Hand-held System Research Articles

A Handheld Microwave Thermoacoustic Imaging System With an Impedance Matching Microwave-Sono Probe for Breast Tumor Screening.

Microwave-induced thermoacoustic imaging (MTAI) is a promising alternative for breast tumor detection due to its deep imaging depth, high resolution, and minimal biological hazards. However, due to the bulky size and complicated system configuration of conventional benchtop MTAI, it is limited to imaging various anatomical sites and its application in different clinical scenarios. In this study, a handheld MTAI system equipped with a compact impedance matching microwave-sono and an ergonomically designed probe was presented and evaluated. The probe integrates a flexible coaxial cable for microwave delivery, a miniaturized microwave antenna, a linear transducer array, and wedge-shaped polystyrene blocks for efficient acoustic coupling, achieving microwave illumination and ultrasonic detection coaxially, and enabling high signal-to-noise ratio (SNR). Phantom experiments demonstrated that the maximum imaging depth is 5 cm (SNR = 8 dB), and the lateral and axial resolutions are 1.5 mm and 0.9 mm, respectively. Finally, three healthy female volunteers of different ages were subjected to breast thermoacoustic tomography and ultrasound imaging. The results showed that the h-MTAI data are correlated with the data of ultrasound imaging, indicating the safety and effectiveness of the system. Thus, the proposed h-MTAI system might contribute to breast tumor screening.

Discrimination between normal coffee beans and peaberries using excitation-emission matrix measured by a hand-held optical system

A method to discriminate between green peaberry beans and normal beans was developed using an excitation and emission spectrometer that can be used to construct a simple optical system to save farm workers' labor. The excitation and emission matrix were obtained in the wavelength range of 300 - 800 nm using a hand-held spectrophotometer combined with a diffraction grating and a diode array. Light sources of 300, 375 nm were used to excite the samples by light-emitting diodes. The acquired spectral information was used to classify the coffee samples into peaberry and normal coffee using the chemometric method of partial least squares discriminant analysis (PLS-DA). The results showed that all coffee samples were discriminated as corresponding classes by PLS-DA. In the PLS-DA model, investigation of the main wavelengths contributing to classification using all sample VIP showed that excitation/emission wavelengths at 300/470, 300/670 375/470, 375/670 nm are important for coffee type determination. These wavelengths were closely related to the excitation-emission wavelengths of several important chemical components in raw coffee beans (caffeine, caffeic acid, and chlorogenic acid (CGA), tocopherol). These results will be useful as basic knowledge to contribute to the labor-saving and automation of coffee bean sorting in the future.

A New Model of Intelligent Nursing Based on 5G Network Architecture and RFID Technology

RFID technology is an emerging automatic identification technology in recent years. Based on the research on RFID indoor positioning system, this paper proposes a clustering SPA relative positioning algorithm based on nearest neighbours in the 5G network architecture system. After analysing the algorithm process, simulation experiments are carried out. The experimental results show that the algorithm can effectively improve the positioning accuracy of the system. Based on the research on the application of RFID in hospital medical care management, the medical care mobile management system is designed, mainly including the database system of the system, the handheld data acquisition and wireless transmission system based on the 5G network platform, and the management running on the desktop PC. The system has been designed in detail, with a view to RFID technology can be applied to medical care management.

Development of a Handheld System for Liquor Authenticity Detection Based on Laser Spectroscopy Technique

In this paper, a handheld liquor authenticity detection system is demonstrated based on the laser spectroscopy technique, which consists of a handheld laser spectrometer and a mobile phone display terminal. In this system, the semiconductor laser is integrated into the spectrometer and the laser beam is further angled to the optical axis of the spectrometer to avoid interference of the fluorescence generated by the bottle wall. During the system operation, the laser excites the tested liquor to generate fluorescence and Raman spectroscopy signals, which are digitized and wirelessly transmitted by Wi-Fi to the Android mobile terminal. After the image processing by the mobile phone APP, the tested liquor spectrum curve is obtained. At the same time, based on the standard liquor spectrum curve stored in the database, the Pearson correlation coefficient is calculated and the matching similarity is given. In addition, this paper proposes a calibration method based on pure water Raman intensity to achieve accurate measurement of fluorescence intensity and minimize the influence of fluorescence intensity saturation on the measurement results. In the experiment, we measured the similarity of 12 brands of Chinese liquor by using our self-developed handheld laser spectrometer. Their authenticity of liquor could be given accurately and effectively.

