with lower energy demands. In addition, this compact liquid chromatography was used as a portable reaction monitoring solution to compare forced degradation kinetics and assess portable liquid chromatography-mass spectrometry capability for the analyses required for pharmaceutical drug product testing.

Portable Electrochemical Sensor for Micromotor Speed Monitoring

Autonomous movement promotes practical applications of micromotors. Understanding the moving speeds is a crucial step in micromotor studies. The current analysis method relies on an expensive optical microscope, which is limited to laboratory settings. Herein, we have developed a lightweight (0.15 g), portable (2.0 × 3.5 cm2), and low-cost (approximately $0.26) micromotor sensor (μ-Motor sensor), composed of water-sensitive materials for micromotor speed monitoring. Moving micromotors induce fluid flow, enhancing the evaporation rate of the liquid medium. Consequently, a high correlation between motor speed and water molecule concentration above the moving medium has been established. The μ-Motor sensor enables a real-time readout of the moving speed in various settings, with high accuracy (≥95% in the lab and ≥90% in field studies at a local beach). The μ-Motor sensor opens up a new way for detecting micro/nanomachine movements, illuminating future applications of micro/nanorobotics for diverse scenarios.

A Low-Cost, Portable, and Mobile-Based Bioimpedance Lymphedema Diagnosis and Monitoring System (Mobilymph): A Validation Study

Background: Breast cancer-related lymphedema (BCRL) is a debilitating chronic illness. Early management and prevention of disease progression rely on lymphedema monitoring and assessment. At present, lymphedema monitoring systems are costly and do not promote remote monitoring. Thus, a low-cost, portable, mobile-based bioimpedance lymphedema monitoring system (Mobilymph) was developed to ensure continuous lymphedema surveillance. Method and Results: Forty-five healthy and 100 BCRL participants were recruited in this study. Mobilymph bioimpedance measurement was validated with a Quadscan 4000 on healthy participants' arms. The interarm bioimpedance ratio was determined to evaluate the discriminatory capability of Mobilymph to detect BCRL. Mobilymph's bioimpedance results show no significant difference compared to Quadscan 4000. The interarm bioimpedance ratios were significantly different (p < 0.001), between participants in healthy and Stage 1, Stage 0 and Stage 1, and Stage 1 and Stage 2. Healthy and Stage 0 participants had similar interarm impedance ratios (p = 0.63). Conclusion: The bioimpedance results show that Mobilymph bioimpedance measurement is comparable to Quadscan 4000 and can detect BCRL arms. Thus, Mobilymph lymphedema monitoring system offers a feasible solution for early lymphedema diagnosis and treatment monitoring. Clinical trial registration number: MREC ID No.: 2020316-8181.

Recent advances in miniaturization of portable liquid chromatography with emphasis on detection

Liquid chromatography is a prominent analytical technique in separation science and chemical analysis, applied across numerous fields of research and within industrial applications. Over the past few decades, there has been a growing interest in the miniaturization of this technique, which has been particularly enabled through new miniature and portable detection technologies for in-field, at-site, and point-of-need (collectively 'out-of-lab') analyses. Accordingly, significant advances have been made in recent years in the development of miniaturized liquid chromatography with photometric, electrochemical, and mass spectrometric detection, enabling the development of field-deployable and portable instruments for various applications. Herein, recent developments in the miniaturization of detection systems for inclusion within, and/or coupling with, portable liquid chromatographic systems, are reviewed in detail together with critical comments and expected future trends in this area.

Portable Bulk-Water Disinfection by Live Capture of Bacteria with Divergently Branched Porous Graphite in Electric Fields

Easy access to clean water is essential to functioning and development of modern society. However, it remains arduous to develop energy-efficient, facile, and portable water treatment systems for point-of-use (POU) applications, which is particularly imperative for the safety and resilience of society during extreme weather and critical situations. Here, we propose and validate a meritorious working scheme for water disinfection via directly capturing and removing pathogen cells from bulk water using strategically designed three-dimensional (3D) porous dendritic graphite foams (PDGFs) in a high-frequency AC field. The prototype, integrated in a 3D-printed portable water-purification module, can reproducibly remove 99.997% E. coli bacteria in bulk water at a few voltages with among the lowest energy consumption at 435.5 J·L^-1_. The PDGFs, costing $1.47 per piece, can robustly operate at least 20 times for more than 8 h in total without functional degradation. Furthermore, we successfully unravel the involved disinfection mechanism with one-dimensional Brownian dynamics simulation. The system is practically applied that brings natural water in Waller Creek at UT Austin to the safe drinking level. This research, including the working mechanism based on dendritically porous graphite and the design scheme, could inspire a future device paradigm for POU water treatment.

Radiofrequency coil design for improving human liver fat quantification in a portable single-side magnetic resonance system

Earlier diagnosis of nonalcoholic fatty liver disease (NAFLD) is important to prevent progression of the disease. Recently, a low-cost portable magnetic resonance (MR) system was developed as a point-of-care screening tool for in vivo liver fat quantification. However, subcutaneous fat may confound the liver fat quantification, particularly in the NAFLD population. In this work, we propose a novel radiofrequency (RF) coil design composed of a set of "saturation" coils sandwiching a main coil to improve human liver fat quantification. By comparison with conventional MR imaging, we demonstrate the capability and effectiveness of the novel RF coil design in phantom experiments as well as in vivo liver scans. In the phantom experiment, the saturation coil reduced the error in the measured proton density fat fraction (PDFF) results from 28.9% to 4.0%, and in the in vivo experiment, it reduced the discrepancy in the PDFF results from 13.2% to 4.0%. The novel coil design, together with the adapted Carr-Purcell-Meiboom-Gill-based sequence, improves the practicability and robustness of the portable single-side MR system.

LeafSpec-Dicot: An Accurate and Portable Hyperspectral Imaging Device for Dicot Leaves

Soybean is one of the world's most consumed crops. As the human population continuously increases, new phenotyping technology is needed to develop new soybean varieties with high-yield, stress-tolerant, and disease-tolerant traits. Hyperspectral imaging (HSI) is one of the most used technologies for phenotyping. The current HSI techniques with indoor imaging towers and unmanned aerial vehicles (UAVs) suffer from multiple major noise sources, such as changes in ambient lighting conditions, leaf slopes, and environmental conditions. To reduce the noise, a portable single-leaf high-resolution HSI imager named LeafSpec was developed. However, the original design does not work efficiently for the size and shape of dicot leaves, such as soybean leaves. In addition, there is a potential to make the dicot leaf scanning much faster and easier by automating the manual scan effort in the original design. Therefore, a renovated design of a LeafSpec with increased efficiency and imaging quality for dicot leaves is presented in this paper. The new design collects an image of a dicot leaf within 20 s. The data quality of this new device is validated by detecting the effect of nitrogen treatment on soybean plants. The improved spatial resolution allows users to utilize the Normalized Difference Vegetative Index (NDVI) spatial distribution heatmap of the entire leaf to predict the nitrogen content of a soybean plant. This preliminary NDVI distribution analysis result shows a strong correlation (R² = 0.871) between the image collected by the device and the nitrogen content measured by a commercial laboratory. Therefore, it is concluded that the new LeafSpec-Dicot device can provide high-quality hyperspectral leaf images with high spatial resolution, high spectral resolution, and increased throughput for more accurate phenotyping. This enables phenotyping researchers to develop novel HSI image processing algorithms to utilize both spatial and spectral information to reveal more signals in soybean leaf images.

