Wireless Handheld Devices Research Articles

Initial description of the novel handheld wireless ultrasound device TE Air with Doppler and Color Duplex imaging.

To test and initially describe a new handheld wireless ultrasound technique (TE Air) for clinical use. In this pilot study, the new ultrasound device TE Air from Mindray was used to examine the hepatic and renal vessels of healthy volunteers for first impressions. The probe has a sector transducer with a frequency range of 1.8-4.5 MHz. The B-mode and color-coded doppler sonography (CCDS) scanning methods were used. A high-end device from the same company (Resona 9, Mindray) was used as a reference. The results were evaluated using an image rating scale ranging from 0 to 5, with 0 indicating not assessable and 5 indicating without limitations. Altogether, 61 participants (n = 34 female [55.7%], n = 27 male [44.3%]), age range 18-83 years, mean age 37.9±16.5 years) could be adequately studied using TE AIR and the high-end device. With one exception, the image quality score for TE Air never fell below 3 and had a mean/median scored of 4.97/5.00 for the B-mode, 4.92/5.00 for the color flow (CF) mode, and 4.89/5.00 for the pulse wave (PW) mode of the hepatic vein, 4.90/5.00 for the portal vein, 4.11/4.00 for the hepatic artery, and 4.57/5.00 for the renal segmental artery. A significant difference in the assessment of flow measurement of the hepatic artery and renal segmental arteries was found between TE AIR and the high-end device. TE Air represents a new dimension in point-of-care ultrasound via wireless handheld devices. Especially, its flow measurement ability offers a relevant advantage over other available handheld models. TE Air provides a formally sufficient image quality in terms of diagnostic significance.

Paradigm Shift from Telemedicine to Autonomous Human Health and Performance for Long-Duration Space Missions

This paper discusses a Prognostics and Health Management [PHM]-based approach to implementing Human Health & Performance [HH&P] technologies. Targeted specifically are NASA Autonomous Medical Decision and Integrated Biomedical Informatics of Human Health, Life Support, and Habitation Systems in Technology Area 06 [TA 06] of NASA integrated technology roadmap [April 2012]. The proposed PHM-based implementation is to bridge PHM, an engineering discipline, to the HH&P technology domain to mitigate space travel risks by focusing on efforts to reduce countermeasure mass and volume, and drive down risks to an acceptable level. NASA Autonomous Medical Decision technology is based on wireless handheld devices and is a result of a necessary paradigm shift from telemedicine to HH&P autonomy. The Integrated Biomedical Informatics technology is based on Crew Electronic Health Records [CEHR], equipped with a predictive diagnostics capability developed for use by crew members rather than by healthcare professionals. This paper further explores the proposed PHM-based solutions for crew health maintenance in terms of predictive diagnostics to provide early and actionable real-time warnings to each crew member about health-related risks and impending health problems that otherwise might go undetected. The paper also discusses the paradigm’s hypothesis and its innovation methodology, as implemented with computed biomarkers. The suggested paradigm is to be validated on the International Space Station [ISS] to ensure that crew autonomy in terms of the inherent predictive capability and two-fault-tolerance of the methodology become the dominant design drivers in sustaining crew health and performance.

Photocurrent-Polarity-Switching Photoelectrochemical Biosensor for Switching Spatial Distance Electroactive Tags.

This work presents a photocurrent-polarity-switching-based photoelectrochemical (PEC) biosensing platform for ultrasensitive detection of microRNA-21 (miR-21) through target-triggered catalytic hairpin assembly (CHA) for modulation of methylene blue (MB) and ferrocene (Fc) positional configurations using double-shelled Cu-doped ZnS nanocages (NCs)-Au nanoparticles (NPs) as photoactive materials. In the presence of miR-21, the assembly of MB-labeled HP1 and Fc-labeled HP2 leads to the generation of a large amount of double-stranded DNA (HP1-HP2), which pushes MB away from the electrode surface and brings Fc close to the electrode surface, resulting in effectively quenching the enhanced PEC signal to activate the photocurrent-polarity-switching system. Benefiting from the distance-controllable strategy, the designed PEC bioanalysis can effectively eliminate false-positive and false-negative signals due to the change of different signal expression patterns (from traditional the "signal-on" mode to the photocurrent-polarity-switching mode), thereby significantly improving the sensing specificity and sensitivity. The proposed PEC sensing system exhibited satisfying photocurrent responses toward target miR-21 within the working range from 1.0 fM to 1 nM at a low limit of detection (LOD) of 0.58 fM. More importantly, we demonstrated the successful integration of the proposed PEC biosensor with a handheld wireless device for instant detection of miR-21 concentrations in practical samples.