Comparison of several strategies for the deployment of a multivariate regression model on several handheld NIR instruments. Application to the quality control of medicines

Chemometrics applied to spectroscopic measurements such as near-infrared are gaining more and more importance for quality control of pharmaceutical products. Handheld near-infrared devices show great promise as a medicines quality screening technique for post-marketing surveillance. These devices are able to detect substandard and falsified medicines in pharmaceutical supply chains and enable rapid action before these medicines reach patients. The instrumental and environmental changes, expected or not, can adversely affect the analytical performances of prediction models developed for routine applications. Based on a previous study, PLS prediction models were developed and validated on three similar handheld NIR transmission spectrophotometers of the same model and from same company. These models have shown to be effective in analyzing metformin tablet samples, but significant spectral differences between handheld systems complicated their deployment for routine analysis. In this study, different strategies have been applied and compared to correct the instrumental variations, including global modelling (GM) and calibration transfer methods (Direct Standardization, DS; Spectral Space Transformation, SST and Slope/Bias correction, SBC), considering the RMSEP and the accuracy profile as assessment criteria. The transfer methods showed good capabilities to maintain the predictive performances comparable to that of the global modelling approach, except for a remaining slight bias. This approach is interesting since very few standardization samples are required to develop an adequate transfer model. GM, SST and SBC were able to correct/handle drifts in the spectral responses of different handheld instruments and thus may help to avoid the need for a long, laborious, and costly full recalibration process due to inter-instrument variations.

Ultrasound for the Aesthetic Injector.

The use of ultrasound has become ubiquitous in the health care industry. Several ultrasound applications may be beneficial for aesthetic injectors. Aesthetic injectors can use ultrasound to visualize needles or cannulas and confirm the exact location of the tip. Using ultrasound guidance can improve nodule management. Perhaps, the most beneficial aspect of ultrasound guidance is its ability to identify and assist with vascular occlusions. The available ultrasound systems appropriate for aesthetic injectors are handheld or cart systems. When purchasing ultrasound systems, practitioners must weigh the advantages and disadvantages of a cart system (i.e., better resolution, higher cost, greater space requirements) compared with the advantages and disadvantages of a handheld system (i.e., increased portability, lower costs, less resolution). High-frequency ultrasound is rapidly being adopted by aesthetic injectors. It is time to consider adding an ultrasound system to your practice to increase safety and provide better outcomes for your patients.

Multispectral Analysis of Small Plots Based on Field and Remote Sensing Surveys—A Comparative Evaluation

Remote sensing is an efficient method of monitoring experiments rapidly and by enabling the collection of significantly more detailed data, than using only field measurements, ensuring new possibilities in scientific research. A small plot field experiment was conducted in a randomized block design with winter oat (Avena sativa L.) varieties in Debrecen, Hungary in the 2020/2021 cropping year. Multiple field measurements and aerial surveys were carried out examining the response of oat on Silicon and Sulfur foliar fertilization treatments thereby monitoring their effects on the physiology, production and stress tolerance. Parallel application of in situ (elevation, soil pH, NDVI, SPAD, chlorophyll content) and aerial (NDVI, NDRE) surveys including unmanned aerial vehicles (UAVs) provided a diverse source of data for evaluation. Both the oat varieties (88.9%) and the foliar fertilization treatments (87.5%) were correctly classified and clearly separated with the discriminant analysis based on measured data. The Pearson correlation analysis showed a very strong positive connection (r = 0.895–1.00) between the NDVI values measured using a hand-held system and UAV-installed camera, except the third measurement time, where the correlation was weaker (r = 0.70). Our results indicate that field experiments can be effectively supported by UAVs.