Wearable and Portable Devices for Acquisition of Cardiac Signals while Practicing Sport: A Scoping Review

Wearable and portable devices capable of acquiring cardiac signals are at the frontier of the sport industry. They are becoming increasingly popular for monitoring physiological parameters while practicing sport, given the advances in miniaturized technologies, powerful data, and signal processing applications. Data and signals acquired by these devices are increasingly used to monitor athletes' performances and thus to define risk indices for sport-related cardiac diseases, such as sudden cardiac death. This scoping review investigated commercial wearable and portable devices employed for cardiac signal monitoring during sport activity. A systematic search of the literature was conducted on PubMed, Scopus, and Web of Science. After study selection, a total of 35 studies were included in the review. The studies were categorized based on the application of wearable or portable devices in (1) validation studies, (2) clinical studies, and (3) development studies. The analysis revealed that standardized protocols for validating these technologies are necessary. Indeed, results obtained from the validation studies turned out to be heterogeneous and scarcely comparable, since the metrological characteristics reported were different. Moreover, the validation of several devices was carried out during different sport activities. Finally, results from clinical studies highlighted that wearable devices are crucial to improve athletes' performance and to prevent adverse cardiovascular events.

Recent Advances in the Development of Portable Electrochemical Sensors for Controlled Substances

This review article summarizes recent achievements in developing portable electrochemical sensing systems for the detection and/or quantification of controlled substances with potential on-site applications at the crime scene or other venues and in wastewater-based epidemiology. Electrochemical sensors employing carbon screen-printed electrodes (SPEs), including a wearable glove-based one, and aptamer-based devices, including a miniaturized aptamer-based graphene field effect transistor platform, are some exciting examples. Quite straightforward electrochemical sensing systems and methods for controlled substances have been developed using commercially available carbon SPEs and commercially available miniaturized potentiostats. They offer simplicity, ready availability, and affordability. With further development, they might become ready for deployment in forensic field investigation, especially when fast and informed decisions are to be made. Slightly modified carbon SPEs or SPE-like devices might be able to offer higher specificity and sensitivity while they can still be used on commercially available miniaturized potentiostats or lab-fabricated portable or even wearable devices. Affinity-based portable devices employing aptamers, antibodies, and molecularly imprinted polymers have been developed for more specific and sensitive detection and quantification. With further development of both hardware and software, the future of electrochemical sensors for controlled substances is bright.

Research progress of portable extracorporeal membrane oxygenation

INTRODUCTION

Extracorporeal membrane oxygenation (ECMO) is primarily used for the supportive treatment of patients suffering from severe cardiopulmonary failure. With the continued development of ECMO technology, the relevant scenarios also extend pre-hospital and inter-hospital. In order to meet the needs of emergency treatment in communities, disaster sites and battlefields, inter-hospital transfer and evacuation; miniaturized and portable ECMO has become a current research hotspot.

AREA COVERED

The paper first introduces the principle, composition and common modes of ECMO and summarizes the research status of portable ECMO, Novalung and wearable ECMO, analyzes the characteristics and shortcomings of existing equipment. finally, we discussed the focus and development trend of portable ECMO technology.

EXPERT OPINION

Currently, portable ECMO has many applications in interhospital transport and there are various studies on portable and wearable ECMO devices, but the development of portable ECMO still faces many challenges. In the future, research related to integrated components, rich sensor arrays, Intelligent ECMO system and lightweight technology can make future portable ECMO more suitable for pre-hospital emergency and interhospital transport.

Modeling of Rapid Pam Systems Based on Electrothermal Micromirror for High-Resolution Facial Angiography

In this paper, a portable photoacoustic microscopy (PAM) system is proposed based on a large stroke electrothermal micromirror to achieve high resolution and fast imaging. The crucial micromirror in the system realizes a precise and efficient 2-axis control. Two different designs of electrothermal actuators with "O" and "Z" shape are evenly located around the four directions of mirror plate. With a symmetrical structure, the actuator realized single direction drive only. The finite element modelling of both two proposed micromirror has realized a large displacement over 550 μm and the scan angle over ±30.43° at 0-10 V DC excitation. In addition, the steady-state and transient-state response show a high linearity and quick response respectively, which can contribute to a fast and stable imaging. Using the Linescan model, the system achieves an effective imaging area of 1 mm × 3 mm in 14 s and 1 mm × 4 mm in 12 s for the "O" and "Z" types, respectively. The proposed PAM systems have advantages in image resolution and control accuracy, indicating a significant potential in the field of facial angiography.

Portable 3D-printed hand orthosis with spatial stiffness distribution personalized for assisting grasping in daily living

Stroke survivors having limited finger coordination require an active hand orthosis to assist them with grasping tasks for daily activities. The orthosis should be portable for constant use; however, portability imposes constraints on the number, size, and weight of the actuators, which increase the difficulty of the design process. Therefore, a tradeoff exists between portability and the assistive force. In this study, a personalized spatial stiffness distribution design is presented for a portable and strengthful hand orthosis. The spatial stiffness distribution of the orthosis was optimized based on measurements of individual hand parameters to satisfy the functional requirements of achieving sufficient grip aperture in the pre-grasping phase and minimal assistive force in the grasping phase. Ten stroke survivors were recruited to evaluate the system. Sufficient grip aperture and high grip strength-to-weight ratio were achieved by the orthosis via a single motor. Moreover, the orthosis significantly restored the range of motion and improved the performance of daily activities. The proposed spatial stiffness distribution can suggest a design solution to make strengthful hand orthoses with reduced weight.

Fabrication and application of a wireless high-definition endoscopic system in urological surgeries

OBJECTIVE

To introduce a wireless high-definition endoscopic system (WHES) and compare it with a Storz high-definition (HD) system for image resolution, colour resolution, weight, and costs.

MATERIALS AND METHODS

The WHES incorporated a portable light-emitting diode light source and a wireless camera module, which can be compatible with different types of endoscopes. Images were wirelessly transmitted to a monitor or mobile platform such as smartphone through a receiver. The International Standards Organization 12233 resolution chart image was used for the comparison of image resolution and Munsell Colour Checker Chart for colour resolution. In all, 38 endourologists used a Likert questionnaire to blindly evaluate cystoscopic images from a patient with haematuria. The surgical team was asked about the overall performance of the WHES in 20 laparoscopic adrenalectomies using a unvalidated subjective survey.