A compact frequency reconfigurable patch antenna with asymmetric armed U and reversed L slots for handheld wireless devices

Abstract A frequency reconfigurable microstrip patch antenna with a combination of an asymmetric armed U-slot and a reversed L-slot etched on a rectangular base patch of 6 GHz resonant frequency designed on an FR4 substrate (ɛr = 4.4) is presented in this paper. Three RF PIN diodes are positioned at inimitable sites of these slots to achieve frequency reconfiguration. A DC bias circuitry, which includes DC blocking capacitors and RF blocking inductors, is integrated with the antenna structure for switching (ON/OFF) the PIN diodes. Six reconfigurable modes with resonant frequencies at 4.33, 4.63, 5.24, 5.87, 5.96, and 6.29 GHz is obtained with different ON-OFF combinations of these PIN diodes. These reconfigurable resonant frequencies cover two continuous bands from 4.21 to 5.43 GHz and 5.69 to 6.6 GHz and is considered to be useful for the applications like aeronautical radio navigation (4.3 GHz), sub-6-GHz 5G (4.4–5 GHz), WLAN (5.2 and 5.8 GHz) and Wi-Fi 6E (5.925–6.425 GHz). Measured gain of the antenna for all the modes varies between 5.86 dBi and 8.72 dBi.

Development and Analysis of Two Quarter Wavelength Patch Antennas

Development of small integrated antennas has played a crucial role in the current rapid progress of commercial wireless communication technology. Incorporating different radio standards, which supports various voice and data applications to a single wireless hand-held device, has now become the need of the hour. Quarter wavelength patch antennas are low profile antennas suitable for such applications. In this paper, two single-feed triple-band quarter wavelength antennas, PIFA and shorted patch antenna, having multi-band capability, are experimentally investigated and characterized. Different specifications of both the antennas are software simulated and experimentally tested. All simulations are performed using CST microwave studio.

A dual‐band circular patch antenna using hexagon‐shaped slots

SummaryThis paper presents the design of a dual‐band circular patch antenna for the application requirements of wireless handheld devices and various wireless sensor modules operating in WiMax and 5G NR Bands. The design originated from a single‐band conventional circular patch antenna and ended up with a dual‐band circular patch. A novel hexagon‐shaped slot was preferred to achieve dual‐band performance in the circular patch antenna. The simulation level performance of the antenna is verified using the Advanced Design System 2019 tool. An FR4 material with a height of 1.6 mm is selected as a substrate for the patch antennas. The return loss and radiation pattern behaviour of the patch antennas are measured using a network analyser and an anechoic chamber. The fabricated prototype achieves dual‐band performance at 3.47 and 6.96 GHz. Simulated and measured results show that the proposed hexagonal‐shaped slot in the circular patch provides a dual‐band behaviour.

Tetra-primer ARMS-PCR combined with dual-color fluorescent lateral flow assay for the discrimination of SARS-CoV-2 and its mutations with a handheld wireless reader.