The City Lung and COVID-19: Effect of Air Quality on Infection Control and Human Health

Throughout history, pandemics affect cities and their shapes, many health problems have been reflected in urban planning. Today, the world faces a general health crisis of COVID-19. The number of people infected by the virus and the increasing number of deaths may result in the city-design strategies. The effect of this pandemic shows the importance of urban design and its effect on viral infections and its role in the health of populations, but this relationship is unclear and ignored; that is why we face this pandemic today. In this study, we are looking to protect the environment and human health by enhancing air quality by designing a new urban space in crowded cities called ‘City Lung’ and green roofs to reduce the effect of air pollutions. Moreover, cleaning the air inside high-density districts by controlling pollution sources was a vital link observed between the lockdown and the reduction of CO2 emissions during the COVID-19 pandemic. This paper will start by searching for a crowded study area with high traffic density, study the impact of urban form and air quality effects on human health, and suggest solutions to this study area. In the beginning, ENVI-MET 4.4.5 software was used to simulate the carbon emission values and validate these values by CI-340 lightweight hand-held photosynthesis system device to get readings to evaluate the urban air quality and its effect. The present study reveals that algae stations improved the oxygen ratio 1.65 times in the study area than the existing values. Also, green roofing as a solution effectively affects air quality near the ground, as an alternative for the green areas in crowded cities and pedestrians areas. This study enables urban planners to determine more greening principles for better urban living environments in high-density cities. Finally, the results give guidelines on improving air quality in the surrounding environment to enhance the quality of life.

Improved joint awareness two years after total knee arthroplasty with a handheld image-free robotic system.

Literature into the short-term follow-up of total knee arthroplasty (TKA) using a handheld image- free robotic system are scarce. The purpose of this study was to compare the clinical outcomes and patient-reported outcome measures (PROMs) between patients operated for TKA with an image- free robotic system (robot group) or conventionally TKA (conventional group) 2 years postoperatively. A total of 147 patients were evaluated after TKA, respectively 73 in the robot and 74 in conventional group. Outcome measures included adverse events (AEs), hospital readmission rate, patient satisfaction and the following PROMs: Pain Visual Analogue Score (VAS), Oxford Knee Score (OKS), Forgotten Joint Score Knee (FJS-12) and the EuroQOL-5D (EQ-5D). There were no statistically significant differences in the number of AEs; 8 (10.8%) in the conventional group versus 7 (9.7%) in the robot group. The FJS (p ≤ 0.05) and OKS (p ≤ 0.05) differed statistically in favour of the robot group. The EQ-5D and EQ-5D VAS did not statistically differed between the groups (p=0.231 and p=0.373 respectively). The VAS pain improved statically significant in both groups when comparing the pre- and postoperative values (5.8 points). Patients operated with a handheld image-free robotic system have the ability to forget their artificial knee joint in everyday life as measured with the FJS-12 at short-term follow-up.

HIGH ACCURACY 3D DIGITISATION OF THE GOETHE ELEPHANT SKULL USING HAND-HELD 3D SCANNING SYSTEMS AND STRUCTURE FROM MOTION – A COMPARATIVE CASE STUDY