RESULTS

There was no difference in image resolution between the two systems (5.82 vs 5.89  line pairs/mm). Without lens and respective light sources, there were better purple (ΔE = 21.48 vs 28.73), blue (ΔE = 34.88 vs 38.6) and red colour resolution (ΔE = 29.01 vs 35.45) for the WHES camera (P  <  0.05), but orange (ΔE = 43.45 vs 36.52) and yellow (ΔE = 52.7 vs 35.93) resolutions were better for the Storz HD camera (P  <  0.05). Comparing the WHES to a Storz laparoscopic system, the Storz system still had better resolution of orange and yellow, while the resolution of purple, blue, and red was similar for the two systems. The expert comments on resolution, brightness, and colour for cystoscopy were not statistically different, but the ergonomics score for the WHES was higher (3.7 vs 3.33, P = 0.038). The overall cost of the WHES was $23  000-25  000 compared with $45  000-50  000 for a Storz system. There were 100% general satisfaction for the WHES in the survey.

CONCLUSION

We developed a new WHES that provides the same resolution images as a Storz laparoscopic system and acceptable colour resolution with the advantages of wireless connection, small volume, low cost, portability, and high-speed wireless transmission.

UnpadStat Design: Portable Potentiostat for Electrochemical Sensing Measurements Using Screen Printed Carbon Electrode

In this research a portable potentiostat was built for electrochemical sensing measurements with three electrodes, specifically SPCEs. The circuit uses a microcontroller as the main controller to manage all activities, starting from adjusting the input voltage for the SPCEs, setting measurement parameters, measuring the resulting current, displaying graphics on the touch screen, sending data to the computer via the USB port, and connecting to the SD card. Measurements and errors with cyclic voltammetry techniques have been compared with commercial potentiostats. The measurement results on a dummy circuit and commercial SPCEs have an accuracy of more than 90% compared to commercial potentiostats. In addition, measurement data can also be saved to an SD card in .CSV format for further purposes.

Non-Destructive and Non-Invasive Measurement of Ethanol and Toxic Alcohol Strengths in Beverages and Spirits Using Portable Raman Spectroscopy

The measurement of ethanol and toxic alcohol (methanol and isopropanol) strengths in beverages and spirits is crucial for health reasons but also for the identification of adulterated products. Many methodologies have been reported in the literature, based mainly on chromatographic and on spectroscopic techniques. Chromatographic techniques are laborious and time-consuming, while spectroscopic techniques are rapid and need no special sample pretreatment. All techniques were only applied to off-line or at-line manner. In the present work, Raman spectroscopy was used for fast and non-destructive measurements. A "through the container" method was developed for a non-invasive analysis, i.e., analysis without unsealing the bottles. This method, coupled with a miniature portable Raman, can serve for in-line measurements in a production line. The optimum laser focus for maximum spirit signal and minimum glass-wall signal was investigated. Calibration curves for the alcohols of interest were constructed and validated. The limits of detections were calculated and proved to be lower than the legitimate values. The influences of the liquor color and the bottle color, shape, and thickness were checked. Twenty-eight alcoholic products were studied. The concentrations found were compared against the nominal values (from the bottle labels).

Portable Multi-Channel Electrochemical Device with Good Interaction and Wireless Connection for On-Site Testing

It is very important to rapidly test the key indicators of water in the field to fully evaluate the quality of the regional water environment. However, a high-resolution measuring device that can generate small currents for low-concentration analytes in water samples is often bulky, complex to operate, and difficult for data sharing. This work introduces a portable multi-channel electrochemical device with a small volume, good interaction, and data-sharing capabilities called PMCED. The PMCED provides an easy-to-operate graphical interactive interface to conveniently set the parameters for cyclic voltammetry or a differential pulse method performed by the four electrode channels. At the same time, the device, with a current sensitivity of 100 nA V^-1, was applied to the detection of water samples with high background current and achieved a high-resolution measurement at low current levels. The PMCED uses the Narrow Band Internet of Things (NB-IoT) to meet the needs for uploading data to the cloud in remote areas. The electrochemical signal preprocessing and chemometrics models run in the cloud, and the final results are visualized on a web page, providing a remote access channel for on-site testing results.

Recent Advances in Aptasensing Strategies for Monitoring Phycotoxins: Promising for Food Safety

Phycotoxins or marine toxins cause massive harm to humans, livestock, and pets. Current strategies based on ordinary methods are long time-wise and require expert operators, and are not reliable for on-site and real-time use. Therefore, it is urgent to exploit new detection methods for marine toxins with high sensitivity and specificity, low detection limits, convenience, and high efficiency. Conversely, biosensors can distinguish poisons with less response time and higher selectivity than the common strategies. Aptamer-based biosensors (aptasensors) are potent for environmental monitoring, especially for on-site and real-time determination of marine toxins and freshwater microorganisms, and with a degree of superiority over other biosensors, making them worth considering. This article reviews the designed aptasensors based on the different strategies for detecting the various phycotoxins.

Acceptability and Feasibility of a Low-Cost Device for Gestational Age Assessment in a Low-Resource Setting: Qualitative Study

BACKGROUND

Ultrasound for gestational age (GA) assessment is not routinely available in resource-constrained settings, particularly in rural and remote locations. The TraCer device combines a handheld wireless ultrasound probe and a tablet with artificial intelligence (AI)-enabled software that obtains GA from videos of the fetal head by automated measurements of the fetal transcerebellar diameter and head circumference.

OBJECTIVE

The aim of this study was to assess the perceptions of pregnant women, their families, and health care workers regarding the feasibility and acceptability of the TraCer device in an appropriate setting.

METHODS

A descriptive study using qualitative methods was conducted in two public health facilities in Kilifi county in coastal Kenya prior to introduction of the new technology. Study participants were shown a video role-play of the use of TraCer at a typical antenatal clinic visit. Data were collected through 6 focus group discussions (N=52) and 18 in-depth interviews.

RESULTS

Overall, TraCer was found to be highly acceptable to women, their families, and health care workers, and its implementation at health care facilities was considered to be feasible. Its introduction was predicted to reduce anxiety regarding fetal well-being, increase antenatal care attendance, increase confidence by women in their care providers, as well as save time and cost by reducing unnecessary referrals. TraCer was felt to increase the self-image of health care workers and reduce time spent providing antenatal care. Some participants expressed hesitancy toward the new technology, indicating the need to test its performance over time before full acceptance by some users. The preferred cadre of health care professionals to use the device were antenatal clinic nurses. Important implementation considerations included adequate staff training and the need to ensure sustainability and consistency of the service. Misconceptions were common, with a tendency to overestimate the diagnostic capability, and expectations that it would provide complete reassurance of fetal and maternal well-being and not primarily the GA.