Several virulent variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have emerged along with the spread of this virus throughout the population. Some variants can exhibit increased transmissibility and reduced immune neutralization reactivity. These changes are deeply concerning issues that may hinder the ongoing effort of epidemic control measures, especially mass vaccination campaigns. The accurate discrimination of SARS-CoV-2 and its emerging variants is essential to contain the coronavirus disease 2019 pandemic. Herein, we report a low-cost, facile, and highly sensitive diagnostic platform that can simultaneously distinguish wild-type (WT) SARS-CoV-2 and its two mutations, namely, D614G and N501Y, within 2 h. WT or mutant (M) nucleic acid fragments at each allelic locus were selectively amplified by the tetra-primer amplification refractory mutation system (ARMS)-PCR assay. Allele-specific amplicons were simultaneously detected by two test lines on a quantum dot nanobead (QB)-based dual-color fluorescent test strip, which could be interpreted by the naked eye or by a home-made fluorescent strip readout device that was wirelessly connected to a smartphone for quantitative data analysis and result presentation. The WT and M viruses were indicated and were strictly discriminated by the presence of a green or red band on test line 1 for the D614G site and test line 2 for the N501Y site. The limits of detection (LODs) for the WT and M D614G were estimated as 78.91 and 33.53 copies per μL, respectively. This assay was also modified for the simultaneous detection of the N and ORF1ab genes of SARS-CoV-2 with LODs of 1.90 and 6.07 copies per μL, respectively. The proposed platform can provide a simple, accurate, and affordable diagnostic approach for the screening of SARS-CoV-2 and its variants of concern even in resource-limited settings.

Home Spirometry Telemonitoring for Early Detection of Bronchiolitis Obliterans Syndrome in Patients with Chronic Graft-versus-Host Disease

Early detection of bronchiolitis obliterans syndrome (BOS) after allogeneic hematopoietic cell transplantation (HCT) depends on recognition of subclinical spirometric changes, which is possible only with frequent interval spirometry. We evaluated the feasibility of home monitoring of weekly spirometry via a wireless handheld device and a web monitoring portal in a cohort of high-risk patients for the detection of lung function changes preceding BOS diagnosis. In this observational study, 46 patients with chronic graft-versus-host disease or a decline in forced expiratory volume in 1 second (FEV1) of unclear etiology after allogeneic HCT were enrolled to perform weekly home spirometry with a wireless portable spirometer for a period of 1 year. Measurements were transmitted wirelessly to a Cloud-based monitoring portal. Feasibility evaluation included adherence with study procedures and an assessment of the home spirometry measurements compared with laboratory pulmonary function tests. Thirty-six patients (78%) completed 1 year of weekly monitoring. Overall adherence with weekly home spirometry measurements was 72% (interquartile range, 47% to 90%), which did not meet the predetermined threshold of 75% for high adherence. Correlation of home FEV1 with laboratory FEV1 was high, with a bias of 0.123 L (lower limit, -0.294 L; upper limit, 0.541 L), which is within acceptable limits for reliability. Of the 12 patients who were diagnosed with BOS or suspected BOS during the study period, 9 had an antecedent FEV1 decline detected by home spirometry. Our data indicate that wireless handheld spirometry performed at home in a high-risk HCT cohort is feasible for close monitoring of pulmonary function and appears to facilitate early detection of BOS.

A Compact Single-Layer Four-Port Orthogonally Polarized Yagi-Like MIMO Antenna System

A wideband compact Yagi-like directional multiple-input- multiple-output (MIMO) antenna system is presented based on a slot loop excitation. Four orthogonally polarized beams are generated by orthogonally feeding the slot loop elements using microstrip lines. The proposed design is based on a single-layer geometry with an overall size of 35 × 90 × 0.76 mm3, which is suitable for compact wireless handheld devices. The conventional vertically polarized omnidirectional beams from each slot loop element are made directional and horizontally polarized by using two passive complementary slot reflector (CSR) elements. The antenna system has a wide measured bandwidth of 620 MHz (3.26-3.88 GHz) targeting the 3.6 GHz WiMAX band. It has a maximum realized gain of 4 dBi and front to back ratio (FBR) of more than 7 dB within the band of operation. The proposed antenna system shows good MIMO performance with a minimum measured isolation of 10 dB between the adjacent ports and more than 20 dB between other ports. The orthogonal beams of the antenna system help in achieving low envelope correlation coefficient (ECC) values of less than 0.1. The measured total efficiency of the antenna system is more than 75% for all the ports of the antenna system.