Abstract. The Goethe Elephant skull is a cultural object of great interest. For the highly accurate 3D digitisation of the object, a hand-held 3D scanning system (Creaform GO!Scan) and Structure-from-Motion (DSLR camera) were used. The aim is a complete spatial reconstruction with a resolution of 0.5 mm and an accuracy level of approximate 0.5 mm. The skull consists of three parts, which have very complex but also very simple surface structures. For both methods the data acquisition and processing is described in detail. In both cases, a complete textured meshed 3D model could be calculated without shadows due to the use of camera-fixed lighting. The 3D models fulfil the desired target resolution and accuracy, verified by independent reference lengths and by the manufacturer's specifications. In addition, the colour values of the texture were calibrated with the help of the ColorChecker Digital SG. A visual and geometric comparison of the two models shows that both methods are very well suited for high-precision 3D object reconstruction on a similar level of accuracy. Furthermore, the advantages and disadvantages of the methods are compared. The main advantage of the applied hand-held scanner is the real-time verification of the model during data acquisition. The established SfM convinces with its flexibility regarding resolution and camera positioning.

A hand-held, real-time, AI-assisted capillary convection PCR system for point-of-care diagnosis of African swine fever virus

A hand-held, low-cost and real-time convection polymerase chain reaction (CPCR) system is developed for point-of-care diagnosis of African swine fever (ASF) virus. In CPCR amplification, the reagent is transferred to denaturation, annealing and extension stages of the reaction repeatedly due to thermal convection. Two different modes of fiber-based optical detection are compared, and it shows that the detection sensitivity, repeatability, and consistency can be significantly improved with bottom collection comparing to sidewall collection. Each capillary tube is illuminated by its own LED from the top through a common optical filter, and meanwhile, a camera equipped with another optical filter is adopted to detect the fluorescence signal from optical fibers. To handle the untypical real-time fluorescence curves of negative tests due to non-specific amplification, AI-based classification methods, for example, artificial neural network (ANN) is adopted to improve the detection specificity up to 97.50% comparing to 47.5% or 75.0% which is achieved with Ct-based method. A smartphone is adopted to run the AI algorithm and custom software, as well as to report an ASF event with the geographical information. Experimental results show that with the hand-held CPCR system, within 30 min, ASF viruses can be successfully detected with acceptable sensitivity and specificity.

Atomic spectrometry update: review of advances in X-ray fluorescence spectrometry and its special applications

This review covers developments in and applications of XRF techniques such as EDXRF, WDXRF, TXRF, XRF microscopy using technologies such as synchrotron sources, X-ray optics, X-ray tubes and detectors in laboratory, mobile and hand-held systems.

An effective automatic detection of tooth cavity using machine cum deep learning concepts and ICDAS measurement

A full scan x-ray machine scans the mouth and detects the tooth with decay or abnormal tooth is identified using the automatic machine learning algorithm. The machine learning algorithm will detect the defected place accurately with the positional number and its intensity come severity and what treatment can be done within duration span everything will be listed to the normal user with the handheld system. Already existing methodologies are just detects using sensors and those are very high cost.

The Use of GPR and Microwave Tomography for the Assessment of the Internal Structure of Hollow Trees

Internal decays in trees can rapidly escalate into a full decomposition of the inner structural layer, i.e., the “heartwood” layer, due to the action of aggressive diseases and fungal infections. This process leads to the formation of big cavities and hollows, which remain surrounded by the sapwood layer only. Estimating the thickness of the sapwood layer with a high degree of accuracy is therefore crucial for correct assessment of the structural integrity of hollow trees, as well as an extremely challenging task. In this context, ground-penetrating radar (GPR) has proven effective in providing details of the internal structure of trees. Nevertheless, the existing GPR processing methods still offer limited information on their internal configuration. This study investigates the effectiveness of GPR enhanced by a microwave tomography inversion approach in the assessment of hollow trees. To this aim, a living hollow tree was investigated by performing a set of pseudocircular scans along the bark perimeter with a hand-held common-offset GPR system. The tree was then felled, and sections were cut for testing purposes. A dedicated data processing framework was developed and tested through numerical simulations of hollow tree sections. The internal structure of the real trunk was therefore reconstructed via a tomographic imaging approach and the outcomes were quantitatively analyzed by way of comparison with the real sections’ main geometric features. The tomographic approach has proven very accurate in locating the sapwood–cavity interface and in the evaluation of the sapwood layer thickness, with a centimeter prediction accuracy.