CONCLUSIONS

This study shows a positive attitude toward TraCer and highlights the potential role of this innovation that uses AI-enabled automation to assess GA. Clarity of messaging about the tool and its role in pregnancy is essential to address misconceptions and prevent misuse. Further research on clinical validation and related usability and safety evaluations are recommended.

Wearable Sensor-Based Monitoring of Environmental Exposures and the Associated Health Effects: A Review

Recent advances in sensor technology have facilitated the development and use of personalized sensors in monitoring environmental factors and the associated health effects. No studies have reviewed the research advancement in examining population-based health responses to environmental exposure via portable sensors/instruments. This study aims to review studies that use portable sensors to measure environmental factors and health responses while exploring the environmental effects on health. With a thorough literature review using two major English databases (Web of Science and PubMed), 24 eligible studies were included and analyzed out of 16,751 total records. The 24 studies include 5 on physical factors, 19 on chemical factors, and none on biological factors. The results show that particles were the most considered environmental factor among all of the physical, chemical, and biological factors, followed by total volatile organic compounds and carbon monoxide. Heart rate and heart rate variability were the most considered health indicators among all cardiopulmonary outcomes, followed by respiratory function. The studies mostly had a sample size of fewer than 100 participants and a study period of less than a week due to the challenges in accessing low-cost, small, and light wearable sensors. This review guides future sensor-based environmental health studies on project design and sensor selection.

Advances, applications, and limitations of portable and rapid detection technologies for routinely encountered foodborne pathogens

Traditional foodborne pathogen detection methods are highly dependent on pre-treatment of samples and selective microbiological plating to reliably screen target microorganisms. Inherent limitations of conventional methods include longer turnaround time and high costs, use of bulky equipment, and the need for trained staff in centralized laboratory settings. Researchers have developed stable, reliable, sensitive, and selective, rapid foodborne pathogens detection assays to work around these limitations. Recent advances in rapid diagnostic technologies have shifted to on-site testing, which offers flexibility and ease-of-use, a significant improvement from traditional methods' rigid and cumbersome steps. This comprehensive review aims to thoroughly discuss the recent advances, applications, and limitations of portable and rapid biosensors for routinely encountered foodborne pathogens. It discusses the major differences between biosensing systems based on the molecular interactions of target analytes and biorecognition agents. Though detection limits and costs still need further improvement, reviewed technologies have high potential to assist the food industry in the on-site detection of biological hazards such as foodborne pathogens and toxins to maintain safe and healthy foods. Finally, this review offers targeted recommendations for future development and commercialization of diagnostic technologies specifically for emerging and re-emerging foodborne pathogens.

A Customizable and Low-Cost Ultraviolet Exposure System for Photolithography

For microfluidic device fabrication in the research, industry, and commercial areas, the curing and transfer of patterns on photoresist relies on ultraviolet (UV) light. Often, this step is performed by commercial mask aligner or UV lamp exposure systems; however, these machines are often expensive, large, and inaccessible. To find an alternative solution, we present an inexpensive, customizable, and lightweight UV exposure system that is user-friendly and readily available for a homemade cleanroom. We fabricated a portable UV exposure system that costs under $200. The wafer holder's adjustable height enabled for the selection of the appropriate curing distance, demonstrating our system's ability to be easily tailored for different applications. The high light uniformity across a 4" diameter wafer holder (light intensity error ~2.9%) was achieved by adding a light diffusing film to the apparatus. These values are comparable to the light uniformity across a 5" diameter wafer holder from a commercial mask aligner (ABM 3000HR Mask Aligner), that has a light intensity error of ~4.0%. We demonstrated the ability to perform photolithography with high quality by fabricating microfluidic devices and generating uniform microdroplets. We achieved comparable quality to the wafer patterns, microfluidic devices, and droplets made from the ABM 3000HR Mask Aligner.

A Torsion-Based Rheometer for Measuring Viscoelastic Material Properties

Rheology and the study of viscoelastic materials are an integral part of engineering and the study of biophysical systems. Tissue rheology is even used in the study of cancer and other diseases. However, the cost of a rheometer is feasible only for colleges, universities, and research laboratories. Even if a rheometer can be purchased, it is bulky and delicately calibrated, limiting its usefulness to the laboratory itself. The design presented here is less than a tenth of the cost of a professional rheometer. The design is also portable, making it the ideal solution to introduce viscoelasticity to high school students as well as for use in the field for obtaining rheological data.

Preventing Patient Falls Overnight Using Video Monitoring: A Clinical Evaluation

Inpatient falls are devastating for patients and their families and an ongoing problem for healthcare providers worldwide. Inpatient falls overnight are particularly difficult to predict and prevent. The aim of this cohort study was to evaluate effectiveness of overnight portable video monitoring as an adjunct falls prevention strategy for high falls risk patients in inpatient clinical units. Over three months, three clinical inpatient wards were provided with baby monitor equipment to facilitate portable video monitoring. Portable video monitoring registers were completed nightly and nursing staff were invited to complete surveys (n = 31) to assess their experiences of using portable video monitoring. A total of 494 episodes of portable video monitoring were recorded over the three-month period, with clinical areas reporting a total of four inpatient falls from monitoring participants (0.8% of total portable video monitoring episodes). Overall, there was a statistically significant reduction in total inpatient falls overnight on the target wards. Surveyed nursing staff reported feeling better equipped to prevent falls and indicated they would like to continue using portable monitoring as a falls prevention strategy. This study provides evidence to support the use of portable video monitoring as an effective falls prevention strategy in the hospital environment.

Integrated Acoustic Chip for Culturing 3D Cell Arrays

Three-dimensional (3D) cell arrays provide an in vitro platform for clinical drug screening, but the bulky culture devices limit their application scenarios. Here, we demonstrate an integrated portable device that can realize contact-free construction of 3D cell spheroids. The interaction between the ultrasound generated by the portable device and the capillary results in periodic pressure nodes or anti-nodes, which lead to form a 3D cell array for cell culture. Such a 3D cell array pattern can be constructed in seconds and requires only 1 μL of cell samples. We further assessed the spheroids formed by the portable device and the impact of the acoustic field on spheroids and demonstrated the drug screening with assembled spheroids. More importantly, the integrated acoustic device can be further integrated with other components for more complex cell culture and all-round analysis. This portable and effective integrated device provides a new avenue for clinical biomedicine.