A Survey to Analyse Routing Algorithms for Opportunistic Network

Abstract A mobile ad-hoc network (MANET) is a continuously self-configuring, infrastructure-less network of the wireless mobile device. Nodes are connected wirelessly and also responsible for data forwarding (no data transfer or routing device is present that is a router, switch, etc.). The opportunistic network is a subcategory of MANET, typically wireless handheld device carried by people. This survey admits a summary of the acquirable OPPNETs routing algorithms, their categorization, and an assessment of five routing protocols (Epidemic, Spray and Wait, First Contact, Prophet, and Max-Prop) in terms of variable buffer size. Detailed computer simulation demonstrates that as the burden or load on the network growths, the efficiency of routing strategies decrease in terms of delivery probability and overhead ratio. The experiments establish that Maxprop routing delivery probability is highest than the others. It has been also observed that the ratio of packet dropped and relayed has been decreased according to buffer size increased. The First Contact routing delivery probability may not differ most with changes the buffer sizes. In terms of overhead ratio, the result of Epidemic is better than Spray and Wait, First Contact, Prophet, MaxProp routing algorithms. Results vary depending on the buffer size, contact times, and speed. The consequences indicate that some can carry and exchange information faster, and improve connectivity in OPPNETs.

Significance of E-Learning as a Tool in Teaching and Learning

The time and age we are living now is much more different than it was few decades ago. The world is changing with great pace so are the teachings and learning methodologies. Before teaching and learning methods mainly focused within classroom confines and do not include all the factors that could impact teaching and learning outcomes. But now the world is increasingly connected and mobile, therefore, the nature of information resources is changing drastically. The new information is not only unlimited and overwhelming in quantity but also it is networked, multimodal and easily accessible anytime anywhere in the world. Advent in digital technologies, such as computers, laptops, tabs, smart phones, wireless handheld devices, and the Internet have made it possible for learners to access to a wide range of learning and teaching resources and tools, in number of different languages (with the option of availability of translation in native languages) anytime and anywhere in the world. Through the emergence of digital technology tools, have made this possible to increase teaching and learning opportunities inside and outside institutionalized school systems. Through the proper use of modern technologies students and learners have full opportunities to take learning beyond traditional classrooms and the school day. By using digital technology tools, learners have opportunities to attend online courses not only anywhere, anytime but also can record and save the information for future use, if needed. Thus, the aim of this study is to focus on the effectiveness of digital technology as a tool in Teaching and Learning (T&L) approach.

Smaller and With More Bars: A Relay Transceiver for IoT/5G Applications

Computers and smartphones have become indispensable parts of human daily life. Driven by various modern applications, the demand for high-speed Internet connection is always growing. Because Internet speed strongly depends on signal strength and quality, a great deal of effort has been spent to increase the number of displayed on the screen of wireless devices. One effective approach toward is deploying microwave relay systems to provide stronger signals, and thus higher data rates, to end users. Microwave relay links facilitate the transmission of signals from one point to another by receiving, recovering, and retransmitting wireless signals with enhanced quality and strength. With more bars on the end-user side, handheld wireless devices also become smaller because of reduced power consumption in their receivers. With the help of sophisticated radio relay links in the last mile of communications networks [1], wireless data can be efficiently communicated among a variety of devices, such as home appliances, smart Internet of Things (IoT) sensors, and autonomous vehicles [2], [3].

Design and Development of Low Profile MIMO Antenna for 5G New Radio Smartphone Applications

A low-profile planar four-element MIMO antenna is proposed in this paper that can be integrated inside wireless handheld devices. Every unit antenna is made of simple planar L-shaped monopole placed over etched non-ground area of 10 × 5 mm2. The optimized antenna elements cover three 5G New Radio bands falling within C-band: n77 band (3.3–4.2 GHz), n78 band (3.3–3.8 GHz) and n79 band (4.4–5 GHz), with isolation better than 18.8 dB, without the requirement of any additional decoupling structure. The designed antenna is fabricated on FR4 substrate of dimension 120 × 65 × 1.6 mm3. Antenna characteristics regarding reflection coefficient, mutual coupling, radiation pattern and gain are measured and discussed. The envelop correlation coefficient is computed and is lower than 0.018 for the entire range of frequency under consideration. The simplicity and compactness of the proposed MIMO antenna provides adequate space for integration of other circuits inside handheld mobile terminal. Further the integration with lower generation antennas are investigated; the result indicates that the placement of the proposed antenna system on the two long arms of ground plane offer adequate space for integration of lower generation antenna without adversely affecting each other’s performance.