Research on the development of a handy palpation sensor system considering a stability of manual scanning y

In recent years, the number of deaths and morbidity from breast cancer has been on the rise, and early detection through self-palpation is required. However, many women do not perform self-palpation because they lack confidence in their ability to detect cancer. Therefore, there is a need to develop a system to detect breast cancer quantitatively without relying on their own senses. In this study, we developed a handheld breast cancer palpation sensor system that detects lumps based on the reaction force generated by scanning the breast. We designed the mechanism of the palpation sensor so that it can be grasped with a whole hand, and performed palpation experiments on a sample that simulates a breast. As a result, the characteristic reaction force fluctuation due to lumps was observed.

An affordable, handheld multimodal microscopic system with onboard cell morphology and counting features on a mobile device.

Microscopes, bright-field (BF) and fluorescence microscopes, in particular, are ubiquitous for clinical diagnostics, cellular and microbiological investigations and in research laboratories. However, the size, cost, fragility and need for skilled personnel to operate these tools restrict their use in resource-limited settings. As an alternative platform, herein, we report a flexible multimodal imaging system that operates in BF and fluorescence modes using a smartphone. Our device utilizes the inbuilt primary camera of phones, and with the aid of easily available optical components, the designed platform is transformed into a high-throughput microscopic device that performs on par with that of a laboratory-grade microscope. The designed platform operates at three different optical magnifications and yields a lateral resolution of 1.21 μm over an acceptable field-of-view (FoV) of diameter ∼4530 μm. The versatility of the device has been demonstrated through imaging of standard microbeads and human blood samples both in BF and fluorescence modes of imaging. Furthermore, the designed imaging platform is equipped with an on-board cell recognition feature which has been obtained through developing a smartphone application for automatic cell counting with high precision.

Evaluation of augmented-reality based navigation for brain tumor surgery

To date, several researchers have introduced augmented reality navigation (ARN) into neurological surgery. While its application in brain tumor surgery seems promising, reports on its utility have been limited, thus warranting further evaluation. To clarify the stages and approaches in which ARN is useful and assess the effect of presurgical discussion with surgeons, we assessed usefulness using a hand-held ARN system we had developed, which displays three-dimensional (3D) virtual structures overlaid on a real-time image of the surgical field via a tablet PC monitor. The system was tested in 20 patients undergoing various procedures, with the first 10 consecutive cases being unselected and the following 10 cases being selected, for whom 3D models were prepared per the surgeons’ request. Thereafter, the surgeons ranked its usefulness during each stage of surgery. Consequently, case selection and presurgical discussions with surgeons considerably improved the usefulness, with the “useful” gradings improving from 50% to 88% across all surgical stages. Accordingly, usefulness improved from 50% to 90%, 67% to 100%, and 40% to 80% during the skin incision and craniotomy, dura incision, and intradural procedure stages, respectively. ARN was useful for superficial tumor resection, but less so for deep-seated tumor resection, except when using the transcortical and interhemispheric approaches. In conclusion, a tablet-type ARN can be useful during skin incisions, craniotomy and dura incisions, superficial tumor resections, and transcortical and interhemispheric approaches for deep-seated tumors. Case selection and presurgical discussions with surgeons were essential for the efficacy of ARN.