On-Skin Flexible Pressure Sensor with High Sensitivity for Portable Pulse Monitoring

Radial artery pulse pressure contains abundant cardiovascular physiological and pathological information, which plays an important role in clinical diagnosis of traditional Chinese medical science. However, many photoelectric sensors and pressure sensors will lose a large number of waveform features in monitoring pulse, which will make it difficult for doctors to precisely evaluate the patients' health. In this letter, we proposed an on-skin flexible pressure sensor for monitoring radial artery pulse. The sensor consists of the MXene (Ti₃C₂T_x)-coated nonwoven fabrics (n-WFs) sensitive layer and laser-engraved interdigital copper electrodes. Benefiting from substantially increased conductive paths between fibers and electrodes during normal compression, the sensor obtains high sensitivity (3.187 kPa^-1), fast response time (15 ms), low detection limit (11.1 Pa), and long-term durability (20,000 cycles). Furthermore, a flexible processing circuit was connected with the sensor mounted on wrist radial artery, achieving wirelessly precise monitoring of the pulse on smart phones in real time. Compared with the commercial flexible pressure sensor, our sensor successfully captures weak systolic peak precisely, showing its great clinical potential and commercial value.

[Portable Multi Channel EEG Signal Acquisition System]

This study introduces a portable multi-channel EEG signal acquisition system. The system is mainly composed of EEG electrode connector, signal conditioning circuit, EEG acquisition part, main control MCU and power supply part. The low-power EEG acquisition front-end ADS1299 and STM32 are used to form the signal acquisition and data communication part. The collected EEG signal can be transmitted to the PC for real-time display. After relevant tests, the system has small volume, low power consumption, high signal-to-noise ratio, and meets the requirements of portable wearable medical devices.

A Comprehensive Review on Water Quality Monitoring Devices: Materials Advances, Current Status, and Future Perspective

Water quality monitoring has become more critical in recent years to ensure the availability of clean and safe water from natural aquifers and to understand the evolution of water contaminants across time and space. The conventional water monitoring techniques comprise of sample collection, preservation, preparation, tailed by laboratory testing and analysis with cumbersome wet chemical routes and expensive instrumentation. Despite the high accuracy of these methods, the high testing costs, laborious procedures, and maintenance associated with them don't make them lucrative for end end-users and field testing. As the participation of ultimate stakeholders, that is, common man for water quality and quantity can play a pivotal role in ensuring the sustainability of our aquifers, thus it is essential to develop and deploy portable and user-friendly technical systems for monitoring water sources in real-time or on-site. The present review emphasizes here on possible approaches including optical (absorbance, fluorescence, colorimetric, X-ray fluorescence, chemiluminescence), electrochemical (ASV, CSV, CV, EIS, and chronoamperometry), electrical, biological, and surface-sensing (SPR and SERS), as candidates for developing such platforms. The existing developments, their success, and bottlenecks are discussed in terms of various attributes of water to escalate the essentiality of water quality devices development meeting ASSURED criterion for societal usage. These platforms are also analyzed in terms of their market potential, advancements required from material science aspects, and possible integration with IoT solutions in alignment with Industry 4.0 for environmental application.

Accuracy and Reproducibility of Laboratory Diffuse Reflectance Measurements with Portable VNIR and MIR Spectrometers for Predictive Soil Organic Carbon Modeling

Soil spectroscopy in the visible-to-near infrared (VNIR) and mid-infrared (MIR) is a cost-effective method to determine the soil organic carbon content (SOC) based on predictive spectral models calibrated to analytical-determined SOC reference data. The degree to which uncertainty in reference data and spectral measurements contributes to the estimated accuracy of VNIR and MIR predictions, however, is rarely addressed and remains unclear, in particular for current handheld MIR spectrometers. We thus evaluated the reproducibility of both the spectral reflectance measurements with portable VNIR and MIR spectrometers and the analytical dry combustion SOC reference method, with the aim to assess how varying spectral inputs and reference values impact the calibration and validation of predictive VNIR and MIR models. Soil reflectance spectra and SOC were measured in triplicate, the latter by different laboratories, for a set of 75 finely ground soil samples covering a wide range of parent materials and SOC contents. Predictive partial least-squares regression (PLSR) models were evaluated in a repeated, nested cross-validation approach with systematically varied spectral inputs and reference data, respectively. We found that SOC predictions from both VNIR and MIR spectra were equally highly reproducible on average and similar to the dry combustion method, but MIR spectra were more robust to calibration sample variation. The contributions of spectral variation (ΔRMSE < 0.4 g·kg−1) and reference SOC uncertainty (ΔRMSE < 0.3 g·kg−1) to spectral modeling errors were small compared to the difference between the VNIR and MIR spectral ranges (ΔRMSE ~1.4 g·kg−1 in favor of MIR). For reference SOC, uncertainty was limited to the case of biased reference data appearing in either the calibration or validation. Given better predictive accuracy, comparable spectral reproducibility and greater robustness against calibration sample selection, the portable MIR spectrometer was considered overall superior to the VNIR instrument for SOC analysis. Our results further indicate that random errors in SOC reference values are effectively compensated for during model calibration, while biased SOC calibration data propagates errors into model predictions. Reference data uncertainty is thus more likely to negatively impact the estimated validation accuracy in soil spectroscopy studies where archived data, e.g., from soil spectral libraries, are used for model building, but it should be negligible otherwise.

A Market Review of Available Airway Suction Technology

INTRODUCTION

Airway injuries are the second leading cause of potentially survivable battlefield death and often require airway management strategies. Airway suction, the act of using negative pressure in a patient's upper airway, removes debris that can prevent respiration, decreases possible aspiration risks, and allows clearer viewing of the airway for intubation. The most important characteristics for a portable airway suction device for prehospital combat care are portability, strong suction, and ease of use.

METHODS

This market review searched academic papers, military publications, Google searches, and Amazon to identify devices. The search included specific characteristics that would increase the likelihood that the devices would be suitable for battlefield use including weight, size, battery life, noise emission, canister size, tubing, and suction power.

RESULTS

Sixty portable airway suction devices were resulted, 31 of which met inclusion criteria - 11 manually powered devices and 20 battery-operated devices. One type of manual suction pump was a bag-like design with a squeezable suction pump that was extremely lightweight but had limited suction capabilities (vacuum pressure of 100mmHg). Another type of manual suction pump had a trigger-like design which is pulled back to create suction with a firm collection canister that had increased suction capabilities (vacuum pressures of 188-600mmHg), though still less than the battery operated, and was slightly heavier (0.23-0.458kg). Battery-operated devices had increased suction capabilities and were easier to use, but they were larger and weighed more (1.18-11.0kg).

CONCLUSION

Future research should work to lighten and debulk battery-operated suction devices with high suction performance.

Portable Waveguide-Based Optical Biosensor

Rapid, on-site diagnostics allow for timely intervention and response for warfighter support, environmental monitoring, and global health needs. Portable optical biosensors are being widely pursued as a means of achieving fieldable biosensing due to the potential speed and accuracy of optical detection. We recently developed the portable engineered analytic sensor with automated sampling (PEGASUS) with the goal of developing a fieldable, generalizable biosensing platform. Here, we detail the development of PEGASUS's sensing hardware and use a test-bed system of identical sensing hardware and software to demonstrate detection of a fluorescent conjugate at 1 nM through biotin-streptavidin chemistry.