A compact triple‐band metamaterial‐inspired antenna for wearable applications

AbstractA low‐profile (28 mm × 32 mm × 0.394 mm), metamaterial‐inspired antenna employing an array of 3 × 5 Hilbert‐shaped unit radiators printed on the upper side of a flexible dielectric substrate while the lower side contains a partial‐ground plane and the rest consists of a periodic square‐slotted ground plane is presented for wearable wireless devices covering Long‐Term Evolution (LTE), Long Term Evolution‐Advanced (LTE‐A), Wireless Local Area Network (WLAN), and Worldwide Interoperability for Microwave Access (WiMAX) bands. The antenna provides steerable radiation patterns for frequencies ranging from 3.3 to 3.9 GHz and a directive end‐fire radiation in the 5.8 GHz band. At 2.45 GHz, the antenna allows short‐range communications between a wearable sensor and handheld wireless device or a nearby base station. Two prototypes are fabricated; the first using traditional wet etching with copper; the second using inkjet printing with silver nano‐particles (SNPs) as the conducting material. We provide a systematic design procedure and a new physical insight into the operation of the antenna, in particular the end‐fire radiation patterns, which is based on the anisotropic dispersion characteristics of the radiating structure along the length axis leading to different effective electrical length to width ratios within the stopband. The realized gain varies from 0 to 2.5 dBi for frequencies ranging from 3.3 to 3.9 GHz where the 3‐dB beamwidth varies from 110° to 140° and the boresight is steered from 0° to 80°. The maximum realized gain varies from 4.75 to 4.5 dBi over the frequency range from 4.4 to 6 GHz, with slight change in the beamwidth and main lobe direction. Experimental measurements for the SNP prototype are reported in air and on a standard phantom model.

A Compact Frequency-Reconfigurable Antenna With Independent Tuning for Hand-Held Wireless Devices

This communication presents the design of a compact loop antenna with independent frequency tuning. The proposed antenna consists of a feed line fed by a $50~\Omega $ coaxial probe and four resonating arms on the adjacent sides of the feed line. The two outer resonating arms are directly coupled to the feed line and the other two inner resonating arms are coupled to the outer arms. The proposed antenna has a footprint of 25 mm $\times 10$ mm $\times0.2$ mm. The designed antenna operates at 0.9, 2.4, 3.5, and 5.5 GHz. Each of these bands is individually tuned using varactor diodes. Thus, the aggregation of these tunable bands provides wide bandwidth. The impedance bandwidth and percentage bandwidth of the antenna are 270/1000/400/700 MHz and 33%/47.6%/11%/12.7%, respectively. Furthermore, the gain and efficiency of the antenna are 1.7/1.3/2.1/2 dBi and 60%/63%/65%/69%, respectively. The prototype antenna is fabricated and tested. The measured impedance and radiation characteristics of the antenna are in good correlation with the simulation results.

Design of inverted-F antenna for long-term evolution-based wireless handhelddevices

In this article, a compact triple-band inverted-F antenna for long-term evolution (LTE)-based wireless handheld devices is presented. The proposed antenna comprises three arms, namely the radiating arm, shorting arm, and feeding arm. The structure of the designed antenna looks like an inverted F with folded L-shaped strip antenna. It has three resonant frequencies of 795, 2050, and 3405 MHz with a reflection coefficient of --11.7 dB, --15.1 dB, and --30.5 dB, respectively. The size of the suggested antenna is 10 $\times$ 35 $\times$ 0.8 mm$^3$ and it is built on the FR-4 substrate which is more compact and easy to integrate with the handheld devices such as laptops, tablets, and smart phones. The performances of the proposed antenna are analyzed with the help of computer simulation using Ansys High Frequency Structure Simulation Software Simulator (HFSS). The measured --10 dB impedance bandwidth of the suggested antenna covers 780--820, 2020--2070, and 3230--3490 MHz, which satisfies the LTE 700, LTE 2100, and LTE 3300. The proposed antenna has the acceptable voltage standing wave ratio (VSWR $\leq$ 2), bandwidth, gain, and radiation characteristics across the operating bands and thus proves its suitability for wireless handheld devices.