Detection and quantification of phosphate in water and soil using a smartphone

We report here a low-cost, field-deployable smartphone-based sensing system for accurate estimation of phosphorus (in phosphate form) in water and agricultural soil. The sensing principle is based on the standard ascorbic acid protocol where heteropoly acid-phosphomolybdic acid reagent changes color upon treatment with ascorbic acid, which can be detected by the designed sensing system. A 3D printed cradle housing the optical source and other optical components of the sensor is coupled to the built-in rear camera of the phone and subsequently, convert it into a compact handheld system. Two freely available android applications have been used for the detection and analysis of phosphate concentration. The HSV (Hue-Saturation-Value) color model's V-channel values of the captured images are used to correlate with the phosphate concentrations of the samples. The results obtained with the proposed sensor are found similar to laboratory-grade spectrophotometer data. The designed sensing system has an ability to measure phosphate concentration variations as low as 0.01 mg/L and 0.03 mg/L in the range 0–1 mg/L and 1–5 mg/L, respectively, with good accuracy (%bias < 1%) and precision (%RSD < 2%).

Rapid, dose-dependent and efficient inactivation of surface dried SARS-CoV-2 by 254 nm UV-C irradiation

Background: The COVID-19 pandemic urges for cheap, reliable, and rapid technologies for disinfection and decontamination. One frequently proposed method is ultraviolet (UV)-C irradiation. UV-C doses necessary to achieve inactivation of high-titre SARS-CoV-2 are poorly defined.Aim: We investigated whether short exposure of SARS-CoV-2 to UV-C irradiation sufficiently reduces viral infectivity and doses necessary to achieve an at least 6-log reduction in viral titres.Methods: Using a box and two handheld systems designed to decontaminate objects and surfaces, we evaluated the efficacy of 254 nm UV-C treatment to inactivate surface dried high-titre SARS-CoV-2.Results: Drying for 2 hours did not have a major impact on the infectivity of SARS-CoV-2, indicating that exhaled virus in droplets or aerosols stays infectious on surfaces for at least a certain amount of time. Short exposure of high titre surface dried virus (3–5*10^6 IU/ml) with UV-C light (16 mJ/cm2) resulted in a total inactivation of SARS-CoV-2. Dose-dependency experiments revealed that 3.5 mJ/cm2 were still effective to achieve a > 6-log reduction in viral titres, whereas 1.75 mJ/cm2 lowered infectivity only by one order of magnitude.Conclusions: SARS-CoV-2 is rapidly inactivated by relatively low doses of UV-C irradiation and the relationship between UV-C dose and log-viral titre reduction of surface residing SARS-CoV-2 is nonlinear. Our findings emphasize that it is necessary to assure sufficient and complete exposure of all relevant areas by integrated UV-C doses of at least 3.5 mJ/cm2 at 254 nm. Altogether, UV-C treatment is an effective non-chemical option to decontaminate surfaces from high-titre infectious SARS-CoV-2.

Ultracompact fluorescence smartphone attachment using built-in optics for protoporphyrin-IX quantification in skin.

Smartphone-based fluorescence imaging systems have the potential to provide convenient quantitative image guidance at the point of care. However, common approaches have required the addition of complex optical attachments, which reduce translation potential. In this study, a simple clip-on attachment appropriate for fluorescence imaging of protoporphyrin-IX (PpIX) in skin was designed using the built-in light source and ultrawide camera sensor of a smartphone. Software control for image acquisition and quantitative analysis was developed using the 10-bit video capability of the phone. Optical performance was characterized using PpIX in liquid tissue phantoms and endogenously produced PpIX in mice and human skin. The proposed system achieves a very compact form factor (<30 cm3) and can be readily fabricated using widely available low-cost materials. The limit of detection of PpIX in optical phantoms was <10 nM, with good signal linearity from 10 to 1000 nM (R2 >0.99). Both murine and human skin imaging verified that in vivo PpIX fluorescence was detected within 1 hour of applying aminolevulinic acid (ALA) gel. This ultracompact handheld system for quantification of PpIX in skin is well-suited for dermatology clinical workflows. Due to its simplicity and form factor, the proposed system can be readily adapted for use with other smartphone devices and fluorescence imaging applications. Hardware design and software for the system is made freely available on GitHub (https://github.com/optmed/CompactFluorescenceCam).