Application of a Novel Biosensor for Salivary Conductivity in Detecting Chronic Kidney Disease

The prevalence of chronic kidney disease (CKD) is increasing, and it brings an enormous healthcare burden. The traditional measurement of kidney function needs invasive blood tests, which hinders the early detection and causes low awareness of CKD. We recently designed a device with miniaturized coplanar biosensing probes for measuring salivary conductivity at an extremely low volume (50 μL). Our preliminary data discovered that the salivary conductivity was significantly higher in the CKD patients. This cross-sectional study aims to validate the relationship between salivary conductivity and kidney function, represented by the estimated glomerular filtration rate (eGFR). We enrolled 214 adult participants with a mean age of 63.96 ± 13.53 years, of whom 33.2% were male. The prevalence rate of CKD, defined as eGFR < 60 mL/min/1.73 m2, is 11.2% in our study. By multivariate linear regression analyses, we found that salivary conductivity was positively related to age and fasting glucose but negatively associated with eGFR. We further divided subjects into low, medium, and high groups according to the tertials of salivary conductivity levels. There was a significant trend for an increment of CKD patients from low to high salivary conductivity groups (4.2% vs. 12.5% vs. 16.9%, p for trend: 0.016). The receiver operating characteristic (ROC) curves disclosed an excellent performance by using salivary conductivity combined with age, gender, and body weight to diagnose CKD (AUC equal to 0.8). The adjusted odds ratio of CKD is 2.66 (95% CI, 1.10−6.46) in subjects with high salivary conductivity levels. Overall, salivary conductivity can serve as a good surrogate marker of kidney function; this real-time, non-invasive, and easy-to-use portable biosensing device may be a reliable tool for screening CKD.

Method of determining technique from weight and height to achieve targeted detector exposures in portable chest and abdominal digital radiography

This study presents a methodology to develop an X-ray technique chart for portable chest and abdomen imaging which utilizes patient data available in the modality worklist (MWL) to reliably achieve a predetermined exposure index (EI) at the detector for any patient size. The method assumes a correlation between the patients' tissue equivalent thickness and the square root of the ratio of the patient's weight to height. To assess variability in detector exposures, the EI statistics for 75 chest examinations and 99 abdominal portable X-ray images acquired with the new technique chart were compared to those from a single portable unit (chest: 3877 images; abdomen: 200 images) using a conventional technique chart with three patient sizes, and to a stationary radiography room utilizing automatic exposure control (AEC) (chest: 360 images; abdomen: 112 images). The results showed that when using the new technique chart on a group of portable units, the variability in EI was significantly reduced (p < 0.01) for both AP chest and AP abdomen images compared to the single portable using a standard technique chart with three patient sizes. The variability in EI for the images acquired with the new chart was comparable to the stationary X-ray room with an AEC system (p > 0.05). This method could be used to streamline the entire imaging chain by automatically selecting an X-ray technique based on patient demographic information contained in the MWL to provide higher quality examinations to clinicians by eliminating outliers. In addition, patient height and weight can be used to estimate the patients' tissue equivalent thickness.

A Novel Integrated APCI and MPT Ionization Technique as Online Sensor for Trace Pesticides Detection

The misuse of pesticides poses a tremendous threat to human health. Excessive pesticide residues have been shown to cause many diseases. Many sensor detection methods have been developed, but most of them suffer from problems such as slow detection speed or narrow detection range. So, the development of rapid, direct and sensitive means of detecting trace amounts of pesticide residues is always necessary. A novel online sensor technique was developed for direct analysis of pesticides in complex matrices with no sample pretreatment. The portable sensor ion source consists of an MPT (microwave plasma torch) with desolventizing capability and an APCI (atmosphere pressure chemical ionization), which provides abundant precursor ions and a strong electric field. The performance which improves the ionization efficiency and suppresses the background signal was verified by using pesticide standard solution and pesticide pear juice solution measurements with an Orbitrap mass spectrometer. The limit of detection (LOD) and the limit of quantization (LOQ) of the method were measured by pear juice solutions that were obtained in the ranges of 0.034-0.79 μg/L and 0.14-1 μg/L. Quantitative curves were obtained ranging from 0.5 to 100 μg/L that showed excellent semi-quantitative ability with correlation coefficients of 0.985-0.997. The recoveries (%) of atrazine, imidacloprid, dimethoate, profenofos, chlorpyrifos, and dichlorvos were 96.6%, 112.7%, 88.1%, 85.5%, 89.2%, and 101.9% with the RSDs ranging from 5.89-14.87%, respectively. The results show that the method has excellent sensitivity and quantification capability for rapid and direct detection of trace pesticide.

A single-walled carbon nanotubes-based electrochemical impedance immunosensor for on-site detection of Listeria monocytogenes

Real-time and sensitive detection of pathogenic bacteria in food is in high demand to ensure food safety. In this study, a single-walled carbon nanotubes (SWCNTs)-based electrochemical impedance immunosensor for on-site detection of Listeria monocytogenes (L. monocytogenes) was developed. A gold-plated wire was functionalized using polyethylenimine (PEI), SWCNTs, streptavidin, biotinylated L. monocytogenes antibodies, and bovine serum albumin (BSA). A linear relationship (R²  = 0.982) between the electron transfer resistance measurements and concentrations of L. monocytogenes within the range of 10³ -10⁸ CFU/ml was observed. In addition, the sensor demonstrated high selectivity towards the target in the presence of other bacterial cells such as Salmonella Typhimurium and Escherichia coli O157:H7. To facilitate the demand for on-site detection, the sensor was integrated into a smartphone-controlled biosensor platform, consisting of a compact potentiostat device and a smartphone. The signals from the proposed platform were compared with a conventional potentiostat using the immunosensor interacted with L. monocytogenes (10³ -10⁵ CFU/ml). The signals obtained with both instruments showed high consistency. Recovery percentages of lettuce homogenate spiked with 10³ , 10⁴ , and 10⁵ CFU/ml of L. monocytogenes obtained with the portable platform were 90.21, 90.44, and 93.69, respectively. The presented on-site applicable SWCNT-based immunosensor platform was shown to have a high potential to be used in field settings for food and agricultural applications. PRACTICAL APPLICATION: The developed immunosensor was developed for on-site detection of L. monocytogenes. The limit of detection of the sensor was 10³ CFU/ml with a detection time of 10 min. In order to facilitate the requirements for effective on-site screening for food safety, the sensor was integrated into a smartphone-controlled platform, so that the bio-molecular interactions were converted into impedance signals and transmitted wirelessly to a smartphone by a hand-held EIS transducer.