A survey on security analysis and privacy issues of wireless multimedia communication system

Wireless multimedia communication (WMC) is an emerging service that integrates voice, video, and data in the same service. The wireless handheld device used to provide multimedia communication such as PDA, Sensor, Mobile phones etc., are resource constrained and also need security protocol for successful multimedia communication between server and user. Many researchers are put their effort to develop secure cryptography algorithms and protocol to allow the user to access the data securely in telemedicine, surveillance system, and video on demand, digital cash, online shopping, digital content delivery and video conferencing technology. This paper focuses on security analysis of different encryption algorithm, secure architecture, encoding algorithm, authentication protocol and video encoding method. It also discuss about security multimedia challenges, characteristics, multimedia services, different attacks, software information and forecasts future perspectives of wireless multimedia technology.

A survey on security analysis and privacy issues of wireless multimedia communication system

Wireless multimedia communication (WMC) is an emerging service that integrates voice, video, and data in the same service. The wireless handheld device used to provide multimedia communication such as PDA, Sensor, Mobile phones etc., are resource constrained and also need security protocol for successful multimedia communication between server and user. Many researchers are put their effort to develop secure cryptography algorithms and protocol to allow the user to access the data securely in telemedicine, surveillance system, and video on demand, digital cash, online shopping, digital content delivery and video conferencing technology. This paper focuses on security analysis of different encryption algorithm, secure architecture, encoding algorithm, authentication protocol and video encoding method. It also discuss about security multimedia challenges, characteristics, multimedia services, different attacks, software information and forecasts future perspectives of wireless multimedia technology.

HARVESTING MICROWAVE SIGNAL POWER FROM THE AMBIENT ENVIRONMENT

To harvest microwave frequencies in the ambient environment and convert into DC is presented in this paper. The RF harvester replaces a dedicated RF source which is used in an applications like wireless sensor networks to battery operated wireless handheld devices. The focus of work is divided into two parts. The first is to design a compact planar prototype microstrip patch antenna using HFSS for the frequencies of 900&1800MHz (GSM band), 1575MHz (GPS band) and 2.4GHz (ISM band). Antenna is fabricated using MITS PCB prototype machine and tested in VNA. Results obtained from the VNA indicates -30dB and -35dB for GSM 900& 1800 MHz, -15dB for GPS 1575 MHz band and -28dB for ISM 2.4GHz band. Second part consists of RF circuit model includes matching and rectification unit which determines the RF to DC conversion efficiency up to 60%. Voltage doubler RF rectification circuit using schottky diode is designed in ADS and it is tested practically. A lumped T type matching network is implemented to provide a proper impedance match

An Integrated Antenna System for 4G and Millimeter-Wave 5G Future Handheld Devices

In this work, an integrated antenna system with Defected Ground Structure (DGS) is presented for Fourth Generation (4G) and millimeter (mm)-wave Fifth Generation (5G) wireless applications and handheld devices. The proposed design with overall dimensions of 110 mm × 75 mm is modeled on 0.508 mm thick Rogers RT/Duroid 5880 substrate. Radiating structure consists of antenna arrays excited by the T-shape 1 × 2 power divider/combiner. Dual bands for 4G centered at 3.8 GHz and 5.5 GHz are attained, whereas the 10-dB impedance bandwidth of 24.4 - 29.3 GHz is achieved for the 5G antenna array. In addition, a peak gain of 5.41 dBi is demonstrated across the operating bandwidth of the 4G antenna array. Similarly, for the 5G mm-wave configuration the attained peak gain is 10.29 dBi. Moreover, significant isolation is obtained between the two antenna modules ensuring efficient dual-frequency band operation using a single integrated solution. To endorse the concept, antenna prototype is fabricated and far-field measurements are procured. Simulated and measured results exhibit coherence. Also the proposed design is investigated for the beam steering capability of the mm-wave 5G antenna array using CST®MWS®. The demonstrated structure offers various advantages including compactness, wide bandwidth, high gain, and planar configuration. Hence, the attained radiation characteristics prove the suitability of the proposed design for the current and future wireless handheld devices.