Analysis of Single Synthetic Fibers Using a Portable Total Reflection X-ray Fluorescence Spectrometer

In this study, single synthetic fibers obtained from several textile products were analyzed by a portable total reflection X-ray fluorescence spectrometer. Characteristic elements, which would originate from such materials as catalysts, delustering agents, and dyes used for manufacturing synthetic fibers, were detected from single synthetic fiber samples, and the difference in the types of characteristic elements among the single synthetic fiber samples was observed.

Impact of intestinal ultrasound with a portable system in the management of Crohn's disease

Background

Intestinal ultrasound (IUS) is a valid cross-sectional imaging technique for the evaluation of Crohn’s disease (CD). With advancements in technology, portable ultrasound systems are becoming widely available, and the inevitable change to their use by non-radiologist clinicians would be a valuable contribution to improving patient care. This study aimed to investigate the diagnostic yield of IUS examination performed by a gastroenterologist with a portable system as an adjunct imaging modality in the routine care of CD patients.

Methods

A total of 117 CD patients were assessed by IUS imaging. Pre- and post-IUS clinical-management decisions were recorded. The primary outcome was to evaluate the change in the patients’ clinical-management decision following the IUS examination. The diagnostic accuracy was compared against the reference decision reached via a multidisiplinary meeting after the evaluation of all patient-related data. The endoscopic disease activity was determined using the simple endoscopic score for Crohn's disease (SES-CD).

Results

The initial clinical-management decision was changed in 47 patients (40.2%) after the IUS examination (P = 0.001). The accuracy of patient-management decisions improved from 63.2% to 90.6% in comparison to reference decisions (P < 0.001). After IUS examination, a further 13 cases (11.1%) were identified for urgent surgical/interventional procedures. The accuracy of colonoscopic (SES-CD ≥3) assessment was shown to be comparable to that of IUS (94% vs 91%). The sensitivity for disease presence was 95% with colonoscopy and 94% with the IUS assessment.

Conclusion

IUS examination with the use of a portable ultrasonography system significantly improves clinical-management decisions. With further supporting data, this practice would possibly become a requirement for CD management.

Development of a Novel Benzimidazole-Based Probe and Portable Fluorimeter for the Detection of Cysteine in Human Urine

The measurement of cysteine in human urine and live cells is crucial for evaluating biological metabolism, monitoring and maintaining the immune system, preventing tissue/DNA damage caused by free radicals, preventing autoimmune diseases, and diagnosing disorders such as cystinuria and cancer. A method that uses a fluorescence turn-on probe and a portable fluorescence spectrometer device are crucial for highly sensitive, simple, rapid, and inexpensive cysteine detection. Herein, we present the synthesis and application of a benzimidazole-based fluorescent probe (ABIA) along with the design and development of a portable fluorescence spectrometer device (CysDDev) for detecting cysteine in simulated human urine. ABIA showed excellent selectivity and sensitivity in detecting cysteine over homocysteine, glutathione, and other amino acids with the response time of 1 min and demonstrated a detection limit of 16.3 nM using the developed CysDDev. Further, ABIA also demonstrated its utility in detecting intracellular cysteine, making it an excellent probe for bio-imaging assay.

MRI at the Bedside: A Case Report Comparing Fixed and Portable Magnetic Resonance Imaging for Suspected Stroke

Magnetic resonance imaging (MRI) provides high-contrast resolution and is the preferred diagnostic tool for neurological disease. However, long exam times discourage MRI in emergency settings, and high-field MRI scanners (1.5-3T) require dedicated imaging suites. New, portable low-field-strength MRI machines (0.064T) have lower resolution than fixed MRI, but do not require restrictive environments or intrahospital transport. We present a case of a 78-year-old male with altered mental status who underwent 0.064T portable MRI and fixed 3T MRI exams in the emergency department. Imaging showed no evidence of acute infarction or intracranial lesions. The 0.064T images were of poor quality relative to 3T sequences, but the results of the portable MRI agreed with the conventional 3T MRI and a computed tomography scan from the same day. The compatible imaging results suggest that portable, low-field MRI can aid in neurological diagnosis without transporting patients to the MRI suite. Further studies should expand this comparison between high- and low-field MRI to better characterize the role and clinical applications of point-of-care MRI.

3D-Printed, Portable, Fluorescent-Sensing Platform for Smartphone-Capable Detection of Organophosphorus Residue Using Reaction-Based Aggregation Induced Emission Luminogens

Development of an easy-to-use, low-cost, household device can help the consumer quickly identify an organophosphorus (OP) residue concentration level. In this work, we demonstrate a 3D-printed, portable, fluorescent-sensing platform for smartphone-capable detection of OPs in vegetables. For development of the proposed device, we utilize the smartphone for capturing the strong thiol-activated fluorescence, which was produced by hydrolysis of OPs in the presence of alkali. The thiol-responsive AIEgen (maleimide-functionalized tetraphenylethylene) was non-emissive in both solution and the solid state but could be readily lighted up by the click addition of thiol to its MI pendant. An android application "Detection" has been developed on the basis of the gray value to analyze the different concentration levels of OPs in vegetable samples. The gray value was linearly related with the concentration of five kinds of organophosphorus residue, ranging from 0 to 20 μg/mL. It was also applied for determination of OPs residue in the leaves of cowpea, celery, and Chinese cabbage. Different from acetylcholinesterase enzyme-based sensors for poor stability under high temperature, the proposed method was a direct detection method for OPs and can be used for rapid monitoring of OPs residue concentration levels before LC-MS analysis.

Sample-to-Answer Diagnostic System for the Detection of Circulating Histones in Whole Blood

Severe internal trauma results in millions of hospitalizations each year, including thousands of deaths caused by subsequent multiple organ failure. The majority of these deaths occur within the first 24 h, and thus, rapid diagnosis of internal trauma severity is necessary for immediate treatment. For early organ damage identification, diagnosis in point-of-care settings is crucial for rapid triage and treatment. Recent reports suggest that circulating histones may serve as a biomarker for severe organ damage and the risk of multiple organ failure. Here, we report a point-of-care diagnostic system that utilizes the inherent interactions between histones and DNA for the fluorescence-based detection of histones in whole blood. In the assay, histones within the sample are wrapped by DNA, thus preventing an intercalating dye from binding the DNA and fluorescing. To allow for quantitative fluorescent measurements to be made in a point-of-care setting, we integrate a rapid, automated blood separation step into our assay. Furthermore, we eliminate manual reagent additions using a thermally responsive alkane partition (TRAP), thus making the system sample-to-answer. Finally, we demonstrate the assay in a portable fluorescence reader compatible with a point-of-care environment. We report a limit of detection 112 ng/mL in whole blood, suggesting that our device can be used to rapidly diagnose internal trauma severity and the likelihood of multiple organ failure in near-patient settings.

LAMP assay coupled with CRISPR/Cas12a system for portable detection of African swine fever virus

African swine fever (ASF) is one of the most severe infectious diseases of pigs. In this study, a loop-mediated isothermal amplification (LAMP) assay coupled with the clustered regularly interspaced short palindromic repeats (CRISPR)/Cas12a system was established in one tube for the detection of the African swine fever virus (ASFV) p72 gene. The single-stranded DNA-fluorophore quencher reporter and CRISPR-derived RNA were screened and selected for the CRISPR detection system. In combination with LAMP amplification assay, the detection limit for the LAMP-CRISPR assay can reach 7 copies/μl of p72 gene per reaction. Furthermore, this method displays no cross-reactivity with other porcine DNA or RNA viruses. The performance of the LAMP-CRISPR assay was compared with real-time qPCR tests for clinical samples; a good consistency between the LAMP-CRISPR assay and real-time qPCR was observed. The method shed a light on the convenient, portable, low cost, highly sensitive and specific detection of ASFV, demonstrating a great application potential for monitoring on-site ASFV in the field.

Low-Cost Hyperspectral Imaging with A Smartphone

Recent advances in smartphone technologies have opened the door to the development of accessible, highly portable sensing tools capable of accurate and reliable data collection in a range of environmental settings. In this article, we introduce a low-cost smartphone-based hyperspectral imaging system that can convert a standard smartphone camera into a visible wavelength hyperspectral sensor for ca. £100. To the best of our knowledge, this represents the first smartphone capable of hyperspectral data collection without the need for extensive post processing. The Hyperspectral Smartphone’s abilities are tested in a variety of environmental applications and its capabilities directly compared to the laboratory-based analogue from our previous research, as well as the wider existing literature. The Hyperspectral Smartphone is capable of accurate, laboratory- and field-based hyperspectral data collection, demonstrating the significant promise of both this device and smartphone-based hyperspectral imaging as a whole.

[3D printed portable gel electrophoresis device for rapid detection of proteins]

The growing demand for rapid, portable, and economical detection methods for environmental analysis has resulted in increasing demands on the portability and miniaturization of analytical instruments. The miniaturization of scientific instruments facilitates analysis in the field of medicine, food, and environment, especially for the under-resourced areas. The gel electrophoresis devices currently available for protein separation are primarily used in laboratories. Miniaturized instruments that can be used for on-site and rapid separation of protein have not yet been reported. In this study, a portable gel electrophoresis device for rapid separation and detection of proteins was developed and manufactured by 3D printing in a laboratory, which was economical, convenient, and quick. First, four kinds of portable gel electrophoresis devices that included three kinds of columnar gel and one slab gel electrophoresis device were designed with computer-aided design software SolidWorks 2017 (Dassault Systemes SE, France); the components including gel tubes, gel plates, and gel electrophoresis tanks were then printed using a 3D printer after optimization of the printing parameters. Then, the performance of the four kinds of gel electrophoresis devices was investigated using prestained protein molecular weight standards. The results showed that the single-channel slab gel electrophoresis design can quickly separate proteins with the best separation efficiency. Moreover, the effect of different separation gel lengths (5, 10, 15, and 20 mm) on protein separation was studied and it was found that 10% separation gels with a length of 5 mm could effectively separate prestained protein molecular weight standards (in the range of 15-250 kD) in 20 minutes. Next, the battery was optimized for the portable GE device and a 25 V lithium battery (70 mm×60 mm×40 mm) was used as the power supply, which could provide a constant voltage of 25 V for 100 hours during gel electrophoresis. Then, the One-Step Blue^TM reagent (Biotium, USA) was used to color the separation results of the five standard proteins (carbonic anhydrase, ovalbumin, bovine serum albumin, conalbumin, ribonuclease A), and the results were recorded by mobile phone. Finally, the proposed gel electrophoresis device was compared with the commercial device. The results showed that the two devices are comparable; however, the slab gel electrophoresis was faster, portable, and economical. In summary, this research designed and manufactured a portable gel electrophoresis device using 3D printing technique, which can be used for on-site analysis and detection of proteins. The device presents the following advantages compared with the commercial devices:1) small and portable:the size of the electrophoresis tank of the device is only 15 mm×20 mm×17 mm and the 25 V lithium battery has a working time of approximately 100 hours; 2) low cost:it can be processed in 5 hours using 3D printing technology, with 10 mL of printing material while the total cost is less than 400 RMB; 3) fast separation:this device can quickly achieve protein separation compared with commercial devices and can further use multiple electrophoresis tanks in parallel to analyze more samples at the same time. Besides, this research also highlights the advantages of 3D printing for the development of miniaturized analytical equipment. Though this study has achieved preliminary results for rapid separation of proteins using gel electrophoresis devices, the quantitative analysis of proteins following protein detection and the application of more samples need further research. Meanwhile, the continued application of 3D printing technology will promote the development of miniaturized and portable experimental equipment.

[Design of Portable EEG and Blood Oxygen Synchronous Acquisition System]

In order to obtain comprehensive brain activity information conveniently in real time, this study designs a portable EEG and blood oxygen synchronous acquisition system for real-time monitoring of brain functional activities. The EEG electrodes filter and amplify the detected EEG signals, and send them to the microprocessor via Bluetooth to analyze the EEG data; the photoelectric probe converts the optical signals into electrical signals, which are amplified and separated, filtered, and AD converted, calculates the brain's oxygenation and blood-red protein (ΔHbO₂) and blood-red protein (ΔHb) by amplification of Lambert-Beer law. Finally, experiments with commercial instruments NuAmps and Oximeter show that the system can calculate ΔHbO₂ and ΔHb while collecting EEG signals.

Machine Learning-Guided Prediction of Central Anterior Chamber Depth Using Slit Lamp Images from a Portable Smartphone Device

There is currently no objective portable screening modality for narrow angles in the community. In this prospective, single-centre image validation study, we used machine learning on slit lamp images taken with a portable smartphone device (MIDAS) to predict the central anterior chamber depth (ACD) of phakic patients with undilated pupils. Patients 60 years or older with no history of laser or intraocular surgery were recruited. Slit lamp images were taken with MIDAS, followed by anterior segment optical coherence tomography (ASOCT; Casia SS-1000, Tomey, Nagoya, Japan). After manual annotation of the anatomical landmarks of the slit lamp photos, machine learning was applied after image processing and feature extraction to predict the ACD. These values were then compared with those acquired from the ASOCT. Sixty-six eyes (right = 39, 59.1%) were included for analysis. The predicted ACD values formed a strong positive correlation with the measured ACD values from ASOCT (R² = 0.91 for training data and R² = 0.73 for test data). This study suggests the possibility of estimating central ACD using slit lamp images taken from portable devices.